Radionuclides proportion and radiological risk assessment of soil samples collected in Covenant University, Ota, Ogun State Nigeria

The activity levels of ²³⁸U, ²³²Th and ⁴⁰K in soil surrounding major office complexes in Covenant University were analyzed for radiological hazards to determine the safety of the residents in such environment. Sixteen (16) soil samples were collected, prepared and sent to Acme laboratory in Canada for analysis with the use of high purity germanium detector. The mean activity concentrations of ²³⁸U, ²³²Th and ⁴⁰K were found to be 45 ± 10, 135 ± 8 and 195 ± 20 respectively. The concentrations of ²³⁸U and ²³²Th were found to be higher than the world recommended standard of 35 and 30, while the result for ⁴⁰K was noted to be lower than the world safe limit. The average values of Raeq, D, AED, I_yr, H_ex and ELCR in this study were estimated to be 252.33 Bq/kg, 110.15 nGy/h, 0.13 mSv/y, 1.78, 0.68 and 0.47 × 10⁻³ respectively. It was noticed that none of the measured parameters was higher than the internationally recommended safe limits. ²³²Th was found to be the major contributor to the environmental radionuclides in the area of study. Therefore, the inhabitants of the office complexes whose environment was assessed are considered not be exposed to any radiological hazards.