by Warren King
Seattle Times
April 25, 2000

Children in agricultural communities are being exposed to pesticides at higher levels than federal regulators consider safe, a University of Washington study indicates.

In urine tests, more than half the preschool children of farmworkers repeatedly showed evidence they had been exposed to possibly unsafe levels during spraying season, researchers found.

None of the children in the study was engaged in farm work. Rather, they were exposed through spraying itself and pesticide residue in their homes, and from food consumption.

"It's cause for concern, but not cause for alarm," said Dr. Richard Fenske, director of the study. "The point is, we don't understand what pesticides do or don't do in small children. And we need to keep an eye on those who get more exposure than others."

The findings will be helpful to scientists looking further into just how children are exposed and how vulnerable their developing nervous systems are to the chemicals.

Scientists don't know whether the children have suffered long-term adverse effects from the exposure. Another extensive UW study is examining what levels might be dangerous for children. Existing federal rules for safe levels of exposure to pesticides focus only on adults.

Fenske said the UW study of 109 children in Chelan and Douglas counties is the first using biological measurements, or urine samples, to show children are being exposed to possibly unsafe levels of pesticides. The study is being published in the June issue of Environmental Health Perspectives, a journal of the National Institutes of Health.

The research shows some children were exposed to levels as much as 20 times the safety standards set for adults by the U.S. Environmental Protection Agency. But most who exceeded the limits were no more than three times over.

For safety reasons, federal exposure limits are lower than the levels that experts guess might be harmful, said Fenske, director of the UW's Pacific Northwest Agricultural Safety and Health Center.

UW researchers looked at the children's exposure during 1995 to two pesticides commonly used to fight coddling moths in apples: azinphos-methyl and phosmet, both of them chemicals called organophosphates.

Metabolites, or broken-down derivatives, of the pesticides were measured in two urine samples from each child.

Of 91 children of farmworkers, 56 percent showed exposures to azinphos-methyl beyond federal limits. Of 18 nonfarmworker children who lived more than a quarter-mile from an orchard, 44 percent had exposures over the limits.

Only 9 percent of the farmworker children and none of the nonfarmworker children exceeded the limits.

Fenske said the exposure levels were measured during the spring spraying season and aren't representative of year-round exposures. Another UW study is under way to measure year-round exposures.

Other research in 1995 found pesticide levels in the house dust of Wenatchee-area agricultural workers were five times that of nonfarmworkers' homes.

The UW is conducting extensive research in pesticide exposure and its effects on children. A five-year, $6.6 million study is looking at everything from how farmworkers bring pesticide residues into their homes, to children's genetic susceptibility to the chemicals.

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