Members publications

          • Long term average radon levels measured in a few days: implications to risk communication and mitigation strategy. Dobromir S. Pressyanov. AARST Symposium proceedings, 2016 (Contact e-mail: Dobromir S. Pressyanov).

Abstract

In the European Council directive (2013/59/EURATOM) the reference levels for radon are based on the annual average concentration (max. 300 Bq/m 3 ). Waiting a year or longer for detector exposure and analysis completion demotivates many stakeholders to give serious consideration to the radon problem and its consequent mitigation. We propose an approach for a speedy problem identification, yet that is still relying on a direct measurement of the annual average radon concentration. The CD/DVD method is used, where one or more compact disks (CDs) or digital versatile disks (DVDs) that were present for a duration of more than one year inside the house are analyzed. A radon problem in the house can then be identified quickly (in days) after the disks are collected and, if necessary, the mitigation can also be initiated shortly thereafter. The whole process is best managed by a radon expert. To perform prompt mitigation, the expert can collaborate with small licensed construction companies. Using this approach, shortly after a radon problem has been identified twenty buildings in Bulgaria (mostly kindergartens and schools) were successfully mitigated.

Pressyanov2016
          • Improving the uncertainty on short-term radon measurements using PADC detector. M. F. Hansen, G. R. Moss, A. P. Fews and D. L. Henshaw. Radiation Protection Dosimetry, 160 (1 – 3), 181 – 183 (Contact e-mail: Maria Hansen)

Abstract

Radon measurements over a short-term period of a few days have proven a popular choice with the general public, despite the issue that the radon concentration can vary significantly over time and longer periods of integration are recommended. Performing short-term radon measurements using a Poly Allyl Diglycol Carbonate (PADC) detector would see a larger contribution from the statistical error associated with the measurements than for longer term measurements. This motivated the investigation to improve the uncertainty on short-term measurements by utilising a new formulation of high-sensitivity PADC and also by investigating the effect of increasing the scan area and extending the measurement time by just a few days.

          • From the European indoor radon map towards an atlas of natural radiation. Tollefsen T, Cinelli C., Bossew P., Gruber V. and De Cort M. Radiation Protection Dosimetry, 162 (1 – 2), 129 – 134; doi:10.1093/rpd/ncu244 (2014) (OPEN ACCESS) (Contact e-mail: Tore Tollefsen)

Abstract

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.

          • Results from the integrated measurements of indoor radon, thoron and their decay product concentrations in schools in the Republic of Macedonia. Stojanovska Z., Zunic Z.S., Bossew P., Bochicchio F., Carpentieri C., Venoso G., Mishra R., Rout R.P., Sapra B.K., Burghele B.D., Cucoş-Dinu A., Boev B., Cosma C. Radiation Protection Dosimetry, 162 (1 – 2), 152-156; doi: 10.1093/rpd/ncu249 (2014) (Contact e-mail: Z. Stojanovska)

Abstract

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 (CRn and CTn) 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 CRn, CTn, 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 (FRn) and thoron and its decay products (FTn>0.5 m) were evaluated: FRn ranged between 0.10 and 0.84 and FTn>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.

          • The planned Brazilian indoor radon survey – concepts and particular challenges. Da Silva N.C, Bossew P. Radiation Protection Dosimetry, 162 (1 – 2), 105 – 109; doi:10.1093/rpd/ncu239 (2014)(Contact e-mail: Peter Bossew)

Abstract

Similar to the tendency in Europe and North America, awareness towards environmental hazards to health has been rising strongly in Brazil for some years. Among these, indoor radon (Rn) is increasingly being acknowledged as an indoor pollutant that contributes to lung cancer and which one therefore attempts to limit by regulations. Scattered regional surveys performed in Brazil have shown that Rn problem may exist in certain regions, but not much is known about its possible overall extent. Therefore, the idea of a national survey has been brought forward. It is still in the conceptual phase; in this contribution, the authors present the state of knowledge and addressing of particular challenges that can be expected to be encountered.

