tag:theconversation.com,2011:/us/topics/glyphosate-10349/articlesGlyphosate – The Conversation2023-12-06T13:27:05Ztag:theconversation.com,2011:article/2136362023-12-06T13:27:05Z2023-12-06T13:27:05ZGlyphosate, the active ingredient in the weedkiller Roundup, is showing up in pregnant women living near farm fields – that raises health concerns<figure><img src="https://images.theconversation.com/files/551447/original/file-20231002-17-ifqt51.png?ixlib=rb-1.1.0&rect=156%2C760%2C1189%2C772&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">As suburbs encroach on farmland, residents' risk of exposure to farm chemicals rises.</span> <span class="attribution"><span class="source">Carly Hyland</span></span></figcaption></figure><p>Living near farmland can significantly increase people’s exposure to glyphosate, the active ingredient in the widely used herbicide Roundup, new research shows. This chemical has been connected to health concerns, including non-Hodgkin lymphoma and a higher risk of preterm birth.</p>
<p>We are <a href="https://www.boisestate.edu/spph/ccurl/">environmental health</a> <a href="https://publichealth.berkeley.edu/people/carly-hyland/">scientists</a> who study <a href="https://www.cdpr.ca.gov/docs/dept/factshts/what2.pdf">pesticide</a> exposures in human populations, including exposures to herbicides. In our <a href="https://ehp.niehs.nih.gov/doi/10.1289/EHP12768">newly published research</a>, we tracked glyphosate levels in pregnant women for 10 months.</p>
<p>We found that those who were living within about a third of a mile (500 meters) of an agricultural field had significantly higher levels of glyphosate in their urine than those who lived farther away. Importantly, we only saw those differences during the time of year when farmers spray glyphosate on their fields, further suggesting agricultural spray as the source of this exposure.</p>
<p>Our <a href="https://doi.org/10.1289/EHP12155">research also found</a> that eating organic food, produced without the use of synthetic pesticides, could reduce glyphosate levels in women living far from farm fields – but not in women who lived near farm fields.</p>
<p>Together, the results provide new insight into how people are exposed to this common and potentially harmful chemical.</p>
<h2>Why it matters</h2>
<p>Glyphosate is the single <a href="https://doi.org/10.1186/s12302-016-0070-0">most heavily used agricultural pesticide in the world</a>. Its use <a href="https://water.usgs.gov/nawqa/pnsp/usage/maps/show_map.php?year=2019&map=GLYPHOSATE&hilo=L&disp=Glyphosate">grew dramatically</a> over the past two decades with the increase in production of genetically modified, herbicide-resistant crops. These crops are engineered to withstand the weed-killing effects of herbicides like glyphosate, which means that an entire field can be sprayed with these chemicals, eliminating the weeds without harm to the crop itself. This is a change from previous practices, where herbicide applications had to be more targeted. </p>
<p>While herbicides like <a href="https://ipm-drift.cfaes.ohio-state.edu/sites/hdrm/files/imce/Overview%20of%20Drift%20Issues%20FINAL.pdf">dicamba and 2,4-D</a> are known to become airborne, glyphosate is not volatile, so there has been less concern over its potential to drift when it is sprayed on crops.</p>
<p>However, our research provides evidence for the first time that agricultural use of glyphosate still reaches people living nearby.</p>
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<a href="https://images.theconversation.com/files/551449/original/file-20231002-27-n4hzko.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A corn field with a road sign reading: 'This road to be extended in the future.' That extension is to build houses in the middle of what is currently a farm field." src="https://images.theconversation.com/files/551449/original/file-20231002-27-n4hzko.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/551449/original/file-20231002-27-n4hzko.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=430&fit=crop&dpr=1 600w, https://images.theconversation.com/files/551449/original/file-20231002-27-n4hzko.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=430&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/551449/original/file-20231002-27-n4hzko.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=430&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/551449/original/file-20231002-27-n4hzko.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=540&fit=crop&dpr=1 754w, https://images.theconversation.com/files/551449/original/file-20231002-27-n4hzko.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=540&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/551449/original/file-20231002-27-n4hzko.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=540&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">Rural communities have dealt with risks from agriculture chemicals for many years.</span>
<span class="attribution"><span class="source">Carly Hyland</span></span>
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<p>It is important to note that <a href="https://doi.org/10.1186/s12302-018-0184-7">there is no consensus</a> on whether or not this widely used herbicide causes cancer.</p>
<p>The International Agency for Research on Cancer, part of the World Health Organization, has determined that glyphosate is “<a href="https://www.iarc.who.int/featured-news/media-centre-iarc-news-glyphosate/">probably carcinogenic to humans</a>,” while the U.S. Environmental Protection Agency has concluded that it is “<a href="https://www.epa.gov/ingredients-used-pesticide-products/glyphosate">not likely to be carcinogenic to humans</a>.” This debate is playing out in <a href="https://www.forbes.com/advisor/legal/product-liability/roundup-lawsuit-update/">courtrooms across the U.S.</a>, with <a href="https://www.reuters.com/legal/litigation/bayer-winning-streak-roundup-litigation-after-huge-initial-losses-2022-09-02/">mixed results</a>.</p>
<p>In addition to concerns about cancer risk, four recent human studies found that glyphosate exposure during pregnancy was associated with <a href="https://doi.org/10.1016%2Fj.envres.2021.111811">reproductive effects</a>. These effects included <a href="https://doi.org/10.1289/EHP7295">preterm birth</a>, <a href="https://doi.org/10.1186/s12940-018-0367-0">shortened gestational duration</a> and <a href="https://doi.org/10.1186/s12940-022-00906-3">reduced fetal growth</a>.</p>
<p>However, scientists <a href="https://doi.org/10.1186/s12940-018-0435-5">know very little</a> about levels and sources of glyphosate exposure among pregnant women. The potential risk and that lack of data is why our study focused on this group.</p>
<h2>How we did our work</h2>
<p>We collected 1,395 urine samples from 40 pregnant women living in southern Idaho. This included weekly urine samples from February through December 2021. Among women living near fields, we found that urinary glyphosate levels were <a href="https://ehp.niehs.nih.gov/doi/10.1289/EHP12768">about 50% higher during the pesticide spray season</a> – May through August in southern Idaho – than they were during the rest of the year.</p>
<p>For two weeks in June, we also provided study participants with a week of <a href="https://doi.org/10.1289/EHP12155">organic food</a> and a week of conventional food, in random order, and collected daily urine samples. Glyphosate levels decreased by about 25% from the conventional to the organic-food week for participants who lived far from fields. But for the women who lived near fields, the shift to an organic diet didn’t change their glyphosate levels.</p>
<p>The results suggest that, for people living in cities and towns, an organic diet can be an effective way to reduce glyphosate exposure. However, for people living near farms, exposure from nearby agricultural applications may matter more.</p>
<h2>What still isn’t known</h2>
<p>Our finding that living near agriculture is associated with higher glyphosate levels in the body provides important new insights about who is exposed to this herbicide. However, we still don’t know exactly how this exposure is occurring.</p>
<p>While many pesticides are transported by airborne drift, it is possible that glyphosate travels in a different way. For example, it may adhere to soil that is blown or tracked into homes.</p>
<p>Understanding this is pivotal to reducing human exposure to chemicals in agricultural areas. It is also important as <a href="https://farmlandinfo.org/wp-content/uploads/sites/2/2020/09/AFT_FUT_StateoftheStates_rev.pdf">urbanization takes over land that was previously farmed</a>. As new subdivisions and residential areas expand into and fragment agricultural areas, homeowners are finding themselves with farm fields, and their chemicals, as neighbors.</p>
<p><em>The Research Brief is a short take on interesting academic work.</em></p>
<p><em><a href="https://theconversation.com/pesticida-glifosato-esta-aparecendo-em-mulheres-gravidas-que-vivem-perto-de-fazendas-nos-eua-219383">Leia em português</a></em>.</p><img src="https://counter.theconversation.com/content/213636/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cynthia Curl receives funding from the National Institute of Environmental Health Sciences NIEHS), a part of the National Institutes of Health (NIH).</span></em></p><p class="fine-print"><em><span>Carly Hyland receives funding from the National Institutes of Environmental Health Sciences (NIEHS) and the National Institute of Occupational Health and Safety (NIOSH). </span></em></p>New research provides evidence for the first time that the primary chemical in Roundup is reaching people in nearby homes, and it isn’t just from the food they eat.Cynthia Curl, Associate Professor of Public and Population Health, Boise State UniversityCarly Hyland, Assistant Professor of Cooperative Extension, University of California, BerkeleyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2173092023-11-28T20:10:03Z2023-11-28T20:10:03ZStriving for transparency: Why Canada’s pesticide regulations need an overhaul<iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/striving-for-transparency-why-canadas-pesticide-regulations-need-an-overhaul" width="100%" height="400"></iframe>
<p><a href="https://www.canada.ca/en/health-canada/news/2021/08/government-of-canada-pauses-decision-on-glyphosate-as-it-strengthens-the-capacity-and-transparency-of-review-process-for-pesticides.html">In 2021, Health Canada announced a freeze on changing maximum residue limits (MRLs)</a> — the maximum allowable pesticide residues acceptable under Canadian law. This decision followed substantial public outcry following Canada’s most widely used weed killer <a href="https://www.canada.ca/en/health-canada/services/consumer-product-safety/pesticides-pest-management/public/consultations/proposed-maximum-residue-limit/2021/glyphosate/document.html">glyphosate’s proposed MRL increase.</a></p>
<p>This year, three ministries (including Health Canada) <a href="https://www.canada.ca/en/health-canada/news/2023/06/government-of-canada-moves-forward-on-federal-pesticide-commitments.html">unpaused</a> the comparatively less complex residue limit adjustments and <a href="https://www.canada.ca/en/health-canada/corporate/about-health-canada/branches-agencies/pest-management-regulatory-agency/transforming/how-we-are-transforming.html">sought to transform</a> the <a href="https://www.canada.ca/en/health-canada/corporate/about-health-canada/branches-agencies/pest-management-regulatory-agency.html">Pest Management Regulatory Agency (PMRA)</a>. </p>
<p>The move was aimed to enhance transparency, modernize their business practices, improve access to information related to pesticide decision-making, and increase the use of real world data and independent advice. </p>
<p>However, trust in the agency remains an issue; only <a href="https://publications.gc.ca/collections/collection_2023/sc-hc/H114-39-2023-eng.pdf">60 per cent of Canadians believe the regulatory system is keeping pace with scientific advancements in pesticide assessment,</a> adding further pressure to Canadian’s eroding trust in science.</p>
<h2>Challenges and controversies</h2>
<p>In spite of ongoing concerns over risks to human and environmental health, global pesticide use has been <a href="https://www.fao.org/faostat/en/#data/RP/visualize">increasing over the past 30 years</a>. </p>
<p>In Canada, increased reliance on pesticides has been largely tied to the intensity of agricultural use in the main crop growing regions of <a href="https://doi.org/10.3389/fenvs.2020.556452">the Canadian Prairies, Southern Ontario and Québec.</a></p>
<p>Advancing pesticide regulation to meet the needs of Canada’s agricultural sector, while protecting human and environmental health, is a growing challenge. </p>
<p>There are <a href="https://www.canada.ca/en/health-canada/services/consumer-product-safety/reports-publications/pesticides-pest-management/corporate-plans-reports/annual-report-2020-2021.html">more than 600 registered active ingredients in more than 7,600 registered pesticide products</a> — a staggering number that continues to rise. </p>
<p>From 2011 to 2021, the PMRA registered between seven and 27 new active pesticide ingredients each year. Meanwhile, it has only <a href="https://doi.org/10.3390/toxics11020121">banned 32 of 531 prohibited active pesticide ingredients regulated in 168 other countries</a>.</p>
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Read more:
<a href="https://theconversation.com/why-there-are-fewer-insects-on-uk-farms-than-there-were-a-century-ago-and-how-to-restore-them-207656">Why there are fewer insects on UK farms than there were a century ago -- and how to restore them</a>
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<p>This influx puts added pressure on the agency to review volumes of scientific data produced by both the registrant and independent scientists, while continuously assessing the growing list of existing products for their safety to humans and risks to environmental health. </p>
<p>Some chemical registration decisions, including <a href="https://beyondpesticides.org/dailynewsblog/2016/01/canada-discontinues-conditional-registrations-for-new-pesticides/">conditional registrations</a>, have been highly controversial, highlighting the lack of transparency or perceived industry bias. </p>
<p>In the case of glyphosate, sales in Canada have topped nearly 470 million kilograms from 2007 to 2018. Public concerns over human health risks and regulated uses have led to <a href="https://www.ctvnews.ca/health/advocates-thrilled-as-court-orders-health-canada-to-reassess-glyphosate-decision-1.5772134">legal challenges</a>. </p>
<p>Similarly, the proposed 2018 decision to phase out three of the most widely used, environmentally persistent and toxic neuro-active <a href="https://www.canada.ca/en/health-canada/services/consumer-product-safety/pesticides-pest-management/growers-commercial-users/neonicotinoid-insecticides.html">neonicotinoid insecticides</a> was later <a href="https://www.nationalobserver.com/2021/04/08/news/feds-wont-ban-pesticides-deadly-bees-bugs-ecosystems">reversed in 2021</a>. Citizens and scientists were left seeking answers on whether industry influence caused the <a href="https://www.wildernesscommittee.org/news/federal-pesticide-regulator-flip-flops-proposed-neonics-ban-after-years-delay">flip-flop</a>.</p>
<h2>Evolving roles</h2>
<p>Last year, as part of the transformation agenda, Health Canada aimed to fortify its pesticide review processes by establishing an <a href="https://www.canada.ca/en/health-canada/corporate/about-health-canada/public-engagement/external-advisory-bodies/science-advisory-committee-pest-control-products.html">independent Science Advisory Committee</a>. </p>
<p>Currently comprising eight academic experts, whose backgrounds were screened for conflict of interest, the committee has been tasked to provide objective, science-based advice to inform regulatory decisions on pest control products. We are four of them.</p>
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<figcaption><span class="caption">An exploration into the connections between pesticide use and disease in humans, produced by Deutsche Welle documentaries.</span></figcaption>
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<p>Since its creation in July 2022, the committee has met five times with Health Canada’s PMRA in a <a href="https://www.canada.ca/en/health-canada/corporate/about-health-canada/public-engagement/external-advisory-bodies/science-advisory-committee-pest-control-products/meetings.html">public forum</a>.</p>
<p>The committee has been tasked with providing input on diverse issues such as communication of MRLs, use of independent data sources, creation of open source toxicity databases, and access to registrant data used in decision-making. </p>
<p>As a positive early sign, the PMRA has been responsive to the <a href="https://www.canada.ca/en/health-canada/corporate/about-health-canada/public-engagement/external-advisory-bodies/science-advisory-committee-pest-control-products/advisory-reports.html">committee’s advice and recommendations</a>, which is anticipated to reinforce public trust and ensure science-based decision-making is at the core of its processes. </p>
<h2>Informing new policies</h2>
<p>Canada is long overdue in establishing a <a href="https://canadacommons.ca/artifacts/1191021/a-canada-wide-framework-for-water-quality-monitoring/1744148/">co-ordinated water monitoring program</a> to systematically measure pesticide levels nationally. </p>
<p>The committee is providing external scientific advice on the new pilot <a href="https://www.canada.ca/en/health-canada/services/consumer-product-safety/pesticides-pest-management/public/protecting-your-health-environment/programs-initiatives/water-monitoring-pesticides/pilot-program.html">Water Monitoring Framework Initiative</a>. </p>
<p>Committee experts are giving input on guidance for site selection, monitoring frequency in different types of surface waters and analytical measurement of current use compounds and their degradation products. </p>
<p>The goal is to ensure this much-needed water quality data is rigorous and usable for future risk assessment and independent scientific research.</p>
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Read more:
<a href="https://theconversation.com/pesticides-are-harming-nigeria-its-time-to-update-the-law-207050">Pesticides are harming Nigeria: it’s time to update the law</a>
