Daily Mortality and Particulate Matter in Different Size Classes in Erfurt, Germany

J Expo Sci Environ Epidemiol. 2007 Aug;17(5):458-67. doi: 10.1038/sj.jes.7500538. Epub 2006 Nov 15.


The link between elevated concentrations of ambient particulate matter (PM) and increased mortality has been investigated in numerous studies. Here we analyzed the role of different particle size fractions with respect to total and cardio-respiratory mortality in Erfurt, Germany, between 1995 and 2001. Number concentrations (NC) of PM were measured using an aerosol spectrometer consisting of a Differential Mobility Particle Sizer and a Laser Aerosol Spectrometer to characterize particles between 0.01 and 0.5 and between 0.1 and 2.5 microm, respectively. We derived daily means of particle NC for ultrafine (0.01-0.1 microm) and for fine particles (0.01-2.5 microm). Assuming spherical particles of a constant density, we estimated the mass concentrations (MC) of particles in these size ranges. Concurrently, data on daily total and cardio-respiratory death counts were obtained from local health authorities. The data were analyzed using Poisson Generalized Additive Models adjusting for trend, seasonality, influenza epidemics, day of the week, and meteorology using smooth functions or indicator variables. We found statistically significant associations between elevated ultrafine particle (UFP; diameter: 0.01-0.1 microm) NC and total as well as cardio-respiratory mortality, each with a 4 days lag. The relative mortality risk (RR) for a 9748 cm(-3) increase in UFP NC was RR=1.029 and its 95% confidence interval (CI)=1.003-1.055 for total mortality. For cardio-respiratory mortality we found: RR=1.031, 95% CI: 1.003-1.060. No association between fine particle MC and mortality was found. This study shows that UFP, representing fresh combustion particles, may be an important component of urban air pollution associated with health effects.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aerosols / analysis
  • Aerosols / chemistry
  • Air Pollutants / analysis
  • Air Pollutants / toxicity*
  • Cardiovascular Diseases / etiology
  • Cardiovascular Diseases / mortality*
  • Cities
  • Environmental Exposure / adverse effects*
  • Environmental Exposure / analysis
  • Environmental Monitoring*
  • Female
  • Germany
  • Humans
  • Inhalation Exposure / adverse effects*
  • Inhalation Exposure / analysis
  • Male
  • Meteorological Concepts
  • Models, Biological
  • Mortality
  • Particle Size
  • Particulate Matter
  • Poisson Distribution
  • Respiratory Tract Diseases / etiology
  • Respiratory Tract Diseases / mortality*
  • Risk Assessment
  • Spectrum Analysis
  • Time Factors
  • Urban Health


  • Aerosols
  • Air Pollutants
  • Particulate Matter