Introduction Lower Silesia is a province in southwestern Poland located at the contact point of Polish, German, and Czech Republic borders. The presence of old and diverse geolog- ical structures makes this region rich in various natural resources, like copper ores, coal, brown coal, and mineral waters of proved healing properties. But simultaneously, the exploration and processing of natural resources, which are fundamental for the local economy, appeared to be – indirectly – the source of environmental deterioration. In the 1980s and ‘90s the region, where the borders of Poland, Germany, and the Czech Republic adjoin, was called the “Black Triangle. ” It was considered one of the most pollut- ed regions in Europe because of numerous power plants without efficient gas cleaning techniques, wide open coal mining areas, and domestic heating based on brown coal. Since the early 1970s deforestation has been the major con- cern due to the extent and severity of the observed damage. Massive areas of forest suffered serious deterioration pre- senting strong visual symptoms of ecological damage [1, 2]. After the political changes great effort was made to reduce the emissions from the highest industrial companies. Permanent air monitoring carried out since 1997 proved the evident decrease of gaseous and particulate pollution [3, 4]. The overall results of our field studies in two health resorts located in the Polish part of the former “Black Polish J. of Environ. Stud. Vol. 19, No. 6 (2010), 1345-1352 Original Research Air Pollution Origins Using PM 10 Data and CO 2 Isotopic Analysis Anna Zwoździak 1 *, Maciej Górka 2 , Izabela Sówka 1 , Dominika Lewicka-Szczebak 2 , Jerzy Zwoździak 1 , Mariusz Orion Jędrysek 2 1 Ecologistics Division, Institute of Environmental Protection Engineering, Wroclaw University of Technology, Pl. Grunwaldzki 9, 50-377 Wrocław, Poland 2 Laboratory of Isotope Geology and Geoecology, Department of Applied Geology and Geochemistry, Institute of Geological Sciences, University of Wroclaw, Cybulskiego 30, 50-205 Wrocław, Poland Received: 11 February 2010 Accepted: 30 April 2010 Abstract PM 10 concentrations (in relation to main gaseous pollutant levels and prevailing meteorological condi- tions) and carbon isotopic composition of atmospheric CO 2 have been analysed in two health resorts in SW Poland (Cieplice and Czerniawa) to determine the main air pollution sources. In Cieplice, PM 10 concentrations followed the variations in NO 2 and CO, as well as SO 2 , suggesting traffic and domestic heating to be the main sources of aerosol particles. Conversely, in Czerniawa periodically pollutant rich air masses originating from regional sources contribute to increases in SO 2 and NO 2 levels, whereas the PM 10 concentrations are at the background level. The analyzed δ 13 C(CO 2 ) values reinforced the conclusions drawn on the basis of tradition- al methods and indicated the different impact of pollution sources between the investigated regions. Czerniawa was controlled by regional sources of CO 2 , whereas Cieplice was dominated by multiple local sources of pol- lutants (mainly traffic pollutants). Keywords: PM 10 , SO 2 , NO x , episode, carbon isotope *e-mail: anna.zwozdziak@pwr.wroc.pl