Assessing naturally occurring radionuclides in soil of Egbeda Local Government for a baseline data of Oyo State, Nigeria

Abstract

The activity concentrations of the natural radionuclides, namely226Ra,232Th, and40K were measured from soil samples collected from different locations of Egbeda Local Government Area, Oyo state, Nigeria, with the aim of establishing radioactivity baseline data for the area. High-resolution gamma spectrometry detector was used to determine the activity concentration of these radionuclides in 45 soil samples taken at a depth of about 15 cm in various communities of Egbeda Local Government Area. The concentration of226Ra was in the range 5.9–61.3 Bq/kg with an average value of 30.5 Bq/kg,232Th in the range 4.0–116.5 Bq/kg with an average value of 50.8 Bq/kg, and40K in the range 27–798 Bq/kg with an average value of 200 Bq/kg. The results obtained in this study were compared with those of different countries in the world. Radiological index parameters were used for the assessment of radiological exposure of the natural radioactivity, and the absorbed dose rate, the radium equivalent activity, the annual effective dose, the external exposure index, and internal exposure index were calculated. There is no radiological risk from soil that may threat the residents around Egbeda Local Government Area. Hence, the probability of occurrence of any of the health effects of radiation is insignificant. Therefore, the radioactivity measurements taken represent the baseline data of the study area.

Keywords

• baseline data
• high-resolution gamma spectrometry
• radiological exposure
• soil radioactivity