鄱阳湖流域溶解态重金属行为特征及健康风险评价

通过测定鄱阳湖流域各断面及入湖口水体溶解态重金属Cu、Zn、Pb和Cr的含量水平,调查了重金属在季节和空间变化下的行为特征,并运用美国环保局推荐的健康风险对其引起的健康风险进行了初步评价。结果表明:鄱阳湖流域不同溶解态重金属季节行为特征差异显著,Cu和Cr主要由人为因素主导,而Zn和Pb受自然因素影响更多;其空间行为特征由开采的矿山分布和人为源释放主导,这在赣江和乐安江表现尤为明显;流域健康风险大小依次为湖区>信江>抚河>赣江>乐安江>修河,由化学非致癌物Cu、Zn、Pb引起的健康危害的个人年均风险值远低于国家辐射防护委员会推荐的通过饮水途径最大可接受风险值5.00×10-5a-1,而化学致癌物Cr的健康危害的风险值超出可接受水平,比化学非致癌物高出5～6个数量级,是主要的健康风险污染物,需引起风险决策部门的重视。

Behavior Characteristics of Dissolved Heavy Metals and Health Risks Assessment from Poyang Lake Basin,China

The concentrations of Cu,Zn,Pb and Cr in the water body of Poyang Lake Basin were analyzed to study the seasonal and spatial behavior characteristics of dissolved heavy metals,and their health risk were evaluated with the method recommended by the US EPA.The results indicated that the seasonal behavior characteristics were significant different among dissolved heavy metals in Poyang Lake,Cu and Cr were mainly driven by human factors,while Zn and Pb were mainly influenced by natural factors;the spatial behaviors of heavy metals were mainly controlled by the distribution of exploited mines and man-made emissions,especially in Gan River and Le’an River;the health risks of these heavy metals followed the order of the main lake area>Xinjiang River>Fu River>Gan River>Le’an River>Xiuhe River.The values of personal annual risk caused by non-carcinogens(Cu,Zn,and Pb) were much lower than the maximum acceptable value(5.00×10-5a-1) for drinking water recommended by the ICRP,but the personal annual risk caused by carcinogen(Cr) beyond the acceptable level,which is 5～6 orders of magnitude larger than non-carcinogens’.As the major health risk pollution,Risk Decision-making Departments should pay attention to it.