Francesco Caridi

In this article, an investigation into the natural radioactivity content in natural inorganic pigments was carried out, together with the assessment of the radiological health risk for the public related to external exposure to ionizing radiations, via High-Purity Germanium (HPGe) γ-ray spectrometry measurements and the calculation of several indices like the absorbed γ-dose rate (D), the annual effective dose equivalent outdoor (AEDEout) and indoor (AEDEin), and the activity concentration index (I). From the obtained results, it was possible to reasonably exclude radiological hazard effects. In addition, Pearson’s correlation, principal component analysis (PCA), and hierarchical cluster analysis (HCA) were carried out with the aim of determining correlations between natural radioactivity content and radiological indices and with the analyzed samples. As a result, five clusters of the investigated pigments were recognized at the highest level of detail based on their chemical composition and mineralogical nature.