Assessment of Natural Radioactivity and Associated Radiological Hazards in Some Building Materials Commonly Used in Pietermaritzburg, South Africa

This study examines the concentrations of naturally occurring radionuclides-uranium-238 (2(3)8U), thorium-232 (2(3)2Th), and potassium-40 (40K)-in five categories of building materials commonly used in Pietermaritzburg, South Africa, using a thallium-doped sodium iodide (NaI(TI)) gamma-ray spectrometry system. The radiological health risks were evaluated by calculating hazard indices with established formulas. The overall mean concentrations of 2(3)8U,2(3)2Th, and 40K in the samples were 153.75 +/- 1.43, 123.68 +/- 0.74, and 397.59 +/- 0.80 Bq kg-1, respectively, exceeding the global averages of 33 Bq kg-1 for 2(3)8U, 45 Bq kg-1 for 2(3)2Th, and 420 Bq kg-1 for 40K, which are considered safe for building materials. The elevated radionuclide levels in the categories of materials resulted in radiological hazard parameters, such as radium equivalent activity and external hazard index, surpassing recommended safety limits. This indicates that prolonged exposure to these materials could pose health risks, particularly in residential environments. When compared with international safety standards, the results emphasize the need for regulatory oversight in the selection and use of building materials. The findings raise concerns about public health, calling for stricter regulations and monitoring to ensure the materials meet safety standards. This study supports more informed and safer material choices in the construction industry, contributing to better public health protection by offering critical data.