Publication Date: 2023/07/21
Abstract: Nigeria as one of the developing countries, has most of its farmlands contaminated by human activities like; mining, waste disposal, industrial waste, agricultural practices, use of inorganic fertilizers, sewage, sludge, and other anthropogenic activities. This research work evaluated the activity concentrations of natural radionuclides, and excess lifetime cancer risk (ELTCR) in soil and crop samples from twenty locations of farmlands in Nasarawa state, Nigeria. High purity Germanium (HpGe) detector was used to determine the activity concentration of radionuclides. The absorbed dose rate and ELTCR for 60 years were forecasted and evaluated using the ResRad off-site computer model. 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 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.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, the total cancer risks in the zone, particularly in Akwanga and Doma, were higher than the safety limits. Excessive use of organic fertilizer on farmland should be checked from time to time.
Keywords: Radionuclide, Res Rad Off-Site Model, Excess Lifetime Cancer Risk, Activity Concentration.
DOI: https://doi.org/10.5281/zenodo.8171251
PDF: https://ijirst.demo4.arinfotech.co/assets/upload/files/IJISRT23JUN2317.pdf
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