Chemical Analyses and Geographical Origins of Residential Attic Dust in Central South Africa

Abstract Particulate matter (PM) serves as widely used air pollution proxy indicator. Substantial supporting evidence links exposure to PM with adverse health effects. This study compared chemical and morphological properties of long-term accumulated particulate matter, and possible sources, from various locations in Bloemfontein, Kimberley and Vanderbijlpark residential areas. Samples were collected from the attics of houses built over forty years ago. Cluster sources were identified by analysing four decades of backward Long-Range Transport (LRT) clustering techniques. Particle morphology and elemental composition of samples were determined using scanning electron microscopy with electron dispersive spectroscopy, and mineral content by X-ray fluorescence, X-ray diffraction and electron probe microscopy techniques. Considering a period spanning over 4 decades, several PM origins were determined by a combination of LRT cluster and mineral analyses, pointing to various moving sources all over Southern Africa.