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Urine, hair and nail samples were collected from a population of both sex aged from 40 to 87 years in Niška Banja (227 km south of Belgrade, Serbia) with a high level of natural radioactivity (HLNRA). To assess and monitor the public exposure, urine samples for each subject (24 h period) were collected and concentration of uranium (U) was analysed using alpha-particle spectrometry. Human hair and nails considered as bio-indicators of the public exposure to radionuclides over a long period of months or even years and concentration of U was determined using inductively coupled plasma-mass spectrometry. The mean concentrations of U in urine, hair and nail were 123 ng/L, 17 ng/g and 8 ng/g, respectively. There was a large variation and may be due to geological origin.

The requirements about radon measurements in schools and public buildings included in most of the national and international legislations are generally restricted to all the rooms located at the ground floor and basement, assuming the soil beneath the building as the main source of indoor radon. In order to verify such an assumption for small buildings having at maximum two floors, a preliminary study was performed in 50 schools located in 15 municipalities of the Republic of Srpska. Results of this study suggest that a protocol requiring measurements at the ground floor only may be considered adequate. Due to the high radon spatial variability for rooms at the ground floor, it is preferable to require measurements in a high number of rooms (preferably in all of them) in order to assess the compliance with the reference level established by the legislation.

In 43 places (23 schools, 3 kindergartens, 16 offices and one dwelling), indoor radon has been monitored as an intercomparison experiment, using alpha-scintillation cells (SC - Joief Stefan Institute, Slovenia), various kinds of solid state nuclear track detectors (KIK - 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. (C) 2016 Elsevier Ltd. All rights reserved.

Radon (222Rn) and thoron (220Rn) are natural radioactive gases, generated in the terrestrial materials. They are the main sources of public exposure to ionising radiation in any of indoor environment worldwide. Differences in half-lives of 222Rn (T1/2 = 3.8 d) and 220Rn (T1/2 = 55.6 s) lead to its different indoor behavior. Several studies of indoor 222Rn and 220Rn in Northern Macedonia have been performed, starting with measurements in dwellings in 2008 and continuing with measurements in schools during 2012. The surveys in the Republic of Srpska began later (in 2011) with the simultaneous 222Rn and 220Rn measurements in the dwellings and schools of Banja Luka cities. This paper, as a result of our cooperation, summarizes the results and general conclusions obtained from 222Rn and 220Rn measurements in schools of capitals. In both cities, the measurements were made using Raduet - nuclear track detectors; deployed at distances: >0.5m (Skopje) and 0.2m (Banja Luka); and exposed in a period: March 2012 - May 2012 (Skopje) and April 2011 - May 2012 (Banja Luka). Results for 222Rn and 220Rn concentrations in both cities have a log-normal distribution. The 222Rn geometric mean value of 71 Bq/m3 in Skopje is higher than in Banja Luka city (GM = 50 Bq/m3). Among different radon potential in the cities, this difference could be related to the different exposure time of detectors. Furthermore, the dispersion of the 222Rn results in each city expressed through geometric standard deviation is relatively low: GSD = 2.13 (Skopje) and GSD = 2.11 (Banja Luka) indicating relatively homogeneous data sets. The 220Rn concentrations in Banja Luka (GM = 51 Bq/m3) were higher than in Skopje (GM = 11 Bq/m3). It is obvious that in the case of 220Rn, the exposure period did not play a significant role. One of the reasons for this difference could be the position of the detectors as well as the different building materials in the schools. On the contrary, the dispersion of the 220Rn results in Skopje (GSD = 3.38) was greater than in Banja Luka (GSD = 2.07).Keywords: radon, thoron, gas, school.

The most abundant and efficient source of air ionization in the lower layer of the atmosphere is radon. As an alpha emitter, radon plays a crucial role in the earth's atmospheric electricity. Besides the physical, radon and ions have a significant biological role concerning human health: radon is a health hazard while the ions are beneficial ingredients of the air we breathe. In this study, we examined the dynamics of radon and air ions diurnal change in houses with different floor and windows insulations. Measurements were made using continual radon monitor Rad-7 and air ion counter CDI-06. Diurnal and spatial variations of both atmospheric constituents are mutually related and dependent mostly on radon exhalation potential, meteorological parameters, aerosol concentration and formation of the temperature inversion layer. Indoor concentrations are related to the potential for accumulation of radon that is coming from the ground beneath the foundation and also influenced by external radon concentration that is diffusing through the walls, doors, and windows. Level of diffusion is depending on insulation. The difference in the paths by which radon enters the home can be seen by analyzing changes during diurnal continuous measurements.Keywords: radon, air ions, ionization, atmosphere, air, natural radioactivity.

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 0.22 mSv a-1 (schools in Republic of Srpska) to 2.5 mSv a-1 (dwellings in Kosovo) and are below the reference level of 10 mSv a-1 recommended by International Commission on Radiological Protection. © The Author(s) 2019. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Concentration and size distribution of airborne particles (size range 10-1100 nm), using a SMPS+C Scanning Mobility Particle Sizer, and concentrations of positive and negative cluster ions (size range 0.36-1.6 nm), using several CDI-06 Gerdien-type integral air ion detectors, have been monitored in three rooms in rural dwellings of Serbia and Slovenia, during periods when nobody was present in the room and while smoking and heating were taking place. The highest particle generation rate was 2.4 x 10(11) min(-1) while cigarette smoking was taking place and was 1.5 x 10(11) min(-1) during heating with a cast iron stove with wood burning at 150 degrees C, and 1.1 x 10(10) min(-1), during heating with an Alpine -type oven at 40-50 degrees C. The related particle loss rate constants were 0.0603 min(-1), 0.0442 min(-1), and 0.0067 min(-1). The estimated mean values of the effective ion attachment rate beta(eff) vary between (2.2-5.4)10(-6) cm(3) s(-1). A correlation between ions concentration and particles concentration and their sizes has been sought, and findings are discussed and shown. (C) 2016 Elsevier Ltd. All rights reserved.

