The Background Dose Assessment of Highly Industrialized Area Used for Building and Construction Purposes in Ogun State, Nigeria

Abstract

A highly industrialized and mining zone has been mapped to ensure the level of radiation exposure and environmental safety of the dwellers in the buildings within the vicinity. The highest values of238U and 232Th which are 48 ± 11 and 134 ± 9 BqKg−1 were found to be higher than the world average values of 30 and 40 BqKg−1 according to UNSCEAR. The mean value of radium equivalent (Raeq)activity of200.89±22.54BqKg−1lies within the limit of 370 BqKg−1 recommended by UNSCEAR. The meanabsorbed dose rate of 87.85 nGyh−1 is 4 % higher than the average world value according to UNSCAER 2000.The geospatial analysis revealed that the natural radionuclides in the region have a trend, NW-SE trending with significant re-deposition at the Southern part through diffusion which may be attributed the combinations of soil geology of Dahomey (Benin) Basin and human activities. 3D scatter and ribbon plots validates the strong positive correlation between the level of radioactivity distributions which is in the order of magnitudes 40K>232Th>238U in the study area. Significantly, the geospatial analysis of the background gamma dose rate has revealed the hot spot in the area that could pose high risk of contributing to indoor exposure if constructions are built for dwellers