The plant transfer factor of natural radionuclides and the soil radiation hazard of some crops

In the present study, the transfer factors of the natural radionuclides 238U, 232Th, and 40K were estimated for several crops cultivated in farms in the suburbs of Baghdad and one farm in Al-Najaf. The transfer factor (TF) is the ratio of activity transfers from soil to plant. The specific activities of the natural radionuclides were measured with a gamma-ray spectrometer with a HPGe detector. The crops include cereals (rice and wheat), fruits (lemons and oranges), podded vegetables (vigna and okra), fruity vegetables (chili peppers and Solanum melongena), and leafy vegetables (Apium graveolens, Raphanus sativus, and Ocimum basilicum). The results showed that the highest transfer factors for 238U, 232Th, and 40K are 0.32, 0.70, and 3.44, respectively, in wheat. The average transfer factors for 238U and 232Th were founded 0.23 and 0.2 which are lower than the default unitiy value but the 1.85 were reported for 40K higher than unity.