南海表层沉积物重金属与生源要素污染特征、生态风险及防治对策OA北大核心CSCDCSTPCD

This study analyzed the contents of Cu,Pb,Zn,Cd,Hg,As,Cr,total nitrogen(TN),total phosphorus(TP),and total organic carbon(TOC)in the surface sediments in the South China Sea from 2021 to 2022.The assessment was conducted using the geo-accumulation index(Igeo),potential ecological risk index(RI),comprehensive pollution index(P),toxicity effect evaluation,and organic index(OI).Results showed that the mean contents of heavy metals Cu,Pb,Zn,Cd,Hg,As,and Cr were 35.63,17.53,99.84,1.30,0.05,9.79,and 57.84 mg/kg,respectively.Igeo evalua-tion showed that Cd was moderately polluted,while RI comprehensive evaluation showed a medium risk level.Pri-mary pollution sources were industrial activities as well as compound contributions from aquaculture and transporta-tion.The mean contents of biogenic elements TN,TP,and TOC were 1.51 mg/g,0.36 mg/g,and 0.67%,respectively.P evaluation showed severe pollution.Toxicity evaluations indicated that TN content may have potential toxic effects on most benthic organisms.OI evaluation was relatively clean,showing that the organic pollution mainly originated from marine sources.Based on the investigation and analysis results,this study further proposed targeted countermeasures and suggestions,including strengthening the control of pollution sources,innovating monitoring and law enforcement mechanisms,and promoting regional collaborative governance.