Levels of Radionuclide Contents in Stream Waters of Some Selected Rivers in Ogbomoso Land, South West Nigeria

The study aims at providing a base-line data for the effective monitoring of unforeseeable radioactive fall-out in the investigated areas. Attempts were made to investigate the radionuclide concentration levels from ten selected streams spread around the five local governments of Ogbomoso land, South-Western Nigeria during 2010/2011 stream flow season. The stream water samples collected from these selected streams were then analyzed using gamma spectrometry with sodium iodide (NaI) detector connected to a multi-channel analyzer. All the stream water samples from these streams were found to contain permissible levels of radionuclides with mean activity values of 100.13±26.82, 6.03±2.10 and 5.54±1.76 for 40K, 238U and 232Th, respectively. The mean absorbed dose rate of the water samples was found to be 0.10 mSv/year which is very low when compared to the International Commission on Radiological Protection’s (ICRP) recommended limit of 1 mSv/year and therefore pose no radiological hazard to the public.