Pesticides, Intelligence, and Behavior

Among the pesticides in common use in the United States today, I am most concerned about the organophosphates – originally commercialized as nerve agents for chemical warfare. A significant study published in the December 2006 Pediatrics links decreased brain development and increased ADHD to organophosphate levels in inner city minority children in New York City.

Researchers from Columbia University, the National Center for Environmental Health, and the CDC measured prenatal pesticide exposure levels and then followed the children for 3 years. After controlling for other variables, the researchers found that those in the high pesticide exposure group were five times more likely to be delayed on the Psychomotor Development Index, almost 2 ½ times more likely to be delayed on the Mental Development Index and significantly more likely to have attention problems, ADHD, or pervasive developmental disorder problems by the time they were 3 years old.

The average child in the U.S. today has evidence of organophosphate exposures about 3 times what the EPA considers safe – some children have 10 times the safe level.

What can be done to reduce exposure levels? The EPA has already moved to restrict the use of these pesticides indoors. I hope the EPA will now take steps to reduce the organophosphates on our food.

In the meantime, though, parents can reduce their family’s exposure by their choices at the supermarket. An encouraging February 2006 study from the NIH journal Environmental Health Perspectives found that evidence of children’s exposure to chlorpyrifos (the same organophosphate in the current New York study) virtually disappeared within 24 hours of typical suburban school kids’ switching to a mostly organic diet.

They didn’t have to learn to like any new foods; they just ate the organic version of the foods they were already eating – if readily available. If a simple substitution was not available, no switch was made.

To me, choosing organic is even more valuable during pregnancy and the first 3 years of life, when kids’ brains are growing the fastest.