Organic choice: pesticides vanish from body after change in diet.

Children can eliminate their bodies' loads of agricultural pesticides by eating organically grown products, a 15-day experiment suggests. The finding bolsters the case that people dining on organic food avoid potentially toxic pesticides, but it doesn't directly address whether such foods provide health benefits.

"Organic food is a viable intervention to control pesticide exposure," environmental health specialist Doug Brugge of Tufts University School of Medicine in Boston says of the new study. "What you would like, in addition, is evidence that those reductions are associated with health improvements."

Pesticides known as organophosphates can cause problems in childhood neurological development. In the past decade, the U.S. government has restricted the use of many of these chemicals. However, the organophosphates malathion and chlorpyrifos are still legally used on many conventional crops.

Chensheng (Alex) Lu of Emory University in Atlanta and his collaborators recruited 23 families in suburban Seattle. Before the study, each child, age 3 to 11 years, are only conventionally grown produce and had no other known exposures to organophosphates. Some of the same researchers had earlier found evidence that switching a child to an organic diet reduces organophosphate concentrations in the body (SN: 2/22/03, p. 120).

Lu's team bought organic-food items and gave them to the children's parents. On days 4 through 8 of the study, the families were asked to substitute the organic foods--including fruits and vegetables, fruit juices, cereals, and pastas--for conventionally grown products. The researchers asked parents to use the substitute products to prepare the same meals that each child would normally eat. After day 8, the families resumed using conventional products.

The parents collected two daily urine samples from each child, and the researchers tested the samples for by-products of malathion, chlorpyrifos, and several less-common organophosphates.

Malathion and chlorpyrifos by-products were present in all the children's urine before and after the 5 days of organic eating. During the organic-food period, however, those by-products were undetectable in most of the urine samples, the researchers report in an upcoming Environmental Health Perspectives.

Organic diets might not substantially reduce organophosphate exposure in all children. Some urban homes contain residues of the pesticides left from efforts to battle insect infestations, Brugge says.

Nevertheless, he adds, "in a population that does not have other pesticide exposures, eating organic foods virtually eliminates organophosphate-pesticide burden in the children."