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Sample records for para determinar radon-222

  1. Design and construction of a system to determine Radon-222 through alpha spectroscopy; Diseno y construccion de un sistema para determinar Radon-222 mediante espectroscopia alfa

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio M, J [Universidad Autonoma del Estado de Mexico. Facultad de Quimica. Toluca (Mexico)

    1992-12-31

    The purpose of this work consists in the design a radon-222 gas measurement system utilizing a surface barrier detector with the objective to obtain a more accurate measurement for this isotope through an alpha particle spectrum and so to address as to avoid the activity influence of the descendants of short half-life, which are too beta particles emitters, already other methods it must be correction series to obtain the real value of radon activity. Here are presented the general properties properties of radon, the experimental part description indicating the design to measure the radon-222 gas and its parts, as well as too the standard separation of radium-226 starting from carnotite mineral. Finally, it is presented the results obtained with a discussion about it. (Author) results obtained with a discussion about it. (Author)

  2. Design and construction of a system to determine Radon-222 through alpha spectroscopy; Diseno y construccion de un sistema para determinar Radon-222 mediante espectroscopia alfa

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio M, J. [Universidad Autonoma del Estado de Mexico. Facultad de Quimica. Toluca (Mexico)

    1991-12-31

    The purpose of this work consists in the design a radon-222 gas measurement system utilizing a surface barrier detector with the objective to obtain a more accurate measurement for this isotope through an alpha particle spectrum and so to address as to avoid the activity influence of the descendants of short half-life, which are too beta particles emitters, already other methods it must be correction series to obtain the real value of radon activity. Here are presented the general properties properties of radon, the experimental part description indicating the design to measure the radon-222 gas and its parts, as well as too the standard separation of radium-226 starting from carnotite mineral. Finally, it is presented the results obtained with a discussion about it. (Author) results obtained with a discussion about it. (Author)

  3. Design and construction of a system for determining Radon-222 through Alpha spectroscopy; Diseno y construccion de un sistema para determinar Radon-222 mediante Espectroscopia alfa

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio, J.; Iturbe, J.L

    1992-02-15

    The study of the present work consists on designing a system to measure gas {sup 222} Rn, using a surface barrier detector, in order to obtaining a more accuracy measure of this isotope by means of an alpha particle spectra and thus to try to avoid the influence of the radioactivity of the isotope descendants of short half life, which are also emitting of alpha particles, since by other methods its should make a series of corrections to obtain the real value of the radon activity. (Author)

  4. Excess bottom radon 222 distribution in deep ocean passages

    International Nuclear Information System (INIS)

    Sarmiento, J.L.; Broecker, W.S.; Biscaye, P.E.

    1978-01-01

    Radon 222 and STD profiles were obtained as part of the Geosecs program in the Vema Channel in the southwest Atlantic Ocean and in the Samoan, Clarion, and Wake Island passages in the Pacific Ocean. The standing crop of excess radon 222 is higher in the passages than at other nearby locations. The most likely explanation for this is that there is a high flux of radon 222 from the floor of the passages. Since much of the floor is covered with manganese nodules and encrustations, the high flux of radon 222 may be attributable to the high concentrations of radium 226 in the outer few millimeters of such deposits. Laboratory measurements of radon 222 emissivity from maganese encrustations obtained in Vema Channel support this hypothesis. The excess radon 222 in the Vema Channel and Wake Island Passage is found in substantial quantities at heights above bottom greatly exceeding the heights at which excess radon 222 is found in nonpassage areas. The horizontal diffusion of radon emanating from the walls of the passages is unlikely to be the cause of the observed concentrations because the ratio of wall surface area to water volume is very low. The profiles must therefore be a result of exceptionally high apparent vertical mixing in the passages. Further work is needed to determine the nature of this apparent vertical mixing. The excess radon 222 and STD data in all four passages have been fit with an empirical model in which it is assumed that the bouyancy flux is constant with distance above bottom. The fits are very good and yield apparent buoyancy fluxes that are between 1 and 3 orders of magnitude greater than those obtained at nearby stations outside the passages for three of the four passages

  5. Method for determination of radon-222 in water by liquid scintillation counting

    International Nuclear Information System (INIS)

    Suomela, J.

    1993-06-01

    The procedure for the determination of radon-222 by liquid scintillation counting is quite specific for this radionuclide. Radon-222 is extracted readily from the water sample by an organic scintillant. The decay products of radon-222 will remain in the water phase whilst radon-222 will be extracted into the organic phase. Before measurement the sample is stored for three hours until equilibrium is reached between radon-222 and its alpha emitting decay products. The alpha activity from radon-222 and its decay products is measured in a liquid scintillation counter

  6. 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

  7. Realization of a reference system for the generation radon 222

    International Nuclear Information System (INIS)

    Guelin, M.

    1990-11-01

    After some general considerations on radon and its calibration techniques, the methods and technologies developed in order to realize a reference system for the generation of radon 222 are presented. Two original patented techniques have been developed. The former technique deals with the realization of radon 222 solid sources from radium 226 deposit on acrylic fibres. This new technology offers the advantage of very quickly obtaining a constant emission rate near to 100%. The latter technique deals with the standard measurement of radon 222 volumic activity via gamma spectrometry of its short-lived daughters. This new procedure is the only one allowing to relate this measure to gaseous standards. An aeraulic/ventilation circuit makes it possible to calibrate the radon measurement instrumentation within a wide volumic activity range from to 4 to 4 000 Bq/m 3

  8. Radon-222 measurements at Chester

    International Nuclear Information System (INIS)

    Fisenne, I.M.

    1982-01-01

    The Environmental Measurements Laboratory has compiled a five year record of continuous hourly radon-222 measurements at Chester, New Jersey. The data for the 1977-1978, 1978-1979, 1979-1980, and 1980-1981 have been reported previously

  9. Instruments to measure radon-222 activity concentration or exposure to radon-222. Intercomparison 2014

    International Nuclear Information System (INIS)

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

    2014-10-01

    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 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.

  10. Measurements of the radon-222 concentration in residences of Lima - Peru; Mediciones de la concentracion de radon 222 en residencias de Lima - Peru

    Energy Technology Data Exchange (ETDEWEB)

    Pereyra, P.; Lopez, M. E.; Perez, B., E-mail: ppereyr@pucp.edu.pe [Pontificia Universidad Catolica del Peru, Seccion Fisica, Av. Universitaria 1801, Lima (Peru)

    2014-08-15

    The measurement of the Radon-222 levels was realized in the first semester of 2013 in residences corresponding to 16 districts of the metropolitan area of Lima, including to the zones North, Center and South of the city, during one period of 3 to 6 months in continuous form, with measurement periods of 1 to 2 months. The houses where the measurements were made were selected considering diverse variables as antiquity, construction materials, coatings, soil type, occupational use of the monitored rooms, etc. The measurements were realized in basements, first and second floor of the residences. For the Radon-222 measurements passive detectors of cellulose nitrate (Lr-115) were used. The procedure of data collection, dosimeters reading and the measurement results are shown in this work; this monitoring is the first one that is carried out in this city. The results are only indicators of the present radon rate, by the detectors type not is possible to discriminate the presence of the Radon-222 descendants. (Author)

  11. RADON 222 AND TROPOSPHERIC VERTICAL TRANSPORT.

    OpenAIRE

    Liu, SC; McAfee, JR; Cicerone, RJ

    1984-01-01

    Radon 222 is an inert gas whose loss is due only to radioactive decay with a half life of 3. 83 days (5. 51-day 'exponential' lifetime). It is a very useful tracer of continental air because only ground level continental sources are significant. Previously published measured **2**2**2Rn profiles are analyzed here by averaging for the summer, winter, and spring-fall seasons. The analysis shows that in summer, about 55% of the **2**2**2Rn is transported above the planetary boundary layer, consi...

