(Beyond Pesticides, August 22, 2017) Streams in the Midwestern U,S. are polluted with complex mixtures averaging over 50 pesticides each, according to a U.S. Geological Survey (USGS) report published earlier this month. This is the latest and also most extensive study on pesticide contamination in U.S. streams to date. The shocking results put many aquatic plants and animals at existential risk, leading health and environmental advocates to ask how the federal government can continue to permit U.S. streams to be used as a mixing bowl for toxic pesticide compounds. Each week between May and August of 2013, USGS sampled 100 streams located in 11 Midwestern states for 228 pesticides and their breakdown products. Based on site location, 88 of these streams are considered agricultural, while 12 are considered urban. “About 150 million pounds of pesticides are applied annually in the Midwestern U.S.,” said Lisa Nowell, PhD, research chemist and lead scientist on the study. “Understanding which pesticides are occurring at levels potentially toxic to aquatic life, and where they occur, is crucial to informing management decisions.” Of the 1,200 samples collected over the study’s 12 week period, scientists detected 183 pesticide compounds (98 of the 124 herbicides tested, 71 of […]

(Beyond Pesticides, June 14, 2017)  Oak trees in Iowa may be the latest victim of widespread chemical-intensive agriculture, according reports in the Des Moines Register. The newspaper indicates that the Iowa Department of Natural Resources (IDNR) has received roughly one thousand calls this spring from residents concerned about the state of their oak trees. Leaves are ‘tattered’ down to the vein, in an appearance one would first think was related to pest damage, according to the newspaper article. However, foresters with IDNR indicate the cause is likely the use of chloroacetanillide herbicides, which are applied throughout the state and region. Advocates say that this situation contributes to mounting environmental problems associated with chemical-intensive food production that support the need for the adoption of non-toxic weed management strategies. Past research has found associations between the use of chloroacetanillide herbicides, such as acetochlor and metolachlor, and oak leaf tatter syndrome. State officials indicate that the increase in resident complaints is likely related to a colder March, which may have retarded leaf development. By the time leaves began unfurling in early spring, herbicide use was at its height, leading to high ambient concentrations of the chemicals in the atmosphere, according to IDNR officials […]

(Beyond Pesticides, May 26, 2017) On Wednesday, the U.S. House of Representatives voted to pass a bill that would reverse an Environmental Protection Agency (EPA) requirement to obtain a permit before spraying pesticides on or near waterways. The passage of HR 953, The Reducing Regulatory Burdens Act (known by environmentalists as the “Poison Our Waters Act”), is the latest update in a multi-year string of attempts to rollback commonsense protections for the public waterways all Americans use for swimming, fishing, and other forms of recreation. It will now move forward to be considered by the Republican-majority Senate, where it will most likely pass and be signed into law. HR 953, if signed into law, would reverse a 2009 decision issued by the 6th Circuit Court of Appeals, in the case of National Cotton Council et al. v. EPA, which held that pesticides applied to waterways should be considered pollutants under federal law and regulated under the Clean Water Act (CWA), through National Pollutant Discharge Elimination System (NPDES) permits. Prior to the decision, the EPA, under the Bush Administration, had allowed the weaker and more generalized standards under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) to be followed. This allowed pesticides to be discharged […]

(Beyond Pesticides, September 27, 2016)  Multinational pesticide manufacturer Syngenta Crop Protection was handed a  $1.2 million fine last week for multiple violations of federal pesticide law, according a settlement reached with the U.S. Environmental Protection Agency (EPA). EPA charged Syngenta with three major violations of the Federal Insecticide Fungicide and Rodenticide Act (FIFRA), including: (1) Failure to have repackaging agreement and/or maintain records on registered pesticides; (2) Distributing misbranded pesticides, and; (3) Failure to maintain data submitted for pesticide registration. However, under the consent agreement reached with EPA, the company neither admits nor denies the allegations. The settlement comes at a time of increased scrutiny of Syngenta, as the company is in the process of reregistering the herbicide atrazine, and Chinese National Chemical Corporation (ChemChina) continues its attempts to complete a $43 billion merger. While the plan appears to have cleared U.S. regulatory hurdles, European lawmakers have yet to sign off on the deal. “The repackaging, sale and distribution of unregistered and misbranded pesticides is illegal and puts people and the environment at risk. Users rely on accurate, up-to-date information about ingredients, directions for use, hazards and safety precautions,” said Anne Heard, Acting Regional Administrator for the Southeast in an […]

