College of Science and Technology

Permanent URI for this communityhttp://itsupport.cu.edu.ng:4000/handle/123456789/28738

Welcome to the community of research works in Science and Technology

Browse

Filters

20251

Settings

Author: search.filters.author.Covenant University ThesisSubject: search.filters.subject.Aero-radiometric data

Search Results

Now showing 1 - 1 of 1
  • No Thumbnail Available
    Item
    ASSESSMENT OF AIRBORNE AND TERRESTRIAL RADIOMETRIC CONCENTRATIONS AND ASSOCIATED HEALTH RISKS IN SELECTED LOCATIONS IN SOUTHWEST NIGERIA
    (Covenant University Ota, 2025-08) MORAKINYO, Ruth Omoseeke; Covenant University Thesis
    Radiation is an inevitable part of the human environment, both from terrestrial and anthropogenic sources. Elevation of radiation levels in an environment above the threshold limit is detrimental to man and the ecosystem. Therefore, monitoring the radiation level of every human environment is expedient because of the harmful effect of exposure to ionizing radiation. The radiometric data of selected locations in southwest Nigeria was collected from the database of the Nigeria Geological Survey Agency (NGSA) and analysed using the Oasis Montaj software. The result of the NGSA data served as a guide in the selection of locations for in-situ assessment using an RS-125 handheld gamma spectrometer. Soil and water samples were collected in those locations and some quarry sites and analysed in the laboratory using NaI (TI) detector. The obtained activity concentrations were used to determine the radiological parameter. The absorbed dose rate for analysed aero radiometry data ranges between 31.92-214.04, 36.31-192.77, 13.82-162.02, 6.57-119.62, 10.83-116.93 and 16.4-63.70 nGy/h for Ado-Ekiti, Akure, Ondo, Apomu, Ibadan, and Ijebu-ode sheets respectively. The mean absorbed dose rate for in-situ assessment for the exact locations ranges between 38.00-149.43, 86.00-179.27, 51.21-116.53, 72.76-109.09, 84.32-194.41, 56.27-64.55nGy/h respectively. The results of soil and water samples of selected locations and quarry sites revealed that the absorbed dose rate in soil samples in 80% of the locations and 100% of the quarry sites was higher than the world average value. The estimated total annual committed dose for various categories of ages in all the water samples were higher than the world average value. The estimated annual effective dose and excess lifetime cancer risk in most locations in in-situ assessment and analysis of soil samples was higher than the global limit. Statistical analysis revealed that the concentration of 232Th contributes significantly to the absorbed dose rate in air and the total annual committed dose due to ingestion of water. In contrast, the activity concentration of 40K contributes significantly to the absorbed dose rate in soil samples in the study area. The need for potable water for the various communities in the region cannot be over-emphasized as the total annual effective dose for all categories of ages was higher than the reference limit. The study concludes that analysis of aero-radiometry data can be an effective guide in monitoring the radioactivity level of an environment.