(Beyond Pesticides, December 17, 2018) Cardiovascular disease is a major cause of poor health and mortality across the world. Much is known about congenital and behavioral contributors to the disease, yet to date, little research has focused on potential environmental factors, including the possible contribution to cardiovascular disease (CVD) of exposures to toxic chemicals in the workplace. A recent study of CVD incidence among Hispanic and Latino workers, by Catherine Bulka, PhD, et al., has evaluated associations of self-reported exposures to organic solvents, metals, and pesticides with CVD. The study was published in the journal Heart on December 11, 2018, and is first to evaluate the role of chemical exposures in the workplace in the incidence of CVD in this demographic sector. As do many scientific investigations, this one points to a need for further study of the links that emerged between such exposures and compromised cardiovascular health. In an editorial in that same issue of Heart, commenting on the study, Dr. Karin Broberg of the Karolinska Institutet in Stockholm, Sweden, noted that “exposure to metals and pesticides is common worldwide, and this study highlights the need to better understand the risks that these exposures cause, and to limit exposure in the […]

(Beyond Pesticides, December 11, 2018) Meltwater and runoff from Alaskan glaciers contain detectable levels of organochlorine pesticides that bioconcentrate in fish and put individuals at risk, according to a new study from researchers at the University of Maine (UMaine). DDT, lindane, and other organochlorines have been detected throughout the world, even in natural areas thought to be untouched, and pristine. As UMaine scientists show, the atmospheric transport and ubiquitous deposition of these pesticides continues to pose risks to U.S. residents long after regulations banned their use. Although most of the highly toxic class of organochlorine pesticides like DDT were banned in the early 1970s, some chemicals retained certain uses. Lindane, for example, had its pest management uses phased out gradually until 2007, but is still allowed today as a scabies and lice shampoo. While use of these pesticides has declined in the U.S., much of the developing world, including many Asian countries, such as China, India, and North Korea, still report use. This results in atmospheric transport of the pesticides, and relevant to the UMaine research, increases the likelihood that the chemicals will eventually be deposited onto Alaskan glaciers through snow or rain. The UMaine research team investigated the amount of […]

(Beyond Pesticides, November 9, 2018) A Tunisian study (published in January 2018) on the effects in pre-pubertal mice of exposure to malathion — an organophosphate pesticide first registered for use in the U.S. in 1956 — demonstrates significant distortion of liver and kidney biochemistry and function in the animals. Deleterious effects include compromise of feeding ability, metabolism performance, neurologic deficits, reduction of overall body weight, and simultaneous increases in the weights of livers and kidneys, with structural anomalies and lesions in those organs. Organophosphates (OPs) have raised alarm bells for years. Some, such as chlorpyrifos and diazinon, have had their registrations cancelled for household uses because of the extreme health risks to children, but agricultural, golf course, and “public health” (mosquito control) uses remain commercially available and in use. Recently, Beyond Pesticides reported on research whose investigators support — and called publicly for — a worldwide ban on the compounds because of the serious health and environmental risks they pose, particularly for children. Beyond Pesticides has written extensively on OP pesticides, including malathion and chlorpyrifos. Both are used widely in agriculture. Chlorpyrifos has been the subject of quite a ping-pong match in recent years: a scheduled ban by the Environmental Protection […]

(Beyond Pesticides, October 17, 2018) The unsustainable life cycle management of pesticides during the past seven decades has created huge stockpiles of these (and other toxic) chemicals across much of the globe, including Eastern Europe, Africa, the Middle East, and Latin America. The journal Environmental Science and Pollution Research has published a special series of articles and reports from the International HCH & Pesticides Association (IHPA), titled “The legacy of pesticides and POPs stockpiles — a threat to health and the environment.” Stockpiles have accumulated because some products have been banned for health or environmental reasons, leaving stocks (aka waste) that are often stored inadequately, and which deteriorate and migrate to contaminate the environment and put people at risk. Those affected are very often in poor, rural communities that may be unaware of the threat in their midst. Beyond Pesticides covered this “chemical time bomb” problem in 2004 and again nearly a decade ago. The special issue of Environmental Science and Pollution Research responds to multiple fronts on this problem of accumulation and storage of toxic compounds, identifying the two largest issues as: (1) the stockpile of some 4–7 million tons of hexachlorocyclohexane (HCH) waste from lindane production; and the 240,000 […]

