Publications

  • 29/11/2016

    Special issue of the Journal of Environmental Radioactivity: Geogenic radiation and its potential use for developing the geogenic radon map - Foreword

    Authors: T. Tollefsen, G. Cinelli, M. De Cort Ref: Journal of Environmental Radioactivity 166 (2017) 209. http://dx.doi.org/10.1016/j.jenvrad.2016.11.008 More

    For several years, the Radioactivity Environmental Monitoring group of the JRC has been working on a European Atlas of Natural Radiation. This Atlas is a collection of maps of Europe displaying the levels of natural radioactivity caused by different sources in Europe. One of these aims to map a variable which measures “what earth delivers” in terms of geogenic radon potential, due to heterogeneity of data sources across Europe. Such a European Geogenic Radon Map will give the possibility to characterize areas for radon risk where indoor radon measurements are not available.

    In 2015, the JRC organized the International Workshop on the European Atlas of Natural Radiation to discuss all these topics with the scientific community. All participants were invited to contribute papers to a special issue of the Journal of Environmental Radioactivity based on a selection of abstracts.

    This special issue on geogenic radiation and its potential use for developing the geogenic radon map addresses the following topics: Uranium, thorium and potassium concentration in bedrock and soil; terrestrial gamma dose rate; soil radon; geology; and the relationship between all these quantities and indoor radon, and radon risk index.

    These papers will contribute to the progress of geogenic radon mapping, both at the European and national levels, as well as the preparation of the European Atlas of Natural Radiation.

  • 23/11/2016

    First map of residential indoor radon measurements in Azerbaijan

    Authors: M. Hoffmann, Ch. S. Aliyev, A. A. Feyzullayev, R. J. Baghirli, F. F. Veliyeva, L. Pampuri, C. Valsangiacomo, T. Tollefsen, G. Cinelli Ref: Radiation Protection Dosimetry (2016). Advance access published 23.11.2016. doi: 10.1083/rpd/ncw284. More

    This article describes results of the first measurements of indoor radon concentrations in Azerbaijan, including description of the methodology and the mathematical and statistical processing of the results obtained. Measured radon concentrations varied considerably: from almost radon-free houses to around 1100 Bq/m3. However, only about 7% of the total number of measurements exceeded the maximum permissible concentrations. Based on this data, maps of the distribution of volumetric activity and elevated indoor radon concentrations in Azerbaijan were created. These maps reflect a mosaic character of distribution of radon and enhanced values that are confined to seismically active areas at the intersection of an active West Caspian fault with sub-latitudinal faults along the Great and Lesser Caucasus and the Talysh mountains. Spatial correlation of radon and temperature behavior is also described. The data gathered on residential indoor radon have been integrated into the European Indoor Radon Map.

  • 08/07/2016

    Assessment of lithogenic radioactivity in the Euganean Hills magmatic district (NE Italy)

    Authors: L. Tositti, G. Cinelli, E. Brattich, A.Galgaro, D. Mostacci, C. Mazzoli, M. Massironi, R. Sassi Ref: Journal of Environmental Radioactivity 166 (2017) 259-269, http://dx.doi.org/10.1016/j.jenvrad.2016.07.011. More

    The Euganean Hills of North East Italy have long been recognised as an area characterized by a higher than average natural radiation background. This is due to two main reasons: a) primary lithogenic radiation due to rhyolitic and trachytic outcrops, which are “acidic alkaline” magmatic rocks potentially enriched in uranium and thorium; b) secondary sources related to a geothermal field - widely exploited for spa tourism in the area since the Roman age - producing surface release of radon-enriched fluids. Though radioactivity levels in the Euganean district have been often investigated in the past -including recent works aimed at assessing the radiation doses from radon and/or total gamma radiation - no effort has been put so far into producing a thorough assessment linking radiation protection data to geological-structural features (lithology, faults, water, organic matter content, etc.). This work represents the first part of the interdisciplinary project “Geological and geochemical control on Radon occurrence and natural radioactivity in the Euganean Hills district (North-Eastern Italy)”, aimed at producing detailed results of the actual radiation levels in connection mainly with lithological parameters. A detailed sampling strategy, based on lithostratigraphy, petrology and mineralogy, has been adopted. The 151 rock samples collected were analyzed by high resolution g-ray spectrometry with ex situ HPGe detectors. Statistical and geostatistical analyses were performed, and outlier values of U and Th - possibly associated with anomalies in the geological formation - were identified. U, Th and K concentration maps were developed using both the entire database and then again after expunging the outliers; the two were then compared. In all maps the highest values can be associated to trachyte and rhyolite lithologies, and the lowest ones to sedimentary formations. The external dose due to natural radionuclides in the soil - the so called terrestrial gamma dose rate - has been calculated using the U, Th and K distribution measured in the bedrock samples.

  • 17/04/2016

    Mapping uranium concentration in soil: Belgian experience towards a European map

    Authors: G. Cinelli, F. Tondeur, B. Dehandschutter, P. Bossew, T. Tollefsen,M. De Cort. Ref: Journal of Environmental Radioactivity 166 (2017) 220-234, http://dx.doi.org/10.1016/j.jenvrad.2016.04.026. More

    A map of uranium concentration in soil has been planned for the European Atlas of Natural Radiation. This Atlas is being developed by the Radioactivity Environmental Monitoring (REM) group of the Joint Research Centre (JRC) of the European Commission. The great interest in uranium compared to other terrestrial radionuclides stems from the fact that radon (222Rn) is in the decay chain of uranium (238U) and that public exposure to natural ionizing radiation is largely due to indoor radon. With several different databases available, including data (albeit not calibrated) from an airborne survey, Belgium is a favourable case for exploring the methodology of uranium mapping. A harmonized database of uranium in soil was built by merging radiological (not airborne) and geochemical data. Using this harmonized database it was possible to calibrate the data from the airborne survey. Several methods were used to perform spatial interpolation and to smooth the data: moving average without constraint, by soil class and by geological unit. When using the harmonized database, it is first necessary to evaluate the uranium concentration in areas without data or with an insufficient number of data points. Overall, there is a reasonable agreement between the maps on a 1 km 1 km grid obtained with the two datasets (airborne U and harmonized soil U) with all the methods. The agreement is better when the maps are reduced to a 10 km 10 km grid; the latter could be used for the European map of uranium concentration in soil.

  • 15/04/2016

    7Be behaviour and meteorological conditions associated with 7Be peak events in Spain

    Authors: Hernández-Ceballos M.A, Brattich E., Lozano R.L., Cinelli G. Ref: Journal of Environmental Radioactivity, http://dx.doi.org/10.1016/j.jenvrad.2016.03.019 More

    This work regards a comprehensive analysis of the overall distribution of 7Be activity concentrations in Spain and the synoptic meteorological conditions associated with the highest 7Be peaks (>8 mBq/m3). The use of four sampling stations (Barcelona, Bilbao, Madrid, and Sevilla) included in REMdb, with different latitudinal location, as well as the relatively long time period used in this study (2001–2010), allowed to improve the understanding of 7Be spatio-temporal distribution in Spain. The comparison of the 7Be activity concentrations mean values indicated a north-south gradient (from 3.1 ± 1.1 mBq/m3 in Bilbao to 4.0 ± 1.8 mBq/m3 in Sevilla), even though not statistically significant (as indicated by the t-test). However, the analysis of frequency distributions and temporal evolutions of 7Be activity concentrations have suggested the presence of two main areas, namely northern (Bilbao and Barcelona) and southern (Sevilla) Spain. The identification and analysis of periods associated with the highest values of 7Be have allowed studying the different synoptic patterns associated with stratospheric–tropospheric transport (STT). In particular, three episodes (one in the north and two in the south) potentially associated with vigorous STT have been identified and analysed in detail. The results displayed that the omega block configuration, extending either over western Russia and Scandinavia or into the Atlantic Ocean, forced the prevailing jet stream to the northeast and south of Spain respectively with subsequent subsidence. In summer, this blocking configuration at high latitudes was combined with the presence of the Azores high pressure system to the west of Spain, affecting the 7Be activity concentration recorded in the south.

