Public exposure to radon and thoron progeny in Romania

Abstract

The purpose of our work was to determine the activity concentrations of short-lived decay products of radon and thoron in dwellings and in free air and to evaluate, in terms of effective doses, the magnitude of the resulting annual exposure of population in eastern Romania. The activity concentrations of 218Po, 214Pb, 214Bi and 212Pb have been measured in 684 typical urban and rural houses. The average values of EEC of radon were 28 Bq m −3 in detached houses and 9 Bq m −3 in block of flats, with individual values ranging from 3.8 to 564 Bq m −3. The average values of EEC of thoron were of 1.3 Bq m −3 in detached houses and 0.6 Bq m −3 in block of flats, with individual values ranging from 0.1 to 12.8 Bq m −3. Outdoor average values of EEC were 4.6 Bq m −3 for radon progeny and 0.2 Bq m −3 for thoron progeny. The overall annual effective dose per capita was 2.0 mSv (1.65 mSv from radon progeny and 0.35 mSv from thoron progeny) with a corresponding annual collective effective dose of 10,370 manSv.