(Beyond Pesticides, September 20, 2018) Babies exposed to higher levels of organochlorine compounds in the womb go on to have worse lung function in childhood, according to new research presented at the European Respiratory Society International Congress. Previous studies have found a link between low lung function in early adulthood and respiratory, cardiovascular, and metabolic issues in later life. Beyond Pesticides has covered in its Daily News studies on a range of adverse effects, including autism in children, caused by organochlorine pesticide exposure, which bioaccumulates in the environment and the human body. Organochlorine compounds, which include the pesticide DDT, as well as electrical insulators and other industrial products, are now banned in most parts of the world. However, because they degrade very slowly, they are still present in the environment and in foods. Previous research has suggests links between exposure to these chemicals in the womb and parents reporting childhood respiratory diseases such as wheezing, asthma, and chest infections. The new study is the first to show a link with objective measures of lung strength and capacity in relation to low-level exposure to these chemicals. Organochlorine compounds can disrupt the hormone system and have been linked to a wide range of […]

(Beyond Pesticides, September 19, 2018) “‘Don’t get pregnant at George Air Force Base’” was the advice imparted from one female Air Force member to another in 1975 at that base, located 100+ miles north of San Diego and used as an active military site from 1941–1992. From the start of their service at George AFB, both parties to this conversation came to be familiar with the shared horror stories of repeated infections, vaginal bleeding, ovarian cysts, uterine tumors, birth defects, and miscarriages among female Air Force members at the site. Many women who served at George AFB in the 1970s, ‘80s, and ‘90s suffered, but did not know what was causing, such health issues, which were frequent enough that even base doctors would sometimes privately warn women off of getting pregnant while serving there. Among the many contaminants found at George AFB and other military sites are organochlorine-based pesticides (OCPs), such as DDT, dieldrin/aldrin, heptachlor, lindane, endrin, chlordane, mirex, toxaphene, hexachlorobenzene, chlordane, and others. (A comprehensive list of OCPs is available here.) Most of these compounds were used on military bases for decades for vegetation control, as building pesticides or fumigants, or for personal pesticide treatments for lice and scabies, and […]

(Beyond Pesticides, August 22, 2018) Mothers with high levels of DDT’s major metabolite, DDE, are more likely to have their children diagnosed with autism, according to a study published in The American Journal of Psychiatry this month. Though this study links autism to long-banned DDT, it raises significant concerns about legacy contamination from this chemical, which remains ubiquitous in the environment and in human bodies. With an increasing number of studies linking autism and other developmental disabilities to pesticides, the need to transition to safer, organic methods of farming is now more important than ever before. The study, Association of Maternal Insecticide Levels With Autism in Offspring From a National Birth Cohort, measured maternal serum levels of Finish women during early pregnancy whose children were born between 1987 and 2005. Specimens were analyzed for DDE as well as PCB contamination. Mothers with DDE at the highest 75% threshold reportedly had a 132% (1.32x odds ratio) increased risk of having a children diagnosed with autism after adjusting for confounders such as age and history of psychiatric disorders. Moms above the 75th percentile had their chances of a child’s autism diagnosis increase by 221% (2.21x odds ratio). The study found no connection […]

(Beyond Pesticides, November 15, 2017) Songbirds exposed to widely used insecticides fail to properly orient themselves for migration, according to a study published by Canadian scientists in Scientific Reports. With the organophosphate chlorpyrifos and the neonicotinoid imidacloprid applied to millions of acres of farmland throughout North America, this new research adds weight to arguments that pesticides are a likely cause in the decline of migratory bird populations. “Studies on the risks of neonicotinoids have often focused on bees that have been experiencing population declines. However, it is not just bees that are being affected by these insecticides,” said Christy Morrissey, PhD, biology professor at the University of Saskatchewan. Researchers captured 57 white crowned sparrows in northern Canada, and held them in an outdoor pen for roughly two weeks, during which time all the birds either gained or maintained their weight. The songbirds were then split into three groups, one exposed to imidacloprid, another to chlorpyrifos, and the last untreated and acting as a control. The imidacloprid and chlorpyrifos exposed groups were each further separated by exposing a portion to the insecticide at 10% of the lethal dose that would kill 50% of a given population (LD50), and another to 25% […]