  • 30/03/2016

    Seasonality of 7Be concentrations in Europe and influence of tropopause height

    Authors: Hernández-Ceballos M.A, Brattich E., Cinelli G., Ajtic J., Djurdjevic V. Ref: Tellus B 2016, 68, 29534, http://dx.doi.org/10.3402/tellusb.v68.29534 More

    This study aims at analysing the latitudinal variability of both the yearly and seasonal pattern of 7Be surface activity concentrations, at addressing the impact of tropopause height (TPH) on 7Be distribution and at evaluating the time lag between TPH and 7Be at European level. With this aim, weekly 7Be and daily TPH data at 17 sampling stations during 10 yr (20012010) are analysed. 7Be shows a clear increasing tendency in the period and generally tends to increase with decreasing latitude. The seasonal pattern generally shows maxima during the warm period and minima during the cold one. The seasonal variogram analysis points out a good spatial correlation for TPH data while a weaker one is observed for 7Be, having TPH a larger influence on 7Be during
    summer. The influence of TPH on 7Be exhibits a large spatial variability, with a clear gap between south and north in the area of the polar front jet. The results identify the presence of two main groups, in particular separating between stations located in northern Europe (50 8N and higher) and stations in southern Europe (south of 50 8N). A similar behaviour for stations located in the same geographical area is also observed when looking at the day of maximum impact of TPH on 7Be concentrations. The results suggest that 7Be concentrations respond in different time ranges to changes in the TPH, observing seasonal differences in each group. These results represent the first European approach to the understanding of the TPH impact on 7Be concentrations at surface levels.

  • 13/02/2016

    Estimating the terrestrial gamma dose rate by decomposition of the ambient dose equivalent rate

    Authors: P. Bossew, G. Cinelli, M. Hernández-Ceballos, N. Cernohlawek, V. Gruber, B. Dehandschutter, F. Menneson, M. Bleher, U. Stöhlker, I. Hellmann, F. Weiler, T. Tollefsen, P.V. Tognoli, M. De Cort Ref: Journal of Environmental Radioactivity 166 (2016) 296-308, http://dx.doi.org/10.1016/j.jenvrad.2016.02.013. More

    An extensive network of dose rate monitoring stations continuously measures ambient dose rate across Europe, as part of the EURDEP system. Its purpose is early warning in radiological emergencies and documenting its temporal and spatial evolution. In normal conditions, when there is no contribution to the dose rate signal coming from fresh anthropogenic contamination, the data represent the radiation “background”, i.e. the combined natural radiation and existing anthropogenic contamination (by global and Chernobyl fallout). These data are being stored, but have so far not been evaluated in depth, or used for any purpose. In the framework of the EU project ‘European Atlas of Natural Radiation’ the idea has emerged to exploit these data for generating a map of natural terrestrial gamma radiation. This component contributes to the total radiation exposure and knowing its geographical distribution can help establishing local ‘radiation budgets’. A further use could be found in terrestrial dose rate as a proxy of the geogenic radon potential, as both quantities are related by partly the same source, namely uranium content of the ground. In this paper, we describe in detail the composition of the ambient dose equivalent rate as measured by the EURDEP monitors with respect to its physical nature and to its sources in
    the environment.We propose and compare methods to recover the terrestrial component from the gross signal. This requires detailed knowledge of detector response. We consider the probes used in the Austrian, Belgian and German dose rate networks, which are the respective national networks supplying data to EURDEP. It will be shown that although considerable progress has been made in understanding the dose rate signals, there is still space for improvement in terms of modelling and model parameters. An indispensable condition for success of the endeavour to establish a Europe-wide map of terrestrial dose rate background is progress in harmonising the European dose rate monitoring network.

  • 10/02/2016

    Calibration with MCNP of NaI detector for the determination of natural radioactivity levels in the field

    Authors: G. Cinelli, L. Tositti, D. Mostacci, J. Bare Ref: Journal of Environmental Radioactivity, Volumes 155–156, May 2016, Pages 31–37 More

    In view of assessing natural radioactivity with on-site quantitative gamma spectrometry, efficiency calibration of NaI(Tl) detectors is investigated. A calibration based on Monte Carlo simulation of detector response is proposed, to render reliable quantitative analysis practicable in field campaigns. The method is developed with reference to contact geometry, in which measurements are taken placing the NaI(Tl) probe directly against the solid source to be analyzed. The Monte Carlo code used for the simulations was MCNP. Experimental verification of the calibration goodness is obtained by comparison with appropriate standards, as reported. On-site measurements yield a quick quantitative assessment of natural radioactivity levels present (40K, 238U and 232Th). On-site gamma spectrometry can prove particularly useful insofar as it provides information on materials from which samples cannot be taken.

  • 07/02/2016

    Identification of airborne radioactive spatial patterns in Europe - Feasibility study using Beryllium-7

    Authors: M.A. Hernández-Ceballos, G. Cinelli, T. Tollefsen, M. Marín Ferrer Ref: Journal of Environmental Radioactivity 155-156 (2016) 55-62. http://dx.doi.org/10.1016/j.jenvrad.2016.02.006 More

    The present study proposes a methodology to identify spatial patterns in airborne radioactive particles in Europe. The methodology is based on transforming the activity concentrations in the set of stations for each month (monthly index), due to the tightly spaced sampling intervals (daily to monthly), in combination with hierarchical and non-hierarchical clustering approaches, due to the lack of a priori knowledge of the number of clusters to be created. Three different hierarchical cluster methodologies are explored to set the optimal number of clusters necessary to initialize the non-hierarchical one (k-means).

    To evaluate this methodology, cosmogenic beryllium-7 (7Be) data, collected between 2007 and 2010 at 19 sampling stations in European Union (EU) countries and stored in the Radioactivity Environmental Monitoring (REM) database, are used. This methodology yields a solution with three distinguishable clusters (south, central and north), each with a different evolution of the 7Be monthly index. Clear differences between monthly indices are shown in both intensity and time trends, following a latitudinal distribution of the sampling stations.

    This cluster result is evaluated performing ANOVA analysis, considering the original 7Be activity concentrations grouped in each cluster. The statistical results (among clusters and sampling stations within clusters) confirm the spatial distribution of 7Be in Europe, and, hence, reinforce the use of this methodology. Finally, the impact of tropopause height on this grouping is successfully tested, suggesting its influence on the spatial distribution of 7Be in Europe. For airborne radioactive particles the analysis gave valuable results that improve knowledge of these
    atmospheric compounds in Europe. Hence, this work addresses a methodology to a grouping of airborne sampling stations, 1) allowing a better understanding of the distribution of 7Be activity concentrations in the EU, and 2) serving as a basis for further investigation of the heterogeneity of airborne radioactivity concentrations in Europe.

