en Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;">Background: This work investigated the transfer factor of radionuclides from clay loam soil to sesame and cowpea plants. Materials and Methods: Twenty samples from the plant and twenty samples from its soil were collected from five different locations (farms). Gamma-ray spectrometry was used to determine the activity concentration for the samples. In addition, the soil physicochemical characteristics such as pH value, the amount of organic content and texture of soil were investigated by pH meter, Walkley-Black and particle size distribution (Pipette) methods, respectively. Results: The average activity concentrations, respectively, of ²²⁶Ra, ²³²Th, and ⁴⁰K were 12.75, 10.20 and 131.75 Bq kg^-1 for the clay loam soil, 5.20, 4.15 and 171.00 Bq kg^-1 for sesame and 6.70, 5.60 and 182.90 Bq kg^-1 for cowpea. The transfer factor from soil to sesame and cowpea was discussed. The average values of transfer factor were 0.51, 0.53 and 1.36 (for cowpea) and 0.42, 0.43 and 1.33 (for sesame), respectively for ²²⁶Ra, ²³²Th and ⁴⁰K. The results showed that the transfer factor in cowpea is much greater than that in sesame. As a result of the ingestion of the radionuclides from the plants, the average annual dose was lower than the 290 &mu;Sv y^-1 world average. Conclusion: Accordingly, the radiological risk due to the intake of the natural radionuclides in these plants was immaterial.</div> Natural radionuclides, clay Loam soil, transfer factor, radiological hazards. 157 166 http://ijrr.com/browse.php?a_code=A-10-1-851&slc_lang=en&sid=1 R. Elsaman reda_m8282@yahoo.com, 7900319475328460015444 7900319475328460015444 Yes Physics Department, Faculty of Sciences, Al-Azhar University, Assiut, 71524, Egypt G.A.M. Ali gomaasanad@azhar.edu.eg, 7900319475328460015445 7900319475328460015445 No Chemistry Department, Faculty of Science, Al-Azhar University, Assiut, 71524, Egypt M.A.M. Uosif 7900319475328460015446 7900319475328460015446 No Physics Department, College of Science, Jouf University, P.O. Box: 2014, Sakaka, Saudi Arabia A. El-Taher 7900319475328460015447 7900319475328460015447 No Physics Department, Faculty of Sciences, Al-Azhar University, Assiut, 71524, Egypt K.F. Chong ckfeng@ump.edu.my 7900319475328460015448 7900319475328460015448 No Faculty of Industrial Sciences & Technology, Universiti Malaysia Pahang, Gambang, 26300 Kuantan, Malaysia