北京高校校园道路灰尘重金属污染特征及健康风险评价

Pollution characteristics and health risk assessment of heavy metals in road dusts of universities in Beijing

为了解高校校园道路灰尘重金属污染特征及其可能带来的健康风险,在北京10所高校共采集了50个道路灰尘样品,测定了灰尘中Cr、Ni、Cu、Zn、Cd和Pb的浓度,采用美国环境保护署(USEPA)推荐的健康风险评价模型对高校道路灰尘重金属做了初步的健康风险评价。结果表明,北京10所高校校园道路灰尘中Cr、Ni、Cu、Zn、Cd和Pb的平均质量浓度分别为0.77、85.07、82.41、34.03、54.30、308.31mg/kg,均高于北京土壤重金属背景值。10所高校的重金属平均地累积指数(Igeo)排序为Zn>Cd>Cu>Cr>Pb>Ni,其中Zn、Cd和Cu处于中度污染水平,Cr和Pb处于轻度污染水平,Ni处于无污染水平。对于非致癌风险,呈现摄食>皮肤接触>呼吸吸入的特征,摄食是主要的暴露途径,Cr和Pb是主要的风险元素。对于致癌风险,Cr、Ni、Cd的致癌风险均低于风险阈值。高校校园道路灰尘重金属引起的健康风险处于较低水平。

In order to understand the pollution characteristics of heavy metals in road dusts and the related health risk,50 road dust samples were collected from 10 universities in Beijing. The concentrations of heavy metals （Cr,Ni,Cu,Zn,Cd and Pb） in these road dust samples were detected and the human health risk assessment method established by US Environmental Protection Agency （USEPA） was introduced to evaluate the non-carcinogenic and carcinogenic risk. The results showed that the average mass concentrations of Cr,Ni,Cu,Zn,Cd and Pb in university road dusts were 0.77,85.07,82.41,34.03,54.30 and 308.31 mg/kg,respectively,which were all higher than the Beijing soil background values. A pollution assessment by Geoaccumulation Index （Igoo） showed that the pollution level of heavy metals was in the following order： Zn〉Cd〉Cu〉Cr〉Pb〉Ni. The pollution level of Zn,Cd and Cu was con- sidered moderately contaminated,with Cr and Pb mildly contaminated,Ni uncontaminated. The exposure pathways of non-carcinogenic risk ranked ingestion〉dermal taken〉inhalation. The highest non-carcinogenic risk was related to ingestion and Cr,Pb were dominated risk elements. The carcinogenic risk of Cr,Ni and Cd was lower than the thresh- old value. In conclusion,there was little significant health risk caused by heavy metals in road dusts of universities in Beijing.