Screening the priority pollutants in coastal systems using multi-pollutant food web model - a case study in the...

Jiaozhou Bay (JZB) is currently facing complex ecological and environmental challenges due to contamination of multiple coexisting pollutants. Identifying priority pollutants is critical for implementing suitable environmental remediation practices; however, there is still a lack of such work in the JZB. In this study, a method based on a multi-pollutant food web model was developed and applied to identify priority pollutants in the JZB. This methodology consisted of two key steps: (1) conducting a preliminary screening using the risk quotient (RQ) method to identify pollutants with potential risks and (2) developing the multi-pollutant food web model for these pollutants with potential risks and employing the model to simulate the growth of species (phytoplankton, invertebrates and vertebrates) with and without the stress of these pollutants. Pollutants with a Potentially Affected Fraction (PAF) of ≥0.05 were ultimately identified as priority pollutants. This threshold is consistent with the HC5 (hazardous concentration protecting 95% of species) based protection concept commonly used in ecological risk assessment and corresponds to protecting 95% of species. By using this approach, Copper (Cu), Lead (Pb), Mercury (Hg), Cadmium (Cd), Chromium (Cr), Zinc (Zn), Arsenic (As), Nickel (Ni), Polychlorinated Biphenyls (PCBs), Polycyclic Aromatic Hydrocarbons (PAHs) and Phthalates (PAEs) were screened as the pollutants with potential risks, while Cr, Cu, Pb, Zn, PAHs, and nutrients were identified as priority pollutants in the JZB.