Estimation of natural radioactivity and radiological hazards in aggregate (stone dust) used as building materials in South Africa

In this study, the radioactivity concentrations of natural radionuclides (Uranium-238, Thorium-232, and Potassiumi-40) in aggregate/stone dust samples used for building construction purposes have been measured with thallium-doped sodium iodide (NaI(TI)) detector. The samples' associated radiological hazard risks were calculated using standard radiological expressions. The mean values of Uranium-238, Thorium-232, and Potassiumi-40 activity concentrations in the studied Quarries' samples were above the World mean values of 35, 30, and 400 Bq.kg−1 for radioactivity concentrations in building materials. The lowest and highest values of all the estimated radiological hazard indices were recorded in samples Afrisam C 5 and Afrimat 3.