(Beyond Pesticides, February 3, 2026) In analyzing the direct and indirect effects of pesticides that act simultaneously upon macrozoobenthos communities (invertebrates living in or on sediment) in standing small water bodies (SWBs) in Germany, researchers find high risks to biodiversity and ecosystem functioning. Published in Hydrobiologia, the experiment finds high risks to invertebrates and highlights how both direct and indirect effects are vital to comprehensive assessments of pesticides. While typically overlooked in regulatory reviews, SWBs are defined as shallow standing or running freshwaters “with a surface area of less than 50 hectares (ha),” such as lakes or ponds, including farm ponds, as well as headwater streams, springs and flushes, and ditches. SWBs are biodiversity hotspots that contribute to numerous ecosystem services and are adversely affected by agricultural land use effects such as pesticide contamination. “Holistic assessments of pesticide effects on invertebrate communities in standing small water bodies have, however, not yet been successful,” the authors note. To address this, the researchers developed an indicator for evaluating pesticide impacts on macrozoobenthos communities, populated with aquatic invertebrates, such as snails, worms, crayfish, and clams, through indirect toxic effects on aquatic plants called INPOND: INdirect Pesticide impacts ON Diversity in standing small water […]

(Beyond Pesticides, January 29, 2026) A study of ecotoxicity risk from neonicotinoid insecticides, published in Environmental Chemistry and Ecotoxicology, finds that chemicals in this class of pesticides, particularly dinotefuron, increase the body temperature of Apis mellifera (European honey bee) and subsequently accelerate the translocation (movement) of contaminants into hives by the honey bees. The research indicates that neonicotinoids affect acetylcholine receptors in the nervous system, leading to an “elevation in octopamine titer [neurotransmitter/hormone] and subsequent increase in the body temperature of honeybees,” the authors report. They continue: “Furthermore, we observed a considerable upregulation [of] the expression of a flight gene flightin in honeybees. This gene accelerates the homing behavior of honeybees and facilitates the rapid and frequent transport of neonicotinoid pesticide-contaminated nectar to the hive.” In describing their results, the researchers state: “For the first time, we propose that neonicotinoid pesticides accelerate the homing ability of honeybees by affecting their body temperature, which leads to more neonicotinoid pesticides entering the hive and explains the prevalence of neonicotinoids and at higher concentrations in terms of their effects on the honeybee body temperature that enhances homing.” This accelerated movement of neonicotinoid pesticides into honey bee hives heightens the toxicity risks to honey […]

(Beyond Pesticides, January 28, 2026) A study published last year in Science of The Total Environment reports widespread pesticide contamination collected from beehive monitoring across the European Union (EU). “This study has produced the first EU-wide distribution map of terrestrial pesticide contamination and demonstrates widespread pesticide contamination of EU environments,” the authors write. The study, led by a cohort of citizen-scientists, documents pesticide drift across the European continent. The results found that 188 of the 429 targeted pesticide compounds were detected in noninvasive, in-hive passive samplers (APIStrips) across 27 EU countries between May and August of 2023. This finding emerges at a time when public health and environmental advocates raise concerns about the European Union’s backtracking on commitments to reduce pesticide use by 2030, although the European Commission announced in July 2025 that “the use and risk of chemical pesticides has decreased by 58% by 2023 [from the 2015-2017 reference period], while the use of more hazardous pesticides fell by 27% over the same period.” Results The study results reveal that no landscape is safe from pesticide exposure, despite the European Union having better regulations in place than most other countries/regions. The researchers found: “There was no sample site where […]