  12. A study of the physico-chemical characteristics of a solid radon 222 source

    International Nuclear Information System (INIS)

    Chuiton, G.

    1990-01-01

    A solid radon 222 source is described; it is made of a manganese oxide impregnated acrylic felt disc on which radium 226 is fixed. The disc is incorporated into a scanning device allowing the passage through the felt of a radon 222 free gas (air or nitrogen) previously led to a relative humidity of air near to saturation. At the device outlet, a stable activity of radon 222 is obtained. The preparation, characteristics and radiochemical stability conditions of the 226 radium source are presented. Following a description of the scanning device, the radon 222 emanation coefficient is studied as a function of the relative humidity of air. The reliability of the device is assessed by an uncertainty calculation for the utilisation conditions recommended. Finally, an approach to the physico-chemical processes governing radon 222 emanation rate in the device is set forth [fr

  13. Exposure to radon Rn-222 of inhabitants of buildings in Olsztyn

    International Nuclear Information System (INIS)

    Gorzkowski, B.; Pachocki, K.; Rozycki, Z.; Majle, T.; Pensko, J.; Krzeslak, A.

    1998-01-01

    The concentrations of radon-222 in the air of some buildings in Olsztyn were measured. The main source of radon in buildings is in general the ground under building and the materials used for building structure. In this work the results of radon-222 concentration measurements in the air of some buildings constructed before the 1939 year, in the buildings constructed after 1945 year with the traditional use of the bricks and in the buildings constructed with the use of great prefabricated plates are presented. The relations between radon-222 concentrations in the basements and in the first floor flats situated above the basement were evaluated. Based on the mean radon concentrations in the air of the various types of buildings investigated the effective doses for the inhabitants of each type of buildings were estimated. (author)

  14. Radon 222 levels in deep well waters of Toluca municipality (county)

    International Nuclear Information System (INIS)

    Olguin Gutierrez, Maria Teresa.

    1990-01-01

    The levels of Radon 222 were determined in 46 deep (50-180m) wells in the city and county of Toluca, as well as the annual radiation dose that the stomach admits when ingesting such water. The method used for the quantification of Radon 222 was liquid scintillation counting. The result revealed that levels of Radon 222 in the studied area in the range of 0 to 320 pCi l -1 . In the case of the equivalent annual dose that the stomach (empty) admits due to ingestion of water from the wells, values are in an interval between 0 to 95 mrem a -1 . This values are well below the level established by the International Commission of Radiological Protection (ICRP). The wells that had the higher concentration of Radon 222 were found in the regions of Lodo Prieto, Seminario; San Antonio Buenavista and La Trinidad Huichochitlan. (Author)

  15. Radon-222 as an indicator of geothermal reservoirs behaviour

    International Nuclear Information System (INIS)

    Segovia, N.; De La Cruz-Reyna, S.; Mena, M.; Seidel, J.L.; Monnin, M.

    1991-01-01

    Radon-222 concentration in soils at shallow depth was measured at the ''Los Azufres'' geothermal field, Michoacan State, Mexico, in order to observe possible temporal variations in relation to the peculiar conditions of the area. A four years' survey is reported using the SSNTD technique. The data obtained indicate the feasibility of the technique for this type of investigation and illustrate the role of Radon-222 as a tracer of pore fluids motion in the substratum. (author)

  16. Assessing urban air quality and its relation with radon (222Rn)

    International Nuclear Information System (INIS)

    Zoran, Maria; Savastru, Dan; Dida, Adrian

    2016-01-01

    This paper focuses on the assessment of air quality and its relation with radon ( 222 Rn) for Bucharest metropolitan area in Romania. Specifically, daily mean concentrations of particle matter (PM2.5, PM10), ozone (O 3 ), nitrogen dioxide (NO 2 ), sulphur dioxide (SO 2 ) and global air quality indices have been analyzed in relation with radon ( 222 Rn) concentrations measured in the air near the ground with AlphaGUARD Radon Monitoring System and CR-39 SSNTDs during 2012 year. Such new information is required by atmospheric sciences to prove suitability of 222 Rn as a tracer for atmospheric dynamics analysis as well as by epidemiological and radiological protection studies. (author)

  17. Properties of membranes to permeation to radon 222. New development for the measurement of radon 222 in water and water-saturated soils

    International Nuclear Information System (INIS)

    Labed, V.; Robe, M.C.

    1992-01-01

    Membranes that exclude water but are permeable to radon can extend the range of environments in which many radon detection systems could operate. We have studied the permeation of 222 Rn through membranes separating air and water phases. The permeation coefficients and the activation energy were calculated for various conditions. Potential applications such as in situ detection of radon in water are discussed

  18. Natural and technologically enhanced sources of radon-222

    International Nuclear Information System (INIS)

    Travis, C.C.; Watson, A.P.; McDowell-Boyer, L.M.; Cotter, S.J.; Randolph, M.L.; Fields, D.E.

    1979-01-01

    An assessment of 222 Rn releases (curies/year) from major natural and technologically enhanced sources in the United States is presented. The resulting inhalation population dose commitments to the bronchial epithelium of the lung (lung-rem) are also estimated. The sources of radon considered are natural soil, evapotranspiration, potable water supplies, building materials, natural gas, uranium mining and milling, coal and phosphate mining, phosphate fertilizer, liquefied petroleum gas, geothermal power facilities, coal-fired power plants, and gas and oil wells. The most important natural source of 222 Rn is decay of 226 Ra in the soil and rocks of the earth's crust. This source results in approximately 40% of the total population dose from all sources of radon. The largest technoligcally enhanced contributor to population dose is airborne 222 Rn in building interiors, which is estimated to contribute 55% to the total population exposure to 222 Rn. Each of the other sources is estimated to contribute less than 3% to the total

  19. Measurements of the radon-222 concentration in residences of Lima - Peru

    International Nuclear Information System (INIS)

    Pereyra, P.; Lopez, M. E.; Perez, B.

    2014-08-01

    The measurement of the Radon-222 levels was realized in the first semester of 2013 in residences corresponding to 16 districts of the metropolitan area of Lima, including to the zones North, Center and South of the city, during one period of 3 to 6 months in continuous form, with measurement periods of 1 to 2 months. The houses where the measurements were made were selected considering diverse variables as antiquity, construction materials, coatings, soil type, occupational use of the monitored rooms, etc. The measurements were realized in basements, first and second floor of the residences. For the Radon-222 measurements passive detectors of cellulose nitrate (Lr-115) were used. The procedure of data collection, dosimeters reading and the measurement results are shown in this work; this monitoring is the first one that is carried out in this city. The results are only indicators of the present radon rate, by the detectors type not is possible to discriminate the presence of the Radon-222 descendants. (Author)

  20. The effect of radon 222 on the oral mucosa of rabbits

    International Nuclear Information System (INIS)

    Minta, A.; Minta, P.; Kochanski, W.

