Controversial Pesticide Causes Early Childhood Development Delays, Study Finds

    • May 19, 2010

Why are children in poor, urban neighborhoods more likely to experience early childhood developmental delays?

One answer to that confounding question involves the higher prevalence of cockroaches in the inner city—and efforts by parents to get rid of them.

In a recent study, Gina Lovasi, M.P.H., Ph.D., an assistant professor of epidemiology at Columbia University and a former Robert Wood Johnson Foundation (RWJF) Health & Society Scholar (2006 – 2009), found that higher prenatal exposure to a pesticide that was commonly used to exterminate cockroaches and other pests led to higher rates of mental and physical deficits in young children. Such impairments can undermine children’s health and educational attainment as they grow.

“There is a clear-cut association between this chemical and delayed mental and motor skill development in children, even when there are other potentially harmful environmental factors present,” Lovasi said.

Called chlorpyrifos, the chemical was banned for residential use in 2001 by the U.S. Environmental Protection Agency (EPA) but is still widely used internationally and in the U.S. agricultural industry. It is currently under review by the EPA and may be banned for agricultural use as well.

Proponents of the chemical say current standards protect consumers and enable farmers to protect crops from insect losses. But critics are calling for tighter restrictions.

Lovasi’s Study Builds on Previous Study of Chlorpyrifos

A study published in 2006 in the journal Pediatrics found that prenatal exposure to the chemical delayed physical and mental development in young children.

The earlier study came under criticism because it did not control for environmental factors such as building dilapidation and neighborhood poverty.

Lovasi joined with the research team to conduct a subsequent study on the same population of low-income expectant mothers in the New York City neighborhoods of the South Bronx and northern Manhattan to weed out other possible explanations for early development problems in their young children. She conducted the research while a Health & Society Scholar at Columbia University’s Mailman School of Public Health.

The study—called “Chlorpyrifos Exposure and Urban Residential Environment Characteristics as Determinants of Early Childhood Neurodevelopment”—was published online on March 18 in the American Journal of Public Health.

“We tested alternative explanations to see whether they could be driving delays in development,” she said. “But what we found reinforced our earlier finding of a pesticide-neurodevelopment association.”

Lovasi noted that she and her team did find that high neighborhood poverty was independently associated with a lag in neurodevelopment in young children. But the link to poverty did not explain away effects of chlorpyrifos, she said.

“We don’t know yet why exactly poverty is affecting neurodevelopment,” she said. “But we do have more confidence that this pesticide is responsible for slower development.”

The Health & Society Scholars program is supported by RWJF. It supports up to 18 doctorally prepared researchers each year to participate in an intensive two-year training program at one of six universities.