淄博市冬季PM2.5载带金属元素污染特征、生态风险评价及来源分析

为研究淄博市城区冬季环境空气PM_2.5载带金属元素的污染特征、来源和生态风险,于2019年1月8～23日在淄博市采集环境空气PM_2.5滤膜样品并分析获取14种金属元素的浓度.结果表明,K含量均值为8 071.6 mg·kg^-1,是含量最高的元素,但未超过山东省A层土壤背景值,说明K主要来自自然源;Zn、 Pb、 Cu、 Cr、 As、 Ni和Cd等元素含量明显低于K元素(28.4～4 282.3 mg·kg^-1),但均明显高于山东省A层土壤背景值,依次为背景值的56.6、 19.0、 7.2、 2.4、 7.3、 1.4和283.8倍,反映出人为源的影响.地累积指数(I_geo)表明,冬季PM_2.5中Cd、 Zn、 Pb、 Cu和As受污染程度较高,均为中度污染及以上.潜在生态风险评价结果显示Cd存在极强的生态危害风险.综合运用相关性分析、富集因子法和主成分分析多种方法解析出,土壤扬尘、机动车尾气、燃煤和冶金行业是淄博市城区环境空气PM_2.5

Characteristics, Ecological Risk Assessment, and Sources of the Polluted Metallic Elements in PM2.5 During Winter in Zibo City

In order to study the pollution characteristics, sources, and ecological risk of the metallic elements in ambient PM_2.5 during winter in Zibo City, ambient PM_2.5 samples were collected in January 2019, after which 14 types of metallic elements were investigated. The results showed that the average value of K content was 8071.6 mg·kg^-1and was highest in the types of metallic elements, which was lower than that of the soil background value in Shandong province. The mean values of Zn, Pb, Cu, Cr, As, Ni, and Cd were 56.6, 19.0, 7.2, 2.4, 7.3, 1.4, and 283.8 times the background values, respectively, which were influenced by anthropogenic sources. The geo-accumulation index (I_geo) indicated that Cd, Zn, Pb, Cu, and As were highly polluted. The potential ecological risk indexes indicated that the potential risk of Cd was extremely high in winter. Source apportionment results were obtained using the enrichment factor (EF) and principal component analysis (PCA), and the results showed that soil dust, vehicle emission, coal burning, and metal smelting were the main sources of metallic elements in ambient PM_2.5 during winter in Zibo City.