Multivariate Statistics, Radioactivity and Radiological Hazard Evaluation in Marine Sediments of Selected Areas from Sicily, Southern Italy

This work reports the findings of an investigation aimed at assessing, for the first time, the natural and anthropogenic radioactivity content of marine sediments collected from selected areas of Sicily, Southern Italy. In particular, it focused on evaluating the average activity concentration of detected radionuclides and the radiological hazard for humans, above all considering the use of this material for nourishing actual eroded beaches. To this aim, the quantification of the average specific activity of 226Ra, 232Th, and 40K natural and 137Cs anthropogenic radioisotopes was addressed through the employment of High-Purity Germanium (HPGe) gamma-ray spectrometry. Furthermore, the absorbed gamma dose rate (D), the annual effective dose equivalent outdoor (AEDEout), the external hazard index (Hex), and the excess lifetime cancer risk (ELCR) were also calculated to evaluate the radiological hazard for humans related to external exposure to ionizing radiations. Furthermore, the average specific activity of 137Cs was found to be less than the lowest detectable activity in all cases, excluding anthropogenic radioactive contamination of the investigated samples. Finally, Pearson correlation, principal component analysis (PCA) and hierarchical cluster analysis (HCA), i.e., multivariate statistics, were carried out by analyzing detected radioactivity and radiological characteristics to evaluate their relationship with the sampling locations.