Aerosol characterization and apportionment using cascade impactors and activation analysis

Collections with cascade impactors operated at three locations in Toronto, Canada, were analyzed by INAA and photonuclear activation. The efficiency and reliability of impactors for aerosol size-distribution characterization was studied by scanning electron microscopy and calculating equivalent aerodynamic diameters; values obtained were in close agreement with predicted ones. Toronto aerosols exhibited both expected and unusual particle-size distribution patterns with many elements exhibiting either size distributions biased toward large (e.g. Al, Sc, Ti, Fe) or small particles (e.g. Br, Cl, Cu). Other elements (viz. Pb, Zn, As, Sb) exhibited different and unusual size distributions. (author) 8 refs.; 3 figs.; 4 tabs