Volume 13, No. 1, February 2013, Pages 24-35 PDF(1.07 MB)
Size-Resolved Respiratory Tract Deposition of Sub-Micrometer Aerosol Particles in a Residential Area with Wintertime Wood Combustion
Adam Kristensson1, Jenny Rissler2, Jakob Löndahl2, Christer Johansson3,4, Erik Swietlicki1
1 Division of Nuclear Physics, Lund University, P. O. Box 118, SE-221 00, Lund, Sweden
2 Division of Ergonomics and Aerosol Technology, Lund University, P. O. Box 118, SE-221 00, Lund, Sweden
3 Department of Applied Environmental Science (ITM), Stockholm University, SE-106 91, Stockholm, Sweden
4 Stockholm Environment and Health Administration, P. O. Box 8136, SE-104 20, Stockholm, Sweden
Particle size distributions and hygroscopic growth were studied in a town in Sweden with extensive emissions from wood combustion. The average deposited fraction of particle number, surface area and volume dose in the human respiratory tract was estimated using the data set, as well as the typical deposition pattern of the two dominant particle source types: wood combustion and traffic exhaust. As far as we know, this is the first report on the deposited fraction and hygroscopicity of ambient particles from domestic wood combustion in the literature. The use of PM2.5 as a substitute for the deposited dose was also tested. Source/receptor modeling and the hygroscopicity measurements showed that wood combustion and traffic exhaust are dominant sources, and that these particles have a low water uptake. Number fractions of 38 and 69% of the wood combustion and traffic particles, respectively, were deposited in the respiratory tract, and 53% of the particles were deposited as an average for the whole period. The deposited fraction of the surface area and volume dose was also calculated for wood combustion particles, with the result being 22% for both parameters. The results also revealed that the PM2.5 average over more than 10 hours correlated well (r2 > 0.80) with the deposited surface area and volume dose. This means that PM2.5 can be used as proxy for the deposited dose when examining health effect relationships during short-term exposure studies if the averaging time is sufficient, while a PM2.5 proxy is not recommended for shorter averaging times.
H-TDMA; ICRP; MPPD; DMPS; Residential wood combustion; Lung deposition.