Can chlorpyrifos pesticide residues in food affect your baby's brain development?

What's actually in it

Chlorpyrifos is an organophosphate insecticide used on fruits, vegetables, and grain crops. 2,4-Dichlorophenoxyacetic acid (2,4-D) is one of the most widely used herbicides on lawns, golf courses, and cereal crops. Both chemicals leave residues on food that you eat, and they can also drift into homes near treated fields.

During pregnancy, both chemicals cross the placenta and reach the developing baby's brain during critical windows of growth.

What the research says

A 2026 study in Environ Int followed pregnant women and measured their exposure to chlorpyrifos and 2,4-D through urine biomarkers. The researchers then assessed the babies' neurodevelopmental outcomes in early childhood.

Babies born to mothers with higher chlorpyrifos levels showed changes in brain connectivity patterns and scored lower on tests of cognitive function and motor development. The effects were strongest when exposure happened during the first trimester, when the brain's basic wiring is being laid down.

2,4-D exposure showed similar but milder associations with behavioral changes and attention problems in toddlers. The combination of both pesticides produced additive effects, meaning the total impact was greater than either chemical alone.

Washing produce thoroughly helps reduce surface residues, but it doesn't remove chemicals that were absorbed into the fruit or vegetable. Buying organic versions of the most heavily sprayed crops (like strawberries, apples, and spinach) during pregnancy is a practical way to lower exposure.