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Sample records for radon potential map

  1. Mapping geogenic radon potential by regression kriging.

    Science.gov (United States)

    Pásztor, László; Szabó, Katalin Zsuzsanna; Szatmári, Gábor; Laborczi, Annamária; Horváth, Ákos

    2016-02-15

    Radon ((222)Rn) gas is produced in the radioactive decay chain of uranium ((238)U) which is an element that is naturally present in soils. Radon is transported mainly by diffusion and convection mechanisms through the soil depending mainly on the physical and meteorological parameters of the soil and can enter and accumulate in buildings. Health risks originating from indoor radon concentration can be attributed to natural factors and is characterized by geogenic radon potential (GRP). Identification of areas with high health risks require spatial modeling, that is, mapping of radon risk. In addition to geology and meteorology, physical soil properties play a significant role in the determination of GRP. In order to compile a reliable GRP map for a model area in Central-Hungary, spatial auxiliary information representing GRP forming environmental factors were taken into account to support the spatial inference of the locally measured GRP values. Since the number of measured sites was limited, efficient spatial prediction methodologies were searched for to construct a reliable map for a larger area. Regression kriging (RK) was applied for the interpolation using spatially exhaustive auxiliary data on soil, geology, topography, land use and climate. RK divides the spatial inference into two parts. Firstly, the deterministic component of the target variable is determined by a regression model. The residuals of the multiple linear regression analysis represent the spatially varying but dependent stochastic component, which are interpolated by kriging. The final map is the sum of the two component predictions. Overall accuracy of the map was tested by Leave-One-Out Cross-Validation. Furthermore the spatial reliability of the resultant map is also estimated by the calculation of the 90% prediction interval of the local prediction values. The applicability of the applied method as well as that of the map is discussed briefly. Copyright © 2015 Elsevier B.V. All rights

  2. Mapping geogenic radon potential by regression kriging

    Energy Technology Data Exchange (ETDEWEB)

    Pásztor, László [Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Department of Environmental Informatics, Herman Ottó út 15, 1022 Budapest (Hungary); Szabó, Katalin Zsuzsanna, E-mail: sz_k_zs@yahoo.de [Department of Chemistry, Institute of Environmental Science, Szent István University, Páter Károly u. 1, Gödöllő 2100 (Hungary); Szatmári, Gábor; Laborczi, Annamária [Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Department of Environmental Informatics, Herman Ottó út 15, 1022 Budapest (Hungary); Horváth, Ákos [Department of Atomic Physics, Eötvös University, Pázmány Péter sétány 1/A, 1117 Budapest (Hungary)

    2016-02-15

    Radon ({sup 222}Rn) gas is produced in the radioactive decay chain of uranium ({sup 238}U) which is an element that is naturally present in soils. Radon is transported mainly by diffusion and convection mechanisms through the soil depending mainly on the physical and meteorological parameters of the soil and can enter and accumulate in buildings. Health risks originating from indoor radon concentration can be attributed to natural factors and is characterized by geogenic radon potential (GRP). Identification of areas with high health risks require spatial modeling, that is, mapping of radon risk. In addition to geology and meteorology, physical soil properties play a significant role in the determination of GRP. In order to compile a reliable GRP map for a model area in Central-Hungary, spatial auxiliary information representing GRP forming environmental factors were taken into account to support the spatial inference of the locally measured GRP values. Since the number of measured sites was limited, efficient spatial prediction methodologies were searched for to construct a reliable map for a larger area. Regression kriging (RK) was applied for the interpolation using spatially exhaustive auxiliary data on soil, geology, topography, land use and climate. RK divides the spatial inference into two parts. Firstly, the deterministic component of the target variable is determined by a regression model. The residuals of the multiple linear regression analysis represent the spatially varying but dependent stochastic component, which are interpolated by kriging. The final map is the sum of the two component predictions. Overall accuracy of the map was tested by Leave-One-Out Cross-Validation. Furthermore the spatial reliability of the resultant map is also estimated by the calculation of the 90% prediction interval of the local prediction values. The applicability of the applied method as well as that of the map is discussed briefly. - Highlights: • A new method

  3. Methodology developed to make the Quebec indoor radon potential map

    Energy Technology Data Exchange (ETDEWEB)

    Drolet, Jean-Philippe, E-mail: jean-philippe.drolet@ete.inrs.ca [Institut national de la recherche scientifique, Eau Terre Environnement Research Centre (ETE-INRS), 490 de la Couronne, G1K 9A9 Quebec (Canada); Martel, Richard [Institut national de la recherche scientifique, Eau Terre Environnement Research Centre (ETE-INRS), 490 de la Couronne, G1K 9A9 Quebec (Canada); Poulin, Patrick [Institut national de santé publique du Québec (INSPQ), 945 avenue Wolfe, G1V 5B3 Quebec (Canada); Dessau, Jean-Claude [Agence de la santé et des services sociaux des Laurentides, 1000 rue Labelle, J7Z 5 N6 Saint-Jérome (Canada)

    2014-03-01

    This paper presents a relevant approach to predict the indoor radon potential based on the combination of the radiogeochemical data and the indoor radon measurements in the Quebec province territory (Canada). The Quebec ministry of health asked for such a map to identify the radon-prone areas to manage the risk for the population related to indoor radon exposure. Three radiogeochemical criteria including (1) equivalent uranium (eU) concentration from airborne surface gamma-ray surveys, (2) uranium concentration measurements in sediments, (3) bedrock and surficial geology were combined with 3082 basement radon concentration measurements to identify the radon-prone areas. It was shown that it is possible to determine thresholds for the three criteria that implied statistically significant different levels of radon potential using Kruskal–Wallis one way analyses of variance by ranks. The three discretized radiogeochemical datasets were combined into a total predicted radon potential that sampled 98% of the studied area. The combination process was also based on Kruskal–Wallis one way ANOVA. Four statistically significant different predicted radon potential levels were created: low, medium, high and very high. Respectively 10 and 13% of the dwellings exceed the Canadian radon guideline of 200 Bq/m{sup 3} in low and medium predicted radon potentials. These proportions rise up to 22 and 45% respectively for high and very high predicted radon potentials. This predictive map of indoor radon potential based on the radiogeochemical data was validated using a map of confirmed radon exposure in homes based on the basement radon measurements. It was shown that the map of predicted radon potential based on the radiogeochemical data was reliable to identify radon-prone areas even in zones where no indoor radon measurement exists. - Highlights: • 5 radiogeochemical datasets were used to map the geogenic indoor radon potential. • An indoor radon potential was determined for

  4. Methodology developed to make the Quebec indoor radon potential map.

    Science.gov (United States)

    Drolet, Jean-Philippe; Martel, Richard; Poulin, Patrick; Dessau, Jean-Claude

    2014-03-01

    This paper presents a relevant approach to predict the indoor radon potential based on the combination of the radiogeochemical data and the indoor radon measurements in the Quebec province territory (Canada). The Quebec ministry of health asked for such a map to identify the radon-prone areas to manage the risk for the population related to indoor radon exposure. Three radiogeochemical criteria including (1) equivalent uranium (eU) concentration from airborne surface gamma-ray surveys, (2) uranium concentration measurements in sediments, (3) bedrock and surficial geology were combined with 3082 basement radon concentration measurements to identify the radon-prone areas. It was shown that it is possible to determine thresholds for the three criteria that implied statistically significant different levels of radon potential using Kruskal-Wallis one way analyses of variance by ranks. The three discretized radiogeochemical datasets were combined into a total predicted radon potential that sampled 98% of the studied area. The combination process was also based on Kruskal-Wallis one way ANOVA. Four statistically significant different predicted radon potential levels were created: low, medium, high and very high. Respectively 10 and 13% of the dwellings exceed the Canadian radon guideline of 200 Bq/m(3) in low and medium predicted radon potentials. These proportions rise up to 22 and 45% respectively for high and very high predicted radon potentials. This predictive map of indoor radon potential based on the radiogeochemical data was validated using a map of confirmed radon exposure in homes based on the basement radon measurements. It was shown that the map of predicted radon potential based on the radiogeochemical data was reliable to identify radon-prone areas even in zones where no indoor radon measurement exists.

  5. Compilation of geogenic radon potential map of Pest County, Hungary

    Science.gov (United States)

    Szabó, K. Zs.; Pásztor, L.; Horváth, Á.; Bakacsi, Zs.; Szabó, J.; Szabó, Cs.

    2010-05-01

    222Rn and its effect on the human health have recently received major importance in environmental studies. This natural radioactive gas accounts for about 9% of lung cancer death and about 2% of all deaths from cancer in Europe due to indoor radon concentrations. It moves into the buildings from the natural decay chain of uranium in soils, rocks and building materials. Radon mapping regionalizes the average hazard from radon in a selected area as a radon risk map. Two major methods (concerning the applied radon data) have been used for mapping. One uses indoor radon data whereas the other is based on soil gas radon data. The outputs of the second approach are the geogenic radon potential maps. The principal objective of our work is to take the first step in geogenic radon mapping in Hungary. Soil samples collected in Pest County (Central Region of Hungary) in the frame of a countrywide soil survey (Soil Information and Monitoring System) were studied to have empirical information of the potential radon risk. As the first two steps radium concentration of soil samples, collected at 43 locations sampling soil profiles by genetic horizons from the surface level down to 60-150 cm, were determined using HPGe gamma-spectroscopy technique, as well as measurement of radon exhalation on the soil samples were carried out applying closed radon accumulation chamber coupled with RAD7 radon monitor detector. From these data the exhalation coefficient was calculated, which shows how many percent of the produced radon can come out from the sample. This rate strongly depends on the depth: at circa 100 cm a drastic decrease have been noticed, which is explained by the change in soil texture. The major source of indoor radon is the soil gas radon concentration (Barnet et al., 2005). We estimated this value from the measured radon exhalation and calculated soil porosity and density. The soil gas radon concentration values were categorized after Kemski et al. (2001) and then the

  6. Mapping of the geogenic radon potential in France to improve radon risk management: methodology and first application to region Bourgogne

    Energy Technology Data Exchange (ETDEWEB)

    Ielsch, G., E-mail: geraldine.ielsch@irsn.f [Institut de Radioprotection et de Surete Nucleaire, DEI/SARG/BRN, BP 17, 92262 Fontenay-aux-Roses cedex (France); Cushing, M.E., E-mail: edward.cushing@irsn.f [Institut de Radioprotection et de Surete Nucleaire, DEI/SARG/BRN, BP 17, 92262 Fontenay-aux-Roses cedex (France); Combes, Ph., E-mail: philippe.combes@geoter.f [GEOTER SAS, Geologie Tectonique Environnement et Risques, 3, rue Jean Monnet, 34830 Clapiers (France); Cuney, M., E-mail: michel.cuney@g2r.uhp-nancy.f [CREGU et UMR G2R 7566, Universite Henri Poincare - NANCY I, Domaine Scientifique Victor Grignard, Entree 3B, BP 70 239 - F54 506 Vandoeuvre-les-Nancy Cedex (France)

    2010-10-15

    In order to improve regulatory tools for radon risk management in France, a harmonised methodology to derive a single map of the geogenic radon potential has been developed. This approach consists of determining the capacity of the geological units to produce radon and to facilitate its transfer to the atmosphere, based on the interpretation of existing geological data. This approach is firstly based on a classification of the geological units according to their uranium (U) content, to create a radon source potential map. This initial map is then improved by taking into account the main additional parameters, such as fault lines, which control the preferential pathways of radon through the ground and which can increase the radon levels in soils. The implementation of this methodology to the whole French territory is currently in progress. We present here the results obtained in one region (Bourgogne, Massif Central) which displays significant variations of the geogenic radon potential. The map obtained leads to a more precise zoning than the scale of the existing map of radon priority areas currently based solely on administrative boundaries.

  7. The use of mapped geology as a predictor of radon potential in Norway.

    Science.gov (United States)

    Watson, Robin J; Smethurst, Mark A; Ganerød, Guri V; Finne, Ingvild; Rudjord, Anne Liv

    2017-01-01

    Radon exposure is considered to cause several hundred fatalities from lung-cancer each year in Norway. A national map identifying areas which are likely to be exposed to elevated radon concentrations would be a useful tool for decision-making authorities, and would be particularly important in areas where only few indoor radon measurements exist. An earlier Norwegian study (Smethurst et al. 2008) produced radon hazard maps by examining the relationship between airborne gamma-ray spectrometry, bedrock and drift geology, and indoor radon. The study was limited to the Oslo region where substantial indoor radon and airborne equivalent uranium datasets were available, and did not attempt to test the statistical significance of relationships, or to quantify the confidence of its predictions. While it can be anticipated that airborne measurements may have useful predictive power for indoor radon, airborne measurement coverage in Norway is at present sparse; to provide national coverage of radon hazard estimates, a good understanding of the relationship between geology and indoor radon is therefore important. In this work we use a new enlarged (n = 34,563) form of the indoor radon dataset with national coverage, and we use it to examine the relationship between geology and indoor radon concentrations. We use this relationship to characterise geological classes by their radon potential, and we produce a national radon hazard map which includes confidence limits on the likelihood of areas having elevated radon concentrations, and which covers the whole of mainland Norway, even areas where little or no indoor radon data are available. We find that bedrock and drift geology classes can account for around 40% of the total observed variation in radon potential. We test geology-based predictions of RP (radon potential) against locally-derived estimates of RP, and produce classification matrices with kappa values in the range 0.37-0.56. Our classifier has high predictive value

  8. An approach to define potential radon emission level maps using indoor radon concentration measurements and radiogeochemical data positive proportion relationships.

    Science.gov (United States)

    Drolet, Jean-Philippe; Martel, Richard; Poulin, Patrick; Dessau, Jean-Claude; Lavoie, Denis; Parent, Michel; Lévesque, Benoît

    2013-10-01

    The aim of this paper is to present the first step of a new approach to make a map of radonprone areas showing different potential radon emission levels in the Quebec province. This map is a tool intended to assist the Quebec government in identifying populations with a higher risk of indoor radon gas exposure. This map of radon-prone areas used available radiogeochemical information for the province of Quebec: (1) Equivalent uranium (eU) concentration from airborne surface gamma-ray surveys; (2) uranium concentration measurements in sediments; and (3) bedrock and surficial geology. Positive proportion relationships (PPR) between each individual criterion and the 1417 available basement radon concentrations were demonstrated. It was also shown that those criteria were reliable indicators of radon-prone areas. The three criteria were discretized into 3, 2 and 2 statistically significant different classes respectively. For each class, statistical heterogeneity was validated by Kruskal-Wallis one way analyses of variance on ranks. Maps of radon-prone areas were traced down for each criterion. Based on this statistical study and on the maps of radon-prone areas in Quebec, 18% of the dwellings located in areas with an equivalent uranium (eU) concentration from airborne surface gamma-ray surveys under 0.75 ppm showed indoor radon concentrations above 150 Bq/m3. This percentage increases to 33% when eU concentrations are between 0.75 ppm and 1.25 ppm and exceeds 40% when eU concentrations are above 1.25 ppm. A uranium concentration in sediments above 20 ppm showed an indoor radon concentration geometric mean of 215 Bq/m3 with more than 69% of the dwellings exceeding 150 Bq/m3 or more than 50% of dwellings exceeding the Canadian radon guideline of 200 Bq/m3. It is also shown that the radon emission potential is higher where a uranium-rich bedrock unit is not covered by a low permeability (silt/clay) surficial deposit.

  9. Radon mapping strategies in Austria.

    Science.gov (United States)

    Gruber, V; Ringer, W; Wurm, G; Friedmann, H

    2015-11-01

    According to current European and international recommendations (e.g. by IAEA, WHO and European Union), countries shall identify high radon areas. In Austria, this task was initiated already in the early 1990s, which yielded the first Austrian Radon Potential Map. This map is still in use, updated with recent indoor radon data in 2012. The map is based on radon gas measurements in randomly selected dwellings, normalised to a standard situation. To meet the current (legal) requirements, uncertainties in the existing Austrian radon map should be reduced. A new indoor radon survey with a different sampling strategy was started, and possible mapping methods are studied and tested. In this paper, the methodology for the existing map as well as the planned strategies to improve this map is discussed.

  10. Estimation of the radon production rate in granite rocks and evaluation of the implications for geogenic radon potential maps: A case study in Central Portugal.

    Science.gov (United States)

    Pereira, A; Lamas, R; Miranda, M; Domingos, F; Neves, L; Ferreira, N; Costa, L

    2017-01-01

    The goal of this study was to estimate radon gas production rate in granitic rocks and identify the factors responsible for the observed variability. For this purpose, 180 samples were collected from pre-Hercynian and Hercynian rocks in north and central Portugal and analysed for a) (226)Ra activity, b) radon ((222)Rn) per unit mass activity, and c) radon gas emanation coefficient. On a subset of representative samples from the same rock types were also measured d) apparent porosity and e) apparent density. For each of these variables, the values ranged as follows: a) 15 to 587 Bq kg(-1), b) 2 to 73 Bq kg(-1), c) 0.01 to 0.80, d) 0.3 to 11.4 % and e) 2530 to 2850 kg m(-3). Radon production rate varied between 40 to 1386 Bq m(-3) h(-1). The variability observed was associated with geologically late processes of low and high temperature which led to the alteration of the granitic rock with mobilization of U and increase in radon (222)Rn gas emanation. It is suggested that, when developing geogenic radon potential maps, data on uranium concentration in soils/altered rock should be used, rather than data obtained from unaltered rock. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Map showing radon potential of rocks and soils in Montgomery County, Maryland

    Science.gov (United States)

    Gundersen, L.C.; Reimer, G.M.; Wiggs, C.R.; Rice, C.A.

    1988-01-01

    This report summarizes the radon potential of Montgomery County in the context of its geology. Radon is a naturally occurring gas produced by the radioactive decay of uranium. Radon produced by uraniferous rocks and soils may enter a house through porous building materials and through openings in walls and floors. Radon gases has a tendency to move from the higher pressure commonly existing in the soil to the lower pressure commonly existing in the house. The U.S. Environmental Protection Agency (U.S. EPA, 1986a) estimates that elevated levels of indoor radon may be associated with 5,000 to 20,000 of the 130,000 lung cancer deaths per year. They also estimate that 8 to 12 percent of the homes in the United States will have annual average indoor radon levels exceeding 4 picoCuries per liter of air (pCi/L). Above this level, the U.S. EPA recommends homeowners take remedial action. May factors control the amount of radon which may enter a home from the geologic environment. Soil drainage, permeability, and moisture content effect the amount of radon that can be released from rocks and soils (known as the emmanation) and may limit or increase how far it can migrate. Well drained, highly permeable soils facilitate the movement of radon. Soils with water content in the 8 to 15 percent range enhance the emmanation of radon (Lindmark, 1985). Daily and seasonal variations in soil and indoor radon can be caused by meteorologic factors such as barometric pressure, temperature, and wind (Clements and Wilkening, 1974; Schery and other, 1984). Construction practices also inhibit or promote entry of radon into the home (U.S. EPA, 1986b). In general, however, geology controls the source and distribution of radon (Akerblom and Wilson, 1982; Gundersen and others, 1987, 1988; Sextro and others, 1987; U.S. EPA, 1983; Peake, 1988; Peake and Hess, 1988). The following sections describe: 1) the methods used to measure radon and equivalent uranium (eU) in soil; 2) the radon potential

  12. Radon potential mapping of the Tralee-Castleisland and Cavan areas (Ireland) based on airborne gamma-ray spectrometry and geology.

    Science.gov (United States)

    Appleton, J D; Doyle, E; Fenton, D; Organo, C

    2011-06-01

    The probability of homes in Ireland having high indoor radon concentrations is estimated on the basis of known in-house radon measurements averaged over 10 km × 10 km grid squares. The scope for using airborne gamma-ray spectrometer data for the Tralee-Castleisland area of county Kerry and county Cavan to predict the radon potential (RP) in two distinct areas of Ireland is evaluated in this study. Airborne data are compared statistically with in-house radon measurements in conjunction with geological and ground permeability data to establish linear regression models and produce radon potential maps. The best agreement between the percentage of dwellings exceeding the reference level (RL) for radon concentrations in Ireland (% > RL), estimated from indoor radon data, and modelled RP in the Tralee-Castleisland area is produced using models based on airborne gamma-ray spectrometry equivalent uranium (eU) and ground permeability data. Good agreement was obtained between the % > RL from indoor radon data and RP estimated from eU data in the Cavan area using terrain specific models. In both areas, RP maps derived from eU data are spatially more detailed than the published 10 km grid map. The results show the potential for using airborne radiometric data for producing RP maps.

  13. Geographically weighted regression and geostatistical techniques to construct the geogenic radon potential map of the Lazio region: A methodological proposal for the European Atlas of Natural Radiation.

    Science.gov (United States)

    Ciotoli, G; Voltaggio, M; Tuccimei, P; Soligo, M; Pasculli, A; Beaubien, S E; Bigi, S

    2017-01-01

    In many countries, assessment programmes are carried out to identify areas where people may be exposed to high radon levels. These programmes often involve detailed mapping, followed by spatial interpolation and extrapolation of the results based on the correlation of indoor radon values with other parameters (e.g., lithology, permeability and airborne total gamma radiation) to optimise the radon hazard maps at the municipal and/or regional scale. In the present work, Geographical Weighted Regression and geostatistics are used to estimate the Geogenic Radon Potential (GRP) of the Lazio Region, assuming that the radon risk only depends on the geological and environmental characteristics of the study area. A wide geodatabase has been organised including about 8000 samples of soil-gas radon, as well as other proxy variables, such as radium and uranium content of homogeneous geological units, rock permeability, and faults and topography often associated with radon production/migration in the shallow environment. All these data have been processed in a Geographic Information System (GIS) using geospatial analysis and geostatistics to produce base thematic maps in a 1000 m × 1000 m grid format. Global Ordinary Least Squared (OLS) regression and local Geographical Weighted Regression (GWR) have been applied and compared assuming that the relationships between radon activities and the environmental variables are not spatially stationary, but vary locally according to the GRP. The spatial regression model has been elaborated considering soil-gas radon concentrations as the response variable and developing proxy variables as predictors through the use of a training dataset. Then a validation procedure was used to predict soil-gas radon values using a test dataset. Finally, the predicted values were interpolated using the kriging algorithm to obtain the GRP map of the Lazio region. The map shows some high GRP areas corresponding to the volcanic terrains (central

  14. A statistical evaluation of the influence of housing characteristics and geogenic radon potential on indoor radon concentrations in France.

    Science.gov (United States)

    Demoury, C; Ielsch, G; Hemon, D; Laurent, O; Laurier, D; Clavel, J; Guillevic, J

    2013-12-01

    Radon-222 is a radioactive natural gas produced by the decay of radium-226, known to be the main contributor to natural background radiation exposure. Effective risk management needs to determine the areas in which the density of buildings with high radon levels is likely to be highest. Predicting radon exposure from the location and characteristics of a dwelling could also contribute to epidemiological studies. Beginning in the nineteen-eighties, a national radon survey consisting in more than 10,000 measurements of indoor radon concentrations was conducted in French dwellings by the Institute for Radiological Protection and Nuclear Safety (IRSN). Housing characteristics, which may influence radon accumulation in dwellings, were also collected. More recently, the IRSN generated a French geogenic radon potential map based on the interpretation of geological features. The present study analyzed the two datasets to investigate the factors influencing indoor radon concentrations using statistical modeling and to determine the optimum use of the information on geogenic radon potential that showed the best statistical association with indoor radon concentration. The results showed that the variables associated with indoor radon concentrations were geogenic radon potential, building material, year of construction, foundation type, building type and floor level. The model, which included the surrounding geogenic radon potential (i.e. the average geogenic radon potential within a disc of radius 20 km centered on the indoor radon measurement point) and variables describing house-specific factors and lifestyle explained about 20% of the overall variability of the logarithm of radon concentration. The surrounding geogenic radon potential was fairly closely associated with the local average indoor radon concentration. The prevalence of exposure to radon above specific thresholds and the average exposures to radon clearly increased with increasing classes of geogenic radon

  15. Comparison of Northern Ireland radon maps based on indoor radon measurements and geology with maps derived by predictive modelling of airborne radiometric and ground permeability data.

    Science.gov (United States)

    Appleton, J D; Miles, J C H; Young, M

    2011-03-15

    Publicly available information about radon potential in Northern Ireland is currently based on indoor radon results averaged over 1-km grid squares, an approach that does not take into account the geological origin of the radon. This study describes a spatially more accurate estimate of the radon potential of Northern Ireland using an integrated radon potential mapping method based on indoor radon measurements and geology that was originally developed for mapping radon potential in England and Wales. A refinement of this method was also investigated using linear regression analysis of a selection of relevant airborne and soil geochemical parameters from the Tellus Project. The most significant independent variables were found to be eU, a parameter derived from airborne gamma spectrometry measurements of radon decay products in the top layer of soil and exposed bedrock, and the permeability of the ground. The radon potential map generated from the Tellus data agrees in many respects with the map based on indoor radon data and geology but there are several areas where radon potential predicted from the airborne radiometric and permeability data is substantially lower. This under-prediction could be caused by the radon concentration being lower in the top 30 cm of the soil than at greater depth, because of the loss of radon from the surface rocks and soils to air. Copyright © 2011. Published by Elsevier B.V.

  16. The predictive power of airborne gamma ray survey data on the locations of domestic radon hazards in Norway: A strong case for utilizing airborne data in large-scale radon potential mapping.

    Science.gov (United States)

    Smethurst, M A; Watson, R J; Baranwal, V C; Rudjord, A L; Finne, I

    2017-01-01

    It is estimated that exposure to radon in Norwegian dwellings is responsible for as many as 300 deaths a year due to lung cancer. To address this, the authorities in Norway have developed a national action plan that has the aim of reducing exposure to radon in Norway (Norwegian Ministries, 2010). The plan includes further investigation of the relationship between radon hazard and geological conditions, and development of map-based tools for assessing the large spatial variation in radon hazard levels across Norway. The main focus of the present contribution is to describe how we generate map predictions of radon potential (RP), a measure of radon hazard, from available airborne gamma ray spectrometry (AGRS) surveys in Norway, and what impact these map predictions can be expected to have on radon protection work including land-use planning and targeted surveying. We have compiled 11 contiguous AGRS surveys centred on the most populated part of Norway around Oslo to produce an equivalent uranium map measuring 180 km × 102 km that represents the relative concentrations of radon in the near surface of the ground with a spatial resolution in the 100 s of metres. We find that this map of radon in the ground offers a far more detailed and reliable picture of the distribution of radon in the sub-surface than can be deduced from the available digital geology maps. We tested the performances of digital geology and AGRS data as predictors of RP. We find that digital geology explains approximately 40% of the observed variance in ln RP nationally, while the AGRS data in the Oslo area split into 14 bands explains approximately 70% of the variance in the same parameter. We also notice that there are too few indoor data to characterise all geological settings in Norway which leaves areas in the geology-based RP map in the Oslo area, and elsewhere, unclassified. The AGRS RP map is derived from fewer classes, all characterised by more than 30 indoor measurements, and the

  17. The European radon mapping project

    Energy Technology Data Exchange (ETDEWEB)

    Bossew, P., E-mail: pbossew@bfs.de [German Federal Office for Radiation Protection, Berlin (Germany); Tollefsen, T.; Gruber, V.; De Cort, M., E-mail: tore.tollefsen@jrc.ec.europa.eu, E-mail: valeria.gruber@gmail.com, E-mail: marc.de-cort@jrc.ec.europa.eu [Institute for Transuranium Elements, Ispra, VA (Italy). DG Joint Research Centre. European Commission

    2013-07-01

    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 o flung 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 Imitating indoor Rn concentration. In 2006 the JRC started a project on mapping Rn at the European level, in addition and complementary lo (but not as a substitute for) national efforts. These maps are part of the European Atlas of Natural Radiation project. which is planned eventually 10 comprise geographical assessments of ali 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 or 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. (author)

  18. Status of the European indoor radon map

    Energy Technology Data Exchange (ETDEWEB)

    Bossew, P.; Tollefsen, T.; De Cort, M. [European Commission, Joint Reserch Centre (JRC) (Italy). Inst. of Environment and Sustainability

    2009-07-01

    Since 2006 a harmonized European indoor radon map is under production. At the moment (June 2009) 15 European countries have contributed data, further input is expected. This article informs about historical and legal backgrounds of the project, outlines the technical procedure and presents some preliminary results. (orig.)

  19. Indoor radon risk potential of Hawaii

    Science.gov (United States)

    Reimer, G.M.; Szarzi, S.L.

    2005-01-01

    A comprehensive evaluation of radon risk potential in the State of Hawaii indicates that the potential for Hawaii is low. Using a combination of factors including geology, soils, source-rock type, soil-gas radon concentrations, and indoor measurements throughout the state, a general model was developed that permits prediction for various regions in Hawaii. For the nearly 3,100 counties in the coterminous U.S., National Uranium Resource Evaluation (NURE) aerorad data was the primary input factor. However, NURE aerorad data was not collected in Hawaii, therefore, this study used geology and soil type as the primary and secondary components of potential prediction. Although the radon potential of some Hawaiian soils suggests moderate risk, most houses are built above ground level and the radon soil potential is effectively decoupled from the house. Only underground facilities or those with closed or recirculating ventilation systems might have elevated radon potential. ?? 2005 Akade??miai Kiado??.

  20. Mapping soil gas radon concentration: a comparative study of geostatistical methods.

    Science.gov (United States)

    Buttafuoco, Gabriele; Tallarico, Adalisa; Falcone, Giovanni

    2007-08-01

    Understanding soil gas radon spatial variations can allow the constructor of a new house to prevent radon gas flowing from the ground. Indoor radon concentration distribution depends on many parameters and it is difficult to use its spatial variation to assess radon potential. Many scientists use to measure outdoor soil gas radon concentrations to assess the radon potential. Geostatistical methods provide us a valuable tool to study spatial structure of radon concentration and mapping. To explore the structure of soil gas radon concentration within an area in south Italy and choice a kriging algorithm, we compared the prediction performances of four different kriging algorithms: ordinary kriging, lognormal kriging, ordinary multi-Gaussian kriging, and ordinary indicator cokriging. Their results were compared using an independent validation data set. The comparison of predictions was based on three measures of accuracy: (1) the mean absolute error, (2) the mean-squared error of prediction; (3) the mean relative error, and a measure of effectiveness: the goodness-of-prediction estimate. The results obtained in this case study showed that the multi-Gaussian kriging was the most accurate approach among those considered. Comparing radon anomalies with lithology and fault locations, no evidence of a strict correlation between type of outcropping terrain and radon anomalies was found, except in the western sector where there were granitic and gneissic terrain. Moreover, there was a clear correlation between radon anomalies and fault systems.

  1. A study on the correlation between soil radon potential and average indoor radon potential in Canadian cities.

    Science.gov (United States)

    Chen, Jing; Ford, Ken L

    2017-01-01

    Exposure to indoor radon is identified as the main source of natural radiation exposure to the population. Since radon in homes originates mainly from soil gas radon, it is of public interest to study the correlation between radon in soil and radon indoors in different geographic locations. From 2007 to 2010, a total of 1070 sites were surveyed for soil gas radon and soil permeability. Among the sites surveyed, 430 sites were in 14 cities where indoor radon information is available from residential radon and thoron surveys conducted in recent years. It is observed that indoor radon potential (percentage of homes above 200 Bq m(-3); range from 1.5% to 42%) correlates reasonably well with soil radon potential (SRP: an index proportional to soil gas radon concentration and soil permeability; average SRP ranged from 8 to 26). In five cities where in-situ soil permeability was measured at more than 20 sites, a strong correlation (R(2) = 0.68 for linear regression and R(2) = 0.81 for non-linear regression) was observed between indoor radon potential and soil radon potential. This summary report shows that soil gas radon measurement is a practical and useful predictor of indoor radon potential in a geographic area, and may be useful for making decisions around prioritizing activities to manage population exposure and future land-use planning. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  2. Mapping of radon in Danish soils 1. Collection of basis data; Kortlaegning af radon i danske jordarter 1. Indsamling af grunddata

    Energy Technology Data Exchange (ETDEWEB)

    Gravesen, P.; Roll Jakobsen, P.; Kelstrup, N.; Ernstsen, V

    2000-07-01

    Danish soils are characterised as regards content of uranium, thorium, radium and radon. This has been done to supplement earlier collected data, to give an overview of the radon emanation from Danish soils, which is reasonably adequate for area and for the common soils. To supply the analysis of soil samples from the field, an airborne measurements of the radioactive radiation on Bornholm, has been carried out which can combine the point measurements, represented by the samples. The aim of the activities has been to prepare the geological basis to describe a radon potential map, where other radon data will to be included. 158 samples have been analysed. (EHS)

  3. Soil gas radon mapping of Muzaffarabad city, Pakistan

    Directory of Open Access Journals (Sweden)

    Tareen Aleem Dad Khan

    2016-01-01

    Full Text Available Soil-based radon investigations are of value in correlating radon production and its transportation into buildings through the processes of convection and diffusion. Such studies can help in identifying land areas that pose special concerns. We present preliminary results of soil radon gas measurements at 60 different locations in an attempt to map out the geohazard zone of the city of Muzaffarabad. The seismic geohazard microzonation for the area includes five microzones based on different hazard parameters: a very high hazard zone, a high hazard zone, a moderate hazard zone, a low hazard zone, and a safe zone. Measurements were taken with an active radon monitoring system at the depths of 30, 40, 50, and 60 cm below the ground surface. The results obtained were explained by the lithology of the area. Average soil radon gas concentrations were correlated with the depth from the ground surface and indoor radon values for the study area. No significant correlation was found between soil radon gas and meteorological parameters, however soil radon gas increases as the depth from the surface of the ground grows. The results showed a linear relation between soil radon concentrations with depth from ground surface (R2 = 0.9577. The minimum soil radon concentration (68.5 Bq/m3 was found at a depth of 30 cm in the very high hazard zone, the maximum value (53.300 Bq/m3 at a depth of 60 cm in the seismically safe zone. Measured soil gas radon concentrations at depths of 30, 40, 50, and 60 cm were mapped for high, moderate, and low radon concentrations. Elevated soil radon gas concentrations were found in the safe zone, otherwise considered to be suitable for any type of construction.

  4. Small area mapping of domestic radon, smoking prevalence and lung cancer incidence--A case study in Northamptonshire, UK.

    Science.gov (United States)

    Denman, Antony R; Rogers, Stephen; Ali, Akeem; Sinclair, John; Phillips, Paul S; Crockett, Robin G M; Groves-Kirkby, Christopher J

    2015-12-01

    Smoking and radon both cause lung cancer, and together the risk is significantly higher. UK public health campaigns continue to reduce smoking prevalence, and other initiatives identify houses with raised radon (radon-222) levels and encourage remedial action. Smoking prevalence and radon levels in the UK have been mapped at Primary Care Trust level. This paper extends that work, using a commercial socio-demographic database to estimate smoking prevalence at the postcode sector level, and to predict the population characteristics at postcode sector level for 87 postcode sectors in Northamptonshire. Likely smoking prevalence in each postcode sector is then modelled from estimates of the smoking prevalence in the different socio-economic groups used by the database. Mapping estimated smoking prevalence, radon potential and average lung cancer incidence for each postcode sector suggested that there was little correlation between smoking prevalence and radon levels, as radon potential was generally lower in urban areas in Northamptonshire, where the estimates of smoking prevalence were highest. However, the analysis demonstrated some sectors where both radon potential and smoking prevalence were moderately raised. This study showed the potential of this methodology to map estimated smoking prevalence and radon levels to inform locally targeted public health campaigns to reduce lung cancer incidence.

  5. A map of radon flux at the Australian land surface

    Directory of Open Access Journals (Sweden)

    A. D. Griffiths

    2010-06-01

    Full Text Available A time-dependent map of radon-222 flux density at the Australian land surface has been constructed with a spatial resolution of 0.05° and temporal resolution of one month. Radon flux density was calculated from a simple model utilising data from national gamma-ray aerial surveys, modelled soil moisture, and maps of soil properties. The model was calibrated against a large data set of accumulation-chamber measurements, thereby constraining it with experimental data. A notable application of the map is in atmospheric mixing and transport studies which use radon as a tracer, where it is a clear improvement on the common assumption of uniform radon flux density.

  6. A map of radon flux at the Australian land surface

    Directory of Open Access Journals (Sweden)

    A. D. Griffiths

    2010-09-01

    Full Text Available A time-dependent map of radon-222 flux density at the Australian land surface has been constructed with a spatial resolution of 0.05° and temporal resolution of one month. Radon flux density was calculated from a simple model utilising data from national gamma-ray aerial surveys; modelled soil moisture, available from 1900 in near real-time; and maps of soil properties. The model was calibrated against a data set of accumulation chamber measurements, thereby constraining it with experimental data. A notable application of the map is in atmospheric mixing and transport studies which use radon as a tracer, where it is a clear improvement on the common assumption of uniform radon flux density.

  7. Evaluation of radon occurrence in groundwater from 16 geologic units in Pennsylvania, 1986–2015, with application to potential radon exposure from groundwater and indoor air

    Science.gov (United States)

    Gross, Eliza L.

    2017-05-11

    Physiographic Province, had a median radon concentration greater than the EPA proposed AMCL of 4,000 pCi/L. Median concentrations of radon in groundwater and indoor air were determined to differ significantly among the geologic units (Kruskal-Wallis test, significance probability, p<0.001), and Tukey’s test indicated that radon concentrations in groundwater and indoor air in the Peters Creek Schist (Xpc) were significantly higher than those in the other units. Also, the Peters Creek Schist (Xpc) was determined to be the area with highest potential of radon exposure from groundwater and indoor air and one of two units with the highest percentage of population assumed to be using domestic self-supplied water (81 percent), which puts the population at greater potential of exposure to radon from groundwater.Potential radon exposure determined from classification of geologic units by median radon concentrations in groundwater and indoor air according to proposed and recommended regulatory limits is useful for drawing general conclusions about the presence, variation, and potential radon exposure in specific geologic units, but the associated data and maps have limitations. The aggregated indoor air radon data have spatial accuracy limitations owing to imprecision of geocoded test locations. In addition, the associated data describing geologic units and the public water supplier’s service areas have spatial and interpretation accuracy limitations. As a result, data and maps associated with this report are not recommended for use in predicting individual concentrations at specific sites nor for use as a decision-making tool for property owners to decide whether to test for radon concentrations at specific locations. Instead, the data and maps are meant to promote awareness regarding potential radon exposure in Pennsylvania and to point out data gaps that exist throughout the State.

  8. Systematic grid-wise radon concentration measurements and first radon map in Cyprus

    CERN Document Server

    Theodoulou, G; Parpottas, Y; 10.1016/j.radmeas.2012.03.019

    2012-01-01

    A systematic study of the indoor airborne radon concentration in the central part of the Nicosia district was conducted, using high-sensitivity active radon portable detectors of the type "RADIM3A". From a total of 108 measurements in 54 grids of 1 km^2 area each, the overall mean value is 20.6 \\pm 13.2 Bq m^-3 (A.M.\\pm S.D.). That is almost twice less than the corresponding average worldwide value. The radon concentration levels in drinking water were also measured in 24 sites of the residential district, using the high-sensitivity radon detector of the type "RADIM3W". The mean value obtained from these measurements is 243.8 \\pm 224.8 mBq L^-1, which is relatively low compared to the corresponding internationally accepted level. The associated annual effective dose rates to each measurement were also calculated and compared to the corresponding worldwide values. From the geographical coordinates of the measuring sites and the corresponding radon concentration values, the digital radon map of the central part...

  9. Pilot study of the application of Tellus airborne radiometric and soil geochemical data for radon mapping.

    Science.gov (United States)

    Appleton, J D; Miles, J C H; Green, B M R; Larmour, R

    2008-10-01

    The scope for using Tellus Project airborne gamma-ray spectrometer and soil geochemical data to predict the probability of houses in Northern Ireland having high indoor radon concentrations is evaluated, in a pilot study in the southeast of the province, by comparing these data statistically with in-house radon measurements. There is generally good agreement between radon maps modelled from the airborne radiometric and soil geochemical data using multivariate linear regression analysis and conventional radon maps which depend solely on geological and indoor radon data. The radon maps based on the Tellus Project data identify some additional areas where the radon risk appears to be relatively high compared with the conventional radon maps. One of the ways of validating radon maps modelled on the Tellus Project data will be to carry out additional indoor measurements in these areas.

  10. Mapping radon-prone areas - a geophysical approach

    Energy Technology Data Exchange (ETDEWEB)

    Shirav, M. [Geological Survey of Israel, Jerusalem (Israel); Vulkan, U. [Soreq Nuclear Research Center, Yavne (Israel)

    1997-06-01

    Radon-prone areas in Israel were mapped on the basis of direct measurements of radon ({sup 222}Rn) in the soil/rock gas of all exposed geological units, supported by the accumulated knowledge of local stratigraphy and sub-surface geology. Measurements were carried out by a modified alpha-track detection system, resulting in high radon levels mainly in rocks of the Senonian-Paleocene-aged Mount Scopus Group, comprised of chert-bearing marly chalks, rich in phosphorite which acts as the major uranium source. Issues of source depth, seasonal variations and comparison with indoor radon levels are addressed as well. This approach could be applied to other similar terrains, especially the Mediterranean Phosphate Belt. (orig.)

  11. Is radon a potential risk in geothermal fields?

    Energy Technology Data Exchange (ETDEWEB)

    Balcazar, M.; Tavera, L.; Lopez, A. [Instituto Nacional de Investigaciones Nucleares, Mexico City (Mexico)

    1998-12-31

    Some environmental groups in Mexico have shown concern, by the fact that natural radon emanation in geothermal fields could be considered as a potential risk for human health. As part of the studies recommended by the Ministry of Energy and to provide technical answers to the request of environmental groups, a study of the radon emanation and its impact to human health was carried out at the Primavera Mexican geothermal energy field under prospecting. It was found that radon concentration decreases with temperature of geothermal fluids and increases with the enthalpy of the well. In any case, using the appropriate corrections, radon values were similar to those of ground water. Radon values in the atmosphere of the field show no potential risk for human health. (author)

  12. Radon

    Science.gov (United States)

    Exposure to radon is the second leading cause of lung cancer after smoking. Radon is a colorless, odorless, tasteless and invisible gas produced by the decay of naturally occurring uranium in soil and water.

  13. Radon

    Science.gov (United States)

    ... can move to air, groundwater, and surface water. Radon-222 has a radioactive half-life of about 4 ... concerns. The main isotope of health concern is radon-222 ( 222 Rn). Many scientists believe that the alpha ...

  14. Preliminary results regarding the first map of residential radon in some regions in Romania.

    Science.gov (United States)

    Cosma, C; Cucoş Dinu, A; Dicu, T

    2013-07-01

    Radon represents the most important contribution of population exposure to natural ionising radiation. This article presents the first indoor radon map in some regions of Romania based on 883 surveyed buildings in the Ştei-BăiŢa radon-prone region and 864 in other regions of Romania. Indoor radon measurements were performed in the last 10 y by using CR-39 nuclear track detectors exposed for 3-12 months on ground floor levels of dwellings. Excluding the Ştei-BăiŢa radon-prone region, an average indoor radon concentration of 126 Bq m(-3) was calculated for Romanian houses. In the Ştei-BăiŢa radon-prone area, the average indoor concentration was 292 Bq m(-3). About 21 % of the investigated dwellings in the Ştei-BăiŢa radon-prone region exceed the threshold of 400 Bq m(-3), while 5 % of the dwellings in other areas of Romania exceed the same threshold. As expected, indoor radon concentration is not uniformly distributed throughout Romania. The map shows a high variability among surveyed regions, mainly due to the differences in geology. The radon emanation rate is substantially influenced by the soil characteristics, such as the soil permeability and soil gas radon concentration. Since higher permeability enables the increased migration of soil gas and radon from the soil into the building, elevated levels of indoor radon can be expected in more permeable soil environments.

  15. Soil radon measurements as potential tracer of seismic and volcanic activity at Etna

    Science.gov (United States)

    Neri, Marco; Giammanco, Salvatore; Galli, Gianfranco; Ferrera, Elisabetta

    2014-05-01

    Radon is a radioactive noble gas present in all rocks of the Earth. It's used by the scientific community as a tracer of natural phenomena related to outgassing from the soil along faults, fractures and crustal discontinuity. Recently, radon has also been used on active volcanoes such as Etna, both as a precursor of volcanic phenomena as well as in the study of the dynamics of faults. The Istituto Nazionale di Geofisica e Vulcanologia (INGV) performs discrete and continuous measurements of radon from soil at Etna since 2002. First studies concerned measurements of radon and thoron emissions from soil carried out on the E and SW flanks of Etna, in zones characterized by the presence of numerous seismogenic and aseismic faults. The statistical treatment of the geochemical data allowed recognizing anomaly thresholds, producing distribution maps that highlighted a significant spatial correlation between soil gas anomalies and tectonic lineaments. These studies confirmed that mapping the distribution of radon and thoron in soil gas can reveal hidden faults buried by recent soil cover. INGV permanent radon monitoring network was installed in July 2005. First results were obtained during the July 2006 eruption. The radon signal recorded at Torre del Filosofo (TdF, ~2950 m asl) was compared with volcanic tremor and thermal radiance data. The onset of explosive activity and a lava fountaining episode were preceded by some hours with increases in radon activity and more gradual increases in volcanic tremor. After 2006, Etna produced dozens of paroxysmal episodes from a new vent opened on the eastern flank of the Southeast Crater (summit area), that have built up a new, huge pyroclastic cone. In many cases we observed increase in radon activity some hours before the eruptive events. These observations suggest that radon emissions from the TdF zone are sensitive to the local geodynamic pressure induced by magma dynamics in the conduit systems. Other promising results were

  16. Procedure for the characterization of radon potential in existing dwellings and to assess the annual average indoor radon concentration.

    Science.gov (United States)

    Collignan, Bernard; Powaga, Emilie

    2014-11-01

    Risk assessment due to radon exposure indoors is based on annual average indoor radon activity concentration. To assess the radon exposure in a building, measurement is generally performed during at least two months during heating period in order to be representative of the annual average value. This is because radon presence indoors could be very variable during time. This measurement protocol is fairly reliable but may be a limiting in the radon risk management, particularly during a real estate transaction due to the duration of the measurement and the limitation of the measurement period. A previous field study defined a rapid methodology to characterize radon entry in dwellings. The objective of this study was at first, to test this methodology in various dwellings to assess its relevance with a daily test. At second, a ventilation model was used to assess numerically the air renewal of a building, the indoor air quality all along the year and the annual average indoor radon activity concentration, based on local meteorological conditions, some building characteristics and in-situ characterization of indoor pollutant emission laws. Experimental results obtained on thirteen individual dwellings showed that it is generally possible to obtain a representative characterization of radon entry into homes. It was also possible to refine the methodology defined in the previous study. In addition, numerical assessments of annual average indoor radon activity concentration showed generally a good agreement with measured values. These results are encouraging to allow a procedure with a short measurement time to be used to characterize long-term radon potential in dwellings.

  17. Probability mapping of indoor radon-prone areas using disjunctive kriging.

    Science.gov (United States)

    Raspa, G; Salvi, F; Torri, G

    2010-01-01

    After a reference to the use of maps of radon-prone areas for indoor radon risk management, and to the methods used to produce them, there is a brief illustration of the geostatistical method of disjunctive kriging (DK) introduced by G. Matheron as a substitute for conditional expectation. There are some good reasons of using this method for the mapping of radon-prone areas as follows: (1) spatial correlation is exploited; (2) unbiasedness is conserved even in the conditions of quasi-stationarity; (3) lognormality of the data is not required; (4) choosing the point estimation allows drawing up smooth probability maps. An application of DK is also presented for the production of probability maps in a campaign of indoor radon measurements conducted by Institute for Environmental Protection and Research, in the provinces of Rome and Viterbo (Central Italy). In the application, it is assessed in particular how much the spatial correlation, even though low, influences the results.

  18. Monitoring the radon flux from gold-mine dumps by gamma-ray mapping

    NARCIS (Netherlands)

    Lindsay, R; de Meijer, RJ; Maleka, PP; Newman, RT; Motlhabane, TGK; de Villiers, D

    2004-01-01

    The exhalation of radon from the large mine dumps at the gold mines in South Africa is a potential health hazard. Determination of radon fluxes from these dumpsites is problematic due to the scatter in the data in time and place and the cost involved in getting a representative sample. gamma-ray spe

  19. Radon risk mapping in southern Belgium: an application of geostatistical and GIS techniques.

    Science.gov (United States)

    Zh, H C; Charlet, J M; Poffijn, A

    2001-05-14

    A data set of long-term radon measurements in approximately 2200 houses in southern Belgium has been collected in an on-going national radon survey. The spatial variation of indoor Rn concentrations is modelled by variograms. A radon distribution map is produced using the log-normal kriging technique. A GIS is used to digitise, process and integrate a variety of data, including geological maps, Rn concentrations associated with house locations and an administrative map, etc. It also allows evaluation of the relationships between various spatial data sets with the goal of producing radon risk maps. Based on geostatistical mapping and spatial analysis, we define three categories of risk areas: high risk, medium risk and low risk area. The correlation between radon concentrations and geological features is proved in this study. High and medium Rn risk zones are dominantly situated in bedrock from the Cambrian to Lower Devonian, although a few medium risk zones are within the Jurassic. It is evident that high-risk zones are related to a strongly folded and fractured context.

  20. Association of School District Policies for Radon Testing and Radon-Resistant New Construction Practices with Indoor Radon Zones.

    Science.gov (United States)

    Foster, Stephanie; Everett Jones, Sherry

    2016-12-13

    Radon is a naturally occurring, colorless, odorless, and tasteless radioactive gas. Without testing, its presence is unknown. Using nationally representative data from the 2012 School Health Policies and Practices Study, we examined whether the prevalence of school district policies for radon testing and for radon-resistant new construction practices varied by district location in relation to the U.S. Environmental Protection Agency Map of Radon Zones. Among school districts located in counties with high predicted average indoor radon, 42.4% had policies for radon testing and 37.5% had policies for radon-resistant new construction practices. These findings suggest a critical need for improved awareness among policy makers regarding potential radon exposure for both students and school staff.

  1. Determination of Geogenic Radon Potential (GEORP) in Pocos de Caldas - Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Marcelo T.; Silva, Nivaldo C.; Guerrero, Eder T.Z., E-mail: apoc@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Navarro, Fabiano C.; Oliveira, Rodrigo J., E-mail: campus.pcaldas@unifal-mg.edu.br [Universidade Federal de Alfenas (UNIFAL), Pocos de Caldas, MG (Brazil). Instituto de Ciencia e Tecnologia

    2015-07-01

    The noble gas {sup 222}Rn is a radioactive isotope of the element radon that can be found in atmospheric air, among others gases, at broad range of concentration. This isotope decays from {sup 238}U series, which is normally found in soil and rocks, especially in fault zones and fractures, where uranium presents greater mobility. The atmospheric high concentration of this gas is frequently related to confined environments including dwellings and other buildings with low air ventilation rate. Inhalation of this gas is acknowledged by international agencies such as WHO, as the second leading cause of lung cancer, being the first among the non-smoker population. That is the reason why, some countries have defined their regions with high radon potential where it is justified the implementation of construction techniques to reduce indoor radon concentration. This paper uses the Geogenic Radon Potential (GEORP) approach aiming to identify radon prone areas in the urban zone of Pocos de Caldas - Brazil. GEORP encompasses simultaneous measurements of the soil gas permeability and radon soil gas concentration. This investigation was accomplished using RADON-JOK permeameter, a device specially developed for in situ soil gas permeability, and ALPHAGUARD, a professional radon monitor. A large variability was observed in both radon soil concentration and soil gas permeability. Some areas have presented low gas permeability due to clayey soil characteristics thus medium GEORP. The majority of the points in this paper have been identified with high radon soil gas concentration showing values that reached 1,000 kBq.m{sup -3} and presenting high radon index. (author)

  2. Soil radon measurements as a potential tracer of tectonic and volcanic activity

    Science.gov (United States)

    Neri, Marco; Ferrera, Elisabetta; Giammanco, Salvatore; Currenti, Gilda; Cirrincione, Rosolino; Patanè, Giuseppe; Zanon, Vittorio

    2016-04-01

    In Earth Sciences there is a growing interest in studies concerning soil-radon activity, due to its potential as a tracer of numerous natural phenomena. Our work marks an advance in the comprehension of the interplay between tectonic activity, volcanic eruptions and gas release through faults. Soil-radon measurements, acquired on Mt. Etna volcano in 2009–2011, were analyzed. Our radon probe is sensitive to changes in both volcanic and seismic activity. Radon data were reviewed in light of the meteorological parameters. Soil samples were analyzed to characterize their uranium content. All data have been summarized in a physical model which identifies the radon sources, highlights the mechanism of radon transport and envisages how such a mechanism may change as a consequence of seismicity and volcanic events. In the NE of Etna, radon is released mainly from a depth of 50 m/day. Three periods of anomalous gas release were found (February 2010, January and February 2011). The trigger of the first anomaly was tectonic, while the second and third had a volcanic origin. These results mark a significant step towards a better understanding of the endogenous mechanisms that cause changes in soil-radon emission at active volcanoes.

  3. Soil radon measurements as a potential tracer of tectonic and volcanic activity.

    Science.gov (United States)

    Neri, Marco; Ferrera, Elisabetta; Giammanco, Salvatore; Currenti, Gilda; Cirrincione, Rosolino; Patanè, Giuseppe; Zanon, Vittorio

    2016-04-15

    In Earth Sciences there is a growing interest in studies concerning soil-radon activity, due to its potential as a tracer of numerous natural phenomena. Our work marks an advance in the comprehension of the interplay between tectonic activity, volcanic eruptions and gas release through faults. Soil-radon measurements, acquired on Mt. Etna volcano in 2009-2011, were analyzed. Our radon probe is sensitive to changes in both volcanic and seismic activity. Radon data were reviewed in light of the meteorological parameters. Soil samples were analyzed to characterize their uranium content. All data have been summarized in a physical model which identifies the radon sources, highlights the mechanism of radon transport and envisages how such a mechanism may change as a consequence of seismicity and volcanic events. In the NE of Etna, radon is released mainly from a depth of 50 m/day. Three periods of anomalous gas release were found (February 2010, January and February 2011). The trigger of the first anomaly was tectonic, while the second and third had a volcanic origin. These results mark a significant step towards a better understanding of the endogenous mechanisms that cause changes in soil-radon emission at active volcanoes.

  4. Soil-Gas Radon Anomaly Map of an Unknown Fault Zone Area, Chiang Mai, Northern Thailand

    Science.gov (United States)

    Udphuay, S.; Kaweewong, C.; Imurai, W.; Pondthai, P.

    2015-12-01

    Soil-gas radon concentration anomaly map was constructed to help detect an unknown subsurface fault location in San Sai District, Chiang Mai Province, Northern Thailand where a 5.1-magnitude earthquake took place in December 2006. It was suspected that this earthquake may have been associated with an unrecognized active fault in the area. In this study, soil-gas samples were collected from eighty-four measuring stations covering an area of approximately 50 km2. Radon in soil-gas samples was quantified using Scintrex Radon Detector, RDA-200. The samplings were conducted twice: during December 2014-January 2015 and March 2015-April 2015. The soil-gas radon map obtained from this study reveals linear NNW-SSE trend of high concentration. This anomaly corresponds to the direction of the prospective fault system interpreted from satellite images. The findings from this study support the existence of this unknown fault system. However a more detailed investigation should be conducted in order to confirm its geometry, orientation and lateral extent.

  5. Radon in Danish dwellings. Mapping of stall, county and municipality values; Radon i danske boliger. Kortlaegning af lands-, amts- og kommunevaerdier

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, C.E.; Damkjaer, A. [Forskningscenter Risoe (Denmark); Ulbak, K. [Statens Inst. for Straalehygiejne (Denmark); Gravesen, P. [Danmarks og Groenlands Geologiske Undersoegelse (Denmark)

    2001-01-01

    A survey of radon in Danish dwellings has been carried out. The concentration of radon-222 has been measured in 3019 single-family houses and 101 multi-family houses (apartment complexes) with the so-called alpha-track technique (CR-39). On this basis, a map has been established. This map shows the percentage of single-family houses in each of the 275 municipalities with levels above 200 Bq/m{sup 3} (i.e. the action level recommended by the Danish building authorities for simple radon remedi-action). For Denmark as a whole, 4.6 % of the single-family houses are above 200 Bq/m{sup 3}. That corresponds to 65 000 houses. In certain parts of the country (e.g. northern Jutland) less than 1 % are above 200 Bq/m{sup 3}. In other places (e.g. certain parts of Funen and Bornholm) the value is above 10 %. In the survey, 15 houses had levels above 400 Bq/m{sup 3}. The relationship between radon and various factors has been investigated with regression analysis. The three most important factors are type of basement, province, and soil type. The analysis confirms that the soil below the houses is the most important source of radon in Danish single-family houses. The study also provides a more detailed picture of the relation between geology and indoor radon. For example, it is shown that clayey till generates different indoor radon levels in the different parts of the country. The study does not indicate that a substantial part of newer Danish houses have an airtight house-soil interface. The report includes a summary in English. (au)

  6. A geographic information systems (GIS) and spatial modeling approach to assessing indoor radon potential at local level

    Energy Technology Data Exchange (ETDEWEB)

    Lacan, Igor [California Department of Health Services, Environmental Health Laboratory Branch, 850 Marina Bay Pkwy, Mailstop G365/EHLB, Richmond, CA 94804 (United States)]. E-mail: ilacan@nature.Berkeley.edu; Zhou, Joey Y. [California Department of Health Services, Environmental Health Laboratory Branch, 850 Marina Bay Pkwy, Mailstop G365/EHLB, Richmond, CA 94804 (United States); Liu, Kai-Shen [California Department of Health Services, Environmental Health Laboratory Branch, 850 Marina Bay Pkwy, Mailstop G365/EHLB, Richmond, CA 94804 (United States); Waldman, Jed [California Department of Health Services, Environmental Health Laboratory Branch, 850 Marina Bay Pkwy, Mailstop G365/EHLB, Richmond, CA 94804 (United States)

    2006-04-15

    This study integrates residential radon data from previous studies in Southern California (USA), into a geographic information system (GIS) linked with statistical techniques. A difference (p<0.05) is found in the indoor radon in residences grouped by radon-potential zones. Using a novel Monte Carlo approach, we found that the mean distance from elevated-radon residences (concentration>74Bqm{sup -3}) to epicenters of large (> 4 Richter) earthquakes was smaller (p<0.0001) than the average residence-to-epicenter distance, suggesting an association between the elevated indoor-radon and seismic activities.

  7. Improved predictive mapping of indoor radon concentrations using ensemble regression trees based on automatic clustering of geological units.

    Science.gov (United States)

    Kropat, Georg; Bochud, Francois; Jaboyedoff, Michel; Laedermann, Jean-Pascal; Murith, Christophe; Palacios Gruson, Martha; Baechler, Sébastien

    2015-09-01

    According to estimations around 230 people die as a result of radon exposure in Switzerland. This public health concern makes reliable indoor radon prediction and mapping methods necessary in order to improve risk communication to the public. The aim of this study was to develop an automated method to classify lithological units according to their radon characteristics and to develop mapping and predictive tools in order to improve local radon prediction. About 240 000 indoor radon concentration (IRC) measurements in about 150 000 buildings were available for our analysis. The automated classification of lithological units was based on k-medoids clustering via pair-wise Kolmogorov distances between IRC distributions of lithological units. For IRC mapping and prediction we used random forests and Bayesian additive regression trees (BART). The automated classification groups lithological units well in terms of their IRC characteristics. Especially the IRC differences in metamorphic rocks like gneiss are well revealed by this method. The maps produced by random forests soundly represent the regional difference of IRCs in Switzerland and improve the spatial detail compared to existing approaches. We could explain 33% of the variations in IRC data with random forests. Additionally, the influence of a variable evaluated by random forests shows that building characteristics are less important predictors for IRCs than spatial/geological influences. BART could explain 29% of IRC variability and produced maps that indicate the prediction uncertainty. Ensemble regression trees are a powerful tool to model and understand the multidimensional influences on IRCs. Automatic clustering of lithological units complements this method by facilitating the interpretation of radon properties of rock types. This study provides an important element for radon risk communication. Future approaches should consider taking into account further variables like soil gas radon measurements as

  8. Study of different factors which can explain the radon exhalation potential of soils; Recherche de differents parametres caracterisant le potentiel d`exhalation en radon des sols

    Energy Technology Data Exchange (ETDEWEB)

    Demongeot, St

    1997-10-27

    Radon is a natural radioactive gas belonging to the Uranium-238 chain, which is present in the earth crust and produced by the disintegration of radium-226. It is considered as the major source of radiological exposure of man to natural radiation because it can accumulate in indoor atmosphere. So, this health risk must be take into account.The aim of this study is to find some tools in order to identify high radon level area. The first part of this study has consisted in measurement of radon emission from different not sufficient for the estimation of the radon exhalation potential in a given area. In the second part of this work, we have studied the variations of in situ radon concentration as a function of different geological and pedologic parameters of the site. With the results obtained, we have determined the data which have to be considered, and the methodology to be applied for the determination of the radon exhalation of a given area. Furthermore, by the mean of numerical simulations (TRACH Model), it was possible to know the scale of radon flux variation in a given point versus the hydric state of the ground and thus the permeability: these parameters are not easy to measure because of their variabilities with time. The methodology ESPERAS (EStimation du Potential d`Exhalation en Radon des Sols) developed during this work was applied first, at a local scale and then to greater area. The values estimated by this way are in a good agreement with the results of measurements. So, we can determine the areas which are affected by high radon levels. (author)

  9. Radon in homes of the Portland, Oregon Area: Radon data from local radon testing companies collected by CRM (Continuous Radon Measurement) machines

    Science.gov (United States)

    Whitney, H.; Lindsey, K.; Linde, T.; Burns, S. F.

    2013-12-01

    Students from the Department of Geology at Portland State University paired up with the Oregon Health Authority to better understand radon gas values in homes of the Portland metropolitan area. This study focuses on radon values collected by continuous radon measurement (CRM) machines, taken by local radon testing companies. The local companies participating in this study include Alpha Environmental Services, Inc., Cascade Radon, Environmental Works, The House Detectives, LLC, and Soil Solutions Environmental Services, Inc. In total, 2491 radon readings spanning across 77 zip codes were collected from local companies in the Portland metropolitan area. The maximum value, average value, percentage of homes greater than 4 pCi/L and total rank sum was calculated and used to determine the overall radon potential for each zip code (Burns et al., 1998). A list and four maps were produced showing the results from each category. Out of the total records, 24 zip codes resulted in high radon potential and the average reading for the entire Portland Metropolitan area was 3.7 pCi/L. High potential zip codes are thought to be a result of sand and gravel (Missoula Flood deposits) and faults present in the subsurface. The CRM data was compared with both long-term and short-term data provided by the Oregon Health Authority to validate radon potentials in each zip code. If a home is located in a zip code with high or moderate radon potential across two types of data sets, it is recommended that those homes be tested for radon gas.

  10. Van der Waals potential and vibrational energy levels of the ground state radon dimer

    Science.gov (United States)

    Sheng, Xiaowei; Qian, Shifeng; Hu, Fengfei

    2017-08-01

    In the present paper, the ground state van der Waals potential of the Radon dimer is described by the Tang-Toennies potential model, which requires five essential parameters. Among them, the two dispersion coefficients C6 and C8 are estimated from the well determined dispersion coefficients C6 and C8 of Xe2. C10 is estimated by using the approximation equation that C6C10 / C82 has an average value of 1.221 for all the rare gas dimers. With these estimated dispersion coefficients and the well determined well depth De and Re the Born-Mayer parameters A and b are derived. Then the vibrational energy levels of the ground state radon dimer are calculated. 40 vibrational energy levels are observed in the ground state of Rn2 dimer. The last vibrational energy level is bound by only 0.0012 cm-1.

  11. Radon resistant potential of concrete manufactured using Ordinary Portland Cement blended with rice husk ash

    Science.gov (United States)

    Chauhan, R. P.; Kumar, Amit

    2013-12-01

    The emission of radon from building materials and soil depends upon the radium content, porosity, moisture content and radon diffusion length of materials. Several techniques have been used to reduce the radon emission from the soil using different flooring materials. But the effectiveness of radon shielding depends upon the diffusion of radon through these materials. The present study proposes a method for producing a radon resistant material for decreasing radon diffusion through it. The method involves rice husk ash (RHA) in addition to cement for the preparation of concrete used for flooring and walls. The radon diffusion, exhalation and mechanical property of concrete prepared by rice husk ash blended cement were studied. The addition of RHA caused the reduction in radon diffusion coefficient, exhalation rates, porosity and enhanced the compressive strength of concrete. The bulk radon diffusion coefficient of cementitious concrete was reduced upto 69% by addition of rice husk ash as compare to that of control concrete.

  12. Development of a predictive methodology for identifying high radon exhalation potential areas; Mise au point d'une methodologie predictive des zones a fort potentiel d'exhalation du radon

    Energy Technology Data Exchange (ETDEWEB)

    Ielsch, G

    2001-07-01

    Radon 222 is a radioactive natural gas originating from the decay of radium 226 which itself originates from the decay of uranium 23 8 naturally present in rocks and soil. Inhalation of radon gas and its decay products is a potential health risk for man. Radon can accumulate in confined environments such as buildings, and is responsible for one third of the total radiological exposure of the general public to radiation. The problem of how to manage this risk then arises. The main difficulty encountered is due to the large variability of exposure to radon across the country. A prediction needs to be made of areas with the highest density of buildings with high radon levels. Exposure to radon varies depending on the degree of confinement of the habitat, the lifestyle of the occupants and particularly emission of radon from the surface of the soil on which the building is built. The purpose of this thesis is to elaborate a methodology for determining areas presenting a high potential for radon exhalation at the surface of the soil. The methodology adopted is based on quantification of radon exhalation at the surface, starting from a precise characterization of the main local geological and pedological parameters that control the radon source and its transport to the ground/atmosphere interface. The methodology proposed is innovative in that it combines a cartographic analysis, parameters integrated into a Geographic Information system, and a simplified model for vertical transport of radon by diffusion through pores in the soil. This methodology has been validated on two typical areas, in different geological contexts, and gives forecasts that generally agree with field observations. This makes it possible to identify areas with a high exhalation potential within a range of a few square kilometers. (author)

  13. Radon flux maps for the Netherlands and Europe using terrestrial gamma radiation derived from soil radionuclides

    NARCIS (Netherlands)

    Manohar, S.N.; Meijer, H.A.J.; Herber, M.A.

    2013-01-01

    Naturally occurring radioactive noble gas, radon (Rn-222) is a valuable tracer to study atmospheric processes and to validate global chemical transport models. However, the use of radon as a proxy in atmospheric and climate research is limited by the uncertainties in the magnitude and distribution o

  14. Radon flux maps for the Netherlands and Europe using terrestrial gamma radiation derived from soil radionuclides

    NARCIS (Netherlands)

    Manohar, S.N.; Meijer, H.A.J.; Herber, M.A.

