title: Associations of ambient air pollution with chronic obstructive pulmonary disease hospitalization and mortality.
abstract: BACKGROUND
  Ambient air pollution has been suggested as a risk factor for chronic obstructive pulmonary disease (COPD). However, there is a lack of longitudinal studies to support this assertion.
  
  
  OBJECTIVE
  To investigate the associations of long-term exposure to elevated traffic-related air pollution and woodsmoke pollution with the risk of COPD hospitalization and mortality.
  
  
  METHODS
  This population-based cohort study included a 5-year exposure period and a 4-year follow-up period. All residents aged 45-85 years who resided in Metropolitan Vancouver, Canada, during the exposure period and did not have known COPD at baseline were included in this study (n = 467,994). Residential exposures to traffic-related air pollutants (black carbon, particulate matter <2.5 μm in aerodynamic diameter, nitrogen dioxide, and nitric oxide) and woodsmoke were estimated using land-use regression models and integrating changes in residences during the exposure period. COPD hospitalizations and deaths during the follow-up period were identified from provincial hospitalization and death registration databases.
  
  
  RESULTS
  An interquartile range elevation in black carbon concentrations (0.97 × 10(-5)/m, equivalent to 0.78 μg/m(3) elemental carbon) was associated with a 6% (95% confidence interval, 2-10%) increase in COPD hospitalizations and a 7% (0-13%) increase in COPD mortality after adjustment for covariates. Exposure to higher levels of woodsmoke pollution (tertile 3 vs. tertile 1) was associated with a 15% (2-29%) increase in COPD hospitalizations. There were positive exposure-response trends for these observed associations.
  
  
  CONCLUSIONS
  Ambient air pollution, including traffic-related fine particulate pollution and woodsmoke pollution, is associated with an increased risk of COPD.
authors: Department of Population Health, Hofstra North Shore-LIJ School of Medicine, Great Neck, NY 11021, USA. wgan@nshs.edu
authors: Wen Qi
authors: WQ
authors: Gan
authors: J Mark
authors: JM
authors: FitzGerald
authors: Chris
authors: C
authors: Carlsten
authors: Mohsen
authors: M
authors: Sadatsafavi
authors: Michael
authors: M
authors: Brauer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000397:Air Pollution / Q000009:adverse effects*; D002170:Canada / Q000453:epidemiology; D015331:Cohort Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D052638:Particulate Matter / Q000009:adverse effects*; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology / Q000401:mortality*; D012044:Regression Analysis; D012307:Risk Factors; D001335:Vehicle Emissions / Q000633:toxicity*
chemical_list: D052638:Particulate Matter; D001335:Vehicle Emissions