Can chlorpyrifos pesticide residues in drinking water damage brain cells?

What's actually in it

Chlorpyrifos is an organophosphate pesticide still used on many crops worldwide, though the EPA banned most U.S. food uses in 2021. Residues can contaminate drinking water through agricultural runoff. People living near farms or in areas with heavy pesticide use may have chlorpyrifos in their tap water.

What the research says

A 2026 study in Toxicol Sci tested what happens when animals drink chlorpyrifos-contaminated water over a long period. The researchers found loss of neurons in the striatum, a brain region critical for movement, learning, and reward. The pesticide also suppressed haptoglobin, a protein that protects against oxidative damage.

The striatum is the same brain area affected in Parkinson's disease. Long-term, low-level exposure through water may contribute to neurodegeneration and movement disorders over time.

If you live near farmland, test your water for pesticides. Use an activated carbon filter to remove organophosphates. Choose organic produce to avoid additional chlorpyrifos exposure from food.