Characteristics and risk assessment of heavy metals pollution in Suzhou River
The distribution of As,Cd,Cr,Cu,Pb and Zn in 13 sampling points along the flow direction of Suzhou River was analyzed by sampling 3 times.The stability of microorganisms in the aquatic phase and sedimentary phase of Suzhou River and the influence of heavy metals on microorganisms were evaluated by principal component analysis and redundancy analysis.Health risk index,Nerome index,geological accumulation index and heavy metals distribution coefficient were calculated to evaluate the risk of heavy metals in surface water to exposed population and the ecological harm of this basin.Results show that the aquatic phase mainly contains Zn,Pb and Cu,while the sedimentary phase has the highest concentration of Zn.There is little change of species richness in the studied basin.As and Cr have different degrees of carcinogenic risk for the adults and children,while Cd has the greatest potential ecological risk.