PIXE ANALYSIS OF SIZE-FRACTIONATED AEROSOL SAMPLES COLLECTED AT BIRKENES, NORWAY, DURING SPRING 1987

A single orifice cascade impactor was used to collect size-fractionated aerosol samples in Birkenes, Southern Norway, during the spring of 1987. The samples were analyzed for about 20 elements by particle-induced X-ray emission (PIXE). On the basis of the average size distributions and mass median diameters (MMDs), the elements could be classified in three different groups. Mg, Al, Cl, Ca, Ti, and Fe exhibited a unimodal size distribution, with a MMD of about 4 μm equivalent aerodynamic diameter (EAD); for Si, K, Cr, Mn, Ni, and Cu the distribution was rather flat or bimodal; and S, V, Br, Zn, and Pb were predominantly associated with < 1 μm EAD particles. The elemental concentrations and aerosol composition (interelement ratios) were examined in relation to the origin of the sampled air masses, as determined from air mass back-trajectories, and substantial differences were observed. Certain samples exhibited enhanced concentrations of fine Si which probably originated from Si and SiC industries in Southern Norway. High crustal enrichment factors were observed for Mn in northern and northwestern air masses, suggesting contributions from Norwegian sources for this element. © 1990.