Multiresidue analysis of urinary pesticide metabolites offer an effective means of measurements of human exposure to the non-persistent pesticides. In studies of different degrees of human exposure to parathion DEP, a metabolite of paraoxon, was the most sensitive indicator of serious exposure. Concentrations in cases of >0.4 microgram/ml were observed in first urines collected in seven cases of poisoning with serious enzyme inhibition. In contrast, from 71 sequential urines in parathion exposed workers on one urine exceeded these concentration. The DEP:DETP ratio was equally informative: the mean ratio being 4.14 in 20 urines from the poison cases and 0.88 in urines of exposed workers. Excretion of metabolites for 91 days after ingesting of Dichlofenthion was observed, emphasizing the significance of exposures to the less polar organophosphates in both acute and chronic effects. A variety of pesticides were identified in a regular air monitoring program for pesticides in South Florida.

EPA Project Officer: Thomas M. Scotti, Pesticides and Toxic Effects Laboratory, National Environmental Research Center. Prepared by the Dept. of Epidemiology & Public Health, University of Miami School of Medicine under Contract No. 68-02-1277 to the U.S. Environmental Protection Agency. "ROAP No. 21AYL." "Program Element No. 1EA078." "March 1975." Includes bibliographical references (pages 75-76).