tag:theconversation.com,2011:/africa/topics/chemical-contamination-2162/articlesChemical contamination – The Conversation2023-08-24T20:20:20Ztag:theconversation.com,2011:article/2117392023-08-24T20:20:20Z2023-08-24T20:20:20ZHow bees can monitor pollution for us – everything from toxic metals to antimicrobial resistance<figure><img src="https://images.theconversation.com/files/544408/original/file-20230824-29-3ydb0.jpg?ixlib=rb-1.1.0&rect=0%2C674%2C4479%2C2975&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Our cities are complex places of work, industry and residential activities. This often makes it hard to pin down the spread of different contaminants throughout them.</p>
<p>This can be a concern, especially given mounting evidence there is <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.2003066">no “safe” limit</a> of exposure for many of the <a href="https://theconversation.com/toxic-chemicals-and-pollutants-affect-kids-brain-development-23342">chemicals we use in our daily lives</a>. The connections between contamination, food, water and human health add to these concerns. </p>
<p>Measuring contamination in soil or dust is a good start. But this can only tell us the level of a contaminant at the place it was sampled. Our two new studies have used backyard bees to better monitor contamination in urban environments. </p>
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Read more:
<a href="https://theconversation.com/bees-can-do-so-much-more-than-you-think-from-dancing-to-being-little-art-critics-204039">Bees can do so much more than you think – from dancing to being little art critics</a>
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<h2>The buzz behind biomonitoring</h2>
<p>When it comes to understanding contamination, honey bees can do the hard work for us. While foraging for nectar, pollen and water, bees are constantly picking up contaminants from their environment. Because we know their lifespan and approximate foraging range, chemical analysis can provide a snapshot of the levels of contaminants in their foraging area at that time. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/544412/original/file-20230824-59036-4vnm2k.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A honey bee foraging on a flower" src="https://images.theconversation.com/files/544412/original/file-20230824-59036-4vnm2k.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/544412/original/file-20230824-59036-4vnm2k.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/544412/original/file-20230824-59036-4vnm2k.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/544412/original/file-20230824-59036-4vnm2k.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/544412/original/file-20230824-59036-4vnm2k.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/544412/original/file-20230824-59036-4vnm2k.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/544412/original/file-20230824-59036-4vnm2k.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&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">Foraging honey bees pick up contaminants in the environment.</span>
<span class="attribution"><span class="source">Mark Patrick Taylor</span></span>
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<p>With the help of backyard beekeepers, our two studies traced toxic metals and antimicrobial resistance genes across two urban centres: <a href="https://doi.org/10.1021/acs.est.3c03775">Sydney, Australia</a>, and <a href="https://www.sciencedirect.com/science/article/pii/S0269749123012599?via%3Dihub">Nouméa, New Caledonia</a>. </p>
<p>European honey bees have long been used as sentinel species to monitor for pests and diseases, including <a href="https://beeaware.org.au/archive-news/port-surveillance-system-targets-exotic-bee-pests/">Varroa mites</a> and <a href="https://phys.org/news/2010-07-bees-air-quality-german-airports.html">chemicals at airports</a>. Bees can also be used as <a href="https://www.nature.com/articles/s41893-019-0243-0">biomonitors</a> to understand contaminants across our urban environments. </p>
<p>As the <a href="https://www.abc.net.au/news/2021-12-04/amateur-beekeeping-on-the-rise-in-australia/100671140">popularity of urban beekeeping</a> has grown, there has been more research on honey bee biomonitoring of a range of contaminants, including <a href="https://pubs.acs.org/doi/10.1021/acs.est.7b04084">metals</a>, <a href="https://www.sciencedirect.com/science/article/pii/S0048969722017909">pesticides</a> and so-called “<a href="https://theconversation.com/controversial-forever-chemicals-could-be-phased-out-in-australia-under-new-restrictions-heres-what-you-need-to-know-210697">forever chemicals</a>”, known as PFAS, <a href="https://link.springer.com/article/10.1007/s00128-016-1840-5">in honey</a>. </p>
<figure class="align-center ">
<img alt="Two children next to a backyard beehive" src="https://images.theconversation.com/files/544470/original/file-20230824-36239-5aa4s1.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/544470/original/file-20230824-36239-5aa4s1.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/544470/original/file-20230824-36239-5aa4s1.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/544470/original/file-20230824-36239-5aa4s1.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/544470/original/file-20230824-36239-5aa4s1.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/544470/original/file-20230824-36239-5aa4s1.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/544470/original/file-20230824-36239-5aa4s1.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">
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<span class="caption">Bees effectively collect environmental samples and bring them back to hives across the city.</span>
<span class="attribution"><span class="source">Mark Patrick Taylor</span></span>
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Read more:
<a href="https://theconversation.com/controversial-forever-chemicals-could-be-phased-out-in-australia-under-new-restrictions-heres-what-you-need-to-know-210697">Controversial ‘forever chemicals’ could be phased out in Australia under new restrictions. Here’s what you need to know</a>
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<h2>How bees help us map pollution</h2>
<p>Honey bees can reveal patterns of contamination that might otherwise go unnoticed. </p>
<p>In Nouméa, we used honey bees to map impacts from the local nickel smelter. We found levels of metals associated with the smelter – nickel, chromium and cobalt – were elevated next to the smelter and decreased farther away. </p>
<p>This might not sound surprising given the smelter is a major source of pollution. However, comparing the data from bees to soil and dust samples revealed bees were the most sensitive and effective marker of smelter contamination. </p>
<p>By mapping trace metals in honey bees in Sydney we could look at the specific factors contributing to metal pollution within their foraging range. For the neurotoxic metal <a href="https://theconversation.com/leaded-petrol-is-gone-but-lead-pollution-may-linger-for-a-very-long-time-167214">lead</a>, we found residential and industrial activity were key influences, especially in heavily populated inner-city areas. </p>
<p>In contrast, less populated locations and larger areas of parks or farms had higher levels of manganese. This likely came from natural soil sources and pesticide use. </p>
<p>We also examined how bees can help us understand emerging concerns such as the spread of antimicrobial resistance (<a href="https://www.amr.gov.au/australias-response/national-amr-strategy">AMR</a>) genes. It’s a key concern in urban areas, driven by the misuse and overuse of antibiotics. </p>
<p>We found these AMR genes were common across Sydney – 83% of bees examined had ingested one or more of the genes we looked for. The source was not strongly linked to industrial activity, but rather the area of water bodies available for the bees to drink from. This may be because these genes can enter the environment through human wastewater and runoff and then be absorbed by foraging bees. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/544416/original/file-20230824-36260-p57sld.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/544416/original/file-20230824-36260-p57sld.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=361&fit=crop&dpr=1 600w, https://images.theconversation.com/files/544416/original/file-20230824-36260-p57sld.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=361&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/544416/original/file-20230824-36260-p57sld.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=361&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/544416/original/file-20230824-36260-p57sld.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=454&fit=crop&dpr=1 754w, https://images.theconversation.com/files/544416/original/file-20230824-36260-p57sld.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=454&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/544416/original/file-20230824-36260-p57sld.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=454&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Bees likely ingest antimicrobial resistance genes from water bodies exposed to runoff from people’s properties or wastewater.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/gutter-to-gut-how-antimicrobial-resistant-microbes-journey-from-environment-to-humans-189446">Gutter to gut: How antimicrobial-resistant microbes journey from environment to humans</a>
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<h2>How do contaminants affect bees?</h2>
<p>We also wanted to know if bees that contained contaminants were actually ingesting them. Our analyses showed contaminants build up within the bee over time and were not present on their exterior. We compared metal concentrations in matched samples of washed and unwashed bees and they were no different, indicating contaminants were inside the bee. Further, metal concentrations were higher in older, dead bees at the end of their lives than in the younger bees. </p>
<p>Using high-resolution imaging, we found only organic non-metal particles on the outside of bees. This may be because bees have very good self-cleaning habits. These behaviours also keep hives free from parasites and fungi brought in by foraging bees.</p>
