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Tag: autism spectrum disorder

Published on Leave a comment on Pyrethroids and Autism Spectrum Disorder

A recent study may contribute to explaining why autism spectrum disorder (ASD) rates are rising so rapidly in the US. The CDC reports that 1 in 36 children have autism spectrum disorder as of 2020!! Researchers and physicians agree that things in the environment (e.g., pesticides) are playing a role in this increase.

Even though the study was conducted in mice, it examined the impact of pesticides called pyrethroids on neurological development. They found that even at low levels that humans are typically exposed to, there were neurological effects on mice who were exposed during pregnancy. Their behaviors were altered in a negative way, for example an increase in repetitive behaviors.

Pyrethroids are being used in increasing amounts in the US for all sorts of insect treatments, both inside and outside of homes. It's very frequently used against mosquitos. Studies find that 70 to 80% of the US population have pyrethroid breakdown products (metabolites) in the blood. This is because we are exposed to chronic low levels - whether in the air, in water, around our homes or workplace.

The researchers wrote in the published research that scientists are especially concerned with pyrethroid exposure because it has a harmful effect on fetal development in both humans and animals. Studies are finding links from pyrethroid exposure during pregnancy or infancy and developmental delays.

"Critically, evidence from recent epidemiology and longitudinal studies suggests that ambient prenatal exposure to pyrethroid pesticides poses a risk for autism, developmental delay, and neurodevelopmental disorders in general. Analysis of data from the CHARGE study showed a significant increase in risk for either ASD or developmental delay from exposure during pregnancy to pyrethroid pesticides being applied up to 1.5 km from the home. A regional study in New York showed an association between areas where aerial application of pyrethroid pesticides was used, and ASD and developmental delay prevalence in the area. Additionally, the presence of pyrethroid metabolites in blood or urine correlates with risk for ADHD in children."

Bottom line: Avoid using pyrethroids around the home and yard. Look into IPM (Integrated Pest Management) or organic and natural ways to deal with pests. Pyrethroids are also toxic to bees, and we need bees. Synthetic pyrethroids (which is what is commonly used) are not like natural extracts from the chrysanthemum flower, and don't let someone tell you they are.

Excerpts from Medical Xpress: Research links common insecticide to neurodevelopmental disorders

A new study from The University of Toledo suggests early exposure to a common class of insecticides called pyrethroids may increase the risk of autism and other developmental disorders, even at levels currently recognized as safe by federal regulators. ...continue reading "Pyrethroids and Autism Spectrum Disorder"

Published on Leave a comment on Vitamin D and Folic Acid Levels During Pregnancy

 Two interesting studies about vitamins during pregnancy and possible effects on the child. One found that low levels of vitamin D3 is linked to behavioral issues and ADHD symptoms in preschool aged children, while the other raises the possibility of very high levels of folic acid during pregnancy linked to autism in the child. More studies are needed.

From Medscape:  Maternal Vitamin D Deficiency and Behavioral Issues in Offspring

Maternal vitamin D deficiency in early pregnancy is associated with an increased risk of behavioral issues and attention-deficit/hyperactivity disorder (ADHD)–like symptoms in preschool children, according to new data from a birth cohort study in Greece. But no association was found between maternal vitamin D deficiency and cognitive scores in the children at age 4, reported Vasiliki Daraki, MD, an endocrinologist from the University of Crete, Heraklion, Greece, who led the analysis, which was  a poster presented at the European Congress of Endocrinology 2016.

The analysis showed that maternal vitamin D levels lower than 50 nmol/L during the first trimester of pregnancy were associated with increased behavioral problems and ADHD-like symptoms among the offspring...."The lower the mother's vitamin D levels, the higher the child's hyperactivity and inattention," reported Dr Daraki.

"I think the role of vitamin D in the developing brain is in neuronal differentiation and axon development, and these are more important for behavioral problems than for cognition," Dr Daraki added.....In the future, she and her colleagues intend to measure the cognitive function and behavioral status at the age of 7 years and determine whether the results still hold at the later age.

From Medical Xpress:  A study asks: Too much folic acid a cause of autism?

For decades, pregnant women and women who may become pregnant have been advised to take folic acid to help prevent certain birth defects. But a new study suggests it may be possible to get too much of a good thing—very high levels of the vitamin in mothers' blood at the time of childbirth was linked to higher risk of their children developing autism years later. (Other research points to an opposite relationship between folic acid and autism, showing that adequate amounts of the vitamin at the time of conception can significantly reduce the risk.) 

Folate is a vitamin found in foods that is important in cell growth and development of the nervous system. A synthetic version, folic acid, is used in supplements and is used to fortify flour and cereals. Decades ago, researchers found certain levels of folic acid could prevent major birth defects of the baby's brain and spine. In the early 1990s, U.S. health officials began recommending that all women who might become pregnant should take 400 micrograms of folic acid daily. And in the late 1990s, federal regulations began mandating that folic acid be added to flour, bread and other grain products.

The new researchers followed 1,391 children who were born at Boston University Medical Center in 1998 through 2013. About 100 of them were later diagnosed with an autism spectrum disorder. The researchers went back and looked at levels of folate and vitamin B12 in the blood of the children's mothers at the time of childbirth. They found that 16 of them had very high levels of folate, and 15 had extremely high levels of vitamin B12. If both levels are extremely high, there is more than a 17-fold greater risk that a child will develop autism, the researchers said. 