(Beyond Pesticides, June 29, 2016) A new report published by Regeneration Vermont finds that herbicide and chemical fertilizer use on Vermont dairy farms nearly doubled from 2002 to 2012, increasing from 1.54 to 3.01 pounds of herbicide per acre, respectively. The report, Vermont’s GMO Legacy: Pesticides, Polluted Water & Climate Destruction, by Will Allen, Ph.D. of Regeneration Vermont and Cedar Circle Farm, focuses on the failed promises of genetically engineered (GE, or GMO) crops to reduce chemical inputs required for crop production. While Vermont leads the nation on the GE labeling front, with its  law set to go into effect on July 1, the report, which highlights the flawed exemption on dairy and meat products, is a sobering reminder that this is only a part of the solution to the effects of GE crops and chemical-intensive agriculture. “While the law will force mainstream food corporations to label GMOs in products like Cheetos and Spaghetti-os before coming into the state, it turns a blind eye to the GMO-derived dairy that is the primary ingredient in, for example, Ben & Jerry’s ice cream and Cabot’s cheddar cheese,” says Dr. Allen. “This is about more than the consumer’s right to know. It’s also […]

(Beyond Pesticides, March 4, 2016) Honey bees experience a learning and memory deficit after ingesting small doses of the insecticide  chlorpyrifos, potentially threatening their success and survival, according to a study in  New Zealand. Chlorpyrifos is a highly neurotoxic organophosphate pesticide used worldwide on crops to protect against insects and mites. The study,  Measurements of Chlorpyrifos Levels in Forager Bees and Comparison with Levels that Disrupt Honey Bee Odor-Mediated Learning Under Laboratory Conditions,  published in  Ecology, examines chlorpyrifos levels in  bees collected from 17 locations in Otago, New Zealand and compared doses of the pesticide that cause sub-lethal effects on learning performance under laboratory conditions with amounts of chlorpyrifos detected in bees in the field. Researchers found chlorpyrifos in 17% of the sites sampled and 12% of the colonies examined. Honey bees are found to experience harmful effects to smell memory and learning, and reduction in specificity of memory recall. Chlorpyrifos is just one of many pesticides that have frequently been detected in honey bees. According to a study conducted last year by the U.S. Geological Survey (USGS), 72% of bees tested positive for pesticide residues, raising concerns about  unintended pesticide exposures where land uses overlap or are in proximity […]

(Beyond Pesticides, November 23, 2015) Commonly-used pesticides can impact aquatic species over multiple weeks, even when chemicals are no longer detectable in water nor  monitored by regulators, according to new research. The study, titled A long-term assessment of pesticide mixture effects on aquatic invertebrate communities,  published in the journal Environmental Toxicology and Chemistry, investigates the long-term effects on aquatic invertebrate communities of commonly-used insecticides: two pyrethroids (permethrin and lambda-cyhalothrin) and an organophosphate (chlorpyrifos). Pesticide applications were based on environmentally relevant concentrations and lethal concentrations (a concentration required to kill a certain percentage of animals tested) ranging from 10% (LC10) to 50% (LC50). Researchers made repeat applications in order to mimic runoff events in a multiple grower or homeowner watershed. The results indicate that insecticide mixtures continue to impact natural systems over multiple weeks, even when bound to particles and no longer detectable in water. Combinations of indirect and direct effects caused consequences across the food chain. Pyrethroids rapidly dissipated from the water column, whereas chlorpyrifos was detectable even six weeks after application. “The effects we observed indicate that many species were affected at a sublethal level,” said Simone Hasenbein, Ph.D., lead author of the study tells Phys.org. “Thus, populations exposed […]