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<a href="https://images.theconversation.com/files/544473/original/file-20230824-21-y2vfqn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="scanning electron microscope images of body surface of bees" src="https://images.theconversation.com/files/544473/original/file-20230824-21-y2vfqn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/544473/original/file-20230824-21-y2vfqn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=470&fit=crop&dpr=1 600w, https://images.theconversation.com/files/544473/original/file-20230824-21-y2vfqn.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=470&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/544473/original/file-20230824-21-y2vfqn.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=470&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/544473/original/file-20230824-21-y2vfqn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=590&fit=crop&dpr=1 754w, https://images.theconversation.com/files/544473/original/file-20230824-21-y2vfqn.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=590&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/544473/original/file-20230824-21-y2vfqn.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=590&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Scanning electron microscope images of Nouméa bees. Where particles could be identified they were found to be not metallic.</span>
<span class="attribution"><span class="source">Authors</span></span>
</figcaption>
</figure>
<p>Research has shown exposure to contaminants including <a href="https://www.sciencedirect.com/science/article/pii/S006528062300005X?via%3Dihub">metals</a> and <a href="https://doi.org/10.1021/acs.est.9b02452">neonicotinoid insecticides</a> can impair honey bee development, foraging ability and survival.</p>
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Read more:
<a href="https://theconversation.com/how-clean-is-your-city-just-ask-the-bees-113981">How clean is your city? Just ask the bees</a>
</strong>
</em>
</p>
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<h2>And what’s in their honey?</h2>
<p>Both honey producers and consumers want to know if their honey is <a href="https://theconversation.com/honeygate-deepens-as-new-tests-reveal-27-of-brands-are-adulterated-104139">safe to eat</a>. While we <a href="https://www.nature.com/articles/s41598-018-32764-w">previously identified</a> some commercial honeys are adulterated with sugar syrups, this new work focused on potentially toxic trace metals in the honey. </p>
<p>The good news is we found trace metals in honey at very low levels that do not pose a concern. In Nouméa, the main smelter element, nickel, was more than 30 times lower in honey than in the bees. </p>
<p>We found similar outcomes in the mining town of <a href="https://pubs.acs.org/doi/10.1021/acs.est.7b04084">Broken Hill, Australia</a> where lead levels in honey were ten times lower than in the bees themselves. </p>
<figure class="align-center ">
<img alt="A researcher in protective beekeeping gear collects bees returning to the hive" src="https://images.theconversation.com/files/544451/original/file-20230824-15-t4fl7p.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/544451/original/file-20230824-15-t4fl7p.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/544451/original/file-20230824-15-t4fl7p.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/544451/original/file-20230824-15-t4fl7p.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/544451/original/file-20230824-15-t4fl7p.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/544451/original/file-20230824-15-t4fl7p.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/544451/original/file-20230824-15-t4fl7p.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&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">Bees returning to the hive are collected by EPA Victoria for analysis of the contaminants they picked up while foraging.</span>
<span class="attribution"><span class="source">Ian Travers</span></span>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/honeygate-deepens-as-new-tests-reveal-27-of-brands-are-adulterated-104139">'Honeygate' deepens as new tests reveal 27% of brands are adulterated</a>
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<h2>Bees aren’t the only biomonitors</h2>
<p>The lessons from this work have led the Environment Protection Authority (EPA) Victoria, with which we are all affiliated, to explore the use of biomonitors (honey bees, house sparrows and birds of prey) in its ongoing environmental contaminant research. As a science-based regulator, the EPA uses these types of studies to better understand the presence, uptake and dispersal of contaminants and protect environmental and human health. </p>
<p>Earth is facing a multitude of interlacing environmental challenges including biodiversity loss, climate change, population growth and pervasive chemical pollution. More comprehensive monitoring, including surveillance using bees, will allow us to respond more quickly and effectively to environmental health challenges.</p><img src="https://counter.theconversation.com/content/211739/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Patrick Taylor received funding via an Australian Government Citizen Science Grant (2017-2020), CSG55984 ‘Citizen insights to the composition and risks of household dust’ (the DustSafe project). The VegeSafe and DustSafe programs are supported by publication donations to Macquarie University. He is a full-time employee of EPA Victoria, appointed to the statutory role of Chief Environmental Scientist.</span></em></p><p class="fine-print"><em><span>Kara Fry is a Senior Health Risk Adviser at EPA Victoria. This research was completed for her Master of Research and supported by a Macquarie University Research Excellence stipend. </span></em></p><p class="fine-print"><em><span>Max M Gillings is involved in research affiliated with and funded by EPA Victoria.</span></em></p>Using bees as biomonitors can be a more sensitive and effective way of detecting contaminants than traditional sampling methods, new research shows.Mark Patrick Taylor, Chief Environmental Scientist, EPA Victoria; Honorary Professor, School of Natural Sciences, Macquarie UniversityKara Fry, Adjunct Fellow, School of Natural Sciences, Macquarie UniversityMax M Gillings, PhD Candidate, School of Natural Sciences, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1996682023-06-05T01:32:27Z2023-06-05T01:32:27ZTreated wastewater in Victoria is still contaminated, study finds. So are we and the environment safe?<figure><img src="https://images.theconversation.com/files/515024/original/file-20230313-24-48y9sf.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6000%2C3988&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Wastewater is a by-product of humanity produced all day, every day. At home, wastewater is the <a href="https://environment.des.qld.gov.au/management/water/pollution/wastewater">used water</a> that disappears when you flush the toilet, empty the sink or drain the washing machine. </p>
<p>Industrial processes also produce wastewater. Around the world, <a href="https://www.sciencedaily.com/releases/2021/02/210208085457.htm">359 billion cubic metres of wastewater</a> is produced each year – equal to 144 million Olympic-sized swimming pools. </p>
<p>In Australia, some of this water is treated and reused. This so-called “recycled” water is used, for example, to wash cars, water crops and gardens. Treated water is also released back into rivers as “discharge”, which is regulated under an operator’s licence.</p>
<p>So is treated wastewater safe? Our <a href="https://www.epa.vic.gov.au/about-epa/publications/2054-2-emerging-contaminants-in-recycled-water">research</a>, published today, found wastewater treatment removes a lot of particles, but some contaminants remain. While it’s not enough to affect human health, effects on the environment are less clearly established.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/we-now-treat-half-the-worlds-wastewater-and-we-can-make-inroads-into-the-other-half-154715">We now treat half the world's wastewater – and we can make inroads into the other half</a>
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<figure class="align-center ">
<img alt="Purple tap and hose for recycled water with sign saying it's not for drinking" src="https://images.theconversation.com/files/515026/original/file-20230313-447-cmkech.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/515026/original/file-20230313-447-cmkech.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/515026/original/file-20230313-447-cmkech.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/515026/original/file-20230313-447-cmkech.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/515026/original/file-20230313-447-cmkech.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/515026/original/file-20230313-447-cmkech.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/515026/original/file-20230313-447-cmkech.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">Recycled water is commonly used to irrigate gardens and crops.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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</figure>
<h2>Making the most of our water</h2>
<p>Water is a precious, finite resource. There is no such things as “<a href="https://cosmosmagazine.com/history/age-of-water/">new</a>” water. Our planet’s water dates back <a href="https://arxiv.org/pdf/2212.05441.pdf">4.5 billion years</a> and is constantly recycled by Earth’s systems. </p>
<p>As Earth’s population grows and the climate dries, we need all the water we can get.</p>
<p>In light of this challenge, the state of Victoria has <a href="https://www.water.vic.gov.au/water-for-victoria">a plan</a> to better use treated wastewater. Other Australian states and territories have <a href="https://water.dpie.nsw.gov.au/plans-and-programs/nsw-water-strategy/the-strategy/our-water-our-future">similar</a> <a href="https://www.rdmw.qld.gov.au/water/how-it-works">plans</a>.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/where-to-find-more-water-eight-unconventional-resources-to-tap-183681">Where to find more water: eight unconventional resources to tap</a>
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</em>
</p>
<hr>
<p>Wastewater comes from homes, businesses, industrial sites and farms, as well as any stormwater or groundwater that enters the sewer system. </p>
<p>Specialised treatment plants process this wastewater. A combination of technologies is used to achieve the treatment objectives, based on the character of raw wastewater and use of the treated wastewater. These processes include primary, secondary and tertiary treatment. </p>
<p>Wastewater treatment seeks to remove:</p>
<ul>
<li><p>organics (proteins, hydrocarbons, oils and fats)</p></li>
<li><p>suspended solids (small particles)</p></li>
<li><p>bacteria (such as <em>E. coli</em>).</p></li>
</ul>
<p>In Victoria, as elsewhere in Australia, wastewater must meet strict standards. Water corporations achieve this by implementing stringent procedures and processes, and monitoring water quality. </p>
<p>But even after treatment, some contaminants can remain. These can be divided into “emerging” and “legacy” contaminants.</p>
<p><a href="https://www.epa.gov/wqc/contaminants-emerging-concern-including-pharmaceuticals-and-personal-care-products">Emerging contaminants</a> include pharmaceuticals, pesticides, phthalates (used to make plastic more durable), industrial chemicals and chemicals in personal care products. </p>
<p>They’re described as “emerging” because of the limited information we have about them, the risks they pose and the dose-response effects, especially at low, ultra-trace concentrations.</p>
