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N. Jankowski, A. Kasper-Giebl:
"Source Apportionment of Particulate Matter and Assessment of its Oxidative Properties";
Vortrag: Topical Issues of Subsoil Usage, St. Petersburg, Russland (eingeladen); 20.04.2011 - 22.04.2011; in: "Proceedings of the International Forum - Competition of Young Researchers", St. Petersburg Mining University, Band II/St. Petersburg (2011), ISBN: 978-5-94211-506-7; S. 124 - 125.

Particulate Matter is a complex mixture of solid and liquid particles of various chemical substances. In the last decades it has been and still is in the centre of scientific interest due to attested adverse impacts on health and the resulting limit value for ambient air concentration set by legislation.

To specify effective reduction steps for particulate matter, the contribution of local and regional sources to ambient particulate matter has to be examined. For gaseous air pollutants the sources can be allocated on the basis of emission inventories, for particulate matter this model is not suitable: On one hand a considerable fraction is formed secondary from gaseous precursors and therefore not declared as particles. On the other hand inventories do not or only to a certain amount comprise fugitative and diffuse emissions due to bulk handling and resuspension of dust and soil. A possible solution of this multidimensional problem is the application of source apportionment models. One of them is the so called "chemical mass balance (CMB)" model: For this model each source contributing to the particle burden at the ambient air site of interest has to be identified and characterized chemically. The source contribution is then estimated by determining the best-fit linear combination of the source profiles. On this basis, the measured chemical composition of the ambient air samples is reconstructed (Watson, 1984).

In different projects at our institute source apportionment with the CMB model was conducted for the major cities in Austria. More than 100 compounds were analysed in ambient air data sets and source profiles: Among them are metals, ionic components, organic sum parameters and trace substances. Profiles were compiled for wood combustion (Schmidl et al., 2008), soil dust, direct and indirect traffic emissions (Jankowski, 2010), thaw salt, secondary inorganic components and plant debris. By the use of the CMB model, about 80 up to 95% of the ambient air concentrations were explained by these sources. The results indicate that some of them, e.g. wood combustion, secondary inorganic components and soil dust are subjected to high seasonal variations: The first two mentioned are highest during the cold period from December to February; soil dust is one of the major sources in spring (April and March).
Beside the sources responsible for high ambient particulate matter concentrations there is a growing interest in the health impacts due to the chemical composition. In an ongoing project at our institute oxidative properties of particulate matter are determined with two different methods: In one of them the time dependent depletion of ascorbic acid - an antioxidant in airway secretion to protect against oxidative stress - is observed in the presence of particulate matter. In the other one the ability of the samples to produce hydroxyl radicals is analysed. Both methods reveal the possibility to induce oxidative stress to the organism, a primary pathway leading to respiratory and inflammatory responses (Gilliland et al., 1999).


References:
Gilliland, F.D., McConnell, R., Peters, J., Gong, H.J., 1999. Theoretical basis for investigating ambient air pollution and children´s respiratory health. Environmental Health Perspectives 107 (supplement 3), p. 403-407.
Jankowski, N., 2010. Particulate matter characterization of mobile emissions and source apportionment in an industrialized region in Austria. PhD Thesis.
Schmidl, C., Marr, I.L., Caseiro, A., Kotianova, P., Berner, A., Bauer, H., Kasper-Giebl, A., Puxbaum, H., 2008. Chemical Characterisation of fine particulate emissions from woodstove combustion of common woods growing in mid-European Alpine regions. Atmospheric Environment 42, p. 126-141.
Watson, J.G., 1984. Overview of receptor model principles. Journal of Air Pollution Control Association 34, p. 619-623.

PM10, Oxidative Properties, Source Apportionment

Projektleitung Anne Kasper-Giebl:
Was geht mich der Feinstaub an? Charakterisierung von Feinstaubproben aus der Immissionsüberwachung und aus Innenräumen hinsichtlich deren Aerosolquellen und Bestimmung der Auslöser für "Oxidativen Stress"