• John Actor Ocheje
• Franca Oyiwoja Oko

Background: In many developing countries like Nigeria, farmlands are contaminated by human activities like; mining, waste disposal, industrial waste, agricultural practices, use of inorganic fertilizers, sewage, sludge, and other anthropogenic activities that have affected man and the environment. In this research work, the activity concentrations of natural radionuclides, transfer factors (TF) from soil to crops, absorbed dose rate (ADR), and excess lifetime cancer risk (ELTCR) have been evaluated in soil and crop samples from twenty places in Nasarawa state, Nigeria. Materials and Method: High purity Germanium (HpGe) detector was used to determine the activity concentration of radionuclides. The absorbed dose rate and ELTCR. Results: The mean activity concentrations of 40K, 232Th, and 238U in the soil samples were 408.69, 24.08, and 30.71 Bq kg−1, respectively, while the average activity concentration of 40K, 232Th, and 238U in crop samples were 142.63, 46.06, and 17.45 Bqkg−1, respectively. The Raeq concentration, the external, and internal hazard indices were evaluated and ranged from 81.77 to 159.09 Bqkg−1, 0.22 to 0.43, and 0.28 to 0.53, with average values of 115.50, 0.31, and 0.40Bqkg−1, respectively. The mean TF for 40K, 232Th, and 238U of the study area were 0.053, 0.369, and 0.366, respectively. The mean for the ADR and annual outdoor effective dose equivalent in soil samples were 105.88 nGyh−1 and 0.13 mSvy−1. The mean AEDR for the study area is higher than the safety limit. The ELTCR ranged from 0.17 ×10−3 to 1.16 ×10−3, with a mean of 0.46 ×10−3. This value is above the average value approved by UNSCEAR 2000. Conclusion: Analysis of238Uand 232Th recorded the highest soil to crop TF compared to 40K in the area. Correlation analysis showed a strong positive correlation between activity concentration of radionuclides in soil and crop for 40K and 232Th and a weak correlation for 238U due to soil type and microbial activities in most of the study area. To save the farmland from further pollution, organic manure should be encouraged, and instructions on the usage of inorganic fertilizer and agrochemical should be ad held strictly to avoid over-usage.

Radionuclide, absorbed dose, transfer factor, excess lifetime cancer risk, activity concentration.

"Evaluation of radionuclide content on farmlands, using radiation dose parameters in Nasarawa State, Nigeria.", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.10, Issue 7, page no.b418-b426, July-2023, Available :http://www.jetir.org/papers/JETIR2307153.pdf

"Evaluation of radionuclide content on farmlands, using radiation dose parameters in Nasarawa State, Nigeria.", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.10, Issue 7, page no. ppb418-b426, July-2023, Available at : http://www.jetir.org/papers/JETIR2307153.pdf