<p>Legacy contaminants include, for example, PFAS, trace metals and insecticides such as DDT. </p>
<p>So should we be concerned about contaminants in treated wastewater? Our <a href="https://www.epa.vic.gov.au/about-epa/publications/2054---recycled-water-emerging-contaminants-report#:%7E:text=Emerging%20contaminants%20include%20pharmaceuticals%2C%20pesticides,environment%20and%2For%20human%20health">new research</a> examined this question.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/pfas-for-dinner-study-of-forever-chemicals-build-up-in-cattle-points-to-ways-to-reduce-risks-201553">PFAS for dinner? Study of 'forever chemicals' build-up in cattle points to ways to reduce risks</a>
</strong>
</em>
</p>
<hr>
<h2>What did the study find?</h2>
<p>EPA scientists partnered with the Victorian Department of Energy, Environment and Climate Action and 13 <a href="https://www.water.vic.gov.au/water-industry-and-customers/victorian-water-corporations">state water corporations</a> to investigate emerging contaminants in wastewater. As a science-based regulator, EPA undertakes problem-based research on pollution and waste to protect the health of Victoria’s community and environment. It uses data and evidence from studies like these to guide future actions.</p>
<p>We collected 230 samples of treated and untreated water at a range of wastewater treatment plants. We analysed these for the presence of 414 emerging and legacy contaminants.</p>
<figure class="align-center ">
<img alt="Outflow from a wastewater treatment plant" src="https://images.theconversation.com/files/514566/original/file-20230309-26-5wmidx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/514566/original/file-20230309-26-5wmidx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/514566/original/file-20230309-26-5wmidx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/514566/original/file-20230309-26-5wmidx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/514566/original/file-20230309-26-5wmidx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/514566/original/file-20230309-26-5wmidx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/514566/original/file-20230309-26-5wmidx.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">For the study, 230 samples of treated and untreated water were collected from wastewater treatment plants.</span>
<span class="attribution"><span class="source">Image: EPA</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We detected 180 contaminants in treated and untreated water. These included:</p>
<ul>
<li>48 chemicals found in pharmaceuticals and personal care products</li>
<li>5 endocrine-disrupting chemicals</li>
<li>21 per- and polyfluoroalkyl substances (PFAS)</li>
<li>34 herbicides</li>
<li>8 insecticides</li>
<li>7 fungicides</li>
<li>12 industrial compounds</li>
<li>7 phenols</li>
<li>28 disinfection byproducts.</li>
</ul>
<p>None of the contaminant levels in treated water exceeded human health guidelines for <a href="https://www.waterquality.gov.au/guidelines/drinking-water">drinking water</a> and water used for <a href="https://www.nhmrc.gov.au/about-us/publications/guidelines-managing-risks-recreational-water">recreation</a>. </p>
<p>As you might expect, concentrations of most emerging contaminants were lower in treated than untreated water. However, some contaminants remained in treated water. Examples included antidepressant venlafaxine and anticonvulsant medication carbamazepine. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-fishy-problem-how-antidepressants-may-impact-the-health-of-our-aquatic-ecosystems-197514">A fishy problem: How antidepressants may impact the health of our aquatic ecosystems</a>
</strong>
</em>
</p>
<hr>
<p>So which treatment method is best? Based on our study, it’s one that combines all of the following:</p>
<ul>
<li><p>an “activated sludge” process, which can be aerobic or anaerobic – if aerobic, air is needed and is introduced into the “mixed liquor” by aeration devices or by natural diffusion</p></li>
<li><p>extended aeration using a mechanical device to aerate the water</p></li>
<li><p>disinfection with ultraviolet light, which uses UV radiation to break down the DNA of pathogens</p></li>
<li><p>microfiltration, a membrane process that removes particles larger than 0.1 micron </p></li>
<li><p>reverse osmosis, which is another membrane process and removes most of the salt and large molecules, producing water with very low dissolved content</p></li>
<li><p>disinfection with chlorination, zonation or UV disinfection. </p></li>
</ul>
<p>But treatment that combines all the above processes is relatively rare. It’s used by only four out of 200 wastewater treatment plants in Victoria. These plants produce the highest grade of recycled water.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-yuck-factor-pushes-a-premier-towards-desalination-yet-again-but-history-suggests-recycled-waters-time-has-come-188795">The 'yuck factor' pushes a premier towards desalination yet again, but history suggests recycled water's time has come</a>
</strong>
</em>
</p>
<hr>
<h2>What does this mean for the environment?</h2>
<p>None of the contaminants we detected in treated wastewater breached human health guidelines. However, we should not forget the environment. </p>
<p>Pharmaceutical pollution, in particular, is a pressing global issue. A <a href="https://www.pnas.org/doi/10.1073/pnas.2113947119">recent study</a> detected pharmaceuticals in 258 rivers in 104 countries across all continents. Pharmaceutical chemicals break down quickly in the environment, but are continually being replenished.</p>
<p><a href="https://www.who.int/publications/i/item/9789241549950">According to</a> the World Health Organization, trace quantities of <a href="https://pubs.acs.org/doi/10.1021/acs.est.8b05592">pharmaceuticals in drinking water</a> are very unlikely to pose risks to human health. But <a href="https://royalsocietypublishing.org/doi/10.1098/rstb.2013.0569">information</a> about the <a href="https://pubmed.ncbi.nlm.nih.gov/29193285/">potential</a> <a href="https://www.tandfonline.com/doi/abs/10.1080/15287394.2017.1352214">environmental</a> <a href="https://pubmed.ncbi.nlm.nih.gov/28063712/">effects</a> remains limited.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1518790308112203776"}"></div></p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/80-of-household-water-goes-to-waste-we-need-to-get-it-back-125798">80% of household water goes to waste – we need to get it back</a>
</strong>
</em>
</p>
<hr>
<h2>You can make a difference</h2>
<p>Environmental authorities regulate how businesses and industry use, store and dispose of their waste. However, your actions at home – no matter <a href="https://www.sustainability.vic.gov.au/recycling-and-reducing-waste/at-home/small-acts-big-impact">how small</a> – can mean fewer contaminants make it to wastewater treatment plants.</p>
<p>Actions you can take include:</p>
<ul>
<li><p>take medicines only as directed and return unwanted and expired medicines to a pharmacy </p></li>
<li><p>choose chemical-free cleaning products</p></li>
<li><p>minimise pesticide use in your garden and bug sprays in your home</p></li>
<li><p>if you have a wastewater management system at home, such as for greywater or blackwater, maintain it regularly and avoid using powerful chemicals. </p></li>
</ul>
<h2>Next steps</h2>
<p>Further research is under way involving the Victorian EPA, water corporations and research institutions. It aims to build our understanding of what, if and how emerging contaminants are present in soil and taken up by crops irrigated with recycled water. </p>
<p>Ultimately, the work will reduce the potential risks to people and the environment posed by wastewater, by ensuring official advice is current and evidence-based.</p>
<hr>
<p><em>The report’s authors are EPA Scientists Minna Saaristo, Simon Sharp, Shanli Zhang and Mark P. Taylor.</em></p><img src="https://counter.theconversation.com/content/199668/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Patrick Taylor is a full-time employee of EPA Victoria, appointed to the statutory role of Chief Environmental Scientist. He is also an Honorary Professor at Macquarie University. This research was supported by funding from the Department of Energy, Environment and Climate Action and Victorian water authorities to EPA Victoria.</span></em></p>We detected 180 contaminants in treated and untreated water. None of those found in treated water breached human health guidelines, but we should not forget about potential impacts on the environment.Mark Patrick Taylor, Victoria's Chief Environmental Scientist, EPA Victoria; Honorary Professor, School of Natural Sciences, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1961682023-01-05T06:18:01Z2023-01-05T06:18:01ZPFAS: you can’t smell, see or taste these chemicals, but they are everywhere – and they’re highly toxic to humans<figure><img src="https://images.theconversation.com/files/500433/original/file-20221212-108108-c5cvm1.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C998%2C663&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">PFAS are persistent and spread through the atmosphere via hydrological processes.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/technician-use-professional-water-testing-equipment-1927772186">Chatchawal Phumkaew/Shutterstock</a></span></figcaption></figure><p>Humans perceive risk based largely on what we can see, smell and taste. Those senses serve us well when there are perceptible dangers to our health and the environment. </p>
<p>We can see and smell raw sewage and as such it is widely perceived as a risk to human and environmental health. The increasing concern of <a href="https://www.bbc.co.uk/news/uk-england-suffolk-63681034">scientists</a> about the presence of antibiotic-resistant bacteria in sewage has confirmed its actual risk. The Environment Agency also reports that pollution from sewage discharge is a leading cause of <a href="https://www.theguardian.com/environment/2020/sep/17/rivers-in-england-fail-pollution-tests-due-to-sewage-and-chemicals">poor river quality</a> in England.</p>
<p>But there are serious chemical threats, called perflouroalkyl and polyfluoroalkyl substances (PFAS), that we cannot perceive because they are colourless and odourless. Now present in our drinking water and natural ecosystems, high level exposure to these toxic chemicals can elicit a range of <a href="https://www.atsdr.cdc.gov/pfas/index.html">negative health effects in humans and wildlife</a>. These include an increased risk of certain cancers, kidney disease, cholesterol, reproductive and developmental disruption and a decreased vaccine response.</p>
<p>Humans cannot see, smell or taste PFAS in our water. Yet they are a serious <a href="https://pubs.acs.org/doi/10.1021/acs.est.2c02765">global threat</a>. The actual risk of PFAS is high, but in my experience as a scientist working on environmental pollution, many people are <a href="https://onlinelibrary.wiley.com/doi/10.1111/1467-9566.13253">unaware of them</a>.</p>
<h2>What are PFAS?</h2>
