Several recent studies suggest a strong connection between exposure to common pesticides and attention deficit hyperactivity disorder (ADHD) in children.
One study tested the urine of more than 1,100 children for chemicals used in common pesticides used on produce and in household products like insect repellent. They followed the children for five years and found that those with these chemicals in their urine had twice the risk of developing ADHD than those who did not, reflecting an overall increase of 35% with every tenfold increase in urinary concentration of the pesticide residue. Additionally, they conducted tests on pregnant mothers and found that those whose urine tested positive for the same byproducts were far more likely to have children that showed signs of ADHD by age five.
These pesticides, known as organophosphates, are most likely being passed on to children through the produce in their diet. A 2008 report by the U.S. Department of Agriculture, which was cited by the recent study, indicated that trace amounts of organophosphates were found on 28% of frozen blueberries, 27% of green beens, 25% of strawberries, 20% of celery, and 17% of peaches. While adults consume these foods too, children are particularly vulnerable to chemical exposure, and the neurotransmitters in their brain, including the one disrupted in children with ADHD, are far more likely to be affected. This is not an entirely surprising finding, given that these chemicals are effective as pesticides because they kill agricultural pests by damaging nerve connections in their brains.
Scientists and physicians emphasize that they are not trying to discourage parents from feeding their children a diet rich in fruits and vegetables. Their suggestion is to buy organically grown produce whenever possible, and to avoid using chemicals such as insect repellent in the home.