Air pollution impact on carbonate building stones in Italian urban sites⋆

In spite of the widely recognized negative effect of air pollution on stone used in historic building heritage located in urban areas and the numerous studies internationally developed on this topic, gaps still remain in measuring deposition fluxes on architectural surfaces and developing proper tools for short- and long-term management of cultural heritage in polluted areas in a changing environment. Two-years long field exposure tests with model samples are currently under execution in Italian cities characterized by different environmental conditions, as a non-invasive methodological approach for investigating the impact of urban pollution on carbonate stones (marble and limestone). Several analytical techniques (both physical and chemical) are used for characterising the state of degradation of the exposed stone specimens while aerosol monitoring campaigns allow to compare the atmospheric components with those actually accumulate on samples surface. After a description of the methodological approach of this study and a general environmental characterisation of each selected site, results of aerosol monitoring campaigns (including bioaerosol) and colorimetric analyses performed during the whole period of exposure in Bologna are here presented and discussed.