by Wyatt Myers
June 16, 2010

Parents already have plenty of reasons to choose organic foods for their babies, given the potential health risks—including cancer, Parkinson’s disease, and mental illness that have been linked to the pesticides found in non-organic foods. While many of the health risks related to pesticides are unproven, some experts believe pesticides pose the greatest risks to infants and children.

A recent study linking pesticide levels in children with attention deficit/hyperactivity disorder, better known as ADHD, gives parents one more reason to choose organic.

Research
The purpose of the study, conducted by researchers from Harvard University and the University of Montreal and published in the May issue of Pediatrics, was to examine the levels of a group of pesticides known as organophosphates in the urine of children ages 8 to 15 to see if there was any correlation between pesticide levels and the risk for developing ADHD. Organophosphates are a common pesticide used on non-organic fruits and vegetables that have been linked before with mental health problems.

“Previous studies have shown that exposure to some organophosphate compounds cause hyperactivity and cognitive deficits in animals,” says lead author Maryse F. Bouchard of the University of Montreal Department of Environmental and Occupational Health and the Sainte-Justine Hospital Research Center. But this is the first time the effects have been examined among a large group of children.

To determine the children’s levels of pesticide exposure, the researchers measured the levels of organophosphates in urine samples taken as part of the much larger National Health and Nutrition Examination Survey (NHANES). Samples from 1,481 children were available for analysis. After eliminating those children with other risk factors for ADHD, such as low birth weight, 1,139 children remained. The results were compared with the National Center for Health Statistics’ data on whether each of these children had been diagnosed with ADHD.

Results
Of the 1,139 children studied, 119 (or 10 percent) had been diagnosed with ADHD. The children with the highest concentrations of organophosphate pesticides in their urine were more likely to be diagnosed with ADHD compared to those with the lowest levels. In fact, children who had high levels of a common indicator of organophosphate levels in the urine (dimethyl thiophosphate) were twice as likely to have ADHD as those children who had undetectable levels of the indicator.

“Our study found that exposure to organophosphates in developing children might have effects on neural systems and could contribute to ADHD behaviors, such as inattention, hyperactivity, and impulsivity,” says Dr. Bouchard.

Recommendations
Although more research is needed, parents should be cautious when choosing foods for their babies. According to a 2008 report by the United States Department of Agriculture (USDA), 28 percent of frozen blueberries, 27 percent of green beans, 25 percent of strawberries, 20 percent of celery, and 17 percent of peaches (among other fruits and vegetables), contain traces of at least one type of organophosphate pesticide.

Organic fruits and vegetables can be expensive, so if you want to know which fruits and vegetables are the most and least pesticide-laden, the Environmental Working Group provides a handy list that you can use as a guide.

Researchers on this study were quick to point out that the findings are preliminary, and a clear-cut connection between ADHD and pesticides is still a ways off. But parents wishing to err on the side of caution might want to consider organic foods, especially when it comes to fruits and veggies.