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Application of in-situ gamma-ray spectrometry in the determinationof activity concentrations of 40K, 238Uand 232Th and mean annual effective dose rate levels in southeastern cities in Nigeria

Published online by Cambridge University Press:  01 December 2005

N. N. Jibiri
Affiliation:
Radiation and Health Physics Research Laboratory, Department of Physics, University of Ibadan, Ibadan, Nigeria
I. P. Farai
Affiliation:
Radiation and Health Physics Research Laboratory, Department of Physics, University of Ibadan, Ibadan, Nigeria
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Abstract

A low cost in-situ gamma-ray spectrometric method for rapid assessment of radiation exposure, identification of radionuclides and detection of changes in environmental radioactivity has been employed in the determination of the natural gamma radiation dose levels in six major cities of the southeastern region of Nigeria. The soil radioactivity concentrations of the primordial radionuclides; 40K, 238U and 232Th were determined and have been related to the γ-dose rates in the cities. The activity concentration of 40K across the region ranged between 0.021 and 0.200 kBq kg–1; 238U was between 0.001 and 0.066 kBq kg–1 while that of 232Th ranged between 0.015 and 0.103 kBq kg–1. The total γ-absorbed dose rates in air in the region ranged between 0.016 and 0.090 μGy h–1 with a mean of 0.039 ± 0.018 μGy h–1. The mean of the annual outdoor effective dose due to the terrestrial gamma radiation for the region was calculated as 50 μSv y–1 representing 66% of the world average value.

Type
Other
Copyright
© EDP Sciences, 2005

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References

Andrasi A., Nemeth I., Zombori P. (1987) Application of Ge-spectrometry for rapid in-situ determination of environmental radioactivity, KFKI-1987-25/K, Hungarian Academy of Science, Central research institute for Physics, Budapest.
Beck H.L. Condon W.J., Lowder M.W. (1964) Spectrometric techniques for measuring environmental gamma radiation, USAEC report, HASL-150
Beck H.L., Decompo J., Gogolak G. (1972) In-situ Ge(Li) and NaI (Tl) gamma-ray, spectromery, USAEC report, HASL-258.
Elegba S.B. (1995) Peaceful application of nuclear energy in Nigeria, An invited paper at the workshop on radiation safety and Nigeria legal system, Zaria, Kaduna State, Nigeria, June 7-8.
Farai, I.P., Jibiri, N.N. (2000) Baseline studies of terrestrial outdoor gamma dose rate levels in Nigeria, Rad. Prot. Dosim. 88, 247-254. CrossRef
Gogolak, C.W. (1984) Rapid determination of noble gas radionuclide concentrations in power reactor plumes, Health Phys. 46, 783-792. CrossRef
Gogolak C.W., Winkelman I., Weiner S., Wolf S., Klopfer P. (1986) Observation of Chernobyl fallout in Germany by in-situ gamma spectrometry, USAEC report, HASL-190.
Helfer, I.K., Miller, I.K. (1988) Calibration factor for field spectrometry, Health Phys. 55, 15-29. CrossRef
ICRP Publication 60 (1991) 1990 Recommendations of the International Commission on Radiological Protection, Ann. ICRP 21(1-3).
IAEA (1983) Calibration gamma source, International Atomic Energy Agency set-22 reference library, Vienna, Austria.
Jibiri N.N. (2000) Application of in-situ gamma-ray spectrometry in baseline studies of outdoor radiation exposure levels in Nigeria, Ph.D. thesis, Department of Physics University of Ibadan, Nigeria.
Jibiri, N.N., Farai, I.P. (1998) Assessment of dose rate and collective effective dose equivalent due to terrestrial gamma radiation in the city of Lagos, Nigeria, Rad. Prot. Dosim. 76, 191-194. CrossRef
Marouf, B.A., Mohamed, A.S., Taha, J.S. (1993) Assessment of exposure rate and collective effective dose equivalent in the city of Baghdad due to natural gamma radiation, Sci. Tot. Environm. 133, 133-137. CrossRef
Miller, K.M., Beck, H.L. (1984) Indoor gamma and cosmic-ray exposure rate measurements using Ge-gamma spectrometer and ionization, Rad. Prot. Dosim. 7, 185-189. CrossRef
Miller K.M., Shebell P. (1993) In-situ gamma-ray spectrometry: A tutorial for environmental radiation scientists. United State Department of Energy, USDOE-report, EML-557.
Miller K.M., Gogolak C.V., Boyle M. (1979) Radiation measurement following the Three Mile Island reactor accident, USDOE- report, EML-357.
NPC (1991) National population Commission of Nigeria, Provisional census result of the Federal Republic of Nigeria.
Obed R.I. (2003) Soil radioactivity concentration and cancer incidence in eighteen cities in Nigeria, Ph.D. thesis, Department of Physics University of Ibadan, Nigeria.
Oshin, I.O., Rahaman, M.A. (1986) Uranium favorability study in Nigeria, J. Africa Earth Sci. 55, 167-175.
UNSCEAR (2000) United Nation Scientific Committee on the effects of Atomic Radiation Sources, Effects and risk of ionizing radiation, Report of UNSCEAR to the General Assembly UN - New York.
Wollenberg, H.A., Smith, R.A. (1990) A geochemical assessment of terrestrial gamma ray absorbed dose rates, Health Phys. 58, 183-189. CrossRef
Zombori, P., Nemeth, I., Koblinger, L., Andrasi, A., Deme, S., German, E., Kemenes, L. (1983) In-situ gamma spectrometric determination in the environment of the Paks nuclear power station, Izotoptechnika 26, 81-93.