Gamma-Ray Spectrometric Determination And Multivariate Analysis Of Radionuclide Fluxes In Shore Sediment At Port Victoria, Kenya

Increased human and industrial activities discharge effluents containing TENORM while geological processes results to NORM directly onto land and in water bodies in L. Victoria basin. River Nzoia is the largest river draining the basin and forms an integral part of the lake shoreline at Port Victoria. In this study, bottom sediments from the shoreline at Port Victoria were sampled and analyzed for radionuclide activity using NaI(Tl) and chemometric techniques; principal component analysis (PCA) and hierarchical cluster analysis (HCA). The mean concentration levels of the radionuclides K-40, U-232 and Th-232 were 523.21±26.53, 66.23±8.55 and 76.23±7.32 Bq/kg which were found to be above the world wide accepted average values of 420, 33 and 45Bq/kg respectively. PCA performed on the measured data indicates that U-238 and Pb-214 are mostly TENORM while Th-232, K-40 and Ac-228 as mostly NORM. HCA apportioned applied fertilizers and oil spills in the Lake basin is the main source of U-238 and Pb-214 while Th-232, Ac-228 and K-40 to be mostly from the geological weathering of the igneous and sedimentary rocks that characterize the Victoria catchment. Through biomagnifications and associated food chains in the aquatic system, radionuclides directly or indirectly ionize the living cells of humans causing somatic effects hence an urgent need to control pollution by radionuclides in the Lake Victoria basin is called for in this study.