徐州北郊大气降尘重金属污染特征与风险评价

采集了徐州北郊第三、四季度大气降尘样品，分析了降尘中As、Cr、Cd、Pb、Cu的污染水平和健康风险.结果表明，研究区域降尘中Pb、Cu、Cr、As和Cd沉降通量分别为1.49，1.21，0.96，0.243mg/（m²·月），以及9.23μg/（m²·月）.降尘中5种元素含量均超过当地土壤背景值，但未超过相关标准值.研究区域内Cu空间变异性最强（110.05%），Pb的沉降通量最高，Cd最低，相较于国内其他工业城市，Cr、Cu的沉降通量偏高，Cd偏低.时间上，第三季度，5种重金属地累积指数排序为：Cu>Pb>Cd>As>Cr；第四季度则为Pb>Cu>Cd>As>Cr.其中Cu、Pb、Cd污染程度均在中度和偏重度以上，As介于轻度和偏中度污染，Cr为轻度污染.10处监测点各重金属均为轻微潜在生态风险，降尘中As对儿童存在一定的非致癌风险和经口摄入的致癌风险.

Characteristics and risk assessment of heavy metals from atmospheric deposition in northern suburban of Xuzhou

The concentrations of heavy metals (As, Cr, Cd, Pb and Cu) were investigated in dust of northern suburb of Xuzhou, China, during the third to fourth season, to analyze the contamination level, ecological risk and health risk due to the atmospheric deposition. The deposition flux of Pb (1.49mg/(m²·month)) was the highest and that of Cd (9.23μg/(m²·month)) was the lowest, The concentrations of five heavy metals were all higher than the local soil background values, but lower than the values regulated by corresponding Chinese National Standard. The deposition fluxes of Cu (1.21mg/(m²·month)) and Cr (0.96mg/(m²·month)) in atmospheric deposition were slightly higher than those of other industrial cities, while Cd (9.23μg/(m²·month)) was relatively lower. Cu indicated the strongest spatial variation, which was 110.05%. The geo-accumulated index of five heavy metals followed the order:Cu > Pb > Cd > As > Cr in the third season, while Pb > Cu > Cd > As > Cr in the fourth season. Cu, Cd and Pb were between moderate and very high pollution level, As was between slight and moderate level, and Cr was classified as slightly uncontaminated. Generally, all of heavy metals at 10 sampling sites had minor ecological hazard, and especially As in dust had both non-carcinogenic risk through hand-mouth intake and carcinogenic risk to children.