Authors : Nwankpa and Alexander Chinyere
Abstract: Gold miners may be exposed to gamma radiation due to radionuclide contaminants associated with the gold. Twenty samples of soil were collected from different illegal mining locations in Erinmo in Osun State of Nigeria and were counted using the high purity germanium detector. The radionuclides identified in all the samples with reliable regularity are 238U, 232Th and 40K. The 238U concentrations in soil range from 9.01±1.7-35.4±3.7 Bq kg–1 with an average of 21.9±2.1 Bq kg–1. The mean specific activities for 232Th range from 10.9±2.8-37.5±4.6 Bq kg–1 with an average of 23.4±2.9 Bq kg–1 and the mean specific activities for 40K in soil ranged from 99.0±12.3-182.8±18.5 Bq kg–1 with a mean of 136.5±18.2 Bq kg–1. The uranium and thorium specific activities fall within the earth crustal mean for normal environmental, hence, no uranium or thorium deposit could be said to be in Erinmo. The total absorbed dose rate in air for Erinmo in Osun State ranged between 15.4 and 47.2 nGyh–1 with an average of 30.7 nGyh–1. The average value of the absorbed dose rate obtained in this work represents 55.8% of the world average of value of 55.0 nGyh–1. These are within the ICRP limit of maximum permissible dose per hour for a radiation worker. Thus, the illegal mining of goldin Erinmo Osun state poses no serious danger to the populace.
Nwankpa and Alexander Chinyere, 2019. Gamma Radiation Associated with Gold Mining in Erinmo, Osun State, Nigeria. Environmental Research Journal, 13: 79-82.