Autism Linked To Pesticide Exposure In New Study
A new study from California has shown that children are more likely to have an autism spectrum disorder if their mothers were exposed to certain pesticides during pregnancy,Yahoo News reports.
The study also linked agricultural pesticides to other types of developmental delays among children, according to its lead author, Janie F. Shelton, of the University of California, Davis.
“Ours is the third study to specifically link autism spectrum disorders to pesticide exposure, whereas more papers have demonstrated links with developmental delay,” Shelton said, although she cautioned that scientists cannot yet definitively say that pesticides cause autism.
According to Irva Hertz-Picciotto, an environmental epidemiologist who is one of the co-authors of the study, explains that pesticides work on the nervous systems of insects, incapacitating them. While adult humans are protected from many of the neurological effects of pesticides by a barrier that prevents transmission of substances between the blood and brain, Hertz-Picciotto tells CBS News that in young children, that barrier isn’t fully formed. Pesticides may therefore impact the nerve cells of young children at a crucially formative period.
The study tracked exposure during pregnancy for the mothers of 970 children. Of that group, 486 had an autism spectrum disorder, while 168 presented symptoms of developmental delay. Researchers found that mothers who were exposed to organophosphate based pesticides were 60 percent more likely to have a child with an autism spectrum disorder. The study also examined pyrethroid insecticides, which also presented an increased risk of autism and developmental delay, as well as carbamate pesticides, which were linked to developmental issues but not autism risk.
The timing of exposure seemed to be important with certain pesticides, while in others, exposure at any time during pregnancy was problematic. When timing was an issue, exposure just before conception or in the last trimester of pregnancy was most critical.
Philippe Grandjean, an adjunct professor at Harvard School of Public Health in Boston, called the results of the study into question, pointing out that since the study looked backward in time, researchers weren’t able to directly measure pesticide exposure through blood and urine samples. Grandjean claimed that the study therefore cannot point to specific substances as a culprit, stating that it also “cannot relate to specific levels of exposure.”
The possible causes of autism have been the center of public debate recently, with theories that vaccination causes autism spectrum disorders promoted by some while being refuted by others, as The Inquisitr has previously reported.
While researchers involved with the study agree that it represents only a small piece of the autism puzzle, it nevertheless provides further support to the theory that pesticides may be a contributing factor to autism spectrum disorders.
[Images via The Daily Radish and USA Today]
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