Concentrations and distributions of neonicotinoids in drinking water treatment plants in South Korea. (1st November 2021) - Kim, Jiwon
Abstract: We investigated the fates of seven neonicotinoids (NNIs) in full-scale drinking water treatment plants and assessed human exposure to NNIs through consuming drinking water. The total NNI concentrations in raw water and treated water samples from the drinking water treatment plants were 20.4–166 ng/L (median 118 ng/L) and 1.11–94.7 ng/L (median 20.4 ng/L), respectively. The dinotefuran (DIN) concentrations in raw water collected in different seasons were different, and the highest DIN concentration was found in summer. The drinking water treatment processes removed >91% of the NNIs except DIN and thiamethoxam (THIAM), for which the mean removal rates were 70% and 74%, respectively. The removal rates for all of the NNIs were higher for the granular activated carbon filtration process (mean 83.5%) than the other drinking water treatment plant processes (coagulation/sedimentation 22.3%, ozonation 29.2%). However, the removal rates in the granular activated carbon process were lower for DIN and THIAM (61.0% and 59.2%, respectively) than the other NNIs. Significant correlations were found between the NNI removal rates and physicochemical properties (solubility in water and log (octanol–water partition coefficient)). The estimated mean human exposure to NNIs in drinking water was 0.528 ng/(kg body weight d). Graphical abstract: Image 1 Highlights: Neonicotinoids (NNIs) were measured in water in drinking water treatment plants. The dinotefuran (DIN) concentration increased during the summer rain season. NNIs were mainly removed by granular activated carbon filtration. The DIN and thiamethoxam removal efficiencies of the DWTPs were lower. Drinking water NNI daily intakes were <4 μg/(kg bw d) (thiacloprid reference dose).