Tianjin Key Laboratory of Urban Transport Emission Research& State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
Tianjin Key Laboratory of Urban Transport Emission Research& State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China; Department of Atmospheric Sciences, Texas A&M University, College Station, TX, 77843, USA.
Environ Pollut. 2020 Nov;266(Pt 2):115268. doi: 10.1016/j.envpol.2020.115268. Epub 2020 Aug 12.
Vehicular non-exhaust emissions account for a significant share of atmospheric particulate matter (PM) pollution, but few studies have successfully quantified the contribution of non-exhaust emissions via real-world measurements. Here, we conduct a comprehensive study combining tunnel measurements, laboratory dynamometer and resuspension experiments, and chemical mass balance modeling to obtain source profiles, real-world emission factors (EFs), and inventories of vehicular non-exhaust PM emissions in Chinese megacities. The average vehicular PM and PM EFs measured in the four tunnels in four megacities (i.e., Beijing, Tianjin, Zhengzhou, and Qingdao) range from 8.8 to 16.0 mg km veh and from 37.4 to 63.9 mg km veh, respectively. A two-step source apportionment is performed with the information of key tracers and localized profiles of each exhaust and non-exhaust source. Results show that the reconstructed PM emissions embody 51-64% soil and cement dust, 26-40% tailpipe exhaust, 7-9% tire wear, and 1-3% brake wear, while PM emissions are mainly composed of 59-80% tailpipe exhaust, 11-31% soil and cement dust, 4-10% tire wear, and 1-5% brake wear. Fleet composition, road gradient, and pavement roughness are essential factors in determining on-road non-exhaust emissions. Based on the EFs and the results of source apportionment, we estimate that the road dust, tire wear, and brake wear emit 8.1, 2.5, and 0.8 Gg year PM in China, respectively. Our study highlights the importance of non-exhaust emissions in China, which is essential to assess their impacts on air quality, human health, and climate and formulating effective controlling measures.
车辆非尾气排放对大气颗粒物（PM）污染有很大的贡献，但很少有研究通过实际测量成功量化非尾气排放的贡献。在这里，我们结合隧道测量、实验室测功机和再悬浮实验以及化学质量平衡模型进行了一项综合研究，以获得中国特大城市车辆非尾气 PM 排放的源谱、实际排放因子（EF）和清单。在四个特大城市（北京、天津、郑州和青岛）的四个隧道中测量的车辆 PM 和 PM EF 平均值范围为 8.8 至 16.0mgkmveh 和 37.4 至 63.9mgkmveh。使用关键示踪剂的信息和每个排气和非排气源的本地化谱进行了两步源分配。结果表明，重建的 PM 排放包含 51-64%的土壤和水泥粉尘、26-40%的排气管尾气、7-9%的轮胎磨损和 1-3%的制动磨损，而 PM 排放主要由 59-80%的排气管尾气、11-31%的土壤和水泥粉尘、4-10%的轮胎磨损和 1-5%的制动磨损组成。车队组成、道路坡度和路面粗糙度是确定道路非尾气排放的重要因素。根据 EF 和源分配的结果，我们估计道路灰尘、轮胎磨损和制动磨损在中国分别排放 8.1、2.5 和 0.8Gg 年 PM。我们的研究强调了非尾气排放在中国的重要性，这对于评估其对空气质量、人类健康和气候的影响以及制定有效的控制措施至关重要。
