Asere, Adeola Margaret; Sedara, Samuel Omosule


Gamma-ray spectrometer was used to measure radiation from radio-nuclides inside and outside five different quarry sites in Ondo State (Sutol, Batista, Aslos, Johnson and Stoneworks) in order to determine the pattern of natural radioactivity, radiogenic heat production effect and radiological health risk to the population within the site vicinity. The average activity concentration of 238U, 232Th and 40K inside the quarries are 47.09±7.49, 95.02±14.11 and 1118.68±126.94 Bqkg-1 and outside the quarries are 35.76±7.83, 83.17±11.85 and 959.71±96.43 Bqkg-1 consecutively. The total heat production and heat flow values estimated for all the quarries varied from 0.97 to 5.37µWm-3 and 7.63 to 42.12 mWm-2 respectively. The radiogenic heat production variations with the radionuclide from the quarries were presented as plots. Thorium concentration is highest (43.5 ppm) followed by uranium (10.4 ppm). The mean values of all the hazard indices calculated were lower than the internationally acceptable limits. This implies that, the people working in the quarries, granite end-users and general public living around the quarries area are safe from radiological health risk. Considering radiogenic and thermal modeling point of view, the Johnson quarry has the highest concentration of uranium, total heat production and heat flow values. It is a manifestation of the geological rock types and presence of highly weathered minerals. So, it is of most promising Uranium mineralization and further probe for potential geothermal exploration.
Read full article PDF


  1. IAEA, (2003). IAEA-TECDOC-1363. Guidelines for Radioelement Mapping Using Gamma Ray Spectrometry Data. IAEA, Vienna.
  2. Killeen, P. (1979). Gamma ray spectrometric methods in uranium exploration. Application and interpretation. Geophys. Geochem. Search Met. Ores 31: 163–230.
  3. Bristow, C. and Williamson, B, (1998). Spectral gamma-ray logs: Core to log calibration, facies analysis and correlation problems in the Southern North Sea. Geol. Soc. Lond. Spec. Publ. 136: 1–7.
  4. Rybach, L., Schwarz, G.F. (1995). Ground gamma radiation maps: Processing of airborne, laboratory, and in situ spectrometry data. First Break , 13: 97–104.
  5. Ray, L., Roy, S. Srinivasan, R. (2008). High Radiogenic Heat Production in the Kerala Khondalite Block, Southern Granulite Province, India. Int. J. Earth Sci.97: 257–267
  6. IAEA, (2003). Extent of environmental contamination by naturally occurring radioactive material and technological options for mitigation. Technical report series. No 419.
  7. Supitha C., Chutima, K. Shinji, T. Napakans, S. Karnwalee, P. and Chanis, P. (2011). Terrestrial Gmma Radiation in Phuket Island, Thailand. Engineering Journal. 15(4): 65-72. doi:10.4 186/ej.2011.15.4.65.
  8. Ajayi, O.S., Faromika, O.P. Lawal, J.I. (2019). Estimation of natural radioactivity and radiological risk in granite from major quarries in Osun state Nigeria. Int.J. of adv. research sci., engineering and techno. 6(7): 1962-1970.
  9. Ministry of Energy, Bristish Columbia, (2014). Common rock types.
  10. McCay, A., Harley, T. Younger, P. Sanderson, D. and Cresswell,A. (2014). Gamma-ray spectrometry in geothermal exploration: state of the art techniques.Energies, 7 (8): 4757-4780. ISSN pp 1996-1073
  11. Kumar, P.S. and Reddy, G. (2004). Radioelements and heat production of an exposed Archaean crustal cross-section, Dharwar craton, south India. Earth Planet.Sci. Lett. 224: 309–324.
  12. Quinn, T., Suzukilll, N.I.M. Takagim, S. (1989). Mineralogy evaluation in a geothermal well using statistical probabilistic log evaluation techniques. Geotherm. Resour. Counc. Trans. 13: 277–287.
  13. Younger, P., Manning, D. (2010). Hyper-permeable granite: Lessons from test-pumping in the Eastgate Geothermal Borehole, Weardale, UK. Q. J. Eng. Geol. Hydrogeol. , 43: 5–10.
  14. UNSCEAR, (2000). Sources and Effects of Ionizing Radiation. Report to the general assembly with Scientific Annexes. United Nations, New York.
  15. Elueze, A.A., (1986). Vertical Components of Ground Magnetic Studies of Ilesha area, Southwest Nigeria: Geological Survey of Nigeria
  16. Rahaman, M.A., (1976). A Review of the Basement Geology of Southwestern Nigeria; Elizabeth Publishing Co. pp 41-58
  17. Joel, E.S., Maxwell, O. Adewoyin, O.O. Olawole, O.C. Arijaje, T.E., Embong, S. and Saeed, M.A. (2019). Investigation of natural environment radioactivity concentration in soil of coastaline area of Ado-Odo/Ota, Nigeria and its radiological implications. Scientific Reports. 9: 4219.
  18. Ibrahim, M.S., Atta E.R. and Zakaria, K.M. (2014). Assessment of natural radioactivity of some quarries raw materials in El-Minya Governorate, Egypt. Arab J. of natural science and application. 47(1): 208-216.
  19. Walley El-Dine, El-Shershaby, A. Ahmed, F. Abdel-Haleem, A.S. (2001). Measurement of radioactivity and radon exhalation rate in different kinds of marble and granites. Appl. Rad. and Iso.. 55: 853-860.
  20. Rybach, L., (1988). Determination of heat production rate. In: Haenel, R., Rybach, L., Stegena, L. (Eds.), Handbook of Terrestrial Heat-Flow Density Determination. Dordrecht: Kluwer Academic Publishers. Dordretcht (1988), pp. 125–142.
  21. Turcotte, D.L., Schubert, G. (2002). Geodynamics 2nd Edition. Cambridge University Press, Cambridge. Pp 456.
  22. UNSCEAR, (2008). Sources and effects of Ionizing Radiation. Report to the General Assembly with Scientific Annexes. Vol 1, United State, New York.
  23. ICRP, (2012). Compendium of Dose Coefficients Based on ICRP Publication 60. Annals of the ICRP. ICRP. 41 (1).
  24. ICRP, (1994). Protection against Rn-222 at home and at work. ICRP Publication 65. Annals of the ICRP, 23, 1-38.
  25. EC (European Commission), (1990). Commission recommendation 90/143/Euratom of 21 February, 1990 on the protection of the public against indoor exposure to radon. Official J L-80 of 27/03/90. Brussels