Spatial distribution and soil-to-plant transfer factors of radionuclides in agricultural soil around the Barapukuria coal mining site, Bangladesh.

In order to investigate the level of radioactivity and translocation of radionuclides from soil to plants, fifteen agricultural soil and fifteen edible plant samples grown in soils were collected from Barapukuria coal mining area, Bangladesh. The physicochemical properties (pH, EC, %OC, %OM, %N, %P, and N/P) were evaluated and the XRD patterns of soil samples were obtained. The gamma activity of U, Th, and K in soil and plant samples was analyzed by gamma-ray spectroscopy with an HPGe detector. The activity concentrations in soil samples varied in the order of K > U > Th. The gross alpha and gross beta activity were also measured by using a ZnS(Ag) scintillation counter. The average gross alpha and gross beta activity in soil and plant samples were found to be 119 ± 4 Bq kg and 384 ± 17 Bq kg, and 35.49 ± 1.94 Bq kg and 249 ± 10 Bq kg, respectively. The calculated mean transfer factors (TFs) for U, Th, and K were 0.21, 0.20 and 0.32, respectively. Spinach () had the highest uptake of U (TF value of 0.30), while cauliflower () showed the greatest (TF value of 0.08). Nonetheless, in the cases of Th and K, the highest TFs were observed for malabar spinach () (TF value of 0.31) and green pea leaf () (TF value of 0.45). According to the radiation hazard assessment, the levels were often lower than the UNSCEAR world-average values. The contamination factor (CF) indicates that the soil samples were moderately contaminated by U. Correlation analysis revealed that Th was mostly responsible for radiation health hazards, whereas for plant samples, K was responsible for the internal hazard index.