Evaluation of Radiological Hazards Associated with Some Selected Mining Sites in Niger State, Nigeria

Abstract

Evaluation of Radiological Hazards associated with some selected mining sites (ie Gadaeragi (GR), Maiwayo (MW) and Kataeragi (KR)) in Niger State, Nigeria was carried out using Nal (TI) Gamma ray spectroscopy. The results shows average activity concentration for 238U, 232Th, and 40K in Gadaeragi mining site are 8.05 ± 0.14 Bq/kg, 14.60 ± 0.30 Bq/kg and 20.62 ± 14.62 Bq/kg respectively. The result shows average activity concentration for 238U, 232Th and 40K in Maiwayo mining site to be 12.03 ± 0.17 Bq/kg, 17.89 ± 0.32 Bq/kg and 151.11 ± 10.04 Bq/kg respectively. Furthermore, the results shows average activity concentration for 238U, 232Th and 40K in Kataeragi mining site are 6.39 ± 0.13 Bq/kg, 13.25 ± 0.29 Bq/kg and 154.87 ± 10.77 Bq/kg respectively. The average activities concentration of 238U, 232Th, and 40K for the three mining sites shows MW>GR>KR, MW>GR>KR and GR>KR> MW respectively. The activity concentrations was  found to be below worldwide accepted average values of 33 Bq/kg, 45 Bq/kg and 420 Bq/kg for 238U, 232Th, and 40K  respectively. The Annual Effective Dose Equivalent for GR, MW and KR mining sites was found to be 0.16, 0.17 and 0.13 mSv/y respectively, which were below the 1.00 mSv/y threshold stipulated by UNSCEAR [1]. Therefore, the mining sites are safe in terms of radiological hazard. The entire environment is within the permissible dose limit for the workers of the mining sites and also for agriculture and construction buildings. Therefore, the mining sites are safe in terms of radiological hazard.