Determination of Natural Radioactivity Levels and Resultants Radiological Hazard from Soil Samples around Gold Mining Area in Ijesa-land South-Western Nigeria

Abstract

Activity concentration levels and some radiological parameters owing to natural radioactivity in the soil samples randomly obtained in gold tailing sites in Ijesa­-land Southwestern Nigeria were analyzed. Analyzed results from 30 soil samples using multi-channeled NaI gamma detector show that the activity concentration of 233U; ranged from 17.42 0.54 to 49.892.42 BqKg-1; 232Th ranged from 22.10 4.70 to 76.557.44BqKg-1 and 40K; ranged from 307.0023.90 to 693.5851.50 BqKg-1 in the samples were measured. The mean absorbed dose rate calculated was marginally higher than the world average of 59nGyh-1. The average annual effective dose rate (outdoor) for all samples ranged from 0.08 + 01. 11mSv.y-1 with a mean of 0.07 which stays far below the permitted worldwide limit of 1mSv.y-1hy by International Commission on Radiation Protection (ICRP 2010). The calculated hazard indices for external and internal remained to be lower than unity signifying that mineworkers and individuals active in such area are not exposed radiation hazard.