(Beyond Pesticides, November 13, 2024) A study in Chemosphere, conducted by researchers from the Institute of Biochemistry and Molecular Biology in Germany, reveals the varied lethal and sublethal effects of different glyphosate mixtures through tests on the South African clawed frog, Xenopus laevis (X. laevis). After exposing embryos to four glyphosate formulations, mortality, morphological defects, altered heartbeat rate, and impaired heart-specific gene expression are observed. Glyphosate, an herbicide and popular weed killer in many Roundup® products, is one of the most commonly detected pesticides in waterbodies worldwide, threatening aquatic organisms and overall biodiversity. This study investigates the effects of Glyphosat TF, Durano TF, Helosate 450 TF, and Kyleo, four formulations containing glyphosate, as compared to the effects of pure glyphosate on embryonic development in amphibians. The formulations consist of varying concentrations of the active ingredient glyphosate, as well as other active and inert ingredients. The authors share that, “Glyphosat TF contains 34% glyphosate and 10–20% d-glucopyranose, while Durano contains 39–44% glyphosate and 1–5% N–N-dimethyl-C12-C14-(even numbered)-alkyl-1-amines. In Helosate most of the ingredients are listed – 50–70% glyphosate, 1–10% isopropylamine, 1–3% lauryl dimethyl betaine, 0.25–1% dodecyl dimethylamine. Kyleo only lists the active ingredients glyphosate (27.9%) and 2,4-D (32%).” 2-cell stage embryos (early […]

(Beyond Pesticides, October 25, 2024) To better understand synergistic interactions between multiple stressors, researchers from the Helmholtz Centre for Environmental Research in Leipzig, Germany, analyze exposure to the pyrethroid insecticide esfenvalerate with two nonchemical environmental factors: elevated temperature and food limitation. In their recent publication in Environmental Pollution, the authors find the greatest synergistic effects when Daphnia magna (D. magna) are subjected to esfenvalerate under conditions experienced with climate change including lower food availability and increased temperature. D. magna, also known as daphnids or water fleas, are small planktonic crustaceans that represent an essential part of the food web in lakes and ponds. Impacts on populations of daphnids can lead to effects throughout multiple trophic levels that impact overall biodiversity. As the researchers state, “Global biodiversity is declining at an unprecedented rate in response to multiple environmental stressors… A key challenge is understanding synergistic interactions between multiple stressors and predicting their combined effects.” To study this, a Stress Addition Model (SAM), which predicts the cumulative effects of interacting stressors, was utilized and compared to laboratory data using 24-hour-old neonates of D. magna. The organisms were subjected to various conditions, singularly and in combination, including increased temperature, lower quantities of food, […]

(Beyond Pesticides, September 24, 2024) Recent commentary in Frontiers in Toxicology by two researchers, Maricel Maffini, PhD and Laura Vandenberg, PhD, highlights the pitfalls in the current regulatory systems in the United States (U.S.) for chemicals that threaten human health. Despite many advancements in science over the past few decades, and the wealth of studies that tie chemical exposure to negative health effects, risk assessments, and subsequent risk management, remain “static” and “outdated,” according to the authors. “There is increasing concern amongst public health professionals, environmental health scientists, and medical organizations about exposures to synthetic chemicals,” the researchers say. “These organizations’ concerns are based on the overwhelming evidence showing associations between chemical exposures and adverse health outcomes in human populations.” Such concerns have sparked a debate on current regulatory methods for chemicals that are present in highly used products, such as pesticides, plastic containers, and food.    The authors continue, “There are now thousands of studies showing associations between these chemicals and adverse health effects in humans including neurological disorders and learning disabilities, metabolic outcomes, infertility, thyroid dysfunction, and cancers.” Additional health effects can be seen in the Pesticide-Induced Diseases Database. Of the many harmful chemicals, per- and polyfluoroalkyl substances […]