(Beyond Pesticides, September 14, 2017) Children whose mothers took folic acid while pregnant had a significantly lower risk of developing autism spectrum disorder (ASD) even when their mothers were exposed to household or agricultural pesticides. Researchers at the University of California, Davis found that taking folic acid during the window around conception, reduced the risk of pesticide-induced autism. In the study, “Combined Prenatal Pesticide Exposure and Folic Acid Intake in Relation to Autism Spectrum Disorder,” children whose mothers took 800 or more micrograms of folic acid (the amount in most prenatal vitamins) had a significantly lower risk of developing autism spectrum disorder, even when their mothers were exposed to household or agricultural pesticides that are associated with increased risk. The study used data from the Childhood Autism Risks from Genetics and the Environment (CHARGE) study, where researchers looked at 296 children between 2 and 5 who had been diagnosed with ASD and 220 who had developed typically. Mothers were interviewed about their household pesticide exposure during pregnancy, as well as their folic acid and B vitamin intake. The team also linked data from California Pesticide Use reports, which provided important details about agricultural spraying, with the mothers’ addresses. The results […]

(Beyond Pesticides, September, 2017) A recently released report, Gallup-Sharecare State of Well-Being: The Face of Diabetes in the United States, looks at high diabetes rates across various U.S. demographic groups, including those in farming. People working in the transportation sector registered the highest incidence of diagnosed diabetes at 10.6%. But those working as farmers and fishermen came in second, with 8.5% reporting a diagnosis of the disease. Based on a self-reporting survey, The Face of Diabetes in the United States did not differentiate between Type 1 diabetes (which typically manifests in childhood or young adulthood) and Type 2 diabetes (which commonly emerges in adulthood). It did, however, consider lifestyle risk factors that can influence development of each form of the disease. The “farmer and fisher” folks placed more-or-less in the mid-range among all occupations vis-à-vis several of the lifestyle factors that can impact development of the disease (smoking, diet, and obesity), and a bit higher in alcohol consumption, but in fact, reported more exercise than any other category of worker. These data points would seem to suggest that farmers would be at less risk than those in some other occupational categories. For instance, those working in “installation and repair” reported […]

(Beyond Pesticides, July 27, 2017) Earlier this week U.S. Senators Tom Udall (D-NM) and Richard Blumenthal (D-CT) introduced a bill that would ban use of the insecticide chlorpyrifos. The Protect Children, Farmers and Farmworkers from Nerve Agent Pesticides Act, S. 1624, comes one week after an appeals court refused to require the U.S. Environmental Protection Agency (EPA) to make a decision over whether to ban the chemical. Removing this neurotoxic insecticide from the environment would significantly reduce health risks for children and farmworkers in underserved rural communities, build pressure to address all toxic organophosphates, and help push U.S. agriculture in a more sustainable direction. As with other organophosphate class chemicals, chlorpyrifos, first registered in 1965 by Dow Chemical, is derived from nerve agents used during World War 2. The chemical is linked to a range of negative health and environmental outcomes that warrant its prohibition. Children are at particular risk from the chemical due to their developing immune, organ, and nervous systems.  As with other organophosphate nerve agents, the chemical acts on the body’s nervous system, inhibiting the movement of neurotransmitters called cholinesterase. Chlorpyrifos chemically binds to the site where cholinesterase would in the body, preventing normal nerve impulse transmission. […]

(Beyond Pesticides, February 23, 2017) Male pesticide applicators who experienced a pesticide spill or another related accident are more likely to harbor changes in their DNA associated with an increased risk of prostate cancer, according to a recent paper published in the journal, Environmental and Molecular Mutagenesis. While the relationship between pesticide exposure and prostate cancer is not new, this study adds to the growing body of evidence that high exposure to specific pesticides may lead to the development of prostate and other cancers. The analysis finds that after experiencing one of these exposure events, men are more likely to have higher DNA methylation of a gene linked with an increased risk of developing prostate cancer. DNA methylation is a form of gene regulation that, if disturbed, can result in gene expression changes that can cause cancer. The researchers used data from the ongoing Agricultural Health Study (AHS), which is a long-term cohort study evaluating cancer and other health outcomes of pesticides applicators and their spouses in North Carolina and Iowa. This paper, High pesticide exposure events and DNA methylation among pesticide applicators in the agricultural health study, analyzed a sample size of 596 male pesticide applicators who underwent three phases of […]

