(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, October 8, 2024) A comprehensive literature review in Endocrines, published in September, amasses hundreds of studies on endocrine-disrupting chemicals (EDCs) that showcase adverse effects on growth, development, reproduction, and metabolism. The authors, a team of scientists and academics from Brazil, shed light on the link between EDC use and thyroid dysfunction, leading to increasingly prevalent illnesses and deadly diseases.     EDCs are any synthetic or natural compounds that hinder endocrine system functions and create harmful effects on organisms. These chemicals can impact the thyroid gland, which is vital in producing hormones and plays a role in several body functions. As the researchers state, “Several EDCs have been classified as thyroid disruptors, impairing thyroid hormone [TH] production, synthesis, metabolism, transport, and/or actions. Notably, thyroid disorders are the second most prevalent endocrine disease worldwide, with incidence increasing significantly in recent years.” The authors continue, “[S]tudies have correlated this rise in thyroid dysfunctions and cancers with increased exposure to EDCs. Although many EDCs are linked to thyroid dysfunction, this review focuses on the deleterious effects of plasticizers, organochlorine pesticides, and per- and poly-fluoroalkyl substances on thyroid function. These contaminants are commonly found in food, water, and everyday products.” This review helps […]

Image: Art Page submission from Sara Grantham, “Sunflower Pollinators”  (Beyond Pesticides, August 23, 2024) A study in Science of The Total Environment calculates and compares pesticide risk in 594 wild bee species associated with crops in North America. Current pesticide risk assessments that analyze effects on bees primarily focus on a limited subset of species and do not provide comprehensive protection of all wild bees. “Species commonly proposed as models for pesticide risk assessments may not accurately represent risk for those bee species facing the highest potential risk in agricultural contexts,” the authors postulate. The researchers continue, “This study presents a novel approach to characterize and compare the relative potential pesticide risk among wild bee species of their association with crops in North America using suites of intrinsic bee traits to quantify species’ vulnerability and extrinsic factors based on the toxic load of crops for bees and the strength of each species’ association with those crops.” In considering multiple factors that vary by species and determining potential harm to each from pesticide exposure, this study highlights the inadequacies of the current risk assessment process used by the U.S. Environmental Protection Agency (EPA).    The system for risk assessment for pesticides that […]

(Beyond Pesticides, August 21, 2024) A literature review, published this month in the Journal of Agricultural and Food Chemistry, explores levels of pesticide residues found in samples of human urine with environmental exposure and dietary intake and confirms prior findings about the benefits of an organic diet. Similar to past findings, lower concentrations of chemicals are detected in the urine of participants who report eating an organic diet. By analyzing 72 scientific research studies published between 2001 to 2023, the review assesses routes of exposure and “explores urinary concentrations and detection frequency of metabolites of organophosphates and pyrethroids, as well as herbicides such as 2,4-D and glyphosate,” the authors say. While “exposure to pesticide residues is influenced by a variety of demographic factors, including occupation, agricultural practices, seasonal variations, residence, diet, age, and gender,” the authors say, the concentrations of pesticides and their metabolites in human urine highlights the disproportionate risk to certain groups as well as the overall threat to the health of humans and the environment. Pesticide exposure can occur from dermal/skin contact or inhalation, through residence or work, and with dietary intake. “Pesticides in urine can be detected as parent compounds, specific metabolites corresponding to a specific […]

(Beyond Pesticides, August 7, 2024) Using mass spectrometry techniques, researchers in Luxemburg and France detect 69 biomarkers of pollutants and pesticides—12 of which are banned—in hair samples from over 200 French children. This study, published in Environment International, is the first to target over 150 biomarkers in a single hair sample, which “represents the most comprehensive assessment of chemical exposome in humans,” the authors say. All children in the study were 3.5 years old and recruited from the Étude Longitudinale Française depuis l’Enfance (ELFE) [French Longitudinal Study since Childhood] cohort in the country of France, a major pesticide consumer in Europe. The ELFE survey is a joint project between the French Institute for Demographic Studies (INED) and the National Institute of Health and Medical Research (INSERM), which provides the first comprehensive national scientific investigation of children in France by following them from birth to adulthood. Through analysis of hair samples from children in the ELFE cohort, this study evaluates pesticide exposure and compares it with prenatal exposure data from their mothers while also, according to the scientists, “investigat[ing] the roles of children’s biological sex and geographical differences as possible determinants of exposure.” Exposure to pesticides during early childhood poses significant […]

