Potential utilization of bivalve hemolymph as a biomonitoring tool for assessment of atrazine contamination.

This study evaluated temporally dynamic bioaccumulation, fates, and biotransformation of atrazine (ATZ) in bivalve hemolymph. Male and female mussels, Hyriopsis bialata, were exposed to ATZ at environmentally-relevant (0.02 and 0.2 mg/L) and high (2 mg/L) concentrations. Untreated mussels served as a control. The hemolymph was collected from the anterior adductor muscle during 28 days of exposure. Pooled hemolymph from individuals of the same sex was subjected to chromatographic analysis of ATZ and its derivatives: desethylatrazine (DEA), desisopropylatrazine (DIA), and hydroxyatrazine (HA). The hemolymph was also used to determine phase I biotransformation via 7-ethoxyresorufin-O-deethylase activity. ATZ-treated mussels showed bioaccumulation of ATZ and its derivatives in their hemolymph, but the control mussels had none. There were no gender-dependent bioaccumulation patterns for these compounds, among which DEA revealed dose- and time-dependent bioaccumulation. Besides, hemolymph-to-water concentration ratios (HWRs) of DEA exhibited concentration and time dependency on nominal ATZ concentrations, especially in the female mussels. ATZ exposure generally did not alter phase I biotransformation capacity in the hemolymph. Interestingly, DEA, aside from ATZ, was a promising candidate marker representing degrees of ATZ contamination. Overall, this study offered opportunity for utilizing the bivalve hemolymph of minimal amounts for rapid, time-series biomonitoring of ATZ contamination in water.