  • 23/10/2015

    Impact of sea-land breezes on 210Pb in southern Iberian Peninsula - Feasibility study on using submicron-sized aerosol particles to analyse 210Pb hourly patterns

    Authors: Hernández-Ceballos M.A., Sorribas M., San Miguel E.G., Cinelli, G., Adame J.A., Bolívar J.P. Ref: Atmospheric Pollution Research, Volume 7, Issue 1, January 2016, Pages 1–8 doi:10.1016/j.apr.2015.06.011 More

    This work addresses the impact of mesoscale circulations on 210Pb concentrations in southwestern Iberian Peninsula by analysing the 210Pb database at El Arenosillo station during 2004–2011 (128 periods with a time scale of 48 h).

    The analysis of surface winds during each one of these periods has revealed the positive impact of the two sea-land breeze patterns (pure and non-pure), previously identified in this region, on 210Pb activity concentrations. An average value of 0.80 ± 0.09 mBq m−3 was obtained for the pure pattern (34 periods), 0.54 ± 0.09 mBq m−3 for the non-pure pattern (23 periods) and 0.46 ± 0.04 mBq m−3 for the rest (71 periods).

    The analysis of one representative period of each sea-land breeze patterns is also presented. To perform this analysis we have used: hourly surface wind observations, surface wind fields simulated by the WRF mesoscale model and the hourly database of sub-micron-particle size range in the accumulation mode (NACC). The use of this type of particles to investigate the hourly temporal variability of 210Pb is based on the high correlation, obtained in the present work, between 210Pb activity and particles in the accumulation mode (R = 0.90).

    The analysis reveals that the highest concentrations of NACC, and hence, 210Pb, are obtained when the sampling area is under the influence of the pure breeze, due to it favours the accumulation of particles previously transported by Mediterranean flows along the Guadalquivir valley. In the case of the non-pure pattern, the increase in the concentration of particles is related to the arrival of background synoptic winds from the continental areas of western Iberian Peninsula. In the latest, the increment of NACC is faster and around 400 particles cm−3, while in the case of the pure pattern, it is progressive up to 1400 particles cm−3.

  • 11/05/2015

    High radon areas in the Walloon region of Belgium

    Authors: F. Tondeur, G. Cinelli, B. Dehandschutter Ref: Radiation Protection Dosimetry (2015), Vol. 164, No. 4, pp. 563–568. doi:10.1016/j.jenvrad.2014.05.015 More

    Indoor radon data from Southern Belgium are organised in 35 geological units (GUs), most of which are homogeneous with respect to the radon risk. The percentage of cases above the reference level (400 Bq m23; 300 Bq m23 in the future) is calculated for these GUs from the observations and from the log-normal distribution fitted to the data. Affected areas are defined as areas with more than 1 % of houses above the reference level. In the north of the region, the old Palaeozoic basement is generally covered by Silesian, Cretaceous and Tertiary rocks, which are unaffected. The affected areas here are hot spots associated with specific Palaeozoic outcrops. In the south, there is generally no cover above Palaeozoic formations, which are often radon affected. The affected areas of Ardenne and Condroz dominate this part, but unaffected areas occur like Famenne and Gaume. About 48 % of theWalloon region is expected to be radon affected.

  • 27/04/2015

    Status of the European Atlas of Natural Radiation

    Authors: P. Bossew, T. Tollefsen, G. Cinelli, V. Gruber and M. De Cort Ref: Radiation Protection Dosimetry (2015), Vol. 167, No. 1–3, pp. 29–36, doi:10.1093/rpd/ncv216 More

    According to the EURATOM (European Atomic Energy Community) Treaty, one of the missions of the Joint Research Centre (JRC) of the European Commission (EC) is to collect, process, evaluate and present data on environmental radioactivity. In 2006, the JRC started the ‘European Atlas of Natural Radiation’ project, in order to give an overview of the geographic distribution of sources of, and exposures to, natural radiation. As a first task, a map of indoor radon concentration was created, because in most cases this is the most important contribution to exposure, and since it could be expected that data collection would take quite some time, because radon (Rn) surveys are very differently advanced between European countries. The authors show the latest status of this map. A technically more ambitious map proved the one of the geogenic Rn potential (RP), due to heterogeneity of data sources across Europe and the need to develop models to estimate a harmonised quantity which adequately measures or classifies the RP. Further maps currently in the making include those of secondary cosmic radiation, of terrestrial gamma radiation and of the concentrations of the elements U, Th and K that are its source. In this article, the authors show the progress of some of these maps.

  • 17/04/2015

    Analysis of peak 210Pb events at Mt. Cimone (1998-2011)

    Authors: E. Brattich, M.l Angel Hernández-Ceballos, G. Cinelli, L.Tositti Ref: Atmospheric Environment 112 (2015) 136-147, doi:10.1016/j.atmosenv.2015.04.020 More

    The present study analyses the peak 210Pb activity concentrations observed all over the 1998-2011 period at the WMO-GAW high altitude site of Mt. Cimone (44.18N, 10.7E, 2165 m asl; Italy) in terms of meteorological conditions, links with other atmospheric species and population dose rate associated with this radiotracer. The highest 210Pb events mainly occurred in the warm period and were associated with prolonged anticyclonic conditions, high temperatures, and low relative humidity values. A correlation with the seasonal pattern of the mixing height was also observed, suggesting the importance of thermal convection promoting uplift of warm air from the atmospheric boundary layer (ABL), transporting high concentrations of 222Rn and thus 210Pb. The main sources of high 210Pb concentrations were identified by means of clusters of back-trajectories applied at three different heights. Sources located at east (central Europe), at west (Spain and France) and south (northern Africa) of Mt. Cimone were distinguished. The clusters obtained at the three heights were compared in order to study the extent between ABL and free troposphere during the highest 210Pb events: a wide influence of the strong coupling among atmospheric vertical layers on 210Pb activity concentrations increases was demonstrated. The annual effective dose from the potential inhalation of this radionuclide during the peak concentration episodes was also calculated. The average dose increase during the selected events represents
    only a small fraction of the total dose from all sources; these results are nevertheless useful for providing information on natural background dose contribution from inhalation which is required for the accurate assessment of dosimetric conditions in the case of nuclear emergencies.

  • 20/02/2015

    Radiological risk from Thoron, a case study: the particularly radon-prone area of Bolsena, and the lesson learned

    Authors: G. Cinelli, B. Capaccioni, M. A. Hernández-Ceballos, D. Mostacci, A. Perghem, L. Tositti Ref: Radiation Physics and Chemistry 116(2015)381–385. http://dx.doi.org/10.1016/j.radphyschem.2015.02.016 More

    The contribution of 220Rn is usually negligible compared to that of 222Rn: its very short half-life makes escape from its source site within the rock very unlikely and it never has time enough to filtrate through the ground and through cracks in the floors or cellar walls to reach living quarters. This however becomes untrue if walls built with 232Th‑rich materials are present: then sizeable amounts of thoron may be detected in the closed areas bounded by those walls. This is the case for many dwellings in central Italy, and the town of Bolsena (northern Latium) is presented as a case study. A typical building of the area, entirely constructed with tuff blocks, is investigated and the annual dose rates calculated for varying distances from the wall. Thoron concentration was found to decrease with a relaxation length of 13 cm. Thoron was found to pose a significant risk. The rate of air exchange was found to produce little effect. Wall plastering acts as a filter: thoron diffuses through it but a HVL of less than 1 cm was found to prevail.

