Radiological Evaluation of Background Ionizing Radiation of Some Selected Solid Mineral Mining Sites in Kogi State, Nigeria

Abstract

This study evaluated the background ionising radiation (BIR) levels of some selected solid mineral mining sites in Kogi State. The BIR measurements were taken using a well-calibrated radiation meter (Digilert 200), placed at an elevation of 1.0m above ground level, and a Global Positioning System (GPS) to determine the geographical locations. Each measurement was repeated three times, with approximately 5-10 minutes spent at each measuring point. The mean exposure dose rates obtained were 0.027, 0.021, 0.055, 0.046, 0.024, 0.020, and 0.026 respectively, in mR/hr. The values are higher than the recommended safe limit of 0.013mR/h. The mean Absorbed Dose Rates obtained are 235.3, 186.4, 482.3, 272.8, 209.0, 178.4 and 225.1 respectively, in nGy/hr. The values are all higher than the recommended safe limit of 84.0nGy/hr. The mean values obtained for AEDE are 0.386, 0.306, 0.769, 0.485, 0.343, 0.293 and 0.370 respectively, in mSV/yr. The mean values obtained for ELCR are 1.35 x 10-3, 1.07 x10-3, 2.75 x10-3, 1.57 x10-3, 1.20 x10-3, 1.02 x10-3 and 1.29 x 10-3 respectively. The values are higher than the ICRP standard of 0.29 x10-3, indicating a detrimental cancer risk for residents of the study area. The results obtained from this research established significantly elevated radiation levels, indicating a possible increase in radiation-induced injuries and long-term cancer among inhabitants. The findings will contribute to baseline data on radiological safety, support risk assessment and the development of regulatory policies, and support a sustainable environmental monitoring structure for mining areas in Kogi State.