SIZE-DIFFERENTIATED COMPOSITION OF AEROSOL IN KHARTOUM, SUDAN

Aerosol samples were collected in Khartoum, Sudan, using a 5-stage cascade impactor. The samples were analyzed for up to 29 elements by particle-induced X-ray emission (PIXE). The size distributions and enrichment factors indicated that most of the elements in the Khartoum aerosol originate from a soil dispersion source and that the anthropogenic contribution is important only for S, Cl, Br, and Pb and to a lesser extent for Cu and Zn. Comparison of the enrichment factors for the elements in the Khartoum aerosol with literature values indicated the lowest enrichment factors reported for these elements so far. Multivariate analysis of the data showed that the anthropogenic contribution was important in the small particle size range (0.25-0.5-mu-m) and that for the larger particles soil dispersion prevailed.