Radiological assessment of rock samples at the national iron ore mining company (NIOMCO) itakpe in kogi state, nigeria

Abstract

Mining activities that involve the extraction of mineral ores have the potential to release naturally occurring radionuclides into the surrounding environment, thereby posing elevated health risks to mine workers and nearby communities. This study presents the results of measurements of the activity concentrations of primordial radionuclides in rock samples collected from the National Iron Ore Mining Company (NIOMCO), Itakpe, situated in Kogi State, north central Nigeria. A NaI(Tl) based gamma ray spectroscopy system was employed for the radiometric analysis. The activity concentrations of 238U ranged from 1.00±0.15 Bq/kg to 8.26±1.02 Bq/kg, those of 232Th varied between 3.46±0.21 Bq/kg and 6.85±0.42 Bq/kg, while 40K values spanned from 4.36±0.24 Bq/kg to 252.11±13.91 Bq/kg. The mean activity concentrations for all three radionuclides fell below the globally recommended averages established by the United Nations Scientific Committee on the Effects of Atomic Radiation. The computed absorbed dose rates and annual effective doses likewise remained within permissible thresholds, indicating no immediate radiological threat to the surrounding population. These findings contribute baseline data that are essential for ongoing environmental radiation monitoring in mining regions of Nigeria. Keywords: Activity concentration; naturally occurring radioactive materials; absorbed dose; gamma ray spectroscopy; iron ore mining; radiological hazard