Considerable radioactivity levels in the granitic rocks of the central areas of the Eastern Desert, Egypt

Abstract

The distribution of the natural radioisotopes ²³⁸U, ²²⁶Ra, ²³²Th, and ⁴⁰K in addition to their radiological parameters in granitic rock samples from five different localities (Gebel El-Missikat, Gebel El-Gidamy, Gebel Ria El-Garra, Gebel El-Aradiya, and Gebel Kab Amira) in the central area of the Eastern Desert, Egypt, was measured using high purity germanium (HPGe) detector-based γ-spectrometry. The average activity concentrations of ²³⁸U, ²²⁶Ra, ²³²Th, and ⁴⁰K in all five studied areas are higher than the corresponding global average values. The highest average activity concentrations of ²³⁸U and ²²⁶Ra were observed in Gebel El-Missikat, whereas the highest average value of ²³²Th activity concentration was found at Gebel El-Gidamy, and the highest concentration of ⁴⁰K was obtained at Gebel El-Aradiya. The radiological hazard parameters radium equivalent (Ra_eq), external hazard index (H_ex), internal hazard index (H_in), absorbed dose rate (ADR), annual effective dose rate (AEDR) outdoors, annual gonadal dose equivalent (AGDE), and excess lifetime cancer risks (ELCR) were calculated to assess the radiation hazards associated with the rock samples. The average values of these parameters are higher than the recommended reference levels. The obtained data provide a valuable future database for estimating the impact of radioactive contamination in the studied area and in the places where the rocks are used.