Summary: A new longitudinal study offers the most compelling evidence to date that prenatal exposure to the insecticide chlorpyrifos (CPF) disrupts brain development and leads to persistent structural and functional abnormalities. In brain imaging and behavioral assessments of more than 270 children from New York City, higher prenatal CPF levels were linked to widespread changes in brain anatomy, metabolism, and motor control that persisted into adolescence.
These results are especially troubling because CPF continues to be used in agriculture, putting farmworkers, pregnant women, and young children at risk. The research team cautions that other organophosphate pesticides could produce similar long-term harms to the developing brain.
Key Facts
- Prenatal risk: In utero exposure to chlorpyrifos was associated with widespread brain abnormalities and reduced fine motor skills in school-aged children.
- Ongoing exposure: Although indoor residential use was banned in 2001, CPF remains in agricultural use on many non-organic crops, creating continuing exposure pathways for communities near farms and for consumers.
- Public health concern: The authors recommend ongoing monitoring of exposure levels during pregnancy and caution against organophosphate pesticide exposure during critical periods of brain development.
Source: Columbia University
Overview: Researchers from Columbia University Mailman School of Public Health, Children’s Hospital Los Angeles, and the Keck School of Medicine of USC report strong associations between prenatal chlorpyrifos exposure and enduring alterations in brain structure, function, and metabolism among children and adolescents.
The study, published in JAMA Neurology, evaluated 270 participants from the Columbia Center for Children’s Environmental Health birth cohort. All participants were born to Latino or African American mothers and had measurable chlorpyrifos in their umbilical cord blood. Between ages 6 and 14, the children underwent multiple neuroimaging modalities and behavioral testing to assess structural, microstructural, metabolic, and functional brain measures as well as motor performance.
Analyses showed that progressively higher prenatal CPF exposure corresponded to progressively larger changes in cortical thickness, white matter volume, diffusion measures, regional blood flow, and markers of neuronal density. Those same exposure gradients were associated with worse fine motor speed and motor programming—demonstrating a dose-response relationship between prenatal CPF and lasting neurodevelopmental effects.
In this cohort, residential pesticide use was the primary source of prenatal exposure. While indoor residential use of CPF was banned in the U.S. in 2001, agricultural application persists on fruits, vegetables, and grains. Agricultural use can contaminate outdoor air and dust near growing areas, contributing to community and occupational exposures among farmworkers and nearby residents.
“These exposure levels, similar to those observed in our sample, continue to put farmworkers, pregnant women, and unborn children at risk,” said Virginia Rauh, ScD, the study’s senior author and the Jane and Alan Batkin Professor of Population and Family Health at Columbia Mailman School. She emphasized the need for continued exposure monitoring in vulnerable populations, especially pregnant women in agricultural communities.
Bradley Peterson, MD, the study’s first author and Vice Chair for Research and Chief of Child & Adolescent Psychiatry at the Keck School of Medicine of USC, noted that the observed disturbances in brain tissue and metabolism were widespread and measurable across multiple imaging techniques. He added that other organophosphate pesticides likely produce similar effects and urged minimizing exposures during pregnancy, infancy, and early childhood—periods of rapid brain development and heightened vulnerability.
Additional authors include Howard Andrews, Wanda Garcia, and Frederica Perera at Columbia Mailman; Sahar Delavari, Ravi Bansal, Siddhant Sawardekar, and Chaitanya Gupte at the Institute for the Developing Mind, Children’s Hospital Los Angeles; and Lori A. Hoepner at SUNY Downstate School of Public Health.
Funding: The study received support from the National Institute of Environmental Health Sciences, the U.S. Environmental Protection Agency STAR program, the National Institute of Mental Health, the John and Wendy Neu Family Foundation, an anonymous donor, Patrice and Mike Harmon, the Inspirit Fund, and the Robert Coury family.
Disclosures: Dr. Peterson is President of Evolve Psychiatry Professional Corporation, an advisor to Evolve Adolescent Behavioral Health (with stock options), and provides expert testimony. Drs. Peterson and Bansal hold U.S. patent filings. All other authors reported no competing or potential conflicts of interest.
About this neurodevelopment research news
Author: Timothy Paul
Source: Columbia University
Contact: Timothy Paul – Columbia University
Image: Image credited to Neuroscience News
Original Research: Open access. “Brain Abnormalities in Children Exposed Prenatally to the Pesticide Chlorpyrifos” by Virginia Rauh et al., JAMA Neurology. (DOI and journal citation available in the published article.)
Abstract
Title: Brain Abnormalities in Children Exposed Prenatally to the Pesticide Chlorpyrifos
Importance
Chlorpyrifos is one of the most widely used insecticides globally. While animal and some clinical studies have suggested prenatal neurotoxicity, there has been limited direct evidence about CPF’s effects on the developing human brain.
Objective
To determine whether prenatal exposure to chlorpyrifos is associated with alterations in brain structure, function, and metabolism in school-aged children.
Design, Setting, and Participants
This prospective, longitudinal pregnancy cohort study spanned January 1998 to July 2015, with data analyzed through November 2024. The community-based cohort from northern Manhattan and the South Bronx initially enrolled 727 pregnant women of African American or Dominican descent; 512 had CPF measured at delivery. Children aged 6 and older were invited for magnetic resonance imaging and neurobehavioral assessment.
Exposure
Prenatal chlorpyrifos exposure measured in umbilical cord blood.
Main Outcomes and Measures
Anatomical MRI for cortical thickness and local white matter volumes; diffusion tensor imaging (DTI) for microstructural integrity; MR spectroscopy for indices of neuronal density; arterial spin labeling for regional cerebral blood flow; and standardized measures of cognitive and motor performance. Predefined hypotheses anticipated CPF-related abnormalities in frontotemporal cortices, basal ganglia, and connecting white matter pathways, along with reduced neuronal density.
Results
The analysis included 270 youths (123 boys, 147 girls) aged 6.0 to 14.7 years (mean 10.4 years), all with mothers who self-identified as Dominican or African American. Higher prenatal CPF exposure correlated with thicker frontal, temporal, and posteroinferior cortical regions alongside reduced white matter volumes in those same areas; increased fractional anisotropy and reduced diffusivity in the internal capsule; decreased regional cerebral blood flow across the brain; lower MR spectroscopy indices consistent with reduced neuronal density in deep white matter tracts; and poorer performance on fine motor (β = −0.30; t261 = −5.0; P < .001) and motor programming (β = −0.27; t261 = −4.36; P < .001) tasks.
Conclusions and Relevance
Prenatal chlorpyrifos exposure was associated with altered differentiation of neuronal tissue into gray and white matter, increased myelination in the internal capsule, widespread impairments in neuronal metabolism, and lasting deficits in motor performance. Chlorpyrifos increases oxidative stress and inflammation, which can impair mitochondrial function, neuronal development, and maturation of oligodendrocyte precursor cells responsible for axonal myelination. These molecular and cellular effects likely contribute to the observed long-term brain and motor outcomes.