(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 22, 2024) A screening and analysis of 36 pesticides finds traces of these chemicals in patients with “unexplained chronic kidney disease” from agricultural communities in the Indian province of Uttar Pradesh. Researchers conducting this study, published in the Journal of Toxicology and Environmental Health Sciences, identify organophosphates, organochlorines, and pyrethroids as the main culprits, building on years of existing research pointing to adverse health impacts originating from bioaccumulation of pesticides after acute and chronic exposure. Chronic kidney disease (CKD) is a condition that afflicts one in ten adults internationally, based on a peer-reviewed analysis from The Lancet. The Centers for Disease Control and Prevention (CDC) estimate that one in seven U.S. adults (or roughly 35.5 million people) have CKD, with as many as nine in ten adults with the disease undiagnosed, based on 2023 data. The correlation between high rates of CKD and multigenerational use of and reliance on pesticides for food production, lawn care, and general land management reinforces the calls of advocates, farmers, and health professionals to adopt a new approach rooted in organic principles. Methodology This study was conducted by a group of researchers from the Department of Chemistry at Babu Banarasi Das University […]

(Beyond Pesticides, August 14, 2024) Pesticide exposure is linked to negative birth outcomes in a recent study in the American Journal of Epidemiology. This study adds to that body of science, but is novel research since, “Epidemiological studies of pesticide exposures and stillbirth in the United States have not been published in the past two decades, a time period that has seen dramatic changes in pesticide use compared to the 20th century,” the authors state. The study analyzes Arizona pesticide use records and birth certificates from 2006-2020. Researchers correlate mothers living within 500 meters of any pyrethroid, organophosphate (OP), or carbamate insecticide applications during specific windows before and during pregnancy with stillbirth. The authors focus on exposure during the prenatal period, as it is a susceptible time frame in which any contact with pesticides can negatively impact health. Numerous studies report several adverse birth and childhood outcomes with prenatal exposure. To link pesticide exposure and negative birth outcomes, Arizona records that encompass 1,237,750 births, 2,290 stillbirths, and 27 pesticides were analyzed. The authors “evaluate associations of pyrethroids, OPs, and carbamate insecticides with stillbirth by using data from the Arizona Pregnant women’s Environment and Reproductive outcomes Study (Az-PEARS), a project that […]

(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 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, March 2, 2023) Populations experiencing higher levels of environmental pollutant exposure, specifically pesticides, also experience a higher rate of irritable bowel syndrome (IBS), according to a study published in Environmental Toxicology and Pharmacology. IBS is a gastrointestinal disorder that causes abdominal pain or discomfort and changes in bowel behaviors. IBS affects 25 to 45 million individuals in the U.S., mostly female (two-thirds). Additionally, a quarter to half of all gastrointestinal-related visits are for IBS symptoms. Despite the unknown etiology of IBS, ample evidence demonstrates environmental contaminants, like pesticides, negatively affect the gut microbiota, causing a microorganism imbalance and resulting in inflammation associated with IBS. The gut, also known as the “second brain,” shares similar structural and chemical parallels to the brain. The microbiota in the gut plays a crucial role in lifelong digestion, immune and central nervous system regulation, as well as other bodily functions. Although studies show how chemical exposures affect overall human health, a growing body of peer-reviewed scientific literature is now questioning how these toxic chemicals influence gut health and the subsequent occurrence of diseases. The study notes, “These findings may help to understand the relationship between pesticide exposure and IBS; however, more epidemiological and experimental research is needed to understand […]

(Beyond Pesticide, December 20, 2022) A meta-analysis published in Chemosphere finds prenatal pesticide exposure, or pesticide exposure during pregnancy has a positive association with autism spectrum disorder (ASD) and attention deficit/hyperactive disorder (ADHD). Particularly, exposure to chemical classes organophosphate (OP) and pyrethroid (PYR) insecticides, in addition to the mother’s age during pregnancy (≥30 years old), increased the risk factor of ASD. ADHD risk increases among offspring whose mothers encounter organochlorine pesticides (OCPs) during gestation. The etiology or cause of ASD and ADHD involves the interaction of multiple components, including lifestyle and genetics. However, emerging evidence indicates that environmental contaminants like pesticides (e.g., occupational exposures, air pollution, solvents, dietary residues, etc.) play a role in disease etiology. Pesticide contamination is widespread in all ecosystems, and chemical compounds can accumulate in human tissues resulting in chronic health effects.  ADHD is estimated to affect 8-12% of school-age children worldwide. While it is a complex disease, and genetics may play a role, no specific genes have been identified, and there is increasing evidence that environmental factors like pesticide exposure facilitate the development of the condition. Additionally, U.S. Centers for Disease Control and Prevention (CDC) estimates that 1 in 54 children have been diagnosed with an autism spectrum […]

(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. […]

(Beyond Pesticides, February 24, 2022) Widespread, intensive pesticide use for mosquito control has allowed genetic mutations to persist among mosquito populations, causing subsequent resistance to future chemical exposure. According to a study published in Scientific Reports, two common species of female mosquitoes learned to evade pesticides following non-fatal exposure through smell. More concerning is the survival rate of these pre-exposed mosquitoes, as it is more than double that of unexposed mosquitoes. Insects, including mosquitoes, use various sensory and cognitive abilities like vision, smell, and hearing to navigate the ecosystem for survival and reproduction. Mosquitoes associate sensory stimuli like smell to a positive or negative experience, thus facilitating a response. Considering the two species of mosquitoes in this study are a vector for numerous diseases in humans, including dengue and Zika and West Nile viruses. Hence, this study highlights the significance of addressing pest resistance in pest management strategies, particularly to mitigate disease exposure and effects. The study notes, “[The] findings highlight the importance of mosquito cognition as determinants of pesticide resistance in mosquito populations targeted by chemical control.” It is essential to understand insect behavior that propagates vector-borne disease transmission that exacerbates the widespread public health crisis. Scientists attribute memory […]

