tag:theconversation.com,2011:/es/topics/particulates-3297/articlesParticulates – The Conversation2024-02-08T13:39:27Ztag:theconversation.com,2011:article/2230572024-02-08T13:39:27Z2024-02-08T13:39:27ZHeart attacks, cancer, dementia, premature deaths: 4 essential reads on the health effects driving EPA’s new fine particle air pollution standard<figure><img src="https://images.theconversation.com/files/574202/original/file-20240207-27-6crply.jpg?ixlib=rb-1.1.0&rect=37%2C7%2C5002%2C3347&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Large industrial facilities like this oil refinery outside Houston are major sources of fine particulate air pollution.</span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/CongressClimateEnvironmentalJustice/c07295f82f9646db873f5d96baf4f089/photo">AP Photo/David J. Phillip</a></span></figcaption></figure><p>The U.S. Environmental Protection Agency has <a href="https://www.epa.gov/pm-pollution/final-reconsideration-national-ambient-air-quality-standards-particulate-matter-pm">announced a new standard</a> for protecting the public from fine particulate air pollution, known as PM2.5 because the particles are smaller than 2.5 millionths of a meter. These minute particles can penetrate deeply into the body and have been linked to many serious illnesses. </p>
<p>The new rule sets an annual limit of 9 micrograms per cubic meter of air, down from the previous level of 12 micrograms. States will be required to meet this standard and to take it into consideration when they evaluate applications for permits for new stationary air pollution sources, such as electric power plants, factories and oil refineries.</p>
<p>Under the Clean Air Act, the EPA is required to set air pollution standards at levels that <a href="https://www.epa.gov/laws-regulations/summary-clean-air-act">protect public health</a>. In the four articles that follow, scholars wrote about the many ways in which exposure to PM2.5 contributes to cardiovascular disease, lung cancer, other illnesses such as dementia, and premature deaths.</p>
<h2>1. An alarming array of health effects</h2>
<p>Scientists have known since the 1993 <a href="http://dx.doi.org/10.1056/NEJM199312093292401">Six Cities Study</a>, which showed that people were dying faster in dirty cities than in clean cities, that exposure to PM2.5 increased the risk of lung cancer and heart disease. Subsequent research has linked fine particulates to a much broader range of health effects. </p>
<p>Once a person inhales PM2.5, “it causes an inflammatory response that sends signals <a href="https://theconversation.com/fine-particle-air-pollution-is-a-public-health-emergency-hiding-in-plain-sight-106030">throughout the body</a>, much as a bacterial infection would,” wrote public and environmental health scholars <a href="https://scholar.google.com/citations?user=1h3u230AAAAJ&hl=en">Doug Brugge</a> of the University of Connecticut and <a href="https://scholar.google.com/citations?user=SDWANZEAAAAJ&hl=en">Kevin James Lane</a> of Boston University. “Additionally, the smallest particles and fragments of larger particles can leave the lungs and travel through the blood.” </p>
<p>In Brugge and Lane’s view, evidence that PM2.5 could affect brain development, cognitive skills and children’s central nervous systems is particularly notable. They termed fine particle pollution an urgent global health threat. </p>
<p>“Developed countries have made progress in reducing particulate air pollution in recent decades, but much remains to be done to further reduce this hazard,” they observed. “And the situation has gotten dramatically worse in many developing countries – most notably China and India, which have industrialized faster and on vaster scales than ever seen before.”</p>
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<a href="https://theconversation.com/fine-particle-air-pollution-is-a-public-health-emergency-hiding-in-plain-sight-106030">Fine particle air pollution is a public health emergency hiding in plain sight</a>
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<figcaption><span class="caption">PM2.5 particles are small enough to evade many of the body’s defenses.</span></figcaption>
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<h2>2. Aging the brain</h2>
<p>Medical researchers are looking closely at air pollution as a possible accelerator of brain aging. University of Southern California preventive medicine specialist <a href="https://scholar.google.com/citations?user=jxckDOcAAAAJ&hl=en">Jiu-Chiuan Chen</a> and his colleagues have found that older women who lived in locations with high levels of PM2.5 suffered <a href="https://theconversation.com/air-pollution-may-contribute-to-alzheimers-and-dementia-risk-heres-what-were-learning-from-brain-scans-148776">memory loss and Alzheimer’s-like brain shrinkage</a> not seen in women living with cleaner air.</p>
<p>Chen and his colleagues compared brains scans taken at five-year intervals of older women who lived in areas with varying levels of air pollution.</p>
<p>“When we compared the brain scans of older women from locations with high levels of PM2.5 to those with low levels, we found dementia risk increased by 24% over the five years,” Chen wrote. </p>
<p>More alarmingly, “(T)hese Alzheimer’s-like brain changes were present in older women with no memory problems,” Chen noted. “The shrinkage in their brains was greater if they lived in locations with higher levels of outdoor PM2.5, even when those levels were within the current (2021) EPA standard.”</p>
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<a href="https://theconversation.com/air-pollution-may-contribute-to-alzheimers-and-dementia-risk-heres-what-were-learning-from-brain-scans-148776">Air pollution may contribute to Alzheimer’s and dementia risk – here's what we're learning from brain scans</a>
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<h2>3. Disadvantaged communities have dirtier air</h2>
<p>As researchers in environmental justice have shown, facilities such as factories and refineries often are concentrated in low-income neighborhoods and communities of color. This means that these areas are exposed to higher pollution levels and face heavier related health burdens.</p>
<p>Regulations put in place under the Clean Air Act have greatly reduced levels of harmful air pollutants across the U.S. over the past 50 years. But when University of Virginia economist <a href="https://scholar.google.co.uk/citations?user=xw8Ml0QAAAAJ&hl=en">Jonathan Colmer</a> and public policy scholar <a href="https://scholar.google.com/citations?user=Z1sqTysAAAAJ&hl=en">Jay Shimshack</a> analyzed data tracing PM2.5 concentrations at more than 8.6 million distinct U.S. locations from 1981 through 2016, they found that the areas that were most polluted in 1981 <a href="https://theconversation.com/fine-particle-air-pollution-has-decreased-across-the-us-but-poor-and-minority-communities-are-still-the-most-polluted-143650">remained the dirtiest nearly 40 years later</a>.</p>
<p>“In 1981 PM2.5 concentrations in the most polluted 10% of census tracts averaged 34 micrograms per cubic meter,” the authors reported. “In 2016 PM2.5 concentrations in the most polluted 10% of census tracts averaged 10 micrograms per cubic meter. PM2.5 concentrations in the least polluted 10% of census tracts averaged 4 micrograms per cubic meter.” In other words, while all areas had cleaner air, people in the most polluted areas still were exposed to PM2.5 levels more than twice as high as people in the cleanest zones.</p>
<p>“For decades, federal and state environmental guidelines have aimed to provide all Americans with the same degree of protection from environmental hazards,” Colmer and Shimshack note. “The EPA’s definition of environmental justice states that ‘no group of people should bear a disproportionate share of the negative environmental consequences.’ On this front, our research suggests that the United States is falling short.”</p>
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<a href="https://theconversation.com/fine-particle-air-pollution-has-decreased-across-the-us-but-poor-and-minority-communities-are-still-the-most-polluted-143650">Fine-particle air pollution has decreased across the US, but poor and minority communities are still the most polluted</a>
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<h2>4. Fine particle pollution hurts wildlife too</h2>
<p>Like the proverbial canaries in coal mines, wild animals can show effects of exposure to pollution that offer broader warnings. One example is wildfires, which produce high levels of gases and particulate matter.</p>
<p>Cornell University conservation biologist <a href="https://scholar.google.com/citations?user=ykHYzwEAAAAJ&hl=en">Wendy M. Erb</a> was studying wild orangutans in Indonesian Borneo when that island suffered large-scale wildfires. Orangutans are semi-solitary animals that communicate with each other through long, booming calls in the tropical forests where they live. </p>
<p>During the fires and for several weeks after the smoke cleared, Erb and her colleagues found that four male orangutans they were following <a href="https://theconversation.com/to-see-how-smoke-affects-endangered-orangutans-we-studied-their-voices-during-and-after-massive-indonesian-wildfires-208153">called less frequently than usual</a> – about three times daily instead of their usual six times. “Their voices dropped in pitch, showing more vocal harshness and irregularities,” Erb reported. “Collectively, these features of vocal quality have been linked to inflammation, stress and disease – including COVID-19 – in human and nonhuman animals.”</p>
<p>Erb hoped to see further study of how toxic smoke affects wildlife. “Using passive acoustic monitoring to study vocally active indicator species, like orangutans, could unlock critical insights into wildfire smoke’s effects on wildlife populations worldwide,” she observed.</p>
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<a href="https://theconversation.com/to-see-how-smoke-affects-endangered-orangutans-we-studied-their-voices-during-and-after-massive-indonesian-wildfires-208153">To see how smoke affects endangered orangutans, we studied their voices during and after massive Indonesian wildfires</a>
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<p><em>Editor’s note: This story is a roundup of articles from The Conversation’s archive.</em></p><img src="https://counter.theconversation.com/content/223057/count.gif" alt="The Conversation" width="1" height="1" />
On Feb. 7, 2024, the EPA strengthened the federal limit for annual levels of fine particulate air pollution, or PM2.5. Many serious health effects have been linked to PM2.5 exposure.Jennifer Weeks, Senior Environment + Cities Editor, The ConversationLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2182312023-11-23T19:04:01Z2023-11-23T19:04:01ZPollution from coal power plants contributes to far more deaths than scientists realized, study shows<figure><img src="https://images.theconversation.com/files/560874/original/file-20231121-4173-worc70.jpg?ixlib=rb-1.1.0&rect=0%2C107%2C5083%2C3435&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Kids jump on a trampoline as steam rises from a coal power plant in Adamsville, Ala., in 2021. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/kids-jump-on-a-trampoline-at-their-grandparents-home-as-news-photo/1232409457?adppopup=true"> Andrew Caballero-Reynolds/AFP via Getty Images</a></span></figcaption></figure><p>Air pollution particles from coal-fired power plants are more harmful to human health than many experts realized, and it’s <a href="https://doi.org/10.1126/science.adf4915">more than twice as likely to contribute to premature deaths</a> as air pollution particles from other sources, new research demonstrates.</p>
<p>In the study, published in the journal Science, colleagues and I mapped how U.S. coal power plant emissions traveled through the atmosphere, then linked each power plant’s emissions with death records of Americans over 65 years old on Medicare.</p>
<p>Our results suggest that air pollutants released from coal power plants were associated with nearly half a million premature deaths of elderly Americans from 1999 to 2020.</p>
<p>It’s a staggering number, but the study also has good news: Annual deaths associated with U.S. coal power plants have fallen sharply since the mid-2000s as <a href="https://theconversation.com/3-reasons-us-coal-power-is-disappearing-and-a-supreme-court-ruling-wont-save-it-187254">federal regulations compelled operators</a> to install emissions scrubbers and many utilities shut down coal plants entirely.</p>
<p>In 1999, 55,000 deaths were attributable to coal air pollution in the U.S., according to our findings. By 2020, that number had fallen to 1,600.</p>
<figure><img src="https://cdn.theconversation.com/static_files/files/2941/lucas-maps-GIF5.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=720&fit=crop&dpr=2"><figcaption> How PM2.5 levels from coal power plants in the U.S. have declined since 1999 as more plants installed pollution-control devices or shut down. Lucas Henneman.</figcaption></figure>
<p>In the U.S., coal is being displaced by natural gas and renewable energy for generating electricity. Globally, however, coal use is <a href="https://www.iea.org/reports/coal-2022">projected to increase</a> in coming years. That makes our results all the more urgent for global decision-makers to understand as they develop future policies.</p>
<h2>Coal air pollution: What makes it so bad?</h2>
<p>A landmark study in the 1990s, known as the <a href="https://www.nejm.org/doi/full/10.1056/NEJM199312093292401">Harvard Six Cities Study</a>, linked tiny airborne particles called PM2.5 to increased risk of early death. Other studies have since linked PM2.5 to <a href="https://doi.org/10.3390/nano12152656">lung and heart disease, cancer</a>, <a href="https://doi.org/10.1001/jamainternmed.2023.3300">dementia</a> and other diseases. </p>
<p>Following that research, the Environmental Protection Agency <a href="https://www.epa.gov/pm-pollution/timeline-particulate-matter-pm-national-ambient-air-quality-standards-naaqs">began regulating PM2.5 concentrations in 1997</a> and has lowered the acceptable limit over time.</p>
<p>PM2.5 – particles small enough to be inhaled deep into our lungs – comes from several different sources, including gasoline combustion in vehicles and smoke from wood fires and power plants. It is <a href="https://www.epa.gov/pm-pollution/particulate-matter-pm-basics#PM">made up of many</a> different chemicals.</p>
<p>Coal is also a mix of many chemicals – <a href="https://doi.org/10.1016/j.atmosenv.2011.04.070">carbon, hydrogen, sulfur, even metals</a>. When coal is burned, <a href="https://www.eia.gov/energyexplained/coal/coal-and-the-environment.php">all of these chemicals</a> are emitted to the atmosphere either as gases or particles. Once there, they are transported by the wind and interact with other chemicals already in the atmosphere.</p>
<p>As a result, anyone downwind of a coal plant may be breathing a complex cocktail of chemicals, each with its own potential effects on human health.</p>
<figure><img src="https://cdn.theconversation.com/static_files/files/2934/lucas-gif1.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=720&fit=crop&dpr=2"><figcaption> Two months of emissions from Plant Bowen, a coal-fired power station near Atlanta, show how wind influences the spread of air pollution. Lucas Henneman.</figcaption></figure>
<h2>Tracking coal PM2.5</h2>
<p>To understand the risks coal emissions pose to human health, we tracked how sulfur dioxide emissions from each of the 480 largest U.S. coal power plants operating at any point since 1999 traveled with the wind and turned into tiny particles – <a href="https://doi.org/10.1126/science.adf4915">coal PM2.5</a>. We used sulfur dioxide because of its known health effects and drastic decreases in emissions over the study period.</p>
<p>We then used a statistical model to link coal PM2.5 exposure to Medicare records of nearly 70 million people from 1999 to 2020. This model allowed us to calculate the number of deaths associated with coal PM2.5.</p>
<p>In our statistical model, we controlled for other pollution sources and accounted for many other known risk factors, like smoking status, local meteorology and income level. We tested multiple statistical approaches that all yielded consistent results. We compared the results of our statistical model with <a href="https://www.science.org/doi/10.1126/sciadv.aba5692">previous results</a> testing the health impacts of PM2.5 from other sources and found that PM2.5 from coal is twice as harmful as PM2.5 from all other sources.</p>
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<img alt="Two people stand outside an older brick home with power plant smokestacks in the background." src="https://images.theconversation.com/files/561153/original/file-20231122-17-wwzsob.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/561153/original/file-20231122-17-wwzsob.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=396&fit=crop&dpr=1 600w, https://images.theconversation.com/files/561153/original/file-20231122-17-wwzsob.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=396&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/561153/original/file-20231122-17-wwzsob.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=396&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/561153/original/file-20231122-17-wwzsob.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=498&fit=crop&dpr=1 754w, https://images.theconversation.com/files/561153/original/file-20231122-17-wwzsob.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=498&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/561153/original/file-20231122-17-wwzsob.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=498&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Residents living near the Cheswick coal-fired power plant in Springdale, Pa., publicly complained about the amount of sulfur dioxide, nitrogen oxide and coal particles from the plant for years.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/marti-blake-speaks-to-the-postman-in-front-of-the-smoke-news-photo/874051624">Robert Nickelsberg/Getty Images</a></span>
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<p>The number of deaths associated with individual power plants depended on multiple factors – how much the plant emits, which way the wind blows and how many people breathe in the pollution. Unfortunately, U.S. utilities located many of their plants upwind of major population centers on the East Coast. This siting amplified these plants’ impacts.</p>
<p>In an <a href="https://cpieatgt.github.io/cpie/">interactive online tool</a>, users can look up our estimates of annual deaths associated with each U.S. power plant and also see how those numbers have fallen over time at most U.S. coal plants.</p>
<h2>A US success story and the global future of coal</h2>
<p>Engineers have been <a href="https://doi.org/10.1002/ep.670200410">designing effective scrubbers</a> and other pollution-control devices that can reduce pollution from coal-fired power plants for several years. And the <a href="https://www.epa.gov/Cross-State-Air-Pollution/overview-cross-state-air-pollution-rule-csapr">EPA has rules</a> specifically to encourage utilities that used coal to install them, and most facilities that did not install scrubbers have shut down.</p>
<p>The results have been dramatic: Sulfur dioxide emissions <a href="https://doi.org/10.1002/ep.670200410">decreased about 90%</a> in facilities that reported installing scrubbers. Nationwide, sulfur dioxide emissions decreased 95% since 1999. According to our tally, deaths attributable to each facility that installed a scrubber or shut down decreased drastically.</p>
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<p>As advances in fracking techniques reduced the cost of natural gas, and regulations made running coal plants more expensive, <a href="https://www.worldscientific.com/doi/abs/10.1142/S2010007819500088">utilities began replacing coal with natural gas</a> plants and renewable energy. The shift to natural gas – a cleaner-burning fossil fuel than coal but still a greenhouse gas <a href="https://theconversation.com/biden-announces-a-sweeping-methane-plan-heres-why-cutting-the-greenhouse-gas-is-crucial-for-protecting-climate-and-health-168220">contributing to climate change</a> – led to even further air pollution reductions.</p>
<p>Today, coal contributes about 27% of electricity in the U.S., <a href="https://www.eia.gov/totalenergy/data/browser/index.php?tbl=T02.06#/?f=A">down from 56% in 1999</a>.</p>
<p>Globally, however, the outlook for coal is mixed. While the U.S. and other nations are headed toward a future with substantially less coal, the International Energy Agency <a href="https://www.iea.org/reports/coal-2022">expects global coal use to increase</a> through at least 2025.</p>
<p>Our study and others like it make clear that increases in coal use will harm human health and the climate. Making full use of emissions controls and a turn toward renewables are surefire ways to reduce coal’s negative impacts.</p><img src="https://counter.theconversation.com/content/218231/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lucas Henneman receives funding from the Health Effects Institute, the National Institute of Health, and the Environmental Protection Agency.</span></em></p>The longest-running study of its kind reviewed death records in the path of pollution from coal-fired power plants. The numbers are staggering − but also falling fast as US coal plants close.Lucas Henneman, Assistant Professor of Engineering, George Mason UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2114812023-09-18T12:20:18Z2023-09-18T12:20:18ZDesert dust storms carry human-made toxic pollutants, and the health risk extends indoors<figure><img src="https://images.theconversation.com/files/547793/original/file-20230912-15-tvy18y.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2995%2C1922&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A massive dust storm billows across the western desert of Iraq on April 26, 2005.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/in-this-picture-released-by-the-u-s-marine-corps-a-dust-news-photo/52726143">Shannon Arledge/USMC via Getty Images</a></span></figcaption></figure><p>Humans have contended with dust storms for thousands of years, ever since early civilizations appeared in the Middle East and North Africa. But modern desert dust storms are different from their preindustrial counterparts.</p>
<p>Around the world, deserts now increasingly border built structures, including urban dwellings, manufacturing, transportation hubs, sewage treatment and landfills. As a result, desert dust lifts a growing load of <a href="https://openknowledge.worldbank.org/entities/publication/0b891a90-3047-5115-8a3f-2c724b6bec36">airborne pollutants</a> and transports these substances over long distances. </p>
<p>This is happening throughout the Global Dust Belt, an arid to semiarid region that stretches from western China through Central Asia, the Middle East and North Africa. Similar storms occur in the U.S. Southwest and central Australia.</p>
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<a href="https://images.theconversation.com/files/544747/original/file-20230825-29-vmv4js.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="World map showing a concentration of dust storms in the Middle East and North Africa." src="https://images.theconversation.com/files/544747/original/file-20230825-29-vmv4js.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/544747/original/file-20230825-29-vmv4js.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=260&fit=crop&dpr=1 600w, https://images.theconversation.com/files/544747/original/file-20230825-29-vmv4js.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=260&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/544747/original/file-20230825-29-vmv4js.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=260&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/544747/original/file-20230825-29-vmv4js.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=327&fit=crop&dpr=1 754w, https://images.theconversation.com/files/544747/original/file-20230825-29-vmv4js.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=327&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/544747/original/file-20230825-29-vmv4js.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=327&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Global pattern of dust frequency estimated from weather records, 1974-2012.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1002/jgrd.50836">Shao et al., 2013</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p>To our thinking, modern desert dust storms have been overlooked as a public health crisis. Elevated exposure to these events is likely to contribute to rising respiratory and other diseases, including <a href="https://doi.org/10.1111/all.15392">asthma and chronic obstructive pulmonary disease</a>. We are <a href="https://scholar.google.com/citations?user=KmHgnMkAAAAJ&hl=en">environmental</a> <a href="https://scholar.google.com/citations?user=sCeK0g8AAAAJ&hl=en">researchers</a> whose work shows a need for better public health practices to protect people from dust storm pollutants. </p>
<h2>Massive, fast-moving dust storms</h2>
<p>To appreciate the scale of the threat, consider the Arabian Peninsula, where asthma rates have been the <a href="https://doi.org/10.1515/reveh-2017-0030">world’s highest for the past two decades</a>. </p>
<p>In spring 2011, one of the <a href="https://doi.org/10.1016/j.aeolia.2020.100592">most severe desert dust storms in recent decades</a> swept across the Middle East at the peak of the dust storm season. Its plumes spread from the west coast of the Persian Gulf to the eastern shores of the Caspian Sea, covering northern Saudi Arabia, southern Iraq, Kuwait and western Iran. One quadrant of this large storm alone covered most of the Arabian Peninsula. </p>
<p>This storm reached vertically as high as 5.5 miles (9 kilometers) above the ground. Its wind speeds exceeded 45 mph (72 kilometers per hour) – higher than average wind speeds in the region. Dust particle concentrations peaked at <a href="https://doi.org/10.1016/j.aeolia.2020.100592">530,000 micrograms per cubic foot</a> (15,000 micrograms per cubic meter), blocking sunlight for days. </p>
<figure>
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<figcaption><span class="caption">This satellite video shows a large dust storm heading southward over the Arabian Peninsula on March 25, 2011. The persistent dark magenta hue of the leading dust front indicates its exceptionally high dust density.</span></figcaption>
</figure>
<p>One study found that a large proportion of individuals exposed to sandstorms <a href="http://dx.doi.org/10.12669/pjms.292.3065">had symptoms</a> that included increased cough, runny nose, wheezing, acute asthmatic attack, eye irritation and redness, headache, sleep disturbance and psychological disturbances. Another study reported that increased dust storm exposure in western Iran led to <a href="https://doi.org/10.1016/j.apr.2016.11.005">increases in hospital admissions</a> for chronic obstructive pulmonary disease and more deaths from respiratory causes. </p>
<h2>Needed: A climate + health framework</h2>
<p>Researchers study desert dust storms in a dozen different fields, each with its own terminology, expertise and body of knowledge. This work includes analyzing satellite images, creating simulation models for predicting dust particle transport, and identifying each dust storm’s particle content. So far, however, the health effects of desert dust storms and their changing particle content have gotten scant attention.</p>
<p>As we discussed in a recent review article, studies have found <a href="https://doi.org/10.1007/s10661-023-11287-6">pollutants in dust storms</a> that include bioreactive metals such as <a href="https://doi.org/10.1016/j.envpol.2020.116190">copper, chromium, nickel, lead and zinc</a>, as well as pesticides, herbicides, radioactive particulates and aerosolized sewage. The extent to which desert dust storms transport a special class of pollution particles, those even smaller than one micron – or one millionth of a meter – is not yet clear.</p>
<p>This is the class of submicron pollutants, abbreviated as PM1.0, which includes degraded microplastics, metallic nanoparticles, diesel exhaust and fine particles from degraded tires. Of all particulate matter classes, submicron particles are the <a href="https://airquality.gsfc.nasa.gov/health#">most harmful to human health</a> because when once inhaled, they enter the bloodstream, affecting every organ in the body, and even crossing the blood-brain barrier.</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/CMbrgymjOuh/?utm_source=ig_web_copy_link\u0026igshid=MzRlODBiNWFlZA==","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<h2>Public health recommendations</h2>
<p>We offer several practices here that we believe would help public health agencies successfully tackle the problem of polluted dust storms.</p>
<p>1: Identify particle content for each dust storm. </p>
<p>Existing technology now makes it possible to identify the types of particles being carried in any particular storm. Scientists can already conduct particle trajectory analysis to trace dust and pollutant particles <a href="https://doi.org/10.1016/j.scitotenv.2014.09.025">back to their sources</a>. </p>
<p>Knowing the particle content of dust storms can identify ways to make these storms less hazardous, whether capping sewage systems or securing waste at ports to prevent materials from being picked up by dust storms. </p>
<p>2: Archive samples from each desert dust storm.</p>
<p>One physical catalog for dust storm particles already exists at the <a href="https://doi.org/10.1111/j.1462-2920.2007.01461.x">19th-century dust storm archive</a> kept by the Natural History Museum at Humboldt University in Berlin. We see a need for a modern archive that collects digital data on particle types, particle trajectory analysis, spatial coordinates and meteorological data. </p>
<p>Keeping both physical samples and data from each dust storm would allow for a comparative understanding of how and why particle content is changing. This has been done to analyze particle content related to <a href="https://doi.org/10.3390/rs12091526">military activity in the Middle East</a>.</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/B7TqO55pETL/?utm_source=ig_web_copy_link\u0026igshid=MzRlODBiNWFlZA==","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<p>3: Protect indoor and closed spaces from the smaller dust storm particles. </p>
<p>During a major dust storm, high-speed winds blow fine particles around windows and doors for days. The particles most likely to penetrate indoors include the smallest, most harmful submicron class. </p>
<p>Typically, a gray, fluffy residue appears inside buildings after a dust storm, but data are not available on the identity and size of these particles. Our concern is that submicron pollutant particles are highly concentrated in this residue.</p>
<p>For a safe cleanup, we recommend that people should avoid dry vacuuming, which lofts particles back into the air. Instead, it is better to remove residues with water and a wet mop. We also recommend wearing face masks indoors before, during and after dust storms, since particulate concentrations start to rise ahead of the main storm. In our view, people should treat dust storm residue inside built structures as hazardous material until studies show otherwise. </p>
<p>4: Educate biomedical and meteorological experts together.</p>
<p>The rising human-made content of desert dust storms, particularly fine and ultrafine submicron particles, is a neglected public health concern that we believe calls for combined medical and meteorological expertise. </p>
<p>By educating biomedical and meteorological experts jointly about dust storms, public health agencies would have more complete strategies for <a href="https://doi.org/10.1002/eap.2275">how to best protect people</a>. It would be valuable to have teams of health and weather experts carry out joint analyses of dust storm exposure data, and then apply the best statistical methods to both civilian and military health records.</p>
<p>Climate change is making already-dry areas around the world <a href="https://www.ipcc.ch/srccl/chapter/chapter-3/">more arid</a>. As deserts increasingly adjoin cities, industry and transportation corridors, desert dust storms will increasingly mirror human activity on land. These storms are becoming flying waste dumps, and we believe a public health perspective will help produce more effective responses.</p><img src="https://counter.theconversation.com/content/211481/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Fatin Samara has received funding from the American University of Sharjah and the Sharjah Research Academy.</span></em></p><p class="fine-print"><em><span>Claire Williams Bridgwater does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Desert dust storms are increasingly picking up materials like sewage, herbicides and other human-made waste and transporting them on tiny particles that are easy to inhale.Claire Williams Bridgwater, Research Professor in Environmental Science, American UniversityFatin Samara, Professor of Environmental Science, American University of SharjahLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2081532023-06-22T12:30:35Z2023-06-22T12:30:35ZTo see how smoke affects endangered orangutans, we studied their voices during and after massive Indonesian wildfires<figure><img src="https://images.theconversation.com/files/533199/original/file-20230621-11493-h6xfhj.jpeg?ixlib=rb-1.1.0&rect=7%2C0%2C4861%2C3080&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An adult male orangutan contemplates his next move in haze produced by Indonesia's 2015 wildfires.</span> <span class="attribution"><span class="source">Wendy Erb</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Bornean orangutans are one of three orangutan species, all <a href="https://www.iucnredlist.org/search?query=orangutan&searchType=species">critically endangered</a>. They thrive in carbon-rich peat swamp forests on the Indonesian island of Borneo. These habitats are also the sites of massive wildfires.</p>
<p>Indonesian wildfires in 2015 caused some of the <a href="https://doi.org/10.3390/rs10040495">worst fire-driven air pollution</a> ever recorded. The fires were driven by an <a href="https://www.noaa.gov/understanding-el-nino#">El Niño climatic cycle</a>, which <a href="https://www.nasa.gov/feature/Goddard/2016/severe-2015-indonesian-fire-season-linked-to-el-nino-drought">caused especially dry weather</a> in the region.</p>
<p>Compared to other wildfires, peatland fires smolder underground and produce exceptionally high levels of hazardous gases and particulate matter – a leading cause of <a href="https://theconversation.com/wildfire-smoke-can-harm-human-health-even-when-the-fire-is-hundreds-of-miles-away-a-toxicologist-explains-why-206057">global pollution-related deaths and illnesses</a>. </p>
<p>Orangutans are well known as an “<a href="https://www.britannica.com/science/indicator-species">indicator species</a>” – one that can serve as a proxy for the health of an ecosystem. Changes in their environments often cause conspicuous changes in the apes’ health and behavior. Frequent and persistent exposure to toxic smoke could have severe consequences for orangutans and other wildlife.</p>
<p>Toxic air pollution also poses serious health and safety risks for researchers. However, <a href="https://doi.org/10.1093/biosci/biy147">remote sensing techniques</a>, such as satellite images, GPS data and acoustic monitoring, are increasingly popular ways to track wildlife populations and see how creatures respond to changes in their environments.</p>
<p>I have studied the behavior, ecology and acoustic communication of <a href="https://scholar.google.com/citations?user=ykHYzwEAAAAJ&hl=en">wild primates in Indonesia</a> since 2005. In a new study, my co-authors and I investigated how wild orangutans in Borneo were affected by toxic emissions from Indonesia’s 2015 peatland wildfires – by <a href="https://doi.org/10.1016/j.isci.2023.107088">studying their voices</a>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/cBnbLJ5TzvE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Indonesia’s degraded peatlands are tinderboxes that can easily ignite with several weeks of dry weather.</span></figcaption>
</figure>
<h2>Smoke exposure poses long-term risks</h2>
<p>Around the world, <a href="https://www.unep.org/news-and-stories/press-release/number-wildfires-rise-50-2100-and-governments-are-not-prepared">wildfires are on the rise</a>. They often produce a thick blanket of haze that contains diverse hazardous gases and particulate matter, or PM. Most recently, smoke from Canadian wildfires blanketed the U.S. East Coast and Midwest in early June 2023, <a href="https://www.youtube.com/watch?v=kLN3kBthm9Y">turning skies orange</a> and triggering public health alerts.</p>
