A peer‑reviewed study of New York City children reports that higher prenatal exposure to the insecticide chlorpyrifos is associated with widespread differences in brain structure, function, and metabolism—and with poorer motor skills—that persist into adolescence.
Researchers from Columbia University’s Mailman School of Public Health, Children’s Hospital Los Angeles, and the Keck School of Medicine of USC examined 270 participants from the Columbia Center for Children’s Environmental Health cohort. Mothers—who identified as African American or Dominican—were recruited in northern Manhattan and the South Bronx between 1998 and 2006. Chlorpyrifos (CPF) levels were measured in umbilical cord or maternal plasma at delivery. Offspring underwent multimodal brain imaging and behavioral testing at ages 6 to 14. The paper, published August 18, 2025, in JAMA Neurology (82[10]:1057–1068), reports associations between prenatal CPF exposure and later brain and motor outcomes. (pmc.ncbi.nlm.nih.gov)
According to the study, progressively higher prenatal CPF levels were linked to thicker cortex in multiple frontal and temporal regions, reduced local white‑matter volumes in overlapping areas, altered diffusion tensor imaging metrics in internal capsule pathways, lower cerebral blood flow, lower MR‑spectroscopy indices of neuronal density, and poorer performance on fine‑motor and motor‑programming tests. The authors describe these abnormalities as “enduring and widespread” across modalities. (pmc.ncbi.nlm.nih.gov)
For this cohort, exposure was attributed largely to indoor residential spraying before household uses of CPF were ended; exposure levels fell after those products left the market. (pmc.ncbi.nlm.nih.gov)
Regulatory context: U.S. residential uses of chlorpyrifos were effectively eliminated following an EPA agreement with manufacturers announced in 2000; indoor household registrations were canceled in 2001 and retail sales ended by late 2002. Food tolerances were revoked in 2021 but reinstated after a November 2, 2023 ruling by the Eighth Circuit. In December 2024, EPA proposed revoking most food tolerances except for 11 specified crops; as of 2025, allowable uses are limited to those crops in certain states, with some states imposing additional restrictions. (epa.gov)
“Disturbances in brain tissue and metabolism” tied to prenatal CPF exposure appeared “remarkably widespread,” said first author Bradley Peterson, MD, urging caution to minimize exposures during pregnancy and early childhood. Senior author Virginia Rauh, ScD, said current exposures still put “pregnant women and unborn children in harm’s way,” calling for continued monitoring in vulnerable communities. (publichealth.columbia.edu)
Funding came from the National Institute of Environmental Health Sciences, the U.S. Environmental Protection Agency (STAR), the National Institute of Mental Health, and private donors. Peterson disclosed advisory work and stock options with Evolve Adolescent Behavioral Health and several patents; other authors reported no competing interests beyond noted grants. (pmc.ncbi.nlm.nih.gov)
