ASSESSMENT OF NATURAL RADIOACTIVITY IN CONCRETE BLOCK, EXTRUDED CLAY BRICK, AND MUD BRICK TAKEN FROM OGBOMOSO, SOUTHWESTERN, NIGERIA

Abstract

This study evaluates the natural radioactivity in concrete block, extruded clay brick, and mud brick taken from Ogbomoso city. The six samples were collected from different part of the city, and were analyzed using highly sensitive HPGe gamma spectrometer. The mean activity concentration in Bq Kg -1 of ⁴⁰K , ²³⁸ U (²²⁶Ra) and ²³²Th were 135.10 ± 3.23, 9.58 ± 3.16 and 14.30 ± 3.32 respectively in concrete block ; 66.34 ± 6.66, 6.81 ± 2.26 and 6.78 ± 2.58 respectively in mud brick; and 69.21 ± 6.88, 7.26 ± 2.54 and 3.51 ± 1.54 respectively in extruded clay brick. Also calculated were the radium equivalent activities, the hazard indexes, the absorbed dose rates and the effective dose rate. The extruded clay brick has the lowest value in all calculated parameters. The absorbed dose rate due to ²³⁸ U (²²⁶Ra), ²³²Th and ⁴⁰K at 1.0 m above the ground level in clay brick was 8.41 nGy h ^-1, annual effective dose was 0.04 mSv yr^-1 and also the internal and external hazard index was 0.07 and 0.02 respectively. All the measured parameters in all the samples were lower than the international criterion values, and therefore posses no radiological hazards.

Keywords

• Radioactivity
• Bricks
• Dose
• Radium
• Thorium

OGBOMOSO, GÜNEYBATI, NİJERYA’DAN ALINAN, BETON BLOK, BOYALI KIL TUĞLA VE KERPİÇ İÇİNDE DOĞAL RADYOAKTİVİTE DEĞERLENDİRİLMESİ

Abstract

Bu çalışmada, Ogbomoso, Güneybatı, Nijerya’dan alınan, beton blok, boyalı kil tuğla ve kerpiç içinde doğal radyoaktivite değerlendirilmiştir. Altı örnek, Şehrin farklı kısımlarından altı örnek toplanmışvesonderecehassas HPGe Gama spektrometresi kullanılarak analiz edilmiştir. 40K , 238 U (226Ra) ve 232Th Bq Kg -1 için ortalama aktivite konsantrasyonu, sırasıyla beton blok içinde; 135.10 ± 3.23, 9.58 ± 3.16 ve 14.30 ± 3.32, kerpiç içinde; 66.34 ± 6,66, 6.81 ± 2.26 ve 6,78 ± 2,58, ve boyalı kil tuğla içinde; 69.21 ± 6.88, 7.26 ± 2.54 ve 3.51 ± 1,54 olarak ölçülmüştür. Ayrıca, radyum eşdeğer faaliyetleri, tehlike indeksler, absorbe edilen doz oranları ve etkin doz oranları hesaplanmıştır. Boyalı kil tuğla, tüm hesaplanan parametreleri için en düşük değerlere sahiptir. Absorbe edilen doz oranları 238 U (226Ra), 232Th veetkin doz 0.04 mSv yr-1 ve sırasıyla iç ve dış tehlike indeksler 0,07 ve 0,02 dir. Bütün örneklerdeki ölçülen tüm parametreler, uluslararası ölçüt değerlerinden düşüktür ve bu nedenle hiçbir radyolojik tehlikeye sahip bir parça yoktur. K için, kil tuğla zemin seviyesinden 1.0 m üzerinde, 8.41 nGy h -1 ve yıllık

