School of Ecology and Environment, Zhengzhou University, No. 100 Science Avenue, Zhengzhou, 450001, China.
Henan Zhongtian High-Tech Smart Technology Co., Ltd, Zhengzhou, 450001, China.
Environ Sci Pollut Res Int. 2024 May;31(21):30454-30466. doi: 10.1007/s11356-024-33194-0. Epub 2024 Apr 12.
The increase in the number of motor vehicles has intensified the impact of traffic sources on air quality. Our aim was to illustrate the characteristics of PM emissions from vehicles fueled with E10 (a blend of 10% ethanol and 90% gasoline). A 21-day PM sampling in a fully enclosed urban tunnel and the component analysis were completed, and the characteristics, sources, and health risks of tunnel PM were studied. Moreover, the PM pH and its sensitivity were investigated by the thermodynamic model (ISORROPIA-II). In addition, exposure models were used to assess the health risks of different heavy metals in PM to humans through respiratory pathways. The two-point Cu/Sb ratio (entrance: 4.0 ± 1.4; exit: 4.4 ± 1.7) was close to the diagnostic criteria indicating a significant impact from brake wear. NO, NH, and SO constituted the main components of water-soluble ions in PM of the tunnel, accounting for 83.0-84.6% of the total concentration of inorganic ions. The organic carbon/elemental carbon ratio of the tunnel was greater than 2, indicating that the contribution of gasoline vehicle exhaust was significant. The average emission factors of PM in the fleet was 31.4 ± 16.6 mg/(veh·km). The pH value of PM in a tunnel environment (4.6 ± 0.3) was more acidic than that in an urban environment (4.9 ± 0.6). The main sensitive factors of PM pH in the urban atmosphere and tunnel environment were total ammonia (sum of gas and aerosol, NH) and temperature, respectively. The results of the health risk assessment showed that Pb posed a potential carcinogenic risk, while As and Cd presented unacceptable risks for tunnel workers. The non-carcinogenic risk index of heavy metals of PM in the tunnel environment exceeded the safety threshold.
机动车数量的增加加剧了交通源对空气质量的影响。本研究旨在阐述以 E10（10%乙醇和 90%汽油的混合物）为燃料的车辆排放的 PM 特征。在一个全封闭的城市隧道中进行了为期 21 天的 PM 采样和成分分析，研究了隧道 PM 的特征、来源和健康风险。此外，还通过热力学模型（ISORROPIA-II）研究了 PM 的 pH 值及其敏感性。另外，还使用暴露模型通过呼吸道途径评估了不同重金属在 PM 中对人体的健康风险。两点 Cu/Sb 比值（入口：4.0±1.4；出口：4.4±1.7）接近表明制动磨损影响显著的诊断标准。NO、NH 和 SO 构成了隧道 PM 中水溶性离子的主要成分，占无机离子总浓度的 83.0-84.6%。隧道中有机碳/元素碳比大于 2，表明汽油车尾气的贡献显著。车队中 PM 的平均排放因子为 31.4±16.6 mg/(veh·km)。隧道环境中 PM 的 pH 值（4.6±0.3）比城市环境中的 pH 值（4.9±0.6）更酸性。城市大气和隧道环境中 PM pH 值的主要敏感因素分别是总氨（气体和气溶胶总和，NH）和温度。健康风险评估的结果表明，Pb 具有潜在的致癌风险，而 As 和 Cd 对隧道工人构成不可接受的风险。隧道环境中 PM 重金属的非致癌风险指数超过了安全阈值。
