Investigating the vertical and spatial extent of radon-based classification of the atmospheric mixing state and impacts on seasonal urban air quality.

A recently-developed radon-based method for combined classification of both diurnal and synoptic timescale changes in the atmospheric mixing state is applied to 1-year of observations in Ljubljana (capital of Slovenia). Five diurnal-timescale mixing classes (#1 to #5) were defined for each season along with an additional mixing class (#6) in non-summer months, representative of synoptic-timescale changes of the atmospheric mixing state associated with "persistent temperature inversion" (PTI) events. Seasonal composite radiosonde profiles and mean sea level pressure charts within each mixing class are used to demonstrate the link between prevailing synoptic conditions and the local mixing state, which drives changes in urban air quality.

Analysis of Ventilation Efficiency as Simultaneous Control of Radon and Carbon Dioxide Levels in Indoor Air Applying Transient Modelling.

The impact of ventilation efficiency on radon (Rn) and carbon dioxide (CO) concentrations in the indoor air of a residential building was studied by applying transient data analysis within the CONTAM 3.4 program. Continuous measurements of Rn and CO concentrations, together with basic meteorological parameters, were carried out in an apartment (floor area about 27 m) located in Ljubljana, Slovenia.

Determination of optimal ventilation rates in educational environment in terms of radon dosimetry.

Introduction: New and renovated energy efficient buildings with minimised ventilation rates together with increased building airtightness are often associated with higher indoor radon concentrations compared to the concentrations in existing buildings. The purpose of our study is to analyse the problem associated with the increased radon concentration and ventilation requirements and recommendations in schools. The radon concentration was critically assessed by varying the design ventilation rates (DVRs) within fifteen cases according to legislative requirements and recommendations.

OCCUPATIONAL EXPOSURE ASSESSMENT AT A THERAPEUTIC RADON SPA FACILITY IN HUNGARY.

In order to estimate occupational exposure of workers in a therapeutic radon spa facility, radon concentration in the workplace air was investigated at Markhot Ferenc Hospital, Eger, Hungary. The investigated balneotherapeutic facility and its natural hot spa water are used for treatments and rehabilitations of rheumatic patients. Radon concentration, radon decay products at a bathhouse, treatment rooms and a consultation room were continuously measured in August and September 2018.

EFFECTIVE DOSES DUE TO OUTDOOR AND INDOOR RADON AT A MEDITERRANEAN SITE.

A year-long continuous measurement of the radon activity concentration in the outdoor air at a Mediterranean site has shown a range of 2-144 Bq m-3 and annual mean of 18 ± 14 Bq m-3. Seasonal means were: 15 ± 10 Bq m-3 in winter, 15 ± 12 Bq m-3 in spring, 22 ± 19 Bq m-3 in summer and 17 ± 12 Bq m-3 in autumn. In summer, the average radon activity concentration in the daytime (6-22 h) was 15.

Radon-based atmospheric stability classification in contrasting sub-Alpine and sub-Mediterranean environments.

A recently-developed radon-based technique is used to investigate relative changes in summertime atmospheric stability at two sites in Slovenia with contrasting geographical settings. Although atmospheric stability for both sites (50 km apart) was shown to be governed by similar synoptic conditions, their contrasting settings caused differences in mixing conditions for each stability category. At the urban sub-Alpine site Ljubljana, situated within a topographic basin, wind speeds associated with the most stable conditions were 0.

EFFECTIVE DOSES ESTIMATED FROM THE RESULTS OF DIRECT RADON AND THORON PROGENY SENSORS (DRPS/DTPS), EXPOSED IN SELECTED REGIONS OF BALKANS.

The main contribution to population exposure is due to radon and thoron progenies and not radon itself. The aim of this study was therefore to estimate annual effective dose using the results of Direct Radon and Thoron Progeny Sensors were exposed in 69 selected schools and 319 dwellings in several regions of Balkans: in Serbia: regions of Sokobanja and Kosovo and Metohija, Republic of Macedonia, Republic of Srpska and Slovenia. Obtained average total effective doses are in the range from 0.

F-choline PET/CT for parathyroid scintigraphy: significantly lower radiation exposure of patients in comparison to conventional nuclear medicine imaging approaches.

Background: Parathyroid subtraction scintigraphy (PSS) is the most commonly used imaging method for localisation of hyperfunctioning parathyroid glands (HPGs) in primary hyperparathyroidism (PHP), a common endocrine disorder. Hybrid (SPECT/CT) imaging with Tc-sestaMIBI (MIBI) at an early and delayed phase (dual-phase imaging) may be the most accurate conventional imaging approach, but includes additional radiation exposure due to added CT imaging. Recently, F-choline (FCH) PET/CT was introduced for HPG imaging, which can also be performed using the dual-phase approach.

Comparison of radon doses based on different radon monitoring approaches.

In 43 places (23 schools, 3 kindergartens, 16 offices and one dwelling), indoor radon has been monitored as an intercomparison experiment, using α-scintillation cells (SC - Jožef Stefan Institute, Slovenia), various kinds of solid state nuclear track detectors (KfK - Karlsruhe Institute of Technology, Germany; UFO - National Institute of Radiological Sciences, Chiba, Japan; RET - University College Dublin, Ireland) and active electronic devices (EQF, Sarad, Germany). At the same place, the radon levels and, consequently, the effective doses obtained with different radon devices differed substantially (by a factor of 2 or more), and no regularity was observed as regards which detector would show a higher or lower dose.

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.

The potential health hazard due to elevated radioactivity in old uranium mines in Dolina Białego, Tatra Mountains, Poland.