(Beyond Pesticides, August 28, 2024) The U.S. Environmental Protection Agency’s (EPA) pesticide labeling requirements fail to adequately communicate acute toxicity levels to the public, as evidenced in a recent study of consumers published last month in the journal Nature. After evaluating whether the current three “signal” words (CAUTION, WARNING, DANGER) on pesticide products adequately convey pesticide toxicity, the authors conclude that current labeling may result in “unintended adverse effects” because it does not “effectively communicate toxicity risks to consumers.” The signal words on pesticide labels, based on laboratory animal testing for determining lethal doses, are intended to protect users of the product from exposure that can kill through inhalation, skin absorption, and ingestion of the pesticide. However, the signal words do not warn about long-effects like cancer, neurological diseases, reproductive harm, as well as other adverse effects associated with pesticide exposure. (See Pesticide-Induced Diseases Database.)   The study tests two prototype labels to evaluate the effectiveness of visual elements in communicating toxicity information, citing research in cognitive psychology that indicates visual elements, like images and graphics, are more effective for conveying information than text alone. This is particularly crucial for pesticide labels, where complex toxicity details need to be communicated quickly […]

(Beyond Pesticides, July 23, 2024) In analyzing the interactions between neonicotinoid pesticides (NNPs) and microplastics (MPs), a recent study in The Science of The Total Environment finds that neonicotinoids such as thiacloprid (THI) become more bioavailable in soils containing traditional and biodegradable plastics. Increased bioavailability, which quantifies the extent to which organisms are exposed to chemicals in soil or sediment, puts soil microbiota at risk and leaves all consumers susceptible to adverse effects in contaminated food crops. This study raises a grave deficiency, among others, in the pesticide registration and regulatory review process, which currently ignores interactions of pesticides with other contaminants, like microplastics, in the environment when conducting health and ecological effects assessments.   The researchers, from China University of Geosciences, Beijing Academy of Agriculture & Forestry Sciences, Chinese Academy of Agricultural Sciences, and University of Swat in Pakistan, chose to study thiacloprid as an example of NNPs to explore “the adsorption-desorption process and mechanism of NNPs on MPs,” as well as the main factors affecting adsorption, since these are two contaminants of concern in agricultural environments.  Adsorption [clinging to the surface] and desorption [releasing after adsorption] of thiacloprid by both traditional and biodegradable MPs, and the impact of MPs […]

(Beyond Pesticides, July 10, 2024) An article last month in Entomology Today, a publication of the Entomological Society of America, highlights the important findings of a study published earlier this year in the Journal of Insect Science. While there has been debate on whether neonicotinoid (neonic) insecticides or Varroa mites (Varroa destructor) are more detrimental to the survival of bees, evidence suggests that neonicotinoids are not only harmful individually but can increase vulnerability to parasitism from mites in western honey bees (Apis mellifera). The Entomology Today article reads: “Some researchers and organizations have pointed to neonics as directly harming bees. Others have pointed to other issues, like Varroa mite infestation, as more hazardous to honey bee populations.” There is scientific evidence supporting each claim, as both cause stress to bee species that can lead to population decline. The study in the Journal of Science, however, is “the first experimental field demonstration of how neonicotinoid exposure can increase V. destructor populations in honey bees and also demonstrates that colony genetic diversity cannot mitigate the effects of neonicotinoid pesticides.”  As the article states, “The researchers were not looking for impacts on Varroa mites at first. Instead, they were looking to understand how […]

