Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 May 23:16:11786302221100041.
doi: 10.1177/11786302221100041. eCollection 2022.

Measurement of Natural Radioactivity and Assessment of Radiological Hazard Indices of Soil Over the Lithologic Units in Ile-Ife Area, South-West Nigeria

Deborah T Esan  1 , Yinka Ajiboye  1 , Rachel I Obed  2 , Joshua Ojo  3 , Mary Adeola  3 , Mynepalli K Sridhar  2
Affiliations

Measurement of Natural Radioactivity and Assessment of Radiological Hazard Indices of Soil Over the Lithologic Units in Ile-Ife Area, South-West Nigeria

Deborah T Esan et al. Environ Health Insights. .

Abstract

The distribution of natural radioactivity levels of 238U, 232Th, and 40K in soils overlying the 3 lithologic units within Obafemi Awolowo University, Ile-Ife, Nigeria was investigated to characterize the gamma radiation dose distribution over the lithologies and to assess the radiation hazard due to the natural radionuclides. A thallium-doped cesium iodide detector was employed to determine the activity concentrations of 238U, 232Th, and 40K in 21 soil samples. The respective average concentrations of the 3 radionuclides are 37.7, 3.2, and 245.6 Bq kg-1 for granite gneiss, 31.9, 2.8, and 241.1 Bq kg-1 for banded gneiss, and 21.1, 1.7, and 196.7 Bq kg-1 for mica schist. The average concentration of 238U in granite gneiss lithology exceeds the world average value. The evaluated values of radiation hazard parameters including average absorbed dose rate, outdoor annual effective dose and external hazard index are below the recommended limits. The spatial distribution of the radiation hazard parameters evaluated over the lithologies has been delineated. The highest average cancer risk of 1.15 per 10 000 population was obtained for the study area within the soil overlying the banded gneiss lithology. Generally, the radiation hazard from the soils in study area poses no significant health hazard.

Keywords: Radioactivity; detector; environmental monitoring; gamma spectrometry; lithology; natural radionuclide.

PubMed Disclaimer

Conflict of interest statement

Declaration of Conflicting Interests: The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Figures

Figure 1.
Figure 1.
Study area map (Inset: maps of Nigeria, Osun State and Ife Central Local Government Area)—Digitized from.
Figure 2.
Figure 2.
Geological map of the study area showing the 3 lithological units and sampling points.
Figure 3.
Figure 3.
Schematic diagram showing the experimental set-up.
Figure 4.
Figure 4.
Efficiency of the CsI (Tl) detector across different energies using the IAEA 375 soil standard.
Figure 5.
Figure 5.
Spatial distribution of 40K within the study area.
Figure 6.
Figure 6.
Spatial distribution of 238U within the study area.
Figure 7.
Figure 7.
Spatial distribution of 232Th within the study area.
Figure 8.
Figure 8.
Spatial distribution of radium equivalent activity within the study area.
Figure 9.
Figure 9.
Interpolated estimation map of the absorbed gamma dose rate.
Figure 10.
Figure 10.
Correlation plots of (a) 238U against 40K, (b) 232Th against 238U, and (c) 232Th against 40K.
See this image and copyright information in PMC

References

    1. Susam LA, Alan HY, Yilmaz A, et al.. Cosmic radiation exposure calculations for international and domestic flights departs from Istanbul and Ankara. Radiat Prot Dosimetry. 2020;192:61-68. - PubMed
    1. Mekhaldi F, Adolphi F, Herbst K, Muscheler R. The signal of solar storms embedded in cosmogenic radionuclides: detectability and uncertainties. J Geophys Res Space Phys. 2021;126:e2021JA029351.
    1. UNSCEAR. Sources and effects of ionizing radiation. ANNEX B:. Exposures from natural radiation sources. UNSCEAR Report; 2000:97-99.
    1. Al-Khawlany A, Khan A, Pathan J. Review on studies in natural background radiation. Radiat Prot Environ. 2018;41:215.
    1. Arunima S, Lekshmi R, Jojo PJ, Mayeen Uddin K. A study on leaching of primordial radionuclides 232Th and 40K to water bodies. Radiat Phys Chem. 2021;188:109658.

LinkOut - more resources