Department of Environmental and Occupational Health, School of Public Health, University of Nevada, Las Vegas, 4505 S. Maryland Pkwy, Las Vegas, NV, 89154, USA; Division of Atmospheric Sciences, Desert Research Institute, 2215 Raggio Pkwy, Reno, NV, 89512, USA.
Division of Atmospheric Sciences, Desert Research Institute, 2215 Raggio Pkwy, Reno, NV, 89512, USA.
Environ Pollut. 2023 Oct 15;335:122283. doi: 10.1016/j.envpol.2023.122283. Epub 2023 Jul 28.
As the importance of non-tailpipe particles (NTP) over tailpipe emissions from urban traffic has been increasing, there is a need to evaluate NTP contributions to ambient particulate matter (PM) using representative source profiles. The Brake and Tire Wear Study conducted in Los Angeles, California in the winter of 2020 collected 64 PM and 64 PM samples from 32 pairs of downwind-upwind measurements at two near-road locations (I-5 in Anaheim and I-710 in Long Beach). These samples were characterized for inorganic and organic markers and, along with locally-developed brake wear, tire wear, and road dust source profiles, subject to source apportionment using the effective-variance chemical mass balance (EV-CMB) model. Model results highlighted the dominance of resuspended dust in both PM (23-33%) and PM (32-53%). Brake and tire wear contributed more to PM than tailpipe exhausts (diesel + gasoline) for I-5 (29-30% vs. 19-21%) while they were comparable for I-710 (15-17% vs. 15-19%). For PM, the brake and tire wear contributions were 2-3 times the exhaust contributions. Different fleet compositions on and near I-5 and I-710 appeared to influence the relative importance of NTP and exhaust sources. The downwind-upwind differences in source contributions were often insignificant, consistent with small and/or nearly equal impacts of adjacent highway traffic emissions on the downwind and upwind sites. The utility of sole markers, such as barium and zinc, to predict brake and tire wear abundances in ambient PM is evaluated.
随着城市交通中非尾气颗粒（NTP）相对于尾气排放的重要性不断增加，有必要使用代表性的源谱来评估 NTP 对环境颗粒物（PM）的贡献。2020 年冬季在加利福尼亚州洛杉矶进行的制动和轮胎磨损研究在两个近路地点（阿纳海姆的 I-5 和长滩的 I-710）从 32 对下风-上风测量中收集了 64 个 PM 和 64 个 PM 样本。这些样本经过无机和有机标记物的特征分析，并结合当地开发的制动磨损、轮胎磨损和道路灰尘源谱，使用有效方差化学质量平衡（EV-CMB）模型进行源分配。模型结果突出了再悬浮灰尘在 PM（23-33%）和 PM（32-53%）中的主导地位。对于 I-5（29-30%对 19-21%），制动和轮胎磨损对 PM 的贡献大于尾气排放（柴油+汽油），而对于 I-710（15-17%对 15-19%）则相当。对于 PM，制动和轮胎磨损的贡献是尾气排放的 2-3 倍。I-5 和 I-710 及其附近的不同车队组成似乎影响了 NTP 和尾气源的相对重要性。源贡献的下风-上风差异通常不显著，这与相邻高速公路交通排放对下风区和上风区的影响较小或几乎相等一致。单独标记物（如钡和锌）预测环境 PM 中制动和轮胎磨损丰度的实用性进行了评估。