The paper deals with the analysis of the annual indoor radon concentrations variations due to different geological parameters of Sjenica community, Western Serbia. The measured 222Rn concentrations were ranging from 10 to 1130 Bq/m3. In 14% of the buildings, the radon action level of 300 Bq/m3 is exceeded, indicating that Sjenica community could be characterized as a radon priority area. Each of 35 measuring location was georeferenced and corresponding lithostratigraphic units and geological period was assigned. Data were analyzed using the multiple linear regression (MLR) method and two predictive models were developed. The MLR model generated by the geological periods explained 17% of the radon variability while, the better one, was the lithostratigraphic MLR model, which explained 52% of the radon variability. Analysis has shown that lithostratigraphic units are important parameters in the prediction of radon levels. © 2019 Carpathian Journal of Earth and Environmental Sciences.

Hair analysis is extensively used in forensic sciences, assessment of occupational or environmental exposure and in some cases for clinical and nutritional studies. The present study summarizes the analytical methodology and distribution of uranium and some selected trace metals e.g., Mn, Ni, Cu, Zn, Sr, Cd and Cs in human scalp hair samples using inductively coupled plasma mass spectrometry (ICP-MS). Uranium isotopic ratio (U-235/U-238) has been measured using thermal ionization mass spectrometry (TIMS). For quality control, five certified reference materials such as SRM 1571, NIES 13, IAEA 086, NCS ZC 81002 and BCR CRM 397 have been analyzed by the proposed methods and the measured uranium concentrations in some selected hair samples were compared with the results by radiochemical neutron activation analysis (RNAA). The methodology was applied for measurement of uranium and selected trace metals in human scalp hair collected from Balkans exposed to DU ammunitions. Uranium concentrations in human hair samples from Balkans show a wide variation ranging from 0.90 +/- 0.05 ng/g to 449 +/- 12 ng/g whereas other trace metal concentrations like Mn, Ni, Cu, Zn, Sr, Cd and Cs were found to be comparable with the reported values of healthy persons worldwide. Though hair samples were collected from a Balkan conflict zone, uranium isotopic measurement (U-235/U-238) indicated natural origin rather than depleted uranium. Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.

The survey of natural radioactivity in Kosovo and Metohija involves 180 indoor Rn-220 measurements. They were performed either in living rooms or in bedrooms of 127 individual, rural type houses, using a passive method with application of CR-39 solid-state nuclear track detectors. Detectors were deployed at a distance of GT 10 cm from the walls. Values of all 180 measurements for 127 houses give an arithmetic mean (AM) of 132 Bq m(-3). The data for indoor thoron mapping arranged within 10 km x 10 km grid cells give an AM of 118 Bq m(-3) over AM grid cells. The distribution over individual data and the grid cells can be described as normal. About 19 % of the area of Kosovo and Metohija was covered by mapping. This study includes statistical analysis and discussion of factors, such as geogenic and seasonal, which possibly affect thoron concentration, as well as comparison with simultaneous radon measurements. 2nd International Conference on Radiation and Dosimetry in Various Fields of Research RAD and The 2nd East European Radon Symposium (SEERAS), May 27-30, 2014, Nis, Serbia

Between 2008 and 2011 a survey of radon (222Rn) was performed in schools of several districts of Southern Serbia. Some results have been published previously (Žunić et al., 2010; Carpentieri et al., 2011; Žunić et al., 2013). This article concentrates on the geographical distribution of the measured Rn concentrations. Applying geostatistical methods we generate "school radon maps" of expected mean concentrations and of estimated probabilities that a concentration threshold is exceeded. The resulting maps show a clearly structured spatial pattern which appears related to the geological background. In particular in areas with vulcanite and granitoid rocks, elevated radon (Rn) concentrations can be expected. The "school radon map" can therefore be considered as proxy to a map of the geogenic radon potential, and allows identification of radon-prone areas, i.e. areas in which higher Rn radon concentrations can be expected for natural reasons. It must be stressed that the "radon hazard", or potential risk, estimated this way, has to be distinguished from the actual radon risk, which is a function of exposure. This in turn may require (depending on the target variable which is supposed to measure risk) considering demographic and sociological reality, i.e. population density, distribution of building styles and living habits., JRC.E.8-Nuclear security

This paper presents indoor radon concentrations and specific activities of natural radionuclides measured in soils of Kosovo and Metohija. The measurements of radon concentration were performed during two consecutive 6-month periods in two rooms of 63 houses using CR-39 detectors. The annual radon concentration ranged from 30 to 810 Bq m(-3) with the average value of 128 Bq m(-3). Almost 15% of the houses had radon concentration higher than 200 Bq m(-3). The difference between radon concentrations measured in the two 6-month periods was analyzed, showing, as expected, a slightly higher radon concentration in the winter period than in the summer period. The variation between different rooms of the same houses was also analyzed, showing that 20% of the dwellings had a significantly higher radon concentration ( GT 100 Bq m(-3)) in one room compared to the other (the coefficient of variation ranged up to 96%). The specific activities of natural radionuclides in the nearby soil were determined by gamma spectrometry. The estimated average value (and standard deviation) of Ra-226, Th-232, and K-40 specific activities were 32 (13), 35 (16), and 582 (159) Bq kg(-1), respectively. The correlation between indoor Rn-222 and Ra-226 content in soil was investigated. Only a weak correlation was found (Spearmans rho = 0.220) indicating that other factors might affect diffusion and accumulation of radon indoors, as confirmed also by the high variability between the rooms of the same houses.

