The use of the multi-residue techniques for urinary metabolites provide the key to worker exposures from mixed organophosphate and carbamate exposures. Highly significant inverse correlations of cholinesterase levels with the dialkyl phosphate urinary metabolites were demonstrated under conditions of work exposure to the more toxic organophosphates such as ethyl-methyl parathion and Phosdrin. DEP, DETP, DMP and DMTP were the only alkyl phosphates regularly found in these occupational exposures. Following 8 hours of a work exposure to Dursban the appropriate dialkyl phosphate and phenolic derivatives persisted in the urine for 36 hours and longer. Severe and protracted illness was observed following intoxication by more polar and fat soluble organophosphates especially di-ethyl dichlorophenol phosphorothioate (VC-13). This pesticide and its metabolites were detected in serum and in urine 48 days after exposure. Additionally air sampling of the South Florida environment confirmed the disappearance of DDT and its metabolites.

Sponsored by Pesticides and Toxic Substances Effects Laboratory, National Environmental Research Center. Contract Number: 68-02-1145 Prepared for Office of Research and Development, U.S. Environmental Protection Agency. "June 1974." "EPA-650/1-74-009." EPA Project Officer: Dr. William F. Durham. Includes bibliographical references (page 40).