The Metabolites of Organophosphorus Pesticides in Urine as an Indicator of Occupational Exposure

The differences in the degree in workers’ exposure to organophosphorus pesticides during the spraying of an apple-orchard were assessed from the urinary content of metabolites: dimethyl phosphorothiolate potassium salt (DMPThK) for Demeton-S- methyl and dimethyl phosphorothionate and phosphorodithioate potassium salts (DMTPK and DMDTPK) for Azinphos-methyl and Methidathion. The highest median concentrations of the metabolites in the urine samples collected after two to three days of work with the pesticides were determined in the mixers preparing pesticide solutions: DM PThK 83 ng cm” (N =7) after exposure to Demeton-S- methyl; DMTPK 2040 and DMDTPK < 20 ng cm -3 (N =7) after exposure to Azinphos-methyl; DMTPK 501 and DMDTPK 88 ng cm -3 (N =6) after exposure to Methidathion. The applicators (sprayers) were the second most exposed group: DMPThK 30 ng cm -3 (N =6) after exposure to Demeton-S-methyl; DMTPK 433 and DMDTPK