Daily Mortality and Fine and Ultrafine Particles in Erfurt, Germany. Part I: Role of Particle Number and Particle Mass

Dr H-Erich Wichmann and colleagues at the National Research Center for Environment and Health in Germany prospectively studied the association of daily mortality data with the number and mass concentrations of ultrafine and fine particles in Erfurt, Germany. Concentrations were measured near a road and a time-series approach was used to look at short-term changes in particle concentration and concurrent deaths due to cardiovascular and respiratory causes over a period of 3.5 years. The analytic technique that the investigators developed to gather air pollution data, especially monitoring of the ultrafine fraction, was unique in the sharp detail of the size ranges. A Poisson regression with a generalized additive model was used to smooth time trends, weather, and other variables.