  • 14/02/2015

    Log-normality of indoor radon data in the Walloon region of Belgium

    Authors: G. Cinelli, F. Tondeur Ref: Journal of Environmental Radioactivity 143 (2015) 100-109 doi:10.1093/rpd/ncv312 More

    The deviations of the distribution of Belgian indoor radon data from the log-normal trend are examined. Simulated data are generated to provide a theoretical frame for understanding these deviations. It is shown that the 3-component structure of indoor radon (radon from subsoil, outdoor air and building materials) generates deviations in the low- and high-concentration tails, but this low-C trend can be almost completely compensated by the effect of measurement uncertainties and by possible small errors in background subtraction. The predicted low-C and high-C deviations are well observed in the Belgian data, when considering the global distribution of all data. The agreement with the log-normal model is improved when considering data organised in homogeneous geological groups. As the deviation from log-normality is often due to the low-C tail for which there is no interest, it is proposed to use the log-normal fit limited to the high-C half of the distribution. With this prescription, the vast majority of the geological groups of data are compatible with the lognormal model, the remaining deviations being mostly due to a few outliers, and rarely to a “fat tail”. With very few exceptions, the log-normal modelling of the high-concentration part of indoor radon data is expected to give reasonable results, provided that the data are organised in homogeneous geological groups.

  • 01/01/2015

    Soil gas radon assessment and development of a radon risk map in Bolsena, Central Italy.

    Authors: G. Cinelli, L. Tositti, B. Capaccioni, E. Brattich, D. Mostacci Ref: Enviromental Geochemistry and Health. (2015) 37:305–319. doi: 10.1007/s10653-014-9649-9 More

    Vulsini Volcanic district in Northern Latium (Central Italy) is characterized by high natural radiation background resulting from the high concentrations of uranium, thorium and potassium in the volcanic products. In order to estimate the radon radiation risk, a series of soil gas radon measurements were carried out in Bolsena, the principal urban settlement in this area NE of Rome. Soil gas radon concentration ranges between 7 and 176 kBq/m3 indicating a large degree of variability in the NORM content and behavior of the parent soil material related in particular to the occurrence of two different lithologies. Soil gas radon mapping confirmed the existence of two different areas: one along the shoreline of the Bolsena lake, characterized by low soil radon level, due to a prevailing alluvial lithology; another close to the Bolsena village with high soil radon level due to the presence of the high radioactive volcanic rocks of the Vulsini volcanic district. Radon risk assessment, based on soil gas radon and permeability data, results in a map where the alluvial area is characterized by a probability to be an area with high Radon Index lower than 20 %, while probabilities higher than 30 % and also above 50 % are found close to the Bolsena village.

  • 01/01/2015

    A climatology of 7Be in surface air in European Union

    Authors: M.A. Hernández-Ceballos, M. Marín Ferrer, G. Cinelli, T. Tollefsen, L. De Felice, E. Nweke, P.V. Tognoli, S. Vanzo, M. De Cort, Ref: Journal of Environmental Radioactivity. Volume 141, March 01, 2015, Pages 62-70 doi:10.1016/j.jenvrad.2014.12.003 More

    This study presents a European-wide analysis of the spatial and temporal distribution of the cosmogenic isotope 7Be in surface air. This is the first time that a long term database of 34 sampling sites that regularly provide data to the Radioactivity Environmental Monitoring (REM) network, managed by the Joint Research Centre (JRC) in Ispra, is used. While temporal coverage varies between stations, some of them have delivered data more or less continuously from 1984 to 2011. The station locations were considerably heterogeneous, both in terms of latitude and altitude, a range which should ensure a high degree of representativeness of the results. The mean values of 7Be activity concentration presented a spatial distribution value ranging from 2.0 to 5.4 mBq/m3 over the European Union. The results of the ANOVA analysis of all 7Be data available indicated that its temporal and spatial distributions were mainly explained by the location and characteristic of the sampling sites rather than its temporal distribution (yearly, seasonal and monthly). Higher 7Be concentrations were registered at the middle, compared to high-latitude, regions. However, there was no correlation with altitude, since all stations are sited within the atmospheric boundary layer. In addition, the total and yearly analyses of the data indicated a dynamic range of 7Be activity for each solar cycle and phase (maximum or minimum), different impact on stations having been observed according to their location. Finally, the results indicated a significant seasonal and monthly variation for 7Be activity concentration across the European Union, with maximum concentrations occurring in the summer and minimum in the winter, although with differences in the values reached.The knowledge of the horizontal and vertical distribution of this natural radionuclide in the atmosphere is a key parameter for modelling studies of atmospheric processes, which are important phenomena to be taken into account in the case of a nuclear accident.


  • 15/12/2014

    The gabbro and serpentinized peridotite of Bonassola (Bracco-Levanto ophiolite, Italy) – An extremely low natural radiation area to improve on-site gamma spectrometry

    Authors: Braga, R. and Cinelli, G. Ref: Ofioliti, 2014, 39 (2), 43-49 - 10.4454/ofioliti.v39i2.428 More

    Outcrops of dunite, serpentinized peridotite and clinopyroxene-rich coarse gabbro around Bonassola (Bracco-Levanto ophiolite, NW Italy) have been analyzed for natural radionuclides using γ-spectrometry. The very low activity concentrations of natural radionuclides in the dunite outcrop (< 9.0 Bq kg-1 226Ra; < 3.5 Bq kg-1 228Ac and < 25 Bq kg-1 40K) indicate that this site is characterized by a very low natural radiation for both cosmic (being at sea level) and terrestrial contributions. Before starting a field radiometric survey it is important to assess the local background, i.e. the g radiation that does not originate from rock, in order to correct the measurements for the local background. Contrary to the general practice regarding the background radiation in γ-spectrometry measurements, the investigated mafic-ultramafic outcrops has been used to estimate the detection limits for in situ measurement of 238U, 232Th and 40K using sodium iodine (NaI) scintillator detectors. These results have proved useful to quantify the minimum detectable amount of activity (MDA) of 238U, 232Th and 40K for the NaI detector; the MDA points at sub ppm levels for 238U and 232Th and 0.01 wt% K2O. This study also permits to assess the radiological risk of dimension stones that are petrographically similar to the serpentinized ultramafics occurring in the Bracco-Levanto ofiolite. The comparison of the activity concentration index I, defined by the EU Basic Safety Standards Directive and depending on the activity concentrations of 226Ra, 232Th and 40K, with other stones used as building material, indicates that the Bonassola mafic-ultramafic rocks provide a negligible contribution to the indoor gamma radiation dose.

