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

摘要

Epidemiologic studies have shown an association between airborne particles andmortality data, but uncertainty persists as to which aspects of the particle mixture are the driving force underlying observed associations. Further, only a small number of studies have investigated the role of ultrafine particles (particles less than 0.1 micro m in diameter). Although ultrafine particles contribute little to mass concentration, they are present in urban air in high numbers and may be important in terms of health effects. One hypothesis is that these particles may be particularly toxic because their small size allows them to deposit efficiently deep in the lungs and that the higher number of ultrafine particles, and therefore their greater total particle surface area, may increase their toxicologic effects. However, the few epidemiologic studies that have tried to isolate effects of ultrafine particles have evaluated respiratory disease, not deaths.