    1975-01-01

    In experiments on 52 rabbits the authors investigated the effects of radon 222 administered by inhalation on the oral mucosa. The experimental animals were divided into 3 groups: 1 - controls, 2 - receiving radon inhalations in concentration 1 nCi/1, 3- receiving similar inhalations in a concentration of 5 nCi/l of air. Sections involving the lower lip with the mucosa were obtained for investigations after 10, 20, 30 and 60 days of inhalation. In the group of animals receiving radon in lower concentration its stimulating effect manifested itself as stimulation of mesenchymal cells and vascular endothelium. In group 3 sebaceous glands, atrophy and excessive keratinization of epidermis. Taking into account the analogy of these processes the authors concluded that in balneotherapy of oral diseases radon water application with low content of radon 222 may be satisfactory and safe. (author)

  1. Ambient Radon-222 Monitoring in Amargosa Valley, Nevada

    International Nuclear Information System (INIS)

    L.H. Karr; J.J. Tappen; D. Shafer; K.J. Gray

    2008-01-01

    As part of a program to characterize and baseline selected environmental parameters in the region around the proposed repository at Yucca Mountain, Nevada, ambient radon-222 monitoring was conducted in the rural community of Amargosa Valley, the community closest to the proposed repository site. Passive integrating radon monitors and a continuous radon monitoring instrument were deployed adjacent to the Community Environmental Monitoring Program (CEMP) (http://www.cemp.dri.edu/index.html) station located in the Amargosa Valley Community Center near the library. The CEMP station provided real-time ambient gamma exposure and meteorological data used to correct the integrated radon measurements as well as verify meteorological data collected by the continuous radon monitoring instrument. Additionally, different types of environmental enclosures that housed the monitors and instrument were used to determine if particular designs influenced the ambient radon measurements

  2. Toprak Radon (222Rn Gazı Anomalilerinin ARIMA Analizi

    Directory of Open Access Journals (Sweden)

    Miraç KAMIŞLIOĞLU

    2014-12-01

    Full Text Available Özet: Zaman serileri analizi, istatistik, ekonomi, fizik ve mühendislik gibi bilim dallarında geniş uygulama alanına sahiptir. Zaman serisi analizi, değişkenlerin gelecekteki değerlerinin doğru bir şekilde tahmin edilmesi için kullanılan bir yöntemdir. Bu çalışmada, bir deprem öncüsü olarak bilinen toprak radon gazı (222Rn ölçümleri ile bir zaman serisi oluşturulmuştur. Bu veriler kullanılarak, otoregresif süreçler (ARIMA yardımıyla dinamik sistem modellemesi yapılmıştır. ARIMA; zaman serileri analizinde, zaman içerisinde rastgele gerçekleşen bir stokastik (olasılıksal sürecin veya hatalarının modellenmesidir. ARIMA modeli, temelde Box-Jenkins modeline dayanmaktadır. Box-Jenkins modeli, tek değişkenli zaman serilerinin ileriye dönük tahmin ve kontrolünde kullanılan istatistiksel tabanlı bir yöntemdir. Elde edilen sonuçlar, ARIMA modellerinin tahmin konusundaki başarısını göstermektedir. Anahtar kelimeler: Zaman Serileri Analizi, Radon Gazı (222Rn, ARIMA ARIMA Analysis of Soil Radon (222Rn Gas Anomalies Abstract: Time series analysis, has wide applications in statistics, economics, physics and engineering such disciplines. This method used for estimate correctly future values of the variables. In this study, is formed a time series with soil radon gas (222Rn measurements known as a pioneer of an earthquake. Dynamic system modelling was performed with autoregressive (ARIMA modelling process by used these measurements. ARIMA; time series analysis is modelled of the recoverable over time a random stochastic (probabilistic process or its errors. ARIMA model is based on Box-Jenkins model. Box-Jenkins model is a statistically based method which is used forward-looking forecasting and control of univariate time series. The obtained results, ARIMA model is indicating success in predict subject. Key words: Time Series Analysis, Radon Gas (222Rn, ARIMA

  3. Factors affecting radon removal from Rn-222 enriched water

    International Nuclear Information System (INIS)

    Abulfaraj, W.H.; Mamoon, A.

    1994-01-01

    Continued use of potable well water that has elevated levels of Rn-222 is harmful to human health. activated carbon, aeration and heating can remove radon from treated water. Water artificially enriched with Rn-222 using a pitchblende source was studied in a laboratory scale model under controlled conditions. (author), 3 figs., 3 refs

  4. Radon-222 signatures of natural ventilation regimes in an underground quarry.

    Science.gov (United States)

    Perrier, Frédéric; Richon, Patrick; Crouzeix, Catherine; Morat, Pierre; Le Mouël, Jean Louis

    2004-01-01

    Radon-222 activity concentration has been monitored since 1999 in an underground limestone quarry located in Vincennes, near Paris, France. It is homogeneous in summer, with an average value of 1700 Bq m(-3), and varies from 730 to 1450 Bq m(-3) in winter, indicating natural ventilation with a rate ranging from 0.5 to 2.4 x 10(-6) s(-1) (0.04-0.22 day(-1)). This hypothesis is supported by measurements in the vertical access pit where, in winter, a turbulent air current produces a stable radon profile, smoothly decreasing from 700 Bq m(-3) at 20 m depth to 300 Bq m(-3) at surface. In summer, a thermal stratification is maintained in the pit, but the radon-222 concentration jumps repeatedly between 100 and 2000 Bq m(-3). These jumps are due to atmospheric pressure pumping, which induces ventilation in the quarry at a rate of about 0.1 x 10(-6) s(-1) (0.009 day(-1)). Radon-222 monitoring thus provides a dynamical characterisation of ventilation regimes, which is important for the assessment of the long-term evolution of underground systems.

  5. Variations in radon-222 in soil and ground water at the Nevada Test Site

    International Nuclear Information System (INIS)

    Wollenberg, H.; Straume, T.; Smith, A.; King, C.Y.

    1977-01-01

    To help evaluate the applicability of variations of radon-222 in ground water and soil gas as a possible earthquake predictor, measurements were conducted in conjunction with underground explosions at the Nevada Test Site (NTS). Radon fluctuations in ground water have been observed during a sequence of aftershocks following the Oroville, California earthquake of 1 August 1975. The NTS measurements were designed to show if these fluctuations were in response to ground shaking; if not, they could be attributed to changes in earth strain prior to the aftershocks. Well waters were periodically sampled and soil-gas 222 Rn monitored prior to and following seven underground explosions of varying strength and distance from sampling and detector locations. Soil-gas 222 Rn contents were measured by the alpha-track method; well water 222 Rn by gamma-ray spectrometry. There was no clearly identifiable correlation between well-water radon fluctuations and individual underground tests. One prominent variation in soil-gas radon corresponded to ground shaking from a pair of underground tests in alluvium; otherwise, there was no apparent correlation between radon emanation and other explosions. Markedly lower soil-gas radon contents following the tests were probably caused by consolidation of alluvium in response to ground shaking

  6. Sorption of radon-222 to natural sediments

    International Nuclear Information System (INIS)

    Wong, C.S.; Chin, Y.P.; Gschwend, P.M.