<p>First developed in the 1940s, PFAS are a large group of more than 4,000 synthetic chemicals. Commonly known as “forever chemicals”, their properties make them water and oil repellent and highly resistant to chemical and thermal breakdown. </p>
<p>They are therefore ingredients in various everyday products and as such are all around us. Non-stick frying pans, waterproof rain jackets, flame retardant sofas and carpets, <a href="https://chemtrust.org/wp-content/uploads/PFAS-UK-food-packaging_CHEMTrust_May2021.pdf">food packaging</a>, makeup and countless other items all contain these chemicals. </p>
<p>But PFAS can persist in the environment for hundreds or thousands of years. <a href="https://pubs.acs.org/doi/10.1021/es0710499">Research</a> estimates that it takes more than 1,000 years on average for the chemical concentration of some PFAS to reduce by 50% in soil.</p>
<h2>PFAS exposure</h2>
<p>Due to their persistence, PFAS have <a href="https://www.nature.com/articles/s41370-018-0094-1">steadily accumulated</a> in drinking water sources and oceans worldwide. This can happen as contaminated water leaks away from landfills into groundwater. PFAS in household items can also be washed into rivers and oceans through sewage systems. </p>
<figure class="align-center ">
<img alt="A garbage truck dumping waste on a landfill." src="https://images.theconversation.com/files/500441/original/file-20221212-109965-hv1x1s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/500441/original/file-20221212-109965-hv1x1s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/500441/original/file-20221212-109965-hv1x1s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/500441/original/file-20221212-109965-hv1x1s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/500441/original/file-20221212-109965-hv1x1s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/500441/original/file-20221212-109965-hv1x1s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/500441/original/file-20221212-109965-hv1x1s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Contaminated water can leak from landfills into groundwater.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/garbage-truck-dumping-on-landfill-529228804">Dalibor Danilovic/Shutterstock</a></span>
</figcaption>
</figure>
<p>In 2019, at least one PFAS was detected in 60% of the public groundwater wells and 20% of the private groundwater wells used as drinking water sources in the <a href="https://pubs.acs.org/doi/10.1021/acs.est.1c04795">eastern USA</a>. And in England, the <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1012230/Poly-_and_perfluoroalkyl_substances_-sources_pathways_and_environmental_data_-_report.pdf">Environment Agency</a> analysed 470 freshwater sites between 2014 and 2019 and found PFAS contamination in 97% of them.</p>
<p>The freshwater contaminants then accumulate in plants and animals, where they can be <a href="https://www.frontiersin.org/articles/10.3389/ftox.2020.601149/full">transferred</a> to humans via ingestion.</p>
<p>In the city of Charleston in South Carolina, scientists <a href="https://www.sciencedirect.com/science/article/pii/S0013935119300222#:%7E:text=PFOS%20was%20predominant%20PFAS%20compound%20in%20fish%20muscle%20and%20whole%20fish.&text=%E2%88%91PFAS%20concentrations%20were%20higher,than%20fillets%20by%202%E2%80%933X.&text=Frequent%20consumption%20of%20wild%20fish%20may%20pose%20health%20risks%20to%20local%20population.&text=PFOS%20levels%20exceeded%20wildlife%20protective,fish%2C%20a%20concern%20for%20dolphins.">recorded</a> concentrations of 11 PFAS in six species of fish. Levels of the most abundant chemical recorded in each species – perfluorooctane sulfonate – exceeded wildlife protective guidelines in 83% of whole fish examined. The consumption of wild fish therefore represents a serious health concern for the local population.</p>
<h2>Here to stay</h2>
<p>Most people in the world are likely to have been exposed to PFAS. In 2012, more than <a href="https://www.mdpi.com/1660-4601/12/6/6098">97% of Americans</a> were estimated to have detectable levels of PFAS in their blood for example.</p>
<p>But, unlike most other chemical pollutants, PFAS are able to cycle continuously in hydrological processes and spread throughout the atmosphere. Scientists have, for example, <a href="https://pubs.acs.org/doi/10.1021/acs.est.2c02765">recorded</a> concentrations of PFAS in rainwater almost everywhere on Earth. This means that contamination may be largely irreversible. </p>
<p>Distributed by the water cycle, PFAS have been allowed to contaminate remote corners of the planet and negatively impact its wildlife. In Antarctica, accumulations of one type of PFAS – perfluorobutanoic acid – in snow <a href="https://pubs.acs.org/doi/10.1021/acs.est.2c02592">increased</a> more than 200-fold between 1957 and 2015.</p>
<p><a href="https://pubs.acs.org/doi/10.1021/acs.est.1c01645">Researchers</a> have also found high concentrations of PFAS in Arctic algae. Algae are an important food source for zooplankton, with their contamination feeding upwards through the food chain to fish and shrimp, then seals, and finally to apex predators such as polar bears. A study of East Greenland polar bears revealed that PFAS contamination can disrupt a <a href="https://www.sciencedirect.com/science/article/pii/S0160412016302732">polar bear’s</a> hormone system, which may negatively impact reproduction. </p>
<figure class="align-center ">
<img alt="Two polar bear cubs eating a fish." src="https://images.theconversation.com/files/500436/original/file-20221212-112724-p3m533.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/500436/original/file-20221212-112724-p3m533.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=344&fit=crop&dpr=1 600w, https://images.theconversation.com/files/500436/original/file-20221212-112724-p3m533.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=344&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/500436/original/file-20221212-112724-p3m533.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=344&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/500436/original/file-20221212-112724-p3m533.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=432&fit=crop&dpr=1 754w, https://images.theconversation.com/files/500436/original/file-20221212-112724-p3m533.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=432&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/500436/original/file-20221212-112724-p3m533.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=432&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">PFAS can be passed through the food chain.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/polar-bear-cubs-eat-fish-1930967618">evaurban/Shutterstock</a></span>
</figcaption>
</figure>
<p>For many people, current PFAS exposure levels are unlikely to be high enough to warrant serious concern. But exposure in <a href="https://www.epa.gov/pfas/our-current-understanding-human-health-and-environmental-risks-pfas">some occupations</a>, including firefighting and chemical manufacturing and processing, are likely to be much higher. As will the risk for people whose <a href="https://www.nature.com/articles/s41370-018-0099-9">drinking water</a> or food sources have been contaminated.</p>
<p>Science, and even <a href="https://www.theguardian.com/film/2020/feb/27/dark-waters-review-todd-haynes-mark-ruffalo-west-virginia-dupont-poison-">Hollywood</a>, has warned us of the global chemical threat posed by PFAS. Yet many of us do not perceive them to be a threat. </p>
<p>This may be due to the fact that PFAS are an “invisible” threat and not as obvious as sewage or plastic pollution. But these toxic chemicals have accumulated in many of our water sources and are now interfering with natural ecosystems. Governments, scientists and the media must improve their communication of the risks associated with PFAS.</p><img src="https://counter.theconversation.com/content/196168/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Patrick Byrne receives funding from the Natural Environment Research Council.</span></em></p>Toxic synthetic chemicals, called PFAS, are a serious threat to humans and wildlife – but many people are unaware of them.Patrick Byrne, Reader in Hydrology and Environmental Pollution, Liverpool John Moores UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/933092018-03-14T13:42:31Z2018-03-14T13:42:31ZRussian spy attack: how toxic chemicals can cause widespread contamination<p>The recent attempted poisoning of the former Russian spy Sergei Skripal and his daughter has led to warnings about the spread of the toxic chemical used in the attack. Hundreds of people who visited the restaurant where the attack is thought to have taken place <a href="https://www.reuters.com/article/us-britain-russia-hammond/hundreds-urged-to-wash-clothes-after-uk-nerve-agent-attack-idUSKCN1GN0AK">have been told</a> to wash their clothes to avoid any chance of contamination with the suspected “Novichok” <a href="https://theconversation.com/nerve-agents-what-are-they-and-how-do-they-work-93079">nerve agent</a>.</p>
<p>The danger to the public is thankfully thought to be minimal, with only a small risk coming from prolonged, repeated exposure to the tiny amounts of the chemical. But how do experts know what the danger really is in a situation like this? In order to assess the situation, they need to consider how much of the chemical was released, how it came into contact with people, and how it spreads and degrades in the environment.</p>
<p>We can be exposed to chemicals through our skin, by breathing them in, eating them, or injecting them into our blood. And the exact route can make a huge difference, just as breathing in oxygen keeps us alive but injecting <a href="https://www.nhs.uk/conditions/Air-embolism/">it can kill us</a>. </p>
<p>The <a href="https://theconversation.com/the-five-most-poisonous-substances-from-polonium-to-mercury-29619">most toxic compounds</a> are lethal even in tiny doses. For example, the botulinum toxins, the most toxic substances ever discovered, can kill with just a few nanograms per kilogram of bodyweight if injected into veins or muscles. If inhaled, the lethal dose is in the tens of nanograms per kilogram of bodyweight.</p>
<p>Many of the best-known lethal substances, such as cyanide or arsenic, must be ingested to take effect. But other deadly compounds can be absorbed simply by touching them. This was what happened in <a href="https://www.acsh.org/news/2016/06/06/two-drops-of-death-dimethylmercury">the case of Katrin Wetterhahn</a>, a professor in analytical chemistry who accidentally dropped a small amount of dimethylmercury onto her latex gloved hand. As this compounds easily diffused through latex, it was taken up by her body through the skin. She died of mercury poisoning five months later.</p>
