Indoor Radon Concentrations In Dwellings Research Articles

Mitigation Methods in High Radon Areas in Germany

A high radon content in soil is the main cause for high indoor radon concentrations in dwellings. The areas around Ellweiler/Hunsruck, Neuenburg/Oberpflaz and Schneeberg/Erzgebirge are known for their high uranium and radium concentrations in soil. An additional region is classified as a 'high radon area' although there are no known uranium anomalies. This region is situated in the Eifel near the Nurburgring in a terrain of volcanic origin. In the Eifel indoor radon values up to 1500 Bq.m-3 have been detected. The indoor values in Ellweiler and around Neuenburg range from several hundreds up to 8000 Bq.m-3, whereas in Schneeberg, radon concentrations up to 300,000 Bq.m-3 in cellars and 100,000 Bq.m-3 in living rooms have been found in some houses. A general mitigation method of equal efficiency for all high radon-exposed houses does not exist. The radon concentration in a recently built house has been reduced successfully to a tenth by a complete insulation of the walls and the floor of the cellar rooms. By removing the subsoil air below the insulated concrete plate of the cellar, the radon concentration has been diminished to 20% and additional air ventilation has halved the radon values again.