(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 26, 2024) In addition to maternal (mothers) exposure, children experience exposure to pyrethroid insecticides earlier in life as levels significantly increase post-natal (after birth), according to a study published in Frontiers in Public Health. This study is one of the few studies to investigate pyrethroid exposure concentrations in the urine of newborns and children within their first year of life. However, this research reiterates what many other studies demonstrate on pyrethroids’ impacts on children’s health, primarily due to their notorious neurotoxic properties. The findings indicate that exposure to pyrethroids during pregnancy and early childhood exposure has links to adverse health effects, including neurodevelopmental delays (e.g., autism), behavioral issues (e.g., attention deficit [hyperactivity] disorder), and endocrine disruption (e.g., delay in puberty). Pesticide exposure during pregnancy is of specific concern as health effects for all life stages can be long-lasting. Just as nutrients are transferable between mother and fetus, so are chemical contaminants. Studies find pesticide compounds in the mother’s blood can transfer to the fetus via the umbilical cord. Therefore, pesticide exposure during pregnancy affects both the mother and child’s health. Beyond Pesticides has covered a variety of pregnancy risks from pesticides and other toxic chemicals, including these in just […]

(Beyond Pesticides, January 24, 2024) A study published in Environmental Sciences Europe finds that 2,4-D, pyrethroid (PRY), and organophosphate (OP) pesticides increase the risk of cancer through oxidative stress (OS). The study highlights that pesticides that increase cancer risk also raise inflammation biomarkers that indicate damage to organs (e.g., liver) via oxidative stress. Additionally, different cancers show different sensitivities to pesticides; thus, cancer risk changes with exposure concentration and pattern. Despite a plethora of studies linking cancer and pesticide exposure, very few cover the mechanisms involved in cancer development, including OS. Only five to ten percent of cancers are hereditary. However, environmental or lifestyle factors, like chemical exposure, can make an individual more susceptible to cancer development through gene mutation. In fact, a vast amalgamation of research links cancer risk to pesticide exposure, which augments the risk of developing both common and rare cancers. Therefore, studies like this highlight the importance of understanding how pesticide use can increase the risk of latent diseases, which do not readily develop upon initial exposure. Using data from the National Health and Nutrition Examination Survey (NHANES), researchers investigated the link between the risk of several cancers and pesticide exposure. The researchers also thoroughly evaluated […]

(Beyond Pesticides, October 17, 2023) In the past month, Paris, France has witnessed a surge in bed bug populations. From public transportation to hotels, hostels, and movie theatres, bed bugs are posing a threat to the city’s two million residents and potentially a broader global population as the infestation spreads.   This resurgence of bed bugs in Paris is not unique. For centuries, these pests have been both adaptable and persistent, presenting an enduring challenge to pest control. However, the current surge in bed bug infestations is not merely a revival of a longstanding problem; it is a complex issue intertwined with the development of resistance to insecticides, mainly through a mechanism known as knockdown resistance. This mechanism, along with three other main resistance mechanisms, has enabled these insects to defy chemical-intensive control methods  Knockdown resistance is a significant factor contributing to the resistance exhibited by bed bugs to insecticides, especially pyrethroids. The mechanism plays a central role in countering the action of these insecticides, which target the nervous system of bed bugs, causing paralysis and eventual death. Knockdown resistance provides the genetic adaptation that provides bed bug populations with resistance to insecticides. It inhibits the effectiveness of certain insecticides. Bed […]

(Beyond Pesticides, October 10, 2023) In recent years, the effects of climate change have become more frequent and more severe, from extreme weather events to rising sea levels. But perhaps one of the most insidious consequences of a warming planet is the way it influences the spread of diseases, often hitting marginalized communities the hardest. This is no more evident than in the case of malaria, where the disease transmission through the Anopheles stephensi mosquito serves as a dire warning of the challenges caused by a changing climate. As this deadly vector of disease expands its territory, it is clear that pesticide-intensive approaches are poorly equipped to cope with the threat as insect resistance to chemical controls steadily grows.  Native to South Asia, the Anopheles stephensi mosquito has been on a relentless journey, crossing continents from the Arabian Peninsula to East Africa and deeper into the African continent. The mosquito’s ability to quickly adapt to new environments, bolstered by shifting climate patterns, illustrates how global warming affects disease vectors. Matthew Thomas, PhD, emphasizes, “Anopheles stephensi has higher thermal tolerance and a capacity to transmit at higher temperatures than Anopheles gambiae [another malaria-spreading mosquito]. This is significant when considering climate change […]