    1992-01-01

    The sorption of radon to sediments was investigated, since this may affect the use of porewater radon profiles for estimating bed irrigation rates. Batch experiments showed that radon has an organic-carbon-normalized sediment-water partition coefficient (K oc , L kg oc -1 ) of 21.1 ± 2.9 for a Boston Harbor sediment, 25.3 ± 2.1 for a Charles River sediment, and 22.4 ± 2.6 for a Buzzards Bay sediment. These values are in close agreement with predictions using radon's octanol-water partition coefficient (K ow ), which was measured to be 32.4 ± 1.5. Temperature and ionic strength effects on K oc were estimated to be small. Given rapid sorption kinetics, the authors suggest that slurry stripping techniques used by many investigators to measure 222 Rn in sediment samples collect both sorbed and dissolved radon. Sorption effects were included in a transport model to obtain revised estimates of irrigation rates from existing literature profiles. Irrigation rates had to be increased over previously reported values in proportion to the sediment organic matter content

  7. Identifying Groundwater Discharge in the Merced River Basin, California Using Radon-222

    Science.gov (United States)

    Shaw, G. D.; Hudson, G. B.; Moran, J.; Conklin, M.

    2004-12-01

    Groundwater flow in fractured granite of the Sierra Nevada is poorly characterized, in particular, contributions of mountain block recharge are not known. Using a combination of water quality and isotopic analyses, groundwater inputs to the Upper Merced River were characterized. Between November 2003 and July 2004, monthly water quality samples were taken from Happy Isles to the inlet of Lake McClure, a 75 km reach. These samples demonstrated the expected dilution due to snowmelt in the spring. In the fall, the spatial profile matched the geology with anion concentrations increasing downstream of the transition from the Sierra Nevada batholith to the country rock, suggesting significant groundwater inputs. From July 19 to 21, 2004, radon-222 and other noble gases (He, Ne, Ar, Kr and Xe abundances and 3He/4He ratio) were measured along a 37 km reach of the Merced River, extending from the top of Yosemite Valley to the confluence of the South Fork of the Merced River. All radon samples were extracted into mineral oil immediately in the field and counted using liquid scintillation; noble gas samples were collected in copper tubes. Radon-222 activity varied from about 1 to 100 pCi/L (at collection time) indicating significant, spatially variable groundwater discharge into the Merced River. Two one-mile reaches of the Merced River were sampled for 222Rn on a fine scale. Large fracture sets in these two locations and previous temperature measurements suggested that groundwater discharge was higher relative to other locations along the river. Radon-222 activity was low upstream and downstream of large fractures observed in the bedrock; whereas, 222Rn activity was high at large fracture zones. Degassing is rapid downstream of fractures where no groundwater discharge is observed. For a representative groundwater end-member, radon-222 activity measured in Fern Spring, Yosemite Valley was about 1200 pCi/L. Excess 4He from U and Th decay is observed in samples with elevated

  8. Diurnal radon-222 concentrations in the outflow of a complex basin

    International Nuclear Information System (INIS)

    Clements, W.E.; Wilkening, M.

    1981-01-01

    Radon 222 concentrations were monitored continuously in the outflow from the Anderson and Putah Creek air drainage basin as part of the Department of Energy's Atmospheric Studies in Complex Terrain September 1980 field studies. Radon 222, an inert gas having a half-life of 3.8 days, can be considered to be exhaled uniformly at a constant rate from the earth's surface throughout the basin. The contribution to the total radon budget from vented steam from geothermal wells in the Geysers area is neglected. Hence, radon in this application is used as an extended-source atmospheric tracer in contrast with point-source release of tracer materials. One of the purposes of this study is to help classify drainage flow nights in terms of the diurnal patterns of radon concentration. As cool slope winds move along the terrain and into the valley, the air masses involved accumulate radon through the night until morning instabilities mix it to greater depths. Hence, the measured diurnal trend of radon in the outflow of the basin reflects the integrated behavior of nocturnal flows in the basin and subsequent breakup in the morning. The use of this technique to classify drainage flows has been used by Wilkening and Rust

  9. Daily fluctuations in radon concentration in a Cordoba factory complex; Fluctuaciones diurnas de la concentracion de {sup 222}Rn en el complejo fabril Cordoba

    Energy Technology Data Exchange (ETDEWEB)

    Germanier, A; Perez, R; Rubio, M [CEPROCOR, Cordoba (Argentina)

    1998-07-01

    Full text: This work shows the fluctuations of indoor radon concentration in some rooms placed inside a Cordoba Factory Complex. The measurements were performed by Victoreen Radon Monitor. The system was shaped to sample single radon concentration values after one hour integration. It utilizes a passive diffusion chamber and a silicon diffused junction detector. A portion of decay products will plate-out onto the detector and emit alpha particles into the depletion region of a diffused junction detector. The alpha energy is deposited in the detector in the form of ionization which generates a charge pulse. Only alpha pulses of an energy level similar Po-218 and Po-214 are detected. The study of the meteorological parameters shows that the daily fluctuations of the radon concentration respond to the transport and dispersion processes of radon gas through the air. Air temperature, wind's direction and speed are found to be fundamentals parameters in the observed time behavior. The meteorological data were obtained by a portable station (Davis Weathe Monitor II). The radon concentration present a maximum value (1850 Bq/m{sup 3}) at the night and a minimum value (150 Bq/m{sup 3}) at the day. (author)S. [Spanish] Texto completo: En este trabajo se estudian las fluctuaciones de la concentracion de radon 222 en aire 'indoor' en distintas habitaciones ubicadas dentro y fuera del predio del Complejo Fabril Cordoba (C.F.C.). Las determinaciones se realizaron con un detector pasivo Radon Monitor 05-418, marca Victoreen. El mismo consta de una camara de difusion electrostatica y de un detector de estado solido (Si) de juntura difundida. Este instrumento se configuro para obtener integraciones para cada una de las horas del dia. El principio de funcionamiento del detector se basa en el conteo de los decaimientos {alpha} del polonio 218 y polonio 214 atrapados dentro de la camara de difusion electrostatica. El build-up ocurrido dentro de esta camara es tenido en cuenta para

  10. A study on the risk from indoor radon 220 and radon 222 exposures

    International Nuclear Information System (INIS)

    Rannou, A.

