title: Long-term dynamics of death rates of emphysema, asthma, and pneumonia and improving air quality.
abstract: BACKGROUND
  The respiratory tract is a major target of exposure to air pollutants, and respiratory diseases are associated with both short- and long-term exposures. We hypothesized that improved air quality in North Carolina was associated with reduced rates of death from respiratory diseases in local populations.
  
  
  METHODS
  We analyzed the trends of emphysema, asthma, and pneumonia mortality and changes of the levels of ozone, sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and particulate matters (PM2.5 and PM10) using monthly data measurements from air-monitoring stations in North Carolina in 1993-2010. The log-linear model was used to evaluate associations between air-pollutant levels and age-adjusted death rates (per 100,000 of population) calculated for 5-year age-groups and for standard 2000 North Carolina population. The studied associations were adjusted by age group-specific smoking prevalence and seasonal fluctuations of disease-specific respiratory deaths.
  
  
  RESULTS
  Decline in emphysema deaths was associated with decreasing levels of SO2 and CO in the air, decline in asthma deaths-with lower SO2, CO, and PM10 levels, and decline in pneumonia deaths-with lower levels of SO2. Sensitivity analyses were performed to study potential effects of the change from International Classification of Diseases (ICD)-9 to ICD-10 codes, the effects of air pollutants on mortality during summer and winter, the impact of approach when only the underlying causes of deaths were used, and when mortality and air-quality data were analyzed on the county level. In each case, the results of sensitivity analyses demonstrated stability. The importance of analysis of pneumonia as an underlying cause of death was also highlighted.
  
  
  CONCLUSIONS
  Significant associations were observed between decreasing death rates of emphysema, asthma, and pneumonia and decreases in levels of ambient air pollutants in North Carolina.
authors.affiliation: Department of Surgery, Duke University, Durham, NC, USA.
authors.forename: Julia
authors.initials: J
authors.lastname: Kravchenko
authors.affiliation: Center for Population Health and Aging, Duke University, Durham, NC, USA.
authors.forename: Igor
authors.initials: I
authors.lastname: Akushevich
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Duke University, Durham, NC, USA.
authors.forename: Amy P
authors.initials: AP
authors.lastname: Abernethy
authors.affiliation: Division of Air Quality, North Carolina Department of Environment and Natural Resources, Raleigh, NC, USA.
authors.forename: Sheila
authors.initials: S
authors.lastname: Holman
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, NC, USA.
authors.forename: William G
authors.initials: WG
authors.lastname: Ross
authors.affiliation: Department of Surgery, Duke University, Durham, NC, USA ; Department of Pathology, Duke University Medical Center, Duke University, Durham, NC, USA.
authors.forename: H Kim
authors.initials: HK
authors.lastname: Lyerly
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects*; D001249:Asthma / Q000175:diagnosis / Q000401:mortality* / Q000517:prevention & control; D002248:Carbon Monoxide / Q000009:adverse effects; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects* / Q000517:prevention & control; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000009:adverse effects; D009657:North Carolina / Q000453:epidemiology; D010126:Ozone / Q000009:adverse effects; D052638:Particulate Matter / Q000009:adverse effects; D011014:Pneumonia / Q000175:diagnosis / Q000401:mortality* / Q000517:prevention & control; D011656:Pulmonary Emphysema / Q000175:diagnosis / Q000401:mortality* / Q000517:prevention & control; D018570:Risk Assessment; D012307:Risk Factors; D013458:Sulfur Dioxide / Q000009:adverse effects; D013997:Time Factors; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D013458:Sulfur Dioxide; D009569:Nitric Oxide; D010126:Ozone; D002248:Carbon Monoxide
keywords: carbon monoxide; chronic obstructive pulmonary disease; nitrogen dioxide; particulate matter; sulfur dioxide