Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
Research Center for Environmental Determinants of Health (RCEDH), Kermanshah University of Medical Sciences, Kermanshah, Iran.
Environ Pollut. 2018 Jun;237:348-355. doi: 10.1016/j.envpol.2018.02.063. Epub 2018 Mar 15.
The air pollutant species and concentrations in taxis' cabins can present significant health impacts on health. This study measured the concentrations of benzene, toluene, ethylbenzene, xylene (BTEX), formaldehyde, and acetaldehyde in the cabins of four different taxi models. The effects of taxi's age, fuel type, and refueling were investigated. Four taxi models in 3 age groups were fueled with 3 different fuels (gas, compressed natural gas (CNG), and liquefied petroleum gas (LPG)), and the concentrations of 6 air pollutants were measured in the taxi cabins before and after refueling. BTEX, formaldehyde, and acetaldehyde sampling were actively sampled using NIOSH methods 1501, 2541, and 2538, respectively. The average BTEX concentrations for all taxi models were below guideline values. The average concentrations (±SD) of formaldehyde in Model 1 to Model 4 taxis were 889 (±356), 806 (±323), 1144 (±240), and 934 (±167) ppbv, respectively. Acetaldehyde average concentrations (±SD) in Model 1 to Model 4 taxis were 410 (±223), 441 (±241), 443 (±210), and 482 (±91) ppbv, respectively. Refueling increased the in-vehicle concentrations of pollutants primarily the CNG and LPG fuels. BTEX concentrations in all taxi models were significantly higher for gasoline. Taxi age inversely affected formaldehyde and acetaldehyde. In conclusion, it seems that refueling process and substitution of gasoline with CNG and LPG can be considered as solutions to improve in-vehicle air concentrations for taxis.
出租车车厢内的空气污染物种类和浓度会对健康产生重大影响。本研究测量了四种不同出租车模型车厢内的苯、甲苯、乙苯、二甲苯（BTEX）、甲醛和乙醛浓度。考察了出租车的年龄、燃料类型和加油的影响。使用 NIOSH 方法 1501、2541 和 2538 分别对 4 种出租车模型（3 个年龄组）的 3 种不同燃料（汽油、压缩天然气（CNG）和液化石油气（LPG））进行了加油前后出租车车厢内 6 种空气污染物浓度的测量。BTEX、甲醛和乙醛采样采用 NIOSH 方法 1501、2541 和 2538 分别进行主动采样。所有出租车模型的 BTEX 浓度平均值均低于指导值。出租车模型 1 至模型 4 的甲醛浓度平均值（±SD）分别为 889（±356）、806（±323）、1144（±240）和 934（±167）ppbv。出租车模型 1 至模型 4 的乙醛浓度平均值（±SD）分别为 410（±223）、441（±241）、443（±210）和 482（±91）ppbv。加油会增加车内污染物浓度，主要是 CNG 和 LPG 燃料。所有出租车模型的 BTEX 浓度在汽油中均明显较高。出租车的年龄对甲醛和乙醛有相反的影响。综上所述，似乎加油过程以及用 CNG 和 LPG 替代汽油可以作为改善出租车车内空气浓度的解决方案。
