Illness and excretion of organophosphate metabolites four months after household pest extermination.

Diethyl phosphate (DEP), an organophosphate metabolite, was found in the urine of symptomatic residents who resided in a household that had been sprayed with diazinon 4.5 mo earlier. Pre- and post-decontamination data with regard to symptoms, DEP, cholinesterase, and surface and air levels underscore the utility of alkyl phosphate metabolites for monitoring exposure. The data also emphasize the efficacy of clean-up measures when baseline data are not available to determine if "within-normal" cholinesterase levels are, in fact, depressed.