(Beyond Pesticides, August 17, 2010) A federal appeals court has revived the fraud and negligent misrepresentation claims by blueberry farmers in New Jersey, who say that a pesticide made by Novartis Crop Protection, Inc. reacted badly with fungicides and ruined their crops. Declaring that the lower court improperly dismissed the farmers’ state law claims as preempted by the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), the federal court concluded that farmers were not suing over the alleged flaws in the warning label-which is federally regulated -rather were complaining about misrepresentations in Novartis’ marketing brochure. The case, Indian Brand Farms Inc. v. Novartis Crop Protection Inc. was filed in the 3rd U.S. Circuit Court of Appeals in New Jersey. Blueberry farmers said Novartis should have warned them that a new version of its pesticide, including diazinon as the active ingredient, also included a surfactant that reacts badly with fungicides. The promotional brochure failed to mention this reaction and when farmers mixed the diazinon pesticide with the fungicides Captan and Captec, it caused phytotoxic damage, including blotches, depressions and spots, and in some cases killed their plants. It was not clear to the appeals court that the practice of combining pesticides with […]

(Beyond Pesticides, January, 21, 2009) A new study concludes that exposures during pregnancy and childhood to insecticides that target the nervous system, such as organophosphates (OPs) and carbamates, are associated with childhood brain tumors. The researchers hypothesize that this susceptibility might be increased in children with genetic variations that affect the metabolism of these chemicals. The study, “Childhood Brain Tumors, Residential Insecticide Exposure, and Pesticide Metabolism Genes,” examines whether childhood brain tumors (CBT) are associated with the functional genetic variations. The study provides evidence that exposure to insecticides, paired with specific metabolism gene variants, may increase the risk of CBT. DNA was extracted from archival screening samples for 201 cases ≤ 10 years of age and born in California or Washington State between 1978 and 1990. Insecticide exposures during pregnancy and childhood were classified based on interviews with participants’ mothers. The children’s mothers reported whether they or anyone else had chemically treated the child’s home for insects including termites, fleas, ants, cockroaches, silverfish, or “other” pests. The results are consistent with the possibility that children with a reduced ability to metabolize organophosphate and carbamate insecticides might be at increased risk of CBT when sufficiently exposed. The researchers observed multiplicative interactions […]

(Beyond Pesticides, January 11, 2010) Yet another study has been published that further supports the causative link between pesticide exposure and Parkinson’s disease. The study, funded by the National Institute of Environmental Health Sciences (NIEHS), is published in the January issue of Epidemiology. The University of California, Los Angeles researchers looked at the association between Parkinson’s disease, organophosphate pesticides and the common gene variant, paraoxonase-1 gene Leu-Met 55 polymorphism (PON1-55 MM). The findings show that study participants with two copies of gene variant have a significantly increased risk of developing Parkinson’s disease when exposed to certain organophosphate pesticides used in agriculture. The population-based case-control study examined the DNA of 351 incident cases and 363 controls from three rural counties in California. The researchers then used pesticide usage reports and a geographic information system (GIS) approach to determine the study participants’ residential exposure to organophosphates. The PON1 gene codes for an enzyme that metabolizes organophosphate pesticides. Individuals with the variant MM PONI1-55 genotype that are exposed to organophosphates exhibit more than twice the risk of Parkinson’s disease compared to carriers of wildtype or heterozygous genotype and no exposure. In regards to exposure to diazinon, carriers of variant MM PONI-55 genotype show […]

(Beyond Pesticides, December 18, 2009) Biologists are finding that short-term, seasonal exposure to pesticides in rivers and basins limit the growth and size of wild salmon populations. Along with the widespread deterioration of salmon habitats, these findings show that exposure to commonly used pesticides continue to detriment the recovery of the salmons’ populations. The findings can be found in the study, “A fish of many scales: extrapolating sublethal pesticide exposures to the productivity of wild salmon populations,” in the December 2009 issue of the Ecological Society of America (ESA) journal, Ecological Applications. “Major efforts are currently underway to restore Pacific salmon habitats in an effort to recover depressed populations,” says David Baldwin, Ph.D., of the National Oceanic and Atmospheric Administration (NOAA), who co-authored the study with NOAA colleagues, “However, not much research has been done to determine the importance of pollution as a limiting factor of ESA-listed species.” The researchers studied the impact of pesticides, such as diazinon and malathion, on individual salmon using pre-existing data, and then devised a model to calculate the productivity and growth rate of the population. They used several exposure scenarios to reflect realistic pesticide use across various landscapes and over time. “An important aim […]

