tag:theconversation.com,2011:/id/topics/neurotoxins-4683/articlesNeurotoxins – The Conversation2024-03-07T13:32:32Ztag:theconversation.com,2011:article/2180212024-03-07T13:32:32Z2024-03-07T13:32:32ZLead from old paint and pipes is still a harmful and deadly hazard in millions of US homes<figure><img src="https://images.theconversation.com/files/572091/original/file-20240130-19-tg1jv8.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3763%2C2822&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">When lead-based paint blisters and cracks, lead dust may be released in the air. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/lead-based-paint-abatement-royalty-free-image/1735464372?phrase=lead%2Bpoisoning%2B">Douglas Rissing/iStock via Getty Images Plus</a></span></figcaption></figure><p>Lead is a potent neurotoxin that causes severe health effects such as <a href="https://doi.org/10.1186/s12889-023-15874-7">neurological damage, organ failure and death</a>. </p>
<p>Widely used in products such as paint and gasoline until the late 1970s, lead continues to contaminate environments and harm the health of people around the world. </p>
<p>The World Health Organization estimates that more than <a href="https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health#">1 million deaths each year are attributable to lead poisoning</a>, with the highest exposures in developing nations. Lead continues leaching from old paint, pipes and industrial sources into soils, homes and waterways across the globe. </p>
<p>In more recent years, this number has risen at an incredible pace, with some research showing that nearly 5.5 million adults <a href="https://doi.org/10.1016/S2542-5196(23)00166-3">die from lead-related health complications</a>.</p>
<p>I am a <a href="https://hhs.purdue.edu/directory/aaron-specht/">health physicist</a> and my research focuses on ways to improve the technology <a href="https://doi.org/10.1021/acs.est.0c06622">used to screen for lead</a> and other <a href="https://doi.org/10.1021/acs.est.1c00937">environmental toxicants</a>. In developing and applying my technologies to see how people are affected by toxicants like lead, I have tested more than 20,000 people around the world over the past five years.</p>
<p>This preventable health crisis especially threatens children during periods of <a href="https://doi.org/10.1289/ehp.7688">critical brain development</a> but can also <a href="https://doi.org/10.1093/aje/kwh333">impair intellectual development</a> and <a href="https://doi.org/10.1016/S2468-2667(18)30025-2">long-term health</a> in adults. Understanding and addressing this persistent problem will require improved monitoring, targeted remediation and a great deal more awareness and dialogue.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/aqWvRh8rfLU?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Lead is especially toxic to children under age 6.</span></figcaption>
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<h2>How lead damages the body</h2>
<p>Lead enters the body through three routes: <a href="https://www.atsdr.cdc.gov/csem/leadtoxicity/exposure_routes.html">ingestion, absorption or inhalation</a>. Once inside, <a href="https://doi.org/10.3390/ijerph182212051">lead mimics calcium</a> by binding to proteins and enzymes where calcium is typically involved. </p>
<p>Lead looks a lot like calcium to many of the systems in our body. By hijacking these calcium-dependent processes, lead disrupts many normal functions ranging from neurological function to cardiovascular health. </p>
<p>When lead replaces calcium in these processes, it causes <a href="https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health#">irreversible damage</a>, even at low levels of chronic exposure. Studies show that low levels of lead are associated with dangerous <a href="https://doi.org/10.1016%2Fj.envres.2016.10.007">lifelong illnesses such as Alzheimer’s</a> and <a href="https://doi.org/10.1289%2Fehp.9785">heart disease</a>.</p>
<p>Furthermore, like calcium, lead accumulates <a href="https://doi.org/10.1289/ehp.919133">in our teeth and bones</a>. This compounds lead’s adverse effects as our bodies grow and age, since the lead in bone will reappear as our body looks to its calcium stores during periods of growth or, critically, during pregnancy. </p>
<p>Lead exposure can come from many sources in our daily life, from water systems using <a href="https://www.epa.gov/ground-water-and-drinking-water/lead-service-lines">lead water lines</a> and <a href="https://www.hud.gov/program_offices/healthy_homes/healthyhomes/lead">legacy exposures from old paint</a> to things that people often don’t think about, such as <a href="https://doi.org/10.1016/j.envres.2023.115719">lead in firearms</a> or <a href="https://doi.org/10.1016/j.envres.2020.109860">metal pots and pans</a>. </p>
<p>Researchers often see <a href="https://doi.org/10.1001/jamapediatrics.2018.2382">exposures from soils</a> in highly polluted areas, but sometimes it can be <a href="https://doi.org/10.1016/j.jenvman.2022.115904">present in old donated toys</a> at a child’s day care. </p>
<p>Late in 2023, investigators working with the Centers for Disease Control and Prevention found <a href="https://www.cdc.gov/nceh/lead/news/lead-poisoning-outbreak-linked-to-cinnamon-applesauce-pouches.html">dangerous levels of lead in applesauce</a>, likely stemming from a cinnamon spice grinder. This highlights the <a href="https://www.nytimes.com/2024/02/27/world/europe/lead-applesauce-food-safety.html">Food and Drug Administration’s failures</a> in keeping lead out of the U.S. food supply. </p>
<h2>Fragmented testing</h2>
<p>Blood lead screening <a href="https://www.cdc.gov/nceh/lead/data/national.htm">serves as the first line of defense</a> against lead exposure, particularly in high-risk individuals and primarily in children. However, <a href="https://toxicfreefuture.org/research/children-at-risk/state-lead-screening-policies/">testing protocols and recommendations vary widely</a>, and most states lack universal testing mandates. </p>
<p>Even in cases where universal screening programs exist, the data obtained can be insufficient. This is because blood tests capture only recent exposure, and universal testing oftentimes mandates only one test of children within a six-year window. </p>
<p>This fragmented system, combined with research indicating that many doctors <a href="https://doi.org/10.1136/oemed-2023-109210">deviate from lead testing guidelines</a>, allows exposures to go undetected until irreversible neurological damage has been done. </p>
<p>We are hopeful that as research like ours draws more attention to the gravity of this issue, universal, standardized screening will become the norm across the U.S. This would save many children – and generations to come – from ongoing and preventable exposures.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/CXD_hh8zRiY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Lead toxicity doesn’t affect just children.</span></figcaption>
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<h2>How testing is done</h2>
<p>Monitoring lead levels typically involves a <a href="https://www.cdc.gov/nceh/lead/prevention/blood-lead-levels.htm">simple blood test</a>, generally ordered by your doctor. These tests are widely available but <a href="https://doi.org/10.1016/j.chemosphere.2021.129832">can easily be inaccurate</a> based on when the test was taken. Since <a href="https://doi.org/10.1038%2Fs41370-018-0036-y">blood lead levels can change quickly</a>, children who get tested several weeks after exposure could falsely test as normal. </p>
<p>Moreover, because there is no requirement for doctors to be trained in how to test for and treat lead exposure, many pediatricians <a href="https://doi.org/10.1136/oemed-2023-109210">lack awareness about lead screening protocols</a>. As a result, many at-risk people <a href="https://doi.org/10.1289/EHP10335">are not being tested</a>. </p>
<p>When tests are given, they may yield inaccurate results due to the <a href="https://doi.org/10.1038%2Fs41370-018-0036-y">rapid changes in blood lead</a>. Or sometimes results are not properly reported to local health departments. Further complicating this, in 2010, the Centers for Disease Control and Prevention declared that the country’s progress in removing lead from gasoline was a <a href="https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6019a5.htm">great public health achievment</a>. As a result, many lead-testing programs in the U.S. were discontinued, leading to critical information gaps. </p>
<p>However, there is some reason for optimism. Some state-based lead surveillance programs that were phased out in the early 2000s have been returning in recent years. A good example is my home state of Indiana. A law that <a href="https://www.in.gov/health/lead-and-healthy-homes-division/information-for-health-care-providers/testing-requirements/">went into effect on Jan. 1, 2023</a>, requires all health care providers serving children to offer lead testing to their patients. </p>
<p>Efforts from statewide programs like these will lead to more opportunities to inform physicians and to screen vulnerable populations.</p>
<h2>Ways to get tested</h2>
<p>Blood is by far the most widely used indicator for lead exposure. However, <a href="https://doi.org/10.1038/s41370-018-0036-y">in blood, lead dissipates quickly</a>, and after about a few weeks to a month, an exposure that was high enough to cause damage is no longer measurable from blood lead.</p>
<p>As part of my research, we have developed a handheld device that is able to <a href="https://doi.org/10.3109/1354750X.2016.1139183">noninvasively measure lead from bone</a> in minutes. Picture a Star Trek tricorder. We have patented the method we use to calculate lead in bone but currently have not commercialized it. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/579700/original/file-20240304-28-hr1ffe.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A hand wrapped around the handle of a small black, silver and gray lead-measuring device." src="https://images.theconversation.com/files/579700/original/file-20240304-28-hr1ffe.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/579700/original/file-20240304-28-hr1ffe.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=798&fit=crop&dpr=1 600w, https://images.theconversation.com/files/579700/original/file-20240304-28-hr1ffe.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=798&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/579700/original/file-20240304-28-hr1ffe.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=798&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/579700/original/file-20240304-28-hr1ffe.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1003&fit=crop&dpr=1 754w, https://images.theconversation.com/files/579700/original/file-20240304-28-hr1ffe.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1003&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/579700/original/file-20240304-28-hr1ffe.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1003&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 author holds the Star Trek-esque device that he and his team developed at Purdue University.</span>
<span class="attribution"><span class="source">Aaron James Specht</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Bone lead is reflective of <a href="https://doi.org/10.1289/ehp.9783">years to decades of exposure</a> and is a more accurate test to reflect the permanence of damage induced by lead in the body. Bone lead has also been shown to have a strong relationship with <a href="https://doi.org/10.1515/reveh.2009.24.1.15">lead accumulation in the brain</a>, since lead hijacks places in both the bone and the brain where calcium is normally present. </p>
<p>Efficient and routine blood lead testing in children during their developmental stages could definitively identify exposure sources as they emerge. </p>
<p>While bone measurements allow researchers and physicians to effectively <a href="https://doi.org/10.1088/1361-6579/aa904f">measure years to decades of exposure</a>, health departments and the CDC currently lack the infrastructure to deploy this technology in communities that are highly affected by lead. </p>
<h2>What you can do</h2>
<p>People concerned about lead exposure <a href="https://www.cdc.gov/nceh/lead/prevention/testing-children-for-lead-poisoning.htm#">should request a blood lead test</a> from their doctor. Parents of young children should proactively ask pediatricians to conduct lead screening. If you live in an old home, especially one with peeling paint, you can contact your local health department to test for possible lead paint. </p>
<p>Additionally, your local water service provider should be able to tell you if lead water lines are in use leading to your home. Unfortunately, lead has no particular smell or taste to differentiate it from other possible contaminants.</p>
<p>Children and adults with elevated blood lead levels should talk to their pediatrician or doctor about effective <a href="https://www.cdc.gov/nceh/lead/advisory/acclpp/actions-blls.htm">follow-up testing</a> and potential dietary changes to promote lead excretion naturally. </p>
<p>For very high exposures, a treatment known as <a href="https://www.atsdr.cdc.gov/csem/leadtoxicity/patient_treatment.html#">chelation therapy</a>, which involves an oral medication that binds to lead so that it can be excreted in urine, has been shown to be <a href="https://doi.org/10.1203/00006450-200011000-00007">effective at reducing blood lead levels</a>. </p>
<p>These people should also notify their local health department, which can identify and remove lead sources in their environment to eliminate the risk to both current and future residents.</p><img src="https://counter.theconversation.com/content/218021/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Aaron Specht receives funding from the National Institutes of Health, Centers for Disease Control, and JPB Foundation. </span></em></p>Although the US banned lead-based paint in 1978, homes built before then commonly contain lead paint.Aaron Specht, Assistant Professor of Health Physics, Purdue UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2116572023-09-14T12:30:25Z2023-09-14T12:30:25ZThe importance of shining a light on hidden toxic histories<figure><img src="https://images.theconversation.com/files/548169/original/file-20230913-23-64mqmc.jpg?ixlib=rb-1.1.0&rect=0%2C4%2C2927%2C1970&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Activists in Newark, N.J., offer tours that teach visitors about the city's legacy of industrial pollution and environmental racism.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/an-aerial-view-of-newark-new-jersey-shows-smoke-news-photo/635229321?adppopup=true">Charles Rotkin/Corbis via Getty Images</a></span></figcaption></figure><p>Indianapolis proudly claims <a href="https://www.wthr.com/article/entertainment/hoosiers-remember-elvis-presley-indianapolis-concert-amid-new-movie-buzz/531-503bd6a9-c645-4704-bfad-7577126aaad6">Elvis’ last concert</a>, <a href="https://www.youtube.com/watch?v=A2kWIa8wSC0">Robert Kennedy’s speech</a> in response to Martin Luther King Jr.’s assassination, and the Indianapolis 500. There’s a 9/11 memorial, a <a href="https://www.indianawarmemorials.org/explore/medal-of-honor-memorial/">Medal of Honor Memorial</a> and a statue of former NFL quarterback Peyton Manning.</p>
<p>What few locals know, let alone tourists, is that the city also houses one of the largest dry cleaning <a href="https://www.epa.gov/superfund/what-superfund">Superfund sites</a> in the U.S.</p>
<p>From 1952 to 2008, Tuchman Cleaners laundered clothes <a href="https://www.doi.org/10.3389/fpubh.2021.638082">using perchloroethylene</a>, or PERC, a neurotoxin and possible carcinogen. Tuchman operated a chain of cleaners throughout the city, which sent clothes to a facility on Keystone Avenue for cleaning. It was also the location where used solution was stored in underground tanks.</p>
<p>Inspectors noted the presence of volatile organic compounds from leaking tanks and possible spills as early as 1989. By 1994, an underground plume had spread to a nearby aquifer. By the time the EPA became involved in 2011, the <a href="https://response.epa.gov/site/site_profile.aspx?site_id=7130">underground chemical plume</a> had seeped more than a mile underneath a residential area, reaching a well that supplies drinking water to the city.</p>
<p>When geographer <a href="https://liberalarts.iupui.edu/departments/geography/directory/owen-dwyer/">Owen Dwyer</a>, earth scientist <a href="https://science.iupui.edu/people-directory/people/filippelli-gabriel.html">Gabe Filippelli</a> and I investigated and wrote about the social and environmental <a href="https://www.taylorfrancis.com/chapters/oa-edit/10.4324/9781003365259-24/dirty-laundry-toxic-heritage-dry-cleaning-indianapolis-indiana-elizabeth-kryder-reid-owen-dwyer-gabriel-filippelli?context=ubx&refId=242e9f98-2f2d-4587-9449-99734e77a875">history of dry cleaning in Indianapolis</a>, we were struck by how few people outside of the dry cleaning and environmental management fields were aware of this environmental damage. </p>
<p>There are no markers or memorials. There is no mention of it – or any other accounts of contamination – in Indianapolis’ many museums. This kind of silence has been called “<a href="https://www.orionmagazine.org/article/environmental-amnesia/">environmental amnesia</a>” or “<a href="https://www.jstor.org/stable/24906248">collective forgetting</a>.”</p>
<p>Societies celebrate heroes and commemorate tragedies. But where in public memory is environmental harm? What if people thought about it not only as a science or policy problem, but also as a part of history? Would it make a difference if pollution, along with biodiversity loss and climate change, was seen as part of our shared heritage? </p>
<h2>The slow violence of contamination</h2>
<p>Environmental harm often takes place gradually and out of sight, and this could be one reason why there’s so little public conversation and commemoration. In 2011, Princeton English professor <a href="https://www.hup.harvard.edu/catalog.php?isbn=9780674072343">Rob Nixon</a> came up with a term for this kind of environmental degradation: slow violence. </p>
<p>As underground storage tanks leak, <a href="https://www.taylorfrancis.com/chapters/oa-edit/10.4324/9781003365259-10/ghost-wrecks-anthropocene-enduring-toxic-legacy-pacific-war-matthew-carter-ashley-meredith-augustine-kohler-ranger-walter-bill-jeffrey-paul-heersink?context=ubx&refId=9df11100-ce32-4e00-b590-5b9769b00df2">shipwrecks corrode</a>, coal ash ponds seep and <a href="https://www.taylorfrancis.com/chapters/oa-edit/10.4324/9781003365259-6/toxic-heritage-forever-confronting-pfas-contamination-toxicity-lived-experience-thomas-pearson-daniel-renfrew?context=ubx&refId=ef6c0e6a-b9da-4008-9689-9a43a2dc3055">forever chemicals spread</a>, the creeping pace of poisoned soil and water fails to garner the attention that more dramatic environmental disasters attract.</p>
<p>Certain interests benefit from hiding the costs of pollution and its remediation. Sociologists <a href="https://www.russellsage.org/publications/sites-unseen">Scott Frickel and James R. Elliott</a> have studied urban pollution, and they highlight three reasons for its pervasiveness and persistence. </p>
<p>First, in cities, small factories, auto repair shops, dry cleaners and other light industries sometimes only stay open for a decade or two, making it challenging to regulate them and track their environmental impacts over time. By the time contamination is discovered, many facilities have long been shuttered or purchased by new owners. And the polluters have a direct financial interest in not being connected with it, since they could be held liable and forced to pay for cleanup.</p>
<p>Similarly, urban neighborhoods tend to have shifting demographics, and local residents are often not aware of historical pollution. </p>
<p>Finally, it can simply be politically expedient to look the other way and ignore the consequences of pollution. Cities may be concerned that publicizing toxic histories discourage investment and depress property values, and politicians are hesitant to fund projects that may have a long-term benefit but short-term costs. Indianapolis, for example, tried for decades to avoid mitigating the raw sewage flowing into the White River and Fall Creek, arguing it was too expensive to deal with. Only when required by a <a href="https://www.epa.gov/sites/default/files/2013-09/documents/indy0610-cd.pdf">consent decree</a> did the city start to address the problem.</p>
<p>Toxic legacies are also difficult to track because their effects may be hidden by distance and time. Anthropologist Peter Little <a href="https://global.oup.com/academic/product/burning-matters-9780190934552?cc=us&lang=en&">traced the outsourcing of electronics waste recycling</a>, which is shipped from the places where electronics are bought and used, to countries such as Ghana, where labor is cheap and environmental regulations lax. </p>
