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New noteworthy research links commonly used household pyrethroid pesticides to attention deficit hyperactive disorder (ADHD) in children and young teens, especially boys. Ome drawback was that the results were based on a single urine sample.Since pyrethroids are non-persistent and rapidly metabolized, then looking at numerous samples over time would have provided a more accurate assessment of typical long-term exposure. Given how many households use pyrethroid pesticides and that there are seasonal variations in pesticide use, then it wouldn't be surprising if there are times when pyrethroid exposure is higher and so the link to ADHD may even be stronger than seen in this original study.From Medical Xpress:

Study links exposure to common pesticide with ADHD in boys

A new study links a commonly used household pesticide with attention deficit hyperactivity disorder (ADHD) in children and young teens.The study found an association between pyrethroid pesticide exposure and ADHD, particularly in terms of hyperactivity and impulsivity, rather than inattentiveness. The association was stronger in boys than in girls.

Due to concerns about adverse health consequences, the United States Environmental Protection Agency banned the two most commonly used organophosphate (organic compounds containing phosphorus) pesticides from residential use in 2000-2001. The ban led to the increased use of pyrethroid pesticides, which are now the most commonly used pesticides for residential pest control and public health purposes. They also are used increasingly in agriculture.

Pyrethroids have often been considered a safer choice because they are not as acutely toxic as the banned organophosphates. Animal studies, on the other hand, suggested a heightened vulnerability to the effects of pyrethroid exposure on hyperactivity, impulsivity and abnormalities in the dopamine system in male mice. Dopamine is a neurochemical in the brain thought to be involved in many activities, including those that govern ADHD.

The researchers studied data on 687 children between the ages of 8 and 15. The data came from the 2000-2001 National Health and Nutrition Examination Survey (NHANES),...included a diagnostic interview of children's ADHD symptoms and pyrethroid pesticide biomarkers. Pesticide exposure measurements were collected in a random sample of the urine of half the 8-11 year olds and a third of the 12-15 year olds. ADHD was determined by meeting criteria on the Diagnosic Interview Schedule for Children,...

Boys with detectable urinary 3-PBA, a biomarker of exposure to pyrethroids, were three times as likely to have ADHD compared with those without detectable 3-PBA. Hyperactivity and impulsivity increased by 50 percent for every 10-fold increase in 3-PBA levels in boys. Biomarkers were not associated with increased odds of ADHD diagnosis or symptoms in girls.

This interesting small study shows how quickly one can eliminate many pesticides from the body by switching to an all organic diet. One Swedish family of 2 adults (aged 40 and 39) and 3 children (aged 12, 10, and 3) who had been eating mainly conventional food were studied. For the study they only ate conventionally grown food for one week and then they switched to an all organic diet for 2 weeks (fruit, vegetables, meat, fish, etc,). Urine was collected every morning from all family members, and a food diary was kept. Common pesticides and their metabolites were analyzed: atrazine, chlorpyrifos, 2.4-D, pyrethroids, MCPA, chlormequat chloride (CCC) etc. However, the most commonly used pesticide in the world - glyphosate (Roundup) was not looked at. The results showed that pesticide levels were reduced very quickly once they started eating an all organic diet.

The family of five. Credit: You Tube/CoopSverige

The report also mentioned that currently pesticide standards are only for one pesticide at a time, but people have exposure to many pesticides in daily life (foods, their environment, cleaning supplies, etc) - thus people are exposed to a chemical cocktail that we know very little about about - whether looking at short-term or long-term effects. Article (and video link) from The Sydney Morning Herald:

Family eats organic for just two weeks, removes nearly all pesticides from body

A Swedish family has shown just how quickly an organic diet change can rid the body of pesticides. In a fortnight-long experiment, the family of five - parents Anette and Mats, and kids Vendela, Evelina and Charlie - swapped their conventional diet for an organic one and found that just two weeks of eating an organic diet managed to rid their bodies of most traces of pesticides.

The video explaining the experiment, which was conducted by Swedish supermarket Coop and the Swedish Environmental Research Institute, has been viewed more than a million times on YouTube. 

The researchers measured the levels of plant growth regulators chlormequat chloride, mepiquat, 3-PBA and cleaning agent TCP in urine samples taken from each family member before and after their two weeks of organic eating. Before the experiment, middle child Evelina's urine was showing nearly five nanograms of chlormequat chloride per millilitre. After eating only organic foods for two weeks, the chemical was unable to be detected in her sample. The most profound effects were found in toddler Charlie's samples. Despite his urine before the experiment showing high levels of all four of the chemicals, after the experiment none of the substances were detected.