(Beyond Pesticides, December 1, 2009) A new study published in the November 2009 issue of Occupational and Environmental Medicine, adds rhinitis, the inflammation of the mucous lining of the nose, to the long list of ailments linked to pesticide exposure. “Rhinitis associated with pesticide exposure among commercial pesticide applicators in the Agricultural Health Study,” examined data from 2,245 Iowa commercial pesticide applicators and evaluated the association between rhinitis and 34 pesticides used in the past year. Seventy-four percent of commercial pesticide applicators in the study reported at least one episode of rhinitis in the past year (current rhinitis), compared with about 20-30% of the general population. Pesticide exposure and rhinitis were assessed at enrollment using two self-administered questionnaires. The first, completed at enrollment, obtained detailed information on use of pesticides on the market at the time of enrolment as well as smoking history, current agricultural activity and demographics. The second questionnaire, sent one month later, more detailed information on the pesticides, as well as medical history, including rhinitis, conjunctivitis, sinusitis and asthma. Respondents reported using 16 herbicides, 11 insecticides, five fungicides and two fumigants in the past year. Five of the pesticides were significantly positively associated with current rhinitis: the […]

(Beyond Pesticides, September 29, 2009) A new study reveals that children exposed to agricultural pesticides applied near their home have up to twice the risk of developing the most common form of childhood leukemia, according to the Northern California Cancer Center (NCCC). The study, “Residential proximity to agricultural pesticide applications and childhood acute lymphoblastic leukemia,” published in the October issue of Environmental Research, used a unique California database to reveal an elevated risk in acute lymphoblastic leukemia (ALL) among children living near applications of certain categories of pesticides used in agriculture. The study, led by Rudolph Rull, Ph.D., shows an elevated risk of ALL associated with moderate exposure, but not high exposure, to pesticides classified as organophosphates (odds ratio (OR) 1.6), chlorophenoxy herbicides (OR 2.0), and triazines (OR 1.9), and with agricultural pesticides used as insecticides (OR 1.5) or fumigants (OR 1.7). California is one of the few states in the country that requires active reporting of pesticide applications, including time, place, and the type and amount of pesticide used. For this study, researchers were able to link children’s entire residential histories from birth to the time of case diagnosis to this pesticide-use reporting database and identify agricultural pesticides that […]

(Beyond Pesticides, September, 15, 2009) On September 11, 2009, the Environmental Protection Agency (EPA) announced plans to place additional limitations on the use of three organophosphate pesticides ”” chlorpyrifos, diazinon and malathion ”” to protect endangered and threatened salmon and steelhead in California, Idaho, Oregon and Washington. The announcement comes in response to a series of lawsuits brought by Pacific Coast Federation of Fishermen’s Associations (PCFFA), the Northwest Coalition for Alternatives to Pesticides, and other salmon advocates, with legal representation from Earthjustice, aimed at removing toxic pesticides from salmon spawning streams throughout the northwest. In response to the litigation, the National Marine Fisheries Service (NMFS) in November of 2008 released a “biological opinion” that set forth a plan for protecting Pacific salmon and steelhead from three toxic organophosphate pesticides. That decision came after almost a decade of legal wrangling between salmon advocates led by Earthjustice and the federal government. The biological opinion prescribed measures necessary to keep these pesticides out of water and to protect salmon populations in Washington, Oregon, California, and Idaho. The announcement from EPA moves this work forward. Although the experts at NMFS recommended prohibiting aerial applications of the three pesticides within 1,000 feet of salmon waters […]

(Beyond Pesticides, September 4, 2009) The U.S. Environmental Protection Agency (EPA) fined a Minden, Nevada-based ornamental tree nursery for misusing pesticides contrary to labeling requirements and failing to comply with federal pesticide worker safety laws. Genoa Tree Nursery misused the pesticide Diazinon AG500 during applications in May and June 2008. The company failed to comply with label directions that require it to minimize the risk of exposure by notifying workers and handlers of recent pesticide applications on particular fields, and failed to provide workers with nearest emergency medical care facility information in case of exposure. The applicator also did not receive safety training during the previous five years as required by law. EPA fined Genoa Tree Nursery a mere $5,440 for these violations. “Notifying employees about potentially harmful pesticide exposure is not just a good idea, it’s the law,” said Katherine Taylor, EPA’s Communities and Ecosystems Division associate director for the Pacific Southwest region. “Employers of agricultural workers must ensure their employees are provided with information and protections that minimize the risk of potential exposure to pesticides””failure to do so is a serious violation.” The Nevada Department of Agriculture discovered the violations during a routine inspection in June 2008. The […]

