Natural Radioactivity in Farmland Soils and Soil-to-Cereal Transfer of Primordial Radionuclides in Chikun Local Government Area, Kaduna State, Nigeria

Radionuclides that are naturally present in agricultural soils have the potential to spread to food crops and provide a route for radiation exposure to humans. In Chikun Local Government Area, Kaduna State, Nigeria, this study assessed the activity concentrations of ⁴⁰K, ²²⁶Ra, and ²³²Th in farming soils and their transfer to certain cereal crops. Four farming villages (Kujama, Rido, KRPC Perimeter, and Sabon Tasha) provided samples of composite soil and related cereal crops (sorghum, millet, and maize). Gamma-ray spectroscopy was used to measure radioactive activity concentrations, and soil-to-cereal transfer factors (TFs) were computed to evaluate radionuclide uptake. Spatial and crop-related changes were assessed using descriptive statistics and one-way analysis of variance (ANOVA). With activity concentrations ranging from 365.24 ± 28.61 to 421.68 ± 34.92 Bq kg⁻¹, the data indicated that the most common radionuclide in the soils was ⁴⁰K. This was followed by ²³²Th (46.53 ± 7.85–58.91 ± 9.36 Bq kg⁻¹) and ²²⁶Ra (31.82 ± 5.74–41.76 ± 7.63 Bq kg⁻¹). Geological enrichment was suggested by the fact that ²³²Th surpassed the global norm, although ⁴⁰K and ²²⁶Ra were generally within the global reference range. The order of the soil-to-cereal transfer factors was ⁴⁰K > ²²⁶Ra > ²³²Th, with maize showing the lowest radioactive uptake and sorghum the highest. Significant variations in transfer factors across cereal crops (⁴⁰K: p = 0.012; ²²⁶Ra: p = 0.021; ²³²Th: p = 0.038) and radionuclide activity concentrations among sampling locations (⁴⁰K: p = 0.014; ²²⁶Ra: p = 0.028; ²³²Th: p = 0.007) were found using one-way ANOVA. The data reveal that local geology greatly influences radioactive distribution and that radionuclide transmission to cereals is crop-dependent. The produced baseline data are useful for radiological risk assessment, environmental radioactivity monitoring, and the creation of evidence-based plans to guarantee food safety and sustainable agricultural output in the research region.

Naturally occurring radionuclides; Farmland soil; Soil-to-cereal transfer factor; Gamma-ray spectrometry; Environmental radioactivity; Chikun LGA.

1. Chen, J. (2026). A brief summary of UNSCEAR evaluation on public exposure to ionizing radiation and research needs. Radiation Medicine and Protection. [Google Scholar] [Crossref]

2. Carvalho, F. P., Oliveira, J. M., & Malta, M. (2016). Preliminary assessment of uranium mining legacy and environmental radioactivity levels in Sabugal region, Portugal. International Journal of Energy and Environmental Engineering, 7(4), 399-408. [Google Scholar] [Crossref]

3. Ujwal, P., Yashodhara, I., Sudeep Kumara, K., Ravi, P. M., & Karunakara, N. (2022). Environmental transfer parameters of strontium for soil to cow milk pathway for tropical monsoonal climatic region of the Indian subcontinent. Scientific reports, 12(1), 7528. [Google Scholar] [Crossref]

4. Isinkaye, M. O., OlaOlorun, O. A., Chandrasekaran, A., Adekeye, A. S., Dada, T. E., Tamilarasi, A., ... & Sulieman, A. (2023). Quantification of radiological hazards associated with natural radionuclides in soil, granite and charnockite rocks at selected fields in Ekiti State, Nigeria. Heliyon, 9(11). [Google Scholar] [Crossref]

5. Balonov, M., Barnett, C. L., Belli, M., Beresford, N. A., Berkovsky, V., Bossew, P., ... & Velasco, R. H. (2010). Handbook of parameter values for the prediction of radionuclide transfer in terrestrial and freshwater environments. International Atomic Energy Agency. [Google Scholar] [Crossref]

