STUDY OF RELATIONSHIPS BEETWEEN POLLUTION AND WEATHERING OF CALCARENITE STONE

The degradation of the cultural heritage begins immediately after its implementation and the speed of degradation depends on both natural and anthropogenic factors. The process of deterioration is progressive and irreversible, and the timing and mode of impact is different depending on the characteristics of the monument (location, orientation, mineralogical and structural properties), microclimate (temperature, humidity, solar radiation, wind regime, precipitations), air pollution (particulate, concentrations of SO2, NOx, CO2 ), presence of specific flora and fauna that are involved. The conservation and restoration of such structures requires the understanding of physical-chemical and biological processes, causing the deterioration of materials, and the knowledge of restoration strategies. The characterisation of structure and microstructure of historical materials is mandatory in preventing and eventually recovering degradation effects. Ideally, the analysis of an artwork should be complete, efficient, rapid and, if possible, non destructive when dealing with precious or unique objects. Thus, measurement should be carried out in-situ or by removing very small amounts of material. XRD, XPS, GPR, MGE and FT-IR are some techniques widely applied to study materials used in historical or artistic artefacts. We investigated the influence and synergistic effects of climatic parameters (temperature, light irradiation, wind intensity, humidity), pollution (SO2, CO, NO2, Ozone and heavy metals), on a little stone building (1 m3) made and placed on purpose between an archaeological site of Lavello, a little town located in the Basilicata Region, and the industrial area surrounding this town. X-ray diffraction, X-ray induced photoelectron spectroscopy (XPS), X-ray fluorescence spectrometry (XRF) and Petrophysical tests were carried out on calcarenite samples. Preliminary results show that climatic parameters (temperature, light irradiation, wind and humidity) and pollution undermine the structure and the compactness of stones favouring the biological colonization especially in the south–east direction of prevailing winds