Meteorological parameters contributing to variability in 222Rn activity concentrations in soil gas at a site in Sapporo, Japan

Continuous 222Rn monitoring in soil gas since November 22, 2004 has revealed variability in activity concentration with time in the semi-natural woods on the campus of Hokkaido University in Sapporo, Japan. Among various factors affecting soil radon levels and variability, temperature was found to be dominant during three seasons when activity concentrations of 222Rn showed a diurnal high and nocturnal low with a boundary around 10 o'clock in the morning. This pattern was disturbed by low pressure fronts with occasional rain. The activity gradually decreased as soil temperatures decreased from late November to mid-December. After the ground surface was completely covered with snow, soil radon levels became low with a small fluctuation. There were several peaks of 222Rn on the time-series chart in winter. Those peaks appearing in early winter and early spring may be interpreted by considering meteorological parameters. In a few cases, the radon activity suddenly increased with increasing pressure in the soil at a depth of 10 cm, which may be associated with subsurface events such as seismic activity in the area

Radon levels and resulting effective doses of residents in Gornja Stubla at Kosovo applying dosimetric lung models based on ICRP 65 and ICRP 66 methodology

The town Gornja Stubla, situated in the South-West part of Kosovo, is a community with high indoor radon level due to its geochemical background. Radon activity concentration in indoor air has been measured by exposing the 960 track-etch detectors for one year, in 172 rooms of 65 dwellings. Annual averages of concentration ranged from 35 Bq/m3 to 6010 Bq/m3. In a first attempt, the effective doses of residents have been calculated applying the ICRP 65 methodology, based on the average radon concentration for the dwelling and for concentrations in the rooms of a dwelling in which they spend fractions of the entire time spent indoors. Both seasonal and annual doses have been calculated. The annual values were in the range of 0.6−107 mSv/a with an average value of 8.6 mSv/a. As nest step we considered that effective dose, being influenced by a number of different parameters and divided into subject and aerosols related parameters, is connected with two crucial parameters, namely, the Dose Conversion Factor (DCF) [mSv/WLM] for a particular person (accounting for real gender, age and physical activity level) and indoor radon concentration and its short lived progeny at field area. Therefore, software based on ICRP Publication 66 was developed for determination of effective dose per unit inhaled activity of radon progeny, DCF. According to the results of indoor radon measurements in the area of Gornja Stubla, the effective dose for its population was estimated by using the dosimetric lung model. The results, obtained according to ICRP 66, were compared with results calculated according to ICRP Publication 65

Radon and thoron doses in kindergartens and elementary schools in Slovenia

International Symposium on Natural Radiation Exposures and Low Dose Radiation Epidemiological Studie

Radon progeny measurement and dose estimation in Hungarian workplaces

A preliminary study of radon concentration and air-quality parameters in Hungarian workplaces revealed that using the same dose conversion factor (7.9 nSv m3 Bq-1 h-1 recommended by ICRP) – e.g. in case of a deep mine and a medicinal bath – may considerably reduce the reliability of the estimated dose.In order to gain more information related to this dose estimation problem, it was necessary to measure radon and its short-lived progenies concentrations; the unattached fraction of radon short-lived progenies; the equilibrium factor; along with temperature and the relative humidity not only in a medicinal bath (14 days) but also in a tourist cave (7 days), in a medicinal cave (7 days), in a manganese deep mine (9 days) and in a deep geological radioactive waste depository under construction (7 days) in Hungary. With the above data obtained, new specific dose conversion factors were determined taking respiration through the nose and through the mouth into consideration. Calculating with the annual labour hours related to each workplace, the effective dose of the workers was estimated.For the radon medicinal bath, the calculated dose conversion factors, distinguished nose and mouth respiration, were lower than the recommended 7.9 nSv m3 Bq-1 h-1, respectively. For the tourist cave, the medicinal cave, the manganese deep mine and the deep geological radioactive waste depository, the dose conversion factors were higher than the recommended one causing significant differences in dose estimation.9th International Conference on High Level Environmental Radiation Areas-For Understanding Chronic Low-Dose-Rate Radiation Exposure Health Effects and Social Impacts (ICHLERA 2018

Thoron, radon and air ions spatial distribution in indoor air

Spatial distribution of radioactive gasses thoron (Tn) and radon (Rn) in indoor air of 9 houses mostly during winter period of 2013 has been studied. According to properties of alpha decay of both elements, air ionization was also measured. Simultaneous continual measurements using three Rn/Tn and three air-ion active instruments deployed on to three different distances from the wall surface have shown various outcomes. It has turned out that Tn and air ions concentrations decrease with the distance increase, while Rn remained uniformly distributed. Exponential fittings function for Tn variation with distance was used for the diffusion length and constant as well as the exhalation rate determination. The obtained values were similar with experimental data reported in the literature. Concentrations of air ions were found to be in relation with Rn and obvious, but to a lesser extent, with Tn

Two examples of high radon levels in living environment in Slovenia

International Symposium on Natural Radiation Exposures and Low Dose Radiation Epidemiological Studie

Measurement of unattached fraction of radon progeny in Hungarian workplaces

International conference on Radioecology and environmental radioactivit