Habitat containing radon

Radon is found mainly in geographical areas following:

• Bretagne
• Corsica
• Massif Central
• Vosges.

You can consult a mapping to find out if your municipality is located in a radon potential zone.

The highest levels of radon are generally observed in regions whose geological formations are naturally rich in uranium, particularly granitic and volcanic subsoils.

However, living in one of these areas does not necessarily mean that your home contains radon. The presence and concentration of this gas depends on several factors such as the tightness between the building and the ground or the renewal of the indoor air.

To check for radon in your home, you can get a commercial dosimeter (or several dosimeters depending on the size of the housing).

For measurements to be reliable, they must be carried out in occupied rooms, located at the lowest levels of the dwelling (mainly the living room and rooms). The measurement must be carried out for a minimum period of 2 months and, preferably, during the heating period (from mid-september to end of april).

When the dosimeter result is greater than 300 becquerels (Bq)/m³, there is a risk to your health.

In this case, it is necessary to make works or put in place measures to reduce the radon concentration in your home.

These measures may include:

• Installation of a mechanical ventilation system or regular ventilation of all the rooms of the housing by opening the windows
• Renovation of basements (e.g. waterproofing) and pipes. The works must be carried out by companies competent in masonry or waterproofing and more particularly in climate engineering.