(Beyond Pesticides, June 13, 2024) A study published in Conservation Letters, a journal of the Society for Conservation Biology, exposes critical shortcomings in the U.S. Environmental Protection Agency’s (EPA) ecological risk assessment (ERA) process for modeling the risks that pesticides pose to bees and other pollinators. For the study, “Risk assessments underestimate threat of pesticides to wild bees,” researchers conducted a meta-analysis of toxicity data in EPA’s ECOTOX knowledgebase (ECOTOX), an EPA-hosted, publicly available resource with information on adverse effects of single chemical stressors to certain aquatic and terrestrial species. The meta-analysis found that the agency’s approach, which relies heavily on honey bee data from controlled laboratory studies, drastically underestimates the real-world threats from neonicotinoid insecticides (and likely other pesticides) to native bees and other pollinators. The study “challenges the reliability of surrogate species as predictors when extrapolating pesticide toxicity data to wild pollinators and recommends solutions to address the (a)biotic interactions occurring in nature that make such extrapolations unreliable in the ERA process.” Beyond Pesticides executive director Jay Feldman remarked, “EPA’s ecological risk assessment process is fundamentally flawed and puts thousands of bee species at risk of pesticide-caused population declines and extinctions.” Mr. Feldman continued, “This underscores the urgent […]

(Beyond Pesticides, June 6, 2024) Researchers link pesticide exposure to behavioral effects on zebrafish (Danio rerio) larvae, signaling a larger issue for overall population and ecosystem effects. In a study published in Biomedicines, the authors conduct a multi-behavioral evaluation of the effects of three pesticides, both individually and as mixtures, on larvae. As the authors state, “Even at low concentrations, pesticides can negatively affect organisms, altering important behaviors that can have repercussions at the population level.” By analyzing effects on individual zebrafish with single compounds and mixtures, this study shows the dangers of pesticides in aquatic systems regarding synergy (a greater combined effect when substances mix) and the ripples created throughout entire ecosystems. Researchers from the Department of Morphology and Animal Physiology, as well as the Department of Physics, from the Rural Federal University of Pernambuco in Brazil collaborated with the Department of Biology at Indiana University in Indianapolis to perform the study. The researchers exposed zebrafish larvae to carbendazim, fipronil, and sulfentrazone to determine any behavioral effects on anxiety, fear, and spatial/social interaction for each compound separately and in combination. Each compound and mixture were applied to embryo medium, exposing fertilized zebrafish eggs. The embryos of zebrafish hatch, or […]

(Beyond Pesticides, June 4, 2024) A study published in the most recent edition of the journal Ecotoxicology and Environmental Safety documents for the first time the presence of the herbicide glyphosate in human sperm. The study looked at 128 French men with an average age of 36 years who tested positive for glyphosate in their blood. Seventy-three out of the 128 men were found to also have glyphosate in their seminal plasma. Not only that, the amount of glyphosate in seminal plasma was nearly four times higher than what was detected in the blood.   Methods  The study involved a population of 128 infertile French men from whom seminal and blood plasma samples were collected. The study was conducted at the “Pole Santé Léonard de Vinci” medical center, located centrally near Tours, France. This region is recognized for its urban characteristics as well as being a major agricultural hub, particularly for grain and wine production. The study authors note, “This area reflects the common herbicide exposure in France” and the district ranks third highest in terms of pesticide purchases. While additional qualitative data was collected, only 47 of 128 participants fully completed a questionnaire about their profession, diet (organic or […]

(Beyond Pesticides, May 15, 2024) A study published recently in the journal Environmental Research finds a significant correlation between exposure to certain pesticides and an elevated risk of inflammatory bowel disease (IBD), a chronic autoimmune condition of the gastrointestinal tract. The study, adding to the body of science on this subject, evaluates self-reported data from licensed pesticide applicators and their spouses exposed to pesticides for over 20 years. In addition, while some of the chemicals found to be most closely associated with incidents of IBD have been banned from use, they are “forever” chemicals that persist in the environment for generations. These findings demonstrate once again the failings of the current regulatory process to identify hazards before they are put into the environment. The study found evidence that exposure to several organochlorine insecticides (dieldrin, DDT, and toxaphene), as well as organophosphate insecticides (parathion, terbufos, and phorate) and herbicides (2,4,5-T, 2,4,5-TP, and metolachlor), is associated with elevated IBD risk. IBD is a generic term for diseases that result in chronic inflammation of the gastrointestinal tract, such as Crohn’s disease and ulcerative colitis. It is estimated that 6.8 million patients globally suffered from IBD in 2017. IBD may result from an imbalance […]