    1986-12-01

    The hazards from radon (radon 220 and 222) in dwelling atmospheres have been studied. In the first part devoted to the present state of the problem, an analysis is made of the formation mechanisms and the evolution of radon and its daughters indoors. The main physical and dosimetric quantities required for the risk evaluation are defined. The theoretical and experimental analysis of the methods of measurements of radon and its daughters used in the measurement campaign are considered in the second part. The progress and the result of the national survey are developed in the third part. The effects of several factors on indoor levels are discussed. The conclusions of a particular study in the Finistere ''department'' are presented. The data collected make it possible to assess the mean exposure of man to natural radiation [fr

  11. Radon-222: tracer of geological systems dynamics. Methodology and signal processing, interpretation of radon-222 behaviour in active geological media

    International Nuclear Information System (INIS)

    Richon, Patrick

    2011-01-01

    detection of the gravimetric waves O1 and M2 in the sub-glacial laboratory of Argentiere tend to prove the relationship between mechanical deformations and variations of radon-222 activity. It is therefore theoretically possible to detect radon variations induced by the mechanical strain linked to an earthquake. However, hydrological effects (piston effect) cannot be not excluded as it is shown with data acquired on the Roselend site. On the Merapi volcano, we also demonstrate that the barometric wave S2, dissimulated in the radon activity and soils gas temperature, allows us to follow the evolution of the fracture self-sealing. This proved to be a precursory process of the 2006 eruption. These results demonstrate the strong potential of the measurement of radon-222 applied to the tracking of natural phenomena, providing, however, that one have a control on the instrumentation, a knowledge of physical processes associated with radon transport, and mostly that the tools of signals processing are applied. These tools are very promising for monitoring and understanding geodynamical processes. (author) [fr

  12. Maximum permissible concentration of radon {sup 222}Rn in air; La concentration maximale admissible du radon 222 dans l'air

    Energy Technology Data Exchange (ETDEWEB)

    Hamard, J; Beau, P G; Ergas, A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires, departement de la protection sanitaire, service d' hygiene atomique

    1968-09-01

    In order to verify the validity of the values proposed for the maximum permissible concentration of {sup 222}Rn in air, one can either approach the problem: - by epidemiological studies tending to determine the relation dose-effect both quantitatively and qualitatively; - or by choosing a lung model and clearance constants allowing a more accurate determination of the delivered dose and the localisation of the more severely irradiated portions of the bronchial tree. The radon MPC have been calculated using the model and the respiration constants set up by the I.C.R.P. Task Group on Lung dynamics. Two cases have been considered, i.e. when the radon daughter products behave as soluble materials and as insoluble ones. The values which have been found have been compared with those given up to now by several national and international bodies. (authors) [French] Deux voies d'approche peuvent etre empruntees pour verifier la validite des valeurs proposees pour la concentration maximale admissible du radon 222 dans l'air: - etudes epidemiologiques tendant a preciser qualitativement et quantitativement la relation dose-effet; - choix d'un modele pulmonaire et de constantes d'epuration permettant une determination plus precise de la dose delivree et la localisation des segments de l'arbre pulmonaire les plus irradies. Les auteurs ont utilise pour le calcul de la CMA du radon le modele et les constantes respiratoires proposees par le Task Group on Lungs dynamics de la C.I.P.R. On a pris en consideration le cas ou les descendants du radon se comportent comme des substances solubles et celui ou ils se comportent comme des substances insolubles. Les valeurs trouvees sont comparees a celles proposees jusqu'alors par divers organismes nationaux et internationaux. (auteurs)

  13. Design and construction of a system to analyze Radon 222 by means of alpha spectroscopy

    International Nuclear Information System (INIS)

    Martinez, J.B.

    1991-01-01

    Design and construction of a system to measure gaseous Radon 222 which arise from a source of Radium 226 electrodeposited in a stainless disc is described. Such a system allows to differentiate the energies of radium where they come from, as well as energies of daughter products. In this way it is possible to have a more precise measure of the alpha activity of this isotope. The system was constructed in a stainless steel hermetic container made of the camera, a cape and a valve, the used sample was a standards of Radium 226 attained from carnotite ore. The Radon 222 alpha particles, as well as the alpha particles of its decay products namely Polonium 210. Polonium 218 and Polonium 214 were identified by a surface barrier detector. The results in this manner obtained shows clearly well definite peaks of Radon 222 and also peaks of the Radon 222 daughter products with energies of 5.43, 5.31, 6.0 and 7.69 Mev respectively. The system allows to separate and to indentify the energies of Radon and its daughter products coming directly from a standard solid sample of Radium 226 (Author)

  14. Time series analysis of soil Radon-222 recorded at Kutch region, Gujarat, India

    International Nuclear Information System (INIS)

    Madhusudan Rao, K.; Rastogi, B.K.; Barman, Chiranjib; Chaudhuri, Hirok

    2013-01-01

    Kutch region in Gujarat lies in a seismic vulnerable zone (seismic zone-v). After the devastating Bhuj earthquake (7.7M) of January 26, 2001 in the Kutch region several researcher focused their attention to monitor geophysical and geochemical precursors for earthquakes in the region. In order to find out the possible geochemical precursory signals for earthquake events, we monitored radioactive gas radon-222 in sub surface soil gas at Kutch region. We have analysed the recorded soil radon-222 time series by means of nonlinear techniques such as FFT power spectral analysis, empirical mode decomposition, multi-fractal analysis along with other linear statistical methods. Some fascinating and fruitful results originated out the nonlinear analysis of the said time series have been discussed in the present paper. The entire analytical method aided us to recognize the nature and pattern of soil radon-222 emanation process. Moreover the recording and statistical and non-linear analysis of soil radon data at Kutch region will assist us to understand the preparation phase of an imminent seismic event in the region. (author)

  15. Radon 222 in drinking water resources of Iran: A systematic review, meta-analysis and probabilistic risk assessment (Monte Carlo simulation).

    Science.gov (United States)

    Keramati, Hassan; Ghorbani, Raheb; Fakhri, Yadolah; Mousavi Khaneghah, Amin; Conti, Gea Oliveri; Ferrante, Margherita; Ghaderpoori, Mansour; Taghavi, Mahmoud; Baninameh, Zahra; Bay, Abotaleb; Golaki, Mohammad; Moradi, Bigard

    2018-03-30

    The current study was performed to review the conducted studies regarding the concentration of radon 222 in the tap drinking water; furthermore, by estimation of ingestion and inhalation effective dose, the health risk assessment in the adults and children using MCS technique was assessed. All related studies published among January 1990 to October 2016; were screened in the available databases such as Web of Science, PubMed, Science Direct, Scopus, SID, and Irandoc. The total effective dose was estimated by calculating E ing (Effective dose of ingestion) and E inh (Effective dose of inhalation) by Monte Carlo simulation (MCS) method. The range of ND ─ 40.9 Bq/L for radon 222 in water resources was proposed after evaluation of data collected from 13 studies with 1079 samples. The overall concentration of radon 222 in drinking water in Iran was 3.98: 95%CI (3.79 ─ 4.17 Bq/L). Also, the effective ingestion dose of radon 222 in adults age groups was 1.35 times higher than children. The rank order of drinking water resources based on the concentration of radon 222 was Spring > Spring and Well > Well > Spring and Qanat > Tap water. The overall concentration of radon 222 in drinking water in Iran was lower than WHO and EPA standard limits. Also, the rank order regarding area studied based on the concentration of radon 222 was Gillan > Mashhad > Mazandaran > Kerman > Yazd > Tehran > Kermanshah > Golestan > Hormozgan. The effective ingestion dose of radon 222 to consumers in the Gillan, Mashhad, Mazandaran, and Kerman were higher than WHO guidance (0.1 mSv/y). Also except consumers in the Hormozgan, inhalation effective dose radon 222, in the other investigated areas were higher than WHO guidance (0.1 mSv/y). Therefore, it is recommended to conduct the required programs regarding control and elimination of radon 222 concentration in Iranian drinking water supply. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Design and construction of a system to determine Radon-222 through alpha spectroscopy

    International Nuclear Information System (INIS)

    Bonifacio M, J.