<p>Sergei Skripal was poisoned with one of a class of nerve agents <a href="https://theconversation.com/what-we-know-about-novichok-the-newby-nerve-agents-linked-to-russia-93264">known as Novichok</a> agents and chemically described as organophosphorus compounds. They act as an acetylcholinesterase inhibitor, which means that they <a href="https://theconversation.com/nerve-agents-what-are-they-and-how-do-they-work-93079">disrupt the central nervous system</a>. These compounds can come in solid, liquid or gas form, and we know nerve agents work when ingested or inhaled. But it’s not yet clear what specific chemical compound was used in this case and how it was administered. Because of this, we don’t know how much of the agent was needed or how the victims were exposed.</p>
<p>How dangerous a chemical can be also depends on how easily it can spread and contaminate the environment. The physicochemistry of a substance plays an important role here. Arsenic has a melting point of over 600°C so if it were sprinkled into food it would be unlikely to travel far from the plate because it is solid at room temperature. </p>
<p>But lethal compounds dispersed as gases, like the alleged use of chlorine gas in the <a href="http://www.bbc.co.uk/news/world-middle-east-42675657">Syrian civil war</a>, can result in the instant spread of the chemical across a wide area. This means they can affect many more people, although as they become more widely dispersed they become less harmful to individuals because the doses people receive are lower. Similarly, poisons in liquid or aerosol form, or <a href="https://www.theguardian.com/world/2016/mar/06/alexander-litvinenko-and-the-most-radioactive-towel-in-history">radioactive solutions</a> can be <a href="https://www.newscientist.com/blog/shortsharpscience/2006/12/newton-explains-litvinenko-mystery.html">easily transferred</a> from one surface to another.</p>
<p>Once they’ve entered the environment, chemicals often begin to change or break down, rendering them less harmful over time. For example, when chlorine gas comes into contact with an oxidisable material, such as wood or clothing, it changes into a harmless, inert chloride compound.</p>
<h2>Radioactive materials</h2>
<p>In the case of radioactive material, how long the substance is dangerous depends on how quickly its atoms lose energy, a process known as radioactive decay and measured by what’s called a half-life. When another former Russian spy, Alexander Litvinenko, was assassinated in the UK in 2006, the murder weapon was radioactive polonium-210 put into his cup of tea. Polonium-210 has a half life of 138 days, meaning after this time half of its atoms have emitted an alpha particle and decayed into lead-206 atoms.</p>
<p>This alpha radiation emitted inside his body after he had drunk the poisoned tea was what made Litvinenko ill and eventually <a href="http://www.bbc.co.uk/news/magazine-33678717">killed him a month later</a>. But those who came into close contact with him, such as his nurses, would have been much less exposed to the radiation. Alpha particles do not travel a long way and are stopped by even minor obstacles such as a piece of paper or human skin.</p>
<p>Organophosphorus nerve agents including Novichok and sarin, which was used in the <a href="http://www.bbc.co.uk/news/av/world-asia-18455007/archive-nerve-gas-attack-shocks-tokyo">Tokyo subway attack</a> that resulted in 13 deaths, are unstable and break down gradually over time or when exposed to water. This is why washing your clothes after being exposed to such a compound could be enough to get rid of it. In fact, organophosphorus-based nerve agents are so unstable that they are often stored as two or more separate compounds and then combined when needed.</p>
<p>The ability to react easily with other substances is what makes lethal chemicals so dangerous, to both their intended victims and innocent bystanders. As a result, these aggressive substances do not typically linger for long. But if they encounter something that holds them on its surface until it releases them again, this can extend their potentially damaging lifetime. Metallic door handles are a good example for the transfer of material from one person to another.</p>
<p>For those cleaning up a contaminated site, all these factors are vital to understanding what they are facing and how they can prevent anyone else falling victim to a deadly chemical.</p>
<p><em>This article has been amended to state that polonium-210 has a half-life of 138 days and decays into lead-206, not 139 days and polonium-206 as originally stated.</em></p>
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Read more:
<a href="https://theconversation.com/sergei-skripal-and-the-long-history-of-assassination-attempts-abroad-93021">Sergei Skripal and the long history of assassination attempts abroad</a>
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<img src="https://counter.theconversation.com/content/93309/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vera Thoss 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>Hundreds of people have been warned after former Russian spy Sergei Skripal was poisoned with Novichok nerve agent.Vera Thoss, Lecturer in Sustainable Chemistry, Bangor UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/418762015-06-02T10:12:05Z2015-06-02T10:12:05ZWhat does exposure to environmental chemicals mean for our health?<figure><img src="https://images.theconversation.com/files/83585/original/image-20150601-6967-1ywo4zf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Environmental chemicals are found in a range of common household products. </span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-85926235/stock-photo-image-of-many-plastic-bottles-with-water-in-a-shop.html?src=VohMyolLWzvRSkwCCzAqNg-1-3">Water bottles via www.shutterstock.com.</a></span></figcaption></figure><p>It is not possible to live in a <a href="https://theconversation.com/five-myths-about-the-chemicals-you-breathe-eat-and-drink-26849">chemical-free world</a> on Earth. Chemicals are all around us, and some, <a href="http://www.sciencedaily.com/releases/2014/06/140605140007.htm">like oxygen and hydrogen</a>, are essential components for <a href="http://ec.europa.eu/environment/chemicals/index_en.htm">living creatures</a> including us humans. However, some other chemicals may be harmful to our health. </p>
<p>Some environmental chemicals (which are often, but not always, human-made) have been linked to physical and cognitive health conditions and even <a href="http://www.clinicalepigeneticsjournal.com/content/7/1/55">DNA change</a>. Many of these chemicals, such as arsenic, phthalates, polyfluoroalkyl and volatile organic compounds, to name a few, are found in a range of common household or industry products that we use or are exposed to on a regular basis, including cleaning supplies, car exhaust and certain kinds of cosmetics.</p>
<h2>How do we study exposure to environmental chemicals and health?</h2>
<p>One of the prime sources for data on exposure to environmental chemicals and human health comes from the National Health and Nutrition Examination Surveys (<a href="http://www.cdc.gov/nchs/nhanes/about_nhanes.htm">NHANES</a>). </p>
<p>This is a program of epidemiological studies run by the US Centers for Disease Control and Prevention. NHANES monitors the health status of adults and children in the US with a representative sample and uses both interviews and physical examinations. </p>
<p>Some of the information collected includes urine and blood samples, which we can use to track exposure to environmental chemicals. This gives us a picture of the emerging risk hazards from chemicals – we can test the volume of a given chemical in urine or blood and see what the associations are with a range of health conditions. Researchers have been doing this since the 1980s, and scores of studies have been released detailing the associations between concentrations of environmental chemicals in the body and different health outcomes.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/81767/original/image-20150514-28638-r5gomg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/81767/original/image-20150514-28638-r5gomg.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=426&fit=crop&dpr=1 600w, https://images.theconversation.com/files/81767/original/image-20150514-28638-r5gomg.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=426&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/81767/original/image-20150514-28638-r5gomg.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=426&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/81767/original/image-20150514-28638-r5gomg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=536&fit=crop&dpr=1 754w, https://images.theconversation.com/files/81767/original/image-20150514-28638-r5gomg.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=536&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/81767/original/image-20150514-28638-r5gomg.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=536&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Overview of main health effects on humans from some common types of pollution.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Health_effects_of_pollution.png">Medical gallery of Mikael Häggström 2014</a></span>
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<h2>Effects on physical health</h2>
<p>The association between exposure to these kinds of chemicals and human health has been well documented in research using data from NHANES. While many environmental chemicals have been studied, I’ll focus on a few chemicals that are fairly well-known.</p>
<p>Looking at NHANES data from 2009-2010, I found an association between <a href="http://informahealthcare.com/doi/abs/10.3109/08037051.2014.925228">high blood pressure</a> in adults and higher concentrations of heavy metals, arsenic and phthalates in urine. Other research has also associated higher urinary arsenic concentrations that could be found in contaminated groundwater or in foods (eg, grains) with impaired <a href="http://www.sciencedirect.com/science/article/pii/S0013935115001085">kidney function</a> and <a href="http://www.sciencedirect.com/science/article/pii/S016041201400350X">gout disease</a>.</p>
<p>Bisphenol-A and triclosan, used in consumer products including soaps, detergents, toys and surgical cleaning treatments, among other things, have been found to affect <a href="http://ehp.niehs.nih.gov/1002883/">immune function</a> and the <a href="http://ehp.niehs.nih.gov/1104748/">age at which menstruation starts</a>.</p>
<p>Phthalates, a chemical that makes plastic and vinyl more flexible, are found in plastic bottles and in pharmaceutical pills and cosmetics. They have been found to play a role in <a href="http://www.ehjournal.net/content/7/1/27">increased body mass index</a>, <a href="http://www.ehjournal.net/content/13/1/6">diabetes</a>, <a href="http://pediatrics.aappublications.org/content/early/2013/08/13/peds.2012-4022">worse insulin resistance</a>, higher <a href="http://ehp.niehs.nih.gov/1206211/">allergy</a> rates and <a href="http://press.endocrine.org/doi/abs/10.1210/jc.2014-2555?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed">decreased testosterone</a> in both adults and children. </p>
<p>Environmental chemicals may be associated with oral health problems as well.
