An evaluation of particle deposition fluxes to cultural heritage sites in Florence, Italy.

The pernicious effects of deposition of airborne particles on monumental stones have been widely demonstrated, but estimates of deposition fluxes on historic buildings remain a hard task because of the lack of careful experiments and modelling. AERBOX is a new box model developed by ENVIROWARE and ENEA, simulating the whole life cycle of aerosols. AERBOX takes into account all the relevant chemical and physical processes involved: emission, chemical reactions in gas and in gas-liquid phases, deposition, entrainment, condensation and nucleation. Concentration and deposition rates of 52 species of gaseous pollutants and 14 species of particulate pollutants are calculated on hourly basis. A modelling system composed by AERBOX and the emission pre-processor Tool for Hourly Speciation of CORINAIR Annual Emissions (THOSCANE) has been applied to estimate the flux of particulate matter deposited on the monumental area of Florence downtown starting from a CORINAIR emission inventory developed by the Tuscany Region including the industrial and mobile sources in the area of Florence and Prato counties. The time and chemical profiles of the emissions have been adapted to the Tuscany region from the reference profiles given by both the California Air Resource Board and EPA and meteorological inputs were given by the Tuscany Meteorological Centre. Concentrations and deposition fluxes were compared with field measurements available in the open literature.