Pollution of heavy metals in the Pearl River Estuary and its assessment of potential ecological risk

This paper dealt with the distribution and enrichment of heavy metals in surface sediments from the Pearl River Estuary, and the method of potential ecological risk index presented by Lars Hakanson was used to assess the heavy metals'ecological risk. The results showed that the contents of Zn, Cr, Cu and Cd appear gradually degressive from northwest to southeast,while those of Pb, As and Hg appear no apparent rule. Among all these heavy metals, the enrichment of Hg appears higher and that of the other heavy metals appear lower. The assessment result of the heavy metals'ecological risk revealed except Hg,which belongs to middle potentioal ecological risk , most heavy metals belong to light potential ecological risk. The order of polluting degree of these heavy metals in surface sediments from the Pearl River Estuary is HgCdPbCuAsCrZn.