As a result of growing concern about the impact of pesticides on the central nervous system in children, researchers from the Harvard School of Public Health recently took a closer look. Their findings were published in the May 2010 issue of Pediatrics journal.  Researchers analyzed the urine from over 1,000 participants ages 8 to 15 for pesticides. More than 100 of the children had symptoms of Attention Deficit Hyperactivity Disorder (ADHD) including impulsive behavior and attention problems.

According to the study, those with the highest concentration of pesticides were more likely to have the disorder, so some type of correlation seems to exist. Put another way, when researchers tracked the pesticides' breakdown products in children's urine, those with high levels were almost twice as likely to develop ADHD as those with undetectable levels.

Young Nervous Systems More Vulnerable

Because their brains are still developing, children are more susceptible to the neurotoxins found in pesticides. Originally developed for chemical warfare, organophosphate pesticides are known to be toxic to the nervous system. There are about 40 organophosphate pesticides registered in the United States, the researchers wrote in the journal. (*Note: Organophosphates malathion and chlorpyrifos are banned for home use but not farming. They are used on a variety of crops and routinely detected in food items commonly consumed by young children.)  Though the study didn't determine the cause of the exposure, for children the most likely culprits are pesticides used on fruits and vegetables ingested in their diet.  Pesticides can also be found in canned fruits and vegetables and other manufactured food.

Critics of the study say relying on one urine sample for each child-rather than multiple samples over time--wasn't ideal.  Clearly, more research is needed to better understand the connection, and to more conclusively determine how avoiding exposure to pesticides on a regular basis impacts the risk.

Playing it Safe

For optimum nutrition, the United States Department of Agriculture (USDA) recommends 5 to 9 servings of fruit and vegetables daily (amounts depend on age, sex and level of activity) so what's a parent to do? Buy fruits you can peel (think bananas and pineapples) or produce with a hard exterior (melons and apples, for example).  Always wash fruit thoroughly with mild soap and water--even fruit you intend to cut since bacteria and pesticides can be pulled through a dirty exterior. 

For more information, go to  and check out the group's pesticide produce guide. The list is broken in two categories--"dirty dozen" and "the clean 15".  According to the EWG, foods high on the pesticide residue contamination list are: celery, strawberries, raspberries and peaches since chemicals can travel more easily through the soft skin. When economically feasible, buy organic produce, which is usually grown without exposure to any dangerous pesticides or at least organic versions of the dirty dozen. Still too pricey? Avoid eating them altogether.




*According to the annual survey by U.S. Department of Agriculture (USDA) Pesticide Data Program (from