  • 01/11/2014

    From the European indoor radon map towards an atlas of natural radiation

    Authors: T. Tollefsen, G. Cinelli, P. Bossew, V. Gruber and M. De Cort Ref: Radiat Prot Dosimetry (2014) 162 (1-2): 129-134. doi: 10.1093/rpd/ncu244 More

    In 2006, the Joint Research Centre of the European Commission launched a project to map radon at the European level, as part of a planned European Atlas of Natural Radiation. It started with a map of indoor radon concentrations. As of May 2014, this map includes data from 24 countries, covering a fair part of Europe. Next, a European map of geogenic radon, intended to show ‘what earth delivers’ in terms of radon potential (RP), was started in 2008. A first trial map has been created, and a database was established to collect all available data relevant to the RP. The Atlas should eventually display the geographical distribution of physical quantities related to natural radiation. In addition to radon, it will comprise maps of quantities such as cosmic rays and terrestrial gamma radiation. In this paper, the authors present the current state of the radon maps and the Atlas.

  • 10/07/2014

    A method to estimate the terrestrial component of ambient dose equivalent rate from EURDEP routine monitoring data to improve the European Geogenic Radon Map

    Authors: Cinelli G., Hernandez-Ceballos M.A., Bossew P, Tollefsen T, Sanchez I, Marín-Ferrer M, Nishev A, Bogučarskis K, Gruber V, De Cort M Ref: Submitted More

    Abstract

    A method to estimate the terrestrial component of ambient dose equivalent rate is presented. Data of ambient dose equivalent rate were taken from the EURDEP database. 54 stations from the Slovenian monitoring network were chosen to apply the method, and preliminary results are reported. The method is based on the identification of peaks and the corresponding valley values in time series of ambient dose equivalent rate by smoothing and applying threshold values. Geological information and detector type are used in an ANOVA analysis, to evaluate the part of variability which can be attributed to those. Applying this method to all suitable EURDEP stations would lead to a database of terrestrial gamma dose rate which covers almost all of Europe. It can be used to create a map of the terrestrial gamma dose rate background and, in a next step, possibly be used as additional predictor of the geogenic radon potential, which is the quantity underlying the European Geogenic Radon Map, currently under development.

  • 25/05/2014

    Homogeneity of geological units with respect to the radon risk in the Walloon region of Belgium

    Authors: F. Tondeur, G. Cinelli, B. Dehandschutter Ref: Journal of Environmental Radioactivity 136 (2014) 140-151 doi:10.1016/j.jenvrad.2014.05.015 More

    In the process of mapping indoor radon risk, an important step is to define geological units well correlated with indoor radon. The present paper examines this question for the Walloon region of Belgium, using a database of more than 18,000 indoor radon measurements. With a few exceptions like the Carboniferous (to be divided into Tournaisian, Visean and Namurian-Westphalian) and the Tertiary (in which all Series may be treated together), the Series/Epoch stratigraphic level is found to be the most appropriate geological unit to classify the radon risk. A further division according to the geological massif or region is necessary to define units with a reasonable uniformity of the radon risk. In particular, Paleozoic series from Cambrian to Devonian show strong differences between different massifs. Local hot-spots are also observed in the Brabant massif. Finally, 35 geological units are defined according to their radon risk, 6 of which still present a clear weak homogeneity. In the case of 4 of these units (Jurassic, Middle Devonian of Condroz and of Fagne-Famenne, Ordovician of the Stavelot massif) homogeneity is moderate, but the data are strongly inhomogeneous for Visean in Condroz and in the Brabant massif. The 35 geological units are used in an ANOVA analysis, to evaluate the part of indoor radon variability which can be attributed to geology. The result (15.4e17.7%) agrees with the values observed in the UK.

  • 25/04/2014

    Radon in indoor air of primary schools: a systematic survey to evaluate factors affecting radon concentration levels and their variability

    Authors: F. Bochicchio, Z. S. Žunić, C. Carpentieri, S. Antignani, G. Venoso, V. Carelli, C. Cordedda, N. Veselinović, T. Tollefsen, P. Bossew Ref: Indoor Air 24 (2014): 315–326. doi:10.1111/ina.12073. More

    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/m3 were found in 5% of schools. The mean annual radon concentration weighted with the number of pupils is 73 Bq/m3, 39% lower than the unweighted 119 Bq/m3 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.

  • 18/04/2014

    An evaluation of thoron (and radon) equilibrium factor close to walls based on long-term measurements in dwellings

    Authors: R. Mishra, Z.S. Žunić, G. Venoso, F. Bochicchio, Z. Stojanovska, C. Carpentieri, R. Prajith, B.K. Sapra, Y.S. Mayya, T. Ishikawa, Y. Omori, N. Veselinović, T. Tollefsen, P. Ujić, P. Bossew Ref: Radiation Protection Dosimetry, 160 (1 – 3): 164 – 168. doi:10.1093/rpd/ncu083. More

    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, measurements of both gas and 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 time-integrated gas and progeny concentrations simultaneously. The equilibrium factor for thoron measured “close to the wall”, FTnW, ranged from 0.001 to 0.077 with GM(GSD) of 0.006 (2.2), whereas the equilibrium factor for radon, FRn, ranged from 0.06 to 0.95 with GM (GSD) of 0.23 (2.0).

  • 01/02/2014

    Geographical distribution of the annual mean radon concentrations in primary schools of Southern Serbia - application of geostatistical methods

    Authors: P. Bossew, Z.S. Zunic, Z. Stojanovska, T. Tollefsen, C. Carpentieri, N. Veselinovic, S. Komatina, J. Vaupotic, R.D. Simovic, S. Antignani, F. Bochicchio Ref: Journal of Environmental Radioactivity 127 (2014) 141-148. http://dx.doi.org/10.1016/j.jenvrad.2013.09.015 More

    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 (Zunic et al., 2010; Capentieri et al., 2011; Zunic et al., 2013). This article concentrates on the geographical distribution of the measured Rn concentrations. Applying geostatistical methods we generate "school radon map" of expected 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 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.

  • 30/05/2013

    Radon. In: Environment and Human Health

    Authors: P. Pärt, M. De Cort, T. Tollefsen, V. Gruber Ref: Joint EEA-JRC Report. EUR Report 25933 EN. European Environment Agency, Copenhagen, Denmark. ISSN 1725-9177. More

    Current background levels of ionising radiation in Europe are low in general, but there are regional differences because of the presence of radon. Radon is a radioactive gas formed from the radioactive decay of uranium; it seeps out of the ground in areas with uranium-containing soils and rocks. The most important pathway for human exposure is permeation of radon gas into buildings, but radon from water, outdoor air and construction materials can also contribute to the total exposure. Radon exposure is not evenly distributed over Europe — the occurrence is patchy with strong regional variations.

  • 01/05/2013

    The European Indoor Radon Map and beyond

    Authors: V. Gruber, T. Tollefsen, P. Bossew, M. De Cort Ref: Carpathian Journal of Earth and Environmental Sciences, May 2013, Vol. 8, No. 2, p. 169 - 176. More

    Started six years ago, the European map of indoor radon concentrations has evolved to include data from 25 countries, covering a fair part of Europe. As of October 2012, the map is composed of more than 18,000 non-empty grid cells with data, based on more than 800,000 individual measurements. The number of measurements per cell ranges from one up to nearly 24,000. The coverage of territory varies widely between the countries: from less than 20% for some up to more than 100% for others (due to a border effect). While the arithmetic mean for all non-empty cells in Europe (for all participating countries) is 100 Bq/m3, the median is 65 Bq/m3. In parallel, a European map of geogenic radon potential is under development, with a first, trial map having been published. These and other maps will eventually form parts of a planned European Atlas of Natural Radiation.

