11
Jul
Pregnant Mothers Exposed to Insecticides More Likely to Have Children Who Develop ADHD
(Beyond Pesticides, July 11, 2019) Pregnant mothers with higher concentrations of pesticide metabolites (breakdown products) in their urine are more likely to have children who develop symptoms of Attention Deficit/Hyperactivity Disorder (ADHD), according to research conducted by the University of Southern Denmark and Odense University Hospital. The results of this study are consistent with past findings from Rutgers University and Cincinnati Children’s Medical Center, indicating a need for researchers to determine causality, and pesticide regulators to rein in toxic insecticide use.
The pesticides investigated by researchers were breakdown products of the organophosphate chlorpyrifos, and the synthetic pyrethroid class of insecticides. The residue of these chemicals are frequently detected on conventional, industrially farmed food products. Although chlorpyrifos is banned from residential use in the U.S., most household bug sprays such as RAID contain high amounts of synthetic pyrethroids.
Among the 948 pregnant Danish women tested, 90% had some level of chlorpyrifos metabolites (3,5,6-trichloro-2-pyridinol) detected in their urine, and 94% were positive for the generic pyrethroid metabolite (3-phenoxybenzoic acid).
Scientists continued to follow up with pregnant women’s children through the first five years of life. A child behavioral check list was completed to determine the relative level of ADHD symptoms.
Concentrations of both chlorpyrifos and pyrethroid breakdown products in maternal urine samples above the median detection rate for the study corresponded with a 98% increase in odds of their children having ADHD scores in the 90th percentile, a strong predictor for an ADHD diagnosis. According to a regression model calculated by researchers, each time maternal urinary concentrations of generic pyrethroid metabolites doubled, it was associated with a 3% higher expected ADHD score, and a 13% higher chance of the child scoring in the 90th percentile. The results were similar regardless of gender reported.
“We see a clear connection between these insecticides in the urine samples of the women and the ADHD symptoms displayed by their children,” Louise Dalsager, a co-author of the study and PhD student to The Copenhagen Post. “It was surprising to see that the connection was noticeable, even if the concentrations weren’t particularly high.”
It is particularly concerning that low levels of pesticide metabolites, chemicals that can be relatively quickly excreted from the body through urine, corresponded with the health endpoints studied in offspring up to five years later. And this concern is buttressed by reports that both children and their parents are increasingly exposed to pyrethroid insecticides.
Studies find that higher rates of ADHD is also associated to direct exposure in children, and pyrethroid metabolites found in children’s urine. In 2015, Cincinnati Children’s Hospital Medical Center found a strong association between urinary pyrethroid concentrations and ADHD, but primarily in boys. Any concentrations found above the level of detection corresponded to a three-fold increase in the chance of developing ADHD, when compared to boys without detectable levels.
Another 2015 study from Rutgers University found that, of over 2,000 children who had ever received an ADHD diagnosis, children with higher urinary pyrethroid metabolite levels were more than twice as likely to be diagnosed with ADHD.
The impact of pyrethroids is not limited to ADHD. A 2017 study by French scientists tracking urinary pyrethroid levels in both pregnant women and their children found associations between both externalizing and internalizing behavioral disorders. A 2013 Canadian study found significant associations between past use of pesticides around the home within the previous month and elevated scores on behavioral and emotional conduct tests. And a 2011 study found that children with high levels of exposure to pyrethroids and the synergist piperonyl butoxide (often added to pyrethroid products to increase their potency) scored lower on tests for cognitive motor development. At the time, renown pediatrician Philip Landrigan remarked that the intelligence lost from pyrethroid exposure was the same level seen by exposure to lead.
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 gene has been found, and there is increasing evidence that environmental factors like pesticide exposure facilitate the development of the condition. The good news is that avoiding pyrethroids and the organophosphate insecticide chloryrifos is possible. Numerous studies find that levels of pesticide metabolites in urine drop precipitously when switching to an all organic diet. And when pest problems occur around the home, you should never need to resort to highly toxic, yet sadly commonly used pyrethroid-based products like RAID. To assist with those pest problems, see Beyond Pesticides ManageSafe database or reach out to our office through [email protected] or 202-543-5450.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: The Copenhagen Post, Environmental Research (peer reviewed journal)
This study on the link between insecticide exposure during pregnancy and the increased risk of ADHD in children is concerning. It emphasizes the importance of minimizing exposure to harmful chemicals, especially during pregnancy when the developing fetus is most vulnerable. It reinforces the need for safer alternatives and stronger regulations to protect the health and well-being of pregnant women and their children. Thank you for shedding light on this important issue!
June 5th, 2023 at 2:45 am