Assessment of Natural Occurring Radioactive Materials and Radiological Hazards Exposure in soil of Ohia in Umuahia South Abia State Nigeria, using High Purity Germanium (HPGe) Gamma Ray Spectrometry

Abstract

Evaluation of natural occurring radioactive materials (NORMs) and radiological exposure are important. The main goal of this work was to determine the NORMs level and radiological exposure risk in Umuahia, using High Purity Germanium Gamma Ray Spectrometry at IPEN, Brazil. The radionuclides (RDNs) such as: 40K, 226Ra and 232Th and radiological parametric indices (RPIs) such as: Absorbed Dose Rate in Air (D), Outdoor and Indoor Annual Effective Dose Equivalent (AEDE), Radium Equivalent Activity (Raeq), Annual Gonadal Equivalent Dose (AGED) and Activity Concentration Index (I) were determined. The mean values of 40K, 226Ra and 232Th in Bq kg-1 were: 147, 28, and 31 while the RPIs mean values for D, ,, AGED, Raeq, and I are: 37 nGy h-1, 0.05 mSv y-1, 0.18 mSv y-1, 260 y-1, 83 Bq kg-1 and 0.29 respectively. Mean value of RDNs were found to be lower than 412 Bq kg-1, 32 Bq kg-1 and 35 Bq kg-1 average value while RPIs were also lower than 59 nGy h-1, 0.08 mSv y-1 for , 0.42 mSv y-1, 300 y-1 for AGED, 370 Bq kg-1 for Raeq, and 1 mSv y-1 respectively global safe limit or mean values. It is concluded that the soil is radiological safe for agriculture, building and construction purposes.