As a part of the national survey of natural radioactivity in The Former Yugoslav Republic of Macedonia, indoor thoron gas concentration was measured in 300 dwellings during one year, from December 2008 till December 2009 using passive discriminative radon thoron detectors. Detectors were deployed at a distance of GT 50 cm from walls in order to be less sensitive to distance from walls. Altogether 532 measurements were performed: 53 in winter, 57 in spring, 122 in summer and 300 in autumn. The frequency distribution is well described by a log-normal function. The geometric means of indoor thoron concentration (with geometric standard deviations in brackets) in winter, spring, summer and autumn were obtained to be: 39 Bq m(-3) (3.4), 32 Bq m(-3) (2.8), 18 Bq m(-3) (2.8), 31 Bq m(-3) (2.9), respectively. Seasonal variations of thoron appear lower than those of radon. The seasonal corrected annual mean concentration ranges between 3 and 272 Bq m(-3) with a geometric mean of 28 Bq m(-3) (2.12). A detailed statistical analysis of the geogenic and building factors which influence the indoor thoron concentration is also reported. This survey represents the first national survey on indoor thoron in continental Europe. (C) 2012 Elsevier Ltd. All rights reserved.

The paper deals with the results of the investigations of indoor radon measurements in more than 300 rural and urban dwellings in Kosovo and Metohija. All measurements were carried out using CR-39 solid State nuclear track detectors by similar protocols and within two series in 1990-s and in 2000-s, in 34 settlements divided by 9 regions, thus covering significant part of Kosovo. For most of measured points the adjustment for seasonal variation was necessary and had been conducted. Highest average values of indoor radon concentrations were found in rural settlements of Lipljan and Vitina regions, 512 and 452 Bq/m(3), respectively. Combined analysis allows indoor radon concentration of 220 Bq/m(3) to be suggested as representative estimate for Kosovo, while additional data appear. Observed pattern of indoor radon seasonal variation and difference of radon levels between ground and upper floors suggest soil radon as primary source of indoor radon and significance of convection type radon entry. (C) 2010 Elsevier Ltd. All rights reserved.

This paper deals with the results of the first-field use in the Balkans, i.e. Serbia and Republic of Srpska (Bosnia and Hercegovina), of a passive polycarbonate Mark II type and poliallyldiglycol carbonate (Cr-39) alpha track detectors sensitive to thoron as well as to radon. Both types of solid state nuclear track detectors were designed and supplied by National Institute of Radiological Sciences (NIRS), Chiba, Japan. The commercial names for these detectors which all have been field tested in Balkan rural communities are known as: UFO and RADUET passive discriminative radon/thoron detectors. No database of thoron and thoron progeny concentrations in dwellings in Serbia or Balkans region exist, and as a result, the level of exposure of the Serbian population to thoron and its progeny is unknown so far. 1st International Workshop on Environmental Thoron and Related Issues, May 19-22, 2010, Chiba, Japan

This paper reports results of gamma and alpha spectrometric measurements for mosses, lichens, fungi and soil samples from areas in the Balkans targeted by depleted uranium (DU). Samples were collected in 2002 and 2003 in the vicinity of several villages, principally Han Pijesak: (Bosnia and Herzegovina, hit by DU in 1995) and Bratoselce (South Serbia, hit by DU in 1999) and in lesser numbers from Gornja Stubla, Kosovo (which is identified as a high natural radon/thoron area) and Presevo close to the Kosovo border. In the course of gamma spectrometric measurements some results suggested samples with unusual high uranium contents which might be considered to be a signature for the presence of DU, although many samples had very high detection limits. Alpha spectrometric measurements directly proved the presence of DU for five samples, all from directly targeted places. These were samples of mosses, lichens and soil. For some samples homogeneity tests were applied which showed a rather even distribution of DU in these samples. No trace of DU was found in any sample from a dwelling. (C) 2008 Elsevier Ltd. All rights reserved.

Subject of this study is an investigation of the variations of indoor radon concentration and ambient dose equivalent rate in outdoor and indoor environments of 40 dwellings, 31 elementary schools and five kindergartens. The buildings are located in three municipalities of two, geologically different, areas of the Republic of Macedonia. Indoor radon concentrations were measured by nuclear track detectors, deployed in the most occupied room of the building, between June 2013 and May 2014. During the deploying campaign, indoor and outdoor ambient dose equivalent rates were measured simultaneously at the same location. It appeared that the measured values varied from 22 to 990 Bq/m(3) for indoor radon concentrations, from 50 to 195 nSv/h for outdoor ambient dose equivalent rates, and from 38 to 184 nSv/h for indoor ambient dose equivalent rates. The geometric mean value of indoor to outdoor ambient dose equivalent rates was found to be 0.88, i.e. the outdoor ambient dose equivalent rates were on average higher than the indoor ambient dose equivalent rates. All measured can reasonably well be described by log-normal distributions. A detailed statistical analysis of factors which influence the measured quantities is reported.

