安徽省城市地表灰尘重金属污染及人体健康风险评价

本研究收集了安徽省合肥、蚌埠、芜湖、淮南、安庆、铜陵和宿州7个城市地表灰尘重金属含量的数据,分别采用地累积指数法、美国环境保护署(USEPA)人体健康风险评价法对地表灰尘重金属污染程度和人体健康风险水平进行评价。结果表明,所研究的安徽省7个城市地表灰尘中Pb、Cd、Cr、Zn和Cu平均含量分别为123.73±81.70、5.34±6.54、96.40±37.36、941.03±1 007.39和269.77±441.59 mg/kg,均高于安徽省土壤环境背景值。地累积指数法评价结果显示,安徽省城市地表灰尘Cr为轻度污染, Pb为中度污染,Zn为重度污染,Cd和Cu为严重污染。人体健康风险评价结果表明,安徽省城市地表灰尘重金属对儿童存在着明显的非致癌健康风险,对成人产生的非致癌健康风险不明显。重金属Cd和Cr致癌风险在安全范围内,不会对人群产生明显的致癌效应。手-口摄入是人体暴露于地表灰尘产生健康风险的主要途径,在同一暴露途径下儿童所遭遇的健康风险高于成人,儿童更容易受到地表灰尘中污染物的危害。

Heavy Metal Pollution and Human Health Risk Assessment of Surface Dust in Urban Areas of Anhui

The heavy metal contents in surface dust samples from seven cities, Hefei, Bengbu, Wuhu, Huainan, Anqing, Tongling and Suzhou, of the Anhui province were measured. The pollution and human health risks of heavy metals in urban surface dust were evaluated repectively by the method of geo-accumulation index and the human health risk assessment method of the United States Environmental Protection Agency (USEPA). The results showed that average contents of Pb, Cd, Cr, Zn and Cu in the surface dust of the seven cities were 123.73±81.70, 5.34±6.54, 96.40±37.36, 941.03±1 007.39 and 269.77±441.59 mg/kg, respectively, all of which were higher than backgrounds in soils of Anhui. The evaluation results of geo-accumulation index showed that, among heavy metals detected in surface dust samples, Cr was at the light pollution level, Pb was at the moderate pollution level, Zn was at the heavy pollution level, Cd and Cu were at the severe pollution level. The human health risk assessment results showed that the non-carcinogenic health risks of heavy metals in urban surface dust samples were notable to children but insignificant to adults. The carcinogenic risks of Cd and Cr were in safe ranges, indicating no significant carcinogenic risk was occurred on the population. The major heavy metal exposure of surface dust to human is intakes by hand or/and by mouth. The health risks were higher to children than to adults if they exposed to surface dust equally, it is to say that children are more vulnerable to the pollution of surface dust.