          • High variability of indoor radon concentrations in uraniferous bedrock areas in the Balkan region. Žunić Z.S., Ujić P., Nađđerđ L., Yarmoshenko I.V., Radanović S.B., Komatina Petrović S., Čeliković I., Komatina M., Bossew P. Applied Radiation and Isotopes 94, 328-337; DOI: 10.1016/j.apradiso.2014.08.018 (2014) (Contact e-mail: P. Ujić)

Abstract

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.

          • Definition of Radon Prone Areas in Friuli Venezia Giulia region, Italy, using geostatistical tools. Cafaro C., Bossew P., Giovani C, Garavaglia M. Journal of Environmental Radioactivity 138, 208 – 219 (2014) (Contact e-mail: C. Cafaro)

Abstract

Studying the geographical distribution of indoor radon concentration, using geostatistical interpolation methods, has become common for predicting and estimating the risk to the population. Here we analyse the case of Friuli Venezia Giulia (FVG), the north easternmost region of Italy. Mean value and standard deviation are, respectively, 153 Bq/m3 and 183 Bq/m3. The geometric mean value is 100 Bq/m3. Spatial datasets of indoor radon concentrations are usually affected by clustering and apparent non-stationarity issues, which can eventually yield arguable results. The clustering of the present dataset seems to be non preferential. Therefore the areal estimations are not expected to be affected. Conversely, nothing can be said on the non stationarity issues and its effects. After discussing the correlation of geology with indoor radon concentration It appears they are created by the same geologic features influencing the mean and median values, and can’t be eliminated via a map-based approach. To tackle these problems, in this work we deal with multiple definitions of RPA, but only in quaternary areas of FVG, using extensive simulation techniques.

          • Geographical distribution of the annual mean radon concentrations in primary schools of Southern Serbia – application of geostatistical methods. P. Bossew, Z. S. Žunić, Z. Stojanovska, T. Tollefsen, C. Carpentieri, N. Veselinović, S. Komatina, J. Vaupotič, R.D. Simović, S. Antignani, F. Bochicchio. Journal of Environmental Radioactivity 127, 141 – 148 (2014) (Contact e-mail: Peter Bossew)

Abstract

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 and 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 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.

          • Determination of radon prone areas by optimized binary classification. P. Bossew. Journal of Environmental Radioactivity 129, 121 – 132 (2014). (Contact e-mail: Peter Bossew)

Abstract

Geogenic radon prone areas are regions in which for natural reasons elevated indoor radon concentrations must be expected. Their identification is part of radon mitigation policies in many countries, as radon is acknowledged a major indoor air pollutant, being the second cause of lung cancer after smoking. Defining and estimating radon prone areas is therefore of high practical interest.
In this paper a method is presented which uses the geogenic radon potential as predictor and thresholds of indoor radon concentration for defining radon prone areas, from which thresholds for the geogenic radon potential are deduced which decide whether a location is flagged radon prone or not, in the absence of actual indoor observations.
The overall results are different maps of radon prone areas, derived from the geogenic radon map, and depending (1) on the criterion which defines what a radon prone area is; and (2) on the choice of score whose maximization defines the optimal classifier. Such map is not the result of a transfer model (geogenic to indoor radon), but of the optimization of a classification rule. The method is computationally simple but has its caveats and statistical traps, some of which are also addressed.

          • Estimation of radon prone areas through binary classification, part 2: radon prone geologies. P. Bossew. Journal of Environmental Radioactivity 141, 44-50; 10.1016/j.jenvrad.2014.11.020. (Contact e-mail: Peter Bossew)

Abstract

A radon prone geology is one for which the probability is increased that in a house built on it, elevated indoor Rn concentration will be encountered, or that its Rn potential will be increased. Labelling geological units as Rn prone or not can be an important support in deciding whether a geographical or administrative region in which that geological unit occurs, should be called Rn prone area, possibly in absence of other predictors. In this article a method is proposed which, given a set of geological classes, sorts the classes into Rn prone and non-Rn prone classes depending on a classification criterion which one can choose according the purpose. The method is computationally simple and is demonstrated on the example of Germany.

