(Beyond Pesticides, April 28, 2026) In Chemical Research in Toxicology, researchers from the Universitat Rovira i Virgili in Catalonia, Spain highlight the threats to human and environmental health with “combined exposures to multiple chemical toxicants, including industrial chemicals, heavy metals, pesticides, endocrine-disrupting chemicals (EDCs), and per- and polyfluoroalkyl substances (PFAS).” As these compounds are encountered in mixtures in real-world settings, the resulting interaction can have additive or synergistic effects that risk assessments fail to adequately capture. As the authors point out: “This leads to a systematic underestimation of health risks, particularly for vulnerable populations. Despite robust evidence on mixture toxicity, major regulatory frameworks such as the U.S. Toxic Substances Control Act (TSCA) and the EU’s [European Union] REACH program continue to assess chemicals in isolation.” Importance and Background Environmental toxicants are ubiquitous throughout nature and within all organisms. In humans, these compounds can accumulate, referred to as ‘Body Burden’, which encompasses numerous chemicals such as pesticide mixtures. “Critically, organisms are rarely exposed to a single chemical in isolation,” the researchers note. “Rather, they continuously encounter complex mixtures of contaminants whose combined effects may differ substantially from those predicted by examining each substance individually.” As the authors explain, regulatory agencies underestimate […]

(Beyond Pesticides, April 14, 2026) A novel study mapping pesticide mixtures and cancer risk, published in Nature Health, “reveals a robust spatial association between environmental pesticide exposure risk and cancer incidence.” The team of international researchers incorporates pesticide risk modeling with Peruvian National Cancer Institute (INEN) registry data to map pesticide-induced cancer clusters in Peru, finding significant associations between pesticide mixtures and cases of carcinogenicity. The study analyzes 31 active ingredients to identify pesticide-associated cancer hotspots, none of which are classified as carcinogenic on their own by international standards. When combined as pesticide mixtures, as experienced in real-world environments, heightened risks and synergistic effects are noted. “Collectively, these findings strongly support a mechanistic [causal] link between pesticide exposure and cancer, challenging assumptions of human non-carcinogenicity derived from reductionist experimental models,” the authors state. “This study redefines the exposome [measure of all environmental, dietary, lifestyle, and social exposures of an individual] as a lineage-conditioned, mechanistically tractable framework and shows how complex pesticide mixtures can contribute to carcinogenic trajectories, with profound and far-reaching implications for global health policy and socio-ecological equity.” Background An extensive body of scientific literature connects individual pesticide active ingredients to a wide array of health and environmental effects […]

(Beyond Pesticides, April 3, 2026) A literature review published in Chemico-Biological Interactions links pyrethroid insecticide exposure to cardiac dysfunction. Through a systematic review and meta-analysis of previous research through July 2025, the authors find emerging evidence that indicates pyrethroids induce adverse cardiovascular effects through pathways of inflammation, oxidative stress, and myocardial injury (damage to the heart muscle). “The meta-analytic findings of this study offer the first comprehensive overview of the cardiotoxic effects of pyrethroids, encompassing electrophysiological, biochemical, inflammatory, and redox disturbances,” the researchers state. “Together, these findings indicate that pyrethroids disrupt cardiac electrical stability and induce cytotoxic [killing or damaging cells], inflammatory, and oxidative damage.” Study Importance Scientific literature connecting various classes of pesticides to adverse health effects continues to mount, with synthetic pyrethroids emerging as a class of increasing concern. Due to their broad spectrum of activity, pyrethroids are extensively used in agriculture and land management but can persist in the environment and can cause neurotoxicity, endocrine disruption, reproductive dysfunction, and cardiovascular health implications. (See here and here.) In particular, pyrethroid exposure is associated with increased risks of developing cardiovascular disease. (See studies here, here, here, and here.) “Cardiac electrical activity is regulated by mechanisms that are highly sensitive […]

