Dermal exposure and risk assessment of tebuconazole applicators in vineyards.

INTRODUCTION: Models used in the pre-marketing evaluation do not cover all work scenarios and may over- or underestimate exposure. OBJECTIVES: Uncertainties present in the extrapolation from pre-marketing to the post-marketing warrant exposure and risk assessment in real-life working conditions. METHODS: Seven vineyard pesticide applicators were followed for a total of 12 work-days. A data collection sheet was developed specifically for this study. Workers' body exposure, hands, and head exposure were measured. Tebuconazole was analyzed using LC-MS/MS. RESULTS: Median potential and actual body exposures were 22.41 mg/kg and 0.49 mg/kg of active substance applied, respectively. The median protection factor provided by the coverall was 98% (range: 90-99%). Hand exposure was responsible for 61% of total actual exposure, and was reduced by more than 50% in workers using gloves. The German Model underestimated the exposure in one work-day, and grossly overestimated it in 3 work-days. CONCLUSIONS: High levels of potential body exposure were efficiently controlled by the cotton coverall. Use of personal protective devices, especially chemically-resistant gloves and head cover is the main determinant of skin protection. Field studies on pesticide exposure in real-life conditions and development of methods and tools for easier risk assessment are necessary to complement and confirm the risk assessment done in the authorization process.

Biological monitoring of exposure to tebuconazole in winegrowers.

Tebuconazole (TEB) is a fungicide widely used in vineyards and is a suspected teratogen for humans. The aim of this research was to identify urinary biomarkers and the best sampling time for the biological monitoring of exposure to TEB in agricultural workers. Seven vineyard workers of the Monferrato region, Piedemont, Italy, were investigated for a total of 12 workdays. They treated the vineyards with TEB for 1-2 consecutive days, one of them for 3 days. During each application coveralls, underwears, hand washing liquids and head coverings were used to estimate dermal exposure. For biomonitoring, spot samples of urine from each individual were collected starting from 24 h before the first application, continuing during the application, and again after the application for about 48 h. TEB and its metabolites TEB-OH and TEB-COOH were measured by liquid chromatography/triple quadrupole mass spectrometry. TEB contamination of coveralls and total dermal exposure showed median levels of 6180 and 1020 µg. Urinary TEB-OH was the most abundant metabolite; its excretion rate peaked within 24 h after product application (post 24 h). In this time frame, median levels of TEB-OH and TEB-COOH ranged from 8.0 to 387.8 µg/l and from 5.7 to 102.9 µg/l, respectively, with a ratio between the two metabolites of about 3.5. The total amount of urinary metabolites (U-TEBeq) post 24 h was significantly correlated with both TEB on coveralls and total dermal exposure (Pearson's r=0.756 and 0.577). The amount of metabolites excreted in urine represented about 17% of total dermal TEB exposure. Our results suggest that TEB-OH and TEB-COOH in post-exposure urine samples are promising candidates for biomonitoring TEB exposure in agricultural workers.