(Beyond Pesticides, October 14, 2015) New research from the Center for Environmental Research and Children’s Health (CERCH) shows that children, especially those in low-income and agricultural families, who switched to an organic diet reduced their bodies’  level of pesticides. This California study is one of several that documents the benefits of eating an organic diet, especially for children who are especially vulnerable to pesticide exposures due to the developing bodies. The study, Effect of Organic Diet Intervention on Pesticide Exposures in Young Children Living in Low-Income Urban and Agricultural Communities  follows 40 children, 3-6 years old from low-income families living in urban and agricultural environments in Oakland and Salinas, California. The children alternated between a conventionally grown diet and organic, and urine samples were analyzed each day. The researchers measure 23 metabolites of several pesticides classes, including organophosphates (OP) and pyrethroid insecticides, and the herbicides 2,4-D and metolachlor. These pesticides are frequently detected (> 72%) in urine samples collected, with metabolites of 2,4-D detected 90 percent of the time, and pyrethroids 82 percent. Overall, among the most frequently detected pesticides, metabolites of OPs  decreases by nearly 50 percent when children are on an organic diet, and levels of 2,4-D falls […]

(Beyond Pesticides, June 05, 2015) A new federal bill was introduced Wednesday that, if passed, would undermine the U.S. Environmental Protection Agency’s (EPA) authority to issue Clean Water Act permits for pesticide spraying over waterways. Titled the Sensible Environmental Protection Act  and introduced by Senators Mike Crapo (R-Idaho) and Claire McCaskill (D-Mo), this new bill would reverse a 2009 federal court decision in National Cotton Council v. EPA that directed EPA to require permits from applicators who spray over “navigable waters,” as outlined in the Clean Water Act (CWA). The bill’s authors claim that the need for water permits is duplicative, given that pesticide applicators also comply with the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), the law that requires applicators to follow instructions on pesticide labels. “This issue is a prime example of an unnecessary, duplicative federal regulation impacting a variety of stakeholders in Idaho and across the nation that must be fixed,” Senator Crapo said in a statement.  “Our rural communities are already under a substantial amount of financial strain and regulatory pressure and are looking to Congress for much-needed relief.” Contrary to  Senator  Crapo’s claims, the  CWA permit serves as a valuable tool that lets authorities know […]

(Beyond Pesticides, April 16, 2015) According to a new study, regulatory limits for insecticides are exceeded in over half of contaminated water samples collected from around the world. The study was based on a review of more than 800 studies conducted in 73 countries over the past five decades and is the first to evaluate the exposure of surface waters to particularly toxic agricultural insecticides on a global scale. Based on these results, the researchers ultimately conclude that “fundamental revisions of current regulatory procedures and pesticide application practices are needed to reverse the global environmental impacts of agro-chemical based high-intensity agriculture.” The analysis, published in the Proceedings of the National Academy of Sciences and titled “Agricultural insecticides threaten surface waters at the global scale,” was led by Sebastian Stehle, Ph.D., and Ralf Schulz, Ph.D, at the Institute for Environmental Sciences at University Koblenz-Landau in Germany. The researchers looked at 28 insecticides, the majority of which are currently approved in the United States and the European Union, represent all major insecticide classes, and are important for global agriculture in terms of annual application rates. While they found that just 2.6 percent of the 2,500 aquatic sites contained measurable levels of insecticides, […]

(Beyond Pesticides, September 12, 2014) A new U.S. Geological Survey (USGS) report finds that levels of pesticides continue to be a concern for aquatic life in many of the Nation’s rivers and streams in agricultural and urban areas. The study, which documents pesticide levels in U.S. waterways for two decades (1992-2011), finds pesticides and their breakdown products in U.S. streams more than 90 percent of the time. Known pesticide water contaminants, such as atrazine, metolachlor, and simazine, continue to be detected in streams more than 50 percent of the time, with fipronil being the pesticide most frequently found at levels of potential concern for aquatic organisms in urban streams. According to the USGS report, “An Overview Comparing Results from Two Decades of Monitoring for Pesticides in the Nation’s Streams and Rivers, 1992—2001 and 2002—2011,” featured in the journal, Environmental Science and Technology and part of the agency’s ongoing National Water-Quality Assessment Program, the proportion of streams with one or more pesticides that exceed an aquatic-life benchmark (or guideline) is similar between the two decades for streams and rivers draining agricultural and mixed-land use areas, but much greater during the 2002-2011 for streams draining urban areas. During both decades, one or […]

