Determination of Activity Concentration and Radiological Risks from Gold Mine Tailings around Ilahun-Ijesa in Obokun Local Government, Osun State, Nigeria

Abstract

In this study, the activity concentrations and radiological risks associated with exposure to NORMS in soils around the gold mine tailings in Ilahun – Ijesa, Obokun Local Government, Osun State, Nigeria was evaluated. A Sodium Iodide (NaI) gamma spectroscopy was used to determine the activity concentrations of the natural radio nuclides in soil samples that were collected from the gold mine tailings.  The mean activity concentration for ²³⁸ U, ²³² Th and ⁴⁰K   were 14.50±2.40, 10.45±3.20 and 332.70±6.10 Bqkg^-1 respectively. The average absorbed dose was calculated to be 26.4 nGy/h and the corresponding average annual effective dose was found to be 0.0031 mSv, which is less than the total annual effective dose of 1 mSv recommended by ICRP for public exposure control. Radiological hazard parameters were evaluated from activity concentrations and the average values were found to be lower than recommended safety limits.