Radiological characterization of materials used in the Italian heritage buildings

Building materials (BMs) can cause significant gamma dose indoors due to their natural radionuclide content. In 2013, the European Directive 59/2013/EURATOM introduced, in annex XIII, a list of types of BMs of interest for the content of gamma-emitting radionuclides among which materials or additives of natural igneous origin, such as granitoids, tuff and lava, are included. These materials have been largely employed for decorative and structural purposes in the course of centuries in the Italian heritage buildings. Aim of this study is to assess the contribute of BMs in terms of alpha exposure. Six samples of different materials, characterized in a previous study by the authors in terms of radiological content by means of a gamma spectrometry, have been analyzed in order to determine the specific exhalation rate of 222Rn, the radon emanation coefficient and excess in indoor radon concentration. Results confirm that BMs of natural igneous origin can play an important role in terms of alpha radiation dose and internal exposure due to the inhalation of the alpha particles emitted.