<p>Then there are the toxic traces of military conflicts, which linger long after the fighting has stopped and troops have returned home. Historian and geologist Daniel Hubé has documented <a href="https://doi.org/10.1080/19475020.2017.1393347">the long-term environmental impact of World War I munitions</a>. </p>
<p>At the end of the war, unused and unexploded bombs and chemical weapons had to be disposed of. In France, at a site known as <a href="https://www.taylorfrancis.com/chapters/oa-edit/10.4324/9781003365259-25/cleaning-battlefields-times-war-polluted-soils-times-peace-case-study-silent-visible-toxic-legacy-great-war-daniel-hub%C3%A9-tobias-bausinger?context=ubx&refId=630129c7-e447-48fd-a959-24bf0bae1d83">Place à Gaz</a>, hundreds of thousands of chemical weapons were burned. Today, the soils have been found to have extraordinarily high levels of arsenic and other heavy metals. </p>
<p>More than a century after the end of the war, little grows on the contaminated, barren land.</p>
<h2>Toxic tours and teaching moments</h2>
<p>There’s a growing movement to make toxic histories more visible.</p>
<p>In Providence, Rhode Island, artist Holly Ewald founded the <a href="http://www.upparts.org/">Urban Pond Procession</a> to call attention to Mashapaug Pond, which was contaminated by <a href="https://medallicartcollector.com/gorham.shtml">a Gorham Silver factory</a>. She worked with community partners to create wearable sculptures, puppets and giant fish, all of which were carried and worn in an annual parade that took place from 2008 to 2017.</p>
<figure class="align-center ">
<img alt="People march along a sidewalk playing instruments and holding signs featuring fish." src="https://images.theconversation.com/files/548175/original/file-20230913-3869-qv2hbs.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/548175/original/file-20230913-3869-qv2hbs.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=415&fit=crop&dpr=1 600w, https://images.theconversation.com/files/548175/original/file-20230913-3869-qv2hbs.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=415&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/548175/original/file-20230913-3869-qv2hbs.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=415&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/548175/original/file-20230913-3869-qv2hbs.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=522&fit=crop&dpr=1 754w, https://images.theconversation.com/files/548175/original/file-20230913-3869-qv2hbs.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=522&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/548175/original/file-20230913-3869-qv2hbs.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=522&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Urban Pond Procession took place each summer for 10 years in Providence, R.I.</span>
<span class="attribution"><span class="source">Photo by Mary Beth Meehan, UPP Collection, Providence Public Library</span></span>
</figcaption>
</figure>
<p>Cultural anthropologist Amelia Fiske collaborated with artist Jonas Fischer to create the graphic novel “<a href="https://utorontopress.com/9781487509538/toxic/">Tóxico</a>,” which will be published in 2024. It depicts petroleum pollution in the Ecuadorian Amazon, as well as the struggles of those fighting for environmental justice. </p>
<p>Toxic tours can educate the public about the histories, causes and consequences of environmental harm. For example, <a href="https://www.taylorfrancis.com/chapters/oa-edit/10.4324/9781003365259-31/environmental-justice-tours-transformative-narratives-struggle-solidarity-activism-ana-isabel-baptista?context=ubx&refId=7e43d2ce-0c5c-41a4-a9b6-40ce10c0848c">Ironbound Community Corporation</a> in Newark, New Jersey, offers a tour of severely contaminated sites, such as the location of the former <a href="https://www.nytimes.com/1998/11/08/nyregion/newark-s-toxic-tomb-six-acres-fouled-dioxin-agent-orange-s-deadly-byproduct.html">Agent Orange factory</a>, where the sediment in the sludge is laced with the carcinogen dioxin. The tour also goes by a detention center <a href="https://www.epa.gov/brownfields/overview-epas-brownfields-program">that’s built on a brownfield</a>, which has only undergone industrial-level remediation because that’s the standard all prisons are held to.</p>
<p>In 2017, the <a href="https://www.humanitiesactionlab.org/">Humanities Action Lab</a> organized “<a href="https://climatesofinequality.org/">Climates of Inequality</a>,” a traveling exhibit co-curated by more than 20 universities and local partners exploring environmental issues affecting communities around the world. The <a href="https://www.taylorfrancis.com/chapters/oa-edit/10.4324/9781003365259-34/toxic-heritage-reparations-activating-memory-environmental-climate-justice-liz-%C5%A1ev%C4%8Denko?context=ubx&refId=e2e664c7-b4d9-4497-b4a4-6d4f5dd1b009">exhibit</a> brings attention to polluted waterways, the impacts of climate change, ecological damage on Indigenous lands and the ways in which immigrant agricultural workers experience heat stress and chronic pesticide exposure. The exhibits also explore the affected communities’ resilience and advocacy.</p>
<p>These stories of pollution and contamination, and their effects on people’s health and livelihoods, represent only a sampling of current efforts to curate toxic heritage. As sociologist Alice Mah writes in her foreword to “<a href="https://www.routledge.com/Toxic-Heritage-Legacies-Futures-and-Environmental-Injustice/Kryder-Reid-May/p/book/9781032429977">Toxic Heritage</a>”: “Reckoning with toxic heritage is an urgent collective task. It is also unsettling work. It requires confronting painful truths about the roots of toxic injustice with courage, honesty, and humility.”</p>
<p>I see public commemoration of hidden toxic histories as a way to push back against denial, habituation and amnesia. It creates a space for public conversation, and it opens up possibilities for a more just and sustainable future.</p><img src="https://counter.theconversation.com/content/211657/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elizabeth Kryder-Reid receives funding from Indiana University and the Fulbright Program.</span></em></p>Societies celebrate heroes and commemorate tragedies. But why is there so little public acknowledgment of environmental disasters?Elizabeth Kryder-Reid, Chancellor's Professor of Anthropology and Museum Studies, Indiana UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1764342022-02-15T13:24:07Z2022-02-15T13:24:07ZHow poisonous mercury gets from coal-fired power plants into the fish you eat<figure><img src="https://images.theconversation.com/files/446121/original/file-20220213-17-gt0hty.jpg?ixlib=rb-1.1.0&rect=0%2C17%2C3000%2C2110&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Coal-fired power plants are a source of mercury that people can ingest by eating fish.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/danielle-gross-casts-his-fishing-line-into-the-potomac-news-photo/478998730">Mark Wilson/Getty Images</a></span></figcaption></figure><p>People fishing along the banks of the White River as it winds through Indianapolis sometimes pass by ominous signs warning about eating the fish they catch. </p>
<p><a href="https://extension.wsu.edu/foodsafety/content/risks-of-mercury-in-fish">One of the risks</a> they have faced is mercury poisoning.</p>
<p>Mercury is a neurotoxic metal that can cause irreparable harm to human health – especially the brain development of young children. It is <a href="https://doi.org/10.1289/ehp.7743">tied to lower IQ</a> and results in decreased earning potential, as well as higher health costs. Lost productivity from mercury alone was calculated in 2005 to reach <a href="https://doi.org/10.1289/ehp.7743">almost $9 billion per year</a>. </p>
<p>One way mercury gets into river fish is with the gases that rise up the smokestacks of coal-burning power plants. </p>
<p><iframe id="FW8zH" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/FW8zH/6/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>The Environmental Protection Agency has had a rule since 2012 limiting mercury emissions from coal-fired power plants. But the Trump administration <a href="https://eelp.law.harvard.edu/2019/03/rolling-back-the-mercury-and-air-toxics-standards-proposed-withdrawal-of-appropriate-and-necessary/">stopped enforcing it</a>, <a href="https://www.reuters.com/article/us-usa-epa-coal-mercury/trump-administration-weakens-mercury-rule-for-coal-plants-idUSKCN21Y1IW">arguing that the costs</a> to industry outweighed the health benefit.</p>
<p>Now, the Biden administration is <a href="https://www.epa.gov/newsreleases/epa-reaffirms-scientific-economic-and-legal-underpinnings-limits-toxic-emissions">moving to reassert it</a>.</p>
<p>I study mercury and its sources as a <a href="https://scholar.google.com/citations?user=MEp4948AAAAJ&hl=en">biogeochemist</a> at Indiana University-Purdue University Indianapolis. Before the EPA’s original mercury rule went into effect, my students and I launched a project to track how Indianapolis-area power plants were increasing mercury in the rivers and soil.</p>
<h2>Mercury bioaccumulates in the food chain</h2>
<p>The risks from eating a fish from a river downwind from a coal-burning power plant depends on both the type of fish caught and the age and condition of the person consuming it.</p>
<p>Mercury is a <a href="https://www.usgs.gov/special-topics/water-science-school/science/mercury-contamination-aquatic-environments">bioaccumulative toxin</a>, meaning that it increasingly concentrates in the flesh of organisms as it makes its way up the food chain.</p>
<figure class="align-center ">
<img alt="A person's hands old a smallmouth bass, with the fish's mouth open" src="https://images.theconversation.com/files/446123/original/file-20220213-87622-e0wm9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/446123/original/file-20220213-87622-e0wm9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/446123/original/file-20220213-87622-e0wm9c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/446123/original/file-20220213-87622-e0wm9c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/446123/original/file-20220213-87622-e0wm9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/446123/original/file-20220213-87622-e0wm9c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/446123/original/file-20220213-87622-e0wm9c.jpg?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">
<figcaption>
<span class="caption">Mercury accumulates as it moves up the food chain.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/holding-a-smallmouth-bass-royalty-free-image/123084571">doug4537 via Getty Images</a></span>
</figcaption>
</figure>
<p>The mercury emitted from coal-burning power plants falls onto soils and washes into waterways. There, the moderately benign mercury is transformed by bacteria into a toxic organic form called methylmercury.</p>
<p>Each bacterium might contain only one unit of toxic methylmercury, but a worm chewing through sediment and eating 1,000 of those bacteria now contains 1,000 doses of mercury. The catfish that eats the worm then get more doses, and so on up the food chain to humans.</p>
<p>In this way, top-level predator fishes, such as smallmouth bass, walleye, largemouth bass, lake trout and Northern pike, typically contain the highest amounts of mercury in aquatic ecosystems. On average, one of these fish contains enough to make eating only <a href="https://www.epa.gov/fish-tech/epa-fda-fish-advice-technical-information">one serving of them per month dangerous</a> for the developing fetuses of pregnant women and for children.</p>
<h2>How coal plant mercury rains down</h2>
<p>In our study, we wanted to answer a simple question: Did the local coal-burning power plants, known to be <a href="https://www.purdue.edu/discoverypark/energy/assets/pdfs/cctr/outreach/Basics2-Mercury-Mar07.pdf">major emitters of toxic mercury</a>, have an impact on the local environment?</p>
<p>The obvious answer seems to be yes, they do. But in fact, quite a bit of research – and coal industry advertising – noted that mercury is a “<a href="https://doi.org/10.1002/etc.1980">global pollutant</a>” and could not necessarily be traced to a local source. A recurring argument is that mercury deposited on the landscape came from coal-burning power plants <a href="https://doi.org/10.1021/es062707c">in China</a>, so why regulate local emissions if others were still burning coal?</p>
<p>That justification was based on the unique chemistry of this element. It is the only metal that is liquid at room temperature, and when heated just to a moderate level, will evaporate into mercury vapor. Thus, when coal is burned in a power plant, the mercury that is present in it is released through the smokestacks as a gas and dilutes as it travels. Low levels of mercury also <a href="https://www.epa.gov/international-cooperation/mercury-emissions-global-context">occur naturally</a>.</p>
<p>Although this argument was technically true, we found it obscured the bigger picture.</p>
<figure class="align-center ">
<img alt="A view of the river with a bridge and the city in the background." src="https://images.theconversation.com/files/446383/original/file-20220214-19-t52yt9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/446383/original/file-20220214-19-t52yt9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/446383/original/file-20220214-19-t52yt9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/446383/original/file-20220214-19-t52yt9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/446383/original/file-20220214-19-t52yt9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/446383/original/file-20220214-19-t52yt9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/446383/original/file-20220214-19-t52yt9.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">People sometimes fish along the White River where it flows through Indianapolis.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/indianapolis-royalty-free-image/520980871?adppopup=true">alexeys via Getty Images</a></span>
</figcaption>
</figure>
<p>We found the overwhelming source of mercury was within sight of the White River fishermen – a large coal-burning power plant on the edge of the city.</p>
<p>This power plant emitted vaporous mercury at the time, though it has since <a href="https://www.transmissionhub.com/articles/2016/02/indianapolis-powers-harding-street-plant-burns-its-last-coal.html">switched to natural gas</a>. We found that much of the plant’s mercury rapidly reacted with other atmospheric constituents and water vapor to <a href="https://doi.org/10.1007/s11270-010-0703-7">“wash out” over the city</a>. It was <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/gbc.20040">raining down mercury on the landscape</a>.</p>
<h2>Traveling by air and water, miles from the source</h2>
<p>Mercury emitted from the smokestacks of coal-fired power plants can fall from the atmosphere with rain, mist or chemical reactions. Several studies have shown <a href="https://doi.org/10.1016/j.jhazmat.2016.01.026">elevated levels of mercury in soils and plants near power plants</a>, with much of the mercury <a href="https://doi.org/10.1038/srep46545">falling within about 9 miles</a> (15 kilometers) of the smokestack.</p>
<p>When we surveyed hundreds of surface soils ranging from about 1 to 31 miles (2 to 50 km) from the coal-fired power plant, then the single largest emitter of mercury in central Indiana, we were shocked. We found <a href="https://doi.org/10.12952/journal.elementa.000059">a clear “plume” of elevated mercury</a> in Indianapolis, with much higher values near the power plant tailing off to almost background values 31 miles downwind. </p>
<p>The White River flows from the northeast to the southwest through Indianapolis, opposite the wind patterns. When we sampled sediments from most of its course through central Indiana, we found that mercury levels started low well upstream of Indianapolis, but <a href="https://doi.org/10.1007/s11270-010-0703-7">increased substantially</a> as the river flowed through downtown, apparently accumulating deposited mercury along its flow path. </p>
<p>[<em>Understand developments in science, health and technology, each week.</em> <a href="https://memberservices.theconversation.com/newsletters/?nl=science&source=inline-science-understand">Subscribe to The Conversation’s science newsletter</a>.]</p>
<p>We also found high levels well downstream of the city. Thus a fisherman out in the countryside, far away from the city, was still <a href="https://doi.org/10.12952/journal.elementa.000059">at significant risk</a> of catching, and eating, high-mercury fish.</p>
<p>The region’s <a href="https://www.in.gov/health/files/Marion_sensitive_fishadvisory.pdf">fish advisories</a> still recommend sharply limiting the amount of fish eaten from the White River. In Indianapolis, for example, pregnant women are advised to <a href="https://www.in.gov/health/files/Marion_sensitive_fishadvisory.pdf">avoid eating some fish</a> from the river altogether.</p>
<h2>Reviving the MATS rule</h2>
<p>The EPA announced the Mercury and Air Toxic Standards rule in 2011 to deal with the exact health risk Indianapolis was facing. </p>
<p>The <a href="https://eelp.law.harvard.edu/2017/09/mercury-and-air-toxics-standards/">rule stipulated</a> that mercury sources had to be sharply reduced. For coal-fired power plants, this meant either installing costly mercury-capturing filters in the smokestacks or converting to another energy source. <a href="https://www.eia.gov/totalenergy/data/monthly/">Many converted to natural gas</a>, which reduces the mercury risk but still contributes to health problems and global warming.</p>
<p>The MATS rule helped tilt the national energy playing field away from coal, until the Trump Administration <a href="https://www.epa.gov/mats/proposed-revised-supplemental-finding-and-results-residual-risk-and-technology-review">attempted to weaken the rule</a> in 2020 to try to bolster the <a href="https://www.eia.gov/todayinenergy/detail.php?id=44155">declining U.S. coal industry</a>. The administration rescinded a “supplemental finding” that determined it is “appropriate and necessary” to regulate mercury from power plants.</p>
<p>On Jan. 31, 2022, the Biden Administration <a href="https://www.epa.gov/stationary-sources-air-pollution/proposed-revocation-2020-reconsideration-and-affirmation">moved to reaffirm that supplemental finding</a> and effectively restore the standards.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/446071/original/file-20220213-15-aw2lhh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/446071/original/file-20220213-15-aw2lhh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=277&fit=crop&dpr=1 600w, https://images.theconversation.com/files/446071/original/file-20220213-15-aw2lhh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=277&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/446071/original/file-20220213-15-aw2lhh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=277&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/446071/original/file-20220213-15-aw2lhh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=348&fit=crop&dpr=1 754w, https://images.theconversation.com/files/446071/original/file-20220213-15-aw2lhh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=348&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/446071/original/file-20220213-15-aw2lhh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=348&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">More than a quarter of U.S. coal-fired power plants currently operating were scheduled as of 2021 to be retired by 2035.</span>
<span class="attribution"><a class="source" href="https://www.eia.gov/todayinenergy/detail.php?id=50658">EIA</a></span>
</figcaption>
</figure>
<p>Some economists have calculated the net cost of the MATS rule to the U.S. electricity sector to be about <a href="https://www.nera.com/content/dam/nera/publications/archive2/PUB_MATS_Rule_0312.pdf">$9.6 billion per year</a>. This is roughly equal to the earlier estimates of productivity loss from the harm mercury emissions cause.</p>