(Beyond Pesticides, March 12, 2026) The science connecting pesticide exposure to neurotoxicity continues to mount. A study in Discover Toxicology highlights neurotoxic pollutants as significant environmental threats, showcasing the adverse impacts on vertebrates’ neurological health from pesticides, including organophosphates, carbamates, and organochlorines. “These substances disrupt normal neurophysiological functions by impairing neurotransmission, generating oxidative stress, provoking neuroinflammation, and initiating neuronal cell death,” the authors say. They continue, “Such disturbances are linked to cognitive deficits, motor impairments, and abnormal neural development.” Neurological conditions can manifest as headaches, muscle weakness, tremors, paralysis, coordination challenges, vision loss, hallucinations, vertigo, seizures, memory loss, slurred speech, trouble breathing with minimal exertion, and more. The range of adverse effects from low-dose, long-term exposure and low-dose (or subchronic) exposure during developmental phases of life raises serious questions about the adequacy of the regulatory review of pesticides, which focuses on acute high and lethal dose exposure. One study on the neurotoxicity of pesticides, published in Chemosphere, concludes, “New regulatory and preventive measures to mitigate the neurotoxic effects of pesticides are needed.” (See also Daily News.) Even at low concentration, chronic exposure to pesticides and other environmental contaminants “poses serious ecological and health concerns” that occur as these chemicals “bioaccumulate […]

(Beyond Pesticides, February 18, 2026) Research finds that widespread agricultural pesticide use increases chronic dietary exposure in poultry and leads to adverse reproductive effects, despite meeting legal residue limits. As published in Poultry Science by researchers in Poland, the study analyzes low-dose exposure of roosters (Gallus gallus domesticus) to the fungicide tebuconazole (TEB), the insecticide imidacloprid (IMI), and the weed killer glyphosate (GLP) individually and in mixtures, with all concentrations at or below the maximum residue limits (MRLs) established by the European Union (EU). “Sub-MRL pesticide exposure impaired male reproductive function, with the most pronounced effects observed following combined treatments,” the authors report. They continue: “[E]xposure resulted in reduced semen quality, decreased fertility and hatchability, and increased embryo mortality, particularly in groups receiving IMI alone or in combination. These functional impairments were accompanied by detectable pesticide residues in reproductive tissues and body fluids, as well as modulation [modification/alteration] of local and systemic immune parameters.” The results of the experiment highlight how combined pesticide exposure, resulting from common use of multiple pesticide active ingredients concurrently, produces “stronger and more persistent reproductive effects than individual compounds, indicating mixture-specific toxicity.” This study is particularly important, as it represents the chronic exposure to MRL-compliant […]

(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 16, 2025) Through a literature review and data analysis of almost 2,000 soil samples, the authors of a recent study find negative effects on the presence of plant-beneficial bacteria (PBB) in soil with pesticide exposure, particularly bacteria with plant growth-promoting traits that are essential for crop productivity. The study, published in Nature Communications, by researchers at China’s Shaoxing University and Zhejiang University of Technology, adds to scientific literature documenting the effects of pesticides on soil health. “Pesticides not only reduce PBB diversity as individual factors, but they also exert synergistic negative effects with other anthropogenic factors… further accelerating the decline in PBB diversity,” the researchers state. They continue, “Increased pesticide risk also leads to a loss of functional gene diversity in PBB about carbon and nitrogen cycling within essential nutrient cycles, and a reduction in specific amino acid and vitamin synthesis.” In elucidating these impacts, this study reinforces previous research that connects pesticide use with deteriorating soil health, further stressing the urgent need for adopting a systems-wide transition to organic agricultural and land management practices. Soil Microbiome Health As the authors discuss, plant–soil–microbe interactions play a critical role in the growth, development, and overall health of plants, […]

(Beyond Pesticides, November 17, 2025) Beyond Pesticides ramped up its campaign to transition parks, playing fields, and schoolyards to organic land management after the release of a study showing synergistic effects of glyphosate (Roundup) and urea fertilizers on earthworms and soil health. The organization’s network is asking Mayors nationwide to lead the transition, pointing to the inadequacy of the current system of regulating pesticides based on risk assessments of individual chemicals or individual chemical families. Chemicals interact, causing increased impacts on human, ecological health, and biodiversity. Moreover, humans, other species, and the biosphere rarely experience exposure to single chemicals or chemical families; exposure to multiple chemicals is the rule, not the exception.   Synergistic effects associated with the use of the weedkiller glyphosate have been implicated in several studies showing magnified adverse impact in soil organisms and in mixture with other chemicals:  The extensive use of glyphosate is linked to effects on nontarget soil organisms, with the risks to soil ecosystems widely studied. (See here, here, here, here, and here.)   One study shows that frequent application in tropical systems of glyphosate “reduced soil macroarthropod richness by 21% and altered community composition.   “A recent global risk assessment of glyphosate further estimated that 67−93% of soils pose high risks to Collembola [springtails] and 43−67% pose medium to high risks to […]

