Biological monitoring of exposure to tebuconazole in winegrowers

Abstract

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.

Identification and Quantification of Metabolites of the Fungicide Tebuconazole in Human Urine

“…Information regarding the study protocol and sample collection has been reported in detail. 12 In particular, during the investigated work shifts applications lasted from 3 to 10 h. Urine samples were autonomously collected by the study subjects, who were provided with instructions and a sampling kit. The workers were asked to collect samples of their urine starting 24 h before the first day of TEB application, then during TEB application, and continuing for 48 h from the end of the last TEB application.…”

Testing a cumulative and aggregate exposure model using biomonitoring studies and dietary records for Italian vineyard spray operators

“…Unfortunately the sample size was not large enough to do a validation of the model. As explained in Fustinoni et al (2014), the data are subject to large variability between individuals due to their differing characteristics and working patterns. There is also the potential for errors in the data.…”

“…As explained in Fustinoni et al (2014), this area was selected based on high sales of tebuconazole from the previous season. Eligible vineyard estates were contacted with assistance from the local health authority and seven volunteers came forward following a meeting of individuals from these estates.…”

“…The ADE values reported below represent the total summed across body, head and hands. Full details of the field study including the dosimetry methods used are described in detail by Fustinoni et al (2014). The analysis of the dermal samples is described in Mandic-Rajcevic, Maria Rubino, Vianello, Fugnoli, Polledri, Mercadante, Moretto, Fustinoni, Colosio (unpublished).…”

“…Correlations were assessed between dermal exposures and urine-based exposures at different time periods. One of the results from Fustinoni et al (2014) used to inform our model testing was that urine samples in the 24 hours immediately after the first application were generally the most highly correlated with dermal exposure. Urine measurements from this time period were therefore used in the comparisons.…”