Concentrations of particulate matter (PM, PM), ultrafine (UFP), particle number (PNC), black carbon (BC), nitrogen dioxide (NO) and nitrogen oxides (NO) were measured in train carriages on diesel and bi-mode trains on inter-city and long-distance journeys in the United Kingdom (UK) using a high-quality mobile measurement system. Air quality on 15 different routes was measured using highly-time resolved data on a total of 119 journeys during three campaigns in winter 2020 and summer 2021; this included 13 different train classes. Each journey was sampled 4–10 times with approximatively 11,000 min of in-train concentrations in total. Mean-journey concentrations were 7.552 µg m (PM); 3.936 µg m (PM); 333–11,300 # cm (PNC); 225–9,131 # cm (UFP); 0.6–11 µg m (BC); 28–201 µg m (NO); and 130–3,456 µg m (NO). The impact of different factors on in-train concentrations was evaluated. The presence of tunnels was the factor with the largest impact on the in-train particle concentrations with enhancements by a factor of 40 greater than baseline for BC, and a factor 6 to 7 for PM and PNC. The engine fuel mode was the factor with the largest impact on NO with enhancements of up to 14-times larger when the train run on diesel compared to the times running on electric on hybrid trains. Train classes with an age < 10 years observed the lowest in-train PM, BC and NO concentrations reflecting improvements in aspects of rail technology in recent years. Air quality on UK diesel trains is higher than ambient concentrations but has lower PM and PNC than most other transport modes, including subway systems, diesel and petrol cars. This paper adds significantly to the evidence on exposure to poor air quality in transport micro-environments and provides the industry and regulatory bodies with reference-grade measurements on which to establish in-train air quality guidelines.

中文翻译：

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英国柴油和混合动力火车上的空气质量


测量柴油和双模火车车厢内的颗粒物 (PM、PM)、超细颗粒物 (UFP)、颗粒物数量 (PNC)、黑碳 (BC)、二氧化氮 (NO) 和氮氧化物 (NO) 浓度使用高质量的移动测量系统在英国 (UK) 进行城际和长途旅行。使用 2020 年冬季和 2021 年夏季三个活动期间总共 119 个行程的高度时间分辨数据测量了 15 条不同路线的空气质量；其中包括 13 个不同的列车等级。每个旅程都会采样 4-10 次，总共大约 11,000 分钟的车内浓度。平均行程浓度为 7.552 µg m (PM)； 3.936 µg m（PM）； 333–11,300 # 厘米（PNC）； 225–9,131 # 厘米（UFP）； 0.6–11 µg m (BC)； 28–201 µg m（NO）；和 130–3,456 µg m（NO）。评估了不同因素对列车内浓度的影响。隧道的存在是对列车内颗粒浓度影响最大的因素，BC 的浓度比基线高 40 倍，PM 和 PNC 的浓度比基线高 6 到 7 倍。发动机燃油模式是对 NO 影响最大的因素，在混合动力列车上使用柴油运行时，NO 的增强程度比使用电力运行时高出 14 倍。车龄 < 10 年的列车等级观察到列车内 PM、BC 和 NO 浓度最低，反映了近年来铁路技术方面的进步。英国柴油列车上的空气质量高于环境浓度，但与大多数其他交通方式（包括地铁系统、柴油和汽油车）相比，PM 和 PNC 较低。 本文显着增加了交通微环境中暴露于不良空气质量的证据，并为行业和监管机构提供了参考级测量结果，以制定列车内空气质量指南。