    2013-01-01

    Naturally occurring radioactive noble gas, radon (Rn-222) is a valuable tracer to study atmospheric processes and to validate global chemical transport models. However, the use of radon as a proxy in atmospheric and climate research is limited by the uncertainties in the magnitude and distribution o

  15. Radon in the soil air of Estonia.

    Science.gov (United States)

    Petersell, Valter; Täht-Kok, Krista; Karimov, Mark; Milvek, Heli; Nirgi, Siim; Raha, Margus; Saarik, Krista

    2017-01-01

    Several investigations in Estonia during 1996¬-1999 have shown that permissible level (200 Bq/m(3)) of radon (222Rn) in indoor air is exceeded in 33% of the inspected dwellings. This makes Estonia one of the five countries with highest radon risk in Europe (Fig 1). Due to correlation between the soil radon risk level and radon concentration in houses, small scale radon risk mapping of soil air was carried out (one study point per 70-100 km(2)). It turned out that one-third of Estonian mainland has high radon risk potential, where radon concentration in soil air exceeds safe limit of 50 kBq/m(3). In order to estimate radon content in soil air, two different methods developed in Sweden were used simultaneously. Besides measuring radon content from soil air at the depth of 80 cm with an emanometer (RnM), maximum potential content of radon in soil (RnG) was estimated based on the rate of eU (226Ra) concentration in soil, which was acquired by using gamma-ray spectrometer. Mapping and following studies revealed that simultaneously measured RnG and RnM in study points may often differ. To inspect the cause, several monitoring points were set up in places with different geological conditions. It appeared that unlike the RnG content, which remains close to average level in repeated measurements, the RnM content may differ more than three times periodically. After continuous observations it turned out that concentration of directly measured radon depended on various factors being mostly controlled by mineral composition of soil, properties of topsoil as well as different factors influencing aeration of soil. The results of Rn monitoring show that reliable level of radon risk in Estonian soils can only be acquired by using calculated Rn-concentration in soil air based on eU content and directly measured radon content of soil air in combination with interpreting specific geological and geochemical situations in the study points. Copyright © 2016 Elsevier Ltd. All rights

  16. Analysis of liver damage from radon, X-ray, or alcohol treatments in mice using a self-organizing map.

    Science.gov (United States)

    Kanzaki, Norie; Kataoka, Takahiro; Etani, Reo; Sasaoka, Kaori; Kanagawa, Akihiro; Yamaoka, Kiyonori

    2017-01-01

    In our previous studies, we found that low-dose radiation inhibits oxidative stress-induced diseases due to increased antioxidants. Although these effects of low-dose radiation were demonstrated, further research was needed to clarify the effects. However, the analysis of oxidative stress is challenging, especially that of low levels of oxidative stress, because antioxidative substances are intricately involved. Thus, we proposed an approach for analysing oxidative liver damage via use of a self-organizing map (SOM)-a novel and comprehensive technique for evaluating hepatic and antioxidative function. Mice were treated with radon inhalation, irradiated with X-rays, or subjected to intraperitoneal injection of alcohol. We evaluated the oxidative damage levels in the liver from the SOM results for hepatic function and antioxidative substances. The results showed that the effects of low-dose irradiation (radon inhalation at a concentration of up to 2000 Bq/m(3), or X-irradiation at a dose of up to 2.0 Gy) were comparable with the effect of alcohol administration at 0.5 g/kg bodyweight. Analysis using the SOM to discriminate small changes was made possible by its ability to 'learn' to adapt to unexpected changes. Moreover, when using a spherical SOM, the method comprehensively examined liver damage by radon, X-ray, and alcohol. We found that the types of liver damage caused by radon, X-rays, and alcohol have different characteristics. Therefore, our approaches would be useful as a method for evaluating oxidative liver damage caused by radon, X-rays and alcohol. © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  17. Dissolved radon and uranium in groundwater in a potential coal seam gas development region (Richmond River Catchment, Australia).

    Science.gov (United States)

    Atkins, Marnie L; Santos, Isaac R; Perkins, Anita; Maher, Damien T

    2016-04-01

    The extraction of unconventional gas resources such as shale and coal seam gas (CSG) is rapidly expanding globally and often prevents the opportunity for comprehensive baseline groundwater investigations prior to drilling. Unconventional gas extraction often targets geological layers with high naturally occurring radioactive materials (NORM) and extraction practices may possibly mobilise radionuclides into regional and local drinking water resources. Here, we establish baseline groundwater radon and uranium levels in shallow aquifers overlying a potential CSG target formation in the Richmond River Catchment, Australia. A total of 91 groundwater samples from six different geological units showed highly variable radon activities (0.14-20.33 Bq/L) and uranium levels (0.001-2.77 μg/L) which were well below the Australian Drinking Water Guideline values (radon; 100 Bq/L and uranium; 17 μg/L). Therefore, from a radon and uranium perspective, the regional groundwater does not pose health risks to consumers. Uranium could not explain the distribution of radon in groundwater. Relatively high radon activities (7.88 ± 0.83 Bq/L) in the fractured Lismore Basalt aquifer coincided with very low uranium concentrations (0.04 ± 0.02 μg/L). In the Quaternary Sediments aquifers, a positive correlation between U and HCO3(-) (r(2) = 0.49, p groundwater investigations.

  18. Inferring coastal processes from regional-scale mapping of {sup 222}Radon and salinity: examples from the Great Barrier Reef, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Stieglitz, Thomas C., E-mail: thomas.stieglitz@jcu.edu.a [AIMS-JCU, Townsville (Australia); Australian Institute of Marine Science, PMB NO 3, Townsville QLD 4810 (Australia); School of Engineering and Physical Sciences, James Cook University, Townsville QLD 4811 (Australia); Cook, Peter G., E-mail: peter.g.cook@csiro.a [CSIRO Land and Water, Private Bag 2, Glen Osmond SA 5064 (Australia); Burnett, William C., E-mail: wburnett@mailer.fsu.ed [Department of Oceanography, Florida State University, Tallahassee, FL 32306 (United States)

    2010-07-15

    The radon isotope {sup 222}Rn and salinity in coastal surface water were mapped on regional scales, to improve the understanding of coastal processes and their spatial variability. Radon was measured with a surface-towed, continuously recording multi-detector setup on a moving vessel. Numerous processes and locations of land-ocean interaction along the Central Great Barrier Reef coastline were identified and interpreted based on the data collected. These included riverine fluxes, terrestrially-derived fresh submarine groundwater discharge (SGD) and the tidal pumping of seawater through mangrove forests. Based on variations in the relationship of the tracers radon and salinity, some aspects of regional freshwater inputs to the coastal zone and to estuaries could be assessed. Concurrent mapping of radon and salinity allowed an efficient qualitative assessment of land-ocean interaction on various spatial and temporal scales, indicating that such surveys on coastal scales can be a useful tool to obtain an overview of SGD locations and processes.

  19. Identification and mapping of radon-prone areas in Croatia-preliminary results for Lika-Senj and the southern part of Karlovac counties.

    Science.gov (United States)

    Radolić, Vanja; Miklavčić, Igor; Stanić, Denis; Poje, Marina; Krpan, Ivana; Mužević, Matko; Petrinec, Branko; Vuković, Branko

    2014-11-01

    Long-term indoor radon measurements performed by LR 115 track etched detectors in Croatian homes during 2003-04 showed that the arithmetic means of radon concentrations in Lika-Senj and the southern part of Karlovac counties were three times higher (198 Bq m(-3)) than in houses at national level (68 Bq m(-3)). Recently, indoor radon measurements in randomly selected houses were investigated. The obtained values in these new measurements have confirmed the values obtained 10 y ago (the average radon value in 225 investigated houses in this area is 223 Bq m(-3)). Radon concentrations in soil gas were measured in September and October 2012 and 2013 with the AlphaGUARD measuring system. Areas with both elevated indoor radon levels and radon in soil gas were identified (some micro locations in Korenica, Ličko Lešće, Generalski Stol, Slunj and Ogulin) and visually presented in the form of maps using the inverse distance weighting approach.

  20. An investigation of the potential causes for the seasonal and annual variations in indoor radon concentrations.

    Science.gov (United States)

    Barazza, F; Gfeller, W; Palacios, M; Murith, C

    2015-11-01

    Indoor radon concentrations exhibit strong variations on short and long timescales. Besides human influences, meteorological factors significantly affect the radon concentrations indoors as well as outdoors. In this article, long-term measurements showing strong annual variations are presented, which take a very similar course in different buildings located in largely separated regions in Switzerland. Also, seasonal variations can be very significant. In general, variations in indoor radon levels can primarily be attributed to human influences. On the other hand, specific weather conditions can have a significant impact on indoor radon levels. In order to further investigate the connection between indoor radon levels and meteorological factors, a measuring campaign has been started in two buildings located in two different regions in Switzerland exhibiting different climatic characteristics. Preliminary results of these investigations are presented, which provide evidence for correlations between indoor radon levels and in particular outdoor temperatures, contributing to seasonal and annual as well as short-term variations in indoor radon concentrations.

  1. Mapping of gas radon in soil of the Fresnillo City, Zacatecas; Mapeo de gas radon en suelo de la Ciudad de Fresnillo, Zacatecas

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Q, I. S.; Lopez del R, H.; Davila R, J. I.; Mireles G, F., E-mail: hlopezdelrio@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2012-10-15

    With the purpose of locating areas with high rates of gas radon exhalation, it has begun to measure the radon flow in soil for residence use in the Fresnillo City, Zacatecas State, Mexico, applying the method of the open vial and liquid scintillation. The gas radon accumulation is made in a camera situated to a depth between 25 and 35 cm. In this work the partial results of the research in course are presented. The values obtained for the radon exhalation have varied of <2.25 up to 14.42 Bq/m{sup 2}{center_dot}h. (Author)

  2. Radon metrology

    Energy Technology Data Exchange (ETDEWEB)

    Naismith, S.; Howarth, C. [National Radiological Protection Board, Chilton (United Kingdom)

    1996-09-01

    NRPB carries out calibrations of various types of radon and radon decay product measurement systems for its own purposes and for laboratories throughout Europe. There are currently two radon calibration facilities at NRPB: a 43 m{sup 3} radon chamber and the Fast Radon Exposure Device (FRED), a sealed steel drum. The radon chamber is used for active radon detection systems and the calibration of large numbers of passive detectors. Fred has a high radon concentration and is used to calibrate small numbers of passive radon gas detectors in a short period. (Author).

  3. Predictive analysis and mapping of indoor radon concentrations in a complex environment using kernel estimation: An application to Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Kropat, Georg, E-mail: georg.kropat@chuv.ch [Institute of Radiation Physics, Lausanne University Hospital, Rue du Grand-Pré 1, 1007 Lausanne (Switzerland); Bochud, Francois [Institute of Radiation Physics, Lausanne University Hospital, Rue du Grand-Pré 1, 1007 Lausanne (Switzerland); Jaboyedoff, Michel [Faculty of Geosciences and Environment, University of Lausanne, GEOPOLIS — 3793, 1015 Lausanne (Switzerland); Laedermann, Jean-Pascal [Institute of Radiation Physics, Lausanne University Hospital, Rue du Grand-Pré 1, 1007 Lausanne (Switzerland); Murith, Christophe; Palacios, Martha [Swiss Federal Office of Public Health, Schwarzenburgstrasse 165, 3003 Berne (Switzerland); Baechler, Sébastien [Institute of Radiation Physics, Lausanne University Hospital, Rue du Grand-Pré 1, 1007 Lausanne (Switzerland); Swiss Federal Office of Public Health, Schwarzenburgstrasse 165, 3003 Berne (Switzerland)

    2015-02-01

    . - Highlights: • Kernel regression was used to map indoor radon concentration in Switzerland. • Our model explains 28% of the variations of radon concentration data. • Maps were generated considering different architectural elements and geology. • Maps showing the local probability to exceed 300 Bq/m3 were proposed. • We developed a confidence index to assess the reliability of the probability map.

  4. Radon progeny monitoring at the Eastern North Atlantic (ENA), Graciosa Island ARM facility and a potential earthquake precursory signal

    Science.gov (United States)

    Barbosa, Susana; Mendes, Virgilio B.; Azevedo, Eduardo B.

    2016-04-01

    Radon has been considered a promising earthquake precursor, the main rationale being an expected increase in radon exhalation in soil and rocks due to stress associated with the preparatory stages of an earthquake. However, the precursory nature of radon is far from being convincingly demonstrated so far. A major hindrance is the many meteorological and geophysical factors diving radon temporal variability, including the geophysical parameters influencing its emanation (grain size, moisture content, temperature), as well as the meteorological factors (atmospheric pressure, moisture, temperature, winds) influencing its mobility. Despite the challenges, radon remains one of the strongest candidates as a potential earthquake precursor, and it is of crucial importance to investigate the many factors driving its variability and its potential association with seismic events. Continuous monitoring of radon progeny is performed at the Eastern North Atlantic (ENA) facility located in the Graciosa island (Azores, 39N; 28W), a fixed site of the Atmospheric Radiation Measurement programme (ARM), established and supported by the Department of Energy (DOE) of the United States of America with the collaboration of the local government and University of the Azores. The Azores archipelago is associated with a complex geodynamic setting on the Azores triple junction where the American, Eurasian and African litospheric plates meet, resulting in significant seismic and volcanic activity. A considerable advantage of the monitoring site is the availability of a comprehensive dataset of concurrent meteorological observations performed at the ENA facility and freely available from the ARM data archive, enabling a detailed analysis of the environmental factors influencing the temporal variability of radon's progeny. Gamma radiation is being measured continuously every 15 minutes since May 2015. The time series of gamma radiation counts is dominated by sharp peaks lasting a few hours and

  5. Use of a geographic information system (GIS) for targeting radon screening programs in South Dakota.

    Science.gov (United States)

    Kearfott, Kimberlee J; Whetstone, Zachary D; Rafique Mir, Khwaja M

    2016-01-01

    Because (222)Rn is a progeny of (238)U, the relative abundance of uranium may be used to predict the areas that have the potential for high indoor radon concentration and therefore determine the best areas to conduct future surveys. Geographic Information System (GIS) mapping software was used to construct maps of South Dakota that included levels of uranium concentrations in soil and stream water and uranium deposits. Maps of existing populations and the types of land were also generated. Existing data about average indoor radon levels by county taken from a databank were included for consideration. Although the soil and stream data and existing recorded average indoor radon levels were sparse, it was determined that the most likely locations of elevated indoor radon would be in the northwest and southwest corners of the state. Indoor radon levels were only available for 9 out of 66 counties in South Dakota. This sparcity of data precluded a study of correlation of radon to geological features, but further motivates the need for more testing in the state. Only actual measurements should be used to determine levels of indoor radon because of the strong roles home construction and localized geology play in radon concentration. However, the data visualization method demonstrated here is potentially useful for directing resources relating to radon screening campaigns.

  6. Validation of a geographic information system for the evaluation of the soil radon exhalation potential in South-Tyrol and Veneto (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Bertolo, A.; Verdi, L

    2001-07-01

    The PERS (soil radon exhalation potential) project was promoted by ANPA (Italian Environmental Protection Agency) together with the Universita Cattolica del Sacro Cuore of Rome: the aim was to produce a geographic information system allowing the discovery of regions with different radon exhalation potential starting from some territorial knowledge. Some environmental measurements were carried out within this project in selected areas in South-Tyrol and Veneto. The measurement of radon in springwater and groundwater as well as in soil gas plays a decisive role for the validation of the algorithm for computing the PERS. Along with technical aspects, a possible use of the PERS method by the Regional Environmental Protection Agencies and by other agencies is discussed with the scope of identifying radon prone areas, as stated in the Italian 'Decreto Legislativo' 26 May 2000, n. 241. Moreover the forecasting power of PERS regarding indoor radon concentration is analysed. (author)

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

    Science.gov (United States)

    Bossew, P; Žunić, Z S; Stojanovska, Z; Tollefsen, T; Carpentieri, C; Veselinović, N; Komatina, S; Vaupotič, J; Simović, R D; Antignani, S; Bochicchio, F

    2014-01-01

    Between 2008 and 2011 a survey of radon ((222)Rn) was performed in schools of several districts of Southern Serbia. Some results have been published previously (Žunić et al., 2010; Carpentieri et al., 2011; Žunić et al., 2013). This article concentrates on the geographical distribution of the measured Rn concentrations. Applying geostatistical methods we generate "school radon maps" of expected 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.

  8. Recognition of microclimate zones through radon mapping, Lechuguilla Cave, Carlsbad Caverns National Park, New Mexico

    Science.gov (United States)

    Cunningham, K.I.; LaRock, E.J.

    1991-01-01

    Radon concentrations range from temperature and barometric pressure, similar to other Type 2 caves. Most of the cave is developed in three geographic branches beneath the entrance passages; these areas maintain Rn levels independent of surface effects, an indication that Rn levels in deep, complex caves or mines cannot be simply estimated by outside atmospheric parameters. These deeper, more isolated areas are subject to convective ventilation driven by temperature differences along the 477-m vertical extent of the cave. Radon concentrations are used to delineate six microclimate zones (air circulation cells) throughout the cave in conjunction with observed airflow data. Suspected surface connections contribute fresh air to remote cave areas demonstrated by anomalous Rn lows surrounded by higher values, the presence of mammalian skeletal remains, CO2 concentrations and temperatures lower than the cave mean, and associated surficial karst features.

  9. 广东中山地区土壤氡浓度填图研究%Mapping of Soil Radon Concentration in Zhongshan,Guangdong Province

    Institute of Scientific and Technical Information of China (English)

    肖磊; 王南萍; 周志广; 储星铭; 曾立晖

    2012-01-01

    为了研究区域土壤氡填图的方法,利用RAD7电子测氡仪和RADON-JOK土壤气体渗透率仪在广东省中山市进行了面积为1 800 km2的测量工作,有效测点数为67个.中山市的平均土壤氡浓度为(100.41±154.64) kBq/m3;最大值和最小值分别为0.74 kBq/m3和1 199.24 kBq/m3.土壤气体渗透率测量结果表明,在风化花岗岩地区,高渗透率和中渗透率占优势;而第四纪沉积物地区大部分土壤气体渗透率较低.基于此,结合研究区土壤氡浓度和土壤气体渗透率,对研究区土壤氡风险进行了分级评价.为土壤氡风险分级的方法研究提供了有参考价值的研究实例.%In order to study the regional mapping method of radon concentration in soils, the survey work was performed in a total survey area of 1 ,800 km2 in Zhongshan, Guangdong Province. The electronic radon monitor RAD7 and the permeameter RADON-JOK were used to measure radon-222 concentration and gas permeability of soils, acquiring 67 valid data. The radon-222 concentrations of soils in Zhongshan vary between 0. 74 kBq/m3 and 1 ,199. 24 kBq/m3, and the average concentration is (100. 41 ± 154. 64) kBq/m3. The gas permeability of the weathered granite soil is dominantly high and medium, and that of most Quaternary sediments is low. Based on these data, the radon risk of soils in the study area is accurately classified, and the result shows that the classification method of radon risk of soil based on the radon concentration and gas permeability is proved to be feasible.

  10. The Austrian radon activities on the way to the national radon action plan.

    Science.gov (United States)

    Gruber, V; Ringer, W; Wurm, G; Haider, W

    2014-07-01

    Based on the new Euratom Basic Safety Standards (BSS), all EU member states will be obliged to design a strategy to address long-term risks from radon exposure, which is laid down in the 'national radon action plan'. In Austria, the National Radon Centre is responsible for the development of the action plan. This paper presents the current and planned radon protection activities on the way to establish the radon action plan--like the national radon database, the definition of radon risk areas by improving the existing radon map, as well as strategies and activities to increase the radon awareness of the public and decision-makers and to involve the building sector. The impact of and the need for actions caused by the BSS requirements on the Austrian radon legislation, strategy and programme are discussed.

  11. Indoor radon, geogenic radon surrogates and geology - Investigations on their correlation.

    Science.gov (United States)

    Friedmann, H; Baumgartner, A; Bernreiter, M; Gräser, J; Gruber, V; Kabrt, F; Kaineder, H; Maringer, F J; Ringer, W; Seidel, C; Wurm, G

    2017-01-01

    The indoor radon concentration was measured in most houses in a couple of municipalities in Austria. At the same time the activity concentration of radium in soil, the soil gas radon concentration, the permeability of the ground and the ambient dose equivalent rate were also measured and the geological situations (geological units) were recorded too. From the indoor radon concentration and different house and living parameters a radon potential (Austrian radon potential) was derived which should represent the radon concentration in a standard room. Another radon potential (Neznal radon potential) was calculated from the soil gas radon concentration and the permeability. The aim of the investigation was to correlate all the different variables and to test if the use of surrogate data (e.g. geological information, ambient dose equivalent rate, etc.) can be used to judge the radon risk for an area without performing numerous indoor measurements.

  12. Indoor radon and radon daughters survey at Campinas-Brazil using CR-39: First results

    CERN Document Server

    Guedes, S; Iunes, P J; Navia, L M S; Neman, R S; Paulo, S R; Rodrigues, V C; Souza, W F; Tello, C A S; Zúñiga, A G

    1999-01-01

    The first results of a radon and radon daughters (RD) survey performed at Campinas-SP, Brazil, are presented. We employed a technique that, potentially, makes possible to measure the radon and RD activity in the air and to separate from this result the activity of radon, alone. In this preliminary paper only the former activity is studied.

  13. Radon programmes and health marketing.

    Science.gov (United States)

    Fojtikova, Ivana; Rovenska, Katerina

    2011-05-01

    Being aware of negative health effects of radon exposure, many countries aim for the reduction of the radon exposure of their population. The Czech radon programme was commenced >20 y ago. Since then experts have gathered a lot of knowledge, necessary legislation has been enacted, tens of thousands of inhabitants have been offered free measurement and subsidy for the mitigation. Despite the effort, the effectiveness of the radon programme seems to be poor. Newly built houses still exhibit elevated radon concentrations and the number of houses mitigated is very low. Is it possible to enhance the effectivity of radon programme while keeping it on a voluntary basis? One possible way is to employ health marketing that draws together traditional marketing theories and science-based strategies to prevention. The potential of using marketing principles in communication and delivery of radon information will be discussed.

  14. Geohydrological control on radon availability in groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Yogesh; Prasad, Ganesh [Department of Physics, H. N. B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal 249 199 (India); Choubey, V.M. [Wadia Institute of Himalayan Geology, Dehradun 248001 (India); Ramola, R.C. [Department of Physics, H. N. B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal 249 199 (India)], E-mail: rcramola@gmail.com

    2009-01-15

    The radon content in groundwater sources depends on the radium concentration in the rock of the aquifer. Radon was measured in water in many parts of the world, mostly for the risk assessment due to consumption of drinking water. The exposure to radon through drinking water is largely by inhalation and ingestion. Airborne radon can be released during normal household activities and can pose a greater potential health risk than radon ingested with water. Transport of radon through soil and bedrock by water depends mainly on the percolation of water through the pores and along fractured planes of bedrock. In this study, radon concentration in springs and hand pumps of Kumaun and Garhwal Himalaya, India was measured using radon emanometry technique. The study shows that radon concentration in springs and hand pumps is controlled by geohydrological characteristics, which in turn is also governed by tectonic processes.

  15. Regularity of harmonic maps with the potential

    Institute of Scientific and Technical Information of China (English)

    CHU; Yuming

    2006-01-01

    The aim of this work is to prove the partial regularity of the harmonic maps with potential. The main difficulty caused by the potential is how to find the equation satisfied by the scaling function. Under the assumption on the potential we can obtain the equation, however, for a general potential, even if it is smooth, the partial regularity is still open.

  16. Indoor radon measurements in Turkey dwellings.

    Science.gov (United States)

    Celebi, N; Ataksor, B; Taskın, H; Bingoldag, N Albayrak

    2015-12-01

    In this work, indoor radon radioactivity concentration levels have been measured in dwellings of Turkey within the frame of the National Radon Monitoring Programme. The (222)Rn concentrations were measured with time-integrating passive nuclear etched track detectors in 7293 dwellings in 153 residential units of 81 provinces, and the radon map of Turkey was prepared. Indoor radon concentrations were distributed in the range of 1-1400 Bq m(-3). The arithmetic mean of the radon gas concentration was found to be 81 Bq m(-3); the geometric mean was 57 Bq m(-3) with a geometric standard deviation of 2.3.

  17. Identifying areas with potential for high indoor radon levels: analysis of the national airborne radiometric reconnaissance data for California and the Pacific Northwest

    Energy Technology Data Exchange (ETDEWEB)

    Moed, B.A.; Nazaroff, W.W.; Nero, A.V.; Schwehr, M.B.; Van Heuvelen, A.

    1984-04-01

    Radon-222 is an important indoor air pollutant which, through the inhalation of its radioactive decay products, accounts for nearly half of the effective dose equivalent to the public from natural ionizing radiation. Indoor radon concentrations vary widely, largely because of local and regional differences in the rate of entry from sources. The major sources are soil and rock near building foundations, earth-based building materials, and domestic water; of these, soil and rock are thought to be predominant in many buildings with higher-than-average concentrations. Thus, one key factor in determining radon source potential is the concentration of radium, the progenitor of radon, in surficial rocks and soils. Aerial radiometric data were analyzed, collected for the National Uranium Resource Evaluation Program, for seven Western states to: (1) provide information on the spatial distribution of radium contents in surficial geologic materials for those states; and (2) investigate approaches for using the aerial data, which have been collected throughout the contiguous United States and Alaska, to identify areas where high indoor radon levels may be common. Radium concentrations were found to be relatively low in central and western portions of Washington, Oregon, and northern California; they were found to be relatively high in central and southern California. A field validation study, conducted along two flight-line segments near Spokane, Washington, showed close correspondence between the aerial data, in situ measurements of both radium content and radon flux from soil, and laboratory measurements of both radium content of and radon emanation rate from soil samples. 99 references, 11 figures, 3 tables.

  18. Scopingsreport Radon

    NARCIS (Netherlands)

    Blaauboer RO; Vaas LH; Hesse JM; Slooff W

    1989-01-01

    Dit scopingsrapport vormt een onderdeel van de voorbereiding tot het opstellen van het basisdocument radon. Het doel van dit rapport is het algemene kennisniveau van de deelnemers aan de scopingsbijeenkomst aangaande radon op eenzelfde peil te brengen en discussie- en beslispunten inzake de inho

  19. Scopingsreport Radon

    NARCIS (Netherlands)

    Blaauboer RO; Vaas LH; Hesse JM; Slooff W

    1989-01-01

    Dit scopingsrapport vormt een onderdeel van de voorbereiding tot het opstellen van het basisdocument radon. Het doel van dit rapport is het algemene kennisniveau van de deelnemers aan de scopingsbijeenkomst aangaande radon op eenzelfde peil te brengen en discussie- en beslispunten inzake de inho

  20. Radon atlas of Finland; Suomen radonkartasto

    Energy Technology Data Exchange (ETDEWEB)

    Voutilainen, A.; Maekelaeinen, I.; Pennanen, M.; Reisbacka, H.; Castren, O.

    1997-11-01

    The most efficient means of reducing indoor radon exposure is to locate and mitigate dwellings with radon concentration exceeding the action level of 400 Bq/m{sup 3} and to build new houses so that radon concentrations do not exceed 200 Bq/m{sup 3}. The maps and tables in this report are useful tools for those who plan and decide what kind of radon mitigation measures are needed in municipalities. STUK (The Radiation and Nuclear Safety Authority) has an indoor radon database of 52 000 dwellings, for which the indoor radon concentration and construction details are known. The building site soil type of about 38 000 dwellings is known. This atlas is a summary of all indoor radon measurements made by STUK in lowrise dwellings and in first-floor flats. The results are shown as arithmetic means of 5- or 10-km squares on maps of the provinces. Three radon maps have been made for each province. On one map the data consist of all measurements the position coordinates of which are known. On the two other maps the building sites of houses are classified into permeable and low-permeable soil types. The tables show statistics for all indoor radon measurements by municipality and building site soil type. (orig.). 11 refs. The publication contains all texts both in Finnish and in English.

  1. Mapping indoor radon-222 in Denmark: Design and test of the statistical model used in the second nationwide survey

    DEFF Research Database (Denmark)

    Andersen, C.E.; Ulbak, K.; Damkjær, A.

    2001-01-01

    In Denmark, a new survey of indoor radon-222 has been carried out. 1-year alpha track measurements (CR-39) have been made in 3019 single-family houses. There are from 3 to 23 house measurements in each of the 275 municipalities. Within each municipality, houses have been selected randomly. One...... important outcome of the survey is the prediction of the fraction of houses in each municipality with an annual average radon concentration above 200 Bq m(-3). To obtain the most accurate estimate and to assess the associated uncertainties, a statistical model has been developed. The purpose of this paper...

  2. Radon monitoring and hazard prediction in Ireland

    Science.gov (United States)

    Elio, Javier; Crowley, Quentin; Scanlon, Ray; Hodgson, Jim; Cooper, Mark; Long, Stephanie

    2016-04-01

    Radon is a naturally occurring radioactive gas which forms as a decay product from uranium. It is the largest source of natural ionizing radiation affecting the global population. When radon is inhaled, its short-lived decay products can interact with lung tissue leading to DNA damage and development of lung cancer. Ireland has among the highest levels of radon in Europe and eighth highest of an OECD survey of 29 countries. Every year some two hundred and fifty cases of lung cancer in Ireland are linked to radon exposure. This new research project will build upon previous efforts of radon monitoring in Ireland to construct a high-resolution radon hazard map. This will be achieved using recently available high-resolution airborne gamma-ray spectrometry (radiometric) and soil geochemistry data (http://www.tellus.ie/), indoor radon concentrations (http://www.epa.ie/radiation), and new direct measurement of soil radon. In this regard, legacy indoor radon concentrations will be correlated with soil U and Th concentrations and other geogenic data. This is a new approach since the vast majority of countries with a national radon monitoring programme rely on indoor radon measurements, or have a spatially limited dataset of soil radon measurements. Careful attention will be given to areas where an indicative high radon hazard based on geogenic factors does not match high indoor radon concentrations. Where such areas exist, it may imply that some parameter(s) in the predictive model does not match that of the environment. These areas will be subjected to measurement of radon soil gas using a combination of time averaged (passive) and time dependant (active) measurements in order to better understand factors affecting production, transport and accumulation of radon in the natural environment. Such mapping of radon-prone areas will ultimately help to inform when prevention and remediation measures are necessary, reducing the radon exposure of the population. Therefore, given

  3. Distance to faults as a proxy for radon gas concentration in dwellings.

    Science.gov (United States)

    Drolet, Jean-Philippe; Martel, Richard

    2016-02-01

    This research was done to demonstrate the usefulness of the local structural geology characteristics to predict indoor radon concentrations. The presence of geologic faults near dwellings increases the vulnerability of the dwellings to elevated indoor radon by providing favorable pathways from the source uranium-rich bedrock units to the surface. Kruskal-Wallis one-way analyses of variance by ranks were used to determine the distance where faults have statistically significant influence on indoor radon concentrations. The great-circle distance between the 640 spatially referenced basement radon concentration measurements and the nearest fault was calculated using the Haversine formula and the spherical law of cosines. It was shown that dwellings located less than 150 m from a major fault had a higher radon potential. The 150 m threshold was determined using Kruskal-Wallis ANOVA on: (1) all the basement radon measurements dataset and; (2) the basement radon measurements located on uranium-rich bedrock units only. The results indicated that 22.8% of the dwellings located less than 150 m from a fault exceeded the Canadian radon guideline of 200 Bq/m(3) when using all the basement radon measurements dataset. This percentage fell to 15.2% for the dwellings located between 150 m and 700 m from a fault. When using only the basement radon measurements located on uranium-rich bedrock units, these percentages were 30.7% (0-150 m) and 17.5% (150 m-700 m). The assessment and management of risk can be improved where structural geology characteristics base maps are available by using this proxy indicator.

  4. Novel method of measurement of radon exhalation from building materials.

    Science.gov (United States)

    Awhida, A; Ujić, P; Vukanac, I; Đurašević, M; Kandić, A; Čeliković, I; Lončar, B; Kolarž, P

    2016-11-01

    In the era of the energy saving policy (i.e. more air tight doors and windows), the radon exhaled from building materials tends to increase its concentration in indoor air, which increases the importance of the measurement of radon exhalation from building materials. This manuscript presents a novel method of the radon exhalation measurement using only a HPGe detector or any other gamma spectrometer. Comparing it with the already used methods of radon exhalation measurements, this method provides the measurement of the emanation coefficient, the radon diffusion length and the radon exhalation rate, all within the same measurement, which additionally defines material's radon protective properties. Furthermore it does not necessitate additional equipment for radon or radon exhalation measurement, which simplifies measurement technique, and thus potentially facilitates introduction of legal obligation for radon exhalation determination in building materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Mineral potential mapping with mathematical geological models

    NARCIS (Netherlands)

    Porwal, A.K.

    2006-01-01

    Mathematical geological models are being increasingly used by natural resources delineation and planning agencies for mapping areas of mineral potential in order to optimize land use in accordance with socio-economic needs of the society. However, a key problem in spatial-mathematical-model-based mi

  6. Mineral potential mapping with mathematical geological models

    NARCIS (Netherlands)

    Porwal, A.K.

    2006-01-01

    Mathematical geological models are being increasingly used by natural resources delineation and planning agencies for mapping areas of mineral potential in order to optimize land use in accordance with socio-economic needs of the society. However, a key problem in spatial-mathematical-model-based

  7. Radon-safe new buildings, documentation and technology development. Appendix; Radonsikring i nybyggeri, documentation og teknologiudvikling. Bilag

    Energy Technology Data Exchange (ETDEWEB)

    Breddam Overgaard, L.; Bruun Petersen, J.; Neerup Jeppesen, M.

    2011-07-01

    The project is carried out as three separate subprojects, with subproject 1 as the principal project. Subproject 1 deals with field tests of radon penetration of different floor design (1A) and the effect of passive sub slab ventilation (1B). Subproject 2 deals with laboratory tests of material and design permeability, and subproject 3 deals with mapping of the radon potential and variation of a defined area. The appendix volume presents the detailed data for the results achieved in the project. (ln)

  8. nowCOAST's Map Service for NOAA NWS NHC Potential Storm Surge Flooding Map

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Map Information: This nowCOAST map service provides maps depicting the latest official NWS Potential Storm Surge Flooding Map for any significant landfalling...

  9. A Radon Progeny Deposition Model

    CERN Document Server

    Guiseppe, V E; Hime, A; Rielage, K; Westerdale, S

    2011-01-01

    The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly Rn-222) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of Pb-210 on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to depos...

  10. Managing Radon in Schools

    Science.gov (United States)

    EPA recommends testing all schools for radon. As part of an effective IAQ management program, schools can take simple steps to test for radon and reduce risks to occupants if high radon levels are found.

  11. Void Profile from Planck Lensing Potential Map

    Science.gov (United States)

    Chantavat, Teeraparb; Sawangwit, Utane; Wandelt, Benjamin D.

    2017-02-01

    We use the lensing potential map from Planck CMB lensing reconstruction analysis and the “Public Cosmic Void Catalog” to measure the stacked void lensing potential. We have made an attempt to fit the HSW void profile parameters from the stacked lensing potential. In this profile, four parameters are needed to describe the shape of voids with different characteristic radii R V . However, we have found that after reducing the background noise by subtracting the average background, there is a residue lensing power left in the data. The inclusion of the environment shifting parameter, {γ }V, is necessary to get a better fit to the data with the residue lensing power. We divide the voids into two redshift bins: cmass1 (0.45Digital Sky Survey voids reside in an underdense region.

  12. Radon surveys and monitoring at active volcanoes: an open window on deep hydrothermal systems and their dynamics

    Science.gov (United States)

    Cigolini, Corrado; Laiolo, Marco; Coppola, Diego

    2017-04-01

    The behavior of fluids in hydrothermal systems is critical in volcano monitoring and geothermal prospecting. Analyzing the time series of radon emissions on active volcanoes is strategic for detecting and interpreting precursory signals of changes in volcanic activity, eventually leading to eruptions. Radon is a radioactive gas generated from the decay of U bearing rocks, soils and magmas. Although radon has been regarded as a potential precursor of earthquakes, radon anomalies appear to be better suited to forecast volcanic eruptions since we know where paroxysms may occur and we can follow the evolution of volcanic activity. Radon mapping at active volcanoes is also a reliable tool to assess diffuse and concentrated degassing as well as efficiently detecting earthquake-volcano interactions. Systematic radon monitoring has been shown to be a key factor for evaluating the rise of volcanic and hydrothermal fluids. In fact, the decay properties of radon, the duration of radon anomalies together with sampling rates may be cross-checked with the chemistry of hydrothermal fluids (and their transport properties) to constrain fluids ascent rates and to infer the permeability and porosity of rocks in sectors surrounding the active conduits. We hereby further discuss the data of radon surveys and monitoring at Somma-Vesuvius, Stromboli and La Soufrière (Guadeloupe, Lesser Antilles). The integrated analysis of seismic and geochemical data, including radon emissions, may be successfully used in testing temperature distributions and variations of porosity and permeability in volcanic hydrothermal systems and can be used as a proxy to analyze geothermal reservoirs.

  13. Radon risk in the house; Il rischio radon nelle abitazioni

    Energy Technology Data Exchange (ETDEWEB)

    Bressa, G. [Padua Univ., Padua (Italy). Dipt. di Farmacologia e Anestesiologia, Lab. di Tossicologia

    2001-04-01

    Radon was discovered in 1900, but its potential dangerousness for man was fully understood only in 1950. Being a radioactive natural gas - and therefore particularly dangerous - radon results from the long decay chain of radionuclides, such as thorium and radium. Some igneous rocks (granite, tufa and lava) as well as coal are considered to be the main sources of this radionuclide. A number of epidemiologic studies have shown the carcinogenicity of this element, particularly among miners and workers subjected to high level exposure in confined spaces such as basements, garages, cellars, etc. There are, however, some techniques to remove radon in order to reduce exposure to minimum values. [Italian] Il radon fu scoperto nel 1900, ma solo nel 1950 si comprese la sua potenziale pericolosita' per l'uomo. Il radon e' particolarmente pericoloso essendo un gas naturale radioattivo. Esso proviene dalla lunga catena di decadimento di radionuclidi come il torio e di radio. Sorgenti di tale radionuclide sono da considerarsi principalmente alcune rocce ignee (graniti, tufi e lave) e il carbone. Diversi studi epidemiologici hanno evidenziato la cancerogenicita' di tale elemento, specie tra i minatori e soggetti esposti ad alti livelli in ambienti confinati quali scantinati, garage sotterranei, ecc.. Esistono comunque tecniche di intervento per la rimozione del gas radon in modo tale da ridurre l'esposizione a valori minimi.

  14. Radon legislation and national guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Aakerblom, G

    1999-07-01

    50-500 Bq/l for public waters and 200-1000 Bq/l for private water supplies. 4 EU member states and 11 non-EU European countries have reference levels for the concentration of radioactive elements in building materials. 8 European countries have guidelines regarding radon at city planning and 13 have mapped the radon risk in their countries. It is essential to the work against radon and to future reduction of radon concentrations in dwellings and workplaces that the national states issue recommendations, regulations, directives or laws on radon limits and building practices. In order to have a significant effect on the radon situation, the questionnaire responses show that radon reference levels and regulations must be enforced or very little progress is achieved. Extensive measurement and research programs have been carried out in many in countries. Heretofore, only those countries with enforced regulations have had successful programs, resulting in remedial actions in more than 10,000 buildings. The only exception is USA, which concentrated on extensive information media campaigns on radon and the training of large numbers of contractors to perform measurements and remedial measures.

  15. Electrostatic potential map modelling with COSY Infinity

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, J.A., E-mail: maloneyja@triumf.ca; Baartman, R.; Planche, T.; Saminathan, S.

    2016-06-01

    COSY Infinity (Makino and Berz, 2005) is a differential-algebra based simulation code which allows accurate calculation of transfer maps to arbitrary order. COSY’s existing internal procedures were modified to allow electrostatic elements to be specified using an array of field potential data from the midplane. Additionally, a new procedure was created allowing electrostatic elements and their fringe fields to be specified by an analytic function. This allows greater flexibility in accurately modelling electrostatic elements and their fringe fields. Applied examples of these new procedures are presented including the modelling of a shunted electrostatic multipole designed with OPERA, a spherical electrostatic bender, and the effects of different shaped apertures in an electrostatic beam line.

  16. Electrostatic potential map modelling with COSY Infinity

    Science.gov (United States)

    Maloney, J. A.; Baartman, R.; Planche, T.; Saminathan, S.

    2016-06-01

    COSY Infinity (Makino and Berz, 2005) is a differential-algebra based simulation code which allows accurate calculation of transfer maps to arbitrary order. COSY's existing internal procedures were modified to allow electrostatic elements to be specified using an array of field potential data from the midplane. Additionally, a new procedure was created allowing electrostatic elements and their fringe fields to be specified by an analytic function. This allows greater flexibility in accurately modelling electrostatic elements and their fringe fields. Applied examples of these new procedures are presented including the modelling of a shunted electrostatic multipole designed with OPERA, a spherical electrostatic bender, and the effects of different shaped apertures in an electrostatic beam line.

  17. Experimental assessment of indoor radon and soil gas variability: the RADON project

    Science.gov (United States)

    Barbosa, S. M.; Pereira, A. J. S. C.; Neves, L. J. P. F.; Steinitz, G.; Zafrir, H.; Donner, R.; Woith, H.

    2012-04-01

    Radon is a radioactive noble gas naturally present in the environment, particularly in soils derived from rocks with high uranium content. Radon is formed by alpha decay from radium within solid mineral grains, but can migrate via diffusion and/or advection into the air space of soils, as well as into groundwater and the atmosphere. The exhalation of radon from the pore space of porous materials into the atmosphere of indoor environments is well known to cause adverse health effects due to the inhalation of radon's short-lived decay products. The danger to human health is particularly acute in the case of poorly ventilated dwellings located in geographical areas of high radon potential. The RADON project, funded by the Portuguese Science Foundation (FCT), aims to evaluate the temporal variability of radon in the soil and atmosphere and to examine the influence of meteorological effects in radon concentration. For that purpose an experimental monitoring station is being installed in an undisturbed dwelling located in a region of high radon potential near the old uranium mine of Urgeiriça (central Portugal). The rationale of the project, the set-up of the experimental radon monitoring station, and preliminary monitoring results will be presented.

  18. Mapping ecosystem services potential in Lithuania

    Science.gov (United States)

    Depellegrin, Daniel; Misiune, Ieva; Pereira, Paulo

    2016-04-01

    Ecosystem services (ES) are understood as the benefits that humans get from ecosystems functions. They are divided in providing, regulating, supporting and cultural. The correct management of ES is fundamental to achieve sustainable development goals. A good assessment of ES potential can be obtained using GIS techniques, in order to have a spatial dimension of ES distribution. This will help to have a better territorial planning, improve ES capacity, and have more benefits. ES potential analysis can be carried out based on the ES matrix developed by Burkhard et al. (2009). This method is based on the attribution a rank from 0 to 5 (0= no capacity to 5=very high relevant capacity) to the land use classes of the corine land cover (CLC). This represents an important advantage since a determined land use can be related with a certain number of services. The objective of this work is to Map the ES potential in Lithuania. The results showed that Lithuania has a high potential for regulating services, followed by cultural and provisioning services. Urban areas provide a very small amount of services, contrary to forest, where the highest potential is observed. The most comon land covers in Lithuania are non-irrigated arable land, complex cultivation patterns, mixed and coniferous forest. Total and regulating and cultural ES had dispersed pattern showing that they are scattered in the territory. They are located mainly in forested and coastal areas. In relation to provisioning services they had a clustered distribution, and they were mainly observed in the central part of Lithuania. References Burkhard B, Kroll F, Müller F, Windhorst W. 2009. Landscapes' capacities to provide ecosystem services - a concept for land-cover based assessments. Landsc. Online. 15:1-22

  19. Mapping indoor radon-222 in Denmark: design and test of the statistical model used in the second nationwide survey.

    Science.gov (United States)

    Andersen, C E; Ulbak, K; Damkjaer, A; Kirkegaard, P; Gravesen, P

    2001-05-14

    In Denmark, a new survey of indoor radon-222 has been carried out, 1-year alpha track measurements (CR-39) have been made in 3019 single-family houses. There are from 3 to 23 house measurements in each of the 275 municipalities. Within each municipality, houses have been selected randomly. One important outcome of the survey is the prediction of the fraction of houses in each municipality with an annual average radon concentration above 200 Bq m(-3). To obtain the most accurate estimate and to assess the associated uncertainties, a statistical model has been developed. The purpose of this paper is to describe the design of this model, and to report results of model tests. The model is based on a transformation of the data to normality and on analytical (conditionally) unbiased estimators of the quantities of interest. Bayesian statistics are used to minimize the effect of small sample size. In each municipality, the correction is dependent on the fraction of area where sand and gravel is a dominating surface geology. The uncertainty analysis is done with a Monte-Carlo technique. It is demonstrated that the weighted sum of all municipality model estimates of fractions above 200 Bq m(-3) (3.9% with 95%-confidence interval = [3.4,4.5]) is consistent with the weighted sum of the observations for Denmark taken as a whole (4.6% with 95%-confidence interval = [3.8,5.6]). The total number of single-family houses within each municipality is used as weight. Model estimates are also found to be consistent with observations at the level of individual counties. These typically include a few hundred house measurements. These tests indicate that the model is well suited for its purpose.

  20. A perspective on risks from radon

    Energy Technology Data Exchange (ETDEWEB)

    Higson, D. J., E-mail: higsond@bigpond.net.a [Australasian Radiation Protection Society, PO Box 7108, Upper Ferntree Gully, Victoria 3156 (Australia)

    2010-10-15

    In its Statement on Radon (November 2009), the International Commission on Radiological Protection (ICRP) has reduced the upper reference level for radon gas in dwellings to 300 Bq m{sup -3}. The recommended level for workplaces is 1000 Bq m{sup -3}. A risk coefficient of 8 x 10{sup -10} per Bq h m{sup -3} is recommended without reference to smoking habits. On the basis of these figures: 1) The estimated risk of fatal cancer from exposure to radon at home and at work could be greater than the observed risk of accidental death from travelling by car, which would be surprising if true. 2) The estimated risk of lung cancer from radon could be greater than the observed risk of lung cancer from all causes, which is actually known to be dominated by smoking. The author is not aware of any direct evidence of risks from inhaling radon in Australian dwellings, 99% of which have radon levels below 50 Bq m{sup -3}. Evidence available from other countries shows that: 1) The effects of radon in the incidences of lung cancer are uncertain at levels less then about 50-100 Bq m{sup -3}. 2) The estimation of risks at levels below 200 Bq m{sup -3} depends on extrapolation from risks observed at higher levels. 3) Risks to non-smokers from radon are 25 times less than risks to smokers. Its concluded that the ICRP Statement on Radon and radon policies in the US and UK have the potential to cause unwarranted concern. Some people may be made to feel they need to spend money modifying their homes and workplaces to protect occupants from exposure to radon when there is no compelling reason to show that this is necessary. The vast majority of non-smokers do not need to be protected from radon. (Author)

  1. Radon Risk Communication Strategies: A Regional Story.

    Science.gov (United States)

    Cheng, Winnie

    2016-01-01

    Risk communication on the health effects of radon encounters many challenges and requires a variety of risk communication strategies and approaches. The concern over radon exposure and its health effects may vary according to people's level of knowledge and receptivity. Homeowners in radon-prone areas are usually more informed and have greater concern over those not living in radon-prone areas. The latter group is often found to be resistant to testing. In British Columbia as well as many other parts of the country, some homes have been lying outside of the radon-prone areas have radon levels above the Canadian guideline, which is the reason Health Canada recommends that all homes should be tested. Over the last five years, the Environment Health Program (EHP) of Health Canada in the British Columbia region has been using a variety of different approaches in their radon risk communications through social media, workshops, webinars, public forums, poster contests, radon distribution maps, public inquiries, tradeshows and conference events, and partnership with different jurisdictions and nongovernmental organizations. The valuable lessons learned from these approaches are discussed in this special report.

  2. The latest trend of the research on radon

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Hiroshi [Science Univ. of Tokyo, Noda, Chiba (Japan). Faculty of Science and Technology

    1996-12-01

    In June, 1995, the international conference of sixth Natural Radiation Environment was held in Montreal. More than 80% of more than 200 published researches were concerned with radon and thoron. The participants came from 32 countries. The classification of the research on radon and the number of the publication are shown. The contents of the researches in respective items of measuring method, concentration level and dose evaluation, indoor model and indoor and outdoor radon balance, the countermeasures for reducing indoor radon, radon potential, dose evaluation model, the particle size distribution of aerosol including the particle size distribution of free daughter nuclides and radon in the atmosphere are described. The research on the radon in water is excluded. The most remarkable trend is the theme of radon potential. The trend of connecting the research on radon in soil and the research on dissipation rate to radon potential and the forecast of indoor and outdoor radon concentration seems to become stronger. As to the research on concentration level, the detection of hot spots and the supplementary measurement for clarifying cause are carried out in the advanced countries concerning radon based on the results of survey in whole country. The researches in schools are conspicuous. (K.I.)

  3. Indoor radon measurements and radon prognosis for the province of Kymi, southeastern Finland; Huoneilman radonmittaukset Kymen laeaenissae: Tilannekatsaus ja radonennuste

    Energy Technology Data Exchange (ETDEWEB)

    Pennanen, M.; Maekelaeinen, I.; Voutilainen, A.

    1996-12-01

    The purpose of the regional radon prognosis is to classify areas with different levels of radon risk. The radon prognosis gives the percentages of future homes expected to have indoor radon concentrations exceeding the levels of 200 and 400 Bq/m{sup 3}. It is assumed that no protection against the entry of radon is used in construction. In this study about 5900 indoor radon measurements made in single family houses, semi-detached houses and row houses were used. Data on the location, geology and construction of buildings were determined from maps and questionnaires. An empirical statistical model, the adjusted indoor radon measurements and geological data were used to assess the radon risk from soil and bedrock in different areas. The building sites of the province of Kymi were divided into thirteen sub-areas. The radon prognosis are calculated for the most radon-prone foundation types including (1) houses with a slab-on-grade and (2) houses with a basement or hillside houses with open stairwells between basement and first floor. The radon levels are generally greater in the western part of the area. The radon risk is highest in gravel-dominated esker areas in southwestern, western (in Pyhtaa, Kotka, Anjalankoski, litti, Valkeala) and central (Taipalsaari) parts of the area. The radon risk is also high in some bedrock and till areas, also in southwestern and western parts of the area. In these areas the level of 200 Bq/m{sup 3} will be exceeded in 80 % of new houses. About half of the future houses in these areas will have indoor radon concentrations exceeding 400 Bq/m{sup 3}. The radon risk is lowest in the eastern part of the province of Kymi in every soil type. In this area the level of 200 Bq/m{sup 3} will be exceeded in 30 % of new houses. Below 10 % will exceed 400 Bq/m{sup 3}. (orig.) (14 refs.).

  4. Criteria of radon risk of territories and methods for their determination.

    Science.gov (United States)

    Ryzhakova, Nadezhda K

    2014-09-01

    The paper analyzes the values used in the assessment of radon potential of territories. It was shown that the most reliable criterion in the assessment of radon risk of territories can be the value of radon activity concentration fixed at large depths. The authors proposed a simple method to assess this value and radon flux density from the soil surface, based on the measurement of radon activity concentration in soil gas at two twice differing depths and the diffusion model of transport.

  5. A complete low cost radon detection system.

    Science.gov (United States)

    Bayrak, A; Barlas, E; Emirhan, E; Kutlu, Ç; Ozben, C S

    2013-08-01

    Monitoring the (222)Rn activity through the 1200 km long Northern Anatolian fault line, for the purpose of earthquake precursory, requires large number of cost effective radon detectors. We have designed, produced and successfully tested a low cost radon detection system (a radon monitor). In the detector circuit of this monitor, First Sensor PS100-7-CER-2 windowless PIN photodiode and a custom made transempedence/shaping amplifier were used. In order to collect the naturally ionized radon progeny to the surface of the PIN photodiode, a potential of 3500 V was applied between the conductive hemi-spherical shell and the PIN photodiode. In addition to the count rate of the radon progeny, absolute pressure, humidity and temperature were logged during the measurements. A GSM modem was integrated to the system for transferring the measurements from the remote locations to the data process center.

  6. Radon as a groundwater tracer in Forsmark and Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Grolander, Sara

    2009-10-15

    caused by the homogenous radon concentrations measured in the Laxemar area. The radon concentrations in near surface water measured in Forsmark showed large variability with both low and high radon concentrations. This large variability in radon concentration could not be explained by the flow pattern of the groundwater since no clear correlation between radon concentration and recharge/discharge classification was found. The radon concentration was also measured at different depths in the soil profile at three locations in the Forsmark area. The results showed large differences with increasing radon concentration with increasing depth. This gradient of radon concentration can be explained largely by the radon emanation potential of the local soil type at different depths. High radon concentrations were found in wells with higher radon emanation potential like till and bedrock. These observations showed the importance of the radon emanation potential of the local soil for the radon concentration in groundwater. The main purpose of this study has been to evaluate the use of radon as a tracer for groundwater flow patterns. The method is based on the ingrowth of radon from its progenitor radium according to the law of radioactive decay. According to this law the radon concentration in groundwater will reach equilibrium conditions after approximately 30 days in contact with the surrounding soil. The equilibrium radon concentration of the near surface groundwater was measured at several location in the Forsmark area and a range of the steady state radon concentration was calculated. The measured steady state radon concentration was then used to evaluate the radon concentrations measured in near surface groundwater in the area. A recharge/discharge classification of the wells was done based on the range of steady state radon concentration and the measured radon concentrations in groundwater. All wells with radon concentration below the steady state radon concentration were

  7. Modeling of geogenic radon in Switzerland based on ordered logistic regression.

    Science.gov (United States)

    Kropat, Georg; Bochud, François; Murith, Christophe; Palacios Gruson, Martha; Baechler, Sébastien

    2017-01-01

    The estimation of the radon hazard of a future construction site should ideally be based on the geogenic radon potential (GRP), since this estimate is free of anthropogenic influences and building characteristics. The goal of this study was to evaluate terrestrial gamma dose rate (TGD), geology, fault lines and topsoil permeability as predictors for the creation of a GRP map based on logistic regression. Soil gas radon measurements (SRC) are more suited for the estimation of GRP than indoor radon measurements (IRC) since the former do not depend on ventilation and heating habits or building characteristics. However, SRC have only been measured at a few locations in Switzerland. In former studies a good correlation between spatial aggregates of IRC and SRC has been observed. That's why we used IRC measurements aggregated on a 10 km × 10 km grid to calibrate an ordered logistic regression model for geogenic radon potential (GRP). As predictors we took into account terrestrial gamma doserate, regrouped geological units, fault line density and the permeability of the soil. The classification success rate of the model results to 56% in case of the inclusion of all 4 predictor variables. Our results suggest that terrestrial gamma doserate and regrouped geological units are more suited to model GRP than fault line density and soil permeability. Ordered logistic regression is a promising tool for the modeling of GRP maps due to its simplicity and fast computation time. Future studies should account for additional variables to improve the modeling of high radon hazard in the Jura Mountains of Switzerland. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Surface-water radon-222 distribution along the west-central Florida shelf

    Science.gov (United States)

    Smith, C.G.; Robbins, L.L.

    2012-01-01

    In February 2009 and August 2009, the spatial distribution of radon-222 in surface water was mapped along the west-central Florida shelf as collaboration between the Response of Florida Shelf Ecosystems to Climate Change project and a U.S. Geological Survey Mendenhall Research Fellowship project. This report summarizes the surface distribution of radon-222 from two cruises and evaluates potential physical controls on radon-222 fluxes. Radon-222 is an inert gas produced overwhelmingly in sediment and has a short half-life of 3.8 days; activities in surface water ranged between 30 and 170 becquerels per cubic meter. Overall, radon-222 activities were enriched in nearshore surface waters relative to offshore waters. Dilution in offshore waters is expected to be the cause of the low offshore activities. While thermal stratification of the water column during the August survey may explain higher radon-222 activities relative to the February survey, radon-222 activity and integrated surface-water inventories decreased exponentially from the shoreline during both cruises. By estimating radon-222 evasion by wind from nearby buoy data and accounting for internal production from dissolved radium-226, its radiogenic long-lived parent, a simple one-dimensional model was implemented to determine the role that offshore mixing, benthic influx, and decay have on the distribution of excess radon-222 inventories along the west Florida shelf. For multiple statistically based boundary condition scenarios (first quartile, median, third quartile, and maximum radon-222 inshore of 5 kilometers), the cross-shelf mixing rates and average nearshore submarine groundwater discharge (SGD) rates varied from 100.38 to 10-3.4 square kilometers per day and 0.00 to 1.70 centimeters per day, respectively. This dataset and modeling provide the first attempt to assess cross-shelf mixing and SGD on such a large spatial scale. Such estimates help scale up SGD rates that are often made at 1- to 10-meter

  9. Radon Guide for Tenants

    Science.gov (United States)

    This guide is for people who rent their apartments or houses. The guide explains what radon is, and how to find out if there is a radon problem in your home. The guide also talks about what you can do if there are high radon levels in your home.

  10. Health Risk of Radon

    Science.gov (United States)

    ... Radon in Homes EPA 402-R-03-003. Summary Fact Sheet on the updated risk assessment . Top of Page Former U.S. Surgeon General ... WHO) launched an international radon project to help countries increase ... reduce radon-related risks. The U.S. EPA is one of several government ...

  11. The Harmonic Decomposition Reconstruction for the Exponential Radon Transform

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The exponential Radon transform, a generalization of the Radon transform, is defined andstudied as a mapping of function spaces. It is represented in terms of Fourier transform of its domain andrange, and this leads to the harmonic decomposition reconstruction. The results are similar results of Tre-tiak and Metz.

  12. MRPM: three visual basic programs for mineral resource potential mapping

    Science.gov (United States)

    Chen, Yongliang

    2004-11-01

    A traditional method for mineral resource potential mapping is to superimpose a number of indicator maps, and to combine geological information with or without the use of multivariate statistical models. More recently, GISs have become widely applied in mineral resource assessment and many statistical models for geological information synthesis have been proposed. GIS-based mineral resource potential mapping has facilitated modern mineral resource assessment. As a contribution to publicly available computer software for GIS-based mineral resource assessment, integrated three Visual Basic programs have been developed on MapInfo platform. The programs integrate map patterns using weights of evidence, applied general C-F, and evidence theory models, and generate posterior probability, combined certainty factor, and combined basic probability assignment maps, respectively. The software is demonstrated by a case study based on a real data set.

  13. The radon indicator

    Science.gov (United States)

    Samuelsson, L.

    2005-11-01

    The radon indicator is an efficient instrument for measuring the radon daughter concentrations in a house or dwelling. Physics or environmental science students could build a radon indicator as a student project. Another possibility would be to use a radon indicator in a student investigation of radon levels in different houses. Finally the radon indicator is an excellent device for producing a radioactive source, free of charge, for the study of α-, β- and γ-radiation. The half-life of the activity collected is approximately 40 min. The radon indicator makes use of an electrostatic method by which charged particles are drawn to a small aluminium plate with a high negative voltage (-5 kV), thus creating a strong electric field between the plate and a surrounding copper wire. The radioactivity on the plate is subsequently measured by a GM-counter and the result calculated in Bq m-3. The collecting time is just 5.5 min and therefore the instrument is only suitable for use in a short-time method for indicating the radon concentration. An improved diagram, ground-radon and/or wall-radon in houses, is presented on the basis of the author's measurements recorded with the radon indicator over many years. This diagram is very useful when discussing how to reduce radiation levels in homes.

  14. Radon data processing and outputs for the needs of the State Office for Nuclear Safety (according to the Czech Radon Programme

    Directory of Open Access Journals (Sweden)

    I. Barnet

    2005-06-01

    Full Text Available Much of the population living in the Czech Republic is exposed to radiation from natural sources, especially to the radon effect. The aim of geological research defined by the State Office for Nuclear Safety (SONS was to detect areas with estimated high radon concentration in soil gas. A uniform method of measurements and uniform methodology of radon risk category assessment of geological units and a centralized radon database was established. Radon risk classification was based on statistical evaluation of soil gas radon concentration and permeability in investigated geological units. Prognostic radon risk maps in various scales were the main outputs of this research. With the help of GIS tools spatial analyses were found a correlation between soil gas radon values in selected geological units and indoor measurements in dwellings. After verification of the efficiency of track etch detectors placed in dwellings with the help of prognostic maps 75% reliability of these maps was proven. This reliability of analyses induced the SONS to widely use radon risk maps to determine areas with predicted high radon risk category.

  15. Indoor radon; Le radon dans les batiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    The radon, a natural radioactive gas, is present almost everywhere on the earth's surface. It can be accumulated at high concentration in confined spaces (buildings, mines, etc). In the last decades many studies conducted in several countries showed that inhaling important amounts of radon rises the risk of lung cancer. Although, the radon is a naturally appearing radioactive source, it may be the subject of a human 'enhancement' of concentration. The increasing radon concentration in professional housing constitutes an example of enhanced natural radioactivity which can induce health risks on workers and public. Besides, the radon is present in the dwelling houses (the domestic radon). On 13 May 1996, the European Union Council issued the new EURATOM Instruction that establishes the basic standards of health protection of population and workers against the ionizing radiation hazards (Instruction 96/29/EURATOM, JOCE L-159 of 29 June 1996). This instruction does not apply to domestic radon but it is taken into consideration by another EURATOM document: the recommendation of the Commission 90/143/EURATOM of 21 February 1990 (JOCE L-80 of 27 March 1990). The present paper aims at establishing in accordance to European Union provisions the guidelines for radon risk management in working places, as well as in dwelling houses, where the implied risk is taken into account. This document does not deal with cases of high radon concentration on sites where fabrication, handling or storage of radium sources take place. These situations must be treated by special studies.

  16. Extract relevant features from DEM for groundwater potential mapping

    Science.gov (United States)

    Liu, T.; Yan, H.; Zhai, L.

    2015-06-01

    Multi-criteria evaluation (MCE) method has been applied much in groundwater potential mapping researches. But when to data scarce areas, it will encounter lots of problems due to limited data. Digital Elevation Model (DEM) is the digital representations of the topography, and has many applications in various fields. Former researches had been approved that much information concerned to groundwater potential mapping (such as geological features, terrain features, hydrology features, etc.) can be extracted from DEM data. This made using DEM data for groundwater potential mapping is feasible. In this research, one of the most widely used and also easy to access data in GIS, DEM data was used to extract information for groundwater potential mapping in batter river basin in Alberta, Canada. First five determining factors for potential ground water mapping were put forward based on previous studies (lineaments and lineament density, drainage networks and its density, topographic wetness index (TWI), relief and convergence Index (CI)). Extraction methods of the five determining factors from DEM were put forward and thematic maps were produced accordingly. Cumulative effects matrix was used for weight assignment, a multi-criteria evaluation process was carried out by ArcGIS software to delineate the potential groundwater map. The final groundwater potential map was divided into five categories, viz., non-potential, poor, moderate, good, and excellent zones. Eventually, the success rate curve was drawn and the area under curve (AUC) was figured out for validation. Validation result showed that the success rate of the model was 79% and approved the method's feasibility. The method afforded a new way for researches on groundwater management in areas suffers from data scarcity, and also broaden the application area of DEM data.

  17. Consumer's Guide to Radon Reduction

    Science.gov (United States)

    ... Radon Share Facebook Twitter Google+ Pinterest Contact Us Consumer's Guide to Radon Reduction: How to Fix Your ... See EPA’s About PDF page to learn more. Consumer's Guide to Radon Reduction: How to Fix Your ...

  18. Integration of In Situ Radon Modeling with High Resolution Aerial Remote Sensing for Mapping and Quantifying Local to Regional Flow and Transport of Submarine Groundwater Discharge from Coastal Aquifers

    Science.gov (United States)

    Glenn, C. R.; Kennedy, J. J.; Dulaiova, H.; Kelly, J. L.; Lucey, P. G.; Lee, E.; Fackrell, J.

    2015-12-01

    Submarine groundwater discharge (SGD) is a principal conduit for huge volumes of fresh groundwater loss and is a key transport mechanism for nutrient and contaminant pollution to coastal zones worldwide. However, the volumes and spatially and temporally variable nature of SGD is poorly known and requires rapid and high-resolution data acquisition at the scales in which it is commonly observed. Airborne thermal infrared (TIR) remote sensing, using high-altitude manned aircraft and low-altitude remote-controlled unmanned aerial vehicles (UAVs or "Drones") are uniquely qualified for this task, and applicable wherever 0.1°C temperature contrasts exist between discharging and receiving waters. We report on the use of these technologies in combination with in situ radon model studies of SGD volume and nutrient flux from three of the largest Hawaiian Islands. High altitude manned aircraft results produce regional (~300m wide x 100s km coastline) 0.5 to 3.2 m-resolution sea-surface temperature maps accurate to 0.7°C that show point-source and diffuse flow in exquisite detail. Using UAVs offers cost-effective advantages of higher spatial and temporal resolution and instantaneous deployments that can be coordinated simultaneously with any ground-based effort. We demonstrate how TIR-mapped groundwater discharge plume areas may be linearly and highly correlated to in situ groundwater fluxes. We also illustrate how in situ nutrient data may be incorporated into infrared imagery to produce nutrient distribution maps of regional worth. These results illustrate the potential for volumetric quantification and up-scaling of small- to regional-scale SGD. These methodologies provide a tremendous advantage for identifying and differentiating spring-fed, point-sourced, and/or diffuse groundwater discharge into oceans, estuaries, and streams. The integrative techniques are also important precursors for developing best-use and cost-effective strategies for otherwise time-consuming in

  19. Systematic effects in radon mitigation by sump/pump remediation

    Energy Technology Data Exchange (ETDEWEB)

    Groves-Kirkby, C.J.; Denman, A.R. [Northampton General Hospital, Medical Physics Dept. (United Kingdom); Groves-Kirkby, C.J.; Woolridge, A.C. [Northampton Univ., School of Health (United Kingdom); Woolridge, A.C.; Phillips, P.S.; Crockett, R.G.M. [Northampton Univ., School of Applied Sciences (United Kingdom); Tornberg, R. [Radon Centres Ltd., Grove Farm, Moulton, Northampton (United Kingdom)

    2006-07-01

    Sump/Pump remediation is widely used in the United Kingdom to mitigate indoor radon gas levels in residential properties. To quantify the effectiveness of this technology, a study was made of radon concentration data from a set of 173 homes situated in radon Affected Areas in and around Northamptonshire, U.K., re-mediated using conventional sump/pump tology. This approach is characterised by a high incidence of satisfactory mitigation outcomes, with more than 75% of the sample exhibiting mitigation factors (defined as the ratio of radon concentrations following and prior to remediation) of 0.2 or better. There is evidence of a systematic trend, where houses with higher initial radon concentrations have higher mitigation factors, suggesting that the total indoor radon concentration within a dwelling can be represented by two components, one susceptible to mitigation by sump/pump remediation, the other remaining essentially unaffected by these remediation strategies. The first component can be identified with ground-radon emanating from the subsoil and bedrock geologies, percolating through the foundations of the dwelling as a component of the soil-gas, potentially capable of being attenuated by sump/pump or radon-barrier remediation. The second contribution is attributed to radon emanating from materials used in the construction of the dwelling, principally concrete and gypsum plaster-board, with a further small contribution from the natural background level, and is essentially unaffected by ground-level remediation strategies. Modelling of such a two-component radon dependency using realistic ground-radon attenuation factors in conjunction with typical structural-radon levels yields behaviour in good agreement with the observed inverse-power dependence of mitigation factor on initial radon concentration. (authors)

  20. Radon therapy; Radon in der Therapie

    Energy Technology Data Exchange (ETDEWEB)

    Spruck, Kaija [Technische Hochschule Mittelhessen, Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz

    2017-04-01

    Radon therapies are used since more than 100 years in human medicine. Today this method is controversially discussed due to the possible increase of ionizing radiation induced tumor risk. Although the exact mode of biological radiation effect on the cell level is still not known new studies show the efficiency of the radon therapy without side effect for instance for rheumatic/inflammatory or respiratory disorders.

