Radiological hazards of alkali feldspar granite bearing radioactive minerals: Safety concerns and environmental...

The alkali feldspar granite is enriched in Th-, U-, Zr-, and REE-mineralization. Thorite, uranothorite, zircon, monazite and xenotime have been recorded in the investigated granite that has been confirmed by an energy dispersive spectrometer (EDS) unit. The high variability in Th/U (0.43-33.91), U/K (0.15-25.38), and Th/K (2.09-19.00) ratios reflects the heterogeneous distribution of radioactive elements within the granite, which is influenced by the mineralogical composition of the samples investigated. The observed concentrations for U-238, Th-232, and K-40 provide essential data for evaluating the radiological hazards associated with using granite in construction. The findings revealed that the activity concentrations of these radionuclides ²³⁸U, ²³²Th, and ⁴⁰K are 177 ± 138, 96 ± 25, and 1682 ± 372 Bq kg-¹, respectively and exceeded the worldwide mean values. The high variability in ²³⁸U concentration highlights the importance of rigorous screening for specific samples, as some outliers may contribute more significantly to radiation exposure. In contrast, the more consistent ²³²Th and ⁴⁰K distributions suggest that these radionuclides might contribute to relatively stable radiation levels when granite is used in construction materials. The results indicate that many granite samples exhibit high radiological hazard indicators, with several samples exceeding international safety limits for indoor exposure. The elevated Ra_eq, D_air, AED, and ELCR values emphasize the need for careful consideration of these granites in construction, particularly for indoor use.