Approach to identification of radon areas in germany

According to the recommendations of the ICRP and the German Commission on RadiologicalProtection, areas should be identified where increased radon concentrations in buildings occur morefrequently than on the country-wide average. Such regions are characterized by an increased radonpotential of the building ground. The highest indoor concentrations were measured in old houses ofgranitic ground and in mining regions.The identification of such areas in the first step is based on a small-scale investigation of the geogenicradon potential. Following this, the territories with an elevated radon potential will be investigatedmore detailed with respect to geology and indoor radon measurements.The great influence of the building condition on the radon concentration in houses will be investigatedin current research projects.Taking into account the regional distribution of the geogenic radon potential, it can be assumed that itis rather unlikely to measure indoor radon concentrations > 250 Bq/m in dwellings (being the upperlimit of the the normal range in Germany) in about 25% of the area in Germany. Radon concentrations> 1000 Bq/m in living rooms can be excluded in these regions. There is no need for indoor radonmeasurements and the planning of development areas can be carried out without consideration ofradon protection measures in these areas.