  1. Radon-Instrumentation; Radon-Instrumentacion

    Energy Technology Data Exchange (ETDEWEB)

    Moreno y Moreno, A. [Departamento de Apoyo en Ciencias Aplicadas, Benemerita Universidad Autonoma de Puebla, 4 Sur 104, Centro Historico 72000 Puebla (Mexico)

    2003-07-01

    The presentation of the active and passive methods for radon, their identification and measure, instrumentation and characteristics are the objectives of this work. Active detectors: Active Alpha Cam Continuous Air Monitor, Model 758 of Victoreen, Model CMR-510 Continuous Radon Monitor of the Signature Femto-Tech. Passive detectors: SSNTD track detectors in solids Measurement Using Charcoal Canisters, disk of activated coal deposited in a metallic box Electrets Methodology. (Author)

  2. Radiological risk assessment of environmental radon

    Science.gov (United States)

    Khalid, Norafatin; Majid, Amran Ab; Yahaya, Redzuwan; Yasir, Muhammad Samudi

    2013-11-01

    Measurements of radon gas (222Rn) in the environmental are important to assess indoor air quality and to study the potential risk to human health. Generally known that exposure to radon is considered the second leading cause of lung cancer after smoking. The environmental radon concentration depends on the 226Ra concentration, indoor atmosphere, cracking on rocks and building materials. This study was carried out to determine the indoor radon concentration from selected samples of tin tailings (amang) and building materials in an airtight sealed homemade radon chamber. The radiological risk assessment for radon gas was also calculated based on the annual exposure dose, effective dose equivalent, radon exhalation rates and fatal cancer risk. The continuous radon monitor Sun Nuclear model 1029 was used to measure the radon concentration emanates from selected samples for 96 hours. Five types of tin tailings collected from Kampar, Perak and four samples of building materials commonly used in Malaysia dwellings or building constructions were analysed for radon concentration. The indoor radon concentration determined in ilmenite, monazite, struverite, xenotime and zircon samples varies from 219.6 ± 76.8 Bq m-3 to 571.1 ± 251.4 Bq m-3, 101.0 ± 41.0 Bq m-3 to 245.3 ± 100.2 Bq m-3, 53.1 ± 7.5 Bq m-3 to 181.8 ± 9.7 Bq m-3, 256.1 ± 59.3 Bq m-3 to 652.2 ± 222.2 Bq m-3 and 164.5 ± 75.9 Bq m-3 to 653.3 ± 240.0 Bq m-3, respectively. Whereas, in the building materials, the radon concentration from cement brick, red-clay brick, gravel aggregate and cement showed 396.3 ± 194.3 Bq m-3, 192.1 ± 75.4 Bq m-3, 176.1 ± 85.9 Bq m-3 and 28.4 ± 5.7 Bq m-3, respectively. The radon concentration in tin tailings and building materials were found to be much higher in xenotime and cement brick samples than others. All samples in tin tailings were exceeded the action level for radon gas of 148 Bq m-3 proposed by EPA except monazite 0.15 kg, struverite 0.15 kg and 0.25 kg. Whereas

  3. Radon activity in the lower troposphere and its impact on ionization rate: a global estimate using different radon emissions

    Directory of Open Access Journals (Sweden)

    K. Zhang

    2011-01-01

    Full Text Available The radioactive decay of radon and its progeny can lead to ionization of air molecules and consequently influence aerosol size distribution. In order to provide a global estimate of the radon-related ionization rate, we use the global atmospheric model ECHAM5 to simulate transport and decay processes of the radioactive tracers. A global radon emission map is put together using regional fluxes reported recently in the literature. The near-surface radon concentrations simulated with this new map compare well with measurements.

    Radon-related ionization rate is calculated and compared to that caused by cosmic rays. The contribution of radon and its progeny clearly exceeds that of the cosmic rays in the mid- and low-latitude land areas in the surface layer. In winter, strong radon-related ionization coincides with low temperature in China, USA, and Russia, providing favorable condition for the formation of aerosol particles. This suggests that it is probably useful to include the radon-induced ionization in global models when investigating the interaction between aerosol and climate.

  4. Indoor Radon Gas Management For Multi-Site Companies: How To Screen For Potentially High-Risk Sites By Studying The Local Geology

    Science.gov (United States)

    Ruggeri, Rudi; Gigliuto, Andrea; Minnei, Tiziana; Savini, Raffaella

    2008-08-01

    In this article, ENSR presents an evaluation tool for Radon gas monitoring programs that companies with large portfolios of properties will find useful in reducing their efforts and expenditures. The World Health Organization (WHO) considers Radon gas the second cause of lung cancer and the first source of natural radiations affecting the human population. In Italy, Legal Decree No. 230 (0/17/95) is the laws that regulate gas Radon concentrations in work places. Hereunder we present the ENSR approach to executing preliminary geologic studies aimed at planning an instrumental monitoring program for companies.

  5. Field experience with soil gas mapping using Japanese passive radon/thoron discriminative detectors for comparing high and low radiation areas in Serbia (Balkan Region).

    Science.gov (United States)

    Zunić, Zora S; Janik, Miroslaw; Tokonami, Shinji; Veselinović, Nenad; Yarmoshenko, Ilia V; Zhukovsky, Michael; Ishikawa, Tetsuo; Ramola, Rakesh C; Ciotoli, Giancarlo; Jovanović, Peter; Kozak, Krzysztof; Mazur, Jadwiga; Celiković, Igor; Ujić, Predrag; Onischenko, Aleksandra; Sahoo, Sarat K; Bochicchio, Francesco

    2009-07-01

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

  6. Mapping of shape invariant potentials by the point canonical transformation

    CERN Document Server

    Setare, M R

    2008-01-01

    In this paper by using the method of point canonical transformation we find that the Coulomb and Kratzer potentials can be mapped to the Morse potential. Then we show that the P\\"{o}schl-Teller potential type I belongs to the same subclass of shape invariant potentials as Hulth\\'{e}n potential. Also we show that the shape-invariant algebra for Coulomb, Kratzer, and Morse potentials is SU(1,1), while the shape-invariant algebra for P\\"{o}schl-Teller type I and Hulth\\'{e}n is SU(2).

  7. A generalization of the Funk-Radon transform

    Science.gov (United States)

    Quellmalz, Michael

    2017-03-01

    The Funk-Radon transform assigns to a function on the two-sphere its mean values along all great circles. We consider the following generalization: we replace the great circles by the small circles being the intersection of the sphere with planes containing a common point {\\boldsymbol{\\zeta }} inside the sphere. If {\\boldsymbol{\\zeta }} is the origin, this is just the classical Funk-Radon transform. We find two mappings from the sphere to itself that enable us to represent the generalized Radon transform in terms of the Funk-Radon transform. This representation is utilized to characterize the nullspace and range as well as to prove an inversion formula of the generalized Radon transform.

  8. The generalized radon transform: Sampling, accuracy and memoryconsiderations

    Energy Technology Data Exchange (ETDEWEB)

    Luengo Hendriks, Cris L.; van Ginkel, Michael; Verbeek, Piet W.; van Vliet, Lucas J.

    2004-09-23

    The generalized Radon (or Hough) transform is a well-known tool for detecting parameterized shapes in an image. The Radon transform is a mapping between the image space and a parameter space. The coordinates of a point in the latter correspond to the parameters of a shape in the image. The amplitude at that point corresponds to the amount of evidence for that shape. In this paper we discuss three important aspects of the Radon transform. The first aspect is discretization. Using concepts from sampling theory we derive a set of sampling criteria for the generalized Radon transform. The second aspect is accuracy. For the specific case of the Radon transform for spheres, we examine how well the location of the maxima matches the true parameters. We derive a correction term to reduce the bias in the estimated radii. The third aspect concerns a projection-based algorithm to reduce memory requirements.

  9. Least-squares reverse time migration with radon preconditioning

    KAUST Repository

    Dutta, Gaurav

    2016-09-06

    We present a least-squares reverse time migration (LSRTM) method using Radon preconditioning to regularize noisy or severely undersampled data. A high resolution local radon transform is used as a change of basis for the reflectivity and sparseness constraints are applied to the inverted reflectivity in the transform domain. This reflects the prior that for each location of the subsurface the number of geological dips is limited. The forward and the adjoint mapping of the reflectivity to the local Radon domain and back are done through 3D Fourier-based discrete Radon transform operators. The sparseness is enforced by applying weights to the Radon domain components which either vary with the amplitudes of the local dips or are thresholded at given quantiles. Numerical tests on synthetic and field data validate the effectiveness of the proposed approach in producing images with improved SNR and reduced aliasing artifacts when compared with standard RTM or LSRTM.

  10. RADON AND CARCINOGENIC RISK IN MOSCOW

    Directory of Open Access Journals (Sweden)

    S. M. Golovanev

    2015-01-01

    Full Text Available Objective: comparative evaluation of carcinogenic risk inMoscowfrom radon in indoor and atmospheric pollutants.Materials and methods: the lung cancer incidence in Moscow; radiation-hygienic passport of the territory; .U.S. EPA estimated average age at all and radon induced deaths, years of life lost; Report of UNSCEAR 2006 and WHO handbook on indoor radon, 2009. Trend analysis of incidence; evaluation of the excess relative risk; assessment of ratio radon-induced population risk and published values оf total population carcinogenic risk from chemical carcinogens.Results: it is shown that the 304 cases of lung cancer per year (1. 85 10-3 on average from 2006 to 2011 (21280diseases for 70 years in addition to background level induced by radon; the differences in average trends of all lungcancer incidence in the districts can exceed 25%.Conclusion. The potential of risk reduction by measures of mitigation radon concentration exceeds 5 times the cost efficiency to reduce emissions from vehicles and can reduce cancer incidence, on average 236 cases per year; population risk 16520 cases over 70 years or save not less than 2832 person-years of life per year. The annual effect of reducing losses from not-survival of 12 years as a result of radon-induced lung cancer deaths exceeds 14160000 dollars. The evaluating of the carcinogenic risk from radon in accordance with the definition of population risk increases the predictive evaluation of the effectiveness of preventive measures more than twice.

  11. EFFECTIVENESS OF RADON CONTROL FEATURES IN NEW HOUSE CONSTRUCTION - SOUTH CENTRAL FLORIDA

    Science.gov (United States)

    The report gives results of a study to evaluate the effectiveness of two slab types (monolithic and slab-in-stem wall) in retarding radon entry in new homes built in accordance with the State of Florida's proposed radon standard for new construction over high radon potential soil...

  12. Radon as geological tracer

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, T.; Anjos, R.M. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Fisica; Valladares, D.L.; Rizzotto, M.; Velasco, H.; Ayub, J. Juri [Universidad Nacional de San Luis (Argentina). Inst. de Matematica Aplicada San Luis (IMASL); Silva, A.A.R. da; Yoshimura, E.M. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2012-07-01

    Full text: This work presents measurements of {sup 222}Rn levels performed in La Carolina gold mine and Los Condores tungsten mine at the province of San Luis, Argentina, today used for tourist visitation, and can evaluate the potential use of such radioactive noble gas as tracer or marker for geological processes in underground environments. By concentrations of {sup 40}K, {sup 232}Th and {sup 23}'8U were also measured in the walls of tunnels were determined the rocks mineral composition, what indicated that the mines have the same composition. In this sense, we used nuclear trace plastic detectors CR-39, gamma spectrometry of rock samples and Geiger-Muller (GM) monitors The patterns of radon gas transportation processes revealed that La Carolina could be interpreted through a model based on a radioactive gas confined into a single entrance tube, with constant cross section and air velocity. Los Condores, which has a second main entrance, could be interpreted through a model based on a radioactive gas confined into a two entrance tube, allowing a chimney effect for air circulation. The results showed the high potential of using {sup 222}Rn as a geological tracer. In what concerns the occupational hazard, in summer (time of more intense tourist activity in the mine) La Carolina presented a mean concentration of the radioactive noble gas that exceeds in four times the action level of 1,5 kBq m{sup -3} recommended by the International Commission of Radiological Protection (ICRP). The chimney effect shows the low mean concentration of radon in Los Condores. (author)

  13. LARGE BUILDING RADON MANUAL

    Science.gov (United States)

    The report summarizes information on how bilding systems -- especially the heating, ventilating, and air-conditioning (HVAC) system -- inclurence radon entry into large buildings and can be used to mitigate radon problems. It addresses the fundamentals of large building HVAC syst...

  14. Radon and Cancer

    Science.gov (United States)

    ... exposure and lung cancer: the Iowa Radon Lung Cancer Study. American Journal of Epidemiology 2000; 151(11):1091–1102. [PubMed Abstract] Frumkin H, Samet JM. Radon. CA: A Cancer Journal for Clinicians 2001; 51(6):337–344. [ ...

  15. LARGE BUILDING RADON MANUAL

    Science.gov (United States)

    The report summarizes information on how bilding systems -- especially the heating, ventilating, and air-conditioning (HVAC) system -- inclurence radon entry into large buildings and can be used to mitigate radon problems. It addresses the fundamentals of large building HVAC syst...

  16. Predictive mapping of the acidifying potential for acid sulfate soils

    DEFF Research Database (Denmark)

    Boman, A; Beucher, Amélie; Mattbäck, S

    Developing methods for the predictive mapping of the potential environmental impact from acid sulfate soils is important because recent studies (e.g. Mattbäck et al., under revision) have shown that the environmental hazards (e.g. leaching of acidity) related to acid sulfate soils vary depending...... on their texture (clay, silt, sand etc.). Moreover, acidity correlates, not only with the sulfur content, but also with the electrical conductivity (EC) measured after incubation. Electromagnetic induction (EMI) data collected from an EM38 proximal sensor also enabled the detailed mapping of acid sulfate soils...... over a field (Huang et al., 2014).This study aims at assessing the use of EMI data for the predictive mapping of the acidifying potential in an acid sulfate soil area in western Finland. Different supervised classification modelling techniques, such as Artificial Neural Networks (Beucher et al., 2015...

  17. Mapping Irrigation Potential in the Upper East Region of Ghana

    Science.gov (United States)

    Akomeah, E.; Odai, S. N.; Annor, F. O.; Adjei, K. A.; Barry, B.

    2009-04-01

    The Upper East Region together with the other two regions in Northern Ghana (Upper West and Northern Region) is seen as the locus of perennial food deficit (GPRS, 2003). Despite, the provision of over 200 small scale dams and various mechanisms aimed at poverty alleviation, the region is still plagued with poverty and yearly food shortages. To achieve food security and alleviate poverty in the region however, modernization of agriculture through irrigation is deemed inevitable. While it is true that considerable potential still exists for future expansion of irrigation, it cannot be refuted that water is becoming scarcer in the regions where the need for irrigation is most important, hence mapping the irrigation potential of the region will be the first step toward ensuring sound planning and sustainability of the irrigation developments. In this study, an attempt has been made to map out the irrigation potential of the Upper East Region. The river basin approach was used in assessing the irrigation potential. The catchments drained by The White Volta river, Red volta river, River Sissili and River Kulpawn were considered in the assessment. The irrigation potential for the sub basins was computed by combining information on gross irrigation water requirements for the selected cash crops, area of soil suitable for irrigation and available water resources. The capacity of 80%, 70%, 60% and 50% time of exceedance flow of the available surface water resources in the respective sub basins was estimated. The area that can be irrigated with this flow was computed with selected cropping pattern. Combining the results of the potential irrigable areas and the land use map of the respective sub basins, an irrigation potential map has been generated showing potential sites in the upper east region that can be brought under irrigation. Keywords: Irrigation potential, irrigation water requirement, land evaluation, dependable flow

  18. Mutagenicity of radon and radon daughters

    Energy Technology Data Exchange (ETDEWEB)

    Evans, H.H.

    1991-01-01

    The objective of our research is to investigate the dose-response relationship of the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose rate dependence and the nature of the DNA lesion will be studied, using the thymidine kinase and HPRT loci to measure mutation frequency. A deficiency in DNA repair is shown to lead to a greater proportion of mutants with intergenic lesions. The cytotoxic effects of radon and its daughters are similar in human TK6 lymphoblasts and mouse L5178Y lymphoblasts, the cell line used in previous experiments. The results of molecular analysis of four spontaneous and 25 X-radiation induced HPRT{sup {minus}} mutants. Eleven radon-induced HPRT{sup {minus}} mutants have been isolated, and will be analyzed in a similar fashion. 9 figs.

  19. Energy potential mapping for energy-producing neighborhoods

    NARCIS (Netherlands)

    Dobbelsteen, van den A.; Broersma, S.; Stremke, S.

    2011-01-01

    Over the past five years, the method of energy potential mapping (EPM) has evolved from a cartoonish charting of climatic features with energy consequences to a detailed methodology for the development of spatial plans based on energy-effective foundations. By means of EPM the rudimentary features

  20. Present and potential land use mapping in Mexico

    Science.gov (United States)

    Garduno, H.; Lagos, R. G.; Simo, F. G.

    1975-01-01

    The Mexican Water Plan (MWP) conducted studies of present and potential land use in Mexico using LANDSAT-1 satellite imagery. Present land use studies were carried out all over the country (197 million hectares); nine soil uses were mapped according to the first classification level recommended by the U.S. Geological Survey. Also 6.3 million hectares of land with advanced erosion were detected. Work was executed at a rate of 8 million hectares per month; reliability was 90% and the cost of only 0.1 cents/hectare. The potential land use study was performed in 45 million hectares at a rate of 4 million hectares per month and at a cost of 0.33 cents/hectare. Soil units according to FAO classification were delineated scale 1:1 million; interpretative maps were also prepared dealing with potential agricultural productivity carrying capacity for cattle, water, erosion risk, and slope ranges.

  1. A proposal of Potentially Meaningful Teaching Unit using concept maps

    Directory of Open Access Journals (Sweden)

    Thaís Rafaela Hilger

    2013-12-01

    Full Text Available This paper presents preliminary results from the implementation of a Potentially Meaningful Teaching Unit in four classes of third grade of secondary educational from a public school in the city of Bagé (Rio Grande do Sul. The proposed content deals with concepts related to Quantum Physics (quantization, uncertainty principle, state and superposition of states, presented in accordance with the sequence of eight steps of Potentially Meaningful Teaching Unit, seeking meaningful learning of these concepts. Are analyzed in this work mental maps and concept maps produced in pairs, as well as the comparison between them. Also presented are some comments from students about their development in the understanding of the concepts covered in the proposal. The proposal was a well received and, although the study is still in progress and part of a broader research, already provide evidence of significant learning, which is the goal of a Potentially Meaningful Teaching Unit.

  2. Current state of radon chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Avrorin, V.V.; Krasikova, R.N.; Nefedov, V.D.; Toropova, M.A.

    1982-01-01

    This article summarizes the data available prior to May 1980 on the physical, chemical and radioactive properties of radon. Tables include a list of the known isotopes together with the half-lives, types of emitted radiation and daughter products and a list of the inert gases Rn, Xe, Kr, Ar and Ne together with the hydrate stability, ionization potential, ionic character of bonding, dissociation energy, electronegativity and others. Experimental difficulties of working with radon, such as its short half-life and its fugitive nature, are mentioned. The compound RNF/sub 2/ can be prepared from several different fluorinating reagents such as ClF/sub 3/, KrF/sub 3/, BrF/sub 3/, K/sub 2/NiF/sub 6/ in HF and others. Until now it has not been possible to prepare organic compounds of inert gases using classical techniques. Noble gas compounds may also be prepared via radiochemical techniques. Some applications of radon compounds, such as in decontamination of reactor and mine effluents, are discussed.

  3. Indoor radon in Slovenia

    Directory of Open Access Journals (Sweden)

    Vaupotič Janja

    2003-01-01

    Full Text Available The Slovenian Radon Programme started in 1990. Since then, radon and radon short-lived decay products have been surveyed in 730 kindergartens, 890 schools, 1000 randomly selected homes, 5 major spas, 26 major hospitals, 10 major municipal water supply plants, and 8 major wineries. Alpha scintillation cells, etched track detectors, electret-based detectors and various continuously measuring devices have been used. On the basis of estimated effective doses, decisions were made on appropriate mitigation. In total, 35 buildings have been appropriately modified. The programme is displayed and results reviewed chronologically and discussed.

  4. Radon Optical Processing in Radon Space.

    Science.gov (United States)

    1986-06-15

    yields one line through the three-dimensional Fourier transform 1. Radon, J., " Uber die Bestimmung von Funktiontn of the three-dimensional function (3...Alamos, New Mexico , April 11-15. 1983.a 6. W. G. Wee, "Application of projection techniques to image image. Figure 1(a) has approximately 8.0 bits/pixel

  5. The Concept of Equivalent Radon Concentration for Practical Consideration of Indoor Exposure to Thoron

    Directory of Open Access Journals (Sweden)

    Deborah Moir

    2012-01-01

    Full Text Available To consider the total exposure to indoor radon and thoron, a concept of equivalent radon concentration for thoron is introduced, defined as the radon concentration that delivers the same annual effective dose as that resulting from the thoron concentration. The total indoor exposure to radon and thoron is then the sum of the radon concentration and the equivalent radon concentration for thoron. The total exposure should be compared to the radon guideline value, and if it exceeds the guideline value, appropriate remedial action is required. With this concept, a separate guideline for indoor thoron exposure is not necessary. For homes already tested for radon with radon detectors, Health Canada’s recommendation of a 3-month radon test performed during the fall/winter heating season not only ensures a conservative estimate of the annual average radon concentration but also covers well any potentially missing contribution from thoron exposure. In addition, because the thoron concentration is much lower than the radon concentration in most homes in Canada, there is no real need to re-test homes for thoron.

  6. Indoor Radon Measurement in Van

    Science.gov (United States)

    Kam, E.; Osmanlioglu, A. E.; Dogan, I.; Celebi, N.

    2007-04-01

    In this study, indoor radon concentrations obtained from the radon surveys conducted in the Van. Radon monitoring was performed by applying a passive, time-integrating measuring technique. For this purpose, CR-39 nuclear track detectors were installed in dwellings for 2 months. After the monitoring period, detectors were collected. In order to make the alpha tracks visible, chemical etching was applied to the exposed detectors. Nuclear track numbers and the corresponding indoor radon concentrations were determined. Annual effective dose equivalents and the risk probabilities caused by indoor radon inhalation were calculated, and the found results compared with the indoor radon concentrations' data measured in different provinces of Turkey.

  7. ROE Radon Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The polygon dataset represents predicted indoor radon screening levels in counties across the United States. These data were provided by EPA’s Office of Radiation...

  8. Radon in Schools

    Science.gov (United States)

    ... strategy below. Top of Page Testing and Mitigation Standards for Schools Copies of the following Radon Standards ... control is a critical component of any comprehensive indoor air quality (IAQ) management program, l earn how to manage ...

  9. Radon i danske lejeboliger

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Skytte Clausen, Louise

    I denne undersøgelse kortlægges radonindholdet i indeluften og det undersøges, hvordan indholdet af radon i indeluften er fordelt og spredes i en ejendom, og om det er muligt at pege på en bygningsdel eller en bygningskomponent som en spredningsvej for radon i boliger. Boligerne er lejeboliger og...... ligger i etageejendomme, kæde- og rækkehuse tilhørende bygningstyper opført fra 1850 og frem. De udvalgte ejendomme ligger i områder af landet, hvor der ved tidligere undersøgelser har vist sig at være en stor andel af huse med et højt indhold af radon i indeluften. Koncentrationen af radon er målt over...

  10. Shallow geothermal potential of Cantone Ticino through map modeling

    Science.gov (United States)

    Perego, Rodolfo; Pera, Sebastian; Belliardi, Marco

    2017-04-01

    Low enthalpy geothermal energy is continuously growing in importance within Europe, since it is a reliable and efficient renewable energy, especially when exploited by closed-loop systems. Switzerland hosts one of the greatest density of low temperature geothermal systems in the world. Cantone Ticino includes more than 4000 probes, with an overall installed length of more than 500 km and the requests are continuously growing: the management of this technology must be therefore accurately faced both from a physical and political standpoint. The current authorization approach for closed-loop systems in Cantone Ticino, however, is mainly based on basic maps taking into account the presence of restrictions arising from the enforcement of the water protection act and ordinance. Closed-loop systems cannot be installed within S groundwater protection zones, and within the Au (usable groundwater) sector the installation of such systems is allowed in specific areas where the presence of conflicts precludes groundwater exploitation for drinking purposes. The described procedure, however, does not consider the subsurface potential nor the techno-economic constraints. More empirically based maps could instead give precious planning indications and they could also be useful, if properly verified, to perform pre-emptive estimates of technical and economic parameters. The procedure for the mapping of the geothermal potential started with the identification of the main parameters affecting it, such as the ground surface temperature (GST), thermal conductivity of both outcrops/unconsolidated material and heat flux/geothermal gradient. Maps for all of these parameters were created and some of them were compared with real measurement data, with satisfactory results. The estimated error for the ground temperature reconstruction was quantified in ±1°C, while the error of the hydraulic conductivity reconstruction was estimated as half of an order of magnitude. A reference set of

  11. Variance of indoor radon concentration: Major influencing factors.

    Science.gov (United States)

    Yarmoshenko, I; Vasilyev, A; Malinovsky, G; Bossew, P; Žunić, Z S; Onischenko, A; Zhukovsky, M

    2016-01-15

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

  12. Environmental Radon Gas and Degenerative Conditions An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Groves-Kirkby, C.J. [Medical Physics Department, Northampton General Hospital, Northampton NN1 5BD (United Kingdom)]|[School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom); Denman, A.R. [Medical Physics Department, Northampton General Hospital, Northampton NN1 5BD (United Kingdom); Woolridge, A.C. [School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom)]|[School of Applied Sciences, University of Northampton, Northampton NN2 7AL (United Kingdom); Phillips, P.S. [School of Applied Sciences, University of Northampton, Northampton NN2 7AL (United Kingdom); Phillips, C. [School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom)

    2006-07-01

    Radon, a naturally occurring radioactive gas, has variable distribution in the environment as a decay product of uranium occurring in a wide range of rocks, soils and building materials. Although radon dissipates rapidly in outdoor air, it concentrates in the built environment, and inhalation of {sup 222}Rn and its progeny {sup 218}Po and {sup 214}Po is believed to provide the majority of the radioactive dose to the respiratory system. While the connection between radon and lung cancer has long been recognised and investigated, recent studies have highlighted potential links between radon and other conditions, among them Multiple Sclerosis, Alzheimer and Parkinson Diseases, and Paget Disease of Bone. A strong case exists for clarifying the relationship between radon and these other conditions, not least since radon remediation to reduce lung cancer may conceivably have additional benefits hitherto unrecognized. The present status of the postulated links between environmental radon gas and degenerative conditions is reviewed, and recommendations for further research into levering current anti-radon campaigns are made. (authors)

  13. Radon og boligen

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    Radon er en radioaktiv og sundhedsskadelig luftart, som ved indånding øger risikoen for lungekræft. Der er ingen dokumenteret nedre grænse for, hvornår radon er ufarligt. Derfor anbefales det, at man tilstræber et så lavt radonindhold i indeluften som muligt. Man kan hverken lugte, se, høre eller...... smage radon, så vil du vide, om du har radon i din bolig, må du måle radonindholdet i indeluften. Radon forekommer naturligt i jorden og kan suges ind sammen med jordluft, hvis der inde er et undertryk, og hvis konstruktionerne mod jord er utætte. Jordluft trænger ind gennem revner og utætte samlinger......, fx omkring rør til kloak, vand og varmeforsyning. Koncentrationen af radon i jorden varierer meget fra sted til sted, også lokalt og gennem året. Tidligere undersøgelser har vist, at der kan forekomme høje koncentrationer i Sydgrønland, specielt i området syd for Narsalik ved Paamiut, 61°30’N....

  14. Mapping the global geographic potential of Zika virus spread

    Science.gov (United States)

    Samy, Abdallah M.; Thomas, Stephanie M; Wahed, Ahmed Abd El; Cohoon, Kevin P; Peterson, A. Townsend

    2016-01-01

    The Americas are presently experiencing the most serious known outbreak of Zika virus (ZIKV). Here, we present a novel set of analyses using environmental characteristics, vector mosquito distributions, and socioeconomic risk factors to develop the first map to detail global ZIKV transmission risk in multiple dimensions based on ecological niche models. Our model predictions were tested against independent evaluation data sets, and all models had predictive ability significantly better than random expectations. The study addresses urgent knowledge gaps regarding (1) the potential geographic scope of the current ZIKV epidemic, (2) the global potential for spread of ZIKV, and (3) drivers of ZIKV transmission. Our analysis of potential drivers of ZIKV distributions globally identified areas vulnerable in terms of some drivers, but not for others. The results of these analyses can guide regional education and preparedness efforts, such that medical personnel will be better prepared for diagnosis of potential ZIKV cases as they appear. PMID:27653360

  15. Mapping the global geographic potential of Zika virus spread

    Directory of Open Access Journals (Sweden)

    Abdallah M. Samy

    Full Text Available The Americas are presently experiencing the most serious known outbreak of Zika virus (ZIKV. Here, we present a novel set of analyses using environmental characteristics, vector mosquito distributions, and socioeconomic risk factors to develop the first map to detail global ZIKV transmission risk in multiple dimensions based on ecological niche models. Our model predictions were tested against independent evaluation data sets, and all models had predictive ability significantly better than random expectations. The study addresses urgent knowledge gaps regarding (1 the potential geographic scope of the current ZIKV epidemic, (2 the global potential for spread of ZIKV, and (3 drivers of ZIKV transmission. Our analysis of potential drivers of ZIKV distributions globally identified areas vulnerable in terms of some drivers, but not for others. The results of these analyses can guide regional education and preparedness efforts, such that medical personnel will be better prepared for diagnosis of potential ZIKV cases as they appear.

  16. Mapping the global geographic potential of Zika virus spread.

    Science.gov (United States)

    Samy, Abdallah M; Thomas, Stephanie M; Wahed, Ahmed Abd El; Cohoon, Kevin P; Peterson, A Townsend

    2016-09-01

    The Americas are presently experiencing the most serious known outbreak of Zika virus (ZIKV). Here, we present a novel set of analyses using environmental characteristics, vector mosquito distributions, and socioeconomic risk factors to develop the first map to detail global ZIKV transmission risk in multiple dimensions based on ecological niche models. Our model predictions were tested against independent evaluation data sets, and all models had predictive ability significantly better than random expectations. The study addresses urgent knowledge gaps regarding (1) the potential geographic scope of the current ZIKV epidemic, (2) the global potential for spread of ZIKV, and (3) drivers of ZIKV transmission. Our analysis of potential drivers of ZIKV distributions globally identified areas vulnerable in terms of some drivers, but not for others. The results of these analyses can guide regional education and preparedness efforts, such that medical personnel will be better prepared for diagnosis of potential ZIKV cases as they appear.

  17. Radon as a natural tracer for underwater cave exploration.

    Science.gov (United States)

    Csondor, Katalin; Erőss, Anita; Horváth, Ákos; Szieberth, Dénes

    2017-07-01

    The Molnár János cave is one of the largest hypogenic caves of the Buda Thermal Karst (Budapest, Hungary) and mainly characterized by water-filled passages. The major outflow point of the waters of the cave system is the Boltív spring, which feeds the artificial Malom Lake. Previous radon measurements in the cave system and in the spring established the highest radon concentration (71 BqL(-1)) in the springwater. According to previous studies, the origin of radon was identified as iron-hydroxide containing biofilms, which form where there is mixing of cold and thermal waters, and these biofilms efficiently adsorb radium from the thermal water component. Since mixing of waters is responsible for the formation of the cave as well, these iron-hydroxide containing biofilms and the consequent high radon concentrations mark the active cave forming zones. Based on previous radon measurements, it is supposed that the active mixing and cave forming zone has to be close to the spring, since the highest radon concentration was measured there. Therefore radon mapping was carried out with the help of divers in order to get a spatial distribution of radon in the cave passages closest to the spring. Based on our measurements, the highest radon activity concentration (84 BqL(-1)) was found in the springwater. Based on the distribution of radon activity concentrations, direct connection was established between the spring and the István-room of the cave, which was verified by an artificial tracer. However, the distribution of radon in the cave passages shows lower concentrations (18-46 BqL(-1)) compared to the spring, therefore an additional deep inflow from hitherto unknown cave passages is assumed, from which waters with high radon content arrive to the spring. These passages are assumed to be in the active cave formation zone. This study proved that radon activity concentration distribution is a useful tool in underwater cave exploration. Copyright © 2016 Elsevier Ltd. All

  18. Radon in land use planning; Radon i arealplanlegging

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Radon poses a health risk. Therefore, it is important that the municipality takes into account radon, in land use planning. This Radiation Info provides an overview of what makes an additional radon prone area and what tools are available to assess this. The background is the Planning and Building Act provisions on risk analysis (ROS) and zones. (eb)

  19. Radon as a hydrological indicator

    Energy Technology Data Exchange (ETDEWEB)

    Komae, Takami [National Research Inst. of Agricultural Engineering, Tsukuba, Ibaraki (Japan)

    1997-02-01

    The radon concentration in water is measured by a liquid scintillation method. After the radioactive equilibrium between radon and the daughter nuclides was attained, the radon concentration was determined by the liquid scintillation analyzer. {alpha}-ray from radon, then two {beta}- and two {alpha}-ray from the daughter nuclei group were released, so that 500% of the apparent counting efficiency was obtained. The detector limit is about 0.03 Bq/l, the low value, which corresponds to about 5.4x10{sup -15} ppm. By determining the radon concentration in groundwater, behavior of radon in hydrological process, the groundwater exchange caused by pumping and exchange between river water and groundwater were investigated. The water circulation analysis by means of radon indicator in the environment was shown. By using the large difference of radon concentration between in river water and in groundwater, arrival of injected water to the sampling point of groundwater was detected. (S.Y.)

  20. $3d$ fermion-boson map with imaginary chemical potential

    CERN Document Server

    Filothodoros, E G; Vlachos, N D

    2016-01-01

    We study the three-dimensional $U(N)$ Gross-Neveu and CP$^{N-1}$ models in the canonical formalism with fixed $U(1)$ charge. For large-$N$ this is closely related to coupling the models to abelian Chern-Simons in a monopole background. We show that the presence of the imaginary chemical potential for the $U(1)$ charge makes the phase structure of the models remarkably similar. We calculate their respective large-$N$ free energy densities and show that they are mapped into each other in a precise way. Intriguingly, the free energy map involves the Bloch-Wigner function and its generalizations introduced by Zagier. We expect that our results are connected to the recently discussed $3d$ bosonization.

  1. Retinotopic mapping of visual event-related potentials.

    Science.gov (United States)

    Capilla, Almudena; Melcón, María; Kessel, Dominique; Calderón, Rosbén; Pazo-Álvarez, Paula; Carretié, Luis

    2016-07-01

    Visual stimulation is frequently employed in electroencephalographic (EEG) research. However, despite its widespread use, no studies have thoroughly evaluated how the morphology of the visual event-related potentials (ERPs) varies according to the spatial location of stimuli. Hence, the purpose of this study was to perform a detailed retinotopic mapping of visual ERPs. We recorded EEG activity while participants were visually stimulated with 60 pattern-reversing checkerboards placed at different polar angles and eccentricities. Our results show five pattern-reversal ERP components. C1 and C2 components inverted polarity between the upper and lower hemifields. P1 and N1 showed higher amplitudes and shorter latencies to stimuli located in the contralateral lower quadrant. In contrast, P2 amplitude was enhanced and its latency was reduced by stimuli presented in the periphery of the upper hemifield. The retinotopic maps presented here could serve as a guide for selecting optimal visuo-spatial locations in future ERP studies.

  2. Radon in soil concentration levels in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, N.; Tamez, E.; Mena, M

    1991-09-15

    Radon in soil surveys in Mexico have been carried out since 1974 both for uranium prospectus and to correlate mean values of the gas emanation with local telluric behaviour. The mapping includes the northern uranium mining region, the Mexican Neo volcanic Belt, the coastal areas adjacent to the zone of subduction of the Cocos Plate under the North American Plate, some of the active volcanoes of Southern Mexico and several sedimentary valleys in Central Mexico. Recording of {sup 222} Rn alpha decay is systematically performed with LR115 track detectors. Using mean values averaged over different observation periods at fixed monitoring stations, a radon in soil map covering one third of the Mexican territory is presented. The lowest mean values have been found in areas associated with active volcanoes. The highest levels are found in uranium ore zones. Intermediate values are obtained in regions with enhanced hydrothermal activity and stations associated with intrusive rocks. (Author)

  3. Geologic influence on indoor radon concentrations and gamma radiation levels in Norwegian dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Sundal, Aud Venche

    2003-09-01

    Indoor radon levels in 1618 Norwegian dwellings located in different geological settings were compared with geological information in order to determine potential correlations between geological factors and indoor radon concentrations in Norway and to establish whether geological information is useful in radon risk analysis. In two geographically limited areas, Kinsarvik and Fen, detailed geological and geochemical investigations were carried out in order to explain their elevated natural radiation environment. Significant correlations between geology and indoor radon concentrations in Norway are found when the properties of both the bedrock and the overburden are taken into account. Areas of high radon risk in Norway include 1) exposed bedrock with elevated levels of radium (mainly alum shale and granites) and b) highly permeable unconsolidated sediments derived from all rock types (mainly glaciofluvial and fluvial deposits) and moderately permeable sediments containing radium rich rock fragments (mainly basal till). More than 20 % of Norwegian dwellings located in the high-risk areas can be expected to contain radon levels exceeding 200 Bq/m3. The elevated radon risk related to penneable building grounds is illustrated in Kinsarvik where the highly permeable sediments and the large vadose zone underlying the Huse residential area enable the transport of radon from large volumes into the dwellings resulting in enhanced indoor radon concentrations. Subterranean air flows caused by temperature/pressure differences between soil air and atmospheric air and elevations differences within the Huse area are shown to strongly affect the annual variations in indoor radon concentrations. The marked contrasts in radon risk potential between different types of building grounds are clearly illustrated in the Fen area where outcrops of the radium rich Fen carbonatites represent areas of high radon risk while only low levels of both indoor radon concentrations and indoor gamma

  4. A COMPARISON OF WINTER SHORT-TERM AND ANNUAL AVERAGE RADON MEASUREMENTS IN BASEMENTS OF A RADON-PRONE REGION AND EVALUATION OF FURTHER RADON TESTING INDICATORS

    Science.gov (United States)

    Barros, Nirmalla G.; Steck, Daniel J.; Field, R. William

    2014-01-01

    The primary objective of this study was to investigate the temporal variability between basement winter short-term (7 to 10 days) and basement annual radon measurements. Other objectives were to test the short-term measurement’s diagnostic performance at two reference levels and to evaluate its ability to predict annual average basement radon concentrations. Electret ion chamber (short-term) and alpha track (annual) radon measurements were obtained by trained personnel in Iowa residences. Overall, the geometric mean of the short-term radon concentrations (199 Bq m−3) was slightly greater than the geometric mean of the annual radon concentrations (181 Bq m−3). Short-term tests incorrectly predicted that the basement annual radon concentrations would be below 148 Bq m−3 12% of the time and 2% of the time at 74 Bq m−3. The short-term and annual radon concentrations were strongly correlated (r=0.87, pradon potential when the reference level is lowered to 74 Bq m−3. PMID:24670901

  5. Mixed Norm Estimate for Radon Transform on Weighted $L^p$ Spaces

    Indian Academy of Sciences (India)

    Ashisha Kumar; Swagato K Ray

    2010-09-01

    We will discuss about the mapping property of Radon transform on $L^p$ spaces with power weight. It will be shown that the Pitt’s inequality together with the weighted version of Hardy–Littlewood–Sobolev lemma imply weighted inequality for the Radon transform.

  6. Quantile regression and Bayesian cluster detection to identify radon prone areas.

    Science.gov (United States)

    Sarra, Annalina; Fontanella, Lara; Valentini, Pasquale; Palermi, Sergio

    2016-11-01

    Albeit the dominant source of radon in indoor environments is the geology of the territory, many studies have demonstrated that indoor radon concentrations also depend on dwelling-specific characteristics. Following a stepwise analysis, in this study we propose a combined approach to delineate radon prone areas. We first investigate the impact of various building covariates on indoor radon concentrations. To achieve a more complete picture of this association, we exploit the flexible formulation of a Bayesian spatial quantile regression, which is also equipped with parameters that controls the spatial dependence across data. The quantitative knowledge of the influence of each significant building-specific factor on the measured radon levels is employed to predict the radon concentrations that would have been found if the sampled buildings had possessed standard characteristics. Those normalised radon measures should reflect the geogenic radon potential of the underlying ground, which is a quantity directly related to the geological environment. The second stage of the analysis is aimed at identifying radon prone areas, and to this end, we adopt a Bayesian model for spatial cluster detection using as reference unit the building with standard characteristics. The case study is based on a data set of more than 2000 indoor radon measures, available for the Abruzzo region (Central Italy) and collected by the Agency of Environmental Protection of Abruzzo, during several indoor radon monitoring surveys. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Description of the behavior of an aquifer by using continuous radon monitoring in a thermal spa

    Energy Technology Data Exchange (ETDEWEB)

    Sainz, Carlos, E-mail: sainzc@unican.es; Rábago, Daniel; Fuente, Ismael; Celaya, Santiago; Quindós, Luis Santiago

    2016-02-01

    Radon ({sup 222}Rn) levels in air and water have been analyzed continuously for almost a year in Las Caldas de Besaya thermal spa, north Spain. Radon is a naturally occurring noble gas from the decay of radium ({sup 226}Ra) both constituents of radioactive uranium 238 series. It has been recognized as a lung carcinogen by the World Health Organization (WHO) and International Agency for Research on Cancer (IARC). Furthermore the Royal Decree R.D 1439/2010 of November, 2010 establishes the obligation to study occupational activities where workers and, where appropriate, members of the public are exposed to inhalation of radon in workplaces such as spas. Together with radon measures several physico-chemical parameters were obtained such as pH, redox potential, electrical conductivity and air and water temperature. The devices used for the study of the temporal evolution of radon concentration have been the RTM 2100, the Radon Scout and gamma spectrometry was complementarily used to determine the transfer factor of the silicone tubes in the experimental device. Radon concentrations obtained in water and air of the spa are high, with an average of 660 Bq/l and 2900 Bq/m{sup 3} respectively, where water is the main source of radon in the air. Radiation dose for workers and public was estimated from these levels of radon. The data showed that the thermal processes can control the behavior of radon which can be also influenced by various physical and chemical parameters such as pH and redox potential. - Highlights: • Radon in water is the major source of indoor air radon concentration in thermal facilities. • Radon in water has been used to characterize the origin of water used for treatments in a spa. • Preliminary dose assessment from radon exposure has been performed.

  8. Indoor radon in a Spanish region with different gamma exposure levels

    Energy Technology Data Exchange (ETDEWEB)

    Quindos, L.S. [RADON Group, Faculty of Medicine, University of Cantabria, c/Cardenal Herrera Oria s/n, 39011 Santander (Spain)], E-mail: quindosl@unican.es; Fernandez, P.L. [RADON Group, Faculty of Medicine, University of Cantabria, c/Cardenal Herrera Oria s/n, 39011 Santander (Spain)], E-mail: pedroluis.fernandez@unican.es; Sainz, C. [RADON Group, Faculty of Medicine, University of Cantabria, c/Cardenal Herrera Oria s/n, 39011 Santander (Spain)], E-mail: sainzc@unican.es; Fuente, I. [RADON Group, Faculty of Medicine, University of Cantabria, c/Cardenal Herrera Oria s/n, 39011 Santander (Spain)], E-mail: ismael.fuente@unican.es; Nicolas, J. [RADON Group, Faculty of Medicine, University of Cantabria, c/Cardenal Herrera Oria s/n, 39011 Santander (Spain)], E-mail: nicolas_jorge@yahoo.es; Quindos, L. [RADON Group, Faculty of Medicine, University of Cantabria, c/Cardenal Herrera Oria s/n, 39011 Santander (Spain)], E-mail: quindosll@unican.es; Arteche, J. [RADON Group, Faculty of Medicine, University of Cantabria, c/Cardenal Herrera Oria s/n, 39011 Santander (Spain)], E-mail: jlag@inm.es

    2008-10-15

    In the beginning of 1990s within the framework of a national radon survey of more than 1500 points, radon measurements were performed in more than 100 houses located in Galicia region, in the Northwest area of Spain. The houses were randomly selected only bearing in mind general geological aspects of the region. Subsequently, a nationwide project called MARNA dealt with external gamma radiation measurements in order to draw a Spanish natural radiation map. The comparison in Galicia between these estimations and the indoor radon levels previously obtained showed good agreement. With the purpose of getting a confirmation of this relationship and also of creating a radon map of the zone, a new set of measurements were carried out in 2005. A total of 300 external gamma radiation measurements were carried out as well as 300 measurements of {sup 226}Ra, {sup 232}Th and {sup 40}K content in soil. Concerning radon, 300 1-m-depth radon measurements in soil were performed, and indoor radon concentration was determined in a total of 600 dwellings. Radon content in soil gave more accurate indoor radon predictions than external gamma radiation or {sup 226}Ra concentration in soil.

  9. The radon EDM apparatus

    Science.gov (United States)

    Tardiff, E. R.; Rand, E. T.; Ball, G. C.; Chupp, T. E.; Garnsworthy, A. B.; Garrett, P.; Hayden, M. E.; Kierans, C. A.; Lorenzon, W.; Pearson, M. R.; Schaub, C.; Svensson, C. E.

    2014-01-01

    The observation of a permanent electric dipole moment (EDM) at current experimentally accessible levels would provide clear evidence of physics beyond the Standard Model. EDMs violate CP symmetry, making them a possible route to explaining the size of the observed baryon asymmetry in the universe. The Radon EDM Experiment aims to search for an EDM in radon isotopes whose sensitivity to CP-odd interactions is enhanced by octupole-deformed nuclei. A prototype apparatus currently installed in the ISAC hall at TRIUMF includes a gas handling system to move radon from a collection foil to a measurement cell and auxiliary equipment for polarization diagnostics and validation. The features and capabilities of the apparatus are described and an overview of the experimental design for a gamma-ray-anisotropy based EDM measurement is provided.

  10. Radon: a bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Lepman, S.R.; Boegel, M.L.; Hollowell, C.D.

    1981-01-01

    The Lawrence Berkeley Laboratory, with the support of the Department of Energy, has developed a computerized database to manage research information in the area of building ventilation and indoor air quality. This literature survey contains references pertaining to the physical properties of radon and its daughters, instrumentation for their measurement, health effects, surveys and measurements, and regulatory information. The references in the bibliography are sequenced in alphabetical order and abstracts are included when supplied by the author. The objective of this report is to disseminate the bibliographic references compiled at the laboratory relating to radon research portion of the program. Interested database users are encouraged to contact the laboratory to receive instructions for direct database acess. A flyer describing the database is supplied at the end of the bibliography and a brief overview of the Radon Research porgram is given.

  11. Electrical mapping of microtubular structures by surface potential microscopy

    Science.gov (United States)

    Zhang, Peng; Cantiello, Horacio F.

    2009-09-01

    Microtubules (MTs) are important cytoskeletal polymers that play an essential role in cell division and transport in all eukaryotes and information processing in neurons. MTs are highly charged polyelectrolytes, composed of hollow cylindrical arrangements of αβ-tubulin dimers. To date, there is little information about electrical properties of MTs. Here, we deposited and dried MTs onto a gold-plated surface to image their topology by atomic force microscopy (AFM), and determined their electrical mapping with surface potential microscopy (SPM). We found a strong linear correlation between the magnitude of relative surface potential and MT parameters, including diameter and height. AFM images confirmed the cylindrical topology of microtubular structures, and the presence of topological discontinuities along their surface, which may contribute to their unique electrical properties.

  12. Radon assay for SNO+

    Energy Technology Data Exchange (ETDEWEB)

    Rumleskie, Janet [Laurentian University, Greater Sudbury, Ontario (Canada)

    2015-12-31

    The SNO+ experiment will study neutrinos while located 6,800 feet below the surface of the earth at SNOLAB. Though shielded from surface backgrounds, emanation of radon radioisotopes from the surrounding rock leads to back-grounds. The characteristic decay of radon and its daughters allows for an alpha detection technique to count the amount of Rn-222 atoms collected. Traps can collect Rn-222 from various positions and materials, including an assay skid that will collect Rn-222 from the organic liquid scintillator used to detect interactions within SNO+.

  13. A reconnaissance study of radon concentrations in Hamadan city, Iran

    Science.gov (United States)

    Gillmore, G. K.; Jabarivasal, N.

    2010-04-01

    This paper presents results of a reconnaissance study that used CR-39 alpha track-etch detectors to measure radon concentrations in dwellings in Hamadan, western Iran, significantly, built on permeable alluvial fan deposits. The indoor radon levels recorded varied from 4 (i.e. below the lower limit of detection for the method) to 364 Bq/m3 with a mean value of 108 Bq/m3 which is 2.5 times the average global population-weighted indoor radon concentration - these data augment the very few published studies on indoor radon levels in Iran. The maximum radon concentration in Hamadan occurs during the winter period (January to March) with lower concentrations during the autumn. The effective dose equivalent to the population in Hamadan is estimated from this study to be in the region of 2.7 mSv/y, which is above the guidelines for dose to a member of the public of 1 mSv/y suggested by the International Commission on Radiological Protection (ICRP) in 1993. This study supports other work in a number of countries that indicates such permeable "surficial" deposits as being of intermediate to high radon potential. In western Iran, the presence of hammered clay floors, the widespread presence of excavated qanats, the textural properties of surficial deposits and human behaviour intended to cope with winds are likely to be important factors influencing radon concentrations in older buildings.

  14. A reconnaissance study of radon concentrations in Hamadan city, Iran

    Directory of Open Access Journals (Sweden)

    G. K. Gillmore

    2010-04-01

    Full Text Available This paper presents results of a reconnaissance study that used CR-39 alpha track-etch detectors to measure radon concentrations in dwellings in Hamadan, western Iran, significantly, built on permeable alluvial fan deposits. The indoor radon levels recorded varied from 4 (i.e. below the lower limit of detection for the method to 364 Bq/m3 with a mean value of 108 Bq/m3 which is 2.5 times the average global population-weighted indoor radon concentration – these data augment the very few published studies on indoor radon levels in Iran. The maximum radon concentration in Hamadan occurs during the winter period (January to March with lower concentrations during the autumn. The effective dose equivalent to the population in Hamadan is estimated from this study to be in the region of 2.7 mSv/y, which is above the guidelines for dose to a member of the public of 1 mSv/y suggested by the International Commission on Radiological Protection (ICRP in 1993. This study supports other work in a number of countries that indicates such permeable "surficial" deposits as being of intermediate to high radon potential. In western Iran, the presence of hammered clay floors, the widespread presence of excavated qanats, the textural properties of surficial deposits and human behaviour intended to cope with winds are likely to be important factors influencing radon concentrations in older buildings.

  15. Description of the behavior of an aquifer by using continuous radon monitoring in a thermal spa.

    Science.gov (United States)

    Sainz, Carlos; Rábago, Daniel; Fuente, Ismael; Celaya, Santiago; Quindós, Luis Santiago

    2016-02-01

    Radon ((222)Rn) levels in air and water have been analyzed continuously for almost a year in Las Caldas de Besaya thermal spa, north Spain. Radon is a naturally occurring noble gas from the decay of radium ((226)Ra) both constituents of radioactive uranium 238 series. It has been recognized as a lung carcinogen by the World Health Organization (WHO) and International Agency for Research on Cancer (IARC). Furthermore the Royal Decree R.D 1439/2010 of November, 2010 establishes the obligation to study occupational activities where workers and, where appropriate, members of the public are exposed to inhalation of radon in workplaces such as spas. Together with radon measures several physico-chemical parameters were obtained such as pH, redox potential, electrical conductivity and air and water temperature. The devices used for the study of the temporal evolution of radon concentration have been the RTM 2100, the Radon Scout and gamma spectrometry was complementarily used to determine the transfer factor of the silicone tubes in the experimental device. Radon concentrations obtained in water and air of the spa are high, with an average of 660 Bq/l and 2900 Bq/m(3) respectively, where water is the main source of radon in the air. Radiation dose for workers and public was estimated from these levels of radon. The data showed that the thermal processes can control the behavior of radon which can be also influenced by various physical and chemical parameters such as pH and redox potential.

  16. Radon emanation from backfilled mill tailings in underground uranium mine.

    Science.gov (United States)

    Sahu, Patitapaban; Mishra, Devi Prasad; Panigrahi, Durga Charan; Jha, Vivekananda; Patnaik, R Lokeswara; Sethy, Narendra Kumar

    2014-04-01

    Coarser mill tailings used as backfill to stabilize the stoped out areas in underground uranium mines is a potential source of radon contamination. This paper presents the quantitative assessment of radon emanation from the backfilled tailings in Jaduguda mine, India using a cylindrical accumulator. Some of the important parameters such as (226)Ra activity concentration, bulk density, bulk porosity, moisture content and radon emanation factor of the tailings affecting radon emanation were determined in the laboratory. The study revealed that the radon emanation rate of the tailings varied in the range of 0.12-7.03 Bq m(-2) s(-1) with geometric mean of 1.01 Bq m(-2) s(-1) and geometric standard deviation of 3.39. An increase in radon emanation rate was noticed up to a moisture saturation of 0.09 in the tailings, after which the emanation rate gradually started declining with saturation due to low diffusion coefficient of radon in the saturated tailings. Radon emanation factor of the tailings varied in the range of 0.08-0.23 with the mean value of 0.21. The emanation factor of the tailings with moisture saturation level over 0.09 was found to be about three times higher than that of the absolutely dry tailings. The empirical relationship obtained between (222)Rn emanation rate and (226)Ra activity concentration of the tailings indicated a significant positive linear correlation (r = 0.95, p < 0.001). This relationship may be useful for quick prediction of radon emanation rate from the backfill material of similar nature. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Publications about Radon

    Science.gov (United States)

    There is no known safe level of exposure to radon. EPA strongly recommends that you fix your home if your test shows 4 picocuries (pCi/L) or more. These publications and resources will provide you with the information you need to fix your home.

  18. What Is Radon?

    Science.gov (United States)

    ... in both cigarette smoke and radon. In some animals, the risk of certain other cancers was also increased. In lab studies using human ... cancer grow is called a carcinogen .) The American Cancer Society looks to these ... laboratory, animal, and human research studies. Based on animal and ...

  19. The Chemistry of Radon

    Science.gov (United States)

    Avrorin, V. V.; Krasikova, R. N.; Nefedov, V. D.; Toropova, M. A.

    1982-01-01

    We shall review the discovery of this element, studies of its chemical nature, and modern ideas on its chemical and physical properties. Possible chemical and nuclear-chemical methods of synthesising new radon compounds and of determining their properties and their identity will be discussed, using information published up to May 1980. 121 references.

  20. Environmental radon studies in Mexico.

    Science.gov (United States)

    Segovia, N; Gaso, M I; Armienta, M A

    2007-04-01

    Radon has been determined in soil, groundwater, and air in Mexico, both indoors and outdoors, as part of geophysical studies and to estimate effective doses as a result of radon exposure. Detection of radon has mainly been performed with solid-state nuclear track detectors (SSNTD) and, occasionally, with active detection devices based on silicon detectors or ionization chambers. The liquid scintillation technique, also, has been used for determination of radon in groundwater. The adjusted geometric mean indoor radon concentration (74 Bq m-3) in urban developments, for example Mexico City, is higher than the worldwide median concentration of radon in dwellings. In some regions, particularly hilly regions of Mexico where air pollution is high, radon concentrations are higher than action levels and the effective dose for the general population has increased. Higher soil radon levels have been found in the uranium mining areas in the northern part of the country. Groundwater radon levels are, in general, low. Soil-air radon contributing to indoor atmospheres and air pollution is the main source of increased exposure of the population.

  1. Radon releases from Australian uranium mining and milling projects: assessing the UNSCEAR approach.

    Science.gov (United States)

    Mudd, Gavin M

    2008-02-01

    The release of radon gas and progeny from the mining and milling of uranium-bearing ores has long been recognised as a potential radiological health hazard. The standards for exposure to radon and progeny have decreased over time as the understanding of their health risk has improved. In recent years there has been debate on the long-term releases (10,000 years) of radon from uranium mining and milling sites, focusing on abandoned, operational and rehabilitated sites. The primary purpose has been estimates of the radiation exposure of both local and global populations. Although there has been an increasing number of radon release studies over recent years in the USA, Australia, Canada and elsewhere, a systematic evaluation of this work has yet to be published in the international literature. This paper presents a detailed compilation and analysis of Australian studies. In order to quantify radon sources, a review of data on uranium mining and milling wastes in Australia, as they influence radon releases, is presented. An extensive compilation of the available radon release data is then assembled for the various projects, including a comparison to predictions of radon behaviour where available. An analysis of cumulative radon releases is then developed and compared to the UNSCEAR approach. The implications for the various assessments of long-term releases of radon are discussed, including aspects such as the need for ongoing monitoring of rehabilitation at uranium mining and milling sites and life-cycle accounting.

  2. The NIST Primary Radon-222 Measurement System

    OpenAIRE

    Collé, R.; Hutchinson, J. M. R.; Unterweger, M. P.

    1990-01-01

    Within the United States, the national standard for radon measurements is embodied in a primary radon measurement system that has been maintained for over 50 years to accurately measure radon (222Rn) against international and national radium (226Ra) standards. In turn, all of the radon measurements made at the National Institute of Standards and Technology (NIST) and the radon transfer calibration standards and calibration services provided by NIST are directly related to this national radon ...

  3. Radon and lung cancer; Radon et cancer du poumon

    Energy Technology Data Exchange (ETDEWEB)

    Baysson, H; Billon, S.; Catelinois, O.; Gambard, J.P.; Laurier, D.; Rogel, A.; Tirmarche, M

    2004-12-01

    Radon is a natural radioactive gas that tends to accumulate in indoor environments; its concentration is highest in areas with granite sub-soils. Epidemiologic studies of uranium miners and animal data demonstrate the radon inhalation increases the risk of lung cancer. The objective of this paper is to present the available data on the French population's exposure to radon and the current epidemiologic knowledge of its effects, from cohort studies of uranium miners and indoor radon case-control studies.

  4. Mapping optimal areas of ecosystem services potential in Vilnius (Lithuania)

    Science.gov (United States)

    Pereira, Paulo; Depellegrin, Daniel; Misiune, Ieva; Cerda, Artemi

    2016-04-01

    Maps are fundamental to understand the spatial pattern of natural and human impacts on the landscape (Brevik et al., 2016; Lavado Contador et al., 2009; Pereira et al., 2010a,b). Urban areas are subjected to an intense human pressure (Beniston et al., 2015), contributing to the degradation of the ecosystems, reducing their capacity to provide services in quality and quantity (Requier-Desjardins et al., 2011; Zhang et al., 2011). Environments that can provide a high number and quality of ecosystem services (ES) must be identified and managed correctly, since are spaces that can mitigate the impacts of human settlements and improve their quality. thus is of major importance have identify the areas that can provide better ES (Deppelegrin and Pereira, 2015). The aim of this work is to identify areas with high ES potential in Vilnius city. Here, we identified a total of 4 different land uses, agricultural areas (32.48%), water bodies (1.46%), forest and semi-natural (31.91%) areas and artificial surfaces (34.16%). CORINE land cover 2006 was used as base information to classify ES potential. The assessment of each land cover potential was carried out using expert assessment. Each land use type was ranked from 0 (no potential) to 5 (High potential). In this work the sum of total regulating, providing and cultural ES were assessed. The areas with optimal ES were the ones with the sum of all ranks equal or higher than the 3rd Quartil of each distribution. After identifying these areas, data was mapped using ArcGIS software. The results showed that on average Vilnius city has a higher potential for regulating services (20.35±15.92), followed by cultural (14.43±8.81) and providing (14.26±8.87). There was a significant correlation among the different type of services. Regulating vs cultural (0.92, p<0.001), regulating vs providing (0.72, p<0.001) and providing vs cultural (0.65, p<0.001). The results of Morans I autocorrelation index showed that regulating (Z-score: 10

  5. Legal issues in radon affairs

    Energy Technology Data Exchange (ETDEWEB)

    Massuelle, M.H. [Inst. de Protection et de Surete Nucleaire, Fontenay aux Roses (France)

    1999-12-01

    In France, it was only recently that cases related to high radon concentrations in dwellings received substantial publicity. This irruption of radon as a public health issue came with the general progress of scientific knowledge and the availability of a research capacity in France able to develop expertise. We are interested here in the legal implications of issues that arise from the lag between the activity of expertsand the regulatory activity in the domain of radon. We use the term expertise very broadly, to cover the practical application of research findings, the relation of the researchers with the community, and finally the acts by which experts provide their knowledge to the community. We first examine the course by which science developed the radon issue and the way they organized to move from research to expertise; here we try to characterize the various needs for radon expertise. We then discuss the legal difficulties associated with radon expertise.

  6. Legal issues in radon affairs

    Energy Technology Data Exchange (ETDEWEB)

    Massuelle, M.H. [Inst. de Protection et de Surete Nucleaire, Fontenay aux Roses (France)

    1999-12-01

    In France, it was only recently that cases related to high radon concentrations in dwellings received substantial publicity. This irruption of radon as a public health issue came with the general progress of scientific knowledge and the availability of a research capacity in France able to develop expertise. We are interested here in the legal implications of issues that arise from the lag between the activity of expertsand the regulatory activity in the domain of radon. We use the term expertise very broadly, to cover the practical application of research findings, the relation of the researchers with the community, and finally the acts by which experts provide their knowledge to the community. We first examine the course by which science developed the radon issue and the way they organized to move from research to expertise; here we try to characterize the various needs for radon expertise. We then discuss the legal difficulties associated with radon expertise.

  7. ERRICCA radon model intercomparison exercise

    DEFF Research Database (Denmark)

    Andersen, C.E.; Albarracín, D.; Csige, I.

    1999-01-01

    Numerical models based on finite-difference or finite-element methods are used by various research groups in studies of radon-222 transport through soil and building materials. Applications range from design of radon remediation systems to morefundamental studies of radon transport. To ascertain ......, still remain. All in all, it seems that the exercise has served its purpose and stimulated improvements relating to the quality of numerical modelling of radon transport. To maintain a high quality of modelling, it is recommendedthat additional exercises are carried out....

  8. Comprehensive investigation of radon exposure in Austrian tourist mines and caves.

    Science.gov (United States)

    Gruber, V; Ringer, W; Gräser, J; Aspek, W; Gschnaller, J

    2014-11-01

    According to Austrian Law, dose assessments in workplaces with potentially enhanced radon exposures are mandatory since 2008, including tourist mines and caves. A pilot study was carried out to evaluate the situation to test the measurement methods and to specify the main parameters controlling the radon concentration in tourist mines and caves. Radon was measured in six mines and three caves for 1 y, along with determining thoron and equilibrium factors and taking into account climatic, geological and site-related effects. The radon concentrations have a seasonal dependence with maximum in summer and minimum in winter, related to natural ventilation. Radon concentrations in the karst caves were quite low, as it was in the salt mine, whereas radon concentrations in copper and silver mines were high. The dose assessment of the employees yielded doses above 6 mSv a(-1) only in the copper mine.

  9. (Mutagenicity of radon and radon daughters)

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The current objective of our research is to investigate the dose-response relationship of the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose-rate dependence will be studied, as well as the nature of the DNA lesions. The effect of DNA repair on the lethal and mutagenic effects of exposure and on the character of the DNA lesions will be investigated by comparing the response of L5178Y strains which differ in their ability to rejoin X radiation-induced DNA double-strand breaks. This report discusses progress incurred from 4/1/1988--10/1/1990. 5 refs., 9 figs., 6 tabs.

  10. The Numerical Method of Inversion for the Interior Radon Transform

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The interior Radon transform arises from a limited data problem in computerized tomography.The corresponding operator R is investigated as a mapping between weightedL2- spaces. Our result is the explicit construction of a singular value decomposition for R. This immediately leads to an inversion formula by series expansion and range characterizations.

  11. From integral manifolds and metrics to potential maps

    Directory of Open Access Journals (Sweden)

    Udriste, C

    2004-01-01

    Full Text Available Our paper contains two main results: (1 the integral manifolds of a distribution together with two Riemann metrics produce potential maps which are in fact least squares approximations of the starting integral manifolds; (2 the least squares energy admits extremals satisfying periodic boundary conditions. Section 1 contains historical and bibliographical notes. Section 2 analyses some elements of the geometry produced on the jet bundle of order one by a semi-Riemann Sasaki-like metric. Section 3 describes the maximal integral manifolds of a distribution as solutions of a PDEs system of order one. Section 4 studies Poisson-like second-order prolongations of first order PDE systems and formulates the Lorentz-Udriste World-Force Law on a suitable semi-Riemann-Lagrange manifold (the base manifold of the jet bundle of order one. Section 5 exploits the idea of least squares Lagrangians, to include the integral manifolds of a distribution into a class of extremals. Section 6 gives conditions for the existence of extremals in conditions of multi-periodicity. Section 7 refers to the canonical forms of the vertical metric d-tensor produced by a density of energy on jet bundle of order one.

  12. The Persistence of Potential Refugia Mapped from Gravel Tracers

    Science.gov (United States)

    Haschenburger, J. K.

    2009-12-01

    Floods disturb aquatic habitats. On an event basis, flood characteristics control the spatial extent and depth of streambed disturbance for a given river and set limits to the amount of channel refugia for biota. The aim of this research is to quantify the area of potential refugia that persists over a long flood series and therefore affects many generations of aquatic populations. Field observations were collected in Carnation Creek, a small gravel-bed river located on the west coast of Vancouver Island, Canada. Streambed disturbance was documented by monitoring the three-dimensional positions of about 2500 magnetically tagged gravels over 277 floods. Tracer movement and burial observations were used to produce cellular maps of the frequency of bed disturbance within a GIS. The streambed exhibits different frequencies of disturbance as expected. The most active areas make up about 1% of the streambed and tend to be located near the channel thalweg. Undisturbed areas constitute more than 25% of the bed, and provide distinct areas of longer-term refugia that persist over the range of flood magnitudes observed. In addition to validating a key aspect of partial sediment transport, the results suggest that the natural variability of floods facilitates diverse aquatic communities by ensuring the availability of channel refugia over time.