(Beyond Pesticides, August 7, 2009) A recent study published in the journal Environmental Health Perspectives has added to evidence that certain pesticides significantly increase one’s risk of developing Parkinson’s disease (PD). Researchers found that rural residents who drank private well water within 500 meters of fields sprayed with certain pesticides had an increased – up to 90 percent – risk of developing PD, and those with Parkinson’s “were more likely to have consumed private well water, and had consumed it on average 4.3 years longer.” The study evaluated more than 700 people, including carefully chosen controls, in Fresno, Kent, and Tulare counties. 17 percent reported drinking private well water between 1974 and 1999. Researchers focused on wells’ proximity to agricultural fields sprayed with pesticides, since private wells are not regulated, and many are shallow enough to be contaminated by pesticides seeping into groundwater. Researchers looked at 26 pesticides and six in particular, “selected for their potential to pollute groundwater or because they are of interest for PD, and to which at least 10% of our population were exposed.” Those are: diazinon, chlorpyrifos, propargite, paraquat, dimethoate, and methomyl. Propargite exposure was most closely correlated with incidence of PD, with a 90 […]

(Beyond Pesticides, July 6, 2009) Last week, the U.S. Environmental Protection Agency (EPA) proposed to formally evaluate the harmful effects of 74 pesticides on 11 endangered and threatened species in the San Francisco Bay Area over the next five years, and to impose interim restrictions on use of these pesticides in and adjacent to endangered species habitats. The proposal stems from a settlement agreement with the Center for Biological Diversity, which sued EPA in 2007 for violating the Endangered Species Act by registering and allowing the use of toxic pesticides in Bay Area endangered species habitats without determining whether the chemicals jeopardize those species’ existence. “Tens of millions of pounds of toxic and poisonous chemicals, known to be deadly to endangered species and harmful to human health, including proven carcinogens and endocrine disruptors, are applied in the Bay Area each year, and many of those find their way through runoff or drift into our soil, creeks and rivers, San Francisco Bay, and sensitive wildlife habitats,” said Jeff Miller, conservation advocate with the Center. “The toxic stew of pesticides in the Bay-Delta has played a major role in the collapse of native fish populations, and pesticides are a leading cause of […]

(Beyond Pesticides, June 17, 2009) A new study finds that toxic pesticides, including those already banned, persist in homes. The study’s results indicate that most floors in occupied homes in the U.S. have measurable levels of insecticides that serve as sources of exposure to home dwellers. These persistent residues continue to expose people, especially vulnerable children, to the health risks associated with these chemicals. Published in Environmental Science and Technology, the study, entitled “American Healthy Homes Survey: A National Study of Residential Pesticides Measured from Floor Wipes,” was conducted as a collaboration between the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Housing and Urban Development. Five hundred randomly selected homes were sampled using alcohol wipes to collect dust from hard surface floors, mostly kitchen floor surfaces. The swipes were analyzed for 24 currently and previously use residential insecticides in the organochlorine, organophosphate, pyrethroid and phenylpyrazole classes, and the insecticide synergist piperonyl butoxide. Researchers found that currently used pyrethroid pesticides were, not surprisingly, at the highest levels with varied concentrations. Fipronil and permethrin, both currently used, were found in 40 percent and 89 percent of homes respectively. However, the researchers found that long discontinued pesticides like DDT and […]

(Beyond Pesticides, May 19, 2009) Nearly six months after federal scientists began issuing restrictions to protect salmon and steelhead in the Pacific Northwest and California, the U.S. Environmental Protection Agency (EPA) has yet to take even the first step toward implementing these protections. This delay follows almost a decade of legal wrangling in which a coalition of environmental and fishing groups, led by the non-profit public interest law firm Earthjustice, won a court order. Tell EPA to stop its foot-dragging and protect salmon and steelhead from toxic pesticides. The six pesticides that scientists have reviewed so far are some of the most dangerous chemicals used today. All six””chlorpyrifos, diazinon, malathion, carbaryl, carbofuran, and methomyl””are neurotoxic and pose serious risks to both humans and wildlife. While many of these pesticides have been phased out for residential use, they continue to expose wildlife and farmworkers through their use in agriculture. Thirty-one more chemicals will undergo review by scientists at the National Marine Fisheries Service (NMFS) in the next three years. The new restrictions require EPA to prohibit application of the six pesticides in or near salmon and steelhead habitat. They also require EPA to prohibit application when the weather may cause the […]

