Radiological characterization of natural building materials from the Campania region (Southern Italy)

The characterization of natural radioactivity content in thirty-one natural building materials representative of the Campania region (South Italy) was carried out. High resolution γ-ray spectrometry for the determination of the 226Ra, 232Th and 40K activity concentrations was used. Commonly-used radiation hazard indexes were computed to evaluate the human exposure to γ-radiation. The results are compared to limit values established by the 2013/59/Euratom Directive and by UNSCEAR: the comparison proves the high natural radioactivity content and the radiation exposure hazard coming from some samples of volcanic origin. The emanated fraction and the exhalation rate of the 222Rn and of the 220Rn from the investigated materials were also measured with the α-spectrometry of the ionized radon daughters. This study is justified by the ever-growing public concern about radon risk associated to building materials from Campania region, locally widely used and exported worldwide. The results show interesting differences about the radioactivity content and the capacity to generate radon, among the different materials. This work contributes to enriching knowledge about natural radioactivity in natural building materials used in Italy.