AIR-POLLUTION STUDY IN THE CAPE-TOWN AREA BY PROTON-INDUCED X-RAY-EMISSION SPECTROSCOPY (PIXE)

A study was conducted during the 1992 winter period in which the trace element composition of the Cape Town brown haze was determined for a limited number of episodes at two sites. Analyses by macro-PIXE indica ted that the most common pollutant elements were Al, Si, P, S, Cl, K, Ca, Ti, Fe, Cu, Zn, Br and Pb, originating mainly from vehicles, towns hips, industries, sea salt and crustal matter. Total suspended particu late concentrations ranged from 23 to 304 mu g m(-3). From micro-PIXE irradiations it was found that the mean standard deviation of element concentrations was significantly higher for a coarser filter, indicati ng a higher degree of inhomogeneity in the deposit.