Transfer Factors Of Natural Radionuclides Analysis

Transfer Factors of Natural Radionuclides
The results of the transfer factors (TF) of 40K, 238U and 232Th are presented from table 4.1 – 4.33. The geometric mean and the geometric standard deviation for each table were calculated using equations 2.47 and 2.49. Since the TFs are the ratios of the concentrations in plant and soil respectively, the geometric mean is used because it is the most appropriate when calculating the mean of ratios. All the values of the TFs stated below are respectively for 40K, 238U and 232Th with the geometric mean and the corresponding geometric standard deviation given in parenthesis. A two-way analysis of variance (ANOVA) was used to test for the significance of the variations observed in the transfer factor values.
4.1.2.1
The TF of cassava tubers harvested from soil group A varied between BDL – 0.47 (0.35  1.34), BDL for all samples and BDL – 0.41 (0.15  2.61); cassava stems varied from 0.16 – 0.62 (0.29  1.85), a single value of 0.04 and from BDL – 0.42 (0.33  1,30) while cassava leaves varied from BDL – 1.61 (0.56  2.86), BDL – 0.41 (0.13  2.17) and BDL – 1.79 (0.77  4.27) respectively for 40K, 238U and 232Th.
(ii) Parts of Cassava plants harvested from Soil Group B
The TF values of 40K, 238U and 232Th for cassava tubers, stems, and leaves harvested from soil group B are presented from tables 4.28 – 4.30. The TF of cassava tubers varied between BDL – 0.01 (0.005  1.84), BDL for all samples and BDL – 0.24 (0.06  2.32); cassava stems varied from BDL – 0.01 (0.006  1.54), a single value of 0.006 and from 0.01 – 0.06 (0.04  1.95) while cassava leaves varied from BDL – 0.16 (0.07  2.20), a single value of 0.01 and BDL – 0.17 (0.05  2.77) respectively for 40K, 238U and