###### Abstract  
In this paper, a thorough radio- and chem-ecological evaluation of ElSibai-Abu ElTiyur granites located within Egypt's crystalline basement rocks was conducted for risk and dose assessments. Twenty granite samples from the study area's various lithological units were analyzed using high-resolution \(\gamma\)-ray spectrometry to determine the natural radioisotopes (U-238, Th-232, and K-40) concentrations. The average concentrations of U-238, Th-232, and K-40 were 38.72, 38.23, and 860.71 Bq/kg, respectively, exceeding the GAV (global average value) documented by UNSCEAR (Scientific Committee on the Effects of Atomic Radiation, Vienna, Austria). The radiological parameters and indices judging the usage of ElSibai-Abu ElTiyur granites in homes were computed. The obtained results showed that ElSibai-Abu ElTiyur granites are safe to be used by inhabitants as superficial building materials, as per the globally accepted values and the recommended safety limits approved by UNSEAR, WHO (World Health Organization, Geneva, Switzerland), ICRP (International Commission on Radiological Protection, Ottawa, ON, Canada), and EC (European Commission, Luxembourg). Further, the samples were subjected to ICP-MS (inductively coupled plasma mass spectrometry) analysis for quantifying radionuclide variations with chemical composition. Geochemically based on the ICP-MS results, the studied granites proved to be highly evolved A-type granites. They span the metaluminous to peralkaline fields. The REE patterns are characterized by the enrichment of the light rare earths (LREE) over the heavy ones (HREE) where (La/Yb)\({}_{n}\) = 5.2, (Gd/Yb)\({}_{n}\) = 1.63 with pronounced negative Eu-anomalies (Eu/Eu\({}^{+}\))\({}_{n}\) = 0.49. The albite granite exhibits the highest concentrations of Ga, Nb, Ta, U, and Y, and REE (Gd, Dy, Ho, Yb) than the Na-metasomatic granites. Finally, the obtained data serve as a valuable future database for finding out the compatibility of the geochemical data with the natural radioactivity levels of granites.  
granites; chemical analysis; natural radioactivity; gamma rays; radiation risks +
Footnote †: journal: Applied Sciences  
Environmentally, the natural radioactivity differs from one location to the other, based on their geological setting. Due to the existence of abnormal amounts of radionuclides in rocks, various regions throughout the world have high levels of natural radiation [3].  
From a geological point of view, the Egyptian deserts contain one of the best-preserved granites in the world. Since no systematic data on environmental radioactivity in Egypt were available, many studies commenced in 2002 with the objective to systematically measure the terrestrial gamma radiation, and determine its contribution to the annual effective dose equivalent to the population (e.g., [4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15]). It has been shown that many of these areas have high levels of radioactivity. No previous study has been conducted to investigate the distribution of natural radionuclides in ElSibai-Abu EITiyur granites. There are three main points that make this study particularly important and interesting for radiometric studies. Firstly, it provides information on the geochemical composition associated with the environmental radioactivity of such granites. Secondly, the study of the enrichment/depletion processes, alteration, metasomatism, that affected the investigated rocks. Thirdly, we assess the possible radiological health hazards and compare the results with the recommended limits of UNSCEAR, EC, and WHO data.