Low ecological risks for heavy metals and total petroleum hydrocarbons on typical coastal petrochemical sewage discharge waters: Monitoring and evaluation under One Health framework

Petrochemical industrial zone wastewater is a complex source of pollutants. This study used a One Health framework to investigate the impact of typical petrochemical industrial zone wastewater discharge on adjacent bay. An analysis was conducted on the content and distribution characteristics of heavy metals (HMs) and total petroleum hydrocarbons (TPHs) in the seawater, sediment, and organisms. The assessment of the marine environment utilized the single-factor standard index method alongside the Hakanson ecological risk index method to investigate potential ecological risks. The findings indicated that the average levels of Cd and As in the water were primarily influenced by the sewage discharge, whereas the concentrations of Pb, Zn, and Hg in the sediments were predominantly impacted by the coastal area. The research sea area is considered to be at low risk, and the sewage discharge from the petrochemical industrial zone and its coastline does not endanger the ecosystem. The ranking of metal element pollution in seawater is as follows: Zn > Cu > As > Pb > Cd > Hg; While in sediments, the order is Zn > Pb > Cu > As > Hg > Cd. Furthermore, both crustaceans and mollusks demonstrate elevated concentrations of HMs, thereby serving mollusks as effective bioindicators for the monitoring of HMs pollutants in seawater and crustaceans as effective bioindicators for the monitoring of HMs pollutants in sediment.