    1991-01-01

    The purpose of this work consists in the design a radon-222 gas measurement system utilizing a surface barrier detector with the objective to obtain a more accurate measurement for this isotope through an alpha particle spectrum and so to address as to avoid the activity influence of the descendants of short half-life, which are too beta particles emitters, already other methods it must be correction series to obtain the real value of radon activity. Here are presented the general properties properties of radon, the experimental part description indicating the design to measure the radon-222 gas and its parts, as well as too the standard separation of radium-226 starting from carnotite mineral. Finally, it is presented the results obtained with a discussion about it. (Author) results obtained with a discussion about it. (Author)

  17. Radon 222 and tropospheric vertical transport

    International Nuclear Information System (INIS)

    Liu, S.C.; McAfee, J.R.; Cicerone, R.J.

    1984-01-01

    Radon 222 is an inert gas whose loss is due only to radioactive decay with a half life of 3.83 days (5.51-day ''exponential'' lifetime). It is a very useful tracer of continental air because only ground level continental sources are significant. Thus it is similar in several ways to many air pollutants (e.g., NO/sub x/) (NO+NO 2 ), SO 2 , and certain hydrocarbons. Previously published measured 222 Rn profiles are analyzed here by averaging for the summer, winter, and spring-fall seasons. The analysis shows that in summer, about 55% of the 222 Rn is transported above the planetary boundary layer, considerably more than during the other seasons. Similarly, in summer, about 20% rises to over 5.5 km (500 mbar). The average profiles have been used to derive vertical eddy diffusion coefficients with maximum values of 5-7 x 10 5 cm 2 s -1 in the midtroposphere and 8 x 10 3 to 5 x 10 4 cm 2 s -1 near the surface

  18. Dosimetry considerations in the replacement of Radon-222 sources by gold-198 sources for the treatment of patients

    International Nuclear Information System (INIS)

    Swindon, T.N.

    1978-10-01

    Radon-222 sources have been used in Australia for the treatment of patients since 1929 and the calculation of absorbed doses from such sources is well established. An alternative to radon-222 is gold-198 which, in suitable form, may be used for permanent implantations and for surface, interstitial or intra-cavitary applications. Because radon-222 and gold-198 have different characteristics, the data to be used in calculating the absorbed dose to a point in a treatment volume will depend on the particular source used. The data are related to the energies and abundances of the beta and gamma rays emitted from the nuclei and on their half-lives (Tsub(1/2)). The energies of the beta and gamma rays emitted by radon-222 (in equilibrium with its decay products) and by gold-198 are given

  19. A study of radon 222 permeation through plastic membranes. Application to a method of radon measurement in water and saturated soils

    International Nuclear Information System (INIS)

    Labed, V.

    1991-04-01

    In order to improve the BARASOL R device and to use it in water-saturated soils and in pressure constraint conditions, we have studied radon 222 permeation through plastic membranes. While the permeation process usually takes place between two media being in the same state, most often gaseous, the present study describes the transfer of radon 222 from the water to the air via a membrane. Polypropylene membranes have been tested with an experimental set-up by monitoring the evolution of radon concentrations in water and in air. The permeation coefficient and the activation energy were calculated in various conditions. With a second experimental set-up, we have tested the polyethylene membrane which has been adapted on the BARASOL. In these conditions, we have shown that it is possible to measure radon in water at concentrations around 10 3 Bq.m -3 [fr

  20. Groundwater flow analysis using radon-222 existing in environment as an indicator

    International Nuclear Information System (INIS)

    Komae, Takami

    1996-01-01

    Several kinds of isotopes have been used to trace water movement in the hydrology including surface and ground water as indicators. But those are not effective to analyze the contaminant movement with groundwater though short distance in short time owing to long life. Radon ( 222 Rn) existing in environment was chosen for this purpose as an short-lived indicator. Radon is a radioactive gas, with a half life of 3.8 days, generated from radium ( 226 Ra) in strata. Radon concentration in groundwater increases to reach an equilibrated value within about three weeks after infiltrating underground. The equilibrated concentration becomes an own value of the aquifer depending on the radium content, the grain size and porosity of aquifer. The characteristic makes it able to identify aquifers and sub basins. Since radon concentration in groundwater is 100 to 1000 times as high as that in surface water, groundwater and surface water interaction is quantitatively analyzed. A liquid scintillation counter was employed to measure radon concentration after extracting radon in water to toluene. We applied those advantage of radon-222 to various field investigations and discussed the applicability. It was really possible to analyze the groundwater flow. Monitoring radon concentration in pumped water, occurrences of squeeze and leakage from the different aquifer were detected. Main aquifer was easily determined from the vertical distribution of radon concentration in bore hole. In the injection test using surface water, the spread of injected water was confirmed by the decrease of radon concentration in bore hole water. The radon method was useful to analyze the dam leakage, effluent seepage of groundwater in river, influent seepage of river water underground, and groundwater recharge with irrigation water through unsaturated zone. (author)

  1. Radon-222 and radium-226 in southeastern Bering Sea shelf waters and sediment

    International Nuclear Information System (INIS)

    Glover, D.M.; Reeburgh, W.S.

    1987-01-01

    Radon-222 and 226 Ra activities were measured in the waters and sediment of the southeastern Bering Sea shelf to evaluate the use of radon as a tracer of gas exchange, water column mixing and sediment-water exchange. Cross-shelf distributions of 222 Rn and 226 Ra are presented. Gas transfer coefficients were estimated using near-surface 222 Rn deficiency measurements. A statistically significant linear relationship between averaged wind speed and transfer coefficient was found. Vertical eddy diffusivities were evaluated by applying a one-dimensional model to near-bottom excess 222 Rn distributions; these diffusivities were compared to independently determined values. The one-dimensional model applied to the near-bottom 222 Rn data was found to be inadequate and a two-dimensional model was applied to improve the fit between model and data. Exchange across the sediment-water interface was computed from the deficiency of 222 Rn measured in sediment cores, standing crop estimates of excess 222 Rn in the water column and 222 Rn production rates of sediment surface grab samples. Biological irrigation of the sediments appeared to be the primary exchange mechanism between the sediment and water columns. Distributions in the water column showed finestructure reported previously and suggested biological removal of 226 Ra. (author)

  2. Investigation of radon-222 in subsurface waters as an earthquake predictor

    International Nuclear Information System (INIS)

    Smith, A.R.; Bowman, H.R.; Mosier, D.F.; Asaro, F.; Wollenberg, H.A.; King, C.Y.

    1975-11-01

    Changes of radon-222 content of well waters in seismically active regions may provide earthquake precursor signals, according to reports of recent Chinese and Russian work. A high-precision γ-ray system for continuous monitoring of radon in wells and springs has been developed at the Lawrence Berkeley Laboratory, where monitoring began in April 1975, and has been extended to other sites including the San Andreas fault zone

  3. Radiometric survey of Radon-222 in Instituto de Engenharia Nuclear - IEN/CNEN-Brazil; Levantamento de radonio-222 no Instituto de Engenharia Nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Gouvea, Vandir de Azevedo; Cardoso, Domingos d' Oliveira; Pedro, Carlos Roberto [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil). Div. de Seguranca e Radioprotecao]. E-mail: vandir@cnen.gov.br; Castro, Carlos Alberto Carvalho [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Nuclear

    2001-07-01

    The radioecological concentrations of Radon-222 indoor and outdoor nuclear facility of IEN, have been determined.The present study has established a radon investigation methodology in occupational areas, besides to suggest solutions for gas concentration minimization, in others work environment like to IEN.

