Short-term controlled exposure to diesel exhaust (DE) in chamber studies have shown mixed results on lung and systemic effects. There is a paucity of studies on well-characterized real-life DE exposure in humans. In the present study, 29 healthy volunteers were exposed to DE while sitting as passengers in diesel-powered trains. Exposure in electric trains was used as control scenario. Each train scenario consisted of three consecutive days (6 h/day) ending with biomarker samplings. Combustion-derived air pollutants were considerably higher in the passenger carriages of diesel trains compared with electric trains. The concentrations of black carbon and ultrafine particles were 8.5 μg/m3 and 1.2–1.8 × 105 particles/cm3 higher, respectively, in diesel as compared to electric trains. Net increases of NOx and NO2 concentrations were 317 μg/m3 and 36 μg/m3. Exposure to DE was associated with reduced lung function and increased levels of DNA strand breaks in peripheral blood mononuclear cells (PBMCs), whereas there were unaltered levels of oxidatively damaged DNA, soluble cell adhesion molecules, acute phase proteins in blood and urinary excretion of metabolites of polycyclic aromatic hydrocarbons. Also the microvascular function was unaltered. An increase in the low frequency of heart rate variability measures was observed, whereas time-domain measures were unaltered. Exposure to DE inside diesel-powered trains for 3 days was associated with reduced lung function and systemic effects in terms of altered heart rate variability and increased levels of DNA strand breaks in PBMCs compared with electric trains. ClinicalTrials.Gov ( NCT03104387 ). Registered on March 23rd 2017

中文翻译：

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暴露在柴油动力火车中的柴油废气对健康的影响

室内试验研究表明，短期控制地暴露于柴油机废气（DE）中对肺部和全身的影响显示出不同的结果。缺乏充分表征的现实生活中的人体DE暴露的研究。在本研究中，有29名健康志愿者在以柴油为动力的火车上作为乘客坐下时暴露于DE。将电动火车中的暴露用作控制方案。每种训练方案均包括连续三天（每天6小时），以生物标记物采样为结束。与电动火车相比，柴油火车的乘客车厢中源自燃烧的空气污染物要高得多。与电动火车相比，柴油中黑碳和超细颗粒物的浓度分别高8.5μg/ m3和1.2–1.8×105颗粒/ cm3。NOx和NO2浓度的净增加量分别为317μg/ m3和36μg/ m3。暴露于DE与外周血单核细胞（PBMC）的肺功能降低和DNA链断裂水平升高有关，而血液中的氧化损伤DNA，可溶性细胞粘附分子，急性期蛋白水平和尿液代谢排泄物水平未改变多环芳烃。而且微血管功能未改变。观察到低频率的心率变异性测量值增加，而时域测量值不变。与电动火车相比，在柴油动力火车内暴露3天的DE会降低心率变异性并增加PBMC中DNA链断裂水平，从而降低肺功能和全身作用。临床试验。政府（NCT03104387）。2017年3月23日注册