珠江口沉积物重金属污染及其潜在生态危害评价

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

对珠江口表层沉积物中重金属的分布及富集状况进行了分析 ,并采用Hakanson潜在生态危害指数法对其生态危害程度进行了评价。结果表明 :珠江口表层沉积物中Zn、Cr、Cu、Cd等重金属含量呈现由西北渐向东南递减的变化特点 ,而Pb、As、Hg等重金属元素的含量分布无明显规律 ;这些重金属中 ,以Hg的富集程度最高 ,其余元素的富集均较低。生态危害评价显示 ,除Hg属中等危害程度外 ,其余的重金属元素均属轻微危害程度 ;珠江口表层沉积物中主要重金属污染程度的顺序为Hg >Cd >Pb >Cu >As>Cr>Zn。

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 Hg>Cd>Pb>Cu>As>Cr>Zn.