Pregnant women who live within a mile of spaces where commercial pesticides are applied appear to have an increased risk of having a child with autism, a new study suggests.
The risk that a child would develop autism appeared to be highest for women who lived near farms, golf courses and other public spaces that were treated with pesticides during the last three months of their pregnancies.
While the association between possible pesticide exposure and autism is interesting, an expert not involved in the research pointed out that it has a major flaw.
Because the study looked back in time, researchers weren't able to collect blood or urine samples to directly measure pesticide exposures. And they looked at risks associated with four different classes of chemicals.
"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," he said.
As a result, he said, the link reported in this study is weak.