(Beyond Pesticides, January 27, 2026) A three-part study published in Molecular Neurodegeneration draws a connection between Parkinson’s disease (PD) and the organophosphate chlorpyrifos. “Since chlorpyrifos (CPF) exposure has been implicated as a risk factor for PD, we investigated its association to incident PD and if this association is biologically plausible using human, rodent, and zebrafish (ZF) studies,” the researchers state. Together, the three experiments “strongly implicate exposure to CPF as a risk factor for developing PD,” as the authors find that exposure, even at very low concentrations, causes selective toxicity to dopaminergic neurons that are critical for functions of movement, cognition, emotion, and more. The results reveal that in humans, long-term residential exposure is associated with more than a 2.5-fold increased risk of developing PD, while exposure in mice causes “motor impairment, dopaminergic neuron loss, microglial activation, and an increase in pathological α-synuclein (α-syn) [proteins primarily found in the brain].” The researchers continue, “Using ZF, we found that CPF-induced dopaminergic neuron loss was at least partially due to autophagy dysfunction and synuclein accumulation, as knocking down LC3 [a protein chain] recapitulated the dopaminergic neuron loss.” These three studies highlight the association of CPF with increased risks for developing PD, as […]

(Beyond Pesticides, January 23, 2026) A fish called a lake skygazer (Culter dabryi) shows accelerated aging when exposed to chronic low doses of the insecticide chlorpyrifos, according to a powerful study by researchers from several Chinese institutions, as well as Carleton University in Canada and the University of Notre Dame in Indiana. The study, in Science, finds that chronic low-dose exposures resulting in the accumulation of sublethal effects over time cause deterioration of molecular, cellular, and organ functions that reduce lifespan and fertility. In the study, the fish showed reduced survival in a “dose- and physiological age-dependent manner,” while acute high doses did not have these effects, the authors write. Because the mechanisms researchers focused on are conserved throughout vertebrates, “even low doses of pesticide may pose long-term risks to longevity” in thousands of species, including humans. The regulation of pesticides is based on laboratory animals’ exposure to acute high doses of a chemical–generally measured as the dose that kills half the test animals within 96 hours of exposure. Thus, the assumption that guides the calibration of “safe” or allowable levels of exposure is that lower doses, even if chronic, pose no threat. The current study unambiguously refutes that assumption, […]

(Beyond Pesticides, January 22, 2026) Published in Environmental Research, a review of experimental studies by George Mason University researchers regarding reproductive toxicity of neonicotinoid pesticides (neonics) in rodents finds that all studies “demonstrated negative impacts on male reproductive endpoints in association with neonic exposure, including reduced sperm count, reduced sperm motility, and altered sperm morphology.” These studies highlight how neonics, designed to target insect nervous systems, can affect mammalian systems, representing risks to human health. Criteria for inclusion in the review was restricted to endocrine and/or reproductive outcomes in male rats and mice, leading the authors to analyze 21 studies published between 2005 and 2025. “This narrative review employed a systematic approach and determined that neonics exhibit reproductive toxicity in male rats and mice, particularly impairing testicular function and sperm quality at high exposure levels,” the researchers report. They continue, “Despite species-specific differences, the conserved nature [core mechanism] of reproductive processes across mammals supports the relevance of these findings to human health.” Study Background Neonicotinoids are a class of insecticides that share a common mode of action that affects the central nervous system of insects, resulting in paralysis and death. There is a wide body of science on the effects […]

(Beyond Pesticides, January 21, 2026) The data in the annual U.S. Department of Agriculture (USDA) pesticide residue report, released earlier this month, continues to show a pattern of pesticide residues in the majority of food tested by the U.S. Department of Agriculture (USDA). Health advocates say low-level pesticide residues in the food supply within legal limits raise serious hazard concerns, while USDA, in its Pesticide Data Program–Annual Summary, Calendar Year 2024, points to controversial residue standards as a measure of safety. The USDA report finds that over 57 percent of tested commodities contain at least one pesticide and that less than one percent of detected residues violate the legal limit set as a tolerance by the U.S. Environmental Protection Agency (EPA). Residues allowed under tolerances establish allowable pesticide use patterns in agriculture that, beyond dietary risks, result in exposure to farmworkers, farmers, waterways, wildlife, and the broad ecosystem in which they are used. (See Eating with a Conscience for a list of pesticides allowed in food production by commodity.) With respect to the preponderance of evidence on adverse health and ecological effects of cumulative exposure to toxic agrichemicals, including pesticides, Beyond Pesticides has called for the transition to organic agriculture. […]