  4. Determining Radium-226 concentration from Radon-222 emanation in building materials: a theoretical model

    International Nuclear Information System (INIS)

    Barreto, Rafael C.; Perna, Allan F.N.; Narloch, Danielle C.; Del Claro, Flavia; Correa, Janine N.; Paschuk, Sergei A.

    2017-01-01

    It was developed an improved theoretical model capable to estimate the radium concentration in building materials solely measuring the radon-222 concentration in a con ned atmosphere. This non-destructive technique is not limited by the size of the samples, and it intrinsically includes back diffusion. The resulting equation provides the exact solution for the concentration of radon-222 as a function of time and distance in one dimension. The effective concentration of radium-226 is a fit parameter of this equation. In order to reduce its complexity, this equation was simplified considering two cases: low diffusion in the building material compared to the air, and a building material initially saturated with radon-222. These simplified versions of the exact one dimension solution were used to t experimental data. Radon-222 concentration was continuously measured for twelve days with an AlphaGUARD TM detector, located at the Laboratory of Applied Nuclear Physics at Universidade Tecnologica Federal do Parana (UTFPR). This model was applied to two different materials: cement mortar and concrete, which results were respectively (15:7 ±8:3) Bq=kg and (10:5±2:4) Bq=kg for the radium-226 effective concentration. This estimation was confronted with the direct measurements of radium in the same materials (same sources) using gamma-ray spectrometry, fulfilled at Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), which results were respectively (13:81±0:23) Bq=kg and (12:61±0:22) Bq=kg. (author)

  5. Determining Radium-226 concentration from Radon-222 emanation in building materials: a theoretical model

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, Rafael C.; Perna, Allan F.N.; Narloch, Danielle C.; Del Claro, Flavia; Correa, Janine N.; Paschuk, Sergei A., E-mail: baarreth@gmail.com, E-mail: allan_perna@hotmail.com, E-mail: daninarloch@hotmail.com, E-mail: aviadelclaro@gmail.com, E-mail: janine_nicolosi@hotmail.com, E-mail: spaschuk@gmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil). Departamento Academico de Fisica e Departamento Academico de Construcao Civil

    2017-07-01

    It was developed an improved theoretical model capable to estimate the radium concentration in building materials solely measuring the radon-222 concentration in a con ned atmosphere. This non-destructive technique is not limited by the size of the samples, and it intrinsically includes back diffusion. The resulting equation provides the exact solution for the concentration of radon-222 as a function of time and distance in one dimension. The effective concentration of radium-226 is a fit parameter of this equation. In order to reduce its complexity, this equation was simplified considering two cases: low diffusion in the building material compared to the air, and a building material initially saturated with radon-222. These simplified versions of the exact one dimension solution were used to t experimental data. Radon-222 concentration was continuously measured for twelve days with an AlphaGUARD{sup TM} detector, located at the Laboratory of Applied Nuclear Physics at Universidade Tecnologica Federal do Parana (UTFPR). This model was applied to two different materials: cement mortar and concrete, which results were respectively (15:7 ±8:3) Bq=kg and (10:5±2:4) Bq=kg for the radium-226 effective concentration. This estimation was confronted with the direct measurements of radium in the same materials (same sources) using gamma-ray spectrometry, fulfilled at Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), which results were respectively (13:81±0:23) Bq=kg and (12:61±0:22) Bq=kg. (author)

  6. Radon-222 measurements aboard an airplane for the description of atmospheric diffusion

    International Nuclear Information System (INIS)

    Bogen, J.

    1973-01-01

    Radon-222 is absorbed aboard an airplane in tubes filled with 50 g of selected charcoal and cooked in Dewars by carbon dioxide and freon. After air collection at different heights up to 5 km, the tubes are evacuated and heated in the laboratory for desorption of the gas molecules and for transfer into a decay chamber covered with zinc-sulfide serving as a scintillator for the detection of alpha activity from radon-222 and its daughters. In general, the measurements show an exponential decrease of the concentration up to 5 km in height, if there is no cloud layer. The height for a reduction by a factor of two is about 900 meters. Assuming a constant diffusion coefficient K 0 up to 5 km, the measurements yield a K 0 of approximately 3.7 x 10 4 cm 2 s -1 . For flights in stratiform clouds a decrease is observed of the concentration up to a certain height, then radon-222 is again increasing or remains constant. This must be explained with respect to the meteorological situation. Assuming only a constant value for K 0 between the different flying heights, it was possible to appraise the development of the eddy diffusion coefficient with height

  7. Calibration of radon-222 detectors using closed circuit radium-226 sources

    International Nuclear Information System (INIS)

    Perna, Allan Felipe Nunes; Paschuk, Sergei Anatolyevich; Correa, Janine Nicolosi; Del Claro, Flavia

    2012-01-01

    This paper presents the results of the calibration of the Radon-222 detectors used by the Laboratories specializing in measuring natural radiation from this gas. The research was conducted in collaboration between UTFPR, CDTN/CNEN, UFRN and IRD/CNEN. During the calibration the detectors were exposed in isolated chambers with radioactive calibrated sources. The calibration procedure was supported with four instant radon monitors AlphaGUARD (SAPHYMO Co.) responsible for radon activity measurements in the experimental chamber. The calibration procedure resulted an equation that relates the number of tracks found in solid-state detector CR-39 (Track-Etch detector) with the concentration of radon in the atmosphere. Obtained results are compatible with previously performed calibration at the National Institute of Radiological Sciences (NIRS, Japan) using high activity levels of radon in air. Present results of calibration give the possibility to expand the calibration curve of CR-39 for medium and low activity levels of radon. (author)

  8. Design and construction of a cryogenic facility providing absolute measurements of radon 222 activity for developing a primary standard

    International Nuclear Information System (INIS)

    Picolo, Jean-Louis

    1995-06-01

    Radon 222 metrology is required to obtain higher accuracy in assessing human health risks from exposure to natural radiation. This paper describes the development of a cryogenic facility that allows absolute measurements of radon 222 in order to obtain a primary standard. The method selected is the condensation of a radon 222 sample on a geometrically defined cold surface with a constant, well known and adjustable temperature and facing an alpha particles detector. Counting of the alpha particles reaching the detector and the precisely known detection geometry provide an absolute measurement of the source activity. After describing the cryogenic facility, the measurement accuracy and precision are discussed and a comparison made with other measurement systems. The relative uncertainty is below 1 pc (1 σ). The facility can also be used to improve our knowledge of the nuclear properties of radon 222 and to produce secondary standards. (author) [fr

  9. Radon gas inside historical buildings in the city of Cordoba; Gas {sup 222}Rn en construcciones historicas de la ciudad de Cordoba

    Energy Technology Data Exchange (ETDEWEB)

    Perez, R; Germanier, A; Rubio, M [CEPROCOR, Cordoba (Argentina); Sbarato, D; Zappino, R [Observatorio Ambiental de la Municipalidad de Cordoba, Cordoba (Argentina)