          • Spatial sampling design for radon surveys. Bossew P. Unpublished. You can download the full document here (Contact e-mail: Peter Bossew)
  • Comparison of multivariate classification and regression methods for the indoor radon measurements. Dimitrije M. MALETIC, Vladimir I. UDOVICIC, Radomir M. BANJANAC, Dejan R. JOKOVIC, Aleksandar L. DRAGIC, Nikola B. VESELINOVIC, and Jelena Z. FILIPOVIC. Nuclear Technology & Radiation Protection: Year 2014, Vol. 29, No. 1, pp. 17-23. (Contact e-mail: Vladimir Udovicic)

Abstract

We present the results of a test usage of multivariate methods, as developed for data analysis in high-energy physics and implemented in the toolkit for multivariate analysis software package, in our analysis of the dependence of the variation of indoor radon concentration on climate variables. The method enables the investigation of the connections of the wide spectrum of climate variables with radon concentrations. We find that multivariate classification and regression methods work well, giving new information and indications, which may be helpful in further research of the variation of radon concentration in indoor spaces. The method may also lead to considerable prediction power of the variations of indoor radon concentrations based on the knowledge of climate variables only.

          • Solving the conflict between basement waterproofing best practice and radon management in the United Kingdom. Martin Freeman. Presented at the AARST International Radon Symposium in Charleston, South Carolina (September 2015). (You can download the full paper here)

Abstract

Cellar conversion and new basement creation is widespread in the UK where basement living and working is frequent. All basements are at risk of elevated radon levels regardless of geographic location. In 1999 a landmark Court ruling altered the approach to waterproofing, steering designers and contractors towards the use of internally fitted drained cavity drain membrane systems. Based on air-gap technology, these membrane systems are not appropriate for gas proofing; in part of continental Europe their use is specifically discouraged for that purpose. The author set about resolving the conflict between good waterproofing practice and radon gas management in basements, producing a successful solution.
The paper explores the background of UK basement use, the key points of the landmark judgment and subsequent code of practice for below ground waterproofing. This code of practice now requires radon to be considered in waterproofing design and implementation, but overlooks how this might be achieved. The paper describes the process that was developed to solve the dilemma and illustrates with case studies. Although construction practices and basement usage differ across the globe, the principles involved may have relevant applications internationally.

          • The Spanish indoor radon mapping strategy. C. Sainz-Fernandez, A. Fernandez-Villar, I. Fuente-Merino, J. L. Gutierrez-Villanueva, J. L. Martin-Matarranz, M. Garcia-Talavera, S. Casal-Ordas and L. S. Quindos-Poncela. Radiation Protection Dosimetry, doi:10.1093/rpd/ncu218.(Contact e-mail: Carlos Sainz)

Abstract

Indoor radon mapping still represents a valuable tool for drawing the picture of the exposure of general public due to radon and radon progeny progeny inhalation in a residential context. The information provided by means of a map is useful not only as awareness and strategic element for authorities and policy-makers, but also as a scientific start-up point in the design of epidemiological and other specific studies on exposure to natural radiation. The requirements for a good mapping are related to harmonisation criteria coming from European recommendations, as well as to national/local characteristics and necessities. Around 12,000 indoor radon measurements have been made since the Spanish national radon programme began at the end of the 1980s. A significant proportion of them resulted from the last campaign performed from 2009 to 12. This campaign completed the first version of a map based on a grid 10 x 10 km2 . In this paper, the authors present the main results of a new map together with the criteria adopted to improve the number of measurements and the statistical significance of them.