In the EU "Integrated Climate and Energy Policy" the increased use of biomass fuels is promoted to reduce the emissions of fossil fuel derived greenhouse gases. An unexpected side effect, the increased emission ofgaseous and particulate organic compounds associated with incomplete combustion (e.g. as occurring during the ignition and the final smouldering phase of solid fuels) has been overlooked in its importance until recently. In the thesis the impact of wood smoke on the air quality of European sites is investigated with special emphasis on fine particles (PM) and the polycyclic aromatic hydrocarbon benzo(a)pyrene (BAP). With a BaP/PM ratio method it was derived, that for regions with wood smoke derived PM10 levels above 5 g/m on an annual basis the EU target value for BaP of 1 ng/m is likely to be exceeded. The results of this study show that wood smoke is the predominant source of BaP in Europe. Elevated PM and BaP levels from wood smoke are to be expected for densely populated European rural and semi rural environments, where wood combustion is a major source of residential heat generation. It appears that larger urban centres are not typical wood smoke combustion areas, while settlements in suburbs and rural areas seem to use fuel wood more frequently, in particular in areas with frequent inversions. Based on the investigation it was concluded that a violation of the EU BaP target value of 1 ng/m is likely to take place at numerous sites in Europe, namely at rural and semi rural settlements in valleys and basins with reduced aerial ventilation and effectual wood supply.