GIS Mapping and Background Ionizing Radiation (BIR) Assessment of Solid Mineral Mining Sites in Enugu State, Nigeria

Abstract

A study of the external background ionizing radiation (BIR) levels in eight solid mineral mining sites in Enugu State has been carried out using two Digilert radiation monitors Radalart-50 and Radalart-100. Thirty two readings of four samplings in each point were taken at different solid mineral sites of the state following standard procedure. The measured BIR levels obtained ranged from 0.012 mR/hr in Nkpologwu silica mining site to 0.028 mR/hr in clay mining site in Enugu-Ekulu with an average of 0.018 ± 0.004 mR/hr, while the corresponding calculated equivalent dose rate ranged from 1.0 mSv/yr to 2.35 mSv/yr with a mean value of 1.51 ± 0.04 mSv/yr. The result obtained indicates that the average exposure level of the studied area is 38.5% higher than the international standard. This suggests the possibility of the presence of radionuclide in the solid minerals mined in Enugu state. However, the values obtained may not cause immediate health challenge to miners and those engaging in commercial activities around these mining sites in Enugu, but may result in long-term health side-effects to residence and miners who put in over twenty-five years in the job. From the forgoing, it is recommended that control mechanism should be adopted for the members of the public, residence, commercial traders as well as miners working in these sites, and to protect the environment.