Radiological Impact Assessment of Mine-Residue from Coal Mining Sites at Awulu-Ika, in Kogi, North-central Geopolitical Region of Nigeria

Coal, as a fossil fuel, plays a vital role in the economic development of nations globally. However, the radiological impact due to coal mining may pose significant health risks to humans. Consequently, it is important to evaluate the radiological impact of coal mining in various regions worldwide. This study focuses on Awulu-Ika in Kogi, Nigeria's north-central geopolitical region, as a representative case. Sixty-two (62) mine-residue samples were randomly collected from the study area, and the activity concentrations of ⁴⁰K, ²²⁶Ra and ²³²Th were measured using a well-calibrated NaI (Tl) detector. Radiological parameters, including gamma absorbed and effective dose rates as well as hazard indices, were calculated using the activity concentrations of the radionuclides obtained in the study. The activity concentrations of ⁴⁰K ranged from below detectable levels (BDL) to 504.2 Bq/kg, ²²⁶Ra ranged from BDL to 193.8 Bq/kg, and ²³²Th ranged from BDL to 115.8 Bq/kg. The mean activity concentration of each radionuclide in the samples was lower than the world-recommended values. The mean effective dose rate of 26.21 μSv/year obtained in the study is significantly below the value recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Although the radioactivity levels in the mine residues are low and may not pose any short-term radiological health effects, long-term exposure to radiation in the area, as well as in similar regions globally, may be detrimental to human health. This underscores the importance of continuous monitoring and assessment of radiological impacts in coal mining areas worldwide to ensure public health safety.