Health Impact Assessment of Naturally Occurring Radioactive Materials (NORMs) from a Gold Mine Tailing in Mpumalanga Province, South Africa
摘要
This study aimed to evaluate the radiological risks posed by radionuclides at gold mine tailings in Mpumalanga Province, South Africa. Twenty-four tailing samples and two control samples were collected and analyzed using Canberra High-Purity Germanium (HPGe) gamma detector, Model GCW-2021 to measure activity concentrations. The average activity concentrations for 238U, 40 K and 232Th were 643.75 ± 8.24, 2013.97 ± 35.87 and 66.08 ± 2.16 Bq·kg −1 respectively for tailing samples and 66.10 ± 1.151, 1643.09 ± 25.7 and 49.02 ± 1.56 Bq·kg−1 for 238U, 40 K and 232Th respectively for control areas. The average activity concentrations for the study area and control were both above the world average. This is likely because uranium is not extracted during the mining process, resulting in its disposal in the tailings. Average Radium Equivalent (Raeq) for tailings and control areas was 890.14 and 262.78 Bq·kg−1 respectively both values were above the world average of 370 Bq·kg−1. The recorded Absorbed Dose rate (D) for tailings and control areas were 403.54 and 131.36 nGyh−1 respectively both values were above the permissible world average of 59 nGyh−1. Recommended safe limits for External hazard (Hex) and the Internal hazard (Hin) is a unit however the study observed values of 2.4 and 4.1 respectively. The Hex and Hin for control areas were both below the recommended world limit of a unit. The study reveals that there is a significant radiological health implication posed by the tailings to the surrounding communities. It is recommended that the mine considers reprocessing the tailings for uranium recovery, implementing erosion control measures, and potentially vegetating the tailings.