南京公园降尘中重金属污染水平及风险评价

Pollution Evaluation and Risk Assessment of Heavy Metals from Atmospheric Deposition in the Parks of Nanjing

分析了南京10个公园大气降尘中重金属As、Cd、Cr、Cu、Ni、Pb和Zn的含量,利用地积累指数法、潜在生态风险指数法和美国EPA健康风险评价方法进行重金属污染水平、生态风险和健康风险的评价.结果表明,重金属污染水平较高的有燕子矶公园、大桥公园和莫愁湖公园.与其他部分城市如长春、武汉和北京相比,南京市公园降尘中的重金属含量偏高.地积累指数评价结果表明,Pb处于中度污染水平,Zn和Cu均处于中度至严重污染水平,而Cd处于严重至极度污染水平.Cd的生态风险水平为很强生态风险.健康风险评价结果显示,各重金属均不存在非致癌风险.Cd、Cr和Ni均不存在致癌风险(风险值<10^(-6)),As的致癌风险在10^(-6)~10^(-4)之间,存在一定的致癌风险,但是在可接受范围之内.

Contents of heavy metals involving As,Cd,Cr,Cu,Ni,Pb and Zn from atmospheric deposition in 10 parks of Nanjing were analyzed. The pollution level,ecological risk and health risk were evaluated using Geoaccumulation Index,Potential Ecological Risk Index and the US EPA Health Risk Assessment Model,respectively. The results showed that the pollution levels of heavy metals in Swallow Rock Park,Swallow Rock Park and Mochou Lake Park were higher than the others. Compared to other cities such as Changchun,Wuhan and Beijing,the contents of heavy metals in atmospheric deposition of parks in Nanjing were higher. The evaluation results of Geoaccumulation Index showed that Pb was at moderate pollution level,Zn and Cu were between moderate and serious levels,while Cd was between serious and extreme levels. The ecological risk level of Cd was high. The assessment results of Health Risk Assessment Model indicated that there was no non-carcinogenic risk for all the seven heavy metals. For carcinogenic risk,the risks of Cd,Cr and Ni were all negligible（ Risk 1 × 10^- 6）,whereas As had carcinogenic risk possibility but was considered to be acceptable（ 10^- 6 Risk 10^- 4）.