(Beyond Pesticides, January 20, 2026) With Monday’s celebration and affirmation of Martin Luther King Jr.’s life and legacy, the question of adequate protection of the people and communities at greatest risk from toxic chemical production, transportation, use, and disposal looms large. This is especially true with the current diminished federal regulatory authority and Bayer/Monsanto’s U.S. Supreme Court challenge of chemical manufacturers’ responsibility to warn users of their products of hazards like cancer. Actions Being Taken In response to the chemical industry campaign to deny people the right to sue under longstanding failure to warn law, groups are calling for public support of U.S Senator Cory Booker’s (D-NJ) bill, Pesticide Injury Accountability Act(S. 2324) seeks to uphold this right  to sue. The groups are calling on the public to “Tell your U.S. Senator to co-sponsor S. 2324, the Pesticide Injury Accountability Act.” This bill will amend the Federal Insecticide, Fungicide, and Rodenticide Act of 1972 (FIFRA) to create a federal right of action for anyone who is harmed by a toxic pesticide.  In an additional action in honor of Martin Luther King, Jr., Beyond Pesticides is calling on the public to “Tell members of Congress to ensure that with the termination of environmental justice programs at EPA, they […]

(Beyond Pesticides, January 17, 2026) The public’s right to sue chemical manufacturers that do not warn of product hazards will be up for review by the U.S. Supreme Court later this year, the justices decided Friday. Bayer/Monsanto is challenging billions of dollars in jury verdicts, which affirm longstanding jurisprudence that holds manufacturers responsible for disclosing hazards even when not required to do so by regulatory authorities. In the case being challenged, Durnell, John L. v. Monsanto, the injured party successfully argued that a chemical manufacturer has a duty to warn of potential hazards on their product label even though the U.S. Environmental Protection Agency (EPA) does not require the warning. The failure-to-warn in the Durnell case resulted in a jury verdict of $1.25 million, and the total number of jury verdicts and settlements on similar cases may amount to over $10 billion in liability if the Supreme Court upholds the lower courts and hundreds of thousands of other plaintiffs with the same claim. The cases involve exposure to the weed killer glyphosate (RoundupTM, which is the most widely used herbicide in the U.S. and worldwide, has been classified as posing a possible risk of cancer by the International Agency for […]

(Beyond Pesticides, January 13, 2026) An important study in Nature Microbiology challenges the entrenched assumption in the chemical industry and among regulators that synthetic chemicals can be targeted for specific uses and have limited effects beyond those uses. The categorization of chemicals into pharmaceuticals, pesticides, and industrial chemicals masks their commonalities and combined potential for deep harm to biological systems. In particular, the effects of the onslaught of xenobiotics (not naturally produced) on human gut microbiota are of increasing concern. The study, by an international team including researchers at the National Institute of Environmental Health Sciences, Cambridge University, and Heinrich Heine University in Germany, tested a set of xenobiotics, including pharmaceutical, pesticide, and industrial compounds, against 22 human gut bacteria. Using both in silico (computers) and in vitro (laboratory experiments), they found 168 chemicals that exerted inhibitory effects on the gut bacteria. Most of these interactions had not been previously reported. Of the xenobiotic categories, fungicides and industrial chemicals were the most influential. The researchers note that the “pervasive use” of synthetic chemicals “and environmental persistence have led to pollution levels exceeding the planetary boundary for stable and resilient Earth systems” [emphasis added] and that “safety assessments for these chemicals […]