The original 2015 report Coop Sverige AB, Report number U 5080, from the Swedish Environmental Research Institute: Human exposure to pesticides from food: A Pilot Study  ...continue reading "Eat Organic Foods to Quickly Lower the Pesticide Levels In Your Body"

The research finding that eating fruits and vegetables with high pesticide residues has a negative effect on sperm is disturbing. It wasn't the amount of fruits and vegetables eaten, it was eating fruits and vegetables with high levels of pesticide residues. Yes, the study does have some limitations (for example, a one time analysis, looked at men at a fertility clinic and not the general population), but...even with these limitations, the results are disturbing. Earlier studies of children showed that switching to an organic diet has almost immediate results of reducing pesticide residues in the body (OP Pesticides in Children’s Bodies: The Effects of a Conventional versus Organic Diet). So the advice here is try to increase the amounts of organic fruits and vegetables in the diet, especially those with high pesticide residue levels. Fruit or vegetables that were low in pesticide residues included peas, beans, grapefruit and onions. Those that had highest pesticide residues included peppers, spinach, strawberries, celery,blueberries, potatoes, peaches, plums, apples and pears. From Time:

A Diet High in Pesticides Is Linked to a Lower Sperm Count

The troubling link between pesticide exposure and fertility isn’t new; scientists have already established that people who work with pesticides tend to have lower fertility than people who don’t. But for the majority of us who don’t work with chemicals, diet is the biggest source of exposure, says Jorge Chavarro, MD, assistant professor of nutrition and epidemiology at Harvard School of Public Health and senior author of a new study published in the journal Human Reproduction.

Chavarro and his colleagues wanted to see if pesticide residues left on fruits and vegetables might have a similar effect on sperm—and their findings suggest that they did. Men who ate fruits and vegetables with a lot of pesticides had lower sperm counts and more oddly shaped sperm than those who had lower levels of dietary pesticide exposure.

Over an 18-month period, the researchers used data from the Environment and Reproductive Health (EARTH) study, including semen samples from 155 men who were being treated at a Boston fertility clinic and a food frequency questionnaire they completed. The researchers determined pesticide exposure by comparing the questionnaire answers with government data about produce pesticide levels in the USDA’s Pesticide Data Program.

The study didn’t tease out individual foods, but the researchers classified produce according to whether it had high or low-to-moderate levels of pesticides. Men who ate the most high-pesticide fruits and vegetables had a 49% lower total sperm count and 32% fewer sperm that were shaped normally, compared to men who ate the least amount of the high-pesticide produce.

Researchers gave each piece of produce a score based on its level of detectable pesticides, its level of pesticides that exceeded the tolerance level established by the U.S. Environmental Protection Agency, and whether the produce had three or more types of detectable pesticides. (The bigger the score, the more it hit all three measures.) Ranked from highest pesticide contamination to lowest, here were the top fruits and vegetables: Green, yellow and red peppers (6), Spinach (6), Strawberries (6), Celery (6), Blueberries (5), Potatoes (5), Peaches and plums (5), Apples or pears (5), Winter squash (4), Kale, mustard greens and chard greens (4), Grapes and raisins (4).

The team didn’t tease out associations with individual pesticides. But they believe that a mixture of pesticides—not just one particular pesticide—is responsible for the link. The strongest variable in their analysis were the proportion of fruits and vegetables consumed that use three or more pesticides. “The more pesticides are applied on any particular crop, that seems to be having a bigger impact,” Chavarro says...But for people who are concerned about their dietary exposure to pesticides, there are ways to lower it, he says, like eating organic and choosing produce not listed on the Environmental Working Group’s dirty dozen list.

From Science  Daily: Pesticides in fruit and vegetables linked to semen quality

Assistant Professor of Nutrition and Epidemiology at the Harvard T.H. Chan School of Public Health in Boston (USA), Jorge Chavarro, said: "These findings should not discourage the consumption of fruit and vegetables in general. In fact, we found that total intake of fruit and vegetables was completely unrelated to semen quality. This suggests that implementing strategies specifically targeted at avoiding pesticide residues, such as consuming organically-grown produce or avoiding produce known to have large amounts of residues, may be the way to go."

