Urinary biomarkers of atrazine exposure among farm pesticide applicators

PURPOSE: This study assessed the feasibility of three laboratory methods for the detection of atrazine, a triazine herbicide, and its related metabolites in urine collected from field applicators. METHODS: Urine samples were collected from 256 randomly sampled field applicators 8 hours post application. Of these, 99 reported atrazine use during the application prior to sample collection and these samples were subsequently analyzed for urinary biomarkers. RESULTS: 37.4% (n = 37) samples showed detectable levels (minimum = 1.0 ng/mL) of deethylatrazine using gas chromatographic mass spectrometry (GCMS) analysis (X = 14.2 ng/mL; s.d. = 13.5). Fifty samples were tested using atrazine mercapturate in urine ELISA methods and 80% (n = 40) of these samples showed detectable levels of atrazine (X = 6.4 ng/mL; s.d. = 7.5). Of 10 samples tested by triazines in water ELISA methods, a common assay used for the detection of atrazine in groundwater, 100% showed detectable levels of atrazine (X = 22.4 ng/mL; s.d. = 13.9). Of the 21 samples collected from non-applicators and tested by GCMS, none evidenced detectable atrazine levels. Using GCMS as the gold standard, analyses showed that the mercapturate in urine ELISA was 48% sensitive and 91% specific whereas the triazines in water ELISA was 69% sensitive and 100% specific. CONCLUSIONS: It is possible to detect one-time atrazine exposures through analysis of urinary biomarkers among pesticide applicators. The feasibility of triazines in water ELISA methods for use in field studies for analyzing the presence of atrazine and related metabolites in urine was supported, but these methods need further testing on larger applicator samples before they can be used for standard screening.