<p>Studies have shown that <a href="https://doi.org/10.1016/j.envres.2014.10.015">human health risks from wildfire smoke</a> include respiratory and cardiovascular illnesses, systemic inflammation and premature death. Much less is known about how smoke affects wildlife, but in a pair of studies published <a href="https://doi.org/10.1016/j.reprotox.2021.08.005">in 2021</a> <a href="https://doi.org/10.1038/s41467-022-29436-9">and 2022</a>, scientists at the <a href="https://cnprc.ucdavis.edu/">California National Primate Research Center</a> reported alarming findings.</p>
<p>After less than two weeks of exposure to high concentrations of particulate matter – in particular, ultrafine particles measuring less than 2.5 microns in diameter, which are known as PM2.5 – captive <a href="https://www.britannica.com/animal/rhesus-monkey">rhesus macaques</a> suffered a spike in pregnancy loss. What’s more, surviving fetuses and infants suffered long-term effects on lung capacity, immune responses, inflammation, cortisol levels, behavior and memory. </p>
<p>During Indonesia’s 2015 fires, Borneo’s air had particulate matter concentrations nearly an order of magnitude higher than the levels in these studies. This made the potential implications for people and wildlife who gasped through Indonesia’s wildfire smoke for nearly two months extremely worrying.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/533205/original/file-20230621-17-x1066c.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Fire and smoke rise from charred ground near a scorched tree." src="https://images.theconversation.com/files/533205/original/file-20230621-17-x1066c.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/533205/original/file-20230621-17-x1066c.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=379&fit=crop&dpr=1 600w, https://images.theconversation.com/files/533205/original/file-20230621-17-x1066c.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=379&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/533205/original/file-20230621-17-x1066c.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=379&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/533205/original/file-20230621-17-x1066c.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=477&fit=crop&dpr=1 754w, https://images.theconversation.com/files/533205/original/file-20230621-17-x1066c.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=477&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/533205/original/file-20230621-17-x1066c.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=477&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A wildfire blazes in a small rubber tree garden along the border of the Tuanan study area during Indonesia’s 2015 wildfires.</span>
<span class="attribution"><span class="source">Wendy Erb</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Orangutans in the haze</h2>
<p>I was studying wild orangutans in the forests of Indonesian Borneo when the 2015 fires started. My colleagues and I at the <a href="https://coreborneo.com/tuanan-research-station/">Tuanan Orangutan Research Station</a> tracked local fires and patrolled nearby hot spots to assess the risk of fire spreading to our research area. </p>
<p>Wearing N-95 masks, we continued to monitor orangutans in hopes of learning how the animals were coping with encroaching fires and thick smoke. A few weeks into the fire season, I noticed a difference in the sound of the males’ “<a href="https://wildambience.com/wildlife-sounds/orangutan/">long call</a>,” which was the focus of <a href="https://wendyerb.weebly.com/projects.html">my research</a>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/cRJoooWf5vU?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">An adult male Bornean orangutan’s long call.</span></figcaption>
</figure>
<p>Long calls are booming vocalizations that can be heard over distances of more than half a mile (1 kilometer). Orangutans are semi-solitary and live in dispersed communities, so these calls serve an important social role. Adult males make them to advertise their prowess to listening females in the area and to scare off any eavesdropping rival males. A couple of weeks after the smoke had appeared, I thought these males sounded raggedy – a little like humans who smoke a lot. </p>
<p>We observed the orangutans for 44 days during the fires, until large blazes encroached on our study area. At that point, we stopped the study to help extinguish the blazes with local firefighting teams and other government and nonprofit groups. Fires burned in our study area for three weeks.</p>
<p>Using data that we collected before, during and after the fires, I led an analysis of this Bornean orangutan population’s <a href="https://doi.org/10.1016/j.isci.2023.107088">behavior and health</a>. My co-authors and I found that in the weeks after the fires, the apes reduced their activities – resting more and traveling shorter distances – and consumed more calories than normal. </p>
<p>But although they were eating more and moving less, we found by collecting and testing the apes’ urine that they were <a href="https://doi.org/10.1038/s41598-018-25847-1">still burning stored fat</a> – a sign that they somehow were using up more energy. We hypothesized that the cause <a href="https://my.clevelandclinic.org/health/symptoms/21660-inflammation#:%7E:text=The%20most%20common%20reasons%20for,from%20an%20infection%20or%20injury">might be inflammation</a> – the swelling, fever, pain and fatigue that human and animal bodies experience in response to infection or injury. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/533206/original/file-20230621-20-pixdob.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An orangutan reclines in a tree surrounded by haze." src="https://images.theconversation.com/files/533206/original/file-20230621-20-pixdob.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/533206/original/file-20230621-20-pixdob.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=380&fit=crop&dpr=1 600w, https://images.theconversation.com/files/533206/original/file-20230621-20-pixdob.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=380&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/533206/original/file-20230621-20-pixdob.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=380&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/533206/original/file-20230621-20-pixdob.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=477&fit=crop&dpr=1 754w, https://images.theconversation.com/files/533206/original/file-20230621-20-pixdob.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=477&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/533206/original/file-20230621-20-pixdob.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=477&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Otto, one of four adult male orangutans observed and recorded for this research, takes a midday smoky nap during Indonesia’s 2015 wildfires.</span>
<span class="attribution"><span class="source">Wendy Erb</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Sentinel sounds</h2>
<p>Studies have shown that when humans are exposed to particulate matter, they can experience inflammation, both in their <a href="https://doi.org/10.1097/JOM.0000000000001775">respiratory tracts</a> and <a href="https://doi.org/10.1164/ajrccm.164.5.2010160">throughout their bodies</a>. We wanted to know whether inhaling wildfire smoke would cause vocal changes in orangutans, just as inhaling cigarette smoke does in humans.</p>
<p>For this study, my co-authors and I carefully analyzed more than 100 sound recordings of four male orangutans that we followed before and during the fires to measure their vocal responses to wildfire smoke. Research has shown that a suite of vocal features – including <a href="https://www.asha.org/practice-portal/clinical-topics/voice-disorders/#collapse_2">pitch, vocal harshness or hoarseness, and shaky voice</a> – reflects the underlying health and condition of both human and nonhuman animals. We were looking for acoustic clues about how this toxic air might be affecting the orangutans. </p>
<p>During the fires and for several weeks after the smoke cleared, these males called less frequently than usual. Normally, orangutans call about six times a day. But during the fires, their call rate was cut in half. Their voices dropped in pitch, showing more vocal harshness and irregularities. </p>
<p>Collectively, these features of vocal quality have been linked to inflammation, stress and disease – including COVID-19 – in <a href="https://doi.org/10.1016/j.eswa.2017.04.012">human</a> and <a href="https://doi.org/10.1038/s41598-021-83614-1">nonhuman</a> animals.</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/CCoXocEBgiv/?utm_source=ig_web_copy_link\u0026igshid=MzRlODBiNWFlZA==","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<h2>Listening to vocal species</h2>
<p>Increasingly frequent and prolonged exposure to toxic smoke could have severe consequences for orangutans and other animals. Our research highlights the urgent need to understand the long-term and far-ranging effects of peatland fires in Indonesia, which is one of the <a href="https://www.cbd.int/countries/profile/?country=id">most biodiverse countries in the world</a>. </p>
<p>By uncovering the linkages between acoustic, behavioral and energetic shifts in orangutans, our study highlights a way for scientists and wildlife managers to safely monitor the health of orangutans and other animals. Using <a href="https://www.birds.cornell.edu/ccb/passive-acoustic-monitoring/">passive acoustic monitoring</a> to study vocally active indicator species, like orangutans, could unlock critical insights into wildfire smoke’s effects on wildlife populations worldwide.</p><img src="https://counter.theconversation.com/content/208153/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Wendy M. Erb is affiliated with the American Society of Primatologists; the Borneo Nature Foundation; and Primate Conservation, Inc. She has received research funding from the American Association of University Women; the American Institute for Indonesian Studies; the American Association of Biological Anthropologists; the American Society of Primatologists; the British Academy; the Conservation, Food, and Health Foundation; Conservation International; Cornell University; Disney Conservation Fund; the Fulbright Program; the International Society of Primatologists; and the National Science Foundation. </span></em></p>Orangutans are vocal animals, so analyzing their calls during events like wildfires can indicate how smoke is affecting their health.Wendy M. Erb, Postdoctoral Associate in Conservation Bioacoustics, Cornell UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2074112023-06-15T20:05:10Z2023-06-15T20:05:10ZImagine the outcry if factories killed as many people as wood heaters<figure><img src="https://images.theconversation.com/files/531902/original/file-20230614-31-hjm88m.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3988%2C2658&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Imagine a fleet of ageing factories operating in neighbourhoods across Australia.</p>
<p>On most days the smoke from their stacks is hardly noticed. But on cold days when the smog settles in the densely populated valleys and towns, doctors notice unusually high numbers of people suffering from a range of problems, especially asthma. </p>
<p>Air-quality researchers are called in to study the problem in more detail. They confirm that neighbourhoods with these old factories have higher concentrations of fine particles, which are <a href="https://www.health.nsw.gov.au/environment/factsheets/Pages/wood-smoke.aspx">toxic air pollutants</a>. </p>
<p>Invisible to the naked eye, particles are inhaled deep into the lungs, enter the bloodstream and cause a range of harms throughout the body. This air pollution is linked to higher rates of heart and lung diseases, strokes, dementia and some cancers. It also increases the risk of adverse pregnancy outcomes and poorer learning outcomes in children. </p>
<p>The researchers calculate that each year pollution from the factories causes 269 premature deaths in <a href="https://www.environment.nsw.gov.au/-/media/OEH/Corporate-Site/Documents/Air/sydney-air-quality-study-stage-2-program-report-220644.pdf">Sydney</a>, 69 in <a href="https://www.mdpi.com/1660-4601/17/9/3264">Tasmania</a> and 14 in <a href="https://onlinelibrary.wiley.com/doi/full/10.5694/mja2.51199">Armidale</a>, New South Wales. </p>
<p>While the factories are supposed to be built, maintained and operated to certain standards, the regulations are rarely if ever enforced. There isn’t even a central register to tell authorities how many of these factories exist, how old they are, and where they are located.</p>
<p>As news of this research is made public, how would the affected communities react? What might they demand of government? </p>
<p>Would it matter if they knew we were not talking about factories, but wood heaters? </p>
<figure class="align-center ">
<img alt="Haze from wood smoke hangs over suburban houses" src="https://images.theconversation.com/files/532110/original/file-20230615-23-2eowb3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/532110/original/file-20230615-23-2eowb3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=282&fit=crop&dpr=1 600w, https://images.theconversation.com/files/532110/original/file-20230615-23-2eowb3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=282&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/532110/original/file-20230615-23-2eowb3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=282&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/532110/original/file-20230615-23-2eowb3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=354&fit=crop&dpr=1 754w, https://images.theconversation.com/files/532110/original/file-20230615-23-2eowb3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=354&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/532110/original/file-20230615-23-2eowb3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=354&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">On a cold winter’s day, the haze from wood heaters hangs over Hobart, Tasmania.</span>
<span class="attribution"><span class="source">John Todd</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/blame-wood-burning-stoves-for-winter-air-pollution-and-health-threats-110662">Blame wood-burning stoves for winter air pollution and health threats</a>
</strong>
</em>
</p>
<hr>
<h2>Heaters produce much of our air pollution</h2>
<p>Every sentence of this story is true if you replace the word “factory” with “wood heater”. </p>
<p>Less than <a href="https://theconversation.com/like-having-a-truck-idling-in-your-living-room-the-toxic-cost-of-wood-fired-heaters-140737">10% of households</a> own a wood heater, but burning wood for heating is the largest source of air pollution in <a href="https://doi.org/10.1016/j.envint.2019.105429">many Australian cities</a> and <a href="https://www.mja.com.au/journal/2021/215/6/effects-mortality-and-associated-financial-costs-wood-heater-pollution-regional">towns</a>. While vehicle manufacturers and industry have greatly reduced emissions following tightened government regulations, domestic heating technology has not kept pace. </p>
<p>Today you would have to drive a diesel truck 500 kilometres to <a href="https://theconversation.com/like-having-a-truck-idling-in-your-living-room-the-toxic-cost-of-wood-fired-heaters-140737">emit as much air pollution</a> as a wood heater does in a single day. And that figure is for a wood heater that meets the current regulatory standards in Australia. Most do not. </p>
<p>Furthermore, wood heater pollution can be many times more severe when owners leave logs to smoulder overnight, burn poorly seasoned wood, or close down the air intake immediately after loading more wood.</p>
<p>Of course, particulate pollution is not all that wood heaters emit. When firewood is sourced from land clearing and illegal wood hooking, wood heaters add to net carbon dioxide and methane emissions in much the same as burning coal does because the carbon is no longer locked away in forests. </p>
<p>The <a href="https://publications.csiro.au/rpr/pub?list=BRO&pid=procite:ae6e5fe6-edfb-4f15-9e8e-7221653c1da1">best estimates</a> are that less than a quarter of firewood is sourced from sustainable plantation suppliers. Even from those sources, the carbon emissions take <a href="https://www.cell.com/chem/pdf/S2451-9294(22)00091-2.pdf">many years to be sequestered</a> into growing trees.</p>
<p>One study estimated that, if we stopped burning wood and clearing forest for heating, Australia would reduce its annual greenhouse gas emissions by <a href="https://doi.org/10.5094/APR.2011.033">8.7 million tonnes</a>. That’s about <a href="https://www.climatecouncil.org.au/wp-content/uploads/2017/09/FactSheet-Transport.pdf">one-fifth</a> of Australia’s car emissions.</p>
<figure class="align-center ">
<img alt="Smoke drifts from a rooftop chimney across a forested background" src="https://images.theconversation.com/files/531567/original/file-20230613-27-4rtpbr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531567/original/file-20230613-27-4rtpbr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=353&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531567/original/file-20230613-27-4rtpbr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=353&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531567/original/file-20230613-27-4rtpbr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=353&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531567/original/file-20230613-27-4rtpbr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=444&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531567/original/file-20230613-27-4rtpbr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=444&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531567/original/file-20230613-27-4rtpbr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=444&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">If we stopped clearing forest and burning wood for heating, the reduction in emissions would be equal to about one-fifth of Australia’s car emissions.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Smoke_from_a_small_chimney_in_fog.jpg">W. Carter/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/like-having-a-truck-idling-in-your-living-room-the-toxic-cost-of-wood-fired-heaters-140737">'Like having a truck idling in your living room': the toxic cost of wood-fired heaters</a>
</strong>
</em>
</p>
<hr>
<h2>The benefits of electrification</h2>
<p>Inevitably, as Australia moves towards a zero-carbon future, the electrification of domestic heating will bring widespread health and economic benefits. It will prevent hundreds of premature deaths each year. </p>
<p>Hospitals will benefit from a reprieve in the cooler months, enabling doctors and nurses to better cope with seasonal pneumonia and COVID-19 outbreaks. And even those outbreaks will be <a href="https://onlinelibrary.wiley.com/doi/pdf/10.1111/resp.14140">less severe with reduced air pollution</a>.</p>
<p>Besides being healthier, Australians will enjoy much lower heating costs as a result of using technologies such as reverse-cycle air conditioners (heat pumps). Remarkably, heat pumps are up to <a href="https://www.energy.gov.au/households/heating-and-cooling">600% efficient</a>. That means, for every unit of energy they consume, they generate up to six units of heating energy. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1568403307944882177"}"></div></p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/air-pollution-can-increase-the-risk-of-covid-infection-and-severe-disease-a-roundup-of-what-we-know-201813">Air pollution can increase the risk of COVID infection and severe disease – a roundup of what we know</a>
</strong>
</em>
</p>
<hr>
<h2>Making the switch</h2>
<p>As people learn about the impacts of wood heaters on their neighbours, friends and relatives — on pregnant women, young children and the elderly — many will make the switch. </p>
<p>Governments need to ensure safe and affordable heating technology is available to everyone regardless of their income. </p>
<p>Already, governments in the <a href="https://www.climatechoices.act.gov.au/policy-programs/wood-heater-replacement-program">Australian Capital Territory</a>, <a href="https://www.abc.net.au/news/2007-06-26/claims-heater-buyback-doing-its-job/81160">Tasmania</a> and <a href="https://www.eeca.govt.nz/co-funding/insulation-and-heater-grants/warmer-kiwi-homes-programme/">New Zealand</a> have programs that reimburse households for the cost of replacing their wood heaters. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1642368997411758080"}"></div></p>
<p>Buy-back schemes, home efficiency subsidies, regulation and enforcement, including property market regulation (ensuring wood heaters are removed prior to sale), and restrictions on new installations all have a role to play. </p>
<p>We are conducting economic modelling to determine the most cost-effective policy settings for maximising the benefits of policies to manage the problem of wood heaters. </p>
<p>Fire and smoke will remain important experiences for Australians. They can be savoured primarily outside the city, under bright stars, in open deserts and rugged coastlines, in beach shacks and farm cottages, and as part of Indigenous cultural practices.</p>
<p>One day we will look back in amazement that we once tolerated wood heaters in our cities, right next to schools, homes and hospitals. We’ll regard them in much the same way that we think of polluting factories today.</p><img src="https://counter.theconversation.com/content/207411/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bin Jalaludin receives funding from the NHMRC and the ARC. </span></em></p><p class="fine-print"><em><span>Fay Johnston is a Director of AirHealth Pty Ltd that supports the AirRater and Melbourne Pollen apps and other pollen prediction services. She receives funding from NHMRC and is the lead Investigator of the Centre for Safe Air, a NHMRC Centre for Research Excellence. She also receives funding from Asthma Australia, The Tasmanian, ACT and NT Departments of Health, the National Environment Research Program, and the NHMRC Healthy Environments and Lives (HEAL) Network.</span></em></p><p class="fine-print"><em><span>Bill Dodd does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>One day we’ll look back in amazement that wood heaters were once tolerated in cities right next to houses, schools and hospitals.Bill Dodd, Knowledge Broker, Centre for Safe Air (NHMRC CRE), University of TasmaniaBin Jalaludin, Conjoint Professor, School of Population Health, UNSW SydneyFay Johnston, Professor, Menzies Institute for Medical Research, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2060572023-05-22T12:26:52Z2023-05-22T12:26:52ZWildfire smoke can harm human health, even when the fire is burning hundreds of miles away – a toxicologist explains why<figure><img src="https://images.theconversation.com/files/534623/original/file-20230628-27-qecwmv.jpg?ixlib=rb-1.1.0&rect=24%2C66%2C4001%2C2728&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Wildfire smoke filled the air at Chicago's Wrigley Field on June 27, 2023.</span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/CanadaWildfiresAirQualityGreatLakesBaseball/e86f2c376cb040da87a614b0abdb8861/photo">AP Photo/Kim Johnson</a></span></figcaption></figure><p><em>Smoke from <a href="https://www.ciffc.ca/">more than 100 wildfires</a> burning across Canada has been rolling into North American cities far from the flames. New York City, Denver, Chicago, Minneapolis and Detroit each made the list of the <a href="https://www.iqair.com/us/world-air-quality-ranking">most polluted cities in the world</a> at times in May and June 2023 because of the fires. The smoke has triggered air quality alerts in several states.</em></p>
<p><em>We asked <a href="https://www.umt.edu/biomedical-pharmaceutical-sciences/people/faculty.php?ID=1345">Chris Migliaccio</a>, a toxicologist at the University of Montana who studies the impact of wildfire smoke on human health, about the health risks people can face when smoke blows in from distant wildfires.</em></p>
<h2>What’s in wildfire smoke that’s a problem?</h2>
<p>When we talk about air quality, we often talk about PM2.5. That’s particulate matter 2.5 microns or smaller – small enough that it can travel deep into the lungs.</p>
<p>Exposure to PM2.5 from smoke or other air pollution, such as vehicle emissions, can exacerbate health conditions like asthma and reduce lung function in ways that can worsen existing respiratory problems and even heart disease.</p>
<p>But the term PM2.5 only tells you about size, not composition – what is burning can make a significant difference in the chemistry.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/534612/original/file-20230628-19-5wd03e.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map of North America shows wildfire smoke from fires in Alberta and Ontario, Canada, detected strongly with poor air quality in the Great Lakes region, Northeast and Midwestern U.S." src="https://images.theconversation.com/files/534612/original/file-20230628-19-5wd03e.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534612/original/file-20230628-19-5wd03e.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534612/original/file-20230628-19-5wd03e.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534612/original/file-20230628-19-5wd03e.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534612/original/file-20230628-19-5wd03e.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534612/original/file-20230628-19-5wd03e.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534612/original/file-20230628-19-5wd03e.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Smoke from wildfires in Canada was detected across a large part of the U.S. on June 28, 2023. Dark purple dots indicate hazardous air quality. Light purple indicates very unhealthy air; red is unhealthy; orange is unhealthy for sensitive groups; and yellow indicates moderate risk. AirNow.gov.</span>
<span class="attribution"><a class="source" href="https://fire.airnow.gov/">AirNow.gov</a></span>
</figcaption>
</figure>
<p>In the northern Rockies, where I live, most fires are fueled by vegetation, but <a href="https://doi.org/10.1289/EHP3450">not all vegetation is the same</a>. If the fire is in the wildland urban interface, manufactured fuels from homes and vehicles may also be burning, and that’s going to <a href="https://nap.nationalacademies.org/catalog/26460/the-chemistry-of-fires-at-the-wildland-urban-interface">create its own toxic chemistry</a>, as well. Chemists often talk about <a href="https://www.cdc.gov/climateandhealth/effects/wildfires.htm">volatile organic compounds</a>, (VOCs), carbon monoxide and PAHs, or <a href="https://www.cdc.gov/biomonitoring/PAHs_FactSheet.html">polycyclic aromatic hydrocarbons</a> produced when biomass and other matter burns having the potential to harm human health.</p>
<h2>How does inhaling wildfire smoke harm human health?</h2>
<p>If you have ever been around a campfire and got a blast of smoke in your face, you probably had some irritation. With exposure to wildfire smoke, you might get some irritation in the nose and throat and maybe <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021GH000578">some inflammation</a>. If you’re healthy, your body for the most part will be able to handle it. </p>
<p>As with a lot of things, the dose makes the poison – almost anything can be harmful at a certain dose.</p>
<p>Generally, cells in the lungs called <a href="https://www.ncbi.nlm.nih.gov/books/NBK513313/">alveolar macrophages</a> will pick up the particulates and clear them out – at reasonable doses. It’s when the system gets overwhelmed that you can have a problem.</p>
<figure class="align-right ">
<img alt="Illustration of a small section of lungs showing the alveoli and, within the alveoli, a close up of a microphage" src="https://images.theconversation.com/files/527320/original/file-20230519-27-a7wgjx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/527320/original/file-20230519-27-a7wgjx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=914&fit=crop&dpr=1 600w, https://images.theconversation.com/files/527320/original/file-20230519-27-a7wgjx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=914&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/527320/original/file-20230519-27-a7wgjx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=914&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/527320/original/file-20230519-27-a7wgjx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1148&fit=crop&dpr=1 754w, https://images.theconversation.com/files/527320/original/file-20230519-27-a7wgjx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1148&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/527320/original/file-20230519-27-a7wgjx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1148&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Where macrophages are found in alveoli, the tiny air sacs in the lungs.</span>
</figcaption>
</figure>
<p>One concern is that smoke can <a href="https://doi.org/10.1038/s41598-018-31459-6">suppress macrophage function</a>, altering it enough that you become more susceptible to respiratory infection. A colleague who looked at lag time in the effect of wildfire smoke exposure found an <a href="https://doi.org/10.1016/j.envint.2020.105668">increase in influenza cases after a bad fire season</a>. Studies in developing countries have also found increases in <a href="https://doi.org/10.1016/j.atmosenv.2022.119055">respiratory infections</a> with people who are <a href="http://dx.doi.org/10.1136/thx.2010.147884">cooking on open fires</a> in homes.</p>
<p>The stress of an inflammatory response can also exacerbate existing health problems. Being exposed to wood smoke won’t independently cause someone to have a heart attack, but if they have underlying risk factors, such as significant plaque buildup, the added stress can increase the risk.</p>
<p>Researchers are also studying potential <a href="https://theconversation.com/breathing-wildfire-smoke-can-affect-the-brain-and-sperm-as-well-as-the-lungs-166548">effects on the brain</a> and <a href="https://ehp.niehs.nih.gov/doi/full/10.1289/EHP10498">nervous system</a> from <a href="https://www.epa.gov/isa/integrated-science-assessment-isa-particulate-matter">inhaled particulate matter</a>.</p>
<h2>When smoke blows over long distances, does its toxicity change?</h2>
<p>We know that the chemistry of wildfire smoke changes. The longer it’s in the atmosphere, the more the <a href="https://theconversation.com/wildfire-smoke-changes-dramatically-as-it-ages-and-that-matters-for-downwind-air-quality-heres-what-we-learned-flying-through-smoke-plumes-151671">chemistry will be altered</a> by ultraviolet light, but we still have <a href="http://doi.org/10.1016/j.etap.2017.08.022">a lot to learn</a>.</p>
<figure class="align-center ">
<img alt="A woman walks past the New York Stock Exchange building in the Wall Street district of New York. The sky is yellow-orange with wildfire smoke, a sky color common in apocalyptic films." src="https://images.theconversation.com/files/534624/original/file-20230628-17-7l230z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534624/original/file-20230628-17-7l230z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534624/original/file-20230628-17-7l230z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534624/original/file-20230628-17-7l230z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534624/original/file-20230628-17-7l230z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534624/original/file-20230628-17-7l230z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534624/original/file-20230628-17-7l230z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Wildfire smoke from Canada turned the skies in New York City an apocalyptic shade of orange on June 7, 2023.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/CanadaWIldfiresPhotoGallery/1601ea44e9bb4515ba755b4f6a7d5fa9/photo">AP Photo/J. David Ake</a></span>
</figcaption>
</figure>
<p>Researchers have found that there seems to be a higher level of oxidation, so oxidants and free radicals are being generated the longer smoke is in the air. The specific health effects aren’t yet clear, but there’s some indication that more exposure leads to <a href="https://doi.org/10.1155/2017/8416763">greater health effects</a>.</p>
<p>The supposition is that more <a href="https://ec.europa.eu/research-and-innovation/en/horizon-magazine/four-times-more-toxic-how-wildfire-smoke-ages-over-time">free radicals are generated</a> the longer smoke is exposed to UV light, so there’s a greater potential for health harm. A lot of that, again, comes down to dose.</p>
<figure class="align-center ">
<img alt="The city skyline disappears as the viewer looks farther into the haze, which is coming from wildfire smoke." src="https://images.theconversation.com/files/534619/original/file-20230628-17-fz8urj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534619/original/file-20230628-17-fz8urj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534619/original/file-20230628-17-fz8urj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534619/original/file-20230628-17-fz8urj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534619/original/file-20230628-17-fz8urj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534619/original/file-20230628-17-fz8urj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534619/original/file-20230628-17-fz8urj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Haze from wildfire smoke envelopes the Minneapolis skyline on June 14, 2023.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/CanadianWildfiresAirQuality/4dedf9a42ab04009a3f199e415fb66b1/photo">AP Photo/Abbie Parr</a></span>
</figcaption>
</figure>
<p>Chances are, if you’re a healthy individual, going for a bike ride or a hike in light haze won’t be a big deal, and your body will be able to recover. </p>
<p>If you’re doing that every day for a month in wildfire smoke, however, that raises more concerns. I’ve worked on studies with residents at Seeley Lake in Montana who were exposed to hazardous levels of PM2.5 from wildfire smoke for 49 days in 2017. We found a <a href="https://doi.org/10.3390/toxics8030053">decrease in lung function a year later</a>. No one was on oxygen, but there was a significant drop.</p>
<p>This is a relatively new area of research, and there’s still a lot we’re learning, especially with the increase in wildfire activity as the planet warms.</p>
<h2>What precautions can people take to reduce their risk from wildfire smoke?</h2>
<p>If there is smoke in the air, you want to decrease your exposure. </p>
<p>Can you completely avoid the smoke? Not unless you’re in a hermetically sealed home. The PM levels aren’t much different indoors and out unless you have a really good HVAC system, such as those with <a href="https://www.epa.gov/indoor-air-quality-iaq/what-merv-rating">MERV 15 or better filters</a>. But going inside decreases your activity, so your breathing rate is slower and the amount of smoke you’re inhaling is likely lower.</p>
<figure class="align-center ">
<img alt="A satellite animation shows smoke moving from fires in Alberta across Canada and into New England." src="https://images.theconversation.com/files/527359/original/file-20230521-119053-ul9mif.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/527359/original/file-20230521-119053-ul9mif.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=406&fit=crop&dpr=1 600w, https://images.theconversation.com/files/527359/original/file-20230521-119053-ul9mif.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=406&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/527359/original/file-20230521-119053-ul9mif.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=406&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/527359/original/file-20230521-119053-ul9mif.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=511&fit=crop&dpr=1 754w, https://images.theconversation.com/files/527359/original/file-20230521-119053-ul9mif.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=511&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/527359/original/file-20230521-119053-ul9mif.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=511&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A satellite captures wildfire smoke on May 16, 2023.</span>
<span class="attribution"><a class="source" href="https://www.earthdata.nasa.gov/worldview/worldview-image-archive/canada-fires-16-may-2023">NASA EarthData</a></span>
</figcaption>
</figure>
<p>We also tend to advise people that if you’re in a susceptible group, such as those with asthma, create a safe space at home and in the office with a high-level stand-alone air filtration system to create a space with cleaner air.</p>
<p>Some <a href="https://doi.org/10.1038/s41370-020-00267-4">masks can help</a>. It doesn’t hurt to have a high-quality N95 mask. Just wearing a cloth mask won’t do much, though.</p>
<p>Most <a href="https://www.airnow.gov/">states have air quality monitors</a> that can give you a sense of how bad the air quality is, so check those sites and act accordingly.</p>
<p><em>This article was updated June 28, 2023, with smoke in Chicago, Minneapolis and Detroit and the latest map of smoke conditions.</em></p><img src="https://counter.theconversation.com/content/206057/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christopher T. Migliaccio has received funding from the NIH and HRSA for his work in wood smoke health effects.