There were no differences seen between men in the four groups who consumed fruit and vegetables with low-to-moderate pesticide residues. In fact, there was a significant trend towards having a higher percentage of normally shaped sperm among men who consumed the most fruit and vegetables with low pesticide residues -- a relative increase of 37% from 5.7% to 7.8%...Note:Pesticide use varies from country to country, but in the USA those used on fruit and vegetables include Atrazine, Malathion, Chlorpyrifos and Carbendazim

Well DUH, of course eating organic foods lowers pesticide exposures. And yes, it can be measured in your body. So, as previous studies have shown, replacing regular fruits and vegetables (conventionally grown) with organic fruits and vegetables will lower your exposure to pesticides and the levels in your body. And why is this important? Research shows health effects from pesticides, so it is healthier for you to lower your pesticide exposures - whether from eating food, or from your house and your yard (breathing it in, getting it on skin).From Science Daily:

Organic food reduces pesticide exposure

While health-conscious individuals understand the benefits of eating fresh fruits and veggies, they may not be aware of the amount of pesticides they could be ingesting along with their vitamin C and fiber. A new study to be published in the Feb. 5 edition of Environmental Health Perspectives is among the first to predict a person's pesticide exposure based on information about their usual diet.

Curl and her colleagues analyzed the dietary exposure of nearly 4,500 people from six U.S. cities to organophosphates (OPs), the most common insecticides used on conventionally grown produce in the United States. OP pesticides are linked to a number of detrimental health effects, particularly among agricultural workers who are regularly exposed to the chemicals.

Results showed that among individuals eating similar amounts of fruits and vegetables, those who reported eating organic produce had significantly lower OP pesticide exposures than those consuming conventionally grown produce. In addition, consuming those conventionally grown foods typically treated with more of these pesticides during production, including apples, nectarines and peaches, was associated with significantly higher levels of exposure. "For most Americans, diet is the primary source of OP pesticide exposure," said Curl "The study suggests that by eating organically grown versions of those foods highest in pesticide residues, we can make a measurable difference in the levels of pesticides in our bodies."

The researchers were able to predict each participant's exposure to OP pesticides based on the amount and type of produce each participant typically ate and the U.S. Department of Agriculture's measurements of pesticide residue levels on those foods. The researchers then compared these predictions to pesticide metabolite levels measured in urine samples from a subset of 720 of these people.

"The next step is to use these exposure predictions to examine the relationship between dietary exposure to pesticides and health outcomes, including neurological and cognitive endpoints. We'll be able to do that in this same population of nearly 4,500 people," she said.

One way people can reduce their pesticide exposure, said Curl, is to eat organic versions of those foods that are listed on the Environmental Working Group's "Dirty Dozen" list, which ranks fruits and vegetables according to pesticide residue level.

Think about all the plastics we use, and all the chemicals we are exposed to. Read labels on personal care products and try to avoid: phthalates, parabens, BPA, triclosan, fragrances. If possible, use glass containers to store and microwave food. Avoid unnecessary pesticides, for example on lawns, and consider organic lawn care and gardening.  From Science Daily:

Earlier menopause linked to everyday chemical exposures

Women whose bodies have high levels of chemicals found in plastics, personal-care products, common household items and the environment experience menopause two to four years earlier than women with lower levels of these chemicals, according to a new study at Washington University School of Medicine in St. Louis.

The researchers looked at levels in blood and urine of 111 chemicals that are suspected of interfering with the natural production and distribution of hormones in the body. While several smaller studies have examined the link between so-called endocrine-disrupting chemicals and menopause, the new research is the first to broadly explore the association between menopause and individual chemicals on a large scale, using a nationally representative sample of patients across the United States.

“Chemicals linked to earlier menopause may lead to an early decline in ovarian function, and our results suggest we as a society should be concerned,” said senior author Amber Cooper, MD, an assistant professor of obstetrics and gynecology. A decline in ovarian function not only can adversely affect fertility but also can lead to earlier development of heart disease, osteoporosis and other health problems. Other problems already linked to the chemicals include certain cancers, metabolic syndrome and, in younger females, early puberty.

“Many of these chemical exposures are beyond our control because they are in the soil, water and air,” Cooper said. “But we can educate ourselves about our day-to-day chemical exposures and become more aware of the plastics and other household products we use.”...Although many of the chemicals included in the study have been banned from U.S. production because of their negative health effects, they still are produced globally and are pervasive in the environment.

