Radiological risk assessment of cement used in contemporary South African buildings

Using a calibrated NaI(TI) and a well-shielded detector connected to a computer-resident quantum multichannel analyser, the radionuclide contents of primordial radionuclides (226Ra, 232Th and 40K) were evaluated in commonly used cement brands in South Africa, and the associated radiation risk parameters were calculated. The reported activity concentrations varied from 8.00 ± 2.83 to 45.00 ± 2.79 Bq/kg, 12.00 ± 0.90 to 32.00 ± 0.51 Bq/kg and 454.00 ± 0.56 to 1765.00 ± 0.93 Bq/kg for 226Ra, 232Th and 40K, respectively. The absorbed gamma dose rate, annual effective dose equivalent, annual gonadal dose equivalent, excess lifetime cancer risk, gamma index and alpha index were utilised as the radiological health impact metrics to evaluate the potential radiation risks. The determined radiological health impact parameter results were below the relevant radiation safety authorities’ recommended reference levels for building materials. Therefore, the use of cement products as building materials presents no significant risk in the study areas.