Determination of Soil-to-Plant Transfer Factors for Ra-226 and Ra-228 in Some Egyptian Crops

Soil to plant transfer factors (TFs) of 226Ra and 228Ra have been determined for different crops, such as Cabbage, Cucumber, Kale, Aubergine, Pepper, Zucchini and Tomato. The crops were collected from some local farms in Al-Qalyubia governorate Egypt under outdoor ambient tropical conditions for two growing seasons 2014 amp 2015. The crops samples and their corresponding soils were analysed for 226Ra and 228Ra using High Purity Germanium Detector (HPGe). Quality assurance objectives were followed through the efficiency calibration of the HPGe detector, background estimation, assessment of combined uncertainties and the analyses of IAEA certified soil and plant reference materials. The total activity concentrations of 226Ra(238U), 232Th and 40K in soil were ranged from 6plusmn1.2 to 87.5plusmn4.5, 3.8plusmn1.2 to 19.3plusmn2.0 and 91.3plusmn4.1 to 781.8plusmn37 Bq kg-1 respectively. The average activities of 226Ra and 228Ra in the crops under this investigation ranged from 0.1 to 2.8 and 0.2 to 13.9 Bq kg-1 dry weight respectively. Cabbage and Cucumber showed maximum concentration ratios of 0.07 for 226Ra whereas for 228Ra Cabbage and Aubergine had relatively higher values of 0.13. The results obtained are within the range of the corresponding values reported by IAEA in 1994 amp 2010. The present work may provide a database of TFs for these agricultural environments to be used in radiological safety assessment models