In the study, Cooper and researchers at the University of Missouri-Kansas City School of Medicine and the Wadsworth Center at the State University of New York at Albany analyzed data collected from 1999-2008 as part of the National Health and Nutrition Examination Survey, conducted by the U.S. Centers for Disease Control and Prevention.The survey included data from 31,575 people, including 1,442 menopausal women who had been tested for levels of endocrine-disrupting chemicals. The average age of these women was 61, and none was using estrogen-replacement therapies or had had surgery to remove ovaries.

The women’s blood and urine samples were analyzed for exposures to 111 mostly man-made chemicals, which included known reproductive toxins and/or those that take more than a year to break down. Chemicals from the following categories were analyzed in the survey: dioxins/furans (industrial combustion byproducts); phthalates (found in plastics, common household items, pharmaceuticals and personal-care products including lotions, perfumes, makeup, nail polish, liquid soap and hair spray); phytoestrogens (plant-derived estrogens); polychlorinated biphenyls (PCBs, coolants); phenolic derivatives (phenols, industrial pollutants); organophosphate pesticides; surfactants; and polycyclic aromatic hydrocarbons (combustion products).

The researchers identified 15 chemicals — nine PCBs, three pesticides, two phthalates and a furan (a toxic chemical) — that warrant closer evaluation because they were significantly associated with earlier ages of menopause and potentially have detrimental effects on ovarian functionagefurans

Read the labels on personal care products, and do NOT buy those with triclosan! (See earlier posts for other reasons to avoid triclosan.) From Science Daily:

The 'dirty' side of soap: Triclosan, a common antimicrobial in personal hygiene products, causes liver fibrosis and cancer in mice

Triclosan is an antimicrobial commonly found in soaps, shampoos, toothpastes and many other household items. Despite its widespread use, researchers report potentially serious consequences of long-term exposure to the chemical.The study, published Nov. 17 by Proceedings of the National Academy of Sciences, shows that triclosan causes liver fibrosis and cancer in laboratory mice through molecular mechanisms that are also relevant in humans.

"Triclosan's increasing detection in environmental samples and its increasingly broad use in consumer products may overcome its moderate benefit and present a very real risk of liver toxicity for people, as it does in mice, particularly when combined with other compounds with similar action," said Robert H. Tukey, PhD, professor in the departments of Chemistry and Biochemistry and Pharmacology. 

Tukey, Hammock and their teams, including Mei-Fei Yueh, PhD, found that triclosan disrupted liver integrity and compromised liver function in mouse models. Mice exposed to triclosan for six months (roughly equivalent to 18 human years) were more susceptible to chemical-induced liver tumors. Their tumors were also larger and more frequent than in mice not exposed to triclosan.

The study suggests triclosan may do its damage by interfering with the constitutive androstane receptor, a protein responsible for detoxifying (clearing away) foreign chemicals in the body. To compensate for this stress, liver cells proliferate and turn fibrotic over time. Repeated triclosan exposure and continued liver fibrosis eventually promote tumor formation.

Triclosan is perhaps the most ubiquitous consumer antibacterial. Studies have found traces in 97 percent of breast milk samples from lactating women and in the urine of nearly 75 percent of people tested. Triclosan is also common in the environment: It is one of the seven most frequently detected compounds in streams across the United States.

More about this study plus a discussion about the FDA's lack of action. From The Atlantic:

The Ingredient to Avoid in Soap

The link between pesticide exposure (pesticides used in the home or in the garden or lawn) and childhood brain tumors has been known for years. From Science Daily:

Factors associated with childhood brain tumors identified

Older parents, birth defects, maternal nutrition and childhood exposure to CT scans and pesticides are increasingly being associated with brain tumors in children, according to new research. Brain and central nervous system tumors are the second leading cause of cancer death in children.

A team of researchers, led by Kimberly Johnson, PhD, assistant professor of social work at the Brown School, a member of the Institute for Public Health and a research member of Siteman Cancer Center, examined studies published since 2004 that analyzed the incidence of childhood brain tumors and survival in different parts of the world.

In this research, binge drinking was defined as drinking four or more units of alcohol in a day on at least one occasion during the pregnancy.From Science Daily:

Binge drinking in pregnancy can affect child's mental health, school results

Binge drinking during pregnancy can increase the risk of mental health problems (particularly hyperactivity and inattention) in children aged 11 and can have a negative effect on their school examination results, according to new research on more than 4,000 participants.  This builds on earlier research on the same children that found a link between binge drinking in pregnancy and their mental health when aged four and seven, suggesting that problems can persist as a child gets older. Other effects, such as on academic performance, may only become apparent later in a child's life.

