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How do the indoor size distributions of airborne submicron and ultrafine particles in the absence of significant indoor sources depend on outdoor distributions?
Author(s) -
Franck U.,
Herbarth O.,
Wehner B.,
Wiedensohler A.,
Manjarrez M.
Publication year - 2003
Publication title -
indoor air
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.387
H-Index - 99
eISSN - 1600-0668
pISSN - 0905-6947
DOI - 10.1034/j.1600-0668.2003.00177.x
Subject(s) - ultrafine particle , particle size , environmental science , indoor air , indoor air quality , range (aeronautics) , particle (ecology) , pollutant , particle size distribution , particle number , drop (telecommunication) , environmental chemistry , aerosol , atmospheric sciences , materials science , environmental engineering , meteorology , chemistry , nanotechnology , physics , composite material , geology , telecommunications , oceanography , plasma , organic chemistry , quantum mechanics , computer science
Although almost all epidemiological studies of smaller airborne particles only consider outdoor concentrations, people in Central Europe actually spend most of their time indoors. Yet indoor pollutants such as organic gases, allergens and dust are known to play a prominent role, often affecting human health more than outdoor ones. The aim of this study was to ascertain how the indoor particle size distributions of submicron and ultrafine particles correlate with the outdoor concentrations in the absence of significant indoor sources. A typical indoor particle size distribution pattern has one or two modes. In the absence of significant indoor activities such as smoking, cooking etc., outdoor particles were found to be a very important source of indoor particles. The study shows that in the absence of significant indoor sources, the number of indoor concentrations of particles in this size range are clearly lower than the outdoor concentrations. This difference is greater, the higher the number of outdoor concentrations. However, the drop in concentration is not uniform, with the decrease in concentration of smaller particles exceeding that of larger ones. By contrast, the findings with larger particle sizes (diameter > 1 microm) exhibit rather linear concentration decreases. The non-uniform drop in the number of concentrations from outdoors to indoors in our measurements considering smaller particles ( >0.01 microm) is accompanied by a shift of the concentration maxima to larger particle diameters.