Seasonal variation and source estimation of polycyclic aromatic hydrocarbons in urban PM of Augsburg, Germany.

The chemical composition of atmospheric aerosol (PM2.5) at an urban background site (Augsburg, Germany) was investigated in a summer (August-September 2007) and winter (February-March 2008) campaigns for 36 and 30 days, respectively. The concentrations of many classes of organics have been simultaneously determined by direct thermal desorption-gas chromatography-time of flight mass spectrometry (DTD-GC-TOFMS). Among them, 11 polycyclic aromatic hydrocarbons (PAH) and 7 oxidized PAH (O-PAH) were investigated. The results indicated that the concentrations during the winter campaign were more than 10 fold higher than during the summer campaign. The results of diagnostic ratios analysis indicated the main sources of PAHs are emissions by gasoline and diesel cars and emissions by heating of buildings and hot water generation, which is done mainly by burning of fossil fuels and to a minor extend by wood and brown coal burning