. </span></em></p>Fires in Canada have sent smoke across several US states, leaving cities including New York, Chicago and Denver with some of the worst air quality in the world – even far from the flames.Christopher T. Migliaccio, Research Associate Professor in Toxicology, University of MontanaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1547202022-12-27T19:20:27Z2022-12-27T19:20:27ZHow to protect yourself against bushfire smoke this summer<figure><img src="https://images.theconversation.com/files/498606/original/file-20221202-20-fswf2q.jpg?ixlib=rb-1.1.0&rect=5%2C0%2C1911%2C1279&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/Ihsi88KpQkE">Matt Palmer/Unsplash</a></span></figcaption></figure><p>It’s bushfire season. So you might be wondering about the best way to protect yourself from the health impacts of smoke.</p>
<p>Guidelines suggest wearing <a href="https://files-em.em.vic.gov.au/public/Smoke/EMK-01.19-Community-SAQH-Protocol.pdf">respirators</a>, <a href="https://www.health.nsw.gov.au/environment/air/Pages/bushfire-protection.aspx">avoiding</a> outdoor air and avoiding vigorous activity outdoors. Many people use the cheaper option of a surgical mask during bushfires. But there has never been a clinical trial to measure how well these interventions work. That’s why our group is <a href="https://kirby.unsw.edu.au/breathe">looking into it</a>.</p>
<p>In the meantime, here’s what you can do to reduce your exposure to bushfire smoke.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/its-summer-so-bushfires-and-covid-collide-3-ways-one-affects-the-other-169833">It's summer, so bushfires and COVID collide. 3 ways one affects the other</a>
</strong>
</em>
</p>
<hr>
<h2>Who’s at risk?</h2>
<p>Australia’s 2019/2020 summer bushfires resulted in <a href="https://www.theguardian.com/australia-news/2020/may/26/australias-summer-bushfire-smoke-killed-445-and-put-thousands-in-hospital-inquiry-hears">more than 400 estimated deaths</a> and thousands of hospitalisations from smoke exposure.</p>
<p>You don’t have to have a lung condition to suffer the <a href="https://theconversation.com/smoke-from-bushfires-poses-a-health-hazard-for-all-of-us-11493">ill-effects of bushfire smoke</a>. Breathing difficulties, eye irritation and heart attacks are among the <a href="https://theconversation.com/how-does-bushfire-smoke-affect-our-health-6-things-you-need-to-know-130126">well-documented</a> short-term impacts.</p>
<p>But people with asthma, <a href="https://theconversation.com/explainer-what-is-chronic-obstructive-pulmonary-disease-25539">emphysema</a>, chronic bronchitis and other lung conditions are particularly susceptible to smoke exposure, triggering asthma attacks and breathing difficulties.</p>
<p>This was the typical pattern we saw during our <a href="https://www.atsjournals.org/doi/10.1164/rccm.202012-4471LE?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed">own research</a>, conducted during the same bushfire season. We showed smoke exposure caused ill health in people with and without existing lung disease.</p>
<p>However, we found people under 65 had a higher risk of ill health after smoke exposure than older people. This may be because younger people tend to go outdoors more during bushfires.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-does-bushfire-smoke-affect-our-health-6-things-you-need-to-know-130126">How does bushfire smoke affect our health? 6 things you need to know</a>
</strong>
</em>
</p>
<hr>
<h2>1. Be prepared</h2>
<p>If you live in an area potentially affected by bushfire smoke, the first thing to do is to get an early alert about fires and smoke using one or more apps. Examples include, the <a href="https://www.rfs.nsw.gov.au/news-and-media/stay-up-to-date">Fires Near Me app</a> or the <a href="https://airrater.org">AirRater app</a> for air quality.</p>
<p>You can also use a <a href="https://iser.med.unsw.edu.au/sites/iser/files/_local_upload/Air%20quality%20self-assessment%20guide.pdf">visual method</a> to assess air quality. This involves identifying a landmark on the horizon about 5 kilometres away and noting if it becomes hazy. This would be the trigger for using a respirator or avoiding outdoor air.</p>
<h2>2. Stay inside if it’s safe</h2>
<p>Try to <a href="https://files-em.em.vic.gov.au/public/Smoke/EMK-01.19-Community-SAQH-Protocol.pdf">avoid exposure</a> to smoke, avoiding outside air and staying indoors if it is practical and safe to do so. Vigorous exercise outdoors can be dangerous as it results in greater smoke inhalation and risks to the heart and lungs.</p>
<p>Close all doors and windows, set air-conditioning to recirculate, and seal gaps under or around doors, windows and wall vents with towels, blankets or plastic. </p>
<p>Unfortunately, these instructions are the opposite of what to do if there is COVID at home, when you would want fresh air in the house. If that is the case, wear a mask indoors in common areas and social distance from the person with COVID.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/our-buildings-arent-made-to-keep-out-bushfire-smoke-heres-what-you-can-do-129367">Our buildings aren't made to keep out bushfire smoke. Here's what you can do</a>
</strong>
</em>
</p>
<hr>
<h2>3. Wear a respirator (not just a surgical mask)</h2>
<p>Most people who need to go outside during a bushfire can use some type of disposable respirator to filter the smokey air.</p>
<p>You will have seen people wearing these P2, P3 or N95 <a href="https://theconversation.com/how-to-get-the-most-out-of-your-n95-mask-or-other-respirator-177229">respirators</a> to protect themselves and others from SARS-CoV-2, the virus that causes COVID.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1496730465981640708"}"></div></p>
<p>These and <a href="https://www.addler.com.au/differences-p1-p2-p3-n95-respirators/">other types of disposable respirators</a> filter very fine particles and fit closely around the face. Choose one with a full band around the back of the head (rather than ear loops) as these provide a better fit.</p>
<p>Some disposable respirators have valves, which means they filter inhaled air but allow you to exhale more comfortably. This option may help people with asthma or lung disease to breathe more comfortably. If you have COVID, though, wearing a respirator with a valve does not reduce the risk of you infecting others, because the air you breathe out through the valve is unfiltered and contaminated.</p>
<p>Respirators will filter particles <a href="https://www.aiha.org/news/201022-osha-addresses-claims-that-n95s-do-not-protect-against-sars-cov-2">larger than 0.3 microns</a> (micrometres). However, they may not filter smaller particles contained in smoke, which is why avoiding outside air is still important.</p>
<p>People who live in bushfire-prone areas may want to consider a type of respirator they can clean and re-use when needed, known as <a href="https://healthcareworkersaustralia.com/elastomeric-mask/">an elastomeric respirator</a>. Their filters need to be changed at specified intervals.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/499478/original/file-20221207-24-nezay8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Elastomeric face mask" src="https://images.theconversation.com/files/499478/original/file-20221207-24-nezay8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/499478/original/file-20221207-24-nezay8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=406&fit=crop&dpr=1 600w, https://images.theconversation.com/files/499478/original/file-20221207-24-nezay8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=406&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/499478/original/file-20221207-24-nezay8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=406&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/499478/original/file-20221207-24-nezay8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=510&fit=crop&dpr=1 754w, https://images.theconversation.com/files/499478/original/file-20221207-24-nezay8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=510&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/499478/original/file-20221207-24-nezay8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=510&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An elastomeric mask, such as this one, can be re-used.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/reusable-halfface-elastomeric-respirator-air-purification-2196383995">Shutterstock</a></span>
</figcaption>
</figure>
<p>If you have trouble getting one of the mentioned respirators, you can use a disposable <a href="https://breathesafeair.com/mask-ratings/">KN95 respirator</a>. However, these have ear loops and do not fit well around the face, so air can leak through. </p>
<p>Surgical masks are not likely to protect you because they are so loose. But medical-grade ones provide good filtering. For this to be effective, wear one with a <a href="https://www.insider.com/ways-to-make-your-face-mask-more-effective-2021-2">mask brace or clip</a> to provide a better fit and to help prevent air leaking in from the sides.</p>
<h2>In a nutshell</h2>
<p>Be prepared by downloading an app to monitor bushfires and air quality near you, and stocking up on good quality respirators ahead of time if you can. You can re-use these if they are not visibly soiled or damaged.</p>
<p>Staying out of the smoke is also important, particularly if you have asthma, emphysema and other lung disease. Young people may be less aware of the health effects of smoke exposure, and even people without lung disease can experience ill health due to smoke.</p>
<hr>
<p><em>Do you have asthma, emphysema, chronic bronchitis or bronchiectasis? Do you live in an area in Australia affected by bushfires or bushfire smoke (including metropolitan areas)? You may be eligible to be part of <a href="https://kirby.unsw.edu.au/breathe">our study</a> into the best way to protect yourself from bushfire smoke.</em></p><img src="https://counter.theconversation.com/content/154720/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>C Raina MacIntyre has consulted for mask companies including Detmold and Ascend. She receives funding from the NHMRC and the MRFF currently.</span></em></p>Be prepared. Download an air quality app, stock up on respirators and stay inside if you can.C Raina MacIntyre, Professor of Global Biosecurity, NHMRC Principal Research Fellow, Head, Biosecurity Program, Kirby Institute, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1928022022-11-01T12:46:19Z2022-11-01T12:46:19ZBeyond passenger cars and pickups: 5 questions answered about electrifying trucks<figure><img src="https://images.theconversation.com/files/491972/original/file-20221026-13-xcxwfu.jpg?ixlib=rb-1.1.0&rect=20%2C10%2C6689%2C4456&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Trucks line up to load and unload at the Port of Los Angeles in Long Beach, California.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/trucks-line-up-to-drop-off-their-loads-at-the-port-of-los-news-photo/1228408112">Genaro Molina/Los Angeles Times via Getty Images</a></span></figcaption></figure><p><em>As part of its effort to reduce air pollution and cut greenhouse gas emissions that contribute to climate change, California is pursuing aggressive policies to promote clean trucks. The state already requires that by 2035, all new cars and other light-duty vehicles sold in the state must be <a href="https://www.greencarcongress.com/2022/08/20220826-acc2.html">zero emission</a>. Its powerful <a href="https://ww2.arb.ca.gov/">Air Resources Board</a> has adopted rules requiring that most trucks be zero emission by 2035, and is now proposing that all trucks sold by 2040 <a href="https://www.latimes.com/california/story/2022-09-21/california-regulators-new-big-rigs-zero-emission-by-2040">must be zero emission</a>. The Conversation asked a panel of transportation experts from the University of California, Davis what’s involved in such a rapid transition.</em></p>
<h2>1. Why is California targeting medium- and heavy-duty trucks?</h2>
<p>Although diesel engines are valuable for moving heavy loads, they also are major polluters. Diesel trucks account for <a href="https://www.eia.gov/energyexplained/diesel-fuel/diesel-and-the-environment.php">one-fourth of greenhouse gas emissions</a> and <a href="https://www.edf.org/sites/default/files/documents/TransportationWhitePaper.pdf">about half of conventional air pollution</a> from transportation in U.S. cities. </p>
<p>Pollutants in diesel exhaust include nitrogen oxides, fine particulates and <a href="https://ww2.arb.ca.gov/resources/overview-diesel-exhaust-and-health">numerous cancer-causing compounds</a>. Since many disadvantaged communities are <a href="https://www.washingtonpost.com/climate-environment/2022/03/09/redlining-pollution-environmental-justice/">located near highways and industrial centers</a>, their residents are especially affected by diesel truck pollution. Two regions in California – the <a href="https://thehill.com/changing-america/sustainability/climate-change/3460147-the-best-and-worst-u-s-cities-for-air-quality/">Central Valley and Los Angeles-Long Beach</a> – have some of the dirtiest air in the U.S., so the state has placed particular emphasis on cutting diesel use. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/j-zybIQbTTE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Almost all diesel fuel in the U.S. is used in trucks, not in passenger vehicles.</span></figcaption>
</figure>
<h2>2. Are zero-emission trucks ready to go?</h2>
<p>To a degree, yes. Some new models, mainly powered by batteries but some by <a href="https://www.energy.gov/public-services/vehicles/hydrogen-fuel-cells">hydrogen fuel cells</a>, are available on the market, and more are being announced almost daily. </p>
<p>But the production volumes are still small, and there are many variations of truck models needed for very diverse applications, from delivering mail locally and plowing snow to hauling goods cross-country. Many of these needs cannot be met with currently offered zero-emission trucks. </p>
<p>Another <a href="https://escholarship.org/uc/item/0p14c77j">hurdle</a> is that new electric truck models have <a href="https://theicct.org/cost-electric-semi-feb22/">higher purchase prices</a> than comparable diesel trucks. However, as the market for zero-emission trucks grows, economies of scale should bring these costs down significantly. We already see this happening with <a href="https://www.iea.org/reports/global-ev-outlook-2022/trends-in-electric-light-duty-vehicles">zero-emission cars and light-duty trucks</a>.</p>
<p>The total cost of ownership for zero-emission trucks, which includes the purchase price, fuel costs and maintenance, is <a href="https://ncst.ucdavis.edu/research-product/current-and-future-performance-and-costs-battery-electric-trucks-review-key">already competitive in some applications</a> with conventional diesel trucks. One example is trucks used for <a href="https://doi.org/10.1016/j.tre.2022.102783">local goods delivery</a> by companies like Amazon, UPS and FedEx. This stage is also known as last-mile delivery – getting a product to a buyer’s door.</p>
<p>These trucks are typically driven less than <a href="https://escholarship.org/uc/item/7kr753nm">150 miles per day</a>, so they don’t need large battery packs. Their lower energy costs and reduced maintenance needs often offset their higher purchase costs, so owners save money on them over time. </p>
<p>Our studies indicate that by 2025 and especially by 2030, many applications for battery trucks, and perhaps hydrogen fuel cell trucks, will have <a href="https://escholarship.org/uc/item/1g89p8dn">competitive or even lower total costs of ownership</a> than comparable diesel trucks. That’s especially true because of California subsidies and <a href="https://doi.org/10.1016/j.jclepro.2021.128353">incentives</a>, such as the <a href="https://californiahvip.org/">Hybrid and Zero-Emission Truck and Bus Voucher Incentive Project</a>, which reduces the cost of new electric trucks and buses. And the state’s <a href="https://ww2.arb.ca.gov/our-work/programs/low-carbon-fuel-standard">Low Carbon Fuel Standard</a> greatly reduces the cost of low-carbon fuels and electricity for truck and bus fleets.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/492193/original/file-20221027-25221-5wsypi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A man in a white shuttle bus painted with branding and '100% Zero Emission.'" src="https://images.theconversation.com/files/492193/original/file-20221027-25221-5wsypi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/492193/original/file-20221027-25221-5wsypi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/492193/original/file-20221027-25221-5wsypi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/492193/original/file-20221027-25221-5wsypi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/492193/original/file-20221027-25221-5wsypi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/492193/original/file-20221027-25221-5wsypi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/492193/original/file-20221027-25221-5wsypi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Zeem Solutions CEO Paul Gioupis poses in one of his company’s vehicles. Zeem, based in Inglewood, California, rents fleets of zero-emission trucks, vans and shuttle buses to other companies for a flat monthly fee.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/paul-gioupis-ceo-of-zeem-solutions-allows-companies-to-news-photo/1408096502">Brittany Murray/MediaNews Group/Long Beach Press-Telegram via Getty Images</a></span>
</figcaption>
</figure>
<p>The market in California is already reacting to these policy signals and is developing quickly. In the past year, there has been a large increase in sales of last-mile electric delivery trucks, and companies have stepped up their pledges to procure such vehicles. </p>
<p>Over 150 zero-emission truck models are commercially available and eligible for state incentive funding. They range from <a href="https://californiahvip.org/vehicle-category/2b/">large pickup trucks</a> to <a href="https://californiahvip.org/vehicle-category/heavy-duty/">heavy-duty tractor units for tractor-trailer combinations</a>.</p>
<h2>3. Is there enough charging infrastructure to support all these vehicles?</h2>
<p>Providing near-zero-carbon electricity for EVs and hydrogen for fuel cells, and expanding charging and hydrogen refueling infrastructure, is just as important as getting zero-emission trucks on the roads.</p>
<p>Fleet owners will need to install chargers that can charge their battery-powered trucks overnight, or sometimes during the day. These stations may require so much power that utilities will need to install additional hardware to bring electricity from the grid to the stations to meet potentially high demands at certain times. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/vP5iRWqV-V4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">This video from the utility Southern California Edison shows some of the steps involved in electrifying medium- and heavy-duty vehicle fleets.</span></figcaption>
</figure>
<p>Fuel cell trucks will require hydrogen stations installed either at fleet depots or public locations. These will allow fast refueling without high instantaneous demands on the system. But producing the hydrogen will require electricity, which will put an additional burden on the electric system.</p>
<p>Presently there are few public or private charging or hydrogen stations for truck fleets in California. But the California Public Utility Commission has allowed utilities to charge their customers to install a significant number of <a href="https://www.cpuc.ca.gov/industries-and-topics/electrical-energy/infrastructure/transportation-electrification/approved-te-investments">stations throughout the state</a>. And the U.S. Department of Energy recently allocated $8 billion for construction of <a href="https://www.energy.gov/articles/doe-launches-bipartisan-infrastructure-laws-8-billion-program-clean-hydrogen-hubs-across">hydrogen hubs</a> – networks for producing, processing, storing and delivering clean hydrogen – across the country. </p>
<p>Despite these efforts, the rollout of charging and hydrogen infrastructure will likely slow the transition to zero-emission trucks, especially long-haul trucks.</p>
<h2>4. Who would be affected by a diesel truck ban?</h2>
<p>California’s rules will affect both truck manufacturers and truck users. The state’s <a href="https://ww2.arb.ca.gov/our-work/programs/advanced-clean-trucks">Advanced Clean Trucks rule</a>, adopted in 2020, requires the sale of increasing percentages of zero emission trucks starting in 2024. By 2035, 40% to 75% of all trucks, depending on the truck type, must be zero emission. </p>
<p>A new proposal scheduled for adoption in early 2023, the <a href="https://ww2.arb.ca.gov/our-work/programs/advanced-clean-fleets">Advanced Clean Fleets rule</a>, would require fleets with over 50 trucks to purchase an increasing number of zero-emission trucks over time, with the requirement that all truck sales and purchases be zero emission by 2040. </p>
<p>These two policies would work together. The Advanced Clean Trucks rule ensures that zero-emission trucks will become available to fleets, and the Advanced Clean Fleets rule would give truck manufacturers confidence that the zero-emission trucks they produce will find buyers. </p>
<p>These two rules are the most ambitious in the world in accelerating a transition to zero-emission trucks. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1285224795530055682"}"></div></p>
<h2>5. Are other states emulating California?</h2>
<p>Yes, there is strong interest in many other states in electrifying trucking. Oregon, Washington, New York, New Jersey and Massachusetts have already <a href="https://www.bloomberg.com/news/articles/2022-01-06/how-zero-emission-laws-will-reshape-u-s-trucking?sref=Hjm5biAW">adopted the Advanced Clean Trucks rule</a>, and <a href="https://www.electrictrucksnow.com/states">others are in the process of doing so</a>. Seventeen states and the District of Columbia have <a href="https://www.electrificationcoalition.org/nevada-joins-multi-state-agreement-to-electrify-trucks-and-buses/">agreed to work together</a> to foster a self-sustaining market for medium- and heavy-duty vehicles. </p>
<p>We expect that transitioning to zero-emission truck fleets will require strong policy support at least until the 2030s and perhaps longer. The transition should become self-sufficient in most cases as production scales up and fleets adapt their operations, resulting in lower costs. This could be soon, especially with medium-duty trucks. </p>
<p>Converting large long-haul trucks will be especially challenging because they need large amounts of onboard energy storage and benefit from rapid refueling. Fuel cell systems with hydrogen may make the most sense for many of these vehicles; fleets will ultimately decide which technologies are best for them. </p>
<p>The transition to zero-emission trucks will be disruptive for many fleets and businesses, and will require government support during the early years of the transition. Overall, though, we believe prospects are bright for zero-emission trucking, with enormous clean air and climate benefits, and eventually, cost savings for truck owners.</p><img src="https://counter.theconversation.com/content/192802/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniel Sperling receives funding from a variety of government agencies and foundations. He is a board member with the California Air Resources Board and the Southwest Energy Efficiency Project. . </span></em></p><p class="fine-print"><em><span>Lewis Fulton, via UC Davis, receives funding from a range of organizations involved in manufacturing vehicles, installing infrastructure, and other activities relevant to the market development of battery-electric vehicles. </span></em></p><p class="fine-print"><em><span>Marshall Miller receives funding via UC Davis from a range of organizations involved in manufacturing vehicles, installing infrastructure, and other activities relevant to the market development of battery-electric vehicles.</span></em></p><p class="fine-print"><em><span>Miguel Jaller receives funding from Federal and State agencies, foundations, truck manufacturers, and other organizations.
He has provided advisory to startup companies in the transportation and trucking fields, and is an Amazon Scholar working on worldwide sustainability efforts for Amazon.</span></em></p>As California goes on regulating air pollution, other states often follow – including the Golden State’s ambitious goals for cleaning up emissions from trucking.Daniel Sperling, Distinguished Blue Planet Prize Professor of Civil and Environmental Engineering and Founding Director, Institute of Transportation Studies, University of California, DavisLewis Fulton, Co-director, STEPS (Sustainable Transportation Energy Pathways), University of California, DavisMarshall Miller, Senior Development Engineer, institute of Transportation Studies, University of California, DavisMiguel Jaller, Associate Professor of Civil & Environmental Engineering, University of California, DavisLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1665372021-09-10T12:28:29Z2021-09-10T12:28:29Z9/11 survivors’ exposure to toxic dust and the chronic health conditions that followed offer lessons that are still too often unheeded<figure><img src="https://images.theconversation.com/files/420128/original/file-20210908-22-728gm5.jpg?ixlib=rb-1.1.0&rect=0%2C125%2C2775%2C1859&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Toxic dust hung in the air around ground zero for more than three months following the 9/11 terrorist attacks.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/an-unidentified-new-york-city-firefighter-walks-away-from-news-photo/1372804?adppopup=true">Anthony Correia/Getty Images</a></span></figcaption></figure><p>The 9/11 terrorist attack on the World Trade Center in New York resulted in the loss of <a href="https://www.cnn.com/2013/07/27/us/september-11-anniversary-fast-facts/index.html">2,753 people in the Twin Towers and surrounding area</a>. After the attack, more than 100,000 responders and recovery workers from every U.S. state – along with <a href="https://www.cdc.gov/wtc/history.html">some 400,000 residents</a> and other workers around ground zero – were exposed to a <a href="https://abcnews.go.com/Health/september-11-toxic-world-trade-center-dust-cloud/story?id=14466933">toxic cloud of dust</a> that fell as a ghostly, thick layer of ash and then hung in the air for more than three months. </p>
<p>The World Trade Center dust plume, or <a href="https://doi.org/10.3109/10408444.2015.1044601">WTC dust</a>, consisted of a dangerous mixture of cement dust and particles, asbestos and a class of chemicals called <a href="https://www.epa.gov/international-cooperation/persistent-organic-pollutants-global-issue-global-response">persistent organic pollutants</a>. These include <a href="https://www.epa.gov/dioxin/learn-about-dioxin">cancer-causing dioxins</a> and <a href="https://www.cdc.gov/biomonitoring/PAHs_FactSheet.html">polyaromatic hydrocarbons, or PAHs</a>, which are byproducts of fuel combustion. </p>
<p>The dust also contained heavy metals that are known <a href="https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health">to be poisonous to the human body and brain</a>, such as lead – used in the manufacturing of flexible electrical cables – and mercury, which is found in float valves, switches and fluorescent lamps. The dust also contained cadmium, a carcinogen <a href="https://doi.org/10.1007/s10534-010-9328-y">toxic to the kidneys</a> that is used in the manufacturing of electric batteries and pigments for paints.</p>
<figure class="align-center ">
<img alt="Smoke pours from the Twin Towers of the World Trade Center in New York City on September 11, 2001." src="https://images.theconversation.com/files/420341/original/file-20210909-27-p4t2aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/420341/original/file-20210909-27-p4t2aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=418&fit=crop&dpr=1 600w, https://images.theconversation.com/files/420341/original/file-20210909-27-p4t2aq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=418&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/420341/original/file-20210909-27-p4t2aq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=418&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/420341/original/file-20210909-27-p4t2aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=526&fit=crop&dpr=1 754w, https://images.theconversation.com/files/420341/original/file-20210909-27-p4t2aq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=526&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/420341/original/file-20210909-27-p4t2aq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=526&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">One of the haunting images from 9/11: Smoke pours from the twin towers of the World Trade Center in New York after they were hit by two hijacked airliners.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/smoke-pours-from-the-twin-towers-of-the-world-trade-center-news-photo/1339505?adppopup=true">Robert Giroux via Getty Images</a></span>
</figcaption>
</figure>
<p><a href="http://www.idph.state.il.us/envhealth/factsheets/polychlorinatedbiphenyls.htm#:%7E:text=Polychlorinated%20biphenyls%20(PCBs)%20are%20a,equipment%20like%20capacitors%20and%20transformers.">Polychlorinated biphenyls</a>, human-made chemicals used in electrical transformers, were also part of the toxic stew. PCBs are <a href="https://www.epa.gov/pcbs/learn-about-polychlorinated-biphenyls-pcbs#healtheffects">known to be carcinogenic</a>, toxic to the nervous system and disruptive to the reproductive system. But they became even more harmful when incinerated at high heat from the jets’ fuel combustion and then carried by very fine particles. </p>
<p><a href="https://doi.org/10.3109/10408444.2015.1044601">WTC dust</a> was made up of both “large” particulate matter and very small, fine and ultrafine ones. These particularly small particles are known to be <a href="https://doi.org/10.1038/s41598-018-35398-0">highly toxic</a>, especially to the nervous system since they can travel directly through the <a href="https://doi.org/10.1016/j.neuro.2011.12.001">nasal cavity to the brain</a>. </p>
<p>Many first responders and others who were directly exposed to the dust developed a <a href="https://doi.org/10.3109/10408444.2015.1044601">severe and persistent cough</a> that lasted for a month, on average. They were treated at Mount Sinai Hospital and received care at the Clinic of Occupational Medicine, a well-known center for work-related diseases.</p>
<p>I am a physician specializing in occupational medicine who began working directly with 9/11 survivors in my role as director of the <a href="https://www.cdc.gov/wtc/">WTC Health Program</a> <a href="https://icahn.mssm.edu/about/departments/environmental-public-health/research/wtc-data-center">Data Center</a> at Mount Sinai beginning in 2012. That program collects data, as well as monitors and oversees the public health of WTC rescue and recovery workers. After eight years in that role, I <a href="https://stempel.fiu.edu/faculty/roberto-lucchini/">moved to Florida International University</a> in Miami, where I am planning to continue working with 9/11 responders who are moving to Florida as they reach retirement age.</p>
<figure class="align-center ">
<img alt="In lower Manhattan near Ground Zero, people run away as the North Tower of the World Trade Center collapses." src="https://images.theconversation.com/files/420343/original/file-20210909-23-1bc9fnj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/420343/original/file-20210909-23-1bc9fnj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/420343/original/file-20210909-23-1bc9fnj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/420343/original/file-20210909-23-1bc9fnj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/420343/original/file-20210909-23-1bc9fnj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/420343/original/file-20210909-23-1bc9fnj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/420343/original/file-20210909-23-1bc9fnj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Remembering 9/11: As the north tower of the World Trade Center collapses, a cloud of toxic gas chases terrified residents and tourists.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/people-run-away-as-the-north-tower-of-world-trade-center-news-photo/1339533?adppopup=true">Jose Jimenez/Primera Hora via Getty Images</a></span>
</figcaption>
</figure>
<h2>From acute to chronic conditions</h2>
<p>After the initial “acute” health problems that 9/11 responders faced, they soon began experiencing a wave of chronic diseases that <a href="https://doi.org/10.3390/ijerph18126383">continue to affect them</a> 20 years later. The persistent cough gave way to <a href="https://doi.org/10.1001/dmp.2011.58">respiratory diseases</a> such as asthma, chronic obstructive pulmonary disease (COPD) and upper airway diseases such as <a href="https://doi.org/10.1136/oemed-2015-103094">chronic rhinosinusitis</a>, laryngitis and nasopharyngitis. </p>
<p>The litany of respiratory diseases also put many of them at risk for <a href="https://doi.org/10.1038/ajg.2011.357">gastroesophageal reflux disease</a> (GERD), which occurs at a <a href="https://doi.org/10.1097/JOM.0b013e3181845f9b">higher rate in WTC survivors</a> than in the general population. This condition occurs when stomach acids reenter the esophagus, or food pipe, that connects the stomach to the throat. As a consequence of either the airway or the digestive disorders, many of these survivors also <a href="https://doi.org/10.1097/JOM.0b013e3182305282">struggle with sleep apnea</a>, which requires additional treatments.</p>
<p>Further compounding the tragedy, about eight years after the attacks, <a href="https://doi.org/10.1093/jncics/pkz090">cancers began to turn up</a> in 9/11 survivors. These include tumors of the blood and lymphoid tissues such as lymphoma, myeloma and leukemia, which are well known to <a href="https://doi.org/10.1186/1745-6673-8-14">affect workers exposed to carcinogens</a> in the workplace. But survivors also suffer from other cancers, including breast, head and neck, prostate, lung and thyroid cancers. </p>
<p>Some have also developed mesothelioma, an aggressive form of cancer related to <a href="http://dx.doi.org/10.1136/thoraxjnl-2013-204161">exposure to asbestos</a>. <a href="https://www.9news.com.au/9stories/september-11-death-toll-from-terror-attack-could-rise-by-millions-due-to-toxic-asbestos-dust/8bc90677-0032-42a2-82f9-4b9baad753d9">Asbestos</a> was used in the early construction of the north tower until public advocacy and broader awareness of its health dangers <a href="https://www.mesothelioma.com/states/new-york/world-trade-center/">brought its use to a halt</a>.</p>
<p>And the psychological trauma that 9/11 survivors experienced has left many suffering from persistent mental health challenges. One <a href="https://doi.org/10.1007/s10488-019-00998-z">study</a> published in 2020 found that of more than 16,000 WTC responders for whom data was collected, nearly half reported a need for mental health care, and 20% of those who were directly affected developed <a href="https://doi.org/10.1016/j.dadm.2016.08.001">post-traumatic stress disorder</a>. </p>
<p>Many have told me that the contact they had with parts of human bodies or with the deadly scene and the tragic days afterward left a permanent mark on their lives. They are unable to forget the images, and many of them suffer from mood disorders as well as <a href="https://doi.org/10.1186/s12940-019-0449-7">cognitive impairments and other behavioral issues</a>, including substance use disorder. </p>
<figure class="align-center ">
<img alt="On 9/11, shortly after the terrorist attack in New York City, a distraught survivor sits outside the World Trade Center." src="https://images.theconversation.com/files/420347/original/file-20210909-23-do7s5e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/420347/original/file-20210909-23-do7s5e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/420347/original/file-20210909-23-do7s5e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/420347/original/file-20210909-23-do7s5e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/420347/original/file-20210909-23-do7s5e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/420347/original/file-20210909-23-do7s5e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/420347/original/file-20210909-23-do7s5e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Remembering 9/11: A distraught survivor sits outside the World Trade Center after the terrorist attack.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/survivor-sits-outside-the-world-trade-center-after-two-news-photo/50833029?adppopup=true">Jose Jimenez/Primera Hora via Getty Images</a></span>
</figcaption>
</figure>
<h2>An aging generation of survivors</h2>
<p>Now, 20 years on, these survivors face a new challenge as they age and move toward retirement – a <a href="https://doi.org/10.3386/w12123">difficult life transition</a> that can sometimes lead to mental health decline. Prior to retirement, the daily drumbeat of work activity and a steady schedule often helps keep the mind busy. But retirement can sometimes leave a void – one that for 9/11 survivors is too often filled with unwanted memories of the noises, smells, fear and despair of that terrible day and the days that followed. Many survivors have told me they do not want to return to Manhattan and certainly not to the WTC. </p>
<p>Aging can also bring with it forgetfulness and other cognitive challenges. But studies show that these natural processes are <a href="https://doi.org/10.1186/s12940-019-0449-7">accelerated and more severe</a> in 9/11 survivors, similar to the experience of veterans from war zones. This is a concerning trend, but all the more so because a growing body of research, including <a href="https://doi.org/10.21203/rs.3.rs-846359/v1">our own preliminary study</a>, is finding links between <a href="https://doi.org/10.1192/bjp.bp.105.014779">cognitive impairment in 9/11 responders and dementia</a>. A recent <a href="https://www.washingtonpost.com/magazine/2021/08/30/911-first-responders-dementia/">Washington Post piece detailed</a> how 9/11 survivors are experiencing these dementia-like conditions in their 50s – far earlier than is typical. </p>
<p>The COVID-19 pandemic, too, has taken a toll on those who have already suffered from 9/11. People with <a href="https://doi.org/10.1016/j.eclinm.2020.100515">preexisting conditions</a> have been at far higher risk during the pandemic. Not surprisingly, a recent study found a <a href="https://doi.org/10.1371/journal.pone.0254713">higher incidence of COVID-19</a> in WTC responders from January through August 2020.</p>
<h2>Honoring the 9/11 survivors</h2>
<p>The health risks posed by direct exposure to the acrid dust was underestimated at the time, and poorly understood. Appropriate personal protective equipment, such as P100 half-face respirators, was not available at that time. </p>
<p>But now, over 20 years on, we know much more about the risks – and we have much greater access to protective equipment that can keep responders and recovery workers safe following disasters. Yet, too often, I see that we have not learned and applied these lessons. </p>
<p>For instance, in the immediate aftermath of the <a href="https://www.nytimes.com/live/2021/07/06/us/miami-building-collapse-updates">condominium collapse</a> near Miami Beach last June, it took days before P100 half-face respirators were fully available and made mandatory for the responders. Other examples around the world are even worse: One year after the <a href="https://www.npr.org/2021/08/04/1024275186/a-year-after-the-beirut-explosion-victims-families-continue-to-push-for-justice">Beirut explosion</a> in August 2020, very little action had been taken to investigate and manage the physical and <a href="https://timep.org/commentary/analysis/the-beirut-explosions-impact-on-mental-health/">mental health consequences </a> among responders and the impacted community.</p>
<p>Applying the lessons learned from 9/11 is a critically important way to honor the victims and the brave men and women who took part in the desperate rescue and recovery efforts back on those terrible days.</p><img src="https://counter.theconversation.com/content/166537/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Roberto Lucchini receives funding from CDC/NIOSH to study the cognitive impacts associated to the WTC exposure to neurotoxins and to intense psychological trauma. </span></em></p>Those directly exposed to toxic dust and trauma on and after 9/11 carry with them a generation of chronic health conditions, which are placing them at higher risk during the pandemic and as they age.Roberto Lucchini, Professor of Occupational and Environmental Health Sciences, Florida International UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1672232021-09-07T15:12:58Z2021-09-07T15:12:58ZAir pollution: science shows there’s no safe limit – here’s how laws must change<figure><img src="https://images.theconversation.com/files/419789/original/file-20210907-15-xhic16.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5315%2C3262&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/milan-italy-january-19-close-cars-173804489">Paolo Bona/Shutterstock</a></span></figcaption></figure><p>Air pollution is the largest environmental risk to public health. Outdoor air pollution causes around <a href="https://www.who.int/health-topics/air-pollution#tab=tab_1">four million premature deaths</a> globally each year, while a further three million deaths are linked to pollution indoors – mainly from open cooking and heating fires in developing countries.</p>
<p>The most harmful air pollutants in urban areas are nitrogen dioxide gas (NO₂) and fine particulate matter, often referred to as PM2.5 – particles smaller than 2.5 micrometres that can be inhaled deep into the lungs. In cities, NO₂ largely comes from roads, particularly older diesel vehicles. PM2.5 sources include combustion, wood fires, industry, cooking, agriculture and vehicle exhausts. These particles last for longer in the air than NO₂ and together are a threat to heart and lung health, contributing to as many as <a href="https://www.gov.uk/government/publications/nitrogen-dioxide-effects-on-mortality/associations-of-long-term-average-concentrations-of-nitrogen-dioxide-with-mortality-2018-comeap-summary">36,000 deaths each year</a> in the UK.</p>
<p>Most countries have laws to maintain air pollution at safe levels in order to protect human health. Air quality standards are supposed to be enforced when these pollution levels are exceeded, but what do scientists know about the safe limit for air pollution?</p>
<p>In England, the legal limit for PM2.5 is set at 25 micrograms per cubic metre of air as a yearly average. Meanwhile, the World Health Organization (WHO) recommends 10 micrograms. But even that radically smaller target was <a href="https://www.euro.who.int/__data/assets/pdf_file/0005/78638/E90038.pdf">set in 2005</a>, and there have been great strides in understanding how air pollution affects the body since then.</p>
<p>Here’s what the science is telling us so far.</p>
<h2>How much is too much?</h2>
<p>When trying to quantify how air pollutants affect health, researchers often measure associations between health conditions and air pollution exposure averaged over a large group of people. These kinds of studies – which resemble those carried out by epidemiologists to study diseases like COVID-19 – capture the health effects of air pollution and are carefully designed to remove the influence of other pollutants, as well as demographic and socio-economic factors. Alongside this, researchers study the ways air pollutants enter the body and affect organs such as the lungs, heart and brain. </p>
<p>A <a href="https://www.sciencedirect.com/journal/environment-international/special-issue/10MTC4W8FXJ">series of recent studies</a> strengthened the confidence scientists have in the effects of pollutants on health. The research showed that there is no evidence for a threshold in the health effects of fine particles. In other words, there’s no level of exposure to PM2.5 below which negative health effects aren’t seen.</p>
<p>Some level of air pollution is unavoidable. Countries are unlikely to eliminate all emissions from their many sources. Even in a net-zero world, we’d probably still breathe in fine particles from the brake pads and tires of electric vehicles. Air quality standards need to be proportionate to society, as well as protect the most vulnerable people.</p>
<h2>Improving air quality laws</h2>
<p>Governments set legally binding air quality targets, and England’s are due to be updated in the autumn’s Environment Bill. The UK government’s <a href="https://www.gov.uk/government/publications/clean-air-strategy-2019">2019 Clean Air Strategy</a> aimed to halve the number of people living in places where the WHO guideline level of 10 micrograms per cubic metre is exceeded, by 2025. There could also be <a href="https://www.gov.uk/government/publications/environment-bill-2020/august-2020-environment-bill-environmental-targets">changes</a> to the national limit of 25 micrograms, in light of the new science.</p>
<p>There is an opportunity here to develop laws that make the air safer to breathe, rather than simply maintain pollution levels at a safe limit, which research suggests probably doesn’t exist. As well as a limit value – a level that is not to be exceeded – new air-quality standards could also include a target for reducing exposure.</p>
<p>Limit values are often treated as a license to pollute up to a threshold and don’t drive improvements in air quality where pollutant levels are high but not over the limit. Exposure reduction targets instead aim to lower air pollution levels across an entire population. These targets can improve air quality for everyone, but inevitably divert resources from measures targeted at the most polluted areas, which tend to be where the most deprived communities live.</p>
<p>Carefully designed, air quality standards can balance both approaches, providing population-wide health benefits while ensuring no areas are exposed to disproportionately high levels of pollution.</p><img src="https://counter.theconversation.com/content/167223/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>William Bloss receives funding from the Natural Environment Research Council (NERC).</span></em></p>Fine particles in air pollution contribute to the deaths of 36,000 people each year in the UK.William Bloss, Professor of Atmospheric Science, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1567272021-03-15T12:56:16Z2021-03-15T12:56:16ZFixing indoor air pollution problems that are raising Native Americans’ COVID-19 risk<figure><img src="https://images.theconversation.com/files/388929/original/file-20210310-14-1meav2z.jpg?ixlib=rb-1.1.0&rect=0%2C4%2C3014%2C1928&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Older homes can have a variety of environmental health risks.</span> <span class="attribution"><span class="source">Kerry F. Thompson and Ryan T. Wilson</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Betty’s home stands on the edge of a striking red cliff. Her family built the home from materials in their environment generations ago and passed it along from mothers to daughters. But it is cold, and the home is small with few windows. Insufficiently ventilated homes in these areas can have high levels of particulate matter, dust, mold and <a href="http://doi.org/10.3390/ijerph17082813">radon</a>, a naturally occurring gas that can cause lung cancer.</p>
<p>Rosa, a great-grandmother, lives in her family home with a large wood-burning stove. On one wall are colorful paintings representing her clan lineage. On another wall, black stains show where an exhaust vent was improperly installed.</p>
<p>Both women live in homes full of meaning and tradition in the Southwest, a region that is home to 574 <a href="https://www.bia.gov/tribal-leaders-directory">recognized tribes</a>. And both face a serious health risk: poor indoor air. </p>
<p>Poor indoor air quality has been linked to <a href="https://www.epa.gov/report-environment/indoor-air-quality">health hazards</a> for decades and is an <a href="https://www.epa.gov/indoor-air-quality-iaq/basic-information-about-indoor-air-quality-tribal-partners-program">ongoing problem</a> in American Indian communities.