(Beyond Pesticides, October 20, 2016) Researchers at the University of Western Australia (UWA) and Murdoch University recently released a study whose findings show that levels of pesticides in breast milk have dropped significantly over the past forty years, though some major concerns remain. Published in the international journal Chemosphere, the research shows a 42-fold decrease in levels of pesticides detected in breast milk, and ties the reduction to government efforts to prohibit persistent organic pollutants (POPs) in Australia, which has lead to decreased exposure over time. Led by UWA’s internationally renowned human lactation researcher Emeritus Professor Peter Hartmann, Dr. Donna Geddes and Murdoch’s Associate Professor Robert Trengove, the study is a testament to the positive impact banning pesticides can have on the health of individuals, especially vulnerable populations like infants, but also shows that there is a long way to go before our bodies are void of any bioaccumulated toxic residues. Researchers often study breast milk because it can bioconcentrate, or accumulate, persistent organic pollutants (POPs). Multiple studies on breast milk have been performed throughout the years, many of them confirming the fact that common toxic chemicals, such as glyphosate and triclosan, build up in our bodies over time. Most […]

(Beyond Pesticides, September 14, 2016) According to a recent study by the U.S. Geological Survey (USGS), high concentrations of dioxins and furans have been detected in tree swallow eggs collected near several sites around the Great Lakes. Other chemicals detected include polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), which were at background levels. The study is part of efforts to clean up a toxic chemical legacy around the Great Lakes, and the researchers believe their results are critical to regulators to assess “bird or animal deformity or reproductive problems” The study, “Concentrations and spatial patterns of organic contaminants in tree swallow (Tachycineta bicolor) eggs at United States and binational Great Lakes Areas of Concern, 2010—2015,” used tree swallows to quantify current exposure to organic contaminants across all five Great Lakes including 59 sites within 27  Areas of Concern (AOCs)  and 10 nearby  locations. The Great Lakes Areas of Concern refers to a U.S.-Canada  Great Lakes Water Quality Agreement  (Annex 1 of the 2012 Protocol) that  defines AOCs as “geographic areas designated by the Parties where significant  impairment of beneficial uses  has occurred as a result of human activities at the local level.” An AOC is a location that has […]

(Beyond Pesticides, August 24, 2016) Researchers at Drexel University report that higher levels of some organochlorine compounds during pregnancy are associated with autism spectrum disorder (ASD) and intellectual disability (ID). The organochlorine compounds under study have long been banned in the U.S., and include pesticides like DDT, underscoring how pervasive and persistent these chemicals are, and their continued impact on human health. The research is reported in the study  Polychlorinated Biphenyl and Organochlorine Pesticide Concentrations in Maternal Mid-Pregnancy Serum Sam ples: Association with Autism Spectrum Disorder and Intellectual Disability,  which examines whether prenatal exposure to polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) influences offspring risk of ASD and intellectual disability without autism (ID). According to the research, children born after being exposed to the highest levels of organochlorines during their mother’s pregnancy are roughly 80 percent more likely to be diagnosed with autism when compared to individuals with the very lowest levels of these chemicals. The team looked at a population sample of 1,144 children born in Southern California between 2000 and 2003. Data was accrued from mothers who had enrolled in California’s Expanded Alphafetoprotein Prenatal Screening Program, which is dedicated to detecting birth defects during pregnancy. Participants’ children were […]

(Beyond Pesticides, July 19, 2016) Exposure to common pesticides at levels often found in the environment can have subtle but significant impacts on the behavioral health of fish, amphibians and other aquatic invertebrates. According to researchers at Northern Arizona University, who analyzed data from nearly 40 experiments to reach their conclusion, fish and amphibians swam 35% slower and were 72% less active after pesticide exposure. Chemical Class Type Example Pesticides Carbamates Insecticide Carbaryl, Aldicarb Organochlorine Insecticide DDT, Endosulfan, Chlordane Organophosphates Insecticide Diazinon, Chlorpyrifos Organotins Biocide Tributyltin Phosphonoglycines Herbicide Glyphosate, Glufosinate Pyrethroids Insecticide Permethrin, Bifenthrin, Esfenvalerate Triazines Herbicide Atrazine, Simazine The study, published in Science of the Total Environment, found that the overall effect on aquatic wildlife varied based on the chemical class the animals encountered. While pyrethroids, carbamates, and organophosphates resulted in a significant decrease in swim speed, triazines and phosphonoglycines showed no overall effect. Pyrethroids, carbamates, organophosphates, organochlorines, and organotins decreased activity, while phosphonoglycines had no overall effect, and triazines actually increased activity. “I didn’t think that we would see [an effect] across such a wide range of pesticides so consistently, but we did,” said study co-author, Catherine Propper, PhD to KNAU, “and that leads to some concerns about […]

