A study of environmental radioactivity measurement of selected Kaolin mining fields in Kwara, Nigeria

Abstract

This article reports an in-situ measurements of the background gamma radiation dose rates and the activity concentrations of 238U, 232Th and 40K, at kaolin mining-fields in Ilorin-south and Ilorin-west, Kwara, Nigeria. Readings were recorded in 90 randomly selected sample points. For Ilorin-south mining site 50 sample points were recorded, while 40 randomly selected sample points were considered for Ilorin-west mining site. A handheld RS-125 Super-Spec gamma spectrometer was utilized to perform the radioactivity measurements on both mine fields. The results of the activity concentrations showed that the locations are enhanced with 40K activity concentration compared with 238U and 232Th. The mean values of 40K, 238U, 232Th and DR for Ilorin-west were found to be 492.19, 35.63, 44.07 Bqkg−1 and 63.28 nGyh−1, respectively. While the mean values for the measured activity concentrations of 40K, 238U, 232Th and DR for Ilorin-south are 263.55, 52.24, 31.29 Bqkg−1 and 54.71 nGyh−1, respectively. Consequently, the mean values of the estimated radiological hazard parameters of Ilorin-west were higher than the estimated mean values for Ilorin-south. This shows that the Ilorin-west Kaolin mine field poses more significant source of radiation hazard. The results in this current work can be used as a significant baseline radioactivity data of the mining areas in Nigeria for future epidemiology and monitoring purposes.

Keywords

• Kaolin
• mining
• Nigeria
• radioactivity
• radiological risk