title: Winter air pollution and disease parameters in advanced chronic obstructive pulmonary disease panels residing in Denver, Colorado.
abstract: BACKGROUND
  Ambient pollution might worsen chronic obstructive pulmonary disease (COPD).
  
  
  OBJECTIVE
  We explored the associations of pollution to pulmonary function, rescue medication, and symptoms over 2 winters in 2 panels of subjects with advanced COPD in Denver, Colorado.
  
  
  METHODS
  Subjects measured lung function and recorded symptoms and rescue medications. Daily ambient pollution concentrations for particulate matter (PM(10) and PM(2.5)), carbon monoxide (CO), and nitrogen dioxide (NO(2)) were obtained for Denver. Estimated effects of pollution on outcomes were derived for the same day and 1 and 2 days after pollution measurements (lags 0, 1, and 2, respectively).
  
  
  RESULTS
  Sixteen (mean age, 65.8 years; mean FEV 1 , 42.3% of predicted value) and 18 (mean age, 67.4 years; mean FEV 1 , 39.4% of predicted value) subjects participated in the first and second winters, respectively. There were no differences in demographic or disease characteristics between the 2 panels. In the first winter no detrimental associations were found. In the second winter, however, there were significant detrimental associations of CO in the morning and PM(10), CO, and NO(2) in the evening, increasing medication use at lag 0. Total symptom score increased at lag 0 with NO(2). The concentrations of particulates were increased in the second winter compared with in the first winter, and this winter was colder and more humid.
  
  
  CONCLUSIONS
  In the second winter, subjects with severe COPD had worse lung function at lags 0 and 1 and increased rescue medication at lag 0 with increases in ambient air pollution. The effects of pollution varied between the 2 winters, perhaps related to levels of pollution and weather patterns. Significant effects were seen despite ambient pollution levels that conformed to US Environmental Protection Agency standards.
authors.affiliation: Department of Pediatrics, National Jewish Medical and Research Medical Center and University of Colorado Health Sciences Center, Denver, CO 80206, USA. philsilkoff@hotmail.com
authors.forename: Philip E
authors.initials: PE
authors.lastname: Silkoff
authors.forename: Lening
authors.initials: L
authors.lastname: Zhang
authors.forename: Steven
authors.initials: S
authors.lastname: Dutton
authors.forename: Esther L
authors.initials: EL
authors.lastname: Langmack
authors.forename: Sverre
authors.initials: S
authors.lastname: Vedal
authors.forename: James
authors.initials: J
authors.lastname: Murphy
authors.forename: Barry
authors.initials: B
authors.lastname: Make
mesh_terms: D000368:Aged; D000397:Air Pollution; D000531:Altitude; D002248:Carbon Monoxide; D002940:Circadian Rhythm; D003120:Colorado; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D008297:Male; D009585:Nitrogen Dioxide; D010316:Particle Size; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000503:physiopathology*; D012129:Respiratory Function Tests; D016879:Salvage Therapy; D012621:Seasons
chemical_list: D002248:Carbon Monoxide; D009585:Nitrogen Dioxide