  13. Radon - environmental pollutant from underground. Radon - Umweltgift aus dem Erdreich

    Energy Technology Data Exchange (ETDEWEB)

    Obertreis, R.

    1988-01-01

    Radon is responsible for about 50% of the natural radiation load of 200 mrem/a in the Federal Republic of Germany. This implies that approximately 190.000 households with about 600.000 citizens of the Federal Republic face an increased risk of lung cancer. Hints are given as to the reduction of radon values in cellars and living rooms. (DG).

  14. A reconnaissance study of radon concentration in Hamadan city, Iran.

    Science.gov (United States)

    Gillmore, G. K.; Jabari Vasal, Naghi

    2009-04-01

    This paper presents results of a reconnaissance study that used CR-39 alpha track-etch detectors to measure radon concentrations in dwellings in Hamadan, western Iran, significantly, built on permeable alluvial fan deposits. The indoor radon levels recorded varied from 4 to 364 Bq/m3 with a mean value of 107.87 Bq/m3 which is 2.5 times the average global population-weighted indoor radon concentration - these data augment the very few published studies on indoor radon levels in Iran. The maximum radon concentration in Hamadan occurs during the winter period (January to March) with lower concentrations during the autumn. The effective dose equivalent to the population in Hamadan is estimated from this reconnaissance study to be in the region of 2.7 mSv/y, which is above the guidelines for dose to a member of the public of 1 mSv/y suggested by the International Commission on Radiological Protection (ICRP) in 1993, although further work is required to confirm these results. This study supports other work in a number of countries that indicates such permeable 'surficial' deposits as being of intermediate to high radon potential. In western Iran, the presence of hammered clay floors, the widespread presence of excavated qanats to distribute water underground, the textural properties of surficial deposits and human behaviour intended to cope with winds are likely to be important factors influencing radon concentrations in older buildings. Keywords: Radon; health; dwellings; clay floors; alluvial fan; surficial geology; Hamadan; Iran

  15. Residential radon and lung cancer incidence in a Danish cohort

    Energy Technology Data Exchange (ETDEWEB)

    Braeuner, Elvira V., E-mail: ole@cancer.dk [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Danish Building Research Institute, Aalborg University (Denmark); Andersen, Claus E. [Center for Nuclear Technologies, Radiation Research Division, Riso National Laboratory for Sustainable Energy, Technical University of Denmark, Roskilde (Denmark); Sorensen, Mette [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Jovanovic Andersen, Zorana [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Center for Epidemiology Screening, Department of Public Health, University of Copenhagen (Denmark); Gravesen, Peter [Geological Survey of Denmark and Greenland, Copenhagen (Denmark); Ulbak, Kaare [National Institute of Radiation Protection, Herlev (Denmark); Hertel, Ole [Department of Environmental Science, Aarhus University, Aarhus (Denmark); Pedersen, Camilla [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Overvad, Kim [Department of Epidemiology, School of Public Health, Aarhus University, Aarhus (Denmark); Tjonneland, Anne; Raaschou-Nielsen, Ole [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark)

    2012-10-15

    High-level occupational radon exposure is an established risk factor for lung cancer. We assessed the long-term association between residential radon and lung cancer risk using a prospective Danish cohort using 57,053 persons recruited during 1993-1997. We followed each cohort member for cancer occurrence until 27 June 2006, identifying 589 lung cancer cases. We traced residential addresses from 1 January 1971 until 27 June 2006 and calculated radon at each of these addresses using information from central databases regarding geology and house construction. Cox proportional hazards models were used to estimate incidence rate ratios (IRR) and 95% confidence intervals (CI) for lung cancer risk associated with residential radon exposure with and without adjustment for sex, smoking variables, education, socio-economic status, occupation, body mass index, air pollution and consumption of fruit and alcohol. Potential effect modification by sex, traffic-related air pollution and environmental tobacco smoke was assessed. Median estimated radon was 35.8 Bq/m{sup 3}. The adjusted IRR for lung cancer was 1.04 (95% CI: 0.69-1.56) in association with a 100 Bq/m{sup 3} higher radon concentration and 1.67 (95% CI: 0.69-4.04) among non-smokers. We found no evidence of effect modification. We find a positive association between radon and lung cancer risk consistent with previous studies but the role of chance cannot be excluded as these associations were not statistically significant. Our results provide valuable information at the low-level radon dose range.

  16. Residential radon and lung cancer incidence in a Danish cohort.

    Science.gov (United States)

    Bräuner, Elvira V; Andersen, Claus E; Sørensen, Mette; Andersen, Zorana Jovanovic; Gravesen, Peter; Ulbak, Kaare; Hertel, Ole; Pedersen, Camilla; Overvad, Kim; Tjønneland, Anne; Raaschou-Nielsen, Ole

    2012-10-01

    High-level occupational radon exposure is an established risk factor for lung cancer. We assessed the long-term association between residential radon and lung cancer risk using a prospective Danish cohort using 57,053 persons recruited during 1993-1997. We followed each cohort member for cancer occurrence until 27 June 2006, identifying 589 lung cancer cases. We traced residential addresses from 1 January 1971 until 27 June 2006 and calculated radon at each of these addresses using information from central databases regarding geology and house construction. Cox proportional hazards models were used to estimate incidence rate ratios (IRR) and 95% confidence intervals (CI) for lung cancer risk associated with residential radon exposure with and without adjustment for sex, smoking variables, education, socio-economic status, occupation, body mass index, air pollution and consumption of fruit and alcohol. Potential effect modification by sex, traffic-related air pollution and environmental tobacco smoke was assessed. Median estimated radon was 35.8 Bq/m(3). The adjusted IRR for lung cancer was 1.04 (95% CI: 0.69-1.56) in association with a 100 Bq/m(3) higher radon concentration and 1.67 (95% CI: 0.69-4.04) among non-smokers. We found no evidence of effect modification. We find a positive association between radon and lung cancer risk consistent with previous studies but the role of chance cannot be excluded as these associations were not statistically significant. Our results provide valuable information at the low-level radon dose range.

  17. Spanish experience on the design of radon surveys based on the use of geogenic information.

    Science.gov (United States)

    Sainz Fernández, C; Quindós Poncela, L S; Fernández Villar, A; Fuente Merino, I; Gutierrez-Villanueva, J L; Celaya González, S; Quindós López, L; Quindós López, J; Fernández, E; Remondo Tejerina, J; Martín Matarranz, J L; García Talavera, M

    2017-01-01

    One of the requirements of the recently approved EU-BSS (European Basic Safety Standards Directive, EURATOM, 2013) is the design and implementation of national radon action plans in the member states (Annex XVIII). Such plans require radon surveys. The analysis of indoor radon data is supported by the existing knowledge about geogenic radiation. With this aim, we used the terrestrial gamma dose rate data from the MARNA project. In addition, we considered other criterion regarding the surface of Spain, population, permeability of rocks, uranium and radium contain in soils because currently no data are available related to soil radon gas concentration and permeability in Spain. Given that, a Spanish radon map was produced which will be part of the European Indoor Radon Map and a component of the European Atlas of Natural Radiation. The map indicates geographical areas with high probability of finding high indoor radon concentrations. This information will support legislation regarding prevention of radon entry both in dwellings and workplaces. In addition, the map will serve as a tool for the development of strategies at all levels: individual dwellings, local, regional and national administration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. APPLICATION OF RADON REDUCTION METHODS

    Science.gov (United States)

    The document is intended to aid homeowners and contractors in diagnosing and solving indoor radon problems. It will also be useful to State and Federal regulatory officials and many other persons who provide advice on the selection, design and operation of radon reduction methods...

  19. Long-term radon variations at a hot spring in China

    Science.gov (United States)

    Yan, Rui; Woith, Heiko; Wang, Rongjiang; Wang, Guangcai

    2017-04-01

    Radon concentration is monitored continuously in mainland China by China Earthquake Administration (CEA) for the purpose of earthquake prediction. An almost gap-free radon record of nearly 40 years (from April 1976 to December 2015) of monitoring of water-dissolved radon at the hot spring site of BangLazhang (BLZ), Southwestern China is analysed. The length of the time series allows the investigation of long-term periodicities of radon. Ancillary observation data, i.e. water temperature, spring discharge rate, barometric pressure, combined with regional rainfall, galactic cosmic ray (as a proxy for solar activity) and regional seismicity are complemented for the same period to identify potentially influencing factors controlling the changes of radon. The long-term variations in radon concentration and ancillary observation data are studied by using the continuous Wavelet Power Spectrum (WPS), Wavelet Coherence (WTC), and Partial Wavelet Coherence (PWC) methods. The results of WPSs and WTCs show that the long-periodic radon concentration is characterized by a significant decadal cycle, matching well with the concurrent periodicity in water temperature, spring discharge rate, and galactic cosmic ray. The analysis of PWCs among radon, discharge rate, water temperature, and galactic cosmic ray reveals that the 11-year solar cycle might influence radon, water temperature, and spring discharge, though a direct physical link between the solar activity and the monitored parameters seems unlikely. Moreover, PWCs of radon, discharge rate and water temperature suggests that water temperature variations explain most of the coherent variability of radon and the discharge rate. Possible mechanisms are discussed. We tentatively propose that the multi-year periodic variations in radon concentration are mainly explained by variations of water temperature and/or spring discharge, which are modified and inter-modulated by earthquakes and decadal variations of unknown origin.

  20. Radon concentration variations between and within buildings of a research institute

    Energy Technology Data Exchange (ETDEWEB)

    Antignani, S., E-mail: sara.antignani@iss.i [Istituto Superiore di Sanita (Italian National Institute of Health), Viale Regina Elena, 299, I-00161 Roma (Italy); Bochicchio, F.; Ampollini, M.; Venoso, G.; Bruni, B.; Innamorati, S.; Malaguti, L.; Stefano, A. [Istituto Superiore di Sanita (Italian National Institute of Health), Viale Regina Elena, 299, I-00161 Roma (Italy)

    2009-10-15

    Radon concentration in indoor air has been measured in many countries in a large number of buildings - mainly in houses but also in apartments and workplaces - mostly as a result of the application of radon policies and regulation requirements. However, few systematic analyses are available on radon concentration variations within buildings and between close buildings, especially as regards workplaces; such variations can have a significant impact on indoor radon exposure evaluation, and ultimately on the assessment of the dose from radon received by workers. Therefore, a project was started in 2006 aimed to study the spatial variation of radon concentration among and within about 40 buildings of the Istituto Superiore di Sanita (ISS), a research institute of public health located in Rome over a small area of less than 1 km{sup 2}. Nuclear track detectors (CR-39) were used to measure radon concentration for two consecutive six-month periods, in more than 700 rooms of the surveyed buildings. The paper describes the project in detail and preliminary results regarding 558 rooms in 29 buildings. Coefficient of variation (CV) was calculated as a measure of relative variation of radon concentration between buildings, between floors, and between rooms on the same floor. The CV between buildings resulted quite high (88%), a lower CV (42%) was found for variation between floors, whereas room-to-room CV on the same floor ranged from 25% at first floor level to 48% at basement level. Floor mean ratios, with ground floor as the reference level, were calculated for each building in order to study the correlation between radon concentration and floor levels. Although no clear trend was observed, the average basement/ground floor ratio of radon concentrations resulted about 2.0, whereas the average sixth floor/ground floor ratio of radon concentrations was 0.5. Some discussion on the potential impact of the results of this study on policies and radon regulations are also included

  1. Monitoring and descriptive analysis of radon in relation to seismic activity of Northern Pakistan.

    Science.gov (United States)

    Jilani, Zeeshan; Mehmood, Tahir; Alam, Aftab; Awais, Muhammad; Iqbal, Talat

    2017-06-01

    Earthquakes are one of the major causes of natural disasters and its forecasting is challenging task. Some precursory phenomenon exists in theory in relation to earthquakes occurrence. The emission of radioactive gas named 'radon' before the earthquakes is a potential earthquake precursory candidate. The study aims to monitor and to analyze the radon in relation to seismic activity in Northern Pakistan. For this purpose RTM-2200 has been used to monitor the changes in radon concentration from August 01, 2014 to January 31, 2015 in Northern Pakistan. Significant temporal variations has been observed in radon concentration. The bivariate analysis of radon with other variables manifests its positive relationship with air pressure and relative humidity and negative relationship with temperature. 2σ upper control limit on monthly basis are computed for detection of anomalous trends in the data. Overall increasing trend is detected in radon concentration. Five earthquakes from August 01, 2014 to January 31, 2015 have been selected from earthquake catalogue, depending upon their magnitude and distance from monitoring station and out of which radon concentration can be associated with only two earthquakes correlated with tectonic effect of radon concentration. Both of events have same magnitude 5.5 and occurred on September 13 and October 14, 2014 respectively. Very large variations have been observed in radon for the last two months of the study period, which may be occurred due to some other geological and environmental changes, but are not related to the earthquake activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Fractal and Chaos Analysis for Dynamics of Radon Exhalation from Uranium Mill Tailings

    Science.gov (United States)

    Li, Yongmei; Tan, Wanyu; Tan, Kaixuan; Liu, Zehua; Xie, Yanshi

    2016-08-01

    Tailings from mining and milling of uranium ores potentially are large volumes of low-level radioactive materials. A typical environmental problem associated with uranium tailings is radon exhalation, which can significantly pose risks to environment and human health. In order to reduce these risks, it is essential to study the dynamical nature and underlying mechanism of radon exhalation from uranium mill tailings. This motivates the conduction of this study, which is based on the fractal and chaotic methods (e.g. calculating the Hurst exponent, Lyapunov exponent and correlation dimension) and laboratory experiments of the radon exhalation rates. The experimental results show that the radon exhalation rate from uranium mill tailings is highly oscillated. In addition, the nonlinear analyses of the time series of radon exhalation rate demonstrate the following points: (1) the value of Hurst exponent much larger than 0.5 indicates non-random behavior of the radon time series; (2) the positive Lyapunov exponent and non-integer correlation dimension of the time series imply that the radon exhalation from uranium tailings is a chaotic dynamical process; (3) the required minimum number of variables should be five to describe the time evolution of radon exhalation. Therefore, it can be concluded that the internal factors, including heterogeneous distribution of radium, and randomness of radium decay, as well as the fractal characteristics of the tailings, can result in the chaotic evolution of radon exhalation from the tailings.

  3. Modern state of radon chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Avrorin, V.V.; Krasikova, R.N.; Nefedov, V.D.; Toropova, M.A. (Leningradskij Gosudarstvennyj Univ. (USSR))

    1982-01-01

    A review of works on radon chemistry published up to May, 1980, is presented. Physical properties of the element, are described as well as peculiarities in the field of its chemical investigations connected with unfavourable nuclear-physical characteristics of radon isotopes, with specificity of its electron structure. Characteristics of the known radon compounds, including impurity compounds, their stability, are given. Possible chemical and nuclear-chemical approaches to the solution of problems of synthesis, determination of properties, and identification of its new compounds are discussed. The advantage of using electron capture processes for radon compound synthesis, possibility to use nuclear reactions induced by accelerated elementary particles, are pointed out. Possible applications of radon compounds are considered.

  4. Soil radon survey to assess NAPL contamination from an ancient spill. Do kerosene vapors affect radon partition ?

    Science.gov (United States)

    De Simone, Gabriele; Lucchetti, Carlo; Pompilj, Francesca; Galli, Gianfranco; Tuccimei, Paola; Curatolo, Pierpaolo; Giorgi, Riccardo

    2017-05-01

    A soil radon-deficit survey was carried out in a site polluted with kerosene (Rome, Italy) in winter 2016 to assess the contamination due to the NAPL residual component in the vadose zone and to investigate the role of the vapor plume. Radon is indeed more soluble in the residual NAPL than in air or water, but laboratory experiments demonstrated that it is also preferentially partitioned in the NAPL vapors that transport it and may influence soil radon distribution patterns. Specific experimental configurations were designed and applied to a 31-station grid to test this hypothesis; two RAD7 radon monitors were placed in-series and connected to the top of a hollow probe driven up to 80-cm depth; the first instrument was directly attached to the probe and received humid soil gas, which was counted and then conveyed to the second monitor through a desiccant (drierite) cylinder capturing moisture and eventually the NAPL volatile component plus the radon dissolved in vapors. The values from the two instruments were cross-calibrated through specifically designed laboratory experiments and compared. The results are in agreement within the error range, so the presence of significant NAPL vapors, eventually absorbed by drierite, was ruled out. This is in agreement with low concentrations of soil VOCs. Accordingly, the radon-deficit is ascribed to the residual NAPL in the soil pores, as shown very well also by the obtained maps. Preferential areas of radon-deficit were recognised, as in previous surveys. An average estimate of 21 L (17 Kg) of residual NAPL per cubic meter of terrain is provided on the basis of original calculations, developed from published equations. A comparison with direct determination of total hydrocarbon concentration (23 kg per cubic meter of terrain) is provided. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Measurement of radon in ground waters of the Western Caucasus for seismological application.

    Science.gov (United States)

    Nevinsky, I; Tsvetkova, T; Nevinskaya, E

    2015-11-01

    Results of radon ((222)Rn) concentration measurement in ground waters in the Western Caucasus are described. In 2010-2011 each day at 12:00 Moscow winter time (9:00 GMT) sampling in volume of 0.5 l of waters was carried out in two wells at depth of 30 m and 180 m. In 2012 three times per day (7:00, 12:00, 17:00) this sampling was already carried out. Radon from water was extracting by degassing method with use of bubbler. Measurements of alpha activity of gas in scintillation (ZnS) chambers were done. The water radon data with seismic, meteorological and the Sun-Lunar data were compared. The mathematical method of definition of "splashes" in radon data before regional earthquakes is considered. The greatest probability in 72% of the forecast of regional earthquakes for the data from a well of 30 m depth was received. Correlation between meteo and radon data is absent. Correlation of lunar phases and solar activity with radon data is discussed. In July-December, 2012 sampling of water from 15 wells and measurements of radon were carried out. The distance between wells was near 50 km. Changes of radon maps in territory of South Russia during earthquakes are shown.

  6. Macrobenthos habitat potential mapping using GIS-based artificial neural network models.

    Science.gov (United States)

    Lee, Saro; Park, Inhye; Koo, Bon Joo; Ryu, Joo-Hyung; Choi, Jong-Kuk; Woo, Han Jun

    2013-02-15

    This paper proposes and tests a method of producing macrobenthos habitat potential maps in Hwangdo tidal flat, Korea based on an artificial neural network. Samples of macrobenthos were collected during field work, and eight control factors were compiled as a spatial database from remotely sensed data and GIS analysis. The macrobenthos habitat potential maps were produced using an artificial neural network model. Macrobenthos habitat potential maps were made for Macrophthalmus dilatatus, Cerithideopsilla cingulata, and Armandia lanceolata. The maps were validated by compared with the surveyed habitat locations. A strong correlation between the potential maps and species locations was revealed. The validation result showed average accuracies of 74.9%, 78.32%, and 73.27% for M. dilatatus, C. cingulata, and A. lanceolata, respectively. A GIS-based artificial neural network model combined with remote sensing techniques is an effective tool for mapping the areas of macrobenthos habitat potential in tidal flats.

  7. CASE STUDY OF RADON DIAGNOSTICS AND MITIGATION IN A NEW YORK STATE SCHOOL

    Science.gov (United States)

    The paper discusses a case study of radon diagnostics and mitigation performed by EPA in a New York State school building. esearch focused on active subslab depressurization (ASD) in the basement and, to a lesser degree, the potential for radon reduction in the basement and slab-...

  8. CASE STUDY OF RADON DIAGNOSTICS AND MITIGATION IN A NEW YORK STATE SCHOOL

    Science.gov (United States)

    The paper discusses a case study of radon diagnostics and mitigation performed by EPA in a New York State school building. esearch focused on active subslab depressurization (ASD) in the basement and, to a lesser degree, the potential for radon reduction in the basement and slab-...

  9. Citizen's Guide to Radon: The Guide to Protecting Yourself and Your Family from Radon

    Science.gov (United States)

    ... Agency Search Search Radon Contact Us Share A Citizen's Guide to Radon: The Guide to Protecting Yourself ... EPA’s About PDF page to learn more. A Citizen's Guide to Radon - Revised December 2016 (PDF) (16 ...

  10. CONTRIBUTION OF RADON FLOWS AND RADON SOURCES TO THE RADON CONCENTRATION IN A DWELLING

    NARCIS (Netherlands)

    DEMEIJER, RJ; STOOP, P; PUT, LW

    1992-01-01

    In this paper a model is presented for analysis of the radon concentrations in a compartment in terms of contributions from transport by flows of air between compartments and from radon sources in the compartment. Measurements were made to study the effect of increased natural ventilation of the cra

  11. CONTRIBUTION OF RADON FLOWS AND RADON SOURCES TO THE RADON CONCENTRATION IN A DWELLING

    NARCIS (Netherlands)

    DEMEIJER, RJ; STOOP, P; PUT, LW

    1992-01-01

    In this paper a model is presented for analysis of the radon concentrations in a compartment in terms of contributions from transport by flows of air between compartments and from radon sources in the compartment. Measurements were made to study the effect of increased natural ventilation of the cra

  12. Potential Marine Benthic Habitat Map of Elkhorn Slough, California

    Science.gov (United States)

    Walton, K.; Garcia-Garcia, A.; Endris, C.

    2015-12-01

    While marine benthic habitat maps have been created for a big portion of California's coastline, the Elkhorn Slough Reserve lacks one. We have tentatively mapped its types of seafloor using a well-known classification system, which includes various types of large-scale and small-scale features, bottom induration, vegetation, surface texture, and slope. Seismic lines and sediment cores were collected to create the map. CSUMB's Seafloor Mapping Lab as well as the Elkhorn Slough National Estuarine Research Reserve provided bathymetry, raster files, and shapefiles to be incorporated into the project. We divided the Slough into three main sections: the Lower, Central, and Upper Slough. Sand sediments were found in the Lower Slough, which is a high-energy environment, whilst mud or silt sediments dominated the rest of the Slough. Five classification categories were used to describe the Slough's seafloor: flat sand sediments, sloped sand sediments, flat mud sediments, sloped mud sediments, and eelgrass on sandy sediment. Bathymetry data was used to discuss the Slough's sediment erosion and accretion. This preliminary map can be used to understand the location of various marine habitats, which is important for the wildlife conservation and planning efforts in the Slough. Acknowledgments: CSUMB (chirp), Ron Eby (ESNEER), Geoff (Triton Imaging Inc.). The Non-Senate Faculty Professional Development Award 19900-433332-ESGARC and ONR grant N00014-14-1-0172 supported this research.

  13. Using the generalized Radon transform for detection of curves in noisy images

    DEFF Research Database (Denmark)

    Toft, Peter Aundal

    1996-01-01

    In this paper the discrete generalized Radon transform will be investigated as a tool for detection of curves in noisy digital images. The discrete generalized Radon transform maps an image into a parameter domain, where curves following a specific parameterized curve form will correspond to a peak...... in the parameter domain. A major advantage of the generalized Radon transform is that the curves are allowed to intersect. This enables a thresholding algorithm in the parameter domain for simultaneous detection of curve parameters. A threshold level based on the noise level in the image is derived. A numerical...

  14. Radon risk management. Construction solutions

    Directory of Open Access Journals (Sweden)

    Borja Frutos Vázquez

    2011-12-01

    Full Text Available Radon gas is a radioactive element that appears in nature by the decay of radium found in terrestrial soils. This gas is able to travel between the pores of the ground and enter into the buildings where the concentration can increase and becoming a health risk to occupants from inhaling. The World Health Organization rate the radon gas as a level 1 carcinogen agent. According to this organization, radon is the second leading cause of lung cancer contraction after tobacco. Based on the perception of risk derived from epidemiological medical studies, some countries have established radon concentration values as safety limits, above which is recommended or required an architectural intervention to reduce levels. From an architectural perspective, there have been studies of several radon protection techniques to reduce radon immission in buildings or to evacuate it, in order to reduce the radon levels below the safety limits. This article develops some protection strategies that have been being used for these purposes, some of which have been tested in Spain thanks to a research project funded by the Nuclear Safety Council, and developed by the Eduardo Torroja Institute and the University of Cantabria.

  15. Mapping the potential of cross-border cooperation in West Africa

    DEFF Research Database (Denmark)

    Walther, Olivier; Vollmer, Sebastian

    2015-01-01

    Mapping the socio-economic potential of border regions can provide great insights as to where cross-border co-operation could be intensified in West Africa.......Mapping the socio-economic potential of border regions can provide great insights as to where cross-border co-operation could be intensified in West Africa....

  16. Levels and potential effect of radon gas in groundwater of some communities in the Kassena Nankana district of the Upper East region of Ghana

    Directory of Open Access Journals (Sweden)

    A.B. Asumadu-Sakyi

    2012-12-01

    Full Text Available Levels of radon gas in groundwater should be of interest due to its variation and exposure to the public since it is now patronized due to unusual interruption of surface water supplies. Dissolved Rn-222 in sampled groundwater has been analyzed using High Purity Germanium (HPGe Detector and Nuclear Track Detector (N.T.D techniques at the Kassena Nankana District in the Upper East region of Ghana. The radon concentrations obtained ranges from 7.86 *10^(-6 to 8.18 *10^(-5 Bq/l with a mean of 4.38 *10^(-5 Bq/l using the Gamma Spectrometry (G.S whiles that of N.T.D ranged from 5.40 to 46.74 Bq/l with a mean of 19.54 Bq/l. In terms of Bq/m^3, the concentrations ranged from 1.2 *10^(-2 to 8.1 *10^(-2 with a mean of 3.67*10^(-2 and 200.00 +-0.23 to 1731.00 +-1.73 with a mean of 723.7 Bq/m^3. The estimated annual effective dose by inhalation ranged from 6.05 to 40.66 mSvy^(-1 with a mean value of 21.91 mSvy^(-1 using N.T.D, whiles that of G.S ranged from 1.39 *10^(-4 to 2.45 *10^(-3 mSvy^(-1 with a mean value of 1.14 *10^(-3 mSvy^(-1. Also the estimated annual effective dose by ingestion ranged from 1.71*10^(-5- 1.32 *10^(-4 uSvy^(-1 with a mean value of 5.60 *10^(-5 uSvy^(-1 obtained using N.T.D technique. G.S ranged from 2.87 *10^(-11 to 2.99 *10^(-10 uSvy^(-1 with a mean value of 1.60 *10^(-10 uSvy^(-1 respectively. The concentrations delineate that inhabitant need to be advised on levels of 222Rn in water.

  17. Uranium mill tailings and radon

    Energy Technology Data Exchange (ETDEWEB)

    Hanchey, L A

    1981-01-01

    The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the US may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action Program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100.

  18. Occurrence and distribution of arsenic and radon in water from private wells in the Rancocas aquifer, southern New Castle and northern Kent Counties, Delaware, 2015

    Science.gov (United States)

    Denver, Judith M.

    2016-10-12

    Water samples were collected and analyzed for arsenic and radon from 36 private, mostly domestic wells that tap the Rancocas aquifer in southern New Castle and northern Kent Counties, Delaware, during the summer of 2015. Both arsenic and radon are from natural mineral sources, in particular glauconitic and other marine-derived sediments, which are important components of the geologic formations comprising the Rancocas aquifer. Routine testing of domestic wells is not required in Delaware; as a result, many homeowners are not aware of potential water-quality problems with these chemicals in their well water. Arsenic has previously been detected at levels of potential concern for human health in this aquifer in adjacent parts of Maryland where it is referred to as the Aquia aquifer. Arsenic and radon also have previously been detected in several Rancocas aquifer wells in Delaware. The Delaware Department of Natural Resources and Environmental Control intends to use the data from this project to better identify areas with potential for levels of concern for domestic well owners. This report includes chemical results and maps showing the distribution of sampled wells and concentrations of arsenic and radon. All data collected for this study also are available in the U.S. Geological Survey’s National Water Information System database.Arsenic was detected above the minimum reporting limit of 0.1 micrograms per liter (µg/L) in 34 of the 36 wells sampled with concentrations ranging from about 0.11 to 27 µg/L. In 15 of the samples, arsenic concentrations were at or above the U.S. Environmental Protection Agency (EPA) Maximum Contaminant Level (MCL) of 10 µg/L for public wells. Most of the higher concentrations are clustered along a band running from the southwest to northeast in the southern part of the study area.Radon, which is an inert gas derived from radium, was detected in all water samples with concentrations ranging from 85 to 1,870 picocuries per liter (p

  19. Guidance on Radon Resistant Construction and Radon Mitigation

    Science.gov (United States)

    This Unnumbered Letter regarding radon gas mitigation applies to all housing and community facilities, low-rise buildings and dwellings for the mentioned programs. Its intention is to guide staff to best serve our borrowers and protect their health.

  20. Estimating large-scale fractured rock properties from radon data collected in a ventilated tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Unger, Andre; Finsterle, Stefan; Bodvarsson, Gudmundur S.

    2003-05-12

    To address regulatory issues regarding worker safety, radon gas concentrations have been monitored as part of the operation of a deep tunnel excavated from a highly fractured tuff formation. The objective of this study was to examine the potential use of the radon data to estimate large-scale formation properties of fractured rock. An iTOUGH2 model was developed to predict radon concentrations for prescribed ventilation rates. The numerical model was used (1) to estimate the permeability and porosity of the fractured formation at the length scale of the tunnel and extending tens of meters into the surrounding rock, and (2) to understand the mechanism leading to radon concentrations that potentially exceed the regulatory limit. The mechanism controlling radon concentrations in the tunnel is a function of atmospheric barometric fluctuations propagated down the tunnel. In addition, a slight suction is induced by the ventilation system. The pressure fluctuations are dampened in the fractured formation according to its permeability and porosity. Consequently, as the barometric pressure in the tunnel drops, formation gases from the rock are pulled into the opening, resulting in high radon concentrations. Model calibration to both radon concentration data measured in the tunnel and gas phase pressure fluctuations observed in the formation yielded independent estimates of effective, large-scale fracture permeability and porosity. The calibrated model was then used as a design tool to predict the effect of adjusting the ventilation-system operation strategy for reducing the probability that radon gas concentrations will exceed the regulatory limit.

  1. Lorenz Curve and Gini coefficient: novel tools for analysing seasonal variation of environmental radon gas.

    Science.gov (United States)

    Groves-Kirkby, C J; Denman, A R; Phillips, P S

    2009-06-01

    Using a methodology derived from Economics, the Lorenz Curve and Gini Coefficient are introduced as tools for investigating and quantifying seasonal variability in environmental radon gas concentration. While the Lorenz Curve presents a graphical view of the cumulative exposure during the course of the time-frame of interest, typically one year, the Gini Coefficient distils this data still further, to provide a single-parameter measure of temporal clustering. Using the assumption that domestic indoor radon concentrations show annual cyclic behaviour, generally higher in the winter months than in summer, published data on seasonal variability of domestic radon concentration levels, in various areas of the UK, Europe, Asia and North America, are analysed. The results demonstrate significantly different annual variation profiles between domestic radon concentrations in different countries and between regions within a country, highlighting the need for caution in ascribing seasonal correction factors to extended geographical areas. The underlying geography, geology and meteorology of a region have defining influences on the seasonal variability of domestic radon concentration, and some examples of potential associations between the Gini Coefficient and regional geological and geographical characteristics are proposed. Similar differences in annual variation profiles are found for soil-gas radon measured as a function of depth at a common site, and among the activity levels of certain radon progeny species, specifically (214)Bi deposited preferentially in human body-fat by decay of inhaled radon gas. Conclusions on the association between these observed measures of variation and potential underlying defining parameters are presented.

  2. Mapping Evapotranspiration on Vineyards: The SENTINEL-2 Potentiality

    Science.gov (United States)

    Ciraolo, Giuseppe; Capodici, Fulvio; D'Urso, Guido; La Loggia, Goffredo; Maltese, Antonino

    2012-04-01

    Estimation of actual evapotranspiration in Sicilian vineyards, is an emerging issue since these agricultural systems. Indeed unlike other agricultural species (Vitis vinifera L.) are generally cultivated under mild water stress, in order to enhance quality (Guadillère et al., 2002. This has significant impacts on the management of the scarce water resources of the region. The choice of the most appropriate methodology for assessing water use in these systems is still an issue of debating, due to the complexity of canopy and root systems and for their high spatial fragmentation. In vineyards, quality and quantity of the final product are dependent on the controlled stress conditions to be set trough irrigation. This paper reports an application of the well-known Penman-Monteith approach, applied in a distributed way, using high resolution remote sensing data to map the potential evapotranspiration (ETp). In 2008 a series of airborne multispectral images were acquired on the "Tenute Rapitalà", a wine farm located in the northwest of Sicily. Five airborne remote sensing scenes were collected using a SKY ARROW 351 650 TC/TCNS aircraft, at a height of about 1000 m a.g.l.. The acquisitions encompassed almost a whole phenological period, between June and September 2008 (approximately one each three weeks). The platform had on board a multi-spectral camera with 3 spectral bands in the green (G, 530-570 nm), red (R, 650-690 nm) and near infrared (NIR, 767-832 nm) wavelengths, and a thermal camera with a broad band in the range 7.5-13 μm. The nominal pixel resolution was approximately 0.7 m for VIS/NIR acquisitions, and 1.7 m for the thermal-IR data. Field data were acquired simultaneously to airborne acquisitions. The former include spectral reflectance in visible, near infrared, middle infrared (VIS, NIR, MIR) regions of the spectrum, leaf area index (LAI), soil moisture at different depths (both in row and below plants). Moreover, meteorological variables and fluxes

  3. Effect of indoor-generated airborne particles on radon progeny dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Trassierra, C. Vargas [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR (Italy); Stabile, L., E-mail: l.stabile@unicas.it [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR (Italy); Cardellini, F.; Morawska, L. [National Institute of Ionizing Radiation Metrology (INMRI-ENEA), Rome (Italy); Buonanno, G. [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR (Italy); International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane (Australia)

    2016-08-15

    Highlights: • Investigation of the interaction between particles and radon progeny dynamics. • Measurements of particles emitted by different indoor sources. • Tests performed in a controlled radon chamber. • Particle size strongly influences the radon progeny dynamics. • Particle surface area concentration is the key parameter of the radon-particle interaction. - Abstract: In order to investigate the interaction between radon progeny and particles, an experimental campaign was carried out in a radon chamber at the Italian National Institute of Ionizing Radiation Metrology, quantifying the amount of attached and unattached radon daughters present in air, as well as the equilibrium factor in the presence of particles generated through indoor sources. A fixed radon concentration was maintained, while particles were generated using incense sticks, mosquito coils and gas combustion. Aerosols were characterized in terms of particle concentrations and size distributions. Simultaneously, radon concentration and attached/unattached potential alpha energy concentration in the air were continuously monitored by two different devices, based on alpha spectroscopy techniques. The presence of particles was found to affect the attached fraction of radon decay products, in such a way that the particles acted as a sink for radionuclides. In terms of sources which emit large particles (e.g. incense, mosquito coils), which greatly increase particle surface area concentrations, the Equilibrium Factor was found to double with respect to the background level before particle generation sessions. On the contrary, the radon decay product dynamics were not influenced by gas combustion processes, mainly due to the small surface area of the particles emitted.

  4. Soil radon dynamics in the Amer fault zone: An example of very high seasonal variations.

    Science.gov (United States)

    Moreno, V; Bach, J; Font, Ll; Baixeras, C; Zarroca, M; Linares, R; Roqué, C

    2016-01-01

    Soil radon levels of the Amer fault zone have been measured for a 4 year-period with the aim of checking seasonal fluctuations obtained in previous studies and to understand radon origin and dynamics. In this manuscript additional results are presented: updated continuous and integrated soil radon measurements, radionuclide content of soil materials and a detailed analysis of an urban profile by means of the electrical resistivity imaging technique and punctual soil radon, thoron and CO2 measurements. Integrated and continuous measurements present a wide range of values, [0.2-151.6] kBq m(-3) for radon, [4.5-39.6] kBq m(-3) for thoron and [4.0-71.2] g m(-2) day(-1) for CO2. The highest soil radon levels in the vicinity of the Amer fault (>40 kBq m(-3)) are found close to the fractured areas and present very important fluctuations repeated every year, with values in summer much higher than in winter, confirming previous studies. The highest radon values, up to 150 kBq m(-3), do not have a local origin because the mean value of radium concentration in this soil (19 ± 5 Bq kg(-1)) could not explain these values. Then soil radon migration through the fractures, influenced by atmospheric parameters, is assumed to account for such a high seasonal fluctuation. As main conclusion, in fractured areas, seasonal variations of soil radon concentration can be very important even in places where average soil radon concentration and radium content are not especially high. In these cases the migration capability of the soil is given not by intrinsic permeability but by the fracture structure. Potential risk estimation based on soil radon concentration and intrinsic permeability must be complemented with geological information in fractured systems.

  5. Maps of North American crustal stability and geothermal potential

    Energy Technology Data Exchange (ETDEWEB)

    Fairbridge, R.W.

    1977-01-01

    A three-year program of analysis of crustal movements in North America was planned with the objective of preparing a series of 1 = 5 million scale maps depicting relative stability/instability. The part of the proposal completed during the first year is described; much of this first year's work was preparatory. Three time scales were considered for the data analysis: 1 - 10/sup 2/ yr., 10/sup 4/ yr., and 10/sup 8/ yr. Significant differences in sign and rate were suspected between short and long-term motions and these are now confirmed. The first part of the program is now complete. It consisted of two principal activities: (a) data collection for the short and mid-term scales on a U.S.-wide basis, excluding Alaska and Hawaii (all of this material has been reduced to compatible computer language and is stored on tape ready for further study, analysis and final cartography); (b) map and data analysis of the long-term scale with a completed draft map, applied specifically to the Mid-West and eastern U.S.

  6. Radon Like atmospheric pollutant; El gas Radon como contaminante atmosferico

    Energy Technology Data Exchange (ETDEWEB)

    Quindos Poncela, L. S.; Sainz Fernandez, C.; Quindos Lopez, L.; Fuente Merino, I.; Arteche, J. L.

    2008-07-01

    In this work different aspects about the problem of the radon in dwellings are approached. This gas of natural origin is virtually present in all the soils in the earths crust due to the presence of uranium and radium in the composition of them. Depending on architectural factors and of occupancy habits of the house, high concentrations of this gas can be reached indoors. In these situations, there is a quantifiable increment of the risk of developing lung cancer in the inhabitants of the housing. In the last years the methodological improvements in the realization of epidemiologic studies have led to the obtaining of scientific evidence about the relationship between the presence of indoor radon and the risk of lung cancer. This relationship fund years ago in workers of uranium mines, has been corroborated in the case of the residential radon by the light of several recent meta-analysis performed on groups of epidemiologic studies. More than 4000 radon measurements have been carried out in spain during the las 25 years. A summary of the results obtained from the main national radon surveys are also presented, as well as the criteria recently established by the Spanish Nuclear Safety Council concerning radon action levels in dwellings and workplaces. (Author) 18 refs.

  7. VENTILATION INFLUENCE UPON INDOOR AIR RADON LEVEL

    Institute of Scientific and Technical Information of China (English)

    田德源

    1995-01-01

    Levels of indoor radon in air are studied by a continuous electrostatic radon monitor under normal living conditions to evaluate the influence of air conditioned ventilation on indoor air radon level.Results show that the indoor air radon concentrations are not much more than those without household conditioner living condition.although using household conditioner requires a sealed room which should lead to a higher radon level.Turning on air conditioner helps lower indoor radon level.Therefore.the total indoor air Rn levels are normal>ventilation>exhaust or indraft> exhaust plus indraft.

  8. Evolution of radon dose evaluation

    Directory of Open Access Journals (Sweden)

    Fujimoto Kenzo

    2004-01-01

    Full Text Available The historical change of radon dose evaluation is reviewed based on the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR reports. Since 1955, radon has been recognized as one of the important sources of exposure of the general public. However, it was not really understood that radon is the largest dose contributor until 1977 when a new concept of effective dose equivalent was introduced by International Commission on Radiological Protection. In 1982, the dose concept was also adapted by UNSCEAR and evaluated per caput dose from natural radiation. Many researches have been carried out since then. However, lots of questions have remained open in radon problems, such as the radiation weighting factor of 20 for alpha rays and the large discrepancy of risk estimation among dosimetric and epidemiological approaches.

  9. A Physician's Guide to Radon

    Science.gov (United States)

    This booklet has been developed for physicians by the U.S. Environmental Protection Agency in consultation with the American Medical Association (AMA). Its purpose is to enlist physicians in the national effort to inform the American public about radon.

  10. Development of Radon-222 as Natural Tracer for Monitoring the Remediation of NAPL in the Subsurface

    Energy Technology Data Exchange (ETDEWEB)

    Brian M. Davis; Lewis Semprini; Jonathan Istok

    2003-02-27

    Naturally occurring 222-radon in ground water can potentially be used as an in situ partitioning tracer to characterize dense nonaqueous phase liquid (DNAPL) saturations. The static method involves comparing radon concentrations in water samples from DNAPL-contaminated and non-contaminated portions of an aquifer. During a push-pull test, a known volume of test solution (radon-free water containing a conservation tracer) is first injected (''pushed'') into a well; flow is then reversed and the test solution/groundwater mixture is extracted (''pulled'') from the same well. In the presence of NAPL radon transport is retarded relative to the conservative tracer. Assuming linear equilibrium partitioning, retardation factors for radon can be used to estimate NAPL saturations.The utility of this methodology was evaluated in laboratory and field settings.

  11. A survey of radon properties in underground shopping centers in Hong Kong

    Energy Technology Data Exchange (ETDEWEB)

    Yu, K.N.; Young, E.C.M.; Stokes, M.J.; Lo, C.H. [City Univ. of Hong Kong, Kowloon (Hong Kong). Dept. of Physics and Materials Science

    1997-06-01

    A number of radon-related properties have been surveyed in underground shopping centers in Hong Kong. These parameters include the radon concentration, the total potential alpha energy concentration of radon progeny, the equilibrium factor and the unattached fraction of radon progeny. The mean values recorded for these were 29.2 {+-} 7.8 Bq/m{sup 3}, 3.60 {+-} 1.53 mWL, 0.46 {+-} 0.16 and 0.05 {+-} 0.03, respectively. Based on these figures, we have calculated the average radon dose received by employees in an underground shopping center in Hong Kong to be 0.22 mSv/yr, which represents an approximate increase of 8% over the total dose of about 2.7 mSv/yr received by the average person in Hong Kong. (author).

  12. [Brain potential mapping by a new method of polynomial interpolation].

    Science.gov (United States)

    Pérez-Cobo, J C; Asencor, F J; Sánchez-Suero, S; Pérez-Arroyo, M

    1993-06-01

    The mapping of evoked cerebral activity is largely determined by the choice of the interpolation system used. When the number of electrodes is very large, practically any interpolation system is valid, but the geometrical and anatomical limitations imposed by the animals normally chosen for these experiments impede the use of a large number of electrodes; hence the overriding importance of a workable interpolation system. The polynomic interpolation method on the monomial structure is presented as valid, and compared with the pseudolineal interpolation method, which is more commonly used.

  13. Indoor radon and thoron concentrations in some towns of central and South Serbia.

    Science.gov (United States)

    Vuckovic, Biljana; Gulan, Ljiljana; Milenkovic, Biljana; Stajic, Jelena M; Milic, Gordana

    2016-12-01

    This study presents the results of indoor radon and thoron activity concentrations of some municipalities in central and south part of Serbia: Krusevac, Brus, Blace and Kursumlija. Measurements were carried out in 60 dwellings during the winter season. Passive discriminative radon-thoron detectors known as UFO detectors were used. The mean values of indoor radon and thoron concentrations were 82 Bq m(-3) and 42 Bq m(-3), respectively. Population-weighted mean values were 76 Bq m(-3) and 40 Bq m(-3), respectively. 26.7% of dwellings had radon concentration higher than 100 Bq m(-3) (one location had even more than 300 Bq m(-3)). There are no statistically significant correlations of indoor radon and thoron concentrations neither with the period of house construction, nor with the existence of a basement. The results of this study represent the first step of investigating radon and thoron levels in these parts of Serbia and therefore could be the basis for creating a radon map. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Radon in Estonian dwellings - Results from a National Radon Survey

    Energy Technology Data Exchange (ETDEWEB)

    Pahapill, Lia; Rulkov, Anne; Rajamaee, Raivo [Estonian Radiation Protection Centre (Kiirguskeskus), Tallinn (Spain); Aakerblom, Gustav [Swedish Radiation Protection Authority, Stockholm (Sweden)

    2003-10-01

    A countrywide survey of radon concentrations in Estonian dwellings was carried out during the period 1998-2001. The survey formed a part of the cooperation program on radiation protection between the Estonian Radiation Protection (Kiirguskeskus) Centre and the Swedish Radiation Protection Authority (SSI). The survey included measurements in a number of dwellings representative for Estonia in detached houses and multifamily buildings (only dwellings on the bottom floor were included in the survey). Altogether, radon concentrations were measured in 515 dwellings, a number large enough to be statistically significant. All measurements were made with alphatrack film detectors of the same type that SSI uses in Sweden. The measurements were made during a 2-3 month period during the winter half-year. Two detectors were used in each dwelling. In Estonia there are 0.17 million dwellings in detached houses and 0.45 million in multi apartment buildings. Of the 1.26 million inhabitants in Estonia. 0.36 million live in detached houses and 0.90 million in multi apartment buildings. Most of the latter were built during the Soviet occupation. Of the dwellings in multifamily buildings 30 % are assumed to be situated on the first floor. The mean radon concentration in dwellings in detached hoses, according to the survey results, is 103 Bq/m{sup 3}, in dwellings on the bottom floor in multi apartment buildings it is 78 Bq/m{sup 3}. In 1% of the dwellings the radon concentration exceeded 400 Bq/m{sup 3}. The highest radon concentration found in the study was 1040 Bq/m{sup 3}. Based on the assumption that the average radon concentration in the dwellings in multi-apartment buildings that are not situated on the bottom floor is 30 Bq/m{sup 3}, and that these dwellings constitute 70% of all dwellings in multi apartment buildings, the mean radon concentration in dwellings in multi apartment buildings is calculated to be 44 Bq/m{sup 3}. The mean value for all Estonia dwellings is calculated

  15. Rapidly calculated density functional theory (DFT) relaxed Iso-potential Phi Si Maps: Beta-cellobiose

    Science.gov (United States)

    New cellobiose Phi-H/Si-H maps are rapidly generated using a mixed basis set DFT method, found to achieve a high level of confidence while reducing computer resources dramatically. Relaxed iso-potential maps are made for different conformational states of cellobiose, showing how glycosidic bond dihe...

  16. Application of Dempster-Shafer theory in mineral resource potential mapping

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The Dempster-Shafer theory has been successfully applied to mineral resource potential mapping in GIS environmental. In this applied form, basic probability assignment and combined basic probability assignment are applied to measuring map pattern and map pattern combination, respectively; and the environment composed of the only two singleton sets (deposit set and non-deposit set), is used for expressing the entire map area. For a subarea in which the certain map pattern combination exists, the combined basic probability assignment corresponding to the map pattern combination existing in this subarea, expresses the belief of inferring the subarea belonging to the deposit set from the evidence that the corresponding map pattern combination existing in the subarea. Thus, it may be served as a statistical index measuring the relative mineral resource potentials of the subarea. And it may be determined like 1) dividing the map area into a series of small equal-sized grid cells and then select the training sample set composed of the well-known grid cells or the entire grid cells; 2) estimating the basic probability assignments corresponding to each map pattern fromthe training sample set; 3) determining the map pattern combination existing in each cell, and then appling the Dempster's Rule of Combination to integrating the all basic probability assignments corresponding to the map patterns existing in the cell into the combined basic probability assignment. Mineral resource potential mapping with the Dempster-Shafer theory is demonstrated on a case study to select mineral resource targets. The experimental results manifest that the model can be compared with the weights of evidence model in the effectiveness of mineral resource target selection.

  17. Mapping organic contaminant plumes in groundwater using spontaneous potentials

    Science.gov (United States)

    Forte, Sarah

    Increased water demands have raised awareness of its importance. One of the challenges facing water resource management is dealing with contaminated groundwater; delineating, characterizing and remediating it. In the last decade, spontaneous potentials have been proposed as a method for delineating degrading organic contaminant plumes in groundwater. A hypothesis proposed that the redox potential gradient due to degradation of contaminants generated an electrical potential gradient that could be measured at the ground surface. This research was undertaken to better understand this phenomenon and find under what conditions it occurs. Spontaneous potentials are electrical potentials generated by three sources that act simultaneously: electrokinetic, thermoelectric and electrochemical sources. Over contaminant plumes electrochemical sources are those of interest. Thermoelectric sources are negligible unless in geothermal areas, but we hypothesized that electrokinetic potentials could be impacted by contaminants altering sediment surface properties. We built and calibrated a laboratory apparatus to make measurements that allowed us to calculate streaming current coupling coefficients. We tested sediment from hydrocarbon impacted sites with clean and hydrocarbon polluted groundwater and found a measurable though inconsistent effect. Moreover, numerical modelling was used to demonstrate that the impact of these changes on field measurements was negligible. Spontaneous potential surveys were conducted on two field sites with well characterized degrading hydrocarbon plumes in groundwater. We did not find a correlation between redox conditions and spontaneous potential, even after the electrical measurements were corrected for anthropogenic noise. In order to determine why the expected signal was not seen, we undertook numerical modelling based on coupled fluxes using two hypothesized types of current: redox and diffusion currents. The only scenarios that produced

  18. Thermo-diffusional radon waves in soils.

    Science.gov (United States)

    Minkin, Leonid; Shapovalov, Alexander S

    2016-09-15

    A new theoretical framework for diurnal and seasonal oscillations of the concentration of radon in soil and open air is proposed. The theory is based on the existing temperature waves in soils and thermo-diffusional gas flux in porous media. As soil is a non-isothermal porous medium, usually possessing a large fraction of microscopic pores belonging to Knudsen's free molecular field, a thermo-diffusional gas flow in soil has to arise. The radon mass transfer equation in soil for sinusoidal temperature oscillations at the soil-atmosphere boundary is solved, which reveals that radon concentration behaves as a damped harmonic wave. The amplitude of radon concentration oscillations and phase shift between radon concentration oscillations and soil temperature depend on the radon diffusion coefficient in soil, rate of radon production, soil thermal conductivity, average soil temperature, decay constant, and heat of radon transfer. Primarily numerical calculations are presented and comparisons with experimental data are shown.

  19. Workshop on dosimetry for radon and radon daughters

    Energy Technology Data Exchange (ETDEWEB)

    Turner, J.E.; Holoway, C.F.; Loebl, A.S. (eds.)

    1978-05-01

    Emphasis is placed on the dosimetry for radon and daughters, rather than on monitoring and instrumentation. The objectives of the meeting were to exchange scientific information, to identify problem areas in radon-daughter dosimetry, and to make any observations or recommendations by the participants through issuance of this report. The discussion topics included the history of dosimetry for radon and daughters, human data, aerosols, deposition and movement in the respiratory tract, dose calculations, dose-to-working-level-month (WLM) conversion factors, animal experiments, and the development of regulations and remedial criteria for reducing population exposures to radon daughters. This report contains a summary of Workshop discussions plus individual statements contributed by several of the participants. The outstanding problem areas from the standpoint of dosimetry appear to involve the appropriate lung organ mass to be used (average lung-tissue dose vs. high-level local dose); recognition of the discrete, rather than continuous, structure of the mucus; lack of knowledge about lung clearance; the variability of dose with the degree of disequilibrium and the unattached fraction of radon daughters for a given WLM; and questions about the character of uranium mine atmospheres actually breathed in the older mines from which much of the epidemiological information originates. The development of criteria for taking remedial action to reduce exposures involves additional concerns of basing long-term risk assessment on short-term sampling and applying WLM data for miners to general populations.

  20. Use of the radon gas as a natural geophysical tracer; Utilizacion del gas radon como un trazador geofisico natural

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P.; Balcazar, M.; Flores R, J.H.; Lopez M, A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2006-07-01

    In this work it is denoted the applications of the radon gas like a natural geophysical radiotracer in the different branches of the Earth Sciences (Geology, geophysics and geochemistry). It importance resides in its employment like one additional tool to register the possible occurrence of seismic events by means of radon anomalies that are presented in land movements (volcanic eruptions and presence of geothermal areas), as well as its potential in environmental works whose purpose is the evaluation of the feather of contamination in the underground water and the porous media for spills of hydrocarbons. The measurement techniques to determine the concentration of radon was carried out by means of Solid Detectors of Nuclear tracks, as well as by Liquid scintillation, Clipperton, Honeywell, AlphaGUARD. The towns where these techniques its were applied were: Mexico City, Estado de Mexico (Toluca, ININ), Jalisco (The Spring), Guerrero coast. (Author)

  1. Mapping of potential neurogenic niche in the human temporal lobe

    Directory of Open Access Journals (Sweden)

    Adriano Barreto Nogueira

    2014-10-01

    Full Text Available The subgranular zone (SGZ of the dentate gyrus and the subventricular zone (SVZ are known neurogenic niches in adult mammals. Nonetheless, the existence of neurogenic niches in adult humans is controversial. We hypothesized that mapping neurogenic niches in the human temporal lobe could clarify this issue. Neurogenic niches and neurogenesis were investigated in 28 temporal lobes via immunostaining for nestin and doublecortin (DCX, respectively. Nestin was observed in a continuous layer formed by the SVZ, the subpial zone of the medial temporal lobe and the SGZ, terminating in the subiculum. In the subiculum, remarkable DCX expression was observed through the principal efferent pathway of the hippocampus to the fimbria. A possible explanation for the results is that the SVZ, the subpial zone of the medial temporal lobe and the SGZ form a unit containing neural stem cells that differentiate into neurons in the subiculum. Curiously, the area previously identified as the human rostral migratory stream may in truth be the fornix, which contains axons that originate in the subiculum. This study suggests that neurogenesis may occur in an orchestrated manner in a broad area of the human temporal lobe.

  2. Origin of radon concentration of Csalóka Spring in the Sopron Mountains (West Hungary).

    Science.gov (United States)

    Freiler, Ágnes; Horváth, Ákos; Török, Kálmán; Földes, Tamás

    2016-01-01

    We examined the Csalóka Spring, which has the highest radon concentration in the Sopron Mountains (West Hungary) (, yearly average of 227 ± 10 Bq L(-1)). The main rock types here are gneiss and micaschist, formed from metamorphism of former granitic and clastic sedimentary rocks respectively. The aim of the study was to find a likely source of the high radon concentration in water. During two periods (2007-2008 and 2012-2013) water samples were taken from the Csalóka Spring to measure its radon concentration (from 153 ± 9 Bq L(-1) to 291 ± 15 Bq L(-1)). Soil and rock samples were taken within a 10-m radius of the spring from debrish and from a deformed gneiss outcrop 500 m away from the spring. The radium activity concentration of the samples (between 24.3 ± 2.9 Bq kg(-1) and 145 ± 6.0 Bq kg(-1)) was measured by gamma-spectroscopy, and the specific radon exhalation was determined using radon-chamber measurements (between 1.32 ± 0.5 Bq kg(-1) and 37.1 ± 2.2 Bq kg(-1)). Based on these results a model calculation was used to determine the maximum potential radon concentration, which the soil or the rock may provide into the water. We showed that the maximum potential radon concentration of these mylonitic gneissic rocks (cpot = 2020 Bq L(-1)) is about eight times higher than the measured radon concentration in the water. However the maximum potential radon concentration for soils are significantly lower (41.3 Bq L(-1)) Based on measurements of radon exhalation and porosity of rock and soil samples we concluded that the source material can be the gneiss rock around the spring rather than the soil there. We determined the average radon concentration and the time dependence of the radon concentration over these years in the spring water. We obtained a strong negative correlation (-0.94 in period of 2007-2008 and -0.91 in 2012-2013) between precipitation and radon concentration.

  3. Modelling of radon transport in porous media

    NARCIS (Netherlands)

    van der Graaf, E.R.; de Meijer, R.J.; Katase, A; Shimo, M

    1998-01-01

    This paper aims to describe the state of the art of modelling radon transport in soil on basis of multiphase radon transport equations. Emphasis is given to methods to obtain a consistent set of input parameters needed For such models. Model-measurement comparisons with the KVI radon transport Facil

  4. Modelling of radon transport in porous media

    NARCIS (Netherlands)

    van der Graaf, E.R.; de Meijer, R.J.; Katase, A; Shimo, M

    1998-01-01

    This paper aims to describe the state of the art of modelling radon transport in soil on basis of multiphase radon transport equations. Emphasis is given to methods to obtain a consistent set of input parameters needed For such models. Model-measurement comparisons with the KVI radon transport Facil

  5. Reducing Radon in Schools: A Team Approach.

    Science.gov (United States)

    Ligman, Bryan K.; Fisher, Eugene J.

    This document presents the process of radon diagnostics and mitigation in schools to help educators determine the best way to reduce elevated radon levels found in a school. The guidebook is designed to guide school leaders through the process of measuring radon levels, selecting the best mitigation strategy, and directing the efforts of a…

  6. Indoor radon levels in selected hot spring hotels in Guangdong, China.

    Science.gov (United States)

    Song, Gang; Zhang, Boyou; Wang, Xinming; Gong, Jingping; Chan, Daniel; Bernett, John; Lee, S C

    2005-03-01

    Guangdong is one of the provinces that have most hot springs in China, and many hotels have been set up near hot springs, with spring water introduced into the bath inside each hotel room for hot spring bathing to attract tourists. In the present study, we measured radon in indoor and outdoor air, as well as in hot spring waters, in four hot spring hotels in Guangdong by using NR-667A (III) continuous radon detector. Radon concentrations ranged 53.4-292.5 Bq L(-1) in the hot spring water and 17.2-190.9 Bq m(-3) in outdoor air. Soil gas intrusion, indoor hot spring water use and inefficient ventilation all contributed to the elevated indoor radon levels in the hotel rooms. From the variation of radon levels in closed unoccupied hotel rooms, soil gas intrusion was found to be a very important source of indoor radon in hotel rooms with floors in contact with soils. When there was spring water bathing in the bathes, average radon levels were 10.9-813% higher in the hotel rooms and 13.8-489% higher in bathes compared to their corresponding average levels when there was no spring water use. Spring water use in the hotel rooms had radon transfer coefficients from 1.6x10(-4) to 5.0x10(-3). Radon in some hotel rooms maintained in concentrations much higher than guideline levels might thus have potential health risks to the hotel workers, and technical and management measures should be taken to lower their exposure of radon through inhalation.

  7. Indoor radon measurements in dwellings and other buildings in the metropolitan region of Belo Horizonte, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Talita de Oliveira [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil)]. E-mail: talitaolsantos@yahoo.com.br; Rocha, Zildete [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Quimica e Radioquimica]. E-mail: rochaz@cdtn.br

    2007-07-01

    Radon is a radioactive noble gas derived from the natural decay series of {sup 238}U, {sup 235}U, and {sup 232}Th, which are present in rocks and soils. By diffusion and convection, radon migrates from the rocks and soils to the surface and through fissures, pipes and holes it may enter the dwellings and other buildings. Another important indoor radon source is the building material construction. Therefore, it may accumulate indoor environments with reduced ventilation rates. Radon progeny attach to the aerosol particle in the air. The attached and unattached radon progeny may deposit in the lungs and irradiate to the lung tissue as they decay. Radon has been recognized as a radiation hazard, that causes excess of lung cancer among underground miners and there is an evidence that radon is also a heath hazard in dwellings and other indoor environments. Radon accounts for about half of all human exposure to natural radiation. Radon concentration measurements were carried out in dwellings, schools and shopping centers in the Metropolitan Region of Belo Horizonte - RMBH. Most part of the inhabitants of the RMBH lives over the granitic gneissic complex, which has a variable depth out coming in some areas. For the radon concentration measurement continuous detectors, AlphaGUARD PQ2000PRO, RAD7 and Pylon Lucas Cells were used and, for Potential Alpha Energy Concentration-PAEC measurement a solid state alpha spectroscope, the DOSEman PRO was used. The experiments showed that most results are below 50 Bqm{sup -3} (mean+3{sigma}). This value is bellowing the action levels of the USEPA, ICRP and others, which varies in the range from 148 to 200 Bqm{sup -3}. The values are in the low range, as it was expected for a tropical climate. (author)

  8. Mechanisms of radon loss from zircon: Microstructural controls on emanation and diffusion

    Science.gov (United States)

    Eakin, Marty; Brownlee, S. J.; Baskaran, M.; Barbero, L.

    2016-07-01

    Understanding how radon escapes from minerals is important for many fields in Earth science, yet few studies have focused on the mechanisms for radon escape. We measured radon emanation rate and radon loss upon heating for crushed aliquots of three large zircon crystals from three localities: Mud Tank (Australia), Bancroft (Canada), and Malawi (Africa). Our study, in conjunction with published data, shows that the room temperature radon emanation coefficient (REC) varies over 5 orders of magnitude in zircon. For low U zircon, Mud Tank, there are variations in REC that appear to be related to annealing at different temperatures, possibly due to annealing of fission tracks, however, all REC values for Mud Tank zircon are within error of one another. Bancroft and Malawi zircons have higher U content and do not show any systematic relationship of REC to annealing temperature. Results from Mud Tank zircon suggest that partial annealing of fission tracks decreases REC, but when all fission tracks are annealed REC reaches a maximum. REC in zircons with high U content, Bancroft and Malawi, is slightly higher than in zircon with lower U, although results are within error. Results of measurements of radon loss upon heating suggest that radon diffusion is slow, ∼30% of the radon is lost during heating at 975 °C for 48 h. Samples heated a second time yield less fractional radon loss, ∼10%, suggesting that diffusion parameters are changed during heating at temperatures ⩾975 °C, which is likely the result of annealing of radiation damage. Diffusion parameters calculated from the fractional loss experiments reflect diffusion in highly radiation damaged or metamict zircons. Our results indicate that internal microstructures in zircon, such as fission tracks and alpha-radiation damage, influence radon escape for diffusion and recoil mechanisms, and hence if these effects can be further characterized, measurements of 222Rn escape have the potential to be useful for probing

  9. Correlative and multivariate analysis of increased radon concentration in underground laboratory.

    Science.gov (United States)

    Maletić, Dimitrije M; Udovičić, Vladimir I; Banjanac, Radomir M; Joković, Dejan R; Dragić, Aleksandar L; Veselinović, Nikola B; Filipović, Jelena

    2014-11-01

    The results of analysis using correlative and multivariate methods, as developed for data analysis in high-energy physics and implemented in the Toolkit for Multivariate Analysis software package, of the relations of the variation of increased radon concentration with climate variables in shallow underground laboratory is presented. Multivariate regression analysis identified a number of multivariate methods which can give a good evaluation of increased radon concentrations based on climate variables. The use of the multivariate regression methods will enable the investigation of the relations of specific climate variable with increased radon concentrations by analysis of regression methods resulting in 'mapped' underlying functional behaviour of radon concentrations depending on a wide spectrum of climate variables. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Mapping Thermal Energy Resource Potentials from Wastewater Treatment Plants

    Directory of Open Access Journals (Sweden)

    Georg Neugebauer

    2015-09-01

    Full Text Available Wastewater heat recovery via heat exchangers and heat pumps constitutes an environmentally friendly, approved and economically competitive, but often underestimated technology. By introducing the spatial dimension in feasibility studies, the results of calculations change considerably. This paper presents a methodology to estimate thermal energy resource potentials of wastewater treatment plants taking spatial contexts into account. In close proximity to settlement areas, wastewater energy can ideally be applied for heating in mixed-function areas, which very likely have a continuous heat demand and allow for an increased amount of full-load hours compared to most single-use areas. For the Austrian case, it is demonstrated that the proposed methodology leads to feasible results and that the suggested technology might reduce up to 17% of the Austrian global warming potential of room heating. The method is transferrable to other countries as the input data and calculation formula are made available. A broad application of wastewater energy with regard to spatial structures and spatial development potentials can lead to (1 increasing energy efficiency by using a maximum of waste heat and (2 a significant reduction of (fossil energy consumption which results in a considerable reduction of the global warming potential of the heat supply (GWP if electricity from renewables is used for the operation of heat pumps.

  11. A methodology for assessing the maximum expected radon flux from soils in northern Latium (central Italy).

    Science.gov (United States)

    Voltaggio, Mario; Masi, Umberto; Spadoni, Massimo; Zampetti, Giorgio

    2006-12-01

    Northern Latium (Italy) is an area where the Rn risk rate is potentially high because of the extensive outcropping of Neogene U-rich volcanics and the presence of major active tectonic lineaments. The lack of data on Rn risk rates in that area, which is undergoing major urban and industrial development, has prompted this study. It proposes a methodology to evaluate the maximum potential diffusive Rn flux from soils based on the measurement of (226)Ra, (232)Th and (40)K activities by gamma-ray spectrometry, and the measurement of main soil parameters influencing the Rn emanation. This methodology provides a simple, reliable and low-cost tool for drawing up radon flux maps useful to both public planners and private individuals, who want to operate safely in the study area. The proposed methodology may also be applied to other geographic areas outside the prescribed study area.

  12. Comparison of radon doses based on different radon monitoring approaches.

    Science.gov (United States)

    Vaupotič, Janja; Smrekar, Nataša; Žunić, Zora S

    2017-04-01

    In 43 places (23 schools, 3 kindergartens, 16 offices and one dwelling), indoor radon has been monitored as an intercomparison experiment, using α-scintillation cells (SC - Jožef Stefan Institute, Slovenia), various kinds of solid state nuclear track detectors (KfK - Karlsruhe Institute of Technology, Germany; UFO - National Institute of Radiological Sciences, Chiba, Japan; RET - University College Dublin, Ireland) and active electronic devices (EQF, Sarad, Germany). At the same place, the radon levels and, consequently, the effective doses obtained with different radon devices differed substantially (by a factor of 2 or more), and no regularity was observed as regards which detector would show a higher or lower dose. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Mutagenicity of radon and radon daughters. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Evans, H.H.

    1991-12-01

    The objective of our research is to investigate the dose-response relationship of the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose rate dependence and the nature of the DNA lesion will be studied, using the thymidine kinase and HPRT loci to measure mutation frequency. A deficiency in DNA repair is shown to lead to a greater proportion of mutants with intergenic lesions. The cytotoxic effects of radon and its daughters are similar in human TK6 lymphoblasts and mouse L5178Y lymphoblasts, the cell line used in previous experiments. The results of molecular analysis of four spontaneous and 25 X-radiation induced HPRT{sup {minus}} mutants. Eleven radon-induced HPRT{sup {minus}} mutants have been isolated, and will be analyzed in a similar fashion. 9 figs.