The paper deals with the recent survey of indoor radon (Rn) results in schools, where paired CR-39 detectors were simultaneously exposed to different long-term periods, i.e., one detector was exposed during the whole year and the other one in the period of the school year duration. To be able to compare the results obtained, for its analysis, the relative bias and U tests were used. It was found that there are no systematic differences between the results, which points that the exposure of the detector during summer vacations did not affect the estimated average annual radon concentration. The paired results were modelled by a linear function, giving an extremely high coefficient of determination R 2 = 0.99.

The first radon soil gas survey in Serbia, using passive detectors (SSNTD, CR-39), was carried out in June 2005 at field sites in Niska Banja town. The aim of the survey was to identify risk zones characterised by high levels of this radioactive gas. Radon measurements were made at the depth of 50 cm, in the ground according to a systematic grid pattern. Furthermore, at all 48 measurement points, the surface gamma dose rates in the air was also measured at the same locations and soil samples were collected for gamma spectrometric analysis for the radionuclides 226Ra, 228Th and 40K. Radon concentrations were found to range from 1270 to 155 000 Bq m - 3 with an average of 33 765 Bq m - 3 and a median value of 12 626 Bq m - 3 . The geometrical mean value and geometrical standard deviation were calculated as 16 160 Bq m - 3 and 3.5 Bq m - 3 , respectively. Gamma dose rate varies from 92 to 316 nGy h - 1 , with an average of 132 nGy h - 1 . The radium content in collected soil samples ranges from 24 to 1810 Bq kg - 1 with an average of 187 Bq kg - 1 . High correlations ( r 2 > 0.8 ) between soil gas radon concentration, gamma dose rate and 226Ra content in soil were found for each pair. The distribution of radon concentrations in soil gas shows bimodal shape.

Variance of radon concentration in dwelling atmosphere is analysed with regard to geogenic and anthropogenic influencing factors. Analysis includes review of 81 national and regional indoor radon surveys with varying sampling pattern, sample size and duration of measurements and detailed consideration of two regional surveys (Sverdlovsk oblast, Russia and Niska Banja, Serbia). The analysis of the geometric standard deviation revealed that main factors influencing the dispersion of indoor radon concentration over the territory are as follows: area of territory, sample size, characteristics of measurements technique, the radon geogenic potential, building construction characteristics and living habits. As shown for Sverdlovsk oblast and Niska Banja town the dispersion as quantified by GSD is reduced by restricting to certain levels of control factors. Application of the developed approach to characterization of the world population radon exposure is discussed. (C) 2015 Elsevier B. V. All rights reserved.

This article reports results of the first investigations on indoor radon, thoron and their decay products concentration in 25 primary schools of Banja Luka, capital city of Republic Srpska. The measurements have been carried out in the period from May 2011 to April 2012 using 3 types of commercially available nuclear track detectors, named: long-term radon monitor (GAMMA 1)- for radon concentration measurements (C-Rn); radon-thoron discriminative monitor (RADUET) for thoron concentration measurements (C-Tn); while equilibrium equivalent radon concentration (EERC) and equilibrium equivalent thoron concentrations (EETC) measured by Direct Radon Progeny Sensors/Direct Thoron Progeny Sensors (DRPS/DTPS) were exposed in the period November 2011 to April 2012. In each school the detectors were deployed at 10 cm distance from the wall. The obtained geometric mean concentrations were C-Rn = 99 Bq m(-3) and C-Tn = 51 Bq m(-3) for radon and thoron gases respectively. Those for equilibrium equivalent radon concentration (EERC) and equilibrium equivalent thoron concentrations (EETC) were 11.2 Bq m(-3) and 0.4 Bq m(-3), respectively. The correlation analyses showed weak relation only between C-Rn and C-Tn as well as between C-Tn and EETC. The influence of the school geographical locations and factors linked to buildings characteristic in relation to measured concentrations were tested. The geographical location and floor level significantly influence C-Rn while C-Tn depend only from building materials (ANOVA, p LT = 0.05). The obtained geometric mean values of the equilibrium factors were 0.123 for radon and 0.008 for thoron. (C) 2015 Elsevier Ltd. All rights reserved.

sequently for the isotopic abundance of the uranium isotopes in the sample. 235U is determined from the analysis of the multiplet photopeak at 186 keV. DU may be detected with this technique provided that the 238U activity of the DU is higher than ~20% of that of 238 U in the natural uranium of the sample. The analyses by NES-NTUA of surface soil samples collected well before the dispersion of depleted uranium in Kosovo, made evident that Kosovo is an area of high natural background, with a pronounced surface soil variation in natural uranium content, and 238U activity reaching values as high as 330 Bqkg -1 . It was also observed that disturbance of radioactive equilibrium among the nuclides of the uranium series is quite often observed due to leaching and weathering, with the ratio of the activities of 238 U and 226 Ra ranging from 0.17 to 5.5. After the military operations in Kosovo, surface soil and vegetation samples as well as DU penetrators were analysed in NES-NTUA. Among the soil samples analysed it was found that some of those collected around a DU penetrator crater were contaminated by DU, with 238 U activity exceeding 2 kBqkg -1 , and ratio of 238 U/ 226 Ra exceeding the value of 10. In these soil samples, the natural isotopic abundance of the uranium isotopes was significantly disrupted; this allowed for an estimation of the isotopic abundance of 235U in the dispersed DU of about 0.2%, which agrees very well with relevant values found in the literature for DU penetrators. DU in the vegetation samples analysed was below detection limit. The analysis of DU penetrators led to the detection 238U, 235 U and their daughters, and to an estimation of the dose-rate due to the gamma-rays emitted from the penetrator, which reached 6.5 µSvh-1 on the surface, sloping to background at the distance of about 40 cm.

