Natural radionuclide content and radiological assessment of clay soils collected from different sites in Ekiti State, southwestern Nigeria.

Clay soil samples collected from different sites in Ekiti State, southwestern Nigeria were analysed for their natural radionuclide contents, using the gamma ray spectrometric method. The overall mean activity concentrations of (226)Ra, (232)Th and (40)K obtained in this study were, respectively, 33.6 +/- 5.3, 20.1 +/- 3.3 and 207.2 +/- 113.0 Bq kg(-1). The radiological hazards incurred from the use of the clay soil as a component of building materials were estimated through various radiation hazard indices. The results indicate that the values obtained fall below the internationally accepted maximum limits and as such, the use of clay as a building material does not pose any significant radiation hazard to individuals in the study area.