Women who are pregnant or who are planning to become pregnant should be aware of the possible risks associated with episodes of heavier drinking during pregnancy, even if this only occurs on an occasional basis.'The consumption of four or more drinks in a day may increase the risk for hyperactivity and inattention problems and lower academic attainment even if daily average levels of alcohol consumption during pregnancy are low.

From Science Daily: Healthy lifestyle could prevent nearly half of all diabetic pregnancies

Nearly half of all cases of diabetes during pregnancy, known as gestational diabetes, could be prevented if young women eat well, exercise regularly and stop smoking before and during pregnancy, finds a study.

Several modifiable risk factors before pregnancy have been identified over the past decade. These include maintaining a healthy weight, consuming a healthy diet, regular physical activity, and not smoking.So a team of researchers based in the United States set out to examine the effect of these "low risk" lifestyle factors on the risk of gestational diabetes -- and measure the portion of the condition that may be preventable through adhering to them.

The strongest individual risk factor for gestational diabetes was pre-existing overweight or obesity -- having a body mass index (BMI) above 25 before pregnancy. Women with a BMI above 33 were over four times more likely to develop gestational diabetes than women who had a normal BMI before pregnancy. ..Compared with women who did not meet any of the low risk lifestyle factors, those meeting all four criteria had an 83% lower risk of developing gestational diabetes.

The study found real differences between organic and conventionally grown foods - organic foods have lower levels of pesticides, higher levels of antioxidants, and lower levels of cadmium. From NY Times:

Study of Organic Crops Finds Fewer Pesticides and More Antioxidants

Adding fuel to the debates over the merits of organic fooda comprehensive review of earlier studies found substantially higher levels of antioxidants and lower levels of pesticides in organic fruits, vegetables and grains compared with conventionally grown produce.

However, the full findings, to be published next week in the British Journal of Nutrition, stop short of claiming that eating organic produce will lead to better health. Still, the authors note that other studies have suggested some of the antioxidants have been linked to a lower risk of cancer and other diseases.

Organic farming, by and large, eliminates the use of conventional chemical fertilizers and pesticides. Those practices offer ecological benefits like healthier soils but produce less bountiful harvests. 

In the new study, an international team of scientists did not conduct any laboratory or field work of their own. Instead, they compiled a database from 343 previously published studies and performed a statistical procedure known as a meta-analysis, which attempts to ferret robust bits of information from studies of varying designs and quality.

Over all, organic crops contained 17 percent more antioxidants than conventionally grown crops, the new study found. For some classes of antioxidants, the difference was larger. A group of compounds known as flavanones, for example, were 69 percent higher in the organic produce. (At very high quantities, as in some supplements, some antioxidants have been shown to be harmful, but the levels in organic produce were not nearly that high.)

The researchers said they analyzed the data in several different ways, and each time the general results remained robust. Charles M. Benbrook, a professor at Washington State University and another author of the paper, said this analysis improved on earlier reviews, in part because it incorporated recent new studies.

The study also found that organically produced foods, particularly grains, contain lower levels of cadmium, a toxic metal that sometimes contaminates conventional fertilizers. Dr. Benbrook said the researchers were surprised by that finding; there was no difference in other toxic metals like mercury and lead.

Informing pregnant women about environmental health hazards is absolutely necessary, especially because steps can be taken to avoid them (such as pesticides, mercury in fish, lead and BPA). Why isn't it happening routinely? Hey obstetricians - are you listening? From Huffington Post:

Doctors Fail To Counsel Pregnant Women On Toxic Chemical Risks

...dozens of environmental chemicals can course through a pregnant woman's body, cross the umbilical cord and wreck havoc on a developing fetus. Birth defects, IQ losses and childhood cancers are just some of the potential risks scientists have now tied to even low levels of exposure.

Among more than 2,500 doctors consulted for the survey, nearly all of them reported counseling patients on factors such as diet, exercise and cigarette smoking. However, only about 20 percent said they addressed environmental exposures. They pegged their hesitation to a number of factors, from the fear of overwhelming patients with anxiety-inducing worries to limited appointment time to a lack of environmental health education.

Just one in 15 doctors said they had received training on the harmful reproductive effects of toxic chemicals. "Medical school and residencies tend to frame their curriculum around the boards and required licensing exams," said Stotland. "This material is not yet on those tests." ... The American College of Obstetrics and Gynecologists (ACOG) and the American Society for Reproductive Medicine (ASRM) issued a statement in October that underscored mounting evidence of "significant and long-lasting effects" caused by industrial chemicals, and emphasized doctors' role in protecting pregnant women.

