Resumen
The Sassi of Matera (Basilicata region, southern Italy) is a peculiar site, but not unique in Italy, from a landscape point of view. Most of the buildings are excavated in rocks of calcarenite origin and used as homes and accommodation facilities. For this reason, the contribution of gamma radiation to the population due to this building material has been investigated for the first time. Even though the type of rock is not mentioned among the construction materials indicated in Italian Legislative Decree 101/2020 to be subjected to radiological characterization, the methodology indicated in the decree was applied, comparing the values with those present in the literature. The content of 226Ra, 232Th and 40K was then investigated with gamma spectroscopy, and the gamma index was calculated. The results obtained showed a low level of activity concentration of natural radionuclides in this type of stone, confirming the radiological safety. This result can also support the recovery and restoration initiatives for these buildings to conserve the architectural and landscape heritage of this village.