Pietra Leccese stone as a building material: radiometric and radiation protection characterization of a calcarenite for new insights

Indoor exposure to radon gas, classified as a Group 1 carcinogen, is regulated by Directive 2013/59/Euratom of the Council of the European Union and its Italian implementation, Decree 101/2020, as well as by the National Radon Action Plan (NRAP). This study reports a radiometric characterization of Pietra Leccese, an Apulian calcarenite, which currently falls into a class of rocks do not subject to radiation protection assessment. However, gamma spectroscopy measurements revealed a226Ra activity concentration of approximately 374 Bq/kg, exceeding the reference level of 300 Bq/kg. In addition, other additional radiation protection parameters such as Index I, Radium Equivalent Activity, External Hazard Index, Internal Hazard Index were calculated. Based on the results obtained, it is possible to consider the possibility of including new geological categories of Building materials to ensure a broader radiation protection approach.