220Rn and its progeny in dwellings of Korea

Concentrations of 220Rn and its progeny were measured in 450 dwellings from 2002 to 2004 using two kinds of simple passive 222Rn and 220Rn monitors, RadopotTMRadopotTM and 220Rn progeny monitor. The annual arithmetic mean (AM) and geometric mean (GM) of 220Rn concentrations were 40.4 and 10.7Bqm-3, respectively. The annual arithmetic mean (AM) of EECTnEECTn concentration was 0.89±0.70Bqm-3, and the annual geometric mean (GM) was 0.60Bqm-3 (95% confidence interval: 0.43–0.78Bqm-3). The concentrations of 220Rn in Korean-style houses built with mud block were about two times higher than those in apartments. The average annual effective dose due to inhalation exposure to 220Rn and its progeny in dwellings was 0.25mSvy-1.