Journal Article

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Browsing Journal Article by Subject "Activity concentrations"

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    Investigation of Radiation Levels in Soil Samples Collected from Selected Locations in Ogun State, Nigeria
    (2014) Usikalu MR; Akinyemi ML; Achuka JA
    Present study measured the terrestrial radiation and evaluated absorbed dose rates from primordial radionuclides 238U, 40K and 232Th in sixty soil samples collected from north, west, east and south of Ewekoro cement factory premises, Owowo village situated adjacent to the factory and Covenant University, Ogun State using the gamma ray spectrometry method. The gamma absorbed rate and annual effective dose equivalent were calculated so as to estimate the hazard index of the primordial radionuclides. Measured concentrations of radionuclides in Ewekoro cement factory soils were as follow: [232U 1.60±1.60 Bqkg−1 (east) - 2.56±0.08 Bqkg−1 (north), 232Th 44.78±1.83 Bqkg−1 (east) - 56.62±1.96 Bqkg−1 (north), 40K 261.54±12.67 Bqkg−1 (south) - 342.08±14.17 Bqkg−1 (east)] and Owowo village [232U 1.78±0.09 Bqkg−1 (east) - 2.62±0.08 Bqkg−1 (north), 232Th 50.07±1.93 Bqkg−1 (west) - 61.69±1.89 Bqkg−1 (north), 40K 244.11±13.38 Bqkg−1 (north) - 296.40±14.90 Bqkg−1 (south)]. These locations have higher concentration of all radionuclides than that of Covenant University soils, which are as follows: [232U 0.62±0.07 Bqkg−1 (south) - 1.07±0.06 Bqkg−1 (north), 232Th 30.23±1.87 Bqkg−1 (south) - 38.87±1.78 Bqkg−1 (east), 40K 243.35±12.57 Bqkg−1 (south) - 301.15±13.55 Bqkg−1 (north)]. The mean absorbed dose and annual equivalent effective dose is 40.88 nGyr-1 and 0.05 mSv respectively. The study found that the activity concentrations and radiological hazard index from samples from Ewekoro and the neighbourhood are consistently higher than those from Covenant University however; the values are less than the recommended safe levels.
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    Radionuclides proportion and radiological risk assessment of soil samples collected in Covenant University, Ota, Ogun State Nigeria
    (2018) Adewoyin OO; Omeje M; Joel ES; Akinwumi SA; Ehi-Eromoseled CO; Embong Z
    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, Iyr, Hex 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.