RATIONALE Epidemiologic research strongly supports an association between air pollution and chronic obstructive pulmonary disease exacerbations. Numerous mechanisms may underlie any association because pollutants are toxic to pulmonary cells and may increase susceptibility to respiratory infections. The relationship between ambient pollution and exacerbation etiology has not been studied. OBJECTIVES To evaluate the characteristics of pollution-associated exacerbations and whether the association is specific to exacerbations of infective or noninfective etiology. METHODS We analyzed the effect of preceding ambient particulate matter less than or equal to 10 μm in aerodynamic diameter, oxides of nitrogen (NOx), and ozone on characterized chronic obstructive pulmonary disease exacerbations in a regression model adjusted for temperature, seasonality, and long-term trend. We specifically examined associations with exacerbations of suspected viral and/or bacterial, or noninfective etiology. For the associations identified we further examined the characteristics of pollution-associated exacerbations. MEASUREMENTS AND MAIN RESULTS A total of 4,173 exacerbations occurred over the 20-year study period. Higher ambient NOx was consistently associated with increased viral-type exacerbations at 2-4 days lag (P = 0.010). Recovery for viral-type exacerbations after higher ambient NOx was significantly prolonged. These findings were consistent in the subset of 2,841 exacerbations treated with oral corticosteroids or antibiotics, with recovery 1.29 (95% confidence interval, 1.17-1.42; P < 0.001) times longer with viral-type exacerbations of onset 3 days after above- versus below-median ambient NOx. A likely bimodal association of particulate matter less than or equal to 10 μm in aerodynamic diameter with infective exacerbations was also evident and supported by a daily time-series analysis. CONCLUSIONS Higher levels of ambient NOx are associated with prolonged exacerbations of likely viral etiology, supporting toxicologic effects of air pollution that increase susceptibility to, and severity of, infection.

中文翻译：

---

周围环境氮氧化物升高后，可能引起病毒性病因的慢性阻塞性肺疾病加剧。

理性理论流行病学研究强烈支持空气污染与慢性阻塞性肺疾病恶化之间的联系。多种机制可能是任何关联的基础，因为污染物对肺细胞有毒并可能增加对呼吸道感染的敏感性。尚未研究环境污染与病因加重之间的关系。目的评估与污染有关的病情恶化的特征，以及该病因是否特定于感染性或非感染性病因的恶化。方法我们根据温度，季节，温度和温度调整回归模型，分析了先前空气动力学直径小于或等于10μm的环境颗粒物，氮氧化物（NOx）和臭氧对特征性慢性阻塞性肺疾病恶化的影响。和长期趋势。我们专门检查了与可疑病毒和/或细菌或非感染性病因加重的关联。对于确定的协会，我们进一步检查了与污染相关的恶化的特征。测量和主要结果在20年的研究期内，总共发生了4,173例病情加重。在2-4天的滞后时，较高的环境NOx始终与病毒型加重相关（P = 0.010）。较高的环境NOx引起的病毒型急性发作的恢复显着延长。这些发现与口服皮质类固醇或抗生素治疗的2,841例急性发作的亚组一致，在上下两天后发病3天，病毒型发作的恢复时间长1.29倍（95％置信区间，1.17-1.42； P <0.001）。 -环境NOx的中位数。空气动力学直径小于或等于10μm的颗粒物与感染加剧的可能的双峰关联也很明显，并通过每日时间序列分析得到支持。结论较高水平的环境NOx与可能的病毒病因的长期恶化有关，支持空气污染的毒理学作用，从而增加了对感染的敏感性和严重性。