厦门贝类养殖区沉积物中重金属的污染水平及其潜在生态危害

The Pollution Level and Potential Ecological Risk of Heavy Metals in Sediments from the Shellfish Culture Areas of Xiamen

根据2005年4月和10月厦门贝类养殖区环境调查资料,着重对贝类养殖区表层沉积物中重金属的含量水平进行分析,并对贝类养殖区的表层沉积物进行质量评价及潜在生态危害评价。结果表明:厦门贝类养殖区沉积物中Cu、Pb、Cd、Zn、Hg、As的平均含量分别为20.0mg.kg-1,39.5mg.kg-1,0.07mg.kg-1,97.3mg.kg-1,0.05mg.kg-1,7.20mg.kg-1。其中同安湾北部和湾顶养殖区及西海域的杏林、东山养殖区,6种元素的含量均较高;位于同安湾的刘五店、澳头养殖区,含量均较低。沉积物质量评价结果表明,贝类养殖区沉积物中重金属的含量符合第一类海洋沉积物质量标准,属于较清洁水平。Hg、As和Cd的潜在生态危害系数大于Cu、Pb、Zn,整个养殖区沉积物中重金属为轻微生态危害,养殖环境良好。

Based on the data of environmental survey from the shellfish culture areas of Xiamen in April and October 2005, the contents and distributions of heavy metals in surface sediments were analyzed. Environmental quality and potential ecological risk of those shellfish areas were also assessed in this paper. The result could be summarized as follows ： the average contents of Cu, Pb, Cd, Zn, Hg and As in sediments were 20. 0mg. kg^-1, 39. 5mg. kg^-1, 0. 07mg. kg^-1, 97. 3mg. kg^-1, 0. 05mg. kg^-1, 7.20mg. kg^-1. The contents of six heavy metals in surface sediments were higher from shellfish culture areas of northern and bayhead of Tong＇an Bay, Xinlin and Dongyu while they were less from Aotou and Liuwudian at Tong＇an Bay Mouth. The results of environmental quality assessment showed that the contents of six heavy metals in sediments were all less than the values of the first degree of Standard for Marine Sediments Quality and belonged to the grade of ＂less green＂. And the potential ecological risks of Hg, As, Cd were more harmful than that of Cu, Pb, Zn. Whereas, the potential ecological risk of heavy metals in sediments of the whole culture areas was light and the environmental quality of culture areas was well.