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<p>Recently, the PMRA has an added responsibility to enhance broader Canadian biodiversity goals and environmental protections by aligning its regulatory work with the <a href="https://www.cbd.int/article/cop15-final-text-kunming-montreal-gbf-221222">2022 Kunming-Montreal Global Biodiversity Framework — aiming to reduce pesticide risk by at least 50 per cent by 2030</a> — alongside the enactment of <a href="https://www.canada.ca/en/environment-climate-change/news/2023/06/bill-s-5-strengthening-environmental-protection-for-a-healthier-canada-act.html">Bill S-5, updating the Canadian Environmental Protection Act of 1999</a>, to consider cumulative pesticide exposure in risk assessments. The committee is currently developing recommendations to inform approaches to best address these significant policy initiatives.</p>
<h2>Towards a pesticide-safe Canada</h2>
<p>The journey to more transparent and scientifically robust pesticide regulation in Canada is long overdue, yet essential. </p>
<p>A greater emphasis on transparency and communication of the science that underpins regulatory decision-making is urgently needed. A lack of access to data and information used in risk assessment undermines the public trust. </p>
<p>An over-reliance on industry supplied confidential studies, limited application of data from independent scientists, a lack of publicly available data on active ingredient pesticide sales, use and environmental monitoring, are all contributing to scepticism. </p>
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Read more:
<a href="https://theconversation.com/the-green-revolution-is-a-warning-not-a-blueprint-for-feeding-a-hungry-planet-182269">The Green Revolution is a warning, not a blueprint for feeding a hungry planet</a>
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<p>As the PMRA transitions to more transparency and reaffirms its evidence-based decision-making for pesticide regulation, insight from independent scientific researchers as part of the committee will play a critical role.</p><img src="https://counter.theconversation.com/content/217309/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Valérie S. Langlois is receiving funding from the Canada Research Chair (CRC) program, the Natural Sciences and Engineering Research Council of Canada (NSERC), Environment and Climate Change Canada (ECCC), the Ministère de l'environnement et de la lutte contre les changements climatiques, Faune et Parcs du Québec (MELCCFP), among others. Dr. Langlois is the co-chair of the Science Advisory Committee (SAC).</span></em></p><p class="fine-print"><em><span>Christy Morrissey currently receives funding from Canada's Natural Sciences and Engineering Research Council, Canada Foundation for Innovation, Environment and Climate Change Canada, Mitacs, Saskatchewan Ministry of Agriculture, and the Molson Foundation. She is a member of the PMRA's Science Advisory Committee (SAC).</span></em></p><p class="fine-print"><em><span>Dr. Eric Liberda receives funding from CIHR and Indigenous Services Canada to conduct research related to pesticides and metal/metalloid exposures. He is a member of the Society of Toxicology and the Society of Toxicology Canada. Dr. Liberda is a co-chair of the Science Advisory Committee (SAC).</span></em></p><p class="fine-print"><em><span>Sean Prager receives funding from NSERC, Canadian Foundation for Innovation, Genome Canada, The Saskatchewan Ministry of Agriculture, several commodity boards and NGOs. He is affiliated with the PMRA Science Advisory Committee (SAC). </span></em></p>Canada is long-overdue for scientifically-driven, robust and transparent pesticide regulation. A newly created Science Advisory Committee aims to address this.Valérie S. Langlois, Professor/Professeure titulaire, Institut national de la recherche scientifique (INRS)Christy Morrissey, Professor in Biology and Ecotoxicology, Toxicology Centre, University of SaskatchewanEric Liberda, Professor, School of Occupational and Public Health, Toronto Metropolitan UniversitySean Prager, Associate Professor and Entomologist, University of SaskatchewanLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2024602023-03-30T15:13:04Z2023-03-30T15:13:04ZWhat’s the most sustainable way of dealing with Japanese knotweed? Here’s what we found<figure><img src="https://images.theconversation.com/files/518139/original/file-20230329-26-j3bjij.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4592%2C2577&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">More than £150 million is spent trying to control Japanese knotweed in the UK annually.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/knotweed-japanese-invasive-expansive-species-dangerous-1993556132">Tomas Vynikal/Shutterstock</a></span></figcaption></figure><p>When it was introduced to Europe in the mid-19th century as an ornamental plant, Japanese knotweed, known as <em>Reynoutria japonica var japonica</em>, quickly went rogue. Despite not being native to the British Isles, it was able to rapidly form self-sustaining colonies in the wild. </p>
<p>Today, this invasive plant is found across much of <a href="https://plantatlas2020.org/atlas/2cd4p9h.7mm4kb">Britain and Ireland</a>. It is often spotted growing in areas influenced by people such as waste ground, along riverbanks, roadsides and railway lines.</p>
<p>From an ecological perspective, this plant is very competitive and decreases biodiversity. This means invaded habitats become degraded and we see fewer native plants and animals. </p>
<p>Controlling knotweed is a <a href="https://www.legislation.gov.uk/ukpga/1981/69">legal requirement</a> in the UK and the costs of managing it are estimated to be around <a href="https://www.researchgate.net/publication/298559361_The_Economic_Cost_of_Invasive_Non-Native_Species_on_Great_Britain">£165 million per year</a>. Its management on construction sites can cost <a href="https://www.nonnativespecies.org/non-native-species/information-portal/view/1495">£1,000 per square meter</a> or more. These costs also impact home and landowners and several legal cases associated with knotweed have made <a href="https://www.theguardian.com/environment/2023/feb/14/legal-victory-uk-japanese-knotweed-case-more-claims">headlines</a> recently. </p>
<p>An entire industry has been built around knotweed management. But until fairly recently, the most effective way of controlling knotweed was unknown. Back in 2018, our research group published the results of the <a href="https://link.springer.com/article/10.1007/s10530-018-1684-5">world’s largest Japanese knotweed trial</a>, which is what informs how we currently tackle the plant. </p>
<h2>Sustainability</h2>
<p>Sustainability has never been a more important issue and there’s increasing pressure to find more sustainable management approaches to dealing with knotweed. Growing concerns around the use of herbicides for the environment and human health have led to an increased focus on physical control methods, such as digging and using <a href="https://www.allthescience.org/what-are-geomembranes.htm">geomembranes</a>. These are synthetic liners which stop Japanese knotweed and other unwanted plants from growing by sealing the earth. </p>
<p>However, when we think about sustainable knotweed management, we tend to focus on the immediate impacts, but that is just the tip of the iceberg. What happens before and after we use products to control knotweed is also important. All products and processes have a life cycle and each stage has different impacts. So, the sustainability of alternative approaches to tackling knotweed is often unclear. </p>
<p>To address this, we investigated the <a href="https://www.nature.com/articles/s41598-023-30366-9">impacts of eight Japanese knotweed management methods</a> using life cycle assessment (<a href="https://pre-sustainability.com/articles/life-cycle-assessment-lca-basics/">LCA</a>). That is when you calculate the environmental impact of a product throughout its entire life cycle. </p>
<p>We used our <a href="https://theconversation.com/weve-found-the-best-way-to-control-japanese-knotweed-95320">knotweed trial</a> as a reference system for our investigation.</p>
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<img alt="A close up of a green leaf with a spray of apple white small flowers in the background." src="https://images.theconversation.com/files/518154/original/file-20230329-18-9wdccw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/518154/original/file-20230329-18-9wdccw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/518154/original/file-20230329-18-9wdccw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/518154/original/file-20230329-18-9wdccw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/518154/original/file-20230329-18-9wdccw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/518154/original/file-20230329-18-9wdccw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/518154/original/file-20230329-18-9wdccw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A Japanese knotweed flower.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/japanese-knotweed-flowers-persicaria-japonica-118949437">Martin Fowler/Shutterstock</a></span>
</figcaption>
</figure>
<p>Of the methods assessed, annual <a href="http://npic.orst.edu/factsheets/glyphogen.html">glyphosate</a> spraying was the most sustainable option in terms of environmental impacts, economic cost and time consumption. This is because it is an approach that uses the fewest amount of materials while being the most effective method at controlling Japanese knotweed.</p>
<p>We found geomembrane covering to be the most damaging. That was due to the production of the plastics needed to manufacture the geomembranes, as well as the ground preparation needed to install them. And we also found that using digging as part of a knotweed management programme was also less sustainable due to the carbon emissions produced from using machinery.</p>
<p>So, the most effective way of controlling knotweed is also the most sustainable. </p>
<p>In light of the current <a href="https://www.ipcc.ch/report/sixth-assessment-report-cycle/">climate crisis</a>, minimising greenhouse gas emissions is vital. As we are aiming to achieve carbon net zero by 2050 in the UK, we need to think carefully about the sustainability of the approaches we use for managing Japanese knotweed and other problematic invasive plants. </p>
<p>Although we recognise the <a href="https://theconversation.com/does-this-cause-cancer-how-scientists-determine-whether-a-chemical-is-carcinogenic-sometimes-with-controversial-results-193431">ongoing discussions</a> regarding the use of glyphosate, its use yields better and more sustainable results than other Japanese knotweed treatments. And understanding the sustainability of different methods also means we can prioritise what we use to control knotweed, which ultimately saves time and money.</p>
<p>One caveat we have is that we evaluated just eight approaches to knotweed management. Assessing environmental impacts relies on comprehensive, long-term data and rigorous record keeping of the time, costs and materials that go into knotweed management. This kind of data can still be hard to come by. But data on the effectiveness and sustainability of different methods will be an essential future consideration for how society selects its weed control treatments.</p>
<p>Our understanding of and ability to quantify the environmental impacts of different products after they have been used is also a growing area of research and something that is not encompassed in our study. This is something we are looking to build upon in the future. It would ensure that different treatments are evaluated in a way that supports the decisions we make as a society over how to control Japanese knotweed.</p><img src="https://counter.theconversation.com/content/202460/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sophie Hocking works for Swansea University. She received funding from Complete Weed Control Ltd as part of her KESS II PhD to support her research. </span></em></p>It’s a plant that is nearly impossible to obliterate, but new research reveals the best way of tackling Japanese knotweed in the most sustainable way.Sophie Hocking, Lecturer in Biosciences, Swansea UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1934312023-01-30T13:12:57Z2023-01-30T13:12:57ZDoes this cause cancer? How scientists determine whether a chemical is carcinogenic – sometimes with controversial results<figure><img src="https://images.theconversation.com/files/506177/original/file-20230124-18-m5hdd.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3000%2C1500&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Carcinogenic chemicals are labeled with a health hazard warning symbol. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/serious-health-hazard-royalty-free-illustration/1353836395">Peter Etchells/iStock via Getty Images Plus</a></span></figcaption></figure><p>People are <a href="https://www.universityofcalifornia.edu/news/toxic-exposure-chemicals-are-our-water-food-air-and-furniture">exposed to numerous chemicals</a> throughout their lifetimes. These chemicals can be from the air, foods, personal care items, household products and medications. Unfortunately, exposure to certain chemicals can cause harmful health effects, including cancer. Substances that cause cancer are called <a href="https://www.genome.gov/genetics-glossary/Carcinogen">carcinogens</a>. Familiar examples include <a href="https://monographs.iarc.who.int/wp-content/uploads/2018/06/mono100E-6.pdf">tobacco smoke</a>, <a href="https://monographs.iarc.who.int/wp-content/uploads/2018/06/mono100D-9.pdf">radon</a>, <a href="https://monographs.iarc.who.int/wp-content/uploads/2018/06/mono100C-11.pdf">asbestos</a> and <a href="https://www.iarc.who.int/news-events/iarc-diesel-engine-exhaust-carcinogenic/">diesel engine exhaust</a>.</p>
<p>To protect the health of the public, national and international health agencies evaluate many new and existing chemicals to determine if they are likely to be carcinogens in a process called <a href="https://pubmed.ncbi.nlm.nih.gov/9715519/">cancer hazard identification</a>. If agencies judge the chemicals to be carcinogenic, they conduct further assessments to determine the level of risk, and legislators may put regulations in place to limit, or completely halt, the production and use of these chemicals.</p>
<p><a href="https://www.engr.colostate.edu/cbe/people/brad-reisfeld/">I am a scientist</a> who studies how the human body processes foreign chemicals, like environmental pollutants and drugs, and the effects of these chemicals on health. As part of my work, I have participated in chemical and cancer hazard identifications for several agencies, including the World Health Organization’s <a href="https://www.iarc.who.int">International Agency for Research on Cancer</a>. Here’s how chemicals can cause cancer, and how we classify chemicals based on on how carcinogenic they are – sometimes with controversial results.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/506173/original/file-20230124-306-u6qsnd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Person in protective suit spraying herbicide on plants" src="https://images.theconversation.com/files/506173/original/file-20230124-306-u6qsnd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506173/original/file-20230124-306-u6qsnd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506173/original/file-20230124-306-u6qsnd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506173/original/file-20230124-306-u6qsnd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506173/original/file-20230124-306-u6qsnd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506173/original/file-20230124-306-u6qsnd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506173/original/file-20230124-306-u6qsnd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Glyphosate, an herbicide used in products like Roundup, was classified by the IARC as probably carcinogenic to humans in 2015.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/person-in-protective-suit-spraying-herbicide-on-royalty-free-image/1327771135">Adriana Duduleanu/EyeEm via Getty Images</a></span>
</figcaption>
</figure>
<h2>How do chemicals cause cancer?</h2>
<p>The mechanisms behind how toxic chemicals can lead to cancer <a href="https://www.ncbi.nlm.nih.gov/books/NBK570326/">are complex</a>. </p>
<p>After a person is exposed to a carcinogen, the chemical is generally absorbed into the body and distributed into different tissues. Once the chemical has moved into the cells, it often undergoes chemical reactions that convert it into other forms. </p>
<p>The products of these reactions can directly or indirectly affect the cell’s genes. Altering genes, which contain the cell’s instructions on how to produce specific molecules, or the processes that regulate them can ultimately result in dysfunctional cells if the genetic damage isn’t repaired. These cells don’t respond normally to cellular signals and can grow and divide at abnormal rates, which are characteristic features of cancer cells.</p>
<h2>How are chemicals classified for carcinogenicity?</h2>
<p>To help safeguard the public and reduce the incidence of cancer, several agencies have developed procedures to classify and categorize chemicals based on their potential to be carcinogenic. </p>
<p><a href="https://www.atsdr.cdc.gov/pha-guidance/conducting_scientific_evaluations/indepth_toxicological_analysis/EvaluateEvidenceCancerEffects.html">Among them</a> are the International Agency for Research on Cancer, or IARC Monographs; the National Toxicology Program, or NTP; and the U.S. Environmental Protection Agency, or EPA. In general, these agencies examine a critical question: How strong is the evidence that a substance causes cancer or biological changes that could be related to cancer in people? Understanding the procedures used to answer this question can help with interpreting the decisions these agencies make.</p>
<p>The <a href="https://monographs.iarc.who.int/iarc-monographs-preamble-preamble-to-the-iarc-monographs/">procedures used by the IARC</a> – because of its long history, credibility and strong international reputation – provide a good example of how this process works. It’s designed to be transparent and minimize bias, spanning over a year from selecting a chemical for evaluation to its final classification. </p>
