This paper will present the latest available data of the levers of PAHs in
the ambient air conducted in Finland. The sampling sites were situated in t
he metropolitan area of Helsinki. It will also compare the latest data agai
nst the data obtained in the 1980'ties. Information about the sources can b
e obtained by comparing emission ratios and profiles of target compounds. A
ll measurements were made using gaschromatography mass spectrometry singel
ion monitoring (GCMS-SIM).