隧道环境PM2.5载带重金属污染特征与健康风险

在南京富贵山隧道开展机动车排放的颗粒物浓度及其载带重金属元素对人群健康的影响研究，对PM_2.5的浓度水平与变化特征、载带重金属元素组分进行分析，并通过美国环保局（US EPA）的健康风险评价模型对重金属的健康风险进行了评价.结果表明，工作日隧道进口和出口处的PM_2.5质量浓度为（78.67±24.58）μg/m³和（164.2±45.13）μg/m³，非工作日颗粒物浓度略低于工作日.采样期间隧道出口处PM_2.5载带的Zn、Cu和Mn元素的浓度质量较高，受机动车污染影响较大.富集因子结果显示，隧道进出口处，Cd、Sb、Sn、Zn、Cu、Mo、Pb和As等元素的EF>10，受人为污染源排放影响，Co、Mn、Cr、Ni、V和Tl等元素EF<10，在隧道中几乎没有富集.健康风险评价结果表明，对于儿童，测试期间隧道进出口处的非致癌风险危险指数（HI）均大于1，具有非致癌风险，对于成人，测试期间隧道进出口处的非致癌风险危险指数（HI）均小于1，非致癌风险在安全范围内.但颗粒物载带的Cr和As元素致癌风险均超过EPA推荐的可接受风险阈值（10^-6），具有明显的致癌效应.

Characteristics and health risk assessment of heavy metal in PM2.5 in tunnel environment

In order to study pollution characteristics health risk of heavy metal elements in particulate matter from vehicle emissions, a tunnel test was conducted the Fu Gui Mountain tunnel in Nanjing, China. The concentration and characteristics of PM_2.5, and the components of heavy metal elements were studied. The health risk of heavy metal elements in PM_2.5 was assessed by using the international recognized health risk assessment method (US EPA). The results showed that the concentration of PM_2.5 in the tunnel entrance and exit at workdays was (78.67±24.58) μg/m³ and (164.2±45.13) μg/m³, and the concentration of particulate matter on non-working days was slightly lower than the working day. During the sampling period, the concentration of Zn, Cu, and Mn in PM_2.5 at tunnel exits was higher quality, which was greatly affected by vehicle. The enrichment factor analysis results show that the EF of the Cd, Sb, Sn, Zn, Cu, Mo, Pb, and As at the entrance and exit of the tunnel were greater than 10, which were affected by the anthropogenic sources emission. The EF of Co, Mn, Cr, Ni, V, and Tl were less than 10, which were almost no enrichment in the tunnel. The health risk assessment results showed that the non-carcinogenic risk index (HI) in the tunnel during the test period was greater than 1for children, which had non-carcinogenic risk. For adults, the HI was less than 1, which were within safe limits. However, two heavy metal elements were carcinogenic to human body, such as Cr and As which had a significant impact on human health.