(Beyond Pesticides, September 27, 2023) A study published in Pesticide Biochemistry and Physiology finds organophosphate (OP), organochlorine (OC), and pyrethroid (PYR) pesticides have links to insulin resistance (IR) associated with metabolic disorders like diabetes, obesity, chronic kidney disease (CKD), and hypertension. Metabolic disorders are among the leading causes of morbidity and mortality, with over 11 percent (>37 million) of individuals in the U.S. having diabetes, and cases are growing by millions annually. Additionally, there is a rise in metabolic disorders among young people. Studies even find low levels of pesticide exposure during pregnancy or childhood cause adverse health effects, including metabolic disorders tied to gut microbiome disruption (dysbiosis). With increasing rates of diabetes and obesity, the two most prominent metabolic diseases in the study, cases among the global population, studies like these highlight the importance of evaluating how chemical contaminants deregulate normal bodily function through metabolic changes.  To investigate the association between pesticide exposure and insulin-related metabolic disorders in humans, researchers searched the PubMed database for articles, performing a systematic review. The study notes, “IR is defined as a pathological state in which a higher-than-normal level of insulin is required to produce the optimal response in cells.” The search generated 4,051 articles related to the topic. However, after excluding duplicates and […]

(Beyond Pesticides, September 20, 2023) Higher concentrations of a pyrethroid metabolite (3-PBA) in the body have an association with increased osteoarthritis (OA) risk among US adults, according to a study published in BMC Public Health. Regardless of analysis sensitivity and population subgroup (e.g., sex, socioeconomic status, etc.), the association between pyrethroid exposure and OA remains. Osteoarthritis is a degenerative joint disease resulting from the degradation (breakdown) of joint cartilage and underlying bone. This disease affects 1 in 7 U.S. adults and is the fourth leading cause of disability in the U.S. Unfortunately, OA is one of the most recently attributed pesticide-induced diseases associated with this dangerous class of chemical insecticides—harm to individual Americans that the U.S. Environmental Protection Agency (EPA) is not considering when it registers pesticides. To remedy the significant deficiencies in EPA’s reviews and protect residents from chronic disease, more and more communities are transitioning to safer, organic pest management practices that do not require pyrethroids and other toxic synthetic pesticides. Thus, this study and others like it highlight the need for increased monitorization of pyrethroid exposure among the general population. Using data from the 1999–2002 and 2007–2014 National Health and Nutrition Examination Survey (NHANES), this study explores the relationship between pyrethroid exposure and osteoarthritis. NHANES is […]

(Beyond Pesticides, August 30, 2023) Invasive yellow-legged hornets have been spotted near Savannah, Georgia, causing concern among agriculture officials. These hornets are known for their ability to prey on honeybees and other pollinators, and their presence in the United States is a cause for alarm. This is the first time a live specimen of this species has been detected in the open United States, according to the Georgia Department of Agriculture. The hornets, which are native to Southeast Asia, have been spotted in other parts of the world, including Europe, where they have caused significant damage to bee populations. They are considered “invasive,” which means the hornet is not native and officials expect their introduction to result in economic, environmental, or health-related damage to humans, animals, plants, or the environment. In response to the sighting in Georgia, officials are taking action to eradicate the hornets before they can cause any harm to US agriculture. One of the methods being used to eradicate the hornets is the localized use of the highly toxic insecticide cypermethrin on nests. The pesticide has been registered for use in agriculture and residential pest control since the 1970s. It kills insects such as mosquitoes, flies, ticks, […]

(Beyond Pesticides, July 20, 2023) Despite evidence of toxicity to pets from Seresto pet collars (manufactured with the neurotoxic insecticide flumethrin, as well as the notorious neonicotinoid imidacloprid), the U.S. Environmental Protection Agency’s (EPA) has announced that the popular flea and tick collars will remain on the market, but with new mitigation measures. However, advocates say that these measures will do little to protect people and pets from chemical exposure using these collars. The agency will require Elanco — the manufacturer of Seresto — to conduct enhanced reporting for various factors, including adverse symptoms, veterinary community outreach, and warnings on the product’s label. Seresto, developed by Bayer and sold by Elanco, has been linked to nearly 1,700 pet deaths, injuries to tens of thousands of animals, and harm to hundreds of people. There are nontoxic ways to protect pets from fleas and other pests while protecting human family members. Children Ignored by the Agency EPA has a history of ignoring the exposure patterns to children who come into close contact with pets and their flea collars and the potential adverse health threats, opting for warnings instead of regulatory action. In 2017, EPA issued a warning for tetrachlorvinphos (TCVP) flea collars that advised: “not […]

