Biologic monitoring of exposure to organophosphorus pesticides in 195 Italian children

One hundred ninety-five 6- to 7-year-old children who lived in the municipa lity of Siena (Tuscany, Italy) underwent biologic monitoring to evaluate ur inary excretion of several alkytphosphates that are metabolites of organoph osphorus pesticides. We evaluated dimethylphosphate (DMP), dimethylthiophas phate (DMTP), dimethyldithiophosphate (DMDTP), diethylphosphate (DEP), diet hylthiophosphate (DETP), and diethyldithiophosphate (DEDTP). We obtained ur ine samples taken in the children's schools, and each sample was accompanie d by a questionnaire about lifestyle and dietary habits. We found DMP and D MTP in detectable concentrations in the greatest number of samples (96 and 94%, respectively). Thr DMP values were geometric mean (CM) 116.7, [geometr ic standard deviation (GSD) 2.5], and a range of 7.4-1,471.5 nmol/g creatin ine. The corresponding DMTP values were GM 104.3 (GSD 2.8) and a range of 4 .0-1,526.0 nmol/g creatinine. DMDTP, DEP, DETP, and DEDTP concentrations we re GM 14.1, (GSD 3.0), and a range of 3.3-754.6 nmol/g creatinine in 34% of the children; GM 33.2, (CSD 2.4), and a range of 5.1-360.1 nmol/g creatini ne in 75% of the children; GM 16.0, (GSD 2.9), and a range of 3.1-284.7 in 48% of the children; and GM 7.7, (GSD 2.1), and a range of 2.3-140.1 in 12% of the children, respectively. The significant variable for urinary excret ion of these metabolites in children was pest control operations performed inside or outside the house in the preceding month; however, the presence o f a vegetable garden near the house rarely emerged. The urinary excretion o f alkylphosphates in children was significantly higher than in a group of t he adult population resident in the same province.