(Beyond Pesticides, March 21, 2024) Alarming levels of a hazardous pesticide plant growth regulator linked to reproductive and developmental effects, chlormequat, is found in 90% of urine samples in people tested, raising concerns about exposure to a chemical that has never been registered for food use in the U.S. but whose residues are permitted on imported food. Published in the Journal of Exposure Science and Environmental Epidemiology in February 2024 and led by Environmental Working Group toxicologist Alexis Temkin, PhD, a pilot study finds widespread chlormequat exposure to a sampling of people from across the country. U.S. Environmental Protection Agency (EPA) regulations only permit the use of chlormequat on ornamental plants and not food crops grown in the U.S. As explained in the journal article, “In April 2018, the U.S. EPA published acceptable food tolerance levels for chlormequat chloride in imported oat, wheat, barley, and some animal products, which permitted the import of chlormequat into the U.S. food supply.” In 2020, EPA increased the allowable level of chlormequat in food. Then in April 2023, EPA proposed allowing the first-ever U.S. use of chlormequat on barley, oat, triticale (a hybrid of wheat and rye), and wheat. Existing regulatory standards explain the […]

(Beyond Pesticides, March 11, 2024) Inside a recent disagreement between the Office of the Inspector (OIG) and the U.S. Environmental Protection Agency’s (EPA) Office of Pesticide Programs (OPP) on the agency’s review of pet flea and tick collars—leading to thousands of deaths and poisonings—is a basic question of the adequacy of pesticide regulation. The disagreement is over the cause of 105,354 incident reports, including 3,000 pet deaths and nearly 900 reports of human injury, and the February 2025 OIG report’s conclusion that “[EPA] has not provided assurance that they can be used without posing unreasonable adverse effects to the environment, including pets.” While the disagreement focuses on a number of EPA process failures, Beyond Pesticides urges that the findings advance the need for the agency to address a key element of chemical mixtures in pesticide products not currently evaluated, potential synergistic effects—the increased toxic potency created by pesticide and chemical combinations not captured by assessing product ingredients individually.  Key to the dispute is what many see as a foundational failure of EPA to evaluate the effect of pesticide mixtures and full formulations of pesticide end products, a longstanding criticism of the agency’s pesticide registration process, which focuses on pesticide products’ active […]

(Beyond Pesticides, March 6, 2024) With over 2,500 pet deaths and 900 reports of adverse effects to people, an Office of Inspector General (OIG) report, published on February 29, 2024, reveals multiple systemic failures by the U.S. Environmental Protection Agency’s (EPA) Office of Pesticide Programs (OPP), citing inadequate safety reviews of Seresto pet collars. The report, The EPA Needs to Determine Whether Seresto Pet Collars Pose an Unreasonable Risk to Pet Health, concludes, “The EPA’s response to reported pesticide incidents involving Seresto pet collars has not provided assurance that they can be used without posing unreasonable adverse effects to the environment, including pets.” At the time the animal effects made headlines in 2021, the agency defended the product’s registration, telling the media that, despite these incidents, EPA deemed Seresto collars “‘eligible for continued registration’ based on best available science, including incident data… No pesticide is completely without harm, but EPA ensures that there are measures on the product label that reduce risk.” Despite the scathing criticism, EPA maintains the position that it conducted an adequate review of the two active insecticide ingredients in the pet collars—the neurotoxic insecticide flumethrin, and the notorious neonicotinoid imidacloprid—proven to have adverse effects on the endocrine system as […]