(Beyond Pesticides, July 22, 2021) A new study published in the Journal of Medical Entomology finds black-legged ticks (Ixodes scapulari) in New York are developing potential resistance to widely used tick-control pyrethroid insecticide, permethrin. The study suggests continuous use of area-wide, 4-poster devices (devices that attract deer and then apply pesticide to their head, ears, and neck) to apply insecticide treatments on deer to control tick populations promotes resistance. Resistance is an ever-present issue among chemical compounds (i.e., antibiotics, antimicrobials, pesticides) used in medicine and agriculture, and threatening the ability to prevent disease outbreaks, such as Lyme disease. Furthermore, increasing populations of rodent and mammalian hosts, in addition to warmer temperatures prompted by the climate crisis, allows for disease-carrying ticks to flourish. Lyme disease is the most common vector disease and a primary concern for the general population. Therefore, studies like this highlight the need to assess resistance among disease-vector pest populations regardless of pesticide application methods. The researchers note, “Permethrin susceptibility of tick populations should be monitored from other 4-poster control areas so that guidelines for managing pesticide resistance in the field can be developed.” Four-poster devices impart selective pressure on tick populations influencing reproduction and natural extinction of species. However, like mosquitoes, a subpopulation of ticks […]

(Beyond Pesticides, July 1, 2021) Yellow fever mosquitoes (Aedes aegypti) are evolving resistance to the pyrethroid insecticide permethrin, according to a study published by Colorado State University, highlighting the need to adopt ecologically-based mosquito management. Widespread, intensive use of the pesticide in mosquito control has allowed genetic mutations to persist among these mosquito populations, causing subsequent resistance to permethrin. Pyrethroids are one of the few remaining classes of insecticides available to control yellow fever mosquitos, and resistance threatens the ability to prevent disease outbreaks with chemical-intensive methods. Yellow fever mosquitoes are a vector for numerous untreatable diseases in humans, including dengue, chikungunya fever, and Zika viruses. Hence, this study highlights the significance of addressing pest resistance to pesticide control, particularly to mitigate disease exposure and effects. The researchers note, “This knowledge can help scientists understand how mosquitoes have evolved resistance and when a population can no longer be controlled with permethrin. This understanding will be necessary to develop tools to support future insecticide management strategies.” Researchers sequenced the genome of resistant and knockdown (either recovered or dead) mosquitoes after permethrin exposure using a bottle bioassay. The aim was to identify genomic variants/biomarkers associated with specific resistance mechanisms. Two common pyrethroid resistance mechanisms occur among […]

(Beyond Pesticides, June 3, 2021) A report published in Royal Society Open Science finds pesticide-resistant parasitic lice (Lepeophtheirus salmonis) are endangering wild and farmed fish populations in the North Atlantic. Extensive use of pesticides to rid the parasite has led to widespread resistance to multiple pesticides, prompting increasing infection rates among North Atlantic salmon populations. Overexploitation of wild fish and other ocean organisms has depleted seafood stocks globally. Some fisheries market aquaculture practices, like fish/seafood farming, as a solution to overfishing. However, the aquaculture industry repeatedly faces sustainability issues and fails to adhere to environmental regulations that threaten marine health. The oceans are essential to human health and well-being, feeding billions, supporting millions of jobs, and supplying medicinal materials. However, environmental contaminants like pesticides have profound impact on the ecosystem and the inhabitants. Therefore, it is necessary to understand how pesticides can influence resistance among lethal pest populations, especially in ecologically vulnerable and highly interconnected ecosystems like ocean basins. The authors of the report caution, “These results demonstrate the speed to which this parasite can develop widespread multi-resistance, illustrating why the aquaculture industry has repeatedly lost the arms race with this highly problematic parasite.” Over the past two decades, organophosphate and pyrethroid insecticides […]

(Beyond Pesticides, April 8, 2021) Pesticide use threatens aquatic and terrestrial invertebrates and plants more than ever, despite declining chemical use and implementation of genetically engineered (GE) crops in the U.S., according to a University Koblenz-Landau, Germany study. Since the publication of Rachel Carson’s Silent Spring (1962), many environmental agencies have banned the use of pesticides like organochlorines, organophosphates, and carbamates for their devastating toxic—sometimes lethal—effects, particularly on vertebrates, including humans. However, this ban created a pathway for a new generation of pesticides (e.g., neonicotinoids, pyrethroids) to take hold. Although these pesticides are more target-specific, requiring lower chemical concentrations for effectiveness, they have over double the toxic effects on invertebrates, like pollinators.  Invertebrates and plants are vital for ecosystem function, offering various services, from decomposition to supporting the food web. Furthermore, invertebrates and plants can act as indicator species (bioindicators) that scientists can observe for the presence and impact of environmental changes and stressors. Therefore, reductions in invertebrate and plant life have implications for ecosystem health that can put human well-being at risk. Study lead author Ralf Schulz, PH.D., notes, “[This study] challenge[s] the claims of decreasing environmental impact of chemical pesticides in both conventional and GM [genetically modified or genetically engineered (GE)] crops and […]