(Beyond Pesticides, January 12, 2026) With a pattern of chemical industry deception of independent scientific review, and the recent retraction of an influential Monsanto ghostwritten article (April 2000) on the weed killer glyphosate (Roundup™), Beyond Pesticides and its network are calling for oversight hearings in Congress. At issue is the reliance of the U.S. Environmental Protection Agency (EPA) on industry data and agency collusion with chemical manufacturers on its decisions. Beyond Pesticides is questioning the underlying reliability of the data, in addition to limitations of the regulatory review process in meeting its statutory duty to protect health and the environment. In addition to the deception, key underlying deficiencies are EPA’s failure to evaluate endocrine disrupting pesticides and synergistic effects of chemical mixtures. Given these deficiencies and the cost effectiveness of organic land management and crop production Beyond Pesticides is asking Congress to hold oversight hearings to determine how EPA can eliminate the use of toxic pesticides that are no longer needed to grow food or manage landscapes cost-effectively.  Critically, the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and EPA’s pesticide program allow toxic chemicals to be dispersed, resulting in widespread negative impacts, without regard for the availability of cost-effective and profitable alternatives that are eco-sensitive and health protective. Consideration of the essentiality of synthetic substance […]

(Beyond Pesticides, January 6, 2026) Editor’s Note: We begin the new year with a clarion call for meaningful strategies to eliminate petrochemical pesticide and fertilizer use, based on the preponderance of science that documents both the hazards of their use and the abject failure of regulations in the U.S. and worldwide to accurately account for their harm to health and the environment. Over the holiday season, we have been cheered by letters to the editor, one from a pediatrician in Missoula, Montana and another from a student in Cedar Falls, Iowa, calling for the elimination of pesticide use in their communities. This call for action in communities targets the places where we live, work, learn, and play—where critical decisions on the use of poisons and contaminants are being made daily in our parks, playing fields, schools, open space, and other public properties. We have the tools to eliminate pesticide use with defined organic practices and compatible materials. We should accept nothing less. The scientific study we write about today (below) details an outrage of huge proportions, a synergistic effect of chemical interactions of widely used synthetic pyrethroid insecticides in combination with environmental stressors—resulting in adverse effects 70 times greater than when […]

(Beyond Pesticides, December 23, 2025) A literature review of military personnel reveals broad evidence linking their toxic exposure to poorer mental health outcomes. The review, written by medical professionals and researchers throughout the U.S. and published in Medical Care, analyzes the existing literature on associations between military environmental exposures (MEEs) to contaminants, including pesticides, and mental health (MH) outcomes. “We used evidence mapping methodology to systematically search MEDLINE, Embase, PsycINFO, and PTSDpubs for studies of toxic exposure during military service and psychiatric outcomes, which included psychiatric diagnoses, psychiatric symptoms, and neurocognitive functioning,” the authors explain. The 49 studies in the review, covering chemical exposures for military members, involve chemical munitions from the Gulf War era and Agent Orange from the Vietnam War era that are associated with symptoms of depression, PTSD, and anxiety, among others. “Overall, available evidence suggests that veterans reporting environmental toxic exposures may report relatively high levels of mental health needs,” the researchers report. They continue: “To date, no studies have synthesized the existing literature linking MEEs to MH outcomes. In this review, we systematically organize and describe peer-reviewed literature studying associations between MEEs and MH and neurocognitive outcomes (ie, diagnoses and symptoms). Our review focused on […]

(Beyond Pesticides, December 19, 2025) While still the exception rather than the norm, a growing movement of Christmas tree farmers across the United States is demonstrating that organically managed systems can also be applied when choosing a tree during this holiday season. Health and environmental advocates across the country are calling for a transition away from toxic pesticide dependency during the holiday season. Beyond Pesticides maintains a webpage, Christmas Trees and Pesticides, and Center for Biological Diversity and Alliance of Nurses for Healthy Environments urged the U.S. Environmental Protection Agency and U.S. Department of Health and Human Services to conduct a “special review of pesticides used on Christmas trees.” The groups sent a letter on December 4, the day the National Christmas Tree was lit at the White House, specifically citing the need to review the pesticides chlorpyrifos, carbaryl, dimethoate, bifenthrin, chlorothalonil, glyphosate, hexazinone, imidacloprid, simazine, and 2,4-D, among others. Christmas is one of the most celebrated holidays in the United States, with Christmas trees grown on Christmas tree farms being brought into homes as part of the celebration. On average, Americans purchase 25 to 30 million Christmas trees annually, according to the National Christmas Tree Association; however, certified organic […]

