舟山近岸海域表层沉积物中5种重金属元素的污染及潜在生态风险评价

Evaluation on pollution and potential ecological risk of 5 heavy metals in the surface sediments of Zhoushan coastal area

利用2006年8月采集于舟山本岛南部近岸海域的表层沉积物监测数据,采用Hakanson生态风险指数法,分析了Hg、As、Pb、Cd和Cu等5种重金属元素含量,并进行了潜在生态风险评价,结果表明:舟山近岸海域表层沉积物中Hg、As、Pb和Cd元素的含量均符合国家海洋沉积物质量一类标准;各重金属元素均为低污染水平,潜在生态风险程度低,重金属元素污染程度由大到小依次为:Cu>Pb>As>Cd>Hg,潜在生态风险由大到小依次为:Hg>Cd>Cu>Pb>As,其中Cu和Pb元素是主要的污染因子,Hg和Cd元素是主要的潜在生态风险因子。个别站位的Cu和Pb元素的污染程度较高,有达到中度污染的趋势,应引起有关部门的高度关注和足够重视。个别站位表层沉积物重金属元素的含量、污染指数和潜在生态风险指数均高于其它站位,这可能与其附近排污口的污水排放入海有关。

According to the monitoring data,heavy metals（Hg,Cd,Pb,As and Cu） in the surface sediments in Zhoushan coastal area in August of 2006 were studied,adopting the method of potential ecological risk index presented by Hakanson.The results showed that the Hg,As,Pb and Cd accord with the first class of the marine sediment quality of National Standards;the pollution status and the potential ecological risk level of these five heavy metals were low.The order of heavy metals pollution index and potential ecological risk was CuPbAsCdHg and HgCdCuPbAs.Cu and Pb were the main environment pollution factors.The pollution indexes of Cu and Pb in some locations were high and probably reached middle pollution level.Hg and Cd were main contributor for RI,which were main factors of potential ecological risks.The content,pollution index and potential ecological risk of heavy metals in individual locations was higher than others.This is probably related to the sewage drainage in adjacent area.