The screening of priority pollutants in the Bohai Sea based on ecological risk assessment

The Bohai Sea (BS) is a semi-enclosed inland sea and China's most polluted coastal sea. With the rapid economic development of the circum-Bohai Sea region, large amounts of pollutants have been discharged into the BS, posing a significant threat to human health and the ecosystem. Great efforts have been made on investigating the levels of various pollutants in the BS; however, the priority pollutants which are required for the implementation of suitable environmental management and remediation measures in this system remain unclear. By using the risk quotient method, this study evaluated the ecological risks of various pollutants (including antibiotics, heavy metals, total petroleum hydrocarbons (TPHs), endocrine disruptors, pesticides, and persistent organic pollutants) in BS water and sediments over the past twelve years to identify the priority pollutants in this system. The results showed that 8 and 10 pollutants were at risk in BS water and sediments, respectively. Overall, 13 pollutants (arsenic (As), copper (Cu), mercury (Hg), nickel (Ni), chromium (Cr), lead (Pb), zinc (Zn), cadmium (Cd), TPHs, bisphenol A (BPA), erythromycin, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs)) in the BS were identified to have potential risks and should be included in the list of priority pollutants. The monitoring of the changes in the contents of these pollutants in BS water and sediments needs to be strengthened in the future.