Determination of Transfer Factor for Some Crops in Selected Cultivated Soils, Khidir City, Iraq

Abstract

The current study dealt with the activity concentrations of some radionuclides in several common plants and corresponding soils in Khidir City, Iraq. The radioactivity measurements are carried out for 226Ra, 232Th, and 40K in some consumable crops and their soils using gamma spectrometry with an HP germanium detector. The sampling process included 8 crops, averaging 7 samples for each plant and surrounding soils equally. The studied crops consisting of okra, onions, cucumber, tomatoes, eggplant, sweet potato, zucchini, and organic pepper showed obvious variability as follows: the activity levels of 226Ra varied from 0.16±0.1 Bq/kg (in eggplant) to 3.984±0.19 Bq/kg (in tomato), with an average of 1.57±0.14 Bq/kg. 232Th were found to be within the range of (0.023±0.01 - 2.93±0.19 Bq/kg) (in onions – in cucumber), and an average value of 0.80±0.12 Bq/kg. For 40K ranged between 87.801±2.24 Bq/kg (in cucumber) and 409.45±2.94 Bq/kg (in tomato), with an average of (273.53±2.43 Bq/kg). On the other hand, the radionuclides activity concentrations in the corresponding soils ranged between 4.644±0.24 Bq/kg, with an average of 16.124±0.50 Bq/kg for 226Ra, and from 1.315±0.11 Bq/kg to 22.783±0.61 Bq/kg, with a mean value of 8.32±0.32 Bq/kg for 232Th, and from 284.482±2.48 Bq/kg to 451.468±3.93 Bq/kg, with a mean value of 406.53±2.77 for 40K. The concentrations of 226Ra and 232Th in the plants and soil samples were lower than the permissible values reported by UNSCEAR. In contrast, the activity level of 40K exceeded the allowed level suggested by UNSCEAR. Moreover, the obtained data were statistically analyzed and discussed in detail. Furthermore, the soil-to-plant transfer factors were calculated for the crops under study. TF of 226Ra was found to be within the range of (0.056-0.143), with an average of 0.095, for 232Th ranged between 0.056 and 0.192, with an average of 0.101, while for 40K, it is found to be varied from 0.933 to 0.216, with an average of 0.669. transfer factors of all crops were lower than the unity value conducted by IAEA.