An extensive investigation is in progress aiming at the characterisation of
the air particulate composition in Florence. For our investigation, we use
the external PIXE-PIGE beam facility of the I.N.F.N. Van de Graaff acceler
ator at the Physics Department of the Florence University. In order to gath
er information on both the longer- and shorter-time trends of the aerosol e
lemental composition, we are analysing both long temporal series (about 1 y
ear) of 24 h Millipore filters collected by the health authorities in 3 dif
ferent sites, and filters collected simultaneously in two of the above site
s for about one month, by two streakers with one-hour resolution, providing
size fractionation between particle size smaller than 2.5 mum and from 2.5
mum to 10 mum. The streakers sampling period includes two days during whic
h the Municipality of Florence has banned the circulation of non-catalytic
cars, due to the increase of NO2 above the "recommended safety values". We
present here the first obtained results for the sampling site located near
a heavy traffic road.