The Swiss radon programme

The very high indoor radon concentrations found in the western part of Switzerland in the early80th were at the origin of an extended research programme between 1987 and 1991. The resultsobtained showed a real need for a further detailed radon programme. This should be based on thestate of knowledge, take economical aspects into account and be practically orientated. The mainaim is to deal with elevated concentrations. Thus three principal pillars were defined to achieve thisgoal: legislation, communication and formation.In 1994, the Swiss Legislation on Radiological Protection fixed a limit value of 1000 Bq/m3 and aguideline value of 400 Bq/m3 for residential and recreational premises. After the investigation ofabout one half of the 3000 municipalities, areas with high concentrations were found principally inAlpine and Jura regions. But, values overcoming the limit were also found on the Swiss Plateau. Inmore than 90% of the measured houses, the radon concentration is situated below the guidelinevalue, but in about one percent the radon concentration exceeds the limit. The arithmetic meanvalue is 75 Bq/m3 for inhabited rooms.The communication with different target groups regarding radon and its harmful effects on healthis very important too. House owners must be motivated to perform measurements and to carry outremedial work if necessary.Finally, construction experts must know the different possibilities to reduce the radon gasconcentrations in the residential and recreational premises. Therefore, an efficient collaborationwith educational establishments and the different professional associations has to be realised.