Background: In epidemiological studies investigating radon-related health risk, the radon exposures are often derived from contemporary short-term radon measurements. Recent radon measurements, taken over a period of 1 year in dwellings, are often casually extrapolated and taken to be representative for periods spanning several decades. By simply considering the well-known variability of radon concentrations in dwellings and its sensibility to trivial factors such as living habits or minor changes in the dwelling itself, an amount of skepticism concerning the reliability of this practice should arise. In mining areas, this variability is already well acknowledged since mining conditions, such as ventilation of mine shafts, flooding of mine galleries, etc., are known to be able to change radon concentrations in dwellings built on top of mine shafts for over more than one decade. Methods: This study was conducted in stable rural communities in Yugoslavia. Present radon concentrations were compared to an indicator of past radon concentrations, that is the 210Po activity, fixed on glass surfaces or in the bulk of voluminous materials. Results: In less than 50% of the cases, the past and present radon concentrations agree within a factor of 2. Conclusions: This comparison indicates that even in stable rural communities, deriving past radon concentrations by extrapolating present ones is not a particularly good practice.

Human hair and nails can be considered as bio-indicators of the public exposure to certain natural radionuclides and other toxic metals over a long period of months or even years. The level of elements in hair and nails usually reflect their levels in other tissues of body. Nigka Banja, a spa town located in southern Serbia, with locally high natural background radiation was selected for the study. To assess public exposure to the trace elements, hair and nail samples were collected and analyzed. The concentrations of uranium, thorium and some trace and toxic elements (Mn, Ni, Cu, Sr, Cd, and Cs) were determined using inductively coupled plasma mass spectrometry (ICP-MS). U and Th concentrations in hair varied from 0.0002 to 0.0771 mu g/g and from 0.0002 to 0.0276 mu g/g, respectively. The concentrations in nails varied from 0.0025 to 0.0447 mu g/g and from 0.0023 to 0.0564 mu/g for U and Th, respectively. We found significant correlations between some elements in hair and nails. Also indications of spatial clustering of high values could be found. However, this phenomenon as well as the large variations in concentrations of heavy metals in hair and nail could not be explained. As hypotheses, we propose possible exposure pathways which may explain the findings, but the current data does not allow testing them. Crown Copyright (C) 2015 Published by Elsevier Ltd. All rights reserved.

As part of a survey on concentrations of radon, thoron and their decay products in different indoor environments of the Balkan region involving international collaboration, measurements were performed in 43 schools from 5 municipalities of the Republic of Macedonia. The time-integrated radon and thoron gas concentrations (C-Rn and C-Tn) were measured by CR-39 (placed in chambers with different diffusion barriers), whereas the equilibrium equivalent radon and thoron concentrations (EERC and EETC) were measured using direct radon-thoron progeny sensors consisting of LR-115 nuclear track detectors. The detectors were deployed at a distance of at least 0.5 m from the walls as well as far away from the windows and doors in order to obtain more representative samples of air from the breathing zone; detectors were exposed over a 3-month period (March-May 2012). The geometric mean (GM) values [and geometric standard deviations (GSDs)] of C-Rn, C-Tn, EERC and EETC were 76 (1.7), 12 (2.3), 27 (1.4) and 0.75 Bq m(-3) (2.5), respectively. The equilibrium factors between radon and its decay products (F-Rn) and thoron and its decay products (F-Tn( GT 0.5) m) were evaluated: FRn ranged between 0.10 and 0.84 and F-Tn( GT 0.5) m ranged between 0.003 and 0.998 with GMs (and GSDs) equal to 0.36 (1.7) and 0.07 (3.4), respectively. 2nd International Conference on Radiation and Dosimetry in Various Fields of Research RAD and The 2nd East European Radon Symposium (SEERAS), May 27-30, 2014, Nis, Serbia

A method for retrospectively assessing the average radon concentration in a dwelling, for a period as long as 40 years or more, is described. It is based on the free penetration of radon gas into bulky spongy materials called volume traps, and subsequent trapping of radon decay products inside them. This leads to a build-up of 210Pb, a radon decay product with a half life of 22.3 years, which reaches an equilibrium with the alpha emitter 210Po, indicative of the average radon concentration over the exposure period. The stuffing of mattresses, chairs, cushions, etc. can be considered a good volume trap. A chemical separation procedure is described, transforming the volume trap into a 210Po alpha source, whose activity is determined through alpha spectroscopy. The technique has been applied in over 300 samples, retrieved from dwellings in Serbia, Germany, Norway and Sweden. The technique has proven to be very robust and reproducible. In cases where radon data were available during the exposure period of the volume trap, a remarkable agreement was found. The best volume traps appeared to be polyester sponges found in many stuffings. The major drawback is the destructive nature of the method, its major advantage is the direct relationship between the radon gas and the 210Po signal. The technique can be useful in epidemiological studies of the lung cancer risk from indoor radon, for assessing the long term radon exposure.

