Abstract
Nuba Mountains, South Kurdufan State, Sudan, includes vital areas for domestic, agricultural, and grazing activities. Unfortunately, several sites in Nuba Mountains have been characterized by its high radioactivity. This study aims at addressing the activity concentrations and soil-to-plant transfer factors (TF) of U-238, (210)pb, and Po-210 in soil and crops (fruits, vegetables, cereals, and oil seeds) in eight sites in Meeri district, Nuba Mountains, Sudan, besides two sites considered as a control area. While Pb-210 and Po-210 activity concentrations were determined using gamma-ray spectrometry, U-238 activity concentrations were deteintined using fluorimetry. The range of activity concentrations (Bq/kg) in soil samples were found to be in the following ranges: U-238 0.1-1.1, Pb-210 0.1-2.5, and Po-210 0.3-1.1, whereas the activity concentrations (Bq/kg) in crops were found to be in the following ranges: U-238 0.0-0.1, Pb-210 0.1-1.5, and Po-210 0.1-0.9. The cluster analysis classified the examined sites into four clusters; one cluster represented the control area. The mean (210)po/Pb-210 ratio in soil was 0.96, while that in in crops were in the range of 0.60-0.9, suggesting secular equilibrium. The TFs were found to be as follows: U-238 0.00-1.00, Pb-210 0.20-1.83, and Po-210 0.24-1.00. The activity concentrations of the examined nuclides as well as the TFs were all above the global mean levels reported by the International Atomic Energy Commission. The study concluded that the consumption of crops in the study area may put human at risk due to high levels of the radiotoxic nuclides.