Geospatial distributions of natural radioactivity in kwara state, nigeria using airborne gamma ray spectrometry data

This study aims to delineate spatial variations in natural radionuclide concentrations—specifically potassium (K), thorium (Th), and uranium (U) across Kwara State, Nigeria, using airborne gamma ray spectrometry data. The radiometric data, obtained from the Nigerian Geological Survey Agency under the World Bank-supported Sustainable Management of Mineral Resources Project (SMMRP), were processed using Oasis Montaj software to generate spatial distribution maps and a composite ternary map. Results reveal that potassium concentrations range from 0.0% to over 2.20%, with the highest levels observed in Ilorin and Afon. Thorium concentrations vary from 6.7 ppm to over 19.0 ppm, with elevated levels in the north-central and southeastern regions, particularly in Agbamu and Ira. Uranium concentrations span 0.0 ppm to 4.2 ppm and above, with notable hotspots in Agbamu, Ilorin, Oro, and Ira. These elevated concentrations, especially in the northwestern and central zones, indicate areas of potential environmental and health concern. The ternary map highlights regions with composite high radioelement content, particularly in white-shaded zones, suggesting potential for elevated radiation exposure, including gamma dose rates and radon gas accumulation. Comparisons with previous studies indicate that Kwara State has a relatively higher natural radiological footprint than regions like the Niger Delta, Ogun State, and parts of Egypt. This study offers critical baseline data for environmental monitoring, land use planning, and public health interventions. It also provides a foundation for future ground-based investigations and the calculation of radiological hazard indices across the state.