Measurement of Radionuclides in Some Foodstuff Consumed in Osun State

Authors: 1Nwankpa, A.C., & 2Aboritoli, Sunday.
Department Of Physics, Adeyemi College Of Education, Ondo
Department of Integrated Science, Kogi State College of Education, Ankpa.

The radionuclides in the foodstuffs obtained in Osun state were measured by means of a well-calibrated, high purity germanium (HPGe) gamma-ray spectrometer. A total number of 391 samples were analysed and the results indicated that the radionuclides identified belong to the naturally occurring series-decay radionuclides headed by 238U and 232Th as well as 40K. The foodstuffs analysed included Garri from cassava, yam flour, leafy vegetables, beef and goat meat, and various species of fish. For yam flour, the specific radionuclide concentrations for 228U range from 0.43 – 4.91Bqkg-1 with a mean value of 1.72 ± 0.10 Bqkg-1, 0.94 – 3.94 Bqkg-1 for 232Th with a mean value of 2.24 ± 0.21 Bqkg-1 and for 40K, the range is from 20.24 – 66.84 Bqkg-1 with a mean value of 37.84 ± 2.40 Bqkg-1. The specific radionuclide concentrations in garri range from 0.41 – 5.13Bqkg-1 with a mean value of 2.00 ± 0.41 Bqkg-1 for 228U, 0.37 – 3.95 Bqkg-1 for 232Th with a mean value of 1.81 ± 0.12 Bqkg-1 and from 12.95 – 63.36 Bqkg-1 for 40K with a mean value of 40.35 ± 3.94 Bqkg-1. The average concentrations of radionuclides in beef samples analysed are in the range of 0.76 – 6.43 Bqkg-1 for 228U with a mean value of 2.98 ± 0.48 Bqkg-1; 0.62 – 3.91 Bqkg-1 for 232Th with a mean value of 2.16 ± 0.12 Bqkg-1 and from 213.72 – 392.55 Bqkg-1 for 40K with a mean value of 274.44 ± 18.26 Bqkg-1. The specific activities recorded for goat meat range from 1.03 – 6.13 Bqkg-1 for 228U with a mean value of 3.41 ± 0.35 Bqkg-1 ; 1.12 – 4.48 Bqkg-1 for 232Th with a mean value of 2.41 ± 0.24 Bqkg-1 and for 40K, the mean specific activity values range from 249.28 – 471.26 Bqkg-1 with a mean value of 360.30 ± 21.41 Bqkg-1.  The specific activities of the radionuclides in fish are in the range 0.94 – 3.78 Bqkg-1 for 228U with a mean value of 1.96 ± 0.23 Bqkg-1 ; 0.63 – 3.63 Bqkg-1 for 232Th with a mean value of 1.46 ± 0.11 Bqkg-1 and for 40K, the mean specific activity values range from 68.45 – 465.26 Bqkg-1 with a mean value of 170.75 ± 9.42 Bqkg-1.  The average concentrations of radionuclides in green samples analysed are in the range of 0.97 – 3.98 Bqkg-1 for 228U with a mean value of 2.28 ± 0.11 Bqkg-1; 0.69 – 3.92 Bqkg-1 for 232Th with a mean value of 1.82 ± 0.32 Bqkg-1 and from 24.43 – 77.29 Bqkg-1 for 40K with a mean value of 48.19 ± 3.42 Bqkg-1. The specific activities recorded for waterleaf range from 0.96 – 5.72 Bqkg-1 for 228U with a mean value of 2.51 ± 0.31 Bqkg-1 ; 0.81 – 3.82 Bqkg-1 for 232Th with a mean value of 2.40 ± 0.12 Bqkg-1 and for 40K, the mean specific activity values range from 33.42 – 77.72 Bqkg-1 with a mean value of 56.17 ± 4.10 Bqkg-1.  The results of the average concentrations of the natural radionuclides showed that 40k was the most abundant radionuclide in the foodstuffs analysed.