title: Personal exposure to PM2.5associated with heavy metals in four travel modes of Tianjin during the summer season.
abstract: Personal exposure to PM2.5associated 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 PM2.5and 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 PM2.5personal exposure were 323.66, 313.37, 214.84 and 160.71 μg/m3for cycling, walking, bus and taxi, which resulted from the difference of source (vehicle exhaust and road dust) of exposure to PM2.5. 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 PM2.5showed 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 10-4when 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 PM2.5exposure and its specific epidemiology effects.
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China. wbqchina@163.com.
authors.forename: Bao Qing
authors.initials: BQ
authors.lastname: Wang
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
authors.forename: Jian Feng
authors.initials: JF
authors.lastname: Liu
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
authors.forename: Bo Wei
authors.initials: BW
authors.lastname: Liu
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
authors.forename: Hong Hong
authors.initials: HH
authors.lastname: Niu
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
authors.forename: Rong Hui
authors.initials: RH
authors.lastname: Chen
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
authors.forename: Ze Bei
authors.initials: ZB
authors.lastname: Wang
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
authors.forename: Jia Jia
authors.initials: JJ
authors.lastname: Zhao
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
authors.forename: Zi Hui
authors.initials: ZH
authors.lastname: Ren
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002681:China; D004391:Dust / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D019570:Inhalation Exposure / Q000032:analysis*; D019216:Metals, Heavy / Q000032:analysis*; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D018570:Risk Assessment; D012621:Seasons; D014186:Transportation; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D004391:Dust; D019216:Metals, Heavy; D052638:Particulate Matter; D001335:Vehicle Emissions
keywords: Heavy metal; PM2.5; Personal exposure; Travel mode