  • 15/04/2013

    The European radon mapping project

    Authors: P. Bossew, T. Tollefsen, V. Gruber, M. De Cort Ref: IX Latin American IRPA Regional Congress on Radiation Protection and Safety - IRPA 2013. Rio de Janeiro, RJ, Brazil, April 15-19, 2013. More

    There is almost unanimous agreement that indoor radon (Rn) represents a hazard to human health. Large-scale epidemiological studies gave evidence that Rn is the second-most important cause of lung cancer after smoking and that also relatively low Rn concentrations can be detrimental. This has increasingly led to attempts to limit Rn exposure through regulation, mainly building codes. The proposed Euratom Basic Safety Standards (BSS) require Member States to establish Rn action plans aimed at reducing Rn risk, and to set reference values for limiting indoor Rn concentration.

    In 2006 the JRC started a project on mapping Rn at the European level, in addition and complementary to (but not as a substitute for) national efforts. These maps are part of the European Atlas of Natural Radiation project, which is planned eventually to comprise geographical assessments of all sources of exposure to natural radiation. Started first, a map of indoor Rn is now in an advanced phase, but still incomplete as national Rn surveys are ongoing in a number of European countries. A European map of geogenic Rn, conceptually and technically more complicated, was started in 2008.

    The main difficulty encountered is heterogeneity of survey designs, measurement and evaluation methods and database semantics and structures. An important part of the work on the Atlas is therefore to harmonize data and methods.

    We present the current state of the Rn maps and discuss some of the methodological challenges.

  • 01/02/2013

    Some results of a radon survey in 207 Serbian schools

    Authors: Z. S. Žunić, C. Carpentieri, Z. Stojanovska, S. Antignani, N. Veselinovic, T. Tollefsen, V. Carelli, C. Cordedda, O. Cuknic, J. Filipovic, P. Bossew, F. Bochicchio Ref: Romanian Journal of Physics, 58 (Supplement) (2013): S320 – S327. http://www.nipne.ro/rjp/2013_58_Suppl/0320_0327.pdf. More

    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 Bq/m3 to 428 Bq/m3 with a median value of 96 Bq/m3. The arithmetic mean (AM) of the 207 annual averages was 118 Bq/m3 with a standard deviation (SD) of 78 Bq/m3. The best distribution fitting of radon concentration by log-normal function. The log-normal parameters are the following: geometric mean (GM) = 97 Bq/m3, geometric standard deviation (GSD) = 1.9. In addition, a spatial distribution of the indoor radon concentration over the investigated areas is observed.

  • 01/02/2013

    Active and passive radon concentration measurements and first-step mapping in schools in Banja Luka City, Republic of Srpska

    Authors: Z. Curguz, Z. S. Žunić, T. Tollefsen, P. Jovanovic, D. Nikezic, P. Kolarz Ref: Romanian Journal of Physics, 58 (Supplement) (2013): S90 – S98. http://www.nipne.ro/rjp/2013_58_Suppl/0090_0098.pdf. More

    Radon concentration measurements were performed in all 25 primary schools in Banja Luka city, the capital of Republic of Srpska, during 2011 and 2012, using both active RAD7 continual radon measuring instruments and CR-39 passive (commercially known as Gamma) detectors. The two complimentary methods were employed not only to obtain annual averages, but also to study the dynamics of radon concentration changes during the week. For each school, average and temporal variations of radon concentrations were analysed, taking into consideration local geology, building materials and meteorological conditions. The influence of forced ventilation, caused by frequent opening of doors and windows during working hours, with typical dawn and weekend peaks is evident in most but not all schools. Elevated levels of radon concentration (>400 Bq/m3) were found in a few schools using both methods. Although high correlation factor of 0.8 between passive and active methods was found, still short-time (one-week) measurements cannot be used for annual estimation of radon activity but only as a screening one. Thus, the conclusion concerns only long time measurements as valid indicator of annual radon activity.

  • 07/01/2013

    The European map of the geogenic radon potential

    Authors: V. Gruber, P. Bossew, M. De Cort, T. Tollefsen Ref: J. Radiol. Prot. 33 (2013) 51–60. doi:10.1088/0952-4746/33/1/51. More

    As part of its projected European Atlas of Natural Radiation (EANR), the Joint Research Centre (JRC) of the European Commission, in cooperation with research institutions and radioprotection authorities all over Europe, is currently developing a map of the geogenic radon potential. In an accompanying report the state of knowledge, mapping approaches and problems are discussed. We explain the rationale and the legal situation in Europe and present an overview on the main problems stemming from the heterogeneity of input datasets between participating countries and from the definition of input variables and their differently implemented sampling procedures or protocols. Further topics are definition of the target variable which quantifies the geogenic radon potential and its estimation from heterogeneous input and proxy variables, as well as problems specific to mapping, such as choice of mapping support and resolution. The geogenic map was preceded by a European map of indoor radon concentrations, which is still growing as ever more countries decide to participate, and which served as training for harmonisation problems occurring in the European data realm. We shall also briefly discuss its main results and implications for the geogenic map.

  • 01/09/2012

    The European map of indoor radon concentrations: status and questions of quality assurance

    Authors: P. Bossew, V. Gruber, T. Tollefsen, M. De Cort Ref: Kerntechnik 77 (2012) 3: 1 - 8. More

    As a first part of the long-term project “European Atlas of Natural Radiation”, a European map of indoor radon concentrations is currently under development. By mid-2011, 21 countries participate to the project, yielding a more or less complete coverage of the European territory. In this article we shortly present the current status before concentrating on questions of quality assurance. Such questions inevitably emerge in a project which attempts to integrate and harmonize large amounts of data of methodically different origin; aggregating them into a common map raises by itself questions of statistical significance.

  • 01/11/2011

    Towards a European atlas of natural radiation: Goal, status and future perspectives

    Authors: M. De Cort, V. Gruber, T. Tollefsen, P. Bossew, A. Janssens Ref: Radioprotection 46 (2011) 6: S737–S743. http://dx.doi.org/10.1051/radiopro/20116871s. More

    One of the tasks of the European Commission (EC) under the Euratom Treaty is to collect, validate and provide information about the levels of radioactivity in the environment. In order to offer to the public a more balanced view on the annual dose that it may receive from environmental radioactivity, a few years ago we decided to explore the feasibility of preparing a European Atlas of Natural Radiation. By now 21 European countries have already provided indoor radon data, and efforts continue to extend this information to more countries. In addition, we started to investigate the feasibility of a “geogenic radon map”, which would show “what earth delivers” in terms of potential radon hazard. In this paper we present the current state of the art of preparing the Atlas and provide detailed statistics for the results already obtained. The current efforts are still focussed on radon, but also progress on other components, such as cosmic rays and terrestrial gamma radiation, will be presented and discussed.

  • 01/06/2011

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

    Authors: C. Carpentieri, Z. S. Zunic, V. Carelli, C. Cordedda, G. Ferrigno, N. Veselinovic, P. Bossew, T. Tollefsen, O. Cuknic, Z. Vojinovic, F. Bochicchio Ref: Radiation Protection Dosimetry (2011), Vol. 145, No. 2–3, pp. 305–311. doi:10.1093/rpd/ncr042. More

    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 organisation 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 exposures 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 CVof 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.

