Time course of excretion of tebuconazole and its metabolites in vineyard workers

Tebuconazole (TEB) is a fungicide widely used in vineyards. This work aimed at the identification of urinary metabolites of TEB for the biological monitoring of exposure, and to study their kinetics of excretion. Major urinary metabolites of TEB in rats are t-butyl-hydroxy-and-carboxy-tebuconazole (TEB-OH and TEB-COOH). TEB and these metabolites were determined in urine samples of 5 wine growers who collected each void before (24 hours), during and after (48 hours) TEB application. These chemicals were found in 95%, 100% and 100% of the samples with levels of < 1.5-13.4 microg/L for TEB, 5.2-749 microg/L for TEB-OH e 2.8-234 microg/l for TEB-COOH. TEB-OH is the major metabolite of TEB, its concentration increases at the end of exposure and peaks after 16-24 hours. TEB-COOH has similar pattern. TEB-OH and TEB -COOH are promising candidates for biological monitoring of TEB exposure; preliminary results suggest the day after the application as the best sampling time.