<p>To a public health expert, this math problem is a no-brainer, and I am pleased to see the rule back in place, protecting the health of generations of future Americans.</p><img src="https://counter.theconversation.com/content/176434/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gabriel Filippelli 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>The Biden administration is moving to revive mercury limits for coal-fired power plants. A scientist explains mercury’s health risks and the role power plants play.Gabriel Filippelli, Chancellor's Professor of Earth Sciences and Executive Director, Indiana University Environmental Resilience Institute, IUPUILicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1658662021-11-12T13:36:08Z2021-11-12T13:36:08ZNeurotoxins in the environment are damaging human brain health – and more frequent fires and floods may make the problem worse<figure><img src="https://images.theconversation.com/files/428985/original/file-20211028-23-ey0fbd.jpg?ixlib=rb-1.1.0&rect=242%2C177%2C3352%2C2204&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Wildfire smoke contains a mixture of toxic pollutants that can be harmful to both the lungs and the brain. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/california-wildfires-royalty-free-image/1281624333?adppopup=true">Bloomberg Creative/ Bloomberg Creative Photos via Getty Images</a></span></figcaption></figure><p>In the summer of 2021, a toxic, smoky haze stemming from <a href="https://www.nbcnews.com/western-wildfires">Western wildfires</a> wafted across large parts of the United States, while hurricanes wrought extensive flooding in the southern and eastern U.S. Air quality websites such as <a href="https://www.airnow.gov">AirNow</a> warned of <a href="https://www.npr.org/2021/07/21/1018865569/the-western-wildfires-are-affecting-people-3-000-miles-away">hazardous conditions</a> on the U.S. East Coast from Western forest fires 3,000 miles away, with recommendations to stay indoors. </p>
<p>Journalists reported the immediate impact of lives lost and homes and property destroyed, but more insidious dangers escaped notice. Few people realize that these <a href="https://www.npr.org/2021/09/11/1035241392/climate-change-disasters-mental-health-anxiety-eco-grief">climate change-fueled</a> <a href="https://www.washingtonpost.com/world/interactive/2021/cop26-extreme-weather-climate-change-action/">disasters</a> – both fires and <a href="https://doi.org/10.1080/10807030903051309">floods</a> – could <a href="https://doi.org/10.1080/10962247.2017.1401017">adversely affect human health</a> in longer-term ways. </p>
<p>I’m a <a href="https://scholar.google.com/scholar?as_ylo=2017&q=Arnold+Eiser&hl=en&as_sdt=0,39">scientist-author</a> who studies the links between environmental factors and the development of neurological disorders, which is the <a href="https://rowman.com/ISBN/9781538158074/Preserving-Brain-Health-in-a-Toxic-Age-New-Insights-from-Neuroscience-Integrative-Medicine-and-Public-Health">subject of my recent book</a>. My <a href="https://doi.org/10.1016/j.brainres.2017.06.032">research on this topic</a> adds to a growing body of evidence that <a href="https://www.nytimes.com/2019/07/15/climate/flooding-chemicals-health-research.html">more frequent environmental disasters</a> may be raising <a href="https://doi.org/10.1007/s11356-015-4913-9">human exposure to neurotoxins</a>.</p>
<h2>Neurotoxic smoke</h2>
<p>Many scientists have identified links between <a href="https://doi.org/10.1016/j.bj.2018.06.001">air pollution</a> in various forms, including from <a href="https://theconversation.com/breathing-wildfire-smoke-can-affect-the-brain-and-sperm-as-well-as-the-lungs-166548">forest fire smoke</a>, and an increased risk and prevalence of adverse health effects, including brain disorders. </p>
<p>Wildfire smoke is a mixture of <a href="https://health.ny.gov/environmental/outdoors/air/smoke_from_fire">countless noxious chemical compounds</a>. Fires burning <a href="https://www.theguardian.com/world/2021/aug/09/fires-rage-around-the-world-where-are-the-worst-blazes%20and%20Australia">across the warming planet</a> – from California to Greece and Australia – are adding dangerous particulate matter to the atmosphere that includes <a href="https://doi.org/10.5772/intechopen.97204">neurotoxic heavy metals</a> such as mercury, lead, cadmium and manganese nanoparticles. <a href="https://theconversation.com/whats-in-wildfire-smoke-a-toxicologist-explains-the-health-risks-and-which-masks-can-help-164597">These toxins</a> are an added environmental burden on top of the pollutants emitted by factories, power plants, trucks, automobiles and other sources. </p>
<p>The greatest potential for health problems comes from minuscule particles, smaller than 2.5 microns – or PM 2.5 (for context, the width of a human hair is typically 50 to 70 microns). This is, in part, because <a href="https://doi.org/10.1164/rccm.201903-0635LE">tiny particles are easily inhaled</a>; from the lungs, they enter the bloodstream and circulate widely throughout the body. <a href="https://doi.org/10.3389/fphys.2020.00155">In the brain</a> they may inflame the microglial cells, the brain’s defensive cells, causing harm to neurons instead of protecting them. Studies show that these extremely tiny particles may damage neurons or brain cells by <a href="https://doi.org/10.1016/j.tins.2009.05.009">promoting inflammation</a>. Brain inflammation can lead to conditions <a href="https://doi.org/10.3233/JAD-180631">like dementia</a> and <a href="https://doi.org/10.1097/JOM.0000000000000451">Parkinson’s disease</a>, a movement disorder in adults.</p>
<p>In addition, <a href="https://doi.org/10.1001/jamapediatrics.2018.3101">prenatal</a> and <a href="https://doi.org/10.1097/EDE.0000000000001109">early-life exposure</a> to air pollution has been linked to an increased risk of autism spectrum disorder in children. Research suggests that <a href="https://doi.org/10.1001/jamanetworkopen.2021.7508">air pollution exposure</a> during these critical periods, particularly in the third trimester of pregnancy and the first few months of life, <a href="https://doi.org/10.1515/tnsci-2016-0005">may impair normal neural development</a>. </p>
<h2>Waterborne neurotoxins</h2>
<p>As part of my book research, I investigated potential links between environmental neurotoxins and related health effects in Finland. Seeking unique environmental factors that might underlie the disproportionately high rates of fatal dementia that occurred in Finland in the past decade, I found that <a href="https://doi.org/10.1016/j.brainres.2017.06.032">water pollution</a> – exacerbated by flooding, use of fertilizer and higher water temperatures – may be affecting brain health. </p>
<p>As I reviewed the environmental concerns in Finland, the widespread presence of <a href="https://www.usgs.gov/centers/kswsc/science/cyanobacterial-blue-green-algal-blooms-tastes-odors-and-toxins-0?qt-science_center_objects=0#qt-science_center_objects">blue-green algae in waterways</a> stood out to me. Though it’s commonly called algae, blue-green algae is actually a type of bacteria called cyanobacteria. These toxic microorganisms thrive and proliferate in warm waterways when excessive nutrients, particularly phosphorus from fertilizer runoff, pour into fresh and brackish water. It produces <a href="https://www.epa.gov/cyanohabs/health-effects-cyanotoxins">cyanotoxins</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/428983/original/file-20211028-23-lejb0a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Blue-green algae bloom on surface of lake with trees in the distance." src="https://images.theconversation.com/files/428983/original/file-20211028-23-lejb0a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/428983/original/file-20211028-23-lejb0a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=372&fit=crop&dpr=1 600w, https://images.theconversation.com/files/428983/original/file-20211028-23-lejb0a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=372&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/428983/original/file-20211028-23-lejb0a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=372&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/428983/original/file-20211028-23-lejb0a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=468&fit=crop&dpr=1 754w, https://images.theconversation.com/files/428983/original/file-20211028-23-lejb0a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=468&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/428983/original/file-20211028-23-lejb0a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=468&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Harmful blooms of blue-green algae on lakes and ponds can be toxic to humans and dogs alike.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/sefton-park-lake-in-liverpool-which-has-been-closed-off-news-photo/1228294229?adppopup=true">Peter Byrne/PA Images via Getty Images</a></span>
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</figure>
<p>One of these cyanotoxins, β-methylamino-L-alanine, or BMAA, is linked to <a href="https://doi.org/10.3389/fnagi.2020.00026">neurodegenerative disorders</a> including amyotrophic lateral sclerosis, or ALS, Parkinson’s disease and Alzheimer’s disease.
In particular I was struck by scientists’ finding high levels of BMAA in <a href="https://doi.org/10.1073/pnas.0914417107">mollusks and fish found in the Baltic Sea</a>, which could potentially play a role in Finland’s high incidence of dementia, as fish is heavily consumed there.</p>
<p>Blue-green algae is found in <a href="https://www.cdc.gov/habs/index.html">rivers, lakes and seas</a>. Its presence is a widespread problem for humans, dogs and wildlife in the U.S. and Canada, as well as around the globe. In 2020, <a href="https://www.bbc.com/news/world-africa-54234396">more than 300 elephants in Botswana died</a> after drinking from water sources contaminated by the cyanobacteria that cause these algal blooms. Blue-green algae is so widely present in Finland that scientists there have developed <a href="https://www.utu.fi/en/news/news/novel-testing-device-will-reveal-whether-water-contains-toxic-blue-green-algae">a quick test to determine whether it is present or not.</a></p>
<h2>Mold neurotoxins</h2>
<p>In Finland, warm, humid air creates the perfect conditions for mold to grow, and water-damaged buildings are particularly susceptible. Some species emit mycotoxins, or mold toxins. Long-term exposure to mycotoxins, even at low levels, can present <a href="https://doi.org/10.1080/00039896.2003.11879142">serious health hazards</a> for both people and animals. </p>
<p>Mold spores are tiny, making them easy to inhale or ingest. Inside the body they can trigger an immune response, leading to chronic inflammation. Ultimately, exposure to these spores may cause <a href="https://doi.org/10.1016/j.shaw.2020.01.003">cognitive impairment</a>, including memory loss, irritability, numbness, tremors and other symptoms. Such a situation is likely to develop after a region has experienced the flooding of residences or workplaces in the weeks after they have been damaged.</p>
<p>Mold toxins, particularly <a href="https://doi.org/10.1002/mnfr.200600137">ochratoxin A</a>, can trigger inflammation that may harm neurons and brain function. It has been <a href="https://doi.org/10.1016/j.jns.2006.06.006">specifically implicated</a> in Parkinson’s disease. </p>
<h2>Reducing risk and a way forward</h2>
<p>Education, greater awareness of environmental health concerns and public action are the best ways to minimize risks from environmental neurotoxins.</p>
<p>By learning to recognize blue-green algae, people may avoid swimming or boating near it and avoid letting their pets near it too. Consumers can advocate for greater environmental monitoring of food and water sources. Exercise that involves sweating can <a href="https://doi.org/10.1155/2017/3676089">help eliminate neurotoxic substances</a>. But before you exercise outdoors, it is prudent to check air quality on an app or website like <a href="https://www.airnow.gov/">AirNow</a>, a partnership of federal, state, local and tribal agencies.</p>
<p>If environmental policies aren’t put into place to mitigate the health risks posed by environmental neurotoxins, <a href="https://doi.org/10.4172/2161-0460.1000249">research suggests</a> that we may continue to experience increases in a variety of neurodegenerative disorders as the toxins rise. Many of these conditions are labeled idiopathic, or lacking a known cause. The neurotoxic connection is rarely considered, and environmental health hazards are <a href="https://doi.org/10.1186/s12909-020-02458-x">often overlooked in American health care</a>. This is in large part because environmental health is rarely taught in medical education, which can lead to a lack of awareness about potential diagnoses related to an environmental illness.</p>
<p>The U.S. Environmental Protection Agency is currently <a href="https://www.epa.gov/system/files/documents/2021-10/draft-policy-assessment-for-the-reconsideration-of-the-pm-naaqs_october-2021_0.pdf">reevaluating</a> air quality standards for particulate matter. A new EPA <a href="https://www.epa.gov/system/files/documents/2021-09/_epaoig_20210929-21-e-0264.pdf">inspector general report</a> calls for a strategic plan to control harmful algal blooms. Ohio, a leading state for public policy initiatives aimed at neurotoxic algal blooms, <a href="https://grist.org/politics/toxic-algae-blooms-are-multiplying-the-government-has-no-plan-to-help">now regulates</a> cyanotoxins in drinking water and advises farmers against adding fertilizer when the ground is saturated or when rain is in the forecast. </p>
<p>Since <a href="https://doi.org/10.1038/s41586-019-1468-9">climate change may be a driver for rising neurotoxins</a>, cutting greenhouse gas emissions and ensuring better environmental stewardship are essential to human health. Achieving this will require strong international and domestic efforts and a wide range of interventions by governments around the world. But all of these efforts must begin with a deeper and more widespread understanding of the profound nature of this problem – which should be a universal, nonpartisan concern. </p>
<p>[<em>Over 115,000 readers rely on The Conversation’s newsletter to understand the world.</em> <a href="https://theconversation.com/us/newsletters/the-daily-newsletter-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=100Ksignup">Sign up today</a>.]</p><img src="https://counter.theconversation.com/content/165866/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Arnold R. Eiser 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>Pollution from more frequent floods and wildfires – exacerbated by the warming climate – is threatening human health and poses particular risks to the brain.Arnold R. Eiser, Emeritus Professor of Medicine, Drexel UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1436762020-08-11T12:10:51Z2020-08-11T12:10:51ZI’m a COVID-19 long-hauler and an epidemiologist – here’s how it feels when symptoms last for months<figure><img src="https://images.theconversation.com/files/350936/original/file-20200803-20-9rnt4a.jpeg?ixlib=rb-1.1.0&rect=9%2C23%2C3070%2C1698&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Margot Gage Witvliet was hospitalized with COVID-19 in March. More than four months later, she has yet to recover.</span> <span class="attribution"><span class="source">Courtesy of Margot Gage Witvliet</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Imagine being young and healthy, a nonsmoker with no preexisting health conditions, and then waking up one morning feeling like you were being suffocated by an unseen force. Back in March, this was my reality. </p>
<p>I had just returned from Europe, and roughly 10 days later started having flu-like symptoms. I became <a href="https://youtu.be/ci0zhXuCv5c">weak overnight</a> and had trouble breathing. It felt like jogging in the Rocky Mountains without being in condition, only I wasn’t moving. I went to the hospital, where I was tested for COVID-19. </p>
<p>I was one of the first people in Texas given a non-FDA-approved test. My results came back negative. As a <a href="http://www.margotwitvliet.com">social epidemiologist</a> who deals with big data, I was certain it was a <a href="https://doi.org/10.7326/M20-1495">false negative</a>. </p>
<p>More than four months later, the symptoms have not gone away. My heart still races even though I am resting. I cannot stay in the sun for long periods; it zaps all of my energy. I have gastrointestinal problems, ringing in the ears and chest pain.</p>
<p>I’m what’s known as a long-hauler – part of a growing group of people who have COVID-19 and have never fully recovered. Fatigue is one of the most common persistent symptoms, but there are many others, including the cognitive effects people often describe as brain fog. As more patients face these persistent symptoms, employers will have to find ways to work with them. It’s too soon to say we’re disabled, but it’s also too soon to know how long the damage will last.</p>
<h2>The frustration of not knowing</h2>
<p>What made matters worse in the beginning was that my doctors were not certain I had COVID-19. My test was negative and I had no fever, so my symptoms did not fit into early <a href="https://www.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19-final-report.pdf">descriptions of the disease</a>. Instead, I was diagnosed with a respiratory illness, prescribed the Z-pack antibotic and a low dosage of an anti-inflammatory medication normally used for arthritis patients. </p>
<p>A <a href="https://doi.org/10.1101/2020.05.13.20101022">Yale study</a> released in May shows COVID-19 deaths in America do not reflect the pandemic’s true mortality rate. If I had died at home, my death would not have been counted as COVID-19. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/ClI_xYCVJGE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Margot Gage Witvliet and her daughters started a video blog before she fell ill. They ended up documenting her COVID-19 experience.</span></figcaption>
</figure>
<p>By the end of March, I was on the road to recovery. Then I had a seizure. In the ER, the doctor said I had COVID-19 and that I was lucky – tests showed my organs did not have lasting damage. After the seizure, I lay in my bedroom for weeks with the curtains drawn, because light and sound had started to hurt. </p>
<h2>The search for answers</h2>
<p>I did not understand why I was not recovering. I began searching for answers online. I found a support group for people struggling with COVID-19 long-term. They called themselves <a href="https://www.bbc.com/news/health-53269391">long-haulers</a>. </p>
<p>COVID-19 support groups show that there are many people not considered sick enough to be hospitalized – yet they are experiencing symptoms worse than the flu. It is possible COVID-19 is <a href="https://doi.org/10.1212/WNL.0000000000009937">neurotoxic</a> and is one of the first illnesses capable of crossing the blood-brain barrier. This might explain why <a href="https://doi.org/10.1016/j.eclinm.2020.100484">many people</a> like me have neurological problems. Many long-haulers are experiencing post-viral symptoms similar to those caused by mononucleosis and <a href="http://doi.org/10.1016/j.mehy.2020.110055">myalgic encephalomyelitis/chronic fatigue syndrome</a>. </p>
<p>A common frustration is that some medical doctors <a href="https://www.yahoo.com/news/women-survived-coronavirus-angry-persistent-224358983.html">dismiss their complaints</a> as psychological. </p>
<p>One woman in the support group wrote: “140 days later, so many are hard to breathe, and no doctors will take me seriously as I was diagnosed with a negative swab and negative antibodies.”</p>
<p>[<em>Get the best of The Conversation, every weekend.</em> <a href="https://theconversation.com/us/newsletters/weekly-highlights-61?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=weeklybest">Sign up for our weekly newsletter</a>.]</p>
<p>Paul Garner was the first epidemiologist to publicly share his COVID status. He described his 7-week fight with the coronavirus <a href="https://blogs.bmj.com/bmj/2020/06/23/paul-garner-covid-19-at-14-weeks-phantom-speed-cameras-unknown-limits-and-harsh-penalties/">in a blog</a> post for the British medical journal The BMJ. In July, I was <a href="https://abc13.com/covid-19-coronavirus-ewn-houston/6331945/">interviewed by ABC</a>. That month, an Indiana University researcher working with an online community of long-haulers released a report identifying over <a href="https://static1.squarespace.com/static/5e8b5f63562c031c16e36a93/t/5f20f07af57a1f3b8b3d5045/1595994237318/2020+Survivor+Corps+COVID-19+%27Long+Hauler%27+Symptoms+Survey+Report+%28revised+July+25%29.pdf">100 symptoms</a>, and the CDC <a href="https://www.cdc.gov/media/releases/2020/p0625-update-expands-covid-19.html">expanded its list</a> of characteristics that put people at greater risk of developing severe COVID-19 symptoms. On July 31, the CDC also acknowledged that young people with no prior medical issues can experience <a href="https://www.cdc.gov/mmwr/volumes/69/wr/mm6930e1.htm">long-term symptoms</a>. </p>
<p>It’s still unclear why COVID-19 impacts some people more severely than others. Emerging <a href="https://doi.org/10.1101/2020.05.31.20114991">evidence suggests blood type</a> might play a role. However, <a href="http://doi.org/10.1007/s00277-020-04169-1">data are mixed</a>. </p>
