中文摘要：

对长江口及其邻近海域表层沉积物中重金属Cu、Mn、Pb、Zn、Cr、Fe、Hg、Cd的含量分布以及富集状况进行分析,并采用Hakanson潜在生态危害指数法评价该海域中Cu、Pb、Zn、Cr、Hg、Cd污染的程度及其潜在的生态危害,结果表明：长江口及其邻近海域表层沉积物中Cu、Mn、Pb、Zn、Cr、Fe的分布特征表现为由近岸向远岸递减的趋势,整体上象山县和舟山群岛近岸海域的含量高于研究区北部含量;Hg在长江口南端含量较高,呈由西向东递减的趋势;Cd在长江口南端以及象山县东含量较高,在研究区中部含量较低。潜在生态危害评价结果表明,长江口及其邻近海域表层沉积物只有部分站点处于生态危害的中等级别,大多站点生态危害轻微,污染程度顺序为Cd〉Hg〉Cu〉Pb〉Cr〉Zn;对长江口及其邻近海域生态环境具有潜在影响的重金属元素首先是Cd,其次是Hg。对底质环境质量进行系统聚类分析结果显示,象山县和长江口外以及济州岛西南近海海域的底质环境较差,应予以重视。

英文摘要：

The concentration and distribution pattern of heavy metals of Cu,Mn,Pb,Zn,Cr,Fe,Hg,Cd in the surface sediments of the Yangtze estuary and its adjacent areas were studied.Hakanson index method was used to evaluate the pollution level of the heavy metals of Cu,Pb,Zn,Cr,Hg,Cd and their ecological vulnerability.It is found that the elements of Cu、Mn、Pb、Zn、Cr、Fe are distributed in a declined pattern from the coast to the offshore within the estuary and its adjacent areas.The contents of these heavy metals are,in general,higher in the Xiangshan County and Zhoushan Islands rather than in the northern part.Hg is higher in the southern estuary and declines from the west to the east,while Cd is high in the south but lower in the middle estuary.Ecological assessment proves that the major part of the surface sediment in the Yangtze estuary and its adjacent areas is slightly vulnerable except some sites which are in the rank of moderate ecological risk.The risk index of these heavy metals are in an order of Cd〉Hg〉Cu〉Pb〉Cr〉Zn.The heavy metals which might bring ecological danger to the environment within the estuary and its adjacent areas are firstly Cd and then Hg.According to the results of cluster analysis,we conclude that Xiangshan County and the offshore area out of the Yangtze Estuary up to the southwest of the Cheju Island are more vulnerable,and,therefore,more attention is required.