Abstract
Mahd Ad Dahab mine is the largest and oldest gold mine in the middle East, situated in the western region of Al-Madina Al-Munawara in Saudi Arabia. By using a high-resolution gamma-ray spectroscopy system, various radionuclides in about 20 rock samples, collected from four different locations of the Mahd Ad Dahab mine, have been identified quantitatively based on their characteristic spectral peaks. The activity concentrations of the natural radionuclides uranium (U-238), thorium (Th-232), and potassium (K-40) as well as some radiological parameters were measured in the rock samples. The activity concentration of uranium was found to vary from 7.94 to 38.52 Bq/kg, thorium from 3.14 to 17.79 Bq/kg and potassium activity from 93.51 to 175.83 Bq/kg. The radon emanation coefficient of the rock samples was estimated. It ranged between 0.48 and 0.55. Moreover, the radium equivalent activity in the samples ranged between 19.3 and 77.49 Bq/kg, which is lower than the allowed maximum value for worker safety. The external and internal hazard indices and gamma-radiation hazard index were found not to exceed the permissible limits.