<p>A <a href="https://innovationorigins.com/dutch-university-hospital-radboudumc-finds-genetic-mutation-tlr7-as-a-cause-for-corona/">Dutch study</a> found immune cells TLR7 – Toll-like receptor 7 located on the X chromosome – which is needed to detect the virus is not operating properly in some patients. This allows COVID-19 to move unchecked by the immune system. Men do not have an extra X chromosome to rely on, suggesting that men, rather than women, may experience more <a href="http://doi.org/10.1001/jama.2020.13719">severe COVID-19 symptoms</a>. </p>
<p>Many COVID-19 survivors report having <a href="https://www.nytimes.com/2020/07/26/health/coronvirus-antibody-tests.html">no antibodies</a> for SARS-CoV-2. Antibody tests have a <a href="http://doi.org/10.1016/j.arth.2020.04.055">low accuracy rate</a>, and data from <a href="https://doi.org/10.1101/2020.06.29.174888">Sweden</a> suggest T-cell responses might be more important for immunity. Emerging <a href="https://doi.org/10.1016/j.cell.2020.05.015">evidence</a> found CD4 and CD8 memory T-cell response in some people recovered from COVID-19, regardless of whether <a href="https://doi.org/10.1038/s41586-020-2550-z">antibodies</a> were present. <a href="https://doi.org/10.1016/j.cell.2020.05.015">A La Jolla Institute for Immunity</a> study identified SARS-CoV-2-specific memory T-cell responses in some people who were not exposed to COVID-19, which might explain why some people get sicker than others. The complete role of T-cell response is unknown, but <a href="https://doi.org/10.1038/s41577-020-0389-z">recent data are promising</a>. </p>
<h2>Looking ahead in an economy of long-haulers</h2>
<p>Like many long-haulers, my goal is to resume a normal life. </p>
<p>I still grapple with a host of post-viral issues, including extreme fatigue, brain fog and headaches. I spend the majority of my day resting. </p>
<p>A big challenge long-haulers face may be sustaining employment. Ultimately, it is too early to classify long-haulers as having a disability. Anthony <a href="https://www.yahoo.com/news/dr-fauci-says-months-more-030510193.html">Fauci reported</a> that “it will take months to a year or more to know whether lingering COVID-19 symptoms in young people could be chronic illnesses.” </p>
<p>Economics is a big driver of health, and the <a href="https://www.rwjf.org/en/library/research/2012/12/how-does-employment--or-unemployment--affect-health-.html">link between employment and health care in America</a> further exacerbates the need to maintain employment to protect health. Employers need to be ready to make accommodations to keep long-haulers working. The stress of being sick long-term, combined with the possibility of job loss, can also contribute to mental health issues. </p>
<p>To effectively fight COVID-19 and understand the risks, these patients with <a href="https://www.healthywomen.org/your-health/covid-19-long-haulers-are-finally-being-heard">continuing symptoms</a> must be studied. Online support groups, meanwhile, are helping long-haulers feel understood.</p><img src="https://counter.theconversation.com/content/143676/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Margot Gage Witvliet 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>Margot Gage Witvliet went from being healthy and active to fearing she was dying almost overnight. An epidemiologist, she dug into the research to understand what’s happening to long-haulers like her.Margot Gage Witvliet, Assistant Professor of Social Epidemiology, Lamar UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1297882020-01-29T19:07:56Z2020-01-29T19:07:56ZPlants safely store toxic mercury. Bushfires and climate change bring it back into our environment<figure><img src="https://images.theconversation.com/files/309828/original/file-20200114-103971-187s8fv.jpg?ixlib=rb-1.1.0&rect=0%2C197%2C5874%2C3763&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Industrial activities like mining, fossil fuel combustion, and cement production release mercury into the environment.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Climate change and bushfire may exacerbate recent mercury pollution and increase exposure to the poisonous neurotoxin, according to our study published in the <a href="https://link.springer.com/article/10.1007%2Fs10933-020-00111-7">Journal of Paleolimnology</a>.</p>
<p>Mercury stored in plants is released during bushfires, suggesting Australia is particularly at risk. </p>
<p>Our study in the Venezuelan Andes examined how mercury deposits responded when the world warmed by about 3°C between 14,500 and 11,500 years ago. (Scientists call this period the transition from the Last Glacial Maximum to the Holocene).</p>
<p>We found the amount of mercury deposited in the environment at this time increased four-fold. </p>
<h2>A dangerous neurotoxin</h2>
<p>Mercury is a naturally occurring but dangerous <a href="https://www.medicalnewstoday.com/articles/320563.php#symptoms">neurotoxin</a> that, in sufficient amounts, can cause impaired motor skills, breathing difficulty and memory problems in humans. </p>
<p>Once in the environment, mercury builds up in the bodies of animals. The build-up is magnified when those animals are then eaten by other animals, and so on. This process is called <a href="http://www.novapublishers.org/catalog/product_info.php?products_id=41858">bioaccumulation and biomagnification</a>.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australia-emits-mercury-at-double-the-global-average-82577">Australia emits mercury at double the global average</a>
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<p>Industrial activities such as mining, fossil fuel combustion and cement production release mercury into the environment. </p>
<p>Over the past 150 years, <a href="https://www.ncbi.nlm.nih.gov/pubmed/29897241">humans have tripled the amount of mercury in the atmosphere</a>. It can remain there for months, and be transported by wind to even the most remote ecosystems on Earth. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/309858/original/file-20200114-103987-1u7d48b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/309858/original/file-20200114-103987-1u7d48b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/309858/original/file-20200114-103987-1u7d48b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/309858/original/file-20200114-103987-1u7d48b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/309858/original/file-20200114-103987-1u7d48b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/309858/original/file-20200114-103987-1u7d48b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/309858/original/file-20200114-103987-1u7d48b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/309858/original/file-20200114-103987-1u7d48b.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"></a>
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<span class="caption">Mercury is dangerous to humans and wildlife.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<h2>Climate change unlocks mercury deposits</h2>
<p>Average global temperatures have <a href="https://earthobservatory.nasa.gov/world-of-change/DecadalTemp">increased by 0.8°C since 1880</a> , with <a href="https://earthobservatory.nasa.gov/world-of-change/DecadalTemp">two-thirds of this warming occurring since 1975</a>. Understanding how mercury responded to past known climate change may help us forecast future mercury exposure as the climate warms. </p>
<p>The Last Glacial Maximum (also known as an ice age), and the start of the Holocene (the present period), occurred between 19,000 and 11,700 years ago. </p>
<hr>
<p>
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<strong>
Read more:
<a href="https://theconversation.com/another-problem-with-chinas-coal-mercury-in-rice-92974">Another problem with China's coal: Mercury in rice</a>
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</em>
</p>
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<p>It was not a smooth transition; global climate oscillated between warm and cold at this time. </p>
<p>Abrupt returns to cold, glacial-like conditions occurred during two periods of time called the <a href="https://theconversation.com/new-evidence-that-an-extraterrestrial-collision-12-800-years-ago-triggered-an-abrupt-climate-change-for-earth-118244">Older Dryas and the Younger Dryas</a>. These climate oscillations provide a unique opportunity to understand how mercury in our environment responds to rapid climate change. </p>
<h2>Looking in lakes</h2>
<p>Layers of sediment settle to the bottom of lakes over thousands of years. By collecting sediment cores, scientists can <a href="https://www.mercury-australia.com.au/monitoring-mercury-in-sediments/">precisely date each layer and reconstruct past climates</a>. Lake sediment also provide a good historical of mercury contamination.</p>
<p>We examined how mercury deposits in a small lake – the Laguna de Los Anteojos in the Venezuelan Andes – changed as the ecosystem shifted with the climate.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/309857/original/file-20200114-103994-e46rc2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/309857/original/file-20200114-103994-e46rc2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/309857/original/file-20200114-103994-e46rc2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/309857/original/file-20200114-103994-e46rc2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/309857/original/file-20200114-103994-e46rc2.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/309857/original/file-20200114-103994-e46rc2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/309857/original/file-20200114-103994-e46rc2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/309857/original/file-20200114-103994-e46rc2.jpeg?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">We studied how mercury deposits in this small lake, named Laguna de Los Anteojos, changed as the climate warmed.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Laguna_los_Anteojos.JPG">Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>We found the amount of mercury in the lake increased rapidly as temperature increased – which doesn’t bode well for us. </p>
<p>It suggests human-caused global warming might drive a similar increase in the amount of mercury deposited in remote ecosystems, even if emissions are reduced.</p>
<p>As the climate warmed, we found, more mercury entered water systems. Once in the aquatic system, it can be absorbed by plants or consumed by animals, and pass on up the food chain in ever-increasing amounts.</p>
<h2>Bushfires dump more mercury into the environment</h2>
<p>Plants can store a significant pool of mercury from the atmosphere, which is good - until fires occur. </p>
<p>Unfortunately, mercury stored by vegetation is <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1797869/">released during burning</a>. This is particularly the case in contaminated areas, where plants store significant quantities of mercury emitted from human activities <a href="https://theconversation.com/mercury-pollution-from-decades-past-may-have-been-re-released-by-tasmanias-bushfires-114603">such as mining</a>. </p>
<p>Given the recent catastrophic fires engulfing large tracts of land in Australia, that’s a worry. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/309856/original/file-20200114-103966-1177p5k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/309856/original/file-20200114-103966-1177p5k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/309856/original/file-20200114-103966-1177p5k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/309856/original/file-20200114-103966-1177p5k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/309856/original/file-20200114-103966-1177p5k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/309856/original/file-20200114-103966-1177p5k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/309856/original/file-20200114-103966-1177p5k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/309856/original/file-20200114-103966-1177p5k.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"></a>
<figcaption>
<span class="caption">Plants can store a significant pool of mercury from the atmosphere, which is good - until bushfires occur.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>There’s a dearth of mercury studies in Australia (a fact <a href="https://www.unenvironment.org/resources/publication/global-mercury-assessment-2018">acknowledged even by the United Nations</a>) so it’s not yet possible to estimate mercury emissions from the recent Australian bushfires. </p>
<p>One thing we do know, however, is the number of bushfires in Australia is not expected to decrease.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/many-of-our-plants-and-animals-have-adapted-to-fires-but-now-the-fires-are-changing-129754">Many of our plants and animals have adapted to fires, but now the fires are changing</a>
</strong>
</em>
</p>
<hr>
<p>It sounds bleak, but <a href="https://www.mercury-australia.com.au/">Australian researchers</a> are working hard to better understand how mercury behaves as our ecosystem changes. </p>
<p>The more we know, the better our chances of mitigating mercury pollution and the risk it poses to humans and wildlife.</p><img src="https://counter.theconversation.com/content/129788/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Larissa Schneider receives funding from The Australian Research Council and from The Brazilian National Council for Scientific and Technological Development. She is affiliated with The Australian National University and The Australian Research Council Centre of Excellence for Biodiversity and Heritage.</span></em></p><p class="fine-print"><em><span>Nathan D Stansell receives funding from the U.S. National Science Foundation. </span></em></p><p class="fine-print"><em><span>Simon Haberle receives funding from the ARC.</span></em></p><p class="fine-print"><em><span>Colin Cooke 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>Plants can store mercury and keep it from contaminating waterways, air and soils. Unfortunately, that mercury is released when plants burn.Larissa Schneider, DECRA fellow, Australian National UniversityColin Cooke, University of AlbertaNathan D Stansell, Associate Professor, Northern Illinois UniversitySimon Haberle, Professor, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/575792016-04-14T07:01:28Z2016-04-14T07:01:28ZWhat causes Parkinson’s disease? What we know, don’t know and suspect<figure><img src="https://images.theconversation.com/files/118639/original/image-20160414-22075-1cr08pm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Motor symptoms of Parkinson's include tremors, stiffness and slowness or loss of spontaneous movement.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/79519692@N00/231180076/in/photolist-mqRMo-7RyWYU-7LtkKX-6p5wTX-aoiRqJ-8hZWGu-D7RaZi-6GHET-DUjfpZ-Ba7N7x-AsJZR3-acQhgV-hsAvvp-68MVC-bnYakX-pALEDN-pDJRmJ-gKpdQk-p19gmW-pZLEbh-beS3gt-onnXYp-7gSTSt-eobJgL-pQUUdQ-oBXnDx-8vqXno-8k9ekD-cF4PXh-eg99jP-7pGmGk-8P3SwX-i1Tip-JVZFK-6tBJaX-7Z6yJz-afjNJ-doJdk-67j9Dg-5Epx4V-tL7a7G-4N7hvv-2dK3NE-5miJj1-aKtnk-bmAHW7-aDBUvk-6rPqC-h1GgW-sbnZCe">Lisa/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Parkinson’s disease is the second-most-prevalent neurodegenerative condition in Australia, with an estimated 70,000 Australians living with the disease. Because of its complex and debilitating nature, Parkinson’s is a great burden on its sufferers and a great <a href="http://www.aihw.gov.au/publication-detail/?id=6442467990">cost</a> to society.</p>
<p>Key motor symptoms include tremors, rigidity and stiffness, slowness or loss of spontaneous movement, and poor balance and co-ordination. Non-motor symptoms can be equally debilitating and include dementia, constipation, pain, sleep disturbance, dizziness when you stand up, and sexual dysfunction. Not all people with Parkinson’s will experience all of these symptoms; there is considerable variability in the severity of symptoms among patients, breadth of symptoms, speed of decline, and responsiveness to therapy. </p>
<p>Currently, there is no cure or drug to slow the underlying disease progression. However, there are now multiple surgical therapies and medicines that can be very effective in managing the motor symptoms of the disease. </p>
<p>There are some known causes of Parkinson’s disease, but these are the exception. The underlying causes of sporadic Parkinson’s are unknown and likely influenced by a number of risk factors – molecular, genetic, behavioural and environmental. </p>
<h2>Known risk factors</h2>
<p><strong>Ageing</strong></p>
<p>Advancing age is the biggest risk factor for Parkinson’s disease. However, not everyone who ages develops Parkinson’s (only around 1-2%) and not everyone who has Parkinson’s is of advanced age (approximately 20% of cases begin before age 60). </p>
<p>It is likely ageing increases the vulnerability of the brain to the degeneration seen with Parkinson’s. Fundamental processes of the cell, such as mitochondrial activity (energy production) and protein degradation, fatigue with age and have been identified as factors involved in cell death leading to the symptoms observed in Parkinson’s. </p>
<p>Iron also accumulates in the brain with age, and especially in people with Parkinson’s. Too much iron can cause cell death by <a href="http://www.ncbi.nlm.nih.gov/pubmed/12666096">oxidative stress</a> – a rusting-type chemical reaction. In fact, rare genetic causes of brain iron elevation often present as Parkinson’s. </p>
<p><strong>Genetics</strong></p>
<p>Approximately 15% of individuals with Parkinson’s have a family history of the disease, which is one of the greatest risk factors. For most cases, however, the genetic contribution is complex. Familial mutations can cause Parkinson’s and account for around 5% of cases. </p>
<p>There are 18 chromosomal gene locations that have been named “PARK” (PARK1-18) because of their link to Parkinson’s. However, mutations in only six genes have been unequivocally shown to cause the disease. Scientists are still trying to determine the functions of these genes and how they interact normally compared to in the diseased state.</p>
<p>Variants in other genes have been shown to increase the risk of Parkinson’s, yet not everyone with these variants develops Parkinson’s. This shows the complex genetic and environmental interactions that underlie the disease.</p>
<p><strong>Toxins</strong></p>
<p>In 1983, a group of injecting drug users injected drugs contaminated with MPTP (1-methyl-4-phenyl-1,2,3,6-tetra hydropyridine), <a href="http://content.time.com/time/magazine/article/0,9171,141542,00.html">resulting in the development of Parkinson’s symptoms</a>. MPTP is a synthetic chemical compound with a similar chemical structure to the herbicide paraquat.</p>
<p>Paraquat and especially MPTP are used routinely in laboratories to induce Parkinson’s in rodents. Rotenone is an organic pesticide that also causes Parkinsonian neurodegeneration in rodents. Historical exposure to pesticides, especially paraquat and rotenone, has been repeatedly associated with increased risk of Parkinson’s in studies throughout the world. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/118649/original/image-20160414-4676-8ierbz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/118649/original/image-20160414-4676-8ierbz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/118649/original/image-20160414-4676-8ierbz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/118649/original/image-20160414-4676-8ierbz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/118649/original/image-20160414-4676-8ierbz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/118649/original/image-20160414-4676-8ierbz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/118649/original/image-20160414-4676-8ierbz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/118649/original/image-20160414-4676-8ierbz.jpg?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">Pesticides are used to give lab rats Parkinson’s.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/jz909/1450513463/in/photolist-3dbg7P-aYJmUR-gdHXEr-4otNGD-nKk49a-o2wq88-bkaH9d-jZtpkk-71EWJx-6pxbhW-nKm11T-9ztKDr-7Zskpt-o2GzZo-FqB8c-pm4ZeY-bkaHgq-hKwMX1-boxv7T-dpuBXG-oVnd6P-bsD2eD-8aXcTA-8aXcP5-3v3yx-6dkuDb-ce7RZw-Nt5QP-6QKkBc-nKkc9E-52LCHk-NYaqJ-2AhCW9-8wQE8x-ds1MuW-ds1MwS-ds1MvU-3HRSHZ-nrqASz-jgp5ru-93nrci-5mEtvZ-pPtEg6-e6EQGQ-23666p-9BJi2j-p7wBdB-kkxxv-5wCTgg-7k9FWP">Jetsandzeppelins/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>A <a href="http://www.ncbi.nlm.nih.gov/pubmed/11022853">meta-analysis</a> reported pesticide exposure was associated with increased Parkinson’s risk with an odds ratio of 1.94. This means persistent exposure to pesticides is associated with almost doubling of the risk for Parkinson’s. It must be clarified that this would only increase the risk from 1-2% to 2-4% in those aged over 50. </p>
