A new study reports evidence of a link between prenatal exposure to the widely used insecticide chlorpyrifos (CPF) and structural abnormalities in the brain and poorer motor function in New York City children and adolescents.

The findings are the first to demonstrate enduring and widespread molecular, cellular, and metabolic effects in the brain, as well as poorer fine motor control among youth with prenatal exposure to the insecticide.

The study by researchers at Columbia University Mailman School of Public Health, Children’s Hospital Los Angeles, and Keck School of Medicine of USC is published in the journal JAMA Neurology.

The 270 children and adolescents are participants in the Columbia Center for Children’s Environmental Health birth cohort study and were born to Latino and African-American mothers. They had measurable quantities of CPF in their umbilical cord blood and were assessed by brain imaging and behavioral tests between the ages of 6 and 14 years.

Progressively higher insecticide exposure levels were significantly associated with progressively greater alterations in brain structure, function, and metabolism, as well as poorer measures of motor speed and motor programming. Links between higher CPF and greater anomalies across different neuroimaging measures suggest that prenatal exposure produces enduring disturbances in brain structure, function, and metabolism in direct proportion to the level of exposure.

Residential use was the primary source of CPF exposure in this cohort. Although the EPA banned indoor residential use in 2001, agricultural use continues for non-organic fruits, vegetables, and grains, contributing to toxic exposures carried by outdoor air and dust near agricultural areas.

“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. It is vitally important that we continue to monitor the levels of exposure in potentially vulnerable populations, especially in pregnant women in agricultural communities, as their infants continue to be at risk,” said Virginia Rauh, ScD, senior author on the study and the Jane and Alan Batkin Professor of Population and Family Health at Columbia Mailman School.

“The disturbances in brain tissue and metabolism that we observed with prenatal exposure to this one pesticide were remarkably widespread throughout the brain. Other organophosphate pesticides likely produce similar effects, warranting caution to minimize exposures in pregnancy, infancy, and early childhood, when brain development is rapid and especially vulnerable to these toxic chemicals,” says first author Bradley Peterson, MD, Vice Chair for Research and Chief of Child & Adolescent Psychiatry in the Department of Psychiatry at the Keck School of Medicine of USC.