<p>In this process, the IARC selects and invites a panel of scientific experts on the chemical to be evaluated. The panel does not conduct new research on its own, but carefully reviews all available papers in the scientific literature on the chemical’s carcinogenicity in cell and bacterial cultures, animals and people. To assess the strength of the evidence, the panel carefully considers the number of studies that are available and the consistency of the results, as well as the scientific quality and relevance of each study to cancer in people.</p>
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<figcaption><span class="caption">Chemicals can be carcinogenic to varying degrees.</span></figcaption>
</figure>
<p>After discussing and deliberating on the results, the panel makes a final consensus classification. This classification places the chemical into one of four groups: Group 1 indicates that the chemical is carcinogenic to people, Group 2A that it is probably carcinogenic to people, Group 2B that it is possibly carcinogenic to people, and Group 3 that it is not classifiable. A Group 3 classification does not indicate that the compound is not carcinogenic, but rather that the panel could not draw a conclusion about whether there is a causal link between the chemical and cancer from available studies. For example, exposure to several chemicals can make it unclear which ones are responsible for a later cancer diagnosis.</p>
<p>During its 50-year history, the IARC has evaluated and classified <a href="https://monographs.iarc.who.int/wp-content/uploads/2018/07/cumulative-cross-index.pdf">over 1,000 chemicals and other hazards</a>. Many of these classifications have had broad societal implications, such as those for tobacco smoke, ambient air pollution, diesel engine exhaust and processed meat. All were classified as Group 1, or confirmed to be carcinogenic to humans. <a href="https://www.iarc.who.int/pressrelease/iarc-classifies-radiofrequency-electromagnetic-fields-as-possibly-carcinogenic-to-humans/">Electromagnetic radiation</a> emitted by mobile phones was classified as Group 2B, or possibly carcinogenic, and <a href="https://www.iarc.who.int/featured-news/media-centre-iarc-news-redmeat/">red meat</a> was classified as Group 2A, or probably carcinogenic. Though they haven’t directly led to any regulations, these classifications have motivated <a href="https://doi.org/10.3389/fpubh.2019.00223">additional</a> <a href="https://doi.org/10.1007/s13668-021-00377-x">scientific studies</a>. While the IARC can advise regulators, it’s up to countries to implement policies.</p>
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<p>It is important to note that classifications do not indicate the size of the risk but are important in supporting health agencies worldwide as they implement actions to limit exposures to known, probable and possible carcinogens. In 2020, when the IARC <a href="https://www.iarc.who.int/news-events/iarc-monographs-evaluation-of-the-carcinogenicity-of-opium-consumption/">classified opium consumption as Group 1</a>, or carcinogenic to humans, this led the government of Iran to <a href="https://www.youtube.com/watch?v=hJDlJhtPeiQ">implement policies</a> to reduce opium addiction in the country.</p>
<h2>Controversies in carcinogenicity classifications</h2>
<p>Though classifications from the IARC are based on robust scientific evidence, some have <a href="https://doi.org/10.1093/carcin/bgv062">proved to be controversial</a>. </p>
<p>For instance, in 2015, the IARC evaluated the carcinogenicity of <a href="https://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Identification-Of-Carcinogenic-Hazards-To-Humans/Some-Organophosphate-Insecticides-And-Herbicides-2017">glyphosate</a>, a widely used weedkiller found in products like Roundup, which is produced by Monsanto. A panel of 17 experts from 11 countries systematically reviewed results from over 1,000 scientific studies and classified glyphosate as “probably carcinogenic to humans,” or Group 2A.</p>
<p>Owing to its widespread usage and <a href="https://www.transparencymarketresearch.com/glyphosate-market.html">multibillion-dollar market value</a>, a cancer classification decision for glyphosate has significant potential financial and legal consequences. Following its evaluation, the IARC received support from many <a href="https://oehha.ca.gov/proposition-65/general-info/oehha-statement-regarding-us-epas-press-release-and-registrant-letter">regulatory</a> and <a href="https://www.env-health.org/campaigns/glyphosate-why-the-eu-needs-to-protect-health-ban-the-popular-weedkiller/">scientific bodies</a> but was <a href="https://www.science.org/content/article/who-rebuts-house-committee-criticisms-about-glyphosate-cancer-warning">criticized by others</a>. Other agencies, <a href="https://www.gao.gov/products/gao-19-280">including</a> <a href="https://www.epa.gov/office-inspector-general/report-epa-needs-improve-transparency-its-cancer-assessment-process">the EPA</a>, have seen similar controversies and politicization of their hazard identifications and regulatory decisions.</p>
<p>I believe that agencies like the IARC play a critical role in evaluating the health effects of certain chemicals and in reducing exposure to potential carcinogens. Helping people better understand how these agencies evaluate chemicals can go a long way to ensure transparency and help protect environmental and public health.</p><img src="https://counter.theconversation.com/content/193431/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brad Reisfeld does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The WHO’s International Agency for Research on Cancer convenes a panel of scientific experts to review available evidence on whether specific chemicals or occupational exposures may cause cancer.Brad Reisfeld, Professor of Chemical and Biological Engineering, Colorado State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1741812022-01-26T13:27:04Z2022-01-26T13:27:04ZThe herbicide dicamba was supposed to solve farmers’ weed problems – instead, it’s making farming harder for many of them<figure><img src="https://images.theconversation.com/files/442064/original/file-20220122-25-9rovsg.jpg?ixlib=rb-1.1.0&rect=51%2C0%2C5760%2C3794&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Soybean plants on an Arkansas farm. Those at left show signs of damage from dicamba; others at right were planted later in the season.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/at-david-wildys-soybean-fields-on-the-left-soybean-plants-news-photo/842398912">Washington Post via Getty Images</a></span></figcaption></figure><p>In October 2021 I was a guest on a popular podcast to discuss my recently published book, “<a href="https://wwnorton.com/books/9781324002048">Seed Money: Monsanto’s Past and Our Food Future</a>,” which examines the agribusiness giant’s influence on the global food system. After the show, I got a lot of calls from around the world, but one really stood out to me: A farmer speaking on his cellphone from the seat of his combine in South Dakota as he harvested soybeans.</p>
<p>Farmers don’t like to stop tractors on good-weather days in the fall, but this was important. The caller wanted to talk about a chemical weedkiller called <a href="http://npic.orst.edu/factsheets/dicamba_gen.html">dicamba</a> that had been sprayed on neighboring fields. He claimed it was damaging his crops. And he wasn’t alone.</p>
<p>In 2021, <a href="https://www.regulations.gov/document/EPA-HQ-OPP-2020-0492-0021">thousands of U.S. growers</a> reported to the Environmental Protection Agency that dicamba sprayed by other farmers – sometimes <a href="https://investigatemidwest.org/2020/10/29/epa-documents-show-dicamba-damage-worse-than-previously-thought/">up to a mile and a half away</a> – damaged crops in their fields. Complaints came from all over the country.</p>
<p><a href="https://www.regulations.gov/document/EPA-HQ-OPP-2020-0492-0021">The list</a> of affected plants was astounding: sycamore, oak and elm trees; azaleas, black-eyed Susans and roses; garden tomatoes, peppers and peas. <a href="https://www.regulations.gov/document/EPA-HQ-OPP-2020-0492-0003">According to an EPA memorandum</a>, there were 2,700 “dicamba incidents,” affecting about 3.6 million acres, in 2017. Two years later, the number of incidents ballooned to 3,300. </p>
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<figcaption><span class="caption">Farmers describe their concerns about dicamba damage in 2017.</span></figcaption>
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<p>This problem has been building for over five years, and the EPA acknowledges that the modest controls it has required, such as creating buffer zones around fields, <a href="https://www.epa.gov/pesticides/epa-releases-summary-dicamba-related-incident-reports-2021-growing-season">aren’t working</a>. But tighter curbs on use of dicamba aren’t likely before the 2022 growing season starts in the spring, because they would require a <a href="https://www.epa.gov/pesticides/epa-releases-summary-dicamba-related-incident-reports-2021-growing-season">complicated legal process</a>. </p>
<p>Why is it so hard to address this national problem? Answering that question requires looking back to 1996, when a revolution transformed American agriculture.</p>
<h2>From Roundup to dicamba</h2>
<p>Weeds have always been an expensive headache for farmers. A 2016 study estimated that if left uncontrolled, weeds would cut corn and soybean yields in North America roughly in half, causing <a href="https://wssa.net/wssa/weed/croploss-2/">US$43 billion in yearly economic losses</a> just from those two crops. One of the problems farmers face is that weeds are very good at evolving resistance to chemical products used to kill them, so herbicides lose their effectiveness over time.</p>
<p>Weed problems became especially bad in the late 1980s and early 1990s as widely used herbicides called ALS inhibitors <a href="https://doi.org/10.1177/074823379901500120">became less and less effective</a>. That’s why farmers were enthusiastic about Monsanto’s “Roundup Ready” crops, first introduced in 1996. </p>
<p>These plants were engineered to resist heavy spraying of Monsanto’s <a href="https://www.nytimes.com/2001/08/02/business/the-power-of-roundup-a-weed-killer-is-a-block-for-monsanto-to-build-on.html">blockbuster herbicide, Roundup</a>. Monsanto had developed and patented glyphosate, Roundup’s active ingredient, in the 1970s, but the advent of Roundup Ready seeds made glyphosate sales explode.</p>
<p>It seemed like a magical system: Farmers could treat fields with glyphosate throughout the growing season without hurting their crops. For a few years, overall herbicide use dropped: Farmers used glyphosate in huge quantities, but stopped buying most other herbicides. </p>
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<figure><figcaption><span class="caption">Use of glyphosate has increased dramatically since the introduction of Roundup Ready seeds starting in 1996 (move slider to compare 1995 and 2019 usage).</span></figcaption></figure>
<p><a href="https://web.archive.org/web/19970714063108/http://www.monsanto.com/monpub/environment/monsantoear96/96earall.pdf">Monsanto asserted</a> that this approach would <a href="http://extension.agron.iastate.edu/weeds/weednews/roundupcottonad.htm">make farming more sustainable</a> by reducing long-term use of herbicides and pesticides – especially older, more toxic brands. Soon, however, the system started to falter. </p>
<p>In the early 2000s, scientists began reporting that weeds were <a href="https://doi.org/10.1002/ps.4760">evolving resistance to Roundup</a>. In response, Monsanto rolled out a new generation of genetically engineered seeds that would make crops resistant to a wider array of older herbicides. Farmers could use these older products along with Roundup, improving their chances of killing most weeds.</p>
<p>One of the chemicals Monsanto bet on was dicamba, first introduced in the 1960s. In 2015 and 2016, the company began producing seeds <a href="https://www.roundupreadyxtend.com/products/pages/default.aspx">branded “Roundup Ready Xtend</a>” that were engineered to tolerate heavy spraying of both dicamba and glyphosate. The logic was that dicamba would eliminate glyphosate-resistant weeds, and glyphosate would wipe out all other unwanted vegetation.</p>
<h2>A solution becomes a problem</h2>
<p>It quickly became clear that this fix was seriously flawed. Dicamba is <a href="https://extension.umn.edu/herbicides/uncovering-dicambas-wayward-ways">one of the most volatile herbicides on the market</a>, meaning that it changes readily from a liquid to a vapor in warm temperatures. When farmers sprayed dicamba on hot days, it tended to vaporize and drift off target, spreading to fields and farms that often were not planted with crops genetically engineered to tolerate it. The South Dakota farmer who called me from his combine was harvesting organic soybeans that did not contain Monsanto’s Xtend traits. </p>
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<p>Maddeningly for farmers, Monsanto had seen this coming. In a 2020 federal court case, <a href="https://casetext.com/case/bader-farms-inc-v-monsanto-co-18">Bader Farms v. Monsanto</a>, confidential company documents revealed that the firm was aware that dicamba sprayed on Xtend crops would likely drift off target. Monsanto sales representatives even called this a sales point for dicamba-tolerant seeds. “Push ‘protection from your neighbor,’” one <a href="https://usrtk.org/wp-content/uploads/2020/02/dicamba-PLTF-22.pdf">slide in an internal 2013 sales presentation suggested</a>. </p>
<p>Farmers started complaining about dicamba drift soon after Monsanto introduced its first Xtend seeds. The Trump administration ordered farmers not to spray dicamba in buffer zones around fields, and to <a href="https://www.epa.gov/sites/default/files/2020-10/documents/dicamba-decision_10-27-2020.pdf">restrict dicamba application to particular times of day</a>, but this had little effect. </p>
<p>Amid this controversy, the EPA extended approval in 2018 for three dicamba-based herbicides. But the U.S. Ninth Circuit Court of Appeals <a href="https://www.centerforfoodsafety.org/files/125--dicamba-opinion_35970.pdf">revoked this decision in June 2020</a>, ruling that the agency had ignored or downplayed evidence of damage from dicamba and failed to consider how its licensed use would “tear the social fabric of farming communities.” In response, EPA approved new dicamba licenses with some <a href="https://www.epa.gov/newsreleases/epa-announces-2020-dicamba-registration-decision">additional control measures</a> that it asserted met the court’s concerns.</p>
<h2>A chemical arms race</h2>
<p>Now the Biden administration is weighing how to address dicamba – and none too soon. Farmers reportedly are seeing weeds that have <a href="https://www.dtnpf.com/agriculture/web/ag/crops/article/2021/07/03/weed-resistance-dicamba-2-4-d-rise">developed resistance to dicamba and other herbicides</a> recommended for use with a new generation of genetically engineered seeds. According to weed specialists, this is happening precisely because farmers are <a href="https://www.nytimes.com/2021/08/18/magazine/superweeds-monsanto.html">using such large quantities of these chemicals</a> during the growing season. </p>
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<p>Seed companies like the German firm Bayer, which now owns Monsanto’s product portfolio, say one solution is for farmers to buy seeds that can tolerate a wider array of weedkillers. Recently, for example, Bayer sought approval for a new line of seeds that would make crops resistant to <a href="https://civileats.com/2020/07/01/bayer-forges-ahead-with-new-crops-resistant-to-5-herbicides-glyphosate-dicamba-2-4-d-glufosinate-quizalofop/">five different types of herbicides</a>.</p>
<p>For farmers, this will mean greater reliance on an expanding array of petrochemicals, and therefore higher costs. Today, U.S. farmers <a href="https://www.nytimes.com/2016/10/30/business/gmo-promise-falls-short.html">use more than twice as much herbicide</a> to grow soybeans as they did before Roundup Ready crops were introduced. </p>
<p>I see dicamba drift as a symptom of a larger petrochemical dependency that threatens the viability of the U.S. food system. My research in this area makes clear that if federal agencies really want to help farmers solve weed problems, they would do well to look to agricultural innovators who are demonstrating that <a href="https://doi.org/10.1038/nplants.2017.8">crops can be grown productively and profitably</a> without relying so heavily on synthetic pesticides. </p>
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<p>In the U.S. and around the world, farmers are seeking alternative ways to deal with weeds. Some are <a href="https://doi.org/10.1371/journal.pone.0219847">diversifying what they grow</a>, using time-honored practices like <a href="https://www.farmers.gov/blog/conservation/discover-cover-managing-cover-crops-suppress-weeds-and-save-money-herbicides">cover cropping</a>, and looking to innovative methods coming out of a resurgent <a href="https://theconversation.com/regenerative-agriculture-can-make-farmers-stewards-of-the-land-again-110570">regenerative farming movement</a>. </p>
<p>If these tools can create a future agricultural economy less reliant on petrochemicals derived from finite resources, I believe it would be welcome news not just to farmers but also to those of us who depend on them for our food.</p><img src="https://counter.theconversation.com/content/174181/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bart Elmore receives funding from the New America Foundation in Washington, DC, and the Nieman Foundation for Journalism at Harvard University and Columbia's University's School of Journalism.</span></em></p>Farmers are stuck in a chemical war against weeds, which have developed resistance to many widely used herbicides. Seed companies’ answer – using more varied herbicides – is causing new problems.Bart Elmore, Associate Professor of History and Core Faculty in the Sustainability Institute, The Ohio State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1611562021-07-02T12:15:12Z2021-07-02T12:15:12ZWhile debate rages over glyphosate-based herbicides, farmers are spraying them all over the world<figure><img src="https://images.theconversation.com/files/408535/original/file-20210627-25-jd7j90.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5039%2C3382&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Containers of the herbicide glyphosate at a farm supply store in northeast Thailand in 2019.</span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/ThailandChemicalBan/da01ccda97714aad8cd2edf54a67f3ac/photo">AP Photo/Sakchai Lalit</a></span></figcaption></figure><p>As North America enters its peak summer growing season, gardeners are planting and weeding, and groundskeepers are mowing parks and playing fields. Many are using the popular weed killer Roundup, which is widely available at stores like <a href="https://www.homedepot.com/p/Roundup-Weed-and-Grass-Killer-III-with-Pump-N-Go-Ready-To-Use-2-1-Sprayer-510011435/100619041">Home Depot</a> and <a href="https://www.target.com/b/roundup/-/N-6dbu?Nao=0">Target</a>.</p>
