Baseline contamination assessment for a new resource facility in Germany .6. Levels and profiles of polycyclic aromatic hydrocarbons (PAH) in ambient air

Total PAH levels in ambient air were analysed at seven urban and one rural sites in or near Augsburg, Germany, for one year. The concentrations varied during the seasons with the highest levels in winter. Ratios and profiles of PAH underwent a seasonal change, too. The variation was more marked for the group of the semivolatile PAH(3-, 4-ring PAH, benzo[b], [k]fluoranthene). The seasonal changes reflect the changes in the contributions of the possible sources like residential heating and traffic to the PAH levels but they are also the result of a higher atmospheric reactivity of PAH during the summer months. The latter was presumably the reason why anthracene and benz[a]anthracene could not be detected in the gas phase in summer. Phenanthrene, fluoranthene and coronene dominated the PAH profiles in summer and are presumably tracers for traffic emissions. A chemical mass balance calculation done with the profile of six particulate (5-, 6-ring) PAH showed that residential heating and traffic each contributed roughly 50% to the ambient PAH levels in winter. Ratios and profiles of semivolatile PAH appear to be promising tools for estimating the contributions of the different sources more precisely. Copyright (C) 1996 Elsevier Science Ltd.