(Beyond Pesticides, December 18, 2025) A study in the International Journal of Hygiene and Environmental Health finds peak concentrations of organophosphate pesticide (OP) metabolites in the urine of pregnant mothers 6-12 hours after consuming contaminated fruits and vegetables. “High detection rates were observed for dimethylthiophosphate (DMTP, 96%), dimethylphosphate (DMP, 94%), diethylphosphate (DEP, 89%), and diethylthiophosphate (DETP, 77%) among 431 urine samples taken from 25 pregnant women, over two 24-hr periods, early in pregnancy,” the researchers report. The levels of metabolites within the urine correlate to the consumption of foods treated with organophosphate pesticides, highlighting the importance of adopting an organic diet—particularly for pregnant individuals and their children. “In 2009–2010, 80 pregnant women were recruited from Ottawa, Canada for the Plastics and Personal-care Product use in Pregnancy (P4) Study,” the authors say. “A subset (n = 25) collected multiple spot urines (up to 10 each; total n = 431) over two 24-h periods in early pregnancy—one weekday and weekend day—while logging their food consumption beginning 24 h prior to the first urine void and continuing through the following 24-h urine collection period.” This is the first study looking at the variability of organophosphate metabolites within 24 hours in maternal urine, giving […]

(Beyond Pesticides, December 15, 2025) With recent proposals by the U.S. Environmental Protection Agency (EPA) to register new pesticides that under international standards are classified as PFAS (Per- and Polyfluoroalkyl Substances), people and organizations are calling for Congress to reverse the agency’s action. Beyond Pesticides announced an action to Tell EPA and Congress to eliminate PFAS chemicals, including those used in pesticides.  In its action Beyond Pesticides pointed to the long history of allowing pesticides on that market that have long residual lives and bioaccumulate in the environment, causing generations of exposure and adverse effects to health and ecosystems. DDT (Dichlorodiphenyltrichloroethane) exemplifies the generational effect of a toxic pesticide whose effects ha endured for decades, even though it was hailed as a miracle solution for agriculture and public health. PFAS, with a wide variety of uses—from nonstick pans to waterproofing fabrics to firefighting foams to pesticides—might similarly lead to the characterization as a “miracle” chemical. PFAS also share the less beneficial characteristics of DDT. Like DDT, PFAS are persistent, leading to the nickname “forever chemicals,” and they are highly toxic. EPA links PFAS to an increased risk of many health effects, including decreased fertility and hypertension in pregnant people; increased risk of prostate, […]

(Beyond Pesticides, December 12, 2025) A study concluding that the weed killer glyphosate did not cause cancer was retracted last week after it was revealed in lawsuit documents that the authors did not disclose their relationship with Monsanto/Bayer. The editor-and-chief, Martin van den Berg, PhD of Regulatory Toxicology and Pharmacology, which published the article 25 years ago, wrote in the journal, “Concerns were raised regarding the authorship of this paper, validity of the research findings in the context of misrepresentation of the contributions by the authors and the study sponsor and potential conflicts of interest of the authors.”  The study, titled “Safety Evaluation and Risk Assessment of the Herbicide Roundup and Its Active Ingredient, Glyphosate, for Humans” and coauthored by three researchers in New York, The Netherlands, and Canada, was referred to as a “Landmark glyphosate safety study” in a recent article by U.S. Right to Know.   While this retraction not only sheds light on Monsanto’s influence through ghostwriting, it adds to the wide body of evidence regarding the regulatory deficiencies currently in place. The revelation is a reminder of related incidents in which Monsanto (Bayer) and other companies have wielded excessive influence at the U.S. Environmental Protection Agency (EPA), undermining the integrity of the science needed to inform the regulatory decisions that safeguard health and the environment. (See Daily News Corruption Problems Persist at EPA.)  EPA Deficiencies  In addition to the initial registration process, the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) requires that EPA conduct a registration review of all pesticide […]