Fine particulate matter and inhalation of other pollutants contributes to high risk for <a href="https://www.cdc.gov/flu/resource-center/freeresources/graphics/aian.htm">influenza</a>, for example. </p>
<p>Research <a href="http://doi.org/10.1126/sciadv.abd4049">in the U.S.</a> and <a href="http://doi.org/10.1016/j.envpol.2020.114465">other countries</a> now suggests that long-term exposure to air pollution can worsen the chances of having serious complications from COVID-19. Indeed, American Indian and Alaska Natives face hospitalizations and death from COVID-19 at higher rates <a href="https://www.cdc.gov/coronavirus/2019-ncov/downloads/covid-data/hospitalization-death-by-race-ethnicity.pdf%20jan%2015,%202021">than any other racial or ethnic group</a>. </p>
<p>Tribes have been taking measures to curb the spread of COVID-19, including enacting stronger prevention measures and rolling out vaccinations more effectively than many states, yet fixing the underlying problems that put people at high risk remains challenging. In response, Native communities are exploring clean energy options and working on improving solutions that weave together meaningful home design and safer, cleaner air. </p>
<figure class="align-center ">
<img alt="A woman and her uncle in a home with a stove for heating." src="https://images.theconversation.com/files/389111/original/file-20210311-16-1qklo48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/389111/original/file-20210311-16-1qklo48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/389111/original/file-20210311-16-1qklo48.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/389111/original/file-20210311-16-1qklo48.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/389111/original/file-20210311-16-1qklo48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/389111/original/file-20210311-16-1qklo48.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/389111/original/file-20210311-16-1qklo48.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A stove for heating stands in the center of a hooghan, a traditional home, in Arizona.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/VIrusOutbreakAWeekPhotoGallery/76043bb3567e440fbec5139ef8c4e05a/photo">AP Photo/Carolyn Kaster</a></span>
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</figure>
<p>As a <a href="https://nau.edu/anthropology/lisahardy/">medical anthropologist</a>, <a href="https://nau.edu/anthropology/kerrythompson/">archaeologist</a> and <a href="https://www.usd.edu/faculty-and-staff/Meghan-OConnell%22%22">family medicine doctor and public health professional</a>, we are concerned about the past, present and future of clean air and the reduction of environmental pollution. Indoor air pollution is part of larger issue of health and safety in Native communities. </p>
<p>Understanding the structural barriers to good health can help explain why COVID-19 affects tribes more severely. And these risks won’t leave with the pandemic.</p>
<h2>The problem of indoor air pollution</h2>
<p>A view from the sky would appear to show clean air in rural areas where many Native people live. But a closer look reveals a different story: environmental pollution inside homes, schools and other buildings.</p>
<p>The reasons for poor indoor air on tribal lands are vast and complex. In many ways, the burden of dispossession endures.</p>
<figure class="align-center ">
<img alt="A woman carries wood logs toward a rural home" src="https://images.theconversation.com/files/389112/original/file-20210311-22-fdgi4p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/389112/original/file-20210311-22-fdgi4p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=370&fit=crop&dpr=1 600w, https://images.theconversation.com/files/389112/original/file-20210311-22-fdgi4p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=370&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/389112/original/file-20210311-22-fdgi4p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=370&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/389112/original/file-20210311-22-fdgi4p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=466&fit=crop&dpr=1 754w, https://images.theconversation.com/files/389112/original/file-20210311-22-fdgi4p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=466&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/389112/original/file-20210311-22-fdgi4p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=466&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A Navajo woman carries wood to heat her rural mobile home in freezing temperatures during the coronavirus pandemic.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/navajo-woman-carries-wood-to-heat-her-rural-mobile-home-news-photo/1208679747">Gina Ferazzi/Los Angeles Times via Getty Images</a></span>
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<p>In parts of the Southwest, many people rely on coal and <a href="https://www.doi.org/10.1111/jcpe.12808">wood-burning stoves</a> that have been linked to <a href="http://doi.org/10.1155/2010/260525">respiratory disease</a>. Electric heat isn’t an option in the thousands of homes that <a href="https://www.publicpower.org/LightUpNavajo">aren’t connected to a power grid</a>. </p>
<p>Homes in some rural areas are at high risk for developing mold or having <a href="https://doi.org/10.3390/ijerph17082813">radon</a>, <a href="http://doi.org/10.1080/10962247.2017.1334717">carbon monoxide</a> and other environmental contaminants. Radon and mold remediation is costly, and repairs and maintenance can be difficult when it’s hard to find licensed contractors. Long distances to hardware stores can make it challenging to obtain supplies and maintain repairs. </p>
<p>In homes without stoves or electricity, the only option may be propane, which can release a host of pollutants into the air when used for heating or cooking.</p>
<p>Leaving behind ancestral homes is a bad solution to the problem. In the past, people were encouraged to <a href="http://doi.org/10.1289/ehp.120-a460">leave homes for trailers</a> funded by the Department of Housing and Urban Development and the Bureau of Indian Affairs up until the 1970s. However, these homes are poorly suited for long-term living. The trailers have thin walls and poor ventilation, making them hot in summer and cold in winter, and low-quality materials don’t stand up well to freezing temperatures and storms. </p>
<figure class="align-center ">
<img alt="A storm-battered coastal home" src="https://images.theconversation.com/files/389114/original/file-20210311-20-1fdfuwm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/389114/original/file-20210311-20-1fdfuwm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/389114/original/file-20210311-20-1fdfuwm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/389114/original/file-20210311-20-1fdfuwm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/389114/original/file-20210311-20-1fdfuwm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/389114/original/file-20210311-20-1fdfuwm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/389114/original/file-20210311-20-1fdfuwm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Homes in Quinhagak, Alaska, near the Bering Sea, are at the mercy of the weather. Older homes can be compromised by water leaks, rot and mold.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/house-sits-on-melting-permafrost-tundra-caused-by-rising-news-photo/1139519564">Mark Ralston/AFP via Getty Images</a></span>
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<p>Inequities in funding for tribal lands continue to create differences in health and life. For example, the Centers for Disease Control and Prevention’s <a href="https://www.cdc.gov/asthma/contacts/default.htm">National Asthma Control Program</a> aims to improve care and decrease health disparities caused by asthma, which often has environmental triggers. However, the program provides funding to only 25 states and no tribes. Many American Indian communities don’t have access to programs because they’re not located in funded states, and state programs are not implemented by tribes. After tribes <a href="https://indiancountrytoday.com/archive/tribes-fight-for-cdc-inclusion">fought for inclusion</a>, the CDC provided <a href="https://www.cdc.gov/tribal/cooperative-agreements/covid-19.html">funding</a> for COVID-19 “preparedness and relief,” though this shift was hard-won. </p>
<h2>What’s being done?</h2>
<p>Solutions to problems of environmental pollution may be most successful when they are designed and led by Native people who know the local tradition and meaning of homes and the relationships and practices of people who live there. Native-led <a href="http://navajoandhopifamiliescovid-19r.godaddysites.com/">COVID-19 relief efforts</a> have met many tribal needs, and the same may be true of long-term housing solutions. </p>
<figure class="align-right ">
<img alt="A home under construction" src="https://images.theconversation.com/files/388924/original/file-20210310-14-1oizxkf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/388924/original/file-20210310-14-1oizxkf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1067&fit=crop&dpr=1 600w, https://images.theconversation.com/files/388924/original/file-20210310-14-1oizxkf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1067&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/388924/original/file-20210310-14-1oizxkf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1067&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/388924/original/file-20210310-14-1oizxkf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1340&fit=crop&dpr=1 754w, https://images.theconversation.com/files/388924/original/file-20210310-14-1oizxkf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1340&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/388924/original/file-20210310-14-1oizxkf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1340&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">New construction can combine tradition and design for safer homes. This hooghan in Arizona will have a wood stove that is correctly sized and installed, with a properly ventilated roof.</span>
<span class="attribution"><span class="source">Kerry F. Thompson and Ryan T. Wilson</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p>National and local programs funded through the Environmental Protection Agency support tribal initiatives in air pollution <a href="https://www.epa.gov/indoor-air-quality-iaq/tribal-indoor-air-quality-programs-spotlight">prevention and mitigation</a>. Local initiatives also build knowledge and skills. For example, the <a href="https://www.nrel.gov/news/features/2020/from-lab-to-tundra-building-more-efficient-future-with-rural-alaska.html">Cold Climate Housing Research Center</a> at the University of Alaska Fairbanks has worked with Native Alaskans to design and build healthy, energy-efficient <a href="http://cchrc.org/cchrc-prototype-design/">prototype homes</a> that meet each community’s unique environment and needs, then shared the construction plans online. </p>
<p>Red Feather Development group, a nonprofit organization led by a Native American board, hosts workshops with a professional stove designer to train people to <a href="https://www.redfeather.org/healthy-home-energy-safety-improvements.html">maintain stoves</a> and helps families swap out poorly functioning stoves for cleaner and more energy-efficient options. The group also teaches people how to weatherize homes and helps improve homes for elders. </p>
<p>The Institute for Tribal Environmental Professionals has a network of professionals and students working to stay up to date on <a href="http://www7.nau.edu/itep/main/iaq/">clean air research and strategies</a> throughout the U.S. This helps American Indian college students gain knowledge and skills to become future leaders in environmental health. These organizations are developing plans to reduce disparities related to environmental health while honoring the strength and structure of tribal nations and the people who live there.</p>
<p>The promise of solar power and other clean energy also brings hope for reducing air pollution in homes. The Native-led organization <a href="https://www.nativerenewables.org/who-we-are">Native Renewables</a> trains and educates people living on the Navajo and Hopi reservations about solar power and other clean energy options and installs clean energy systems on a small scale. <a href="https://gridalternatives.org/what-we-do/tribal-program">Grid Alternatives</a> provides workforce development, education and financing for solar power and other renewable energy for tribes.</p>
<p>The pandemic could soon begin to subside as the vaccine rollout gains momentum, but health disparities will remain. We believe that larger national programs implemented and led by Native people in tribal communities are crucial for saving lives and traditions and ensuring clean air for everyone.</p><img src="https://counter.theconversation.com/content/156727/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lisa Hardy has consulted in the past for Red Feather Development group with foundation funding however she is not affiliated at this time. </span></em></p><p class="fine-print"><em><span>Meghan Curry O’Connell receives funding from CDC Foundation. </span></em></p><p class="fine-print"><em><span>Kerry F. Thompson does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Poor indoor air on tribal lands can cause a range of respiratory illnesses, including viral infections. Here’s how people are fixing the problem while preserving traditional ways.Lisa J Hardy, Associate Professor of Anthropology and Director of the Social Science Community Engagement Lab, Northern Arizona UniversityKerry F. Thompson, Associate Professor of Anthropology & Department Chair, Northern Arizona UniversityMeghan Curry O’Connell, Assistant Professor, Department of Family Medicine, University of South DakotaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1540712021-02-07T19:06:22Z2021-02-07T19:06:22ZOn an electric car road trip around NSW, we found range anxiety (and the need for more chargers) is real<figure><img src="https://images.theconversation.com/files/381539/original/file-20210131-20282-7r5yh2.jpg?ixlib=rb-1.1.0&rect=0%2C73%2C5472%2C3563&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"></span> <span class="attribution"><span class="license">Author provided</span></span></figcaption></figure><p>Replacing cars that run on fossil fuels with electric cars will be important in meeting climate goals – road transport produces <a href="https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_chapter8.pdf">more than 20% of global greenhouse gas emissions</a>. But there are obstacles to wider uptake, particularly in Australia.</p>
<p>Too much of the debate about these vehicles revolves around abstract, technical calculations and assumptions about cost and benefit. Tariffs, taxes and incentives are important in shaping decisions, but the user experience is often overlooked. To better understand this we took a Tesla on a road trip from Sydney through some regional towns in New South Wales. </p>
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<strong>
Read more:
<a href="https://theconversation.com/the-us-jumps-on-board-the-electric-vehicle-revolution-leaving-australia-in-the-dust-154566">The US jumps on board the electric vehicle revolution, leaving Australia in the dust</a>
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<p>We soon found “range anxiety” is real. That’s the worry that the battery will run out of power before reaching the destination or a charging point. It’s often cited as the most important reason for <a href="https://discover.agl.com.au/energy/range-anxiety-becomes-thing-of-past/">reluctance to buy an electric vehicle</a>. </p>
<p>Even as <a href="https://www.racv.com.au/royalauto/moving/news-information/australias-cheapest-ev.html">prices come down</a> and hire and <a href="https://www.evee.com.au/">share</a> options become more widespread, range anxiety about electric vehicles is hindering their wider uptake. We found it can largely be overcome through a range of strategies readily available now.</p>
<h2>Lessons from our road trip</h2>
<p>The first is simply to accumulate driving experience with a particular vehicle. Teslas promise a far simpler machine with fewer moving parts, but also incredibly sophisticated sensing and computational technology to help control your trip. This means you need to get a feel for the algorithms that calculate route and range. </p>
<p>These algorithms are black boxes – their calculations are invisible to users, only appearing as outputs like range calculations. On our trip, range forecasts were surprisingly inaccurate for crossing the Great Dividing Range, for example.</p>
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<strong>
Read more:
<a href="https://theconversation.com/how-superfast-charging-batteries-can-help-sell-the-transition-to-electric-vehicles-153872">How superfast charging batteries can help sell the transition to electric vehicles</a>
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<p>Second, we found it very helpful to connect with other electric vehicle users and share experiences of driving. Just like any new technology, forming a community of users is a good way to gain an understanding of the vehicle’s uses and limits. Owner associations and lively online groups such as <a href="https://www.facebook.com/groups/1737462746527033/">Electric Vehicles for Australia</a> make finding fellow enthusiasts easy.</p>
<p>This connection can also help with the third strategy. It involves developing an understanding of how companies like Tesla control their vehicles and issue “over the air” software updates. If these specify different parameters for acceptable battery charge, that can change the vehicle’s range.</p>
<h2>Public investment in charging network will help</h2>
<p>Public investment in charging infrastructure could – and should – further ease range anxiety. <a href="https://electricvehiclecouncil.com.au/wp-content/uploads/2020/08/EVC-State-of-EVs-2020-report.pdf">Better planning and co-ordination are needed</a>, too, to build on networks like the <a href="https://www.mynrma.com.au/cars-and-driving/electric-vehicles">NRMA’s regional network</a> of 50 kilowatt chargers.</p>
<figure class="align-center ">
<img alt="electric car travelling at speed on highway" src="https://images.theconversation.com/files/382422/original/file-20210204-18-ax56ot.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/382422/original/file-20210204-18-ax56ot.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/382422/original/file-20210204-18-ax56ot.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/382422/original/file-20210204-18-ax56ot.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/382422/original/file-20210204-18-ax56ot.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/382422/original/file-20210204-18-ax56ot.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/382422/original/file-20210204-18-ax56ot.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Long driving distances call for better planning and co-ordination of a nationwide charging network.</span>
<span class="attribution"><span class="source">alexfan32/Shutterstock</span></span>
</figcaption>
</figure>
<p>Understanding what is involved for users is also crucial to the environmental benefits of electric vehicles. Their sustainability isn’t just a function of taxes and technologies. The <a href="https://journals.sagepub.com/doi/full/10.1177/0162243912441029">practices of people driving electric cars</a> matter too. </p>
<p>You learn with experience what efficient driving requires of you. You can also work out how your charging patterns could match solar generation at home, for those lucky enough to have rooftop PV panels.</p>
<p>These vehicles can deliver significant environmental benefits. They produce zero tailpipe emissions, reducing both local air pollution and global greenhouse gas emissions. </p>
<p><a href="https://theconversation.com/heres-why-electric-cars-have-plenty-of-grunt-oomph-and-torque-115356">Regenerative braking</a> also reduces brake particulate emissions. That’s because the electric motor operating in reverse can slow the car while recharging its battery. </p>
<h2>Electric vehicles won’t cure all ills</h2>
<p>Switching from internal combustion to electric cars won’t address all the problems of our current car-based system. Some, such as road congestion, could <a href="https://theconversation.com/think-taxing-electric-vehicle-use-is-a-backward-step-heres-why-its-an-important-policy-advance-150644">get worse</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/think-taxing-electric-vehicle-use-is-a-backward-step-heres-why-its-an-important-policy-advance-150644">Think taxing electric vehicle use is a backward step? Here's why it's an important policy advance</a>
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<hr>
<p>Road traffic will still cause <a href="https://theconversation.com/delivery-rider-deaths-highlight-need-to-make-streets-safer-for-everyone-150752">deaths and injuries</a>. Electric vehicles will still produce <a href="https://theconversation.com/fine-particle-air-pollution-is-a-public-health-emergency-hiding-in-plain-sight-106030">deadly PM2.5 particulates</a> as long as they use conventional brakes and tyres. Many models do, providing <a href="https://www.youtube.com/watch?v=wd2ArceiJd0">similar driving experiences to combustion vehicles</a>.</p>
<p>Congestion and the costs of providing and maintaining roads, parking and associated infrastructure will still create enormous social, economic and environmental burdens. Electric vehicles need to be part of a much wider transformation – especially in urban areas where other transport options are available.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/delivery-rider-deaths-highlight-need-to-make-streets-safer-for-everyone-150752">Delivery rider deaths highlight need to make streets safer for everyone</a>
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</em>
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<h2>Rural and regional Australia can benefit too</h2>
<p>Longer distances and lower densities make walking, cycling and public transport more challenging in rural and regional areas. Better support for electric vehicles, particularly chargers, could make a significant difference here. </p>
<p>These vehicles can help rural and regional areas in other ways too. Many holiday towns rely on tourist incomes but their electricity supply is at the mercy of long thin power lines that run through bushland. Electric vehicles could potentially help with this problem: <a href="https://www.energynetworks.com.au/news/energy-insider/2020-energy-insider/could-vehicle-to-grid-accelerate-the-ev-revolution/">when parked they can feed power back into the grid</a>. </p>
<figure class="align-center ">
<img alt="Tesla being charged at a rural charging point" src="https://images.theconversation.com/files/382420/original/file-20210204-14-7gnof5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/382420/original/file-20210204-14-7gnof5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/382420/original/file-20210204-14-7gnof5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/382420/original/file-20210204-14-7gnof5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/382420/original/file-20210204-14-7gnof5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/382420/original/file-20210204-14-7gnof5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/382420/original/file-20210204-14-7gnof5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Improving rural and regional charging networks can benefit those areas as well as the drivers of electric vehicles.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/yorke-peninsula-south-australia-january-18-1900371982">Shutterstock</a></span>
</figcaption>
</figure>
<p>Regional economic planning that supports visits by electric vehicle drivers can reduce the need to invest in energy generation or battery systems. There are huge opportunities to integrate electricity planning and the (re)building of bushfire-affected towns, which a <a href="https://www.ausnetservices.com.au/en/About/News-Room/News-Room-2018/AusNet-Services-to-Install-Gippslands-First-Big-Battery-at-Mallacoota">trial in Mallacoota</a> will explore. </p>
<p>Pooled together, the batteries of an all-electric national vehicle fleet could provide power equivalent to that of <a href="https://www.anu.edu.au/news/all-news/electric-vehicle-fleets-set-to-be-on-call-to-backup-the-grid">five Snowy 2.0s</a>. This would boost energy security and flexibility.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/owners-of-electric-vehicles-to-be-paid-to-plug-into-the-grid-to-help-avoid-blackouts-132519">Owners of electric vehicles to be paid to plug into the grid to help avoid blackouts</a>
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</em>
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<hr>
<p>In the US, President Joe Biden has <a href="https://electrek.co/2021/01/25/president-biden-will-make-entire-645k-vehicle-federal-fleet-electric/">announced</a> electric vehicles will replace the entire federal fleet of 645,000 vehicles. An extra <a href="https://www.bloomberg.com/news/articles/2020-12-02/joe-biden-plan-to-fight-climate-change-could-sell-25-million-electric-cars">500,000 public charging stations</a> are to be built within a decade. </p>
<p>In Australia, the policy landscape is more <a href="https://www.abc.net.au/news/science/2020-11-26/ev-tax-slow-electric-vehicle-report/12891524">[contested]</a>. It’s time we caught up here.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1353809013348171778"}"></div></p>
<p>We can start by recognising the importance of governments in the progress made internationally. Examples include the <a href="https://www.wired.com/2009/06/tesla-loan/">US$465 million US government loan to Tesla</a> in 2009 to develop the landmark Model S, and Norway’s co-ordinated national approach to properly <a href="https://elbil.no/english/norwegian-ev-policy/">accounting for the environmental and social costs</a> of cars. Norway’s success is now the focus of a laugh-out-loud <a href="https://twitter.com/GM/status/1356966012646789120">Superbowl ad</a> from GM, a company that in the past <a href="https://en.m.wikipedia.org/wiki/Who_Killed_the_Electric_Car%3F">killed the electric car</a>.</p>
<p>We need to understand users and have democratic debates about planning for charging infrastructure before we can sit back and enjoy the ride.</p><img src="https://counter.theconversation.com/content/154071/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amelia Thorpe receives funding for research on EVs from the UNSW Digital Grid Futures Institute and the RACE for 2030 CRC. </span></em></p><p class="fine-print"><em><span>Declan Kuch receives research funding from The Australian Renewable Energy Agency, UNSW Digital Grid Futures Institute and RACE for 2030 CRC. </span></em></p><p class="fine-print"><em><span>Sophie Adams receives funding for research on EVs from the Australian Renewable Energy Agency, UNSW Digital Grid Futures Institute and RACE for 2030 CRC.</span></em></p>Australia has a lot of work to do to overcome the challenges facing electric vehicles users, starting with the lack of a comprehensive national charging network.Amelia Thorpe, Associate Professor in Law, UNSW SydneyDeclan Kuch, Vice Chancellor's Research Fellow, Institute for Culture and Society, Western Sydney UniversitySophie Adams, Research Fellow, School of Humanities and Languages, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1516712020-12-17T13:27:48Z2020-12-17T13:27:48ZWildfire smoke changes dramatically as it ages, and that matters for downwind air quality – here’s what we learned flying through smoke plumes<figure><img src="https://images.theconversation.com/files/374614/original/file-20201213-24-1qko1mw.jpg?ixlib=rb-1.1.0&rect=0%2C10%2C699%2C511&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Sampling wildfire smoke sometimes means sticking a tube out the window of an airplane.</span> <span class="attribution"><span class="source">Brett Palm/University of Washington</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>The year 2020 will be remembered for many reasons, including its <a href="https://theconversation.com/the-year-the-west-was-burning-how-the-2020-wildfire-season-got-so-extreme-148804">record-breaking wildfires</a> that turned San Francisco’s skies an <a href="https://www.nytimes.com/2020/09/09/us/pictures-photos-california-fires.html">apocalyptic shade of red</a> and blanketed large parts of the West in smoke for weeks on end.</p>
<p>California experienced <a href="https://www.fire.ca.gov/media/11416/top20_acres.pdf">five of its six largest fires</a> on record in 2020, including the first modern “<a href="https://www.vox.com/2020/10/5/21502397/august-complex-gigafire-wildfire-california-record">gigafire</a>,” a wildfire that burned over 1 million acres. Colorado saw its <a href="https://coloradosun.com/2020/10/20/colorado-largest-wildfire-history/">three largest fires</a> on record.</p>
<p>While the smoke can make for beautiful sunsets, it can also have dire consequences for human health. </p>
<p>I am an <a href="https://scholar.google.com/citations?user=LnQkoXcAAAAJ&hl=en">atmospheric chemist</a>, and the atmosphere is my laboratory. When I look at the sky, I see a mixture of many <a href="https://theconversation.com/whats-in-wildfire-smoke-and-why-is-it-so-bad-for-your-lungs-144790">thousands of different chemical compounds</a> interacting with each other and with sunlight. </p>
<p>The reactions and transformations in the atmosphere cause wildfire smoke to change dramatically as it travels downwind, and studies have shown that it can grow <a href="https://phys.org/news/2020-07-toxic-wildfire-ages.html">more toxic as it ages</a>. In order to accurately forecast the effects of wildfire emissions on downwind populations and issue more-targeted air quality warnings as wildfire seasons worsen, we have to understand which chemicals are being emitted and how smoke changes with time. </p>
<p>To figure that out, my colleagues and I flew airplanes into the smoke plumes of some of the West’s large wildfires. </p>
<h2>How we study wildfires</h2>
<p>Large wildfires and the way wind carries their smoke cannot be easily replicated in a laboratory. This makes them difficult to study. One of the best ways to learn about real wildfire smoke chemistry is to sample it directly in the atmosphere.</p>
<p>In <a href="https://www.eol.ucar.edu/field_projects/we-can">2018</a> and <a href="https://csl.noaa.gov/projects/firex-aq/">2019</a>, my colleagues and I crisscrossed the sky over active wildfires in specialized airplanes loaded with scientific instruments. Each instrument is designed to sample a different part of the smoke, often by literally sticking a tube out the window.</p>
<figure class="align-center ">
<img alt="A map of the air sampling flights." src="https://images.theconversation.com/files/374618/original/file-20201213-16-m7a3al.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/374618/original/file-20201213-16-m7a3al.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=436&fit=crop&dpr=1 600w, https://images.theconversation.com/files/374618/original/file-20201213-16-m7a3al.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=436&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/374618/original/file-20201213-16-m7a3al.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=436&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/374618/original/file-20201213-16-m7a3al.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=548&fit=crop&dpr=1 754w, https://images.theconversation.com/files/374618/original/file-20201213-16-m7a3al.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=548&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/374618/original/file-20201213-16-m7a3al.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=548&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">To sample smoke as it moves downwind, scientists flew back and forth across smoke plumes. The gray lines are the flights from 2018. They turn red where the path crossed a smoke plume.</span>
<span class="attribution"><span class="source">Brett Palm/University of Washington</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<figure class="align-center ">
<img alt="Scientists aboard one of the flights." src="https://images.theconversation.com/files/374615/original/file-20201213-23-1m2nbzp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/374615/original/file-20201213-23-1m2nbzp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/374615/original/file-20201213-23-1m2nbzp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/374615/original/file-20201213-23-1m2nbzp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/374615/original/file-20201213-23-1m2nbzp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/374615/original/file-20201213-23-1m2nbzp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/374615/original/file-20201213-23-1m2nbzp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Scientific aircraft used for these experiments are filled with instruments that measure wildfire smoke in different ways.</span>
<span class="attribution"><span class="source">Brett Palm/University of Washington</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Wildfire smoke is far more complex and dynamic than meets the eye. It contains thousands of different compounds, most of which are molecules containing various amounts of carbon, hydrogen, nitrogen and oxygen atoms. There are gases (individual molecules) as well as particles (millions of molecules coagulated together).</p>
<p>No single instrument can measure all of these molecules at once. In fact, some specific compounds are a challenge to measure at all. Many scientists, including myself, dedicate their careers to designing and building new instruments to improve our measurements and continue to advance our understanding of the atmosphere and how it affects us.</p>
<figure class="align-center ">
<img alt="Satellite images of smoke plumes." src="https://images.theconversation.com/files/374619/original/file-20201213-23-1cuq69e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/374619/original/file-20201213-23-1cuq69e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=826&fit=crop&dpr=1 600w, https://images.theconversation.com/files/374619/original/file-20201213-23-1cuq69e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=826&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/374619/original/file-20201213-23-1cuq69e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=826&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/374619/original/file-20201213-23-1cuq69e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1038&fit=crop&dpr=1 754w, https://images.theconversation.com/files/374619/original/file-20201213-23-1cuq69e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1038&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/374619/original/file-20201213-23-1cuq69e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1038&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Smoke plumes from western wildfires reached across the U.S. in mid-September 2020.</span>
<span class="attribution"><a class="source" href="https://earthobservatory.nasa.gov/images/147293/a-meeting-of-smoke-and-storms">Joshua Stevens/NASA Earth Observatory</a></span>
</figcaption>
</figure>
<p>In newly published research from the 2018 wildfires, <a href="https://doi.org/10.1073/pnas.2012218117">my colleagues and I showed</a> how the smoke particles changed rapidly as they were carried downwind. </p>
<p>Some of the particles were evaporating into gases, similar to a rain puddle evaporating into water vapor when the Sun comes out. At the same time, some of the gases in smoke were going through reactions to form new particles, similar to water vapor condensing to form a cloud or dew droplets. Meanwhile, chemical reactions were occurring, changing the molecules themselves.</p>
<p>As these molecules reacted with sunlight and other gases in the atmosphere, the smoke was fundamentally transformed. This is what we mean when scientists talk about smoke “aging” or getting “stale” over time. Other recent research has started to show how wildfire smoke can become <a href="https://doi.org/10.1021/acs.est.9b01034">more toxic as it ages</a>.</p>
<h2>What do all these changes mean for health?</h2>
<p>The health damage from smoke is largely a result of how much PM2.5 it contains. These are tiny particles, a fraction of the width of a human hair, that can be breathed deep into the lungs where they can irritate the respiratory tract. Even short-term exposure can <a href="https://theconversation.com/whats-in-wildfire-smoke-and-why-is-it-so-bad-for-your-lungs-144790">aggravate heart and lung problems</a>.</p>
<figure class="align-center ">
<img alt="Illustration of the size of PM2.5 compared to a human hair and grain of sand." src="https://images.theconversation.com/files/374596/original/file-20201213-13-kesnz8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/374596/original/file-20201213-13-kesnz8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=419&fit=crop&dpr=1 600w, https://images.theconversation.com/files/374596/original/file-20201213-13-kesnz8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=419&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/374596/original/file-20201213-13-kesnz8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=419&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/374596/original/file-20201213-13-kesnz8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=527&fit=crop&dpr=1 754w, https://images.theconversation.com/files/374596/original/file-20201213-13-kesnz8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=527&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/374596/original/file-20201213-13-kesnz8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=527&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">PM2.5 particles are tiny at less than 2.5 microns across.</span>
<span class="attribution"><a class="source" href="https://www.epa.gov/pm-pollution/particulate-matter-pm-basics">U.S. Environmental Protection Agency</a></span>
</figcaption>
</figure>