  • 06/05/2011

    Seasonal indoor radon concentration in FYR of Macedonia

    Authors: Z. Stojanovska, J. Januseski, P. Bossew, Z.S. Zunic, T. Tollefsen, M. Ristova Ref: Radiation Measurements (2011) 1-9. doi:10.1016/j.radmeas.2011.04.022 More

    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 obatined to be: 115 Bq/m3 (2.02), 72 Bq/m3 (1.97), 46 Bq/m3 (1.95), 92 Bq/m3 (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.

  • 02/04/2011

    Status of the European Indoor Radon Map

    Authors: T. Tollefsen, V. Gruber, P. Bossew, M. De Cort Ref: Radiation Protection Dosimetry (2011), Vol. 145, No. 2–3, pp. 110–116. doi:10.1093/rpd/ncr072 More

    Since 2006 a European map of indoor radon (Rn) concentration is in the making. So far 20 countries have contributed with national data, allowing a fair coverage of parts of Europe. This paper presents the current (September 2010) state of the map, discusses its rationale, presents some statistical findings and addresses a few problems which arose during the work. It also briefly presents the European Atlas of Natural Radiation project, of which the Rn map will be part, and further, planned maps of environmental natural radioactivity.

  • 01/07/2010

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

    Authors: J. Nikolić, N. Veselinović, T. Tollefsen, I. Čeliković, D. Kisić, O. Čuknić, Z. Žunić Ref: Nuclear Technology and Radiation Protection 25(1): 37-40. doi: 10.2298/NTRP1001037N More

    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.

  • 18/05/2010

    Special Issue of Journal of Environmental Radioactivity: Advances in Radon Mapping

    Authors: M. De Cort (Guest Editor) Ref: Journal of Environmental Radioactivity 1010 (2010) 785. doi:10.1016/j.jenvrad.2010.04.011 More

    In 2005 the Radioactivity Environmental Monitoring (REM) group at the Institute for Environment and Sustainability (IES), Joint Research Centre (JRC), Ispra, Italy, started to explore the possibility of generating European radon maps in the frame of preparing a European Natural Radiations Atlas. Based on lessons learned from these efforts, the JRC co-organized, together with the Swedish Radiation Protection Authority (SSI), the Geological Survey of Sweden (SGU), the University of Oslo and the Czech radon monitoring company Radon v.o.s., the 9th International Symposium on Geological Aspects of Radon Risk Mapping on 12 and 13 August 2008. This was followed by a one-day Workshop entitled “Radon Risk Mapping: From Soil-gas to Indoor Concentrations”.

    The Symposium addressed scientific and technical issues related to the latest developments in the preparation of radon risk maps derived from indoor and soil-gas measurements, and ongoing efforts to produce a harmonized European map of indoor radon levels. The discussion continued in the Workshop to explore possible means to prepare a geogenic radon map of Europe.

    This special issue on radon mapping is a selection of the presentations made in the above-mentioned Symposium and some further developments. They present the current state of progress in mapping indoor radon concentrations, as well as techniques and the challenges still ahead to come to a European geogenic radon map.

  • 22/04/2010

    First steps towards a European atlas of natural radiation: status of the European indoor radon map

    Authors: G. Dubois, P. Bossew, T. Tollefsen, M. De Cort Ref: Journal of Environmental Radioactivity 101 (2010): 786-798. doi:10.1016/j.jenvrad.2010.03.007. More

    Within the context of its institutional scientific support to the European Commission, in 2005 the Radioactivity Environmental Monitoring (REM) group at the Joint Research Centre of the European, started to explore the possibility of mapping indoor radon in European houses as a first step towards preparing a European Atlas of Natural Radiations. The main objective of such an atlas is to contribute to familiarizing the public with its naturally radioactive environment. The process of preparing the atlas should also provide the scientific community with a database of information that can be used for further studies and for highlighting regions with elevated levels of natural radiation. This document presents the status of the European indoor radon (Rn) map, first statistical results and outlines of forthcoming challenges.

  • 01/03/2010

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

    Authors: Z. Žunić, P. Bossew, N. Veselinović, F. Bochicchio, V. Carelli, J. Vaupotić, O. Čuknić, R. Simović, Z. Vojinović, D. Kisić, T. Tollefsen Ref: Nukleonika 55(4): 419 - 427. http://www.nukleonika.pl/www/back/full/vol55_2010/v55n4p419f.pdf. More

    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.

  • 01/06/2008

    Geostatistical challenges encountered in mapping indoor radon concentrations

    Authors: P. Bossew, G. Dubois Ref: In: “Geostatistics 2008”, G J. Ortiz and X. Emery, (Eds), ECAMIN Ltd, Santiago, Chile, pp. 851-860. More

    Radon has been identified as an important radiological hazard, being second only to smoking in causing lung cancer, and large efforts have been made in many countries to map indoor radon concentration levels. The use of geostatistics in the field is however relatively recent, mainly because of the apparent lack of spatial correlation of indoor radon over short distances. If some significant progress has been made, a number of serious difficulties affecting a geostatistical approach still remain. Among the main obstacles which we believe are the most important are the need for a clear and shared definition of the working variable "indoor radon concentration"; the understanding of microscale variations due to "longitudinal" variability in Rn concentration at one point; and the proper definition of the support of a geostatistical variable "Rn concentration".

  • 27/08/2007

    Investigations on indoor Radon in Austria, part 2: Geological classes as categorical external drift for spatial modelling of the Radon potential

    Authors: P. Bossew, G. Dubois, T. Tollefsen Ref: Journal of Environmental Radioactivity 99 (2008) 81 - 97. doi:10.1016/j.jenvrad.2007.06.013. More

    Geological classes are used to model the deterministic (drift or trend) component of the Radon potential (Friedmann’s RP) in Austria. It is shown that the RP can be grouped according to geological classes, but also according to individual geological units belonging to the same class. Geological classes can thus serve as predictors for mean RP within the classes. Variability of the RP within classes or units is interpreted as the stochastic part of the regionalized variable RP; however, there does not seem to exist a smallest unit which would naturally divide the RP into a deterministic and a stochastic part. Rather, this depends on the scale of the geological maps used, down to which size of geological units is used for modelling the trend. In practice, there must be a sufficient number of data points (measurements) distributed as uniformly as possible within one unit to allow reasonable determination of the trend component.

  • 17/08/2007

    Investigations on indoor radon in Austria, Part 1: Seasonality of indoor radon concentration

    Authors: P. Bossew, H. Lettner Ref: Journal of Environmental Radioactivity 98(3) (2007): 329-345. http://dx.doi.org/10.1016/j.jenvrad.2007.06.006. More

    In general, indoor radon concentration is subject to seasonal variability. The reasons are to be found (1) in meteorological influence on the transport properties of soil, e.g. through temperature, frozen soil layers and soil water saturation; and (2) in living habits, e.g. the tendency to open windows in summer and keep them closed in winter, which in general leads to higher accumulation of geogenic Rn in closed rooms in winter. If one wants to standardize indoor Rn measurements originally performed at different times of the year, e.g. in order to make them comparable, some correction transform as a function of measurement time which accounts for these effects must be estimated. In this paper, the seasonality of indoor Rn concentration measured in Austria is investigated as a function of other factors that influence indoor Rn. Indoor radon concentration is clearly shown to have seasonal variability, with higher Rn levels in winter. However, it is complicated to quantify the effect because, as a consequence of the history of an Rn survey, the measurement season maybe correlated to geological regions, which may introduce a bias in the estimate of the seasonality amplitude.

