[Occurrence Characteristics and Health Risk Assessment of Organophosphate Esters in Tap Water of Shanghai]

To explore the occurrence characteristics and health risk levels of the new pollutants organophosphate esters （OPEs） in tap water in Shanghai, based on the water supply areas of the Qingcaosha Reservoir, Chenhang Reservoir, Dongfeng Xisha Reservoir, and Upstream Huangpu River water sources, a total of 52 large shopping malls in Shanghai were selected as tap water sampling sites. Solid phase extraction and gas chromatography-triple quadrupole mass spectrometry were used to determine eight types of OPEs in tap water from shopping malls, including three types of chlorinated OPEs, two types of alkyl OPEs, and three types of aryl OPEs. On this basis, the health risk assessment of the substances with high detection frequency and concentration was carried out. The results showed that six types of OPEs were generally detected, and the average levels of eight types of OPEs in tap water collected in summer and winter were 64.3 ng·L^-1 and 60.5 ng·L^-1, respectively. The concentration levels and detection rates of different types of OPEs in tap water followed the order of： chlorinated OPEs > alkyl OPEs > aryl OPEs. From the perspective of water sources, the average concentration of OPEs in tap water with Upstream Huangpu River water sources as the water source was the highest （132 ng·L^-1 in summer and 170 ng·L^-1 in winter）, and OPEs in tap water with Dongfeng Xisha Reservoir as the water source was the lowest （25.1 ng·L^-1 in summer and 6.62 ng·L^-1 in winter）. The average concentration of chlorinated OPEs in summer （62.1 ng·L^-1） was higher than that in winter （53.9 ng·L^-1）. Based on the reference dose of OPEs, there were no health risks to people of all ages through drinking water exposure. However, the OPE exposure in tap water of Shanghai was higher compared with that of other countries and regions, which requires further attention and research.