TROPOSPHERIC AEROSOLS ABOVE THE THERMAL INVERSION LAYER OF SANTIAGO, CHILE - SIZE DISTRIBUTION OF ELEMENTAL CONCENTRATIONS

This paper reports on elemental concentration distribution versus size of particulate matter under 10.2 mum, above the thermal inversion layer in Santiago, Chile. Forty-eight-hour samples were collected with Andersen and Berner cascade impactors. Atomic Absorption Spectrophotometry was used to quantify Mg, Ca, Mn, Fe, Zn, Pb, Ni, Cr and Cd. These last three elements were found under the detection limit of the technique. The concentration of Ca, Fe, Mg and Mn increases as the sizes of particles increase, while the concentration of Pb increases as the sizes of particles decrease. Analysis by enrichment factors using Fe from local soils as reference shows that Mg, Ca and Mn have a natural origin, and Pb and Zn an anthropogenic origin. The principal component analysis indicates that Mg, Ca, Mn and Fe are very probably coming from peripheral soils or dust from unpaved roads and streets; Pb from motor vehicles; and Zn and Cu from industrial emissions.