(Beyond Pesticides, November 4, 2025) A study of earthworms published in Environmental Science & Technology highlights how chemical mixtures can have both synergistic and species-specific effects, threatening the soil microbiome and overall soil health. In exposing two species, Eisenia fetida and Metaphire guillelmi, to the weed killer glyphosate alone and in combination with urea, a form of synthetic nitrogen fertilizer, the researchers find enhanced toxicity with co-exposure as well as varying health effects between the two species. These results emphasize the need to test a wide variety of nontarget organisms for impacts from environmental contaminants, since species, even within the same genus or family, can exhibit vastly different effects. Glyphosate, as one of the most widely used herbicides worldwide, is highly researched, with a multitude of studies linking the weed killer to effects on humans, wildlife, and soil ecosystems. Since simultaneous application of glyphosate and urea frequently occurs in agriculture, the effects of this mixture on earthworms are crucial for understanding the overall impacts on soil health. In exposing the two species to the individual compounds and as a mixture, the authors report increased glyphosate residues in earthworm gut contents, reduced body weight, aggravated intestinal tissue damage, sharply decreased digestive […]

(Beyond Pesticides, October 21, 2025) A study, published in International Journal of Hygiene and Environmental Health, calculates cumulative dietary pesticide exposure and finds a significant positive association between pesticide residues in food and urine when analyzing over 40 produce types. The research uses data for 1,837 individuals from the 2015–2016 National Health and Nutrition Examination Survey (NHANES) and compares them to biomonitoring samples of the participants. According to the researchers, “Here we show that consumption of fruits and vegetables, weighted by pesticide load, is associated with increasing levels of urinary pesticide biomarkers.” They continue, “When excluding potatoes, consumption of fruits and vegetables weighted by pesticide contamination was associated with higher levels of urinary pesticide biomarkers for organophosphate, pyrethroid, and neonicotinoid insecticides.” The NHANES data is derived from a national biomonitoring survey from the U.S. Centers for Disease Control and Prevention (CDC), which collects information about consumption of fruits and vegetables as well as urine samples. Background As the study authors explain: “Hundreds of millions of pounds of synthetic pesticide active ingredients are used every year in the United States, and pesticide exposure can occur through food, drinking water, residential proximity to agricultural spraying, household pesticide use, and occupational use. Pesticide […]

(Beyond Pesticides, October 15, 2025) The latest Scientific Investigations Report for 2025 from the U.S. Geological Survey (USGS), entitled “National Water Quality Program: Multidecadal Change in Pesticide Concentrations Relative to Human Health Benchmarks in the Nation’s Groundwater,” finds moderate concentrations of five pesticides, with the highest percentages in agricultural wells, and concentrations of the carcinogenic soil fumigant DBCP (1,2-dibromo-3-chloropropane), which also causes infertility, that are greater than the maximum containment level, despite being banned over 45 years ago. These results highlight the persistence of pesticides used in agriculture and the elevated risks of pesticide contamination in agricultural areas. This report monitors concentrations of pesticides in well networks across the U.S. in decadal intervals, with this last one incorporating data ranging from 1993-2023. Additionally, DBCP in one well network in the San Joaquin-Tulare River Basin in California continues to be assessed due to previous levels exceeding the human health benchmark (HHB) established by the U.S. Environmental Protection Agency (EPA). The limitations of the study are disclosed in the text of the report. As the authors state: “Only pesticides with an HHB were included in the multidecadal pesticide change analysis… The total number of pesticides included in this study is less than […]

