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Apr 22, 2011

Lower I.Q. Scores in Children Exposed to Common Pesticides

Multiple studies have now shown that school-aged children whose mothers were exposed to high levels of common pesticides (organophosphates) during pregnancy have lower I.Q. scores than their peers.  Three long-term studies, all funded by the National Institute of Environmental Health Sciences and Environmental Protection Agency, were recently published in the journal Environmental Health Perspectives.  Blood, urine, and some umbilical cord blood samples were measured for pesticide exposure in about 1000 pregnant women in New York and California.  After the mothers gave birth, researchers  observed the development  of the children and monitored pesticide levels through regular urine samples.  In one study, overall I.Q. scores dropped 5.5 points for every 10-fold increase in organophosphate exposure identified during pregnancy.   Children with the highest degrees of exposure to prenatal pesticides scored 7 points below those children with the lowest degrees of exposure on intelligence tests.

Back in the 1980s, the newly discovered link between childhood lead exposure and lowered I.Q. led to the eventual removal of lead from gasoline, paints, and other products.   “When we took lead out of gasoline, we reduced lead poisoning by 90 percent, and we raised the I.Q. of a whole generation of children by four or five points,’’ said Dr. Philip Landrigan, a professor of pediatrics and director of the Children’s Environmental Health Center at Mount Sinai.  Maybe history will repeat itself here as we continue to learn more about the toxic effects that common pesticides have on our children.   

Individuals and families can do a lot to limit their exposure to dangerous pesticides and chemicals.  Choosing to buy organic foods as much as possible is a huge step toward reducing exposures.  When you can’t buy 100% organic, at least choose organic when it comes to the Dirty Dozen.  These are the most heavily sprayed fruits and vegetables.  Visit for more information.  If you do end up buying conventional produce, at least make sure to wash your items thoroughly and peel if possible to help remove some of the pesticide residues.    

Dr. Shana McQueen