Determination of radioactivity concentrations in phosphate ore and fertilizer to assess their radiological impacts using gamma spectrometry technique in Saudi Arabia

Abstract

This study measures the radioactivity concentration in phosphate ore and final product samples, as well as the radiological risk from the mining area that has an impact on the environment in the Al-Jalamid mining region of Saudi Arabia. The contents of ²²⁶Ra (²³⁸U), ²³²Th, ⁴⁰ K, and ²³⁸U/²²⁶Ra ratio were measured using gamma-ray spectrometry. The results show that the concentrations of ²²⁶Ra (²³⁸U), ²³²Th, and ⁴⁰ K in the ore ranged from 62.3 to 333.5 with an average value of 253.6, 0.53 to 2.37 with an average value of 1.54, 3.2 to 8.1 with an average value of 4.58 Bq kg⁻¹, respectively. The results for the fertilizer samples show that the activity concentrations for ²²⁶Ra (²³⁸U), ²³²Th, and ⁴⁰ K range from 2.32 to 2.62 with an average value of 2.48, 0.54 to 0.73 with an average value of 0.66, 9.41 to 10.98 with an average value of 10.36 Bq kg⁻¹, respectively. A good correlation was found between ²³⁸U and ²²⁶Ra. The value of the radium equivalent ranged from 63.40 to 337.48 with an average value of 255.73 Bq kg⁻¹. The gamma radiation hazard indices of the radium equivalent activity, external and internal indices, and annual effective dose due to the presence of these radionuclides in the studied samples were assessed. The results were compared with those from the world average value.