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

The principal component analysis (PCA) indicated the major contribution of PAH and O-PAH sources in summer and winter. For the summer data, the first principal component, accounting for 41% of the total variance, was interpreted as vehicle exhaust due to high loading of the dominant four–five rings PAHs, which has been identified as typical tracers of vehicular source of PAHs. The data collected in the colder period show an increased influence of non-traffic sources: the 60% of the variance was accounted by the first principal component that is heavily loaded with PAHs, benzo[a]anthacene, chrysene and benzo[k]fluoranthene, that are usually considered as the markers of coke ovens and natural gas combustion