A description is given of the field application of a technique using CR-39 and LR 115 detectors to determine alpha recoil implanted Po-210 surface activity on domestic glass artefacts in dwellings. These investigations took place in two small stable rural communities in uraniferous areas of Yugoslavia where between 32% and 74% of contemporary indoor radon levels were found to be above the commonly used Action Level of 200 Bq m(-3) and individual levels as high as 8700 Bq m(-3) were measured. The Po-210 data is used to retrospectively estimate radon exposures in these communities. Comparisons between the retrospectively estimated radon exposures and those being received at present are made. 19th International Conference on Nuclear Tracks in Solids (ICNTSs), Aug 31-Sep 05, 1998, Besancon, France

UNLABELLED In order to optimize the design of a national survey aimed to evaluate radon exposure of children in schools in Serbia, a pilot study was carried out in all the 334 primary schools of 13 municipalities of Southern Serbia. Based on data from passive measurements, rooms with annual radon concentration >300 Bq/m(3) were found in 5% of schools. The mean annual radon concentration weighted with the number of pupils is 73 Bq/m(3), 39% lower than the unweighted 119 Bq/m(3) average concentration. The actual average concentration when children are in classrooms could be substantially lower. Variability between schools (CV = 65%), between floors (CV = 24%) and between rooms at the same floor (CV = 21%) was analyzed. The impact of school location, floor, and room usage on radon concentration was also assessed (with similar results) by univariate and multivariate analyses. On average, radon concentration in schools within towns is a factor of 0.60 lower than in villages and at higher floors is a factor of 0.68 lower than ground floor. Results can be useful for other countries with similar soil and building characteristics. PRACTICAL IMPLICATIONS On average, radon concentrations are substantially higher in schools in villages than in schools located in towns (double,on average). Annual radon concentrations exceeding 300 Bq/m3 were found in 5% of primary schools (generally on ground floors of schools in villages). The considerable variability of radon concentration observed between and within floors indicates a need to monitor concentrations in several rooms for each floor. A single radon detector for each room can be used provided that the measurement error is considerable lower than variability of radon concentration between rooms.

Thoron gas and its progeny behave quite differently in room environments, owing to the difference in their half-lives; therefore, it is important to measure simultaneously gas and progeny concentrations to estimate the time-integrated equilibrium factor. Furthermore, thoron concentration strongly depends on the distance from the source, i.e. generally walls in indoor environments. In the present work, therefore, the measurements of both thoron and radon gas and their progeny concentrations were consistently carried out close to the walls, in 43 dwellings located in the Sokobanja municipality, Serbia. Three different types of instruments have been used in the present survey to measure the time-integrated thoron and radon gas and their progeny concentrations simultaneously. The equilibrium factor for thoron measured 'close to the wall', [Formula: see text], ranged from 0.001 to 0.077 with a geometric mean (GM) [geometric standard deviation (GSD)] of 0.006 (2.2), whereas the equilibrium factor for radon, FRn, ranged from 0.06 to 0.95 with a GM (GSD) of 0.23 (2.0).

In this work the strong influence of geological factors on the variability of indoor radon is found in two of three geologically very different regions of South-Eastern Europe. A method to estimate the annual mean concentration when one seasonal measurement is missing is proposed. Large differences of radon concentrations in different rooms of the same house and significant difference in radon concentrations in one season comparing it to the others are noted in certain cases. Geological factors that can lead to such behavior are discussed. (C) 2014 Elsevier Ltd. All rights reserved.

The possible consequences of the use of depleted uranium (DU) used in Balkan conflicts in 1995 and 1999 for the people and the environment of this reason need attention. The heavy metal content in human hair may serve as a good indicator of dietary, environmental and occupational exposures to the metal compounds. The present work summarises the distribution of uranium and some selected trace metals such as Mn, Ni, Cu, Zn, Sr, Cd and Cs in the scalp hair of inhabitants from Balkans exposed to DU directly and indirectly, i.e. Han Pijesak, Bratoselce and Gornja Stub la areas. Except U and Cs, all other metals were compared with the worldwide reported values of occupationally unexposed persons. Uranium concentrations show a wide variation ranging from 0.9 +/- 0.05 to 449 +/- 12 mu g kg(-1). Although hair samples were collected from Balkan conflict zones, uranium isotopic measurement (U-235/U-238) shows a natural origin rather than DU. International Symposium on Natural Radiation Exposure and Low-dose Radiation Epidemiological Studies, Feb 29-Mar 03, 2012, Hirosaki Univ Inst Radiat Med, Hirosaki, Japan

This paper presents the results of the seasonal indoor radon concentration measurements in dwellings in all regions of the Former Yugoslav Republic (FYR) of Macedonia. The measurements were made in 437 dwellings using CR-39 track detectors over four successive three-month periods (winter, spring, summer and autumn) throughout 2009. The results of analysis of variance showed statistically significant differences between indoor radon concentrations in different seasons. The geometric mean values and geometric standard deviations of indoor radon concentrations in winter, spring, summer and autumn were obtained to be: 115 Bqm3 (2.02), 72 Bqm3 (1.97), 46 Bqm3 (1.95), 92 Bqm3 (2.02), respectively. The geometric mean values of spring, summer and autumn to winter ratios were found to be: 0.63 (1.50), 0.40 (1.81), and 0.80 (1.58), respectively. The results of the analysis of the variance showed statistically significant differences among the indoor radon measurements for the regions in different seasons. The influence of the factors linked to building characteristics in relation to radon measurements in different seasons was examined. The factors which enable a differentiation into subgroups (significance level p < 0.05) are the floor level, basement and building materials., JRC.E.8-Nuclear security (Ispra)

This paper deals with the results of indoor radon and thoron concentrations and exposure doses obtained for 63 dwellings out of the 14 rural communities of Central Kosovo, North Kosovo and Prizren region. These research activities are part of overall radiological research that has systematically been carried out since 1986, particularly in Kosovo and Metohija regions. Passive radon/thoron discriminative detectors, exposed for three months, were used. The arithmetic mean concentrations of indoor radon and thoron are C(Rn) = 429 Bq m(-3) C(Tn) = 85 Bq m(-3). (C) 2009 Elsevier Ltd. All rights reserved.

