This website is no longer actively maintained
Some material and features may be unavailable

New study links pesticides and attention deficit in kids

Does eating organic really make a difference? A new study says it does.

The study, published in the May 2010 issue of the journal Pediatrics, revealed that children exposed to toxic pesticides known as organophosphates are at increased risk for attention-deficit/hyperactivity disorder (ADHD).

According to the Centers for Disease Control and Prevention, ADHD is one of the most common neurobehavioral disorders in children, with diagnoses increasing 3 percent a year between 1997 and 2006, and totaling 4.5 million children. Symptoms include difficulties paying attention and controlling impulsive behavior, and they can be caused by genetics as well as exposures to environmental toxins.

The study’s research team, led by Maryse Bouchard, a researcher at the University of Montreal, analyzed urine samples from 1,139 children ages 8 to 15. Children with higher urinary levels of dialkyl phosphate metabolites (DAP), which are markers of organophosphate exposure, were more likely to be diagnosed as having ADHD. With each tenfold increase in DAP, the odds of having ADHD rose by more than half.

“What was surprising was that we saw there was an increased risk of ADHD even at low levels of exposure,” Bouchard said in a recent phone interview. “We saw that children with above-average levels of exposure had twice the risk of ADHD as those with undetectable levels.”

According to the U.S. Environmental Protection Agency (EPA), organophosphate pesticides were first used as nerve agents in World War II. Today, they are the most widely used insecticides available, with more than 40 types registered for use. In 2001, approximately 73 million pounds of organophosphates were used in the U.S. The EPA states that all organophosphates “run the risk of acute and subacute toxicity” and “pose significant health risks to people who are exposed to them through their work.”

But CropLife America, which represents pesticide manufacturers, said in response to the study that “more research is needed” to ascertain if there is a direct link between pesticide exposure and ADHD: “The class of crop protection compound that is the subject of this study has been approved and registered by the U.S. EPA, and when used according to the label, the EPA has determined it to be safe.”

Organophosphates have already been proven to have adverse health effects in infants and children, Bouchard and her research team reported, including behavioral problems, developmental delays and poorer short-term memory. According to the National Academy of Sciences, infants and children receive most of their exposures to pesticides through diet. Because of their lower body weight and developing brains, they are more susceptible to pesticide toxicity than adults. A 2008 report from the U.S. Department of Agriculture’s Pesticide Data Program found detectable levels of the organophosphate insecticide malathion in 28 percent of frozen blueberry samples, 25 percent of fresh strawberry samples and 19 percent of celery samples.

The Union of Concerned Scientists writes that the growth of industrial agriculture, which views the farm as a factory, has led to a rise in pesticide use. According to the group, a key feature of industrial agriculture is cultivating a single crop, or monoculture, which depletes the soil and invites pests, resulting in an increased need for more herbicides and pesticides. The U.S. grows all of its major commodity crops in monoculture, a practice bolstered by government subsidies and agribusinesses that manufacture seeds, pesticides and fertilizers.

“This is the first study on the subject so we can’t be definitive, but I think it’s fair for parents to want to be prudent and reduce exposure to pesticides,” said Bouchard. She recommended not using pesticides in or outside of the home and washing all fruits and vegetables carefully, even with a little soap, to get rid of pesticide residues in produce like apples or bell peppers.

But even the organic label isn’t a guarantee. “Buying organic is a good idea, but I know it’s hard for a lot of families because it’s so expensive,” Bouchard said. As an alternative, she suggested buying fruits and vegetables at a farmers’ market. “Even if it’s not labeled organic, the produce from a small producer will contain less pesticides, since they don’t do monocultures.”

Related: Read the study