In a recent study, I found that people with <a href="http://link.springer.com/article/10.1007/s11356-015-4749-3">gum disease, bone loss around the mouth, and teeth loose not due to injury</a> were found to have higher levels of heavy metals, phthalates, phenols, parabens and pesticides (among other chemicals) in their urine. Such harmful exposure could cause defects in the development of <a href="https://www.jstage.jst.go.jp/article/pjab/85/10/85_10_500/_article">tooth enamel</a>.</p>
<h2>Environmental chemicals in the brain</h2>
<p>Environmental chemicals could also influence brain development, particularly in children and older adults. </p>
<p>For example, frequent use of household products with higher levels of pyrethroid insecticides and polyfluoroalkyl chemicals are linked to <a href="http://www.karger.com/?DOI=000342310">learning problems</a> and <a href="http://ehp.niehs.nih.gov/1001898/">impaired attention</a> in children. </p>
<p>In the elderly, <a href="http://www.sciencedirect.com/science/article/pii/S016041201200253X">vision, hearing and balance</a> might be altered through chronic exposure to a range of chemicals including heavy metals, phthalates, arsenic, pesticides, phenols, hydrocarbons and polyfluorinated compounds. And it has been further observed that these chemicals might lead to <a href="http://link.springer.com/article/10.1007%2Fs11356-015-4261-9">difficulties in thinking or remembering</a> as well. It is thought that these chemicals may <a href="http://informahealthcare.com/doi/abs/10.1081/DCT-200039780%20">disrupt nerve regulation</a> in the brain.</p>
<h2>Effects on emotions</h2>
<p>If environmental chemicals could impair our organs and change our <a href="http://www.jimmunol.org/content/135/2/820.long">nervous system</a>, then they might have effects on our emotional health as well. </p>
<p>In recent research, I found that higher levels of parabens and polyaromatic hydrocarbons in urine might suggest that some people need more <a href="http://link.springer.com/article/10.1007%2Fs11356-015-4561-0">emotional support</a>, such as talking over problems or help making difficult decisions, than others with lower concentrations do. Such relationship exists whether or not people might have other health conditions. </p>
<p>These chemicals are both quite common. Parabens are often used as preservatives in cosmetic and pharmaceutical products, and polyaromatic hydrocarbons are found in exhaust, asphalt, coal tar, smoke, soil and charbroiled foods. </p>
<p>These chemicals may trigger a physical reaction that ultimately leads to the disruption of emotions. Daily exposure to these chemicals could lead to a person developing a dependency on them. This can induce inflammation or immune function to alert cell injury or damage. And that could, in turn, chronically disturb neuron functioning, leading to the <a href="http://www.jimmunol.org/content/135/2/820.long">disruption of emotions</a>, and hence a need for more emotional support. </p>
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<img alt="" src="https://images.theconversation.com/files/82292/original/image-20150519-30528-3j2xkb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/82292/original/image-20150519-30528-3j2xkb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=387&fit=crop&dpr=1 600w, https://images.theconversation.com/files/82292/original/image-20150519-30528-3j2xkb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=387&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/82292/original/image-20150519-30528-3j2xkb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=387&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/82292/original/image-20150519-30528-3j2xkb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=486&fit=crop&dpr=1 754w, https://images.theconversation.com/files/82292/original/image-20150519-30528-3j2xkb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=486&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/82292/original/image-20150519-30528-3j2xkb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=486&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">We can’t live in a chemical-free world.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-150303686/stock-photo-row-of-modern-townhouses-in-vancouver-canada.html?src=b0MSJm-Iz_MyRdqxtf0yrQ-1-23">Homes via www.shutterstock.com.</a></span>
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<h2>How do we know when we are exposed to unnecessary environmental chemicals?</h2>
<p>Once we know the relationships of harmful chemicals and health, we can start to figure out how to lessen or prevent exposure to these chemicals. This could mean reducing our use of the consumer products that contain these substances.</p>
<p>Buildings <a href="http://link.springer.com/article/10.1007%2Fs11356-014-3468-5">built more than 30 years ago</a> could be another source of exposure and therefore need our attention to renovate. They could emit chemicals that harm our health because they have building materials that may contain these harmful chemicals or have other pollutants like <a href="http://www.sciencedirect.com/science/article/pii/S0013935115000304">mold</a>.</p>
<p>A <a href="http://omicsgroup.org/journals/building-engineering-epidemiology-northern-ireland-house-condition-survey-2168-9717.1000112.php?aid=21453">screening program</a> is one of the ways to identify housing and chemical issues at an early stage. </p>
<p>Another way is through an <a href="http://link.springer.com/article/10.1007/s11356-015-4671-8">unpleasant smell</a> which is exactly what it sounds like. The presence of unpleasant odors might direct us to where the excess chemicals around us are. These issues could also be detected by reviewing <a href="http://link.springer.com/article/10.1007/s11356-015-4604-6">self-rated health</a>. This is an indicator of physical and mental health issues, created by asking people questions about their health. </p>
<p>And based on new research about environmental chemicals and oral health, one could also <a href="http://link.springer.com/article/10.1007/s11356-015-4749-3">look at teeth</a> from time to time. </p>
<p>These types of preventative measures could be carried out on a regular basis for individuals and each household to suggest when to examine and remove the unnecessary environmental chemicals in order to improve and sustain our health, well-being and quality of life.</p><img src="https://counter.theconversation.com/content/41876/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ivy Shiue (Scthiue) 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>Chemicals in a wide array of consumer products have been linked to conditions affecting physical, cognitive and emotional health.Ivy Shiue (Scthiue), Senior research associate, Northumbria University, NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/293622014-07-21T13:06:05Z2014-07-21T13:06:05ZWhy are Fukushima engineers creating walls of ice under a contaminated nuclear plant?<p>Engineers at Fukushima nuclear power plant have been trying to create a £185m ice wall to isolate contaminated water from mixing with groundwater. However, there has been a <a href="http://www.theguardian.com/environment/2014/jul/13/doubts-giant-ice-wall-fukushima-nuclear-reactors">steady stream</a> of <a href="http://www.theguardian.com/environment/2014/jun/17/fukushima-ice-wall-radioactive-water">news articles</a> reporting on problems associated with the work so far. They are simply adding to the <a href="https://theconversation.com/is-fukushima-the-new-normal-for-nuclear-reactors-17391">sense of despair and distrust</a> that has hung over the clean-up operation since the disaster occurred at the site more than three years ago. However, a closer look at the technology inspires hope.</p>
<h2>Strong foundations</h2>
<p>Artificial ground freezing (AGF) is not as crazy as it might sound. It is a technique that has been used in civil engineering for more than a century. Invented by German engineer FH Poetsch in the 1880s for use in the mining industry, the principle of the process has not changed since then. </p>
<p>The idea is to pipe brine solution (extremely salty water) at –30°C to extract heat from the under the surface, and to cause the water in cracks and pores to freeze. The ice binds the rock and soil grains together in a sheet up to several metres thick, while also preventing the movement of unfrozen water through the ground.</p>
<p>At Fukushima, they will insert 1,550 pipes that go 33 metres deep. In the last month 100 pipes have been put in place, and testing has begun.</p>
<p>The freezing of the ground has two effects – improved strength and reduced permeability – which make AGF a useful solution to a range of civil engineering problems. As well as stabilising shafts and preventing water from entering working areas in mines, AGF is widely used in construction of dams and tunnels, where water can make the excavation impossible.</p>
<p>Two of the largest, most complex infrastructure projects in the US in recent years – the “<a href="http://en.wikipedia.org/wiki/Big_Dig">Big Dig</a>”, tunnelling an interstate beneath downtown Boston, and the New York <a href="http://en.wikipedia.org/wiki/East_Side_Access">East Side Access project</a> which involves boring a new rail tunnel beneath already-buried road and rail networks – have used AGF extensively. It has also been one of the standard options on the table for engineers on London’s £15 billion <a href="http://www.bbc.co.uk/news/magazine-23518137">Crossrail project</a>. </p>
<p>In all these cases, ice-wall technology holds advantages over other methods. It is completely reversible with minimal environmental footprint. It can accommodate a wide range of soil formations and structures, critically giving it the ability to operate in sites which already harbour buried structures and services, such as at Fukushima.</p>
<h2>Complex, but not sci-fi</h2>
<p>Despite the long history of ice-wall technology in civil engineering, every project is different and subsurface environments are notoriously complex. Things can, and do, go wrong. Nevertheless, the key risk factors are well known. Poor design and maintenance of the refrigeration system is a predictable hazard, manageable through strong project leadership and use of well-informed AGF specialists in both the specification and implementation phases.</p>
<p>Less predictable is the effect of groundwater flow, which is a critical factor at Fukushima since groundwater management is the primary objective of building an ice wall there. Moving water freezes less easily than stationary water, and when it does it is not easy to predict how it would do so. Improvements in computer simulation of freezing behaviour in porous media and in modelling the complexity of subsurface environments are key.</p>
<p>So the scale of the challenges faced by the ice-wall engineers at Fukushima are huge. But they are not unprecedented. Ground freezing has even been used for radiation mitigation before, for example at mining operations in <a href="https://www.imwa.info/docs/imwa_2011/IMWA2011_Newman_253.pdf">Canada</a> and Australia where radioactive radon gas is a threat to the health and safety of mineworkers. The idea of using ice-wall technology to isolate and treat a volume of contaminated groundwater – exactly the objective at Fukushima – is based on patents outlining the concept of an underground ice-walled storage volume dating back to the 1960s.</p>
<p>None of this diminishes the magnitude of the problems facing engineers and managers at the world’s highest-profile contaminated site. But the ice-wall technology itself is not the bizarre stunt that has sometimes been portrayed. It might even work.</p>
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<p><em>Next, read this: <a href="https://theconversation.com/what-is-acceptable-risk-when-planning-a-nuclear-power-plant-22192">What is the ‘acceptable risk’ when planning a nuclear power plant?</a></em></p><img src="https://counter.theconversation.com/content/29362/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jonathan Bridge receives funding from the Natural Environmental Research Council and the Technology Strategy Board. He consults to the UK National Nuclear Laboratory.</span></em></p>Engineers at Fukushima nuclear power plant have been trying to create a £185m ice wall to isolate contaminated water from mixing with groundwater. However, there has been a steady stream of news articles…Jonathan Bridge, Lecturer in Environmental Engineering, University of LiverpoolLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/282552014-06-25T03:32:34Z2014-06-25T03:32:34ZBook review: Poisoned Planet<figure><img src="https://images.theconversation.com/files/51970/original/2w22hp5q-1403570171.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">You can still fish for fun in Sydney Harbour, but there are rules for how much fish your should eat because past tests have shown elevated levels of dioxins in fish and crustaceans.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/hindmarsh/12197895894/in/photolist-4ab6FB-87RZpL-jzTptU-y63Ae">Peter Hindmarsh/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>The <a href="http://safepla.net/exp-who.html">World Health Organization estimates</a> that one in every 12 deaths worldwide is due to chemical exposure, sometimes acute but mostly chronic. This eclipses the annual death tolls from malaria, car crashes and HIV/AIDS. </p>
