Radioactivity and radiological hazards from a kaolin mining field in Ifonyintedo, Nigeria

T.A Adagunodo,A.I George,I.A Ojoawo,K Ojesanmi,R Ravisankar

doi:10.1016/j.mex.2018.04.009

Abstract

The concentrations of the radionuclides in the subsurface formation (soils and rocks) solely depend on their geological origin, which enables its variation from point to point on the Crust. Construction materials can possess elevated concentrations of radioactivity if their byproducts are mined from contaminated radionuclide sources. In this article, results of in situ measurements of radioactivity concentrations of 40K, 232Th, and 238U as well as gamma doses and radiological hazards from kaolin mining field were presented and evaluated. Eleven stations were randomly occupied in order to cover the upper axis of a kaolin mining field in Ifonyintedo. The radiometric survey was achieved using Super-Spec (RS-125), equipment capable of measuring activity concentrations and gamma doses. For each location, measurements were taken four times, while its mean and standard deviation values were estimated for better accuracy. The overall mean activity concentrations (for 40K, 232Th and 238U) and gamma dose were estimated as 93.9?Bq?kg-1, 65.1?Bq?kg-1, 38.2?Bq?kg-1, and 59.6?nGyh-1 respectively. The estimated radiological hazards from the measured parameters showed that the overall mean concentrations of Radium Equivalent, External and Internal Hazards, Annual Effective Dose, Gamma and Alpha Indices, and Representative Level index are 138.5?Bq?kg-1, 0.37 0.48, 0.29?mSvyr-1, 0.48, 0.19, and 0.97 respectively. By comparing the mean values of the activity concentrations and their radiological risks with the several world standards from the literature, kaolin deposits in Ifonyintedo are highly rich in thorium.

Highlights

When compared to the limit, it has been revealed that the range is slightly above the limit, while the overall mean %1. This implies that the Representative Level Index (RLI) of kaolin deposits in the upper axis of Ifonyintedo field may pose radiation hazard, which might be harmful to the miners and the users of the product(s) from the kaolin deposits if proper periodic monitoring and assessment are neglected on the field
For the eleven locations covered in this study, the radiometric measurements of radioactivity concentrations of 40K, 232Th and 238U as well as the gamma doses over a kaolin mining field in Ifonyintedo, Nigeria were achieved using Super-Spec (RS-125) detector
The radiological hazards associated with mining of this mineral deposits and its usability as building material were evaluated

Summary

Method Article

Radioactivity and radiological hazards from a kaolin mining field in Ifonyintedo, Nigeria. T.A. Adagunodoa,*, A.I. Georgea, I.A. Ojoawob, K. Ravisankard a Department of Physics, Covenant University, Ota, Ogun State, Nigeria b Department of Physics, University of Ibadan, Ibadan, Oyo State, Nigeria c Department of Chemistry, Covenant University, Ota, Ogun State, Nigeria d Post Graduate and Research Department of Physics, Government Arts College, Tiruvanamalai 606603, Tamilnadu, India

Method details

Materials and methods

Method descriptions

Findings

Conclusion