There is an ongoing debate on the question which size fraction of particles in ambient air may be responsible for short-term responses of the respiratory system as observed in several epidemiological studies.
However, the available data on ambient particle concentrations in various size ranges are not sufficient to answer this question.
Therefore, on 180 days during the winter 1991/92 daily mean size distributions of ambient particles were determined in Erfurt, a city in Eastern Germany.
In the range 0.01-0.3 mum particles were classified by an electrical mobility analyzer and in the range 0.1-2.5 mum by an optical particle counter.
From the derived size distributions, number and mass concentrations were calculated.
The mean number concentration over this period of time was governed by particles smaller than 0.1 mum (72%), whereas the mean mass concentration was governed by particles in the size range 0.1-0.5 mum (83%). The contribution of particles larger than 0.5 mum to the overall number concentration was negligible and so was the contribution of particles smaller than 0.1 mum to the overall mass concentration.
Furthermore, total number and mass concentrations in the range 0.01-2.5 mum were poorly correlated.
The results suggest that particles larger than 2.5 mum (or even larger than 0.5 pm) are rare in the European urban environment so that the inhalation of these particles is probably not relevant for human health. (...)
Mots-clés Pascal : Allemagne, Europe, Zone urbaine, Pollution air, Particule en suspension, Aérosol, Particule ultrafine, Teneur air ambiant, Nombre particule, Dimension particule, Granularité, Variation temporelle, Variation saisonnière, Toxicité, Inhalation, Exposition risque environnement
Mots-clés Pascal anglais : Germany, Europe, Urban area, Air pollution, Suspended particle, Aerosols, Ultrafine particle, Ambient air concentration, Particle number, Particle size, Grain size distribution, Time variation, Seasonal variation, Toxicity, Inhalation, Environmental exposure
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0539788
Code Inist : 001D16C02. Création : 24/03/1998.