(Beyond Pesticides, October 9, 2025) The 42nd National Forum Series, The Pesticide Threat to Environmental Health: Advancing Holistic Solutions Aligned with Nature—scheduled to begin on October 29, 2025, 1:00-3:30pm (Eastern time, US), will focus on aligning land management with nature in response to current chemical-intensive practices that pose a threat to health (see Pesticide-Induced Diseases Database), biodiversity, and climate. The virtual Forum is free to all participants. ➡️ Register here. The Call to the Forum, states: We are all affected by how land is managed, food is grown, and nature is protected. Different experiences and perspectives may bring us to care about health and the environment and the devastating adverse effects of pesticides and toxic substances. However, ensuring a livable future requires us to cultivate a collective concern about daily decisions on the management of our personal and community spaces, the practices used to grow the food we buy, and the care that we as a society give to complex and fragile interrelationships that sustain the natural world on which we depend.   The Pesticide Threat to Environmental Health: Advancing Holistic Solutions Aligned with Nature challenges participants—as concerned families, community residents, purchasers of products, advocates for policy, decision makers, and workers—to think […]

(Beyond Pesticides, September 17, 2025) A study in Environmental Science & Technology finds additive effects of a synthetic pyrethroid insecticide (cypermethrin) and two fungicides (azoxystrobin and prochloraz) on biological control, biomass of major invertebrate trophic groups (position in food web), and soil ecosystem processes in arable systems (land suitable for growing crops). The study authors further highlight the failure of pesticide regulations to consider elaborate trophic interactions and pesticide mixtures, as well as additive and synergistic effects within their assessments, calling attention to the complexity of real-world exposures and the lack of research to fully understand the implications of chemical use for agricultural and land management purposes. “Arable systems have a high dependence on diverse natural biota to support pest control, soil bioturbation, and nutrient recycling,” the researchers write. These communities rely on a balance of organisms within various trophic levels in order to function and provide vital ecosystem services. Disruptions caused by environmental contaminants, such as pesticides to nontarget organisms, impact entire ecosystems and overall biodiversity. As the authors state, current risk assessments underestimate the real-world risks of petrochemical pesticides and synthetic fertilizers that, despite a wide body of science connecting exposure to deleterious health and environmental effects, are […]

(Beyond Pesticides, September 15, 2025) With residues of the widely used weed killer glyphosate (Roundupᵀᴹ) in the food supply long documented, scientific attention has turned to the synergistic effects of the weedkiller— a magnified effect greater than the individual chemical effects added together. The authors of an article in World’s Poultry Science Journal write, “The synergistic toxic effects of commercial glyphosate formulations and their bioaccumulation in animal tissues are often overlooked in current safety assessments.” Following up on a previous action, Beyond Pesticides is telling Congress and the U.S. Environmental Protection Agency (EPA) that the agency must consider the effects of pesticides in the context in which they are used and promote the organic alternative.  Glyphosate residues in animal feed, as well as in water and through other exposure routes from food generally and residential areas, pose risks to both animal and human health, as these residues can bioaccumulate. As previously examined by Beyond Pesticides, the effects of pesticides are not limited to the crops to which they are applied. Synergistic effects of multiple chemical exposures are the rule, rather than the exception.   With poultry, the herbicide enters the production system through residues in genetically engineered feed. An earlier article in Scientific Reports concludes that glyphosate’s […]

(Beyond Pesticides, September 12, 2025) A team of Argentinian researchers conducted a study published in Environmental Toxicology and Pharmacology of the combined effects of the herbicide glyphosate and the pyrethroid insecticide cypermethrin. The researchers observed significantly higher apoptosis in cells exposed to the mixtures than to the individual pesticides—a synergistic response. Apoptosis, also known as programmed cell death, is a standard way that tissues handle damaged cells to remove threats to their function. The researchers sought to investigate the cellular toxicity of each chemical, individually and in combination, and assessed whether the effects of the mixture were additive or synergistic. Additive effects occur when two individual chemicals amplify the same sort of response, often because the chemicals have similar structures. Synergism can occur when chemicals have different mechanisms of action but work together to create more powerful effects. Mixtures of pesticides are the least-studied area of research conducted for regulatory purposes. While regulators provide instructions to applicators regarding which pesticides can be applied together and combined in tank mixtures, there is no control over how pesticides travel through the environment once applied, as they flow through the air as spray drift, lodge in soils and water, and are incorporated into […]

