中文摘要：

在秦淮河流域采集河流表层沉积物样品,研究其毒害微量元素含量的空间分布和生态风险.流域沉积物中毒害微量元素的含量表现出明显的空间分异.Hg、Cd、Pb、Cu和Zn受流域城市化过程的影响最为显著,其富集主要集中在流域中、下游的老城区、新城区和城乡过渡区.As的分布除了与城市工业企业的排污有关外,还可能受农业活动的影响.毒害微量元素在部分河段沉积物中的积累已经具有较强的潜在生态风险,污染程度由高到低为Cd〉Hg〉Cu〉Zn〉Pb〉As.污染程度最高的元素为Cd和Hg,但多数情况下为多元素复合性污染,少数河段达到重度污染程度.河流表层沉积物中毒害微量元素的污染特征说明秦淮河流域内可能仍然存在有较强的污染源.

英文摘要：

Surface stream sediment samples collected from 29 stations along the Qinhuai River were analyzed for the concentrations of six elements in each sample.Distribution and contamination level of toxic trace elements were discussed in this paper.The average concentrations of Hg,Cd,Pb,As,Cu and Zn were 0.20,0.52,37.1,11.0,53.7 and 136.2 mg · kg-1 respectively,with a wide range of concentrations for each element.Urban discharge was the major contributor for most of the elements in the sediments,resulting in the enrichment of these elements in the lower reach regions.In terms of the extent of anthropogenic impact,those toxic elements could be ranked in a decending order of CdHgCuZnPbAs.Calculated index of geoaccumulation indicated moderate to strong cadmium and mercury contamination in the lower reach sediments.The results of our investigation suggested that there were still quite strong recent discharges of these toxic elements into Qinhuai River.