<p>Clearly, we need to be doing more about major health risks like malaria, as well as other environmental risks to health from ongoing changes to the world’s climate, soils, ocean chemistry, biodiversity and other natural systems. But a new book raises an important question: what are the consequences of diverting our gaze from another global environmental health hazard?</p>
<p>The dangers associated with urban-industrial air pollutants have long been apparent, though they are now also implicated in <a href="http://www.chicagotribune.com/health/sns-rt-us-pollution-aging-cognitive-function-20140618,0,6259317.story">old-age mental decline</a>. Yet apart from acute environmental disasters such as <a href="http://www.ncbi.nlm.nih.gov/pubmed/7734058">Minamata</a> in the late 1950s and <a href="https://www.google.com.au/#q=bhopal+disaster">Bhopal</a> in 1984, most of the rising tide of long-lasting synthetic chemicals, heavy metals and other contaminants diffusing through the environment has been invisible. </p>
<p>Further, the ecological and health risks are not well understood – and are widely assumed to be negligible because actual exposures are presumably low. </p>
<p>That assumption is challenged by Australian science writer Julian Cribb in his new book <a href="http://www.allenandunwin.com/default.aspx?page=94&book=9781760110468">Poisoned Planet</a>. He argues that the Earth’s surface is now chemically contaminated from the Arctic to the ocean floor – and that each of us is unwittingly a “walking contaminated site”.</p>
<h2>A rising tide of toxins</h2>
<p>In Western countries, national concerns and legislation over environmental contamination by human-generated chemical effluent and wastes peaked in the 1970s.</p>
<p>Yet since 1960, annual synthetic chemical production worldwide has increased 20-fold. Over 140,000 newly synthesised industrial and agricultural chemicals have been registered in North America, Europe and Australia.</p>
<p>Persistent organochlorines such as <a href="http://www.epa.gov/pesticides/factsheets/chemicals/ddt-brief-history-status.htm">DDT</a> and polychlorinated biphenyls (PCBs), heavy metals (especially lead and mercury) and many volatile aromatic hydrocarbons all have known toxic effects. And what of nano-pollutants, with their bioactivity transformed by miniscule size? </p>
<p>Climate change can cause floods, mobilise mosquitoes and diminish harvests, and the adverse human impacts are easy to see. </p>
<p>In contrast, long-lasting chemical contaminants act more covertly, spreading through air, soil, water, foods and ecosystems. Some are benign, some overtly toxic, but many act by insidious weakening or disruption of healthy biological functions: affecting specific organ systems, altering hormonal profiles, switching genes on or off, and contributing to various cancerous, neurological and behavioural changes. Humans, other species and ecosystems are thus endangered. </p>
<p><a href="http://www.farmlandbirds.net/sites/default/files/Grandjean%20Landrigan%20Lancet%202014_0.pdf">A silent epidemic</a> may be occurring, warns <a href="http://www.sciencealert.com.au/jca.html">Cribb</a>, who is an award-winning science writer and founder of the <a href="http://www.sciencealert.com.au/">ScienceAlert website</a>.</p>
<p>Drawing on diverse scientific research, a coherent picture emerges in this book of wide-ranging potential harm to bodies, brains and babies from chemical contamination, mostly food-borne.</p>
<p>Some of Cribb’s evidence is unavoidably thin, some is contested. But when viewed overall, it’s hard not to agree that humanity is fouling its nest. </p>
<p>For instance, a recent <a href="http://www.sciencedaily.com/releases/2014/06/140617093224.htm">European-wide study concluded</a> that the ecological risks from toxic chemicals greatly exceed previous assumptions.</p>
<p>Many persistent contaminants have spread globally into polar ice, mountain glaciers, seals and whales. Humans dine at nature’s high table, often eating industrially-produced food, grown, processed and packaged in ways that impart traces of many chemical hazards – a trade-off for the undoubted privilege of abundant and affordable food.</p>
<h2>A silent epidemic?</h2>
<p>There is much to be celebrated about modern life. </p>
<p>Urbanisation and industrialisation have ushered in the high-water mark of human material achievement. Poverty, starvation, infectious diseases and brute labour, though still with us, are no longer the norm. The contagion, filth and stench of medieval times has given way to clean water, sanitation, safe food, vaccines, better housing – and longer lives.</p>
<p>But is it mere coincidence that rising rates of cognitive impairment and child-and-adolescent behavioural abnormalities in recent decades have accompanied the increase in low-level environmental chemical exposures? We know that foetal and perinatal biology renders tiny humans vulnerable to toxic insult, so it is not unreasonable to at least ask such questions. And are increases in allergic conditions, even autism, also part of this picture? </p>
<p>Scientific evidence is also accruing that some chemical exposures contribute to <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3385443/">obesity</a> and the diabetes that is often a consequence of that obesity.</p>
<p>The average person’s in-out energy imbalance in modern society – that is, we’re consuming more food energy than we’re physically expending – is an acknowledged cause of weight gain. However, biologically, that energy imbalance exerts effects via various metabolic, cellular and hormonal changes, as do various assimilated chemical contaminants.</p>
<p>A thought experiment shows the difficulty of assessing consequences of chronic low-level exposure to chemicals. If the urbanised Romans’ use of lead for plumbing and in drinking vessels caused gradual intellectual impairment and loss of imperial authority, who would have noticed the link, or foreseen the future consequences? </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/51971/original/n5p9wby6-1403570894.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/51971/original/n5p9wby6-1403570894.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/51971/original/n5p9wby6-1403570894.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/51971/original/n5p9wby6-1403570894.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/51971/original/n5p9wby6-1403570894.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/51971/original/n5p9wby6-1403570894.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/51971/original/n5p9wby6-1403570894.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/51971/original/n5p9wby6-1403570894.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"></a>
<figcaption>
<span class="caption">Beijing in February this year.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/sunsetnoir/12657650665/in/photolist-khvLyi-aZvRBp-5EZVuf-khwrQc-khvL4v-khvLKa-khvMcx-dfBggo-56SV8H-5cajhC-3CA2AA-3CwweD-3Cwmmx-3Cw1d4-3CvLZX-3CAAZs-3CAcK3-3Cw6nz-3CB7wN-3CB2Bf-3CwRjc-5cfPts-e3iKm5-xffKG-khvLfT-xffMw-xffQo-xnM2L-xnLUw-3CwrwZ-3CzWHL-3CwbPB-3CwAYF-ht5Xw6-4reGZy-dfBdLx-dfBgzN-5gJCoK-bk8Bhd-dH5ba-9kCSPZ-dfBguL-4wkopU-dfBgxm-dfBdJD-dfBgsJ-dfBgCq-dfBgqo-2SXuBS-4DKm5J">Lei Han/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>What we can do</h2>
<p>Poisoned Planet may unsettle some readers, and raise eyebrows among others. </p>
<p>But Cribb’s message – emphasising the need for both information and precaution – warrants our serious attention. The problem of persistent environmental chemical contamination could well have long-lasting effects on human biology, health and longevity, and we owe it to ourselves and coming generations to debate the questions he raises.</p>
<p>In the meantime, there are solutions to toxic pollution that we can act on today. These changes include improving the way we grow, manufacture, transport, consume, and dispose of chemical wastes. </p>
<p>International conventions on chemical contamination must be ratified and complied with. </p>
<p>And citizens all over the world can also exert influence through existing social and political channels. </p>
<p>For inspiration, we need look no further than China, where the spread of the internet has helped millions of individuals speak up with a common voice about environmental hazards – such as <a href="https://theconversation.com/china-cant-smother-growing-public-demands-to-clear-the-air-23811">deadly air pollution</a> – to demand genuine improvements to clear the air. </p>
<p><em>Poisoned Planet: How constant exposure to man-made chemicals is putting your life at risk by Julian Cribb is published by <a href="http://www.allenandunwin.com/default.aspx?page=94&book=9781760110468">Allen and Unwin</a>.</em></p><img src="https://counter.theconversation.com/content/28255/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tony McMichael receives funding from the National Health and Medical Research Council. He is affiliated with the Frank Fenner Foundation ('Healthy People on a Healthy Planet').</span></em></p>The World Health Organization estimates that one in every 12 deaths worldwide is due to chemical exposure, sometimes acute but mostly chronic. This eclipses the annual death tolls from malaria, car crashes…Tony McMichael, Emeritus Professor, National Centre for Epidemiology & Population Health, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/53782012-02-19T19:37:49Z2012-02-19T19:37:49ZReducing chemical use reduces chemical spills: it’s obvious, so let’s do it<figure><img src="https://images.theconversation.com/files/7718/original/fv9b4z3d-1329272713.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fewer toxins could reduce the incidence of spills, like those from some Orica plants.</span> <span class="attribution"><span class="source">AAP</span></span></figcaption></figure><p>On August 8 last year, there <a href="http://www.health.nsw.gov.au/resources/news/2011/pdf/stockton_health_risk.pdf">was a leak</a> of about <a href="http://www.abc.net.au/news/2012-02-16/epa-admits-mistake-over-orica-spill/3833112">a kilogram</a> of hexavalent chromium from the Orica chemical plant on Kooragang Island, near Newcastle. </p>
<p>Hexavalent chromium is a known respiratory irritant, and an established carcinogen (<a href="http://en.wikipedia.org/wiki/List_of_IARC_Group_1_carcinogens">IARC group 1</a>). A health risk assessment concluded there was <a href="http://www.health.nsw.gov.au/resources/news/2011/pdf/orica_report_on_nsw_healt.pdf">negligible risk</a> to residents of Stockton. But there is understandable community concern about the spill itself and about the communication of information about the spill to those who were potentially affected. In truth, the long term effects remain unknown.</p>
<p>These sort of events are, unfortunately, not rare. During 2011 the Orica plant mentioned above had six chemical leaks. It eventually closed for several months for audit and repairs. In December 2011 a Melbourne glue manufacturer was fined <a href="http://www.abc.net.au/news/2011-12-07/company-faces-fine-of-up-to-241m-for-chemical-leak/3717544">after a leak</a> of n-butylamine, a flammable and corrosive chemical. In the Northern Territory, there were <a href="http://www.perthnow.com.au/news/chemical-leak-fears-from-derailed-train-highway-cut-in-northern-territory/story-e6frg12c-1226231326768">fears of chemicals leaking</a> into floodwaters after a <a href="https://theconversation.com/insuring-the-environment-who-pays-when-mining-goes-wrong-5060">train was washed off a track</a> in December 2011.</p>
<p>Rather than just being outraged at yet another chemical spill, Australia has the option to act to reduce use of known toxic chemicals - including established carcinogens. We can and should implement systems to protect workers and the community living around industrial sites, rather than worrying about one-off effects. </p>
<p>A very successful example of how legislation can reduce exposure to toxic agents is the [Massachusetts Toxics Use Reduction Act](http://www.mass.gov/dep/toxics/toxicsus.htm) (TURA). TURA has established a list of specific chemicals known as “toxics”. </p>
<p>The Act focusses on companies using large quantities of these toxics. They must evaluate their sites for pollution prevention opportunities, produce a plan to reduce the use and release of toxics, update the plan regularly, report their results on an annual basis, and pay a fee for their toxics use. </p>
