扬州市不同行政区域空气重金属污染评价

采用活藓监测法,选择广泛分布的小羽藓为材料,对扬州市区、高邮市、仪征市、宝应县4个区域空气中Pb、Zn、Cd、Cr、Ni、Zn、Hg 7种重金属元素污染情况进行监测.利用污染因子分析法、内梅罗综合指数分析法及重金属污染潜在生态风险评价法对不同区域空气重金属危害等级进行评价.结果表明:Zn、Pb、Cd元素主要污染地区为扬州市区,Cu元素主要污染地区为仪征市,Ni、Hg元素主要污染地区为宝应县,Cr元素主要污染地区为高邮市.4个区域空气重金属均处于重度污染水平,存在强生态风险.就整体而言,7种重金属元素中Cd、Zn、Hg为主要污染元素,污染情况最为严重,而Cu、Ni污染程度相对较轻.区域间空气重金属污染特征差别显著,制造业与港口航运发达的南部仪征市、江都区等地比以农业为主的北部宝应县污染重,污染程度由高到低为扬州市区仪征市高邮市宝应县.

Assessment of airborne heavy metal pollution in four different administrative regions of Yangzhou

In order to assess airborne heavy metal pollution in Yangzhou, we used living mosses (bryophytes) from the genus Haplocladium to measure ambient concentration of Pb, Zn, Cd, Cr, Ni, Zn and Hg. We adopted pollution factor analysis, nemerow composite and potential ecological risk indices to evaluate the risk of heavy metal air pollution in four regions. Results showed that the highest Zn, Pb and Cd loadings were found in Yangzhou City was the area most highly polluted by Zn, Pb and Cd, while Cu, Ni and Hg, and Cr showed their maximum values in Yizheng City, Baoying City, and Gaoyou City, respectively. All four areas experienced severe air pollution and were subject to high ecological risk. Overall, Cd, Zn and Hg were the major heavy metals in pollution, while the contribution from Cu and Ni was relatively slight. There was a large spatial difference in the characteristics heavy metal pollution. Southern regions such as Jiangdu and Yizheng City with concentrated manufacturing industry and port shipping were generally with higher pollution than the northern regions such as Baoying City mainly in rural areas. Pollution levels in four administrative regions were in a descending order of Yangzhou City, Yizheng City, Gaoyou City, and Baoying City.