(Beyond Pesticides, May 28, 2014) A statewide pilot pesticide sampling project has found over 20 different types of pesticides in Hawaiian waterways, some of which are no longer registered for use in Hawaii. State officials believe the pesticides, many detected in urban areas, are from residential and golf course applications. These preliminary findings help highlight the need for local oversight of pesticide use, currently a controversial issue in the state. Conducted in partnership with the Hawaiian Department of Agriculture, the U.S. Geological Survey (USGS) and the Hawaiian Department of Health, the survey-study finds herbicides like glyphosate (Roundup) and atrazine, as well as a fungicide that is no longer registered for use in the state, contaminating the state’s waterways. The study measured pesticides in surface waters and in sediment at multiple locations in Hawaii. 25 herbicides, 11 insecticides and 6 fungicides were detected, with atrazine the most commonly found. This pilot survey responds to growing community concerns about the impacts of pesticides on local communities and ecosystems, and provides preliminary information on pesticide residues in state waterways. Recently, Kauai County passed an ordinance —Ordinance 960—  that requires public disclosure of pesticides used and the location of genetically engineered (GE) crops, as […]

(Beyond Pesticides, February 5, 2014) According to a new study published in Environmental Health Perspectives, chemical contaminants in waterways that mimic estrogen -endocrine disruptors- target developing heart valves in fish and impair the growth of fish hearts. The study illustrates that these hormone-mimicking compounds, which include some pesticides, pharmaceuticals, and other household chemicals often found in sewage effluent and runoff that flows into waterways, are being linked to mounting science that show serious human and environmental adverse effects. Researchers from the Fish Health Branch of the U.S. Geological Survey (USGS) and the Carnegie Institution for Science exposed zebrafish embryos to water from 19 sites in the Susquehanna, Delaware, Allegheny and Shenandoah watersheds. Water from 16 of the sites triggered proteins in the fish that were estrogen receptors, indicating that the rivers contained endocrine disrupting chemicals. These receptors are attached to DNA, which turn genes on and off. While such activity is common in the liver, this is the first experiment to show estrogenic activity in heart valves. “This tells us that endocrine-disrupting chemicals could lead to improper heart development. We were quite surprised, since this is something that others hadn’t observed before,” said study co-author Luke Iwanowicz, PhD, and research […]

(Beyond Pesticides, December 13, 2013) A recent survey conducted by researchers at the U.S. Geologic Survey (USGS) and the U.S. Environmental Protection Agency (EPA) found traces of 18 unregulated chemicals in drinking water from more than one third of U.S. water utilities. Of the 21 total chemicals found, researchers discovered among them 11 perfluorinated chemicals, an herbicide, two solvents, caffeine, an antibacterial chemical, a metal and an antidepressant. Preliminary findings were presented by scientists at an annual toxicology conference held by the Society of Environmental Toxicology and Chemistry last month in Nashville. Federal researchers took samples from 25 U.S. utilities from around the nation who voluntarily participated in the study, providing samples of treated and untreated water. Disturbingly, 18 of the chemicals found are not regulated under the Safe Water Drinking Act, meaning utility companies are not required to treat, limit, or even monitor for their presence. “The good news is the concentrations are generally pretty low,” said USGS research hydrologist Dana Kolpin, PhD. to Environmental Health News. “But,” he continued “there’s still the unknown. Are there long-term consequences of low-level exposure to these chemicals?” While there is a paucity of data on some of the contaminants, regulated chemicals such […]

(Beyond Pesticides, January 23, 2013) A new federal report finds toxic contamination remains widespread in the Chesapeake Bay, with severe impacts in some places, which health and environmental advocates say lends support to their push in Maryland for legislative action on pesticides and other hazardous chemicals. In spite of some cleanup, the health of the Bay has not significantly improved. The report, “Technical Report on Toxic Contaminants in the Chesapeake Bay and its Watershed: Extent and Severity of Occurrence and Potential Biological Effects” is based on a review of integrated water-quality assessment reports from the jurisdictions in the Bay watershed (Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia, and Washington, D.C.), Federal and State reports, and articles in scientific journals. It notes that nearly three-fourths of the Bay’s tidal waters are “fully or partially impaired” by toxic chemicals, with people warned to limit fish consumption from certain areas. Contamination is severe in a handful of “hot spots” around the Bay, including Baltimore’s harbor, largely a legacy of past industrial and shipping activity. Previous reports have called on federal, state and local government to accelerate research into what threats chemical contamination may pose to the Bay, and to step up efforts […]

