Brain Abnormalities Seen in Children Exposed Prenatally to the Pesticide Chlorpyrifos
A major new study published in JAMA Neurology has found that children exposed in the womb to the pesticide chlorpyrifos (CPF) show long-term structural brain abnormalities and poorer motor function.
The research, conducted by Columbia University’s Mailman School of Public Health in collaboration with Children’s Hospital Los Angeles and USC’s Keck School of Medicine, is the first to demonstrate widespread, enduring effects of prenatal CPF exposure on the developing brain.
What the Study Found
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270 children and adolescents from the Columbia Center for Children’s Environmental Health birth cohort were assessed. All were born to Latino and African-American mothers in New York City.
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Their umbilical cord blood contained measurable CPF levels at birth.
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Brain imaging and behavioral testing between ages 6–14 showed:
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Significant structural and functional brain changes
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Disruptions in brain metabolism
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Poorer fine motor control, motor speed, and motor planning
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The effects were dose-dependent: higher prenatal CPF levels produced greater abnormalities.
“These disturbances in brain tissue and metabolism were remarkably widespread throughout the brain,” said Dr. Bradley Peterson of USC. He warned that other organophosphate pesticides could cause similar harms during pregnancy, infancy, and early childhood, when the brain is especially vulnerable.
Chlorpyrifos: Still in Use
Although the U.S. EPA banned indoor residential use of chlorpyrifos in 2001, agricultural use continues on non-organic fruits, vegetables, and grains. That means farmworkers, pregnant women, children, and rural communities remain at risk through air drift, dust, and food residues.
In Canada, chlorpyrifos has been gradually phased out, but residues persist in imported food, and Health Canada’s PMRA regulatory decisions often lag behind emerging science.
Why This Matters
The findings confirm what parents and health advocates have long feared: prenatal pesticide exposures can alter children’s brain development for life.
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These changes are not subtle — they involve measurable alterations in brain structure and metabolism.
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The harms fall disproportionately on marginalized communities, particularly children of farmworkers and families living near agricultural areas.
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This study raises urgent questions about the continued use of organophosphates and the failure of regulators to prioritize children’s health over industry demands.
A Call for Precaution
Dr. Virginia Rauh, senior author of the study, stressed the need for ongoing monitoring:
“Current widespread exposures, at levels comparable to those experienced in this sample, continue to place farm workers, pregnant women, and unborn children in harm’s way.”
For families and advocates, the message is clear:
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Support organic and pesticide-free farming whenever possible.
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Push for stronger protections for vulnerable populations, especially pregnant women and children.
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Demand that regulators adopt a precautionary approach rather than waiting decades for “conclusive proof” after damage is already done.
Protecting Children’s Health
Children’s brains are still developing well into adolescence. Exposing them to neurotoxic chemicals like chlorpyrifos — even before birth — is a recipe for long-term harm.
As this landmark study shows, the cost is measured not only in lab tests and imaging scans, but in lost potential, impaired development and diminished health for a generation of children.
Source: Columbia University
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