DIURNAL VARIATIONS OF RADON AND THORON ACTIVITY CONCENTRATIONS AND EFFECTIVE DOSES IN DWELLINGS IN NISKA BANJA, SERBIA

摘要

In Niska Banja, a spa town in a radon-prone area in southern Serbia, radon (~(222)Rn) and thoron (~(220)Rn) activity concentrations were measured continuously for one day in indoor air of 10 dwellings with a SARAD RTM 2010-2 Radon/Thoron Monitor, and equilibrium factor between radon and its decay products and the fraction of unattached radon decay products with a SARAD EQF 3020-2 Equilibrium Factor Monitor. Radon concentration in winter time ranged from 26 to 73 100 Bq m~(-3) and that of thoron, from 10 to 8650 Bq m~(-3). In the same period, equilibrium factor and the unattached fraction varied in the range of 0.08 to 0.90 and 0.01 to 0.27, respectively. One-day effective doses were calculated and were in winter conditions from 4 to 2599 μSv d~(-1) for radon and from 0.2 to 73 μSv d~(-1) for thoron.