  14. Instruments to measure radon-222 activity concentration or exposure to radon-222. Intercomparison 2014; Messgeraete zur Bestimmung der Radon-222-Aktivitaetskonzentration oder der Radon-222-Exposition. Vergleichspruefung 2014

    Energy Technology Data Exchange (ETDEWEB)

    Foerster, Elisabeth; Beck, Thomas; Buchroeder, Helmut; Doering, Joachim; Schmidt, Volkmar

    2014-10-15

    According to the Directive 96/29/EURATOM the monitoring of occupational radiation exposures shall base on individual measurements carried out by an approved dosimetric service. Pursuant to the European Directive an approved dosimetric service is a body responsible for the calibration, reading or interpretation of individual monitoring devices.., whose capacity to act in this respect is recognized by the competent authorities. This concept will also be applied to radon services issuing passive radon measurement devices. Passive radon measurement devices{sup 1} using solid state nuclear track detectors or electrets are recommended for individual monitoring of exposures to radon. German regulations lay down that radon measuring devices are appropriate for purposes of occupational radiation monitoring if the devices are issued by recognized radon measurement services, and the measurement service submits devices of the same type issued for radon monitoring to regular intercomparisons conducted by the Bundesamt fuer Strahlenschutz (BfS). A radon measuring service is recognized by the competent authority if it proves its organisational and technical competence, e. g. by accreditation. These regulations have been introduced in the area of occupational radiation exposures. Nevertheless, it is recommended that radon measuring services which carry out radon measurements in other areas (e.g. dwellings) should subject themselves to these measures voluntarily. The interlaboratory comparisons comprise the organization, exposure, and evaluation of measurements of radon activity concentration or exposure to radon. The comparisons only concern radon-222; radon-220 is not in the scope. Radon services being interested can get further information from the European Information System on Proficiency Testing Schemes (EPTIS) and from the BfS websites.

  15. Radon diffusion coefficients in soils of varying moisture content

    Science.gov (United States)

    Papachristodoulou, C.; Ioannides, K.; Pavlides, S.

    2009-04-01

    Radon is a naturally occurring radioactive gas that is generated in the Earth's crust and is free to migrate through soil and be released to the atmosphere. Due to its unique properties, soil gas radon has been established as a powerful tracer used for a variety of purposes, such as exploring uranium ores, locating geothermal resources and hydrocarbon deposits, mapping geological faults, predicting seismic activity or volcanic eruptions and testing atmospheric transport models. Much attention has also been given to the radiological health hazard posed by increased radon concentrations in the living and working environment. In order to exploit radon profiles for geophysical purposes and also to predict its entry indoors, it is necessary to study its transport through soils. Among other factors, the importance of soil moisture in such studies has been largely highlighted and it is widely accepted that any measurement of radon transport parameters should be accompanied by a measurement of the soil moisture content. In principle, validation of transport models in the field is encountered by a large number of uncontrollable and varying parameters; laboratory methods are therefore preferred, allowing for experiments to be conducted under well-specified and uniform conditions. In this work, a laboratory technique has been applied for studying the effect of soil moisture content on radon diffusion. A vertical diffusion chamber was employed, in which radon was produced from a 226Ra source, was allowed to diffuse through a soil column and was finally monitored using a silicon surface barrier detector. By solving the steady-state radon diffusion equation, diffusion coefficients (D) were determined for soil samples of varying moisture content (m), from null (m=0) to saturation (m=1). For dry soil, a D value of 4.1×10-7 m2s-1 was determined, which increased moderately by a factor of ~3 for soil with low moisture content, i.e. up to m ~0.2. At higher water fractions, a decrease

  16. Durability of radon remedial actions

    Energy Technology Data Exchange (ETDEWEB)

    Naismith, S. [National Radiological Protection Board, Chilton (United Kingdom)

    1997-10-01

    In the UK, approximately 3600 householders are believed to have taken action to reduce high radon concentrations in their homes. In 1993 a number of those householders who had taken successful remedial actions were invited to participate in a study of durability of radon remedial actions. This involved the radon concentration being remeasured annually. Results for 26 such homes where a complete set of data are available and a further 32 with incomplete data are discussed here. All remedial actions were shown to remain durable during a period of 5 years. The largest variation in effectiveness was found in houses with natural ventilation of the underfloor void. The failure rate for all remedial measures was found to be 4.0% per annum, but in most cases the problems were noticed by the householder and corrected. The frequency of failures which were not noticed until a remeasurement was carried out was 0.4% per annum. (Author).

  17. Thermo-diffusional radon waves in soils

    Energy Technology Data Exchange (ETDEWEB)

    Minkin, Leonid, E-mail: lminkin@pcc.edu [Portland Community College, 12000 SW 49th Ave, Portland, OR 97219 (United States); Shapovalov, Alexander S. [Saratov State University, 83 Astrakhanskay Street, Saratov 410012 (Russian Federation)

    2016-09-15

    A new theoretical framework for diurnal and seasonal oscillations of the concentration of radon in soil and open air is proposed. The theory is based on the existing temperature waves in soils and thermo-diffusional gas flux in porous media. As soil is a non-isothermal porous medium, usually possessing a large fraction of microscopic pores belonging to Knudsen's free molecular field, a thermo-diffusional gas flow in soil has to arise. The radon mass transfer equation in soil for sinusoidal temperature oscillations at the soil–atmosphere boundary is solved, which reveals that radon concentration behaves as a damped harmonic wave. The amplitude of radon concentration oscillations and phase shift between radon concentration oscillations and soil temperature depend on the radon diffusion coefficient in soil, rate of radon production, soil thermal conductivity, average soil temperature, decay constant, and heat of radon transfer. Primarily numerical calculations are presented and comparisons with experimental data are shown. - Highlights: • Temperature oscillations in atmosphere generate radon waves in soil. • Radon flux in atmosphere is a harmonic function of time. • Radon concentration waves in soil have the same frequency as the temperature waves.

  18. Laser Diagnostic Method for Plasma Sheath Potential Mapping

    Science.gov (United States)

    Walsh, Sean P.

    Electric propulsion systems are gaining popularity in the aerospace field as a viable option for long term positioning and thrusting applications. In particular, Hall thrusters have shown promise as the primary propulsion engine for space probes during interplanetary journeys. However, the interaction between propellant xenon ions and the ceramic channel wall continues to remain a complex issue. The most significant source of power loss in Hall thrusters is due to electron and ion currents through the sheath to the channel wall. A sheath is a region of high electric field that separates a plasma from a wall or surface in contact. Plasma electrons with enough energy to penetrate the sheath may result emission of a secondary electron from the wall. With significant secondary electron emission (SEE), the sheath voltage is reduced and so too is the electron retarding electric field. Therefore, a lower sheath voltage further increases the particle loss to the wall of a Hall thruster and leads to plasma cooling and lower efficiency. To further understand sheath dynamics, laser-induced fluorescence is employed to provide a non-invasive, in situ, and spatially resolved technique for measuring xenon ion velocity. By scanning the laser wavelength over an electronic transition of singly ionized xenon and collecting the resulting fluorescence, one can determine the ion velocity from the Doppler shifted absorption. Knowing the velocity at multiple points in the sheath, it can be converted to a relative electric potential profile which can reveal a lot about the plasma-wall interaction and the severity of SEE. The challenge of adequately measuring sheath potential profiles is optimizing the experiment to maximize the signal-to-noise ratio. A strong signal with low noise, enables high resolution measurements and increases the depth of measurement in the sheath, where the signal strength is lowest. Many improvements were made to reduce the background luminosity, increase the

  19. Identification of high radon areas with passive methods and geological assessments in some Italian regions

    Science.gov (United States)

    Rossetti, Marta; Bartolomei, Paolo; Esposito, Massimo; Marrocchino, Elena; Vaccaro, Carmela

    2010-05-01

    Internationally the indoor radon exposition as health hazard is widely recognized; so in many countries specific laws and regulations and so-called radon - risk maps have been introduced. Few Italian Regions have started surveys for the identification of 'radon prone areas', with independent standards and protocols and this involves a bigger uncertainty on the definition of a national risk map failing guidelines. In the present work a standardized methodology for indoor radon measurements has been set up by U-Series Srl (Bologna), with attention to the development of a passive measurement technique (solid state nuclear track detectors) on large scale. The developed technique has been validated through an inter-laboratory comparison conducted by the German Federal Office for Radiation Protection (BfS) in 2008 and repeated in 2009. An indoor radon monitoring survey has been conducted in all Italian Regions with the developed methodology and 5425 measurements have been elaborated to obtain the annual average radon concentration in regional scale and the relapse of seasonal fluctuations on radon concentrations were verified. For the survey, the detectors were installed in underground rooms in workplaces and the measurements were performed over one solar year. As a consequence of our developed methodology (measurements only in underground rooms), indoor radon concentrations resulted generally higher than the concentrations obtained in the National Survey; we estimated an annual mean radon concentration of 110 Bqm3 compared to 70 Bq/m3 obtained by the National Survey. Only for the Italian Regions with the largest number of sampling (Lombardia, with the case studies of Milano Province and Milano city, Emilia Romagna, Toscana, Puglia) the data obtained were georeferentiated and we elaborated these data using geostatistical technique in order to produce distribution maps of the annual average indoor radon concentration. We have integrated the elaborated maps with the

  20. Hybrid geomorphological maps as the basis for assessing geoconservation potential in Lech, Vorarlberg (Austria)

    Science.gov (United States)

    Seijmonsbergen, Harry; de Jong, Mat; Anders, Niels; de Graaff, Leo; Cammeraat, Erik

    2013-04-01

    Geoconservation potential is, in our approach, closely linked to the spatial distribution of geomorphological sites and thus, geomorphological inventories. Detailed geomorphological maps are translated, using a standardized workflow, into polygonal maps showing the potential geoconservation value of landforms. A new development is to semi-automatically extract in a GIS geomorphological information from high resolution topographical data, such as LiDAR, and combine this with conventional data types (e.g. airphotos, geological maps) into geomorphological maps. Such hybrid digital geomorphological maps are also easily translated into digital information layers which show the geoconservation potential in an area. We present a protocol for digital geomorphological mapping illustrated with an example for the municipality of Lech in Vorarlberg (Austria). The protocol consists of 5 steps: 1. data preparation, 2. generating training and validation samples, 3. parameterization, 4. feature extraction, and 5. assessing classification accuracy. The resulting semi-automated digital geomorphological map is then further validated, in two ways. Firstly, the map is manually checked with the help of a series of digital datasets (e.g. airphotos) in a digital 3D environment, such as ArcScene. The second validation is field visit, which preferably occurs in parallel to the digital evaluation, so that updates are quickly achieved. The final digital and coded geomorphological information layer is converted into a potential geoconservation map by weighting and ranking the landforms based on four criteria: scientific relevance, frequency of occurrence, disturbance, and environmental vulnerability. The criteria with predefined scores for the various landform types are stored in a separate GIS attribute table, which is joined to the attribute table of the hybrid geomorphological information layer in an automated procedure. The results of the assessment can be displayed as the potential

  1. 30 CFR 57.5046 - Protection against radon gas.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Protection against radon gas. 57.5046 Section... Protection against radon gas. Where radon daughter concentrations exceed 10 WL, respirator protection against radon gas shall be provided in addition to protection against radon daughters. Protection against...

  2. XENON1T radon assay

    Energy Technology Data Exchange (ETDEWEB)

    Bruenner, Stefan [MPIK, Heidelberg (Germany); Collaboration: XENON-Collaboration

    2016-07-01

    The radioactive isotope {sup 222}Rn is one of the most dominant intrinsic background sources for experiments dealing with a low event rate like the XENON1T Dark Matter detector. Being part of the primordial decay chain of {sup 238}U the noble gas {sup 222}Rn permanently emanates from almost all materials. Therefore, it is crucial to determine the radon emanation rate of those detector components that will be in contact with the xenon target. The technique of the radon emanation measurements, making use of ultra low background proportional counters is presented as well as selected results for XENON1T.

  3. Mapping of electrical potentials from the chest surface - preprocessing and visualization

    Directory of Open Access Journals (Sweden)

    Vaclav Chudacek

    2005-01-01

    Full Text Available The aim of the paper is to present current research activity in the area of computer supported ECG processing. Analysis of heart electric field based on standard 12lead system is at present the most frequently used method of heart diseasediagnostics. However body surface potential mapping (BSPM that measures electric potentials from several tens to hundreds of electrodes placed on thorax surface has in certain cases higher diagnostic value given by data collection in areas that are inaccessible for standard 12lead ECG. For preprocessing, wavelet transform is used; it allows detect significant values on the ECG signal. Several types of maps, namely immediate potential, integral, isochronous, and differential.

  4. Mineral resource potential map of the Muddy Mountains Wilderness Study Area, Clark County, Nevada

    Science.gov (United States)

    Bohannon, Robert G.; Leszcykowski, Andrew M.; Esparza, Leon E.; Rumsey, Clayton M.

    1982-01-01

    The Muddy Mountains Wilderness Study Area (WSA 050-0229), Clark County, Nevada, has a high potential for mineral deposits of calcium borates and lithium. The known and potential mineral deposits are concentrated in the east-central and south-central parts of the study area (see map). Zeolites (in particular clinoptilolite) are present in some tuff beds throughout much of the study area, and this resource potential is probably moderate to high. Stream-sediment sampling suggests that the Muddy Mountains area has little potential for mineral deposits of metals (other than lithium). Clay minerals are mined at one locality in the (!rea (see map). Building stone and silica sand have moderate to low potential in some places. Oil and gas potential within the study area is low, but complete evaluation of its potential is not possible without drilling.

  5. Molecular potentials and wave function mapping by high-resolution electron spectroscopy and ab initio calculations

    Energy Technology Data Exchange (ETDEWEB)

    Kimberg, Victor, E-mail: victor.kimberg@pks.mpi.de [Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden (Germany); Miron, Catalin, E-mail: miron@synchrotron-soleil.fr [Synchrotron SOLEIL, l’Orme des Merisiers, Saint-Aubin, BP 48, FR-91192 Gif-sur-Yvette Cedex (France)

    2014-08-15

    Highlights: • Some studies related to the vibrational wave functions mapping phenomenon are reviewed. • The core-excited vibrational wave functions were mapped using dissociative and bound final states. • High-resolution experimental data is accompanied by ab initio calculations. • The mapping phenomenon allows one to extract constants of the molecular potentials. • The mapping techniques are general and can be applied for the study of many systems. - Abstract: The recent development of high brightness 3{sup rd} generation soft X-ray sources and high energy resolution electron spectrometers made it possible to accurately trace quantum phenomena associated to the vibrational dynamics in core-excited molecules. The present paper reviews the recent results on mapping of vibrational wave functions and molecular potentials based on electron spectroscopy. We discuss and compare the mapping phenomena in various systems, stressing the advantages of the resonant X-ray scattering for studying of the nuclear dynamics and spectroscopic constants of small molecules. The experimental results discussed in the paper are most often accompanied by state-of-the-art ab initio calculations allowing for a deeper understanding of the quantum effects. Besides its fundamental interest, the vibrational wave function mapping is shown to be useful for the analysis of core- and valence-excited molecular states based on the reflection principle.

  6. The correlation between indoor and in soil radon concentrations in a desert climate

    Science.gov (United States)

    Al-Khateeb, H. M.; Aljarrah, K. M.; Alzoubi, F. Y.; Alqadi, M. K.; Ahmad, A. A.

    2017-01-01

    This study examines the levels and the correlation between indoor and in soil radon concentration in a desert climate. The measurements are carried out, in Jordan desert in AlMafraq district, using the passive integrated technique. An intelligent automated tracks counting system, modified recently by our group, is used to estimate the overlapping tracks and to decrease the counting percentage error. Results show that radon concentration in soil expands from 4.09 to 11.30 kBq m-3, with an average of 7.53 kBq m-3. Indoor radon concentrations vary from 20.2 Bq m-3 in the AlMafraq city to 46.7 Bq m-3 in Housha village and with an average of 29.6 Bq m-3. All of individual indoor radon concentrations are lower than the limit (100 Bq m-3) recommended by WHO except two dwellings in Housha village which found being higher than this limit. A moderate linear correlation (R2=0.66) was observed between indoor and in soil radon concentrations in the investigated region. Our results showed that an in soil radon measurement can be a satisfactory predictor for indoor radon potential.

  7. Characterization of blowholes as radon and thoron sources in the volcanic region of La Garrotxa, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, V., E-mail: victoria.moreno@uab.ca [Grup de Fisica de les Radiacions, Departament de Fisica, Edifici Cc, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Bach, J. [Unitat de Geodinamica Externa i d' Hidrogeologia, Departament de Geologia, Edifici Cs, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Baixeras, C.; Font, Ll. [Grup de Fisica de les Radiacions, Departament de Fisica, Edifici Cc, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)

    2009-10-15

    In the volcanic region of La Garrotxa there are natural holes in the soil from which a flow of air can reach the outdoor/indoor environment. In a previous study, these holes (called blowholes) have been found to have a big influence on indoor radon levels in a couple of houses. This finding triggered the interest to characterize these blowholes as radon/thoron sources. In this work, a total of 26 holes have been identified and characterized by geological field observations and by measuring their dimensions, air speed, temperature, humidity, and radon and thoron concentrations. Radon has been measured with passive (Makrofol) and active detectors (monitors PRASSI and RAD 7, being the latter used also to measure thoron). One of the indoor blowholes has been studied in detail and important temporal variations have been found, showing that radon levels are clearly correlated with the soil-outdoor temperature difference. There is not a significant radiological risk for the inhabitants and workers of the studied homes and workplaces with indoor blowholes. However, taking into account that in warm seasons buildings with blowholes in pyroclastic materials from volcanoes or in volcanic scoria under a compact lava flow may have high indoor radon levels (up to 1.5 kBq m{sup -3}) we conclude that volcanic regions with similar geological features and with presence of blowholes should be considered as areas with a potential radon/thoron radiological risk.

  8. Improved mixing height monitoring through a combination of lidar and radon measurements

    Directory of Open Access Journals (Sweden)

    A. D. Griffiths

    2013-02-01

    Full Text Available Surface-based radon (222Rn measurements can be combined with lidar backscatter to obtain a higher quality time series of mixing height within the planetary boundary layer (PBL than is possible from lidar alone, and a more quantitative measure of mixing height than is possible from only radon. The reason why lidar measurements are improved is that there are times when lidar signals are ambiguous, and reliably attributing the mixing height to the correct aerosol layer presents a challenge. By combining lidar with a mixing length scale derived from a time series of radon concentration, automated and robust attribution is possible during the morning transition.

    Radon measurements provide mixing information during the night, but concentrations also depend on the strength of surface emissions. After processing radon in combination with lidar, we obtain nightly measurements of radon emissions and are able to normalise the mixing length scale for changing emissions. After calibration with lidar, the radon-derived equivalent mixing height agrees with other measures of mixing on daily and hourly timescales and is a potential method for studying intermittent mixing in nocturnal boundary layers.

  9. Human exposure to indoor radon: a survey in the region of Guarda, Portugal.

    Science.gov (United States)

    Louro, Alina; Peralta, Luís; Soares, Sandra; Pereira, Alcides; Cunha, Gilda; Belchior, Ana; Ferreira, Luís; Monteiro Gil, Octávia; Louro, Henriqueta; Pinto, Paulo; Rodrigues, António Sebastião; Silva, Maria João; Teles, Pedro

    2013-04-01

    Radon ((222)Rn) is a radioactive gas, abundant in granitic areas, such as the city of Guarda at the northeast of Portugal. This gas is recognised as a carcinogenic agent, being appointed by the World Health Organization as the second leading cause of lung cancer after tobacco smoke. Therefore, the knowledge of radon concentrations inside the houses (where people stay longer) is important from the point of view of radiological protection. The main goal of this study was to assess the radon concentration in an area previously identified with a potentially high level of residential radon. The radon concentration was measured using CR-39 detectors, exposed for a period of 2 months in 185 dwellings in the Guarda region. The radon concentration in studied dwellings, ranged between 75 and 7640 Bq m(-3), with a geometric mean of 640 Bq m(-3) and an arithmetic mean of 1078 Bq m(-3). Based on a local winter-summer radon concentration variation model, these values would correspond to an annual average concentration of 860 Bq m(-3). Several factors contribute to this large dispersion, the main one being the exact location of housing construction in relation to the geochemical nature of the soil and others the predominant building material and ventilation. Based on the obtained results an average annual effective dose of 15 mSv y(-1) is estimated, well above the average previously estimated for Portugal.

  10. Indoor radon measurements in south west England explained by topsoil and stream sediment geochemistry, airborne gamma-ray spectroscopy and geology.

    Science.gov (United States)

    Ferreira, Antonio; Daraktchieva, Zornitza; Beamish, David; Kirkwood, Charles; Lister, T Robert; Cave, Mark; Wragg, Joanna; Lee, Kathryn

    2016-05-20

    Predictive mapping of indoor radon potential often requires the use of additional datasets. A range of geological, geochemical and geophysical data may be considered, either individually or in combination. The present work is an evaluation of how much of the indoor radon variation in south west England can be explained by four different datasets: a) the geology (G), b) the airborne gamma-ray spectroscopy (AGR), c) the geochemistry of topsoil (TSG) and d) the geochemistry of stream sediments (SSG). The study area was chosen since it provides a large (197,464) indoor radon dataset in association with the above information. Geology provides information on the distribution of the materials that may contribute to radon release while the latter three items provide more direct observations on the distributions of the radionuclide elements uranium (U), thorium (Th) and potassium (K). In addition, (c) and (d) provide multi-element assessments of geochemistry which are also included in this study. The effectiveness of datasets for predicting the existing indoor radon data is assessed through the level (the higher the better) of explained variation (% of variance or ANOVA) obtained from the tested models. A multiple linear regression using a compositional data (CODA) approach is carried out to obtain the required measure of determination for each analysis. Results show that, amongst the four tested datasets, the soil geochemistry (TSG, i.e. including all the available 41 elements, 10 major - Al, Ca, Fe, K, Mg, Mn, Na, P, Si, Ti - plus 31 trace) provides the highest explained variation of indoor radon (about 40%); more than double the value provided by U alone (ca. 15%), or the sub composition U, Th, K (ca. 16%) from the same TSG data. The remaining three datasets provide values ranging from about 27% to 32.5%. The enhanced prediction of the AGR model relative to the U, Th, K in soils suggests that the AGR signal captures more than just the U, Th and K content in the soil. The

  11. The inventorying and mapping of landslide potential in Manado – Indonesia

    OpenAIRE

    2016-01-01

    Landslide constitutes a frequent problem occurs in Manado. It happens for many times from year to year and brings both material disadvantage and casualty. The way and hilly topography of Manado, unstabel geological condition, high rainfall, and the improper land use are assumed to be the trigger for the problem. The objective of this study is to inventory and map landslide potential area as well as to design the preventive plan. Mapping method employs spatial approach by using land unit as th...

  12. 76 FR 72006 - Draft Interim Staff Guidance: Evaluations of Uranium Recovery Facility Surveys of Radon and Radon...

    Science.gov (United States)

    2011-11-21

    ... COMMISSION Draft Interim Staff Guidance: Evaluations of Uranium Recovery Facility Surveys of Radon and Radon... Recovery Facility Surveys of Radon and Radon Progeny in Air and Demonstrations of Compliance with 10 CFR 20... that existing guidance does not sufficiently detail how the NRC staff reviews surveys of radon and...

  13. Advances in the regulatory framework for the protection against radon in Spain; Avances en el marco regulador de la proteccion contral El radon en Espana

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Talavera, M.; Martin Matarranz, J. L.; Rey, C.; Salas, R.; Ramos, L.

    2013-07-01

    In recent years, the control of exposure to radon has acquired a greater role. A basic tool is the identification of the geographical areas where a significant percentage of buildings requiring concentrations above the reference level. The objective of this work is to develop a methodology to identify these areas and map nationwide. (Author)

  14. Transient radon signals driven by fluid pressure pulse, micro-crack closure, and failure during granite deformation experiments

    Science.gov (United States)

    Girault, Frédéric; Schubnel, Alexandre; Pili, Éric

    2017-09-01

    In seismically active fault zones, various crustal fluids including gases are released at the surface. Radon-222, a radioactive gas naturally produced in rocks, is used in volcanic and tectonic contexts to illuminate crustal deformation or earthquake mechanisms. At some locations, intriguing radon signals have been recorded before, during, or after tectonic events, but such observations remain controversial, mainly because physical characterization of potential radon anomalies from the upper crust is lacking. Here we conducted several month-long deformation experiments under controlled dry upper crustal conditions with a triaxial cell to continuously monitor radon emission from crustal rocks affected by three main effects: a fluid pressure pulse, micro-crack closure, and differential stress increase to macroscopic failure. We found that these effects are systematically associated with a variety of radon signals that can be explained using a first-order advective model of radon transport. First, connection to a source of deep fluid pressure (a fluid pressure pulse) is associated with a large transient radon emission increase (factor of 3-7) compared with the background level. We reason that peak amplitude is governed by the accumulation time and the radon source term, and that peak duration is controlled by radioactive decay, permeability, and advective losses of radon. Second, increasing isostatic compression is first accompanied by an increase in radon emission followed by a decrease beyond a critical pressure representing the depth below which crack closure hampers radon emission (150-250 MPa, ca. 5.5-9.5 km depth in our experiments). Third, the increase of differential stress, and associated shear and volumetric deformation, systematically triggers significant radon peaks (ca. 25-350% above background level) before macroscopic failure, by connecting isolated cracks, which dramatically enhances permeability. The detection of transient radon signals before rupture

  15. Least-squares reverse time migration with local Radon-based preconditioning

    KAUST Repository

    Dutta, Gaurav

    2017-03-08

    Least-squares migration (LSM) can produce images with better balanced amplitudes and fewer artifacts than standard migration. The conventional objective function used for LSM minimizes the L2-norm of the data residual between the predicted and the observed data. However, for field-data applications in which the recorded data are noisy and undersampled, the conventional formulation of LSM fails to provide the desired uplift in the quality of the inverted image. We have developed a leastsquares reverse time migration (LSRTM) method using local Radon-based preconditioning to overcome the low signal-tonoise ratio (S/N) problem of noisy or severely undersampled data. A high-resolution local Radon transform of the reflectivity is used, and sparseness constraints are imposed on the inverted reflectivity in the local Radon domain. The sparseness constraint is that the inverted reflectivity is sparse in the Radon domain and each location of the subsurface is represented by a limited number of geologic dips. The forward and the inverse mapping of the reflectivity to the local Radon domain and vice versa is done through 3D Fourier-based discrete Radon transform operators. The weights for the preconditioning are chosen to be varying locally based on the relative amplitudes of the local dips or assigned using quantile measures. Numerical tests on synthetic and field data validate the effectiveness of our approach in producing images with good S/N and fewer aliasing artifacts when compared with standard RTM or standard LSRTM.

  16. Evaluation of radon levels in indoor gymnasia of Palermo (Sicily and Sassari (Sardinia

    Directory of Open Access Journals (Sweden)

    Alberto Firenze

    2009-12-01

    Full Text Available

    Background: In the last decades, there has been increased worldwide interest in the management of health risks from indoor radon.

    Methods: From 2006 to 2008, a survey on air radon levels was carried out in a total of 57 indoor gymnasia respectively located in the urban area of Palermo (Sicily and Sassari (Sardinia.

    Results: The indoor radon levels were generally low with different geometric means in the two geographic areas (14.3 Bq/m3 in Palermo and 36 Bq/m3 in Sassari, respectively. Overall, in both groups increasing values of radon were found during the night and the early morning, with radon concentrations significantly lower during working time than at other times. The analysis of structural parameters showed that direct contact with the soil significantly correlated with increased levels of radon in gymnasia located in Palermo’s area (p<0.05. Furthermore, higher radon levels in Sicilian structures were also associated, although not significantly, with lack of sumps (19.3 vs 12.9 Bq/m3, location below the ground level (18.8 vs 8.7 Bq/m3, lack of windows (25 vs 13.2 Bq/m3, presence of forced ventilation (15.5 vs 7.3 Bq/m3 and with cracks or moisture tracks (15.7 vs 13.2 Bq/m3.

    Conclusions: Radon tends to accumulate in indoor sites and it’s monitoring, especially in buildings with potentially overcrowded conditions, could be of public health interest. Mitigation measures and minimization of the number of structural and functional risk parameters should be strongly encouraged in order to limit radon accumulation especially in countries with higher radium concentration in the soil.

  17. Efficacy of radon remedial measures

    Energy Technology Data Exchange (ETDEWEB)

    Naismith, S. (National Radiological Protection Board, Chilton (United Kingdom))

    1994-04-01

    About 2000 householders in the UK have taken remedial action to reduce high radon levels in their homes. Some 800 of these householders have sought measurements to confirm the effectiveness of the action. Results for 528 such homes are discussed. (author).

  18. Robust Image Hashing Using Radon Transform and Invariant Features

    Directory of Open Access Journals (Sweden)

    Y.L. Liu

    2016-09-01

    Full Text Available A robust image hashing method based on radon transform and invariant features is proposed for image authentication, image retrieval, and image detection. Specifically, an input image is firstly converted into a counterpart with a normalized size. Then the invariant centroid algorithm is applied to obtain the invariant feature point and the surrounding circular area, and the radon transform is employed to acquire the mapping coefficient matrix of the area. Finally, the hashing sequence is generated by combining the feature vectors and the invariant moments calculated from the coefficient matrix. Experimental results show that this method not only can resist against the normal image processing operations, but also some geometric distortions. Comparisons of receiver operating characteristic (ROC curve indicate that the proposed method outperforms some existing methods in classification between perceptual robustness and discrimination.

  19. Low Radon Cleanroom at the University of Alberta

    Science.gov (United States)

    Grant, Darren; Hallin, Aksel; Hanchurak, Stephen; Krauss, Carsten; Liu, Shengli; Soluk, Richard

    2011-04-01

    A cleanroom laboratory designed to create and maintain a low concentration of radon in the air has been designed and is now under construction. We describe the clean room, the radon stripping system, and various radon monitoring tools.

  20. Uranium mining industry views on ICRP statement on radon.

    Science.gov (United States)

    Takala, J

    2012-01-01

    In 2009, the International Commission on Radiological Protection issued a statement on radon which stated that the dose conversion factor for radon progeny would likely double, and the calculation of risk from radon should move to a dosimetric approach, rather than the longstanding epidemiological approach. Through the World Nuclear Association, whose members represent over 90% of the world's uranium production, industry has been examining this issue with a goal of offering expertise and knowledge to assist with the practical implementation of these evolutionary changes to evaluating the risk from radon progeny. Industry supports the continuing use of the most current epidemiological data as a basis for risk calculation, but believes that further examination of these results is needed to better understand the level of conservatism in the potential epidemiological-based risk models. With regard to adoption of the dosimetric approach, industry believes that further work is needed before this is a practical option. In particular, this work should include a clear demonstration of the validation of the dosimetric model which includes how smoking is handled, the establishment of a practical measurement protocol, and the collection of relevant data for modern workplaces. Industry is actively working to address the latter two items.

  1. Radon concentration in waters of geothermal Euganean basin--Veneto, Italy.

    Science.gov (United States)

    Bertolo, A; Bigliotto, C

    2004-01-01

    Since ancient times the warm thermal waters of Euganean basin, Italy, have been used for therapeutic purposes. The radioactive characteristics, assumed in depth, are due, in particular, to radon gas, which when released during the therapies in the indoor thermal room, determines exposure for the workers. The preliminary results of the project, the purpose of which is to analyze the totality of thermal springs, are presented. The concentrations, obtained by gamma spectrometry, show a high variability, and are comparable to those in other thermal springs in Italy and abroad. Possible correlations with geophysical factors, such as the temperature and depth of springs, have been investigated. A geostatistical analysis of the radon data has also been carried out, through the study of the experimental variogram, obtained by kriging one map of the radon concentration: such an approach is useful not only for mapping but also for giving one possible interpretation of the examined phenomenon through structural geologic characteristics.

  2. 9th Saxonian radon day. 11th meeting on radon safe structural engineering; 9. Saechsischer Radontag. 11. Tagung radonsicheres Bauen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-07-01

    The proceedings of the meeting in radon-safe structural engineering covers contributions on the following issues: implementation of the EU standards, radon protection in underground cavities, radon protection at working places, reports on experiences.

  3. Study on the solubility of radon in tissues; Untersuchung der Loeslichkeit von Radon in Gewebe

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, Claudia; Kraft, Gerhard; Maier, Andreas; Beek, Patrick van [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany)

    2016-08-01

    At the GSI Helmholtz Center in Darmstadt a radon chamber with conditions similar to the radon galleries was built for studies on the solubility of radon in tissues using cell cultures and animals. The samples are investigated using gamma spectroscopy following the radon exposure measuring Pb-214 and Bi-214. The original concentration of Rn-222 in the sample is determined by the time dependence of the decay rates of Rn-222. The experimental conditions and preliminary measurements are described.

  4. A European-wide 222Radon and 222Radon progeny comparison study

    OpenAIRE

    Schmithüsen, Dominik; Chambers, Scott; Fischer, Bernd; Gilge, Stefan; Hatakka, Juha; Kazan, Victor; Neubert, Rolf; Paatero, Jussi; Ramonet, Michel; Schlosser, Clemens; Schmid, Sabine; Vermeulen, Alex; Levin, Ingeborg

    2016-01-01

    A European-wide 222Radon/222Radon progeny comparison study has been conducted in order to determine correction factors that could be applied to existing atmospheric 222Radon data sets for quantitative use of this tracer in atmospheric transport model validation. Two compact and easy-to-transport Heidelberg Radon Monitors (HRM) were moved around to run for at least one month at each of the nine European measurement stations that were included in the comparison. Linear regressions between paral...

  5. Underground Potential for Urban Sustainability: Mapping Resources and Their Interactions with the Deep City Method

    Directory of Open Access Journals (Sweden)

    Michael R. Doyle

    2016-08-01

    Full Text Available In the process of urban growth, the underground is often only addressed once all surface alternatives have been exhausted. Experience shows that this can lead to unforeseen conflicts (e.g., subsidence, groundwater pollution and to lost opportunities (e.g., combined geothermal systems and building foundations or recycling of excavation materials. One challenge is how the underground potentials are assessed by urban actors; data collection, analysis and visualization for the different resources are often conducted in separate disciplinary corners and administrative divisions. This paper presents a mapping method developed within the Deep City project at the Swiss Federal Institute of Technology in Lausanne (EPFL and its application to San Antonio, Texas. San Antonio is interesting in its lack of major underground infrastructure and its few means and political support for short-term underground development. We will specifically look at the production of a series of interaction maps, an original mapping strategy that is complementary to the resource potential maps we have produced in prior work. After situating this research within larger theoretical and philosophical questions, we will show how mapping the combined potentiality of underground resources can serve as a compass for future interdisciplinary discussions that address the urban underground as a source of opportunity, rather than as an afterthought.

  6. Mineral Potential Mapping for Tungsten Polymetallic Deposits in the Nanling Metallogenic Belt, South China

    Institute of Scientific and Technical Information of China (English)

    Yue Liu; Qiuming Cheng; Qinglin Xia; Xinqing Wang

    2014-01-01

    The Nanling belt in South China has considerable resources of tungsten polymetallic commodities and is one of the most important metallogenic belts in the world. Data-driven weights-of-evidence (WofE) and fuzzy logic models are used to evaluate the tungsten polymetallic po-tential of the Nanling belt. Initially, seven ore-controlling factors derived from multi-source geospatial datasets (e.g., geological, geochemical, and geophysical) are used for data integration in the two models. Two mineral potential maps are generated that efficiently predicate the locations of the deposits. The WofE map predicate 81%of the deposits within 13.6%of the study area, whereas the fuzzy logic map predicate 81.5%of the deposits within 13%of the area. The predictive maps are syntheses of spatial association rules, which provide better understanding of those factors that control the distribution of mineralization and trigger eventual exploration work in new areas. Subsequently, in order to evaluate the success rate accuracy, the receiver operating characteristic curves and area under the curves (AUCs) for the two potential maps are constructed. The results show that the AUCs for the WofE and fuzzy logic models are 0.775 7 and 0.840 6, respectively. The higher AUC value for the fuzzy logic model implies that it delineate a greater number of favorable areas compared with the WofE model. Overall, the capabilities of both models for correctly classifying areas with existing mineral deposits are satisfactory.

  7. Consideration of tidal influences in determining measurement periods when monitoring built-environment radon levels

    Energy Technology Data Exchange (ETDEWEB)

    Crockett, R.G.M.; Phillips, P.S. [Northampton Univ., School of Applied Sciences (United Kingdom); Gillmore, G.K. [Bradford Univ., School of Archaeological, Geographical and Environmental Sciences (United Kingdom); Denman, A.R.; Groves-Kirkby, C.J. [Northampton General Hospital, Medical Physics Dept. (United Kingdom)

    2006-07-01

    of 14-15 days is therefore recommended and, to minimise the potential distortions arising from the inclusion of unmatched partial tidal-periods in a radon measurement period, longer measurement periods should be integral multiples of this period. (authors)

  8. The radon: evaluation and risk management; Le radon: evaluation et gestion du risque

    Energy Technology Data Exchange (ETDEWEB)

    Lacoste, A.C. [Direction Generale de la Surete Nucleaire et de la Radioprotection, 75 - Paris (France); Masse, R. [Academie des Technologies, 75 - Paris (France); Aurengo, A. [Hopital Pitie-Salpetriere, Service de Medecine Nucleaire, 75 - Paris (France); Erich Wichmann, H. [Neuberberg Munich Univ. (Germany); Timarche, M.; Laurier, D.; Robe, M.Ch. [Institut de Radioprotection et de Surete Nucleaire (IRSN), 92 - Clamart (France); Baubron, J.C.; Bonijoly, D. [BRGM, 75 - Paris (France); Collignan, B. [Centre Scientifique et Technique du Batiment, (CSTB), 75 - Paris (France); Berrier, H. [Direction Gle de l' Urbanisme de l' Habitat et de la Construction, 75 - Paris (France); Jaouen, J. [Direction Departementale des Affaires Sanitaires et Sociales de la Haute-Vienne (France); Caamano, D. [Direction Departementale des Affaires Sanitaires et Sociales de l' Essonne, 91 (France); Guiot, F. [Direction Departementale des Affaires Sanitaires et Sociales de la Haute-Marne (France); Grall, B. [Direction Departementale des Affaires Sanitaires et Sociales de Bretagne (France); Frutos Vasquez, B.; Olaya Adan, M. [Istituto de Ciencias de la Construction (Italy); Garcia Cadierno, J.P.; Martin Matarranz, J.L.; Serrano Renedo, J.; Suarez Mahou, E. [Consejo de Seguridad Nuclear, Madrid (Spain); Fernandez, J.A. [ENUSA Industrias Avanzadas (Spain); Mjones, L.; Pirard, P. [Institut de veille sanitaire, 94415 - Saint-Maurice (France); Godet, J.L.; Rougy, Ch. [Direction Gle de la Surete Nucleaire et de la Radioprotection, 75 - Paris (France)

    2003-06-15

    The radon exposure constitutes for the French population the first cause of natural irradiation among the different natural sources of irradiation. It is possible to have a significant action on it, either by making draught proof in order to avoid to radon to get inside houses, either by ventilating in order to dispel the radon and improve air quality. (N.C.)

  9. Radon concentration measurements in bituminous coal mines.

    Science.gov (United States)

    Fisne, Abdullah; Okten, Gündüz; Celebi, Nilgün

    2005-01-01

    Radon measurements were carried out in Kozlu, Karadon and Uzülmez underground coal mines of Zonguldak bituminous coal basin in Turkey. Passive-time integrating method, which is the most widely used technique for the measurement of radon concentration in air, was applied by using nuclear etched track detectors (CR-39) in the study area. The radon concentration measurements were performed on a total of 42 points in those three mines. The annual exposure, the annual effective dose and lifetime fatality risk, which are the important parameters for the health of workers, were estimated based on chronic occupational exposure to the radon gas, which is calculated using UNCEAR-2000 and ICRP-65 models. The radon concentrations at several coal production faces are higher than the action level of 1000 Bq m(-3). It is suggested that the ventilation rates should be rearranged to reduce the radon concentration.

  10. The distribution of indoor radon in Transylvania (Romania) - influence of the natural and anthropogenic factors

    Science.gov (United States)

    Cucos Dinu, Alexandra; Baciu, Calin; Dicu, Tiberius; Papp, Botond; Moldovan, Mircea; Bety Burghele, Denissa; Tenter, Ancuta; Szacsvai, Kinga

    2017-04-01

    Exposure to radon in homes and workplaces is now recognized as the most important natural factor in causing lung cancer. Radon activity is usually higher in buildings than in the outside atmosphere, as it may be released from building materials and soil beneath the constructions, and the concentration builds-up indoor, due to the low air renewal rates. Indoor radon levels can vary from one to multiple orders of magnitude over time and space, as it depends on several natural and anthropogenic factors, such us the radon concentration in soil under the construction, the weather conditions, the degree of containment in the areas where individuals are exposed, building materials, outside air, tap water and even city gas, the architecture, equipment (chimney, mechanical ventilation systems, etc.), the environmental parameters of the building (temperature, pressure, etc.), and on the occupants' lifestyle. The study presents the distribution of indoor radon in Transylvania, Romania, together with the measurements of radon in soil and soil water. Indoor radon measurements were performed by using CR-39 track detectors exposed for 3 months on ground-floor level of dwellings, according to the NRPB Measurement Protocol. Radon concentrations in soil and water were measured using the LUK3C device. A complete map was plotted at the date, based on 3300 indoor radon measurements, covering an area of about 42% of the Romanian territory. The indoor radon concentrations ranged from 5 to 3287 Bq m-3, with an updated preliminary arithmetic mean of 179 Bq m-3, and a geometric mean of 122 Bq m-3. In about 11% of the investigated grid cells the indoor radon concentrations exceed the threshold of 300 Bq m-3. The soil gas radon concentration varies from 0.8 to 169 kBq m-3, with a geometric mean of 26 kBq m-3. For water samples, the results show radon concentrations within the range of 0.3 - 352.2 kBq m-3, with a geometric mean of 7.7 Bq L-1. A weak correlation between the three sets of values

  11. Three-dimensional mapping and regulation of action potential propagation in nanoelectronics-innervated tissues

    Science.gov (United States)

    Dai, Xiaochuan; Zhou, Wei; Gao, Teng; Liu, Jia; Lieber, Charles M.

    2016-09-01

    Real-time mapping and manipulation of electrophysiology in three-dimensional (3D) tissues could have important impacts on fundamental scientific and clinical studies, yet realization is hampered by a lack of effective methods. Here we introduce tissue-scaffold-mimicking 3D nanoelectronic arrays consisting of 64 addressable devices with subcellular dimensions and a submillisecond temporal resolution. Real-time extracellular action potential (AP) recordings reveal quantitative maps of AP propagation in 3D cardiac tissues, enable in situ tracing of the evolving topology of 3D conducting pathways in developing cardiac tissues and probe the dynamics of AP conduction characteristics in a transient arrhythmia disease model and subsequent tissue self-adaptation. We further demonstrate simultaneous multisite stimulation and mapping to actively manipulate the frequency and direction of AP propagation. These results establish new methodologies for 3D spatiotemporal tissue recording and control, and demonstrate the potential to impact regenerative medicine, pharmacology and electronic therapeutics.

  12. Use of health economics in the development of a national radon control strategy in Ireland.

    Science.gov (United States)

    Pollard, D; Fenton, D

    2014-07-01

    A health economics evaluation of different radon intervention strategies was undertaken including the incorporation of prevention into new buildings, the incorporation of potential remedial measures into new buildings and remediation of existing buildings. The analysis shows that (1) the incorporation of prevention into new houses at the time of construction is generally more cost effective than remediation of existing houses and (2) that the cost effectiveness of programmes aimed at encouraging householders to test and remediate their houses may be poor if they are not undertaken within the context of coherent radon reduction strategy. The results of this evaluation were used to identify the most cost-effective radon interventions in an Irish context in support of the development of a National Radon Control Strategy.

  13. A new method specifically designed to expose cells isolated in vitro to radon and its decay products.

    Science.gov (United States)

    Petitot, F; Morlier, J P; Debroche, M; Pineau, J F; Chevillard, S

    2002-06-01

    A system was set up to provide direct exposure of cells cultured in vitro to radon and its decay products. Radon gas emanating from a uranium source was introduced at a measured concentration in a closed 10-m(3) exposure chamber. Cells were cultured on the microporous membrane of an insert that was floating over the culture medium in a six-well cluster plate. Plates with cells were placed in an open thermoregulated bath within the chamber. Under these conditions, cells were irradiated by direct deposition of radon and radon decay products. During exposure, all parameters, including radon gas concentrations, decay product activities, and potential alpha-particle energy concentrations, were determined by periodic air-grab samplings inside the chamber. The energy spectrum of deposited decay products was characterized. An estimation of alpha-particle flux density on the area containing cells was performed using CR-39 detector films that were exposed in cell-free wells during the cell exposure. The number of alpha-particle traversals per cell was deduced both from the mean number of CR-39 tracks per surface unit and from measurements of entire cells or nuclear surfaces. This paper describes the design of experiment, the dosimetry of radon and radon decay product, and the procedures for aerosol measurements. Our preliminary data show the usefulness of the in vitro cell culture approach to the study of the early cellular effects of radon and its decay products.

  14. The radon influence of SAGE results

    CERN Document Server

    Gavrin, V N; Mirmov, I N

    2002-01-01

    The method for evaluating systematic errors, connected with radon, is described in the experiment on determining the SAGE solar neutrino flux. The systematic error by the measured neutrino capture rate in the gallium 75 SNU target does not exceed 0.3 SNU. The obtained value (0.3 SNU) is the upper limit of the radon systematic error. Its low value means, that radon does not contribute significantly to the SAGE result

  15. A Fuzzy Radon Transform for Track Recognition

    CERN Document Server

    De Laat, C T A M; CERN. Geneva; Lourens, W; Kamermans, R

    1993-01-01

    In this contribution a fuzzy Radon transform is shown for application in ALICE and ATLAS (typical track density of 8000 in one unit of rapidity). Resolution is introduced by the "broadening" of the matching tracks in the Radon transform, which is obtained by making a convolution of the matching tracks with Gaussian kernel. In a good approximation, an analytical expression for the fuzzy Radon transform is given. An example of two track separation with noisy input is added.

  16. Using structure restoration maps to comprehensively identify potential faults and fractures in compressional structures

    Institute of Scientific and Technical Information of China (English)

    OU Cheng-hua; CHEN Wei; LI Chao-chun

    2016-01-01

    Faults and fractures of multiple scales are frequently induced and generated in compressional structural system. Comprehensive identification of these potential faults and fractures that cannot be distinguished directly from seismic profile of the complex structures is still an unanswered problem. Based on the compressional structural geometry and kinematics theories as well as the structural interpretation from seismic data, a set of techniques is established for the identification of potential faults and fractures in compressional structures. Firstly, three-dimensional (3D) patterns and characteristics of the faults directly interpreted from seismic profile were illustrated by 3D structural model. Then, the unfolding index maps, the principal structural curvature maps, and tectonic stress field maps were obtained from structural restoration. Moreover, potential faults and fractures in compressional structures were quantitatively identified relying on comprehensive analysis of these three maps. Successful identification of the potential faults and fractures in Mishrif limestone formation and in Asmari dolomite formation of Buzurgan anticline in Iraq demonstrates the applicability and reliability of these techniques.

  17. Breaking Concept Boundaries to Enhance Creative Potential: Using Integrated Concept Maps for Conceptual Self-Awareness

    Science.gov (United States)

    Kao, Gloria Yi-Ming; Lin, Sunny S. J.; Sun, Chuen-Tsai

    2008-01-01

    The authors address the role of computer support for building conceptual self-awareness--that is, enabling students to think outside of concept boundaries in hope of enhancing creative potential. Based on meta-cognition theory, we developed an integrated concept mapping system (ICMSys) to improve users' conceptual self-awareness in addition to…

  18. Textbook Treatments of Electrostatic Potential Maps in General and Organic Chemistry

    Science.gov (United States)

    Hinze, Scott R.; Williamson, Vickie M.; Deslongchamps, Ghislain; Shultz, Mary Jane; Williamson, Kenneth C.; Rapp, David N.

    2013-01-01

    Electrostatic potential maps (EPMs) allow for representation of key molecular-level information in a relatively simple and inexpensive format. As these visualizations become more prevalent in instruction, it is important to determine how students are exposed to them and supported in their use. A systematic review of current general and organic…

  19. Using the Large Fire Simulator System to map wildland fire potential for the conterminous United States

    Science.gov (United States)

    LaWen Hollingsworth; James Menakis

    2010-01-01

    This project mapped wildland fire potential (WFP) for the conterminous United States by using the large fire simulation system developed for Fire Program Analysis (FPA) System. The large fire simulation system, referred to here as LFSim, consists of modules for weather generation, fire occurrence, fire suppression, and fire growth modeling. Weather was generated with...

  20. Mapping of groundwater potential zones in the Musi basin using remote sensing data and GIS

    NARCIS (Netherlands)

    Ganapuram, Sreedhar; Vijaya Kumar, G.T.; Murali Krishna, I.V.; Kahya, Ercan; Demirel, M. Cüneyd

    2009-01-01

    The objective of this study is to explore the groundwater availability for agriculture in the Musi basin. Remote sensing data and geographic information system were used to locate potential zones for groundwater in the Musi basin. Various maps (i.e., base, hydrogeomorphological, geological, structur

  1. The inventorying and mapping of landslide potential in Manado – Indonesia

    Directory of Open Access Journals (Sweden)

    Mithel Kumajas

    2016-05-01

    Full Text Available Landslide constitutes a frequent problem occurs in Manado. It happens for many times from year to year and brings both material disadvantage and casualty. The way and hilly topography of Manado, unstabel geological condition, high rainfall, and the improper land use are assumed to be the trigger for the problem. The objective of this study is to inventory and map landslide potential area as well as to design the preventive plan. Mapping method employs spatial approach by using land unit as the analysis unit. The technique of analysis applies the assistance of GIS with its ArcView soft ware. The result of mapping shows that the level landslide potential from potential until very potential category in Manado is 1.815,72 Ha; potential is 1282,10 ha and very potential category is 533,62 ha. The faktors cause the landslide comprise of rocky declivity, high rainfall, and the condition of stone as well as the unstabel and porous soil. The existence of Cesar zone extends to the center of the city and the use of settlement land located in improper zone become the trigger that quicken the occurrence of landslide. The strategy implemented to manage the landslide potential area can be carried out through 1 law enforcement in relation to city lay out, 2 landslide prevention through civil and vegetative technique, 3 the improvement of social consciousness of the danger of landslide disaster and the attempt for social empowerment, and 4 the provision of the landslide potential danger map as the ground for policy making in the effort to manage the landslide disaster.

  2. Prestimulus EEG microstates influence visual event-related potential microstates in field maps with 47 channels.

    Science.gov (United States)

    Kondakor, I; Lehmann, D; Michel, C M; Brandeis, D; Kochi, K; Koenig

    1997-01-01

    The influence of the immediate prestimulus EEG microstate (sub-second epoch of stable topography/map landscape) on the map landscape of visually evoked 47-channel event-related potential (ERP) microstates was examined using the frequent, non-target stimuli of a cognitive paradigm (12 volunteers). For the two frequent prestimulus microstate classes (oriented left anterior-right posterior and right anterior-left posterior), ERP map series were selectively averaged. The post-stimulus ERP grand average map series was segmented into microstates; 10 were found. The centroid locations of positive and negative map areas extracted as landscape descriptors. Significant differences (MANOVAs and t-tests) between the two prestimulus classes were found in four of the ten ERP microstates. The relative orientation of the two ERP microstate classes was the same as prestimulus in some ERP microstates, but reversed in others. Thus, brain electric microstates at stimulus arrival influence the landscapes of the post-stimulus ERP maps and therefore, information processing; prestimulus microstate effects differed for different post-stimulus ERP microstates.

  3. Radon in Himalayan springs: a geohydrological control

    Energy Technology Data Exchange (ETDEWEB)

    Choubey, V.M.; Bartarya, S.K. [Wadia Inst. of Himalayan Geology, Dehra Dun (India); Ramola, R.C. [Garhwal Univ., Srinagar, Uttar Pradesh (India). Dept. of Physics

    2000-04-01

    This paper presents the results of radon measurements in springs of the Himalayan region by using radon emanometry technique. The radon was measured in different springs, draining from different geohydrological setups, and from stream water in order to find the geohydrological control over radon concentration in groundwater emanating in the form of spring. The radon values were found to vary from 0.4 Bq/l to 887 Bq/l, being observed lowest for a turbulent stream and highest for the spring. The radon values were recorded highest in the springs draining through gneiss, granite, mylonite, etc. Radon concentrations have been related with four spring types viz. fracture-joint related spring, fault-lineament related spring, fluvial related spring and colluvial related spring, showing geohydrological characteristics of the rocks through which they are emanating. The high radon concentration in fracture-joint and fault-lineament springs is related to increased ratio of rock surface area to water volume and uranium mineralisation in the shear zones present in the close vicinity of fault and thrust. The low concentration of radon in fluvial and colluvial springs is possibly because of high transmissivity and turbulent flow within such deposits leading to natural de-emanation of gases. (orig.)

  4. Radon transfer and intracorporal deposition of radon decay products under balneotherapeutic conditions; Radon-Transfer und intrakorporale Deposition von Radon-Folgeprodukten unter balneotherapeutischen Bedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Grunewald, Wolfgang A. [Kurmittelhaus Sibyllenbad, Neualbenreuth (Germany); Just, Guenther [Forschungsbuero Radon, Grosspoesna (Germany); Petzold, Juergen [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum, Leipzig (Germany); Philipsborn, Henning von [Radiometrisches Seminar, Univ. Regensburg (Germany)

    2009-07-01

    The intracorporal deposition of radon decay products was determined on four persons after 40 and 30 min respectively in radon water with about 1500 Bq/L by whole-body gamma spectrometry. The measurements started about 2 1/2h after exposure. In addition, the radon activity concentration of inspiratory and expiratory air was measured on one person during and after exposure and the deposition of radon decay products on the skin was measured on another person. The radon activity leaving the body with the expiratory air during exposure in the water (called ''radon transfer'') amounts to about 800 Bq. An intracorporal radon activity immediately after therapeutic exposure of about 3000 Bq was obtained as a result of first measurements by extrapolation from measurements starting about 2 1/2 hours later. Additional studies are necessary. There are indications that both the radon transfer and the intracorporal deposition can be increased by exposure in mixed radon-CO{sub 2} water. (orig.)

  5. Low-Cost Radon Reduction Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Rose, William B. [Partnership for Advanced Residential Retrofit, Champaign, IL (United States); Francisco, Paul W. [Partnership for Advanced Residential Retrofit, Champaign, IL (United States); Merrin, Zachary [Partnership for Advanced Residential Retrofit, Champaign, IL (United States)

    2015-09-01

    The aim of the research was to conduct a primary scoping study on the impact of air sealing between the foundation and the living space on radon transport reduction across the foundation-living space floor assembly. Fifteen homes in the Champaign, Illinois area participated in the study. These homes were instrumented for hourly continuous radon measurements and simultaneous temperature and humidity the foundation was improved. However, this improved isolation did not lead to significant reductions in radon concentration in the living space. Other factors such as outdoor temperature were shown to have an impact on radon concentration.

  6. Spatial data analysis and integration for regional-scale geothermal potential mapping, West Java, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Carranza, Emmanuel John M.; Barritt, Sally D. [Department of Earth Systems Analysis, International Institute for Geo-information Science and Earth Observation (ITC), Enschede (Netherlands); Wibowo, Hendro; Sumintadireja, Prihadi [Laboratory of Volcanology and Geothermal, Geology Department, Institute of Technology Bandung (ITB), Bandung (Indonesia)

    2008-06-15

    Conceptual modeling and predictive mapping of potential for geothermal resources at the regional-scale in West Java are supported by analysis of the spatial distribution of geothermal prospects and thermal springs, and their spatial associations with geologic features derived from publicly available regional-scale spatial data sets. Fry analysis shows that geothermal occurrences have regional-scale spatial distributions that are related to Quaternary volcanic centers and shallow earthquake epicenters. Spatial frequency distribution analysis shows that geothermal occurrences have strong positive spatial associations with Quaternary volcanic centers, Quaternary volcanic rocks, quasi-gravity lows, and NE-, NNW-, WNW-trending faults. These geological features, with their strong positive spatial associations with geothermal occurrences, constitute spatial recognition criteria of regional-scale geothermal potential in a study area. Application of data-driven evidential belief functions in GIS-based predictive mapping of regional-scale geothermal potential resulted in delineation of high potential zones occupying 25% of West Java, which is a substantial reduction of the search area for further exploration of geothermal resources. The predicted high potential zones delineate about 53-58% of the training geothermal areas and 94% of the validated geothermal occurrences. The results of this study demonstrate the value of regional-scale geothermal potential mapping in: (a) data-poor situations, such as West Java, and (b) regions with geotectonic environments similar to the study area. (author)

  7. A semi-quantitative technique for mapping potential aquifer productivity on the national scale: example of England and Wales (UK)

    Science.gov (United States)

    Abesser, Corinna; Lewis, Melinda

    2015-12-01

    The development and validation of aquifer productivity and depth-to-source maps for England and Wales are described. Aquifer productivity maps can provide valuable support for the assessment, planning and management of groundwater and renewable heat energy resources. Aquifer productivity is often mapped using geostatistical interpolation techniques such as kriging, but these techniques tend to be unsuitable for mapping at the national scale due to the high data (and time) demands. A methodology is outlined for mapping aquifer productivity at the national scale using existing national-scale data sets. Pumping test data are used to characterise the potential borehole yields that different geological formations of varying lithologies and ages can provide. Based on this analysis and using expert knowledge, the corresponding map codes on the geological map are assigned to potential productivity classes. The subsurface (concealed) extent of aquifer units is mapped from geophysical data, and together with the attributed geological map, provide the bedrock-aquifer productivity map. Drilling and pumping costs can be an important consideration when evaluating the feasibility of developing a groundwater source. Thus, a map of the approximate depth to source is developed alongside the aquifer productivity map. The maps are validated using independent data sets, and map performance is compared against performance from maps derived by random and uniform attribution. The results show that the maps successfully predict potential productivity and approximate depth to the water source, although utility of the depth-to-source map could be improved by increasing the vertical discretisation at which depth intervals are mapped.

  8. Potential Natural Vegetation Map of Eastern Africa (Burundi, Ethiopia, Kenya Malawi, Rwanda, Tanzania, Uganda and Zambia). Version 2.0

    DEFF Research Database (Denmark)

    van Breugel, Paulo; Kindt, Roeland; Lillesø, Jens-Peter Barnekow;

    2015-01-01

    The potential natural vegetation (PNV) map of eastern and southern Africa covers the countries Burundi, Ethiopia, Kenya, Uganda, Rwanda, Tanzania, and Zambia. The first version of the map was developed by various partners in East Africa and Europe in 2010 and has now reached version 2. The map is...

  9. Regional gold potential mapping in Kelantan (Malaysia) using probabilistic based models and GIS

    Science.gov (United States)

    Yusoff, Suhaimizi; Pradhan, Biswajeet; Manap, Mohamad Abd; Shafri, Helmi Zulhaidi Mohd

    2015-06-01

    The aim of this study is to test and compare two probabilistic based models (frequency ratio and weightsof- evidence) with regard to regional gold potential mapping at Kelantan, Malaysia. Until now these models have not been used for the purpose of mapping gold potential areas in Malaysia. This study analyzed the spatial relationship between gold deposits and geological factors such as lithology, faults, geochemical and geophysical data in geographical information system (GIS) software. About eight (8) gold deposits and five (5) related factors are identified and quantified for their spatial relationships. Then, all factors were combined to generate a predictive gold potential map. The predictive maps were then validated by comparing them with known gold deposits using receiver operating characteristics (ROC) and "area under the curve" (AUC) graphs. The results of validation showed accuracies of 80% for the frequency ratio and 74% for the weightsof- evidence model, respectively. The results demonstrated the usefulness of frequency ratio and weights-of-evidence modeling techniques in mineral exploration work to discover unknown gold deposits in Kelantan, Malaysia.

  10. Durability of radon remedial actions

    Energy Technology Data Exchange (ETDEWEB)

    Naismith, S. [National Radiological Protection Board, Chilton (United Kingdom)

    1997-07-01

    It is estimated that at least 3600 householders in the UK have taken remedial action to reduce radon concentrations found to be above the government Action Level. A study has been carried out on the durability of these remedial actions. It involved annual reassessment of the radon levels in a number of homes. The results for 26 of these homes where data over five years are available show that in general the remedial actions remained effective. The remedy with the largest variation in efficacy was natural ventilation of the underfloor void. The failure rate was found to be 4.0% per annum for all measures, but in the majority of cases the failure was discovered by the householder and rectified. The rate of failures not noticed by the householders was 0.4% per annum. (UK).

  11. Predictive GIS Model for Potential Mapping of Cu, Pb, Zn Mineralization

    Institute of Scientific and Technical Information of China (English)

    Tarik. B. Benomar; BIAN Fuling

    2006-01-01

    The geologic features indicative of Cu, Pb, Zn mineral deposits in a area are fractures (structure), and host rock sediments. Datasets used include Cu, Pb, Zn deposit points record, geological data, remote sensing imagery (Landsat TM5). The mineral potential of the study area is assessed by means of GIS based geodata integration techniques for generating predictive maps. GIS predictive model for Cu, Pb, Zn potential was carried out in this study area (Weixi) using weight of evidence. The weights of evidence modeling techniques is the data driven method in which the spatial associations of the indicative geologic features with the known mineral occurrences in the area are quantified, and weights statistically assigned to the geologic features. The best predictive map generated by this method defines 24% the area having potential for Cu, Pb, Zn mineralization further exploration work.

  12. Energy Potential Mapping: Visualising Energy Characteristics for the Exergetic Optimisation of the Built Environment

    Directory of Open Access Journals (Sweden)

    Michiel Fremouw

    2013-01-01

    Full Text Available It is difficult to fully satisfy the energy demand of today’s society with renewables. Nevertheless, most of the energy we use is lost as non-functional waste energy, whereas a large part of the built environment’s energy demand is only for low-quality energy, so the initial demand for primary, high-quality energy can be reduced by more effective usage, such as by low-exergy means. Gaining insight into the parameters of energy demands and local renewable and residual energy potentials enables matching energy demand with a fitting potential, not only concerning quantity but taking into account location, temporality and quality as well. The method of Energy Potential Mapping (EPM aims to visualise the energy potentials and demands by making information of quantity, quality and location of demand and supply accessible. The aspect of quality specifically applies to heat and cold. The methodology of EPM will be described and explained with case studies. The focus specifically lies on mapping heat (and cold, one of the main reasons for energy demand in the built environment. The visualisation of exergy, to be simplified as the quality of energy, becomes an extra parameter in the case of Dutch Heat Maps. These maps can help finding opportunities of practical implementations of exchanging or cascading heat or cold. This way EPM and Heat Mapping (HM enables application of exergy principles in the built environment. EPM and HM can be seen as a local energy catalogue and can be useful in spatial planning for energy-based urban and rural plans.

  13. Radon as an Anthropogenic Indoor Air Pollutant

    Science.gov (United States)

    Gillmore, Gavin; Crockett, Robin

    2016-04-01

    Radon is generally regarded as a naturally occurring radiological hazard but we report here measurements of significant, hazardous radon concentrations that arise from man-made sources, including granite ornaments/artefacts, uranium glass and glazed objects as well radium dial watches. This presentation concerns an examination and assessment of health risks from radium and uranium found in historical artefacts, many of which were once viewed as everyday items, and the radon that emanates from them. Such objects were very popular in industrialised countries such as the USA, UK and European countries) particularly between and including the two World Wars but are still readily available. A watch collection examined gave rise to a hazardous radon concentration of 13.24 kBq•m-3 approximately 67 times the Domestic Action Level of 200 Bq•m-3.The results for an aircraft altimeter are comparable to those of the watches, indicating radon activity equivalent to several watches, and also indicate an equilibrium concentration in the 16.3 m3 room ca. 33 times the UK domestic Action Level. Results from a granite block indicate a radon emanation of 19.7 Bq•kg-1, but the indicated equilibrium concentration in the 16.3 m3 room is only ca. 1.7% of the UK domestic Action Level. Uranium-glazed crockery and green uranium glass were scoped for radon activity. The former yielded a radon concentration of ca. 44 Bq•m-3 in a small (7 L) sealed container. The latter yielded a lower radon concentration in a larger (125 L) sealed container of ca. 6 Bq•m-3. This is barely above the background radon concentration in the laboratory, which was typically ca. 1-2 Bq•m-3. Individual items then are capable of giving rise to radon concentrations in excess of the UK Domestic Action Level in rooms in houses, particularly if poorly ventilated. We highlight the gap in the remediation protocols, which are focused on preventing radon entering buildings from outside, with regard to internally

  14. The uncertainty in the radon hazard classification of areas as a function of the number of measurements.

    Science.gov (United States)

    Friedmann, H; Baumgartner, A; Gruber, V; Kaineder, H; Maringer, F J; Ringer, W; Seidel, C

    2017-07-01

    The administration in many countries demands a classification of areas concerning their radon risk taking into account the requirements of the EU Basic Safety Standards. The wide variation of indoor radon concentrations in an area which is caused by different house construction, different living style and different geological situations introduces large uncertainties for any classification scheme. Therefore, it is of importance to estimate the size of the experimental coefficient of variation (relative standard deviation) of the parameter which is used to classify an area. Besides the time period of measurement it is the number of measurements which strongly influences this uncertainty and it is important to find a compromise between the economic possibilities and the needed confidence level. Some countries do not use pure measurement results for the classification of areas but use derived quantities, usually called radon potential, which should reduce the influence of house construction, living style etc. and should rather represent the geological situation of an area. Here, radon indoor measurements in nearly all homes in three municipalities and its conversion into a radon potential were used to determine the uncertainty of the mean radon potential of an area as a function of the number of investigated homes. It could be shown that the coefficient of variation scales like 1/√n with n the number of measured dwellings. The question how to deal with uncertainties when using a classification scheme for the radon risk is discussed and a general procedure is proposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Conductance maps of quantum rings due to a local potential perturbation

    Science.gov (United States)

    Petrović, M. D.; Peeters, F. M.; Chaves, A.; Farias, G. A.

    2013-12-01

    We performed a numerical simulation of the dynamics of a Gaussian shaped wavepacket inside a small sized quantum ring, smoothly connected to two leads and exposed to a perturbing potential of a biased atomic force microscope tip. Using the Landauer formalism, we calculated conductance maps of this system in the case of single and two subband transport. We explain the main features in the conductance maps as due to the AFM tip influence on the wavepacket phase and amplitude. In the presence of an external magnetic field, the tip modifies the ϕ0 periodic Aharonov-Bohm oscillation pattern into a ϕ0/2 periodic Al’tshuler-Aronov-Spivak oscillation pattern. Our results in the case of multiband transport suggest tip selectivity to higher subbands, making them more observable in the total conductance map.

  16. Indoor Radon in Micro-geological Setting of an Indigenous Community in Canada: A Pilot Study for Hazard Identification.

