Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
Thorax. 2011 Jan;66(1):12-9. doi: 10.1136/thx.2010.140053. Epub 2010 Sep 13.
Exposure to traffic-derived air pollutants, particularly diesel emissions, has been associated with adverse health effects, predominantly in individuals with pre-existing respiratory disease. Here the hypothesis that this heightened sensitivity reflects an augmentation of the transient inflammatory response previously reported in healthy adults exposed to diesel exhaust is examined.
32 subjects with asthma (mild to moderate severity) and 23 healthy controls were exposed in a double-blinded crossover control fashion to both filtered air and diesel exhaust (100 μg/m(3) PM(10)) for 2 h. Airway inflammation was assessed by bronchoscopy 18 h postexposure. In addition, lung function, fraction of exhaled nitric oxide and bronchial reactivity to metacholine were examined in the subjects with asthma.
In healthy control subjects a significant increase in submucosal neutrophils (p=0.004) was observed following the diesel challenge. Significant increases in neutrophil numbers (p=0.01), and in the concentrations of interleukin 6 (p=0.03) and myeloperoxidase (p=0.04), were also seen in bronchial wash after diesel, relative to the control air challenge. No evidence of enhanced airway inflammation was observed in the subjects with asthma following the diesel exposure.
Exposure to diesel exhaust at concentrations consistent with roadside levels elicited an acute and active neutrophilic inflammation in the airways of healthy subjects. This response was absent in subjects with asthma, as was evidence supporting a worsening of allergic airway inflammation.
接触交通衍生的空气污染物，尤其是柴油排放物，与不良健康影响有关，主要是在已有呼吸道疾病的个体中。这里检验了这样一种假设，即这种敏感性的增加反映了先前在接触柴油废气的健康成年人中报告的短暂炎症反应的增强。
32 名哮喘患者（轻度至中度严重程度）和 23 名健康对照者以双盲交叉对照方式暴露于过滤空气和柴油废气（100 μg/m(3) PM(10)）中 2 小时。暴露后 18 小时通过支气管镜检查评估气道炎症。此外，还检查了哮喘患者的肺功能、呼出一氧化氮分数和对乙酰甲胆碱的支气管反应性。
在健康对照组中，暴露于柴油后观察到粘膜下嗜中性粒细胞显著增加（p=0.004）。与对照空气挑战相比，支气管灌洗后还观察到嗜中性粒细胞数量（p=0.01）和白细胞介素 6（p=0.03）和髓过氧化物酶（p=0.04）浓度的显著增加。在哮喘患者中，暴露于柴油后未观察到气道炎症的增强。
在与路边水平一致的浓度下暴露于柴油废气会在健康受试者的气道中引起急性和活跃的嗜中性粒细胞炎症。这种反应在哮喘患者中不存在，也没有证据支持过敏气道炎症的恶化。