<p>In the past two years, three U.S. juries have awarded <a href="https://www.courthousenews.com/roundup-cancer-trial-verdict-upheld-but-damages-slashed/">multimillion-dollar verdicts</a> to plaintiffs who asserted that glyphosate, the active ingredient in Roundup, gave them <a href="https://www.cancer.org/cancer/non-hodgkin-lymphoma/about/what-is-non-hodgkin-lymphoma.html">non-Hodgkin lymphoma</a>, a cancer of the immune system. Bayer, a German chemical company, <a href="https://www.businessinsider.com/monsanto-beyer-merge-drop-monsanto-name-2018-6">bought Roundup’s inventor, Monsanto, in 2018</a> and inherited some 125,000 pending lawsuits, of which it has settled all but about 30,000. The company is now considering ending U.S. retail sales of Roundup to reduce the risk of further lawsuits from residential users, who have been the <a href="https://www.reuters.com/business/healthcare-pharmaceuticals/us-judge-rejects-bayers-2-bln-deal-resolve-future-roundup-lawsuits-2021-05-26/">main source of legal claims</a>. </p>
<p>As scholars who study <a href="https://scholar.google.com/citations?user=EnsiK4gAAAAJ&hl=en">global trade</a>, <a href="https://scholar.google.com/citations?user=OZUSfzMAAAAJ&hl=en">food systems</a> and their <a href="https://scholar.google.com/citations?user=U73rXq8AAAAJ&hl=en">effects on the environment</a>, we see a bigger story: Generic glyphosate is ubiquitous around the globe. Farmers use it on <a href="https://doi.org/10.1016/j.scitotenv.2020.137167">a majority of the world’s agricultural fields</a>. Humans spray enough glyphosate to coat every acre of farmland in the world with <a href="https://doi.org/10.1186/s12302-016-0070-0">half a pound of it every year</a>.</p>
<p>Glyphosate is now showing up in humans, but scientists are <a href="https://www.sfpublicpress.org/scientists-split-over-herbicide-risk-leaving-public-in-lurch/">still debating its health effects</a>. One thing is clear, though: Because it’s an effective and very cheap weedkiller, it has become pervasive. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/trtgLoKJmns?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Research on glyphosate’s possible human health effects in inconclusive, but concern is rising over its heavy use worldwide.</span></figcaption>
</figure>
<h2>How glyphosate went global</h2>
<p>When glyphosate was commercialized under the Roundup brand name in 1974, it was widely viewed as safe. Monsanto scientists claimed that it would <a href="https://www.cabdirect.org/cabdirect/abstract/19972301931?gitCommit=4.13.20-5-ga6ad01a">not harm people or other nontarget organisms</a> and did not persist in <a href="https://www.cabdirect.org/cabdirect/abstract/19972301931?gitCommit=4.13.20-5-ga6ad01a">soil and water</a>. Scientific reviews determined that it <a href="https://doi.org/10.1006/rtph.1999.1371">did not build up</a> in animal tissue.</p>
<p>Glyphosate killed <a href="https://www.sciencedirect.com/book/9780123814951/a-history-of-weed-science-in-the-united-states">more target weed species than any other herbicide before or since</a>. Farmers started spraying it on fields to prepare for the next cropping cycle. </p>
<p>In the 1990s Monsanto began packaging glyphosate with crops that were genetically modified to be resistant to it, including corn, soybeans, cotton and canola. Farmers who used these “<a href="https://www.nytimes.com/2001/08/02/business/the-power-of-roundup-a-weed-killer-is-a-block-for-monsanto-to-build-on.html">Roundup Ready</a>” seeds could apply a single herbicide to manage weeds during the growing season, saving time and simplifying production decisions. Roundup became the <a href="https://doi.org/10.1002/(SICI)1526-4998(200004)56:4%3C309::AID-PS143%3E3.0.CO;2-C">highest-selling and most profitable herbicide</a> ever to appear on the global market. </p>
<p>In the late 1990s, as the last patents for glyphosate expired, the generic pesticide industry began to offer <a href="https://doi.org/10.1002/(SICI)1526-4998(200004)56:4%3C309::AID-PS143%3E3.0.CO;2-C">low-cost versions</a>. In Argentina, for example, prices dropped from <a href="https://repositorio.iica.int/handle/11324/12252">$40 per liter in the 1980s to $3 in 2000</a>.</p>
<p>In the mid-1990s, China began to manufacture pesticides. <a href="https://doi.org/10.1016/j.apgeog.2020.102244">Weak environmental, safety and health regulations</a> and energetic promotion policies initially made Chinese glyphosate very cheap. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/408536/original/file-20210627-15-1e2yvao.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Man driving forklift loads pallets onto warehouse shelves." src="https://images.theconversation.com/files/408536/original/file-20210627-15-1e2yvao.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/408536/original/file-20210627-15-1e2yvao.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/408536/original/file-20210627-15-1e2yvao.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/408536/original/file-20210627-15-1e2yvao.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/408536/original/file-20210627-15-1e2yvao.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/408536/original/file-20210627-15-1e2yvao.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/408536/original/file-20210627-15-1e2yvao.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An employee arranging boxes of agricultural chemicals at a warehouse of Anhui Fengle Agrochemical Co. on Feb. 26, 2021, in Hefei, China.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/an-employee-drives-a-forklift-while-arranging-boxes-of-news-photo/1304299110">Ruan Xuefeng/VCG via Getty Images)</a></span>
</figcaption>
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<p>China still dominates the pesticide industry – it exported <a href="https://doi.org/10.1080/24694452.2021.1898322">46% of all herbicides worldwide</a> in 2018 – but now other countries are getting into the business, including Malaysia and India. Pesticides used to flow from Europe and North America to developing nations, but now developing countries export many pesticides to wealthy nations. More pesticide factories in more places leads to oversupply and even lower prices, with critical implications for human health and the environment. </p>
<h2>Health controversies</h2>
<p>Thanks to cheap globalized manufacturing, glyphosate has become ubiquitous on farmland worldwide – and in human bodies. Researchers have detected it in the urine of <a href="https://doi.org/10.1080/24694452.2020.1761285">children in remote villages in Laos</a> and <a href="https://doi.org/10.1186/s12940-020-00673-z">babies in New York and Seattle</a>.</p>
<p>The question of whether glyphosate causes cancer in humans has been hotly debated. In 2015 the International Agency for Research on Cancer, an agency of the World Health Organization, <a href="https://www.iarc.who.int/featured-news/media-centre-iarc-news-glyphosate/">classified it as a probable human carcinogen</a> based on “limited” evidence of cancer in humans from actual real-world exposures and “sufficient” evidence of cancer in experimental animals. </p>
<p>There also are questions about possible linkages between glyphosate and other human health problems. A 2019 study found that children whose mothers experienced prenatal exposure to glyphosate had a <a href="https://doi.org/10.1136/bmj.l962">significantly higher risk of autism spectrum disorder</a> than a control population. </p>
<p>Studies have found that glyphosate <a href="https://doi.org/10.1186/s12940-015-0056-1">causes liver and kidney damage in rats</a> and <a href="https://doi.org/10.1073/pnas.1803880115">alters honey bees’ gut microbiomes</a>. Mice exposed to it have shown increased disease, obesity and birth abnormalities <a href="https://doi.org/10.1038/s41598-019-42860-0">three generations after the exposure</a>. Although glyphosate breaks down in the environment relatively quickly, it is present in aquatic systems at a volume large enough to be detected in <a href="https://doi.org/10.1016/j.envint.2021.106493">blood samples from Florida manatees</a>. </p>
<p>However, the U.S. Environmental Protection Agency and the European Food Safety Authority maintain that glyphosate is unlikely to cause cancer in humans and <a href="https://www.epa.gov/ingredients-used-pesticide-products/glyphosate">does not threaten human health</a> when used according to the manufacturer’s directions. </p>
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<h2>A challenge for regulators</h2>
<p>In the 1990s and early 2000s, the world community adopted <a href="http://www.brsmeas.org/">several groundbreaking agreements</a> to restrict or monitor sales and use of hazardous pesticides. These agreements – the <a href="https://www.unido.org/our-focus-safeguarding-environment-implementation-multilateral-environmental-agreements/stockholm-convention">Stockholm</a> and <a href="https://treaties.un.org/pages/ViewDetails.aspx?src=TREATY&mtdsg_no=XXVII-14&chapter=27">Rotterdam</a> conventions – target compounds that are either acutely toxic or persist in the environment and accumulate in animals, including humans. Glyphosate does not appear to meet these criteria, but humans may be more exposed to it because of its ubiquity <a href="https://doi.org/10.1111/jawr.12159">in soil and water</a> and <a href="https://doi.org/10.1007/s11356-016-7425-3">on food</a>. </p>
<p>Today a handful of countries, including <a href="https://pan-international.org/pan-international-consolidated-list-of-banned-pesticides/">Luxembourg</a> and <a href="https://www.agweb.com/news/crops/corn/mexican-judge-rejects-industry-bid-halt-gmo-corn-glyphosate-ban">Mexico</a>, have banned or restricted the use of glyphosate, citing health concerns. In most countries, however, it remains legal with few restrictions. </p>
<p>Scientists are unlikely to reach consensus soon about glyphosate’s health and environmental impacts. But that has also been true of other pesticides. </p>
<p>For example, DDT – which is <a href="https://doi.org/10.1186/s12936-017-2050-2">still used in developing countries</a> to control mosquitoes that spread malaria and other diseases – was <a href="https://www.epa.gov/ingredients-used-pesticide-products/ddt-brief-history-and-status">banned in the U.S. in 1972</a> for its effects on wildlife and potential harm to humans. But it was not thought to cause cancer in humans until 2015, when scientists analyzed data from women whose mothers were exposed to DDT while pregnant in the 1960s, and found that these women were <a href="https://doi.org/10.1210/jc.2015-1841">more than four times as likely to develop breast cancer</a> than others who were not exposed. This study was published 65 years after the first congressional testimony on DDT’s human health impacts.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/zmslbUoPLEQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">In 1946, health officials who believed incorrectly that polio was spread by insects ordered widespread fogging with DDT in San Antonio, Texas, decades before the pesticide’s health and environmental effects were understood.</span></figcaption>
</figure>
<p>Science can take a long time to reach conclusive results. Given how widely glyphosate is used now, we expect that if it is definitively found to harm human health, its effects will be widespread, difficult to isolate and extremely challenging to regulate. </p>
<p>And finding a cheap silver bullet to safely replace it could be hard. Many substitutes on the market today are <a href="https://doi.org/10.1038/ncomms14865">more acutely toxic</a>. Nonetheless, there’s a need for better options, because weeds are <a href="http://dx.doi.org/10.1002/ps.4760">developing resistance to glyphosate</a>. </p>
<p>In our view, growing concerns about glyphosate’s effectiveness and possible health impacts should accelerate research into <a href="https://doi.org/10.1007/s13593-020-00631-6">alternative solutions</a> to chemical weed control. Without more public support for these efforts, farmers will turn to more toxic herbicides. Glyphosate looks cheap now, but its true costs could turn out to be much higher. </p>
<p><em>This article has been updated to remove a reference to glyphosate detection in breast milk, which was based on a study that was not peer-reviewed.</em></p><img src="https://counter.theconversation.com/content/161156/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marion Werner receives funding from the US National Science Foundation.</span></em></p><p class="fine-print"><em><span>Annie Shattuck is currently on the global advisory board for the Agroecology Fund, a multi-donor fund supporting agroecological practices and policies around the world. She has received past funding from the National Science Foundation.</span></em></p><p class="fine-print"><em><span>Ryan Galt receives funding from the US National Science Foundation and the John D. and Catherine T. MacArthur Foundation.</span></em></p>Roundup may be taking a beating in the US, where three juries have concluded that it gave plaintiffs cancer, but it’s still widely used around the globe.Marion Werner, Associate Professor of Geography, University at BuffaloAnnie Shattuck, Assistant Professor of Geography, Indiana UniversityRyan Galt, Professor of Geography, University of California, DavisLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1127712019-03-07T19:06:50Z2019-03-07T19:06:50ZResearch Check: do we need to worry about glyphosate in our beer and wine?<figure><img src="https://images.theconversation.com/files/262573/original/file-20190307-100787-1qzaux0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Research out of the US tested different varieties of beer and wine for the presence of glyphosate – but there's lots to consider when interpreting the findings.</span> <span class="attribution"><span class="source">From shutterstock.com</span></span></figcaption></figure><p>Glyphosate is back in the news again. The common weed killer, which has previously <a href="https://medium.com/@gidmk/glyphosate-isnt-giving-you-cancer-f4597a35f87e">attracted controversy</a> for its possible link to cancer, has been found in beer and wine.</p>
<p>Researchers in the US tested 15 different types of beer and five different types of wine, <a href="https://uspirg.org/sites/pirg/files/reports/WEB_USP_Glyphosate-pesticide-beer-and-wine_REPORT_022619.pdf">finding traces</a> of the pesticide in 19 out of the 20 beverages.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1100908528133386241"}"></div></p>
<p>So how much should we be worried? Hint: not at all. The amount detected was well below a level which could cause harm. And there are insufficient details in the methods section to feel confident about the results.</p>
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Read more:
<a href="https://theconversation.com/stop-worrying-and-trust-the-evidence-its-very-unlikely-roundup-causes-cancer-104554">Stop worrying and trust the evidence: it's very unlikely Roundup causes cancer</a>
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<h2>How was this study conducted?</h2>
<p>One of the first things I do when evaluating a piece of research is to check the methods – so how the researchers went about collecting the data. What I found didn’t fill me with confidence.</p>
<p>The authors say they set up their experiment based on a technique called a <a href="https://www.chemguide.co.uk/analysis/masspec/howitworks.html">mass spectroscopy method</a>. This methodology has been used to measure the <a href="https://journals.tdl.org/regsci/index.php/regsci/article/view/15">quantities of glyphosate in milk</a> (but not alcoholic drinks). Mass spectroscopy is a very sensitive and specific method, and the authors quote the concentrations that can be reliably detected in milk with this approach.</p>
<p>But the method they actually used is called <a href="https://en.wikipedia.org/wiki/ELISA">enzyme linked immunosorbent assay</a> (ELISA). Importantly, you can’t use the concentrations that can be reliably detected with the mass spectroscopy to describe ELISA sensitivity. They’re not compatible.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/262577/original/file-20190307-100802-10j6abc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/262577/original/file-20190307-100802-10j6abc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/262577/original/file-20190307-100802-10j6abc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/262577/original/file-20190307-100802-10j6abc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/262577/original/file-20190307-100802-10j6abc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/262577/original/file-20190307-100802-10j6abc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/262577/original/file-20190307-100802-10j6abc.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">Glyphosate is the pesticide which makes up many weed killers.</span>
<span class="attribution"><span class="source">From shutterstock.com</span></span>
</figcaption>
</figure>
<p>ELISA is sensitive, but typically not as sensitive as mass spectroscopy, which uses an entirely different physical method to measure glyphosate. </p>
<p>ELISA also has issues of cross contamination. Biological samples for glyphosate measurement, whether ELISA or mass spectroscopy, need careful sample preparation to avoid cross-reaction with any other materials in the sample such as the common amino acid glycine, which looks quite similar to glyphosate and is present in much higher quantities. But the authors didn’t give any detail about the sample preparation used.</p>
<p>These issues make it difficult to be confident in the results.</p>
<p>We’ve seen this before with <a href="https://www.momsacrossamerica.com/glyphosate_testing_results">claims of detection of glyphosate in breast milk</a>, which <a href="https://www.ncbi.nlm.nih.gov/pubmed/27030536">could not be duplicated</a>. So given the lack of detail around the methodologies used, we should be cautious about taking these figures at face value.</p>
<h2>What did they find?</h2>
