Ecological risk assessment of 50 emerging contaminants in surface water of the Greater Bay Area, China.

Ecological risk assessment of emerging contaminants (ECs) is an international research hotspot and is also the focus of China's "14th Five-Year Plan". The Greater Bay Area (GBA) is one of the four major bay areas in the world and the most dynamic region in China. However, there are few studies on the risk assessment of ECs in the GBA, and there needs to be a systematic and comprehensive assessment of the ecological risk of ECs. We selectively collected environmental concentration and toxicity data reported in the literature before 2022 for 50 representative ECs. We use risk quotient (RQ), semi-probability, Margin of Safety (MOS), and joint Probability curve (JPC) methods for multiple-level risk assessment. The RQ results showed that there were primary ecological risks in 20 ECs. Nine ECs were screened by the semi-probability, MOS, and JPC methods. The total risk probability of nonylphenol (NP) to the GBA was 12.11 %, and the risk to the aquatic ecological environment was the highest, followed by α-endosulfan (α-END) and erythromycin (ERY). At the same time, a comprehensive assessment method was adopted to screen the list of medium and high-risk priority pollutants in the GBA. According to the comprehensive evaluation results, although the risk is low, perfluorooctanoic acid (PFOA) still deserves widespread attention. The results showed that NP, α-END, ERY, and PFOA may be the most concerned ECs in the GBA. This research fills the gap on the ECs ecological risk assessment of the GBA and can provide a theoretical reference for managers in the follow-up of ECs regulatory governance.