Assessment of Radionuclide Concentrations in Water Supply from Bore-holes in Ogbomosoland, Western Nigeria

摘要

The level of radionuclide concentration in water from bore-holes in selected areas of Ogbomosoland, a region consisting of five local governments, was determined. Concentration of ~(238)U, ~(232)Th, and ~(40)K was determined for the water samples from eight bore-holes around Ogbomosoland by γ-ray spectrometry with a high-purity germanium (HPGe) detector connected to a multichannel analyzer. All the water samples from these bore-holes were found to contain acceptable levels of radionuclides with mean activity values of 3.98±0.26, 11.00±2.58, and 17.73± 5.04Bql~(-1) for ~(40)K, ~(232)Th, and ~(238)U, respectively showing that the mean activity of ~(238)U for all the samples is the highest when compared with those of ~(40)K and ~(232)Th. Water samples from lkoyi had the highest radionuclide content although ~(40)K concentration was below detectable level. Water samples from Gambari were next to Ikoyi in radionuclide content, followed by Saja, Ajinopai, Kajola, Isale-Ora, Iresa-Apa, and Owode in that order. The mean absorbed dose rate for all the area is 0.123 mSvyr~(-1) which is very low when compared to the recommended limit of 1 mSvyr~(-1) for bore-hole water. Overall, the radionuclide concentration of the bore-hole water supply in Ogbomosoland is, negligible and poses no radiological hazards to the public.