(Beyond Pesticides, September 10, 2025) After being criticized by the chemical industry and allied agribusiness and service industry groups on the Make America Healthy Again (MAHA) report in May, the strategy document, released yesterday, has tamped down efforts to reform government programs that regulate pesticides. There are no specific recommendations on improving the regulation of pesticides. Rather, the strategy appears to embrace business-as-usual and could even ramp up government efforts to tout the need for pesticides and claims that current regulatory reviews are effective and comprehensive. In a section of the strategy entitled “Increasing Public Awareness and Knowledge,” the document says: “EPA, partnering with food and agricultural stakeholders, will work to ensure that the public has awareness and confidence in EPA’s pesticide robust review procedures and how that relates to the limiting of risk for users and the general public and informs continual improvement.” This is at odds with the earlier MAHA assessment report which identified pesticides as substances of concern that, citing deficiencies in chemical reviews, “may be neglecting potential synergistic effects and cumulative burdens, thereby missing opportunities to translate cumulative risk assessment into the clinical environment in meaningful ways.” While the earlier report, Make Our Children Healthy Again: Assessment, […]

(Beyond Pesticides, September 10, 2025) Published earlier this year, a review of over 1,700 studies in Nature Communications finds pesticides affect a diverse range of nontarget organisms and contribute to global biodiversity loss. The authors* reveal “negative responses of the growth, reproduction, behaviour and other physiological biomarkers within terrestrial and aquatic systems” for nontarget plants, animals, and microorganisms. “To our knowledge, there has been no systematic and overarching synthesis of how different types of pesticides affect the diversity of multiple non-target eukaryotic and prokaryotic organisms across all trophic levels,” the researchers write. They continue, “Furthermore, current syntheses have not considered how the impacts of pesticides differ globally across climatic zones or for major mechanisms of exposure, such as those acting in aquatic or terrestrial environments.” In particular, pesticide regulatory risk assessments analyze a limited range of model species, including rats, zebrafish, clawed frogs, honeybees, and earthworms, among others. As such, they are unlikely to capture the variety of responses to pesticide exposure seen across the diversity of species and communities found in both managed and natural systems,” the authors state. *Authors include Beyond Pesticides 2023 National Forum speaker Dave Goulson—see the Daily News on his keynote address here. Research Results […]

(Beyond Pesticides, September 8, 2025) Beyond Pesticides today called on Congress to require the U.S. Environmental Protection Agency (EPA) to incorporate real world science into its evaluation of pesticide safety calculations by recognizing that daily exposure involves multiple chemicals and synergistic interactions— a magnified effect greater than the individual chemical effects added together. The organization cites numerous scientific studies that call public attention to this issue; that a realistic assessment of the human and environmental harm potentially caused by pesticides cannot be evaluated based on single-chemical, single-species tests. Given the numerous complexities associated with this type of assessment, the group points to organic land management in agriculture and residential areas as a more cost-effective approach, sending this message to Congress: EPA must consider the effects of pesticides in the context in which they are used and with reference to the organic alternative. A recent study, covered by Beyond Pesticides in its Daily News, found that the presence of Varroa mites in combination with the neonicotinoid insecticide imidacloprid increases the risk of bee mortality and disrupts the larval gut microbiome. The study found synergy (a greater combined effect) between Varroa destructor, a parasitic mite that attacks and feeds on honey bees, and imidacloprid. The findings were published last […]

(Beyond Pesticides, August 21, 2025) The presence of Varroa mites in combination with the neonicotinoid insecticide imidacloprid increases the risk of bee mortality and disrupts the larval gut microbiome, according to a study of the synergy (a greater combined effect) between Varroa destructor, a parasitic mite that attacks and feeds on honey bees, and imidacloprid. The study in Pesticide Biochemistry and Physiology adds to the growing body of science on the severely declining bee population by investigating the toxic effects of both the parasites and pesticide stressors in honey bees (Apis mellifera). “Given that V. destructor may increase bees’ sensitivity to imidacloprid by compromising their physiological health and immunity, this study systematically assesses the effects of V. destructor infestation and imidacloprid exposure on honey bee survival, detoxification enzyme activity, and gut microbiota,” the authors explain. The intestinal tract and gut microbiome are crucial for digestion, metabolism, nutrient absorption, immune regulation, and pathogen defense. Within honey bees, the gut microbiome is “highly susceptible to external environmental stressors, such as pesticide exposure and parasitic infections [and] these disturbances can lead to microbial imbalances, ultimately affecting bee health.” (See studies here and here.) Previous research earlier this year, captured in Daily News Variability […]

