江西乐安江流域稻田土重金属累积变化与德兴矿集区关系

对乐安江流域稻田表层土壤中Pb、Cd、Cu、Zn的分布特征进行分析，按照单因子污染指数法和内梅罗综合污染指数法，依据土壤环境背景值标准和国家土壤环境质量标准对乐安江流域稻田土壤的重金属进行评价。结果表明，矿集区上游水稻田土壤重金属综合污染指数等级尚在安全范围内，矿集区周边Cd和Cu的单项污染指数大于1，综合污染指数达到7.82，属于重污染；矿集区下游接近警戒值。研究表明，矿集区矿业开发释放的重金属元素对乐安江中下游流域水稻田土壤的重金属累积具有重要影响。

Relationship between heavy metal accumulation of rice field topsoils along the Le'an River and the Dexing ore concentration area,northeast Jiangxi Province

To investigate the influence of ore exploration on soil environment, the authors conducted investigations in the rice field topsoils of the Le'an River. The concentrations of heavy metals Cd, Cu, Pb and Zn in the topsoils were analyzed, and the soil environmental quality on the basis of the environmental background value criteria were evaluated by single factor index and Nemerow multi- factor index method, respectively. The results show that the soils were polluted by heavy metals Pb, Cd, Cu and Zn, with the National Standard (GB15618-1995) as the evaluation standard. In addition, heavy metals pollution in various degrees occurs in the areas along the lower and middle reaches of the Lea'n River. The results indicate that the average concentrations of heavy metals (Cd and Cu) in the soil exceed the background values, and the integrated contamination index of all samples has exceeded 7.82. The heavy metal levels in the soils are closely related to local geological environment and controlled by one or more leading factors of geological environment．