Abstract:
29 surficial sediment samples were collected in the Zhujiang estuary and its adjacent area in May, 2012, in order to study the total content, speciation and ecological risk assessment of six trace metals (Cr, Cu, Zn, As, Cd, Pb) in the surficial sediment samples. The modified BCR method was used to identify the chemical forms and the acid extractable fraction of trace metals was used to assess potential ecological risk. In general, total content of six trace metals decreased gradually from the northwest to the southeast, with higher values in western coast areas, which received terrestrial inputs and under strong anthropogenic activities. The BCR results showed that Cr, Cu, Zn and As were mainly present in residual form, Pb was present in reducible form and Cd was present in acid-soluble form, respectively. The proportion of non-residential form was highest in Cd, which indicated the mobility of Cd was high. The risk assessment of the six trace metals indicated that Cr, Cu, Pb, Zn and As were all at low pollution level while the pollution level of Cd was relatively high, which was accordant with the BCR result.