(Beyond Pesticides, May 16, 2016) Pesticide exposure may increase the risk of amyotrophic lateral sclerosis (ALS), according to a study entitled Association of Environmental Toxins With Amyotrophic Lateral Sclerosis, which was  published in JAMA Neurology. ALS, also known as Lou Gehrig’s disease, is a progressive neurodegenerative disease that affects nerve cells in the brain and spinal cord. The study, which investigated a total of 122 persistent environmental pollutants, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and brominated flame retardants (BFRs), found that pesticide exposure increased ALS risk five-fold. Researchers conducting the study  looked at 156 patients with ALS and 128 without the disease. Participants were asked about occupational and residential exposure to environmental toxicants  and blood samples were taken to measure their concentrations. Researchers found that the organochlorine pesticides pentachlorobenzene and cis-chlordane increased ALS risk two-fold and nearly six-fold, respectively. This study does not prove that pesticides cause ALS, but it does build on an association suggested in previous research, study co-author Stephen Goutman, MD, told  HealthDay. Dr. Goutman recommends avoiding pesticides. This is especially wise for anyone with a family history of ALS, he added. The link between pesticide exposure and neurological damage has been studied extensively. In 2008, […]

(Beyond Pesticides, April 29, 2016) Traces of pesticides, including the long-banned organochlorine chemical DDT, have been found in Western pond turtles, insects, and soil sediment at Sequoia National Park, according to a study.  The study, entitled Organic contaminants in western pond turtles in remote habitat in California  and published in the journal Chemosphere, surveys a suite of 57 current- and historic-use pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in the western pond turtle, along with their potential prey items and habitat. California study sites include Sequoia National Park, Whiskeytown National Recreation Area, and Six Rivers National Forest, all of which are downstream of undeveloped watersheds and varied in distance from agricultural and urban pollution sources. Researchers found that organic pollutants are widespread in the western pond turtle, which has conservation status; that pesticides are prominent in Sequoia National Park, which is downwind of heavy agriculture; and that the legacy  pesticides and PCB concentrations indicate that bioaccumulation is occurring. Brian Todd, Ph.D., an associate professor of wildlife, fish, and conservation biology at University of California Davis, co-authored the study. Dr. Todd said controlling the flow of pesticides into national parks is pretty much impossible. “Sequoia National Park is very […]

(Beyond Pesticides, February 25, 2016) Feminine care products sold in France may contain “potentially toxic residues,” according to a study conducted by 60 Millions de Consommateurs, a French consumer rights group. The study finds  traces of chemicals, such as dioxins and insecticides, in 5 of 11 products tested. A separate analysis conducted by Corman, a manufacturer of feminine care products, also finds  residues of the weedkiller glyphosate, which was classified in March 2015  as a probable carcinogen by the International Agency for Research on Cancer (IARC). Researchers at 60 Millions  reported finidng traces of halogenated waste, a by-product related to the processing of raw materials, in Tampax Compak Active Regular Fresh tampons. The researchers also detected residues of organochlorine and pyrethroid pesticides, linked to a wide range of adverse health impacts, in some Always sanitary towels. Highly toxic dioxins, which can be cause cancer, reproductive and developmental problems and damage the immune system, according to the World Health Organization, were also found in products by OB and the European Nett brands. Corman, which makes Organyc panty liners, told the Agence France-Presse (AFP) news agency that it conducted its own analysis that confirmed the trace amounts of glyphosate, the active ingredient […]

