Activity Concentration of Gamma Emitting Natural Radionuclides in Building Materials

Abstract

In this work, the natural radionuclide contents of some building materials widely used in Nigeria were measured by the means of gamma-ray spectrometry using Na(I)Tl detector. A total of 15 samples were assayed from different materials. The mean of ²²⁶Ra, ²³²Th and ⁴⁰K concentrations determined are 30.35±8.69BqKg^-1_, 20.12±6.00 BqKg^-1 and 241.95±76.31 BqKg^-1 respectively. These values were lower than permissible global values except for potassium which is higher than that of global permissible value of 52.2, 41.0 and 230.0 (BqKg^-1 ) respectively by UNSCEAR. The obtained mean absorbed dose rate for all the collected building materials samples is 39.90(nGgh^-1). These results, along with the results of the estimated annual effective dose rates, radium equivalent (Ra_eq), external hazard index (H_ex) are presented and they are found below the internationally accepted safe limits. It suffices to say therefore the analyzed samples could be used for building and construction purposes. It is safe to say that there is no threat pose to any users of the materials.

Keywords: Natural radionuclide, Building materials, absorbed dose, Radium equivalent