孝感市开放源扬尘重金属污染特征、来源及健康风险评价

Pollution characteristics,sources and health risk assessment of heavy metals in open-source dusts in Xiaogan City

为了解开放扬尘源重金属成分谱特征,对孝感市孝南区道路扬尘、土壤扬尘、城市降尘、建筑扬尘和堆场扬尘进行调查取样,利用电感耦合等离子体发射光谱法分析扬尘中重金属的含量,并通过地累积指数法、相关分析、聚类分析和人体健康风险评价法对扬尘重金属污染程度和人体健康风险进行评价.结果表明,扬尘中Mn、Cr、Zn、Cu、Co和Pb的平均含量分别为716.4、127.6、574.3、42.9、17.9、69.0 mg·kg^(-1),均高于湖北省土壤背景值.地累积指数法评价结果显示不同类型扬尘中Zn污染程度最高,其次为Pb,Mn和Co清洁无污染,其中城市降尘污染最严重,土壤扬尘污染程度最轻.相关分析和聚类分析结果表明,Cu、Co、Pb和Cr等4种元素主要受工业活动、交通污染源的影响,而Mn和Zn元素则分别来自土壤母质和交通生活混合污染源.健康风险评价结果表明非致癌风险暴露的主要途径是手-口接触,且儿童所受非致癌风险大于成人.不同类型扬尘单项重金属致癌风险指数和致癌总风险指数均低于10^(-4),说明不会对人群产生明显的致癌风险.

In order to understand the characteristics of the heavy metal composition in the opensource dust,five different types of dusts which contained road dust,soil dust,urban dustfall,construction dust,and stack yard dust were sampled in Xiaogan City,Hubei Province.The concentrations of heavy metals including Mn,Cr,Zn,Cu,Co,and Pb were measured by the inductively coupled plasma emission spectroscopy(ICP-MS),and the pollution characteristics,sources,and human health risk of heavy metals were evaluated.The results showed that the average contents of Mn,Cr,Zn,Cu,Co,and Pb in the dust samples were 716.4,127.6,574.3,42.9,17.9 and69.0 mg·kg^(-1),respectively,which were all higher than the soil background values of Hubei Province.The pollution assessment by geo-accumulation index showed that the pollution level of Zn was the highest,followed by Pb,while Mn and Co were non-polluting.Among the five types of dust,the most serious polluted was urban dust and the least polluted was soil dust.The results of correlation analysis and cluster analysis showed that Cu,Co,Pb,and Cr were mainly affected by industrial activities and traffic pollution sources,while Mn and Zn might come from soil parent materials and/or mixed pollution sources of traffic and daily life.Human health risk assessment indicated that the major way of non-carcinogenic exposure was hand-mouth intake,and the non-carcinogenic risks for children were higher than those for adults.The carcinogenic risks of heavy metals in different open-source dusts were lower than 10^(-4),indicating that there is no carcinogenic risk.