Distribution and ecological risk assessment of heavy metals in sediments of a river in Southwest China

ABSTRACT: Base on the data of heavy metals in the sediments of a river, we analyzed the pollution degree of heavy metals and calculated the ecological risk by Geoaccumulation Index (Igeo) and Hakanson’s Risk Index (RI). Besides, we analyzed the speciation of Pb, Zn and Cu and evaluated the bioavailability. The results of both Igeo and RI methods indicate the sediments have been polluted by Pb, As, Cu, Zn, and the high risk sites concentrate on the middle reach of the river. The speciation analysis shows that the residual fraction of low bioavailability is dominant.