The actual study from Plos One summed up the importance of knowing about exposures to environmental hazards during pregnancy very nicely in the introduction:

Counseling Patients on Preventing Prenatal Environmental Exposures - A Mixed-Methods Study of Obstetricians

Exposure to hazardous environmental chemicals, i.e., manufactured chemicals and metals, is linked to adverse health outcomes across all stages of the human life cycle including fertility, conception, pregnancy, child and adolescent development, and adult health [1][5]. Human exposure to environmental chemicals is ubiquitous. A population-based study found that virtually all pregnant women in the U.S. had measureable levels of at least 43 different environmental chemicals in their bodies, including chemicals that were measured at levels similar to those associated with adverse developmental and reproductive health outcomes in epidemiologic studies [6]. There are currently over 80,000 chemicals in commerce [7][8], and exposure occurs through air, water, food and consumer products in the home and workplace. The majority of industrial chemicals have not been tested for potential reproductive/developmental harm [9].

Obstetricians are uniquely positioned to help prevent exposures to environmental chemicals with adverse developmental and reproductive health effects [2]. Pregnancy is a time when exposure to environmental contaminants can disrupt or interfere with the physiology of a cell, tissue, or organ [4], leading to permanent and lifelong adverse health outcomes that may be passed down to future generations [10]. Pregnancy is also an opportune time to prevent harmful exposures as it is a period when patient interest about health can be extremely high.

The researchers of this study looked at proximity to farm fields (how close a pregnant woman lives to a farm) and certain farm pesticides and found a link between exposure to farm pesticides during pregnancy and having a child with autism. But too bad they didn't also include pesticide exposures from homes (for pest control), gardens, and yards which would have given a more accurate measure of total exposure. However, it's a start. From Science Daily:

Association found between maternal exposure to agricultural pesticides and autism

Pregnant women who lived in close proximity to fields and farms where chemical pesticides were applied experienced a two-thirds increased risk of having a child with autism spectrum disorder or other developmental delay, a study by researchers with the UC Davis MIND Institute has found. The associations were stronger when the exposures occurred during the second and third trimesters of the women's pregnancies.

The large, multisite California-based study examined associations between specific classes of pesticides, including organophosphates, pyrethroids and carbamates, applied during the study participants' pregnancies and later diagnoses of autism and developmental delay in their offspring. It is published online in Environmental Health Perspectives. "... the message is very clear: Women who are pregnant should take special care to avoid contact with agricultural chemicals whenever possible."

California is the top agricultural producing state in the nation, grossing $38 billion in revenue from farm crops in 2010. Statewide, approximately 200 million pounds of active pesticides are applied each year, most of it in the Central Valley, north to the Sacramento Valley and south to the Imperial Valley on the California-Mexico border. While pesticides are critical for the modern agriculture industry, certain commonly used pesticides are neurotoxic and may pose threats to brain development during gestation, potentially resulting in developmental delay or autism.

The study was conducted by examining commercial pesticide application using the California Pesticide Use Report and linking the data to the residential addresses of approximately 1,000 participants in the Northern California-based Childhood Risk of Autism from Genetics and the Environment (CHARGE) Study. The study includes families with children between 2 and 5 diagnosed with autism or developmental delay or with typical development. "We mapped where our study participants' lived during pregnancy and around the time of birth. In California, pesticide applicators must report what they're applying, where they're applying it, dates when the applications were made and how much was applied," Hertz-Picciotto said. "What we saw were several classes of pesticides more commonly applied near residences of mothers whose children developed autism or had delayed cognitive or other skills."

Organophosphates applied over the course of pregnancy were associated with an elevated risk of autism spectrum disorder, particularly for chlorpyrifos applications in the second trimester. Pyrethroids were moderately associated with autism spectrum disorder immediately prior to conception and in the third trimester. Carbamates applied during pregnancy were associated with developmental delay.

Exposures to insecticides for those living near agricultural areas may be problematic, especially during gestation, because the developing fetal brain may be more vulnerable than it is in adults. Because these pesticides are neurotoxic, in utero exposures during early development may distort the complex processes of structural development and neuronal signaling, producing alterations to the excitation and inhibition mechanisms that govern mood, learning, social interactions and behavior.