ESTIMATION OF RADIOLOGICAL HEALTH HAZARD INDICES FROM NATURAL RADIOACTIVITY LEVELS IN GEM BERYL SAMPLES FROM OLODE, SOUTHWESTERN NIGERIA

Abstract

Gem beryl crystal samples obtained from mining sites in Olode area were investigated for their natural radioactivity due to 238U, 232Th and 40K. In-situ gamma ray doses were measured with Ludlum dose rate meter, at 1 meter above the surface, using laboratory-based gamma-ray spectroscopy. The mean activity concentrations for 40K, 226Ra and 232Th were 289.82 ± 11.0 Bq/kg, 5.99 ± 1.20 Bq/kg and 12.18 ± 1.50 Bq/kg respectively. The level of in-situ gamma-ray doses varied from 0.01µsv/h to 0.05µsv/h. The calculated mean absorbed dose rate (av. 23.06 nGy/hr) and mean radium equivalent (Raeq ) concentration (av. 45.68 Bq/Kg) were compared and found less than the respective world averages (55 nGy/hr, 370Bq/Kg). The calculated mean external (Hex) and internal (Hin) hazardous indices of 0.12 and 0.11 were less than the recommended limit of 1. The results therefore confirm that the beryl minerals being mined in Olode mining sites are not radiologically hazardous to human health. This study reveals that mining activities in Olode pose no radiological hazard to the general public, thereby ensuring environmental safety and public health protection. The findings contribute valuable data for sustainable mining practices and offer reassurance to communities, regulators, and industries that gemstone exploitation in the area is safe for both miners and end-users.

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