Wang Bao Qing, Liu Jian Feng, Liu Bo Wei, Niu Hong Hong, Chen Rong Hui, Wang Ze Bei, Zhao Jia Jia, Ren Zi Hui
College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
Environ Sci Pollut Res Int. 2017 Mar;24(7):6667-6678. doi: 10.1007/s11356-016-8179-7. Epub 2017 Jan 13.
Personal exposure to PM associated with heavy metals were investigated at and around the same road by cycling, walking, taxi and bus in Tianjin, China. One trip on each mode was undertaken during 4 h of both morning and evening peak hours. Results of one-way analysis of variance (ANOVA) to compare mean concentrations of PM and each metal measured by four modes, the enrichment level of heavy metals in four modes and the carcinogenic, non-carcinogenic risk and probabilistic estimation of health risks of metals (Cr, Ni, Cu, Zn and Pb). Arithmetic means of PM personal exposure were 323.66, 313.37, 214.84 and 160.71 μg/m for cycling, walking, bus and taxi, which resulted from the difference of source (vehicle exhaust and road dust) of exposure to PM. Na has the highest concentration, followed by Al, Ca, K, Fe, Mg, Zn, Ni, Pb, Cu and Cr. The higher Na concentrations were observed in Tianjin in light of its major sea salt influence. The concentrations of Ca, Mg, Fe and Zn in four modes followed different orders, while other metals have no significant difference between four modes. Enrichment factors of metals in PM showed that some metals are enriched, ranging from contaminated to extremely contaminated, for example, Ni, Cu, Zn, Pb, Na and Cr. Others are barely enriched such as Ca, K, Mg and Fe. It illustrated the former is mainly effected by anthropogenic activates and the source of latter comes from crust. From the results of non-carcinogenic and carcinogenic risks of metals, the intake of metals with inhalation for 4 h by four modes did not pose a significant potential chronic-toxic risk and was an acceptable or tolerable risk at present. But uncertainty analysis of health risks showed there were 4.05 and 6.87% probability that make carcinogenic risk values to exceed 10 when male choose walking/cycling to work. Commuters' rush hour exposures were significantly influenced by mode of transport. We suggest that future work should focus on further research between heavy metals in PM exposure and its specific epidemiology effects.
在中国天津，通过骑自行车、步行、乘坐出租车和公交车等方式，对同一条道路及其周边区域与重金属相关的个人颗粒物暴露情况进行了调查。在早晚高峰时段的4小时内，每种出行方式各进行了一次行程。采用单向方差分析（ANOVA）比较了四种出行方式所测颗粒物及每种金属的平均浓度、四种出行方式中重金属的富集水平、金属（铬、镍、铜、锌和铅）的致癌、非致癌风险及健康风险概率估计。骑自行车、步行、乘坐公交车和出租车时，个人颗粒物暴露的算术平均值分别为323.66、313.37、214.84和160.71μg/m³，这是由于颗粒物暴露源（车辆尾气和道路扬尘）的差异所致。钠的浓度最高，其次是铝、钙、钾、铁、镁、锌、镍、铅、铜和铬。鉴于天津受海盐影响较大，钠的浓度较高。四种出行方式中钙、镁、铁和锌的浓度顺序不同，而其他金属在四种出行方式之间无显著差异。颗粒物中金属的富集因子表明，部分金属存在富集现象，从轻度污染到极度污染不等，例如镍、铜、锌、铅、钠和铬。其他金属如钙、钾、镁和铁几乎没有富集。这表明前者主要受人为活动影响，后者的来源是地壳。从金属的非致癌和致癌风险结果来看，四种出行方式4小时吸入金属的摄入量目前未构成显著的潜在慢性毒性风险，属于可接受或可耐受风险。但健康风险的不确定性分析表明，男性选择步行/骑自行车上班时，致癌风险值超过10的概率分别为4.05%和6.87%。通勤高峰时段的暴露情况受交通方式的显著影响。我们建议未来的工作应侧重于进一步研究颗粒物暴露中的重金属与其特定流行病学效应之间的关系。
