Babies exposed to pesticides before birth may have significantly lower intelligence scores by age 7 than children who were not exposed, three separate studies published on Thursday said. Results from the studies -- two in New York and one in an agricultural community in California -- suggest prenatal exposure to pesticides can have a lasting effect on intelligence.
In one study, a team at the University of California Berkeley found that every tenfold increase in prenatal exposure to organophosphate pesticides corresponded with a 5.5 point drop in overall IQ scores in children by age 7.
"That difference could mean, on average, more kids being shifted into the lower end of the spectrum of learning, and more kids needing special services in school," Berkeley's Brenda Eskenazi, who led one of the three studies published online in Environmental Health Perspectives, said in a statement.
The two other studies -- one at Mount Sinai Medical Center and the other at Columbia University -- also examined prenatal exposure to pesticides and IQ in children at age 7.
The teams at Berkeley and Mount Sinai sampled pesticide residues in maternal urine, while the team at Columbia tested umbilical cord blood levels of chlorpyrifos, part of a class of pesticides known as organophosphates that are known to be toxic to brain cells.