<p>Paraquat is a widely used herbicide, while the use of rotenone has declined significantly throughout the world. Farming practices have changed dramatically over many years. It is possible that the increased risk of Parkinson’s associated with pesticides reflects the use of these and other chemicals in a time when they were handled less safely. </p>
<p><strong>Metals</strong></p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/16325915">Manganism</a> is a condition with symptoms that resemble Parkinson’s and is caused by chronic exposure to the metal manganese. Animal experiments have shown that iron exposure in infancy is associated with Parkinsonian neurodegeneration later in life. <a href="https://www.researchgate.net/profile/Monique_Breteler/publication/7067653_Epidemiology_of_Parkinson's_disease/links/53f4adef0cf2888a74911323.pdf">Epidemiological evidence</a> of exposure to iron and heavy metals is inconclusive (although brain iron has been repeatedly observed in Parkinson’s independent of environmental exposure).</p>
<h2>Suspected risk factors</h2>
<p><strong>Head trauma</strong></p>
<p><a href="http://oem.bmj.com/content/70/12/839.long">Epidemiological studies</a> linking head injuries to the development of Parkinson’s have been inconsistent, with varying strengths of association reported. </p>
<p>The nature of the head trauma appears to have relevance in determining risk. <a href="http://archneur.jamanetwork.com/article.aspx?articleid=591102">Injuries causing concussion or loss of consciousness</a> have been more strongly related to Parkinson’s disease. </p>
<p>Many believe chronic brain damage from boxing led to Muhammad Ali developing Parkinson’s. It is not possible, however, to determine that <a href="https://patients.aan.com/resources/neurologynow/index.cfm?event=home.showArticle&id=ovid.com%3A%2Fbib%2Fovftdb%2F01222928-200602020-00005">boxing definitely</a> led to the development of Ali’s Parkinson’s.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/118654/original/image-20160414-4674-kdb0e3.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/118654/original/image-20160414-4674-kdb0e3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/118654/original/image-20160414-4674-kdb0e3.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=446&fit=crop&dpr=1 600w, https://images.theconversation.com/files/118654/original/image-20160414-4674-kdb0e3.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=446&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/118654/original/image-20160414-4674-kdb0e3.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=446&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/118654/original/image-20160414-4674-kdb0e3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=561&fit=crop&dpr=1 754w, https://images.theconversation.com/files/118654/original/image-20160414-4674-kdb0e3.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=561&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/118654/original/image-20160414-4674-kdb0e3.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=561&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Most assume Muhammad Ali’s boxing career led to Parkinson’s disease.</span>
<span class="attribution"><span class="source">Youtube</span></span>
</figcaption>
</figure>
<h2>Protective factors</h2>
<p>Some studies have suggested <a href="https://www.researchgate.net/profile/Monique_Breteler/publication/7067653_Epidemiology_of_Parkinson's_disease/links/53f4adef0cf2888a74911323.pdf">antioxidants, vitamins and smoking</a> may have a small protective effect on the development of Parkinson’s. Caffeine intake has been consistently associated with decreased Parkinson’s risk, particularly for men, and lower Parkinson’s incidence is reported in people who have ever smoked cigarettes.</p>
<p>Most of the studies to date have been case control studies or cross-sectional surveys, which are prone to recall and selection bias. These studies cannot determine causation. More robust epidemiological studies, such as large cohort studies looking at large populations and incidences of the disease, are required to further investigate the causes of Parkinson’s.</p>
<p>The main research challenges are the lack of clear markers of the disease, lack of diagnostic tests, and the later age of onset of the disease. Parkinson’s research requires significant commitment on the part of community members, researchers, community-based stakeholders, the health sector, governments and other funding agencies.</p><img src="https://counter.theconversation.com/content/57579/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Darshini Ayton has received funding from Parkinson's Victoria. </span></em></p><p class="fine-print"><em><span>Narelle Warren receives funding from the National Health and Medical Research Council, the Australian Research Council, Limbs 4 Life, UCB Australia, and Parkinson's Victoria. This research was funded by Parkinson's Victoria. </span></em></p><p class="fine-print"><em><span>Scott Ayton receives funding from NHMRC, ARC, Bethlehem Griffiths Research Foundation, Alzheimer's Association, Alzheimers' Research UK, The Michael J. Fox Foundation, Weston Brain Institute, and Parkinson's Victoria. He is a member of the Liberal party. </span></em></p>Parkinson’s disease is the second-most-prevalent neurodegenerative condition in Australia, with an estimated 70,000 living with the disease. But what do we know about the causes and risk factors?Darshini Ayton, Research Fellow and Lecturer, Monash UniversityNarelle Warren, Lecturer in Anthropology, Monash UniversityScott Ayton, Research Fellow, Florey Institute of Neuroscience and Mental Health, Florey Institute of Neuroscience and Mental HealthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/536342016-02-03T11:09:55Z2016-02-03T11:09:55ZIn kids, even low lead levels can cause lasting harm<figure><img src="https://images.theconversation.com/files/109727/original/image-20160129-3898-1l6evrr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lead exposure is more common than you think.</span> <span class="attribution"><span class="source">CDC/Dawn Arlotta</span></span></figcaption></figure><p>The recent firestorm over lead exposure from drinking water in Flint, Michigan is a reminder of the enduring risk posed by environmental lead. While we can all agree that it is unacceptable for children to be exposed to dangerously high levels of lead, there is less awareness of what this means. </p>
<p>Flint is just one of many cities in the country where lead exposure is a serious issue. For cities with an industrial past and much <a href="http://www.cdc.gov/nceh/lead/tips.htm">pre-1978 housing stock</a>, like Cleveland, where we work, the risks to today’s children is of continuing concern. In recent years, we and our colleagues have been examining the incidence and effects of lead exposure on young children in Cleveland and its first-ring suburbs. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/109721/original/image-20160129-3910-hbfagf.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/109721/original/image-20160129-3910-hbfagf.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/109721/original/image-20160129-3910-hbfagf.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/109721/original/image-20160129-3910-hbfagf.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/109721/original/image-20160129-3910-hbfagf.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/109721/original/image-20160129-3910-hbfagf.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/109721/original/image-20160129-3910-hbfagf.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/109721/original/image-20160129-3910-hbfagf.JPG?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">Even though lead paint was banned in 1978, many old homes still have it.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File%3ALeadPaint1.JPG">Thester11 via Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Lead is a known neurotoxin that is <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1257652/">associated with cognitive deficits</a> in children – <a href="http://eric.ed.gov/?id=ED509746">even at low levels of exposure</a>. In fact, reports indicate that most of the harm may occur at levels of <a href="http://www.biologicaldiversity.org/campaigns/get_the_lead_out/pdfs/health/Bellinger_2008b.pdf">exposure well below current standards</a> for concern. Though lead is no longer used in household paint and has been removed from gasoline, there is still plenty of it out there. Lead leaching into water pipes, in paint dust and chips, and soil remains a serious threat to children. </p>
<p>Children living in low-income neighborhoods, children of color and children whose families live in rental housing are statistically <a href="https://www.huduser.gov/portal/periodicals/em/fall14/highlight1.html">at the greatest risk of exposure to lead</a>. That means the children most at risk of lead exposure also disproportionately face the effects of poverty, low-resource communities and trauma.</p>
<h2>Lead’s effects never go away</h2>
<p>Often attention is focused on the number of children who have an elevated lead test result in a given year. This is an important metric, but it can mask the <a href="http://www.cdc.gov/nceh/lead/ACCLPP/meetingMinutes/lessThan10MtgMAR04.pdf">cumulative role of lead exposure</a> on child development.</p>
<p>For example, in <a href="http://www.ccbh.net/lead-level-maps">Cuyahoga County</a>, where nearly 25,000 children are tested each year, we have seen the number of children with an elevated blood lead level (above 5 micrograms per deciliter) drop from 35 percent in 2004 to 9 percent in 2013. This is a very encouraging trend showing success from public health efforts. </p>
<p>Despite the fact that the number of children with high lead level rates seems to be going down, it is important to think about the overall share of children that have ever had a positive lead test. These children carry those effects with them as they age.</p>
<p>In a recent unpublished analysis using integrated data from multiple sources, we found that fully 35 percent of children in a sample of preschool classrooms had an elevated blood lead level at some point in their lives. </p>
<p>The treatment options for children with elevated blood lead levels include dietary approaches and dealing with the effects of lead by managing sensory exposures. At greater exposures, <a href="http://pediatrics.aappublications.org/content/116/4/1036">chelation therapy</a> – in which a synthetic compound is injected into the bloodstream which binds itself to the heavy metals – can be used. Though chelation has been shown to significantly reduce blood lead levels in the short term, there is evidence of a rebound in lead levels after therapy has concluded. Also, blood lead levels do not fully capture the retention of <a href="http://www.who.int/selection_medicines/committees/expert/18/applications/4_2_LeadOralChelators.pdf">lead in bone and deep tissue</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/109722/original/image-20160129-3905-67tthx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/109722/original/image-20160129-3905-67tthx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/109722/original/image-20160129-3905-67tthx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/109722/original/image-20160129-3905-67tthx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/109722/original/image-20160129-3905-67tthx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/109722/original/image-20160129-3905-67tthx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/109722/original/image-20160129-3905-67tthx.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">
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<span class="caption">Kids with lead exposure start behind nonexposed kids.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-338318210/stock-photo-smiling-kids-playing-with-modelling-clay-at-their-desk.html?src=aLBhNAKxA1a7a7-PF5YhxQ-7-20">Children image via www.shutterstock.com.</a></span>
</figcaption>
</figure>
<h2>Long-term consequences</h2>
<p>Children exposed to lead are at elevated risk for learning delays and academic issues. We have also found that students with confirmed early childhood lead exposure have lower kindergarten readiness scores. </p>
<p>In tracking the experiences of children in our community, we find that lead-exposed children entering high-quality preschool start the year significantly behind their nonexposed peers.</p>
<p>In our ongoing research, we have found that on standardized measures these children score 10-30 percent below their peers on skills such as identifying letters, numbers and shapes. More sobering is the reality that while these children show significant progress during preschool they still finish the year, on average, below where their nonexposed peers start the preschool year. </p>
<p>This disparity is likely to grow as children age unless special efforts are made to address it. Results from Detroit show that these children are much more likely to <a href="http://www.ncbi.nlm.nih.gov/pubmed/23327265">experience academic challenges as they age</a>.</p>
<p>And it looks like it doesn’t take much lead to cause harm. Other research has shown that blood levels well below the current standard for intervention can also <a href="http://pediatrics.aappublications.org/content/early/2013/05/08/peds.2012-2277">cause negative effects on school readiness</a> for young children.</p>
<h2>There is no known safe level of lead exposure</h2>
<p>Until a few years ago, the federal standard for action was 10 micrograms per deciliter of blood, and in 2012 it was <a href="http://www.cdc.gov/nceh/lead/">lowered by half</a> in recognition of evidence showing a lower threshold of concern. </p>
<p>But the truth is there is no known safe level of blood lead for children, and the <a href="https://www.aap.org/en-us/about-the-aap/aap-press-room/pages/AAP-Statement-CDC-Revised-Lead-Exposure-Guidelines.aspx">American Academy of Pediatrics</a> and the <a href="http://www.cdc.gov/nceh/lead/ACCLPP/Final_Document_030712.pdf">Centers for Disease Control and Prevention</a> have said as much.</p>
<p>The medical research community has documented negative impacts on children with even lower levels of lead exposure than the current 5 micrograms per deciliters standard. With that view, we might consider every child with a confirmed nonzero lead test as at-risk. </p>
<p>Based on our analysis of lead data <a href="http://www.ccbh.net/lead-level-maps">in our county</a>, we calculate that if this standard were adopted in the U.S., our lead exposure rate for kids younger than 6 in a single year would climb from 9 percent to 3-4 times this rate.</p>
<p>Short of ensuring that every housing structure has been certified as lead-safe, parents and caregivers should be the first line of defense in keeping children from this exposure. Testing lead blood levels in children is simply too late.</p>
<p>This is akin to the TSA searching for lethal weapons after the passengers have boarded the flight and the plan has taken off. Once the lead is in the bloodstream, the damage is real and lasting for these children, and the options for response are far fewer and less effective.</p><img src="https://counter.theconversation.com/content/53634/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robert L Fischer receives funding from the Cleveland Department of Public Health and the Cuyahoga County Office of Early Childhood, both of which have an interest in reducing childhood lead exposure and addressing its effects. </span></em></p><p class="fine-print"><em><span>Elizabeth Anthony 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>Children exposed to lead are at elevated risk for learning delays and academic issues.Robert L. Fischer, Co-Director of the Center on Urban Poverty and Community Development, Case Western Reserve UniversityElizabeth Anthony, Research Assistant Professor, Center on Urban Poverty and Community Development, Case Western Reserve UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/529812016-01-20T00:43:55Z2016-01-20T00:43:55ZExposure to algae toxin increases the risk of Alzheimer’s-like illnesses<figure><img src="https://images.theconversation.com/files/108489/original/image-20160119-31831-1eolgpd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Blue-green algae blooms are increasing in size and frequency as global temperatures rise.</span> </figcaption></figure><p>A paper published today suggests chronic exposure to an environmental toxin may increase the risk of neurodegenerative illness. </p>
<p>For the first time, researchers have shown that feeding vervet monkeys a toxin produced by blue-green algae resulted in protein deposits in the brain, consistent with those seen in human Alzheimer’s.</p>
<p>Neurodegenerative disease is an umbrella term which includes Alzheimer’s, Parkinson’s and motor neurone disease (MND). The causes remain largely unknown, and the role of environmental factors is poorly understood. </p>
<p>Owing to its role in an unusual illness suffered by Chamorro villagers on the Pacific island of Guam, researchers <a href="http://www.sciencedirect.com/science/article/pii/S0031942200860185">have been investigating</a> an algal toxin called <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3194113/">BMAA</a> for more than 40 years. </p>
<p>The Chamorros’ diet was contaminated with BMAA and they suffered from dementia as well as a combination of symptoms typical of Alzheimer’s, Parkinson’s and MND. </p>
<p>In the study published today in the <a href="http://rspb.royalsocietypublishing.org/">Royal Society Proceedings B</a>, researchers fed vervets fruit: some with BMAA, some with a placebo and some with a known inhibitor of BMAA, an amino acid called L-serine. </p>
<p>After 140 days, they detected protein tangles and plaques, a hallmark of neurodegenerative disease, in the brain tissue of all the animals fed BMAA, but not in the placebo animals. While the role of tangles and plaques in neurodegeneration has not been conclusively established, they are the prime suspects for causing the death of brain cells. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/108520/original/image-20160119-29798-enw848.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/108520/original/image-20160119-29798-enw848.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=480&fit=crop&dpr=1 600w, https://images.theconversation.com/files/108520/original/image-20160119-29798-enw848.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=480&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/108520/original/image-20160119-29798-enw848.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=480&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/108520/original/image-20160119-29798-enw848.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=603&fit=crop&dpr=1 754w, https://images.theconversation.com/files/108520/original/image-20160119-29798-enw848.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=603&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/108520/original/image-20160119-29798-enw848.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=603&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The cause of neurodegenerative disease remains largely unknown, and the role of environmental factors is poorly understood.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/evilmutent/14373309286/">Hugo Chisholm/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
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</figure>
<p>This is the first time researchers have been able to produce Alzheimer’s-like protein deposits in an animal model with an environmental toxin. </p>
<p>Even more fascinating was that the vervets fed BMAA plus L-serine showed a significant reduction in the number and density of protein tangles in the brain. This suggests that L-serine may be useful as a preventive therapy in people at risk of neurodegenerative illness. </p>
<p>L-serine was first reported to block BMAA toxicity in cell culture in 2013, but this is the first evidence it can prevent the formation of protein deposits in the brain. </p>
<h2>Testing the hypothesis</h2>
<p>What makes these findings so compelling is that while we’ve known for decades that BMAA was toxic, this is the first time it has been shown to directly cause disease. </p>
<p>BMAA was first suspected as a neurotoxin when it was linked to the Alzheimer’s-like illness in Guam, which at its peak killed 25% of the men of one village. </p>
<p>When the search for a genetic link turned up nothing, environmental triggers became the focus. BMAA was isolated from flour made from cycad seeds, which the villagers used to make tortillas. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/108517/original/image-20160119-29762-1gc59qn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/108517/original/image-20160119-29762-1gc59qn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/108517/original/image-20160119-29762-1gc59qn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/108517/original/image-20160119-29762-1gc59qn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/108517/original/image-20160119-29762-1gc59qn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/108517/original/image-20160119-29762-1gc59qn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/108517/original/image-20160119-29762-1gc59qn.jpg?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">