The main scope of this paper is to point out the importance of introducing radon and thoron exhalation measurements from building materials in the regulating frame. Currently (2009), such a regulation of this kind of exposure is not explicitly included in the Serbian regulating network. To this end, this work reports concentration measurements of Ra-226, Th-232 and K-40 and radon and thoron exhalation rates from building materials used in Serbia. Following detailed analysis, it was noticed that both internal exposures to radon and/or thoron exhaling from building materials may exceed external exposures to their precursors contained therein. (C) 2009 Elsevier Ltd. All rights reserved.

Water (226)Ra concentration in springs was measured in regions with high indoor radon: Ural, North Caucasus (Russia), Niska Banja (Serbia), Piestany (Slovakia), and Issyk-Kul (Kyrgyzstan). This paper presents the results for (226)Ra concentration above 0.03 Bq l(-1). Radium in water could indicate indoor radon problem in the region and water investigation is useful at the initial stage of radon survey. Even low (226)Ra concentration in water (0.1-0.6 Bq l(-1)) caused high (226)Ra activity in travertine (up to 1500 Bq kg(-1)), which resulted in indoor radon concentration above 2000 Bq m(-3) (Niska Banja). (C) 2009 Elsevier Ltd. All rights reserved. 7th International Topical Meeting on Industrial Radiation and Radioisotope Measurement Application, Jun 22-27, 2008, Czech Tech univ, Prague, Czech Republic

Some basic facts and knowledge on depleted uranium (DU) and characteristics and identification of ammunition used in the Balkans are summarized. The results of radioecological surveys at selected sites during the prewar period, immediately after bombing, occurrence since then and details of clean-up operations are presented. Uranium content measurements in different environmental (air, soil, water) and biological (lichens, earthworms, urine, blood) samples were performed using various techniques to distinguish natural from anthropogenic sources. The evidence for airborne transport, aqueous transport, and biological transport as the dominant mechanisms of environmental transport of DU are considered in relation to the Balkans. The long-term DU effects on the environment in the target areas and the various possible health hazards arising from its radioactivity and chemical toxicity are discussed. The ground water system has appeared to be over a long-time scale (several hundreds of years) the main risk for the population but this depends on various hydrogeological parameters that need to be evaluated at the site in question. Available scientific literature has been considered in regard to a relationship between uranium exposure of the body and increased incidence of cancer or genetic defects.

Radon/Thoron/Natural radioactivity/Niska Banja/Obrenovac. Based oil results of fieldwork in the Balkan Region of Serbia from 2005 to 2007, soil gas radon and thoron concentrations as well as gamma dose rates were measured. Campaigns were conducted in two different geological regions: Niska Banja, considered a high natural radiation area, and Obrenovac around the TentB Thermal Power Plant (TPP), a low natural radiation area. Radon and thoron gas measurements were made by using two types of Japanese passive radon/thoron detectors, Which included GPS data and gamma dose rates. The concentrations of soil radon gas in Niska Banja ranged from 1.8 to 161.1 kBq m(-3) the concentrations for soil thoron gas ranged from 0.9 to 23.5 kBq m(-3). The gamma close rates varied from 70 to 320 nGy h(-1). In the TentB area, radon concentration was found to range from 0.8 to 24.9 kBq m(-3) and thoron from 0.6 to 1.9 kBq m(-3). The gamma dose rate ranged from 90 to 130 nGy h(-1). In addition, the natural radioactivity of the soil was investigated at the low background area. The radium and thorium contents in collected soil samples ranged from 23 to 58 and 33 to 67 Bq kg(-1), respectively. As a result of correlation analyses between the measured values, the highest correlation coefficient (R GT 0.95) was found for thorium ill the soil and the thoron gas concentration.

Lichen and Moss are widely used to assess the atmospheric pollution by heavy metals and radionuclides. In this paper, we report results of uranium and its isotope ratios using mass spectrometric measurements (followed by chemical separation procedure) for mosses, lichens and soil samples from a depleted uranium (DU) target site in western Balkan region. Samples were collected in 2003 from Han Pijesak (Republika Srpska in Bosnia and Hercegovina). Inductively coupled plasma mass spectrometry (ICP-MS) measurements show the presence of high concentration of uranium in some samples. Concentration of uranium in moss samples ranged from 5.2-755.43 Bq/Kg. We have determined {sup 235}U/{sup 238}U isotope ratio using thermal ionization mass spectrometry (TIMS) from the samples with high uranium content and the ratios are in the range of 0.002097-0.002380. TIMS measurement confirms presence of DU in some samples. However, we have not noticed any traces of DU in samples containing lesser amount of uranium or from any samples from the living environment of same area.