<p>Chemical reactions control how much PM2.5 is in wildfire smoke as it is transported away from the fires and into population centers. Using our aircraft measurements to understand these processes, we chemists can better predict how much PM2.5 will be present in aged smoke. </p>
<p>Combined with meteorology forecasting that predicts where the smoke will go, this could lead to improved air quality models that can tell people downwind whether they will be exposed to unhealthy air.</p>
<h2>Better air quality forecasting</h2>
<p>With wildfires increasingly in the news, more people have become aware of their own air quality. Resources such as <a href="https://gispub.epa.gov/airnow/">AirNow</a> from the U.S. Environmental Protection Agency provide current and forecasted air quality data, along with explanations of the health hazards. Local information is often available from state or regional agencies as well.</p>
<figure class="align-center ">
<img alt="People ride past a ballpark under an orange sky." src="https://images.theconversation.com/files/375499/original/file-20201216-21-dcgk7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/375499/original/file-20201216-21-dcgk7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=428&fit=crop&dpr=1 600w, https://images.theconversation.com/files/375499/original/file-20201216-21-dcgk7d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=428&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/375499/original/file-20201216-21-dcgk7d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=428&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/375499/original/file-20201216-21-dcgk7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=538&fit=crop&dpr=1 754w, https://images.theconversation.com/files/375499/original/file-20201216-21-dcgk7d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=538&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/375499/original/file-20201216-21-dcgk7d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=538&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Smoke from wildfires turned the midday sky orange in San Francisco on Sept. 9, 2020.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/MarinersGiantsBaseball/5d68784905604ce9adfe7f9d1469f7b4/photo">AP Image/Tony Avelar</a></span>
</figcaption>
</figure>
<p>Air quality measurements and forecasts can help people <a href="https://www.airnow.gov/sites/default/files/2018-04/air-quality-guide_pm_2015_0.pdf">avoid unhealthy situations</a>, especially sensitive groups such as people with asthma. During predicted periods of unhealthy air quality, local or state governments can use forecasts to reduce other pollution sources, such as discouraging residential wood burning or high-emitting industrial activities.</p>
<p>Looking to the future, wildfire smoke is likely to be widespread across the West each year for several reasons. <a href="https://science.sciencemag.org/content/313/5789/940.abstract">Rising temperatures</a> are leaving the landscape drier and more flammable. At the same time, more people are building homes in the <a href="https://doi.org/10.1073/pnas.1718850115">wildland-urban interface</a>, creating more opportunities for fires to start. </p>
<p>A large community of scientists including me are working to better understand wildfire emissions and how they change as they blow into downwind communities. That knowledge will improve forecasts for air quality and health impacts of wildfire smoke, so people can learn to adapt and avoid the worst health consequences.</p><img src="https://counter.theconversation.com/content/151671/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brett Palm receives funding from the National Science Foundation and the National Oceanic and Atmospheric Administration.</span></em></p>Thousands of chemical compounds in wildfire smoke are interacting with each other and sunlight as the smoke travels. For people downwind, it can become more toxic over time.Brett B. Palm, Postdoctoral Researcher in Atmospheric Chemistry, University of WashingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1510772020-12-03T15:20:53Z2020-12-03T15:20:53ZNairobi’s air has been polluted for decades: new review suggests a path forward<figure><img src="https://images.theconversation.com/files/372543/original/file-20201202-15-la05io.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
Black exhaust fumes from lorry envelope a motorcyclist and his passenger on a busy road in the Kenyan capital, Nairobi. </span> <span class="attribution"><span class="source"> EPA-EFE/Daniel Irungu</span></span></figcaption></figure><p>According to the State of the Global Air 2020 <a href="https://www.stateofglobalair.org/">report</a>, ambient air pollution was responsible for around 5,000 premature deaths in Kenya in 2019 alone. It is the fourth most important <a href="http://www.healthdata.org/kenya">risk factor</a> in driving death and disability combined in Kenya. Indeed, the <a href="https://s3-eu-west-1.amazonaws.com/s3.sourceafrica.net/documents/118383/Kenya-National-Bureau-of-Statistics-Economic.pdf">2017</a> national economic survey estimated that 19.9 million Kenyans suffer from respiratory ailments that are exacerbated by poor air quality.</p>
<p>Kenya’s national environmental management <a href="https://www.nema.go.ke/">agency</a> imposed <a href="https://www.nema.go.ke/images/Docs/Regulations/air%20quality%20regulations2014-1.pdf">regulations</a> in 2014 for national ambient air quality standards. These set out the maximum permissible concentrations of different widespread pollutants for residential and industrial areas. The regulations also laid out steps to be taken for “prevention, control and abatement” of pollution in recognition of the toll it takes on health. </p>
<p>So far, however, the enforcement of these regulations has been minimal due to a lack of high quality air quality monitoring data, to compare with the standards. Measurements of pollution from regulatory government-operated monitors, the world over are considered as the gold standard by the scientific community. This is because such instruments produce high quality estimates of air quality concentrations to accurately identify if the standards are being met. </p>
<p>Such measurements are used extensively to evaluate the health consequences of pollution on health, trends in air pollution around the world, major sources, and the impact of policies on air quality. These efforts have been crucial in the development of effective air pollution mitigation plans.</p>
<p>In Kenya, there is no publicly available, official air quality monitoring data. But there have been 33 air pollution studies that report concentrations of widespread pollutants in Kenya since the early 1980s. The majority of these studies were carried out in Nairobi. Many are limited, in space, time and instrumentation.</p>
<p>And yet, taken as a whole, they provide consistent and important insights about pollution in Nairobi. My <a href="https://link.springer.com/article/10.1007%2Fs11869-020-00902-x">analysis</a> of this cumulative evidence reveals that particulate matter in some parts of Nairobi, such as the Industrial Area district, where factories exist side by side with crowded poor settlements, have been unsafe as far back as the early 1980s. </p>
<p>The review also points to gaps in our understanding of air pollution in Kenya. This could inspire further targeted research to fill in the gaps.</p>
<h2>High pollution levels</h2>
<p>Emissions from industrial sources have been found to be important pollution sources. Multiple <a href="https://www.sciencedirect.com/science/article/pii/S0013935116300974?casa_token=YrQwgYse6vsAAAAA:F9DfNBiRqFA_aPkTGnrhwlj6r5NvGLIQe2tUQ7DF-gv_GLeMjGTzrGN9vaXWBJgBhqtPlFMPwQ">studies</a> have demonstrated that air pollution levels in poor neighbourhoods exhibit fine particulate levels of several 100 μg/m3, an order of magnitude higher than current standards. These neighbourhoods include Korogocho to Nairobi’s north, Viwanda in the east, and Kibera to the south.</p>
<p>All studies demonstrate that vehicular emissions are an important pollution source in Nairobi. Black carbon produced from the incomplete combustion of fuel, typically produced from older vehicles, forms a large fraction of particulate matter in Nairobi, with levels among the <a href="https://www.sciencedirect.com/science/article/abs/pii/S1361920917300639?casa_token=e2PVR_WQP5EAAAAA:SSHQTif7hK_cnarYy9PmCITBYJ8g4ya1Qrp-9ptsuiQ_ToVp-vAF9kHEy4-leIlK8pBfLycyKQ">highest</a> in the world.</p>
<p>Other <a href="https://www.mdpi.com/1996-1073/12/6/1177">research</a> has found that the fuel economy of vehicles in Nairobi is 2-3 times worse than in countries like Japan, India and China from which these vehicles tend to be imported. Studies also found much higher levels of lead and manganese (additives to petroleum fuels) in Nairobi than in European countries in the late 1990s and early 2000s. Less work has been carried out to evaluate levels after 2006, when leaded gasoline was phased out.</p>
<p>These findings present evidence for policymakers to urgently enforce the ban of importing vehicles above a certain age. They suggest the need to improve the infrastructure to enable non-motorised transport in Nairobi to serve the majority of the population that does not own a car. They speak to the need to incorporate air pollution concerns into the environmental impact assessment of transport related projects, such as the building of <a href="https://www.infrastructure-exchange.com/post/construction-to-begin-on-nairobi-expressway">new highways</a> in the city.</p>
<p>The review of the literature also provides evidence that sources of pollution in Nairobi’s Industrial Area need to be mitigated. The national environment management authority requires industrial facilities to contract designated laboratories with the necessary equipment to report smokestack emissions. Provisions should be made for continuous monitoring in line with the 2014 regulations. As a first step, these emissions data should be made public for key polluters to be identified so that action can be taken.</p>
<p>The review also points to gaps in our understanding of air pollution in Kenya that could inspire further targeted research to fill in the gaps. For example, few studies report the concentrations gaseous pollutants. These include volatile organic compounds, sulphur dioxide and surface ozone, which are likely to be high in the industrial area. In addition, most past research conducted so far has focused on Nairobi. Little work has been done to characterise air quality in other cities and towns, including the busy port of Mombasa.</p>
<p>More work is also needed to track the impacts of different policies and transport interventions on pollution in Nairobi. There is an urgent need to set up a real-time continuous air quality monitoring system to capture such information. This review, however, suggests that there are certain policy interventions that can and must be made based on our current understanding of air pollution patterns in Kenya. </p>
<p>This review also reveals larger gaps in the infrastructure of air pollution governance in Kenya. Specifically, the review finds that many studies have been conducted by researchers at the Kenya Meteorological Department using official air quality monitors. <a href="http://repository.usp.ac.fj/11518/1/IJSRES-15-46.pdf">Some</a> of these studies show that air pollution levels in Nairobi violate the current standards. However, the data from many of these studies are not publicly available. The department currently <a href="https://www.theelephant.info/features/2018/07/05/every-breath-you-take-who-is-monitoring-air-quality-in-kenya/">charges for this data</a>. There is a need for a push to make this data more transparent for science and policy purposes.</p>
<h2>Small steps forward</h2>
<p>Kenyan researchers have <a href="https://twitter.com/AirQualityKenya">teamed up</a> with policymakers to form the Kenya Air Quality Network to develop evidence-based air pollution management plans. Through these efforts, Nairobi county has become the first to lay out an air quality <a href="https://www.eci-africa.org/wp-content/uploads/2019/05/Nairobi-Air-Quality-Action-Plan_Final_ECI_31.12.2018.pdf">action plan</a>. Such policy efforts need to be supported.</p>
<p>It’s also important to highlight the initiatives underway in the Kenyan citizen science space. For example, <a href="https://open.africa/dataset/sensorsafrica-airquality-archive-nairobi">Code for Africa</a> has teamed up with journalists, providing them with low-cost air quality monitors so that they could track and monitor specific factories that residents have long complained about. </p>
<p>Such work has been crucial in raising awareness of air pollution among the public. These studies highlight the value of strategic partnerships between scientists and advocates to achieve common goals. These efforts can and should inspire future research design and questions on air pollution science in Kenya, and need to be taken seriously.</p><img src="https://counter.theconversation.com/content/151077/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Priyanka deSouza does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Studies demonstrate that vehicular emissions are a huge pollution source in Nairobi.Priyanka deSouza, PhD researcher at the Department of Urban Studies and Planning, Massachusetts Institute of Technology (MIT)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1480812020-10-30T12:46:20Z2020-10-30T12:46:20ZStudies link COVID-19 deaths to air pollution, raising questions about EPA’s ‘acceptable risk’<figure><img src="https://images.theconversation.com/files/366571/original/file-20201030-15-1fkqrl0.jpg?ixlib=rb-1.1.0&rect=426%2C0%2C2155%2C1378&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">By the end of October, more than 228,000 Americans who got COVID-19 had died.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/smoke-pours-from-the-exhaust-pipes-on-a-truck-on-november-news-photo/1185741323?adppopup=true&uiloc=thumbnail_more_from_this_event_adp">Joe Raedle/Getty Images</a></span></figcaption></figure><p>The pandemic is putting America’s air pollution standards to the test as the COVID-19 <a href="https://coronavirus.jhu.edu/map.html">death toll</a> rises.</p>
<p>The U.S. government sets limits on hazardous air pollutants to try to protect public health, but it can be difficult to determine where to draw the line for what is considered “acceptable risk.” Power plants, factories and other pollution sources release <a href="https://www.epa.gov/air-emissions-inventories/2017-national-emissions-inventory-nei-data">hundreds of million pounds of hazardous pollutants</a> into the air every year. </p>
<p>As the coronavirus spreads, the pattern of deaths suggests there are serious weaknesses in the current public safeguards.</p>
<p>Several studies have explored connections between air pollution and severe cases of the respiratory illnesses. The latest, published on Oct. 26, estimates that <a href="https://academic.oup.com/cardiovascres/advance-article/doi/10.1093/cvr/cvaa288/5940460">about 15% of people who died from COVID-19</a> worldwide had had long-term exposure to fine particulate air pollution. </p>
<p>My research as an <a href="https://scholar.google.com/citations?hl=en&user=d579LQ4AAAAJ&view_op=list_works&gmla=AJsN-F4XBT-7M6-OYyoczc86bMRRUVHswRBq0i_yJvactpDLzj81v2dUwPFtBSWEnV_aeYmYklZ49Q-WzxIc6esd-pMJzMybYgqgl5CKVbT_FgtXiBpax3E">environmental health scientist</a> looks closer at individual hazardous air pollutants and shows how higher rates of <a href="https://coronavirus.jhu.edu/map.html">COVID-19 deaths</a> across the U.S. – particularly in the South – have been associated with higher levels of pollutants, particularly diesel exhaust and acetaldehyde, a compound widely used in industry.</p>
<h2>Many of these chemicals are all around us</h2>
<p>The delivery boxes piled up in my living room offer a snapshot of how pervasive hazardous air pollutants can be. Toxic gases like <a href="https://pubchem.ncbi.nlm.nih.gov/compound/Acetaldehyde">acetaldehyde</a> are exhaled by the paper mill that <a href="https://enviro.epa.gov/facts/tri/ef-facilities/#/Facility/71292MNVLL1031J">manufactured the boxes in Louisiana</a>, the diesel trucks that delivered them, and even the gas furnace that keeps me warm as I open them. The Environmental Protection Agency regulates acetaldehyde, in part because in 1986 Dutch scientists found that it damages the respiratory system of rodents.</p>
<p>Acetaldehyde is quite common. In addition to being used in industry, it’s found in decaying vegetation, alcohol and cigarette smoke.</p>
<figure class="align-center ">
<img alt="A couple plays with their dogs at a Louisiana home with a refinery in the background." src="https://images.theconversation.com/files/366568/original/file-20201029-13-1eooi2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/366568/original/file-20201029-13-1eooi2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/366568/original/file-20201029-13-1eooi2g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/366568/original/file-20201029-13-1eooi2g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/366568/original/file-20201029-13-1eooi2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/366568/original/file-20201029-13-1eooi2g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/366568/original/file-20201029-13-1eooi2g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Petroleum refineries and chemical plants are sources of hazardous air pollutants.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/family-living-right-next-door-to-a-shell-petroleum-refinery-news-photo/1188931939">Andrew Lichtenstein/Corbis via Getty Images</a></span>
</figcaption>
</figure>
<p>I generally don’t think about the toxic emissions resulting from my consumer behavior, but I can’t help but think about health risks now, and how to reduce them.</p>
<p>In the early days of the pandemic, I isolated myself. I dusted off my bicycle. <a href="https://www.ewg.org/tapwater/">I identified the contaminants in my water system</a> and installed a reverse osmosis filter. To put it bluntly, I was afraid. Overweight men were not faring well against the virus, according to an early <a href="https://doi.org/10.1371/journal.ppat.1008520">study</a>, so I tried to modify my risk.</p>
<p>But what can I do about the air I breathe? I cannot stop the trucks from driving past my house, or the <a href="https://enviro.epa.gov/facts/tri/ef-facilities/#/Facility/13209CRCBLSTATE">steel mill</a> down the street from releasing emissions from its smokestack.</p>
<h2>Studies reveal the health risks</h2>
<p><a href="https://projects.iq.harvard.edu/covid-pm">Harvard University</a> and <a href="https://doi.org/10.1016/j.xinn.2020.100047">Emory University</a> have investigated the role of particulate matter, ozone and nitrogen oxides in COVID-19 deaths by comparing county death rates to pollution levels and other potential factors. Similar studies have been done in <a href="https://doi.org/10.1016/j.envpol.2020.114732">Italy</a>, <a href="https://doi.org/10.1016/j.envpol.2020.115859">England</a> and <a href="https://doi.org/10.1016/j.scitotenv.2020.140396">China</a>. </p>
<p>All of these studies found an association between higher death rates from COVID-19 and long-term pollution exposure.</p>
<p>While the causal factors are still unclear, the association may be related to air pollution exposure weakening the <a href="http://doi.org/10.1016/j.jaci.2011.11.021">respiratory</a>, <a href="https://www.sciencedirect.com/science/article/pii/S0891584919315217">immune</a> and <a href="https://doi.org/10.1038/s41569-020-0371-2">cardiovascular</a> systems. Exposed populations have greater vulnerability and less resistance to the virus.</p>
<p>My colleagues and I investigated specific hazardous air pollutants, including acetaldehyde, that are elevated in Southern rural areas that have been hit hard by the virus. </p>
<p>In states such as Mississippi, Alabama, Georgia and Louisiana, high COVID-19 death rates have been attributed in part to an <a href="https://doi.org/10.1002/emp2.12127">older population</a> that’s more likely to have chronic illnesses and live in poverty. We controlled for these factors, as well as population health and preventive behaviors, and found that long-term hazardous air pollutant exposure is putting pressure on COVID-19 patients in these areas.</p>
<p><iframe id="Y7jB3" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/Y7jB3/10/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>While federal standards suggest that the pollution levels in these areas aren’t harmful, our findings suggest officials need to reevaluate some of those standards.</p>
<h2>The problem with thresholds</h2>
<p>In 1991, the EPA extrapolated from rodents to humans to set the <a href="https://cfpub.epa.gov/ncea/iris/iris_documents/documents/subst/0290_summary.pdf#nameddest=rfd">safety limit for acetaldehyde</a> at 9 micrograms per cubic meter of air – similar in volume to a cup of water in an Olympic-size swimming pool. This standard assumes contaminated air below this level will not lead to any harm, excluding cancer.</p>
<p>But even acceptable exposures to these chemicals may be contributing to COVID-19 mortality rates. There is still a lot that scientists don’t know about the impact of hazardous air pollutants on humans.</p>
<p>There are some reasons we might observe effects below the threshold. First, animal reactions to toxins <a href="http://doi.org/10.1016/j.jacbts.2019.10.008">do not always predict human reactions</a>. Second, hazardous air pollutants do not act alone, and exposure to multiple toxins can have <a href="http://doi.org/10.1289/ehp.9330">cascading impacts</a>. Third, methods of monitoring and estimating exposures to air toxins are not adequate for characterizing risks to human health, especially for <a href="https://www.cdc.gov/mmwr/volumes/69/wr/mm6942e1.htm">vulnerable populations</a>.</p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p>The <a href="https://www.epa.gov/laws-regulations/summary-toxic-substances-control-act">Toxics Substance Control Act</a> is responsible for addressing risks from chemicals and limiting use of such substances as PCBs and asbestos. A 2016 amendment increased the government’s authority to <a href="http://doi.org/10.1371/journal.pbio.3000372">review risks for communities living near high-emissions sources</a>. But these risks <a href="https://news.bloomberglaw.com/product-liability-and-toxics-law/epa-denies-pledge-to-cancer-alley-communities-on-chemical-risks">have yet to take a major role in the assessment process</a>. The government in recent years has also cut funding for the <a href="https://www.epa.gov/iris">Integrated Risk Information Service</a>, which identifies health hazards.</p>
<h2>What to do about it</h2>
<p>More research is needed into effective pollution limits to address multiple chemical exposures and their effect on vulnerable populations.</p>
<p>Limits, along with funding for pollution prevention and control technology, could provide incentives for cleaner production practices and cleaner vehicles. These can be important strategies for strengthening the nation’s defenses against this and future respiratory disease pandemics.</p><img src="https://counter.theconversation.com/content/148081/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Petroni receives funding from State University of New York Discovery Challenge Fund. </span></em></p>Air pollution can weaken people’s respiratory, immune and cardiovascular systems, leaving them more vulnerable when they get COVID-19.Michael Petroni, PhD Candidate and Research Fellow, State University of New York College of Environmental Science and ForestryLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1480312020-10-16T14:16:45Z2020-10-16T14:16:45ZDrive-throughs are busier than ever during the pandemic – but they’re hotspots for air pollution<figure><img src="https://images.theconversation.com/files/363716/original/file-20201015-23-1cid3ja.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4592%2C3056&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">In the US, the average time spent waiting in fast food drive-throughs has risen by half a minute during the pandemic.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/drive-thru-fast-food-restaurantmotion-blur-38753656">Ministr-84/Shutterstock</a></span></figcaption></figure><p>Over <a href="https://www.euro.who.int/en/media-centre/sections/press-releases/2015/04/air-pollution-costs-european-economies-us%24-1.6-trillion-a-year-in-diseases-and-deaths,-new-who-study-says">90% of EU citizens</a> each year are exposed to levels of outdoor air pollution that are above the World Health Organization’s air quality guidelines. In Birmingham, the UK’s second largest city, air quality <a href="https://www.birmingham.gov.uk/downloads/file/11938/air_quality_annual_status_report_2018_containing_data_for_2017">in 2018</a> breached both national air quality limits for nitrogen dioxide (NO₂) and the WHO guideline for particulate matter. Children who live in Birmingham could have their lives <a href="https://www.uk100.org/wp-content/uploads/2019/05/KCL-UK100-Birmingham-City-Health-and-Economic-Impact-2019.pdf">cut short</a> by an average of up to seven months because of poor air quality alone. </p>
<p>Air pollution is a public health crisis, but it’s currently overshadowed by coronavirus. As the virus has restricted our access to cafes and restaurants, drive-through services have swollen. They might allow a semblance of normal life to continue, but what might it mean for the air we breathe?</p>
<p>In research conducted at the outset of the pandemic, my colleagues and I discovered that many drive-throughs in the UK are air pollution hotspots. Without measures to limit exposure, these sites could contribute to chronic health problems among drive-through workers and the people they serve.</p>
<figure class="align-center ">
<img alt="A car exhaust surrounded by fumes." src="https://images.theconversation.com/files/363717/original/file-20201015-17-1nsyyzf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/363717/original/file-20201015-17-1nsyyzf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/363717/original/file-20201015-17-1nsyyzf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/363717/original/file-20201015-17-1nsyyzf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/363717/original/file-20201015-17-1nsyyzf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/363717/original/file-20201015-17-1nsyyzf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/363717/original/file-20201015-17-1nsyyzf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Air pollution is a leading cause of illness worldwide.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/car-exhaust-pipe-which-comes-out-574315432">Jarhe Photography/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Convenience at a cost</h2>
<p>In February 2020, mere weeks before lockdown began in the UK, we published <a href="https://www.coventry.ac.uk/news/2020/coventry-university-research-reveals-high-levels-of-air-pollution-which-could-harm-health-of-drive-thru-staff-and-customers/">a study</a> on air pollution around the drive-through windows of fast food outlets in 10 major cities throughout the UK. To find out how it might be affecting customers and employees, we used <a href="https://www.aqmesh.com/">monitors</a> to measure levels of pollution every 15 minutes for two weeks.</p>
<p>At a drive-through in Erith, south-east London, 61% of NO₂ measurements exceeded the UK’s safe limit. In Hull, 27% of measurements revealed unsafe levels of NO₂ and in Birmingham, 19% exceeded the limit. NO₂ levels seemed to peak during lunch and in the evening, while concentrations of particulate matter were highest in the morning during the breakfast rush.</p>
<p>In all of these places, drive-through employees were regularly exposed to toxic fumes that can have long-term health effects. Customers in their cars weren’t much safer either. Rather than being protected from emissions inside a vehicle, <a href="https://airqualitynews.com/2019/10/07/drivers-are-exposed-to-the-highest-levels-of-harmful-air-pollution-and-taxi-drivers-are-most-at-risk/">studies</a> show that pollutants can accumulate <a href="https://www.berkeleywellness.com/healthy-community/environmental-health/article/pollution-inside-your-car">within your car</a> while you’re sat inside, often to higher levels in the confined space than outside it.</p>
<h2>Clearing the air</h2>
<p>Ours was the first study to investigate pollution levels at drive-throughs. Since then, drive-through <a href="https://www.bbc.co.uk/news/av/health-51660561">coronavirus testing sites</a> have sprung up across the UK and in the US, a “<a href="https://www.cnbc.com/2020/08/05/coronavirus-pandemic-sparks-a-building-boom-for-restaurant-drive-thrus.html">building boom</a>” for restaurant drive-throughs is underway.</p>
<p>Traffic pollution contains a number of harmful substances. Nitrogen dioxide (<a href="https://www.epa.gov/no2-pollution/basic-information-about-no2">NO₂</a>) is a noxious gas found in exhaust fumes that has been linked to asthma and birth complications. <a href="https://pubs.rsc.org/en/content/articlelanding/2020/MT/C9MT00253G#!divAbstract">Particulate matter</a> is another form of air pollution that’s like a fine dust, shed during combustion in the engine or from the <a href="https://theconversation.com/how-your-car-sheds-microplastics-into-the-ocean-thousands-of-miles-away-142614">wear and tear of brakes</a>. </p>
<p>These tiny fragments often measure less than 2.5 thousandths of a millimetre, or one-thirtieth the width of a human hair. <a href="https://www.epa.gov/pm-pollution/health-and-environmental-effects-particulate-matter-pm#:%7E:text=Exposure%20to%20such%20particles%20can,a%20variety%20of%20problems%2C%20including%3A&text=decreased%20lung%20function,airways%2C%20coughing%20or%20difficulty%20breathing.">But when inhaled</a>, they can infiltrate the bloodstream and weaken the lungs or contribute to heart disease.</p>
<p>Although there are permissible standards for these substances that are set by the government, no studies can claim that a harmless level of air pollution exists. People with underlying health problems can be affected even at very low levels of exposure.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/air-pollution-your-exposure-and-health-risk-could-depend-on-your-class-ethnicity-or-gender-128272">Air pollution: your exposure and health risk could depend on your class, ethnicity or gender</a>
</strong>
</em>
</p>
<hr>
<p>Employers have a duty to protect drive-through workers from air pollution. <a href="https://www.researchgate.net/publication/305273924_An_Evaluation_of_the_Effects_of_Drive-Through_Configurations_on_Air_Quality_at_Fast_Food_Restaurants">Proper precautionary measures</a> to minimise their exposure could also benefit the public. Using a reverse-flow fan system to prevent exhaust from entering the drive-through windows, encouraging stationary drivers to turn off their engines while waiting and preventing pregnant staff from working on the drive-through are just a few small steps that could make a big difference.</p>
<p>Scientists have found that hospital admissions for COVID-19 tend to flare up <a href="https://theconversation.com/air-pollution-exposure-linked-to-higher-covid-19-cases-and-deaths-new-study-141620">where air pollution</a> is most severe, as chronic exposure to airbone pollutants can make people <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7128509/">more vulnerable</a>. Using drive-through services instead of eating inside cafes and restaurants might limit your contact with coronavirus, but the hidden health consequences of air pollution should not be ignored.</p><img src="https://counter.theconversation.com/content/148031/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Anitha Chinnaswamy received support from BBC West Midlands to conduct this research.</span></em></p>Staff and customers with underlying health conditions are likely to be most at risk at drive-through windows.Anitha Chinnaswamy, Assistant Professor of Environment and Computing, Coventry UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1447902020-08-20T18:52:42Z2020-08-20T18:52:42ZWhat’s in wildfire smoke, and why is it so bad for your lungs?<figure><img src="https://images.theconversation.com/files/353786/original/file-20200820-20-x4dbvp.jpg?ixlib=rb-1.1.0&rect=0%2C9%2C6038%2C4001&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The health impact of wildfire exposure depends in part on the fire itself and how much smoke a person breathes in, how often and for how long.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/APTOPIX-California-Wildfires/7ea408ebdfa04aa6960fd28130f1cd8f/33/0">AP Photos/Noah Berger</a></span></figcaption></figure><p>If I dare to give the coronavirus credit for anything, I would say it has made people more conscious of the air they breathe.</p>
<p>A friend texted me recently after going for a jog in the foothills near Boise, Idaho, writing: “My lungs are burning … explain what’s happening!!!”</p>
<p>A wildfire was burning to the east of town – one of hundreds of fires that were sending smoke and ash through communities in <a href="https://inciweb.nwcg.gov/">hot, dry western states</a>. As <a href="https://www.boisestate.edu/ceh/luke-montrose/">an environmental toxicologist</a>, I research how air pollution, particularly wood smoke, impacts human health and disease. </p>
<p>I gave my friend the short answer: The state had issued a yellow, or moderate, air quality index warning due in part to wildfires. The high temperature for the day was expected to reach 100 degrees Fahrenheit, and it was already approaching 90. <a href="https://www.epa.gov/pm-pollution/how-smoke-fires-can-affect-your-health">That combination of high temperatures and elevated levels of particles</a> from a fire can affect even healthy lungs. For someone with lung damage or respiratory illness, moderate levels of smoke particulate can <a href="http://doi.org/10.1289/ehp.1409277">exacerbate respiratory problems.</a></p>
<p>That’s only the start of the story of how wildfire smoke affects humans who breathe it. The rest, and how to stay healthy, is important to understand as the western wildfire season picks up. </p>
<h2>What’s in wildfire smoke?</h2>
<p><a href="http://doi.org/10.1038/s41370-018-0064-7">What exactly is in a wildfire’s smoke</a> depends on a few key things: what’s burning – grass, brush or trees; the temperature – is it flaming or just smoldering; and the distance between the person breathing the smoke and the fire producing it.</p>
<p>The distance affects the ability of smoke to “age,” meaning to be acted upon by the sun and other chemicals in the air as it travels. <a href="http://doi.org/10.1021/acs.est.9b01034">Aging can make it more toxic</a>. Importantly, large particles like what most people think of as ash do not typically travel that far from the fire, but small particles, or aerosols, can travel <a href="https://doi.org/10.1016/j.atmosenv.2018.06.006">across continents</a>.</p>
<figure class="align-center ">
<img alt="Smoke from wildfires obscures the California sky on Aug. 19, 2020." src="https://images.theconversation.com/files/353792/original/file-20200820-24-1jjsnzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353792/original/file-20200820-24-1jjsnzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=471&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353792/original/file-20200820-24-1jjsnzn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=471&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353792/original/file-20200820-24-1jjsnzn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=471&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353792/original/file-20200820-24-1jjsnzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=591&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353792/original/file-20200820-24-1jjsnzn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=591&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353792/original/file-20200820-24-1jjsnzn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=591&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Smoke from wildfires obscures the California sky on Aug. 19, 2020.</span>
<span class="attribution"><a class="source" href="https://earthobservatory.nasa.gov/images/147146/thick-smoke-obscures-california-skies">Lauren Dauphin/NASA Earth Observatory</a></span>
</figcaption>
</figure>
<p>Smoke from wildfires contains <a href="https://www3.epa.gov/airnow/wildfire-smoke/wildfire-smoke-guide-revised-2019.pdf">thousands of individual compounds</a>, including carbon monoxide, volatile organic compounds (VOCs), carbon dioxide, hydrocarbons and nitrogen oxides. The most prevalent pollutant by mass is particulate matter less than 2.5 micrometers in diameter, roughly 50 times smaller than a grain of sand. Its prevalence is one reason health authorities issue air quality warnings using PM2.5 as the metric.</p>
<h2>What does that smoke do to human bodies?</h2>
<p>There is another reason <a href="https://www.calhospital.org/sites/main/files/file-attachments/wildfire_smoke_considerations_for_californias_public_health_officials_august_2019.pdf">PM2.5 is used to make health recommendations</a>: It defines the cutoff for particles that can travel deep into the lungs and cause the most damage.</p>
<p>The human body is equipped with natural defense mechanisms against particles bigger than PM2.5. As I tell my students, if you have ever <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/mucociliary-clearance">coughed up phlegm</a> or blown your nose after being around a campfire and discovered black or brown mucus in the tissue, you have witnessed these mechanisms firsthand.</p>
<p>The really small particles bypass these defenses and disturb the air sacks where oxygen crosses over into the blood. Fortunately, we have specialized immune cells present in the air sacks called macrophages. It’s their job to seek out foreign material and remove or destroy it. However, <a href="http://doi.org/10.2105/AJPH.2020.305744">studies</a> have shown that repeated exposure to elevated levels of wood smoke can suppress macrophages, leading to increases in lung inflammation.</p>
<h2>What does that mean for COVID-19 symptoms?</h2>