<figcaption>
<span class="caption">People who live by lakes that have frequent algal blooms are at a higher risk of MND.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/mpcaphotos/23008172424/">MPCA Photos/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
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</figure>
<p>The <a href="http://www.ncbi.nlm.nih.gov/pubmed/3603037">very first experiment</a> done in the 1980s found that BMAA was able to cause symptoms consistent with neurodegeneration, but was quickly discounted when it was argued that an equivalent human dose would require the consumption of more than 1,000 kilograms of cycad seed flour. And so BMAA was off the hook, at least for a few years. </p>
<p>A key missing puzzle piece was how BMAA might stick to proteins as was seen in the cycad flour. Its chemical structure meant it was water-soluble, so how was it building up in the flour? </p>
<p>It wasn’t until more than 40 years later that a plausible explanation was proposed. <a href="https://theconversation.com/toxic-load-blue-green-algaes-role-in-motor-neuron-disease-16041">A 2013 paper I worked on</a> reported that BMAA was similar in structure to another amino acid that humans use when they make proteins. So similar in fact, that we showed it could be mistakenly inserted into the protein chain when they were synthesised, rendering them toxic and subsequently killing cells. </p>
<h2>Role of blue-green algae</h2>
<p>Not only do the findings of today’s study provide evidence for what we’ve long suspected, they implicate a widely distributed toxin in a growing and formidable human health problem: dementia. </p>
<p>BMAA is made by blue-green algae (more accurately known as cyanobacteria). The algae have evolved over 3.5 billion years to grow in fresh and salt water, in the desert crusts of Qatar, and in the thermal pools of Yellowstone National Park, in Wyoming. </p>
<p>Blooms commonly occur where nutrients are high, such as in areas where agricultural run-off occurs, and can be identified by their bright green colour and putrid smell. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/108534/original/image-20160119-29750-5vphx1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/108534/original/image-20160119-29750-5vphx1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/108534/original/image-20160119-29750-5vphx1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/108534/original/image-20160119-29750-5vphx1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/108534/original/image-20160119-29750-5vphx1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/108534/original/image-20160119-29750-5vphx1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/108534/original/image-20160119-29750-5vphx1.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">Cyanobacterial mats in Yellowstone National Park. Pretty but toxic.</span>
<span class="attribution"><span class="source">scepdoll/flickr</span></span>
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</figure>
<p>The problem is these blooms are increasing in size and frequency as global temperatures rise. And Australia is not immune, having had the world’s <a href="https://books.google.com.au/books?id=FGu5V3_xjxQC&pg=PA330&lpg=PA330&dq=algal+bloom+in+the+summer+of+1991%E2%80%9392+australia&source=bl&ots=yWqZ3ut62v&sig=xEErROo7DpMSoxxzhVmRTiDJcxY&hl=en&sa=X&ved=0ahUKEwi7wou3kLfKAhXIX5QKHZioADgQ6AEISjAJ#v=onepage&q=algal%20bloom%20in%20the%20summer%20of%201991%E2%80%9392%20australia&f=false">largest freshwater</a> algal bloom in the summer of 1991–92 in the Barwon-Darling river system. </p>
<p>Even more concerning, and similar to what was observed on Guam, there is <a href="http://www.drrachie.com/research/2016/1/18/watering-wheat-with-bmaa-contaminated-water-results-in-bmaa-accumulating-in-roots-and-leaves">evidence</a> that BMAA can be absorbed into the proteins of grain crops if they’re irrigated with contaminated water.</p>
<p>We also <a href="http://discovermagazine.com/2011/may/22-seafood-toxins-causing-als-alzheimers-parkinsons">know</a> that BMAA concentrates in seafood, such as mussels, pink shrimp, prawns and lobsters, when they grow in waters where blooms flourish. </p>
<p>Studies <a href="http://www.tandfonline.com/doi/abs/10.3109/17482960903278485#.Vp3U7GR97dQ">show</a> that people who live by lakes subject to frequent algal blooms have an increased risk of contracting MND. The risk is even higher if you live downwind, suggesting a role for inhalation as a route for toxicity. </p>
<p>While the risk for exposure via these routes for those of us who have a balanced diet and live in the city is probably low, we simply don’t know how much BMAA is present in the environment because food and water is not routinely screened. <a href="http://www.ncbi.nlm.nih.gov/pubmed/26651568">Methods are available</a>, but they’re expensive and require a high level of skill to conduct accurately. This makes them impractical to implement on a commercial level. </p>
<p>Also, blue-green algae does not always make BMAA – ideal conditions include precise concentrations of nutrients and warm temperatures. </p>
<p>So if BMAA is already distributed throughout the environment, meaning we’ve all been potentially exposed to some degree, why don’t we all have some form of dementia? </p>
<p>Recent scientific modelling <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4197338/">suggests</a> that multiple “triggers” are required for disease to occur. Iin the case of neurodegeneration it’s likely you need a combination of genetic susceptibility, exposure to any number of environmental toxins (including BMAA) and other triggers as yet unknown. </p>
<p>In the meantime, the best advice is to take precautions – reduce your risk of exposure to BMAA by staying away from green, smelly blooms, don’t drink the water and take heed of warning signs. </p>
<p>Because even though we now know BMAA can cause disease, we don’t yet have a cure, so there’s much more work to do.</p><img src="https://counter.theconversation.com/content/52981/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rachael Dunlop is an inventor on a patent pending for L-serine as a treatment for neurodegenerative disease. She receives funding from The Institute for Ethnomedicine, Jackson, WY. </span></em></p>For the first time, researchers have shown that feeding vervet monkeys a toxin produced by blue-green algae resulted in protein deposits in the brain, consistent with those seen in human Alzheimer’s.Rachael Dunlop, Visiting associate , Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/497262015-12-22T11:08:37Z2015-12-22T11:08:37ZFrom blood diamonds to dirty gold: how to buy gold less tainted by mercury<figure><img src="https://images.theconversation.com/files/102909/original/image-20151123-18255-15hsbsk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A speck of gold from a mine in Liberia, Africa. </span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/dw-akademie-africa/6719515309/in/album-72157628924113415/">dw-akademie-africa</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>When a customer walks into a jewelry store, weddings or special occasions are usually front of mind. Rarely does that customer think of where the jewelry comes from, let alone its social and environmental costs. </p>
<p>The tragedy of <a href="http://www.amnestyusa.org/our-work/issues/business-and-human-rights/oil-gas-and-mining-industries/conflict-diamonds">“blood diamonds”</a> – illegally traded diamonds used to fund conflicts in Africa – has managed to permeate consumer consciousness and <a href="http://www.kimberleyprocess.com/">generate change</a>, yet most consumers have little idea of where their gold jewelry comes from or how it’s produced.</p>
<p><a href="http://www.artisanalgold.org/publications/articles/world-artisanal-gold-production">Around 20% of the gold</a> in a jewelry store comes from artisanal and small-scale gold mining. And this sector is now the <a href="http://www.unep.org/PDF/PressReleases/GlobalMercuryAssessment2013.pdf">leading source of man-made mercury pollution in the world</a>, emitting 727 metric tons of mercury into the environment in 2013, more than twice the amount in 2005.</p>
<p><a href="http://www2.epa.gov/mercury/health-effects-exposures-mercury">Mercury is a potent neurotoxin</a> that harms the brains, muscles and vital organs of adults and especially children. While most people now know about the threat from <a href="https://theconversation.com/the-mercury-level-in-your-tuna-is-getting-higher-37147">mercury in their tuna</a>, few know of its connection to the jewelry on the hand lifting their fork. </p>
<p>Restoring luster to the jewelry industry requires understanding what made it tarnish. A journey to the remote mountains, deserts and rainforests housing the world’s gold deposits reveals the story of desperate subsistence miners relying on mercury to make ends meet.</p>
<h2>Mercury in gold mining</h2>
<p>The artisanal and small-scale gold mining sector comprises 15-30 million men, women and children in <a href="http://www.mercurywatch.org/">over 60 developing countries</a> using rudimentary tools to mine small volumes of gold. </p>
<p>In researching ethics and global businesses, I’ve dug into how artisanal gold is produced and traded using reports from <a href="http://www.unep.org/chemicalsandwaste/Metals/GlobalMercuryPartnership/ArtisanalandSmall-ScaleGoldMining/tabid/3526/Default.aspx">intergovernmental organizations</a>, <a href="http://www.artisanalgold.org/">nongovernmental organizations</a> and <a href="https://www.researchgate.net/publication/272568475_Private_and_civil_society_governors_of_mercury_pollution_from_artisanal_and_small-scale_gold_mining_A_network_analytic_approach">academics</a>, as well as my own interviews with <a href="http://www.fairjewelry.org/about-us/">activists and industry representatives</a>. </p>
<p>Mining often occurs informally, meaning that miners forego acquiring permits to work whatever land they can find, be that land owned by large-scale multinational mining firms or ecologically sensitive land protected by the government. </p>
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<p>Once miners dig up a portion of promising earth from mountainsides or riverbeds, they grind it, mix it with water and then pour pure or elemental <a href="http://www.worstpolluted.org/projects_reports/display/87">mercury</a> on top, which binds to the gold in the earth thanks to the chemical attraction between the two elements. This divides the slurry into balls of a mercury-gold amalgam and a soup of muddy mercury-laced wastewater called “tailings.” </p>
<p>The tailings are dumped into local waterways, where the mercury is ingested by microorganisms and accumulates up aquatic food chains to end up in fish like tuna. Meanwhile, the mercury-gold amalgam balls are burned with blowtorches or on kitchen stovetops, a process which vaporizes the mercury into the atmosphere, leaving behind a semipure, sellable piece of gold.</p>
<p>Miners use mercury because it is the cheapest, easiest and fastest way to mine gold, and because they are unaware of its risks or ways of avoiding them. </p>
<p>Miners buy mercury from local black market dealers and many have no way of knowing that the invisible, odorless mercury vapor toxin is the source of their health problems, since it causes symptoms similar to other local ailments, such as malaria and STDs. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/102910/original/image-20151123-18246-1a8rxwk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/102910/original/image-20151123-18246-1a8rxwk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/102910/original/image-20151123-18246-1a8rxwk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/102910/original/image-20151123-18246-1a8rxwk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/102910/original/image-20151123-18246-1a8rxwk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/102910/original/image-20151123-18246-1a8rxwk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/102910/original/image-20151123-18246-1a8rxwk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/102910/original/image-20151123-18246-1a8rxwk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Children digging earth for gold in Liberia in 2011.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/dw-akademie-africa/6719514747/in/album-72157628924113415/">dw-akademie-africa</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Some miners, such as the <a href="http://www.pbs.org/newshour/bb/globalhealth-july-dec11-peru_12-27/">Aurelsa cooperative in Peru</a>, have managed to save enough money to upgrade to the cyanide leaching technique used by large-scale mining firms, which as the recent <a href="http://time.com/3991302/colorado-waste-water-spill/">Colorado mining disaster</a> shows, carries its own suite of hazards. </p>
<p>But the experience of miners in places like <a href="http://www.unep.org/hazardoussubstances/Portals/9/Mercury/Documents/ASGM/Formalization_ARM/Case%20Study%20Tanzania%20June%202012.pdf">Tanzania</a>, <a href="http://www.unep.org/chemicalsandwaste/Portals/9/Mercury/Documents/ASGM/Formalization_ARM/Case%20Studies%20Mongolia%20June%202012.pdf">Mongolia</a> and <a href="http://www.pbs.org/newshour/bb/extracting-gold-mercury-exacts-lethal-toll/">Indonesia</a> is more typical: families toil for generations without breaking above the poverty line or transitioning to safer livelihoods. Children often skip school to <a href="https://www.hrw.org/news/2013/08/28/tanzania-hazardous-life-child-gold-miners">help their families mine</a>, only to fall sick and never return. With no education, their only option is to continue the cycle of mining and poverty as adults.</p>
<h2>A top-heavy value chain</h2>
<p>With an everyday commodity like coffee, it’s understandable why producers don’t make much. There’s little scarcity in the natural world, and consumers purchase it everyday with little fanfare. But luxury goods are very different. Gold wedding rings are (theoretically…) once-in-a-lifetime purchases steeped in sentimental meaning. People do research and save for years in order to buy a ring that matches their preferences. </p>
<p>My own research shows that the price for an 18 karat gold wedding ring of average size and width can vary from about <a href="http://www.amazon.com/Womens-Yellow-Comfort-Plain-Wedding/dp/B001AEJVNW/ref=sr_1_1?ie=UTF8&qid=1449160939&sr=8-1&keywords=18k+yellow+gold+wedding+ring">US$200 at Amazon.com</a> to about <a href="http://www.tiffany.com/jewelry/rings/lucida-band-ring-GRP00364/lucida-band-ring-14765514?trackpdp=bg&fromgrid=1&fromcid=288152&search=0&search_params=p+1-n+10000-c+288152-s+5-r+-t+-ni+1-x+-lr+-hr+-ri+-mi+-pp+1841.6+6&origin=browse&searchkeyword=&prolookupsearchadd=&prolookupsearchwn=&prolookupsearchradio=&prolookupsearchcheck=">$800 at Tiffany & Co.</a> A typical price is around <a href="http://www.costofwedding.com/index.cfm/action/search.weddingcost/zipcode/00000/?sg_sessionid=1449163605_56607b55bf7e88.01564089&__sgtarget=-1&__sgbrwsrid=d62a3c3861892cc7c0864dd3f8edd956#sgbody-2438529">$500</a>. </p>
<p>The value of the gold in a ring is set daily by the <a href="http://www.lbma.org.uk/pricing-and-statistics">London Bullion Market Association</a>. When miners sell their gold into the value chain, large-scale firms earn about 98% of this value, while artisanal miners earn <a href="http://www.fairgold.org/q-a/">at most 70%</a>. This amounts to $74 for a typical $500 wedding ring and an average annual income hovering near or well below the <a href="http://econ.worldbank.org/WBSITE/EXTERNAL/EXTDEC/EXTRESEARCH/0,,contentMDK:22510787%7EpagePK:64165401%7EpiPK:64165026%7EtheSitePK:469382,00.html">World Bank’s measures</a> for extreme and moderate poverty ($1.25 to $2.50 per day). Without the money to send children to school and invest in cleaner technology, the mercury problem will persist.</p>
<p>So where is the rest of the $500 going? While this varies, my interviews with jewelry store owners in the <a href="http://www.reflectivejewelry.com/">US</a>, <a href="http://www.valeriojewellery.com/">UK</a> and <a href="http://www.studio1098customjewellery.com/">Canada</a> suggest that over 75% of the customer’s dollars go to the last two links in the value chain – the wholesaler and the retailer. </p>
<iframe src="https://datawrapper.dwcdn.net/UiDMt/2/" frameborder="0" allowtransparency="true" allowfullscreen="allowfullscreen" webkitallowfullscreen="webkitallowfullscreen" mozallowfullscreen="mozallowfullscreen" oallowfullscreen="oallowfullscreen" msallowfullscreen="msallowfullscreen" width="100%" height="400"></iframe>
<p>The first three links – the traders who buy gold from artisanal mines, the <a href="http://www.swissinfo.ch/eng/precious-goods_switzerland--the-world-s-gold-hub/33706126">mostly Swiss</a> refineries who purify it, and the manufacturers who alloy it into jewelry inputs – collectively take only 7% of the $500. Compared to the roughly 15% that goes to the miner, it’s easy to see why some actors are enjoying market power, while others are relying on toxins to survive.</p>
<h2>Fair trade for gold</h2>
<p>Until very recently, jewelry consumers were blind to where their money went and whether it supported mercury pollution. Today, however, they can choose to see. Two new value chain certification and labeling programs provide consumers with full knowledge of how and where their gold was produced.</p>
<p>In 2011, <a href="http://www.fairtrade.net/">Fairtrade International</a> expanded its focus from agricultural goods to minerals by partnering with the <a href="http://www.responsiblemines.org/en">Alliance for Responsible Mining</a> to bring the first ethical artisanal gold to market. In 2013, the organizations split and now offer competing programs.</p>
<p>Both programs require miners to acquire permits, use a mercury-reducing device called a retort, and ban children from the mining site. In return, both pay miners 95% of the international gold price plus a social premium miners invest in their communities. Gold sourced in this way that is also fully traceable may bear the program’s label. And both programs offer a semi-traceable, non-labeled option for businesses wanting to mix certified with noncertified gold. </p>
<p>Where the programs differ is in their approach to driving demand and thus benefits to miners. <a href="http://www.fairgold.org/">Fairtrade</a> pays miners a social premium of $2,000 per kilogram, whereas the <a href="http://www.fairmined.org/">Alliance</a> pays them $4,000. </p>
<p>Fairtrade’s approach of keeping premiums and therefore jewelry prices low may help drive sales, as may their policy of waiving licensing fees for small businesses. The Alliance’s model gives more money to miners upfront, and hopes to offset any lower sales by allowing large businesses to donate to the Alliance instead of sourcing gold from certified mines. </p>
<p>Which organization’s approach will result in better poverty and pollution outcomes is an open question. Until we get more money to miners and other subsistence producers, pollution problems will continue. </p>
<p>Currently <a href="http://www.worstpolluted.org/">one in seven people</a> in developing countries die of toxic pollution each year, and <a href="http://www.worstpolluted.org/projects_reports/display/129">19 million</a> are at risk of mercury associated harm worldwide. This is a horrible price for luxury that the world can’t afford to pay.</p><img src="https://counter.theconversation.com/content/49726/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kristin Sippl 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>Shopping for a gold ring? New guidelines seek to be the rough equivalent of Fair Trade for small-scale gold mining.Kristin Sippl, Susilo Institute for Ethics in the Global Economy, Boston UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/449952015-07-23T10:08:43Z2015-07-23T10:08:43ZExplainer: biosafety and biosecurity in South Africa<figure><img src="https://images.theconversation.com/files/89350/original/image-20150722-1479-8qygt2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">South Africa needs to ensure that it is equipped to deal with bioterrorism attacks and possible laboratory outbreaks.</span> <span class="attribution"><span class="source">Mariana Bazo/Reuters</span></span></figcaption></figure><p>In the scientific world, laboratories provide the crucial space for scientists to work and test hypotheses that they are working on. There are dangers involved, though. Laboratories may contain many hazardous chemicals and the spread of these could have devastating effects on the environment, humans, livestock and agriculture. </p>
