[Non-targeted Screening and Ecological Risk Assessment of Emerging Contaminants in Beijiang Drinking Water Source of the Pearl River Delta].

To investigate the spatial and temporal distribution characteristics and assess the ecological risks associated with emerging contaminants （ECs） in the Beijiang drinking water source, non-targeted screening was conducted using the ultra-high performance liquid chromatography-mass spectrometry technique （UPLC-MS） for one year （June 2022 to May 2023）. This study also involved the quantitative detection of eight typical ECs. The results showed that through the non-targeted screening, a total of 346 pollutants were identified, with industrial materials, pharmaceuticals, and pesticides being the predominant pollutants, collectively accounting for 88.2%. Concentrations of eight representative ECs ranged from n.d （undetected） to 180 ng·L, with detection rates exceeding 80% for six of them. Notably, higher concentrations were found in endocrine disruptors such as bisphenol A （BPA） and 4-nonylphenol （4-NP）, along with the pesticides atrazine （ATZ） and propisochlor （PPS）, with median concentrations ranging from 8.12 to 35.58 ng·L. The concentrations of ATZ, PPS, roxithromycin （ROX）, and ibuprofen （IBU） were significantly higher in the spring season compared to those in other seasons （<0.05）. Elevated ecological risk levels （RQ>1） were observed at sampling point 1 （S1） and sampling point 3 （S3） for ATZ and Lomefloxacin （LOM）, while for 4-NP, it was determined to be high only at sampling site 2 （S2）. Given their high detection rates and ecotoxicity, particular attention should be paid to ATZ and 4-NP. The concentration level of ATZ exhibited significant seasonal variation due to its agricultural origin, so it is recommended to strengthen control during spring. Overall, this research provides critical insights into a comprehensive understanding of the presence and impact of ECs in this specific region.