en Radiation Biology Radiation Biology تحقيق بديع Original Research <p dir="ltr" style="text-align: justify;"><strong>Background:</strong> Natural radionuclides are always present in the environment. Human exposure to the background radiation is inevitable. It is therefore important to assess health risk associated with these radionuclides.<strong> Materials and Methods:</strong> The distribution of natural radionuclides ²³⁸U, ²³²Th and ⁴⁰K in soil samples collected from all the twenty (20) local Governments headquarter areas in Ogun state, Nigeria were determined by gamma spectroscopy using a high-purity germanium detector. The measured concentrations were used in estimating the radiological risk pose to people living in these communities. <strong>Results: </strong>The activity concentrations measured ranged between 3 &plusmn; 1 Bqkg^-1(Otta) to 27 &plusmn; 6 Bqkg^-1(odeda) for ²³⁸U, 10 &plusmn; 1 Bqkg^-1(Otta) to 126 &plusmn; 6 Bqkg^-1(Ijebu Igbo) for ²³²Th and 7 &plusmn; 6 Bqkg^-1(Aiyetoro) to 497 &plusmn; 1 Bqkg^-1(Odeda) for ⁴⁰K. The mean radium equivalent calculated was 77.6 Bqkg^-1 which is lower than 370 Bqkg^-1 of the world average and the hazard indices calculated were lower than unity. <strong>Conclusion:</strong> The absorbed rate and annual effective dose estimated for most of the locations are in good agreement with world average values except for Akomoje, Ake-Abeokuta, Ogere, Ijebu-Igbo and Odeda.&nbsp;</p> <p></p> Natural radioactivity, absorbed dose rate, radium equivalent, hazard indices, Ogun State 355 361 http://ijrr.com/browse.php?a_code=A-10-1-583&slc_lang=en&sid=1 Mojisola Usikalu moji.usikalu@covenantuniversity.edu.ng 790031947532846007646 790031947532846007646 Yes Department of Physics, Covenant University P.P. Maleka 790031947532846007647 790031947532846007647 No Environmental Radioactivity Laboratory M. Malik 790031947532846007648 790031947532846007648 No Material Science Department K.D. Oyeyemi 790031947532846007649 790031947532846007649 No Department of Physics, Covenant University O.O. Adewoyin 790031947532846007650 790031947532846007650 No Department of Physics, Covenant University