Keywords

• Radyoaktivite
• Tuğla
• Doz
• Radium
• Thorium

References

1. Ademola, J.A. and Farai, I.P. (2005). Annual effective dose due to natural radionuclides in building blocks in eight cities of Southwestern Nigeria. Radiation. Protection Dosimetry 114(4), 524–526.
2. Ajayi, O.S. and Ajayi, I.R. (1999). Survey of environmental gamma radiation levels of some areas of Ekiti and Ondo State, Southwestern part of Nigeria. Nigeria Journal of Physics 11, 17-21.
3. Awodugba, A.O., Adelabu, J.S.A., Awodele, M.K. and Ishola, G.A. (2007). Material and the end product from West African Portland cement plc, Ewekoro, south western part of Nigeria. Indoor and Built Environment 16, 569.
4. Beck, H.L. (1972). The physics of environmen- tal radiation fields, Natural Radiation en- vironment II. CONF-720805p2. Proc se- cond Intl. Symp. Natural Radiation Envi- ron 101-133.
5. Beretka, J. and Mathew, P.J. (1985). Natural radioactivity of Australian building mate- rials, industrial wastes and by-products. Health Phys. 48, 87-95.
6. Hewamanna,R.,Sumithrachchi,C.S.,Mahawatte, P., Nanayakkara, H.L.C. and Ratnayake, H.C. (2001). Natural radioactivity and gamma dose from Sri Lankan clay bricks used in building construction. Applied Radiation Isotopes 54(2), 365-369.
7. Hizem, N., Ben Fredj, A. and Ghedira, L. (2005). Determination of natural radioac- tivity in building materials used in tunisi- an dwellings by gamma ray spectrometry. radiation protection dosimetry 114, 533- 537.
8. ICRP, (1977). International Commission on Radiological Protection, Recommenda- tions of ICRP, Publication 26. Pergamum Press, Oxford.

9. International Commission on Radiological Pro- tection, (1991). 1990 Recommendations of the International Commission on Radi- ological Protection. Publication 60. 21(1– 3).
10. Islam, M.N., Alam, M.N., Mustafafa, M.N., Saddiqua, N., Miah, N.M.H., Chowdbury, M.I., Shah, S.H., Ali, L. and Roy, P.K. (1990). Characteristics of shielding ar- rangement for a HPGe detector designed and fabricated locally. Chittagong Uni- versity Studies, part II: Science. 14(2), 105-111.
11. Krieger, R. (1981). Radioactivity of construction materials. Technology 47, 468-473.
12. Mehdizadeh, S., Faghihi, R. and Sina, S. (2011). Natural radioactivity in building materials in iran. Nukleonika, 56, 363−368.
13. Mollah, A.S., Ahmad, G.U., Hussain, S.R. and Rahman, M.M. (1986). The natural radio- activity of some building materials used in Bangladesh, Health Physics 50, 849– 851.
14. Nour, K.A. (1991). Measurement of natural ra- dioactivity in building material in Quena city, upper Egypt. Journal of environmen- tal Radioactivity 83, 91-99.
15. Olomo, J.B., Tchokossa, P. and Aborisade, C.A. (2003). Study of radiation protection guidelines in the use of building materials for urban dwelling in southwestern Nige- ria. Nigeria Journal of Physics 15(1), 7- 13.
16. Pilkyte, L., Butkus, D. and Morkunas, G. (2006). Assessment of external dose in- door in lithuania. radiation protection do- simetry 121, 140–147.
17. Schotzing, V. and Debetin, K. (1983). Photon emission probabilities per decay of 226Ra and 232Th equilibrium with there daughter products, Internationa Journal Applied Radiation Isotopes 34, 533-538.
18. Slunga, E. (1988). Radon classification of build- ing ground. Radiation Dosimetry 24(114), 39-42. Protection
19. Stranden, E. (1976). Some aspects on radioactiv- ity of building materials, Health Physics 8, 167-177.
20. Tchokossa, P. (2006). Radioactivity in food ma- terials in Delta area and River State, Nige- ria. PhD thesis, Obafemi Awolowo Uni- versity, Ile Ife.
21. Turhan, S. and Gurbuz, G. (2008). Radiological significance of cement used in building construction in Turkey. Radiation Protec- tion Dosimetry 129(4), 391-396.
22. United Nations Scientific Committee on the Ef- fects of atomic Radiation, Sources and ef- fects of ionizing radiation, UNSCEAR, (1993). New York.
23. United Nations Scientific Committee on the Ef- fects of Atomic Radiation, Sources and effects of ionizing radiation, UNSCEAR (2000) Report, New York.
24. UNSCEAR, (1982). Ionizing radiation sources and biological effects, United Nations Scientific Committee on the Effects of Atomic Radiation, Report to General As- sembly, With Annexes, United Nations, New York.
25. UNSCEAR, (1988). Sources, effects and risks of ionizing radiation, United Nations Scien- tific Committee on The Effects of Atomic Radiation. Annex A, B United Nations, New York.