<p>For the sake of argument, let’s accept the researchers’ values and take a look at what they mean.</p>
<p>The highest level of glyphosate they measured was 51.4 parts per billion in one wine (in most of the beverages they found much less). That’s equivalent to 0.0514 miligrams per litre (mg/L). </p>
<p>The authors cite California’s Office of Environmental Health Hazard’s proposed “No Significant Risk Level” for glyphosate consumption of <a href="https://oehha.ca.gov/media/downloads/crnr/glyphosatensrlfsor041018.pdf">0.02 mg/kg body weight/day</a>. The limits are based on body weight, so a heavier person can be exposed to more than a person who weighs less, taking into account body volume and metabolism.</p>
<p>This is much lower than the EU Food Safety Authorities’ and <a href="https://apvma.gov.au/node/26596">Australia’s regulatory allowable daily intake</a> of 0.3 mg/kg body weight/day.</p>
<p>But again, for argument’s sake, let’s use the Californian proposed limits and look at the wine in which the researchers measured the highest amount of glyphosate. With those limits, an average Australian male weighing 86kg would need to drink <em>33 litres</em> of this wine every day to reach the risk threshold. A 60kg person would need to drink 23 litres of this wine each day.</p>
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<strong>
Read more:
<a href="https://theconversation.com/drink-drank-drunk-what-happens-when-we-drink-alcohol-in-four-short-videos-100206">Drink, drank, drunk: what happens when we drink alcohol in four short videos</a>
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<p>If you’re drinking 33 litres of wine a day you have much, much bigger problems than glyphosate. </p>
<p>Alcohol is a <a href="https://canceraustralia.gov.au/publications-and-resources/position-statements/lifestyle-risk-factors-and-primary-prevention-cancer/lifestyle-risk-factors/alcohol">class 1 carcinogen</a>. Those levels of alcohol consumption would give you a <a href="https://www.cancer.gov/about-cancer/causes-prevention/risk/alcohol/alcohol-fact-sheet#q3">five times greater risk</a> of head, neck and oesophageal cancer (and an increased risk of other cancers). The risk of glyphosate causing cancer is nowhere near these levels. The irony is palpable.</p>
<p>This isn’t even taking into account the likelihood of dying of alcohol poisoning by drinking at this level – which will get you well before any cancer.</p>
<p>And that’s using the highly conservative Californian limits. Using the internationally accepted limits, an average adult male would have to drink over 1,000 litres of wine a day to reach any level of risk.</p>
<h2>So how should we interpret the results?</h2>
<p>The report does not contain a balanced representation of the risks of glyphosate.</p>
<p>They cite the International Agency for Research on Cancer’s finding of <a href="https://monographs.iarc.fr/iarc-monographs-on-the-evaluation-of-carcinogenic-risks-to-humans-4/">glyphosate as class 2</a> (probably) carcinogenic (alcohol is class 1, a known carcinogen). </p>
<p>But they don’t mention the <a href="https://www.efsa.europa.eu/en/efsajournal/pub/4302">European Food Safety authority finding</a> that glyphosate posed no risk of cancer, or the <a href="https://echa.europa.eu/documents/10162/22863068/glyphosate_jmpr_en.pdf/7dbc05a9-d81b-054d-e750-0f762b579fe7">WHO Joint Meeting on Pesticide Residues report</a> showing no significant cancer risk to consumers under normal exposure.</p>
<p>They cite a paper on glyphosate supposedly increasing the <a href="https://www.ncbi.nlm.nih.gov/pubmed/23756170">rate of breast cancer cell growth</a>, but not <a href="https://www.scireslit.com/Toxicology/AJTCR-ID23.pdf">the papers</a> that find <a href="https://journals.tdl.org/regsci/index.php/regsci/article/view/15">no such thing</a>. </p>
<p>They don’t cite the most important study of human exposure, the <a href="https://academic.oup.com/jnci/article/110/5/509/4590280">Agricultural Health Study</a> which is the largest and longest study of the effect of glyphosate use. This study found no significant increase in cancer in highly exposed users.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/research-check-can-even-moderate-drinking-cause-brain-damage-79036">Research Check: can even moderate drinking cause brain damage?</a>
</strong>
</em>
</p>
<hr>
<p>The “report” claiming that there is glyphosate in wine and beer provides inadequate information to judge the accuracy of the claimed detection, and does not put the findings in context of exposure and risk.</p>
<p>Even taking their reported levels at face value, the risk from alcohol consumption vastly outweighs any theoretical risk from glyphosate. Their discussion does not fairly consider the evidence and is weighted towards casting doubt over the safety of glyphosate.</p>
<p>So you may enjoy your beer and wine (in moderation), without fear of glyphosate.</p>
<h2>Blind peer review</h2>
<p>This is a fair and accurate assessment of the study and its findings. That said, it is prudent for the scientific community to remain attentive to changes within the food supply and issues of potential risk to public health. Considering the increasing use of glyphosate by the food industry, we need continued diligence in this area. <strong>– Ben Desbrow</strong></p>
<hr>
<p><em><a href="https://theconversation.com/au/topics/research-check-25155">Research Checks</a> interrogate newly published studies and how they’re reported in the media. The analysis is undertaken by one or more academics not involved with the study, and reviewed by another, to make sure it’s accurate.</em></p><img src="https://counter.theconversation.com/content/112771/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ian Musgrave has previously received funding from the National Health and Medical Research Council to study adverse reactions to herbal medicines and has previously been funded by the Australian Research Council to study potential natural product treatments for Alzheimer's disease. He has collaborated with SA water on studies of cyanobacterial toxins and their implication for drinking water quality. He does not consult or work for any Agricultural crop company. He did give an invited talk on glyphosate at the 5th South Australia Weeds Conference, for which he received a rather nice muffin and a free cup of coffee.</span></em></p><p class="fine-print"><em><span>Ben Desbrow 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>The amount of alcohol you’d have to drink before glyphosate posed even a negligible risk would harm you well before the glyphosate would.Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1125672019-03-05T19:57:30Z2019-03-05T19:57:30ZHigh-tech agriculture: farmers risk being ‘locked in’ to unsustainable practices<figure><img src="https://images.theconversation.com/files/262172/original/file-20190305-48429-1v69cx4.jpg?ixlib=rb-1.1.0&rect=8%2C43%2C1189%2C700&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Two driverless tractors spray vines in a Texas vineyard. Each one is controlled from a single command station (2012).</span> <span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:Autonomous_compact_tractors_in_a_Texas_vineyard,_Nov_2012.jpg">ASIrobots/Wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Since World War II, Europe’s agricultural sector has been very receptive to new technology, and the result has been staggering productivity gains – for four generations, farmers have produced more than their parents did. At the same time, however, agricultural prices have fallen around the world and price subsidies have been cut. This has led to a cruel paradox: while farmers have never produced so much, many can no longer make a living from farming.</p>
<h2>Digital technology is a big tent</h2>
<p>Digital approaches in farming are called “precision agriculture”, which aims to measure the needs of crops or livestock as precisely as possible to be able to apply “the right amount at the right time”. This has proven to be a valuable approach, particularly for crops, and has been driven by the development of embedded computing, GPS guidance and machine control interfaces.</p>
<p>The precision-agriculture approach can also help reduce inefficiencies and waste. For example, precision pesticide application methods can significantly reduce spray falling outside areas to be treated and thus the amount of pesticide entering the environment. In this way, sprayers can maintain treatment effectiveness while reducing application rates 20% to 40%.</p>
<p>However, precision agriculture does not call into question pesticide use. It works by refining current practices and does not encourage the exploration of alternatives. This is what scientists call “technological lock-in”, with precision approaches reinforcing pesticide use rather than eliminating it. This in no way prepares us for farming that is less reliant on pesticides – farmers become locked in.</p>
<p>Like digital approaches developed in other industrial sectors, those for farming tend to impose standardisation and optimisation under well-controlled conditions. The risk, therefore, is that digital technology could increase productivity but also cut employment in the sector, boost farm size, and deepen technological dependence, with <a href="http://new-compass.net/articles/why-competition-agriculture-unsustainable">relatively little positive impact on sustainability</a>.</p>
<h2>A different type of digital agriculture</h2>
<p>On the other hand, digital technology could also be used to empower those working together to improve farming practices, change regulations and influence markets, all built upon the real needs of individual farmers and society. By facilitating such cooperation at the national and multinational scale, digital technology would make it possible for farmers and the wider public to “have a say” in national farming issues. In bringing supply and demand closer together, collaborative digital farming would provide a framework for championing the interests of both producers and consumers, equitably.</p>
<p>In a context of increasing competition, this would protect rural employment, while assuring that agriculture is more widely valued, with farmers being seen as professionals. Existing cooperative approaches, such a local “box schemes”, contribute to this, but <a href="https://www.irishexaminer.com/breakingnews/farming/life-on-farms-is-shared-across-the-world-with-digital-technology-890341.html">digital technology would accelerate and extend this process</a>.</p>
<p>The potential of new digital technologies in agriculture is astonishing. Linking farmers digitally would allow them to organise and share equipment, facilitate the sharing or exchanging of fields and support alternative supply and production channels, as well as promoting solidarity. In short, collaborative digital technologies could promote aspects of social and environmental sustainability that the current form of the market neither recognises nor finances.</p>
<h2>What technology should be used for</h2>
<p>The current system will not change if we do not change the criteria we use for <a href="https://theconversation.com/the-battle-for-the-future-of-farming-what-you-need-to-know-106805">evaluating its performance and the way it is managed</a>. We need to be clear as a society about what farming should do. To date, agriculture has been given goals that were not necessarily its own. Some have no direct market value, such as for the maintenance of common resources, including air and water. Others appear to have little immediate societal value, such as the <a href="https://theconversation.com/how-carbon-farming-can-help-solve-climate-change-86087">storage of carbon to mitigate climate change</a>, or do not reward farmers for their efforts. As an example, the value of lavender fields for tourism and for the industry of honey-making exceeds the direct income from selling the lavender for cosmetic use, and yet the lavender farmer will often receive no extra income for supporting these other industries.</p>
<p>It can be argued that the competitiveness of European agriculture will not be achieved by a race for productivity, but rather by doing those things we do well and value that bit better. We need to recognise that agriculture has become much more than a means to produce food, fibre and fuel. It is, just as importantly, a context in which questions of animal welfare and the management of the countryside landscape and resources need to be addressed.</p>
<h2>The million-dollar question</h2>
<p>The processes that take place in the agricultural environment are highly dynamic, changing over seasons and between landscapes, determined by the quality of an animal’s or plant’s interaction with its environment, and this itself evolves over time.</p>
<p>To monitor or change how agricultural systems function, digital technology should be used to evaluate material and energy flows. Just as an industrial system or supply chain must maintain and regulate its proper functioning, agriculture must be able to quantify what constitutes appropriate functioning. At present, we are unable to carry out the measurements needed to support, maintain or even improve the functioning of the agro-ecosystem. The future development of new sensors will revolutionise animal and plant health management.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/262215/original/file-20190305-48432-b6l76r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/262215/original/file-20190305-48432-b6l76r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/262215/original/file-20190305-48432-b6l76r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/262215/original/file-20190305-48432-b6l76r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/262215/original/file-20190305-48432-b6l76r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/262215/original/file-20190305-48432-b6l76r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/262215/original/file-20190305-48432-b6l76r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In Australia, many farmers rely on large populations of feral European honeybees to polinate crops. These services, long undervalued, are now under threat. Here, Dr. Denis Anderson of CSIRO Entomology examines a cherry farm near Young, New South Wales (2007).</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:CSIRO_ScienceImage_6807_Dr_Denis_Anderson_of_CSIRO_Entomology_examining_in_a_hive_at_a_cherry_farm_near_Young_New_South_Wales.jpg">Nick Pitsas/CSIRO/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>It is possible to reduce this vision of digital technology to a simplistic level; that one sensor is used to measure a single variable, such as the weight of an animal. Our vision is that digital technology has the power to be transformative. Multiple sensors measuring multiple variables simultaneously could revolutionise the use of pesticides, for example, by quantifying the state of each field and the risk to human health that pesticides present. This might be by analysing sensor data with artificial intelligence to evaluate soil activity of both the pesticide and pesticide-detoxifying bacteria; estimating whether naturally present biological control agents have the capacity to protect the system from pests; and predicting when crop resistance to fungal pathogens is “switched on”. In effect, this would evaluate whether the system is resilient, being able to both to absorb shock and to rebound to a healthy state.</p>
<h2>High performance, not just high production</h2>
<p>The principle of pesticide-free agriculture must be at the heart of this future, digitally supported agricultural system. Simply characterising the performance of agriculture as one of a production system supported by pesticides will not deliver sustainability. Measures of system performance based on a single economic criterion do not reflect all the other dimensions of sustainability. Instead, digital technology must deliver a transition to a holistic appreciation of agriculture. It will allow us to appreciate aspects of the system that we know are critical but, due to poor measurement or recognition, we only notice once they are gone. Pollination by wild insects is an example of something farmers have, to date, received for free and so have undervalued. It is only now that we are discovering that these insects are in decline there are no longer enough to meet our needs.</p>
<p>Rather than locking in farmers to unsustainable, pesticide-based management, the agricultural digital revolution must show that there are other viable approaches and alternative measures of system performance. At a time when the European Union’s <a href="https://ec.europa.eu/info/food-farming-fisheries/key-policies/common-agricultural-policy/cap-glance_en">common agricultural policy</a> and other global trade and agricultural agreements are being renegotiated, we must ensure that environmental sustainability and social justice – for both producers and consumers – are central to how performance is measured, and that they can’t just be sacrificed for a few more percentage points of productivity.</p><img src="https://counter.theconversation.com/content/112567/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Les auteurs ne travaillent pas, ne conseillent pas, ne possèdent pas de parts, ne reçoivent pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'ont déclaré aucune autre affiliation que leur organisme de recherche.</span></em></p>Digital innovations have the potential to empower farmers and revolutionise agriculture, but many could also lock them in to unsustainable methods.Xavier Reboud, Chercheur en agroécologie, InraeDavid Bohan, Quantitative ecologist, InraeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1045542018-10-08T07:08:28Z2018-10-08T07:08:28ZStop worrying and trust the evidence: it’s very unlikely Roundup causes cancer<figure><img src="https://images.theconversation.com/files/239671/original/file-20181008-72103-8as2pz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Roundup is the most common weed killer used worldwide.</span> <span class="attribution"><span class="source">from shutterstock.com</span></span></figcaption></figure><p>The common weed killer <a href="http://npic.orst.edu/factsheets/glyphogen.html">Roundup</a> (glyphosate) is back in the news after a <a href="https://www.smh.com.au/world/north-america/dying-cancer-patient-awarded-a395m-in-monsanto-roundup-case-20180811-p4zwww.html">US court ruled</a> it contributed to a man’s terminal cancer (non-Hodgkin lymphoma). Following the court’s order for manufacturer Monsanto to compensate the former school ground’s keeper US$289 million, more than 9,000 people are reportedly also suing the company.</p>
