Characterization of airborne particulate matter in an industrial district near Florence by PIXE and PESA

The composition of airborne particulate matter in Montelupo Fiorentino (a small town about 20 km west of Florence characterized by the presence of a large number of ceramic and glass factories) was studied by means of continuous and sequential sampling, ion beam analysis (IBA) techniques and statistical methods. The aerosol PM(10) fraction was collected on a daily basis for about 9 months (September 2002-June 2003). To investigate the elemental size distribution, fora shorter period (about 3 weeks) we collected PM(10), PM(2.5) and PM, simultaneously. A continuous streaker sampler was also used, which allows the study of the aerosol composition with 2 h time resolution. Mass concentrations were obtained using an analytical balance. The elemental analysis was performed at the INFN accelerator laboratory at the Physics Department of Florence University by particle-induced x-ray emission and particle elastic scattering analysis (the latter implemented for this campaign). The use of the two techniques allowed a complete reconstruction of the gravimetric mass. An absolute principal component analysis showed industrial sources to be, on average, the main contributors to PM(10) mass; however, the weight of the 'soil' source (connected to local soil re-suspension and to long-range Saharan transport episodes) becomes dominant during some of the days when the 50 mu g m(-3) limit is exceeded.