Estimation of Annual Dose Rate of Natural Radionuclides in Man from Crabs in River Odeomi Ijebu Waterside Ogun State Nigeria

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Author(s) O. Sowole | K.W. Giwa
Pages 438-441
Volume 2
Issue 6
Date June, 2013
Keywords Radionuclides, Crabs, Radionuclide concentration, Dose rate, Gamma spectrometry.

Radioactivity concentrations and dose rates of 40K, 226Ra and 228Ra in crabs from river Odeomi, Ogun State Southwest of Nigeria had been determined by gamma spectrometry using NaI (TI) detector coupled with a pre-amplifier base to a multiple channel analyzer (MCA). 10 samples of crabs were collected from the river having three species. Callinectes pallidus had the highest mean concentration and dose rate of 40K of values 120.34 ± 12.78Bqkg-1 and 0.0108mGyhr-1 respectively. The highest mean concentration and dose rate of 228Ra was found in Cardiosoma armatum with values 9.57 ± 3.34Bqkg-1 and 1.14 x 10-12 mGyhr-1 respectively. 226Ra was not detected in the samples. The average dose rates of 40K in the crabs was calculated to be 0.0101mGyhr-1 and that of 228Ra was 9.93 x 10-13mGyhr-1 which are below the 0.4mGyhr-1 limit recommended by NCRP (1991) as reported by Blaylock et al (1993). The annual dose rate in man consuming the aquatic animal species was estimated to be 0.068mSv y-1 which was below the recommended limit of 1 mSvyr-1. All the values obtained show that there is no negative radiological health implication to the aquatic animals and man that consumes them.

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