(HealthDay News) -- A new, small study links maternal exposure to a commonly used insecticide to unusual changes in the brain structures of young children, although the research doesn't definitely prove that the pesticide is at fault.
The findings raise more questions about the safety of the insecticide, known as chlorpyrifos, which is used to treat farm products in the United States but has been almost entirely banned in homes. The U.S. Environmental Protection Agency says exposure to the insecticide in children through food is "below the level of concern."
"People should wash their fruits and vegetables very carefully before eating, and pregnant women should not be working in agricultural settings where there might be an occupational exposure," said study lead author Virginia Rauh, deputy director of the Columbia Center for Children's Environmental Health at Columbia University.
Chlorpyrifos is widely used to kill insects on farms. "It is used on corn, many types of fruits, many types of leafy green vegetables and cotton," Rauh said. "It's also used for a variety of other commercial purposes -- as a spray to control pests on golf courses, road medians, Christmas tree farms and at various other places." People are often exposed through insecticide residue on fruits and vegetables, Rauh said.
Previous research has linked indoor residential exposure in pregnant mothers to lower birth weights. "We found evidence that there was poorer cognitive [mental] development and potentially more behavior problems in kids who were exposed," Rauh said.
In the new study, the researchers used MRI machines to scan the brains of 40 children aged 5 to 11 years. The mothers of 20 of them had high levels of exposure to the insecticide while they were pregnant with the children.
The mothers of the other 20 kids had low levels of exposure. The brains of the kids with high exposure were more likely to have certain enlarged structures in the brain. They also had thinning in some parts of the brain.