en Radiation Biology Radiation Biology گزارش کوتاه Short Report <p style="text-align: justify;">Background: Measurement of the radiation dose distribution is important in assessing the health risk a population and serve as reference in documenting changes to environmental radioactivity in soil due to man-made activities. Materials and Methods: The activity concentration of ²³⁸U, ²³²Th and ⁴⁰K in soil samples obtained from different locations in Ajaokuta Local Government area was measured using Hyper Pure germanium Detection System (HPGe). Results: The calculated average concentration of the radionuclides ranged from 12 &plusmn; 1 Bqkg^-1 to 59 &plusmn; 2 Bqkg^-1 for ²³⁸U, 14 &plusmn; 1 Bqkg^-1 to 78 &plusmn; 5 Bqkg^-1 for ²³²Th and 49 &plusmn; 2 Bqkg^-1 to 1272 &plusmn; 23 Bqkg^-1 for ⁴⁰K. In order to evaluate the radiological hazards due to natural radionuclides within Ajaokuta, the absorbed dose rate, gamma index, radium equivalent and excess lifetime cancer risk were estimated. According to measured data from the top soil (0-10 cm), the estimated radium equivalent (Ra_eq) ranges from 55.7 Bqkg^-1 at Steel Complex to 253.3 Bqkg^-1 obtained from Forest samples. Conclusion: The mean absorbed dose rate, annual effective dose and gamma radiation index evaluated were 66.2 nGyh^-1, 81.2 &micro;Svy^-1 and 1.05 respectively which are higher than the recommended limit for normal background radiation. Thus, we conclude that people living in these locations may be exposed to higher radiation.</p> <p></p> Radiation hazard, gamma index, excess lifetime cancer risk, soil, Ajaokuta. 219 224 http://ijrr.com/browse.php?a_code=A-10-1-669&slc_lang=en&sid=1 M.R. Usikalu moji.usikalu@covenantuniversity.edu.ng 790031947532846009732 790031947532846009732 Yes Department of Physics, Covenant University, P.M.B 1023, Otta, Ogun State, Nigeria A.B. Rabiu 790031947532846009733 790031947532846009733 No Centre for Atmospheric Research, NASRDA, Kogi State University, Ayimgba, Nigeria K.D. Oyeyemi 790031947532846009734 790031947532846009734 No Department of Physics, Covenant University, P.M.B 1023, Otta, Ogun State, Nigeria J.A. Achuka 790031947532846009735 790031947532846009735 No Department of Physics, Covenant University, P.M.B 1023, Otta, Ogun State, Nigeria M. Maaza 790031947532846009736 790031947532846009736 No Material Science Department, iThemba Labs, Somerset West, South Africa