中文摘要：

于2005年11月采集了东洞庭湖与大通湖区的湖水、沉积物和生物样品，并测定了水、沉积物和水生生物样品中重金属（Cd、Pb、Hg、As）的含量。结果表明，东洞庭湖与大通湖区的湖水绝大部分都属于I类水质，且Cd、Pb、Hg的含量低于洞庭湖湖水的背景值，As的含量高于洞庭湖湖水的背景值。沉积物中的Cd、Pb、Hg、As的含量都高于相应的洞庭湖沉积物背景值，其中以岳阳港和鹿角附近的沉积物中Cd、Pb、Hg、As的含量最高，是污染最严重的地方，且高于美国和加拿大淡水沉积物的上限，很有可能会对周围的生物体产生危害。不同鱼类中重金属含量的大小顺序是：中下层鱼类〉中上层鱼类，肉食性鱼类〉植食性鱼类，方形环棱螺肉体中重金属含量是东洞庭湖的东岸大于东洞庭湖的西岸，以鹿角和岳阳港最高，且鱼类和螺类重金属含量都没有超过无公害水产品的限量标准和人体消费标准，是比较安全放心的食品。

英文摘要：

Samples of lake water, bottom sediment and organisms＇muscles were obtained from East Dongting Lake and Datong Lake in November 2005, concentrations of Cd, Pb, Hg and As in water, bottom sediment andorganisms were analyzed. Results showed that most sampies＇ concentrations of Cd, Pb, Hg and As in lake water were lower than the values of class Ⅰ of Chinese surface fresh water quality standards, and average concentrations of Cd, Pb, Hg in lake water were lower than environmental background concentrations of Dongting Lake water, however average concentrations of As in lake water were higher than that. Average concentrations of Cd, Pb, Hg and As in sediments were higher than environmental background concentrations of Dongting lake sediments, and concentrations of Cd, Pb, Hg and As in LuJiao and YueYang Port were higher than other samples sites and the values of fresh water sediment standards in USA and Canada, and is probably dangerous to other organisms in water and sediments or to humans feed on the organisms. There were different concentrations of cadmium, lead, mercury and arsenic in different fish species, i.e. concentrations of Cd, Pb, Hg and As in demersal fish species were higher than that in pelagic fish species, and concentrations of Cd, Pb, Hg and As in piscivorous fish species were higher than that in herbivorous fish species. Concentrations ofCd, Pb, Hg and As in Bellamyaquadratafrom east shore of East Dongting Lake are higher than that from west shore of East Dongting Lake, and concentrations of Cd, Pb, Hg and As in the place of LuJiao and Yueyang Harbor is the highest. Concentrations of Cd, Pb, Hg and As in fish species and Bellamya quadrata were all lower than the values of nonpollution aquatic products, fish and Bellamya quadrata in East Dongting Lake and Datong Lake were all safe foods.