    Science.gov (United States)

    Sarkar, Atanu; Wilton, Derek Hc; Fitzgerald, Erica

    2017-04-01

    Radon is the second leading cause of lung cancer after smoking. In Canada, the health authorities have no access to comprehensive profile of the communities built over uranium-rich micro-geological settings. The present indoor radon monitoring guideline is unable to provide an accurate identification of health hazards due to discounting several parameters of housing characteristics. To explore indoor radon levels in a micro-geological setting known for high uranium in bedrock and to develop a theoretical model for a revised radon testing protocol. We surveyed a remote Inuit community in Labrador, located in the midst of uranium belt. We selected 25 houses by convenience sampling and placed electret-ion-chamber radon monitoring devices in the lowest levels of the house (basement/crawl space). The standard radon study questionnaire developed and used by Health Canada was used. 7 (28%) houses had radon levels above the guideline value (range 249 to 574 Bq/m(3)). Housing characteristics, such as floors, sump holes, ventilation, and heating systems were suspected for high indoor radon levels and health consequences. There is a possibility of the existence of high-risk community in a low-risk region. The regional and provincial health authorities would be benefited by consulting geologists to identify potentially high-risk communities across the country. Placing testing devices in the lowest levels provides more accurate assessment of indoor radon level. The proposed protocol, based on synchronized testing of radon (at the lowest level of houses and in rooms of normal occupancy) and thorough inspection of the houses will be a more effective lung cancer prevention strategy.

  17. Radon Levels Measured at a Touristic Thermal Spa Resort in Montagu (South Africa) and Associated Effective Doses.

    Science.gov (United States)

    Botha, R; Newman, R T; Maleka, P P

    2016-09-01

    Radon activity concentrations (in water and in air) were measured at 13 selected locations at the Avalon Springs thermal spa resort in Montagu (Western Cape, South Africa) to estimate the associated effective dose received by employees and visitors. A RAD-7 detector (DURRIDGE), based on alpha spectrometry, and electret detectors (E-PERM®Radelec) were used for these radon measurements. The primary source of radon was natural thermal waters from the hot spring, which were pumped to various locations on the resort, and consequently a range of radon in-water analyses were performed. Radon in-water activity concentration as a function of time (short term and long term measurements) and spatial distributions (different bathing pools, etc.) were studied. The mean radon in-water activity concentrations were found to be 205 ± 6 Bq L (source), 112 ± 5 Bq L (outdoor pool) and 79 ± 4 Bq L (indoor pool). Radon in-air activity concentrations were found to range between 33 ± 4 Bq m (at the outside bar) to 523 ± 26 Bq m (building enclosing the hot spring's source). The most significant potential radiation exposure identified is that due to inhalation of air rich in radon and its progeny by the resort employees. The annual occupational effective dose due to the inhalation of radon progeny ranges from 0.16 ± 0.01 mSv to 0.40 ± 0.02 mSv. For the water samples collected, the Ra in-water activity concentrations from samples collected were below the lower detection limit (~0.7 Bq L) of the γ-ray detector system used. No significant radiological health risk can be associated with radon and progeny from the hot spring at the Avalon Springs resort.

  18. Indoor Radon in Micro-geological Setting of an Indigenous Community in Canada: A Pilot Study for Hazard Identification

    Directory of Open Access Journals (Sweden)

    Atanu Sarkar

    2017-04-01

    Full Text Available Background: Radon is the second leading cause of lung cancer after smoking. In Canada, the health authorities have no access to comprehensive profile of the communities built over uranium-rich micro-geological settings. The present indoor radon monitoring guideline is unable to provide an accurate identification of health hazards due to discounting several parameters of housing characteristics. Objective: To explore indoor radon levels in a micro-geological setting known for high uranium in bedrock and to develop a theoretical model for a revised radon testing protocol. Methods: We surveyed a remote Inuit community in Labrador, located in the midst of uranium belt. We selected 25 houses by convenience sampling and placed electret-ion-chamber radon monitoring devices in the lowest levels of the house (basement/crawl space. The standard radon study questionnaire developed and used by Health Canada was used. Results: 7 (28% houses had radon levels above the guideline value (range 249 to 574 Bq/m3. Housing characteristics, such as floors, sump holes, ventilation, and heating systems were suspected for high indoor radon levels and health consequences. Conclusion: There is a possibility of the existence of high-risk community in a low-risk region. The regional and provincial health authorities would be benefited by consulting geologists to identify potentially high-risk communities across the country. Placing testing devices in the lowest levels provides more accurate assessment of indoor radon level. The proposed protocol, based on synchronized testing of radon (at the lowest level of houses and in rooms of normal occupancy and thorough inspection of the houses will be a more effective lung cancer prevention strategy.

  19. The Hesse potential, the c-map and black hole solutions

    Science.gov (United States)

    Mohaupt, T.; Vaughan, O.

    2012-07-01

    We present a new formulation of the local c-map, which makes use of a symplectically covariant real formulation of special Kähler geometry. We obtain an explicit and simple expression for the resulting quaternionic, or, in the case of reduction over time, para-quaternionic Kähler metric in terms of the Hesse potential, which is similar to the expressions for the metrics obtained from the rigid r- and c-map, and from the local r-map. As an application we use the temporal version of the c-map to derive the black hole attractor equations from geometric properties of the scalar manifold, without imposing supersymmetry or spherical symmetry. We observe that for general (non-symmetric) c-map spaces static BPS solutions are related to a canonical family of totally isotropic, totally geodesic submanifolds. Static non-BPS solutions can be obtained by applying a field rotation matrix which is subject to a non-trivial compatibility condition. We show that for a class of prepotentials, which includes the very special (`cubic') prepotentials as a subclass, axion-free solutions always admit a non-trivial field rotation matrix.

  20. Improved mixing height monitoring through a combination of lidar and radon measurements

    Directory of Open Access Journals (Sweden)

    A. D. Griffiths

    2012-09-01

    Full Text Available Surface-based radon (222Rn measurements can be combined with lidar backscatter to obtain a higher quality time series of mixing height within the Planetary Boundary-Layer (PBL than is possible from lidar alone, and a more quantitative measure of mixing height than is possible from only radon. The lidar measurements benefit because even when aerosol layers are detected, reliably attributing the mixing height to the correct layer presents a challenge. By combining lidar with a mixing length scale derived from a time series of radon concentration, automated and robust attribution is possible during the morning transition.

    Radon measurements also provide mixing information during the night and with the addition of lidar these measurements become insensitive to night-to-night changes in radon emissions. After calibration with lidar, the radon-derived equivalent mixing height agrees with other measures of mixing on daily and hourly time scales and is a potential method for studying intermittent mixing in nocturnal boundary layers.

  1. Radon studies for extending Los Azufres geothermal energy field in Mexico

    CERN Document Server

    Tavera, L; Camacho, M E; Chavez, A; Pérez, H; Gómez, J

    1999-01-01

    Los Azufres is a 98 MW producing geothermal energy field situated in the Mexican volcanic belt at the west part of the country. Recently, hydrothermal activity and geochemical analysis of geothermal fluids from the north part of the geothermal field gave indications of a possible geothermal-production area, similar to the already producing field. In order to investigate the activity of geological structures, which are considered the means of geothermal fluids transporters, radon mapping was carried out using sets of 240 LR-115 detectors in the area of interest. Radon values higher than 10 kBq m sup - sup 3 were considered anomalous and indicative of geothermal anomalies.

  2. Mapping the fissure potential zones based on microtremor measurement in Denpasar City, Bali

    Science.gov (United States)

    Prabowo, U. N.; Marjiyono; Sismanto

    2016-01-01

    Denpasar City and its vicinity considered as the areas with excessive ground water exploitation and high earthquake intensity. These conditions will cause these area potential with land subsidence which is triggering ground fissures. This research aims are to mapping the fissures potential areas based on microtremor measurement in Denpasar City and its vicinity. Ground fissures will happen if the land subsidence occurs in the areas which have different bedrock height beneath its sedimentary layer. The height of bedrock is determined by reducing surface elevation with the sedimentary layer thickness. This sedimentary layer thickness obtained from microtremor measurement using HVSR method, and Shear wave velocity (VS) obtained from microtremor array measurement which is analyzed by Spatial Auto Correlation (SPAC) method. The result from HVSR method as well as Peak Ground Acceleration (PGA) value are then analyzed to get ground shear strain value, which is the soil surface strain and its effect when earthquake occurs. Based on the bedrock map, it can be estimated that the bedrock layer forms structure in the southern part of the research areas and the potential fissuring area due to the massive ground water exploitation is in the west Denpasar Subdistrict. In addition, based on the bedrock map and ground shear strain value which combined with Simple Additive Weight (SAW) method, there are two areas having Assuring potential, i.e west and south Denpasar Subdistricts.

  3. Electrical coupling in ensembles of nonexcitable cells: modeling the spatial map of single cell potentials.

    Science.gov (United States)

    Cervera, Javier; Manzanares, Jose Antonio; Mafe, Salvador

    2015-02-19

    We analyze the coupling of model nonexcitable (non-neural) cells assuming that the cell membrane potential is the basic individual property. We obtain this potential on the basis of the inward and outward rectifying voltage-gated channels characteristic of cell membranes. We concentrate on the electrical coupling of a cell ensemble rather than on the biochemical and mechanical characteristics of the individual cells, obtain the map of single cell potentials using simple assumptions, and suggest procedures to collectively modify this spatial map. The response of the cell ensemble to an external perturbation and the consequences of cell isolation, heterogeneity, and ensemble size are also analyzed. The results suggest that simple coupling mechanisms can be significant for the biophysical chemistry of model biomolecular ensembles. In particular, the spatiotemporal map of single cell potentials should be relevant for the uptake and distribution of charged nanoparticles over model cell ensembles and the collective properties of droplet networks incorporating protein ion channels inserted in lipid bilayers.

  4. Find a Radon Test Kit or Measurement and Mitigation Professional

    Science.gov (United States)

    Find a qualified radon service professional to fix or mitigate your home. If you have questions about a radon, you should contact your state radon contact and/or contact one or both of the two privately-run National Radon Proficiency Programs

  5. Systematic radon survey over active volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, J.L.; Monnin, M.; Garcia Vindas, J.R. [Centre National de la Recherche Cientifique, Montpellier (France). Lab. GBE; Ricard, L.P.; Staudacher, T. [Observatoire Volcanologique Du Pitou de la Fournaise, La Plaine des Cafres (France)

    1999-08-01

    Data obtained since 1993 on Costa Rica volcanos are presented and radon anomalies recorded before the eruption of the Irazu volcano (December 8, 1994) are discussed. The Piton de la Fournaise volcano is inactive since mid 1992. The influence of the external parameters on the radon behaviour is studied and the type of perturbations induced on short-term measurements are individuate.

  6. Radon Measurements in Schools: An Interim Report.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC. Office of Radiation Programs.

    Radon-222 is a colorless, odorless, tasteless, radioactive gas that occurs naturally in soil, rocks, underground water, and air. The United States Environmental Protection Agency (EPA) and other scientific organizations have identified an increased risk of lung cancer associated with exposure to elevated levels of radon in homes. Schools in many…

  7. Domestic Radon and Childhood Cancer in Denmark

    DEFF Research Database (Denmark)

    Raaschou-Nielsen, Ole; Andersen, Claus Erik; Andersen, Helle P.

    2008-01-01

    Background: Higher incidence rates of childhood cancer and particularly leukemia have been observed in regions with higher radon levels, but case-control studies have given inconsistent results. We tested the hypothesis that domestic radon exposure increases the risk for childhood cancer. Methods...

  8. Removal of Radon from Household Water.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC. Office of Research and Development.

    By far, the greatest risk to health from radon occurs when the gas enters the house from underlying soil and is inhaled. The U.S. Environmental Protection Agency (EPA) is studying ways to reduce radon in houses, including methods to remove the gas from water to prevent its release in houses when the water is used. While this research has not…

  9. Radon Measurement in Schools. Revised Edition.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC.

    The Environmental Protection Agency (EPA) and other major national and international scientific organizations have concluded that radon is a human carcinogen and a serious environmental health problem. The EPA has conducted extensive research on the presence and measurement of radon in schools. This report provides school administrators and…

  10. Radon Reduction Methods: A Homeowner's Guide.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC.

    The U.S. Environmental Protection Agency (EPA) is studying the effectiveness of various ways to reduce high concentrations of radon in houses. This booklet was produced to share what has been learned with those whose radon problems demand immediate action. The booklet describes nine methods that have been tested successfully--by EPA and/or other…

  11. Potential and limitations of using soil mapping information to understand landscape hydrology

    Directory of Open Access Journals (Sweden)

    F. Terribile

    2011-12-01

    Full Text Available This paper addresses the following points: how can whole soil data from normally available soil mapping databases (both conventional and those integrated by digital soil mapping procedures be usefully employed in hydrology? Answering this question requires a detailed knowledge of the quality and quantity of information embedded in and behind a soil map.

    To this end a description of the process of drafting soil maps was prepared (which is included in Appendix A of this paper. Then a detailed screening of content and availability of soil maps and database was performed, with the objective of an analytical evaluation of the potential and the limitations of soil data obtained through soil surveys and soil mapping. Then we reclassified the soil features according to their direct, indirect or low hydrologic relevance. During this phase, we also included information regarding whether this data was obtained by qualitative, semi-quantitative or quantitative methods. The analysis was performed according to two main points of concern: (i the hydrological interpretation of the soil data and (ii the quality of the estimate or measurement of the soil feature.

    The interaction between pedology and hydrology processes representation was developed through the following Italian case studies with different hydropedological inputs: (i comparative land evaluation models, by means of an exhaustive itinerary from simple to complex modelling applications depending on soil data availability, (ii mapping of soil hydrological behaviour for irrigation management at the district scale, where the main hydropedological input was the application of calibrated pedo-transfer functions and the Hydrological Function Unit concept, and (iii flood event simulation in an ungauged basin, with the functional aggregation of different soil units for a simplified soil pattern.

    In conclusion, we show that special care is required in handling data from soil

  12. Potential and limitations of using soil mapping information to understand landscape hydrology

    Science.gov (United States)

    Terribile, F.; Coppola, A.; Langella, G.; Martina, M.; Basile, A.

    2011-12-01

    This paper addresses the following points: how can whole soil data from normally available soil mapping databases (both conventional and those integrated by digital soil mapping procedures) be usefully employed in hydrology? Answering this question requires a detailed knowledge of the quality and quantity of information embedded in and behind a soil map. To this end a description of the process of drafting soil maps was prepared (which is included in Appendix A of this paper). Then a detailed screening of content and availability of soil maps and database was performed, with the objective of an analytical evaluation of the potential and the limitations of soil data obtained through soil surveys and soil mapping. Then we reclassified the soil features according to their direct, indirect or low hydrologic relevance. During this phase, we also included information regarding whether this data was obtained by qualitative, semi-quantitative or quantitative methods. The analysis was performed according to two main points of concern: (i) the hydrological interpretation of the soil data and (ii) the quality of the estimate or measurement of the soil feature. The interaction between pedology and hydrology processes representation was developed through the following Italian case studies with different hydropedological inputs: (i) comparative land evaluation models, by means of an exhaustive itinerary from simple to complex modelling applications depending on soil data availability, (ii) mapping of soil hydrological behaviour for irrigation management at the district scale, where the main hydropedological input was the application of calibrated pedo-transfer functions and the Hydrological Function Unit concept, and (iii) flood event simulation in an ungauged basin, with the functional aggregation of different soil units for a simplified soil pattern. In conclusion, we show that special care is required in handling data from soil databases if full potential is to be achieved

  13. Radon transforms of the Wigner operator on hyperplanes

    Institute of Scientific and Technical Information of China (English)

    Chen Jun-Hua; Fan Hong-Yi

    2009-01-01

    The generalization of tomographic maps to hyperplanes is considered. We find that the Radon transform of the Wigner operator in multi-dimensional phase space leads to a normally ordered operator in binomial distribution-amixed-state density operator. Reconstruction of the Wigner operator is also feasible. The normally ordered form and the Weyl ordered form of the Wigner operator are used in our derivation. The operator quantum tomography theory is expressed in terms of some operator identities,with the merit of revealing the essence of the theory in a simple and concise way.

  14. Measurements of radon around closed uranium mines

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Sadaaki E-mail: furuta@ningyo.jnc.go.jp; Ito, Kimio; Ishimori, Yuu

    2002-07-01

    There are several waste rock yards at closed uranium mines around Ningyo-toge, in the Western Honshu Island of Japan, and measurements of radon were carried out by both the passive method and the sampling method around these yards. As comparatively high radon concentrations were observed in two districts through routine measurements, more detailed measurements were made by the passive method in these districts. The impact of radon emanation from the waste rock yards was small for both residential districts and around these yards when considering the natural background level of radon. In addition, by simultaneous continuous measurements of radon and its progeny at two locations, it was estimated that the effective dose caused by the representative uranium waste rock yards was less than the public effective dose limit of 1 mSv year{sup -1} at the fenced boundary of the waste rock site.

  15. Indoor radon survey in the Vojvodina region

    Energy Technology Data Exchange (ETDEWEB)

    Forkapic, S.; Todorovic, N.; Bikit, I.; Mrda, D.; Slivka, J.; Veskovic, M. [Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad (Serbia)

    2010-07-01

    The results of an indoor radon survey in the Vojvodina region (Serbia) are presented. Long-term average radon measurements in an existing building can be measured relatively simply and inexpensively using a passive device, such as an alpha track detector. Houses in the suburbs were chosen as the target locations of the present investigations. Indoor radon concentrations were measured with CR-39 alpha track detectors at {approx}1000 locations in Vojvodina during the winter period. Effect of floor level, space under the rooms, boarding and the heating system on radon accumulation are discussed in this paper. For the dwellings typical of such regions, we measure a mean annual radon activity concentration of 112 Bq/m{sup 3} (747 measurements using the alpha track detector CR-39). (authors)

  16. Radon in houses and soil of Croatia

    Energy Technology Data Exchange (ETDEWEB)

    Radolic, V.; Vukovic, B.; Stanic, D.; Miklavcic, I.; Planinic, J. [Osijek Univ., Dept. of Physics (Croatia)

    2006-07-01

    Long-term indoor radon measurements in thousand Croatian homes, randomly selected, were performed by the LR-115 track etch detectors during a year 2003/2004. The obtained values of arithmetic means of radon concentrations in 20 Croatian counties were in range from 33 to 198 Bq/m{sup 3}, while the arithmetic and geometric means for Croatia were 68 and 50 Bq/m{sup 3}, respectively. Indoor radon concentrations follow log-normal distribution and the percentage of dwellings with concentrations above 400 Bq/m{sup 3} was 1.8 %. Radon concentrations in soil gas, at depth of 0.8 m, were measured by 'Alphaguard' measuring system. Association between levels of indoor and soil radon was investigated. (authors)

  17. Radon exposure and oropharyngeal cancer risk.

    Science.gov (United States)

    Salgado-Espinosa, Tania; Barros-Dios, Juan Miguel; Ruano-Ravina, Alberto

    2015-12-01

    Oropharyngeal cancer is a multifactorial disease. Alcohol and tobacco are the main risk factors. Radon is a human carcinogen linked to lung cancer risk, but its influence in other cancers is not well known. We aim to assess the effect of radon exposure on the risk of oral and pharyngeal cancer through a systematic review of the scientific literature. This review performs a qualitative analysis of the available studies. 13 cohort studies were included, most of them mortality studies, which analysed the relationship between occupational or residential radon exposure with oropharyngeal cancer mortality or incidence. Most of the included studies found no association between radon exposure and oral and pharyngeal cancer. This lack of effect was observed in miners studies and in general population studies. Further research is necessary to quantify if this association really exists and its magnitude, specially performing studies in general population, preferably living in areas with high radon levels.

  18. Automated mapping of glacial overdeepenings beneath contemporary ice sheets: Approaches and potential applications

    Science.gov (United States)

    Patton, Henry; Swift, Darrel A.; Clark, Chris D.; Livingstone, Stephen J.; Cook, Simon J.; Hubbard, Alun

    2015-03-01

    Awareness is growing on the significance of overdeepenings in ice sheet systems. However, a complete understanding of overdeepening formation is lacking, meaning observations of overdeepening location and morphometry are urgently required to motivate process understanding. Subject to the development of appropriate mapping approaches, high resolution subglacial topography data sets covering the whole of Antarctica and Greenland offer significant potential to acquire such observations and to relate overdeepening characteristics to ice sheet parameters. We explore a possible method for mapping overdeepenings beneath the Antarctic and Greenland ice sheets and illustrate a potential application of this approach by testing a possible relationship between overdeepening elongation ratio and ice sheet flow velocity. We find that hydrological and terrain filtering approaches are unsuited to mapping overdeepenings and develop a novel rule-based GIS methodology that delineates overdeepening perimeters by analysis of closed-contour properties. We then develop GIS procedures that provide information on overdeepening morphology and topographic context. Limitations in the accuracy and resolution of bed-topography data sets mean that application to glaciological problems requires consideration of quality-control criteria to (a) remove potentially spurious depressions and (b) reduce uncertainties that arise from the inclusion of depressions of nonglacial origin, or those in regions where empirical data are sparse. To address the problem of overdeepening elongation, potential quality control criteria are introduced; and discussion of this example serves to highlight the limitations that mapping approaches - and applications of such approaches - must confront. We predict that improvements in bed-data quality will reduce the need for quality control procedures and facilitate increasingly robust insights from empirical data.

  19. Radon measurements in an area of tectonic zone: A case study in Central Slovakia.

    Science.gov (United States)

    Mojzeš, Andrej; Marko, František; Porubčanová, Barbara; Bartošová, Andrea

    2017-01-01

    General overviews of the spatial distribution of radon and other natural radionuclides in the geological basement as commonly presented on regional or country maps tend to offer a low density of information, insufficient for gaining relevant knowledge of the environmental impact, especially in the areas of tectonic zones often assumed to be radon prone and therefore dangerous for the human population. An additional survey, employing radon measurements in soil and indoor air, was carried out seeking to provide a more detailed characterization of the expressive fault zone of the Malá Magura in the Horná Nitra region of Central Slovakia. Eventually, the results of soil (222)Rn volume activity measurements along two short profiles crossing the assumed fault line did not reveal any indication of active nature of local tectonics, but merely pointed to an existence of a zone of contact between different types of rocks. The results of indoor radon measurements in dwellings of two villages lying on the studied fault showed values that were lower than those commonly observed on the Slovak territory, ruling out any negative health impact on population. Nevertheless, in order to add new findings to an already well established study of geological structure of the region, the indoor radon data collected through a previous survey require a further analysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Radon and thoron daughter activities in the environment of the King George Island (West Antarctica

    Directory of Open Access Journals (Sweden)

    A. T. Solecki

    2005-06-01

    Full Text Available Results of 253 gamma spectrometric analyses of radon daughters in soil and bedrocks of the King George Island (West Antarctica are presented. Measured values range from 0.1 to 58.4 Bq/kg, and from 4.9 to 75.5 Bq/kg for 214Bi and 208Tl respectively, but most measurements fall in the lower part of this range due to predominantly basaltic character of the geological basement. Obtained gamma spectrometric data correspond well to very low soil gas radon content measured by means of Kodak LR115 being below 454 Bqm-3. Low soil gas radon content and characteristic type of architecture is responsible for low indoor radon activity in Arctowski Station being as low as 10- 15 Bqm-3. The highest 105 Bqm-3 indoor Rn activity has been measured in the greenhouse bungalow of the station. This increased value was probably connected with the presence of about 1000 kg of imported soil material in the greenhouse room of the bungalow. Local zones of increased uranium and thorium content, discovered as a result of radiometric mapping, can potentaily influence atmospheric radon used for meteorological interpretation.

  1. Potential and limitations of using soil mapping information to understand landscape hydrology

    Science.gov (United States)

    Terribile, F.; Coppola, A.; Langella, G.; Martina, M.; Basile, A.

    2011-05-01

    The role of soil properties and their spatial distribution in the landscape are already recognised as crucial issues greatly affecting rainfall-runoff dynamics and hence landscape hydrology. This becomes even more important when hydrological monitoring data are lacking. This applies to the critical issue of making hydrological predictions for ungauged basins. The rapid development of hydropedology along with Digital Soil Mapping (DSM) is promising to both enhance our understanding and (spatial) prediction capacity of rainfall-runoff processes and to be a powerful tool for environmental policy research. Despite these developments and broad conceptualizations, the crucial point as to how the soil data from typically available soil mapping databases can be usefully employed by the hydrologist has yet to be addressed. This question implies detailed knowledge of the quality and quantity of information embedded in and behind a soil map. This work produced an analytical evaluation of the potential and limitations of soil data obtained through soil surveys and soil mapping. This evaluation is made from a landscape hydrology viewpoint and is also developed through the following Italian case studies: irrigation management at the district scale, assessment of groundwater vulnerability, flood peak forecasting, and land evaluation for maize production. We show that special care is required in handling soil database data if their full potential is to be achieved. Further, all the case studies agree on the appropriate degree of complexity of the soil hydrological model to be applied. We also emphasise that effective interaction between pedology and hydrology to address landscape hydrology requires (i) better awareness of the hydrologic community about the type of soil information behind a soil map or soil database, (ii) the development by the pedological community of a better quantitative framework for evaluating surveyed hydrological features, and (iii) quantitative information

  2. Potential and limitations of using soil mapping information to understand landscape hydrology

    Directory of Open Access Journals (Sweden)

    F. Terribile

    2011-05-01

    Full Text Available The role of soil properties and their spatial distribution in the landscape are already recognised as crucial issues greatly affecting rainfall-runoff dynamics and hence landscape hydrology. This becomes even more important when hydrological monitoring data are lacking. This applies to the critical issue of making hydrological predictions for ungauged basins. The rapid development of hydropedology along with Digital Soil Mapping (DSM is promising to both enhance our understanding and (spatial prediction capacity of rainfall-runoff processes and to be a powerful tool for environmental policy research. Despite these developments and broad conceptualizations, the crucial point as to how the soil data from typically available soil mapping databases can be usefully employed by the hydrologist has yet to be addressed. This question implies detailed knowledge of the quality and quantity of information embedded in and behind a soil map.

    This work produced an analytical evaluation of the potential and limitations of soil data obtained through soil surveys and soil mapping. This evaluation is made from a landscape hydrology viewpoint and is also developed through the following Italian case studies: irrigation management at the district scale, assessment of groundwater vulnerability, flood peak forecasting, and land evaluation for maize production. We show that special care is required in handling soil database data if their full potential is to be achieved. Further, all the case studies agree on the appropriate degree of complexity of the soil hydrological model to be applied. We also emphasise that effective interaction between pedology and hydrology to address landscape hydrology requires (i better awareness of the hydrologic community about the type of soil information behind a soil map or soil database, (ii the development by the pedological community of a better quantitative framework for evaluating surveyed hydrological features, and (iii

  3. A comparison of contemporary and retrospective radon gas measurements in high radon dwellings in Ireland

    Energy Technology Data Exchange (ETDEWEB)

    Kelleher, K.; McLaughlin, J.P. [University College Dublin (Ireland); Fenton, D.; Colgan, P.A. [Radiological Protection Institute of Ireland, Dublin (Ireland)

    2006-07-01

    Little correlations has been found between contemporary radon gas measurements made in the past and retrospective radon gas measurements in Irish dwellings. This would suggest that these two techniques would result in two significantly different cumulative radon exposure estimates. Contemporary radon gas measurements made a few years apart in the same room of a dwelling were found to be significantly different. None of these differences could be explained by known changes to the rooms themselves., such ventilation or structural alterations to the room. This highlights the limitations of the contemporary radon gas measurements as a surrogate measurement for use in residential radon epidemiology. The contemporary radon gas measurements made by the Radiological Protection Institute of Ireland (R.P.I.I.) and University College of Dublin (U.C.D.) do not cover the same exposure period as the retrospective estimates and so the accuracy of the retrospective measurements cannot be demonstrated. A weak correlation can be seen between the retrospective radon gas estimates and a combination of the two contemporary radon gas estimates. It is not unreasonable to expect improvement in the correlation if further contemporary radon gas measurements were made in these rooms. (N.C.)

  4. Multidisciplinary analysis of Finnish esker sediment in radon source identification.

    Science.gov (United States)

    Breitner, Dániel; Turtiainen, Tuukka; Arvela, Hannu; Vesterbacka, Pia; Johanson, Bo; Lehtonen, Marja; Hellmuth, Karl-Heinz; Szabó, Csaba

    2008-11-01

    In order to define the naturally-occurring radioactive materials that are the source of radon in natural environments, a comprehensive analytical (geochemical, physical and chemical) methodology was employed to study sand samples from the Hollola esker in the city of Hollola (Lahti area, Finland). Techniques such as gamma-spectrometry, emanation measurements, sequential chemical extraction, scanning electron microscopy (SEM), electron probe microanalyses (EPMA) and inductively-coupled plasma mass spectrometry (ICP-MS) were used to determine the potential source of radon. Monazite and xenotime, uranium- and thorium-bearing minerals and potential radon sources, occurred in significant amounts in the samples and were also the main reason for the distribution of uranium and thereby radium in separate grain-size fractions. Following deposition, the esker sand has been exposed to no significant weathering, and radium has not therefore been much separated from uranium. However, considering its non-compatibility with crystal lattices, it was recognized rather in easily leachable species (44% of the total (226)Ra) than uranium (21% of the total (238)U) in our analyses. The smallest grain-size fraction of the esker sand had a higher emanation power (0.24) than the other fractions (around 0.17). Due to the small relative proportion of this fraction, however, it contributed only slightly to the total emanation (4%). The emanation power of the leachable species was about three times higher (ca. 0.20) than that of the species tightly bound to the crystal lattice (ca. 0.07).

  5. Synthesizing radar maps of polar regions with a Doppler-only method.

    Science.gov (United States)

    Roulston, M S; Muhleman, D O

    1997-06-10

    A method for producing a radar-reflectivity map of the polar regions of the Moon or a planet from polar orbit with only the frequency shift of the reflected signals is described and simulated. A Radon transform of the reflectivity is obtained during multiple passes over the pole. Inversion of this Radon transform enables a map of radar reflectivity to be synthesized.

  6. Spatial distribution of soil radon as a tool to recognize active faulting on an active volcano: the example of Mt. Etna (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Neri, Marco, E-mail: marco.neri@ct.ingv.it [Istituto Nazionale di Geofisica e Vulcanologia, Piazza Roma, 2 - 95123 Catania (Italy); Giammanco, Salvatore [Istituto Nazionale di Geofisica e Vulcanologia, Piazza Roma, 2 - 95123 Catania (Italy); Ferrera, Elisabetta; Patane, Giuseppe [Universita degli Studi di Catania, Dip. Scienze della Terra, Corso Italia, 52 - 95129 Catania (Italy); Zanon, Vittorio [Centro de Vulcanologia e Avaliacao de Riscos Geologicos - Universidade dos Acores, Rua Mae de Deus, 9501-801 Ponta Delgada (Portugal)

    2011-09-15

    This study concerns measurements of radon and thoron emissions from soil carried out in 2004 on the eastern flank of Mt. Etna, in a zone characterized by the presence of numerous seismogenic and aseismic faults. The statistical treatment of the geochemical data allowed recognizing anomaly thresholds for both parameters and producing distribution maps that highlighted a significant spatial correlation between soil gas anomalies and tectonic lineaments. The seismic activity occurring in and around the study area during 2004 was analyzed, producing maps of hypocentral depth and released seismic energy. Both radon and thoron anomalies were located in areas affected by relatively deep (5-10 km depth) seismic activity, while less evident correlation was found between soil gas anomalies and the released seismic energy. This study confirms that mapping the distribution of radon and thoron in soil gas can reveal hidden faults buried by recent soil cover or faults that are not clearly visible at the surface. The correlation between soil gas data and earthquakes depth and intensity can give some hints on the source of gas and/or on fault dynamics. - Highlights: > We performed measurements of radon from soil carried out on Mt. Etna. > The sampled zone is characterized by the presence of numerous active faults. > Radon mapping reveal dangerous hidden faults buried by recent soil cover. > Our study gives some hints on the source of gas and on fault dynamics. > We recognized areas where radon activity represents a hazard to the population.

  7. Radon estimation in water resources of Mandi - Dharamshala region of Himachal Pradesh, India for health risk assessments

    Science.gov (United States)

    Kumar, Gulshan; Kumari, Punam; Kumar, Mukesh; Kumar, Arvind; Prasher, Sangeeta; Dhar, Sunil

    2017-07-01

    The present study deals with the radon estimation in 40 water samples collected from different natural resources and radium content in the soils of Mandi-Dharamshala Region. Radon concentration is determined by using RAD-7 detector and radium contents of the soil in vicinity of water resources is as well measured by using LR-115 type - II detector, which is further correlated with radon concentration in water samples. The potential health risks related with 222Rn have also been estimated. The results show that the radon concentrations within the range of 1.51 to 22.7Bq/l with an average value of 5.93 Bq/l for all type of water samples taken from study area. The radon concentration in water samples is found lower than 100Bq/l, the exposure limit of radon in water recommended by the World Health Organization. The calculated average effective dose of radon received by the people of study area is 0.022 mSv/y with maximum of 0.083 mSv/y and minimum 0.0056 mSv/y. The total effective dose in all sites of the studied area is found to be within the safe limit (0.1 mSv/year) recommended by World Health Organization. The average value of radium content in the soil of study area is 6.326 Bq/kg.

  8. High sensitivity radon emanation measurements.

    Science.gov (United States)

    Zuzel, G; Simgen, H

    2009-05-01

    The presented radon detection technique employs miniaturized ultra-low background proportional counters. (222)Rn samples are purified, mixed with a counting gas and filled into a counter using a special glass vacuum line. The absolute sensitivity of the system is estimated to be 40 microBq (20 (222)Rn atoms). For emanation investigations two metal sealed stainless steel vessels and several glass vials are available. Taking into account their blank contributions, measurements at a minimum detectable activity of about 100 microBq can be performed.

  9. Application of support vector machines for copper potential mapping in Kerman region, Iran

    Science.gov (United States)

    Shabankareh, Mahdi; Hezarkhani, Ardeshir

    2017-04-01

    The first step in systematic exploration studies is mineral potential mapping, which involves classification of the study area to favorable and unfavorable parts. Support vector machines (SVM) are designed for supervised classification based on statistical learning theory. This method named support vector classification (SVC). This paper describes SVC model, which combine exploration data in the regional-scale for copper potential mapping in Kerman copper bearing belt in south of Iran. Data layers or evidential maps were in six datasets namely lithology, tectonic, airborne geophysics, ferric alteration, hydroxide alteration and geochemistry. The SVC modeling result selected 2220 pixels as favorable zones, approximately 25 percent of the study area. Besides, 66 out of 86 copper indices, approximately 78.6% of all, were located in favorable zones. Other main goal of this study was to determine how each input affects favorable output. For this purpose, the histogram of each normalized input data to its favorable output was drawn. The histograms of each input dataset for favorable output showed that each information layer had a certain pattern. These patterns of SVC results could be considered as regional copper exploration characteristics.

  10. Measurements of radon and chemical elements: Popocatepetl volcano; Mediciones de radon y elementos quimicos: Volcan Popocatepetl

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P.; Segovia, N.; Lopez, B.; Reyes, A.V. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Armienta, M.A.; Valdes, C.; Mena, M. [IGFUNAM, Ciudad Universitaria, 04510 Mexico D.F. (Mexico); Seidel, J.L.; Monnin, M. [UMR 5569 CNRS Hydrosciences, Montpellier (France)

    2002-07-01

    The Popocatepetl volcano is a higher risk volcano located at 60 Km from Mexico City. Radon measurements on soil in two fixed seasons located in the north slope of volcano were carried out. Moreover the radon content, major chemical elements and tracks in water samples of three springs was studied. The radon of soil was determined with solid detectors of nuclear tracks (DSTN). The radon in subterranean water was evaluated through the liquid scintillation method and it was corroborated with an Alpha Guard equipment. The major chemical elements were determined with conventional chemical methods and the track elements were measured using an Icp-Ms equipment. The radon on soil levels were lower, indicating a moderate diffusion of the gas across the slope of the volcano. The radon in subterranean water shown few changes in relation with the active scene of the volcano. The major chemical elements and tracks showed a stable behavior during the sampling period. (Author)

  11. Radon, Smoking, and Lung Cancer: The Need to Refocus Radon Control Policy

    Science.gov (United States)

    Mendez, David; Philbert, Martin A.

    2013-01-01

    Exposure to radon is the second leading cause of lung cancer, and the risk is significantly higher for smokers than for nonsmokers. More than 85% of radon-induced lung cancer deaths are among smokers. The most powerful approach for reducing the public health burden of radon is shaped by 2 overarching principles: public communication efforts that promote residential radon testing and remediation will be the most cost effective if they are primarily directed at current and former smokers; and focusing on smoking prevention and cessation is the optimal strategy for reducing radon-induced lung cancer in terms of both public health gains and economic efficiency. Tobacco control policy is the most promising route to the public health goals of radon control policy. PMID:23327258

  12. Observations of surface radon in Central Italy

    Science.gov (United States)

    Carlo, Piero Di; Pitari, Giovanni; de Luca, Natalia; Battisti, Domenico

    2009-07-01

    Two years of in situ radon concentration measurements in the atmospheric surface layer have been collected in a central Italy town (L’Aquila), located in the Aterno river valley. These data have been analyzed in order to study the controlling mechanisms of surface radon abundance; observations of coincident meteorological parameters confirmed the role of dynamics on the local removal rate of this tracer. The relatively high negative correlation of hourly data of surface wind speed and radon activity concentration ( R = -0.54, on annual scale) suggests that dynamical removal of radon is one of the most important controlling processes of the tracer accumulation in the atmospheric surface layer. An attempt is made to quantify the precipitation impact on radon soil fluxes. No anticorrelation of radon and precipitation comes out from the data ( R = -0.15), as in previous studies. However, since the main physical parameter affecting the ground radon release is expected to be the soil accumulation of water, snow or ice, the emission flux has also been correlated with soil moisture; in this way a much clearer anticorrelation is found ( R = -0.54).

  13. A Rapid Method for Radon Determination

    Energy Technology Data Exchange (ETDEWEB)

    Enkhbat, N.; Shin, S. G.; Key, Y. U.; Cho, M. H. [POSTECH, Pohang (Korea, Republic of); Norov, N. [National University of Mongolia, Ulaanbaatar (Mongolia); Kim, G. [Kungpook National University, Daegu (Korea, Republic of); Namkung, W.; Lee, H. S. [Pohang Accelerator Laboratory, Pohang (Korea, Republic of)

    2015-05-15

    Research carried out in last decades has shown that more than 70% of a total annual radioactive dose received by people originates from natural sources of ionizing radiation, whereby 40% is due to inhalation and ingestion of natural radioactive gas radon {sup 222}Rn and its progeny. Radon has 3.5 days of half-life. However, its progeny is dangerous than Radon in the view of radiation protection. Radon measurement is commonly used in controlling radon concentration in underground mine, closed room and in forecasting earthquake. Radon gas emission rate in the immediate opening of the west ventilation shaft depends on the operation of the ventilation system, duration of ventilation system operation, and the air flow rate through the underground development. Specific activity of radon progeny in air (RaA (Po-218), RaB (Pb-214) and RaC (Bi-214)) and Ra-222 in radioactive equilibrium was calculated by formula 1 and 2, respectively. We include result of measurement carried out in the air around a mining. In Fig.2 shown that the distribution of Po-218, Pb-214, Bi-214 and Ra-222 isotopes releasing from west ventilation shaft in Gurvanbulag underground uranium mine in the eastern part of Mongolia.

  14. Determining the radon exhalation rate from a gold mine tailings dump by measuring the gamma radiation.

    Science.gov (United States)

    Ongori, Joash N; Lindsay, Robert; Newman, Richard T; Maleka, Peane P

    2015-02-01

    The mining activities taking place in Gauteng province, South Africa have caused millions of tons of rocks to be taken from underground to be milled and processed to extract gold. The uranium bearing tailings are placed in an estimated 250 dumps covering a total area of about 7000 ha. These tailings dumps contain considerable amounts of radium and have therefore been identified as large sources of radon. The size of these dumps make traditional radon exhalation measurements time consuming and it is difficult to get representative measurements for the whole dump. In this work radon exhalation measurements from the non-operational Kloof mine dump have been performed by measuring the gamma radiation from the dump fairly accurately over an area of more than 1 km(2). Radon exhalation from the mine dump have been inferred from this by laboratory-based and in-situ gamma measurements. Thirty four soil samples were collected at depths of 30 cm and 50 cm. The weighted average activity concentrations in the soil samples were 308 ± 7 Bq kg(-1), 255 ± 5 Bq kg(-1) and 18 ± 1 Bq kg(-1) for (238)U, (40)K and (232)Th, respectively. The MEDUSA (Multi-Element Detector for Underwater Sediment Activity) γ-ray detection system was used for field measurements. The radium concentrations were then used with soil parameters to obtain the radon flux using different approaches such as the IAEA (International Atomic Energy Agency) formula. Another technique the MEDUSA Laboratory Technique (MELT) was developed to map radon exhalation based on (1) recognising that radon exhalation does not affect (40)K and (232)Th activity concentrations and (2) that the ratio of the activity concentration of the field (MEDUSA) to the laboratory (HPGe) for (238)U and (40)K or (238)U and (232)Th will give a measure of the radon exhalation at a particular location in the dump. The average, normalised radon flux was found to be 0.12 ± 0.02 Bq m(-2) s(-1) for the mine dump.

  15. Soil radon levels across the Amer fault

    Energy Technology Data Exchange (ETDEWEB)

    Font, Ll. [Grup de Fisica de les Radiacions, Edifici Cc, Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain)], E-mail: lluis.font@uab.cat; Baixeras, C.; Moreno, V. [Grup de Fisica de les Radiacions, Edifici Cc, Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Bach, J. [Unitat de Geodinamica externa, Departament de Geologia, Edifici Cs, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain)

    2008-08-15

    Soil radon levels have been measured across the Amer fault, which is located near the volcanic region of La Garrotxa, Spain. Both passive (LR-115, time-integrating) and active (Clipperton II, time-resolved) detectors have been used in a survey in which 27 measurement points were selected in five lines perpendicular to the Amer fault in the village area of Amer. The averaged results show an influence of the distance to the fault on the mean soil radon values. The dynamic results show a very clear seasonal effect on the soil radon levels. The results obtained support the hypothesis that the fault is still active.

  16. Risks related to exposure to radon

    Directory of Open Access Journals (Sweden)

    Juan Miguel Barros Dios

    2010-12-01

    Full Text Available They discuss the different scientific evidence that radon and its short half-life descendants are responsible for the appearance of a considerable number of lung cancers among the exposed population in homes and public buildings (occupational exposure. It also draws a small glimpse at the road traveled by this knowledge and acceptance difficult administrations in many countries and, in particular, of Spain, as well as the various investigations that the team do Galego Radon and Radon Laboratory from Galicia, the area of Public Health, University of Santiago de Compostela (USC, are contributing to scientific knowledge. Finally, they appreciate the few legislative initiatives on the problem in Spain.

  17. Indoor radon concentration forecasting in South Tyrol.

    Science.gov (United States)

    Verdi, L; Weber, A; Stoppa, G

    2004-01-01

    In this paper a modern statistical technique of multivariate analysis is applied to an indoor radon concentration data base. Several parameters are more or less significant in determining the radon concentration inside a building. The elaboration of the information available on South Tyrol makes it possible both to identify the statistically significant variables and to build up a statistical model that allows us to forecast the radon concentration in dwellings, when the values of the same variables involved are given. The results confirm the complexity of the phenomenon.

  18. Radon screening for XENON1T

    Energy Technology Data Exchange (ETDEWEB)

    Lindemann, Sebastian [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2015-07-01

    Radon with its isotope {sup 222}Rn is one of the dominant sources of internal background in liquid xenon detectors searching for low energetic rare events like WIMP-nucleon scattering. In my talk I briefly review the problem posed by {sup 222}Rn and motivate the screening strategy followed by XENON1T. I introduce the radon emanation technique making use of ultra low background proportional counters and present selected results obtained during the design and construction phases of XENON1T. Finally, I sketch advances in radon emanation assay techniques and give a short outlook on upcoming measurements.

  19. Radon - kilder og måling

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Wraber, Ida Kristina

    Når man skal vurdere en bygnings indeklima er det vigtigt at have viden om radonindholdet. Denne viden får man ved måling, da radon hverken kan ses, lugtes, høres, smages eller føles. Denne anvisning redegør for radons oprindelse og indvirkning på menneskers sundhed. Anvisningen beskriver metoder...... til måling og analyse af radonindholdet i en bygnings indeluft. Læseren får indsigt i, hvordan man relativt let med standardiserede metoder kan eftervise, om en bygning opfylder bygningsreglementets krav til radon i indeluften. Anvisningen henvender sig til bygningsejere, bygherrer, projekterende og...

  20. Coprecipitation of radon oxide with cesium fluoroxenate

    Energy Technology Data Exchange (ETDEWEB)

    Avrorin, V.V.; Krasikova, R.N.; Nefedov, V.D.; Toropova, M.A.

    1986-03-01

    This paper presents a study of the processes of coprecipitation of radon oxide with cesium fluoroxenate in aqueous solutions. It has been shown that the reason for the coprecipitation in the case at hand is the occurrence of a process of isomorphous cocrystallization. The results obtained are examined as a confirmation of the suggestion that the hydrolysis product of the radon fluoride which is formed on thermal initiation of reaction in the rn-F2-BrF5-NaF system is radon trioxide, Rno3.

  1. Counting radon tracks in Makrofol detectors with the 'image reduction and analysis facility' (IRAF) software package

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, F. [Laboratorio de Fisica Medica y Radioactividad Ambiental, Departamento de Medicina Fisica y Farmacologia, Universidad de La Laguna, 38320 La Laguna, Tenerife (Spain)]. E-mail: fimerall@ull.es; Gonzalez-Manrique, S. [Laboratorio de Fisica Medica y Radioactividad Ambiental, Departamento de Medicina Fisica y Farmacologia, Universidad de La Laguna, 38320 La Laguna, Tenerife (Spain); Karlsson, L. [Laboratorio de Fisica Medica y Radioactividad Ambiental, Departamento de Medicina Fisica y Farmacologia, Universidad de La Laguna, 38320 La Laguna, Tenerife (Spain); Hernandez-Armas, J. [Laboratorio de Fisica Medica y Radioactividad Ambiental, Departamento de Medicina Fisica y Farmacologia, Universidad de La Laguna, 38320 La Laguna, Tenerife (Spain); Aparicio, A. [Instituto de Astrofisica de Canarias, 38200 La Laguna, Tenerife (Spain); Departamento de Astrofisica, Universidad de La Laguna. Avenida. Astrofisico Francisco Sanchez s/n, 38071 La Laguna, Tenerife (Spain)

    2007-03-15

    Makrofol detectors are commonly used for long-term radon ({sup 222}Rn) measurements in houses, schools and workplaces. The use of this type of passive detectors for the determination of radon concentrations requires the counting of the nuclear tracks produced by alpha particles on the detecting material. The 'image reduction and analysis facility' (IRAF) software package is a piece of software commonly used in astronomical applications. It allows detailed counting and mapping of sky sections where stars are grouped very closely, even forming clusters. In order to count the nuclear tracks in our Makrofol radon detectors, we have developed an inter-disciplinary application that takes advantage of the similitude that exist between counting stars in a dark sky and tracks in a track-etch detector. Thus, a low cost semi-automatic system has been set up in our laboratory which utilises a commercially available desktop scanner and the IRAF software package. A detailed description of the proposed semi-automatic method and its performance, in comparison to ocular counting, is described in detail here. In addition, the calibration factor for this procedure, 2.97+/-0.07kBqm{sup -3}htrack{sup -1}cm{sup 2}, has been calculated based on the results obtained from exposing 46 detectors to certified radon concentrations. Furthermore, the results of a preliminary radon survey carried out in 62 schools in Tenerife island (Spain), using Makrofol detectors, counted with the mentioned procedure, are briefly presented. The results reported here indicate that the developed procedure permits a fast, accurate and unbiased determination of the radon tracks in a large number of detectors. The measurements carried out in the schools showed that the radon concentrations in at least 12 schools were above 200Bqm{sup -3} and, in two of them, above 400Bqm{sup -3}. Further studies should be performed at those schools following the European Union recommendations about radon concentrations in

  2. Residential radon and lung cancer: a cohort study in Galicia, Spain

    Directory of Open Access Journals (Sweden)

    Raquel Barbosa-Lorenzo

    Full Text Available Case-control studies show an association between residential radon and lung cancer. The aim of this paper is to investigate this association through a cohort study. We designed an ambispective cohort study using the Galician radon map, Spain, with controls drawn from a previous case-control study. Subjects were recruited between 2002 and 2009. The data were cross-checked to ascertain lung cancer incidence and then analysed using a Cox regression model. A total of 2,127 subjects participated; 24 lung cancer cases were identified; 76.6% of subjects were drawn from the radon map. The adjusted hazard ratio was 1.2 (95%CI: 0.5-2.8 for the category of subjects exposed to 50Bq/m3 or more. This risk rose when subjects from the case-control study were analyzed separately. In conclusion, we did not observe any statistically significant association between residential radon exposure and lung cancer; however, it appears that with a sample of greater median age (such as participants from the case-control study, the risk of lung cancer would have been higher.

  3. Radon and thoron analysis of soil gas survey case study of Rajabasa geothermal field

    Science.gov (United States)

    Haerudin, Nandi; Wahyudi, Suryanto, Wiwit

    2013-09-01

    Radon and Thoron concentration of soil gas was measured by Scintrex Radon detector RDA 200 in the Rajabasa geothermal field, South Lampung regency, Indonesia. This study is aimed todeterminethe buried fault zoneunder theoverburdenlayer. The survey areacovers three geothermal manifestations in the southern part of Rajabasageothermalfield. The result indicates fault system trending SW-NE (N 60° E) and SSW-NNE (N 8° E). The contour map of Radon concentration performed high value in the three manifestations which was included survey area; those are 123 cpm in Gunung Botak hot spring, 145 cpm in Kunjir fumarole and 382 cpm about 300 m from Bulakan (Way Belerang) fumarole. Three manifestations were connected by two fault. The first fault passed begin from Gunung Botak directed to Kunjir and the other across the first fault from SSW to Bulakan. The contour map of Radon and Thoron ratio indicated that the second fault system is not only indicate the presence of the fault/fracture zones but also show the extension of the faults/fractures from the depth to the surface.

  4. Correlation analysis of the natural radionuclides in soil and indoor radon in Vojvodina, Province of Serbia.

    Science.gov (United States)

    Forkapic, S; Maletić, D; Vasin, J; Bikit, K; Mrdja, D; Bikit, I; Udovičić, V; Banjanac, R

    2017-01-01

    The most dominant source of indoor radon is the underlying soil, so the enhanced levels of radon are usually expected in mountain regions and geology units with high radium and uranium content in surface soils. Laboratory for radioactivity and dose measurement, Faculty of Sciences, University of Novi Sad has rich databases of natural radionuclides concentrations in Vojvodina soil and also of indoor radon concentrations for the region of Vojvodina, Northern Province of Serbia. In this paper we present the results of correlative and multivariate analysis of these results and soil characteristics in order to estimate the geogenic radon potential. The correlative and multivariate analysis were done using Toolkit for Multivariate Analysis software package TMVA package, within ROOT analysis framework, which uses several comparable multivariate methods for our analysis. The evaluation ranking results based on the best signal efficiency and purity, show that the Boosted Decision Trees (BDT) and Multi Layer Preceptor (MLP), based on Artificial Neural Network (ANN), are multivariate methods which give the best results in the analysis. The BDTG multivariate method shows that variables with the highest importance are radio-nuclides activity on 30 cm depth. Moreover, the multivariate regression methods give a good approximation of indoor radon activity using full set of input variables. On several locations in the city of Novi Sad the results of indoor radon concentrations, radon emanation from soil, gamma spectrometry measurements of underlying soil and geology characteristics of soil were analyzed in detail in order to verify previously obtained correlations for Vojvodina soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Mapping of diffusion in confined systems (beyond the concept of entropic potential)

    Science.gov (United States)

    Kalinay, Pavol

    2010-12-01

    Typical biological structures, like pores or fibers, are quasi one-dimensional (1D). We have to solve 3+1 dimensional differential equations to describe correctly transport through them or along them, but only the transport in the longitudinal direction is interesting in general. The question is to get rid of the transverse degrees of freedom in a mathematically correct way and to arrive at a pure 1D description of the system. We study this mathematical problem in the case of diffusion in a channel of varying cross section. We start with the simplest concept of entropic potential, logarithm of the number of states at some longitudinal position x, leading to the Fick-Jacobs equation. We present a rigorous mapping technique generating systematically corrections to the spatial operator of this equation in a small parameter ɛ, representing the ratio of the typical transverse and longitudinal lengths of the channel. Based on the result of this mapping, we discuss a hierarchy of various approximations, which can be applied to describe diffusion in the channel as purely one-dimensional. Finally, we give an outlook of possible extension of this mapping.

  6. Mosquito habitat and dengue risk potential in Kenya: alternative methods to traditional risk mapping techniques

    Directory of Open Access Journals (Sweden)

    David F. Attaway

    2014-11-01

    Full Text Available Outbreaks, epidemics and endemic conditions make dengue a disease that has emerged as a major threat in tropical and sub-tropical countries over the past 30 years. Dengue fever creates a growing burden for public health systems and has the potential to affect over 40% of the world population. The problem being investigated is to identify the highest and lowest areas of dengue risk. This paper presents “Similarity Search”, a geospatial analysis aimed at identifying these locations with- in Kenya. Similarity Search develops a risk map by combining environmental susceptibility analysis and geographical infor- mation systems, and then compares areas with dengue prevalence to all other locations. Kenya has had outbreaks of dengue during the past 3 years, and we identified areas with the highest susceptibility to dengue infection using bioclimatic variables, elevation and mosquito habitat as input to the model. Comparison of the modelled risk map with the reported dengue epi- demic cases obtained from the open source reporting ProMED and Government news reports from 1982-2013 confirmed the high-risk locations that were used as the Similarity Search presence cells. Developing the risk model based upon the bio- climatic variables, elevation and mosquito habitat increased the efficiency and effectiveness of the dengue fever risk mapping process.

  7. Mosquito habitat and dengue risk potential in Kenya: alternative methods to traditional risk mapping techniques.

    Science.gov (United States)

    Attaway, David F; Jacobsen, Kathryn H; Falconer, Allan; Manca, Germana; Rosenshein Bennett, Lauren; Waters, Nigel M

    2014-11-01

    Outbreaks, epidemics and endemic conditions make dengue a disease that has emerged as a major threat in tropical and sub-tropical countries over the past 30 years. Dengue fever creates a growing burden for public health systems and has the potential to affect over 40% of the world population. The problem being investigated is to identify the highest and lowest areas of dengue risk. This paper presents "Similarity Search", a geospatial analysis aimed at identifying these locations within Kenya. Similarity Search develops a risk map by combining environmental susceptibility analysis and geographical information systems, and then compares areas with dengue prevalence to all other locations. Kenya has had outbreaks of dengue during the past 3 years, and we identified areas with the highest susceptibility to dengue infection using bioclimatic variables, elevation and mosquito habitat as input to the model. Comparison of the modelled risk map with the reported dengue epidemic cases obtained from the open source reporting ProMED and Government news reports from 1982-2013 confirmed the high-risk locations that were used as the Similarity Search presence cells. Developing the risk model based upon the bioclimatic variables, elevation and mosquito habitat increased the efficiency and effectiveness of the dengue fever risk mapping process.

  8. Water deficit and water surplus maps for Brazil, based on FAO Penman-Monteith potential evapotranspiration

    Directory of Open Access Journals (Sweden)

    Ronalton Evandro Machado

    2008-12-01

    Full Text Available The climatological water balance (CWB proposed by Thornthwaite and Mather (1957 is a useful tool for agricultural planning. This method requires the soil water holding capacity (SWHC, rainfall (R and potential evapotranspiration (PET data as input. Among the methods used to estimate PET, the one proposed by Thornthwaite (1948 is the simplest and the most used in Brazil, however it presents limitations of use, which is caused by its empirical relationships. When Thornthwaite PET method is used into the CWB, the errors associated to PET are transferred to the output variables, mainly water deficit (WD and water surplus (WS. As all maps of WD and WS for Brazil are based on Thornthwaite PET, the objective of this study was to produce new maps of these variables considering Penman-Monteith PET. For this purpose, monthly normal climate data base (1961-1990 from Brazilian Meteorological Service (INMET, with 219 locations in all country, was used. PET data were estimated by Thornthwaite (TH and FAO Penman-Monteith (PM methods. PET, from both methods, and R data were used to estimate the CWB for a SWHC of 100 mm, having as results actual ET (AET, WD and WS. Results obtained with PET from the two methods were compared by regression analysis. The results showed that TH method underestimated annual PM PET by 13% in 84% of the places. Such underestimation also led to AET and WD underestimations of 7% (in 69% of places and 40% (in 83% of places, respectively. For WS, the use of TH PET data in the CWB resulted in overestimations of about 80% in 78% of places. The differences observed in the CWB variables resulted in changes in the maps of WD and WS for Brazil. These new maps, based on PM PET, provide more accurate information, mainly for agricultural and hydrological planning and irrigation and drainage projects purposes.

  9. DETERMINATION OF RADIUM AND RADON CONCENTRATIONS IN SOME ROCK SAMPLES

    OpenAIRE

    BAYKARA, Oktay

    2006-01-01

    The concentrations of radium (226Ra), radon (222Rn) and radon exhalation rate in nine rock samples have been determined using solid-state nuclear track detectors (CR-39). The measured maximum values of radium, radon and radon exhalation rate in rock samples were found to be 24.62 Bq/kg, 4911.32 Bq/m3 and 4,86 Bqm-2h-1, respectively. Linear correlation was observed among radon concentration, radon exhalation and radium concentration. The linear correlation coefficient between radium content an...

  10. Thorough investigations on indoor radon in Baita radon-prone area (Romania)

    Energy Technology Data Exchange (ETDEWEB)

    Cucos, Alexandra; Cosma, Constantin [Faculty of Environmental Science and Engineering, ' Babes-Bolyai' University, Fantanele No. 30, 400294, Cluj-Napoca (Romania); Dicu, Tiberius, E-mail: tiberius.dicu@ubbcluj.ro [Faculty of Environmental Science and Engineering, ' Babes-Bolyai' University, Fantanele No. 30, 400294, Cluj-Napoca (Romania); Begy, Robert; Moldovan, Mircea; Papp, Botond; Nita, Dan; Burghele, Bety [Faculty of Environmental Science and Engineering, ' Babes-Bolyai' University, Fantanele No. 30, 400294, Cluj-Napoca (Romania); Sainz, Carlos [Faculty of Environmental Science and Engineering, ' Babes-Bolyai' University, Fantanele No. 30, 400294, Cluj-Napoca (Romania); Department of Medical Physics, Faculty of Medicine, University of Cantabria, c/Herrera Oria s/n., 39011, Santander (Spain)

    2012-08-01

    A comprehensive radon survey has been carried out in Baita radon-prone area, Transylvania, Romania, in 4 localities (Baita, Nucet, Finate, and Cimpani) situated in the vicinity of former Romanian uranium mines. Indoor radon concentrations have been measured in 1128 ground floor rooms and cellars of 303 family houses by using CR-39 diffusion type radon detectors. The annual average of indoor radon concentration for Baita area was found to be 241 {+-} 178 Bq m{sup -3}, which is about two times higher than the average value of 126 Bq m{sup -3}, computed for Romania. About 28% of investigated houses exceed the reference level of radon gas in dwellings of 300 Bq m{sup -3}. The indoor radon measurements on each house have been carried out in several rooms simultaneously with the aim of obtaining a more detailed picture on the exposure to radon in the studied area. An analysis on the variability of radon levels among floors (floor-to-floor variation) and rooms (room-to-room variation) and also the influence of factors like the presence of cellar or the age of the building is presented. The coefficient of variation (CV) within ground floor rooms of the same house (room-to-room variation) ranged between 0.9 and 120.8%, with an arithmetic mean of 46.2%, a large variability among rooms within surveyed dwellings being clearly identified. The mean radon concentration in bedrooms without cellar was higher than in bedrooms above the cellar, the difference being statistically significant (t test, one tail, p < 0.001, n = 82). For houses built during 1960-1970 an increasing trend for radon levels was observed, but overall there was no significant difference in indoor radon concentrations by age of dwelling (one-way ANOVA test, p > 0.05). - Highlights: Black-Right-Pointing-Pointer The annual average of indoor radon concentration for Baita area was 241 {+-} 178 Bq m{sup -3}. Black-Right-Pointing-Pointer A large variability among rooms within surveyed dwellings was clearly evidenced

  11. Radon-safe new buildings, documentation and technology development. Main report; Radonsikring i nybyggeri, dokumentation og teknologiudvikling. Hovedrapport

    Energy Technology Data Exchange (ETDEWEB)

    Breddam Overgaard, L.; Bruun Petersen, J.; Neerup Jeppesen, M.

    2011-07-01

    penetrations with silicone sealant is also the most effective method. In the study it is furthermore concluded that there is no immediate difference in the two radon cavity barrier solutions (above and below the slab). Subproject 3 (radon potential in soil). At an introductory level it has been attempted to survey the radon potential (the amount of radon released from the soil) at the location of the construction of the subproject 1 residential development. The main part of the study consisted of developing and testing a method of ''passive sampling'' by immersion of measuring equipment in 1 m deep drillings. In the study significant radon levels were demonstrated in soil containing tertiary clay (black, micaceous). In comparing the aforementioned passive approach with previous ''active measurements'', it is estimated that passive measurements obtain an approximate expression (average) of the radon level of the entire borehole profile, while soil gas extraction sampling merely expresses a concentration at a level specific point (x m below the surface). The evaluation of the study concluded that satisfactory results had been achieved. It would however be relevant to improve the setup for future follow-up studies (as with subproject 2), and conduct repeated measurements prior to final conclusions. (LN)

  12. Comparison of retrospective and contemporary indoor radon measurements in a high-radon area of Serbia

    Energy Technology Data Exchange (ETDEWEB)

    Zunic, Z.S. [Institute of Nuclear Sciences ' Vinca' , Belgrade (Serbia); Yarmoshenko, I.V. [Institute of Industrial Ecology, Ural Branch of Russian Academy of Sciences, Ekaterinburg (Russian Federation)], E-mail: ivy@ecko.uran.ru; Kelleher, K. [Radiological Protection Institute of Ireland, Dublin (Ireland); Paridaens, J. [SCK.CEN Mol (Belgium); Mc Laughlin, J.P. [School of Physics, University College Dublin (Ireland); Celikovic, I.; Ujic, P. [Institute of Nuclear Sciences ' Vinca' , Belgrade (Serbia); Onischenko, A.D. [Institute of Industrial Ecology, Ural Branch of Russian Academy of Sciences, Ekaterinburg (Russian Federation); Jovanovic, S.; Demajo, A. [Institute of Nuclear Sciences ' Vinca' , Belgrade (Serbia); Birovljev, A. [Radonlab Ltd., Oslo (Norway); Bochicchio, F. [Italian National Institute of Health, Rome (Italy)

    2007-11-15

    In Niska Banja, Serbia, which is a high-radon area, a comparison was made between two retrospective radon measuring methods and contemporary radon measurements. The two retrospective methods derive the radon concentrations that occurred in dwellings over longer periods in the past, based on the amount of trapped {sup 210}Po on the surface of glass objects (surface traps, ST) or in the bulk of porous materials (volume traps, VT). Both surface implanted {sup 210}Po in glass objects and contemporary radon in air were measured in 46 rooms, distributed in 32 houses of this radon spa-town, using a dual alpha track detector configuration (CR-39 and LR115) and CR-39 track etched detectors, respectively. In addition to the use of surface trap measurements, in 18 rooms (distributed in 15 houses) VT samples of suitable material were also collected, allowing to compare ST and VT retrospective radon concentration estimates. For each room, contemporary annual radon concentrations (CONT) were measured or estimated using seasonal correction factors. The distribution of the radon concentration in all data sets was found to be close to lognormal (Chi-square test > 0.05). Geometric means (GM) are similar, ranging from 1040 to 1380 Bq m{sup -3}, whereas geometric standard deviations (GSD) for both the retrospective methods are greater than for the CONT method, showing reasonable agreement between VT, ST and CONT measurements. A regression analysis, with respect to the lognormal distribution of each data set, shows that for VT-ST the correlation coefficient r is 0.85, for VT-CONT r is 0.82 and for ST-CONT r is 0.73. Comparison of retrospective and contemporary radon concentrations with regard to supposed long-term indoor radon changes further supports the principal agreement between the retrospective and conventional methods.

  13. Comparison of retrospective and contemporary indoor radon measurements in a high-radon area of Serbia.

    Science.gov (United States)

    Zunić, Z S; Yarmoshenko, I V; Kelleher, K; Paridaens, J; Mc Laughlin, J P; Celiković, I; Ujić, P; Onischenko, A D; Jovanović, S; Demajo, A; Birovljev, A; Bochicchio, F

    2007-11-15

    In Niska Banja, Serbia, which is a high-radon area, a comparison was made between two retrospective radon measuring methods and contemporary radon measurements. The two retrospective methods derive the radon concentrations that occurred in dwellings over longer periods in the past, based on the amount of trapped (210)Po on the surface of glass objects (surface traps, ST) or in the bulk of porous materials (volume traps, VT). Both surface implanted (210)Po in glass objects and contemporary radon in air were measured in 46 rooms, distributed in 32 houses of this radon spa-town, using a dual alpha track detector configuration (CR-39 and LR115) and CR-39 track etched detectors, respectively. In addition to the use of surface trap measurements, in 18 rooms (distributed in 15 houses) VT samples of suitable material were also collected, allowing to compare ST and VT retrospective radon concentration estimates. For each room, contemporary annual radon concentrations (CONT) were measured or estimated using seasonal correction factors. The distribution of the radon concentration in all data sets was found to be close to lognormal (Chi-square test>0.05). Geometric means (GM) are similar, ranging from 1040 to 1380 Bq m(-3), whereas geometric standard deviations (GSD) for both the retrospective methods are greater than for the CONT method, showing reasonable agreement between VT, ST and CONT measurements. A regression analysis, with respect to the lognormal distribution of each data set, shows that for VT-ST the correlation coefficient r is 0.85, for VT-CONT r is 0.82 and for ST-CONT r is 0.73. Comparison of retrospective and contemporary radon concentrations with regard to supposed long-term indoor radon changes further supports the principal agreement between the retrospective and conventional methods.

