Monitoring the radon flux from gold-mine dumps by gamma-ray mapping

The exhalation of radon from the large mine dumps at the gold mines in South Africa is a potential health hazard. Determination of radon fluxes from these dumpsites is problematic due to the scatter in the data in time and place and the cost involved in getting a representative sample. gamma-ray spectroscopic analysis of soil samples from a dumpsite indicates that as much as 30% of the formed radon may escape, resulting in a disturbance to the secular equilibrium of the U-238 decay series. A method is proposed to quantitatively assess the radon flux from such dumpsites by using a mobile gamma-ray detector system. (C) 2003 Elsevier B.V. All rights reserved.