(Beyond Pesticides, September 10, 2012) Traces of pesticides in drinking water were found in eleven rural elementary schools in Oregon, according to a U.S. Department of Agriculture (USDA) study released on August 30. The study shows a disturbing variety of pesticides that when combined could have dramatic impacts on the health of the children that consume this water on a daily basis. The study found traces of several different types of pesticides in the drinking water of Dixie and Fairplay, the elementary schools that service Corvallis, Oregon. Some of the pesticides that were found in the Dixie school water include atrazine, bromacil, diuron, imidacloprid, metolachlor, norflurazon, and simazine. In the nine other schools that were found to have pesticides in their drinking water, seven different pesticides were found in the water at Applegate Elementary in Eugene, and multiple pesticides were also found in the drinking water of Ontario’s Pioneer and Cairo elementary. Children face unique hazards from pesticide exposure. They take in more pesticides relative to their body weight than adults in the food they eat and air they breathe. Their developing organ systems often make them more sensitive to toxic exposure. The body of evidence in scientific literature shows […]

(Beyond Pesticides, July 19, 2011) According to a U.S. Department of Agriculture (USDA) study published in the Journal of Environmental Quality, the volatilization of atrazine and metolachlor, two herbicides known to contaminate surface and ground water, consistently results in herbicide movement off the target site that exceeds nontarget field runoff, varying widely depending upon weather conditions. Linked to endocrine disruption, cancer, developmental effects, and more, increased levels of these hazardous pesticides in the air is cause for concern. When averaged over the two herbicides, loss by volatilization is about 25 times larger than movement from surface runoff, despite low vapor pressures. Agricultural Research Service (ARS) soil scientist Timothy Gish, PhD and ARS micrometeorologist John Prueger, PhD led the investigation, which looks at the field dynamics of these two herbicides commonly used in corn production. Prior to this field study, many experts believed that volatilization was not a contributing factor to water contamination because atrazine and metolachlor had a low vapor pressure. However, the monitoring of both herbicide volatilization and surface runoff at the field-scale over multiple years had never been done. So the team set up a 10-year study in an experimental field in Beltsville that is equipped with remote […]

(Beyond Pesticides, March 29, 2011) According to a French study published March 2, 2011 in the online edition of Environmental Health Perspectives, prenatal exposure to the herbicide atrazine is linked to small head circumference and fetal growth restriction. The authors say the study “raises particular concerns for countries where atrazine is still in use.” Atrazine is a widespread contaminant in drinking water and is linked to various birth defects, endocrine disruption and cancer, even at concentrations below EPA standards. Although it has been excluded from re-registration in the European Union because it is found above allowable thresholds in groundwater, it is still one of the most widely used herbicides in the U.S. and around world. The study, “Urinary Biomarkers of Prenatal Atrazine Exposure and Adverse Birth Outcomes in the PELAGIE Birth Cohort,” used a case-cohort design nested in a prospective birth cohort conducted in the Brittany region from 2002 through 2006. It collected maternal urine samples to examine pesticide exposure biomarkers before the 19th week of gestation. Quantifiable levels of atrazine were found in urine samples from 5.5% of 579 pregnant women, and various metabolites were identified in 20-40% of samples. The presence versus absence of quantifiable levels of atrazine […]

(Beyond Pesticides, February 25, 2011) The U.S. Environmental Protection Agency (EPA) has released a new report detailing sales and usage of pesticides in the U.S. for the years 2006 and 2007 and showing a modest decrease in pesticide use. The report compiles data from EPA, the U.S. Department of Agriculture (USDA), and other sources in order to track pesticide trends and monitor usage. Previous industry use reports had been published every two years between 1994 and 2001; however, the last report was published ten years ago, in 2001, leaving a gap in the data. In one of the more promising findings, the report shows that pesticide use in the country did decrease throughout most of the last decade. Use of conventional pesticides, measured in pounds applied, decreased about 3% from 2002 to 2007 and 11% from 1997 to 2007. However, the total pounds of pesticide use decreased only by approximately 8% — from 1.2 to 1.1 billion pounds — during the years from 2000 to 2007. While any decrease in the use of toxic chemicals is a hopeful sign, this marginal reduction does not go far enough. The fact that chemicals which are known to adversely affect human health and […]