<p>Dose, frequency and duration are important when it comes to smoke exposure. Short-term exposure can irritate the eyes and throat. Long-term exposure to wildfire smoke over days or weeks, or breathing in heavy smoke, can raise the risk of <a href="https://www.calhospital.org/sites/main/files/file-attachments/wildfire_smoke_considerations_for_californias_public_health_officials_august_2019.pdf">lung damage</a> and may also contribute to <a href="https://health.ny.gov/environmental/outdoors/air/smoke_from_fire.htm">cardiovascular problems</a>. Considering that it is the macrophage’s job to remove foreign material – including smoke particles and pathogens – it is reasonable to make a <a href="http://doi.org/10.3109/08958378.2012.756086">connection</a> between smoke exposure and risk of viral infection.</p>
<p>Recent evidence suggests that long-term exposure to PM2.5 may make the coronavirus more deadly. A nationwide study found that even a small increase in PM2.5 from one U.S. county to the next was associated with a <a href="https://doi.org/10.1101/2020.04.05.20054502">large increase in the death rate</a> from COVID-19.</p>
<figure class="align-center ">
<img alt="Wildfire smoke pours over palm trees in Azusa, Calif., on Aug. 13, 2020." src="https://images.theconversation.com/files/353785/original/file-20200820-20-dsdu2t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/353785/original/file-20200820-20-dsdu2t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/353785/original/file-20200820-20-dsdu2t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/353785/original/file-20200820-20-dsdu2t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/353785/original/file-20200820-20-dsdu2t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/353785/original/file-20200820-20-dsdu2t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/353785/original/file-20200820-20-dsdu2t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Wildfire smoke pours over palm trees lining a street in Azusa, Calif., on Aug. 13, 2020.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/California-Wildfires/90e2257bf5394b46835b9d8b75b70e5c/15/0">AP Images/Marcio Jose Sanchez</a></span>
</figcaption>
</figure>
<h2>What can you do to stay healthy?</h2>
<p>The advice I gave my friend who had been running while smoke was in the air applies to just about anyone downwind from a wildfire.</p>
<p>Stay informed about air quality by identifying local resources for air quality alerts, information about active fires, and recommendations for better health practices. </p>
<p>If possible, avoid being outside or doing strenuous activity, like running or cycling, when there is an air quality warning for your area.</p>
<p>Be aware that not all face masks protect against smoke particles. In the context of COVID-19, the best data currently suggests that a cloth mask benefits public health, especially for those around the mask wearer, but also to some extent <a href="https://theconversation.com/cloth-masks-do-protect-the-wearer-breathing-in-less-coronavirus-means-you-get-less-sick-143726">for the person wearing the mask</a>. However, most cloth masks will not capture small wood smoke particles. That requires an N95 mask in conjunction with fit testing for the mask and training in how to wear it. Without a proper fit, N95s do not work as well.</p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p>Establish a clean space. Some communities in western states have offered “clean spaces” programs that help people take refuge in buildings with clean air and air conditioning. However, during the pandemic, being in an enclosed space with others can create other health risks. At home, a person can create clean and cool spaces using a window air conditioner and a <a href="https://www.youtube.com/watch?v=kH5APw_SLUU">portable air purifier</a>. </p>
<p><a href="https://www.epa.gov/pm-pollution/how-smoke-fires-can-affect-your-health">The EPA also advises</a> people to avoid anything that contributes to indoor air pollutants. That includes vacuuming that can stir up pollutants, as well as burning candles, firing up gas stoves and smoking.</p><img src="https://counter.theconversation.com/content/144790/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Luke Montrose does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Wildfires blanketing several Western cities are creating hazardous health conditions. Don’t count on cloth masks to protect your lungs.Luke Montrose, Assistant Professor of Community and Environmental Health, Boise State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1436502020-07-30T18:34:55Z2020-07-30T18:34:55ZFine-particle air pollution has decreased across the US, but poor and minority communities are still the most polluted<figure><img src="https://images.theconversation.com/files/350492/original/file-20200730-33-gwk7e.jpg?ixlib=rb-1.1.0&rect=0%2C5%2C3594%2C2365&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fresno, California and the surrounding San Joaquin Valley have some of the nation's highest levels of fine particle air pollution.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/California-Dirty-Air/606b75cb83d241a58c7b79be829bf550/208/0">AP Photo/Gary Kazanjian</a></span></figcaption></figure><p>Air pollution contributes to as many as 9 million premature deaths worldwide each year – twice as many as <a href="https://doi.org/10.1016/S0140-6736(17)32345-0">war, other violence, HIV/AIDS, tuberculosis and malaria combined</a>. Fine particulate matter air pollution is especially dangerous: Microscopic particles readily enter the lungs, bloodstream and brain, with <a href="https://theconversation.com/fine-particle-air-pollution-is-a-public-health-emergency-hiding-in-plain-sight-106030">health effects</a> that include infant death, reduced life expectancy for adults, cancer, lung disease and heart disease. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/350470/original/file-20200730-25-1trx4js.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/350470/original/file-20200730-25-1trx4js.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/350470/original/file-20200730-25-1trx4js.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/350470/original/file-20200730-25-1trx4js.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/350470/original/file-20200730-25-1trx4js.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/350470/original/file-20200730-25-1trx4js.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/350470/original/file-20200730-25-1trx4js.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/350470/original/file-20200730-25-1trx4js.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Fine particulate air pollution is referred to as PM2.5 because the particles are less than 2.5 microns in diameter – 40 times smaller than a grain of sand.</span>
<span class="attribution"><a class="source" href="https://ecology.wa.gov/Air-Climate/Air-quality/Air-quality-targets/Air-quality-standards/Particle-pollution">Washington department of Ecology</a></span>
</figcaption>
</figure>
<p>Fine particle matter pollution concentrations in the United States have declined by roughly 70% since 1981. However, in a <a href="https://science.sciencemag.org/content/369/6503/575">newly published study</a>, we show that the areas that were most polluted in 1981 are still the most polluted today, and the least polluted areas in 1981 are still the least polluted today. </p>
<p>Areas that were whiter and richer in 1981 have become relatively less polluted over time. Areas that became whiter and richer between 1981 and 2016 have become relatively less polluted over time. In contrast, the neighborhoods and population groups that were most exposed to fine particle pollution 40 years ago – disproportionately low-income and minority communities – are still exposed to higher pollution levels.</p>
<p>As scholars who focus on <a href="https://scholar.google.com/citations?user=xw8Ml0QAAAAJ&hl=en">environmental economics</a> and <a href="https://scholar.google.com/citations?user=Z1sqTysAAAAJ&hl=en">public policy</a>, we believe that the persistence of air pollution disparities matters. We care about who is advantaged and disadvantaged. In addition, our results have implications for environmental public policy. To the extent that policy aims to reduce pollution disparities, the job is far from finished.</p>
<h2>Mapping pollution at a neighborhood scale</h2>
<p>Researchers have known for decades that air pollution varies across locations due to economic activity, climate and other factors. It is also <a href="https://doi.org/10.1146/annurev-environ-082508-094348">well documented</a> that lower-income households, people of color and other disadvantaged communities are disproportionately exposed to air pollution. Since research shows that air pollution is associated with <a href="https://www.who.int/airpollution/ambient/health-impacts/en/">early death, lower educational attainment and lower lifetime earnings</a>, these differences <a href="http://doi.org/10.1257/jep.33.1.185">promote economic, health and social inequality</a>.</p>
<p>What has not been clear is how much air pollution disparities have changed over time. We wanted to understand particulate matter air pollution disparities in a more systematic way, for the entire U.S. over many years. </p>
<p>Until recently, the information needed to answer this question simply wasn’t available. The U.S. Environmental Protection Agency <a href="https://www.epa.gov/air-trends/particulate-matter-pm25-trends">monitors levels of fine particle pollution</a>, known as PM2.5, nationwide. But its monitors offer relatively sparse coverage and are concentrated in disproportionately urban locations. </p>
<p>In our study, we leverage <a href="https://doi.org/10.1021/acs.est.8b06875">newly available data</a> that captures PM2.5 concentrations at more than 8.6 million distinct U.S. locations from 1981 through 2016. These data were constructed from satellite observations and pollution transport modeling, along with pollution monitor records. They provide a detailed year-by-year picture of fine particulate matter concentrations for each of the roughly 65,000 Census tract “neighborhoods” in the United States.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/GVBeY1jSG9Y?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Fine particle air pollution moves from the lungs into the bloodstream and can have widespread health impacts throughout the body.</span></figcaption>
</figure>
<h2>Persistent disparities</h2>
<p>Our analysis shows that there has been some progress over the past 35 years in reducing gaps between the most polluted and least polluted locations. In 1981 PM2.5 concentrations in the most polluted 10% of census tracts averaged 34 micrograms per cubic meter. PM2.5 concentrations in the least polluted 10% of census tracts averaged 13 micrograms per cubic meter. The difference was 22 micrograms per cubic meter. </p>
<p>In 2016 PM2.5 concentrations in the most polluted 10% of census tracts averaged 10 micrograms per cubic meter. PM2.5 concentrations in the least polluted 10% of census tracts averaged 4 micrograms per cubic meter. The difference was 6 micrograms per cubic meter.</p>
<p>These reduced gaps likely imply that differences in pollution-induced health, wealth and productivity across locations are also declining. But while pollution gaps have declined for some disadvantaged communities, this hasn’t been universal.</p>
<p>Next we wanted to see whether specific locations had more or less pollution than other locations, and whether the most polluted locations were the same through time. To explore these questions, we ranked each neighborhood from most polluted to least polluted for every year that we had data. </p>
<p>We then evaluated how these rankings changed between 1981 and 2016, and found that they remained remarkably persistent. The most polluted areas in 1981 remain the most polluted areas today, and the least polluted areas in 1981 remain the least polluted areas today. Communities that were disadvantaged in 1981 remain exposed to higher levels of pollution today. If anything, relative disparities have worsened for poorer and Hispanic communities.</p>
<iframe frameborder="0" class="juxtapose" width="100%" src="https://cdn.knightlab.com/libs/juxtapose/latest/embed/index.html?uid=2f5684b8-d288-11ea-bf88-a15b6c7adf9a" height="400"></iframe>
<figure><figcaption><span class="caption">While PM2.5 concentrations decreased nationwide between 1981 and 2016, the same areas generally are still most and least polluted.</span></figcaption></figure>
<p>A disproportionate share of the most polluted areas over the past 40 years are in Southern California, while the least polluted areas are more dispersed across the U.S. As an example, a child born in Los Angeles County in 2016 was exposed to 42% more fine particle pollution than the average child born in the United States, and 26% more pollution than a child born in New York City.</p>
<p>A few areas did see improvements or declines in their relative standing. Ohio, West Virginia, eastern Kentucky and the Northeast Corridor became relatively less polluted from 1981 through 2016. California’s Central and Imperial valleys, southwestern Arizona, southern Texas and portions of Arkansas and Oklahoma became relatively more polluted.</p>
<h2>Fairness, equity and public policy</h2>
<p>Our findings underline the scope, scale and persistence of air pollution disparities in the United States. But if particulate matter air quality has improved over time – which should translate into improvements in health, wealth and productivity for most Americans – why should we be concerned about relative disparities between some locations and others?</p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p>In our view, persistent disparities between the most and least polluted communities matter because fairness, equity and justice are relative concepts. We define them based on who is advantaged and who is disadvantaged at any given time. Pollution disparities translate into health, economic and social disparities.</p>
<p>For decades, federal and state environmental guidelines have aimed to provide all Americans with the same degree of protection from environmental hazards. The EPA’s definition of environmental justice states that “no group of people should bear a <a href="https://www.epa.gov/environmentaljustice/learn-about-environmental-justice">disproportionate share of the negative environmental consequences</a>.” On this front, our research suggests that the United States is falling short.</p>
<p><em>Ian Hardman, research associate at Stanford University’s Program on Energy and Sustainable Development, and John Voorheis, lead economist at the U.S. Census Bureau’s Center for Economist Studies, co-authored the study described in this article. Any opinions and conclusions expressed here are those of the authors and do not necessarily reflect the views of the U.S. Census Bureau.</em></p><img src="https://counter.theconversation.com/content/143650/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A new study shows that while fine particle air pollution has declined nationwide over the past 40 years, the health and environmental benefits haven’t been shared evenly.Jonathan Colmer, Assistant Professor of Economics, University of VirginiaJay Shimshack, Associate Professor of Public Policy and Economics, University of VirginiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1346102020-05-08T12:18:51Z2020-05-08T12:18:51ZCOVID-19 shutdowns are clearing the air, but pollution will return as economies reopen<figure><img src="https://images.theconversation.com/files/333198/original/file-20200506-49542-1tfscjx.jpg?ixlib=rb-1.1.0&rect=72%2C0%2C8067%2C5373&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Clear skies over Los Angeles, April 17, 2020.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/view-of-downtown-los-angeles-with-clear-blue-skies-during-news-photo/1219498626?adppopup=true">Araya Diaz/Getty Images</a></span></figcaption></figure><p>With many economies locked down to slow the spread of coronavirus, people from <a href="https://www.youtube.com/watch?v=9654d4dwVmw">Beijing</a> to <a href="https://www.space.com/coronavirus-california-emissions-reduced-blue-skies-ozone-increase.html">Los Angeles</a> have noticed bluer skies and less smog. Photos from <a href="https://www.cnn.com/travel/article/himalayas-visible-lockdown-india-scli-intl/index.html">Punjab</a> and <a href="https://www.npr.org/sections/coronavirus-live-updates/2020/04/14/833996289/from-nairobi-a-rare-clear-glimpse-of-mt-kenya-drives-disbelief-on-social-media">Nairobi</a> reveal mountains that had been shrouded in haze for years. Satellites show cleaner air extending across broad swaths of <a href="https://www.nytimes.com/interactive/2020/climate/coronavirus-pollution.html">Asia</a>, <a href="https://www.space.com/europe-air-pollution-drop-during-coronavirus-lockdowns.html">Europe</a> and <a href="https://www.cnn.com/2020/03/23/health/us-pollution-satellite-coronavirus-scn-trnd/index.html">North America</a>. </p>
<p>These stunning images reflect how the air is changing as the world confronts COVID-19. People are staying home, driving less and taking fewer flights and cruises. This crisis provides a unique experiment to see how the atmosphere responds as nations cut their emissions.</p>
<p>The air is getting cleaner, although these blue skies may be temporary. But it isn’t getting cooler. The buildup of greenhouse gas pollution <a href="https://www.esrl.noaa.gov/gmd/ccgg/trends/">continues</a>, and global temperatures are <a href="https://www.ncdc.noaa.gov/sotc/global/202003/supplemental/page-2">still rising</a>.</p>
<p>Why this difference? As an <a href="https://scholar.google.com/citations?user=U4vSW6MAAAAJ&hl=en">atmospheric scientist</a>, I see it as an illustration of the contrasting challenges posed by air pollution and climate change.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/RFsxDqQWjhk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Although cities around the world are seeing the clearest skies in decades, 2020 is still on track to be the warmest year on record.</span></figcaption>
</figure>
<h2>The view from above</h2>
<p>You may have seen maps in the news showing blotches of air pollution that have shrunk since economies started shutting down in the past few months. Most of those maps are plotted from satellite observations of nitrogen dioxide, or NO2, a gas that triggers respiratory illnesses such as <a href="https://www.lung.org/clean-air/outdoors/what-makes-air-unhealthy/nitrogen-dioxide">asthma</a>. It also reacts in the air to form other types of pollution, such as smog, haze and acid rain. </p>
<p>Nitrogen dioxide can be observed from space because it absorbs unique slivers of sunlight’s rainbow of colors. Those observations tell us a lot about what’s happening on Earth.</p>
<p>Some NO2 comes from natural sources like lightning and soils. Those aren’t affected by the current crisis. What has changed is the amount of pollution coming from burning fossil fuels, especially in cars, airplanes and ships. </p>
<p>You can see the impacts of those reductions in satellite observations comparing NO2 concentrations over the United States in the spring of 2020 with the same period in 2019. They show that pollution levels are declining far more sharply over urban regions, where human sources of NO2 tend to dominate, than rural ones.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/333244/original/file-20200506-49565-1iynyj3.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/333244/original/file-20200506-49565-1iynyj3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/333244/original/file-20200506-49565-1iynyj3.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=250&fit=crop&dpr=1 600w, https://images.theconversation.com/files/333244/original/file-20200506-49565-1iynyj3.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=250&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/333244/original/file-20200506-49565-1iynyj3.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=250&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/333244/original/file-20200506-49565-1iynyj3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=315&fit=crop&dpr=1 754w, https://images.theconversation.com/files/333244/original/file-20200506-49565-1iynyj3.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=315&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/333244/original/file-20200506-49565-1iynyj3.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=315&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/333245/original/file-20200506-49538-19ood3l.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/333245/original/file-20200506-49538-19ood3l.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/333245/original/file-20200506-49538-19ood3l.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=259&fit=crop&dpr=1 600w, https://images.theconversation.com/files/333245/original/file-20200506-49538-19ood3l.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=259&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/333245/original/file-20200506-49538-19ood3l.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=259&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/333245/original/file-20200506-49538-19ood3l.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=325&fit=crop&dpr=1 754w, https://images.theconversation.com/files/333245/original/file-20200506-49538-19ood3l.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=325&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/333245/original/file-20200506-49538-19ood3l.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=325&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Nitrogen dioxide over the United States from March 16 to April 29 in 2019 (top) and 2020 (bottom).</span>
<span class="attribution"><a class="source" href="https://giovanni.gsfc.nasa.gov/giovanni/">Both images from Daniel Cohan, via NASA Giovanni</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Haze at ground level</h2>
<p>In addition to images from space, many people are sharing photos that show haze giving way to blue skies and clearer views of landmarks and mountains. These reflect another change: declining levels of particulate air pollution. </p>
<p>Particles are tiny bits of soot and other substances floating in the air. They too come from a wide range of natural and man-made sources, including fossil fuel combustion, cooking meat, wildfires, trees and dust. As with nitrogen dioxide, the COVID-19 crisis provides an unplanned opportunity to better understand the sources of particulate matter.</p>
<p>This is important because particles are responsible for most of the <a href="https://www.who.int/airpollution/ambient/health-impacts/en/">4.2 million deaths</a> that outdoor air pollution causes globally each year. Those deaths come from respiratory ailments, as well as heart attacks and strokes, since particles can be small enough to pass through the lungs into the bloodstream. </p>
<p>There’s even some preliminary evidence that exposure to <a href="https://projects.iq.harvard.edu/covid-pm">particulate matter</a> and <a href="http://dx.doi.org/10.1016/j.scitotenv.2020.138605">nitrogen dioxide</a> may make people more vulnerable to dying from COVID-19, although major uncertainties remain and more research is needed.</p>
<h2>No COVID cooling</h2>
<p>So what about carbon dioxide, or CO2, the leading cause of global warming? As we breathe cleaner air and see less haze, is that falling too? </p>
<p>Unfortunately, no. </p>
<p>Some observers estimate that the global response to COVID-19 could cause CO2 emissions in 2020 to fall by about 8%, which would be the <a href="https://www.carbonbrief.org/analysis-coronavirus-set-to-cause-largest-ever-annual-fall-in-co2-emissions">sharpest drop in modern history</a>. But unlike the temporary improvements we’re seeing in nitrogen dioxide and particulate matter, the decline in CO2 emissions won’t reduce total atmospheric concentrations of CO2. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/332428/original/file-20200504-83736-1rh9azh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/332428/original/file-20200504-83736-1rh9azh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/332428/original/file-20200504-83736-1rh9azh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=487&fit=crop&dpr=1 600w, https://images.theconversation.com/files/332428/original/file-20200504-83736-1rh9azh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=487&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/332428/original/file-20200504-83736-1rh9azh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=487&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/332428/original/file-20200504-83736-1rh9azh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=612&fit=crop&dpr=1 754w, https://images.theconversation.com/files/332428/original/file-20200504-83736-1rh9azh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=612&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/332428/original/file-20200504-83736-1rh9azh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=612&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Global emissions (top) and annual change (bottom) of carbon dioxide from energy use, in gigatons.</span>
<span class="attribution"><a class="source" href="https://www.iea.org/reports/global-energy-review-2020/global-energy-and-co2-emissions-in-2020#abstract">IEA Global Energy Review 2020</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>That’s because CO2 can stay in the air for centuries, while most other pollutants last for only days before they rain out or chemical reactions break them down. Carbon dioxide levels in the air will stabilize only when emissions reach a “net-zero” balance, in which sources are not emitting more CO2 than carbon sinks, such as vegetation, oceans and carbon-capturing devices, can remove. </p>
<p>This year’s declines will be nowhere near enough to achieve that balance. So carbon dioxide levels in the atmosphere are <a href="https://www.esrl.noaa.gov/gmd/ccgg/trends/">still rising</a>, albeit at a somewhat slower rate than they would under business as usual. So are temperatures. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/329796/original/file-20200422-47832-17lrimq.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/329796/original/file-20200422-47832-17lrimq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/329796/original/file-20200422-47832-17lrimq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=467&fit=crop&dpr=1 600w, https://images.theconversation.com/files/329796/original/file-20200422-47832-17lrimq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=467&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/329796/original/file-20200422-47832-17lrimq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=467&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/329796/original/file-20200422-47832-17lrimq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=587&fit=crop&dpr=1 754w, https://images.theconversation.com/files/329796/original/file-20200422-47832-17lrimq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=587&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/329796/original/file-20200422-47832-17lrimq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=587&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Levels of carbon dioxide in the air continue to increase.</span>
<span class="attribution"><a class="source" href="https://www.esrl.noaa.gov/gmd/ccgg/trends/">NOAA</a></span>
</figcaption>
</figure>
<p>Even as billions of people around the world stayed home and fossil-fuel-powered economies slowed down, March 2020 was the <a href="https://www.ncei.noaa.gov/news/global-climate-202003">second-warmest March on record</a>. </p>
<p>Paradoxically, it’s possible that responses to COVID-19 could actually cause a temporary bump in warming because of the way in which particles impact climate. </p>
<p>While CO2 traps the Earth’s heat, many types of particles reflect sunlight away from Earth, which provides a cooling effect. Lower particle pollution levels will allow more sunlight to reach the Earth’s surface. That could <a href="https://doi.org/10.1073/pnas.1819989116">temporarily accelerate warming</a>, although scientists are <a href="https://www.ipcc.ch/report/ar5/wg1/">uncertain how strong that effect might be</a>. </p>
<p>Coincidentally, 2020 marks the start of a global effort to <a href="http://www.imo.org/en/MediaCentre/HotTopics/Pages/Sulphur-2020.aspx">cut sulfur emissions from ships</a>. Those emissions are a leading source of particles <a href="https://earthzine.org/could-cuts-in-sulfur-from-coal-and-ships-help-explain-the-2015-spurt-in-northern-hemisphere-temperatures/">over the oceans</a>. Together, cleaner ships and less fossil fuel use this year will provide an unprecedented test of how climate responds to particles.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/329895/original/file-20200422-47804-h6a6dr.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/329895/original/file-20200422-47804-h6a6dr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/329895/original/file-20200422-47804-h6a6dr.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/329895/original/file-20200422-47804-h6a6dr.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/329895/original/file-20200422-47804-h6a6dr.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/329895/original/file-20200422-47804-h6a6dr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/329895/original/file-20200422-47804-h6a6dr.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/329895/original/file-20200422-47804-h6a6dr.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This March was the second hottest on record, even though carbon dioxide emissions fell.</span>
<span class="attribution"><a class="source" href="https://www.ncdc.noaa.gov/sotc/global/202003/supplemental/page-1">NOAA</a></span>
</figcaption>
</figure>
<h2>What lies ahead</h2>
<p>What does all of this mean for air and climate beyond the current crisis? Air pollution can return as quickly as it faded if fossil fuel use rebounds. In fact, nitrogen dioxide levels are <a href="https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Sentinel-5P/COVID-19_nitrogen_dioxide_over_China">already beginning to rise</a> over China as its lockdown eases.</p>
<p>Meanwhile, long-lasting carbon dioxide will continue to accumulate, making it difficult to stabilize the climate even as nations work to cut emissions. Only technologies, policies and investments that replace fossil fuels with energy efficiency and clean fuels can sustainably achieve cleaner air and a stable climate.</p>
<p>[<em>Get facts about coronavirus and the latest research.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=upper-coronavirus-facts">Sign up for The Conversation’s newsletter.</a>]</p><img src="https://counter.theconversation.com/content/134610/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniel Cohan has previously received funding from NASA, the National Science Foundation, and the U.S. Environmental Protection Agency. </span></em></p>From Nairobi to Los Angeles, pandemic lockdowns have cleared pollution from the skies. But those blue vistas may be temporary, and shutdowns aren’t slowing climate change.Daniel Cohan, Associate Professor of Environmental Engineering, Rice UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1362262020-05-01T18:27:16Z2020-05-01T18:27:16ZEPA decides to reject the latest science, endanger public health and ignore the law by keeping an outdated fine particle air pollution standard<figure><img src="https://images.theconversation.com/files/331833/original/file-20200430-42951-1gk6a9u.jpg?ixlib=rb-1.1.0&rect=17%2C0%2C2000%2C1257&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Diesel emissions are a major source of fine particle pollution.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/truck-driver-mel-garcia-of-phoenix-in-the-cab-of-his-knight-news-photo/567369417?adppopup=true">Bob Chamberlin/Getty Images</a></span></figcaption></figure><p>The COVID-19 pandemic and economic shutdown have temporarily produced <a href="https://www.nationalgeographic.com/science/2020/04/pollution-made-the-pandemic-worse-but-lockdowns-clean-the-sky/#close">clearer skies across the U.S.</a> Meanwhile, however, the U.S. Environmental Protection Agency has been busy finding reasons not to pursue long-lasting air quality gains. </p>
<p>On April 30, 2020, the agency published a proposed new rule that retains current National Ambient Air Quality Standards for Particulate Matter <a href="https://www.federalregister.gov/documents/2020/04/30/2020-08143/review-of-the-national-ambient-air-quality-standards-for-particulate-matter">without any revisions</a>. It took this action after a five-year review process, in which scientific evidence showed unequivocally that these standards are not adequate to protect public health.</p>
<p>I have studied air pollution and air quality for over 30 years, and have been directly involved for a decade with EPA’s reviews of <a href="https://www.sciencemag.org/news/2018/12/qa-air-pollution-expert-advised-epa-decade-now-he-s-leading-critic">scientific findings on air pollution</a>. This includes serving on the agency’s Clean Air Scientific Advisory Committee, or CASAC, and on 10 specialized panels focused on individual pollutants.</p>
<p>As I have written previously, the Trump administration has <a href="https://theconversation.com/a-rush-to-judgment-the-trump-administration-is-taking-science-out-of-air-quality-standards-106507">watered down the role of science</a> in what is supposed to be a science-based process of setting national air quality standards. This new proposal – which I expect will be challenged in court when finalized – is the result.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/BxeY8E9Ms_A?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Recent studies indicate that reducing PM2.5 standards below current levels could avert thousands of premature deaths.</span></figcaption>
</figure>
<h2>Fine particle air pollution is deadly</h2>
<p>Fine particles, known as PM2.5 because they measure 2.5 microns or less in diameter, can penetrate deeply into the lungs and bloodstream. EPA staff scientists have reaffirmed that daily and annual exposure to PM2.5 <a href="https://www.epa.gov/isa/integrated-science-assessment-isa-particulate-matter">causes premature death and a variety of illnesses</a>. </p>
<p>Scientists have <a href="http://dx.doi.org/10.1056/NEJM199312093292401">known this for decades</a>, but since the national standard was last revised in 2012, new studies have strengthened these findings. They include an epidemiologic study with the <a href="http://dx.doi.org/DOI:%2010.1056/NEJMoa1702747">largest ever number of subjects</a> and several that include PM2.5 concentrations <a href="http://dx.doi.org/10.1289/ehp.1409111">well below the current standard</a>. </p>
<p>EPA’s scientific staff estimates, based on multiple epidemiologic studies, that currently an average of 13,500 to 51,300 people <a href="https://www.epa.gov/sites/production/files/2020-01/documents/final_policy_assessment_for_the_review_of_the_pm_naaqs_01-2020.pdf">die prematurely each year</a> from breathing fine particles. Although these numbers are uncertain, the likelihood of thousands of deaths per year would typically spur regulators to tighten existing standards. However, EPA’s current political leadership disagrees.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/331853/original/file-20200430-42951-1kcirjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/331853/original/file-20200430-42951-1kcirjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/331853/original/file-20200430-42951-1kcirjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=357&fit=crop&dpr=1 600w, https://images.theconversation.com/files/331853/original/file-20200430-42951-1kcirjv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=357&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/331853/original/file-20200430-42951-1kcirjv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=357&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/331853/original/file-20200430-42951-1kcirjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=449&fit=crop&dpr=1 754w, https://images.theconversation.com/files/331853/original/file-20200430-42951-1kcirjv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=449&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/331853/original/file-20200430-42951-1kcirjv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=449&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">EPA Administrator Andrew Wheeler, a former coal industry lobbyist, has asserted that uncertainty around recent studies suggesting that current PM2.5 standards don’t adequately protect public health justifies retaining the current standard.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Fact-Check-Week/e98542b1443e4645a40ebf1d6ba1e951/3/0">AP Photo/J. Scott Applewhite</a></span>
</figcaption>
</figure>
<h2>What the law requires</h2>
<p>The Clean Air Act directs the EPA to set air quality standards based on an accurate and thorough <a href="https://www.law.cornell.edu/uscode/text/42/7408">review of the latest science</a>. This function is performed by <a href="https://yosemite.epa.gov/sab/sabproduct.nsf/WebCASAC/currentcharter?OpenDocument">CASAC</a>, which I <a href="https://www.sciencemag.org/news/2018/12/qa-air-pollution-expert-advised-epa-decade-now-he-s-leading-critic">chaired from 2012 to 2015</a>. </p>
<p>CASAC has seven members, which isn’t enough to provide the breadth, depth and diversity of expertise, experience and perspectives needed for these <a href="https://yosemite.epa.gov/sab/sabproduct.nsf/086D8B853E0B63AE8525835F004DC679/$File/PMRP+Letter+to+CASAC+181210+Final+181210.pdf">complex reviews</a>. Recognizing this, for four decades the EPA has augmented the committee by convening <a href="https://ucs-documents.s3.amazonaws.com/science-and-democracy/pm-panel-meeting-docs/4-ipmrp-history.pdf">expert review panels for each pollutant</a>. They include scientists with extensive knowledge of <a href="https://www.federalregister.gov/documents/2015/02/04/2015-02265/request-for-nominations-of-experts-for-the-clean-air-scientific-advisory-committee-casac-particulate">epidemiology, toxicology, medicine, air quality, exposure, risk, statistics and other fields</a>. I served on the 20-member <a href="https://theconversation.com/a-rush-to-judgment-the-trump-administration-is-taking-science-out-of-air-quality-standards-106507">CASAC PM Review Panel</a> that was appointed in 2015 to help CASAC review the PM2.5 standard. </p>