<p>In light of this, Cancer Council Australia is calling for <a href="http://www.abc.net.au/news/2018-08-11/cancer-council-monsanto-should-come-clean/10109760">Australia to review glyphosate’s safety</a>. And tonight’s <a href="http://www.abc.net.au/4corners/">Four Corner’s</a> report centres around Monsanto’s possible cover-up of the evidence for a link between glyphosate and cancer.</p>
<p>Juries don’t decide science, and this latest court case produced no new scientific data. Those who believe glyphosate causes cancer often refer to the 2015 report by the <a href="http://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Evaluation-Of-Carcinogenic-Risks-To-Humans/Some-Organophosphate-Insecticides-And-Herbicides-2017">International Agency for Research on Cancer</a> (IARC) that classified the herbicide as “probably carcinogenic to humans”.</p>
<p>IARC’s conclusion was arrived at using a narrower base of evidence than other recent peer-reviewed papers and governmental reviews. Australia’s regulator, the Australian Pesticides and Veterinary Medicines Authority (<a href="https://apvma.gov.au/">APVMA</a>), reviewed the safety of glyphosate after IARC’s determination. It’s <a href="https://apvma.gov.au/node/13891">2016 report</a> concluded that</p>
<blockquote>
<p>based on current risk assessment the label instructions on all glyphosate products – when followed – provides adequate protection for users.</p>
</blockquote>
<p>The <a href="https://www.ncbi.nlm.nih.gov/pubmed/29136183">Agricultural Health Study</a>, which followed more than 50,000 people in the US for over ten years, was published in 2018. This real world study in the populations with the highest exposure to glyphosate showed that if there is any risk of cancer from glyphosate preparations, it is exceedingly small. </p>
<p>It also showed that the risk of non-Hodgkin lymphoma is negligible. It is unclear to what extent this study was used in the recent court case.</p>
<h2>What did the IARC and others find?</h2>
<p>Glyphosate is one of the most used herbicides worldwide. It kills weeds by targeting a specific pathway (the <a href="https://en.wikipedia.org/wiki/Shikimate_pathway">shikimic acid pathway</a>) that exists in plants and a type of bacteria (eubacteria), but not animals (or humans). </p>
<p>In terms of short-term exposure, glyphosate is less toxic than table salt. However, it’s chronic, or long-term, exposure to glyphosate that’s causing the controversy. </p>
<p>Pesticides and herbicides are periodically re-evaluated for their safety and several studies have done so for glyphosate. For instance, in 2015, Germany’s <a href="https://www.bfr.bund.de/en/the_bfr_has_finalised_its_draft_report_for_the_re_evaluation_of_glyphosate-188632.html">Federal Institute for Risk Assessment</a> suggested glyphosate was neither mutagenic nor carcinogenic.</p>
<p>But then came the IARC’s surprising classification. And the subsequent 2015 review by the <a href="https://www.efsa.europa.eu/en/efsajournal/pub/4302">European Food Safety Authority</a>, that concluded glyphosate was unlikely to pose a carcinogenic hazard, didn’t alleviate sceptics. </p>
<p>The key differences between the IARC’s and other reports revolve around the breadth of evidence considered, the weight of human studies, consideration of physiological plausibility and, most importantly, risk assessment. The IARC did not take into account the extent of exposure to glyphosate to establish its association with cancer, while the others did.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/council-workers-spraying-the-weed-killer-glyphosate-in-playgrounds-wont-hurt-your-children-54831">Council workers spraying the weed-killer glyphosate in playgrounds won't hurt your children</a>
</strong>
</em>
</p>
<hr>
<h2>Demonstrating the mechanism</h2>
<p>Establishing whether a chemical can cause cancer in humans involves demonstrating a mechanism in which it can do so. Typical investigations examine if the chemical causes mutations in bacteria or damage to the DNA of mammalian cells.</p>
<p>The studies reviewed by IARC, and the other bodies mentioned, that looked at glyphosate’s ability to produce mutations in bacteria and to mammalian cells were negative. The weight of evidence also indicated glyphosate was unlikely to cause significant DNA damage.</p>
<h2>Animal studies</h2>
<p>Animal studies are typically conducted in rats or mice. The rodents are given oral doses of glyphosate for up to 89% of their life spans, at concentrations much higher than humans would be exposed to. </p>
<p>Studies examined by the <a href="https://www.efsa.europa.eu/en/efsajournal/pub/4302">European Food Safety Authority</a> included nine rat studies where no cancers were seen. Out of five mouse studies, three showed no cancers even at the highest doses. One study showed tumours, but these were not dose dependent (suggesting random variation, not causation) and in one study tumours were seen at highest doses in males only. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/239674/original/file-20181008-72130-z8h3sq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/239674/original/file-20181008-72130-z8h3sq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/239674/original/file-20181008-72130-z8h3sq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/239674/original/file-20181008-72130-z8h3sq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/239674/original/file-20181008-72130-z8h3sq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/239674/original/file-20181008-72130-z8h3sq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/239674/original/file-20181008-72130-z8h3sq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/239674/original/file-20181008-72130-z8h3sq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Glyphosate works by disrupting a pathway that exists in plants but not animals or humans.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<p>This led to the European Food Safety Authority’s overall conclusion that glyphosate was unlikely to be a carcinogenic hazard to humans.</p>
<p>The <a href="https://monographs.iarc.fr/iarc-monographs-on-the-evaluation-of-carcinogenic-risks-to-humans-4/">IARC</a> evaluation included only six rat studies. In one study, cancer was seen but this wasn’t dose dependent (again suggesting random variation). They evaluated only two mouse studies, one of which was negative for cancer and that showed a statistically significant “trend” in males. </p>
<p>The IARC thus concluded there was sufficient evidence of carcinogenicity in animals but there was no consistency in tumour type (mouse vs rat) or location.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/are-common-garden-chemicals-a-health-risk-65643">Are common garden chemicals a health risk?</a>
</strong>
</em>
</p>
<hr>
<h2>Human studies</h2>
<p>This is an enormous field so I can only briefly summarise the research. The <a href="https://www.efsa.europa.eu/en/efsajournal/pub/4302">European Food Safety Authority </a> looked at 21 human studies and found no evidence for an association between cancer and glyphosate use. The <a href="https://monographs.iarc.fr/iarc-monographs-on-the-evaluation-of-carcinogenic-risks-to-humans-4/">IARC</a> looked at 19 human trials and found no statistically significant evidence for an association with cancer. It did find three small studies that suggested an association with non-Hodgkin lymphoma (not statistically significant).</p>
<p>As already mentioned, the large Agricultural Health Study found no association between cancer and glyphosate in humans. And the 2016 review by Australia’s regulator concluded glyphosate was safe if used as directed.</p>
<p>It’s possible the animus towards Monsanto and genetically modified organisms may have influenced the recent juries’ decision far more than any science. However, these materials <a href="http://www.efsa.europa.eu/sites/default/files/topic/20170608_glyphosate_statement.pdf">had no impact on the scientific findings</a>.</p><img src="https://counter.theconversation.com/content/104554/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ian Musgrave has previously received funding from the National Health and Medical Research Council to study adverse reaction to herbal medicines and has previously been funded by the Australian Research Council to study potential natural product treatments for Alzheimer's disease. He has collaborated with SA water on studies of cyanobacterial toxins and their implication for drinking water quality. He does not consult or work for any Agricultural crop company. He did give an invited talk at the 5th South Australia Weeds Conference, for which he received a rather nice muffin and a free cup of coffee.</span></em></p>A US court recently ruled the weed killer Roundup contributed to a former gardener’s cancer. Juries don’t decide science. The weight of evidence shows Roundup has little association with cancer.Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1016672018-08-22T22:38:52Z2018-08-22T22:38:52ZWith Monsanto, Bayer will need more Aspirin<figure><img src="https://images.theconversation.com/files/232969/original/file-20180821-149493-fn3957.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Activists protest against the acquisition of the U.S. agrochemical company Monsanto by the German Bayer company in Bonn, Germany, Friday, May 25, 2018. </span> <span class="attribution"><span class="source">(AP Photo/Martin Meissner)</span></span></figcaption></figure><p>Monsanto, now a division of Bayer, has been <a href="https://www.cnn.com/2018/08/10/health/monsanto-johnson-trial-verdict/index.html">ordered to pay a whopping US$289 million to a single American person</a>, a former gardener, who developed cancer, allegedly through the use of their products. </p>
<p>Dewayne Johnson testified that he applied the product — Ranger Pro, a highly concentrated version of Roundup weedkiller, which contains glyphosate — 20 to 30 times per year while working as a school groundskeeper. He told a jury in San Francisco that <a href="https://www.sfchronicle.com/business/article/Monsanto-case-Bay-Area-man-with-cancer-awarded-13147891.php">he had two accidents at work, in which he was soaked with the product</a>. In 2014, he was diagnosed with non-Hodgkin’s lymphoma.</p>
<p>Earlier this year, Bayer bought Monsanto for US$62 billion — all cash — in hopes to grow its business on both sides of the Atlantic and beyond. But even if Monsanto’s brands no longer exist as such, its legacy remains. </p>
<p>Given that <a href="https://www.reuters.com/article/us-monsanto-cancer-lawsuit/first-trial-alleging-monsantos-roundup-causes-cancer-goes-to-jury-idUSKBN1KS2G8">5,000 other similar cases regarding Roundup are currently in progress in the United States alone</a>, Bayer will need to write a new chapter in its public relations playbook.</p>
<h2>A mega-acquisition with tax benefits</h2>
<p>Bayer bought Monsanto because it wanted its thriving crop science division to be complemented by Monsanto’s high-performing chemicals and pesticides. The potential of capitalizing on market dynamics and resolving dissimilar sale cycles between divisions also made the deal attractive, with the possibility of making revenues more predictable regardless of commodity prices. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/232968/original/file-20180821-149484-15tfuo1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/232968/original/file-20180821-149484-15tfuo1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=451&fit=crop&dpr=1 600w, https://images.theconversation.com/files/232968/original/file-20180821-149484-15tfuo1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=451&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/232968/original/file-20180821-149484-15tfuo1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=451&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/232968/original/file-20180821-149484-15tfuo1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=567&fit=crop&dpr=1 754w, https://images.theconversation.com/files/232968/original/file-20180821-149484-15tfuo1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=567&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/232968/original/file-20180821-149484-15tfuo1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=567&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Containers of Roundup, a weed killer made by Monsanto, are shown on a shelf at a hardware store in Los Angeles in 2017.</span>
<span class="attribution"><span class="source">(AP Photo/Reed Saxon, File)</span></span>
</figcaption>
</figure>
<p>And finally, given Germany’s lower tax rate versus that of the United States, the deal provided substantial tax benefits to Bayer. This mega-acquisition was generally <a href="https://www.bloomberg.com/news/articles/2018-06-07/bayer-closes-monsanto-deal-to-cap-63-billion-transformation">well-received by the markets</a>.</p>
<p>But Bayer did go in with a sobering and realistic approach regarding Monsanto. Knowing that Monsanto was damaged goods in the eyes of the public due to years of attacks and criticism by environmental groups, Bayer vowed to dump the name Monsanto as well as its brands while the products would remain the same. </p>
<p>Everyone — Monsanto most of all — wanted the name to disappear. Anyone who has ever Googled the word Monsanto will know that <a href="https://www.greenbiz.com/article/how-monsanto-can-rehabilitate-its-image">the name has been obliviated due to years of successful campaigning by influential voices</a>.</p>
<h2>The ‘Frankenfoods’ of ‘Monsatan’</h2>
<p>Genetic engineering in agriculture has been a divisive issue for years now. Biotech companies, including Monsanto and Bayer, have been selling agricultural solutions to farmers for decades, but have only recently started to engage with the public. </p>
<p>By the time the sector realized it had <a href="https://www.macleans.ca/opinion/what-canadians-dont-understand-about-farming-and-what-they-need-to/">never really received a “social licence”</a> from the public to operate, it was too late, at least for Monsanto. Words like <a href="https://twitter.com/hashtag/monsatan?lang=en">“Monsatan”</a> and <a href="https://www.cbsnews.com/pictures/frankenfood-does-it-deserve-the-name/2/">“Frankenfoods”</a> were already widely used in media and social culture. Books, ads — most were manufactured to nurture some sort of collective hatred towards the St. Louis-based company. </p>
<p>Still, some studies suggest that <a href="https://nationalpost.com/pmn/news-pmn/canada-news-pmn/canadians-confused-about-gm-foods-support-mandatory-labelling-study">most consumers are not capable of explaining what genetic engineering is, nor how it relates to agriculture</a>. </p>
<p>This highly polarized public discourse points to the failure of the sector to properly communicate risks to the public, back when genetically modified crops were first produced in the early 1990s.</p>
<p>That political baggage is starting to sting now. After the California ruling, <a href="http://fortune.com/2018/08/16/bayer-stock-monsanto-roundup-glyphosate/">Bayer’s stock is in a nosedive</a>. The California jury found Monsanto liable for selling glyphosate-based weed killers, including its Roundup brand, which according to certain studies causes cancer. </p>
<h2>Uncertain cancer risk</h2>
<p>It’s not clear whether glyphosate does cause cancer as there are several published studies suggesting the opposite. <a href="https://www.nature.com/news/widely-used-herbicide-linked-to-cancer-1.17181"><em>The Lancet</em>, a reputable academic journal, and the International Agency for Research on Cancer</a> have suggested that glyphosate may possibly cause cancer, but have never stated any clear conclusions on the issue.</p>
<p>The jury in California deliberated for more than three days before concluding that Monsanto did not provide enough information to the plaintiff about cancer risks. In other words, regardless of the science, doubts remain, which may have influenced the jury in favour of the plaintiff. Bayer will appeal, of course, but few really know where things will end up.</p>
<p>Throughout these litigations, what remains unknown is how Monsanto’s past could potentially contaminate Bayer’s 156-year-old history. Bayer and some other major players in the biotech sector were never really targeted by damaging crusades against genetically modified seeds and pesticides used in farming. </p>
<p>In the public eye, the California ruling could trigger a new movement, a shift against the sector’s new menace, Bayer. With many cases to come, Bayer’s communications department will only get busier.</p>
<p>This ruling signals, if anything, that consumers were taken for granted for far too long. Before the deal, while Monsanto was being viciously attacked, Bayer was merely an onlooker. </p>
<p>By virtue of well-known consumer brands, the German giant had historically more exposure to the public than Monsanto has ever had, but this will now likely warrant a new chapter in the company’s public relations playbook.</p><img src="https://counter.theconversation.com/content/101667/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sylvain Charlebois 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>Bayer, the new owner of Monsanto, will need to up its PR efforts, in the wake of last week’s legal ruling on glyphosate weedkillers.Sylvain Charlebois, Professor in Food Distribution and Policy, Dalhousie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/883632017-12-06T10:24:39Z2017-12-06T10:24:39ZA controversial weedkiller has won a new five-year lease in Europe, but citizens are fighting back<p>The controversial <a href="http://www.bbc.co.uk/news/world-europe-42135437">pesticide Glyphosate</a> – which is the key ingredient in one of the world’s bestselling weedkillers – has recently had its license renewed by the EU for another five years. This means it will continue to be used by both farmers and homeowners, and will be available for sale across Europe. This is despite ongoing debates about <a href="https://www.theguardian.com/environment/2017/nov/27/controversial-glyphosate-weedkiller-wins-new-five-year-lease-in-europe">how safe the pesticide actually is</a>.</p>
<p>The decision came just weeks before the current license was due to expire in December and broke a months long impasse between member states who had previously rejected renewals for 15 and ten years. </p>
