Dept. of Earth, Ocean, and Atmospheric Sciences, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
Dept. of Geography, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
Environ Pollut. 2017 Apr;223:376-383. doi: 10.1016/j.envpol.2017.01.034. Epub 2017 Jan 24.
Transport of coal by train through residential neighborhoods in Metro Vancouver, British Columbia, Canada may increase the possibility of exposure to particulate matter at different size ranges, with concomitant potential negative health impacts. This pilot study identifies and quantifies train impacts on particulate matter (PM) concentrations at a single location. Field work was conducted during August and September 2014, with the attributes of a subset of passing trains confirmed visually, and the majority of passages identified with audio data. In addition to fixed ground based monitors at distances 15 and 50 m from the train tracks, an horizontally pointing mini-micropulse lidar system was deployed on three days to make backscatter and depolarization measurements in an attempt to identify the zone of influence, and sources, of train-generated PM. Ancillary wind and dust fall data were also utilized. Trains carrying coal are associated with a 5.3 (54%), 4.1 (33%), and 2.6 (17%) μgm average increase in concentration over a 14 min period compared to the average concentrations over the 10 min prior to and after a train passage ("control" or "background" conditions), for PM, PM, and PM, respectively. In addition, for PM and PM, concentrations during train passages of non-coal-carrying trains were not found to be significantly different from PM concentrations during control conditions. Presence of coal dust particles at the site was confirmed by dust fall measurements. Although enhancements of PM concentrations during 14 min train passages were generally modest, passing coal trains occasionally enhanced concentrations at 50 m from the tracks by ∼100 μgm. Results showed that not every train passage increased PM concentrations, and the effect appears to be highly dependent on wind direction, local meteorology and load related factors. LiDAR imagery suggests that re-mobilization of track-side PM by train-induced turbulence may be a significant contributor to coarse particle enhancements.
加拿大不列颠哥伦比亚省大温哥华地区的火车运输煤炭可能会增加不同粒径范围的颗粒物暴露的可能性，同时也会带来潜在的负面健康影响。本试点研究旨在确定并量化火车对单一地点颗粒物（PM）浓度的影响。现场工作于 2014 年 8 月和 9 月进行，通过视觉确认了一部分过往列车的属性，并通过音频数据确定了大部分列车的通行。除了在距离铁轨 15 和 50 米处的固定地面监测器外，还在三天内部署了一个水平指向的微型脉冲激光雷达系统，以进行后向散射和去偏振测量，试图识别火车产生的 PM 的影响区域和来源。还利用了辅助风和降尘数据。与“背景”条件相比，运输煤炭的火车在 14 分钟内分别使 PM、PM 和 PM 的浓度平均增加了 5.3（54%）、4.1（33%）和 2.6（17%）μgm；在非运煤火车经过时，PM 和 PM 的浓度与“背景”条件下的浓度相比没有明显差异。降尘测量证实了现场存在煤尘颗粒。虽然火车经过 14 分钟时 PM 浓度的增加通常较为温和，但偶尔会使 50 米处的浓度增加约 100μgm。结果表明，并非每列火车经过都会增加 PM 浓度，其影响似乎高度依赖于风向、当地气象和与负荷相关的因素。激光雷达图像表明，火车引起的紊流可能会重新移动轨道旁的 PM，这是粗颗粒增强的一个重要因素。
