Occurrence, risk assessment, and priority screening of 102 emerging contaminants in the Yangtze River estuary and Hangzhou Bay, China

Emerging contaminants (ECs) in aquatic environments pose significant risks to biodiversity and ecosystem health, and have garnered widespread attention. The risk ranking and identifying priority control ECs are of crucial for effective water quality management. This study investigated the occurrence and distribution of 102 ECs in the surface water of the Yangtze River estuary and Hangzhou Bay, and conducted risk assessments and priority identification using toxicity-weighted concentration (TWC) and the toxicological priority index (ToxPi). 88 ECs were detected by target analysis, including 42 antibiotics (ANTs), 16 polycyclic aromatic hydrocarbons (PAHs), 14 organochlorine pesticides (OPs), 4 polychlorinated biphenyls (PCBs), tetrabromobisphenol A (TBBPA), 3 hexabromododecanes (HBCDs), 6 polybrominated diphenyl ethers (PBDEs) sample and 2 per- and polyfluoroalkyl substances (PFAS). Risk assessment based on the TWC scheme revealed that 5 ANTs and 4 PAHs posed high risks to aquatic organisms (TWC > 1.0). The ToxPi method effectively integrated detection frequency, concentration, toxicity data, and TWC, providing a ranked list and identifying 12 ECs (5 ANTs, 4 PAHs and 3 OPs) as high priority. This study conducted ecological risk assessment and priority screening of ECs in the Yangtze River estuary and Hangzhou Bay, providing important information for effective management and priority control of ECs.