(Beyond Pesticides, December 10, 2025) On November 21, 2025, the International Agency for Research on Cancer (IARC), a branch of the World Health Organization (WHO), designated the endocrine-disrupting herbicide atrazine (as well as the herbicide alachlor) as “probably carcinogenic to humans.” Manufactured by the multinational, China-based pesticide corporation Syngenta, atrazine has been linked to various adverse health effects and runoff into waterways across the continental United States for years. Tyrone Hayes, PhD, researcher and professor of Integrative Biology at the University of California, Berkeley, who studies the endocrine-disrupting properties of atrazine and other chemicals, has said that atrazine induces cancer by turning on the enzyme aromatase. Dr. Hayes told conferees of Beyond Pesticides’ 31st National Pesticide Forum that: “[W]hat is concerning about aromatase expression and estrogen in mammals is breast cancer and prostate cancer. With regard to prostate cancer, there is an 8.4-fold increase in prostate cancer in men who work in atrazine factories and bag atrazine. There is at least one correlational study, which I didn’t publish, that shows women whose well water is contaminated with atrazine are more likely to develop breast cancer than women who live in the same community, but don’t drink the well water. (Kettles, […]

(Beyond Pesticides, December 9, 2025) In the Journal of Environmental Quality, researchers at the U.S. Department of Agriculture (USDA) report that a 4-year organically managed corn-soybean-oat system reduces nitrogen (N) loads by 50 percent with corn and soybean yields “equivalent to or higher than conventional [chemical-intensive] in most years.” The findings from a 7-year study comparing nitrate loss in organic and chemical-intensive management found that organically managed perennial pasture reduced nitrogen loads significantly. The study, which focused on nitrate pollution in agriculture that harms biodiversity, threatens waterways, drinking water, and public health, and releases nitrous oxide (an extremely potent greenhouse gas), was conducted at USDA’s National Laboratory for Agriculture and the Environment. Organic and regenerative organic farmers and businesses posit that if commodity crops can be grown in organically managed systems with competitive yields, then this supports their argument for alternative systems not only feasible but economically sustainable and responsible. Background and Methodology The researchers note that, in the eastern and U.S. Midwest, “subsurface tile drainage” (the practice of manually draining fields below the surface soil to assist fields that are otherwise challenging to drain due to wet areas/highly compacted soils) has exacerbated nitrogen and nutrient runoff, ultimately leading to diminished soil health. […]

(Beyond Pesticides, December 5, 2025) A study published this month in Environmental Pollution analyzes the role of neonicotinoid insecticide exposure on bird populations, finding a significant negative effect of imidacloprid use on insectivorous bird abundance. In comparing the effects of the insecticide imidacloprid on bird abundance in France before and after the 2018 ban, the researchers show a weak recovery of bird populations after 2018. The persistent nature of imidacloprid, however, as well as the continued use of other petrochemical pesticides that have adverse effects on bird species, continues to impact populations of all types of birds and other wildlife, leading to cascading impacts on biodiversity.    “Our study shows that imidacloprid is a major covariate of the abundance of birds, in addition to other pesticides that are also negatively related to bird populations, and that these effects are not uniform across species,” the authors report. They continue in saying that the relationship between neonicotinoids and bird abundance varied across bird diets, as “the abundance of insectivorous birds was consistently lower under increasing pesticide use, in particular imidacloprid.” Background As shared in the study and on Beyond Pesticides’ Birds page, bird species can be exposed to pesticides directly through ingestion […]

