Biological monitoring survey of organophosphorus pesticide exposure among preschool children in the Seattle metropolitan area

In this study we assessed organophosphorus (OP) pesticide exposure among ch ildren living in two Seattle metropolitan area communities by measuring uri nary metabolites, and identified possible exposure risk factors through a p arental interview. We recruited children in clinic acid outpatient waiting rooms. We obtained spot urine samples in the spring and fall of 1998 from 1 10 children ages 2-5 years, from 96 households. We analyzed urine samples f or six dialkylphosphate (DAP) compounds, the common metabolites of the OP p esticides. Through parental interviews we gathered demographic and resident ial pesticide use data. At least one of the DAP metabolites was measured in 99% of the children, and the two predominant metabolites (DMTP and DETP) w ere measured in 70-75% of the children. We found no significant differences in DAP concentrations related to season, community, sex, age, family incom e, or housing type. Median concentrations of dimethyl and diethyl DAPs were 0.11 and 0.04 mu mol/L, respectively (all children). Concentrations were s ignificantly higher in children whose parents reported pesticide use in the garden (0.19 vs. 0.09 mu mol/L For dimethyl metabolites, p = 0.05; 0.04 vs . 0.03 mu mol/L for diethyl metabolites, p = 0.02), but were not different based on reported pet treatment or indoor residential use. Nearly all child ren in this study had measurable levels of OP pesticide metabolites. Some o f this exposure was likely due to diet. Garden pesticide use was associated with elevated metabolite levels. It is unlikely that these exposure levels would cause acute intoxication, but the longterm health effects of such ex posures are unknown. We recommend that OP pesticide use be avoided in areas where children are likely to play.