Atrazine and its metabolites (ATZs) in source water, finished water, and tap water from drinking water treatment plants and its human risk assessment in Zhoukou City, China

A study to monitor atrazine (ATZ) and its metabolites (ATZs) (including DEA, deethylatrazine; DIA, deisopropylatrazine; HA, hydroxyatrazine) in drinking water treatment plants from water source to consumers tap in Zhoukou City was undertaken. A total of 20 source water, 36 finished water, and 36 tap water samples were collected during the period from July to August in 2020. Based on the survey results, a human health non-carcinogenic and carcinogenic risk assessment was conducted for adults and children. The results showed that the ΣATZs concentrations in source water, finished water, and tap water ranged from 0.609 to 55.985 ng/L (mean = 6.065 ng/L), 0.445 to 46.3 ng/L (mean = 4.507 ng/L), and 0.475 to 91.9 ng/L (mean = 7.139 ng/L), respectively. The predominant compounds of ATZs in tap water was ATZ, with a detection frequency of 91.67%, followed by DIA (58.33%), DEA (52.78%), and HA (27.78%). The highest concentrations of ΣATZs (mean = 15.110 ng/L) in tap water was found in the Central of Zhoukou City, followed by Southern (mean = 2.817 ng/L), Western (mean = 2.338 ng/L), Eastern (mean = 1.027 ng/L), and Northern (mean = 0.51 ng/L). The HQ of ΣATZs in tap water of Zhoukou City was lower than 1 and the highest value was 4.59E − 04, which suggesting that ATZs are considered unlikely to pose non-carcinogenic effects to individuals. Carcinogenic risk caused by ΣATZs for adults was much lower than 1.0E − 06, while the highest risk caused by ΣATZs for children through tap water was 6.34E − 06.