太原市叶面尘中重金属分布特征及其健康风险评价

微量金属污染普遍存在于城市环境的各个区域，了解城市痕量重金属污染现状，对污染控制和城市发展具有重要的意义.为探讨太原市叶面尘中重金属的污染水平及其对人类健康的影响，以太原市5个不同功能区冬青卫矛（Euonymus japonicus Thunb.）叶面尘为研究对象，采用ICP-MS测定了As、Cd、Cr、Pb、Zn、Cu的含量，通过地积累指数法和Hankanson潜在风险指数法对重金属的生态风险进行了评价，并采用美国EPA健康风险评价模型对重金属的儿童致癌和非致癌健康风险进行了评估.结果表明，太原市居民区冬青卫矛叶面滞尘量最高为47.18 mg·g^-1，文教区最低为11.92 mg·g^-1，其中，Cd、Cr和Zn为叶面尘的主要污染物，平均含量分别为土壤背景值的8.00、2.69和2.04倍.地积累指数和生态风险因子分析表明，Cd是叶面尘中主要的生态风险因子，其生态风险贡献率在不同功能区的叶面尘中占比为78.47%~87.19%.非致癌风险评价表明，Cr、Cd和As的风险均小于1.0，非致癌总风险值在不同功能区的叶面尘中为1.03~1.77，均超过了阈值1.0，表明对儿童健康存在一定的风险.而儿童致癌风险评价表明，Cr、Cd和As无致癌风险.Pearson相关性分析及主成分分析表明，叶面尘中重金属的来源为煤燃烧、交通排放和金属冶炼.

Distribution characteristics and health risk assessment of heavy metals in foliage dust in Taiyuan City

Trace metal pollution generally exists in the urban environment. It is of great significance for pollution control and urban development to understand the current situation of trace heavy metal pollution in cities. The purpose of this study is to explore the pollution level of heavy metals in foliage dust in Taiyuan and its effect on human health. The foliage dust of Euonymus japonicus Thunb. in five different functional areas of Taiyuan were sampled, the contents of As, Cr, Cd, Cu, Zn and Pb were determined by ICP-MS, and the ecological risk of heavy metals was evaluated by calculating the geoaccumulation index and the Hankanson potential ecological risk index. Finally, EPA health risk assessment model was used to assess the carcinogenic and non carcinogenic health risks of heavy metal for children. The results showed that the dust retention of Euonymus japonicus was the highest in residential area (47.18 mg·g^-1), and the lowest in educational area (11.92 mg·g^-1). The average contents of Cr, Cd and Zn as the main pollutants of foliage dust were 8.00, 2.69 and 2.04 times of soil background value, respectively. Cd was the main ecological risk factor in foliage dust, and its ecological risk contribution rate was 78.47%~87.19% in different functional areas. Non carcinogenic risk assessment showed that the risk of Cd, Cr and As were less than 1.0, the total risk value of non carcinogenic in different functional areas were 1.03~1.77 in foliage dust exceeded the threshold value of 1.0 in each functional area, suggesting there was a certain risk to children''s health. However, Cr, Cd and As had no carcinogenic risk. Person correlation analysis and principal component analysis showed that the sources of heavy metals in foliage dust were coal combustion, traffic emissions and metal smelting.