Elemental composition of urban aerosol collected in Florence, Italy

An extensive investigation is in progress aiming at the characterisation of the air particulate composition in Florence. The aim is to determine the aerosol elemental concentrations as well to identify pollution sources. For our investigation, we use the external PIXE-PIGE beam facility of the Van de Graaff accelerator of INFN at the Physics Department of the Florence University. We report here an overview of the results of the PIXE analysis of a long temporal series (about 1 yr) of PM10 particulate collected on Millipore filters on a daily basis in three different sites (characterised by different urban settings). Daily concentrations of more than 20 elements have been obtained. From the observed elemental concentrations seasonal variation were found. A relevant decrease of S, Pb and Pr levels has been found with respect to 10 yr ago. Four main sources (traffic, sulphates, soil-dust and wind-transported sea-salt) have been extracted with the help of factor analysis. (C) 2000 Elsevier Science B.V. All rights reserved.