(Beyond Pesticides, May 5, 2023) Low level exposure to pyrethroid insecticides found in common pesticide brands like RAID and ORTHO result in neurodevelopmental damage to laboratory animals, reinforcing evidence of harm found in epidemiological studies on human exposure to these chemicals. According to research published in PNAS Nexus, mice exposed to the pyrethroid deltamethrin displayed atypical behavior similar to humans with developmental disorders. “We are not saying these mice have autism or that they have ADHD. That’s not the goal here,” said James Burkett, PhD, study coauthor and assistant professor of neuroscience in the UToledo College of Medicine. “What we are saying is that something in their brain has been altered by this exposure and it’s resulting in the same kinds of behaviors that we see in children with autism.” Scientists arrived at this determination by exposing a group of mouse mothers to consistent low levels of deltamethrin in their food during preconception, pregnancy, and lactation. The study notes that the amount of pesticide provided was “well below the benchmark dose for regulatory guidance.” A separate control group was given no pesticide in its food. Offspring from the female mice were then put through behavioral tests on social behavior, restrictive […]

(Beyond Pesticides, January 5, 2022) The use of insecticidal bed nets (IBNs) to prevent mosquito bites in malaria-endemic communities can result in resistance developing in secondary pests like bed bugs, according to research published in Parasites and Vectors. Decreased efficacy against bed bugs and other non-mosquito pests may result in misuse of both mosquito adulticides and bed nets, hampering efforts to stop the spread of malaria and other insect-borne disease. With resistance following a predicable pattern in both disease-transmitting and secondary pests, there is a critical need to embrace safer, nonchemical solutions, including both ecological and structural approaches to pest management. Researchers investigated the efficacy of untreated bed nets along with those treated with the commonly used synthetic pyrethroids deltamethrin and permethrin against both a population of insecticide-susceptible and pyrethroid resistant bed bugs. Insecticidal netting was secured between two glass jars in both an aggregation and blood meal experiment. For the aggregation experiment, fully fed bed bugs were set up to cross through the bed net to reach a darker resting location. With the blood meal experiment, unfed bed bugs were set up to cross the netting to receive a blood meal. Both experiments show the bed nets carrying little […]

(Beyond Pesticides, October 7, 2022) Pyrethroid insecticides are associated with the growing worldwide epidemic of non-alcoholic fatty liver disease (NAFLD), a condition that causes swelling of the liver and can eventually lead to cirrhosis, cancer, or liver failure. According to research published in Environmental Science and Ecotechnology, exposure to pyrethroids like bifenthrin can induce gut microbiota dysbiosis (an imbalance in microorganisms in the intestines). This dysbiosis results in abnormal lipid (fat) metabolism and subsequent accumulation of lipids in liver cells, contributing to NAFLD development. Gut microbiota plays a crucial role in lifelong digestion, immune and central nervous system regulation, as well as other bodily functions. Through the gut biome, pesticide exposure can enhance or exacerbate the adverse effects of additional environmental toxicants on the body. Since the gut microbiome shapes metabolism, it can mediate some toxic effects of environmental chemicals. However, with prolonged exposure to various environmental contaminants, critical chemical-induced changes may occur in the gut microbes, influencing adverse health outcomes. Considering NAFLD is becoming the most prevalent form of liver disease, impacting at least 25 percent of the globe, and a growing body of evidence demonstrates the significance gut microbiota play in overall health, safety analyses that currently do not consider the […]

(Beyond Pesticides, October 5, 2022) Exposure to widely used synthetic pyrethroids, present in many mosquito adulticides and household insecticides like RAID, is associated with a diagnosis of rheumatoid arthritis, according to research published in Environmental Science and Pollution Research. This is the latest pesticide-induced disease associated with this dangerous class of chemicals – a harm to individual Americans that the U.S. Environmental Protection Agency (EPA) is not considering when it registers pesticides. To remedy the major deficiencies in EPA’s reviews, and protect residents from chronic disease, more and more communities are transitioning to safer, organic pest management practices that do not require pyrethroids and other toxic synthetic pesticides. Rheumatoid arthritis (RA) is an autoimmune disease that causes systemic inflammation throughout the body, resulting in progressive damage to an individual’s joints. In the United States, roughly 1.3 million adults suffer from RA, accounting for nearly 1% of the adult population. Health care costs associated with the disease reach nearly $20 billion annually. To better understand the etiology behind the disease, an international team of researchers from China, Illinois, and Missouri analyzed data from the 2007-2014 National Health and Nutrition Examination Survey (NHANES), a long-running program that began in the early 1960s […]

