AYINMODE, Bolaji Omogbemiga University of Ibadan - Department of Physics, Nigeria , FAMAKINWA, Rebecca Oluwadamilola University of Ibadan - Department of Physics, Nigeria , AJAYI, Jonathan Olanipekun Ladoke Akintola University of Technology - Department of Pure and Applied Physics, Nigeria

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

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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.

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Radioactivity , Bricks , Dose , Radium , Thorium.

Anadolu University Journal of Science and Technology. A : Applied Sciences and Engineering

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