中文摘要：

2009年在东太湖运用重力采样器采集得到岩芯钻孔（DJZ和DQG）。运用核素210Pb和137Cs对沉积物钻孔进行定年,同时分析了沉积物金属元素,并研究近代东太湖重金属污染以及人类活动对其的影响。本文运用Fe元素作为粒度的代用指标对重金属进行标准化,并获取了重金属富集系数和人为污染的重金属通量。研究表明,除了钻孔的表层样以外,东太湖DQG和DJZ钻孔的Pb、Zn、Cu、Cr和Ni的富集系数都不超过2,并且Cr、Ni的富集系数接近1。结果表明最近几十年来的重金属铅、铜、锌在不断富集,尤其是在20世纪70年代以来。20世纪70年代至90年代,东太湖来源于人为污染的Pb、Zn、Cu的通量维持在一定的水平,90年代以来,东太湖来源于人为污染的Pb、Zn、Cu的通量在不断增加,这与区域污染工业类型及经济发展阶段相吻合。东太湖2000s初以来Pb通量特别是人为污染的Pb的通量出现下降,这可能部分与含铅汽油的禁用有关,另外也与该阶段流域工业结构的调整有关。

英文摘要：

Taihu Lake is the third largest freshwater lake in China.East Taihu Lake with an area of 131 km2 and water depth of 0.9 m,dominated by macrophyte,is important drinking water source of Suzhou and Shanghai City.Sedimentary cores named DJZ and DQG were collected from East Taihu Lake in 2009 using gravity corer.The length of DJZ and DQG is 59 and 33 cm,respectively.Radio nuclides including 210Pb and 137Cs were also analyzed for dating the sediments at both cores.Sediment accumulation rate（SAR） of DQG was averaged to be 0.15 g/cm2/a based on 1963 dating marker of 137Cs.At DJZ core,SAR was higher relative to DQG core showing variation between 1.0~2.0 g/cm2/a.Elements including copper,lead,zinc,chromium,nickel,ferrum and others were analyzed for the purpose of understanding metal accumulation and human impact at East Taihu Lake combined with dating results.Between bottom to 30 cm,Cu,Pb,Zn,Cr and Ni in DJZ core showed increase trend.In the upper 30 cm sediments of DJZ core,the profiles of Pb,Cr and Ni showed relatively constant value while Cu and Zn demonstated upward increase in these sections.The average contents of Cu,Pb,Zn,Cr and Ni in DQG core were 22.34,50.83,98.35,66.19,26.74 mg/kg respectively for sediments between 0 and 9 cm,while 13.18,26.25,46.33,58.95,20.45 mg/kg for 9~33 cm sediments.In this paper Fe element as a proxy of grain size was selected for normalization and calculation of metal enrichment factor（EF） and anthropogenic heavy metal fluxes.The results showed that,except the cores surface sediment,Pb,Zn,Cu,Cr and Ni enrichment factors did not exceed 2,and EF of Cr and Ni was nearly 1.It was revealed that the heavy metals including lead,copper,zinc were continuously enriched in recent decades,especially since the 1970s at East Taihu Lake.From 1970s to 1990s anthropogenic fluxes of Pb,Zn,Cu changed slightly,and then increased corresponding to development of industry in catchment.Since early 2000s,the total and anthropogenic Pb fluxes declined,which may be due to forbidden use of leaded petrol in C