Assessment of Radiation Exposure Levels and Associated Health Risks in Calabar Free Trade Zone, Nigeria

Document Type : Original Paper

Authors

1 University of Calabar, Calabar Nigeria

2 Department of Physics University of Uyo Uyo, Akwa Ibom State Nigeria

3 Department of Physics University of Calabar Calabar, Cross River State Nigeria

Abstract

Introduction
Exposure to chronic levels of ionizing radiation could be detrimental to health even at very low doses. Calabar free trade zone (CFTZ) was established to promote export business in Nigeria and it is yet to produce exposure data of the Zone.
Materials and Methods
The Zone was divided into three categories depending on the type of business. Category A had facilities with manufacturing businesses, Category B was service providers while Category C was oil and gas businesses. Exposure levels within the CFTZ were measured with exposure meter and results obtained were converted to annual effective dose in mSv/yr. The evaluated doses were used to estimate health risks to workers in the Zone in terms of lifetime cancer incidence and mortality for persons aged between 18 – 65 years using the conversion factors in BEIR VII.
Results
Category B facilities had dose values between 0.21 – 0.31 mSv/yr followed by Category A with dose values between 0.23 – 0.35 mSv/yr. Category C facilities had the highest dose values between 0.33 – 0.40 mSv/yr. The evaluated cancer incidence and mortality rates were generally less than 2 persons in 1,000 persons for both male and female workers.
Conclusion
The study shows that the exposure levels in business facilities within the CFTZ were higher than the background radiation level. The effective doses were not uniform for the different categories. The estimated cancer incidence and mortality were low, and simple linear equations were generated to relate cancer incidence to mortality.  

Keywords

Main Subjects

References

  1. 1.Ibrahim NM, Abd El Ghani AH, Shawky EM, Ashraf EM, Farouk MA. Measurement of radioactivity levels in soils in the Nile Delta and Middle Egypt. Journal of Health Physics. 1993; 64: 620–627.

    2.Malanca A, Pessina V, Dallara G. Assessment of the natural radioactivity in the Brazillian State of Rio Grende Do Norte. Journal of Health Physics. 1996; 65: 298–302.

    3.STUK. The radioactivity of building materials and ash. Helsinke, Radiation and Nuclear Safety Authority; 2010

    4.United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Sources, Effects and Risks of Ionizing Radiation. New York, United Nations: United Nations Scientific Committee on the Effects of Atomic Radiation; 2000.

    5.Drek H C, May C C, Zanat C. Global networking for bio-dosimetry laboratory capacity in radiation emergencies. Health Physics. 2010; 92(2): 168 – 171.

    6.Agba E H, Onjefu S A, Uqwuani J U. Preliminary investigation of ambient radiation levels of the mining sites in Benue States, Nigeria, Nigerian Journal of Physics. 2006; 18: 219 – 222.

    7.Inyang S O, Essien I E, Egbe N O Exposure levels within building materials shops in Calabar, Cross River State, Nigeria. Journal of Physical Science International. 2016; 7(1): 12 – 17.

    8.Olomo JB. The natural radioactivity in some Nigerian foodstuffs. Nuclear Instrument and Methods in Physics Research 1990; A2999: 666 – 669.

    9.Akinloye MK, Olomo J B. The radioactivity in some grasses in environment of nuclear research facilities located within the Obafemi Awolowo University, Ile-Ife, Nigeria. Nigerian Journal of Physics. 2005; 17: 219 – 225. 

    1. Al Harbi W R, Alzahrani J H, Abbady A G E. Assessment of radiation hazards indices from granite rocks of Southern Arabian shield, Kingdom of Saudi Arabia. Australian Journal of Basic and Applied Sciences. 2011; 5(6): 672 – 682. 
    2. Inyang S O, Inyang I S, Egbe N O. Radiation exposure levels within timber industries in Calabar, Nigeria. Journal of Medical Physics. 2009; 34(2): 97-100
    3. Jibiri NN, Obarhua STU. Indoor and outdoor Gamma dose rate exposure levels in major commercial building material distribution outlets and their radiological implication and occupant in Ibadan, Nigeria. Journal of Natural Sciences Research. 2013; 3(3): 25 – 31.
    4. Essien I E, Essiett A A. Investigation of radiological Hazards Indices within Uyo Metropolis Central Dumpsites, Akwa Ibom State, Nigeria, International Journal of Scientific Research Publications. 2016; 6(5): 687 – 691.
    5. Olubosede O, Akinnagbe, O B, Adekoya O. Assessment of radiation emission from waste dumpsites in Lagos State of Nigeria. International Journal of Computational Engineering Research. 2012; 2(3): 806 – 811. 
    6. Avwiri G O, Esi E O.  Evaluation of background ionization radiation level in some selected dumpsites in Delta State, Nigeria. Advances in Physics Theories and Applications, 2014; 35: 36 – 43.
    7. Essien I E, Umoh U A. Measurement of background radiation level from central automobile mechanic village, Akwa Ibom State. Journal of Basic and Applied Research International. 2016; 18(1): 36 – 39.  
    8. James I U, Moses I F, Vandi J N. Measurement of gamma radiation in an automobile mechanic village in Abuja, North Central, Nigeria. J. Appl. Sci. Environ. Manage 2014; 18 (2): 293 – 298.
    9. Avwiri GO, Ebeniro J O. A survey of the background radiation levels of the sub-industrial areas of Port Harcourt. Global J. of Pure and Applied Sci. 2002; 8: 111 – 113.
    10. Daib H M, Nouh S A, Handy A, El-Fiki S A. Evaluation of natural radioactivity in a cultivated area around a fertilizer factory. Journal of Nuclear and Radiation Physics.2008; 3(1): 53 – 62.
    11. Mobbs S, Watson S, Harrison J, Muirhead C, Bouffler S. An introduction to the estimation of risks arising from exposure to low doses of ionizing radiation. Chilton; Health Protection Agency, 2009.
    12. National Research Council. Health risks from exposure to low levels of ionizing radiation: BEIR VII – Phase 2. Washington: National Academies Press. 2006
    13. European Commission. Radiological protection principles concerning the natural radioactivity of building materials. Radiation Protection 112. Luxembourg: Office for Official Publications of the European Communities; 2000.
    14. Uwah E J, Inyang SO (1998): Studies of Environmental Radioactivity Levels in Calabar. Global Journal of Pure and Applied Sciences. 1998; 4: 187 – 190.
Iranian Journal of Medical Physics
Volume 14, Issue 1
March and April 2017
Pages 38-46

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History

  • Receive Date: 13 October 2016
  • Revise Date: 23 March 2017
  • Accept Date: 23 December 2016

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