The regional distribution of indoor radon concentration in Germany

摘要

According to the recommendations of the ICRP and the German Commission on Radiological Protection, areas should be identified where increased radon concentrations in buildings occur more frequently than on the countrywide average. Based on investigations of radon concentration in soil air, the areas of Germany have been classified. Comparing the soil gas classes with the radon concentrations in dwellings, we found that in regions with a soil gas radon concentration of up to 10 kBq/m~3 (about 25% of the total area of Germany), the probability that indoor concentrations above 400 Bq/m~3 occur is in the order of 0.1%; values of more than 1000 Bq/m~3 can be excluded. The assessment of about 20 000 indoor measurements in areas with radon concentrations in soil air in the range between 10 and 100 kBq/m~3 showed that radon concentrations >400 Bq/m~3 occur only in 0.2% of the investigated dwelling stock. However, occurrences of more than 1000 Bq/m~3 cannot be excluded completely. A rather clear increase of the number of dwellings with radon concentrations greater than 400 and 1000 Bq/m~3 has been found in areas with soil gas radon concentration >100 kBq/m~3 (about 6% of the area).