<p>It is imperative that the necessary precautions are taken to ensure that hazardous material and potentially dangerous pathogens are handled safely and securely.</p>
<p>Biosafety generally means the adherence to good laboratory practices and <a href="http://www.medicinenet.com/script/main/art.asp?articlekey=33817">procedures</a>. It also refers to the use of appropriate safety equipment and facilities in order to ensure the safe handling, storage and disposal of biological material. This includes <a href="http://www.phac-aspc.gc.ca/publicat/lbg-ldmbl-04/ch2-eng.php">pathogens</a> – infectious agents that cause disease. </p>
<p>Measures to prevent harm caused by the accidental exposure to harmful pathogens and toxins fall under the term biosafety. Physical containment barriers and practices are <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2493080/">mandatory</a>. This is to prevent unintentional exposure to biological agents. They are also required to prevent accidental release into the environment.</p>
<p><a href="http://www.epa.gov/agriculture/tbis.html">Biosecurity</a> refers to the misuse or abuse of biological material. This includes pathogens and their products. There need to be ways to protect their misuse from causing harm to humans, livestock or crops. </p>
<p>Measures need to be implemented to control any harm in the event of exposure. This includes the protection, control and accountability for harmful biological materials – specifically in <a href="http://www.who.int/csr/resources/publications/biosafety/WHO_CDS_EPR_2006_6.pdf">laboratories</a>, in order to prevent their unauthorised access, loss or theft.</p>
<p>Bio-risk assessment is the quantitative and/or qualitative assessment of the possibility of a particular biological event. This includes natural disease outbreaks such as Ebola, accidents or the deliberate misuse of biological agents. The type of biological event that may adversely affect the health of humans, animals and crops. </p>
<h2>Why it is relevant to South Africa</h2>
<p>The use of biological material for harmful purposes is becoming an increasing threat. Even though it is not widely publicised, there have been incidents of both unintentional and deliberate exposure to harmful biological agents. Some of the most common agents used in bioterrorism include <a href="http://gulfnews.com/news/americas/usa/sarin-how-nazis-developed-deadly-neurotoxin-1.1179868">sarin neurotoxin</a>, <a href="http://www.bbc.co.uk/news/uk-england-merseyside-33607623">ricin</a> and <a href="http://www.npr.org/2011/02/15/93170200/timeline-how-the-anthrax-terror-unfolded">anthrax</a>. </p>
<p>Existing legislation and capacity to monitor and deal with these types of problems is <a href="http://uctscholar.uct.ac.za/R/?func=dbin-jump-full&object_id=1277&local_base=GEN01">fragmented</a> in South Africa. This is scattered across a number of <a href="http://www.acgt.co.za/wp-content/uploads/2014/07/South-Africa-status-with-respect-to-biotechnology-and-biosafety_Hennie-Groenewald.pdf">departments</a> such as Agriculture, Health, and Trade and Industry. This makes reporting and monitoring very difficult. </p>
<p>It would be appropriate for one department, such as Science and Technology, to take overall responsibility for the implementation of biorisk assessment legislation in South Africa. </p>
<p>South Africa has excellent ethical guidelines in place for human and animal <a href="http://www.kznhealth.gov.za/research/ethics3.pdf">experimentation</a>. But there is a lack of education and training in research ethics for life scientists working with harmful biological <a href="http://sabioriskassociation.org/">material</a>. </p>
<p>There is a conspicuous absence of a database of both public and commercial laboratories working on such material within South Africa. There is generally a disconcerting low level of awareness among life scientists about national and international conventions, laws and regulations related to their research.</p>
<h2>How vulnerable is South Africa?</h2>
<p>South Africa has largely been spared the threats of bioterrorism. But given that South Africa is the <a href="http://www.southafrica.info/africa/">gateway</a> to Africa and the transit route to many Western and Eastern destinations, we will not be immune from such threats forever. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/89349/original/image-20150722-1473-lfqsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/89349/original/image-20150722-1473-lfqsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=389&fit=crop&dpr=1 600w, https://images.theconversation.com/files/89349/original/image-20150722-1473-lfqsa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=389&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/89349/original/image-20150722-1473-lfqsa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=389&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/89349/original/image-20150722-1473-lfqsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=489&fit=crop&dpr=1 754w, https://images.theconversation.com/files/89349/original/image-20150722-1473-lfqsa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=489&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/89349/original/image-20150722-1473-lfqsa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=489&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">All scientists in South Africa need to be aware of the dangers that stem from laboratories.</span>
<span class="attribution"><span class="source">Wolfgang Rattay/Reuters</span></span>
</figcaption>
</figure>
<p>Research and development in the life sciences are crucial in driving the bio-economy in South Africa. It is also imperative that such research is conducted in a safe, secure and ethically sound manner. There is a general attitude that “this does not apply to me or my work” or “my work cannot be used for harmful purposes by <a href="http://www.gov.za/minister-naledi-pandor-international-symposium-bio-safety-genetically-modified-organisms">scientists”</a>. </p>
<p>Creating awareness and accepting that the misuse of scientific technology is a reality is in the interest of both South Africans and the life science community.</p>
<p>Although the South African legislative framework is robust and comprehensive, it suffers from several <a href="http://innovationsymposium.wits.ac.za/usrfiles/users/1/pdfs/Pamela_Andanda.pdf">limitations and challenges</a>. These include:</p>
<ul>
<li><p>Lack of coherence in the categorisation of pathogens;</p></li>
<li><p>The lack of harmonisation of guidelines; and</p></li>
<li><p>The deficiency in infrastructure and capacity to meet the challenges for implementation of the legislation. </p></li>
</ul>
<p>South Africa also has a complex set of regulations governing the detection, identification, control, and prevention of human, animal and plant diseases caused by infectious agents. There is a definite need to develop a single, locally relevant list of infectious agents. There is also a need for their control and eradication. This list should be dynamic and regularly updated. </p>
<p>One should not be alarmist, but given the increasing threats elsewhere in the world, South Africa should not be complacent. The country should rather be proactive in putting in place preventative measures to protect its population. Criminal elements intending to use technology for harmful purposes are always a threat anywhere in the word. </p>
<hr>
<p><em>Find the official Academy of Science of South Africa report <a href="http://www.assaf.co.za/wp-content/uploads/2011/10/Final-WEB-K-12423-ASSAF-Biosafety-and-Biosecurity-Report_DevV11LR.pdf">here</a>.</em></p><img src="https://counter.theconversation.com/content/44995/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Iqbal Parker receives research funding from the South African Medical Research Council (MRC) and the National Research Foundation (NRF)</span></em></p>In the science world, laboratories are essential but safety precautions should be taken to prevent any incidents like the Ebola outbreak or biochemical attacks.Iqbal Parker, Director, International Centre for Genetic Engineering and Biotechnology, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/419692015-05-19T05:27:51Z2015-05-19T05:27:51ZThe verdict’s in: we must better protect kids from toxic lead exposure<figure><img src="https://images.theconversation.com/files/82169/original/image-20150519-25407-ku88dy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Reducing lead exposure has health, social and economic benefits.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-64713451/stock-photo-biracial-family-on-playground-playing-with-sand.html?src=DBDC9FP9o_uTwpqPL6_6-g-1-69">rSnapshotPhotos/Shutterstock</a></span></figcaption></figure><p>The National Health and Medical Research Council (NHMRC) today released <a href="https://www.nhmrc.gov.au/media/releases/2015/nhmrc-releases-statement-and-information-paper-impacts-lead-human-health">new guidelines</a> aimed at reducing children’s harmful exposure to lead. Soil, dust, water and air-based exposure to lead can interfere with the development of the nervous systems and cause behavioural and developmental problems. </p>
<p>The effects of lead exposure are greatest in unborn children and those aged under five years, when their growing brains absorb high levels of calcium. Because lead (Pb2+) <a href="http://www.ncbi.nlm.nih.gov/pubmed/11097627">mimics calcium</a> (Ca2+), children in lead-rich environments absorb larger amounts of lead in place of calcium.</p>
<p>The NHMRC is <a href="https://www.nhmrc.gov.au/media/releases/2015/nhmrc-releases-statement-and-information-paper-impacts-lead-human-health">lowering the level</a> of lead in children’s blood at which the sources of exposure are to be investigated, from ten to five micrograms per decilitre. This marks an important milestone in Australian public health; maximum blood lead levels for Australian’s children were last lowered in 1993, from 25 to ten micrograms per decilitre. </p>
<p>Still, reaching this new, more protective intervention level of five micrograms per decilitre has taken <a href="http://www.sciencedirect.com/science/article/pii/S0160412014001482">far too long</a> – and the NHMRC’s message doesn’t go far enough to protect children. </p>
<h2>More cautious than overseas regulators</h2>
<p>The conclusions from the review that formed the basis of the new guidelines indicate the NHMRC may be more interested in minimising the evidence linking low-level lead toxicity than minimising widespread exposure to a widely recognised poison. </p>
<p>The NHRMC is far more cautious than other international scientific advisory panels. The NHMRC concluded that:</p>
<blockquote>
<p>The evidence for health effects occurring as a result of blood lead levels less than ten micrograms per decilitre is less clear.</p>
</blockquote>
<p>This conclusion contrasts starkly with the more strongly worded conclusions of other federal and international agencies. The United States Environmental Protection Agency report, for example, identified that childhood blood lead levels between two and eight micrograms per decilitre were causally related to decrements in cognitive function. </p>
<p>The United Nations Environmental Programme and the US Centers for Disease Control concluded that:</p>
<blockquote>
<p>there is no evidence of a “threshold” or safe exposure. </p>
</blockquote>
<p>The US National Toxicology Program reported that there was sufficient evidence to conclude that blood lead concentrations less than five micrograms per decilitre are associated with intellectual deficits (lower IQ score), academic disabilities, attention-related behaviours and problem behaviours: </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/82170/original/image-20150519-25437-231lac.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/82170/original/image-20150519-25437-231lac.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/82170/original/image-20150519-25437-231lac.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=520&fit=crop&dpr=1 600w, https://images.theconversation.com/files/82170/original/image-20150519-25437-231lac.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=520&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/82170/original/image-20150519-25437-231lac.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=520&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/82170/original/image-20150519-25437-231lac.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=654&fit=crop&dpr=1 754w, https://images.theconversation.com/files/82170/original/image-20150519-25437-231lac.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=654&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/82170/original/image-20150519-25437-231lac.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=654&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"><span class="source">National Toxicology Program Monograph on Health Effects of Low-Level Lead</span></span>
</figcaption>
</figure>
<h2>Children in mining communities</h2>
<p>The most heavily contaminated children are located in Australia’s premier lead mining and smelting towns where lead emissions in the air and dust remain far too high: Mount Isa, Port Pirie and Broken Hill. </p>
<p>Not surprisingly, approximately 50% of children under five years of age have a blood lead above five micrograms per decilitre. These levels are <a href="http://ehp.niehs.nih.gov/1307558/">comparable</a> with children from lower-income, rapidly industrialising countries. </p>
<p>To be fair, there have been significant recent financial investments to improve environmental quality in Australia’s major lead mining and smelting towns:</p>
<ul>
<li><p>The <a href="http://www.minerals.dmitre.sa.gov.au/press_and_events/news_releases/sa_government_guarantee_secures_port_piries_long-term_future">upgrade of the smelter</a> at Port Pirie will cost in excess of A$500 million. </p></li>
<li><p>The Mount Isa Mine <a href="http://www.livingwithlead.com.au/wp-content/uploads/2013/04/LWLA-2012-2013-Report.pdf">will spend</a> more than A$600 million on critical projects to improve environmental performance and reduce pollution by the end of 2016. </p></li>
<li><p>The New South Wales government <a href="http://www.epa.nsw.gov.au/resources/MinMedia/EPAMin150213.pdf">funded</a> a new environmental lead program for Broken Hill in early 2015 at a cost of A$13 million over five years. </p></li>
</ul>
<p>Nevertheless, emissions from mining and smelting are the <a href="http://www.sciencedirect.com/science/article/pii/S1875963715000336">primary source</a> of exposure in these communities, and local children’s blood lead levels signify a public health crisis. </p>
<p>A detailed plan to dramatically lower lead emissions and reduce the fraction of children who have blood lead levels above five micrograms per decilitre to zero by the year 2020 should be established immediately. </p>
<h2>What about other Australian children?</h2>
<p>The NHMRC was unable to estimate the average level of lead in Australian children’s blood outside of lead mining and smelting towns because there is no surveillance. </p>
<p>A <a href="http://www.sciencedirect.com/science/article/pii/S0946672X08000394">2008 study</a> of a small cohort of children in Sydney showed 7.5% had a blood lead level more than ten micrograms per decilitre. If that number is remotely reflective of current exposures, we are failing to protect a very large number of children. </p>
<p>It’s critical to conduct a random survey of Australian children to quantify lead exposure, including enrichment of children from higher risk areas. These data are essential to develop policies to protect children and develop evidence-based policies. </p>
<p>The NHMRC report wrongly focuses on managing suspected cases of lead exposure, when, in fact, the key to preventing lead poisoning – and the reason for the dramatic reduction in blood lead levels over the past 40 years – is the universal reduction of ongoing contamination of lead exposure. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/82171/original/image-20150519-25422-1qo46q8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/82171/original/image-20150519-25422-1qo46q8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=506&fit=crop&dpr=1 600w, https://images.theconversation.com/files/82171/original/image-20150519-25422-1qo46q8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=506&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/82171/original/image-20150519-25422-1qo46q8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=506&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/82171/original/image-20150519-25422-1qo46q8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=636&fit=crop&dpr=1 754w, https://images.theconversation.com/files/82171/original/image-20150519-25422-1qo46q8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=636&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/82171/original/image-20150519-25422-1qo46q8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=636&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Blood lead concentrations less than five micrograms per decilitre can still cause intellectual deficits.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-71933407/stock-photo-a-handsome-teenage-boy-with-a-notebook-and-pen-struggling-with-school-work.html?src=FvQTPJLprB5LhnwqSOv4Bw-1-4">littleny/Shutterstock</a></span>
</figcaption>
</figure>
<p>The NHMRC strategy is to target high-risk children. But unless there is a threshold, the high-risk approach will inevitably fail to protect the majority of those affected, albeit at lower levels. This is called the prevention paradox. </p>
<p>Lead-associated IQ deficits offer a compelling example. Targeting children who have a blood lead concentration above five micrograms per decilitre is efficient because it captures individuals most affected; the average lead-associated IQ loss for these children is about 6.2 IQ points. </p>
<p>However, in a <a href="http://www.annualreviews.org/doi/full/10.1146/annurev-publhealth-031912-114413">six-year cohort</a> of US children, those who have a blood lead concentration above five micrograms per decilitre account for fewer than three million (around 18%) of the 23 million IQ points lost due to lead toxicity. </p>
<p>So, by focusing only on high-risk children, we will ultimately fail to protect the majority of children who are affected adversely by lead and other toxins. </p>
<h2>Towards cleaner air, soil and water</h2>
<p>Early and effective intervention is important because the emerging evidence shows that the <a href="http://www.sciencedirect.com/science/article/pii/S0892036214001184">effects</a> of childhood lead exposure <a href="http://www.sciencedirect.com/science/article/pii/S0161813X13001277">do not remit</a> with age. </p>
<p>Proper, long-term intervention won’t be easy, but reducing lead exposure is extraordinarily cost-beneficial. American economist Elise Gould <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2717145/">estimated</a> that for every US$1 invested in reducing childhood lead exposure from residential hazards, society would benefit from US$17 to US$221, a cost-benefit ratio comparable with childhood vaccines (US$1 to US$16.5). </p>
<p>So, now that interventions are expected to occur at the new lower level of five micrograms per decilitre, it is important that the relevant environment and health agencies promulgate better standards for the most likely sources of exposure in children: air, dust, soil and water. </p>
<p>Air and dust quality are the most important aspects for mining and smelting communities, because contaminant emissions form toxic depositions in yards, homes, and on surfaces that children interact with resulting in subsequent exposure. </p>
<p>In environments where legacy emissions have contaminated soils, it will be important to lower the acceptable standard for soils in domestic residences from 300 mg/kg to something that aligns with California’s acceptable level of 80 mg/kg to provide <a href="http://oehha.ca.gov/risk/pdf/LeadCHHSL091709.pdf">proper protection</a>. </p>
<p>In these situations, exposure risks are well known and because they are modifiable, we have duty to act in terms of dealing with the ongoing contemporary sources of emissions. </p>
<p>However, these initiatives will not work without continued pressure to improve environmental standards along with significant efforts to ensure lead-safe messages are both current and constant.</p><img src="https://counter.theconversation.com/content/41969/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Patrick Taylor is affiliated with:
Broken Hill (NSW) Lead Reference Group, 2015 – ongoing.
NSW EPA Expert working group - Lead exposure management for suburbs around the former Boolaroo (NSW) Pasminco smelter site, Dec 2014 – ongoing
LEAD Group Inc. Elected Committee Member (Australia, 2011 – ongoing.
