Health

The risk of lung cancer increases when radon, a naturally occurring radioactive gas, accumulates in rooms. Based on recent scientific evidence, the Federal Council in 2011 adopted the “National Action Plan concerning Radon 2012-2020”.

Radon risk map of Switzerland
Radon risk in Switzerland: arithmetic means of the municipalities
© FOPH

Summary

Radon arises from the decay of uranium in the soil zone and is present there in variable concentrations. The more permeable the soil is, the easier the gas rises to the Earth’s surface. Because a slight negative pressure often prevails in occupied houses, it is practically sucked in and accumulates in rooms – especially if the building is not sufficiently sealed off from the ground.

The risk of lung cancer increases when radon is regularly inhaled in elevated concentrations. In Switzerland, radon is the second most common cause of lung cancer and results in 200 – 300 deaths annually. The geological and climatological conditions in Switzerland aggravate the problem: uraniferous granite regions and karst soils, long heating periods with little ventilation.

The radon concentration – measured in Becquerel per cubic meter [Bq/m3] – is easily and economically recorded using small dosimeters. The Radiation Protection Ordinance (StSV) of 22 June 1994 provides for a limit of 1,000 Becquerel per cubic meter (Bq/m3) in living and recreation rooms. The guideline value for new and renovated buildings is 400 Bq/m3. Based on latest epidemiological studies, international committees now recommend a maximum value of 300 Bq/m3. The whole of Switzerland is therefore affected by the radon problem. In 2011 the federal government adopted a national radon action plan that defines measures for an adaptation strategy up to 2020, in particular the revision of the Radiation Protection Ordinance. The Federal Office of Public Health (FOPH) will reassess the radon risk map based on the revised legal framework.

Who is who

In 2011 the federal government adopted a national radon action plan that defines measures for an adaptation strategy up to 2020, in particular the revision of the Radiation Protection Ordinance. The Federal Office of Public Health (FOPH) will reassess the radon risk map based on the revised legal framework.


Cantonal geoportals more accurately portray the radon risk.


The institute of radiophysics (CHUV) in Lausanne is developing modeling software for the Federal Office of Public Health (FOPH) in order to produce accurate radon maps (from 2014)

Data

Health: Data

The radon risk map displays the arithmetic mean for each municipality. The measured values in living rooms and recreation rooms per municipality determine a low, medium or high risk category. In some cases, the cantons have rated the municipalities based on other criteria such as for example according to the geology or if the radon risk was estimated with insufficient measurements.


Cantonal geoportals more accurately portray the radon risk.


Predictive modeling of radon concentrations is being researched at the institute of radiophysics (CHUV) in Lausanne. Measurements from buildings as well as natural environment factors (e.g., sediment thickness, tectonics or lithology) are used as input.


Geology in everyday life