A Gamma Spectrometeric Analysis and Radium Equivalent Activity Index of Water in Abak, Nigeria: A Baseline Survey

Abstract

This study evaluated the concentration of radionuclides and radiation hazard indices for water with the use of gamma spectrometer in 10 different communities of Abak Local Government Area of Akwa Ibom State, Nigeria to serve as baseline data on the radiological status of the area. The results show that the commonly occurring radionuclides are not uniformly distributed in the water. The mean activity concentration of 40K, 238U and 232Th in the samples were estimated to be 105.46±8.16 Bq/l, 13.02±3.13 Bq/l and 2.44±0.21; Bq/l respectively. These values are well below internationally determined permissible exposure limits. The hazard indices radium equivalent activity, absorbed dose rate, effective dose rate, external and internal hazard indices had mean values of 24.6±4.06 Bq/l, 11.9±1.92 nGy/h, 0.02±0.002mSv/yr, 0.07±0.01 and 0.1±0.02 respectively.The computed hazard indices are all below the recommended standards. Therefore the water at the present time poses no radiological health threat to the populace. Keywords: Radionuclide concentration, radium equivalent, absorbed dose rate, internal hazard index