Survey of indoor radon (Rn-222) entry and concentrations in different types of building in Kalisz, Poland

Indoor radon ( 222 Rn) was surveyed in a total of 141 individual houses and apartments used precalibrated passive PicoRad Detectors. The radon activity in the soil gas around the dwellings was simultaneously measured. The arithmetic mean values of indoor radon concentrations for detached houses, old buildings (up to four-stories), prefabricated blocks of flats (mostly five stories) and high-rise residential buildings (10-stories) were:, 70.9; 46.5; 38.4, and 56.6 Bq m −3 , respectively. The average arithmetic mean value for all measured rooms equals 51.8 Bq m −3 . The calculated average effective dose from indoor radon for the local population was equal to 2.2 mSv.