CHEMICAL RELATIONS BETWEEN ATMOSPHERIC AEROSOLS, DEPOSITION AND STONEDECAY LAYERS ON HISTORIC BUILDINGS AT THE MEDITERRANEAN COAST

To evaluate the effects of the environment on weathering of historical buildings in the Mediterranean Basin. an elaborate study has been car ried out at four monuments, with specific interest directed on the act ion of air pollution and marine salts. The composition of the atmosphe re around the monuments has been investigated by monitoring the aeroso ls and the total deposition. These results are combined with the stone decay phenomena to interpret the deterioration at the respective monu ments. In Eleusis, Greece, a highly industrialized area, high concentr ations of heavy metals and sulphate are found in the aerosols and depo sition and in the decay layers of the stone, while the marine influenc e is obscured, in spite of its location close to the sea. In Malta and in Cadiz (Spain), the influence of the sea dominates in the stone wea thering process. In Bari (Italy), next to the effects of marine aeroso ls on the stone decay inside and outside the building, high concentrat ions of sulphate are observed on the outside stones. The aerosols and depositions reflect a relatively small influence of anthropogenic deri ved elements; this points out the action of gaseous SO2 on the stones. (C) 1997 Elsevier Science Ltd.