(Beyond Pesticides, December 16, 2010)The Center for Biological Diversity notified the U.S. Fish and Wildlife Service (USFWS) and U.S. Environmental Protection Agency (EPA) December 15 of its intent to sue the agencies for failing to study and act on threats posed by more than 60 pesticides to the threatened California red-legged frog. A 2006 legal settlement secured by the Center required the EPA to assess the impacts of pesticides on the frog, then consult with the U.S. Fish and Wildlife Service (USFWS) under the Endangered Species Act to address those impacts, by 2009. The completed assessments were submitted to the Wildlife Service between March 2007 and October 2009. Although EPA determined that 64 registered pesticides are likely to harm the frogs, the Service has not completed any consultations or adopted protective measures. “The EPA acknowledges that scores of pesticides may be dangerous to California’s rare red-legged frogs, but nothing’s been done about it,” said Jeff Miller, a conservation advocate with the Center. “This three-year delay violates the Endangered Species Act and jeopardizes the future of the largest native frog in California.” Historically abundant throughout California, red-legged frogs have declined in numbers over 90 percent and have disappeared from 70 percent […]

(Beyond Pesticides, December 21, 2009) Earlier this month, Congressman Jim Moran of Northern Virginia and Senator John Kerry of Massachusetts introduced legislation to explore linkages between hormone disrupting chemicals in the environment and everyday products and the dramatic increase of autism, hyperactivity, diabetes, obesity, breast cancer, prostate cancer and other hormone related disorders. After the identification of endocrine disruptors, the legislation requires federal agencies with regulatory authority to report to Congress on the action it plans to take. For years, scientists have noted strange anomalies in fish and wildlife in locations where endocrine disrupting chemicals (EDCs) are found. A recent study found that an astounding 100 percent of small mouth bass in certain sites of the Potomac River basin have exhibited both male and female organs, a characteristic linked to EDCs. According to a 2009 study by the U.S. Geologic Survey, the occurrence of “intersex” fish is now found to be nationwide. “These fish are the proverbial ”˜canaries in the coal mine,’ a symptom of a larger sickness in our environment. The implications for humans are real and deeply troubling,” said U.S. Representative Moran, who worked with experts for roughly a year to craft the legislation. “We need facts driven […]

(Beyond Pesticides, October 5, 2009) An analysis of more than 100 scientific studies conducted on atrazine, published in the online edition of Environmental Health Perspectives, demonstrates the toxicity of atrazine to aquatic animals. Biologists at the University of Southern Florida (USF) have found evidence that atrazine harms fish and frogs. Atrazine is disruptive to the development and behavior of aquatic animals, and negatively effects their immune, hormone, and reproductive systems, according to the studies done by USF assistant professor Jason R. Rohr and postdoctoral fellow Krista A. McCoy. Atrazine is commonly used on lawns, golf courses, and sugarcane fields in Florida, and has recently been the topic of much controversy. While atrazine typically does not kill amphibians and freshwater fish, the USF report says it did: ”¢ Reduce the size of amphibians at or near metamorphosis in 19 of 19 studies. ”¢ Make amphibians and fish more active in 12 of 14 studies but reduced behaviors used to evade predators in six of seven studies. ”¢ Alter at least one aspect of male frogs’ reproductive development in eight of 10 studies. ”¢ Reduce the functioning of animals’ immune systems and often put them at risk of infection. Atrazine, a common […]

(Beyond Pesticides, September 18, 2009) Previously documented in the Potomac River, which flows through downtown Washington, DC, the occurrence of “intersex” fish is now found to be nationwide. U.S. Geological Survey (USGS) researchers published their study, “Widespread occurrence of intersex in black basses from U.S. rivers” in the online edition of Aquatic Toxicology. USGS researchers examined 16 different species of fish across the U.S. between 1995 and 2004. The condition of intersex fish, male fish producing eggs, is most commonly found in smallmouth and largemouth bass. One third of male smallmouth bass and one fifth of the male largemouth bass are intersex. Scientists tested sites in the Apalachicola, Colorado, Columbia, Mobile, Mississippi, Pee Dee, Rio Grande, Savannah, and Yukon River basins. Research shows intersex fish in approximately one-third of all examined sites. The only site where researchers found no intersex fish is the Yukon River basin. While the study did not look for the causes for intersex fish, scientists believe endocrine disruptors, chemicals that interfere with the body’s hormonal systems, are certainly to blame. “We know that endocrine-active compounds have been associated with intersex in fish, but we lack information on which fish species are most sensitive to such compounds, […]