Study Links Exposure to Pesticides during Pregnancy to Autism Risk
During pregnancy, women are recommended to avoid certain foods, beverages and environmental settings out of concern for the health of an unborn fetus. According to a new study, pregnant women who lived near areas with high levels of pesticides were more likely to have a baby with autism spectrum disorder (ASD), a neurodevelopmental disorder characterized by poor social and communication skills.
"Ours is the third study to specifically link autism spectrum disorders to pesticide exposure, whereas more papers have demonstrated links with developmental delay," said lead author Janie F. Shelton, from the University of California, Davis according to FOX News.
In this study, the team examined data on roughly 1,000 families who had children between the ages of two and five. There were around 486 autistic children, 168 children with some kind of developmental delay and 316 children who were developing typically. The researchers examined the relationship between the mother's residence during pregnancy and her risk of having an autistic child.
The researchers found that children who were exposed to pesticides in the womb had a 60 to 200 percent greater risk of being diagnosed with autism. The risk was dependent on the types of chemicals used, the proximity of the residence to the treated area and the time of exposure. The team reported that exposure during the third trimester increased a baby's risk of autism the most. Pregnant women who lived near farms, gold courses and other public areas that used pesticides also had a higher risk of giving birth to an autistic child.
"These neurodevelopment disabilities are not the function of a single factor," said study author Irva Hertz-Picciotto, an environmental epidemiologist at the MIND Institute at University of California, Davis according to Philly. "I would suspect that there's a number of different factors at play that have to do with maternal health, maternal nutrition, as well as chemicals that are used around the home as well as other factors like air pollution. It's going to be an accumulation of factors for any one woman."
Even though the researchers stated that autism risk can increase due to a combination of factors, they reasoned that pesticides alone could greatly increase autism risk because pesticides affect neurons. In insects, pesticides work by attacking the nervous system. These chemicals could be affecting the fetus' brain in similar ways.
Despite the study's findings, critics stated that one major flaw in the study's design is that the researchers examined data gathered previously. They did not collect and look at new samples.
"So this study cannot pinpoint specific substances as a culprit," said Philippe Grandjean, an adjunct professor of environmental health at Harvard School of Public Health in Boston, "Also, they cannot relate to specific levels of exposure, and they have not taken into account the possible contribution by residues in food."
The study was published in the journal, Environmental Health Perspectives.