Evaluation of natural radioactivity in soil, sediment and water samples of Niger Delta (Biseni) flood plain lakes, Nigeria
Department of Physics, Federal University of Petroleum Resources, Effurun, Nigeria; Dept. of Radiation Biophysics, Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria
Agbalagba, E.O., Department of Physics, Federal University of Petroleum Resources, Effurun, Nigeria; Onoja, R.A., Dept. of Radiation Biophysics, Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria
This paper presents the findings of a baseline study undertaken to evaluate the natural radioactivity levels in soil, sediment and water samples in four flood plain lakes of the Niger Delta using a hyper pure germanium (HPGe) detector. The activity profile of radionuclides shows low activity across the study area. The mean activity level of the natural radionuclides 226Ra, 232Th and 40K is 20 ± 3, 20 ± 3 and 180 ± 50 Bq kg-1, respectively. These values are well within values reported elsewhere in the country and in other countries with similar environments. The study also examined some radiation hazard indices. The mean values obtained are, 76 ± 14 Bq kg-1, 30 ± 5.5 ηGy h-1, 37 ± 6.8 μSv y-1, 0.17 and 0.23 for Radium Equivalent Activity (Raeq), Absorbed Dose Rates (D), Annual Effective Dose Rates (Eff Dose), External Hazard Index (Hex) and Internal Hazard Index (Hin) respectively. All the health hazard indices are well below their recommended limits. The soil and sediments from the study area provide no excessive exposures for inhabitants and can be used as construction materials without posing any significant radiological threat to the population. The water is radiologically safe for domestic and industrial use. The paper recommends further studies to estimate internal and external doses from other suspected radiological sources to the population of the Biseni kingdom. © 2011.
Absorbed dose rate; Activity levels; Activity profile; Annual effective dose; Construction materials; External dose; External hazard index; Flood plain lakes; Flood plains; Hazard indices; Industrial use; Internal hazard index; Mean values; Natural radioactivity; Natural radionuclides; Niger Delta; Nigeria; Radiological sources; Radium equivalent activity; Soil and sediment; Study areas; Water samples; Anoxic sediments; Germanium; Health hazards; Health risks; Industrial applications; Lakes; Radiation; Radiation hazards; Radioisotopes; Radiology; Radiometry; Radium; Sedimentology; Soils; Radioactivity; germanium; potassium 40; radium 226; radon; thorium 232; water; detection method; floodplain; germanium; radioactive pollution; radioactivity; radionuclide; radium isotope; sediment pollution; soil pollution; thorium isotope; absorbed dose rate; annual effective dose rate; article; external hazard index; gamma radiation; internal hazard index; lake sediment; natural radioactivity; Nigeria; radiation detection; radiation exposure; radiation hazard; radiation safety; radiological parameters; radium equivalent activity; soil; Background Radiation; Fresh Water; Geologic Sediments; Nigeria; Potassium Radioisotopes; Radiation Monitoring; Radium; Soil; Thorium; Niger Delta; Nigeria