(Beyond Pesticides, March 5, 2009) A new study published in the March 2009 issue of Environmental Health Perspectives finds that pesticide combinations cause more harm to endangered salmon than ndividual pesticide exposure. This means that single-pesticide risk assessments required by the Environmental Protection Agency (EPA) inadequately assess hazards. Mixtures of organophosphate and carbamate pesticides are commonly detected in freshwater habitats that support threatened and endangered species of Pacific salmon. According to the researchers from the National Oceanic and Atmospheric Administration (NOAA) Fisheries and Washington State University, these pesticides inhibit the activity of acetylcholinesterase (AChE) and thus have potential to interfere with behaviors that may be essential for salmon survival. The researchers measured brain AChE inhibition in juvenile coho salmon exposed to sublethal concentrations of the organophosphates diazinon, malathion, and chlorpyrifos, as well as the carbamates carbaryl and carbofuran. The pesticides were tested individually and in combination. They plotted AChE levels on a curve to determine whether the toxicologic responses to binary mixtures were additive, antagonistic (lesser than additive) effect, or synergistic (greater than additive). The authors observed addition and synergism, with a greater degree of synergism at higher exposure concentrations. Several combinations of organophosphates were lethal at concentrations that were […]

(Beyond Pesticides, December 16, 2008) According to a new study, published in the December 2008 issue of Environmental Health Perspectives by researchers at Columbia University’s Mailman School of Public Health, pregnant women continue to be exposed to pesticides in the home. In fact, 75% of the sampled homes of pregnant women in inner-city New York are contaminated with piperonyl butoxide (PBO), a pesticide synergist linked to cancer and other health problems. Following the Environmental Protection Agency’s phase-out agreements with the manufacturers of organophosphate insecticides chlorpyrifos and diazinon in 2000 and 2001, the Columbia University researchers sought to determine the impact of the new regulations on pest infestation levels, pesticide use, and pesticides measured in indoor air samples. They enrolled 511 pregnant women from inner-city New York between 2000 and 2006. Permethrin, a pyrethroid insecticide; PBO, a pyrethroid synergist; chlorpyrifos; and diazinon were measured in 48-hr prenatal personal air samples. Data on pest infestation and pesticide use were collected via questionnaire. 88% of women report using pesticides during pregnancy and 55% report using higher-exposure pesticide applications (spray cans, pest bombs and/or professional pesticide applicators). Self-reported pest sightings and use of higher-exposure applications increased significantly after the regulations were implemented. PBO, cis-, […]

(Beyond Pesticides, December 8, 2008) A new study by a National Institute for Occupational Safety and Health (NIOSH) researcher finds the pesticide poisoning incidence rate among U.S. agricultural workers is thirty-nine times higher than the incidence rate found in all other industries combined. The study, “Acute Pesticide Poisoning Among Agricultural Workers in the United Sates, 1998-2005,” published in the December issue of the American Journal of Industrial Medicine, is believed to be the first detailed multi-state assessment of acute pesticide poisonings among agricultural workers. From 1998 to 2005, a total of 3,271 cases of acute occupational pesticide-related illness/injury among agricultural workers were identified in ten states. According to EPA, the Worker Protection Standards are designed to reduce the risk of injury or illness to agricultural field workers resulting from exposure to pesticides. Although the WPS was expanded in 1995 and in 2005 EPA developed a new WPS How to Comply (HTC) Manual, the NIOSH findings indicate that agricultural workers continue to have an elevated risk for acute pesticide poisoning. Furthermore, female agricultural workers experienced nearly twice the risk of pesticide poisoning of male agricultural workers. The most common factors that contributed to pesticide exposure included off-target drift, early reentry into […]

