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RADIOACTIVITY IN BALNEOTHERAPY IN HUNGARY AND SLOVENIA

P.Szerbin 1 , J.Vaupotic 2 , Gy.Köteles 1 , I.Csige 3 , I.Kobal 2 and I.Hunyadi 3 ,
1 "Frédéric Joliot-Curie" National Research Institute for Radiobiology and Radiohygiene, POB 101,
1775 Budapest, Hungary 2 “J. Stefan“ Institute, Jamova 39, POB 3000, 1001 Ljubljana, Slovenia 3 Institute of Nuclear Research of Hungarian Academy of Science, POB 51, 4001 Debrecen,
Hungary

ABSTRACT
In Hungary and Slovenia a lot of thermal water occurrences providing mineral water for spas are
used for curative therapeutic purposes in cases of locomotor and gastrointestinal diseases. In these
balneotherapeutic facilities the atmosphere can contain radon and radon daughters at high
concentrations. Radon diffusing from the pores and cracks of the minerals being dissolved in
underground waters is taken up by spa wells and in the spas the radon emanates from the water. In
the premises of balneotherapy workers can sometimes be exposed to radiation at levels, comparable
to those of uranium miners. The aim of the study was to identify the site-specific radon sources,
variation of the radon concentration, and to estimate the dose to the personnel, patients and visitors
of these facilities from the radon daughters.
Sampling was performed in intervals, sufficient to reveal diurnal and seasonal variations of radon
concentrations. By simultaneous radon and radon progeny measurements (Pylon Electronics Inc.
AB-5 type monitors, CPRD passive radon detector and AEP-47 working level detector, and
SARAD 3020) the equilibrium factor was usually about 0.5, this value was used in dose
calculations. Besides, nuclear track and electret detectors were used for long-term integrated
measurements of radon concentrations (Radamon, E-perm). From the mean radon concentrations
cumulative WLM exposures, bronchial dose and effective dose equivalent values were calculated
for the staff and visitors.
Systematic diurnal variations of radon concentrations were found in some thermal spas. The diurnal
variations of the radon levels were attributed to the technology of operation of the bath. It was
shown, that the ventilation can significantly reduce the radon concentration at balneotherapeutic
workplaces. The effective dose equivalent values for the spa personnel generally do not exceed the
20 mSv per year limit, recommended for workers by the ICRP 60 publication. In cases when
calculated dose was higher, the management of the bath was recommended to introduce a more
effective ventilation system or reduce the occupancy in the high radon atmosphere. The doses for
visitors and patients were one or two magnitude lower, than that of the personnel.