title: The short-term association of selected components of fine particulate matter and mortality in the Denver Aerosol Sources and Health (DASH) study.
abstract: BACKGROUND
  Associations of short-term exposure to fine particulate matter (PM2.5) with daily mortality may be due to specific PM2.5 chemical components. Daily concentrations of PM2.5 components were measured over five years in Denver to investigate whether specific PM2.5 components are associated with daily mortality.
  
  
  METHODS
  Daily counts of total and cause-specific deaths were obtained for the 5-county Denver metropolitan region from 2003 through 2007. Daily 24-hour concentrations of PM2.5, elemental carbon (EC), organic carbon (OC), sulfate and nitrate were measured at a central residential monitoring site. Using generalized additive models, we estimated relative risks (RRs) of daily death counts for daily PM2.5 and four PM2.5 component concentrations at single and distributed lags between the current and three previous days, while controlling for longer-term time trend and meteorology.
  
  
  RESULTS
  RR of total non-accidental mortality for an inter-quartile increase of 4.55 μg/m(3) in PM2.5 distributed over 4 days was 1.012 (95 % confidence interval: 0.999, 1.025); RRs for EC and OC were larger (1.024 [1.005, 1.043] and 1.020 [1.000, 1.040] for 0.33 and 1.67 μg/m(3) increases, respectively) than those for sulfate and nitrate. We generally did not observe associations with cardiovascular and respiratory mortality except for associations with ischemic heart disease mortality at lags 3 and 0-3 depending on the component. In addition, there were associations with cancer mortality, particularly for EC and OC, possibly reflecting advanced deaths of a frail population.
  
  
  CONCLUSIONS
  PM2.5 components possibly from combustion-related sources are more strongly associated with daily mortality than are secondary inorganic aerosols.
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington School of Public Health, Seattle, WA, USA. puha0@uw.edu.|Institute of Health and Environment, Seoul National University, Seoul, Korea. puha0@uw.edu.
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Kim
authors.affiliation: National Center for Environmental Assessment, U.S. Environmental Protection Agency, RTP, NC, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Dutton
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington School of Public Health, Seattle, WA, USA.|Department of Biostatistics, University of Washington School of Public Health, Seattle, WA, USA.
authors.forename: Lianne
authors.initials: L
authors.lastname: Sheppard
authors.affiliation: Departments of Mechanical Engineering, College of Engineering and Applied Science, University of Colorado, Boulder, CO, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Hannigan
authors.affiliation: Departments of Mechanical Engineering, College of Engineering and Applied Science, University of Colorado, Boulder, CO, USA.
authors.forename: Shelly L
authors.initials: SL
authors.lastname: Miller
authors.affiliation: Departments of Mechanical Engineering, College of Engineering and Applied Science, University of Colorado, Boulder, CO, USA.
authors.forename: Jana B
authors.initials: JB
authors.lastname: Milford
authors.affiliation: Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Peel
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington School of Public Health, Seattle, WA, USA.
authors.forename: Sverre
authors.initials: S
authors.lastname: Vedal
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D002244:Carbon / Q000633:toxicity; D002318:Cardiovascular Diseases / Q000401:mortality*; D003120:Colorado / Q000453:epidemiology; D004781:Environmental Exposure; D004784:Environmental Monitoring; D006801:Humans; D009369:Neoplasms / Q000401:mortality*; D009566:Nitrates / Q000633:toxicity; D010316:Particle Size; D052638:Particulate Matter / Q000633:toxicity*; D012140:Respiratory Tract Diseases / Q000401:mortality*; D012621:Seasons; D013431:Sulfates / Q000633:toxicity
chemical_list: D000393:Air Pollutants; D009566:Nitrates; D052638:Particulate Matter; D013431:Sulfates; D002244:Carbon