(Beyond Pesticides, November 17, 2008) A toxic soup of the most commonly used pesticides frequently detected in nature can adversely affect the environment and decimate amphibian populations even if the concentration of the individual chemicals are within limits considered safe, according to University of Pittsburgh research published in the online edition of Oecologia. The results of this study build on a nine-year effort to understand potential links between the global decline in amphibians, routine pesticide use, and the possible threat to humans in the future. Amphibians are considered an environmental indicator species because of their unique sensitivity to pollutants. Their demise from pesticide exposure could foreshadow the fate of less sensitive animals, according to study author Dr. Rick Relyea, Ph.D., an associate professor of biological sciences in the University of Pittsburgh’s School of Arts and Sciences. Leopard frogs, in particular, are vulnerable to contamination; once plentiful across North America, their population has declined in recent years as pollution and deforestation has increased. Dr. Relyea exposed gray tree frog and leopard frog tadpoles to small amounts of the ten pesticides that are widely used throughout the world. Dr. Relyea selected five insecticides: carbaryl, chlorpyrifos, diazinon, endosulfan, and malathion; and five herbicides: […]

(Beyond Pesticides, October 6, 2008) University of Pittsburgh researchers have found that the commonly used insecticide malathion can decimate tadpole populations by altering their food chain. The study, published in the October 1 edition of Ecological Applications, finds that gradual amounts of malathion that were too small to directly kill developing leopard frog tadpoles instead sparked a biological chain of events that deprived them of their primary food source. As a result, nearly half the tadpoles in the experiment did not reach maturity and would have died in nature. The results build on a nine-year effort to investigate whether there is a link between pesticides and the global decline in amphibians, which are considered an environmental indicator species because of their sensitivity to pollutants. According to the researchers, their deaths may foreshadow the poisoning of other less environmentally-sensitivespecies, including humans. According to the U.S. Environmental Protection Agency (EPA), malathion is the most commonly used insecticide in U.S. agriculture and the third most commonly used insecticide in the U.S. home and garden sector. It has been detected in the wetlands where frogs and other amphibians live. The researchers created simulated ponds from 300-gallon outdoor tanks containing wood frog and leopard frog […]

(Beyond Pesticides, October 1, 2008) Last week, a jury awarded $1 million in compensation to an organic farm in Santa Cruz, California, whose herbs were contaminated by pesticides. The jury found that organophosphate pesticides, used on vegetables on neighboring farms, drifted onto the organic farm, leaving the herbs in violation of organic standards. The organic farm, Jacobs Farm Del Cabo, filed a lawsuit against the pesticide application company Western Farm Service, Inc. in May 2007. The suit sought an order to stop Western Farm Service from spraying pesticides that contaminate crops at Wilder Ranch State Park, where Jacobs Farm leases 120 acres. Compensation for losses, in the sum of $1 million, which resulted from pesticide contamination, was also sought. The court ruled that pesticide applications by Western Farm Service resulted in trespass of the pesticides onto Jacobs Farm and were legally determined to be a nuisance depriving Jacobs Farm of the right to use and enjoy the land, caused by negligence on the part of Western Farm Services. The jury found that Jacobs Farm was damaged in the sum of $1 million and Judge Robert Atack ordered judgment in that amount against Western Farm Service. The organophosphates, chlorpyrifos, diazinon, and […]

(Beyond Pesticides, September 29, 2008) A new study by Pesticide Action Network North America (PANNA) confirms that school children in Florida continue to breathe air contaminated by hazardous pesticides. Air monitoring near South Woods Elementary School in Hastings detected four agricultural chemicals in the air, often at levels that pose unacceptable risks to children. The report mirrors the results of a similar study released in April 2007, confirming the existence of an ongoing problem of pesticide contamination that is more extensive than previously documented. The new test results show that in October, November and December 2007 the air in Hastings was contaminated with the pesticides endosulfan, diazinon https://www.beyondpesticides.org/gateway/pesticide/diazinon.htm, trifluralin and chlorothalonil. Of these, two are neurotoxins, two are suspected carcinogens, and three are or will soon be banned in Europe. Endosulfan, the pesticide of greatest concern, was found in 87% of the samples, and, on several days, exceeded levels of concern. The air monitoring was conducted by concerned area residents using a “Drift Catcher” device, a simple air sampling system that sucks air into tubes, where the pesticides are absorbed and captured. The tubes are then sent to a laboratory, where the chemicals can be identified and the concentrations measured. […]

