The transfer factors of radionuclides (226 Ra, 238 U, 232 Th, 40 K and fallout radionuclides 137 Cs) from soil to plant and grass collected from the northwest of West Bank environment-Palestine were measured. For soil to plant, the average transfer factor (TF) values were found to be 0.60, 0.50, 0.31, and 1.70 for 226 Ra, 238 U, 232 Th and 40 K respectively. For soil to grass the TF values were found to be 1.26, 1.12, 1.15 and 1.20 for 226 Ra, 238 U, 232 Th and 40 K respectively. For soil to plant, the average transfer factor values were found to be 0.27 for fallout radionuclides 137 Cs. The TF showed wide variation in different species, while a few species of plants indicated preferential uptake of these radionuclides. TF average values from soil to grass were found to be higher than from soil to plant. Results showed that part of the total 226 Ra in agricultural soils were from phosphate fertilizers. Because the species of plants were directly involved in the human food chain, information on the concentration level and transfer of radionuclides from soil to plants will provide important data for the environmental risk assessment in such zones. These results have been compared with those of different countries of the world.

The activity concentrations of naturally occurring radioactive materials such as (226)Ra, (238)U, (232)Th, (40)K and (137)Cs were measured for 44 plant samples collected from different locations in the northwestern region of the West Bank, Palestine, using high-resolution gamma ray spectroscopy. The activity concentrations of radionuclides in the investigated plant samples ranged from 7.5 to 157.6 Bq kg(-1) for (226)Ra, 7.5 to 66.1 Bq kg(-1) for (238)U, 1.8 to 48.5 Bq kg(-1) for (232)Th, 14.3 to 1622 Bq kg(-1) for (40)K and <0.1 to 4.7 Bq kg(-1) for (137)Cs. The average values of these activities were 48.3, 26.5, 10.1, 288.0 and 2.2 Bq kg(-1), for (226)Ra, (238)U, (232)Th, (40)K and (137)Cs, respectively. The study presents the total gamma radiation dose rate assessed from natural radionuclides,(137)Cs and cosmic radiation, the dose rate of each radionuclide and the effective dose for all the samples. The radiological health implication to the population that may result from these doses is found to be low, except in few cases. The measurements have been taken as representing a baseline database of values of these radionuclides in the plants in the area.