(Beyond Pesticides, January 19, 2024) A study published in Environmental Health Perspective is one of the first to indicate a link between exposure to the herbicides 2,4-D and glyphosate and the impairment of behavioral performance (i.e., attention/inhibitory control, memory/learning, language, visuospatial processing, and social perception). These adverse effects associated with the neurotoxic impacts of pesticides on behavior have been previously documented. For example, a study in August 2023 finds oral intake (e.g., eating contaminated foods), inhalation, and dermal exposure to glyphosate lowered cognitive function scores, increased the likelihood of severe depressive symptoms, and impaired auditory (hearing) function. Although previous studies find neurotoxic effects from exposure to these herbicides, very few until now have evaluated how this neurotoxic exposure impacts neurotypical behavior among youth (children and teenagers). The ubiquitous use of glyphosate and 2,4-D use in agriculture—which leaves residues of the toxic chemicals in food and in public areas (e.g., parks and walkways) creates a creates a significant risk for exposure. Glyphosate is already implicated in or proven to lead to the development of numerous health anomalies, including cancer, while 2,4-D also has a range of potential hazards, including cancer. Therefore, studies like this help local and government officials make holistic decisions regarding the use […]

(Beyond Pesticides, January 17, 2024) Science continues to find a link between mental health and occupational (work-related) chemical exposure, with a study published in Toxicology finding an increased risk of depression among farmers exposed to pesticides. Conventional, chemical-intensive farming is a profession notorious for higher-than-average pesticide exposure occurrences, thus explaining why the study concludes that individuals within this occupation can suffer from chemically induced oxidative stress, inflammation, and lower education-based cognition that exacerbate depressive symptoms. However, besides psychological symptoms, the study indicates potential physiological issues from pesticide exposure, such as renal (kidney) and hepatic (liver) issues. Studies like this one can directly pinpoint risks of developing depression, especially among agricultural workers and landscapers who use pesticides. Usually, research on pesticide-induced diseases commonly investigates pesticide exposure concerning the development of various physical illnesses. However, previous studies show that occupational risks of developing depression are high in agriculture, where pesticide use is rampant. Acute exposure to chemicals, including organophosphate, organochlorine, triazine, and carbamate pesticides, tends to put farmers at greater risk of suicide than the general population. There is a lack of information connecting pesticide exposure to the subsequent psychological (psychiatric) effects on the general population. Although the etiology of depression—and many other psychiatric disorders—is often genetic, […]

(Beyond Pesticides, January 10, 2024) Exposure to endocrine-disrupting chemicals (EDCs) negatively impacts testicular function and may cause sperm count declines over time, according to a 2022 review published in Endocrine. The findings indicate that this occurs regardless of whether exposure is prenatal (before birth) or postnatal (after birth). More recent work from October 2023 confirms the connection between male reproductive health and exposure to organophosphate and carbamate insecticides and the weed killer glyphosate—as many pesticide products containing these chemicals are classifiable as endocrine disruptors (ED). Just last year, a meta-analysis from researchers at Mount Sinai Medical Center, the Hebrew University of Jerusalem, and the University of Copenhagen, among others, finds that the drop in global sperm count is accelerating, dropping by 51.6 percent from 1973 through 2018. The U.S. regulatory system, under the authority of the U.S. Environmental Protection Agency (EPA), has not kept pace with the science and does not fully evaluate pesticides in wide use for endocrine disruption, despite a requirement in 1996 law (the Food Quality Protection Act) to begin that testing and evaluation nearly three decades ago. In 2021, Beyond Pesticides reported that the Office of the Inspector General (OIG) for EPA issued a damning report on the […]

(Beyond Pesticides, January 4, 2024) A review published in the Journal of Neurosciences in Rural Practice finds an association between farmers’ pesticide exposure and cognitive impairment. Specifically, farmers suffer from attention deficit, lack of information processing, non-comprehension of verbal cues, slow processing speed, memory loss, sluggishness, speech difficulties, and impaired motor function. Additionally, the risk of adverse effects from exposure increases with time spent around pesticides, like in other occupational (work-related) settings. Although pesticide exposure may not be the only factor involved in cognitive impairment, exposure can work synergistically (together) with other factors, triggering neurotoxicity. Pesticides play various roles in causing or exacerbating adverse health outcomes like neurotoxic effects and chemical damage to the brain. Numerous pesticides impair neurological function, especially for chronically exposed individuals (e.g., farmworkers) or during critical windows of vulnerability and development (e.g., childhood, pregnancy). Mounting evidence over the past years shows that chronic exposure to sublethal (low) levels of pesticides adversely affects the central nervous system (CNS) and neural receptors, such as connections between nerves, the brain, enzymes, and DNA. Specifically, researchers identify agricultural chemical exposure as a cause of many adverse CNS impacts and neurological diseases, including Alzheimer’s, amyotrophic lateral sclerosis (ALS), and Parkinson’s disease. The researchers reviewed scientific articles published in […]

