Radiological Hazard Assessment due to Natural Background Radiation in Yewa South Local Government Area, Ogun State, NigeriaGovernment Area, Nigeria.


  • Inioluwa Oladipupo Olowofila The Federal Polytechnic Ilaro



Annual Effective Dose, Annual Gonadal Dose Equivalent, Activity concentration, Gamma Ray Spectrometry, Radionuclide, Radium Equivalent.


The radiological hazard assessment due to the Natural Background Radiation in the Yewa South Local Government area has been carried out. Twenty (25) soil samples were collected from selected towns in Yewa South which include Idogo, Ilaro, Itolu, Iweke and Owode. The collected samples were air-dried, pulverized and homogenized before being analysed by gamma ray spectrometry. The mean activity concentration of 226Ra, 232Th and 40K in soil samples were 12.9 ± 3.38, 6.40 ± 0.37 and 91.45 ± 4.63 Bq/kg respectively for Idogo; 5.72 ± 0.33 and 70.71 ± 3.60 to 148.40 ± 7.82 Bq/kg respectively for Ilaro; 24.66 ± 2.75, 5.35 ± 1.32 and 80.97 ± 4.12 Bq/kg for Itolu; 7.91 ± 1.02, 4.42 ± 0.28 and 105.25 ± 5.36 Bqkg-1 for Iweke and 26.20 ± 3.25, 4.84 ± 0.29 and 61.68 ± 3.26 Bqkg-1 for Owode. The mean activity concentration values of 226Ra and 232Th and 40K obtained from all study sites were lower than their respective world average values of 35 and 30 Bqkg-1 and 400Bqkg-1 [12]. The average absorbed dose rates at 1m above the ground delivered to the general public of the study areas were all lower than the world average value of 58 nGyh-1. The average values of Radium Equivalent (Raeq) for all the study areas were found to be below the world average of 370Bqkg-1 and the computed mean Annual effective dose (AED) from all study sites was also found to be below the safety limit of unity. Thus, based on the results obtained from this study, no hazardous radiological effects are posed to the populace in the vicinity of the investigated locations.

Keywords: Activity concentration, Gamma Ray Spectrometry, Radionuclide.

Author Biography

Inioluwa Oladipupo Olowofila, The Federal Polytechnic Ilaro

Physics and Lecturer III