Most of the moms in the study said they took multivitamins—which would include folic acid and vitamin B12—throughout their pregnancy. But the researchers say they don't know why some women had such high levels in their blood. It may be related to taking too many supplements and eating too many fortified foods. Or there could be a genetic reason that caused some women to absorb more folate than others. Or there could be a combination, they said.

Published on

Two studies finding various forms of air pollution having effects on the developing fetus - the first one (fine particulate air pollution) to autism, and the second (outgassing of new flooring) to later breathing problems.

From Medical Xpress: Fine particulate air pollution linked with increased autism risk

Women exposed to high levels of fine particulate matter specifically during pregnancy—particularly during the third trimester—may face up to twice the risk of having a child with autism than mothers living in areas with low particulate matter, according to a new study from Harvard School of Public Health (HSPH). The greater the exposure, the greater the risk, researchers found. It was the first U.S.-wide study exploring the link between airborne particulate matter and autism.

"Our data add additional important support to the hypothesis that maternal exposure to air pollution contributes to the risk of autism spectrum disorders," said Marc Weisskopf, associate professor of environmental and occupational epidemiology and senior author of the study.... Prior studies have suggested that, in addition to genetics, exposure to airborne environmental contaminants, particularly during pregnancy and early life, may affect risk of autism. This study focused specifically on the pregnancy period.

The study population included offspring of participants living in all 50 states in Nurses' Health Study II, a cohort of more than 116,000 female U.S. nurses begun in 1989. The researchers collected data on where participants lived during their pregnancies as well as data from the U.S. Environmental Protection Agency and other sources on levels of fine particulate matter air pollution (PM2.5)—particles 2.5 microns in diameter or smaller—in locations across the U.S. The researchers identified 245 children who were diagnosed with autism spectrum disorder (ASD) and a control group of 1,522 children without ASD during the time period studied.

Exposure to PM2.5 was significantly associated with autism during pregnancy, but not before or after, the study found. And during the pregnancy, the third trimester specifically was significantly associated with an increased risk. Little association was found between air pollution from larger-sized particles (PM10-2.5) and autism.

From Science Daily: New floor covering can lead to breathing problems in babies

New flooring in the living environment of pregnant women significantly increases the risk of infants to suffer from respiratory diseases in their first year of life. This is the result of a study that demonstrates that exposure to volatile organic compounds in the months before and after birth induces breathing problems in early childhood. The scientists therefore recommend that redecoration should be avoided during pregnancy or in the first year of children’s life.

The observed health risks are caused by increased concentrations of volatile organic compounds (in short: VOCs), such as styrene or ethylbenzene, which escape from new flooring and are then absorbed through the respiratory air. "We therefore do not recommend that laminate, carpet or floor coverings be laid in the homes of pregnant women. Although the concentrations of these volatile chemicals are lower if no adhesive is used when installing the flooring, even then the concentrations are still high enough to significantly increase the risk of infants suffering from respiratory complaints in their first few months," explains Dr. Ulrich Franck from the UFZ. 

Earlier studies from Leipzig had already shown that chemicals from home renovations lead to changes in the immune system of new-born children.... According to our results, exposure to these volatile chemical compounds seems to be more critical in pregnancy than in the first year of a child's life," concludes Dr. Irina Lehmann from the UFZ, who is in charge of the LINA study on lifestyle and environmental factors and their influence on the risk of allergies in newborn babies. An analysis of the data showed that renovations after the birth of a child had a much lower impact on respiratory problems than during pregnancy.

Published on

Another reason to be concerned about air pollution. And another study showing a link with environmental chemicals (this time coarse and fine particulate matter, known as PM10, which arises in part from traffic-related air pollution) and autism. From Science Daily:

Researcher adds to evidence linking autism to air pollutants

A researcher at the University of Wisconsin-Milwaukee (UWM) has added to a growing body of evidence that links autism to air pollutants such as those generated by cars and trucks.

Amy Kalkbrenner's study, published this week online at the journal Epidemiology, showed that pollution's impact on autism rates in North Carolina is similar to results of pollution-autism studies in California -- despite weather and climate differences between the two states. In addition, the work of Kalkbrenner and her colleagues, building on previous studies, showed that women in the third trimester of pregnancy were more susceptible to the damaging effects of air pollution on their unborn child.

"It adds another piece supporting the hypothesis that environmental chemicals are part of the autism puzzle," says Kalkbrenner, an assistant professor in UWM's Joseph J. Zilber School of Public Health. Autism, a spectrum of disorders affecting interpersonal relations and work achievement, now affects some 1 in 68 children in the U.S.

Her research team focused on exposure to coarse and fine particulate matter, known as PM10, which arises in part from traffic-related air pollution...Researchers used a new, more exact tool to measure the levels of particulate matter in smaller slices of time, based on pollution at the family's address during pregnancy. With this method, they were able to compare exposures during specific weeks of pregnancy. The approximately one thousand children who later developed some form of autism spectrum disorders were then compared to all other children.

Reasons for increased susceptibility in the third trimester of pregnancy are not known at this time. However, Kalkbrenner says this finding is consistent with theories that show links between autism and altered brain network development, specifically synaptic connections that are developing during the final months of pregnancy.

Published on

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.