title: Estimated short-term effects of coarse particles on daily mortality in Stockholm, Sweden.
abstract: BACKGROUND
  Although serious health effects associated with particulate matter (PM) with aerodynamic diameter ≤ 10 μm (PM₁₀) and ≤ 2.5 μm (PM(2.5); fine fraction) are documented in many studies, the effects of coarse PM (PM(2.5-10)) are still under debate.
  
  
  OBJECTIVE
  In this study, we estimated the effects of short-term exposure of PM(2.5-10) on daily mortality in Stockholm, Sweden.
  
  
  METHODS
  We collected data on daily mortality for the years 2000 through 2008. Concentrations of PM₁₀, PM(2.5), ozone, and carbon monoxide were measured simultaneously in central Stockholm. We used additive Poisson regression models to examine the association between daily mortality and PM2.5-10 on the day of death and the day before. Effect estimates were adjusted for other pollutants (two-pollutant models) during different seasons.
  
  
  RESULTS
  We estimated a 1.68% increase [95% confidence interval (CI): 0.20%, 3.15%] in daily mortality per 10-μg/m³ increase in PM(2.5-10) (single-pollutant model). The association with PM(2.5-10) was stronger for November through May, when road dust is most important (1.69% increase; 95% CI: 0.21%, 3.17%), compared with the rest of the year (1.31% increase; 95% CI: -2.08%, 4.70%), although the difference was not statistically significant. When adjusted for other pollutants, particularly PM(2.5), the effect estimates per 10 μg/m³ for PM(2.5-10) decreased slightly but were still higher than corresponding effect estimates for PM(2.5).
  
  
  CONCLUSIONS
  Our analysis shows an increase in daily mortality associated with elevated urban background levels of PM(2.5-10). Regulation of PM(2.5-10) should be considered, along with actions to specifically reduce PM(2.5-10) emissions, especially road dust suspension, in cities.
authors.affiliation: Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine, Umeå University, Umeå, Sweden. kadri.meister@envmed.umu.se
authors.forename: Kadri
authors.initials: K
authors.lastname: Meister
authors.forename: Christer
authors.initials: C
authors.lastname: Johansson
authors.forename: Bertil
authors.initials: B
authors.lastname: Forsberg
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D002248:Carbon Monoxide / Q000633:toxicity; D004391:Dust / Q000032:analysis; D004781:Environmental Exposure; D006801:Humans; D009026:Mortality; D010126:Ozone / Q000633:toxicity; D010316:Particle Size; D052638:Particulate Matter / Q000633:toxicity*; D012044:Regression Analysis; D012621:Seasons; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D014504:Urban Health
chemical_list: D000393:Air Pollutants; D004391:Dust; D052638:Particulate Matter; D010126:Ozone; D002248:Carbon Monoxide