Multidisciplinary Approach for Evaluating the Geochemical Degradation of Building Stone Related to Pollution Sources in the Historical Center of Naples (Italy)

Natural stones have represented one of the main building materials since ancient times. In recent decades, a worsening in degradation phenomena related mostly to environmental pollution was observed, threatening their conservation. The present work is focused on the minero-petrographic and geochemical characterization of black crust (BC) samples taken from the historical center of Naples, after selecting two pilot monumental areas. The latter were chosen based on their historical importance, type of material, state of preservation and position in the urban context (i.e., high vehicular trac area, limited trac area, industrial area, etc.). The building materials used and their interaction with environmental pollutions were studied comparing the results obtained by means of dierent analytical techniques such as polarized light Optical Microscopy (OM), scanning electron microscopy with energy dispersion system (SEM-EDS), X-ray powder diraction (XRPD) and laser ablation coupled with inductive plasma mass spectrometry (LA-ICP-MS).