Urine and hair specimens for biomonitoring short and long term penconazole exposure

OBJECTIVES: Penconazole (PEN) is a fungicide widely used in vineyards. Objective of this work was the identification of urinary metabolites for biological monitoring of occupational exposure (1). We also assessed the ability to use hair matrix to evaluate long-term exposure to PEN. METHODS: Urine samples from 21 vineyard workers exposed to PEN during mixing and loading, application and re-entry were analyzed by LC-MS/MS to obtain a profile of candidate metabolites. Based on the presence of the triazole moiety in the full scan mass spectra major candidates were found. From their mass spectra hydroxy and carboxy-penconazole (PEN-OH and PEN-COOH), both as free molecules and as glucuronide conjugates, were identified (2). Urine samples were submitted to hydrolysis with glucuronidase to obtain the free chemicals,that were quantified. Hair samples of pre and post-exposure (PRE and POST-EXP) were analyzed. PEN in hair was desorbed with acetonitrile for 3 hours at 45°C and extracts were analyzed by LC-MS/MS. RESULTS: PEN-OH was the most abundant metabolite, with mean concentration about 3-fold higher (from 1.3 to 16.8) than PEN-COOH and a wide inter-subject variability. In investigated subjects mean levels in 24 h post-exposure urine samples PEN-OH ranged from 1.3 to 258 μg/L and PEN-COOH from 1.0 to 20 μg/L. Excretion of PEN metabolites increased with consecutive work shifts. Urinary metabolites were correlated with the potential and actual dermal exposure assessed measuring PEN on the work clothes and on the skin, with Pearson r up to 0.543. Median level of hair PEN were 0.010 and 0.060 ng/mg hair in PRE and POST-EXP samples respectively (p=0.005). CONCLUSIONS: Our results suggest that PEN-OH in post-exposure urine sample and hair PEN are promising candidate for biomonitoring shortshort shortshort- and longand longand longand long and longand longand long-term exposure toterm exposure toterm exposure toterm exposure toterm exposure to term exposure toterm exposure toterm exposure toterm exposure toterm exposure to term exposure toterm exposure to PEN in agriculture workers.