(Beyond Pesticides, August 14, 2025) A review in Clinical and Experimental Obstetrics & Gynecology links various classes of environmental pollutants including pesticides and per- and polyfluoroalkyl substances (PFAS), both of which Beyond Pesticides has extensively covered, to adverse effects on the female reproductive system and common mechanisms of toxicity. These chemicals “disrupt the hypothalamic-pituitary-gonadal axis (HPG), impair ovarian function, and contribute to reproductive dysfunction through mechanisms such as oxidative stress, hormonal disruption, and epigenetic [gene expression or behavior] modifications,” the authors say. This leads to menstrual irregularities, infertility, and pregnancy complications, as well as increases in the risk of reproductive system disorders such as endometriosis, polycystic ovary syndrome (PCOS), and ovarian cancer, among others. “Additionally, transgenerational effects mediated by epigenetic modifications, germ cell damage, and placental transfer may adversely affect offspring health, increasing the risk of reproductive dysfunction, neurodevelopmental disorders, metabolic diseases, and cancer,” the researchers explain. This study, integrating recent epidemiological and experimental findings, provides an overview of major chemical classes that threaten women’s health and highlights the need for immediate action. As the authors point out, female reproductive health is important not only for those who choose to plan for a family but also for the overall well-being […]

(Beyond Pesticides, July 25, 2025) The scientific literature shows that microplastics (MPs) and pesticides, both ubiquitous throughout the environment, have synergistic effects that threaten aquatic organisms. This means the combined toxicity of the two substances is greater than the sum of two individual exposures. The most recent study to demonstrate this, published in Ecotoxicology, focuses on the impacts of MPs and chlorpyrifos (CPF), a widely used organophosphate insecticide, on cladocerans, a group of microcrustaceans. As Beyond Pesticides has previously reported, microplastics are found in all environments and threaten not only human health but all wildlife in both aquatic and terrestrial ecosystems. The universal distribution of plastics means that they cannot be avoided. Humans and other organisms take up plastics in the form of microparticles and nanoparticles by inhalation, ingestion, and skin contact every day. Microplastics are about the width of a human hair; nanoplastics are much smaller, about twice the width of a DNA strand. Larger pieces of plastic are ground down to these tiny sizes by weathering, temperature, biological processes, and chemical conditions. (See additional Daily News coverage on the health and environmental hazards of plastics here, here, and here.) The authors of the current study, in exposing two […]

(Beyond Pesticides, July 18, 2025) A study in Royal Society Open Science shows intraspecific differences (between individuals of a species) in wild bumblebees (Bombus vosnesenskii) exposed to an herbicide (glyphosate), a fungicide (tebuconazole), and an insecticide (imidacloprid), with gut microbiome health as a factor. “Wild pollinator declines are increasingly linked to pesticide exposure, yet it is unclear how intraspecific differences contribute to observed variation in sensitivity, and the role gut microbes play in the sensitivity of wild bees is largely unexplored,” the authors explain. “Here, we investigate site-level differences in survival and microbiome structure of a wild bumble bee exposed to multiple pesticides, both individually and in combination.” In collecting 175 individuals of this wild, foraging species from an alpine meadow, a valley lake shoreline, and a suburban park and exposing them to a diet with individual pesticides and mixtures, the researchers assess the varying lethal and sublethal effects that can occur with pesticide exposure. Between the three sites, the survival differences “emphasize the importance of considering population of origin when studying pesticide toxicity of wild bees” and highlight how pesticide sensitivity not only varies between species but within individuals of the same species with site-specific impacts. (See previous Daily […]