<p>EPA Administrator Andrew Wheeler <a href="https://www.sciencemag.org/news/2018/10/trump-s-epa-scraps-air-pollution-science-review-panels">disbanded that panel in October 2018</a>. Wheeler also continued a makeover of CASAC, started by his predecessor, Scott Pruitt, that <a href="https://www.eenews.net/stories/1060780563">removed leading researchers from the committee</a>. Now CASAC has no epidemiologists – a key discipline for assessing PM2.5 health effects. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1148377090061983745"}"></div></p>
<h2>What our expert panel recommended</h2>
<p>Realizing that EPA would not otherwise get the science advice it needs, the disbanded PM review panel <a href="https://theconversation.com/the-epa-disbanded-our-clean-air-science-panel-we-met-anyway-and-found-that-particle-pollution-regulations-arent-protecting-public-health-125779">reconvened itself</a> in October 2019. We found that current fine particle standards <a href="https://yosemite.epa.gov/sab/sabproduct.nsf/81DF85B5460CC14F8525849B0043144B/$File/Independent+Particulate+Matter+Review+Panel+Letter+on+Draft+PA.pdf">are not protective of public health</a>. </p>
<p>The studies published since 2012 demonstrating that exposure to fine particles causes premature death at concentrations below current standards were key to our decision. We advised the EPA that the annual standard should be reduced from its current level of 12 micrograms per cubic meter to a range of between 10 and 8 micrograms per cubic meter. </p>
<p>For the 24-hour standard, which regulates short-term air quality spikes, we recommended reducing the limit from the current level of 35 micrograms per cubic meter to between 30 and 25 micrograms per cubic meter. These scientific findings were based on multiple epidemiologic studies, augmented with evidence from controlled experiments with animals and humans.</p>
<h2>Failing to protect the public</h2>
<p>Administrator Wheeler claims that recent studies since the last time the standards were revised “<a href="https://www.govinfo.gov/content/pkg/FR-2020-04-30/pdf/2020-08143.pdf">do not provide a basis for revising the standards</a>.” Wheeler acknowledges that studies based on long-term exposures below the current standards show “associations” between air quality and premature death. However, he argues that this research does not show a causal relationship. Yet, based on the overall body of evidence, he acknowledges that “a causal relationship exists between long-term PM2.5 exposure and total mortality.” In my view, his rationale is illogical and is inconsistent with the evidence. </p>
<p>The Clean Air Act requires regulators to set standards that will provide an “<a href="https://www.law.cornell.edu/uscode/text/42/7409">adequate margin of safety</a>.” This means that they should be stringent enough to protect sensitive populations, such as older adults, people with preexisting cardiovascular or respiratory diseases and children with asthma. </p>
<p>The EPA proposal acknowledges that these groups exist, but does not specify how it will protect them from PM2.5 in the air. Wheeler is also silent regarding the role of racial and ethnic differences in exposure and risk, even though a federal court called EPA to task in 2009 for <a href="https://www.courtlistener.com/opinion/187302/american-farm-bureau-federation-v-epa/">not specifically addressing at-risk groups</a>. </p>
<p>Preliminary evidence suggests that exposure to particles <a href="https://projects.iq.harvard.edu/covid-pm">worsens the effects of COVID-19</a>. While this finding needs <a href="https://theconversation.com/air-pollution-covid-19-and-death-the-perils-of-bypassing-peer-review-136376">peer review</a> and additional study, existing evidence of risk for sensitive populations shows the need for a more protective standard.</p>
<p>EPA currently faces lawsuits for multiple instances in which it has either sought to weaken, or failed to strengthen, air pollution regulations. They include rolling back <a href="https://eelp.law.harvard.edu/2017/09/corporate-average-fuel-economy-standards-greenhouse-gas-standards/">motor vehicle greenhouse gas emission standards</a>, failing to implement stringent rules limiting <a href="https://eelp.law.harvard.edu/2017/09/cross-state-air-pollution-rule-and-section-126-petitions/">interstate air pollution</a> and repealing the Obama administration’s Clean Power Plan to limit <a href="https://eelp.law.harvard.edu/2017/09/clean-power-plan-carbon-pollution-emission-guidelines/">carbon emissions from power plants</a>. Unless EPA modifies its position on particle air quality to address the law and the science, I expect that this regulation too will end up in court.</p>
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<p class="fine-print"><em><span>H. Christopher Frey receives funding from the North Carolina Department of Transportation and the HSBC 150th Anniversary Charity Programme via the Hong Kong University of Science and Technology. In the last two years, Dr. Frey has been the principal investigator of research grants and contracts at North Carolina State University sponsored by the North Carolina Department of Transportation, the U.S. Environmental Protection Agency via the Health Effects Institute and Eastern Research Group, and the Urban Air Initiative. Dr. Frey’s research work at the Hong Kong University of Science and Technology, where he is an adjunct professor, is funded by the HSBC 150th Anniversary Charity Programme. Dr. Frey has also conducted work for the Hong Kong Environmental Protection Department. Dr. Frey’s current affiliations include serving as a member of the Transportation and Air Quality (ADC20) Committee of the Transportation Research Board, and as a member of the Publications Committee and the Critical Review Committee of the Air & Waste Management Association (A&WMA) . He is also on the editorial board of the journal Atmospheric Environment and serving as a guest editor for the journals Atmospheric Environment and Science of the Total Environment. He is chair of the nongovernmental Independent Particulate Matter Review Panel.</span></em></p>After a 5-year review, the EPA is leaving US standards for fine particle air pollution unchanged, even though recent studies suggest that tightening them could save thousands of lives yearly.H. Christopher Frey, Glenn E. Futrell Distinguished University Professor of Environmental Engineering, North Carolina State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1318752020-02-21T12:33:16Z2020-02-21T12:33:16ZAir pollution kills thousands of Americans every year – here’s a low-cost strategy to reduce the toll<figure><img src="https://images.theconversation.com/files/316033/original/file-20200218-11000-371mgc.jpg?ixlib=rb-1.1.0&rect=49%2C0%2C5472%2C3637&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Reducing fine particle air pollution from petrochemical complexes, like this one near the Houston Ship Channel in Texas, is a low-cost way to lower air pollution mortality.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Harvey/928217f2b7374673bac894a63d7c7535/36/0">AP Photo/David J. Phillip</a></span></figcaption></figure><p>About <a href="https://doi.org/10.1016/S0140-6736(18)32225-6">1 of every 25 deaths</a> in the U.S. occurs prematurely because of exposure to air pollution. Dirty air kills roughly 110,000 Americans yearly, which is more than <a href="https://www.cdc.gov/nchs/data/nvsr/nvsr67/nvsr67_05.pdf">all transportation accidents and shootings combined</a>. </p>
<p>When the U.S. Environmental Protection Agency weighs decisions about air pollution regulations, it typically selects candidate actions from one or more sectors, such as electric power generation and industry. For each strategy considered, the agency carefully estimates the costs and benefits, then decides which actions to pursue. </p>
<p>We study <a href="https://sph.unc.edu/adv_profile/jason-west-phd/">air pollution</a> and <a href="https://scholar.google.com/citations?user=SDTX4PQAAAAJ&hl=en">options for reducing it</a>. In a <a href="https://doi.org/10.1038/s41467-020-14783-2">newly published study</a>, we flipped the traditional approach around by starting with the goal of finding emission control actions, among all sources, that could save a specified number of lives for the lowest cost. In doing so, we identified a set of low-cost actions to reduce air pollutant emissions from highly polluting industrial and residential sources, such as residential wood-burning furnaces, that can provide highly cost-effective health benefits.</p>
<p>The U.S. has made <a href="https://gispub.epa.gov/air/trendsreport/2019/#summary">tremendous progress</a> in reducing air pollution since 1990, and this has produced <a href="https://doi.org/10.5194/acp-18-15003-2018">significant public health improvements</a>. But air pollution still imposes a serious health burden on the U.S. population, and there are signs that past progress in improving air quality <a href="https://www.nytimes.com/interactive/2019/10/24/climate/air-pollution-increase.html?action=click&module=Top%20Stories&pgtype=Homepage">may now be</a> <a href="https://www.popsci.com/story/environment/air-pollution-gains-slow-report-2018/">leveling off</a>. New ways of analyzing actions to control air pollution and its health impacts can help. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/316034/original/file-20200218-11000-10ygfvw.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/316034/original/file-20200218-11000-10ygfvw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/316034/original/file-20200218-11000-10ygfvw.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/316034/original/file-20200218-11000-10ygfvw.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/316034/original/file-20200218-11000-10ygfvw.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/316034/original/file-20200218-11000-10ygfvw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/316034/original/file-20200218-11000-10ygfvw.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/316034/original/file-20200218-11000-10ygfvw.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The number of bad air days in 35 major U.S. cities has plateaued since 2013.</span>
<span class="attribution"><a class="source" href="https://gispub.epa.gov/air/trendsreport/2019/#unhealthy_aq_days">USEPA</a></span>
</figcaption>
</figure>
<h2>An alternative approach</h2>
<p>Under the 1970 Clean Air Act, it is the EPA’s job to set <a href="https://www.epa.gov/criteria-air-pollutants/naaqs-table">National Ambient Air Quality Standards</a>. These regulations limit concentrations of six major air pollutants that harm public health and the environment. Then each state adopts actions that will meet these standards, such as reducing emissions from power plants or large industries. </p>
<p>The EPA also sets limits on emissions from some specific sources over which it has legal authority, including new power plants and motor vehicles. In doing so, the agency aims for air that is considered healthy for all Americans to breathe. </p>
<p>For each strategy considered, the EPA often runs a full cost-benefit analysis. This approach requires a complex atmospheric model to estimate how each proposed action will affect air pollutant concentrations, and the health impacts that will result. This limits the number of options that can be considered. </p>
<p>Our study focused on fine particulate matter, known as PM2.5. We created a framework that simplified the complexity of the atmosphere and air pollution’s health impacts. For each U.S. state we calculated <a href="https://doi.org/10.1038/s41467-020-14783-2">impact factors</a>, which represent deaths related to PM2.5 exposure per ton of emissions of different chemical components from different sources. Then we fed these impact factors into an economic model of the U.S. energy system, allowing the model to calculate deaths for any strategy.</p>
<p>Next we set a limit on total deaths caused by PM2.5, and let the model select the least expensive set of actions that would meet energy needs – an important factor because energy use is a major air pollution source - while keeping PM2.5-related deaths below our ceiling. Our model projected future scenarios to 2050, so we considered different ceilings at various points in time, and observed the actions the model selected. </p>
<p>This alternative approach has the advantage of considering a wide range of possible control strategies that affect many different sources. It prioritizes the actions that most cost-effectively reduce premature deaths. Further, by considering these actions in the context of the broader energy system, we can include actions like fuel switching and energy efficiency as alternatives, and quantify consequences of actions throughout the U.S. energy system. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/GVBeY1jSG9Y?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">How PM2.5 affects your body once it’s inhaled.</span></figcaption>
</figure>
<h2>High particulate emitters</h2>
<p>Using this approach, we pinpointed a set of sources whose emissions contribute disproportionately to PM2.5 mortality impacts. They include factories and other industrial facilities powered by coal and oil, and wood-fired residential furnaces. Emissions from these sources are rising and <a href="https://doi.org/10.1088/1748-9326/ab59cb">may continue to increase</a> in the future without additional controls. </p>
<p>Our model showed that reducing emissions from these sources – mainly by electrifying them – could cut projected national air pollution-related deaths in 2050 in half very cost-effectively. Overall national health benefits from these reductions would be roughly seven times the cost of the pollution controls. As many studies have found, air pollution controls <a href="https://www.epa.gov/clean-air-act-overview/benefits-and-costs-clean-air-act-1990-2020-second-prospective-study">tend to be very cost-effective</a> because these emissions cause people to die prematurely through cardiovascular diseases, stroke, lung cancer and other long-term illnesses.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/316205/original/file-20200219-10995-zgb8sy.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/316205/original/file-20200219-10995-zgb8sy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/316205/original/file-20200219-10995-zgb8sy.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=368&fit=crop&dpr=1 600w, https://images.theconversation.com/files/316205/original/file-20200219-10995-zgb8sy.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=368&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/316205/original/file-20200219-10995-zgb8sy.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=368&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/316205/original/file-20200219-10995-zgb8sy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=463&fit=crop&dpr=1 754w, https://images.theconversation.com/files/316205/original/file-20200219-10995-zgb8sy.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=463&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/316205/original/file-20200219-10995-zgb8sy.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=463&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Reductions in the costs of PM2.5-related deaths due to emission reductions from each state, from a scenario that cuts projected national PM2.5-related deaths in 2050 in half.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1038/s41467-020-14783-2">Ou et al., 2020.</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Our study shows that this approach would reduce PM2.5-related emissions in each state. Progress would be greatest in northern and eastern states, including Ohio and Pennsylvania. These regions have many large industrial sources and are densely populated, which means that many people benefit from cleaner air. </p>
<p>Ohio has the largest potential for cost-effectively reducing PM2.5 deaths through cutting industrial coal emissions. California would benefit most from controls on residential wood burning, and Texas would see the greatest reductions in emissions from large petrochemical industries. </p>
<p>We also found that these actions had little influence on overall energy usage in the U.S., and therefore little effect on greenhouse gas emissions. This was interesting because previous research has found that most initiatives to reduce greenhouse gases – which typically involve switching to less-polluting fuels, such as going from coal to natural gas to renewables – <a href="https://doi.org/10.1038/nclimate2009">also reduce air pollutant emissions</a>, with significant <a href="https://iopscience.iop.org/article/10.1088/1748-9326/aa8f76">benefits for public health</a>. But the opposite is not true: Low-cost air pollution controls do not appear to have a big influence on U.S. greenhouse gas emissions.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/316515/original/file-20200220-92541-1q5ey6b.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/316515/original/file-20200220-92541-1q5ey6b.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/316515/original/file-20200220-92541-1q5ey6b.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=435&fit=crop&dpr=1 600w, https://images.theconversation.com/files/316515/original/file-20200220-92541-1q5ey6b.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=435&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/316515/original/file-20200220-92541-1q5ey6b.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=435&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/316515/original/file-20200220-92541-1q5ey6b.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=547&fit=crop&dpr=1 754w, https://images.theconversation.com/files/316515/original/file-20200220-92541-1q5ey6b.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=547&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/316515/original/file-20200220-92541-1q5ey6b.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=547&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The costs and health benefits of identified low-cost actions to reduce projected national 2050 PM2.5-related deaths by 10% to 50%.</span>
<span class="attribution"><span class="source">Yang Ou</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Looking forward to cleaner air</h2>
<p>Our approach finds the least-cost way of reducing the health impacts of fine particle pollution among all Americans. But it does not ensure that current standards will be met everywhere. One limitation of our method is that we analyzed emissions at the state level, but our current model does not permit us to look more closely at air quality and health impacts for individual urban areas within states that exceed fine particle standards. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/316036/original/file-20200218-11011-1i4lb41.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/316036/original/file-20200218-11011-1i4lb41.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/316036/original/file-20200218-11011-1i4lb41.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=715&fit=crop&dpr=1 600w, https://images.theconversation.com/files/316036/original/file-20200218-11011-1i4lb41.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=715&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/316036/original/file-20200218-11011-1i4lb41.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=715&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/316036/original/file-20200218-11011-1i4lb41.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=898&fit=crop&dpr=1 754w, https://images.theconversation.com/files/316036/original/file-20200218-11011-1i4lb41.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=898&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/316036/original/file-20200218-11011-1i4lb41.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=898&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Inefficient wood stoves and wood-burning furnaces are major fine particle sources.</span>
<span class="attribution"><a class="source" href="https://www.publichealthmdc.com/environmental-health/air-quality/outdoor-air-quality/wood-smoke-pollution">Madison & Dane County Public Health</a></span>
</figcaption>
</figure>
<p>Still, our methods offer another tool that the EPA and states can use to help in planning air quality improvements, and the actions identified as being cost-effective for improving health can be compared with those currently being pursued. Spotlighting alternative pollution reduction options can help federal and state regulators make decisions about energy resources and their environmental and health impacts for the coming decades. </p>
<p>As natural gas and renewable energy prices fall, energy industries are in the <a href="https://theconversation.com/fight-or-switch-how-the-low-carbon-transition-is-disrupting-fossil-fuel-politics-122376">midst of a transition</a> driven by new technologies and changing economics. As this shift takes place, it is important to consider how to meet new energy demands while reducing greenhouse emissions and the health impacts of air pollutants. We hope our methods will be useful in informing these decisions in the U.S. and elsewhere. </p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p><img src="https://counter.theconversation.com/content/131875/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jason West receives funding from the EPA, NASA, NSF, the Donald and Jennifer Holzworth Faculty Acceleration Fund in Climate Change, and the State of North Carolina. </span></em></p><p class="fine-print"><em><span>Yang Ou was supported by the Research Participation Program at the Center for Environmental Measurement and Modeling, U.S. Environmental Protection Agency, administered by the Oak Ridge Institute for Science and Education (ORISE).</span></em></p>A new study takes an innovative approach to reducing fine particle air pollution and spotlights key sources: factories that burn coal and oil, petrochemical plants and burning wood for home heating.Jason West, Professor of Environmental Sciences and Engineering, University of North Carolina at Chapel HillYang Ou, Postdoctoral Associate, Pacific Northwest National LaboratoryLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1282722020-01-10T13:38:25Z2020-01-10T13:38:25ZAir pollution: your exposure and health risk could depend on your class, ethnicity or gender<figure><img src="https://images.theconversation.com/files/309433/original/file-20200110-97145-1ie5tgt.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4254%2C2855&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Smoke covers a street market in Palermo, Italy. October 8 2019.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/palermo-italy-smog-over-street-market-1605742414">Radiokafka/Shutterstock</a></span></figcaption></figure><p>Poor air quality is responsible for over <a href="https://www.eea.europa.eu/publications/air-quality-in-europe-2018">half a million deaths in Europe</a> every year, but not everyone is equally at risk. Our <a href="https://www.mdpi.com/1660-4601/16/17/3127">new review found that across Europe</a>, the most deprived people have the worst air quality. This means that the people already experiencing multiple deprivations because of their social class, ethnicity or gender, also have the unhealthiest environments to live in.</p>
<p>In Wales, <a href="https://doi.org/10.1093/pubmed/fdw084">deprived areas have the highest levels</a> of major pollutants, such as nitrogen dioxide and particulate matter, from traffic exhausts, industrial pollution and wood-burning stoves. Particulate matter forms a fine mist of toxic debris that <a href="https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health">affects more people than any other type of pollution</a>. Inhaling it can contribute to heart attacks and respiratory diseases, including lung cancer. </p>
<p>For the very smallest particles, there’s no safe threshold below which “<a href="https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health">no damage to health is observed</a>”, according to the World Health Organization (WHO). Nitrogen dioxide meanwhile is linked to <a href="https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health">reduced lung function and growth in children and exacerbates asthma</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/309436/original/file-20200110-97130-eqf5cb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/309436/original/file-20200110-97130-eqf5cb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/309436/original/file-20200110-97130-eqf5cb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/309436/original/file-20200110-97130-eqf5cb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/309436/original/file-20200110-97130-eqf5cb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/309436/original/file-20200110-97130-eqf5cb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/309436/original/file-20200110-97130-eqf5cb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Particulates are microscopic solids that escape combustion, often through car exhausts.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/car-exhaust-pipe-coming-out-diesel-1058593964">Andrekoehn/Shutterstock</a></span>
</figcaption>
</figure>
<p>In <a href="https://doi.org/10.1016/j.envpol.2014.12.014">England and the Netherlands</a>, areas where more people live on income support or where there is a larger non-white population experience poorer air quality. In <a href="http://dx.doi.org/10.1136/jech-2016-208674">France, deprivation is clearly linked</a> to higher pollution in nearly all areas, with small exceptions in some rural areas. In Italy, places with <a href="https://www.researchgate.net/profile/Tiziana_Laureti/publication/285817154_Estimating_the_effects_of_road_transportation_on_environmental_quality/links/56e002d408aec4b3333cf76c.pdf">higher numbers of single mothers have more air pollution</a>.</p>
<p>Ethnicity is also a factor when it comes to pollution. Asian and Latin American immigrants <a href="https://doi.org/10.1016/j.geoforum.2015.12.008">in Madrid</a> are exposed to higher levels of pollution, but European immigrants aren’t. Whereas in Barcelona, all immigrants regardless of ethnicity have poorer air quality than native-born people. In <a href="https://doi.org/10.1289/ehp.1002564">southern Sweden</a>, higher levels of nitrogen oxides occur in areas with non-Nordic mothers. In <a href="https://www.vlieghinder.nl/images/knipsels/AircraftNoise_Epidemiology21(6)_november_2010(2).pdf">Switzerland</a>, foreign nationals and the unemployed are both likely to live nearer to main roads and so encounter higher levels of particulates in the air they breathe.</p>
<p>The EU has pressured national governments to deal with air pollution, but 19 countries still <a href="https://meta.eeb.org/2019/04/30/air-pollution-14-governments-fail-to-produce-crucial-plans/">exceed the agreed nitrogen dioxide limits</a> and 14 are breaching these limits for particulates smaller than 10 microns. But even air with pollutants at these supposedly safe limits may not be safe to breathe. The lower the level of air pollution, the lower the impact on health, and it’s likely that the WHO’s ongoing review will recommend even lower levels.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/recycling-poorer-countries-can-now-refuse-plastic-waste-imports-this-could-make-the-system-fairer-117707">Recycling: poorer countries can now refuse plastic waste imports – this could make the system fairer</a>
</strong>
</em>
</p>
<hr>
<h2>Poverty makes pollution worse</h2>
<p>Not only does your exposure to air pollution mirror existing inequalities, but so does your vulnerability to the health consequences. The same level of air pollutant will affect different people differently. For example, children, whose bodies are still forming, will be <a href="https://www.nejm.org/doi/full/10.1056/NEJMoa1414123">more affected than fully grown adults</a>.</p>
<p>Vulnerability also varies among adults. In deprived areas, more people are likely to have existing health conditions, making them more vulnerable to poor air quality. A UK study found that even a general improvement in air quality over time benefited the most deprived least, and <a href="https://iopscience.iop.org/article/10.1088/1748-9326/10/10/105009/pdf">the gap between rich and poor</a> – in terms of the levels of particulates in the air – actually increased. Often poorer populations have <a href="https://journals.sagepub.com/doi/abs/10.1068/a35240">lower levels of car ownership</a> but are exposed to more motorists driving through their neighbourhoods.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/309441/original/file-20200110-97134-853off.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/309441/original/file-20200110-97134-853off.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=472&fit=crop&dpr=1 600w, https://images.theconversation.com/files/309441/original/file-20200110-97134-853off.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=472&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/309441/original/file-20200110-97134-853off.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=472&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/309441/original/file-20200110-97134-853off.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=593&fit=crop&dpr=1 754w, https://images.theconversation.com/files/309441/original/file-20200110-97134-853off.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=593&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/309441/original/file-20200110-97134-853off.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=593&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Expanding electrified public transport can help reduce air pollution and overcome inequalities in access to affordable transport.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/gbwm6sEFb2Q">Yaoqi LAI/Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Traffic is a major source of air pollution. Cities need to provide cheap, reliable mass transport systems, such as trams, buses and underground rail, but they also need to create separate infrastructure for cyclists and walkers to make it much easier for drivers to switch. More electric vehicle charging zones, pedestrianisation of city roads and more barriers to private cars entering the city will also help.</p>
<p>Efforts to improve air quality should target areas with vulnerable people first and should prioritise public health. Rather than seeking to beautify already affluent areas, action on pollution should address existing inequality by providing good quality public transport and investing in healthcare for deprived communities. Pollution is political – and so are its remedies.</p><img src="https://counter.theconversation.com/content/128272/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jon Fairburn receives funding from the UK government to produce the air quality index in the Index of Multiple Deprivation for England. He also works with the World Health Organisation (WHO) on the issue of air pollution. </span></em></p>Pollutants like nitrogen dioxide are a silent killer, but everyone isn’t equally at risk.Jon Fairburn, Professor of Sustainable Development, Staffordshire UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1257792019-10-29T12:58:23Z2019-10-29T12:58:23ZThe EPA disbanded our clean air science panel. We met anyway – and found that particle pollution regulations aren’t protecting public health<figure><img src="https://images.theconversation.com/files/298812/original/file-20191027-113944-khmjw7.jpg?ixlib=rb-1.1.0&rect=53%2C0%2C5902%2C3931&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Vehicles are a major source of particulate air pollution.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/air-pollution-vehicle-exhaust-pipe-on-1256313274?src=90GKTmBcJq9G3a68WJ1LDg-1-39">Deliris/Shutterstock</a></span></figcaption></figure><p>Since 1980, emissions of six common air pollutants have <a href="https://www.epa.gov/air-trends/air-quality-national-summary">decreased by 67%</a>, thanks largely to government regulation. At the same time, U.S. gross domestic product has increased by 165%. While some assert that regulation acts as <a href="https://theconversation.com/do-environmental-regulations-do-more-harm-or-good-presidential-candidates-disagree-55989">a drag on the economy</a>, this record indicates that environmental protection does not have to undercut economic growth. </p>
<p>I have <a href="https://scholar.google.com/citations?user=o8_V-4kAAAAJ&hl=en">studied air pollution and air quality</a> for over 30 years, and have been directly involved for a decade with the U.S. Environmental Protection Agency’s reviews of scientific findings on air pollution. This includes seven years of service on the agency’s <a href="https://yosemite.epa.gov/sab/sabpeople.nsf/webcommittees/CASAC">Clean Air Scientific Advisory Committee</a> and stints on 10 specialized panels focused on individual pollutants. </p>
<p>The Clean Air Scientific Advisory Committee is currently reviewing the <a href="https://www.epa.gov/pm-pollution/table-historical-particulate-matter-pm-national-ambient-air-quality-standards-naaqs">national standard for regulating particulate matter</a> – tiny solid particles and droplets that measure <a href="https://www.epa.gov/pm-pollution/particulate-matter-pm-basics#PM">a fraction of the width of a human hair</a> and penetrate deeply into the lungs when inhaled. Health effects of exposure to fine particulate air pollution include <a href="https://www3.epa.gov/ttn/naaqs/standards/pm/s_pm_2007_risk.html">respiratory, cardiovascular and other diseases and premature death</a>. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/298811/original/file-20191027-113948-5xzcxd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/298811/original/file-20191027-113948-5xzcxd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/298811/original/file-20191027-113948-5xzcxd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=419&fit=crop&dpr=1 600w, https://images.theconversation.com/files/298811/original/file-20191027-113948-5xzcxd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=419&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/298811/original/file-20191027-113948-5xzcxd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=419&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/298811/original/file-20191027-113948-5xzcxd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=526&fit=crop&dpr=1 754w, https://images.theconversation.com/files/298811/original/file-20191027-113948-5xzcxd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=526&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/298811/original/file-20191027-113948-5xzcxd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=526&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Size comparisons for particulate air pollution.</span>
<span class="attribution"><a class="source" href="https://www.epa.gov/sites/production/files/2016-09/pm2.5_scale_graphic-color_2.jpg">EPA</a></span>
</figcaption>
</figure>
<p>But on Oct. 10, 2018, I and other scientists on a panel that advised the Clean Air Scientific Advisory Committee on this issue learned that the <a href="https://www.epa.gov/newsreleases/acting-administrator-wheeler-announces-science-advisors-key-clean-air-act-committee">EPA abruptly disbanded our panel</a>. Now the particulate matter review is moving forward <a href="https://www.ucsusa.org/about/news/dismissed-science-advisors-will-convene-evaluate-air-pollution">without the scientific expertise and experience</a> that it needs. </p>
<p>To help fill this gap, we <a href="https://www.ucsusa.org/meeting-independent-particulate-matter-review-panel">reconvened ourselves independently</a>, and have met over the past year to <a href="https://yosemite.epa.gov/sab/sabproduct.nsf/086D8B853E0B63AE8525835F004DC679/$File/PMRP+Letter+to+CASAC+181210+Final+181210.pdf">produce scientific advice for EPA</a> aimed at protecting public health. The <a href="https://ucsusa.org/about">Union of Concerned Scientists</a>, a nonprofit group that advocates for the use of rigorous, independent science to solve global problems, <a href="https://blog.ucsusa.org/gretchen-goldman/the-epa-cut-science-out-of-air-pollution-standard-setting-were-putting-it-back">hosted our most recent meeting</a> on Oct. 10 and Oct. 11, 2019. We reported our conclusions directly to the EPA, and panel members donated their time and expertise.</p>
<p>In contrast, the Clean Air Scientific Advisory Committee has been restructured over the past several years with <a href="https://www.epa.gov/newsreleases/acting-administrator-wheeler-announces-science-advisors-key-clean-air-act-committee">new appointees</a> who appear to be developing advice aimed at <a href="https://thinkprogress.org/wheeler-science-pruitt-epa-panel-be0a783aa55b/">pleasing the EPA administrator</a>.</p>
<h2>A serious threat to public health</h2>
<p>Fine particle air pollution comes from many sources, including burning <a href="https://theconversation.com/fine-particle-air-pollution-is-a-public-health-emergency-hiding-in-plain-sight-106030">fossil fuels</a>. Today more than 20 million Americans live in areas with <a href="https://www3.epa.gov/airquality/greenbook/kbtc.html">high levels of fine particles</a>. </p>
<p>Average annual fine particulate levels in the U.S. fell by nearly 25% between 2009 and 2016, but this trend <a href="https://www.npr.org/2019/10/26/773675407/spike-in-air-pollution-in-u-s">may be reversing</a>. Increasingly <a href="https://doi.org/10.1073/pnas.1617394114">frequent and severe wildfires</a>, such as those currently <a href="https://www.cnn.com/2019/10/28/us/california-fires-power-outages-monday/index.html">raging in California</a>, are one likely source. </p>