Natural radioactivity is one of the essential components of the environment. Unlike the Sudety mountains area in Poland, the Tatra Mountains were not the subject of wide survey as regards the levels of natural radioactivity. Especially, the concentrations of radon (natural radioactive gas) have not been investigated there in terms of their possible negative health impact.

Systematic survey of natural radioactivity of soil in Slovenia.

Soil samples, from 70 points uniformly distributed over entire Slovenia, were analysed for (40)K, (232)Th and (226)Ra using gamma spectrometry, and for (234)U and (238)U using alpha spectrometry. The following ranges and averages of activity concentrations (Bq kg(-1)) were obtained: 98-2600 and 800 ± 520 for (40)K, 9-170 and 77 ± 33 for (232)Th, 12-270 and 63 ± 44 for (226)Ra, 12-84 and 34 ± 19 for (234)U, and 11-90 and 34 ± 19 for (238)U. With respect to lithology, the highest average values for (40)K and (232)Th were found at clastic sediments containing clay and for (226)Ra on carbonate rocks.

Prokaryotic and eukaryotic airborne microorganisms as tracers of microclimatic changes in the underground (Postojna Cave, Slovenia).

Bioaerosols in cave air can serve as natural tracers and, together with physical parameters, give a detailed view of conditions in the cave atmosphere and responses to climatic changes. Airborne microbes in the Postojna Cave system indicated very dynamic atmospheric conditions, especially in the transitory seasonal periods between winter and summer. Physical parameters of cave atmosphere explained the highest variance in structure of microbial community in the winter and in the summer.

Nanoaerosols including radon decay products in outdoor and indoor air at a suburban site.

Nanoaerosols have been monitored inside a kitchen and in the courtyard of a suburban farmhouse. Total number concentration and number size distribution (5-1000 nm) of general aerosol particles, as measured with a Grimm Aerosol SMPS+C 5.400 instrument outdoors, were mainly influenced by solar radiation and use of farming equipment, while, indoors, they were drastically changed by human activity in the kitchen.

Dose estimation and radon action level problems due to nanosize radon progeny aerosols in underground manganese ore mine.

One of the essential parameters influencing of the dose conversion factor is the ratio of unattached short-lived radon progeny. This may differ from the value identified for indoor conditions when considering special workplaces such as mines. Inevitably, application of the dose conversion factors used in surface workplaces considerably reduces the reliability of dose estimation in the case of mines.

Effect of radon measurement methods on dose estimation.

Different radon measurement methods were applied in the old and new buildings of the Turkish bath of Eger, Hungary, in order to elaborate a radon measurement protocol. Besides, measurements were also made concerning the radon and thoron short-lived decay products, gamma dose from external sources and water radon. The most accurate results for dose estimation were provided by the application of personal radon meters.

Tracing the sources of gaseous components (222Rn, CO2 and its carbon isotopes) in soil air under a cool-deciduous stand in Sapporo, Japan.

Radon ((222)Rn) and carbon dioxide were monitored simultaneously in soil air under a cool-temperate deciduous stand on the campus of Hokkaido University, Sapporo, Japan. Both (222)Rn and CO(2) concentrations in soil air varied with atmospheric (soil) temperature in three seasons, except for winter when the temperature in soil air remained constant at 2-3 degrees C at depth of 80 cm. In winter, the gaseous components were influenced by low-pressure region passing through the observation site when the ground surface was covered with snow of ~1 m thickness.

Levels of nanosize radon decay products in indoor air: a comparison for different environments.

The fraction of unattached (fun) nanosized 222Rn short-lived decay products in indoor air has been measured in different environments and the following ranges obtained: 0.03-0.25 in kindergartens, 0.

Radon concentration in thermal water as an indicator of seismic activity.

Radon concentration in thermal springs at Hotavlje and Bled has been measured from October 2005 to June 2008 and from October 2005 to September 2007, respectively. At both locations several anomalies in radon concentration were observed, that might have been caused by seismic events. In this study all earthquakes with ratio (D/R) between strain radius (D) and distance to the epicenter (R) greater than 0.

Comparison of various methods of estimating radon dose at underground workplaces in wineries.

Levels of radon were surveyed in the air at underground workplaces of eight major Slovenian wineries. Geometric mean and geometric standard deviation values, respectively, obtained with different devices were 81 Bq m(-3) and 2.3 with alpha scintillation cells, 114 Bq m(-3) and 2.

Dissolved radon and gaseous mercury in the Mediterranean seawater.

Vertical profiles of radioactive radon gas ((222)Rn) and dissolved gaseous mercury (DGM) in seawater in the Mediterranean Basin have been measured. They were found in the range 1.7-19.

Nanosize radon short-lived decay products in the air of the Postojna Cave.

At two points in the Postojna Cave, short-term monitoring in summer and in winter of air concentrations of radon and radon decay products, equilibrium factor, unattached fraction of radon decay products (f(un)), barometric pressure, relative air humidity in the cave and air temperature in the cave and outdoor has been carried out, with the emphasis on f(un). Dose conversion factors, calculated on the basis of f(un) values obtained (ranging from 0.09 to 0.

Nano-size radon short-lived progeny aerosols in Slovenian kindergartens in wintertime.

Indoor air concentrations of radon and radon short-lived decay products, equilibrium factors, unattached fractions of radon short-lived decay products (f(un)), relative humidity, and temperature have been measured in 29 rooms of 13 Slovenian kindergartens, with an emphasis on f(un) as a crucial parameter in dose assessment. Dose conversion factors, based on the measured f(un) values were compared to epidemiology-based value of 5 mSv WLM(-1).

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

Continuous (222)Rn 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 (222)Rn 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.