T68 Environmental and Engineering Division Geology Student Research Competition (Posters)

Sunday, 22 October 2017
9:00 AM - 5:30 PM
Halls 4EF

POTENTIAL OCCUPATIONAL RADIATION EXPOSURE DUE TO NATURALLY OCCURING RADIOACTIVE MATERIALS (NORM) ARISING FROM EXPLOITATION OF RARE-METAL PEGMATITES OF THE IBADAN-OSHOGBO FIELDS, OLODE, IBADAN, SOUTHWESTERN NIGERIA

Paper number: T68-12
Program: Technical Sessions
Time: 9:00 AM – 5:30 PM

Authors

Abstract

Rock, ground water and mine waste samples collected from the Gbayo mines near Olode village, Southeastern Ibadan, Nigeria, were investigated with the aim of determining the levels of radioactivity due to naturally occurring radioactive materials (NORM) associated with gemstone (beryl) mining in the area, and to assess the health implications of the exploitation.

Fifteen (15) samples comprising rocks, mine wastes and water were obtained from three (3) mines while a sample of topsoil collected two kilometers away from the mine site served as control. The activity concentrations due to 214Bi in the 238U decay series and 208Tl in the 232Th decay series and 40K were determined using the HPGe gamma ray spectrometer at the National Institute for Radiation Protection and Research (NIRPR), University of Ibadan, Ibadan.

The activity concentration of the radionuclides from these samples range between 86.42 ± 6.67 Bq/Kg and 2200.71 ± 92.04 Bq/Kg, 3.00 ± 2.05 Bq/kg and 13.11 ± 5.81 Bq/kg, 6.09 ± 1.12 Bq/kg and 11.95 ± 1.97 Bq/kg for 40K, 238U and 232Th respectively. The absorbed dose rate for the samples range between 8.99 nGy/hr and 112.97 nGy/hr and their corresponding dose equivalent range between 0.005 mSv/yr and 0.692 mSv/yr. The gemstone bearing pegmatite rock from mine 1 has the highest dose equivalent value of 0.692 mSv/yr but this value is lower than the 1 mSv/yr threshold limit set by the International Commission on Radiation Protection (ICRP) for the general public.

Geological Society of America Abstracts with Programs. Vol. 49, No. 6

doi: 10.1130/abs/2017AM-306474

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