LEAD Group Inc. Technical Advisory Board (Australia), 2010 – ongoing.
Provides occasional advice to the North Queensland Conservation Council in regard to dust issues in Townsville, September 2014 - ongoing.
Runs VegeSafe, a community (free) soil metal testing program at Macquarie University: <a href="http://research.science.mq.edu.au/vegesafe/">http://research.science.mq.edu.au/vegesafe/</a>
</span></em></p><p class="fine-print"><em><span>Dr. Lanphear served as an expert witness in California for the plaintiffs in a public nuisance case of childhood lead poisoning, a Proposition 65 case on behalf of the California Attorney General’s Office, a case involving lead-contaminated water in a new housing development in Maryland, and Canadian tribunal on trade dispute about using lead-free galvanized wire in stucco lathing but he received no personal compensation for these services. He is currently representing the government of Peru as an expert witness in a suit involving Doe Run vs Peru, but he is receiving no personal compensation. Dr. Lanphear has served as a paid consultant on a US Environmental Protection Agency research study, NIH research awards and the California Department of Toxic Substance Control. Dr. Lanphear has received federal research awards from the National Institute of Environmental Health, the US Environmental Protection Agency, the Centers for Disease Control and the US Department of Housing and Urban Development. He is also the recipient of federal research awards from the Canada Institutes of Health Research and Health Canada.</span></em></p>Soil, dust and air-based exposure to lead can interfere with a child’s developing nervous systems and cause behavioural and developmental problems.Mark Patrick Taylor, Professor of Environmental Science, Macquarie UniversityBruce Lanphear, Professor of Children's Environmental Health, Simon Fraser UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/160412013-09-25T21:01:34Z2013-09-25T21:01:34ZToxic load: blue-green algae’s role in motor neuron disease<figure><img src="https://images.theconversation.com/files/31918/original/h53k9xjt-1380085395.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Pretty but deadly: researchers now understand how blue-green algae is linked to neurodegenerative diseases.</span> <span class="attribution"><span class="source">Mark Sadowski</span></span></figcaption></figure><p>Scientists have known for <a href="https://www.jstage.jst.go.jp/article/plantbiotechnology/25/3/25_3_227/_article">some time now</a> that exposure to blue-green algae is linked to increased incidence of several neurodegenerative diseases. But the reason for the link has been a mystery until now. Research published in the journal PLOS ONE today may have the answer.</p>
<p>An algal toxin called BMAA has long been <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3194113/?tool=pmcentrez&rendertype=abstract">associated</a> with the increased incidence of a motor neurone disease called amyotrophic lateral sclerosis (ALS). But for many years, the hypothesis suffered <a href="http://www.ncbi.nlm.nih.gov/pubmed/16990532">repeated blows</a> as sceptics poked at the gaping hole in the theory – the lack of a plausible mechanism. </p>
<p>Now, a team of cell biologists and ethnobotanists, including myself, has revealed that BMAA mimics an amino acid that our bodies naturally use to make proteins called L-Serine. Mistaking the toxin for the amino acid, the body incorporates it into human proteins, rendering them harmful.</p>
<p>Because people can have low levels of exposure to BMAA over long periods, it can take between 10 and 15 years before ALS appears. But the time from diagnosis to death can be as short as 3 years. </p>
<h2>How fruit bats in Guam provided clues</h2>
<p>BMAA was first identified <a href="http://www.sciencedirect.com/science/article/pii/S0031942200860185?via=ihub">over 40 years ago</a>, but was not linked to disease until ethnobotanist Paul Cox descended into the jungles of the Pacific island of Guam. </p>
<p>He was searching for the causes of a devastating neurological disease called amyotrophic lateral sclerosis/
Parkinson’s dementia like-complex (ALS/PDC), which had killed nearly half the adult indigenous population, the Chamorros.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/31919/original/gmgqjykn-1380085869.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/31919/original/gmgqjykn-1380085869.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/31919/original/gmgqjykn-1380085869.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/31919/original/gmgqjykn-1380085869.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/31919/original/gmgqjykn-1380085869.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/31919/original/gmgqjykn-1380085869.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/31919/original/gmgqjykn-1380085869.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">BMAA was first identified in the jungles of Guam.</span>
<span class="attribution"><span class="source">NASA's Earth Observatory</span></span>
</figcaption>
</figure>
<p>Although about 20 genes have been <a href="http://en.wikipedia.org/wiki/Amyotrophic_lateral_sclerosis#Genetic_factors">linked to ALS</a>, around 90% of cases are of unknown cause and there’s no cure. Predictably, a search for genetic causes on Guam quickly reached a dead end.</p>
<p>But the trip was not wasted. Cox noted that <a href="http://www.sbs.com.au/shows/costa/listings/detail/i/4/article/7767/Cycad-Ceremony">like Australian Aboriginals</a>, the Chamorros relied heavily on the seeds of the cycad palm to make flour for tortillas and dumplings. Also like their Australian counterparts, they knew the unwashed flour contained a “poison” so they washed it thoroughly before use. </p>
<p>Cox and his colleague Sandra Banack found a neurotoxin in the flour, but it was in such low quantities that locals would need to consume over one tonne of it before they got sick.</p>
<h2>Tasty but nasty treat</h2>
<p>Also of interest to Cox and Banack was the Chamorros’ voracious appetite for fruit bat coconut soup – a delicacy described by the locals as “like nothing you’ve ever tasted.” </p>
<p>The bats also ate the cycad seeds but curiously they had what appeared to be exorbitantly high levels of BMAA for what they consumed. </p>
<p>An analysis of their tissue found BMAA stuck to their proteins, enabling it to concentrate in their flesh; when the Chamorros ate the bats, they got a huge dose of BMAA. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/31921/original/wr5pncrd-1380087013.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/31921/original/wr5pncrd-1380087013.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/31921/original/wr5pncrd-1380087013.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/31921/original/wr5pncrd-1380087013.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/31921/original/wr5pncrd-1380087013.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/31921/original/wr5pncrd-1380087013.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/31921/original/wr5pncrd-1380087013.jpg?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">
<figcaption>
<span class="caption">Like Australian Aboriginals, the Chamorros used Cycad palm seeds to make flour.</span>
<span class="attribution"><span class="source">Pamla J. Eisenberg</span></span>
</figcaption>
</figure>
<p>This process, now termed “bioconcentration” has since been observed in shellfish, crustaceans and sharks. But how is it linked to neurodegeneration?</p>
<p>BMAA has been found in the brain tissue of ALS/PDC patients from Guam, as well as Alzheimer’s patients from North America. Other populations that also consume cycad flour – the Kii Peninsula of Japan and Western Papua New Guinea – have also experienced clusters of amyotrophic lateral sclerosis.</p>
<p>An elegant Google Maps analysis of New Hampshire in the United States tracked ALS patients to having lived by lakes or other bodies of water that were subject to frequent algal blooms.</p>
<h2>Natural doesn’t mean safe</h2>
<p>The idea that non-human amino acids can cause disease is not a new one; plants make thousands of mimics that have been linked to human and animal illnesses. Neurolathyrism, for example, is a permanent paralytic condition that predominantly occurs in famine-affected areas, and is caused by an unusual amino acid called ODAP. </p>
<p>In our lab, we’ve spent more than ten years looking at the drug used in Parkinson’s disease, called levodopa or <a href="http://en.wikipedia.org/wiki/L-DOPA">L-DOPA</a>, which is very similar to the human amino acid tyrosine. </p>
<p>Like BMAA, L-DOPA can also be “mis-incorporated” into our proteins, and also like BMAA, the resulting proteins do not fold correctly and build up as “junk” inside the cell over time. This “junk” eventually chokes the cell, sending it into programmed cell death or suicide. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/31926/original/76q8hw42-1380088003.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/31926/original/76q8hw42-1380088003.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/31926/original/76q8hw42-1380088003.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/31926/original/76q8hw42-1380088003.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/31926/original/76q8hw42-1380088003.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/31926/original/76q8hw42-1380088003.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/31926/original/76q8hw42-1380088003.jpg?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">
<figcaption>
<span class="caption">An aerial photo of a blue green algae plume stretched across some 800km of the Murray River between Albury and west of Swan Hill, in north-west Victoria, April 2009.</span>
<span class="attribution"><span class="source">AAP</span></span>
</figcaption>
</figure>
<p>Cell suicide induced by misfolded proteins is now <a href="http://www.hindawi.com/isrn/cell.biology/2013/256404/">known</a> to occur in a variety of neurodegenerative disorders such as Alzheimer’s, Parkinson’s, and importantly, ALS.</p>
<h2>Blue-green algae and ALS</h2>
<p>The size and frequency of algal blooms, which typically appear as a green carpet on lakes and rivers, is increasing with rising water temperatures and an excessive richness in nutrients in bodies of water, such as lakes (eutrophication). </p>
<p>Indeed, Australia is the proud owner of the <a href="http://www.water.nsw.gov.au/Water-Management/Water-quality/Algal-information/Dangers-and-problems/Dangers-and-problems/default.aspx">largest fresh-water algal bloom</a>, which occurred in the summer of 1991/1992 covering 1,200 kilometres of the Barwon-Murray basin. But if we’re all being exposed to BMAA, then why then do we all not have ALS?</p>
<p>With an incidence of about one in 100,000 ALS is relatively rare; exposure to BMAA alone does not appear to be sufficient to cause disease. Like many illnesses, it’s likely that ALS is a multifactorial condition requiring several factors to come together to trigger disease. </p>
<p>Research is beginning to point the finger at the role of <a href="http://www.nature.com/scitable/topicpage/protein-misfolding-and-degenerative-diseases-14434929">poorly functioning recycling and refolding machinery</a> in our cells. As these age, their function declines and likely contributes to neurodegenerative disorders.</p>
<p>BMAA might be just one factor in this devastating disease, but at least we now know how it might be causing toxicity. And because we have evidence for a role for BMAA replacing L-serine, these findings might go some way to developing a therapy. That is something for patients, many of whom have nothing.</p><img src="https://counter.theconversation.com/content/16041/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rachael Dunlop is a co-inventor on a patent for L-serine use in neurodegenerative disorders. She receives funding from the Institute for Ethnomedicine, WY, USA. </span></em></p>Scientists have known for some time now that exposure to blue-green algae is linked to increased incidence of several neurodegenerative diseases. But the reason for the link has been a mystery until now…Rachael Dunlop, Post-doctoral fellow, University of Technology SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/87992013-03-24T19:04:45Z2013-03-24T19:04:45ZDoes aluminium cause Alzheimer’s and breast cancer?<figure><img src="https://images.theconversation.com/files/21651/original/rggk7rqd-1363930063.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The vast majority of us will never be exposed to aluminium in high enough concentrations to do damage.</span> <span class="attribution"><span class="source">ezioman/Flickr</span></span></figcaption></figure><p>Silvery, ductile, malleable and so very, very useful, aluminium is the most common metal in the Earth’s crust. But despite its importance (or perhaps because of it), there are fears that this metal causes everything from cancer to Alzheimer’s disease.</p>
<p>From aircraft to tableware, aluminium forms an important and ubiquitous part of our lives. It’s so common now, in fact, that it’s difficult to believe that, at one stage, metallic aluminium was so hard to make that having aluminium plates was a symbol of wealth. </p>
<p>But as it has become more commonplace, aluminium’s safety profile has come into question, with particular emphasis on <a href="http://jnci.oxfordjournals.org/cgi/ijlink?linkType=FULL&journalCode=jnci&resid=92/18/1469">aluminium in antiperspirants</a>. The evidence for its supposed harms is weak, if not non-existent.</p>
<p>Yes, aluminium can be toxic, but in the spirit of <a href="https://theconversation.com/you-named-your-column-what-6072">my blog’s patron</a>, remember it’s the dose that makes the poison. </p>
<p>The metal’s toxic effects can be seen in people working at aluminium smelters or those who have had similar industrial exposures with inadequate workplace safety measures. People on dialysis who have been exposed to higher than normal aluminium levels in their dialysis fluid also show a range of adverse effects, including damage to the brain and the nervous system. </p>
<p>And you can show neurotoxic effects in animals at lower (but still substantial) concentrations, if you inject aluminium directly into the brain. But the vast majority of us will never be exposed to such high concentrations of aluminium as in these cases. Our exposures will come from drinking water, food, antacid tablets and rubbing antiperspirant with aluminium on our skin. </p>
<p>The aluminium we’re exposed to in these ways is in the form of aluminium salts. These salts are surprisingly hard to get into the body; only <a href="http://ukpmc.ac.uk/abstract/MED/14871578/reload=0;jsessionid=qKechXjYOfuu6BUAy8As.0">0.1% of ingested aluminium</a> is absorbed into the body. </p>
<p>Skin absorption is also <a href="http://www.sciencedirect.com/science/article/pii/S0162013412000578">quite weak</a> and skin absorption of aluminium from antiperspirants contributes <a href="http://www.sciencedirect.com/science/article/pii/S0278691500001186">to less than 3%</a> of blood levels of aluminium (the rest comes from gut absorption). So you need to go to some effort to get toxic levels of aluminium from these sources.</p>
<p>Indeed, according to the results of long-term animal studies you need to consume <a href="http://www.sciencedirect.com/science/article/pii/S0306452211005409">around 10,000 times</a> the amount of aluminium in our water supplies to see the beginnings of neurotoxicity. Even if you were chewing antacids every day while rubbing antiperspirants all over yourself, you would still not have enough aluminium in your system to suffer from neurotoxicity. </p>
<p>So, while animal studies are all very well, is there any evidence from humans that our modest consumption of aluminium over long periods of time is toxic?</p>
<h2>Alzheimer’s disease</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/14582/original/65n6y66t-1345728180.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/14582/original/65n6y66t-1345728180.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/14582/original/65n6y66t-1345728180.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/14582/original/65n6y66t-1345728180.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/14582/original/65n6y66t-1345728180.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/14582/original/65n6y66t-1345728180.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/14582/original/65n6y66t-1345728180.jpg?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">
<figcaption>
<span class="caption">Beta amyloid.</span>
<span class="attribution"><span class="source">Ian Musgrave via Jmol</span></span>
</figcaption>
</figure>
<p>A common misconception about aluminium is that it causes Alzheimer’s disease. And since a large chunk of <a href="http://peer.ccsd.cnrs.fr/docs/00/56/27/46/PDF/PEER_stage2_10.1016%252Fj.bbadis.2006.12.001.pdf">my research</a> is on finding treatments for Alzheimer’s disease, I have a bit of insight into such claims. </p>
<p>Some very early studies suggested that there was <a href="http://dx.doi.org/10.1080/10937400701597766">more aluminium</a> in the brains of people with Alzheimer’s disease than those without. Almost immediately, people selling stainless steel cookware seized on this result to promote their pots over aluminium ones (we were buying new cookware at this time, and I had some interesting discussions with these people).</p>
<p>Aluminium is rather hard to measure at the low levels that are in the brain, and <a href="http://dx.doi.org/10.1080/10937400701597766">later studies with better methods</a> failed to find elevated aluminium levels in the brains of people with Alzheimer’s. Actually, there’s good evidence the positive results were <a href="http://www.sciencedirect.com/science/article/pii/S0304394097009403">due to contamination</a>. </p>
<p>Personally, I wouldn’t have been surprised to find increased aluminium in the brains of Alzheimer’s sufferers. There’s an accumulation of a toxic protein called <a href="http://en.wikipedia.org/wiki/Beta_amyloid">beta amyloid</a> in the brains of people with Alzheimer’s disease. This protein binds metals including aluminium, but it binds copper, zinc and iron more strongly. In part, this binding of copper and zinc contributes to the protein’s toxicity. Despite significant amounts of copper in the <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2517409/?tool=pmcentrez">accumulated amyloid in the brains of people with Alzheimer’s</a> however, there’s no evidence that high levels of copper exposure increase the disease’s incidence. </p>
<p>What’s more, people on dialysis who are exposed to much higher concentrations of aluminium than most people for long periods of time <a href="http://www.ncbi.nlm.nih.gov/pubmed/11307619">don’t have a higher incidence of Alzheimer’s disease</a> than people not on dialysis.</p>
<p>So, aluminium and Alzheimer’s disease, no.</p>
<h2>Breast cancer</h2>
<p>In breast cancer, the upper outer quadrant of the breast is more likely to be the site where tumours first appear than anywhere else. Since this quadrant is closest to the lymphatic drainage from the armpit, people have leapt to the conclusion that aluminium from application of antiperspirants is the culprit. </p>
<p>But the incidence of tumours is directly related to the amount of breast tissue, and that quadrant happens to have the most breast tissue. </p>
<p>Epidemiological data is rather sparse, but what little there is makes the aluminium-breast cancer link unlikely. <a href="http://jnci.oxfordjournals.org/content/94/20/1578.full">A 2002 study found no correlation</a> between aluminium containing antiperspirant use and breast cancer. A <a href="http://www.ncbi.nlm.nih.gov/pubmed/18829420">more recent meta-analysis</a> found few high-quality studies, but those they found showed no evidence of an antiperspirant link to breast cancer. </p>
<p>So, aluminium and breast cancer, highly unlikely.</p>
<p>Alzheimer’s disease and breast cancer are devastating to both those who develop the diseases and their families. Everyone involved wants to know why these diseases strike. These are complex diseases, with complex and still poorly understood causes, but we can be pretty certain that the aluminium in antiperspirants is not one of those causes.</p><img src="https://counter.theconversation.com/content/8799/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ian Musgrave receives funding from the Australian Research Council, and has previously been funded by the National Health and Medical Research Council. Some of this funding was to investigate treatments for neurodegenerative disease. </span></em></p>Silvery, ductile, malleable and so very, very useful, aluminium is the most common metal in the Earth’s crust. But despite its importance (or perhaps because of it), there are fears that this metal causes…Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.