  • 02/10/2005

    Exploring European thematic maps for radioecological modelling

    Authors: T. Tollefsen, G. Dubois, P. Bossew Ref: In: “Proceedings from 2nd International Conference on Radioactivity in the Environment”. P. Strand, P. Børretzen and T. Jølle (Eds.). ISBN 82-90362-21-8. Norwegian Radiation Protection Authority, Østerås, Norway. 2 - 6 October 2005. Nice, France. More

    Geographic Information Systems (GIS) have been widely used for ecological modelling as they have been designed to simulate spatial aspects of our environment. These tools have also been extensively adapted to radioecology to model the behaviour of radionuclides in the environment. Among other applications, GIS have been used to map radioactive deposition patterns, assess the transfer of radionuclides in food chains and calculate external radiation doses. The apparent simplicity of these tools, their convincing approach and their aesthetic output can easily delude the users by hiding the many simplifications made in modelling the environment. Therefore, it is not a surprise that new research activities in the field of GIS largely focus on data uncertainty and error propagation. Radioecological modelling by means of GIS is particularly exposed to errors because it depends largely on transfer factors (TFs). These are defined as the ratio of the concentration of a radionuclide in a receiving compartment to the concentration in the source compartment. Hence, whether the models are able to predict correctly the behaviour of radionuclides in the environment depends largely on the quality of the thematic maps used to describe these compartments. Thus it appears that the fate of GIS in the field of radioecology will depend largely on developing datasets that are appropriate for describing the various ecological compartments. In this paper, we briefly review radioecological studies made by other authors who used GIS. Then we discuss the use and needs of thematic maps for radioecological modelling, with an emphasis on soil maps derived from the recently released European Soil Data Base. The latter are expected to play an important role in terrestrial radioecology, especially for studies at a continental scale.

  • 07/07/2005

    EURDEP: A Standard Data-format and Network for Exchanging Radiological Monitoring Data

    Authors: De Vries G., De Cort M., Tanner V. Ref: Conference Proceeding 2005 International Conference on Monitoring, Assessments and Uncertainties for Nuclear and Radiological Emergency Response; 21st - 25th November 2005, Rio de Janeiro, Brazil.
  • 01/06/2005

    An overview of radon surveys in Europe

    Authors: G. Dubois (Editor) Ref: Luxembourg: Office for Official Publications of the European Communities. ISBN 92-79-01066-2. EUR 21892 EN. European Communities 2005. More

    With the aim of preparing a European atlas of natural radiation, the Institute for Environment and Sustainability (IES) of the Directorate General Joint Research Centre (JRC) of the European Commission (EC) has conducted a European survey to assess the means and methods used by national authorities to describe radon levels in their countries.

    Radon is a naturally radioactive gas that is, by far, the main contributor to the exposure received by the population from natural background radiation. It is also considered to be the main leading cause of lung cancer second to smoking, and most European countries have therefore adopted a number of regulations and made large efforts to identify radon-prone areas. Because indoor radon levels can fluctuate largely over short scale, establishing radon risk maps can become very difficult. It is the purpose of this report to explore the variety of the means and methods used in the European countries to measure and report radon levels.

    By presenting the radon maps derived by the various authorities, this report should also help make its readers aware that part of their environment is also naturally radioactive.

  • 01/06/2004

    GIS and radioecology: A data perspective

    Authors: G. Dubois, T. Tollefsen, P. Boosew, M. De Cort Ref: In: "Proceedings of the 10th EC-GI & GIS workshop. ESDI: The state of the art". June 2004, Warsaw, Poland. More

    Geographic Information Systems (GIS) have proven to be very valuable tools in radioecology. After the Chernobyl nuclear power plant accident, GIS have been further developed and used to describe deposition patterns, quantify levels of radioactivity and model the transfer of radionuclides in various ecosystems. Radioecological models rely, among other parameters, on transfer factors (TFs), which are defined as the ratio of the concentration of a radionuclide in a receiving compartment to the concentration in the source compartment. Consequently, the ability of these models to predict correctly the behaviour of radionuclides in the environment depends not only on a correct description of these compartments by means of thematic maps, but also on a correct definition of a number of variables that affect the transfer and that are also derived from these maps. By reviewing a few GIS developed in the field of radioecology, we here discuss the use and needs of the main thematic maps involved in radioecological modelling, with an emphasis on the prediction of radionuclide concentrations in the human food-chain at the European scale.

  • 17/07/2003

    User Manual: Eurdep Data Format Converter

    Authors: Kalenderski S., de Vries G. Ref: Special Pub 2003 S.P.I. 03.156. JRC Ispra, Italy.
  • 01/03/1998

    Atlas of Caesium deposition on Europe after the Chernobyl accident

    Authors: M. De Cort, G. Dubois, S. Fridman, M. Germenchuk, Y. Izrael, A. Janssens, A. Jones, G. Kelly, E. Knaviskova, I. Matveenko, I. Nazarov, Y. Pokumeiko, V. Sitak, E. Stukin, L. Tabachny, Y. Tsaturov and S. Avdyushin. Ref: EUR 16733 EN/RU, EC, Luxembourg: Publications Office of the European Union. ISBN 92-828-3140-X. 176 pp. More

    After the Chernobyl accident various compilations have been made of the contamination of particular countries or regions in Europe resulting from the radioactive material released during the accident. These compilations have been made for different purposes and consequently there are significant differences in their resolution and quality. In many cases improved data have since been, and continue to be, obtained through more refined and extensive monitoring, in particular in those areas where greater contamination occurred. A comprehensive atlas of the caesium contamination across Europe was published by the tenth anniversary of the accident. In addition to the more obvious interest in and use of the factual content of the atlas, it was expected to provide most useful and needed perspective, especially in the former Soviet Union, for judging the significance of the contamination. The compilation of the atlas was performed within the Joint Study Project 6 (JSP6) of the CEC/CIS Collaborative Programme on the Consequences of the Chernobyl Accident which was implemented within the European Commission's Radiation Protection Research Action. Data were collected from all over Europe and, after data validation and inter-comparison, maps are electronically prepared by scientists of the above mentioned institutes, using a geographic information system for the calculation of the isolines.

  • 10/07/1997

    The European Union Radiological Data Exchange Platform (EURDEP): Two Years of International Data Exchange Experience

    Authors: De Cort M., de Vries G. Ref: Conference Proceeding 1997 Proceedings of the 4th International Workshop on Real-time Computing of the Environmental Consequences of an Accidental Release from a Nuclear Installation. 7-11 October 1996. Aronsberg, Sweden. Radia.
  • 25/04/1997

    EURDEP: A System for Radiological Data Exchange in Europe

    Authors: De Cort M., de Vries G., Breitenbach L., Dubois G. Ref: Conference Proceeding 1997 Proceedings of the Sixth Topical Meeting on Emergency Preparedness and Response. 22-25 April 1997. San Francisco, California, USA. American Nuclear Society, pp. 53-56.
  • 13/09/1995

    The EU Radiological Data Exchange Platform (EURDEP): Recent Developments

    Authors: De Cort M., de Vries G. Ref: Conference Proceeding 1995 Proceedings of the OECD /NEA Workshop. 13-14 September 1995. Zurich, Switzerland, pp.285-294.