Application of the tracer gas technology to investigate convective radon transport processes between mine workings and houses

In areas featuring air-filled mine workings the convective radon transport through the disturbed bedrock is a frequent cause of high radon concentrations in dwellings. The vertical transport distance of the radon propagation can be more than one hundred meters. The application of tracer gases that can be detected by gas chromatography at extreme low concentrations allows the clear detection of mine-originated radon in dwellings and provides knowledge on the complex processes of radon transport. The successful application of the method is demonstrated on the basis of investigations of the impact of former uranium mine sites on the radon situation in dwellings.