Environmental radioactivity and geochemical characterization of granite: Implications for sustainable construction

The geochemical characteristics of the Wadi Biam granitoids have been thoroughly investigated to assess their suitability for use in building materials. Granitic rocks in the study area comprise tonalite-granodiorite, monzogranite and syenogranite as well as their related pegmatitic bodies. The geochemical characteristics demonstrate that Wadi Biam granite is distinguished mainly by the peraluminous domain, high-K calc-alkaline series and fall in syn-collision and volcanic arc granites. It is ranging from proper granite to syenogranite in composition. It has relatively high levels in LILE (Cs, Rb) when compared with HFSE (Nb, Ta, Zr and Y), with a marked trough in Ba, K and Ti. The REEs pattern of the investigated granite is characterized by the lowest REEs concentration with a marked enriched LREEs than HREEs. REEs have no sign of Eu anomaly. The radioactivity levels were also measured, revealing a mean concentration of Uranium-238 at 65 Bq kg−1, Thorium-232 at 69 Bq kg−1, and Potassium-40 at 1368 Bq kg−1. These values suggest that the syenogranite has relatively low radiological risks, with the average radium equivalent activity (Raeq) at 269 Bq.kg−1, below the safety threshold of 370 Bq kg−1. However, indoor radiation levels, particularly the annual effective dose (AEDin) averaging 0.63 mSv, exceed global safety standards, indicating potential health risks if used in poorly ventilated indoor environments.