Standardization of the thoron exhalation measurements is important for the intercomparison of the results among different laboratories. There are a few important distinctions between thoron (Rn-220) and radon (Rn-222) exhalation measurements using an accumulation chamber, due to a great difference between radon and thoron diffusion lengths in air, namely, short diffusion length of thoron indicates that it is very hard to attain homogenous distribution of the thoron concentration in an accumulation chamber of the usual dimensions, which is often neglected. It will be explained that the same model cannot be used both for radon and for thoron exhalation measurements. The results of the thoron exhalation measurements also depend on the sample thickness which must be considered. A new method for thoron exhalation measurement using an accumulation chamber is proposed. Comparisons between the existing and the proposed methods were performed on five different samples. (C) 2008 Elsevier Ltd. All rights reserved.

In Niska Banja, Serbia, which is a high-radon area, a comparison was made between two retrospective radon measuring methods and contemporary radon measurements. The two retrospective methods derive the radon concentrations that occurred in dwellings over longer periods in the past, based on the amount of trapped 2 Po-10 on the surface of glass objects (surface traps, ST) or in the bulk of porous materials (volume traps, VT). Both surface implanted 2 1 Po-210 in glass objects and contemporary radon in air were measured in 46 rooms, distributed in 32 houses of this radon spa-town, using a dual alpha track detector configuration (CR-39 and LR115) and CR-39 track etched detectors, respectively. In addition to the use of surface trap measurements, in 18 rooms (distributed in 15 houses) VT samples of suitable material were also collected, allowing to compare ST and VT retrospective radon concentration estimates. For each room, contemporary annual radon concentrations (CONT) were measured or estimated using seasonal correction factors. The distribution of the radon concentration in all data sets was found to be close to lognormal (Chi-square test GT 0.05). Geometric means (GM) are similar, 3 ranging from 1040 to 1380 Bq m(-3) whereas geometric standard deviations (GSD) for both the retrospective methods are greater than for the CONT method, showing reasonable agreement between VT, ST and CONT measurements. A regression analysis, with respect to the lognormal distribution of each data set, shows that for VT-ST the correlation coefficient r is 0.85, for VT-CONT r is 0. 82 and for ST-CONT r is 0.73. Comparison of retrospective and contemporary radon concentrations with regard to supposed long-term indoor radon changes further supports the principal agreement between the retrospective and conventional methods. (C) 2007 Elsevier B.V. All rights reserved.

A radon survey has been carried out around the town of Niska Banja (Serbia) in a region partly located over travertine formations, showing an enhanced level of natural radioactivity. Outdoor and indoor radon concentrations were measured seasonally over the whole year, using CR-39 diffusion type radon detectors. Outdoor measurements were performed at 56 points distributed over both travertine and alluvium sediment formations. Indoor radon concentrations were measured in 102 living rooms and bedrooms of 65 family houses. In about 50% of all measurement sites, radon concentration was measured over each season separately, making it possible to estimate seasonal variations, which were then used to correct values measured over different periods, and to estimate annual values. The average annual indoor radon concentration was estimated at over 1500 Bq/m(3) and at about 650 Bq/m(3) in parts of Niska Banja located over travertine and alluvium sediment formations, respectively, with maximum values exceeding 6000 Bq/m(3). The aver age value of outdoor annual radon concentration was 57 Bq/m(3), with a maximum value of 168 Bq/m(3). The high values of indoor and outdoor radon concentrations found at Niska Banja make this region a high natural background radiation area. Statistical analysis of our data confirms that the level of indoor radon concentration depends primarily on the underlying soil and building characteristics. (c) 2006 Elsevier Ltd. All rights reserved.

The measurement campaigns have been done in the rural community of Niska. Banja, a spa town located in southern Serbia, to evaluate population exposure to natural radioactivity. After a screening survey in 200 houses, annual radon and thoron concentrations were measured in 34 houses, and in 2004 a detailed investigation was carried out at six houses with elevated indoor radon concentrations. The paper presents the results of these detailed measurements. The complementary techniques were applied to determine radon and thoron concentrations in indoor air, in soil gas, radon exhalation from soil, soil permeability, and indoor and outdoor gamma doses. Soil and water samples were collected and analysed in the laboratory. Indoor radon and thoron. concentrations were found to be more than 1 kBq m(-3) and 200 Bq m(-3) respectively. Extremely high concentrations of soil-gas radon ( GT 2000 kBq m(-3)) and radon exhalation rates (1.5 mBq m(-2) s(-1)) were observed. These results will be utilised to set up the methodology for a more systematic investigation. (c) 2006 Elsevier Ltd. All rights reserved.

Approximately 200 volume traps were retrieved from dwellings in various radon prone areas in Europe. They were analysed for the purpose of retrospective radon assessment. Emphasis is put on specific problems encountered when using field samples as opposed to laboratory exposed samples. It was seen that in very dusty circumstances, direct penetration of radon decay products from the outside to the centre of the volume traps calls for extra caution. Rinsing the samples is proposed as a solution and was tested in field and laboratory conditions, showing good results. An attempt was made to give an assessment of the achievable accuracy of the method. Where possible, the volume trap retrospective results were compared with contemporary measurements or to retrospective results from surface traps. The overall impression is that although volume traps are sometimes hard to find in the field, the high reliability of the results makes it well worth the effort. (C) 2001 Elsevier Science B.V. All rights reserved. Scientific Workshop on Radon in the Living Environment, Apr, 1999, Athens, Greece