Children who were exposed to organophosphate pesticides while in the womb have a greater risk for developing attention disorders, such as attention-deficit hyperactivity disorder (ADHD), according to a study published in Environmental Health Perspectives and reported by HealthDay News.

Organophosphate pesticides are used in agriculture, homes, gardens and veterinary practices to kill bugs, but the chemicals in them can also harm the brains and nervous systems of animals and humans.

For the study, researchers analyzed the attention tests of 300 children of Mexican-American farm workers. They also measured organophosphate metabolites in the urine of the children’s mothers and collected behavior data from the moms and professional observers.

Researchers found a significant link between attention problems and pesticide exposure among children age 5, especially boys. (The effects weren’t as significant in children younger than 5 years old.)

“We saw that children were making more errors on the test and that it was significantly related to the mother’s prenatal metabolite levels for those pesticides,” said Brenda Eskenazi, PhD, senior study author.

The problem is that children don’t have high levels of a certain enzyme to metabolize organophosphate pesticides until they’re much older, researchers added. In addition, there’s also “suggestive evidence” that some children may have genetic variations that make them more susceptible to the neurocognitive effects (problems concentrating and remembering) of pesticides.

To avoid these problems, experts suggest families take these precautions to limit pesticide exposure: wash produce thoroughly before eating, buy organic produce when you can (or grow your own), and use less toxic alternatives for lawn care.

Parents: Click here to learn more about ADHD.