Natural radioactivity content, radon exhalation and mineralogical composition assessment of the Ignimbrite campana stone: a case study

Abstract

The natural radioactivity content of the Ignimbrite campana stone, as well as its radon exhalation and mineralogical composition, were assessed and reported as a case study in the present paper. In particular, the High Purity Germanium (HPGe) gamma spectrometry and the Closed Chamber Method (CCM) with the Durridge Rad7 setup were employed to quantify the specific activities of ²²⁶Ra, ²³²Th and ⁴⁰K, and the radon exhalation rate, respectively. In addition, several indexes were calculated to evaluate the radiological health risk related to radiation exposure from the analyzed natural stone, i.e. the absorbed gamma dose rate (D), the annual effective dose equivalent (AEDE), the activity concentration index (I), and the alpha index (I_α). Finally, X-Ray Diffraction (XRD) and Micro-Raman Scattering (MRS) investigations were performed to correlate the chemical composition and mineralogical characteristics of the investigated natural stone with its natural radioactivity content and radon exhalation rate.