Indoor Air 2008

Aalborg Universitet Outdoor and indoor sources to ultrafine and fine particles in an urban apartment Glasius, Marianne; Wåhlin, Peter; Jensen, Keld Alstrup; Schneider, Thomas; Gunnarsen, Lars Bo; Nielsen, Ole John; Palmgren, F. Published in: Indoor Air 2008 Publication date: 2008 Document Version Publisher's PDF, also known as Version of record Link to publication from Aalborg University Citation for published version (APA): Glasius, M., Wåhlin, P., Jensen, K. A., Schneider, T., Gunnarsen, L. B., Nielsen, O. J., & Palmgren, F. (2008). Outdoor and indoor sources to ultrafine and fine particles in an urban apartment. In P. Strøm-Tejsen, B. W. Olesen, P. Wargocki, D. Zukowska, & J. Toftum (Eds.), Indoor Air 2008: Proceedings of the 11th International Conference on Indoor Air Quality and Climate Technical University of Denmark (DTU). 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Downloaded from vbn.aau.dk on: November 30, 2023 Indoor Air 2008, 17-22 August 2008, Copenhagen, Denmark - Paper ID: 414 Outdoor and indoor sources to ultrafine and fine particles in an urban apartment Marianne Glasius1,2,*, Peter Wåhlin1, Keld Alstrup Jensen3, Thomas Schneider3, Lars Gunnarsen4, Ole John Nielsen5 and F. Palmgren1 1 Department of Atmospheric Environment, National Environmental Research Institute, University of Aarhus, DK-4000 Roskilde, Denmark 2 Now at Department of Chemistry, University of Aarhus, DK-8000 Aarhus C, Denmark 3 National Research Centre for the Working Environment, DK-2100 Copenhagen Ø, Denmark 4 Department of Health and Comfort, Danish Building Research Institute, DK-2970 Hørsholm, Denmark 5 Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark * Corresponding email: marianne@glasius.dk Keywords: Indoor exposure, Aerosol, Particle penetration Introduction Aerosols in the indoor environment are of concern due to their potential effects on comfort and health. We investigated the sources of particles in an inhabited apartment at a busy street in Copenhagen, Denmark. The apartment was situated on the third floor of a five-storey building. Indoor measurements were carried out simultaneously with outdoor measurements at a nearby street site and an urban background site. Methods Measurements of particles (10-700 nm) and CO were carried out for two weeks (23 October – 5 November 2003) using Vienna type Differential Mobility Particle Sizers and CO-monitors, respectively. Both the occupant and some of the neighbours kept a diary of their indoor activities. Weekly-averaged ventilation rates of the study apartment were measured using the perfluoro tracer technique. A previously developed model (Schneider et al., 2004) was used to calculate indoor particle concentrations from penetration of outdoor air, and the difference between measured and penetrated particle concentrations was used to identify episodes with indoor particle sources. Results and Discussion The results show that indoor particle volume concentrations are only partly explained by the outdoor concentrations. The variations in particle concentration seem more related to indoor activities in the study apartment and activities in the neighbouring apartments than outdoor levels. Generally sharp increases in particle volume and numbers could be explained by opening of windows and cooking in the apartment studied or by smoking in neighbouring apartments (Glasius et al., 2008). Particle lifetimes according to size and source were determined from highly time-resolved measurements (5 min). Nanoparticles (<20 nm) from traffic showed a very fast decay within 1030 minutes to background concentrations in indoor air, while concentrations of larger particles (up to 700 nm) decayed much slower during several hours to background levels. This difference in decay rates is caused by the particle size dependent differences in chemical composition and removal processes. Glasius M., Wåhlin P., Jensen K.A., Schneider T., Gunnarsen L., Nielsen O.J., and Palmgren F. 2008. Outdoor and indoor sources to ultrafine and fine particles in an urban apartment; in preparation. Schneider T., Jensen K.A., Clausen P.A., Afshari A., Gunnarsen L., Wåhlin P., Glasius M., Palmgren F., Nielsen O.J., Fogh C.L. 2004. Prediction of indoor concentration of 0.5-4 µm particles of outdoor origin in an uninhabited apartment. Atmos Environ 2004; 38:6349-6359.