Long-term outdoor radon levels in mining regions of Germany

Mining residues can potentially contribute to increased outdoor radon concentrations in mining regions. Surveillance was carried out to determine the long-term average values for outdoor radon concentrations at many different sites. Subsequently, the results of the measurements were evaluated. The natural concentration level for most of the mining regions concerned was assessed. Average values for radon concentrations in residential areas exceed a value of 80 Bq/m3, only in four mining regions. In addition, the effects of remedial actions carried out by the Wismut company in the mining region of Ronneburg were analyzed. Only values for radon concentrations at locations close to mining relics were correlated with decommissioning and remediation activities. (orig.)