<p>Despite Brexit, the UK is still affected by the EU’s decision, because it is part of the EU’s agriculture, environment and food safety regimes until March 2019. After that date, a separate process, and a longer license for glyphosate, may beckon. </p>
<h2>Why the controversy?</h2>
<p>Glyphosate is so controversial because it has previously been linked to cancer. In 2015, The World Health Organization’s <a href="http://monographs.iarc.fr/ENG/Monographs/vol112/index.php">International Agency for Research on Cancer</a> stated that glyphosate was “probably carcinogenic to humans”. But since then, two EU agencies – the European Food Safety Agency and the European Chemicals Agency – have concluded that it is safe.</p>
<p>In the run up to the re-licensing decision, around four million European citizens signed various petitions <a href="https://twitter.com/alemannoEU/status/935156666663915523">calling for a ban</a> on the pesticide. Behind the scenes, the organisation <a href="https://www.wemove.eu">WeMove.EU</a> – which describes itself as a citizens’ movement campaigning for a better Europe – has been coordinating much of the effort.</p>
<h2>How have they campaigned so far?</h2>
<p>Cmpaigners have used a range of strategies – days of action, petitions, protests – but most prominently, earlier this year <a href="https://www.wemove.eu">WeMove.EU</a> launched a <a href="https://stopglyphosate.org/en/">European Citizens’ Initiative</a>, which has given the campaign a way into the formal EU decision making process. </p>
<p>The European Citizens’ Initiative is the EU’s flagship (but still not widely known) effort to establish participatory democracy in the EU. It was introduced by the <a href="http://ec.europa.eu/citizens-initiative/public/welcome">Lisbon treaty</a> and has since become a major instrument in addressing democratic change. </p>
<p>A citizens’ initiative has to be backed by at least one million EU citizens, coming from at least seven out of the 28 member states. These citizens can then call upon the Commission to make a legislative proposal on an issue where it is perceived that EU action is required</p>
<h2>Has this ever happened before?</h2>
<p>Since <a href="http://ec.europa.eu/citizens-initiative/public/basic-facts">the initiative</a> was launched in April 2012, only four campaigns (including Ban Glyphosate) <a href="http://ec.europa.eu/citizens-initiative/public/initiatives/successful">have succeeded</a> in gaining one million signatures out of 47 that have been proposed. A further 21 have been rejected outright on the grounds that they fell outside the treaties. Over zealousness by the Commission in implementing the European Citizens’ Initiative, excessive requirements on organisers, and a lack of follow-up have been blamed for the low legislative impact. </p>
<p>So it’s not hard to see why by 2016 – just four years after coming into operation – the initiative was almost on the point of collapse. But reforms to the regulation which governs the initiative have been proposed, and the Glyphosate campaign – as well as Brexit which has prompted four <a href="http://ec.europa.eu/citizens-initiative/public/initiatives/open">additional campaigns</a> – has breathed new life into it.</p>
<h2>So has the campaign made a difference?</h2>
<p>Ban Glyphosate is the fastest growing campaign in the history of the European Citizens’ Initiative. And by the beginning of July 2017, the campaign had met both the <a href="http://ec.europa.eu/citizens-initiative/public/initiatives/successful/details/2017/000002">thresholds</a> in terms of signature count and countries involved.</p>
<p>WeMove managed this through a combination of their network of partner organisations – including Greenpeace, Corporate Europe Observatory, Campact and over 90 other organisations. They also used a sophisticated online signature collection system, and an active social media strategy formed around the slogan: “We could get toxic Glyphosate banned, but only if we act together”.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"833667041458585600"}"></div></p>
<p>In the UK, the campaign also received an early boost when the link was retweeted by the celebrity naturalist Chris Packham. Support from citizens in the UK was considerable and with over 94,000 signatures, it is the only one of the four successful European Citizens’ Initiatives to meet the threshold in the UK.</p>
<h2>What’s next?</h2>
<p>Despite the re-licensing of glyphosate, the organisers say that banning a single pesticide was only one part of the campaign. It is claimed that highlighting the strength and depth of citizen opposition to widespread pesticide use and to the existing approval system were the ultimate goals. And efforts will no doubt continue in the EU up to Brexit, and well beyond.</p>
<p>That said, the UK was one of the <a href="https://ec.europa.eu/food/sites/food/files/plant/docs/sc_phyto_20171127_pppl_summary.pdf">18 member states</a> that voted to renew the license. And ultimately, in light of this decision, the main aim of the campaign – an outright ban on the sale and use of glyphosate – looks to have so far been unsuccessful. </p>
<p>But despite this, the pesticide remains a source of controversy. Germany’s support for its re-licensing turned out to be the the result of a decision made by the agriculture minister, Christian Schmidt, against the views of other <a href="https://www.politico.eu/article/angela-merkel-says-christian-schmidt-did-not-follow-protocol-on-glyphosate-vote/">ministers and without consulting Angela Merkel</a>. While in France, Emmanuel Macron vowed to press ahead with a <a href="https://twitter.com/EmmanuelMacron/status/935194060062642176">phasing out of the chemical within three years regardless</a> of the re-licensing. And given that the Commission is obliged to give a response to the European Citizens’ Initiative by early next year, it may still be a case of watch this space.</p><img src="https://counter.theconversation.com/content/88363/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elizabeth Monaghan 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>The weedkiller glyphosate has previously been linked to cancer, and now Europe’s citizens want to see it banned.Elizabeth Monaghan, Lecturer in Politics, University of HullLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/656432016-09-27T19:22:22Z2016-09-27T19:22:22ZAre common garden chemicals a health risk?<figure><img src="https://images.theconversation.com/files/139359/original/image-20160927-20135-1dghxh8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Gardening in Australia requires, to varying degrees depending where in the country you are, pesticides, herbicides and fertilisers. </span> <span class="attribution"><span class="source">from shutterstock.com</span></span></figcaption></figure><p><em>As the weather warms and days lengthen, your attention may be turning to that forgotten patch of your backyard. This week we’ve asked our experts to share <a href="https://theconversation.com/au/topics/gardening-series-31530">the science behind gardening</a>. So grab a trowel and your green thumbs, and dig in.</em></p>
<hr>
<p>Gardening is good for your health, but it can pose some risks if you’re not careful. For example, you should use <a href="http://www.cancer.org.au/preventing-cancer/sun-protection/campaigns-and-events/slip-slop-slap-seek-slide.html">sensible protection against the sun</a> to prevent cancer, a significant cause of death in Australia. </p>
<hr>
<p><em><strong>Further reading:</strong> <a href="https://theconversation.com/the-science-is-in-gardening-is-good-for-you-65251">The science is in: gardening is good for you</a></em></p>
<hr>
<p>Gardening in Australia also requires, to varying degrees depending where in the country you are, pesticides, herbicides and fertilisers. There is an enormous number of agents with multiple formulations, depending on what you are doing, what plants you are tending, the size of your garden and the kind of soil. </p>
<p>These garden treatments are designed to be specific and potent, so they can be applied less often and work (mostly) only on the things you want them to work on. All of them – even the “natural” ones such as sulfur dusts to control caterpillars and mildew – are chemicals, which means they have health risks.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/139376/original/image-20160927-20144-h18iwe.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/139376/original/image-20160927-20144-h18iwe.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/139376/original/image-20160927-20144-h18iwe.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=706&fit=crop&dpr=1 600w, https://images.theconversation.com/files/139376/original/image-20160927-20144-h18iwe.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=706&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/139376/original/image-20160927-20144-h18iwe.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=706&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/139376/original/image-20160927-20144-h18iwe.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=887&fit=crop&dpr=1 754w, https://images.theconversation.com/files/139376/original/image-20160927-20144-h18iwe.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=887&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/139376/original/image-20160927-20144-h18iwe.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=887&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Even sulfur dusts are chemicals, which means they have health risks.</span>
<span class="attribution"><a class="source" href="http://www.yates.com.au/products/pest-control/insects-ready-to-use/yates-tomato-vegetable-dust/#PwBHZmf42HZVca1A.97">Yates Tomato and Vegetable Dust product webpage/Screenshot</a></span>
</figcaption>
</figure>
<h2>Regulation of chemicals</h2>
<p>While not perfect, gardening product safety is regulated in Australia. Let me introduce you to the <a href="http://apvma.gov.au/">Australian Veterinary Medicines and Pesticides Authority</a>. This body regulates pesticide (a substance that kills pests such as insects and weeds) and herbicide (a substance that kills only weeds) products sold in Australia. </p>
<p>The AVPMA regularly reviews products for safety concerns, though the reviews may be decades apart. It co-ordinates with World Health Organisation bodies and its counterparts in Europe, Canada and the United States. </p>
<p>Given the sheer number of compounds and formulations available, I can’t possibly cover the safety of all chemicals, or even all groups of chemicals. If you are concerned about a particular product, you can search the AVPMA site for the ingredients in a given pesticide, herbicide or fertiliser. </p>
<p>This may be tricky, as some will not necessarily have a chemical name on them, just the trade name. However, most pesticides and herbicides from reputable companies should have a <a href="http://www.worksafe.vic.gov.au/safety-and-prevention/health-and-safety-topics/material-safety-data-sheets">material safety data sheet</a> (MSDS) with them. This should give you the details you need to check through the AVPMA site.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/139377/original/image-20160927-20114-qgqq1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/139377/original/image-20160927-20114-qgqq1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/139377/original/image-20160927-20114-qgqq1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=540&fit=crop&dpr=1 600w, https://images.theconversation.com/files/139377/original/image-20160927-20114-qgqq1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=540&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/139377/original/image-20160927-20114-qgqq1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=540&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/139377/original/image-20160927-20114-qgqq1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=679&fit=crop&dpr=1 754w, https://images.theconversation.com/files/139377/original/image-20160927-20114-qgqq1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=679&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/139377/original/image-20160927-20114-qgqq1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=679&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">There are several ways to deal with pests: repel, smother or poison them.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<h2>Pesticides</h2>
<p>There are three ways to deal with pests (well, four if you count laboriously picking them off your plants): repel, smother or poison them. All these can harm people if they are exposed to significant quantities. But in an urban garden, exposure to pesticides is typically small and of limited duration.</p>
<p>Common smothering pesticides are oils such as petroleum oils used to control, say, leaf pests on citrus, or pests in a variety of other circumstances. If you apply these often, without gloves, you might get skin irritation; or <a href="https://toxnet.nlm.nih.gov/cgi-bin/sis/search2/f?./temp/%7E3mAY3J:1">lung irritation</a> if you breath the spray in. So always follow the directions, which include wearing gloves and spraying so the wind doesn’t blow the spray back into your face.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/139378/original/image-20160927-20100-pseqwt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/139378/original/image-20160927-20100-pseqwt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/139378/original/image-20160927-20100-pseqwt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/139378/original/image-20160927-20100-pseqwt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/139378/original/image-20160927-20100-pseqwt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/139378/original/image-20160927-20100-pseqwt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/139378/original/image-20160927-20100-pseqwt.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">Pyrethrums are found naturally in some chrysanthemum flowers.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<p>Modern poisoning insecticides include the <a href="http://apvma.gov.au/node/19186">pyrethrums</a> which are found naturally in some chrysanthemum flowers. Both the natural pyrethrum and synthetic pyrethroids have low toxicity to humans – <a href="http://apvma.gov.au/node/2760">particularly at the doses</a> found in garden products. Continuous use of pyrethroid insecticides <a href="http://npic.orst.edu/factsheets/pyrethrins.pdf">has no health implications</a> for humans if instructions are followed.</p>
<p>Neonicotinoids are synthetic insecticides that mimic nicotine, which is toxic to insects. These have a place in pest control if used thoughtfully and sparingly. Unlike pyrethroids, these insecticides target a pathway in the insect nervous system shared with humans, so could potentially harm us.</p>
<p>When used as directed, <a href="http://npic.orst.edu/factsheets/imidagen.html">poisoning should not occur</a> and animal studies suggest human exposure should not lead to <a href="http://npic.orst.edu/factsheets/imidagen.html#study">significant health effects</a>. Neonicotinoids <a href="http://apvma.gov.au/node/12291">are toxic to bees</a>, although <a href="https://theconversation.com/neonicotinoids-linked-to-wild-bee-and-butterfly-declines-in-europe-and-us-63999">Australia has not had the big bee crash</a> seen in the US and parts of Europe.</p>
<hr>
<p><em><strong>Further reading:</strong> <a href="https://theconversation.com/birds-bees-and-bugs-your-garden-is-an-ecosystem-and-it-needs-looking-after-65226">Birds, bees and bugs: your garden is an ecosystem, and it needs looking after</a></em></p>
<hr>
<p>Chronic use of neonicotinoids in a human gardening population has not been assessed for long-term health effects, but a <a href="http://ehp.niehs.nih.gov/wp-content/uploads/advpub/2016/7/EHP515.acco.pdf">small study of agricultural workers</a> has shown no effect of chronic exposure. Another small study, however, suggests some association with memory loss. </p>
<h2>Herbicides</h2>
<p>Again, there is a bewildering variety of herbicides, depending on what weedy species is being targeted and how the weed is being killed. </p>
<p>Right out of the gate is glyphosate, used for <a href="http://www.lawncareadvice.com.au/lawn-weeds/94-controlling-broadleaf-weeds.html">broadleaf weeds</a>. This chemical, commonly sold as Roundup, <a href="https://www.theguardian.com/cities/2015/apr/21/glyphosate-probably-carcinogenic-pesticide-why-cities-use-it">caused some controversy</a> after the <a href="http://www.iarc.fr/en/about/index.php">International Agency for Research on Cancer</a> (IARC) concluded it was a probable human carcinogen. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/139352/original/image-20160927-20105-10s6c0u.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/139352/original/image-20160927-20105-10s6c0u.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/139352/original/image-20160927-20105-10s6c0u.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=347&fit=crop&dpr=1 600w, https://images.theconversation.com/files/139352/original/image-20160927-20105-10s6c0u.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=347&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/139352/original/image-20160927-20105-10s6c0u.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=347&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/139352/original/image-20160927-20105-10s6c0u.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=436&fit=crop&dpr=1 754w, https://images.theconversation.com/files/139352/original/image-20160927-20105-10s6c0u.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=436&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/139352/original/image-20160927-20105-10s6c0u.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=436&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="http://www.lawncareadvice.com.au/lawn-weeds/94-controlling-broadleaf-weeds.html">The Lawn Care Advice site/Screenshot</a></span>
</figcaption>
</figure>
<p>However, the IARC’s determination was based on only a small number of animal studies and didn’t include a number of animal studies where glyphosate did not cause cancer. It also said <a href="https://theconversation.com/council-workers-spraying-the-weed-killer-glyphosate-in-playgrounds-wont-hurt-your-children-54831">nothing about risk</a>; that is, what is the likelihood glyphosate would cause cancer at the concentrations humans are usually exposed to? </p>
