Most organophosphorus pesticides have been phased out for residential use, but they are still widely used in agriculture. High doses in agricultural workers can be deadly.
The study, in the October issue of Environmental Health Perspectives, included 20 children living in Oakland, Calif., and 20 in the agricultural community of Salinas, about 100 miles south. The children ate a conventional diet for four days and an organic diet for seven days and then returned to conventional foods for five days.
About 72 percent of their urine samples, collected daily, contained evidence of pesticides. Of the six most frequently detected pesticides, two decreased by nearly 50 percent when children were on the organic diet, and levels of a common herbicide fell by 25 percent. Amounts of three other pesticides were not significantly lower on the organic diet. Levels were generally higher in the Salinas children than in the Oakland children.
“There’s evidence that diet is one route of exposure to pesticides, and you can reduce your exposure by choosing organic food,” said the lead author, Asa Bradman, associate director of the Center for Environmental Research and Children’s Health at the University of California, Berkeley. “But I would never say that conventional fruits and vegetables are unsafe. They’re all healthy.”