(Beyond Pesticides, December 19, 2023) Last week, farmworker organizations and Beyond Pesticides, represented by the Center for Food Safety, filed a petition with the U.S. Environmental Protection Agency (EPA) urging that the weed killer glyphosate be removed from the market. The petition cites 200 studies, which represent a fraction of the independent scientific literature on the hazards of glyphosate and formulation ingredients of glyphosate products. This action follows previous litigation in 2022 in which a federal court of appeals struck down EPA’s human health assessment, finding that the agency wrongfully dismissed glyphosate’s cancer risk. The farmworker groups petitioning include Farmworker Association of Florida, Organización en California de Lideres Campesinas, Alianza Nacional de Campesinas, and the Rural Coalition.   Meanwhile, verdicts against glyphosate’s manufacturer, Bayer, continue to pile up with a December jury verdict in Pennsylvania awarding $3.5 million and a November jury in Missouri ordering $1.56 billion to be paid to four plaintiffs. All link their cancer to use of the Roundup. Bayer has lost almost all of the cases filed against it for compensation and punitive damages associated with plaintiffs’ charge that its product (previously manufactured by Monsanto) caused them harm.  The petition summarizes its purpose and justification as […]

(Beyond Pesticides, August 22, 2023) A U.S. Geological Survey (USGS) and National Park Service collaborative survey report finds a harmful mixture of pollutants, including pesticides, pharmaceuticals, caffeine, methylparaben, algal toxins, and fecal and parasitic bacteria, in Pipestone Creek at Pipestone National Monument in Minnesota, U.S.— adding to evidence of widespread pesticide contamination in waterways across the U.S. Pesticide contamination in waterways is historically commonplace. A 1998 USGS analysis revealed pesticides are commonly found in all U.S. waterways, with at least one pesticide detectable. Thousands of tons of pesticides enter rivers and streams around the US from agricultural and nonagricultural sources, which contaminate essential drinking water sources, such as surface water and groundwater. As the number of pesticides in waterways increases, it has detrimental impacts on aquatic ecosystem health, especially as some pesticides work synergistically with others to increase the severity of the effect. Reports like these are significant tools for determining appropriate regulatory action to protect human, animal, and environmental health.  The survey collected water samples from Pipestone Creek, the pipestone quarries, and Winnewissa Falls, all of which are on the U.S. Environmental Protection Agency’s (EPA) list of impaired waters for turbidity (reduced water clarity) and fecal coliform bacteria (E. coli). Turbidity and fecal coliform […]

(Beyond Pesticides, November 17, 2022) A report published in Toxicology and Applied Pharmacology finds organophosphate (OP) insecticides and the coronavirus (SARS-CoV-2/Covid-19) illicit similar damage to the heart and co-occurring exposure to both can escalate cardiac (heart) injury. Previous research suggests OPs may increase the ability of SARS-CoV-2 to cause COVID-19, especially among vulnerable individuals with underlying medical conditions. OPs have a wide range of biological uses—from insecticides to flame retardants—that make these chemicals ubiquitous, significantly contributing to ecosystem contamination. These compounds have a global distribution, with evaporation and precipitation facilitating long-range atmospheric transport, deposition, and bioaccumulation of hazardous chemicals in the environment. OPs are highly toxic, originating from the same compounds as World War II nerve agents, and residues are consistently present in human and animal blood, urine, tissues, and milk. Moreover, OPs are one of the leading causes of poisoning globally. Therefore, it is vital to understand how OP exposure will impact human health in conjunction with other immunologically compromising diseases like COVID-19. Cardiovascular diseases are among the leading causes of death globally. Additionally, heart conditions are one leading cause of disability in the U.S., as research demonstrates environmental pollutant exposure can increase the risk of developing cardiovascular disease, including stroke, heart attack, heart failure, atrial fibrillation, and cardiac […]

