Radon in soil: new map provides information

Prediction: radon concentration in soil air (at 1 m depth)

The Federal Office for Radiation Protection has published a new map of the radon situation in Germany. The map shows the expected radon concentration in soil air at a resolution of 1x1 kilometres.

The map is aimed at everyone seeking information about the radon situation in their region. It can provide building planners with initial information as to whether they should consider radon measurements in the subsoil or additional protective measures against radon.

Radon in buildings increases the risk of lung cancer

Radon is a radioactive gas found in all soils. The higher the radon concentration in the soil, the higher the likelihood that large quantities of radon will enter buildings and accumulate there. If a person lives or works in rooms with increased radon levels for a prolonged period of time, they are at a greater risk of developing lung cancer.

Map with higher spatial resolution

The new radon map was developed based on new measurement data and with the help of machine learning. In addition, the calculations took account of existing measurement data, geology, soil characteristics and the climate. The map replaces an existing, older map.

Thanks to improved calculation methods and a larger data basis, the new map is significantly more accurate and has a higher spatial resolution than its predecessors.

Radon pathways from the soil to the surface

At the same time, there is less risk of underestimating the radon situation: whereas the old map indicated the expected average values, the values shown in the new map are selected so that the radon concentration present at a location in the soil is less than or identical to the value shown in the map in 90% of cases. For the remaining 10% of cases, higher levels cannot be ruled out due to localised geological characteristics.

Localised higher levels of radon in soil air that are atypical for the surrounding area cannot be precisely located using mathematical calculation methods. They can only be located or ruled out by taking radon measurements in the soil.

Map and specialist application available online

The "Radon in the soil" map is available as an overview map for the whole of Germany on the BfS website at www.bfs.de/radon-karte. Detailed research can be carried out using a specialist application known as the BfS-Geoportal.

Measuring radon in existing buildings

Incidentally, the map does not provide information on the radon concentration inside existing buildings or in the soil of an individual plot of land. This value must be determined by means of a radon measurement.

Radon measurements in buildings are cheap and straightforward to carry out. Please refer to www.bfs.de/radon-messen for more information.