  14. Thorough investigations on indoor radon in Băiţa radon-prone area (Romania).

    Science.gov (United States)

    Cucoş Dinu, Alexandra; Cosma, Constantin; Dicu, Tiberius; Begy, Robert; Moldovan, Mircea; Papp, Botond; Niţă, Dan; Burghele, Bety; Sainz, Carlos

    2012-08-01

    A comprehensive radon survey has been carried out in Băiţa radon-prone area, Transylvania, Romania, in 4 localities (Băiţa, Nucet, Fînaţe, and Cîmpani) situated in the vicinity of former Romanian uranium mines. Indoor radon concentrations have been measured in 1128 ground floor rooms and cellars of 303 family houses by using CR-39 diffusion type radon detectors. The annual average of indoor radon concentration for Băiţa area was found to be 241±178 Bq m(-3), which is about two times higher than the average value of 126 Bq m(-3), computed for Romania. About 28% of investigated houses exceed the reference level of radon gas in dwellings of 300 Bq m(-3). The indoor radon measurements on each house have been carried out in several rooms simultaneously with the aim of obtaining a more detailed picture on the exposure to radon in the studied area. An analysis on the variability of radon levels among floors (floor-to-floor variation) and rooms (room-to-room variation) and also the influence of factors like the presence of cellar or the age of the building is presented. The coefficient of variation (CV) within ground floor rooms of the same house (room-to-room variation) ranged between 0.9 and 120.8%, with an arithmetic mean of 46.2%, a large variability among rooms within surveyed dwellings being clearly identified. The mean radon concentration in bedrooms without cellar was higher than in bedrooms above the cellar, the difference being statistically significant (t test, one tail, pradon levels was observed, but overall there was no significant difference in indoor radon concentrations by age of dwelling (one-way ANOVA test, p>0.05).

  15. Radon measurements in some areas in Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Hamid Khan, M.A. [Physics Division, Atomic Energy Centre, Bangladesh Atomic Energy Commission, P.O. Box 164, Dhaka-1000 (Bangladesh)], E-mail: hamidkhan1950@yahoo.com; Chowdhury, M.S. [Physics Department, Dhaka University, Dhaka-1000 (Bangladesh)

    2008-08-15

    A survey of radon level measurements using CR-39 has been carried out in some of urban and rural residential areas and one gas explosion area in Bangladesh. The lowest level of radon concentration was found to be 49Bqm{sup -3} inside a hospital in Cox's Bazar district and the highest level was found to be 835Bqm{sup -3} inside a mud-made old residential house in Sylhet city. It was observed that old residential houses were found to have higher levels of radon concentrations compared to newly built houses. The radon level at the gas explosion area at Magurchara in Moulvibazar district was found to be 408{+-}98Bqm{sup -3}.

  16. GEOMETRICALLY INVARIANT WATERMARKING BASED ON RADON TRANSFORMATION

    Institute of Scientific and Technical Information of China (English)

    Cai Lian; Du Sidan; Gao Duntang

    2005-01-01

    The weakness of classical watermarking methods is the vulnerability to geometrical distortions that widely occur during normal use of the media. In this letter, a new imagewatermarking method is presented to resist Rotation, Scale and Translation (RST) attacks. The watermark is embedded into a domain obtained by taking Radon transform of a circular area selected from the original image, and then extracting Two-Dimensional (2-D) Fourier magnitude of the Radon transformed image. Furthermore, to prevent the watermarked image from degrading due to inverse Radon transform, watermark signal is inversely Radon transformed individually.Experimental results demonstrate that the proposed scheme is able to withstand a variety of attacks including common geometric attacks.

  17. Dependency of radon entry on pressure difference

    Science.gov (United States)

    Kokotti, H.; Kalliokoski, P.; Jantunen, M.

    Radon levels, ventilation rate and pressure differences were monitored continuously in four apartment houses with different ventilation systems. Two of them were ventilated by mechanical exhaust, one by mechanical supply and exhaust, and one by natural ventilation. The two-storey houses were constructed from concrete elements on a slab and located on a gravel esker. It was surprising to find that increasing the ventilation rate increased levels of radon in the apartments. Increased ventilation caused increased outdoor-indoor pressure difference, which in turn increased the entry rate of radon and counteracted the diluting effect of ventilation. The increase was significant when the outdoor-indoor pressure difference exceeded 5 Pa. Especially in the houses with mechanical exhaust ventilation the pressure difference was the most important factor of radon entry rate, and contributed up to several hundred Bq m -3 h -1.

  18. Radon measurement using a liquid scintillation spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Taeko; Morishima, Hiroshige; Kawai, Hiroshi; Kondo, Sohei (Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.); Mifune, Masaki; Konishi, Masanobu; Shirai, Chiaki

    1992-12-01

    A convenient radon detecting device for the purpose of estimating natural radiation exposure is described. The [alpha] radioactivity of radon gas absorbed in fine active carbon particles exposed to air is measured with a liquid scintillation spectrometer (Packard-PICO-RAD system). Its detection limits are 2mBq/l in air and 0.5 Bq/l in water with an accuracy of about 10 %. Radon concentrations at Misasa hot springs in Tottori prefecture were measured using this method. They were 0.16 [approx] 7.7 Bq/l in a bath room and 0.057 [approx] 0.36 Bq/l outdoors. Radon concentrations of the hot springs were 82 [approx] 1,700 Bq/l. (author).

  19. Radon Transform and Light-Cone Distributions

    Science.gov (United States)

    Teryaev, O. V.

    2016-08-01

    The relevance of Radon transform for generalized and transverse momentum dependent parton distributions is discussed. The new application for conditional (fracture) parton distributions and dihadron fragmentation functions is suggested.

  20. Radon in private drinking water wells.

    Science.gov (United States)

    Otahal, P; Merta, J; Burian, I

    2014-07-01

    At least 10% of inhabitants in the Czech Republic are supplied with water from private sources (private wells, boreholes). With the increasing cost of water, the number of people using their own sources of drinking water will be likely to increase. According to the Decree of the State Office for Nuclear Safety about the Radiation Protection 307/2002 as amended by Decree 499/2005, the guideline limit for the supplied drinking water ('drinking water for public supply') for radon concentration is 50 Bq·l(-1). This guideline does not apply to private sources of drinking water. Radon in water influences human health by ingestion and also by inhalation when radon is released from water during showering and cooking. This paper presents results of measurements of radon concentrations in water from private wells in more than 300 cases. The gross concentration of alpha-emitting radionuclides and the concentrations of radium and uranium were also determined.

  1. El gas radon y la hormesis

    National Research Council Canada - National Science Library

    Garzon Valencia, Gustavo

    2006-01-01

    ..., el cual sale desde el interior de la Tierra. Una construccion con poca ventilacion puede servir de lugar de acumulacion del gas radon y por lo tanto puede aumentar las dosis efectivas de radiactividad sobre el organismo de sus residentes...

  2. Radon Exhalation Considered in Building Material Standard

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>In order to investigate the relationship between radon exhalation and specific activity of natural nuclides in building material, here different kinds of samples of building materials were measured by the

  3. Novel Radon Sub-Slab Suctioning System

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2013-01-01

    the zone below the ground-floor construction. For this purpose a new system of prefabricated lightweight elements is introduced. The effectiveness of the system is demonstrated for the case of a ground-floor reinforced concrete slab situated on top of a rigid insulation layer (consisting of a thermal......A new principle for radon protection is currently presented which makes use of a system of horizontal pressurised air ducts located within the lower part of the rigid insulation layer of the ground-floor slab. The function of this system is based on the principles of pressure reduction within...... a grid of horizontal air ducts with low pressure which are able to remove air and radon from the ground. Results showed the system to be effective in preventing radon infiltrating from the ground through the ground-floor slab, avoiding high concentrations of radon being accumulated inside houses...

  4. Distribution of indoor radon levels in Mexico

    CERN Document Server

    Espinosa, G; Rickards, J; Gammage, R B

    1999-01-01

    Our laboratory has carried out a systematic monitoring and evaluation of indoor radon concentration levels in Mexico for ten years. The results of the distribution of indoor radon levels for practically the entire country are presented, together with information on geological characteristics, population density, socioeconomic levels of the population, and architectural styles of housing. The measurements of the radon levels were made using the passive method of nuclear tracks in solids with the end-cup system. CR-39 was used as the detector material in combination with a one-step chemical etching procedure and an automatic digital- image counting system. Wherever a high level was measured, a confirming measurement was made using a dynamic method. The results are important for future health studies, including the eventual establishment of patterns for indoor radon concentration, as it has been done in the USA and Europe.

  5. Manifestation of an Analytic Hierarchy Process (AHP Model on Fire Potential Zonation Mapping in Kathmandu Metropolitan City, Nepal

    Directory of Open Access Journals (Sweden)

    Sachin Kumar Chhetri

    2015-03-01

    Full Text Available Even though fewer people die as a result of fire than other natural disasters, such as earthquake, flood, landslide, etc., the average loss of property due to fire is high. Kathmandu Metropolitan City is becoming more vulnerable to fire due to haphazard urbanization and increase in population. To control problems due to fire, systematic studies are necessary, including fire potential mapping and risk assessment. This study applies an Analytic Hierarchy Process (AHP method in Kathmandu Metropolitan City, Nepal for generation of fire potential zonation map. The fire potential zonation map is prepared on the basis of available data of land use, fuel stations, and population density. This map shows that 58.04% of the study area falls under low fire potential zone, 32.92% falls under moderate fire potential zone and 9.04% falls under high fire potential zone. The map is also validated through major past fire incidents. The results show that the predicted fire potential zones are found to be in good agreement with past fire incidents, and, hence, the map can be used for future land-use planning.

  6. Subsurface mapping in the Iberian Pyrite Belt using seismic reflection profiling and potential-field data

    Science.gov (United States)

    Carvalho, João; Inverno, Carlos; Matos, João Xavier; Rosa, Carlos; Granado, Isabel; Branch, Tim; Represas, Patrícia; Carabaneanu, Livia; Matias, Luís; Sousa, Pedro

    2017-04-01

    The Iberian Pyrite Belt (IPB) hosts world-class massive sulphide deposits, such as Neves-Corvo in Portugal and Rio Tinto in Spain. In Portugal, the Palaeozoic Volcanic-Sedimentary Complex (VSC) hosts these ore deposits, extending from the Grândola-Alcácer region to the Spanish border with a NW-SE to WNW-ESE trend. In the study area, between the Neves-Corvo mine region and Alcoutim (close to the Spanish border), the VSC outcrops only in a small horst near Alcoutim. Sparse exploration drill-hole data indicate that the depth to the top of the VSC varies from several 100 m to about 1 km beneath the Mértola Formation Flysch cover. Mapping of the VSC to the SE of Neves-Corvo mine is an important exploration goal and motivated the acquisition of six 2D seismic reflection profiles with a total length of approximately 82 km in order to map the hidden extension of the VSC. The data, providing information deeper than 10 km at some locations, were integrated in a 3D software environment along with potential-field, geological and drill-hole data to form a 3D structural framework model. Seismic data show strong reflections that represent several long Variscan thrust planes that smoothly dip to the NNE. Outcropping and previously unknown Late Variscan near-vertical faults were also mapped. Our data strongly suggest that the structural framework of Neves-Corvo extends south-eastwards to Alcoutim. Furthermore, the VSC top is located at depths that show the existence within the IPB of new areas with good potential to develop exploration projects envisaging the discovery of massive sulphide deposits of the Neves-Corvo type.

  7. Potential Deep Seated Landslide Mapping from Various Temporal Data - Benchmark, Aerial Photo, and SAR

    Science.gov (United States)

    Wang, Kuo-Lung; Lin, Jun-Tin; Lee, Yi-Hsuan; Lin, Meei-Ling; Chen, Chao-Wei; Liao, Ray-Tang; Chi, Chung-Chi; Lin, Hsi-Hung

    2016-04-01

    Landslide is always not hazard until mankind development in highly potential area. The study tries to map deep seated landslide before the initiation of landslide. Study area in central Taiwan is selected and the geological condition is quite unique, which is slate. Major direction of bedding in this area is northeast and the dip ranges from 30-75 degree to southeast. Several deep seated landslides were discovered in the same side of bedding from rainfall events. The benchmarks from 2002 ~ 2009 are in this study. However, the benchmarks were measured along Highway No. 14B and the road was constructed along the peak of mountains. Taiwan located between sea plates and continental plate. The elevation of mountains is rising according to most GPS and benchmarks in the island. The same trend is discovered from benchmarks in this area. But some benchmarks are located in landslide area thus the elevation is below average and event negative. The aerial photos from 1979 to 2007 are used for orthophoto generation. The changes of land use are obvious during 30 years and enlargement of river channel is also observed in this area. Both benchmarks and aerial photos have discovered landslide potential did exist this area but how big of landslide in not easy to define currently. Thus SAR data utilization is adopted in this case. DInSAR and SBAS sar analysis are used in this research and ALOS/PALSAR from 2006 to 2010 is adopted. DInSAR analysis shows that landslide is possible mapped but the error is not easy to reduce. The error is possibly form several conditions such as vegetation, clouds, vapor, etc. To conquer the problem, time series analysis, SBAS, is adopted in this research. The result of SBAS in this area shows that large deep seated landslides are easy mapped and the accuracy of vertical displacement is reasonable.

  8. Subsurface mapping in the Iberian Pyrite Belt using seismic reflection profiling and potential-field data

    Science.gov (United States)

    Carvalho, João; Inverno, Carlos; Matos, João Xavier; Rosa, Carlos; Granado, Isabel; Branch, Tim; Represas, Patrícia; Carabaneanu, Livia; Matias, Luís; Sousa, Pedro

    2016-06-01

    The Iberian Pyrite Belt (IPB) hosts world-class massive sulphide deposits, such as Neves-Corvo in Portugal and Rio Tinto in Spain. In Portugal, the Palaeozoic Volcanic-Sedimentary Complex (VSC) hosts these ore deposits, extending from the Grândola-Alcácer region to the Spanish border with a NW-SE to WNW-ESE trend. In the study area, between the Neves-Corvo mine region and Alcoutim (close to the Spanish border), the VSC outcrops only in a small horst near Alcoutim. Sparse exploration drill-hole data indicate that the depth to the top of the VSC varies from several 100 m to about 1 km beneath the Mértola Formation Flysch cover. Mapping of the VSC to the SE of Neves-Corvo mine is an important exploration goal and motivated the acquisition of six 2D seismic reflection profiles with a total length of approximately 82 km in order to map the hidden extension of the VSC. The data, providing information deeper than 10 km at some locations, were integrated in a 3D software environment along with potential-field, geological and drill-hole data to form a 3D structural framework model. Seismic data show strong reflections that represent several long Variscan thrust planes that smoothly dip to the NNE. Outcropping and previously unknown Late Variscan near-vertical faults were also mapped. Our data strongly suggest that the structural framework of Neves-Corvo extends south-eastwards to Alcoutim. Furthermore, the VSC top is located at depths that show the existence within the IPB of new areas with good potential to develop exploration projects envisaging the discovery of massive sulphide deposits of the Neves-Corvo type.

  9. Transancestral fine-mapping of four type 2 diabetes susceptibility loci highlights potential causal regulatory mechanisms

    Science.gov (United States)

    Horikoshi, Momoko; Pasquali, Lorenzo; Wiltshire, Steven; Huyghe, Jeroen R.; Mahajan, Anubha; Asimit, Jennifer L.; Ferreira, Teresa; Locke, Adam E.; Robertson, Neil R.; Wang, Xu; Sim, Xueling; Fujita, Hayato; Hara, Kazuo; Young, Robin; Zhang, Weihua; Choi, Sungkyoung; Chen, Han; Kaur, Ismeet; Takeuchi, Fumihiko; Fontanillas, Pierre; Thuillier, Dorothée; Yengo, Loic; Below, Jennifer E.; Tam, Claudia H.T.; Wu, Ying; Abecasis, Gonçalo; Altshuler, David; Bell, Graeme I.; Blangero, John; Burtt, Noél P.; Duggirala, Ravindranath; Florez, Jose C.; Hanis, Craig L.; Seielstad, Mark; Atzmon, Gil; Chan, Juliana C.N.; Ma, Ronald C.W.; Froguel, Philippe; Wilson, James G.; Bharadwaj, Dwaipayan; Dupuis, Josee; Meigs, James B.; Cho, Yoon Shin; Park, Taesung; Kooner, Jaspal S.; Chambers, John C.; Saleheen, Danish; Kadowaki, Takashi; Tai, E. Shyong; Mohlke, Karen L.; Cox, Nancy J.; Ferrer, Jorge; Zeggini, Eleftheria; Kato, Norihiro; Teo, Yik Ying; Boehnke, Michael; McCarthy, Mark I.; Morris, Andrew P.

    2016-01-01

    To gain insight into potential regulatory mechanisms through which the effects of variants at four established type 2 diabetes (T2D) susceptibility loci (CDKAL1, CDKN2A-B, IGF2BP2 and KCNQ1) are mediated, we undertook transancestral fine-mapping in 22 086 cases and 42 539 controls of East Asian, European, South Asian, African American and Mexican American descent. Through high-density imputation and conditional analyses, we identified seven distinct association signals at these four loci, each with allelic effects on T2D susceptibility that were homogenous across ancestry groups. By leveraging differences in the structure of linkage disequilibrium between diverse populations, and increased sample size, we localised the variants most likely to drive each distinct association signal. We demonstrated that integration of these genetic fine-mapping data with genomic annotation can highlight potential causal regulatory elements in T2D-relevant tissues. These analyses provide insight into the mechanisms through which T2D association signals are mediated, and suggest future routes to understanding the biology of specific disease susceptibility loci. PMID:26911676

  10. A Method to Analyze the Potential of Optical Remote Sensing for Benthic Habitat Mapping

    Directory of Open Access Journals (Sweden)

    Rodrigo A. Garcia

    2015-10-01

    Full Text Available Quantifying the number and type of benthic classes that are able to be spectrally identified in shallow water remote sensing is important in understanding its potential for habitat mapping. Factors that impact the effectiveness of shallow water habitat mapping include water column turbidity, depth, sensor and environmental noise, spectral resolution of the sensor and spectral variability of the benthic classes. In this paper, we present a simple hierarchical clustering method coupled with a shallow water forward model to generate water-column specific spectral libraries. This technique requires no prior decision on the number of classes to output: the resultant classes are optically separable above the spectral noise introduced by the sensor, image based radiometric corrections, the benthos’ natural spectral variability and the attenuating properties of a variable water column at depth. The modeling reveals the effect reducing the spectral resolution has on the number and type of classes that are optically distinct. We illustrate the potential of this clustering algorithm in an analysis of the conditions, including clustering accuracy, sensor spectral resolution and water column optical properties and depth that enabled the spectral distinction of the seagrass Amphibolis antartica from benthic algae.

  11. Quantitative Interpretation of Air Radon Progeny Fluctuations in Terms of Stability Conditions in the Atmospheric Boundary Layer

    Science.gov (United States)

    Salzano, Roberto; Pasini, Antonello; Casasanta, Giampietro; Cacciani, Marco; Perrino, Cinzia

    2016-09-01

    Determining the mixing height using a tracer can improve the information obtained using traditional techniques. Here we provide an improved box model based on radon progeny measurements, which considers the vertical entrainment of residual layers and the variability in the soil radon exhalation rate. The potential issues in using progeny instead of radon have been solved from both a theoretical and experimental perspective; furthermore, the instrumental efficiency and the counting scheme have been included in the model. The applicability range of the box model has been defined by comparing radon-derived estimates with sodar and lidar data. Three intervals have been analyzed ("near-stable", "transition" and "turbulent"), and different processes have been characterized. We describe a preliminary application case performed in Rome, Italy, while case studies will be required to determine the range limits that can be applied in any circumstances.

  12. Fuzzy logic-based assessment for mapping potential infiltration areas in low-gradient watersheds.

    Science.gov (United States)

    Quiroz Londoño, Orlando Mauricio; Romanelli, Asunción; Lima, María Lourdes; Massone, Héctor Enrique; Martínez, Daniel Emilio

    2016-07-01

    This paper gives an account of the design a logic-based approach for identifying potential infiltration areas in low-gradient watersheds based on remote sensing data. This methodological framework is applied in a sector of the Pampa Plain, Argentina, which has high level of agricultural activities and large demands for groundwater supplies. Potential infiltration sites are assessed as a function of two primary topics: hydrologic and soil conditions. This model shows the state of each evaluated subwatershed respecting to its potential contribution to infiltration mainly based on easily measurable and commonly used parameters: drainage density, geomorphologic units, soil media, land-cover, slope and aspect (slope orientation). Mapped outputs from the logic model displayed 42% very low-low, 16% moderate, 41% high-very high contribution to potential infiltration in the whole watershed. Subwatersheds in the upper and lower section were identified as areas with high to very high potential infiltration according to the following media features: low drainage density (<1.5 km/km(2)), arable land and pastures as the main land-cover categories, sandy clay loam to loam - clay loam soils and with the geomorphological units named poorly drained plain, channelized drainage plain and, dunes and beaches.

  13. Modeling and mapping potential distribution of Crimean juniper (Juniperus excelsa Bieb.) using correlative approaches.

    Science.gov (United States)

    Özkan, Kürşad; Şentürk, Özdemir; Mert, Ahmet; Negiz, Mehmet Güvenç

    2015-01-01

    Modeling and mapping potential distribution of living organisms has become an important component of conservation planning and ecosystem management in recent years. Various correlative and mechanistic methods can be applied to build predictive distributions of living organisms in terrestrial and marine ecosystems. Correlative methods used to predict species' potential distribution have been described as either group discrimination techniques or profile techniques. We attempted to determine whether group discrimination techniques could perform as well as profile techniques for predicting species potential distributions, using elevation (ELVN), parent material (ROCK), slope (SLOP), radiation index (RI) and topographic position index (TPI)) as explanatory variables. We compared potential distribution predictions made for Crimean juniper (Juniperus excelsa Bieb.) in the Yukan Gokdere forest district of the Mediterranean region, Turkey, applying four group discrimination techniques (discriminate analysis (DA), logistic regression analysis (LR), generalized addictive model (GAM) and classification tree technique (CT)) and two profile techniques (a maximum entropy approach to species distribution modeling (MAXENT), the genetic algorithm for rule-set prediction (GARP)). Visual assessments of the potential distribution probability of the applied models for Crimean juniper were performed by using geographical information systems (GIS). Receiver-operating characteristic (ROC) curves were used to objectively assess model performance. The results suggested that group discrimination techniques are better than profile techniques and, among the group discrimination techniques, GAM indicated the best performance.

  14. Half-cell potential mapping to assess repair work on RC structures

    Energy Technology Data Exchange (ETDEWEB)

    Elsener, B. [Cagliari Univ., Dept. of Materials Science (Italy)

    2000-07-01

    Results on the successful use and on the limitations of half-cell potential mapping as an assessment technique after completion of repair work on a concrete structure are reviewed. Examples of repair discussed include traditional repair, electrochemical chloride removal, electrochemical realkalization and the application of surface applied corrosion inhibitors. Results indicate that half-cell potential measurements after traditional repair work or electrochemical chloride removal provide direct evidence of repassivation of the rebars when performed several weeks after the repair work (readings during the first few days after repair tend to show very negative potentials). Special attention must be given to the use of polymer-modified mortars when used in surface treatment of rebars; half-cell potential could remain permanently negative due to restricted oxygen access. Half-cell potential measurements are not considered effective in measuring the efficiency and durability of surface applied corrosion inhibitors due to pore solution pH and composition, and the mostly unknown mechanism of action of inhibitor blends. 18 refs., 8 figs.

  15. The Influence of Internal Wall and Floor Covering Materials and Ventilation Type on Indoor Radon and Thoron Levels in Hospitals of Kermanshah, Iran

    Science.gov (United States)

    Pirsaheb, Meghdad; Najafi, Farid; Haghparast, Abbas; Hemati, Lida; Sharafi, Kiomars; Kurd, Nematullah

    2016-01-01

    Background Building materials and the ventilation rate of a building are two main factors influencing indoor radon and thoron levels (two radioactive gases which have the most important role in human natural radiation exposure within dwellings). Objectives This analytical descriptive study was intended to determine the relationship between indoor radon and thoron concentrations and the building materials used in interior surfaces, as well as between those concentrations and the type of ventilation system (natural or artificial). Materials and Methods 102 measurements of radon and thoron levels were taken from different parts of three hospital buildings in the city of Kermanshah in the west of Iran, using an RTM-1688-2 radon meter. Information on the type of building material and ventilation system in the measurement location was collected and then analyzed using Stata 8 software and multivariate linear regression. Results In terms of radon and thoron emissions, travertine and plaster were found to be the most appropriate and inappropriate covering for walls, respectively. Furthermore, granite and travertine were discovered to be inappropriate materials for flooring, while plastic floor covering was found suitable. Natural ventilation performed better for radon, while artificial ventilation worked better for thoron. Conclusions Internal building materials and ventilation type affect indoor radon and thoron concentrations. Therefore, the use of proper materials and adequate ventilation can reduce the potential human exposure to radon and thoron. This is of utmost importance, particularly in buildings with a high density of residents, including hospitals.

  16. Personal radon dosimetry from eyeglass lenses.

    Science.gov (United States)

    Fleischer, R L; Meyer, N R; Hadley, S A; MacDonald, J; Cavallo, A

    2001-01-01

    Eyeglass lenses are commonly composed of allyl-diglycol carbonate (CR-39), an alpha-particle detecting plastic, thus making such lenses personal radon dosemeters. Samples of such lenses have been obtained, etched to reveal that radon and radon progeny alpha tracks can be seen in abundance, and sensitivities have been calibrated in radon chambers as a primary calibration, and with a uranium-based source of alpha particles as a convenient secondary standard. With one exception natural, environmental (fossil) track densities ranged from less than 3,000 to nearly 70,000 per cm2 for eyeglasses that had been worn for various times from one to nearly five years. Average radon concentrations to which those wearers were exposed are inferred to be in the range 14 to 130 Bq x m(-3) (0.4 to 3.5 pCi x l(-1)). A protocol for consistent, meaningful readout is derived and used. In the exceptional case the fossil track density was 1,780,000 cm(-2) and the inferred (24 h) average radon concentration was 6500 Bq x m(-3) (175 pCi x l(-1)) for a worker at an inactive uranium mine that is used for therapy.

  17. Radon emanation from radium specific adsorbents.

    Science.gov (United States)

    Alabdula'aly, Abdulrahman I; Maghrawy, Hamed B

    2010-01-01

    Pilot studies were undertaken to quantify the total activity of radon that is eluted following no-flow periods from several Ra-226 adsorbents loaded to near exhaustion. The adsorbents studied included two types of barium sulphate impregnated alumina (ABA-8000 and F-1) and Dowex MSC-1 resin treated by either barium hydroxide or barium chloride. In parallel, radium loaded plain activated aluminas and Dowex MSC-1 resin were similarly investigated. The results revealed that radon was quantitatively eluted during the first few bed volumes of column operation after no-flow periods. Although similar radon elution profiles were obtained, the position of the radon peak was found to vary and depended on the adsorbent type. Radon levels up to 24 and 14 kBq dm(-3) were measured after a rest period of 72h from radium exhausted Dowex MSC-1 treated with barium chloride and F-1 impregnated alumina with barium sulphate, respectively. The eluted radon values measured experimentally were compared to those calculated theoretically from accumulated radium quantities for the different media. For plain adsorbents, an agreement better than 10% was obtained. For treated resin-types a consistency within 30% but for impregnated alumina-types high discrepancy between respective values were obtained.

  18. The radon gas. An air pollutant

    Directory of Open Access Journals (Sweden)

    Luis Santiago Quindós Poncela

    2010-12-01

    Full Text Available In this work different aspects about the problem of the radon in dwellings are approached. This gas of natural origin is virtually present in all the soils in the earth’s crust due to the presence of uranium and radium in the composition of them. Depending on architectural factors and of occupancy habits of the house, high concentrations of this gas can be reached indoors. In these situations, there is a quantifiable increment of the risk of developing lung cancer in the inhabitants of the housing. In the last years the methodological improvements in the realization of epidemiologic studies have led to the obtaining of scientific evidences about the relationship between the presence of indoor radon and the risk of lung cancer. This relationship, found years ago in workers of uranium mines, has been corroborated in the case of the residential radon by the light of several recent meta-analysis performed on groups of epidemiologic studies. More than 6.000 radon measurements have been carried out in Spain during the last 25 years. A summary of the results obtained from the main national radon surveys are also presented, as well as the criteria recently established by the Spanish Nuclear Safety Council concerning radon action levels in dwellings and workplaces.

  19. Pre-seismic variations of atmospheric radon activity as a possible reason for abnormal atmospheric effects

    Directory of Open Access Journals (Sweden)

    Vadim V. Surkov

    2015-11-01

    Full Text Available Possible atmospheric effects associated with pre-seismic variations of atmospheric radon concentration occasionally observed prior to earthquake occurrence are subjected to theoretical study in order to assess their potential effectiveness. Altitude distribution of atmospheric conductivity is examined as a function of radon and aerosol concentrations. Horizontal components of atmospheric electric fields and currents, which can arise near a boundary of seismo-active region, are estimated. We speculated that changes in radon-induced air ionization can have an impact on fair-weather spectra of ULF electric pulsations. Particular emphasis has been placed on hypothesis for correlation between variations of pre-seismic radon activity and upward thermal radiation measured by satellite over the high seismicity regions. This hypothesis is based on assumption that the radon-induced ionization of atmospheric surface layer can trigger water vapor condensation which in turn results in release of the vaporization heat. Our analysis has shown that the upward thermal flux has to be many orders of magnitude lower than that predicted on the basis of this hypothesis.

  20. Radon in Soil Gas Above Bedrock Fracture Sets at the Shepley’s Hill Superfund Site

    Energy Technology Data Exchange (ETDEWEB)

    J.R. Giles; T.L. McLing; M.V. Carpenter; C.J. Smith; W. Brandon

    2012-12-01

    The Idaho National Laboratory (INL) recently provided technical support for ongoing environmental remediation activities at the Shepley’s Hill remediation site near Devens, MA (Figure 1). The technical support was requested as follow-on work to an initial screening level radiation survey conducted in 2008. The purpose of the original study was to assess the efficacy of the INL-developed Backpack Sodium Iodide System (BaSIS) for detecting elevated areas of natural radioactivity due to the decay of radon-222 gases emanating from the underlying fracture sets. Although the results from the initial study were mixed, the BaSIS radiation surveys did confirm that exposed bedrock outcrops have higher natural radioactivity than the surficial soils, thus a high potential for detecting elevated levels of radon and/or radon daughter products. (INL 2009) The short count times associated with the BaSIS measurements limited the ability of the system to respond to elevated levels of radioactivity from a subsurface source, in this instance radon gas emanating from fracture sets. Thus, it was postulated that a different methodology be employed to directly detect the radon in the soil gases. The CR-39 particle track detectors were investigated through an extensive literature and technology search. The relatively long deployment or “detection” time of several days, as well as the sensitivity of the measurement and robustness of the detectors made the CR-39 technology promising for deployment at the Shepley’s Hill site.

  1. RADON REDUCTION AND RADON-RESISTANT CONSTRUCTION DEMONSTRATIONS IN NEW YORK - VOLUME 2: APPENDICES

    Science.gov (United States)

    Growing concern about health risks associated with exposure to indoor radon, a radioactive gas found in varying amounts in nearly all houses, has underscored the need for dependable radon reduction methods in existing and newly constructed houses. Responding to this need, the U....

  2. Radon and radon-daughter concentrations in air in the vicinity of the Anaconda Uranium Mill

    Energy Technology Data Exchange (ETDEWEB)

    Momeni, M H; Lindstrom, J B; Dungey, C E; Kisieleski, W E

    1979-11-01

    Radon concentration, working level, and meteorological variables were measured continuously from June 1977 through June 1978 at three stations in the vicinity of the Anaconda Uranium Mill with measurements integrated to hourly intervals. Both radon and daughters show strong variations associated with low wind velocities and stable atmospheric conditions, and diurnal variations associated with thermal inversions. Average radon concentration shows seasonal dependence with highest concentrations observed during fall and winter. Comparison of radon concentrations and working levels between three stations shows strong dependence on wind direction and velocity. Radon concentrations and working-level distributions for each month and each station were analyzed. The average maximum, minimum, and modal concentration and working levels were estimated with observed frequencies. The highest concentration is 11,000 pCi/m/sup 3/ on the tailings. Working-level variations parallel radon variations but lag by less than one hour. The highest working levels were observed at night when conditions of higher secular radioactive equilibrium for radon daughters exist. Background radon concentration was measured at two stations, each located about 25 km from the mill, and the average is 408 pCi/m/sup 3/. Average working-level background is 3.6 x 10/sup -3/.

  3. Determination of air-loop volume and radon partition coefficient for measuring radon in water sample.

    Science.gov (United States)

    Lee, Kil Yong; Burnett, William C

    A simple method for the direct determination of the air-loop volume in a RAD7 system as well as the radon partition coefficient was developed allowing for an accurate measurement of the radon activity in any type of water. The air-loop volume may be measured directly using an external radon source and an empty bottle with a precisely measured volume. The partition coefficient and activity of radon in the water sample may then be determined via the RAD7 using the determined air-loop volume. Activity ratios instead of absolute activities were used to measure the air-loop volume and the radon partition coefficient. In order to verify this approach, we measured the radon partition coefficient in deionized water in the temperature range of 10-30 °C and compared the values to those calculated from the well-known Weigel equation. The results were within 5 % variance throughout the temperature range. We also applied the approach for measurement of the radon partition coefficient in synthetic saline water (0-75 ppt salinity) as well as tap water. The radon activity of the tap water sample was determined by this method as well as the standard RAD-H2O and BigBottle RAD-H2O. The results have shown good agreement between this method and the standard methods.

  4. Application of a radon model to explain indoor radon levels in a Swedish house

    CERN Document Server

    Font, L; Jönsson, G; Enge, W; Ghose, R

    1999-01-01

    Radon entry from soil into indoor air and its accumulation indoors depends on several parameters, the values of which normally depend on the specific characteristics of the site. The effect of a specific parameter is often difficult to explain from the result of indoor radon measurements only. The adaptation of the RAGENA (RAdon Generation, ENtry and Accumulation indoors) model to a Swedish house to characterise indoor radon levels and the relative importance of the different radon sources and entry mechanisms is presented. The building is a single-zone house with a naturally-ventilated crawl space in one part and a concrete floor in another part, leading to different radon levels in the two parts of the building. The soil under the house is moraine, which is relatively permeable to radon gas. The house is naturally-ventilated. The mean indoor radon concentration values measured with nuclear track detectors in the crawl-space and concrete parts of the house are respectively 75+-30 and 200+-80 Bq m sup - sup 3...

  5. RADON REDUCTION AND RADON-RESISTANT CONSTRUCTION DEMONSTRATIONS IN NEW YORK - VOLUME 2: APPENDICES

    Science.gov (United States)

    Growing concern about health risks associated with exposure to indoor radon, a radioactive gas found in varying amounts in nearly all houses, has underscored the need for dependable radon reduction methods in existing and newly constructed houses. Responding to this need, the U....

  6. A national survey on radon concentration in underground inspection rooms and in buildings of a telephone company: methods and first results

    Energy Technology Data Exchange (ETDEWEB)

    Carelli, V., E-mail: vinicio.carelli@telecomitalia.i [Safety and Environment Dept., Telecom-Italia S.p.A., Via di Valcannuta 182, I-00168 Roma (Italy); Bianco, V.; Cordedda, C. [Safety and Environment Dept., Telecom-Italia S.p.A., Via di Valcannuta 182, I-00168 Roma (Italy); Ferrigno, G.; Carpentieri, C.; Bochicchio, F. [Istituto Superiore di Sanita (Italian National Institute of Health), Viale Regina Elena 299, I-00161 Roma (Italy)

    2009-10-15

    A national survey has been carried out to measure radon concentration in a large sample of Telecom-Italia small underground inspection rooms, which form a particularly dense net in urban areas. Measuring radon in such underground places is interesting both for a possible contribution to radon mapping activities and to evaluate workers exposures. Radon concentration was also measured in Telecom buildings (i.e. buildings housing plant equipment, including telephone switches, often also offices, etc.) close and partially connected to the selected inspection rooms. The methodology and the first results of the survey related to the first year of measurements, for a total of 1438 inspection rooms and 1414 Telecom buildings, are reported. Radon concentration was measured with passive devices containing CR-39 detectors for about 12 consecutive months, in order to average seasonal variations. In underground inspection rooms, measured radon concentration reached values up to about 44,000 Bq/m{sup 3}, with a regional median ranging from about 90 Bq/m{sup 3} up to about 1600 Bq/m{sup 3}. In Telecom buildings, the regional median concentration ranged from 13 Bq/m{sup 3} to 174 Bq/m{sup 3}. These results show that radon concentration in underground inspection rooms can reach very high values, whereas medians in monitored buildings are generally lower than those measured in dwellings in a representative national survey.

  7. Existence, uniqueness, and construction of the density-potential mapping in time-dependent density-functional theory.

    Science.gov (United States)

    Ruggenthaler, Michael; Penz, Markus; van Leeuwen, Robert

    2015-05-27

    In this work we review the mapping from densities to potentials in quantum mechanics, which is the basic building block of time-dependent density-functional theory and the Kohn-Sham construction. We first present detailed conditions such that a mapping from potentials to densities is defined by solving the time-dependent Schrödinger equation. We specifically discuss intricacies connected with the unboundedness of the Hamiltonian and derive the local-force equation. This equation is then used to set up an iterative sequence that determines a potential that generates a specified density via time propagation of an initial state. This fixed-point procedure needs the invertibility of a certain Sturm-Liouville problem, which we discuss for different situations. Based on these considerations we then present a discussion of the famous Runge-Gross theorem which provides a density-potential mapping for time-analytic potentials. Further we give conditions such that the general fixed-point approach is well-defined and converges under certain assumptions. Then the application of such a fixed-point procedure to lattice Hamiltonians is discussed and the numerical realization of the density-potential mapping is shown. We conclude by presenting an extension of the density-potential mapping to include vector-potentials and photons.

  8. The potential of lidar imaging for ecosystem mapping in Glacier Bay National Park, Alaska.

    Science.gov (United States)

    Kidd, Chris; Klaar, Megan; Larsen, Chris; Malone, Edward; Milner, Alexander

    2014-05-01

    Data from remotely sensed Earth observation facilitates the mapping and monitoring of remote regions enabling us to improve our understanding of key areas of the Earth System. In particular, the mapping of changes to these systems as a result of recent climate change is important to help assess and predict the impact of these changes, and the implications for the wider Earth System. One of the best-studied regions for the succession in landscape evolution is Glacier Bay National park (GBNP) in Alaska which has experienced rapid glacial retreat over the last 250 years. This study assesses the potential of aircraft-derived lidar data to map a number of catchments in GBNP for the purpose of studying the biogeochemical cycles and ecosystem change in this region. Three catchments were selected for the study, Ice Valley, Stonefly Creek and Wolf Point, representing a range of between 38-133 years since glacial retreat and therefore providing different levels of vegetation succession and vegetation maturity. The lidar used in this study, an aircraft mounted Riegl LMS-Q240i, operates at 905 nm in the near infrared, scans 30 degrees either side of nadir, and samples 10,000 points per second, resulting in a pixel density of about 1-1.2 points/m with a sample resolution of about 20 cm. On-board waveform processing records alternately records the first and last return from the surface, together with the intensity of the return. The high repetition rate allows the aggregation of data over areas enabling the three-dimensional distribution of the vegetation to be measured, and thus improving the identification of canopy tops. Post-processing of the data is tailored towards the detailed mapping of the riparian system and surrounding environments and in particular, gathering information on the vegetation and potential watershed pathways. Bespoke software is used to extract vegetation cover, slope of ground surface, break in slope etc. This enables regions where the confluence of

  9. Representation of Molecular Electrostatic Potentials of Biopolymer by Self-organizing Feature Map

    Institute of Scientific and Technical Information of China (English)

    QIAO,Xue-Bin(乔学斌); JIANG,Bo(姜波); HOU,Ting-Jun(侯廷军); XU,Xiao-Jie(徐筱杰)

    2001-01-01

    The Kohonen serf-organizing map was introduced to map theprotein molecular surface features.The protein or polypeptideproperties,such as shape and molecular electrostatic poten-rial,can be visualized by seff-organizing map,which wastrained by the 3D surface coordinates.Such maps allow thevisual comparison of molecular properties between proteinshaving common topological or chemical features.``

  10. Radon soil-gas concentration and exhalation from mine tailings dams in South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Ongori, J.; Lindsay, R. [University of the Western Cape, Department of Physics, Private Bag X17, Bellville 7535 (South Africa); Newman, R. [Stellenbosch University, Department of Physics, Private Bag X1 Matieland 7602 (South Africa); Maleka, P. [iThemba LABS, Department of Nuclear Physics, P. O. Box 722, Somerset West 7129 (South Africa)

    2014-07-01

    , temperature, moisture and atmospheric pressure influence radon exhalation. At Kloof mine dump radon exhalation was mapped using a novel technique by means of a MEDUSA (Multi-Element Detector for Underwater Sediment Activity) gamma-ray detection system. The MEDUSA detector uses a CsI(Na) crystal and was mounted on the front of a 4x4 vehicle, 0.6 m off the ground. With this setup the MEDUSA detector measures the average activity concentration in the top 30 cm when accessible parts are traversed. The spectra acquired by the MEDUSA system were analysed and the activity concentrations for {sup 238}U, {sup 40}K and {sup 232}Th, were extracted using the Full Spectrum Analysis approach. Radon exhalation from a particular location in the mine dump was obtained by comparing the ratios of the activity concentrations of the {sup 214}Bi obtained in the field using the MEDUSA gamma-ray detector system to the activity concentrations of the {sup 214}Bi obtained in the laboratory using the HPGe gamma-ray detector system. In this case it is assumed that the {sup 40}K and {sup 232}Th series activity concentrations are not or hardly affected by radon exhalation. The application of this new technique gave an average normalised radon flux of 0.12±0.02 Bq.m{sup -2}.s{sup -1} for the mine dump. Document available in abstract form only. (authors)

  11. On the interaction between radon progeny and particles generated by electronic and traditional cigarettes

    Science.gov (United States)

    Vargas Trassierra, C.; Cardellini, F.; Buonanno, G.; De Felice, P.

    2015-04-01

    During their entire lives, people are exposed to the pollutants present in indoor air. Recently, Electronic Nicotine Delivery Systems, mainly known as electronic cigarettes, have been widely commercialized: they deliver particles into the lungs of the users but a "second-hand smoke" has yet to be associated to this indoor source. On the other hand, the naturally-occurring radioactive gas, i.e. radon, represents a significant risk for lung cancer, and the cumulative action of these two agents could be worse than the agents separately would. In order to deepen the interaction between radon progeny and second-hand aerosol from different types of cigarettes, a designed experimental study was carried out by generating aerosol from e-cigarette vaping as well as from second-hand traditional smoke inside a walk-in radon chamber at the National Institute of Ionizing Radiation Metrology (INMRI) of Italy. In this chamber, the radon present in air comes naturally from the floor and ambient conditions are controlled. To characterize the sidestream smoke emitted by cigarettes, condensation particle counters and scanning mobility particle sizer were used. Radon concentration in the air was measured through an Alphaguard ionization chamber, whereas the measurement of radon decay product in the air was performed with the Tracelab BWLM Plus-2S Radon daughter Monitor. It was found an increase of the Potential Alpha-Energy Concentration (PAEC) due to the radon decay products attached to aerosol for higher particle number concentrations. This varied from 7.47 ± 0.34 MeV L-1 to 12.6 ± 0.26 MeV L-1 (69%) for the e-cigarette. In the case of traditional cigarette and at the same radon concentration, the increase was from 14.1 ± 0.43 MeV L-1 to 18.6 ± 0.19 MeV L-1 (31%). The equilibrium factor increases, varying from 23.4% ± 1.11% to 29.5% ± 0.26% and from 30.9% ± 1.0% to 38.1 ± 0.88 for the e-cigarette and traditional cigarette, respectively. These growths still continue for long

  12. Assessment of dose due to exposure to indoor radon and thoron progeny

    Directory of Open Access Journals (Sweden)

    Prasad Ganesh

    2010-01-01

    Full Text Available The components of the effective dose through inhalation from radon and its progeny are important for human health since they contribute to more than 50% of the total radiation dose from natural sources. As a consequence, radon has been identified as the second leading cause of lung cancer after smoking. Radon and its short lived decay products (218Po, 214Pb, 214Bi, 214Po present in dwellings are a radiation hazard, particularly if such sources are concentrated in the enclosed areas like poorly ventilated houses and underground mines. The indoor radon, thoron, and progeny concentrations were measured in a small hilly town of Budhakedar and the surrounding area of Tehri Garhwal, India, by using LR-115 Type II plastic track detector in a twin cup radon dosimeter. The concentrations of radon progeny were measured as the highest in winter and the lowest in summer while the thoron progeny concentration was found maximum in rainy season and minimum in autumn. The annual exposure to the potential alpha energy of radon and thoron were found to vary from 0.04 WLM to 0.69 WLM with an average value of 0.29 WLM, and 0.03 WLM to 0.37 WLM with an aver- age value of 0.16 WLM, respectively. The annual effective dose due to the exposure to indoor radon and progeny in Budhakedar homes was found to vary from 0.16 mSv to 2.72 mSv with an average value of 1.14 mSv and the effective dose due to the exposure to thoron and progeny was found to vary from 0.18 mSv to 2.49 mSv with an average value of 1.05 mSv. The results of systematic study have been obtained by considering the room as a space in which the radon and thoron levels are directly related to the dynamic and static parameters.

  13. Predicting and mapping malaria under climate change scenarios: the potential redistribution of malaria vectors in Africa

    Directory of Open Access Journals (Sweden)

    Kangalawe Richard YM

    2010-04-01

    Full Text Available Abstract Background Malaria is rampant in Africa and causes untold mortality and morbidity. Vector-borne diseases are climate sensitive and this has raised considerable concern over the implications of climate change on future disease risk. The problem of malaria vectors (Anopheles mosquitoes shifting from their traditional locations to invade new zones is an important concern. The vision of this study was to exploit the sets of information previously generated by entomologists, e.g. on geographical range of vectors and malaria distribution, to build models that will enable prediction and mapping the potential redistribution of Anopheles mosquitoes in Africa. Methods The development of the modelling tool was carried out through calibration of CLIMEX parameters. The model helped estimate the potential geographical distribution and seasonal abundance of the species in relation to climatic factors. These included temperature, rainfall and relative humidity, which characterized the living environment for Anopheles mosquitoes. The same parameters were used in determining the ecoclimatic index (EI. The EI values were exported to a GIS package for special analysis and proper mapping of the potential future distribution of Anopheles gambiae and Anophles arabiensis within the African continent under three climate change scenarios. Results These results have shown that shifts in these species boundaries southward and eastward of Africa may occur rather than jumps into quite different climatic environments. In the absence of adequate control, these predictions are crucial in understanding the possible future geographical range of the vectors and the disease, which could facilitate planning for various adaptation options. Conclusion Thus, the outputs from this study will be helpful at various levels of decision making, for example, in setting up of an early warning and sustainable strategies for climate change and climate change adaptation for malaria

  14. Mining for diagnostic information in body surface potential maps: A comparison of feature selection techniques

    Directory of Open Access Journals (Sweden)

    McCullagh Paul J

    2005-09-01

    Full Text Available Abstract Background In body surface potential mapping, increased spatial sampling is used to allow more accurate detection of a cardiac abnormality. Although diagnostically superior to more conventional electrocardiographic techniques, the perceived complexity of the Body Surface Potential Map (BSPM acquisition process has prohibited its acceptance in clinical practice. For this reason there is an interest in striking a compromise between the minimum number of electrocardiographic recording sites required to sample the maximum electrocardiographic information. Methods In the current study, several techniques widely used in the domains of data mining and knowledge discovery have been employed to mine for diagnostic information in 192 lead BSPMs. In particular, the Single Variable Classifier (SVC based filter and Sequential Forward Selection (SFS based wrapper approaches to feature selection have been implemented and evaluated. Using a set of recordings from 116 subjects, the diagnostic ability of subsets of 3, 6, 9, 12, 24 and 32 electrocardiographic recording sites have been evaluated based on their ability to correctly asses the presence or absence of Myocardial Infarction (MI. Results It was observed that the wrapper approach, using sequential forward selection and a 5 nearest neighbour classifier, was capable of choosing a set of 24 recording sites that could correctly classify 82.8% of BSPMs. Although the filter method performed slightly less favourably, the performance was comparable with a classification accuracy of 79.3%. In addition, experiments were conducted to show how (a features chosen using the wrapper approach were specific to the classifier used in the selection model, and (b lead subsets chosen were not necessarily unique. Conclusion It was concluded that both the filter and wrapper approaches adopted were suitable for guiding the choice of recording sites useful for determining the presence of MI. It should be noted however

  15. Towards automated electron holographic tomography for 3D mapping of electrostatic potentials

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Daniel, E-mail: Daniel.Wolf@Triebenberg.de [Triebenberg Laboratory, Institute of Structure Physics, Technische Universitaet Dresden, 01062 Dresden (Germany); Lubk, Axel; Lichte, Hannes [Triebenberg Laboratory, Institute of Structure Physics, Technische Universitaet Dresden, 01062 Dresden (Germany); Friedrich, Heiner [Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Sorbonnelaan 16, 3584 CA, Utrecht (Netherlands)

    2010-04-15

    Electron-holographic tomography (EHT), that is, the combination of off-axis electron holography with electron tomography, was successfully applied for the quantitative 3D mapping of electrostatic potentials at the nanoscale. Here we present the first software package (THOMAS) for semi-automated acquisition of holographic tilt series, a prerequisite for efficient data collection. Using THOMAS, the acquisition time for a holographic tilt series, consisting of object and reference holograms, is reduced by a factor of five on average, compared to the previous, completely manual approaches. Moreover, the existing software packages for retrieving amplitude and phase information from electron holograms have been extended, now including a one-step procedure for holographic tilt series reconstruction. Furthermore, a modified SIRT algorithm (WSIRT) was implemented for the quantitative 3D reconstruction of the electrostatic potential from the aligned phase tilt series. Finally, the application of EHT to a polystyrene latex sphere test-specimen and a pn-doped Ge 'needle'-shaped specimen are presented, illustrating the quantitative character of EHT. For both specimens the mean inner potential (MIP) values were accurately determined from the reconstructed 3D potential. For the Ge specimen, additionally the 'built-in' voltage across the pn junction of 0.5 V was obtained.

  16. Mapping irrigation potential from renewable groundwater in Africa - a quantitative hydrological approach

    Science.gov (United States)

    Altchenko, Y.; Villholth, K. G.

    2015-02-01

    Groundwater provides an important buffer to climate variability in Africa. Yet, groundwater irrigation contributes only a relatively small share of cultivated land, approximately 1% (about 2 × 106 hectares) as compared to 14% in Asia. While groundwater is over-exploited for irrigation in many parts in Asia, previous assessments indicate an underutilized potential in parts of Africa. As opposed to previous country-based estimates, this paper derives a continent-wide, distributed (0.5° spatial resolution) map of groundwater irrigation potential, indicated in terms of fractions of cropland potentially irrigable with renewable groundwater. The method builds on an annual groundwater balance approach using 41 years of hydrological data, allocating only that fraction of groundwater recharge that is in excess after satisfying other present human needs and environmental requirements, while disregarding socio-economic and physical constraints in access to the resource. Due to high uncertainty of groundwater environmental needs, three scenarios, leaving 30, 50 and 70% of recharge for the environment, were implemented. Current dominating crops and cropping rotations and associated irrigation requirements in a zonal approach were applied in order to convert recharge excess to potential irrigated cropland. Results show an inhomogeneously distributed groundwater irrigation potential across the continent, even within individual countries, mainly reflecting recharge patterns and presence or absence of cultivated cropland. Results further show that average annual renewable groundwater availability for irrigation ranges from 692 to 1644 km3 depending on scenario. The total area of cropland irrigable with renewable groundwater ranges from 44.6 to 105.3 × 106 ha, corresponding to 20.5 to 48.6% of the cropland over the continent. In particular, significant potential exists in the semi-arid Sahel and eastern African regions which could support poverty alleviation if developed

  17. Cowichan Valley energy mapping and modelling. Report 1 - GIS mapping of potential renewable energy resources in the CVRD. Final report. [Vancouver Island, Canada

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-06-15

    The driving force behind the Integrated Energy Mapping and Analysis project was the identification and analysis of a suite of pathways that the Cowichan Valley Regional District (CVRD) can utilise to increase its energy resilience, as well as reduce energy consumption and GHG emissions, with a primary focus on the residential sector. Mapping and analysis undertaken will support provincial energy and GHG reduction targets, and the suite of pathways outlined will address a CVRD internal target that calls for 75% of the region's energy within the residential sector to come from locally sourced renewables by 2050. The target has been developed as a mechanism to meet resilience and climate action target. The maps and findings produced are to be integrated as part of a regional policy framework currently under development. The first task in the project was the production of a series of thematic GIS maps and associated databases of potential renewable energy resources in the CVRD. The renewable energy sources mapped were solar, wind, micro hydro, and biomass (residues and waste). Other sources were also discussed (e.g. geothermal heat) but not mapped due to lack of spatially explicit input data. The task 1 findings are detailed in this report. (LN)

  18. The study of the correlation between (α, γ) induced events with respect to Radon annual modulation.

    Science.gov (United States)

    Tiwari, Ashok; Zhang, Chao; Mei, Dongming

    2017-01-01

    We observed (α, γ) reaction that generates high energy gammas in Soudan mine with a 12 liter liquid scintillation detector. With a model established to describe the correlation between (α, γ) induced events with radon annual modulation, we demonstrate that (α, γ) induced events are highly correlated with the radon modulation. These (α, γ) induced events can be potential background events for rare event physics. This work is supported by NSF in part by the NSF PHY-0758120, DOE grant DE-FG02-10ER46709, and the state of South Dakota.

  19. How to Ensure Low Radon Concentrations in Indoor Environments

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Wraber, Ida Kristina

    2011-01-01

    This paper focuses on methods for measuring radon levels in the indoor air in buildings as well as on concrete solutions that can be carried out in the building to prevent radon leakage and to lower the radon concentration in the indoor air of new buildings. The radon provision in the new Danish...... Building Regulations from 2010 has been tightened as a result of new recommendations from the World Health Organization. Radon can cause lung cancer and it is not known whether there is a lower limit for its harmfulness. It is therefore important to reduce the radon concentration as much as possible in new...... buildings. The airtightness is a major factor when dealing with radon in buildings. Above the ground it is important to build airtight in compliance with energy requirements and against the ground it is important to prevent radon from seeping into the building. There is a direct connection between...

  20. Radon exhalation rates of some granites used in Serbia

    Directory of Open Access Journals (Sweden)

    Nikolić Mladen D.

    2015-01-01

    Full Text Available In order to address concern about radon exhalation in building material, radon exhalation rate was determined for different granites available on Serbian market. Radon exhalation rate, along with mass exhalation rate and effective radium content were determined by closed chamber method and active continuous radon measurement technique. For this research, special chambers were made and tested for back diffusion and leakage, and the radon concentrations measured were included in the calculation of radon exhalation. The radon exhalation rate ranged from 0.161 Bq/m2h to 0.576 Bq/m2h, the mass exhalation rate from 0.167 Bq/kgh to 0.678 Bq/kgh, while the effective radium content was found to be from 12.37 Bq/kg to 50.23 Bq/kg. The results indicate that the granites used in Serbia have a low level of radon exhalation.

  1. Radon removal from gaseous xenon with activated charcoal

    Science.gov (United States)

    Abe, K.; Hieda, K.; Hiraide, K.; Hirano, S.; Kishimoto, Y.; Kobayashi, K.; Koshio, Y.; Liu, J.; Martens, K.; Moriyama, S.; Nakahata, M.; Nishiie, H.; Ogawa, H.; Sekiya, H.; Shinozaki, A.; Suzuki, Y.; Takachio, O.; Takeda, A.; Ueshima, K.; Umemoto, D.; Yamashita, M.; Hosokawa, K.; Murata, A.; Otsuka, K.; Takeuchi, Y.; Kusaba, F.; Motoki, D.; Nishijima, K.; Tasaka, S.; Fujii, K.; Murayama, I.; Nakamura, S.; Fukuda, Y.; Itow, Y.; Masuda, K.; Nishitani, Y.; Takiya, H.; Uchida, H.; Kim, Y. D.; Kim, Y. H.; Lee, K. B.; Lee, M. K.; Lee, J. S.; Xmass Collaboration

    2012-01-01

    Many low background experiments using xenon need to remove radioactive radon to improve their sensitivities. However, no method of continually removing radon from xenon has been described in the literature. We studied a method to remove radon from xenon gas through an activated charcoal trap. From our measurements we infer a linear relationship between the mean propagation velocity vRn of radon and vXe of xenon in the trap with vRn/vXe=(0.96±0.10)×10-3 at -85 °C. As the mechanism for radon removal in this charcoal trap is its decay, knowledge of this parameter allows us to design an efficient radon removal system for the XMASS experiment. The verification of this system found that it reduces radon by a factor of 0.07, which is in line with its expected average retention time of 14.8 days for radon.

  2. Renewable energy: GIS-based mapping and modelling of potentials and demand

    Science.gov (United States)

    Blaschke, Thomas; Biberacher, Markus; Schardinger, Ingrid.; Gadocha, Sabine; Zocher, Daniela

    2010-05-01

    Worldwide demand of energy is growing and will continue to do so for the next decades to come. IEA has estimated that global primary energy demand will increase by 40 - 50% from 2003 to 2030 (IEA, 2005) depending on the fact whether currently contemplated energy policies directed towards energy-saving and fuel-diversification will be effectuated. The demand for Renewable Energy (RE) is undenied but clear figures and spatially disaggregated potentials for the various energy carriers are very rare. Renewable Energies are expected to reduce pressures on the environment and CO2 production. In several studies in Germany (North-Rhine Westphalia and Lower Saxony) and Austria we studied the current and future pattern of energy production and consumption. In this paper we summarize and benchmark different RE carriers, namely wind, biomass (forest and non-forest, geothermal, solar and hydro power. We demonstrate that GIS-based scalable and flexible information delivery sheds new light on the prevailing metaphor of GIS as a processing engine serving needs of users more on demand rather than through ‘maps on stock'. We compare our finding with those of several energy related EU-FP7 projects in Europe where we have been involved - namely GEOBENE, REACCESS, ENERGEO - and demonstrate that more and more spatial data will become available together with tools that allow experts to do their own analyses and to communicate their results in ways which policy makers and the public can readily understand and use as a basis for their own actions. Geoportals in combination with standardised geoprocessing today supports the older vision of an automated presentation of data on maps, and - if user privileges are given - facilities to interactively manipulate these maps. We conclude that the most critical factor in modelling energy supply and demand remain the economic valuation of goods and services, especially the forecast of future end consumer energy costs.

  3. Radon

    Science.gov (United States)

    ... face' showdown over Obama-era tailpipe rule Blog: Yoga, Tai Chi and Your Lungs: The Benefits of ... list_name').hide(); } $("#local_list_xml").quickPagination(); }, error: function() { console.log("An error occurred while processing XML ...

  4. Functional mapping of the sensorimotor cortex: combined use of magnetoencephalography, functional MRI, and motor evoked potentials

    Energy Technology Data Exchange (ETDEWEB)

    Morioka, T. [Dept. of Neurosurgery, Neurological Inst., Kyshu Univ., Fukuoka (Japan); Fujii, K. [Dept. of Neurosurgery, Neurological Inst., Kyshu Univ., Fukuoka (Japan); Fukui, M. [Dept. of Neurosurgery, Neurological Inst., Kyshu Univ., Fukuoka (Japan); Mizushima, A. [Dept. of Radiology, Kyushu Univ. Fukuoka (Japan); Matsumoto, S. [Dept. of Radiology, Kyushu Univ. Fukuoka (Japan); Hasuo, K. [Dept. of Radiology, Kyushu Univ. Fukuoka (Japan); Yamamoto, T. [Dept. of Otolaryngology, Kyushu Univ. Fukuoka (Japan); Tobimatsu, S. [Dept. of Clinical Neurophysiology, Neurological Inst., Kyushu Univ., Fukuoka (Japan)

    1995-10-01

    Combined use of magnetoencephalography (MEG), functional magnetic resonance imaging (f-MRI), and motor evoked potentials (MEPs) was carried out on one patient in an attempt to localise precisely a structural lesion to the central sulcus. A small cyst in the right frontoparietal region was thought to be the cause of generalised seizures in an otherwise asymptomatic woman. First the primary sensory cortex was identified with magnetic source imaging (MSI) of somatosensory evoked magnetic fields using MEG and MRI. Second, the motor area of the hand was identified using f-MRI during handsqueezing. Then transcranial magnetic stimulation localised the hand motor area on the scalp, which was mapped onto the MRI. There was a good agreement between MSI, f-MRI and MEP as to the location of the sensorimotor cortex and its relationship to the lesion. Multimodality mapping techniques may thus prove useful in the precise localisation of cortical lesions, and in the preoperative determination of the best treatment for peri-rolandic lesions. (orig.)

  5. The morphology of the Milky Way - I. Reconstructing CO maps from simulations in fixed potentials

    CERN Document Server

    Pettitt, Alex R; Acreman, David M; Price, Daniel J

    2014-01-01

    We present an investigation into the morphological features of the Milky Way. We use smoothed particle hydrodynamics (SPH) to simulate the interstellar medium (ISM) in the Milky Way under the effect of a number of different gravitational potentials representing spiral arms and bars, assuming the Milky Way is grand design in nature. The gas is subject to ISM cooling and chemistry, enabling us to track the evolution of molecular gas. We use a 3D radiative transfer code to simulate the emission from the SPH output, allowing for the construction of synthetic longitude-velocity (l-v) emission maps as viewed from the Earth. By comparing these maps with the observed emission in CO from the Milky Way, we infer the arm/bar geometry that provides a best fit to our Galaxy. We find that it is possible to reproduce nearly all features of the l-v diagram in CO emission. There is no model, however, that satisfactorily reproduces all of the features simultaneously. Models with 2 arms cannot reproduce all the observed arm fea...

  6. Mapping the potential risk of mycetoma infection in Sudan and South Sudan using ecological niche modeling.

    Science.gov (United States)

    Samy, Abdallah M; van de Sande, Wendy W J; Fahal, Ahmed Hassan; Peterson, A Townsend

    2014-10-01

    In 2013, the World Health Organization (WHO) recognized mycetoma as one of the neglected tropical conditions due to the efforts of the mycetoma consortium. This same consortium formulated knowledge gaps that require further research. One of these gaps was that very few data are available on the epidemiology and transmission cycle of the causative agents. Previous work suggested a soil-borne or Acacia thorn-prick-mediated origin of mycetoma infections, but no studies have investigated effects of soil type and Acacia geographic distribution on mycetoma case distributions. Here, we map risk of mycetoma infection across Sudan and South Sudan using ecological niche modeling (ENM). For this study, records of mycetoma cases were obtained from the scientific literature and GIDEON; Acacia records were obtained from the Global Biodiversity Information Facility. We developed ENMs based on digital GIS data layers summarizing soil characteristics, land-surface temperature, and greenness indices to provide a rich picture of environmental variation across Sudan and South Sudan. ENMs were calibrated in known endemic districts and transferred countrywide; model results suggested that risk is greatest in an east-west belt across central Sudan. Visualizing ENMs in environmental dimensions, mycetoma occurs under diverse environmental conditions. We compared niches of mycetoma and Acacia trees, and could not reject the null hypothesis of niche similarity. This study revealed contributions of different environmental factors to mycetoma infection risk, identified suitable environments and regions for transmission, signaled a potential mycetoma-Acacia association, and provided steps towards a robust risk map for the disease.

  7. Active versus passive radon monitoring at the Yucca Mountain site

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, M.D. [Science Applications International Corp., Las Vegas, NV (United States)

    1994-12-31

    Federal Regulations have mandated that a baseline assessment for the Yucca Mountain Site be performed. This includes the detection and monitoring of specific radionuclides present at the site. These radionuclides include radon 222, a decay progeny of naturally occurring uranium. Two radon monitoring systems are utilized at the Yucca Mountain site to detect ambient levels of radon. The first is a passive time integrated system, and the second is a continuous radon monitoring (CRM) system.

  8. Fuzzy Cognitive Maps for Glacier Hazards Assessment: Application to Predicting the Potential for Glacier Lake Outbursts

    Science.gov (United States)

    Furfaro, R.; Kargel, J. S.; Fink, W.; Bishop, M. P.

    2010-12-01

    Glaciers and ice sheets are among the largest unstable parts of the solid Earth. Generally, glaciers are devoid of resources (other than water), are dangerous, are unstable and no infrastructure is normally built directly on their surfaces. Areas down valley from large alpine glaciers are also commonly unstable due to landslide potential of moraines, debris flows, snow avalanches, outburst floods from glacier lakes, and other dynamical alpine processes; yet there exists much development and human occupation of some disaster-prone areas. Satellite remote sensing can be extremely effective in providing cost-effective and time- critical information. Space-based imagery can be used to monitor glacier outlines and their lakes, including processes such as iceberg calving and debris accumulation, as well as changing thicknesses and flow speeds. Such images can also be used to make preliminary identifications of specific hazardous spots and allows preliminary assessment of possible modes of future disaster occurrence. Autonomous assessment of glacier conditions and their potential for hazards would present a major advance and permit systematized analysis of more data than humans can assess. This technical leap will require the design and implementation of Artificial Intelligence (AI) algorithms specifically designed to mimic glacier experts’ reasoning. Here, we introduce the theory of Fuzzy Cognitive Maps (FCM) as an AI tool for predicting and assessing natural hazards in alpine glacier environments. FCM techniques are employed to represent expert knowledge of glaciers physical processes. A cognitive model embedded in a fuzzy logic framework is constructed via the synergistic interaction between glaciologists and AI experts. To verify the effectiveness of the proposed AI methodology as applied to predicting hazards in glacier environments, we designed and implemented a FCM that addresses the challenging problem of autonomously assessing the Glacier Lake Outburst Flow

  9. Comprehensive personal RF-EMF exposure map and its potential use in epidemiological studies.

    Science.gov (United States)

    Gonzalez-Rubio, Jesus; Najera, Alberto; Arribas, Enrique

    2016-08-01

    In recent years, numerous epidemiological studies, which deal with the potential effects of mobile phone antennas on health, have almost exclusively focused on their distance to mobile phone base stations. Although it is known that this is not the best approach to the problem, this situation occurs due to the numerous difficulties when determining the personal exposure to the radiofrequency electromagnetic fields (RF-EMF). However, due to the rise of personal exposimeters, the evolution of spatial statistics, the development of geographical information systems and the use of powerful software, new alternatives are available to deal with these epidemiological studies and thus overcome the aforementioned difficulties. Using these tools, this paper presents a lattice map of personal RF-EMF exposure from exterior mobile phone base stations, covering the entire 110 administrative regions in the city of Albacete (Spain). For this purpose, we used a personal exposimeter, Satimo EME Spy 140 model, performing measurements every 4s The exposimeter was located inside the plastic basket of a bicycle, whose versatility permitted the access to all the zones of the city. Once the exposure map was prepared, its relation with the known antenna locations was studied. The 64 mobile telephone antennas of the city were also georeferenced; the randomness of both variables (exposure and antennas) were studied by means of the Moran's I test. Results showed that the distribution of the antennas follows a grouped pattern (pvalues have a random distribution (p=0.618). In addition, we showed two Spearman correlation studies: the first between the average exposure values and the number of mobile telephone antennas per administrative region, and the second, also considering the antennas of the neighbouring regions. No substantial correlation was detected in either of the two cases. This study also reveals the weaknesses of the epidemiological studies, which only take into account the distance

  10. The reliability of radon as seismic precursor

    Science.gov (United States)

    Emilian Toader, Victorin; Moldovan, Iren Adelina; Ionescu, Constantin; Marmureanu, Alexandru

    2016-04-01

    Our multidisciplinary network (AeroSolSys) located in Vrancea (Curvature Carpathian Mountains) includes radon concentration monitoring in five stations. We focus on lithosphere and near surface low atmosphere phenomena using real-time information about seismicity, + / - ions, clouds, solar radiation, temperature (air, ground), humidity, atmospheric pressure, wind speed and direction, telluric currents, variations of the local magnetic field, infrasound, variations of the atmospheric electrostatic field, variations in the earth crust with inclinometers, electromagnetic activity, CO2 concentration, ULF radio wave propagation, seismo-acoustic emission, animal behavior. The main purpose is to inform the authorities about risk situation and update hazard scenarios. The radon concentration monitoring is continuously with 1 hour or 3 hours sample rate in locations near to faults in an active seismic zone characterized by intermediate depth earthquakes. Trigger algorithms include standard deviation, mean and derivative methods. We correlate radon concentration measurements with humidity, temperature and atmospheric pressure from the same equipment. In few stations we have meteorological information, too. Sometime the radon concentration has very high variations (maxim 4535 Bq/m3 from 106 Bq/m3) in short time (1 - 2 days) without being accompanied by an important earthquake. Generally the cause is the high humidity that could be generated by tectonic stress. Correlation with seismicity needs information from minimum 6 month in our case. For 10605 hours, 618 earthquakes with maxim magnitude 4.9 R, we have got radon average 38 Bq/m3 and exposure 408111 Bqh/m3 in one station. In two cases we have correlation between seismicity and radon concentration. In other one we recorded high variation because the location was in an area with multiple faults and a river. Radon can be a seismic precursor but only in a multidisciplinary network. The anomalies for short or long period of

  11. Development of GIS-based Wind Potential Map of Makkah Province, Saudi Arabia

    Science.gov (United States)

    Nayyar, Z. A.; Zaigham, N. A.; Aburizaiza, O. S.; Mahar, G. A.; Eusufi, S. N.

