Prenatal Pesticide Exposure May Harm Babies’ Brains

Pesticide exposure is linked to lower IQ scores.

In case you needed another reason to choose organic—here’s the latest: three new studies have found that in utero exposure to pesticides can harm a baby’s brain and affect intelligence levels, with adverse cognitive effects that continue into early childhood. The three studies were published ahead of print in the journal Environmental Health Perspectives and a press release issued by the journal stated, “The fact that three research groups reached such similar conclusions independently adds considerable support to the validity of the findings.”[1][2][3]

Researchers are quick to point out that the results of the studies show an association, not a causative link, between pesticide exposure and cognitive effects. However, research will likely be ongoing to continue to explore the association. The studies were conducted in New York and California, in both urban and rural areas, indicating that the results are not limited by region or type of environment.

Each of the studies found a link between prenatal pesticide exposure and lower IQ scores at age seven. One study found that kids with the highest pesticide exposure in the womb scored seven points lower on IQ tests than kids with the lowest exposure levels. The implications of the results are profound—an increasing number of children with cognitive challenges could result in an increased need for special services in schools nationwide.

Prenatal exposure can occur when pregnant moms eat foods that have been exposed to pesticides or when they are exposed to pesticides in the environment. For example, farm workers, gardeners, and florists might have a greater exposure to pesticides than the general population.

The takeaway message? Everyone—especially pregnant women—should exercise common sense regarding pesticide exposure. If you want to reduce your exposure to potentially neurotoxic chemicals:

  • Reduce the use of home pesticides
  • Buy organic produce whenever possible
  • Thoroughly wash produce with a soft brush
  • Avoid areas where pesticides and sprays are being used


[1] Bouchard MF, Chevrier J, Harley KG, et al. Prenatal exposure to organophosphate pesticides and IQ in 7-year-old children. Environmental Health Perspectives. Published early online: April 21, 2011.

[2] Engel SM, Wetmur J, Chen J, et al. Prenatal exposure to organophosphates, paraoxanase 1 and cognitive development in childhood. Environmental Health Perspectives. Published early online: April 21, 2011.

[3] Rauh V, Arunajadai S, Horton M, et al. Seven-year neurodevelopmental scores and prenatal exposure to chlorpyrifos, a common agricultural pesticide. Environmental Health Perspectives. Published early online: April 21, 2011.