Estimated short-term effects of coarse particles on daily mortality in Stockholm, Sweden

Environ Health Perspect. 2012 Mar;120(3):431-6. doi: 10.1289/ehp.1103995. Epub 2011 Dec 19.


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.

Method: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants / toxicity*
  • Carbon Monoxide / toxicity
  • Dust / analysis
  • Environmental Exposure*
  • Humans
  • Mortality*
  • Ozone / toxicity
  • Particle Size*
  • Particulate Matter / toxicity*
  • Regression Analysis
  • Seasons
  • Sweden / epidemiology
  • Time Factors
  • Urban Health


  • Air Pollutants
  • Dust
  • Particulate Matter
  • Ozone
  • Carbon Monoxide