(Beyond Pesticides, August 19, 2008) Three toxic pesticides used heavily in the United States ”” chlorpyrifos, diazinon, and malathion ”” harm children and farmworkers, poison wildlife, and taint food and drinking water, and despite well-documented hazards, the Environmental Protection Agency (EPA) allows homeowners, farmers and others to use these poisons in ways that harm salmon and steelhead. Coupled with public pressure, a recent scientific analysis from the National Marine Fisheries Service (NMFS) could force EPA to adopt new restrictions on the use of these pesticides in the Pacific Northwest and California. In a draft study — called a “biological opinion” — released on July 31, 2008, NMFS concluded that chlorpyrifos, diazinon, and malathion are contaminating rivers and streams jeopardizing protected salmon and steelhead. Please urge NMFS and EPA to adopt strong measures to protect Pacific salmon from these poisons. It is their responsibility under the Endangered Species Act. Please send an email addressed to both: Jim Lecky Director of Office of Protected Resources, NMFS [email protected] James Gulliford Assistant Administrator, US EPA Headquarters [email protected] You can be sure that chemical companies are working to ensure the unabated use of their products. Make sure the voice of the public is heard. Harmful […]

(Beyond Pesticides, August 14, 2008) The first report released by the National Marine Fisheries Service (NMFS) as a result of a lawsuit (NCAP et al. v. NMFS, No. 07-1791 RSL) settlement reveal “overwhelming evidence” to suggest that the pesticides chlorpyrifos, malathion, and diazinon increase the chance of extinction for protected salmon and steelhead. The report on the three pesticides and their effects on threatened fish is the first in what is expected to be a four year review process of 37 pesticides. “These are pesticides that EPA [the Environmental Protection Agency] has swept under the rug for years. These are three that stood out as the nastiest of the (pesticides) that are still in widespread use,” said Joshua Osborne-Klein, an attorney for Earthjustice who represented the plaintiff, Northwest Coalition for Alternatives to Pesticides (NCAP). The 377-page report is clear in its conclusion that current use patterns of these three toxic pesticides threaten the salmon and steelhead protected by the Endangered Species Act, but it does not delineate the next steps to reduce the risk. A report on mitigation measures, which could include restrictions or bans, is expected in the next few months. The timing of the report coincides with other […]

(Beyond Pesticides, July 29, 2008) On July 28, 2008, a coalition of farmworker, public health, and environmental groups -including Beyond Pesticides- filed a lawsuit challenging the Environmental Protection Agency’s (EPA) decision to allow continued use of the toxic pesticide diazinon. “The lack of action on diazinon is yet another example of EPA’s failure to fully consider the risks to farmworkers, children, and the environment from pesticides,” said Jay Feldman, executive director of Beyond Pesticides. The lawsuit is part of the coalition’s multi-year campaign to protect children, farmworkers, and wildlife from the most dangerous pesticides and to reform EPA’s lackadaisical regulation of public and environmental health. The coalition has filed a series of lawsuits targeted at the worst poisons on the market: diazinon is near the top of that list. “EPA’s system for protecting the public from the dangers of pesticides like diazinon is broken,” said Joshua Osborne-Klein, an attorney for Earthjustice, the public interest law firm that represents the coalition. “The agency should be protecting farmworkers and children, not the profits of pesticide manufacturers.” Diazinon is an organophosphate pesticide that originates from nerve gases the Nazis developed during World War II. Farmworkers who are exposed to diazinon can suffer muscle […]

(Beyond Pesticides, June 10, 2008) According to scientists at Simon Fraser University in British Columbia, Canada, real-world pesticide combinations, such as those found in Canada’s Nicomekl River, may contribute to latest decline in the region’s endangered salmon populations. The study, published in Environmental Science and Technology (ES&T), a publication of the American Chemical Society, examines the impact by simulating the river’s low-level pesticide mixture to examine its effects on fish. The study used steelhead trout, a member of the salmon family, and found that the pesticide mix can deaden the trout’s sense of smell. This could harm the fish’s ability to avoid predators, find mates, and migrate back to sea, the researchers say, and could contribute to the threatened and endangered status of salmon species. “Most laboratory studies examine the effects of a single chemical, often at high concentrations, but real-world streams contain a mixture of chemicals at very low concentrations,” Keith Tierney, Ph.D., the study’s coauthor, told ES&T. Dr. Tierney and his colleagues re-created river water in the laboratory under controlled conditions with carefully measured levels of the 10 most frequently occurring pesticides in British Columbia’s Nicomekl River. The mixture contained four major classes of pesticides, including the commonly […]