<p>TURA has established a number of innovative approaches to help companies reduce their use of toxics. These include a Toxics Use Reduction Institute which works with companies to find “greener” substitutes.</p>
<p>In the 20 years since TURA was established, emissions from Massachusetts plants decreased by 56% and use of toxic chemicals <a href="http://turadata.turi.org/Success/index.html">decreased by 21%</a> (after adjusting for production decreases). The TURA program has won several environmental awards and has been adapted by the Canadian province of Ontario and the city of Toronto. </p>
<p>It’s time for Australia to consider adopting this innovative, successful program. If we do that we can reduce the number of headlines about toxic chemical spills, and the anxiety, productivity loss and health concerns that go with them. Better still, we will boost the confidence of Australian workers that they can do a day’s work without increasing their risk of a serious disease.</p>
<p><em>Read more at the <a href="http://www.mja.com.au/public/issues/196_03_200212/fri10485_fm.html">Medical Journal of Australia</a>.</em></p><img src="https://counter.theconversation.com/content/5378/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lin Fritschi 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>On August 8 last year, there was a leak of about a kilogram of hexavalent chromium from the Orica chemical plant on Kooragang Island, near Newcastle. Hexavalent chromium is a known respiratory irritant…Lin Fritschi, Professor of Epidemiology, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/50002012-01-24T19:38:06Z2012-01-24T19:38:06ZIs your health at risk from fish and frying pans?<figure><img src="https://images.theconversation.com/files/7139/original/nr5vmwn3-1327375938.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Researchers aren't sure whether a relatively common environmental chemical compromises our immune response to vaccines.</span> <span class="attribution"><span class="source">Chris RubberDragon</span></span></figcaption></figure><p>Will our desire for seafood and non-stick frying pans compromise the effectiveness of vaccines intended to protect us from nasty diseases? Research published today in the Journal of the American Medical Association (JAMA) will likely be represented in the media that way, but this excellent study isn’t quite so simple. </p>
<p>Before talking about the study itself, let me set up a bit of background.</p>
<p>Trace levels of certain synthetic chemicals in our environment and food can be potentially harmful, but we need to maintain some degree of perspective; the most important toxicological maxim is – <em>it’s the dose that makes the poison</em>. </p>
<h2>Chemicals in the environment</h2>
<p>While there are a number of synthetic (and very scary sounding) chemicals in our environment, only some have the potential to cause harm. One of the particularly worrisome groups is <a href="http://www.epa.gov/international/toxics/pop.html">persistent organic pollutants</a> (POPs). These are a group of chemicals that break down very slowly, and have the ability to accumulate in animal tissue. This is important because while contaminant levels in water, soil or air may be low, continuous exposure may have them accumulate to toxic levels in the body.</p>
<p>One of the least well-understood groups of these chemicals are perfluorinated compounds. These are basically long carbon chains with hydrogen replaced by fluorine. Perfluorinated compounds (PFCs) are used as water and stain repellents, and in making <a href="http://www.rsc.org/chemistryworld/Issues/2005/September/Cooking.asp">Teflon</a>. </p>
<p>These chemicals are widely distributed in the environment, as well as in animals and humans. They bind to the proteins in animals’ bodies, and are very persistent, which means it can take over four years for half of a single dose of PFC to be eliminated from a human body (if you were to swallow 10 mg of PFC, half that amount would still be in your body four years later). </p>
<p>The ability of these compounds to accumulate in animals is important, because their major source for humans is from eating flesh, particularly fish. But while high concentrations are clearly toxic, the effect of levels similar to what people are generally exposed to <a href="http://www.efsa.europa.eu/de/scdocs/doc/653.pdf">is less clear</a>. </p>
<p>One particular worry is the effect PFCs have on the immune system. Some studies in mice suggest that levels of perfluorinated compounds within the range seen in humans may reduce the ability of the immune system to respond to infection, but others have found much higher levels are needed to make an impact. The differences in these studies may be due to the strain of mice used, or <a href="http://www.sciencedirect.com/science/article/pii/S0300483X09005393">how the perfluorinated compound was administered</a>. </p>
<h2>The latest study</h2>
<p>This new JAMA study attempts to throw light on the PFC effect by examining a real-world outcome – our ability to mount an immune response to vaccination. Researchers measured the antibody response in children vaccinated against diphtheria and tetanus. And they measured the levels of perfluorinated compounds (PFCs) in their blood, and in stored samples of their mothers’ blood from when the children were born. </p>
<p>The children and their mothers lived on the <a href="http://en.wikipedia.org/wiki/Faroe_Islands">Faroe Islands</a>, a Danish protectorate halfway between Scotland and Iceland. This is important because there are good medical records for the children, and the islanders have a diet high in marine foods, which potentially exposes them to high levels of PFCs. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/7140/original/s62htgw6-1327377149.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/7140/original/s62htgw6-1327377149.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=345&fit=crop&dpr=1 600w, https://images.theconversation.com/files/7140/original/s62htgw6-1327377149.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=345&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/7140/original/s62htgw6-1327377149.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=345&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/7140/original/s62htgw6-1327377149.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=434&fit=crop&dpr=1 754w, https://images.theconversation.com/files/7140/original/s62htgw6-1327377149.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=434&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/7140/original/s62htgw6-1327377149.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=434&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">Google maps</span></span>
</figcaption>
</figure>
<p>One of the hardest things to be certain about in this kind of research is whether the levels of a compound measured in a single blood sample accurately represents the levels over many years. If you measure someone’s blood sample at five years of age, does it remain the same or is it higher or lower later in life?</p>
<p>But because the researchers measured the mothers’ blood levels as well as that of the children and because these compounds are expelled from the body very slowly (remember: four years or more for half a single dose), it’s likely the concentrations of PFCs the children were exposed to over the first seven years of their life (when their vaccination responses were monitored by the researchers) were not wildly different to the levels measured when they were five years old (when they were given their vaccination booster shots). </p>
<h2>What they found</h2>
<p>The researchers found that increasing levels of PFCs correlated with decreased antibody levels in response to vaccination. Importantly, the levels of PFCs in the children’s blood were similar to levels found in other populations, such as the <a href="http://ehp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1289%2Fehp.10598">United States</a>. But how concerned should we be about this result?</p>
<p>Firstly, correlation is not causation. Sure, it may waggle its eyebrows suggestively while mouthing “look over there”, but we need to be very careful about interpreting these results. Because of their seafood-rich diet, the Faroese children are exposed to a lot of chemicals that could potentially cause problems. </p>
<p>And while the level of PFC may be similar between Faroese and other children, the source of the contaminant may be different. That is, PFC levels in Faroese kids may simply be a marker for high seafood consumption, and the antibody problems may be due to other reasons. The only way to confirm the effect of PFC on vaccine response would be to examine the immune response of other children with similar levels of PFC in their blood but who are not exposed to other contaminants. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/7150/original/y9j63hkd-1327384106.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/7150/original/y9j63hkd-1327384106.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=308&fit=crop&dpr=1 600w, https://images.theconversation.com/files/7150/original/y9j63hkd-1327384106.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=308&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/7150/original/y9j63hkd-1327384106.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=308&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/7150/original/y9j63hkd-1327384106.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=388&fit=crop&dpr=1 754w, https://images.theconversation.com/files/7150/original/y9j63hkd-1327384106.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=388&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/7150/original/y9j63hkd-1327384106.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=388&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The chemical structure of Perfluorooctanesulfonic acid (PFC).</span>
<span class="attribution"><span class="source">Ian Musgrave</span></span>
</figcaption>
</figure>
<p>Indeed, the same researchers had previously shown that polychlorinated biphenyl (a chemical that makes plastics more mouldable) levels in Faroese children correlated with low vaccine response. So for this study, they also measured polychlorinated biphenyl levels and tried to adjust for it in their results. </p>
<p>But again, given the number of contaminants the children were exposed to through their diet, more evidence is needed before we can decisively say PFCs are the reason for their decreased antibody response. The authors of the study say this themselves.</p>
<h2>What does it all mean?</h2>
<p>From the point of view of those who want to eat lots of fish, this may seem like nitpicking; we already know that we ought to limit fish consumption because of methyl mercury contamination, especially in top predators like tuna. </p>
<p>The other issue is interpreting the fall in antibody concentrations – while there’s a statistically significant fall in antibody levels, its clinical significance is unclear. It’s generally considered that for decent protection against infection you need antibody levels greater than 0.1 IU/mL (international units per millilitre) in your blood, but even at the highest levels of PFCs the antibody levels never really fall below 0.25 IU/mL. IU is a measure of how much antibody is in your blood. </p>
<p>If we extrapolate from the Faroese to other communities going on blood concentrations alone, then 95% of all children would be well protected by vaccination despite exposure to PFCs. </p>
<p>But this brings us to another issue: can we actually extrapolate from the Faroese? Despite the children’s blood concentrations being similar to those of children in the <a href="http://ehp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1289%2Fehp.10598">United States</a>, the <a href="http://www.ncbi.nlm.nih.gov/pubmed/11485834">higher intake of other chemicals</a> such as polychlorinated biphenyls and methyl mercury may significantly alter their immune response. </p>
<p>This is an important paper but it’s only the first step in understanding the effect of PFCs on human immunity. The authors themselves say this. We may see some scary headlines as a result of it but the data presented suggests the vast majority of children will be well protected by vaccination despite exposure to PFCs. </p><img src="https://counter.theconversation.com/content/5000/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ian Musgrave receives funding from the Australian Research Council.</span></em></p>Will our desire for seafood and non-stick frying pans compromise the effectiveness of vaccines intended to protect us from nasty diseases? Research published today in the Journal of the American Medical…Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.