(Beyond Pesticides, May 5, 2022) A report published in Biological Conservation finds environmental pollutants, including pesticides, pharmaceuticals, plastics, and particulate matter, adversely affect tropical terrestrial wildlife. Specifically, these contaminants can interact with one another, altering the chemical landscape of the ecosystem, and causing changes in the endocrine and microbiome systems of mammals. Since the publication of Rachel Carson’s Silent Spring (1962), global attention to the danger of pesticides has increased, with environmental agencies banning the use of legacy pesticides like organochlorines for their devastating toxic—sometimes lethal—effects. However, these chemicals can remain in the environment for decades and interact with various current-use pesticides, including organophosphates, neonicotinoids, and pyrethroids. Although many studies demonstrate that environmental pollution plays a significant role in premature deaths among humans, there is a lack of research on how environmental pollution directly affects tropical species mortality. Considering human and wildlife habitats tend to overlap, and chemical pollutants can drift from chemically treated areas, wildlife populations are more likely to experience similar health effects. With the number of chemicals in the ecosystem growing, studies like these highlight the need for pesticide policies that protect human health in addition to the integrity of the chemical landscapes accommodating wildlife. The researchers note, “Using […]

(Beyond Pesticides, January 7, 2021) Insecticides and road salts adversely interact to alter aquatic ecosystems, reducing organism abundance and size, according to a study in the journal Environmental Pollution. Pesticide use is ubiquitous, and contamination in rivers and streams is historically commonplace, containing at least one or more different chemicals. Although road salts can prevent hazardous ice formation during the colder months, the study raises critical issues regarding the adverse interaction between road salts and pervasive environmental pollutants that threaten human, animal, and environmental health and safety. Authors of the study note, “Our results highlight the importance of multiple-stressor research under natural conditions. As human activities continue to imperil freshwater systems, it is vital to move beyond single-stressor experiments that exclude potentially interactive effects of chemical contaminants.” To assess the impact of road salts and insecticides on aquatic communities, researchers created a mesocosm (controlled outdoor experimental area) to examines the natural environment under controlled conditions. These communities include zooplankton, phytoplankton, periphyton, and leopard frog (Rana pipiens) tadpoles. Researchers performed a toxicity evaluation of six insecticides from three chemical classes (neonicotinoids: thiamethoxam, imidacloprid; organophosphates: chlorpyrifos, malathion; pyrethroids: cypermethrin, permethrin). Additionally, researchers note the potentially interactive effects of these insecticides with three concentrations of […]

(Beyond Pesticides, October 30, 2020) The European Union (EU) adopted, in mid-October, a new strategy on chemicals — including pesticides — that seeks to deal with their combined (synergistic) and cumulative impacts on human and environmental health. A highlight of the new strategy is the acceleration of work, already begun across the EU, to address the “chemical cocktail” impacts of pesticides and other chemicals. Human exposures to such “cocktails” can happen through use of multiple different agricultural pesticides that can persist as residues on food, and via industrial processes and consumer products. Beyond Pesticides has insisted for years that, here in the states, the Environmental Protection Agency (EPA) has been way behind the eight ball in dealing with the potential synergistic and cumulative impacts of the pesticides its registers for use. Advocates have argued that the agency must be far more rigorous in evaluating impacts of exposures to multiple pesticides, as well as cumulative impacts. The toxicity problem the EU seeks to address is that interacting chemicals can have synergistic effects, even at very low levels — effects greater than and/or different from the expected impacts of each chemical per se. Pesticides can also have cumulative “toxic loading” effects in both […]