<p>A recent study found that fine particle levels <a href="https://www.nber.org/papers/w26381">rose 5.5% between 2016 and 2018</a> and estimated that this increase was associated with some 9,700 premature deaths in 2018 that would not have occurred otherwise. Our panel noted the recent uptick in fine particle levels in our <a href="https://yosemite.epa.gov/sab/sabproduct.nsf//81DF85B5460CC14F8525849B0043144B/$File/Independent+Particulate+Matter+Review+Panel+Letter+on+Draft+PA.pdf">latest report, released last week</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/298476/original/file-20191024-31471-1bxwjml.png?ixlib=rb-1.1.0&rect=103%2C0%2C2679%2C1008&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/298476/original/file-20191024-31471-1bxwjml.png?ixlib=rb-1.1.0&rect=103%2C0%2C2679%2C1008&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/298476/original/file-20191024-31471-1bxwjml.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=211&fit=crop&dpr=1 600w, https://images.theconversation.com/files/298476/original/file-20191024-31471-1bxwjml.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=211&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/298476/original/file-20191024-31471-1bxwjml.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=211&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/298476/original/file-20191024-31471-1bxwjml.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=265&fit=crop&dpr=1 754w, https://images.theconversation.com/files/298476/original/file-20191024-31471-1bxwjml.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=265&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/298476/original/file-20191024-31471-1bxwjml.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=265&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">National fine particulate matter concentrations for 2015 to 2017 (annual average, left, and daily average, right). Readings coded yellow approach current standards; those coded red exceed them.</span>
<span class="attribution"><a class="source" href="https://www.epa.gov/sites/production/files/2019-09/documents/draft_policy_assessment_for_pm_naaqs_09-05-2019.pdf">EPA</a></span>
</figcaption>
</figure>
<h2>Science-based standards</h2>
<p>The <a href="https://www.law.cornell.edu/uscode/text/42/7409">Clean Air Act</a> requires the EPA to conduct <a href="https://www.epa.gov/criteria-air-pollutants/process-reviewing-national-ambient-air-quality-standards">regular reviews of national air quality standards</a>. The Clean Air Scientific Advisory Committee’s job is to review the <a href="https://www.law.cornell.edu/uscode/text/42/7408">“latest scientific knowledge</a>” underpinning regulations for major air pollutants. If the science indicates that existing standards are not adequately protecting public health, the agency must revise them. </p>
<p>The committee has <a href="https://yosemite.epa.gov/sab/sabproduct.nsf/WebCASAC/currentcharter?OpenDocument">seven members</a>, appointed by the EPA administrator. But air pollution standards draw on many scientific disciplines, including <a href="https://yosemite.epa.gov/sab/sabproduct.nsf/0/EB862B233FBD0CDE85257DDA004FCB8C/$File/Determination%20memo-CASAC%20PM.pdf">air quality, epidemiology, toxicology, medicine, biostatistics, ecology, climate and risk assessment</a>. For decades, EPA has organized <a href="https://yosemite.epa.gov/sab/sabproduct.nsf/WebProjectsbyTopicCASAC?OpenView">panels of additional experts</a> to help the Clean Air Scientific Advisory Committee review the latest research – until now. </p>
<p>Our nongovernmental panel has multiple experts in epidemiology, toxicology, medicine, exposure assessment, risk assessment, statistics, air quality measurement and modeling. <a href="https://news.bloombergenvironment.com/environment-and-energy/undeterred-dismissed-scientists-plod-through-air-quality-reviews">The Clean Air Scientific Advisory Committee doesn’t have an epidemiologist</a>, although epidemiology is a central discipline in analyzing health effects from exposure to fine particle pollution. </p>
<p>In fact, <a href="https://www.nbcnews.com/news/us-news/fired-epa-scientists-release-air-pollution-report-they-say-agency-n1064456">the committee admitted this</a>, and asked the EPA in April 2019 to <a href="https://yosemite.epa.gov/sab/sabproduct.nsf/LookupWebReportsLastMonthCASAC/6CBCBBC3025E13B4852583D90047B352/%24File/EPA-CASAC-19-002+.pdf">reinstate our panel</a>. EPA Administrator Andrew Wheeler <a href="https://yosemite.epa.gov/sab/sabproduct.nsf/0/6CBCBBC3025E13B4852583D90047B352/$File/EPA-CASAC-19-002_Response.pdf">refused</a>. Instead he appointed a smaller group that is <a href="https://www.theguardian.com/environment/2019/sep/25/clean-air-scientists-fired-by-epa-to-reconvene-in-snub-to-trump">not allowed to deliberate with the Clean Air Scientific Advisory Committee</a>. </p>
<h2>Breaking the review process</h2>
<p>EPA officials began undermining the scientific review process in 2017, when then-Administrator Scott Pruitt <a href="https://www.epa.gov/sites/production/files/2017-10/documents/final_draft_fac_memo-10.30.2017.pdf">wrote a memorandum</a> that <a href="https://www.sciencemag.org/news/2017/10/trump-s-epa-has-blocked-agency-grantees-serving-science-advisory-panels-here-what-it">bars scholars who hold EPA research grants</a> from serving on the Clean Air Scientific Advisory Committee. But often these are precisely the highly respected scientific leaders that the committee needs. </p>
<p>The federal government has long recognized that holding a research grant does not infringe on a scientist’s “<a href="https://www.cio.noaa.gov/services_programs/pdfs/OMB_Peer_Review_Bulletin_m05-03.pdf">ability to offer independent scientific advice</a>.” In contrast, Pruitt allowed <a href="https://www.latimes.com/local/california/la-me-epa-pollution-study-20190321-story.html">people who received funding from regulated industries to serve on the Clean Air Scientific Advisory Committee</a>.</p>
<p>On Oct. 10, 2018, Pruitt’s successor, Andrew Wheeler, <a href="https://www.epa.gov/newsreleases/acting-administrator-wheeler-announces-science-advisors-key-clean-air-act-committee">replaced five Clean Air Scientific Advisory Committee members</a>. The committee now includes one researcher, staff from one federal and <a href="https://www.washingtonpost.com/energy-environment/2018/10/14/epa-scraps-pair-air-pollution-science-panels/?noredirect=on&utm_term=.5c3510ace26e">four state agencies</a> and an <a href="https://www.revealnews.org/article/trumps-air-pollution-adviser-clean-air-saves-no-lives/">industry consultant</a>. Wheeler has also shortened the science review schedule and <a href="https://yosemite.epa.gov/sab/sabproduct.nsf/0/6CBCBBC3025E13B4852583D90047B352/$File/EPA-CASAC-19-002_Response.pdf">dropped key assessment documents from the review</a>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/zu5F_gNEgvQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Air quality in San Francisco deteriorates over 3 weeks in November 2018 as smoke from Northern California wildfires reaches the city.</span></figcaption>
</figure>
<h2>Ignoring the science</h2>
<p>Past Clean Air Scientific Advisory Committee reviews of national air quality standards took <a href="http://pubs.awma.org/flip/EM-Dec-2018/frey.pdf">three years on average</a>. They focused on <a href="http://pubs.awma.org/flip/EM-May-2015/frey.pdf">three major EPA staff reports</a> that 1) <a href="https://www.epa.gov/isa">summarized scientific findings on health effects</a>, 2) established the <a href="https://www3.epa.gov/ttn/naaqs/standards/pm/s_pm_2007_risk.html">scientific basis for quantifying health risk</a> and 3) identified potential options for <a href="https://www.epa.gov/naaqs/particulate-matter-pm-standards-policy-assessments-current-review-0">retaining, revising or rescinding current standards or setting a new ones</a>. These steps were <a href="https://www3.epa.gov/ttn/naaqs/pdfs/memo_process_for_reviewing_naaqs.pdf">carefully designed</a> to clearly establish the science before making judgments about policy.</p>
<p>Now, however, the Clean Air Scientific Advisory Committee’s Integrated Science Assessment on particulate air pollution – the first step in the three-stage sequence – is still in draft form, and EPA is introducing policy issues before the science is settled. We expect that the agency will be sued for this and other procedural irregularities.</p>
<p>Our panel <a href="https://ucs-documents.s3.amazonaws.com/science-and-democracy/pm-panel-meeting-docs/ipmrp-agenda.pdf">met publicly</a> to carry out a <a href="https://www.youtube.com/watch?v=wpodC23hJnQ">scientific review of EPA’s policy assessment</a>. We concluded that existing annual and 24-hour standards for fine particle air pollution <a href="https://yosemite.epa.gov/sab/sabproduct.nsf//81DF85B5460CC14F8525849B0043144B/$File/Independent+Particulate+Matter+Review+Panel+Letter+on+Draft+PA.pdf">are not protective of public health</a>. </p>
<p>Currently, federal regulations set an annual standard of 12 micrograms per cubic meter of air, or ug/m3. We recommend lowering this standard to a range of <a href="https://www.theguardian.com/us-news/2019/oct/22/scientists-warn-fine-particle-pollution-standards-dont-protect-people">8-10 ug/m3</a>. Similarly, we recommend revising the existing 24-hour standard – which applies to short-term pollution spikes – from 35 ug/m3 to 25-30 ug/m3. </p>
<p>These scientific findings are based on consistent epidemiological evidence from multiple studies, at ambient concentrations below the levels of the current standards. The epidemiologic results are supported by results from toxicological and controlled human studies.</p>
<p>In contrast, when the Clean Air Scientific Advisory Committee met on Oct. 24 and Oct. 25, two of its six members supported tightening the relevant standards, but the other four concluded that <a href="https://news.bloombergenvironment.com/environment-and-energy/epa-advisers-unable-to-agree-on-air-pollution-standard">existing standards are good enough</a>. This view ignores compelling new evidence, including the <a href="http://dx.doi.org/10.1056/NEJMoa1702747">largest-ever U.S. epidemiologic study</a> for fine particles, published in 2017. This study and others clearly show adverse health effects – including premature death – at exposure levels below current U.S. standards.</p>
<p>We believe the EPA should <a href="https://grist.org/article/these-fired-air-pollution-experts-just-did-the-job-the-epa-didnt-want-them-to-do/">follow the law</a>, which requires a thorough review of the science underpinning air pollution standards. A first step would be reappointing our panel to provide the Clean Air Scientific Advisory Committee with the expertise on particulate matter that it needs.</p>
<p><em>This is an updated version of an <a href="https://theconversation.com/a-rush-to-judgment-the-trump-administration-is-taking-science-out-of-air-quality-standards-106507">article</a> originally published on Nov. 26, 2018.</em></p>
<p>[ <em>Like what you’ve read? Want more?</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=likethis">Sign up for The Conversation’s daily newsletter</a>. ]</p><img src="https://counter.theconversation.com/content/125779/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>In the last two years, Dr. Frey has been the principal investigator of research grants and contracts at North Carolina State University sponsored by the North Carolina Department of Transportation, the U.S. Environmental Protection Agency via the Health Effects Institute and Eastern Research Group, and the Urban Air Initiative. Dr. Frey’s research work at the Hong Kong University of Science and Technology, where he is an adjunct professor, is funded by the HSBC 150th Anniversary Charity Programme. Dr. Frey has also conducted work for the Hong Kong Environmental Protection Department. Dr. Frey’s current affiliations include serving as a member of the Transportation and Air Quality (ADC20) Committee of the Transportation Research Board, and as a member of the Publications Committee and the Critical Review Committee of the Air & Waste Management Association (A&WMA) . He is also on the editorial board of the journal Atmospheric Environment and serving as a guest editor for the journals Atmospheric Environment and Science of the Total Environment. He is chair of the nongovernmental Independent Particulate Matter Review Panel.</span></em></p>Scientists who were appointed to advise the EPA on air pollution kept meeting independently after the agency dissolved their panel. They say current regulations aren’t strict enough.H. Christopher Frey, Glenn E. Futrell Distinguished University Professor of Environmental Engineering, North Carolina State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1167042019-05-09T15:01:57Z2019-05-09T15:01:57ZWant to help cut air pollution? You might need to keep your engine on<figure><img src="https://images.theconversation.com/files/273588/original/file-20190509-183086-dih46e.jpg?ixlib=rb-1.1.0&rect=58%2C0%2C6480%2C4316&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/car-exhaust-pipe-which-comes-out-358772042?src=_MFUDG4HJsB_N1sMUieB9g-1-1">Jarhe Photography/Shutterstock</a></span></figcaption></figure><p>Air pollution may have <a href="https://www.theguardian.com/environment/2017/nov/09/pollution-problem-is-just-being-pushed-around">fallen</a> since the 1970s, but it remains a major health risk in the UK. More than <a href="https://www.thetimes.co.uk/article/air-pollution-on-streets-is-poisoning-2-6m-schoolchildren-xgcrzmlzk">2.6m</a> schoolchildren nationwide are exposed to dangerous levels. Exposure to toxic gases and particulate matter <a href="https://wintoncentre.maths.cam.ac.uk/news/does-air-pollution-kill-40000-people-each-year-uk">shortens the lives</a> of more than 30,000 citizens a year, and costs the NHS <a href="https://www.gov.uk/government/news/new-tool-calculates-nhs-and-social-care-costs-of-air-pollution">millions</a>.</p>
<p>Increases in public awareness of these health effects, triggered in part by the death of schoolgirl <a href="https://www.bbc.co.uk/news/uk-england-london-48132490">Ella Kissi-Debrah</a> and Volkswagen’s “<a href="https://theconversation.com/dieselgate-is-the-wake-up-call-to-look-seriously-at-alternative-car-technologies-48194">dieselgate</a>” scandal, have spurred the UK government to make the quality of the country’s air a <a href="https://www.huffingtonpost.co.uk/entry/michael-gove-says-cleaning-up-uks-toxic-air-is-one-of-his-top-priorities_uk_594953d7e4b05eccf2b47261?guccounter=1">priority concern</a>.</p>
<p>As part of this, the government’s recently published comprehensive long-term <a href="https://www.gov.uk/government/news/government-launches-world-leading-plan-to-tackle-air-pollution">strategy</a> for clean air aims to eliminate wood- and coal-burning stoves <a href="https://www.politicshome.com/news/uk/environment/environmental-protection/news/101062/michael-gove-vows-ban-wood-burning-stoves">from 2022</a> and sets ambitious targets to reduce harmful emissions – although concrete short-term action has yet to be taken.</p>
<p>Now, government agency Public Health England has <a href="https://www.gov.uk/government/publications/improving-outdoor-air-quality-and-health-review-of-interventions">recommended</a> some promising solutions to tackle air pollution here and now. But one key aspect of its proposals – a sustained anti-idling campaign – is not fully thought through.</p>
<p>On the surface, turning off your engine whenever waiting in a car – be it when picking the kids up from school, or stuck in a traffic jam – seems like a sensible idea. When an engine is switched off, it doesn’t emit anything. However, the full story is more complex.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fact-check-are-diesel-cars-really-more-polluting-than-petrol-cars-76241">Fact Check: are diesel cars really more polluting than petrol cars?</a>
</strong>
</em>
</p>
<hr>
<h2>Catalysts need heat</h2>
<p>Petrol vehicles made after 1993 have catalysts (often known as catalytic converters) fitted to their exhausts. These are devices that convert harmful exhaust emissions, such as unburned fuel, oxides of nitrogen, and carbon monoxide, into harmless gases. Since 2017, most diesel cars have been fitted with the <a href="https://www.dieselforum.org/about-clean-diesel/what-is-scr">latest iteration of these catalysts</a>, to neutralise the particularly high level of air pollutants that <a href="https://theconversation.com/fact-check-are-diesel-cars-really-more-polluting-than-petrol-cars-76241">older cars emitted</a>.</p>
<p>But such catalysts require engine heat to function – every minute an engine is switched off takes them further away from their ideal operating temperature, and they do not work at all when cold. Thus, while anti-idling campaigns may help cut levels of climate pollutants not captured by catalysts, such as carbon dioxide, they pose a real risk of unintended immediate harm to human health.</p>
<p>Using a petrol-powered 2011 Ford Fusion as an example, the US Department of Energy <a href="https://afdc.energy.gov/files/u/publication/which_is_greener.pdf">showed</a> that restarting a warm engine emits 4.5 times more hydrocarbon gases, 19 times more nitrogen oxides, and 390 times more carbon monoxide than 30 seconds of idling. Restarting a cold engine is even worse, emitting nearly 1,000 times more carbon monoxide and 760 times more nitrogen oxides than idling for half a minute.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/273601/original/file-20190509-183096-137bpvq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/273601/original/file-20190509-183096-137bpvq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=299&fit=crop&dpr=1 600w, https://images.theconversation.com/files/273601/original/file-20190509-183096-137bpvq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=299&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/273601/original/file-20190509-183096-137bpvq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=299&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/273601/original/file-20190509-183096-137bpvq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=376&fit=crop&dpr=1 754w, https://images.theconversation.com/files/273601/original/file-20190509-183096-137bpvq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=376&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/273601/original/file-20190509-183096-137bpvq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=376&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Switching off your engine may reduce CO2 emissions, but produces much higher levels of air pollutants.</span>
<span class="attribution"><span class="source">Felix Leach/US Department of Energy</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>According to these figures, you could leave the engine running for ten minutes before emitting as much nitrogen oxide as if you had switched off and restarted the engine. For carbon monoxide, the figure is nearly eight hours. And that’s before even considering particulates, particularly harmful carcinogens that can cause <a href="https://www.annualreviews.org/doi/10.1146/annurev.pu.15.050194.000543">acute respiratory effects</a>, and which are <a href="https://www.mdpi.com/1996-1073/11/6/1417">emitted</a> in high quantities during engine starts. Thanks to a lag in regulations, most modern petrol cars on UK roads today are not fitted with particulate filters, making restarts of these vehicles particularly problematic. </p>
<h2>Air vs atmosphere</h2>
<p>It’s true that leaving your car running will increase planet-warming CO₂ emissions – but not by as much as you might think. For the example above, roughly six minutes of idling produces the same amount of CO₂ as driving <a href="https://www.car-emissions.com/cars/view/45550">one kilometre</a>. This seems a small price to pay to preserve the health of the children you’re picking up from school, or pedestrians walking the streets.</p>
<p>Of course, it’s important to note that these data are based on just one car. Surprisingly, there is only one existing study on this issue. But as an expert in vehicle emissions, there is no reason to assume that other petrol cars would behave any differently.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/273581/original/file-20190509-183109-ihe6i3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/273581/original/file-20190509-183109-ihe6i3.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=355&fit=crop&dpr=1 600w, https://images.theconversation.com/files/273581/original/file-20190509-183109-ihe6i3.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=355&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/273581/original/file-20190509-183109-ihe6i3.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=355&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/273581/original/file-20190509-183109-ihe6i3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=447&fit=crop&dpr=1 754w, https://images.theconversation.com/files/273581/original/file-20190509-183109-ihe6i3.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=447&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/273581/original/file-20190509-183109-ihe6i3.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=447&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Diesel versions of the UK’s top-selling cars emit less CO2 than their petrol equivalents.</span>
<span class="attribution"><span class="source">Felix Leach</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The UK government’s post-“<a href="https://www.theguardian.com/business/2018/apr/21/dieselgate-uk-car-industry-sales-slump">dieselgate</a>” switch to demonising the diesel engine – now <a href="https://theconversation.com/fact-check-are-diesel-cars-really-more-polluting-than-petrol-cars-76241">no more polluting</a> than petrol equivalents – left owners confused and <a href="https://www.bbc.co.uk/news/uk-39492829">out of pocket</a>, and resulted in vehicle CO₂ emissions <a href="https://www.acea.be/press-releases/article/co2-emissions-from-new-cars-up-as-petrol-overtakes-diesel-2017-data-shows">increasing</a> in 2017 for the first time in two decades.</p>
<p>London’s Ultra Low Emissions Zone further penalises drivers who bought older diesel cars thinking they were greener, while <a href="https://www.theguardian.com/environment/2017/nov/09/pollution-problem-is-just-being-pushed-around">allowing</a> unlimited deadly particulate emissions from petrol cars and motorbikes. Now, on current evidence, Public Health England’s advice to curb car idling may actually dirty the country’s air, not clean it.</p>
<p>If the government is to avoid further loss of trust and harm to health, clear, confident and, most importantly, accurate messaging is now essential for keeping the public on board with tackling air pollution. Substantial research testing more vehicles is urgently needed to enable effective policy-making on car-idling. Until then, if you want to cut air pollution, you might be better off ignoring the government and leaving your engine running.</p>
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<img alt="" src="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=140&fit=crop&dpr=1 600w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=140&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=140&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=176&fit=crop&dpr=1 754w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=176&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=176&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><a href="https://theconversation.com/imagine-newsletter-researchers-think-of-a-world-with-climate-action-113443?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=Imagineheader1116704">Click here to subscribe to our climate action newsletter. Climate change is inevitable. Our response to it isn’t.</a></em></p><img src="https://counter.theconversation.com/content/116704/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Felix Leach receives or has received funding from EPSRC, APC UK, Jaguar Land Rover, BP, and the University of Oxford. He is affiliated with the Institution of Mechanical Engineers and the Society of Automotive Engineers. He has previously collaborated with Cambustion UK.</span></em></p>Leaving your car running will marginally increase CO2 emissions, but it may massively reduce exposure to the toxic gases and particulates that are shortening thousands of lives.Felix Leach, Associate Professor of Engineering Science, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1159752019-05-02T10:43:56Z2019-05-02T10:43:56ZAs air pollution increases in some US cities, the Trump administration is weakening clean air regulations<figure><img src="https://images.theconversation.com/files/271823/original/file-20190430-136810-1y9ttcc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Oil refineries and other industrial sources in and around Houston create some of the highest ozone levels in the nation. </span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Oil-Refineries-Air-Pollution/caf2c6a56e6f49ce869981476ca4783e/5/0">AP Photo/Pat Sullivan</a></span></figcaption></figure><p>Air pollution kills. In the United States, <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(18)32225-6/fulltext">1 of every 25 deaths</a> occurs prematurely because of exposure to outdoor air pollution. </p>
<p>It <a href="https://www.cdc.gov/nchs/data/nvsr/nvsr67/nvsr67_05.pdf">kills more Americans than all transportation accidents and gun shootings</a> combined. More than diabetes or than breast cancer plus prostate cancer. More than Parkinson’s disease plus leukemia plus HIV/AIDS. And unlike diabetes or Parkinson’s, deaths from air pollution are entirely preventable.</p>
<p>We study air pollution and its interactions with <a href="https://haqast.org/staff/west-jason/">climate change</a> and <a href="https://www.semanticscholar.org/author/Barbara-J.-Turpin/4521292">human health</a>. In our view, this problem does not receive the attention it deserves as a public health threat. No death certificate lists air pollution as the cause of death – rather, it is considered a risk factor, like smoking or obesity. But it influences several of the most important causes of death: heart attacks, strokes, chronic obstructive pulmonary disease and lung cancer. </p>
<p>According to the American Lung Association’s latest <a href="https://www.lung.org/our-initiatives/healthy-air/sota">“State of the Air” report</a>, about 43% of Americans – 140 million people – live in counties with unhealthy air. The report also shows that although air quality has improved since 1990, this trend may be starting to erode. In 2015-2017, more U.S. cities had days with high ozone or fine particle pollution than in 2014-2016. Whether conditions worsen or improve in the next few years depends strongly on decisions by President Trump and Environmental Protection Agency Administrator Andrew Wheeler.</p>
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<h2>Progress through science-based regulation</h2>
<p>The long-term news is good: Since 1990, U.S. air quality has improved. Controlling for population growth, air pollution-related deaths <a href="https://doi.org/10.5194/acp-18-15003-2018">decreased by about 30% from 1990 to 2010</a>. Average life expectancy has likely <a href="http://dx.doi.org/10.1056/NEJMsa0805646">increased by several months</a>, just from <a href="https://doi.org/10.1289/EHP507">cleaner air</a>.</p>
<p>These improvements result directly from emission controls on power plants, factories, motor vehicles and other sources, driven mainly by EPA regulations implementing the <a href="https://www.epa.gov/laws-regulations/summary-clean-air-act">1970 Clean Air Act and its 1990 Amendments</a>. These programs were supported by the development of new control technologies and different energy sources – for example, replacing dirtier coal-fired electricity with power produced from natural gas and wind. </p>
<p>A central requirement in the Clean Air Act directs the EPA to set <a href="https://www.epa.gov/criteria-air-pollutants/naaqs-table">National Ambient Air Quality Standards</a> based on the best available science. EPA’s programs have been incredibly successful in improving air quality and reducing related deaths.</p>
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<a href="https://images.theconversation.com/files/271824/original/file-20190430-136794-zaos08.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/271824/original/file-20190430-136794-zaos08.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/271824/original/file-20190430-136794-zaos08.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=412&fit=crop&dpr=1 600w, https://images.theconversation.com/files/271824/original/file-20190430-136794-zaos08.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=412&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/271824/original/file-20190430-136794-zaos08.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=412&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/271824/original/file-20190430-136794-zaos08.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=517&fit=crop&dpr=1 754w, https://images.theconversation.com/files/271824/original/file-20190430-136794-zaos08.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=517&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/271824/original/file-20190430-136794-zaos08.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=517&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Between 1970 and 2017, combined emissions of six common pollutants (PM2.5 and PM10, SO2, NOx, VOCs, CO and Pb) dropped by 73%, while the U.S. economy continued to grow, Americans drove more miles and population and energy use increased.</span>
<span class="attribution"><a class="source" href="https://gispub.epa.gov/air/trendsreport/2018/#growth_w_cleaner_air">EPA</a></span>
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<h2>Weakening air pollution controls</h2>
<p>Despite this strong record, Trump and Wheeler are now taking what we and <a href="https://www.nytimes.com/2019/04/14/opinion/air-pollution-trump.html">many other critics</a> view as unprecedented steps to challenge or weaken Clean Air Act regulations. President Trump <a href="http://www.whitehouse.gov/briefings-statements/remarks-president-trump-joint-address-congress/">claims to favor clean air</a>, but Wheeler and his predecessor, Scott Pruitt, have <a href="http://www.nytimes.com/2017/12/10/us/politics/pollution-epa-regulations.html">weakened enforcement of air quality regulations</a> and <a href="https://www.epa.gov/sites/production/files/2018-09/documents/oil_and_gas_technical_proposal_fact_sheet.9.11.18_0.pdf">removed emission controls on oil and gas drilling sites</a>. </p>
<p>Trump’s decisions to <a href="https://theconversation.com/why-trumps-decision-to-leave-paris-accord-hurts-the-us-and-the-world-78707">pull out of the Paris Climate Agreement</a>, <a href="https://www.npr.org/2018/08/21/639396683/trump-moves-to-let-states-regulate-coal-plant-emissions">weaken proposed regulations on CO2 from power plants</a> and <a href="https://www.reuters.com/article/us-autos-emissions-epa/u-s-epa-to-revise-proposed-freeze-of-vehicle-fuel-economy-rules-idUSKCN1RN321">roll back fuel efficiency standards</a> for new motor vehicles are also harmful. These actions don’t just hamper efforts to address climate change – they also slow transitions from coal to less-polluting electricity sources, and to cleaner, more efficient vehicles. This protracts air quality problems and harms health, particularly for children and the elderly. </p>
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<figcaption><span class="caption">Smoke from intense wildfires created unhealthy air pollution across much of California in November 2018.</span></figcaption>
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<h2>Politicizing science</h2>
<p>The Environmental Protection Agency is also weakening the scientific foundation for air quality standards. Under the Clean Air Act, the agency is required to comprehensively review the science characterizing air pollutants and their effects on health and welfare every five years, including epidemiologic studies that quantify the impact of pollutants on public health. </p>
<p>EPA’s <a href="https://yosemite.epa.gov/sab/sabpeople.nsf/webcommittees/casac">Clean Air Scientific Advisory Committee</a> and its subsidiary panels oversee this review and recommend new standards, which are ultimately set by the administrator. However, this winter the agency <a href="https://www.nytimes.com/2019/04/14/opinion/air-pollution-trump.html">dismissed a 20-member panel</a> of scientists specializing in fine particle air pollution, including one of us (Barbara Turpin), and <a href="https://theconversation.com/a-rush-to-judgment-the-trump-administration-is-taking-science-out-of-air-quality-standards-106507">changed the advisory committee’s membership</a> so that it now includes only one academic scientist and no epidemiologist. </p>
<p>As such, the new committee <a href="https://www.eenews.net/stories/1060102455">lacks expertise to review the science</a>. And it is being held to expedited timetables that appear to be motivated to allow new standards to be set <a href="https://www.epa.gov/sites/production/files/2018-05/documents/image2018-05-09-173219.pdf">during the lame-duck period after the 2020 election</a>. </p>
<p>Further, the new committee is advocating a new way of determining which epidemiology studies can be included in the review. Many of these studies have shown that adverse health effects occur more frequently in populations that are exposed to higher air pollution. However, while they find associations between air pollution and health, most do not go further to test for whether air pollution can be identified as the cause. </p>
<p>But when all relevant studies finding these associations are reviewed together, health scientists and the EPA have <a href="https://doi.org/10.1080/10473289.2006.10464485">repeatedly determined</a> that <a href="https://cfpub.epa.gov/ncea/isa/recordisplay.cfm?deid=216546">air pollution causes health effects</a>. </p>
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<a href="https://images.theconversation.com/files/271887/original/file-20190501-136794-b58ihf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/271887/original/file-20190501-136794-b58ihf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/271887/original/file-20190501-136794-b58ihf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=494&fit=crop&dpr=1 600w, https://images.theconversation.com/files/271887/original/file-20190501-136794-b58ihf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=494&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/271887/original/file-20190501-136794-b58ihf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=494&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/271887/original/file-20190501-136794-b58ihf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=621&fit=crop&dpr=1 754w, https://images.theconversation.com/files/271887/original/file-20190501-136794-b58ihf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=621&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/271887/original/file-20190501-136794-b58ihf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=621&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Air pollution has many health impacts, from asthma to heart disease and cancer.</span>
<span class="attribution"><a class="source" href="https://lung.app.box.com/s/gtq5qmm01qq9vv0gm9k5llwxs1vq3aqs/file/61105378093">American Lung Association</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p>Now the new CASAC chair proposes to consider only <a href="http://dx.doi.org/10.1126/science.aaw9460">studies that directly test for causation</a>, using specific statistical techniques that are not widely used. This change could disqualify many of the most important studies that link air pollution with health impacts.</p>
<p>Still another proposed change would preclude considering health studies if they do not make their <a href="https://theconversation.com/why-the-epas-secret-science-proposal-alarms-public-health-experts-96000">underlying data publicly available</a>. Since many air pollution epidemiology studies use health data from individuals that are protected by privacy agreements, this shift also seems likely to <a href="http://www.nytimes.com/2018/03/26/climate/epa-scientific-transparency-honest-act.html">exclude important studies</a>. </p>
<p>We do not believe there is a scientific justification for these proposed changes, which are not required in other fields of medicine and public health.</p>
<h2>Independent science supports sound decisions</h2>
<p>EPA leaders have argued for these changes based on <a href="https://www.epa.gov/sites/production/files/2018-05/documents/image2018-05-09-173219.pdf">efficiency</a> and <a href="http://www.nytimes.com/2018/03/26/climate/epa-scientific-transparency-honest-act.html">transparency</a>. But we see them as an unprecedented and politically motivated attack on the scientific foundation underlying public health protection. Past presidents have also sought to <a href="http://dx.doi.org/10.2105/AJPH.2018.304396">roll back environmental regulations</a>. But every administration since the agency was created in 1970 has based its air quality decisions on independent scientific input. </p>
<p>Administrator Wheeler has the discretion not to follow scientific advice in setting air quality standards. But he does not have the power to determine scientific truth or consensus. As the American Lung Association report makes clear, it would be a mistake to take 30 years of air quality gains for granted – especially when political leaders are pushing in the opposite direction.</p><img src="https://counter.theconversation.com/content/115975/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jason West receives funding from the EPA, NASA, NSF, the Donald and Jennifer Holzworth Faculty Acceleration Fund in Climate Change, and the State of North Carolina. </span></em></p><p class="fine-print"><em><span>Barbara Turpin receives funding from the Alfred P. Sloan Foundation, National Oceanic and Atmospheric Administration, and the State of North Carolina. She a former member of EPA’s CASAC Particulate Matter Review Panel, which Administrator Andrew Wheeler disbanded in 2018.</span></em></p>Air quality in the US has improved greatly since 1990, but a new report finds progress stalling in some cities. Meanwhile, the Trump administration is rolling back air pollution controls.Jason West, Professor, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel HillBarbara Turpin, Professor and Chair, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel HillLicensed as Creative Commons – attribution, no derivatives.