Assessment of geogenic natural radionuclide contentsudof soil samples collected from Ogun State, Southudwestern, Nigeria

摘要

Background: Natural radionuclides are always present in the environment.udHuman exposure to the background radia�on is inevitable. It is thereforeudimportant to assess health risk associated with these radionuclides. Materialsudand Methods: The distribu�on of natural radionuclides 238U, 232Th and 40K inudsoil samples collected from all the twenty (20) local Governmentsudheadquarter areas in Ogun state, Nigeria were determined by gammaudspectroscopy using a high-purity germanium detector. The measuredudconcentra�ons were used in es�ma�ng the radiological risk pose to peopleudliving in these communi�es. Results: The ac�vity concentra�ons measuredudranged between 3 ± 1 Bqkg-1(O0a) to 27 ± 6 Bqkg-1(odeda) for 238U, 10 ± 1udBqkg-1(O0a) to 126 ± 6 Bqkg-1(Ijebu Igbo) for 232Th and 7 ± 6 Bqkg-1(Aiyetoro)udto 497 ± 1 Bqkg-1(Odeda) for 40K. The mean radium equivalent calculated wasud77.6 Bqkg-1 which is lower than 370 Bqkg-1 of the world average and theudhazard indices calculated were lower than unity. Conclusion: The absorbedudrate and annual effec�ve dose es�mated for most of the loca�ons are in goodudagreement with world average values except for Akomoje, Ake-Abeokuta,udOgere, Ijebu-Igbo and Odeda.