Organophosphate pesticide residues in urine of farmworkers and their children in Fresno County, California

Background Childhood cancer, notably leukemia, brain cancer, non-Hodgkin's lymphoma, soft tissue sarcoma, and Hodgkin's disease, has been associated w ith pesticide exposure, often with greater relative risks than among expose d adults, suggesting greater susceptibility, in children. These differences in risk may be due to developmental factors or differences in pesticide ex posure. Methods A feasibility, study was conducted to determine levels of pesticide metabolites in urine of adults (n = 18) and children (n = 9) in Fresno Cou nty, California, an intensely agricultural county in the Central San Joaqui n Valley. Spot urine samples were obtained and analyzed for six metabolites of organophosphate (OP) pesticides using gas chromatography with flame pho tometric detection methods. The metabolites of OP pesticides included DMP, DEP, DMTP, DMDTP, DETP, and DEDTP. Results Levels were generally low for both adults and children for most met abolites tested. Frequencies of detection ranged from 0 to 37%, with mean l evels ranging from non-detectable to 13.22 pph. However levels of several m etabolites were higher in children than in adults. The most frequently, det ected metabolite, DMP, was found among 44% of the children and 33% of the a dults. DMTP was detected among 33% of the children and 28% of the adults. Conclusions These results are difficult to interpret given the sampling var iation associated with the small sample size. Nevertheless, because OP pest icides have been associated with increased cancer risk in animal and human studies, these results indicate a need to closely monitor children's exposu re to environmental chemicals. (C) 2001 Wiley-Liss, Inc.