Assessment of Natural Radioactivity Level and Radiation Hazard from Soils Used as Major Material for Building in Lere Sheet 147, North Central Nigeria

Abstract

Natural radionuclides (²³⁸U, ²³²Th and ⁴⁰K) content of soil commonly used as building material in Lere Sheet 147, North Central Nigeria have been determined using RS-230 Gamma Ray Spectrometer. The results show that the mean concentration of ²³⁸U, ²³²Th, and ⁴⁰K in the soils is 7.53 ppm, 28.93 ppm and 1.94 % respectively, while the mean activity concentration for each of these radionuclides is 92.97, 117.46 and 608.31 Bq kg⁻¹for ²³⁸U, ²³²Th and ⁴⁰K respectively. The calculated average value for radium equivalent activity for the soils is 307.78 Bq kg⁻¹ which is lower than the permitted value of 370 Bq/Kg, while the average external and internal hazard indices are 0.83 and 1.08 respectively. The annual effective dose equivalent (internal and external), are less than 1 mSvy^-1, thus suggesting that radiological hazard parameters of the soils are generally lower than their respective precautionary limits. In terms of radiological safety, the soils from the study area are safe for use as building material.

Keywords: Soils. Uranium. Thorium. Potassium. Activity Concentration. Radiation hazards.

Lere Sheet 147.