Biological monitoring of pyrethroid metabolites in urine of pest control operators.

Due to their low mammalian toxicity but high insectical activity, pyrethroids are increasingly used for pest control. The objective of the present study was the development of a biological monitoring program to determine exposure to pyrethroids. A diastereoselective detection of the major pyrethroid metabolites cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid, cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylic acid, 3-phenoxybenzoic acid and fluorophenoxybenzoic acid by capillary gas chromatography in combination with mass selective detection was applied. The limits of determination ranged between 0.5 and 1 microgram/l urine, depending on the metabolite concerned. It was demonstrated that pyrethroid metabolites were detectable in urine for a period of elimination up to 3.5 days after exposure to cyfluthrin. Fluorophenoxybenzoic acid was shown to be a suitable biomarker for exposure to cyfluthrin. The presented method was adequate for monitoring pyrethroids in occupationally exposed subjects.