Switching to organic foods provides children "dramatic and immediate" protection from pesticides that are widely used on a variety of crops, according to a study by a team of federally funded scientists.
Concentrations of two organophosphate pesticides -- malathion and chlorpyrifos -- declined substantially in the bodies of elementary school-age children during a five-day period when organic foods were substituted for conventional foods.
The two chemicals are the most commonly used insecticides in U.S. agriculture. More than 2 million pounds were applied to California crops in 2003, according to records of the state Department of Pesticide Regulation.
The health effects of exposure to minute amounts of pesticides found in food are largely unknown, especially for children. Some research, however, suggests that the residue may harm the developing nervous system.
For 15 days, a team of environmental health scientists from the University of Washington, Emory University and the Centers for Disease Control and Prevention tested the urine of 23 elementary school-age children in the Seattle area.
During the first three days and last seven days, the children ate their normal foods. But during the middle five days, organic items were substituted for most of their diet, including fruits, vegetables, juices and wheat- and corn-based processed items such as cereal and pasta.
Average levels of both pesticides in the children "decreased to the nondetect levels immediately after the introduction of organic diets and remained nondetectable until the conventional diets were reintroduced," the researchers reported Thursday in the online version of the scientific journal Environmental Health Perspectives.
When they ate organic foods, the children on average had zero malathion detected in their urine, with a high of seven parts per billion in one child. But when the children returned to eating conventional foods, one child had as much as 263 parts per billion and the average increased to 1.6 parts per billion.
For chlorpyrifos, the children had less than one part per billion when they ate organic foods, but the average increased fivefold as soon as they returned to their previous diet.
