昭通市周边扬尘重金属污染特征及健康风险

Pollution Characteristics and Health Risk of Heavy Metals in Fugitive Dust Around Zhaotong City

为研究昭通市主城区扬尘中重金属的污染特征及健康风险,2019年5月在昭通市昭阳区采集了道路尘和周边土壤尘样品,使用颗粒物再悬浮系统将尘样悬浮并采集PM_(2.5)(空气动力学当量直径≤2.5μm的颗粒物),并利用ICP-MS和ICP-OES检测了PM_(2.5)中Ca、Al、Fe、Mg、Ti、V、Cr、Mn、Co、Ni、Cu、Zn、As、Cd和Pb等15种金属元素.对其中10种重金属的研究表明,Mn在土壤尘中含量最高,其次为Cr、Ni、Zn、Cu、Co、Pb、V、As和Cd;Zn在道路尘中含量最高,其次为Mn、Cu、Cr、Pb、Ni、As、Co、V和Cd,且道路尘中Cu、Zn和Pb的含量高于土壤尘,表现为中度富集.两种扬尘的Cd均表现为高度富集.相关性和主成分分析表明,两种扬尘中重金属均受燃煤源的影响,但土壤尘和道路尘中重金属还分别受到农业活动源和交通源的影响而存在一定的来源差异.健康风险研究表明,土壤尘中Cr、Co、Ni、As和Cd的终身致癌风险均高于道路尘.两种扬尘中重金属的儿童非致癌风险均高于成人,且道路尘中Cu、Zn和Pb的非致癌风险高于土壤尘.

In order to explore the pollution characteristics and health risks of heavy metals in fugitive dust around the urban areas of Zhaotong City, road dust and soil dust samples were collected in the Zhaoyang District of Zhaotong City in May 2019. The dust samples were suspended using a particle resuspension system to obtain PM_(2.5)(particulate matter with an aerodynamic diameter less than or equal to 2.5 μm). The concentrations of Ca, Al, Fe, Mg, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb in PM_(2.5)were quantified by ICP-MS and ICP-OES. By analyzing 10 types of heavy metals in PM_(2.5), the results showed that the average concentration of Mn was the highest in the soil fugitive dust, followed by Cr, Ni, Zn, Cu, Co, Pb, V, As, and Cd. The average concentration of Zn in the road fugitive dust was the highest, followed by Mn, Cu, Cr, Pb, Ni, As, Co, V, and Cd. The enrichment factor(EF) indicated that Cd was strongly enriched in the two types of fugitive dust. The EFs of Cu, Zn, and Pb in road fugitive dust showed a moderate enrichment, and they were higher than those in soil fugitive dust. Correlation and principal component analysis showed that heavy metals in the two types of fugitive dust were affected by coal burning sources. At the same time, heavy metals in soil fugitive dust were affected by agricultural activity sources, and heavy metals in road fugitive dust were affected by traffic sources. The results of the health risk assessment indicated that the carcinogenic risks of Cr, Co, Ni, As, and Cd in soil fugitive dust were higher than those in road fugitive dust. The non-carcinogenic risks of heavy metals in the two types of fugitive dust for children were higher than those for adults, and the non-carcinogenic risks of Cu, Zn, and Pb in road fugitive dust were higher than those in soil fugitive dust.