Some results of a radon survey in 207 Serbian schools

In this paper the results of radon concentration measurements performed in 207 schools in 7 communities of Southern Serbia are presented. The annual radon concentration varied from 17 Bqm-3 to 428 Bq m-3 with a median value of 96 Bq m-3. The arithmetic mean (AM) of the 207 annual averages was 118 Bq m-3 with a standard deviation (SD) of 78 Bq m-3. The best distribution fitting of radon concentration by log-normal function was obtained. The log-normal parameters are the following: geometric mean (GM) = Bq m-3, geometric standard deviation (GSD) = 1.9. In addition, a spatial distribution of the indoor radon concentration over the investigated areas is observed.JRC.E.8-Nuclear securit

A Comparison of Retrospective Radon Gas Measurement Techniques Carried Out in the Serbian Spa of Niska Banja

Indoor radon retrospective concentrations were obtained and compared using two radon measurement methods. Both methods rely on the measurement of the long-lived radon progeny (210)Pb, collected either on the surfaces (surface trap technique), most frequently glass, or in a volume trap, usually sponge from furniture (volume trap technique). These techniques have been used to retrospectively estimate radon gas concentrations that have existed in dwellings in the past. The work presented here compares the results provided by the surface trap technique devised at the University College of Dublin, Ireland, and the volume trap technique devised at the Scientific Research Center, Mol, Belgium. The field campaign was carried out by the research team of the ECE Laboratory of the Vinca Institute of Nuclear Sciences at the spa of Niska Banja, identified as a region of Serbia with a high indoor radon and ground water radium and radon content

A map of radon in primary schools of Southern Serbia.

Between 2008 and 2011 a survey of radon was performed in primary schools of several districts in Southern Serbia. The survey design and some of the results have been published previously (Zunic et al., 2010; Carpentieri et al., 2011). This article deals with the geographical distribution of the measured radon concentrations. Applying geostatistical methods we generate “school radon maps” of expected mean concentrations and 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 Rn concentrations can be expected. The “school map” can therefore be considered as proxy to a map of the geogenic radon potential, and allows identification of radon-prone zones, e.g., areas in which higher Rn concentrations can be expected for natural reasons. It must be stressed that the “radon hazard”, or potential risk, estimated in 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) the number of persons affected, occupancy factors of buildings and anthropogenic factors, and a more general approach

Soil gas mapping in the vicinity of Nikola Tesla thermo power plant disposal field

This paper presents the results of identification of natural ionizing irradiation in the vicinity of Nikola Tesla B power plant ash disposal field. The investigations have comprised the determination of natural gas (radon and thoron) activities with a passive discriminative nuclear track detector (CR 39) in the air column of the depth of 80 cm in the soil. The determination of gamma dose rate has been given as well, including the corresponding GPS coordinates of 28 measuring points

Some results of a radon survey in 207 Serbian schools

In this paper the results of radon concentration measurements performed in 207 schools in 7 communities of Southern Serbia are presented. The annual radon concentration varied from 17 Bqm-3 to 428 Bq m-3 with a median value of 96 Bq m-3. The arithmetic mean (AM) of the 207 annual averages was 118 Bq m-3 with a standard deviation (SD)of 78 Bq m-3. The best distribution fitting of radon concentration by log-normal function was obtained. The log-normal parameters are the following: geometric mean (GM) = 97 Bq m-3, geometric standard deviation (GSD) = 1.9. In addition, a spatial distribution of the indoor radon concentration over the investigated areas is observed

Assessment of long-term radon concentration measurement precision in field conditions (Serbian schools) for a survey carried out by an international collaboration

In an international collaboration, a long-term radon concentration survey was carried out in schools of Southern Serbia with radon detectors prepared, etched and read-out in Italy. In such surveys it is necessary to evaluate measurement precision in field conditions, and to check whether quality assurance protocols were effective in keeping uncertainties under control, despite the complex organization of measurements. In the first stage of the survey, which involves only some of the total number of municipalities, paired detectors were exposed in each monitored room in order to experimentally assess measurement precision. Paired passive devices (containing CR-39 detectors) were exposed for two consecutive 6-month periods. Two different measurement systems were used to read out CR-39s of the first and second period, respectively. The median of the coefficient of variation (CV) of the measured exposure was 8% for 232 paired devices of the first 6-month period and 4% for 242 paired devices of the second 6-month period, respectively. This difference was mainly due to a different track count repeatability of the two read-out systems, which was 4 and 1%, respectively, as the median value of CV of repeated countings. The in-field measured precision results are very similar to the precision assessed in calibration conditions and are much lower than the room-to-room variation of radon concentration in the monitored schools. Moreover, a quality assurance protocol was followed to reduce extra-exposures during detector transport from Rome to schools measured and back.JRC.E.8-Nuclear securit

Traces of DU in samples of environmental bio-monitors (non-flowering plants, fungi) and soil from target sites of the Western Balkan region

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

The indoor radon survey in Serbian schools: can it reflect also the general population exposure?

A systematic indoor radon survey in elementary schools of Serbia is underway since 2008. Its current first phase covers all elementary schools in predominantly rural communities of Southern Serbia. The design of the survey, its implementation and the current state of its realization is shortly described. Part of this paper is devoted to discussion of the question if this survey could produce results representative also of the radon concentration in dwellings and of radon exposure of the general population, discussing some statistical aspects of representativity which arose during the work, namely, if the implementation leads to an unbiased estimate of the targeted quantities.International Conference on Radon in Environment, May 10-14, 2009, Zakopane, Polan

State of knowledge for the ongoing indoor radon survey in Serbian schools: part 2 results and mapping

The goals of the previous research project (2006-2010) and current one (2011-2014), funded by the Serbian Ministry of Science, now Ministry of Education and Science, is the systematic indoor radon survey in elementary schools of Serbia. This survey has been under way since 2008 through an international collaboration, involving so far 340 schools in 13 communities within two districts of South Serbia. The field activities were divided into two phases: Part 1(encompassing 6 communities with 124 elementary schools) and Part 2 (encompassing another 206 elementary schools). In this paper the results of radon concentration measurement for 206 schools in 7 communities (Part 2) are provided. The number of rooms monitored per school, depending on school size, ranged from 1 to 10, with an average of 1.8 rooms. In each monitored room, two CR-39 detectors were exposed side-by-side for two consecutive six-month periods. For each school, the annual radon concentration average of the monitored rooms was calculated. The arithmetic mean of the 206 annual averages is 118 Bq/m3 with a standard deviation of 78 Bq/m3. The minimum radon concentration is 17 Bq/m3, and the maximum 428 Bq/m3. The median is 96 Bq/m3, with the first and third quartiles being 62 Bq/m3 and 152 Bq/m3, respectively. The lognormal parameters are the following: geometric mean = 97 Bq/m3, geometric standard deviation = 1.89. A short comparison with the part 1 results of of the indoor radon concentration in 124 schools is reported. Moreover, a spatial estimate of the radon concentration in investigated schools is also reported

The concentrations and exposure doses of radon and thoron in residences of the rural areas of Kosovo and Metohija

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