(Beyond Pesticides, October 4, 2022) A study published in Environmental Pollution finds pyrethroid insecticides contribute to a secondary source of contamination in water resources. Various pyrethroids, including bifenthrin, are detectable in urban catch basins (storm drains) that collect runoff water before draining into the open environment. There is a lack of information regarding the pesticides’ presence in urban catch basins. However, pesticide contamination in water resources is historically commonplace and widespread throughout U.S. rivers and streams, with at least five different pesticides present in 90 percent of water samples. Moreover, thousands of tons of pesticides not only enter waterways (e.g., rivers, streams, lakes, oceans) around the U.S. through urban catch basins but agricultural and nonagricultural sources as well, contaminating essential drinking water sources, such as surface water and groundwater. Reports like these are essential for determining appropriate regulatory action to protect the human, animal, and environmental health from chemical toxicant contamination, especially if chemical contamination is highly detectable. The study notes, “The high detection frequency of bifenthrin and overall pyrethroid concentrations, especially for particle-bound residues, suggest that underground urban catch basins constitute an important secondary source for extended and widespread contamination of downstream surface waters by pesticides such as pyrethroids in urban […]

(Beyond Pesticides, September 1, 2022) Low level exposure to synthetic pyrethroid insecticides at 6-8 months of age is associated with language development delays in two-year old toddlers, according to research published in Neurotoxicology this month. This is the latest study to link this class of chemicals to developmental delays in young children. Despite a steady drum of concerning research, the U.S. Environmental Protection Agency (EPA) in 2019 removed a crucial “safety factor” intended to protect children’s health from synthetic pyrethroids, allowing higher levels of the insecticides to be sprayed on food, in homes, and playing fields around the country.   To investigate the impact of synthetic pyrethroids on language development, scientists enrolled 327 expectant mothers in their third trimester. The mothers, all from rural areas of China, were selected if they had no history of significant pesticide exposure or family history of serious disease. Urine samples were taken from the women during pregnancy, and from infants 6-8 months after birth. Scientists analyzed samples for concentrations of three different synthetic pyrethroid breakdown products (metabolites), including 3-phenoxybenzoic acid (3PBA), 4-fluoro-3-phenoxybenzoic acid (4F3PBA), and cis-2,2dibromovinyl-2,2-dimethylcyclopropane-1-carboxylic acid (DBCA). While 3PBA is a metabolite of many synthetic pyrethroids, 4F3PBA a more specific metabolite of cypermethrin, […]

(Beyond Pesticides, August 3, 2022) A systematic review of scientific studies on pesticides and fertility finds exposure associated with lower semen quality, DNA fragmentation, and chromosomal abnormalities. Published in the journal Andrology, the review is yet another warning from a long string of researchers sounding the alarm over the connection between global fertility and toxic chemical exposure. With data from the U.S. Centers for Disease Control and Prevention (CDC)  indicating roughly 1 in 5 couples are unable to conceive after a year of trying, and trends continuing to slope downwards, it is critical that contributing factors be identified so that protective changes can be made.   After screening over 1,300 studies, researchers narrowed their review down to 64 papers assessing semen parameters and DNA integrity after pesticide exposure. Each study is analyzed for its design, the pesticide investigated,  the population studied, controls, and reproductive effects determined. Pesticides are evaluated for their impacts to sperm quality and DNA integrity based on their chemical class. Organochlorine insecticides, which are all banned but still persistent in soil, air, water, and food in the United States, include a range of impacts to sperm quality. Higher levels of DDT or its breakdown metabolite DDE are […]

(Beyond Pesticides, May 12, 2022) A report published in Environmental Health finds that exposure to environmentally relevant concentrations of pesticides can alter gut microbial communities, as demonstrated through fecal samples. Over 300 environmental contaminants and their byproducts, including pesticides, are chemicals commonly present in human blood and urine samples. Ample evidence demonstrates that environmental contaminants, including pesticides, negatively affect the human mouth and gut microbes. However, fecal samples provide an accurate representation of the microbial community existing in the gut. These toxicants can alter hormone metabolism, which adversely affects health outcomes. Adverse health effects of environmental contaminants include reproductive and developmental defects, diabetes, cardiovascular disease, liver disease, obesity, thyroid disorders, and improper immune operation. Although studies show how chemical exposures affect human health, more research is now questioning how these toxic chemicals influence gut health. Therefore, studies like these highlight the importance of evaluating how chemical contaminants deregulate normal bodily function through microbiome changes. The report notes, “Our results highlight the need for future dietary intervention studies to understand effects of pesticide exposure on the gut microbiome and possible health consequences.” Researchers examined dietary exposure to 186 common pesticide residues in the fecal excrement to determine impacts on the microbiome among 65 twins in the United Kingdom. […]