Skip to content

    Health & Pregnancy

    Font Size

    Pesticide Exposure in Womb Linked to Lower IQ

    Studies Show Kids Exposed in Pregnancy May Also Have Later Problems With Attention and Memory

    Study of Farmworkers

    The third study was conducted in a community of California farmworkers.

    Researchers at University of California, Berkeley measured metabolites of organophosphates in urine samples collected from 326 pregnant women and from their children at age 6 months and ages 1, 2, 3.5, and 5 years.

    About 44% of the women worked on farms during the study, but they were not pesticide applicators.

    Kids who were exposed to the highest levels of organophosphates during pregnancy had IQ scores that were an average of 7 points lower than the IQ scores of kids with the lowest pesticide exposures.

    In fact, every tenfold increase in a pregnant mother’s pesticide exposure was associated with a more than 5-point drop in her child’s IQ at age 7.

    There was no association between the pesticide levels measured in the children’s urine and learning or memory problems.

    “This is not a trivial association,” says study researcher Brenda Eskenazi, PhD, professor of epidemiology and maternal and child health at the University of California, Berkeley.

    Normal IQs range from 85 to 115. Children who score lower than 85 often need special education classes in school to make up for trouble with reading, comprehension, and attention.

    “On a population basis, it means more kids are going to be driven down into the range that we’re concerned about,” Eskenazi says. “You’re going to have more kids below 85 IQ, which means that they may need to have special services.”

    The studies were published in the journal Environmental Health Perspectives.

    What the Findings Mean

    “This range of effects that these three studies are reporting are very similar to the effects that we associate with lower levels of exposure to lead,” says Philip J. Landrigan, MD, a pediatrician and Ethel H. Wise Professor and Chair of the department of community and preventive medicine at the Mount Sinai School of Medicine, in New York City.

    “These are kids who are going to be a couple of beats slower in thinking things through,” Landrigan tells WebMD.

    “Their working memory, which is the aspect of memory that we use to deal with tasks in the here and now, is going to be somewhat diminished. They’re going to have a shorter attention span, which means that they’re going to have trouble concentrating on tasks, focusing in school,” he says.

    Pregnancy Week-By-Week Newsletter

    Delivered right to your inbox, get pictures and facts on
    what to expect each week of your pregnancy.

    Today on WebMD

    hand circling date on calendar
    Track your most fertile days.
    woman looking at ultrasound
    Week-by-week pregnancy guide.
    Pretty pregnant woman timing contaction pains
    The signs to watch out for.
    pregnant woman in hospital
    Are there ways to do it naturally?
    slideshow fetal development
    pregnancy first trimester warning signs
    What Causes Bipolar
    Woman trying on dress in store
    pregnant woman
    Woman looking at pregnancy test
    calendar and baby buggy
    dark chocolate squares