AIR-POLLUTION LOADS ON HISTORICAL MONUMENTS - AN AIR-QUALITY MODEL APPLICATION TO THE MARBLE ARCH-OF-TITUS IN ROME

Atmospheric pollution is one of the reasons for stone weathering of mo numental structures; at the same time old town centres are high concen tration areas of pollutant sources (traffic and domestic heating) and of outdoor works of art. The use of air dispersion models represents a short means of answering many questions concerning pollution and it i s a complementary way to the traditional ad hoc measurement of polluta nt concentrations. An application of DIMULA, an analytical multisource dispersion model, and of CALINE 3, an air dispersion model specially developed for pollutant line sources (road links) will be described. T he first was applied to the entire urban area of Rome and the second t o the surroundings of the Arch of Titus. A simulation was performed re lative to the period of in situ monitoring of air pollutant species an d meteorological conditions. Moreover simulations of the effect of pos sible actions to reduce pollution around the monument (e.g., traffic l imitation, use of different fuels) have been performed. Once the model has been validated, this approach, compared with the traditional appr oach involving a large amount of measurements, has the merits of being reliable and economical.