RESEARCH ARTICLE Open Access Indoor pollutant exposure m i

Full list of author information is available at the end of the articleBackground Chronic obstructive pulmonary disease (COPD) is char-acterized by progressive airflow limitation [1] and is a serious public health concern as it is the third leading cause of death in the United States [2]. COPD manifests after extended inhalation exposure to toxic agents such as cigarette smoke [3], and continued exposure among those with established disease is associated with worse disease severity [1]. We have previously shown that indoor air pollution, particularly particulate matter less than 2.5 micron in diameter (PM2.5), even at relatively low concentrations observed in US homes, was associ-ated with increased respiratory symptoms and risk of severe COPD exacerbations in former smokers with moderate to severe COPD [4]. In addition, the presence of allergic sensitization has also been linked to wors