    2011-12-01

    Global energy scenario is changing drastically toward decline, as new major discoveries of fossil fuel are not coming up significantly on regional basis. In case of Saudi Arabia, one of the largest fossil fuel producers, the major oil fields have started exhausting significantly as revealed from the literature research study. Considering the future energy crisis, different other renewable options presently have became imperative to be consider anticipating for the national development. Wind energy in one of them. The development of wind energy technology requires the baseline data relevant to the wind trends and their potentials. Under the present study, an attempt has been made to develop wind power density map of the Makkah Province of Saudi Arabia based on the meteorological data collected at different sparsely located weather stations. GIS application has provided a good option to interpolate the gap areas between the sparsely located weather recording stations. This paper describe the methodology and results of the present study.

  12. Radon concentration in soil gas around local disjunctive tectonic zones in the Krakow area.

    Science.gov (United States)

    Swakoń, J; Kozak, K; Paszkowski, M; Gradziński, R; Łoskiewicz, J; Mazur, J; Janik, M; Bogacz, J; Horwacik, T; Olko, P

    2005-01-01

    The purpose of this study was to investigate radon in the vicinity of geologic fault zones within the Krakow region of Poland, and to determine the influence of such formations on enhanced radon concentrations in soil. Radon ((222)Rn and (220)Rn) concentration measurements in soil gas (using ionization chamber AlphaGUARD PQ2000 PRO and diffusion chambers with CR-39 detectors), as well as radioactive natural isotopes of radium, thorium and potassium in soil samples (using gamma ray spectrometry with NaI(Tl) and HPGe detectors), were performed. Site selection was based on a geological map of Krakow. Geophysical methods (ground penetrating radar and shallow acoustic seismic) were applied to recognize the geological structure of the area and to locate the predicted courses of faults. Elevated levels of radon and thoron in soil gas were found in the study area when compared with those observed in an earlier survey covering Krakow agglomeration. For (222)Rn, the arithmetic mean of registered concentration values was 39 kBq/m(3) (median: 35.5 kBq/m(3)). For (220)Rn, the arithmetic mean was 10.8 kBq/m(3) and median 11.8 kBq/m(3).

  13. Identifying Potential Areas for Siting Interim Nuclear Waste Facilities Using Map Algebra and Optimization Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Omitaomu, Olufemi A [ORNL; Liu, Cheng [ORNL; Cetiner, Sacit M [ORNL; Belles, Randy [ORNL; Mays, Gary T [ORNL; Tuttle, Mark A [ORNL

    2013-01-01

    The renewed interest in siting new nuclear power plants in the United States has brought to the center stage, the need to site interim facilities for long-term management of spent nuclear fuel (SNF). In this paper, a two-stage approach for identifying potential areas for siting interim SNF facilities is presented. In the first stage, the land area is discretized into grids of uniform size (e.g., 100m x 100m grids). For the continental United States, this process resulted in a data matrix of about 700 million cells. Each cell of the matrix is then characterized as a binary decision variable to indicate whether an exclusion criterion is satisfied or not. A binary data matrix is created for each of the 25 siting criteria considered in this study. Using map algebra approach, cells that satisfy all criteria are clustered and regarded as potential siting areas. In the second stage, an optimization problem is formulated as a p-median problem on a rail network such that the sum of the shortest distance between nuclear power plants with SNF and the potential storage sites from the first stage is minimized. The implications of obtained results for energy policies are presented and discussed.

  14. Direct motor evoked potentials and cortical mapping using the NIM® nerve monitoring system: A technical note.

    Science.gov (United States)

    Bharadwaj, Suparna; Haji, Faizal; Hebb, Matthew; Chui, Jason

    2017-04-01

    Motor evoked potentials (MEPs) are commonly used to prevent neurological injury when operating in close proximity to the motor cortex or corticospinal pathway. We report a novel application of the NIM® nerve monitoring system (Medtronic@ NIM response 3.0) for intraoperative direct cortical (dc)-MEPs monitoring. A 69-year-old female patient presented with a 4month history of progressive left hemiparesis resulting from a large right sided posterior frontal meningioma that abutted and compressed the motor cortex. Motor cortical mapping and MEPs were indicated. The patient was anesthetized and maintained on total intravenous anesthetics. Compound muscle action potentials (CMAP) of the right upper limb were monitored using the NIM system. After a craniotomy was performed, we first used the Ojemann stimulator (monopolar) for dc-stimulation and then switched to use the monopolar nerve stimulator probe of the NIM system. The CMAP response was successfully elicited using the NIM stimulating probe (pulse width=250s, train frequency=7pulses/s, current=20mA). A gross total resection of the tumor was achieved with intermittent cortical mapping of MEPs. There were no intraoperative complications and the patient's motor function was preserved after the surgery. In this case, we reported the successful use of the NIM nerve monitoring system to elicit dc-MEPs under general anesthesia. The advantages of using this system include a simple set up and application, neurosurgeon familiarity, wide availability and lower cost. dc-MEPs can be achieved using the NIM system. We conclude that the NIM nerve monitoring system is a feasible alternative to standard neurophysiological monitoring systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Crossing and Radon Tomography for Generalized Parton Distributions

    CERN Document Server

    Teryaev, O V

    2001-01-01

    The crossing properties of the matrix elements of non-local operators, parameterized by Generalized Parton Distribution, are considered. They are especially simple in terms of the Double Distributions which are common for the various kinematical regions. As a result, Double Distributions may be in principle extracted from the combined data in these regions by making use of the inverse Radon transform, known as a standard method in tomography. The ambiguities analogous to the ones for the vetor potential in the two-dimensional magneto-statics are outlined. The possible generalizations are discussed.

  16. Review of low-energy construction, air tightness, ventilation strategies and indoor radon: results from Finnish houses and apartments.

    Science.gov (United States)

    Arvela, H; Holmgren, O; Reisbacka, H; Vinha, J

    2014-12-01

    Low-energy and passive house construction practices are characterised by increased insulation, high air tightness of the building shell and controlled mechanical ventilation with heat recovery. As a result of the interaction of mechanical ventilation and high air tightness, the pressure difference in a building can be markedly enhanced. This may lead to elevated indoor radon levels. Minor leakages in the foundation can affect the radon concentration, even in the case where such leaks do not markedly reduce the total air tightness. The potential for high pressures to affect indoor radon concentrations markedly increases when the air tightness ACH50, i.e. the air change per hour induced by a pressure difference of 50 Pa, is houses having mechanical supply and exhaust ventilation with heat recovery (MSEV) are typically 2-3 Pa, clearly lower than the values of 5-9 Pa in houses with only mechanical exhaust ventilation (MEV). In MSEV houses, radon concentrations are typically 30% lower than in MEV houses. In new MSEV houses with an ACH50 of 0.6 h(-1), the limit for passive construction, the analytical estimates predict an increase of 100% in the radon concentration compared with older houses with an ACH50 of 4.0 h(-1). This poses a challenge for efficient radon prevention in new construction. Radon concentrations are typically 30% lower in houses with two storeys compared with only one storey. The introduction of an MSEV ventilation strategy in typically very airtight apartments has markedly reduced pressure differences and radon concentrations.

  17. RESOLVING THE RADON PROBLEM IN CLINTON, NEW JERSEY HOUSES

    Science.gov (United States)

    The paper discusses the resolution of a radon problem in Clinton, New Jersey, where significantly elevated radon concentrations were found in several adjacent houses. The U.S. EPA screened 56 of the houses and selected 10 for demonstration of radon reduction techniques. Each of t...

  18. RESOLVING THE RADON PROBLEM IN CLINTON, NEW JERSEY HOUSES

    Science.gov (United States)

    The paper discusses the resolution of a radon problem in Clinton, New Jersey, where significantly elevated radon concentrations were found in several adjacent houses. The U.S. EPA screened 56 of the houses and selected 10 for demonstration of radon reduction techniques. Each of t...

  19. Assessment of indoor radon gas concentration change of college

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hoon Hee; Jeong, Eui Hwan; Kim, Hak Jae; Lyu, Kang Yeul [Dept. of of Radiological Technology, Shingu College, Seongnam (Korea, Republic of); Lee, Ju Young [Dept. of Radiological Technology, Songho College, Hoengseong (Korea, Republic of)

    2017-03-15

    The purpose of this study was to assess the impact by comparing the concentration of indoor radon and look for ways to lower the concentration of indoor radon gas measurements of three variables, the year of completion, volume of the building and ventilation. Measurement target is six classrooms on the sixth floor of building that was constructed in 1973 and was extended in 2011. Selected classroom's volume is different. Four classrooms were selected to compare the radon concentration in accordance with the year of completion, Classrooms that is same year of completion were selected to compare the radon concentration in accordance with the volume, six classroom was performed closure and ventilation to compare radon concentration according to ventilation. Radon concentrations in accordance with the year of building completion showed a high concentration of radon in a building recently built. Also, Radon concentration in volume is high the smaller the volume. Radon concentration change according to ventilation showed a reduction of about 80% when the ventilation than during closing. Especially, The radon concentrations were high detected while the recently year of building completion and the smaller volume. Ventilation of the three variables is considered that can be expected to exposure reduction effect by radon affecting the greatest radon concentration reduction.

  20. From Complex Fractional Fourier Transform to Complex Fractional Radon Transform

    Institute of Scientific and Technical Information of China (English)

    FAN Hong-Yi; JIANG Nian-Quan

    2004-01-01

    We show that for n-dimensional complex fractional Fourier transform the corresponding complex fractional Radon transform can also be derived, however, it is different from the direct product of two n-dimensional real fractional Radon transforms. The complex fractional Radon transform of two-mode Wigner operator is calculated.

  1. A prediction model for assessing residential radon concentration in Switzerland

    NARCIS (Netherlands)

    Hauri, D.D.; Huss, A.; Zimmermann, F.; Kuehni, C.E.; Roosli, M.

    2012-01-01

    Indoor radon is regularly measured in Switzerland. However, a nationwide model to predict residential radon levels has not been developed. The aim of this study was to develop a prediction model to assess indoor radon concentrations in Switzerland. The model was based on 44,631 measurements from the

  2. 40 CFR 61.203 - Radon monitoring and compliance procedures.

    Science.gov (United States)

    2010-07-01

    ..., each owner or operator of an inactive phosphogypsum stack shall test the stack for radon-222 flux in... the radon-222 flux testing. Each report shall also include the following information: (i) The name and... provide EPA with a report detailing the actions taken and the results of the radon-222 flux testing....

  3. Fractional Radon Transform and Transform of Wigner Operator

    Institute of Scientific and Technical Information of China (English)

    FAN Hong-Yi; CHEN Jun-Hua

    2003-01-01

    Based on the Radon transform and fractional Fourier transform we introduce the fractional Radon trans-formation (FRT). We identify the transform kernel for FRT. The FRT of Wigner operator is derived, which naturallyreduces to the projector of eigenvector of the rotated quadrature in the usual Radon transform case.

  4. Mapping Global Potential Risk of Mango Sudden Decline Disease Caused by Ceratocystis fimbriata.

    Directory of Open Access Journals (Sweden)

    Tarcísio Visintin da Silva Galdino

    Full Text Available The Mango Sudden Decline (MSD, also referred to as Mango Wilt, is an important disease of mango in Brazil, Oman and Pakistan. This fungus is mainly disseminated by the mango bark beetle, Hypocryphalus mangiferae (Stebbing, by infected plant material, and the infested soils where it is able to survive for long periods. The best way to avoid losses due to MSD is to prevent its establishment in mango production areas. Our objectives in this study were to: (1 predict the global potential distribution of MSD, (2 identify the mango growing areas that are under potential risk of MSD establishment, and (3 identify climatic factors associated with MSD distribution. Occurrence records were collected from Brazil, Oman and Pakistan where the disease is currently known to occur in mango. We used the correlative maximum entropy based model (MaxEnt algorithm to assess the global potential distribution of MSD. The MaxEnt model predicted suitable areas in countries where the disease does not already occur in mango, but where mango is grown. Among these areas are the largest mango producers in the world including India, China, Thailand, Indonesia, and Mexico. The mean annual temperature, precipitation of coldest quarter, precipitation seasonality, and precipitation of driest month variables contributed most to the potential distribution of MSD disease. The mango bark beetle vector is known to occur beyond the locations where MSD currently exists and where the model predicted suitable areas, thus showing a high likelihood for disease establishment in areas predicted by our model. Our study is the first to map the potential risk of MSD establishment on a global scale. This information can be used in designing strategies to prevent introduction and establishment of MSD disease, and in preparation of efficient pest risk assessments and monitoring programs.

  5. Mapping Global Potential Risk of Mango Sudden Decline Disease Caused by Ceratocystis fimbriata.

    Science.gov (United States)

    Galdino, Tarcísio Visintin da Silva; Kumar, Sunil; Oliveira, Leonardo S S; Alfenas, Acelino C; Neven, Lisa G; Al-Sadi, Abdullah M; Picanço, Marcelo C

    2016-01-01

    The Mango Sudden Decline (MSD), also referred to as Mango Wilt, is an important disease of mango in Brazil, Oman and Pakistan. This fungus is mainly disseminated by the mango bark beetle, Hypocryphalus mangiferae (Stebbing), by infected plant material, and the infested soils where it is able to survive for long periods. The best way to avoid losses due to MSD is to prevent its establishment in mango production areas. Our objectives in this study were to: (1) predict the global potential distribution of MSD, (2) identify the mango growing areas that are under potential risk of MSD establishment, and (3) identify climatic factors associated with MSD distribution. Occurrence records were collected from Brazil, Oman and Pakistan where the disease is currently known to occur in mango. We used the correlative maximum entropy based model (MaxEnt) algorithm to assess the global potential distribution of MSD. The MaxEnt model predicted suitable areas in countries where the disease does not already occur in mango, but where mango is grown. Among these areas are the largest mango producers in the world including India, China, Thailand, Indonesia, and Mexico. The mean annual temperature, precipitation of coldest quarter, precipitation seasonality, and precipitation of driest month variables contributed most to the potential distribution of MSD disease. The mango bark beetle vector is known to occur beyond the locations where MSD currently exists and where the model predicted suitable areas, thus showing a high likelihood for disease establishment in areas predicted by our model. Our study is the first to map the potential risk of MSD establishment on a global scale. This information can be used in designing strategies to prevent introduction and establishment of MSD disease, and in preparation of efficient pest risk assessments and monitoring programs.

  6. Mapping rivers with a potential danger of damage by flash flooding and debris flows

    Science.gov (United States)

    Peereboom, I.; Svegården, J.; Fergus, T.

    2009-04-01

    Landforms associated with past debris flows such as alluvial fans are typical locations for settlements in Norway. Flash floods with associated debris flows in small and steep river catchments cause a great deal of damage to infrastructure and housing located on alluvial fans. The Norwegian Water Resources and Energy Resources Directorate (NVE) is the national authority responsible for flood and landslide hazard management in Norway. Mapping areas with a risk of damage from flooding and landslides coupled with advice on land use planning, results in better land use practices and an increased awareness of the potential hazard among local authorities and citizens. Methods for mapping floodplain inundation for large rivers are well developed. This is not the case for rivers with small and steep catchments with a potential for high rates of erosion and sediment transport. A method for identifying and mapping rivers with a potential danger of flash flooding and associated debris flows is currently being developed at NVE. The resultant maps will assist local authorities in the first step in land use planning where they are required to identify if there is a potential hazard in the area. The method makes use of spatial data available for the whole country and is based on a 25*25 m terrain model. The method is based on two simple assumptions adapted to the available data: i) Under normal hydraulic conditions there is a balance between processes of erosion and sedimentation. A debris flow will first occur when this balance is disturbed. This is quantified by the relative difference between the discharge of an extreme flood and floods that occur more frequently, ie. if the difference is large the probability of a debris flow occurring is greater and vice versa. ii) Steep rivers with a large difference in height between cells have more energy available for erosion and sediment transport and therefore a larger potential for erosion and sediment transport than less steep rivers

  7. Shallow circulation groundwater - the main type of water containing hazardous radon concentration

    Science.gov (United States)

    Przylibski, Tadeusz

    2010-05-01

    surface water forming a stream, radon very quickly escapes to the atmosphere. This is the main reason, that even in regions, where the bottoms of streams and rivers are formed by the rocks containing high amounts of radium (and uranium), surface waters very quickly lose radon escaping to the atmosphere. Concluding, surface waters cannot be the source of hazardous radon concentration. One may expect completely different situation in the case of groundwater. When the groundwater is exploited without any contact with the atmosphere, it contains higher concentration of Rn-222, than surface water in the same neighbourhood with regard to geological structure. Concentration of radon dissolved in groundwater depends first of all on the emanation coefficient of the reservoir rock. This coefficient may be calculated taking into account a few parameters, like cancentration of parent Ra-226 isotope in the reservoir rocks, effective porosity of the rock and the density of the grain framework of the rock. The way of radium atoms disposition in crystals or mineral grains of rock with reference to the pores and cracks filled with groundwater is also an important parameter. Calculations made by the author for more than 100 intakes of groundwater proove, that the highest values of emanation coefficient are characteristic for the rocks in the weathering zone - on the depths between surface level and 30 - 50 m below surface level. Groundwater exploited from the rocks of this zone contains the highest concentration of Rn-222. On the greater depths even high Ra-226 content in the reservoir rock does not affect to the Rn-222 concentration in groundwater flowing through this rock. Summing up, potentially the great radon concentration may contain groundwater of shallow circulation (up to ~50 m b.s.l.), flowing through weathered resrvoir rock with high content of parent Ra-226 isotope.

  8. Radon and thoron levels, their spatial and seasonal variations in adobe dwellings - a case study at the great Hungarian plain.

    Science.gov (United States)

    Szabó, Zsuzsanna; Jordan, Gyozo; Szabó, Csaba; Horváth, Ákos; Holm, Óskar; Kocsy, Gábor; Csige, István; Szabó, Péter; Homoki, Zsolt

    2014-06-01

    Radon and thoron isotopes are responsible for approximately half of the average annual effective dose to humans. Although the half-life of thoron is short, it can potentially enter indoor air from adobe walls. Adobe was a traditional construction material in the Great Hungarian Plain. Its major raw materials are the alluvial sediments of the area. Here, seasonal radon and thoron activity concentrations were measured in 53 adobe dwellings in 7 settlements by pairs of etched track detectors. The results show that the annual average radon and thoron activity concentrations are elevated in these dwellings and that the proportions with values higher than 300 Bq m(-3) are 14-17 and 29-32% for radon and thoron, respectively. The calculated radon inhalation dose is significantly higher than the world average value, exceeding 10 mSv y(-1) in 7% of the dwellings of this study. Thoron also can be a significant contributor to the inhalation dose with about 30% in the total inhalation dose. The changes of weather conditions seem to be more relevant in the variation of measurement results than the differences in the local sedimentary geology. Still, the highest values were detected on clay. Through the year, radon follows the average temperature changes and is affected by the ventilation, whereas thoron rather seems to follow the amount of precipitation.

  9. Radon emanometry as a geothermal exploration technique; theory and an example from Roosevelt Hot Springs KGRA, Utah

    Energy Technology Data Exchange (ETDEWEB)

    Nielson, D.L.

    1978-12-01

    Four radon survey lines were established over the geothermal field of Roosevelt Hot Springs KGRA. The radon flux was determined using the Westinghouse Alpha 2 system which measures the flux at each station over a period of 30 days using an alpha-sensitive dosimeter. The method was very successful in locating mapped fault systems that communicate with the structurally controlled geothermal reservoir. It is concluded that this method, coupled with a structural analysis, can be useful as a site-specific exploration tool, particularly in locating exploration holes in known geothermal areas.

  10. RADON PREVENTION IN THE DESIGN & CONSTRUCTION OF SCHOOLS & OTHER LARGE BUILDINGS

    Science.gov (United States)

    It is typically easier and much less expensive to design and construct a new building with radon-resistant and/or easy-to-mitigate features, than to add these features after the building is completed and occupied. Therefore, when building in an area with the potential for elevate...

  11. CASE STUDIES OF RADON REDUCTION RESEARCH IN MARYLAND, NEW JERSEY, AND VIRGINIA SCHOOLS

    Science.gov (United States)

    The report gives results of radon mitigation research conducted in 1991 and 1992 in school buildings in Maryland, New Jersey, and Virginia. One school in each state was selected. In two schools, the objective was to evaluate the potential for modifying the school ventilation sy...

  12. RADON PREVENTION IN THE DESIGN & CONSTRUCTION OF SCHOOLS & OTHER LARGE BUILDINGS

    Science.gov (United States)

    It is typically easier and much less expensive to design and construct a new building with radon-resistant and/or easy-to-mitigate features, than to add these features after the building is completed and occupied. Therefore, when building in an area with the potential for elevate...

  13. CASE STUDIES OF RADON REDUCTION RESEARCH IN MARYLAND, NEW JERSEY, AND VIRGINIA SCHOOLS

    Science.gov (United States)

    The report gives results of radon mitigation research conducted in 1991 and 1992 in school buildings in Maryland, New Jersey, and Virginia. One school in each state was selected. In two schools, the objective was to evaluate the potential for modifying the school ventilation sy...

  14. A Web-based tool for processing and visualizing body surface potential maps.

    Science.gov (United States)

    Bond, Raymond R; Finlay, Dewar D; Nugent, Chris D; Moore, George

    2010-01-01

    The body surface potential map (BSPM) is potentially more accurate for diagnosing cardiac pathologies when compared to the standard 12-lead electrocardiogram (ECG). However, a contributing factor to the lack of widespread adoption of the BSPM is the shortage of standard methods for its storage and visualization. Based on these observations, a BSPM storage format based on the eXtensible Markup Language has been developed within this study, alongside a Web-based BSPM viewer. This viewer was created using a lossless vector graphics tool (Adobe Flash) to maintain the quality of the ECG waveforms when they are enlarged. The viewer also runs inside the Web browser to facilitate BSPM visualization independent of the clinician's geographical location. This online nature enabled the creation of a comments system that can be used to assist in a collaborative diagnosis. This is useful because BSPM diagnostic criteria are not well established. Moreover, using the viewer's innovative tools (ie, calipers, isopotential maps), the clinician can explore BSPM datasets. Algorithms have also been integrated within the system to extract and display the 12-lead ECG and the vectorcardiogram from the BSPM. This viewer has been available online for 10 months alongside a Weblog, which has been used to record the user's feedback. During this period, 12 experts from both the clinical and visualization domains evaluated the viewer and contributed to its design. It has been the general consensus of all experts that the application is an effective solution for visualizing BSPMs. This viewer has been tested to visualize 2 different BSPMs using a PC (3 GHz CPU, 3 GB RAM, 6 MB broadband). The Lux-192 BSPM and the Kornreich-117 BSPM where both uploaded and visualized within 3.8 seconds (mean time from 10 trials). This BSPM storage format and its associated viewer provide a framework for a BSPM management system. If this system is made widely available, it has the potential to provide BSPM

  15. Environmental analysis of radiation exposure by radon in Saxon buildings and impact of the EnEV. An old problem in a new dimension; Umweltanalyse zur Strahlenbelastung durch Radon in saechsischen Gebaeuden und Auswirkungen der EnEV. Ein altes Problem mit neuen Dimensionen

    Energy Technology Data Exchange (ETDEWEB)

    Gottwald, Jan; Schneider, Lutz [Stoller Ingenieurtechnik GmbH, Dresden (Germany); Koeter, Nico [TU Bergakademie Freiberg (Germany)

    2015-07-01

    Radon in buildings is being widely studied since the 1990s. These studies have revealed some cases of very high radiation exposure for the inhabitants of residential buildings in Saxony in particular. Even a proposed raising of the radon reference values from 100 Bq/m{sup 3} to 300 Bq/m{sup 3} (in the case of an eventually 1:1 implementation of the EU recommendations into German law), would not even slightly aid the situation in the designated areas with high radon availability, as the standards of the Energieeinsparverordnung (Energy Saving Ordinance, EnEV) can result in significant radiation exposure, if no comprehensive radon protection is implemented. Based on long-term radon measurements in Saxony from the nineties, before the introduction of the EnEV, this report will show potential outcomes and estimate the extend of suitable remediation measures.

  16. Metrology of the radon in air volume activity at the italian radon reference chamber

    Energy Technology Data Exchange (ETDEWEB)

    Sciocchetti, G.; Cotellessa, G.; Soldano, E.; Pagliari, M. [Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti, ENEA Centro Ricerche Casaccia Roma (Italy)

    2006-07-01

    The approach of the Italian National Institute of Ionising Radiations (I.N.M.R.I.-ENEA) on radon metrology has been based on a complete and integrated system which can be used to calibrate the main types of {sup 222}Rn in air measuring instruments with international traceability. The Italian radon reference chamber is a research and calibration facility developed at the Casaccia Research Center in Roma. This facility has an inner volume of one m{sup 3}. The wall is a cylindrical stainless steel vessel coupled with an automated climate apparatus operated both at steady and dynamic conditions. The control and data acquisition equipment is based on Radotron system, developed to automate the multitasking management of different sets of radon monitors and climatic sensors. A novel approach for testing passive radon monitors with an alpha track detector exposure standard has been developed. It is based on the direct measurement of radon exposure with a set of passive integrating monitors based on the new ENEA piston radon exposure meter. This paper describes the methodological approach on radon metrology, the status-of-art of experimental apparatus and the standardization procedures. (authors)

  17. Radon in soil gas in Kosovo.

    Science.gov (United States)

    Kikaj, Dafina; Jeran, Zvonka; Bahtijari, Meleq; Stegnar, Peter

    2016-11-01

    An assessment of the radiological situation due to exposure to radon and gamma emitting radionuclides was conducted in southern Kosovo. This study deals with sources of radon in soil gas. A long-term study of radon concentrations in the soil gas was carried out using the SSNTDs (CR-39) at 21 different locations in the Sharr-Korabi zone. The detectors were exposed for an extended period of time, including at least three seasonal periods in a year and the sampling locations were chosen with respect to lithology. In order to determine the concentration of the natural radioactive elements (238)U and (226)Ra, as a precursor of (222)Rn, soil samples were collected from each measuring point from a depth of 0.8 m, and measured by gamma spectrometry. The levels (Bq kg(-1)) of naturally occurring radionuclides and levels (kBq m(-3)) of radon in soil gas obtained at a depth 0.8 m of soil were: 21-53 for (226)Ra, 22-160 for (238)U and 0.295-32 for (222)Rn. With respect to lithology, the highest value for (238)U and (226)Ra were found in limestone and the highest value for (222)Rn was found in metamorphic rocks. In addition, the results showed seasonal variations of the measured soil gas radon concentrations with maximum concentration in the spring months. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Indoor radon concentrations in Adana, Turkey.

    Science.gov (United States)

    Degerlier, M; Celebi, N

    2008-01-01

    The indoor radon concentration in Adana, Turkey was measured in living rooms of 52 houses during winter 2005 and 57 houses during summer 2005. Forty-four houses were selected for both winter and summer researches for estimating seasonal variations. Indoor radon concentrations were measured seasonally over hotter and colder 2 months over the whole year, using CR-39 passive nuclear track radon detectors. The radon concentrations were ranged from 15 to 97 Bq m(-3) on January-February 2005 for 60 d and from 5 to 70 Bq m(-3) on June-July 2005 for 60 d. The average summer concentration measured was 25.8 Bq m(-3) and the average winter concentration was 48.9 Bq m(-3) in 44 houses that observed seasonal variations. The differences between winter and summer periods were ranged from 1 to 77 Bq m(-3). The average value in both winter and summer periods is 37 Bq m(-3) in 44 houses that observed seasonal variations. This value is below the worldwide indoor radon concentration distribution of 46 Bq m(-3). The annual effective dose equivalent from (222)Rn was 0.9 mSv y(-1).

  19. Radon measurements with a PIN photodiode

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Martin, A. [Laboratorio de Investigacion en Baja Radiactividad (LIBRA), Edificio I-D, Campus Miguel Delibes, Universidad de Valladolid, Valladolid 47011 (Spain) and Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, Valladolid 47011 (Spain)]. E-mail: alonsomm@libra.uva.es; Gutierrez-Villanueva, J.L. [Laboratorio de Investigacion en Baja Radiactividad (LIBRA), Edificio I-D, Campus Miguel Delibes, Universidad de Valladolid, Valladolid 47011 (Spain); Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, Valladolid 47011 (Spain); Munoz, J.M. [Departamento de Electricidad y Electronica, Universidad de Valladolid, Valladolid 47011 (Spain); Garcia-Talavera, M. [Laboratorio de Investigacion en Baja Radiactividad (LIBRA), Edificio I-D, Campus Miguel Delibes, Universidad de Valladolid, Valladolid 47011 (Spain); Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, Valladolid 47011 (Spain); Adamiec, G. [Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, Valladolid 47011 (Spain); Iniguez, M.P. [Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, Valladolid 47011 (Spain)

    2006-10-15

    Silicon photodiodes are well suited to detect alphas coming from different sources as neutron reactions or radon daughters. In this work a radon in air detecting device, using an 18x18 mm silicon PIN photodiode is studied. The ionized airborne decay products formed during radon diffusion were focused by an accelerating high voltage to the PIN surface. Several conducting rings were disposed inside a cylindrical PVC vessel in such a way that they reproduced the electric field created by a punctual charge located behind PIN position. Alpha spectra coming from the neutral and ionized species deposited on the PIN surface, dominated by {sup 218}Po and {sup 214}Po progeny peaks, were recorded for varying conditions. Those include radon concentration from a Pylon source, high voltage (thousands of volts) and PIN inverse bias voltage. Different parameters such as temperature and humidity were also registered during data acquisition. The increase in the particle collection efficiency with respect to zero electric field was compared with the corresponding to a parallel plates configuration. A discussion is made in terms of the most appropriate voltages for different radon concentrations.

  20. Radon monitoring in Bologna (Italy) homes

    Energy Technology Data Exchange (ETDEWEB)

    Beozzo, M.; Bottazzi, E.; Degli Esposti, L.; Folesani, M.; Frassinetti, J.; Giacomelli, G.; Lembo, L.; Maltoni, G.; Massera, F.; Nicoli, F. (Bologna Univ. (Italy). Dept. di Fisica ENEA Centro Ricerche Energia, Bologna (Italy). Area Energia, Ambiente e Salute Istituto Nazionale di Fisica Nucleare, Bologna (Italy))

    1991-01-01

    This paper first reviews the origin and behaviour of naturally present radon gas which is thought to account for more than 50% of radiation doses derived from natural radioactivity and deemed responsible for increased risk of lung cancer. An analysis is made of the many factors influencing radon concentration levels in residential buildings. These include such factors as the presence of thermal bridges, type of ventilation and seasonal climatic variations. In addition, since the density of radon is eight times greater than that of air, concentration levels vary greatly according to room height above ground level. The paper then reports on a home radon monitoring campaign conducted by ENEA (Italian Commission for New Technologies, Energy and Environment) with the aim of providing sufficient and accurate information to public health authorities to enable them to set up and implement effective radiation protection policies. The monitoring was done with two methods to allow comparisons to be made. One was based on the use of a passive nuclear trace detector (CR-39), the other, based on the use of gas adsorption by activated carbon. Results with the two methods agreed well and only modest amounts of indoor radon were detected.

  1. RADON MITIGATION IN SCHOOLS: CASE STUDIES OF RADON MITIGATION SYSTEMS INSTALLED BY EPA IN FOUR MARYLAND SCHOOLS ARE PRESENTED

    Science.gov (United States)

    The first part of this two-part paper discusses radon entry into schools, radon mitigation approaches for schools, and school characteristics (e.g., heating, ventilation, and air-conditioning -- HVAC-- system design and operation) that influence radon entry and mitigation system ...

  2. RADON MITIGATION IN SCHOOLS: CASE STUDIES OF RADON MITIGATION SYSTEMS INSTALLED BY EPA IN FOUR MARYLAND SCHOOLS ARE PRESENTED

    Science.gov (United States)

    The first part of this two-part paper discusses radon entry into schools, radon mitigation approaches for schools, and school characteristics (e.g., heating, ventilation, and air-conditioning -- HVAC-- system design and operation) that influence radon entry and mitigation system ...

  3. Determination of Radon concentration in air using scinti-cell radon monitor

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Taeko [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst; Morishima, Hiroshige; Arai, Naoki; Shiraishi, Masatoshi; Shigehara, Makiko [Dept. of Nuclear Engineering, School of Science and Technology, Kinki Univ., Higashi-Osaka, Osaka(Japan); Mifune, Masaaki

    2000-01-01

    This study is carried out the methodology characteristics of {sup 222}Rn (Radon) concentration in air using the scinti-cell radon monitor (Trace environmental level detector (PMT-TEL) and Lucas cell (300 A), Pylon Co. and the determination of Radon concentrations in air on Misasa spa area in Tottori pref. and Ikeda spa in Shimane pref. on November 1995 and 1996. We have reached to the following results; (1) Minimum detectable Radon concentrations in air using the scinti-cell monitor are 7.6 Bq/m{sup 3} with 23% of accuracy (relative standard deviation) on the grab sampling of Lucas cell and 0.58 Bq/m{sup 3} with that of 17% on the continuous measuring of PMT-TEL, when it measured after 3.5 hours on the air sampling to determine the mean radon concentrations. The radon concentrations by the PMT-TEL method is about ten times more detectable than those by Lucas cell, that the former is the most sensitive among the detectors used on this research and is able to detect low level environmental concentrations, particularly outdoor and the later is valuable to use conveniently and portably on grab spot sampling of high level radon concentrations indoor air. (2) On the comparison of characteristics on spot monitoring of radon in air, a pico-rad method is suitable for the determination of the mean concentration for continuous sampling period by PMT-TEL and Lucas cell 300 A, and the variation of radon concentration can be observed on elapse of time course. (author)

  4. MAPPING OF TOURISM POTENTIAL: THE PRECONDITIONS FOR THE DEVELOPMENT OF TOURISM IN CONTINENTAL CROATIA

    Directory of Open Access Journals (Sweden)

    Mario Banožić

    2015-07-01

    Full Text Available Many Croatian scientists indicate that there are significant opportunities in tourism that can beneficially influence the overall socio-economic development of Croatia. It is recognised that Croatia has to follow more closely the contemporary tourism trends, in which much greater attention is given to ecology, the cultural identity of the destination, active vacations, service quality and selective forms of tourism development. There is also agreement that the clean sea, the coast, and the abundance of natural and cultural beauty are the advantages of Croatia’s tourism supply in the maritime part of the country. However, there are some discussions that the Continental part of Croatia is also abundant in natural beauty, cultural wealth, and gastronomy, and that it has many other underutilised tourism potentials. Different viewpoints on tourism in Croatia are based on statistical indicators, such as the level of development of tourist regions expressed through investments in infrastructure, the number of employed and the direct benefit of tourism to the economy. Despite the fact that the Continental part of Croatia abounds in tourism potential, what is offered is recognised only locally. This problem has negative impacts at the strategic level, as project planning and financing need to have a regional dimension. Some authors (Kušen, 1999; Koščak, 1998; Krippendorf, 1986; Müller, 1994; Stabler, 1996; Travis et al., 1994 have developed a cadastre of tourism potential, which has never been implemented. Therefore, this paper aims to map the tourism potentials of Continental Croatia by using the triple helix model, based on which regional tourism can be developed and future project funding ensured.

  5. Radon exhalation rates corrected for leakage and back diffusion – Evaluation of radon chambers and radon sources with application to ceramic tile

    Directory of Open Access Journals (Sweden)

    M. Abo-Elmagd

    2014-10-01

    Full Text Available The natural radon decay, leakage and back diffusion are the main removal processes of radon from its container. Ignoring these processes leads to underestimate the measured value of radon related parameters like exhalation rate and radium content. This work is aimed to evaluate two different radon chambers through determining their leakage rate λv and evaluation of radon source by determine its back diffusion rate λb inside the evaluated radon chambers as well as a small sealed cup. Two different methods are adapted for measuring both the leakage rate and the back diffusion rate. The leakage rate can be determined from the initial slope of the radon decay curve or from the exponential fitting of the whole decay curve. This can be achieved if a continuous monitoring of radon concentration inside the chamber is available. Also, the back diffusion rate is measured by sealing the radon source in the chamber and used the initial slope of the buildup curve to determine λb and therefore the exhalation rate of the source. This method was compared with simple equation for λb based on the ratio of the source to the chamber volume. The obtained results are applied to ceramic tile as an important radon source in homes. The measurement is targeted the ceramic glaze before and after firing as well as the obtained tile after adhere the glaze on the tile main body. Also, six different tile brands from Egyptian market are subjected to the study for comparison.

  6. Occupational radon exposure and lung cancer mortality: estimating intervention effects using the parametric G formula

    Science.gov (United States)

    Edwards, Jessie K.; McGrath, Leah J.; Buckley, Jessie P.; Schubauer-Berigan, Mary K.; Cole, Stephen R.; Richardson, David B.

    2015-01-01

    Background Traditional regression analysis techniques used to estimate associations between occupational radon exposure and lung cancer focus on estimating the effect of cumulative radon exposure on lung cancer, while public health interventions are typically based on regulating radon concentration rather than workers’ cumulative exposure. Moreover, estimating the direct effect of cumulative occupational exposure on lung cancer may be difficult in situations vulnerable to the healthy worker survivor bias. Methods Workers in the Colorado Plateau Uranium Miners cohort (N=4,134) entered the study between 1950 and 1964 and were followed for lung cancer mortality through 2005. We use the parametric g-formula to compare the observed lung cancer mortality to the potential lung cancer mortality had each of 3 policies to limit monthly radon exposure been in place throughout follow-up. Results There were 617 lung cancer deaths over 135,275 person-years of follow-up. With no intervention on radon exposure, estimated lung cancer mortality by age 90 was 16%. Lung cancer mortality was reduced for all interventions considered, and larger reductions in lung cancer mortality were seen for interventions with lower monthly radon exposure limits. The most stringent guideline, the Mine Safety and Health Administration standard of 0.33 working level months, reduced lung cancer mortality from 16% to 10% (risk ratio 0.67; 95% confidence interval 0.61, 0.73). Conclusions This work illustrates the utility of the parametric g-formula for estimating the effects of policies regarding occupational exposures, particularly in situations vulnerable to the healthy worker survivor bias. PMID:25192403

  7. A linear radio frequency plasma reactor for potential and current mapping in a magnetized plasma.

    Science.gov (United States)

    Faudot, E; Devaux, S; Moritz, J; Heuraux, S; Molina Cabrera, P; Brochard, F

    2015-06-01

    Langmuir probe measurements in front of high power ion cyclotron resonant frequency antennas are not possible or simply too noisy to be analyzed properly. A linear experiment is a radio frequency (RF) magnetized plasma discharge reactor designed to probe the rectified potential in front of such antennas but at low power level (1 kW) to next improve antenna design and mitigate sheath effects. The maximum magnetic field is 0.1 T, and the RF amplifier can work between 10 kHz and 250 MHz allowing ion cyclotron resonances for argon or helium. The first measurements with no magnetic field are presented here, especially 2D potential maps extracted from the RF compensated probe measurements yield ni ≈ 10(15) m(-3) and Te ≈ 2 eV for RF power lower than 100 W. Series resonances in the chamber are highlighted and allow to deduce the plasma parameters from a simple equivalent impedance model of the plasma in helium gas. Next studies will be focused on magnetized plasmas and especially magnetized RF sheaths.

  8. Mapping oil and gas development potential in the US Intermountain West and estimating impacts to species.

    Directory of Open Access Journals (Sweden)

    Holly E Copeland

    Full Text Available BACKGROUND: Many studies have quantified the indirect effect of hydrocarbon-based economies on climate change and biodiversity, concluding that a significant proportion of species will be threatened with extinction. However, few studies have measured the direct effect of new energy production infrastructure on species persistence. METHODOLOGY/PRINCIPAL FINDINGS: We propose a systematic way to forecast patterns of future energy development and calculate impacts to species using spatially-explicit predictive modeling techniques to estimate oil and gas potential and create development build-out scenarios by seeding the landscape with oil and gas wells based on underlying potential. We illustrate our approach for the greater sage-grouse (Centrocercus urophasianus in the western US and translate the build-out scenarios into estimated impacts on sage-grouse. We project that future oil and gas development will cause a 7-19 percent decline from 2007 sage-grouse lek population counts and impact 3.7 million ha of sagebrush shrublands and 1.1 million ha of grasslands in the study area. CONCLUSIONS/SIGNIFICANCE: Maps of where oil and gas development is anticipated in the US Intermountain West can be used by decision-makers intent on minimizing impacts to sage-grouse. This analysis also provides a general framework for using predictive models and build-out scenarios to anticipate impacts to species. These predictive models and build-out scenarios allow tradeoffs to be considered between species conservation and energy development prior to implementation.

  9. The c-map, Tits Satake subalgebras and the search for N = 2 inflaton potentials

    Energy Technology Data Exchange (ETDEWEB)

    Fre, P. [Dipartimento di Fisica, Universita di Torino (Italy); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); INFN, Torino (Italy); Sorin, A.S. [Bogoliubov Laboratory of Theoretical Physics and Laboratory of High Energy Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Trigiante, M. [Department of Applied Science and Technology, Politecnico di Torino, Torino (Italy)

    2015-04-01

    In this paper we address the general problem of including inflationary models exhibiting Starobinsky-like potentials into (symmetric) N = 2 supergravities. This is done by gauging suitable abelian isometries of the hypermultiplet sector and then truncating the resulting theory to a single scalar field. By using the characteristic properties of the global symmetry groups of the N = 2 supergravities we are able to make a general statement on the possible α-attractor models which can obtained upon truncation. We find that in symmetric N = 2 models group theoretical constraints restrict the allowed values of the parameter α to be α = 1, (2)/(3), (1)/(3). This confirms and generalizes results recently obtained in the literature. Our analysis heavily relies on the mathematical structure of symmetric N = 2 supergravities, in particular on the so called c-map connection between Quaternionic Kaehler manifolds starting from Special Kaehler ones. A general statement on the possible consistent truncations of the gauged models, leading to Starobinsky-like potentials, requires the essential help of Tits Satake universality classes. The paper is mathematically selfcontained and aims at presenting the involved mathematical structures to a public not only of physicists but also of mathematicians. To this end the main mathematical structures and the general gauging procedure of N = 2 supergravities is reviewed in some detail. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Thec-map, Tits Satake subalgebras and the search for N=2 inflaton potentials

    Science.gov (United States)

    Fré, P.; Sorin, A. S.; Trigiante, M.

    2015-04-01

    In this paper we address the general problem of including inflationary models exhibiting Starobinsky-like potentials into (symmetric) $\\mathcal{N}=2$ supergravities. This is done by gauging suitable abelian isometries of the hypermultiplet sector and then truncating the resulting theory to a single scalar field. By using the characteristic properties of the global symmetry groups of the $\\mathcal{N}=2$ supergravities we are able to make a general statement on the possible $\\alpha$-attractor models which can obtained upon truncation. We find that in symmetric $\\mathcal{N}=2$ models group theoretical constraints restrict the allowed values of the parameter $\\alpha$ to be $\\alpha=1,\\,\\frac{2}{3},\\, \\frac{1}{3}$. This confirms and generalizes results recently obtained in the literature. Our analysis heavily relies on the mathematical structure of symmetric $\\mathcal{N}=2$ supergravities, in particular on the so called $c$-map connection between Quaternionic K\\"ahler manifolds starting from Special K\\"ahler ones. A general statement on the possible consistent truncations of the gauged models, leading to Starobinsky-like potentials, requires the essential help of Tits Satake universality classes. The paper is mathematically self-contained and aims at presenting the involved mathematical structures to a public not only of physicists but also of mathematicians. To this end the main mathematical structures and the general gauging procedure of $\\mathcal{N}=2$ supergravities is reviewed in some detail.

  11. Predicting and mapping potential Whooping Crane stopover habitat to guide site selection for wind energy projects.

    Science.gov (United States)

    Belaire, J Amy; Kreakie, Betty J; Keitt, Timothy; Minor, Emily

    2014-04-01

    Migratory stopover habitats are often not part of planning for conservation or new development projects. We identified potential stopover habitats within an avian migratory flyway and demonstrated how this information can guide the site-selection process for new development. We used the random forests modeling approach to map the distribution of predicted stopover habitat for the Whooping Crane (Grus americana), an endangered species whose migratory flyway overlaps with an area where wind energy development is expected to become increasingly important. We then used this information to identify areas for potential wind power development in a U.S. state within the flyway (Nebraska) that minimize conflicts between Whooping Crane stopover habitat and the development of clean, renewable energy sources. Up to 54% of our study area was predicted to be unsuitable as Whooping Crane stopover habitat and could be considered relatively low risk for conflicts between Whooping Cranes and wind energy development. We suggest that this type of analysis be incorporated into the habitat conservation planning process in areas where incidental take permits are being considered for Whooping Cranes or other species of concern. Field surveys should always be conducted prior to construction to verify model predictions and understand baseline conditions.

  12. Capacitive ECG system with direct access to standard leads and body surface potential mapping.

    Science.gov (United States)

    Oehler, Martin; Schilling, Meinhard; Esperer, Hans Dieter

    2009-12-01

    Capacitive electrodes provide the same access to the human electrocardiogram (ECG) as galvanic electrodes, but without the need of direct electrical skin contact and even through layers of clothing. Thus, potential artifacts as a result of poor electrode contact to the skin are avoided and preparation time is significantly reduced. Our system integrates such capacitive electrodes in a 15 sensor array, which is combined with a Tablet PC. This integrated lightweight ECG system (cECG) is easy to place on the chest wall and allows for simultaneous recordings of 14 ECG channels, even if the patient is slightly dressed, e.g., with a t-shirt. In this paper, we present preliminary results on the performance of the cECG regarding the capability of recording body surface potential maps (BSPMs) and obtaining reconstructed standard ECG leads including Einthoven, Goldberger and, with some limitations, Wilson leads. All signals were measured having the subject lie in a supine position and wear a cotton shirt. Signal quality and diagnostic ECG information of the extracted leads are compared with standard ECG measurements. The results show a very close correlation between both types of ECG measurements. It is concluded that the cECG lends itself to rapid screening in clinically unstable patients.

  13. Potential use and challenges of functional connectivity mapping in intractable epilepsy

    Directory of Open Access Journals (Sweden)

    Robert Todd Constable

    2013-05-01

    Full Text Available This review focuses on the use of resting-state functional magnetic resonance imaging data to assess functional connectivity in the human brain for surgical planning in intractable epilepsy. This approach has the potential to predict outcomes for a given surgical procedure based on the pre-surgical functional organization of the brain. Functional connectivity can also identify cortical regions that are organized differently in epilepsy patients either as a direct function of the disease or through indirect compensatory responses. Functional connectivity mapping can also potentially help identify epileptogenic tissue, whether this is a single focal location or a network of seizure-generating tissues and this information can assist in guiding the implantation of electrodes for invasive monitoring. This review covers the basics of connectivity analysis and discusses particular issues associated with analyzing such data. These issues include how to define nodes, as well as differences between connectivity analyses of individual nodes, groups of nodes, and whole-brain assessment at the voxel level. The need for arbitrary thresholds in some connectivity analyses is discussed and a solution to this problem is reviewed. Overall, functional connectivity analysis is becoming an important tool for assessing functional brain organization in surgical planning in epilepsy.

  14. Multagenicity of radon and radon daughters. Final technical report, January 1, 1993--December 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Evans, H.H.

    1997-06-01

    The objective of this research was to investigate the dose-response relationship with regard to the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose-rate dependence was studied, as well as the nature of the DNA lesions. The effect of DNA repair on the lethal and mutagenic effects of exposure and on the character of the DNA lesions was investigated by comparing the response of L5178Y strains that differ in their ability to rejoin X radiation-induced DNA double strand breaks. The nature of radon/radon daughter-induced mutational lesions in human lymphoblasts was also investigated.

  15. The use of track registration detectors to reconstruct contemporary and historical airborne radon ( sup 2 sup 2 sup 2 Rn) and radon progeny concentrations for a radon-lung cancer epidemiologic study

    CERN Document Server

    Steck, D J

    1999-01-01

    Epidemiologic studies that investigate the relationship between radon and lung cancer require accurate estimates for the long-term average concentrations of radon progeny in dwellings. Year-to-year and home-to-home variations of radon in domestic environments pose serious difficulties for reconstructing an individual's long-term radon-related exposure. The use of contemporary radon gas concentrations as a surrogate for radon-related dose introduces additional uncertainty in dose assessment. Studies of glass exposed in radon chambers and in a home show that radon progeny deposited on, and implanted in, glass hold promise for reconstructing past radon concentrations in a variety of atmospheres. We developed an inexpensive track registration detector for the Iowa Radon Lung Cancer Study (IRLCS) that simultaneously measures contemporary airborne radon concentrations, surface deposited alpha activity density, and implanted sup 2 sup 1 sup 0 Po activity density. The implanted activity is used to reconstruct the cum...

  16. Testing the Potential of Volunteered Geoinformation in the Case of OpenStreetMap in Croatia

    Directory of Open Access Journals (Sweden)

    Baldo Stančić

    2014-12-01

    Full Text Available The development of technologies, especially the information and communications technology (ICT and navigation technology, opened the possibility for collecting geospatial data to all interested parties. This trend has led to a new paradigm in the form of volunteered geoinformation (VGI. The speed of data collection as well as the amount of this data makes their use a great potential. On the other hand, there is a question of the quality of such data. They are by default collected by volunteers who have no formal training in the collection of spatial data. It is therefore important to examine the quality as well as to establish appropriate standards for data collection, but also for usage. This paper gives an overview of the phenomenon of VGI, its definition, the links with spatial data infrastructures (SDIs and the possibilities of its use. Some examples of collecting through and using the various VGI-based applications in Croatia are shown. Furthermore, an analysis of data completeness in the case of OpenStreetMap has been performed. The results of this research indicate that the completeness of VGI depends primarily on the interests of those who collect and use them. In the case of the OpenStreetMap data for Croatia, it is evident that the content of information is more complete in urban as well as coastal areas, while this is not the case in suburban and rural areas. A general trend of collecting and increasing the amounts of VGI already provides an alternative to the official spatial databases to a certain extent. Through appropriate standardization, VGI data can serve as a good source for the database updating and maintenance.

  17. Mapping the potential risk of mycetoma infection in Sudan and South Sudan using ecological niche modeling.

    Directory of Open Access Journals (Sweden)

    Abdallah M Samy

    2014-10-01

    Full Text Available In 2013, the World Health Organization (WHO recognized mycetoma as one of the neglected tropical conditions due to the efforts of the mycetoma consortium. This same consortium formulated knowledge gaps that require further research. One of these gaps was that very few data are available on the epidemiology and transmission cycle of the causative agents. Previous work suggested a soil-borne or Acacia thorn-prick-mediated origin of mycetoma infections, but no studies have investigated effects of soil type and Acacia geographic distribution on mycetoma case distributions. Here, we map risk of mycetoma infection across Sudan and South Sudan using ecological niche modeling (ENM. For this study, records of mycetoma cases were obtained from the scientific literature and GIDEON; Acacia records were obtained from the Global Biodiversity Information Facility. We developed ENMs based on digital GIS data layers summarizing soil characteristics, land-surface temperature, and greenness indices to provide a rich picture of environmental variation across Sudan and South Sudan. ENMs were calibrated in known endemic districts and transferred countrywide; model results suggested that risk is greatest in an east-west belt across central Sudan. Visualizing ENMs in environmental dimensions, mycetoma occurs under diverse environmental conditions. We compared niches of mycetoma and Acacia trees, and could not reject the null hypothesis of niche similarity. This study revealed contributions of different environmental factors to mycetoma infection risk, identified suitable environments and regions for transmission, signaled a potential mycetoma-Acacia association, and provided steps towards a robust risk map for the disease.

  18. Where is MAP Going? A review and future potential of modified atmosphere packaging for meat.

    Science.gov (United States)

    McMillin, Kenneth W

    2008-09-01

    Modified atmosphere packaging (MAP) is the removal and/or replacement of the atmosphere surrounding the product before sealing in vapor-barrier materials. While technically different, many forms of MAP are also case-ready packaging, where meat is cut and packaged at a centralized location for transport to and display at a retail store. Most of the shelf life properties of meat are extended by use of MAP, but anoxic forms of MAP without carbon monoxide (CO) do not provide bloomed red meat color and MAP with oxygen (O(2)) may promote oxidation of lipids and pigments. Advances in plastic materials and equipment have propelled advances in MAP, but other technological and logistical considerations are needed for successful MAP systems for raw chilled fresh meat. Current MAP options of air-permeable overwrapped trays in master packs, low O(2) formats of shrunk film vacuum packaging (VP) or MAP with carbon dioxide (CO(2)) and nitrogen (N(2)) and their peelable barrier film derivatives, and high O(2) MAP each have advantages and disadvantages. Packaging technology innovations and ingenuity will continue to provide MAP that is consumer oriented, product enhancing, environmentally responsive, and cost effective, but continued research and development by the scientific and industry sectors will be needed.

  19. Residential radon in Finland: sources, variation, modelling and dose comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Arvela, H.

    1995-09-01

    The study deals with sources of indoor radon in Finland, seasonal variations in radon concentration, the effect of house construction and ventilation and also with the radiation dose from indoor radon and terrestrial gamma radiation. The results are based on radon measurements in approximately 4000 dwellings and on air exchange measurements in 250 dwellings as well as on model calculations. The results confirm that convective soil air flow is by far the most important source of indoor radon in Finnish low-rise residential housing. (97 refs., 61 figs., 30 tabs.).

  20. Indoor radon and decay products: Concentrations, causes, and control strategies

    Energy Technology Data Exchange (ETDEWEB)

    Nero, A.V.; Gadgil, A.J.; Nazaroff, W.W.; Revzan, K.L.

    1990-11-01

    This report is another in the on going technical report series that addresses various aspects of the DOE Radon Research Program. It provides an overview of what is known about the behavior of radon and its decay products in the indoor environment and examines the manner in which several important classes of factors -- structural, geological, and meteorological -- affect indoor radon concentrations. Information on US indoor radon concentrations, currently available monitoring methods and novel radon control strategies are also explored. 238 refs., 22 figs., 9 tabs.

  1. Measurement of soil and indoor radon in Italy

    Energy Technology Data Exchange (ETDEWEB)

    Torri, G.; Azimi-Garakani, D.; Oppon, O.C.; Piermattei, S.; Susanna, A.F.; Seidel, J.-L.; Tommasino, L.; Ardanese, L. (ENEA, Rome (Italy))

    1988-01-01

    In spite of the fact that in the majority of cases the most important radon source is the soil and the rock beneath the house, no large scale survey of soil radon has ever been made in Italy. In this paper the results of a large scale survey of soil radon are presented from measurements made in hundreds of different sites in Latium and Campania. For several locations, results of measurements gathered for different years are described and up-dated. As a pilot project for indoor radon survey monthly variations of radon concentrations in typical houses have been investigated. (author).

  2. Lung cancer attributable to indoor radon exposure in France using different risk models

    Energy Technology Data Exchange (ETDEWEB)

    Catelinois, O.C.; Laurier, D.L.; Rogel, A.R.; Billon, S.B.; Tirmarche, M.T. [Institute for Radiological Protection and Nuclear Safety, 92 - Fontenay aux Roses (France); Hemon, Dh. [INSERM -U170-IFR69, 94 - Villejuif (France); Verger, P.V. [Regional Health Observatory Provence Alpes Cote d' Azur, 13 - Marseille (France)

    2006-07-01

    Full text of publication follows: Radon exposure is omnipresent for the general public, but at variable levels, because radon mainly comes from granitic and volcanic subs oils as well as from certain construction materials. Inhalation of radon is the main source of exposure to radioactivity in the general population of most countries. In 1988, the International Agency for Research on Cancer declared radon to be carcinogenic for humans (lung cancer): radon is classed in the group 1. The exposure of the overall general population to a carcinogenic component led scientists to assess the lung cancer risk associated to indoor radon. The aim of this work is to provide the first lung cancer risk assessment associated with indoor radon exposure in France, using all available epidemiological results and performing an uncertainty analysis. The number of lung cancer deaths potentially associated with radon in houses is estimated for the year 1999 according to several dose-response relationships which come from either cohorts of miners or joint analysis of residential case-controls studies. The variability of indoor radon exposure in France and uncertainties related to each of the dose-response relationships are considered. The assessment of lung cancer risk associated with domestic radon exposure considers 10 dose-response relationships resulting from miners cohorts and case-control studies in the general population. A critical review of available data on smoking habits has been performed and allowed to consider the interaction between radon and tobacco. The exposure data come from measurements campaigns carried out since the beginning of the 1980's by the Institute for Radiation protection and Nuclear Safety and the Health General Directory in France. The French lung cancer mortality data are provided by the INSERM. Estimates of the number of attributable cancers are carried out for the whole country, stratified by 8 large regions and b y 96 departments for the year

  3. Sky and Elemental Planetary Mapping Via Gamma Ray Emissions

    Science.gov (United States)

    Roland, John M.

    2011-01-01

    Low-energy gamma ray emissions ((is) approximately 30keV to (is) approximately 30MeV) are significant to astrophysics because many interesting objects emit their primary energy in this regime. As such, there has been increasing demand for a complete map of the gamma ray sky, but many experiments to do so have encountered obstacles. Using an innovative method of applying the Radon Transform to data from BATSE (the Burst And Transient Source Experiment) on NASA's CGRO (Compton Gamma-Ray Observatory) mission, we have circumvented many of these issues and successfully localized many known sources to 0.5 - 1 deg accuracy. Our method, which is based on a simple 2-dimensional planar back-projection approximation of the inverse Radon transform (familiar from medical CAT-scan technology), can thus be used to image the entire sky and locate new gamma ray sources, specifically in energy bands between 200keV and 2MeV which have not been well surveyed to date. Samples of these results will be presented. This same technique can also be applied to elemental planetary surface mapping via gamma ray spectroscopy. Due to our method's simplicity and power, it could potentially improve a current map's resolution by a significant factor.

  4. Turbidimetry for measurement of radon concentration

    Energy Technology Data Exchange (ETDEWEB)

    Wang Huanqiang [HuBei Provincial Academy of Medical Sciences, WuHan (China). Inst. of Radioactive Protection

    1993-12-31

    This paper describes a turbidimetric technique counting the tracks registered on CR-39 foils exposed to radon. Instead of eyeview through microscope, by using the differential spectrophotometer, strong correlation between the radon cumulative concentration and track turbidence was observed(r=0.999). Under the etching condition of 7.07 mol{center_dot}L{sup -1} KOH water solution at 80{sup o}C for 16 hr, linear regression showed that the ratio of track turbidence and cumulative concentration of radon exposure was 1.99 x 10{sup -1} turbidence (KBq m{sup -1}h){sup -1} and the determination limit was 36 KBq m{sup -3}h. The details of the experiments are represented in this paper. (Author).

  5. Radon barrier: Method of testing airtightness

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Buch-Hansen, Thomas Cornelius

    2017-01-01

    The test method NBI 167/02 Radon membrane: Test of airtightness can be used for determining the airtightness of a radon barrier as a system solution. The test determines the air infiltration through the radon barrier for a number of levels of air pressure differences. The airflow through versus...... the difference in air pressure over the barrier is measured. The air pressure difference is kept constant, at a number of manually controlled levels. At each pressure level, the difference is measured in a single point close to the point where the suction for lowering the air pressure is located. Improvements...... to the test method were suggested. A digital stirring and control system, and a method for determining the mean air pressure difference, as well as a method for testing barriers with a very low air infiltration, were provided. The digital stirring and control system ensured automatic control and measuring...

  6. Biological and therapeutical effects of Radon

    Energy Technology Data Exchange (ETDEWEB)

    Deetjen, P. [Institute of Physiologie and Balneologie, University of Innsbruck (Austria)

    1998-12-31

    In spas with a somewhat elevated Radon{sup 222} (Rn) activity (between 300 and 3000 Bq/l), the empirical medicine ended - in all parts of the world - with the same list of indications. It mainly includes the more painful rheumatic diseases such as deformation or degeneration of the joints and non bacterial inflammation of muscles, tendons or joints; Morbus Bechterew and other diseases of the vertebral column like spondylosis, spondylarthrosis or osteochondrosis. While informer times these effects were seldom documented in an objective manner, in recent years several prospective randomized double-blind studies proved the pain reducing efficacy of Radon therapy in patients with cervical pain syndromes, with chronic polyarthritis or with Morbus Bechterew. Studies in experimental animal models have accumulated remarkable data in organs, tissue and cultured cells that provide a rationale to explain the observed effects of Radon therapy in patients. (author)

  7. Geomatics for Mapping of Groundwater Potential Zones in Northern Part of the United Arab Emiratis - Sharjah City

    Science.gov (United States)

    Al-Ruzouq, R.; Shanableh, A.; Merabtene, T.

    2015-04-01

    In United Arab Emirates (UAE) domestic water consumption has increased rapidly over the last decade. The increased demand for high-quality water, create an urgent need to evaluate the groundwater production of aquifers. The development of a reasonable model for groundwater potential is therefore crucial for future systematic developments, efficient management, and sustainable use of groundwater resources. The objective of this study is to map the groundwater potential zones in northern part of UAE and assess the contributing factors for exploration of potential groundwater resources. Remote sensing data and geographic information system will be used to locate potential zones for groundwater. Various maps (i.e., base, soil, geological, Hydro-geological, Geomorphologic Map, structural, drainage, slope, land use/land cover and average annual rainfall map) will be prepared based on geospatial techniques. The groundwater availability of the basin will qualitatively classified into different classes based on its hydro-geo-morphological conditions. The land use/land cover map will be also prepared for the different seasons using a digital classification technique with a ground truth based on field investigation.

  8. Mapping epistemic cultures and learning potential of participants in citizen science projects.

    Science.gov (United States)

    Vallabh, Priya; Lotz-Sisitka, Heila; O'Donoghue, Rob; Schudel, Ingrid

    2016-06-01

    The ever-widening scope and range of global change and interconnected systemic risks arising from people-environment relationships (social-ecological risks) appears to be increasing concern among, and involvement of, citizens in an increasingly diversified number of citizen science projects responding to these risks. We examined the relationship between epistemic cultures in citizen science projects and learning potential related to matters of concern. We then developed a typology of purposes and a citizen science epistemic-cultures heuristic and mapped 56 projects in southern Africa using this framework. The purpose typology represents the range of knowledge-production purposes, ranging from laboratory science to social learning, whereas the epistemic-cultures typology is a relational representation of scientist and citizen participation and their approach to knowledge production. Results showed an iterative relationship between matters of fact and matters of concern across the projects; the nexus of citizens' engagement in knowledge-production activities varied. The knowledge-production purposes informed and shaped the epistemic cultures of all the sampled citizen science projects, which in turn influenced the potential for learning within each project. Through a historical review of 3 phases in a long-term river health-monitoring project, we found that it is possible to evolve the learning curve of citizen science projects. This evolution involved the development of scientific water monitoring tools, the parallel development of pedagogic practices supporting monitoring activities, and situated engagement around matters of concern within social activism leading to learning-led change. We conclude that such evolutionary processes serve to increase potential for learning and are necessary if citizen science is to contribute to wider restructuring of the epistemic culture of science under conditions of expanding social-ecological risk.

  9. Radon concentration in houses over a closed Hungarian uranium mine

    Energy Technology Data Exchange (ETDEWEB)

    Somlai, Janos; Kovacs, Tibor [University of Veszprem Department of Radiochemistry, H-8200, Veszprem P.O.B.: 158 (Hungary); Gorjanacz, Zoran [Mecsek Ore Environmental Protection Co. H-7614, Pecs, P.O.B.: 121 (Hungary); Varhegyi, Andras [Mecsek-OEko Environmental Protection Co. H-7614, Pecs, P.O.B.: 121 (Hungary)

    2006-08-31

    High radon concentration (average 410 kBq m{sup -3}) has been measured in a tunnel of a uranium mine, located 15-55 m below the village of Kovagoszolos, Hungary. The mine was closed in 1997; the artificial ventilation of the tunnel was then terminated and recultivation works begun. In this paper, a study has been made as to whether the tunnel has an influence on the radon concentration of surface dwellings over the mining tunnel. At different distances from the surface projection of the mining tunnel, radon concentration, the gamma dose, radon exhalation and radon concentration of soil gas were measured. The average radon concentration in the dwellings was 483 Bq m{sup -3}. Significantly higher radon concentrations (average 667 Bq m{sup -3}) were measured in houses within +/-150 m from the surface projection of the mining tunnel +50 m, compared with the houses further than the 300-m belt (average 291 Bq m{sup -3}). The average radon concentration of the soil gas was 88.8 kBq m{sup -3}, the average radon exhalation was 71.4 Bq m{sup -2} s{sup -1} and higher values were measured over the passage as well. Frequent fissures crossing the passage and running up to the surface and the high radon concentration generated in the passage (average 410 kBq m{sup -3}) may influence the radon concentration of the houses over the mining tunnel. (author)

  10. Variation in residential radon levels in new Danish homes.

    Science.gov (United States)

    Bräuner, E V; Rasmussen, T V; Gunnarsen, L

    2013-08-01

    Radon-222 gas arises from the radioactive decay of radium-226 and has a half-life of 3.8 days. This gas percolates up through soil into buildings, and if it is not evacuated, there can be much higher exposure levels indoors than outdoors, which is where human exposure occurs.