中文摘要：

为研究采矿炼矿活动对农田和稻谷重金属累积的影响,评估其对人体健康的潜在风险,对湖南北部某镇一硫铁矿附近典型污染稻田土壤—水稻系统8种重金属（锰（Mn）、铜（Cu）、锌（Zn）、钴（Co）、镍（Ni）、铬（Cr）、镉（Cd）和铅（Pb））含量进行监测。结果表明：该冶炼厂附近稻田土壤Cd污染最严重,单因素污染指数达12.85,为重度污染;Cu、Zn、Co和Ni为轻度污染。土壤重金属综合污染指数达重度污染。重金属生物富集因子的研究表明：Cd和Mn极易从土壤中被水稻根系吸收,尤其Cd被水稻根系吸收的能力远超其他重金属元素;而Cu、Pb、Co、Cr、Zn和Ni相对不易被水稻根系吸收。重金属在植株组织的分配也表现出差异：Pb、Co、Cu、Cd和Cr被水稻根吸收后,主要蓄积于根部,在根部的浓度百分比分别为82.5%、70.6%、64.8%、59.4%和57.5%;Mn、Zn和Ni被根系吸收后,会迅速向地上部组织迁移。研究区稻田出产的糙米Cd污染严重,Cd的超标率达100%,＂镉米＂的产出率达53.3%。糙米Cu和Ni的超标率也分别达到了40%和86.7%。若居民食用研究区稻米,每人每日摄入Cd量高于FAO/WHO推荐的标准限值5.9倍,表明研究区稻米存在很大安全风险。

英文摘要：

【Objective】Hunan Province in Central South China,is a well known nonferrous metal mining base in China.The activities of mining and smelting,however,pose great threat to the cultivated land in the province.This study is to investigate the influences of mining and smelting on heavy metal pollution of soils and rice plants,and to assess its potential risks on human health.【Method】An investigation was carried out in a town in the northern part of Hunan Province rich in mineral resources,and found that a pyrite smelting factory located at Y Town discharged wastewater,severely polluting a creek and the paddy fields around.Contents of Mn,Cu,Zn,Co,Ni,Cr,Cd and Pb in the soil-rice system of the paddy field on the two sides of the polluted creek nearby the pyrite mine at the town were monitored.【Result】Results show that the soils were heavily polluted by Cd,with an over-standard rate being 100%,and by Cu,Zn,Co and Ni,too,with an over-standard rate being 86.7%,60%,80% and 60%,respectively.The single-factor pollution index of Cd in the soils reached 12.85,indicating a heavy pollution level,and that of Cu,Zn,Co and Ni was 1.54,1.26,1.15 and 1.13,respectively,indicating a light pollution level.The comprehensive pollution index of the eight heavy metal elements in the soils was 9.39,also indicating that the soils as a whole,were heavily polluted.Analysis of heavy metals bio-accumulation factors indicates that Cd and Mn in the soils were easily taken up by rice roots,especially,Cd,of which the availability to rice was much higher than that of all the others,with bio-accumulating factor being 11.84 on average,but Cu,Pb,Co,Cr,Zn and Ni were relatively hard.Pb,Co,Cu,Cd and Cr was mainly accumulated in rice roots,making up 82.5%,70.6%,64.8%,59.4% and 57.5%,respectively,of the total in the plant.Mn,Zn and Ni,however,was rapidly translocated to the shoots of rice plants after being taken up by roots,with only 16.3%,29.9% and 49.9%,respectively,left in the roots.The brown rice produced in the studied paddy fields was commo