Determination of Natural Radioactivity Concentration Levels in Soil Samples in Odigbo Local Government Area

Abstract The aim of this study was to evaluate the level of natural radioactivity  concentrations of 238U, 232Th and 40K in the surface (0-5cm) soil samples collected from Odigbo in the Southwestern region of Nigeria. The surface soils were collected along the streets of this city. The activity concentrations of naturally-occurring radioactive materials in the 238U, 232Th and 40K were determined by means of a Sodium Iodide (NaI) gamma-ray spectrometry system detector in a low background configuration. The mean activity concentrations of 238U, 232Th and 40K for Odigbo were found to be 179.07±11.36, 152.32 ±32.71 and 1617.43±9.90 Bq kg-1. The results of this current study have been compared with the world mean values of 37, 33 and 400 Bq kg-1, respectively specified by the United Nations Scientific Committee on the Effects of Atomic Radiation. The average annual effective dose obtained from this study is 0.22 mSv y-1 for Odigbo, which is still less than the recommended limit of 1 mSv y-1 by International Commission on Radiation Protection [ICRP] for non occupational population. Also the mean radium equivalent for Odigbo is 535.56 Bq kg-1 and its absorbed dose is 175.21 nGy h-1. It was shown that in most of the locations studied 40K has the highest concentration.

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Updated: May 8, 2018 — 9:00 am