Association Between Outdoor Air Pollution and Acute Exacerbations of Respiratory Diseases in Pittsburgh

Rationale: Pittsburgh lags behind other major cities in improving outdoor air quality.  Contributing factors include the perception that Pittsburgh air is cleaner than in past decades and lack of public awareness that regional levels of outdoor air pollution (OAP) are associated with adverse health effects.  The purpose of this study was to evaluate the association between OAP and acute exacerbations of respiratory diseases in the Pittsburgh region.      

Methods: This study was approved by the Allegheny Singer Research Institute-Allegheny Health Network Institutional Review Board.   Retrospective analysis of emergency department (ED) visits to the healthcare system was conducted from 07/01/2008 to 06/30/2013 to identify primary discharge diagnoses for acute exacerbations of respiratory diseases.   Corresponding EPA air quality index (AQI) data was downloaded.   F test with stepwise regression was used to evaluate the significance of OAP levels on day of ED visit and mean exposure over the previous week.    

Results: 67,898 visits were included (mean + SD age of 40.3 + 25.2 years, 25.6% African American, 59.6% female).  There was a direct association between levels of nitrogen dioxide (p<0.001) levels on both day of and week prior to ED visit for acute exacerbations of respiratory diseases.  There was no significant association between ozone, PM_2.5, carbon monoxide, sulfur dioxide or lead and ED visits.    

Conclusions: Elevations of nitrogen dioxide were retrospectively associated with ED visits for acute exacerbations of respiratory diseases.  Future efforts need to disseminate these results to local public health officials and ultimately improve health outcomes.