<p>The European Food Safety Authority and the AVPMA have evaluated the evidence and determined that <a href="http://apvma.gov.au/node/13891">under appropriate handling conditions</a> applicable to general backyard gardeners, there is no risk to humans.</p>
<p>As a comparison, a homemade herbicide of salt, vinegar and soap that is claimed as a replacement for glyphosate is <a href="https://www.geneticliteracyproject.org/2014/06/06/homemade-herbicide-of-salt-vinegar-and-soap-more-expensive-and-toxic-than-glyphosate-in-roundup/">more toxic than glyphosate</a>.</p>
<p>Another herbicide for woody weeds, like blackberry, is <a href="http://www.pesticideinfo.org/Detail_Chemical.jsp?Rec_Id=PC34645">Triclopyr</a>. This can cause eye and skin irritation, but has no serious long-term health impacts if proper safety procedures are followed.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/139382/original/image-20160927-20114-1tif0jm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/139382/original/image-20160927-20114-1tif0jm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=428&fit=crop&dpr=1 600w, https://images.theconversation.com/files/139382/original/image-20160927-20114-1tif0jm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=428&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/139382/original/image-20160927-20114-1tif0jm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=428&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/139382/original/image-20160927-20114-1tif0jm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=538&fit=crop&dpr=1 754w, https://images.theconversation.com/files/139382/original/image-20160927-20114-1tif0jm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=538&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/139382/original/image-20160927-20114-1tif0jm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=538&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">When using garden chemicals, always wear gloves to avoid irritation.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<h2>Fertilisers</h2>
<p>There are many formulations and varieties of fertilisers depending on soil type and location (where I live is basically sand). Health risks are basically related to long-term inhalation of fine particles, which could cause breathing difficulties. Once again follow the safety instruction.</p>
<h2>Caveat</h2>
<p>Just because a given product is not, or minimally, toxic to humans, that does not mean you should apply it to your garden by the bucket load. Always apply any garden chemical with care and thought, using the right amount at the right time for the right purpose.</p>
<p>Any agent you apply or spray can cause adverse reactions if you don’t use it as directed. Getting <a href="http://www.abc.net.au/gardening/stories/s2817126.htm">“organic” garlic and soap insecticide spray</a> in your eyes will hurt like billy-o, just like the latest you-beaut synthetic pyrethrum spray, even though both are pretty much non-toxic to humans. </p>
<p>Inhaling dusts can irritate your lungs. Always make sure you are wearing gloves, apply sprays and dusts downwind and wear goggles if necessary. Always follow the directions.</p>
<hr>
<p><em>You can read the other articles in our gardening series <a href="https://theconversation.com/au/topics/gardening-series-31530">here</a>.</em></p><img src="https://counter.theconversation.com/content/65643/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ian Musgrave receives funding from the National Health and Medical Research Council for screening herbal medicines for toxins. He has previously held ARC and NHMRC funding for work related to Alzheimer's disease. </span></em></p>When working with garden chemicals, always make sure you are wearing gloves. Apply sprays and dusts downwind and wear goggles if necessary. Always follow the directions.Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/548312016-02-17T10:43:44Z2016-02-17T10:43:44ZCouncil workers spraying the weed-killer glyphosate in playgrounds won’t hurt your children<figure><img src="https://images.theconversation.com/files/111757/original/image-20160217-19275-14g9ag8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Roundup, or the chemical glyphosate, is a very common herbicide used to kill weeds.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/jeepersmedia/14874003257">Mike Mozart/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>A group of rural Victorians has <a href="http://www.abc.net.au/news/2016-02-16/councils-still-using-herbicide-that-probably-causes-cancer/7168464">petitioned their local council</a> to stop using the household weed-killer Roundup (glyphosate). </p>
<p>Their concerns centre around an <a href="http://www.theguardian.com/cities/2015/apr/21/glyphosate-probably-carcinogenic-pesticide-why-cities-use-it">assessment made last year by the International Agency for Research on Cancer (IARC)</a> – an arm of the World Health Organisation – that the common herbicide was “probably carcinogenic to humans”.</p>
<p>The IARC had found <a href="http://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(15)70134-8/fulltext">limited evidence of carcinogenicity</a> in humans for non-Hodgkin’s lymphoma, mostly in agricultural workers.</p>
<p>Victoria’s Mount Alexander Shire Council has <a href="http://www.theage.com.au/victoria/weedkilling-herbicide-remains-councils-number-one-weapon-despite-community-cancer-concerns-20160216-gmvjzg.html">resolved to continue</a> using the herbicide. Councillors have, however, adopted a resolution to “seek alternative methods” to reduce “the use of glyphosate and other weed control chemicals”. </p>
<p>In Queensland, <a href="http://www.abc.net.au/news/2016-02-17/qld-council-peak-body-seeks-legal-advice-on-weedkiller/7176460">councils are also investigating</a> whether they should continue using glyphosate for the same reason.</p>
<p>But the concern of the councils and residents isn’t warranted. Glyphosate isn’t actually dangerous at the levels at which children, or the incidental park passerby, are exposed.</p>
<h2>‘Probably’ carcinogenic</h2>
<p><a href="http://www.glyphosate.eu/glyphosate-basics/how-glyphosate-works">Glyphosate is an organic compound</a> that kills weeds by interfering with the plants’ metabolism. In Australia, <a href="http://apvma.gov.au/node/13891">it’s been registered for use</a> for more than 40 years.</p>
<p>But it’s also classified as “probably carcinogenic to humans”, which means children should stay away from it. Right? Well, no.</p>
<p>The <a href="http://monographs.iarc.fr/ENG/Classification/">IARC classifies agents that “probably” cause human cancers</a> into Group 2A. This is below Group 1 that hosts agents definitely proven to be carcinogenic to humans. They include tobacco smoke and asbestos. </p>
<p>For Group 1 substances, relevant studies are consistent and indicate cancer causation definitively. But then there’s Group 2A with the term “probably”. Here some scientific data fall short of proof. For glyphosate and many other chemicals, the relevant studies are not consistent.</p>
<p>The people most heavily exposed to glyphosate are those employed to spray or apply it. These were the people subject to investigations on which IARC based its determination.</p>
<p><a href="http://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(15)70134-8/fulltext">Some studies have shown workers using glyphosate</a> have more of a certain type of lymphoma (a cancer of blood-forming cells) than the average population. Other studies, including the biggest such investigation, have not. </p>
<p>Discrepancies are common in epidemiology, which is a study of diseases in populations. Epidemiologists use qualifiers such as “probably” or “possibly” rather than indicating that one or more studies are wrong. </p>
<p>But people often misunderstand what action must be taken when something has been determined as “probably carcinogenic”.</p>
<h2>Risk assessment</h2>
<p>The IARC evaluations identify hazards – that is, whether a certain substance has the biological capability to cause cancer. A hazard identification is only one part of the process to determine whether a chemical is dangerous for use.</p>
<p>If it is capable of causing cancer, or probably is, then a separate level of investigation is needed to determine under what circumstances people are exposed to the chemical, and then, what the likelihood is of it causing the cancer. </p>
<p>This exercise is called a “risk assessment” and is not addressed by IARC. </p>
<p>Risk assessment is the business of statutory authorities. For pesticide use in Australia, the relevant authority is the Australian Pesticides and Veterinary Medicines Authority (APVMA). </p>
<p>The APVMA regulates how glyphosate is to be used safely. Authorities like this take into account factors such as the circumstances of a chemical’s use, the level of exposure and availability of alternatives and protective measures – such as warning labels and protective equipment and clothing.</p>
<p>As already mentioned, glyphosate has only been found to be “probably” carcinogenic, and the studies on which this determination was based were confined to those most exposed to the chemical (those who use it occupationally). </p>
<p>But what about the rest of us, as in, the vast majority of Australians whose job doesn’t involve using glyphosate? </p>
<h2>Glyphosate and the average child</h2>
<p>Negative health effects of chemicals are mainly determined by the level of exposure to them. The good news is that <a href="https://en.wikipedia.org/wiki/Glyphosate">soil microbes degrade glyphosate</a> in a matter of days. It doesn’t accumulate the way some pesticides do. </p>
<p>The carcinogenicity evidence for glyphosate doesn’t involve incidental exposure for children. Such level of exposure, if measurable at all, would be hundreds of times below that of occupational exposure. </p>
<p>And when it comes to children, it’s not only the level of exposure that must be considered. It’s also the frequency of exposure when compared to those using it occupationally (possibly most days over a period of years, if not decades). So clearly, much less.</p>
<p>Children get to parks by crossing roads. That’s a risk and there are warning signs for it. When they get to a park, they also risk attack by dogs or humans, being struck by lightning or bitten by snakes. Although those risks are real, they don’t (in most cases) merit warning signs. </p>
<p>And then there’s the even lesser risk of cancer from residual glyphosate, which has never been documented. Just forget it.</p><img src="https://counter.theconversation.com/content/54831/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bernard Stewart 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>The World Health Organization classifies the common herbicide glyphosate as “probably carcinogenic to humans”. But this doesn’t mean using it to kill weeds in playgrounds will hurt children.Bernard Stewart, Professor, Paediatrics, Cancer and related disorders, Epidemiology, Biochemistry and Cell Biology, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/275962014-06-05T05:06:00Z2014-06-05T05:06:00ZIconic monarch butterflies under threat from rising herbicide use<figure><img src="https://images.theconversation.com/files/50282/original/64k9vvby-1401898772.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Monarch butterfly: not scared of wearing bold colours.</span> <span class="attribution"><a class="source" href="http://ko.fotopedia.com/items/flickr-8871733731">Dean Morley</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Monarch butterflies are known for their striking flame-orange and black appearance, and especially for their mass migration in their millions to spend winters in the mountain forests of Mexico. But despite growing problems with <a href="http://www.usatoday.com/story/news/world/2013/09/09/logging-monarch-butterflies-mexico/2790039/">deforestation</a> in Mexico, their struggle begins at home in the United States and Canada.</p>
<p>The butterflies that fly to Mexico are the great-great-great grandchildren of the monarchs that were in Mexico the previous winter. In 2013 the overwintering population in Mexico covered 0.67 hectares of fir forest (about 44 million butterflies) the lowest since counts began in 1994. Since 1999 their numbers have declined 82%.</p>
<p>What could have caused this? During their larval stage monarchs, which can be found from the US central states to the east coast and into southern Canada, feed exclusively on milkweed plants. We observed in 2001 that many monarchs were feeding <a href="http://www.pnas.org/content/98/21/11913.full">on milkweeds in agricultural fields</a> – more than 80% of monarchs from the Midwest. Since then, milkweeds in and around agricultural crop fields have gradually been eliminated, through a combination of spraying with Roundup (glyphosate) herbicide and increased planting of corn and soybeans genetically modified to be resistant to the herbicide. </p>
<p>In <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1752-4598.2012.00196.x/abstract">previous studies</a>, we’ve shown that the magnitude of monarch population decline in Mexico matched the magnitude of the decline in the abundance of milkweeds in butterflies’ prime breeding habitat – the Corn Belt region of the US. This strongly suggests that milkweed loss is the primary factor in the species’ decline. </p>
<p>In a recently published paper, Tyler Flockhart and colleagues in Canada and Australia <a href="http://rspb.royalsocietypublishing.org/content/280/1768/20131087.short">examined the monarch population decline</a> and tried to gauge the relative roles of all the factors that may lie behind it. Besides the loss of milkweeds in the breeding area, these include climate change, the loss of forests at the overwintering sites, and <a href="https://www.monarchlab.org/Lab/app/upload/pdf/OW-6%20Brower%20et%20al%20catastrophic%20winter%20storm%20mortality%20Monarch%20Chapter%2020.pdf">occasional catastrophic weather events</a>.</p>
<p>The research team developed a population model that incorporated information about birth and death rates for each of the roughly four generations that comprise the monarch annual migration cycle. A number of pieces of information necessary to generate such a population model are unknown or poorly known, so assumptions had to be made. With that caveat, they were able to confirm that the primary driving force behind the population decline was loss of milkweeds in the breeding area, with the other factors playing a minor role.</p>
<p>With population models, not only can you examine the past but also extrapolate into the future. The good news is that the population model projects the population to decline by only a further 14% over the next century – much less than the precipitous drop in numbers over the last 20 years. The bad news is that the new, much lower population level makes the species more vulnerable to events such as catastrophic heatwaves or severe winters that can wipe out millions at a stroke. The model puts the chance of population extinction in the next century at a low but distinctly non-trivial 5%.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/50284/original/mr34fxg8-1401898867.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/50284/original/mr34fxg8-1401898867.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=403&fit=crop&dpr=1 600w, https://images.theconversation.com/files/50284/original/mr34fxg8-1401898867.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=403&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/50284/original/mr34fxg8-1401898867.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=403&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/50284/original/mr34fxg8-1401898867.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=507&fit=crop&dpr=1 754w, https://images.theconversation.com/files/50284/original/mr34fxg8-1401898867.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=507&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/50284/original/mr34fxg8-1401898867.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=507&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The monarch has equally fetching attire as a caterpillar.</span>
<span class="attribution"><a class="source" href="http://www.public-domain-image.com/full-image/fauna-animals-public-domain-images-pictures/insects-and-bugs-public-domain-images-pictures/butterflies-and-moths-pictures/monarch-butterfly/monarch-butterfly-caterpillar-insect-danaus-plexippus.jpg-royalty-free-stock-photo.html">Singer Ron/USFWS</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The chief reason why future declines will not be as pronounced is because milkweeds have been virtually eliminated from farmland, meaning that losses stemming from that habitat have already been accounted for. At present there are two main habitats that provide milkweeds for monarch butterflies. </p>
<p>The Conservation Reserve Program (<a href="http://sustainableagriculture.net/publications/grassrootsguide/conservation-environment/conservation-reserve-program/">CRP</a>) provides incentives to farmers to set aside land from growing crops. This land is typically planted with grasses to prevent erosion but often has milkweeds. I have estimated that there are 1.4m hectares (3.6m acres) of CRP land in the Midwest providing suitable milkweed habitat – if there were incentives for farmers to plant milkweed on their CRP land, this could prevent further declines and even promote a population comeback. Unfortunately at present the high demand for corn means farmers are tempted to convert CRP land back to crops. </p>
<p>The second important habitat is roadsides. Transportation Department officials need to be informed about the impact of roadside management practices, such as spraying with herbicide and mowing, on monarchs.</p>
<p>Incentives to plant other flowering species besides milkweed in CRP land and roadsides would help. Pollinators such as bees and butterflies are in serious decline, largely due to loss of habitat. Other threats to pollinators such as the widespread use of insecticides such as neonicotinoids could also be eliminated.</p><img src="https://counter.theconversation.com/content/27596/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Pleasants receives funding from USDA, EPA, US-AID</span></em></p>Monarch butterflies are known for their striking flame-orange and black appearance, and especially for their mass migration in their millions to spend winters in the mountain forests of Mexico. But despite…John Pleasants, Adjunct Assistant Professor of Ecology, Evolution and Organismal Biology, Iowa State UniversityLicensed as Creative Commons – attribution, no derivatives.