Estimating indoor radon concentrations based on the uranium content of geological units in South Africa

Very few studies have been done on radon in South Africa, even though South Africa holds nearly a tenth of the global uranium deposits. This study aimed to map and estimate the radon risk for South Africa, and to identify potential hotspots. In this study, the uranium content of the different types of rock was determined and uranium concentrations in geological units were then projected. A uranium distribution map of South Africa was then constructed, and indoor radon concentrations were estimated and mapped based on the uranium levels of areas. Towns in areas where indoor radon measurements were conducted compared well with the estimated radon values. The maps predicted high estimated indoor radon concentrations in areas at several geological structures. Towns in these areas that have not been measured were identified. The south-western and north-eastern regions of South Africa pose the highest radon risk according to this study, and extensive radon measurements in the towns of these regions is proposed.