Distribution and Pollution Assessment of Heavy Metals in Sediments and Soils in Maixi River of Guizhou

By means of field investigation and laboratory analysis,the concentrations,distribution characteristics and enrichment situations of Pb,Cd,Cr,Cu,Zn,As and Hg in soils and sediments in Maixi River were studied.The ecological risk assessment of heavy metal pollution in soils and sediments in Maixi River was discussed with potential ecological risk index.Furthermore,correlation analysis was used to analyze the sources of heavy metals.The results showed that the soils and sediments in Maixi River were polluted by heavy metals,and their concentrations were all above the background values.The enrichment degree of heavy metals ranked as follows : CdHgZnPbCuCrAs.Pb,Cr,Cu,Zn and As presented a similar input source,however Cd and Hg,obviously related with human activities,had a different source from other metals.The potential ecological risk of Pb,Cu,As,Zn and Cr were at the low levels,while Cd and Hg were generally at the extremely high risk levels but they presented high or moderate risk level in some areas.