Toxicity of natural radioactivity in water samples from a gold mine in Gauteng Province, South Africa

Abstract

A radiological toxicity assessment of natural radioactivity in water samples from a gold mine in the Gauteng Province of South Africa was evaluated. In this study, 29 water samples were collected from the mine and 5 were collected from a control area. A broad energy germanium detector was used to measure the activity concentrations of Uranium-238, Thorium-232, and Potassium-40. Their activity concentrations were then used to calculate radiological hazard parameters in water for the area. The average value of the Radium Equivalent Activity (Raeq) in water samples from the mining area and from the control area was found to be lower than the allowable limit of 370 Bq.L-1. The Annual Effective Dose Equivalent (AEDE) was found to be equal to 1.29×10-3 mSv.y-1, a value below worldwide average of 2.4 mSv.y-1 for natural radiation. The external hazard (Hex) and internal hazard (Hin) index for water samples from the mining area were less than unity, making water samples safe to the population in the area.

Keywords

• broad energy germanium detector, natural radioactivity
• activity concentration, gold mine, radiological hazard