6. Popoola, O. J., Olubi, O. E., Adewalure, O. S., & Raphael, A. E. (2025). Elevated natural radionuclides in soils and stream sediments: pollution, spatial distribution, radiological hazards, and cancer risks in peri-urban Emure-Ekiti, southwest Nigeria. Discover Soil, 2(1), 70. [Google Scholar] [Crossref]

7. Kanmi, A. S., Ibrahim, U., Goki, N. G., Rilwan, U., Sayyed, M. I., Maghrbi, Y., ... & Wais, T. Y. (2025). Assessment of natural radioactivity and its radiological risks in the soil of local government areas (Asa, Ilorin East, Ilorin South, Irepodun, Moro, and Oyun) in Kwara State, Nigeria. Case Studies in Chemical and Environmental Engineering, 11, 101040. [Google Scholar] [Crossref]

8. Doering, C., Twining, J., Rout, S., Iurian, A. R., & Howard, B. (2021). A revised IAEA data compilation for estimating the soil to plant transfer of radionuclides in tropical environments. Journal of environmental radioactivity, 232, 106570. [Google Scholar] [Crossref]

9. Wais, T. Y., Namq, B. F., Najam, L. A., Othman, S. Q., Hussein, Z. A., Al-Taii, H. A., ... & Kumar, A. (2025). Investigation of natural radionuclide transfer from soil to wheat. Scientific Reports, 15(1), 35785. [Google Scholar] [Crossref]

10. Dirican, A., Dikmen, H., Şahin, M., Gülay, Y., Özkök, Y. Ö., Kaya, N., & Vural, M. (2024). Transfer factors of 238U, 232Th, 40K, 210Pb to crops and radiation impact assessment in semi-arid environment. Journal of Radioanalytical and Nuclear Chemistry, 333(11), 5597-5606. [Google Scholar] [Crossref]

11. Olowomofe, O., & Faweya, B. Radionuclide Transfer from Soil to Crops and Health Risk Assessment in Fertilized Farmlands of Benue State, Nigeria. [Google Scholar] [Crossref]

12. United Nations Scientific Committee on the Effects of Atomic Radiation. (1982). Ionizing radiation: sources and biological effects. 1982 report to the general assembly, with annexes. [Google Scholar] [Crossref]

13. Essien, I., Akankpo, A., Nyong, A., & Inyang, E. (2021). Determination of activity concentrations and soil to cassava transfer factors of natural radionuclides in Ikot Ekpene Local Government Area, Akwa Ibom State, Nigeria. Journal of Geography, Environment and Earth Science International, 25(7), 28-35. [Google Scholar] [Crossref]

14. Isibor, J. G., Ibrahim, U., Yusuf, S. D., Mustapha, I. M., & Mundi, A. A. (2025). Radioactivity Concentrations in Soil and Plants Farmed Around Crude Oil Producing Areas of Edo State, Nigeria. [Google Scholar] [Crossref]

15. Orosun, M. M., Usikalu, M. R., Oyewumi, K. J., Omeje, M., Awolola, G. V., Ajibola, O., & Tibbett, M. (2022). Soil-to-plant transfer of 40K, 238U and 232Th and radiological risk assessment of selected mining sites in Nigeria. Heliyon, 8(11). [Google Scholar] [Crossref]

• Enhancing Formation Control of Multi Agent Systems Using Ann Based Technique
• Improving Sliding Mode Control with Chattering Reduction using Fuzzy Based Technique
• Cooking Quality, Fasting Blood Glucose, Glycemic Index and Load of High–Fiber Noodles Made from Wheat, Tiger Nut Residue and Cassava Flour Blends
• Matrix Rhythm Therapy Versus Interferential Therapy Combined with Lumbar Stabilization Exercises in Chronic Non-Specific Low Back Pain: A Randomized Comparative Trial
• Formulation and Sensory Evaluation of Functional Cake Prepared from Sweet Potato Powder