(Beyond Pesticides, December 11, 2015) Milk contaminated with the long-banned and toxic organochlorine pesticide heptachlor in Hawaii has been found  in the brains of men that were more likely to develop Parkinson’s disease, according to a new study. This study adds to a large body of evidence linking pesticide exposure to Parkinson’s disease. Researchers of the study, titled “Midlife milk consumption and substantia nigra neuron density at death” and published in the journal Neurology, collected milk intake data from 1965 to 1968 for 449 men aged 45-68 years withpostmortem examinations from 1992 to 2004. Neuron density was measured in an area of the brain called substantia nigra (SN). As Parkinson’s develops, cells are destroyed in certain parts of the brain stem, particularly in the SN, a crescent-shaped cell mass. Measurements of brain residues of heptachlor epoxide, a heptachlor metabolite that is persistent and more toxic than its parent chemical, were also taken. “Among those who drank the most milk, residues of heptachlor epoxide were found in 9 of 10 brains as compared to 63.4%…for those who consumed no milk,” the researchers wrote. Neuron density was lowest in subjects who consumed the highest amounts of milk. The researchers looked at milk […]

(Beyond Pesticides, November 10, 2015) Exposure to organochlorine chemicals, such as DDE and PCBs, is linked to increased rates of sperm abnormalities that may lead to fertility problems, according to a new study published in the journal Environmental Health Perspectives. This is the latest study in a long line of research implicating endocrine (hormone)-disrupting chemicals in reproductive diseases. Researchers investigated this issue by observing the blood serum and sperm quality of 90 men, aged 22-44, participating in health studies in the Faroe Islands, an archipelago under  Denmark’s control that is  located between Iceland, the UK and Norway. Faroe islanders consume a high seafood diet that often consists of pilot whale, integral historically as a  food source for the Faroese people. However, this practice exposes the Faroese to higher than average levels of environmental contaminants. For the study, data on umbilical cord blood and blood serum at age 14 was available for 40 of the participants, allowing a researchers to measure lifetime impacts. Faroese participants were screened for sperm aneuploidy, a condition which usually involves an abnormal number of X or Y chromosomes in sperm, and is suspected as contributing to congenital abnormalities and up to 50% of early pregnancy losses. […]

(Beyond Pesticides, September 22, 2015) A meta-analysis presented at the annual meeting of the European Association for the Study of Diabetes in Sweden concludes that exposure to pesticides is associated with an increased risk of diabetes. Although diabetes is long-suspected as involving an interplay between genetics and environmental factors, emerging research is revealing that contaminants like pesticides may play an important role in the pathogenesis of the disease. These findings add to a growing body of evidence demonstrating that pesticides play a key role in the development of a wide range of all-too-common diseases in the 21st century. To assess the association between pesticide exposure and diabetes, the recent research, Association between diabetes and exposure to pesticides: a systematic review and meta-analysis, examine 21 relevant studies comprising over 66,000 people. Most studies determined pesticide exposure through urinary or blood biomarker analysis, a highly reliable method of testing body burden. Exposure to any pesticide is linked to a 61% increase in diabetes. When looking specifically at type 2 diabetes, researchers found similar results, with any pesticide exposure increasing risk of developing the disease by 64%. However, researchers found that, although on the whole pesticides increased the chance of any diabetes diagnosis, […]

(Beyond Pesticides, August 20, 2015) Just as children go  back to school, research  finds that lice in 25 of 30 states in a  U.S. study have developed resistance to common over-the-counter treatments like permethrin, calling into questions the justification for exposing children to a neurotoxic and carcinogenic pesticide and elevating the need to consider nontoxic alternatives. The  research was presented Tuesday at the 250th National Meeting and Exposition of the American Chemical Society (ACS), by Kyong Yoon, Ph.D., of Southern Illinois University, Edwardsville. Classified as a synthetic pyrethroid insecticide, permethrin is “likely carcinogenic” and a suspected endocrine disruptor, immunotoxic, neurotoxic, and highly toxic to fish, aquatic animals, and bees. Dr. Yoon and his colleagues describe the threefold mutations that lice have developed over time due to the constant use of synthetic pyrethroid insecticides. This new finding builds on his team’s previous research, which found that 99.6% of lice are resistant to chemical treatment, adding weight to the fact that chemical treatments not only are unnecessary given effective least-toxic alternatives, but also are not able to provide the lice control that manufacturers claim. “We are the first group to collect lice samples from a large number of populations across the U.S.,” […]