Endocrine disrupting compounds (EDCs) in source water, finished water, and tap water from drinking water treatment plants and its human risk assessment in Chengdu Plain, China

A study to monitor endocrine disrupting compounds (EDCs) [including pesticides, phthalate acid esters (PAEs), and polychlorinated biphenyls (PCBs)] in drinking water treatment plants from water source to consumers tap in Chengdu Plain was undertaken. A total of 37 source water, 37 finished water, and 37 tap water samples were collected during the period from July to August in 2021. Based on the survey results, a human health noncarcinogenic and carcinogenic risk assessment was conducted for adults and children. The results showed that the pesticides: atrazine, acetochlor, alachlor, heptachlor, and chlorpyrifos were detected in source, finished, and tap water, the detection rate of heptachlor was the highest in source (29.73%), finished (21.62%), and tap water (29.73%). Hexachlorobenzene and chlorothalonium were not detected in source, finished, and tap water. The concentrations of total PAEs ranged from not detected (nd)—1788.79 ng/L (median = 470.23 ng/L), nd to 3755.13 ng/L (median = 423 ng/L), and nd to 4095.89 ng/L (median = 585.12 ng/L) for source, finished, and tap water, respectively. The ΣPCBs were from nd to 239.65 ng/L (median = 91.03 ng/L), nd to 50.4 ng/L (median = 18.04 ng/L), and nd to 157.96 ng/L (median = 58.13 ng/L) for source, finished, and tap water, respectively. The hazard quotient (HQ) of EDCs in tap water of Chengdu Plain was lower than 1 and the highest value was 1.60E-02, which suggests that EDCs are considered unlikely to pose noncarcinogenic effects to individuals. Carcinogenic risk caused by EDCs for adults (both in median and highest concentration) was much lower than the 1.0E-04 cancer risk level, while the highest risk caused by EDCs for children through tap water was 9.48E-05.