(Beyond Pesticides, December 4, 2025) In a news release last week on November 26, 2025, the U.S. Environmental Protection Agency (EPA) “issued a comprehensive fact-check addressing dangerous misinformation circulating about EPA’s recent pesticide approvals” that, according to health and environmental advocates, continues to deceive the public about the true risks for health and the environment from petrochemical pesticides including, but not limited to, per- and polyfluoroalkyl substances (PFAS). Also published on November 26, coverage titled The EPA Is Embracing PFAS Pesticides. These Are The Health Risks in Time further highlights EPA’s deficiencies and the threats of PFAS, which Beyond Pesticides has extensively covered. (See here and here.)  The controversy erupted as a result of EPA’s latest proposal to allow a new fluorinated pesticide to the list of four other similar compounds now widely available for use in homes and gardens, buildings, and agriculture. The newest pesticide proposed for EPA registration, epyrifenacil (agricultural weed killer), joins cyclobutrifluram (soil fungicide/nematicide), isocycloseram (household and agricultural insecticide), diflufenican (lawn and agricultural weed killer), and trifludimoxazin (agricultural weed killer), making a total of five PFAS pesticide proposals this year that have been associated with national and worldwide contamination of food, land, and water. Two of these, cyclobutrifluram and isocycloseram, have been approved. “Instead of constraining the use of fluorinated pesticides—persistent and highly toxic […]

(Beyond Pesticides, December 3, 2025) Childhood cancers are on the rise globally; in the U.S. cancer is the second most common cause of death in children between one and 14 years old, and the fourth most common in adolescents. A recent study of Nebraska pesticide use and pediatric cancer incidence by researchers from the University of Nebraska Medical Center and the University of Idaho Department of Fish and Wildlife Sciences found positive associations between pesticides and overall cancer, brain and central nervous system cancers, and leukemia among children (defined as under age 20). The study’s lead author, Jabeen Taiba, PhD, of the University of Nebraska Medical Center, will discuss the study results on December 4, 2025, at the second session of Beyond Pesticides’ 42nd National Pesticide Forum, The Pesticide Threat to Environmental Health – Advancing Holistic Solutions Aligned with Nature. The first session recordings and materials are available here. The authors’ emphasis on evaluating mixtures, and their innovative technical methods for doing so, highlight the direction environmental health research and regulation must take. Studying pesticides singly is an inadequate approach, according to the authors, because pesticides are not applied individually anymore, but very often in mixtures of herbicides, insecticides, and […]

(Beyond Pesticides, December 2, 2025) Recently published in Reproductive Toxicology, researchers in Denmark and Iceland investigate the impacts of pesticides on sex hormones, finding that “prenatal exposure to [the insecticide] chlorpyrifos and [weed killer] 2,4-D may affect the reproductive hormones in girls, but not boys, during minipuberty, which may have long-term implications.” Based on their analysis of urinary maternal concentrations of the pesticides and their metabolites and hormone levels in infants, the authors report, “This study examined the association between maternal pesticide exposure and pituitary, gonadal, and adrenal hormones in offspring during infancy.” The sex-specific findings highlight a public health concern with potentially long-lasting transgenerational effects. “We recruited pregnant women from 2010 to 2012 in the Odense Child Cohort, including 489 mother-child pairs,” the authors state. They continue: “Maternal urinary concentrations of the generic pyrethroid metabolite 3-phenoxybenzoic acid (3-PBA), the chlorpyrifos metabolite 3,5,6-trichloro-2-pyridinol (TCPY), and the herbicide 2,4-D were measured at gestational week 28. Serum concentrations of luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone (T), estrone (E1), estradiol (E2), 17-hydroxyprogesterone (17-OHP), Androstenedione (Adione), and Dehydroepiandrosterone sulfate (DHEAS) were assessed in infancy.” The results of the analyses show that in girls, higher maternal urinary TCPY and 2,4-D concentrations are significantly […]