    1998-07-01

    Full text: In this work measurements of the Radon ({sup 222}Rn) concentration in the inside of historical buildings which date back to the end of the 17th and the beginning of the 18th Centuries have been carried out in the city of Cordoba (Argentina). Meteorological factors such as room temperature and atmospheric pressure have not shown to affect, to a great extent, the results obtained. By comparing the concentration of {sup 222}Rn in environments at different levels we inferred that the soil underlying the buildings does not represent an important source of {sup 222}Rn. The main occurrence of the element was found in room walls, which shows that local building materials are an important source of {sup 222}Rn. Among the materials used in these buildings are granitic rocks, and to a lesser extent, lime, sand and marble. The {sup 222}Rn concentrations recorded in some of the rooms surveyed reach values which are close to the minimum intervene level set by international standards in 4pCi/l. The study of the effects of ventilation in the concentration of {sup 222}Rn allows us to conclude that its values decrease to accepted levels by means of a natural and efficient ventilation of the rooms. (author) [Spanish] Texto completo: En este trabajo se han realizado mediciones de la concentracion de radon (radon 222) en el interior de edificios de la ciudad de Cordoba que datan de finales del siglo XVII y comienzos del siglo XVIII. Las concentraciones de radon 222 se determinaron con un detector pasivo Radon Monitor 05-418, marca Victoreen. El mismo consta de una camara de difusion electrostatica y un detector de estado solido (Si) de juntura difundida. No se observo, en los resultados obtenidos, influencias causadas por factores meteorologicos como la temperatura ambiente y la presion atmosferica. Por comparacion de la concentracion de radon 222 en ambientes ubicados en distintas plantas se dedujo que el suelo subyacente bajo los edificios representa una fuente secundaria

  10. Is radon 222 an appropriate tracer for the study of seismic precursors?

    International Nuclear Information System (INIS)

    Richon, P.; Heritier, T.; Sebe, O.; Maffat, I.; Holtzappfel, T.; Le Hesran, E.; Geber, O.; Ulziibat, M.; Demberel, S.; Oyun-Erdene, M.; Bilguun, M.

    2015-01-01

    Radon 222 is a natural radionuclide that can be measured in air, water, and soil in very, very small quantities. Experiments performed in laboratories have shown that a local strain on a rock has an impact on the mobility of the radon gas and as local strains increase with the approach of an earthquake, it is considered that radon abnormal measurements may help predicting earthquakes. The first stage to extrapolate laboratory results to large-scale application is to master the metrology of the radon gas. A campaign of measurements achieved in Mongolia on the Emeelt site has allowed an optimization of radon metrology and of the positioning of the probes. Preliminary results have shown that abnormal values of radon concentrations that are not correlated with local meteorology, appear a few days before local seismic activity resumes

  11. Radon-222 emissions and control practices for licensed uranium mills and their associated tailings piles. Final report

    International Nuclear Information System (INIS)

    1985-06-01

    The report is organized into five main sections. The conclusions of the effort are summarized in Chapter 2. A general description of current milling and tailings management practices and a summary of the site-specific characteristics of operating and standby uranium mills are contained in Chapter-3. The sources and emission rates of radon-222 at licensed mills and their associated tailings piles are contained in Chapter 4 along with the results of an effort to develop generic procedures to estimate radon-222 emissions for milling operations and tailings disposal. Control practices that are being or could be applied to the milling operation and tailings disposal areas and their estimated cost and effectiveness in reducing radon-222 emissions are presented in Chapter 5. The appendices contain detailed information on mill site data and emission estimates

  12. Study of radon 222 permeation through plastic membranes. Application to a measurement method of radon in water

    International Nuclear Information System (INIS)

    Labed, V.; Rannou, A.; Robe, M.C.

    1990-01-01

    Gaseous permeation is a complex phenomenon of gas transfer through some polymers. Original in respect of conventional studies where permeation occurs between two gaseous phases, the present study concerns radon 222 transfer between water and air through a membrane. Polypropylene membranes are tested with an experimental device following time evolution of the phenomenon by measurement of volume activity in water and in air. An application of this study to a method for determination of radon concentration in water by measurement of concentration in air is discussed [fr

  13. Radon-222 exhalation from Danish building materials: H + H Industri A/S results

    International Nuclear Information System (INIS)

    Andersen, C.E.

    1999-08-01

    This report describes a closed-chamber method for laboratory measurements of the rate at which radon-222 degasses (exhales) from small building material samples. The chamber is 55 L in volume and the main sample geometry is a slab of dimensions 5x30x30 cm 3 . Numerical modelling is used to assess (and partly remove) the bias of the method relative to an ideal measurement of the free exhalation rate. Experimental results obtained with the method are found to be in agreement with the results of an open-chamber method (which is subject to different sources of error). Results of radon-222 exhalation rate measurements for 10 samples of Danish building materials are reported. Samples include ordinary concrete, lightweight aggregate concrete, autoclaved aerated concrete, bricks, and gypsum board. The maximum mass-specific exhalation rate is about 20 mBq h -1 kg -1 . Under consideration of the specific applications of the investigated building materials, the contribution to the indoor radon-222 concentration in a single-family reference house is calculated. Numerical modelling is used to help extrapolate the laboratory measurements on small samples to full scale walls. Application of typical materials will increase the indoor concentration by less than 10 Bq m -3 . (au)

  14. Determination of Radon-222 and Thoron Concentration in Decorative Stone Warehouses Indoor Air and the Received Effective Dose by Staff

    Directory of Open Access Journals (Sweden)

    Amir Hossein Mahvi

    2015-06-01

    Full Text Available Background: Radon is a colorless, odorless, and radioactive gas that can be emitted from decorative stones such as granite, marble, etc. Inhaling radon gas in a long period may cause for incidence of lung cancer among peoples. Material and Methods: In this cross-sectional descriptive study, Radon 222 and Thoron concentrations in background and indoor air were measured in four decorative stones warehouse using portable radon meter(RTM1688-2 model. Totally, 24 samples of 24- hours concentrations in indoor air and 24 samples of 4-hours concentrations of Radon 222 and thoron in the background air at three stages were measured. Then, received effective dose of Radon 222 and Thoron was calculated by UNSCEAR equations. Results: The mean radon concentrations for indoor and background air were 74±37 and 34±16 Bq/m3, respectively. The mean radon concentrations for indoor air in decorative stones warehouses for DSW1, DSW2, DSW3 and DSW4 were 72.50±34, 98.25±43, 34.42±18 and 88.92±51 Bq/m3, respectively. The received effective dose mean of Radon 222 and Thoron by the staff at 8 working hours was 0.53±0.18 and 0.05±0.03 mSv/y and in 16 working hours was 1.05±0.36 and 0.11±0.07 mSv/y, respectively. Generally, the mean received effective dose by staff from Radon at 8 and 16 working hours was 0.58±0.2  and 1.16±0.41 mSv/y, respectively. Conclusions: Radon concentration mean in indoor air and the received effective dose mean by staff was lower than the standards level. Decorative stone warehouses were the resources for accumulation of Radon gas that can be reduced by corrective actions.

  15. E-perm radon monitors for determining waterborne concentrations of dissolved in radon 222Rn

    International Nuclear Information System (INIS)

    Jester, W.A.; Kotrappa, P.

    1989-01-01

    This paper describes a simple and relatively inexpensive method in which E-Perm radon monitors are used to determine the concentration of dissolved 222 Rn in drinking water. This procedure takes advantage of E-Perm's ability to accurately measure the integral radon exposure under conditions of high humidity. The method was evaluated against the liquid scintillation procedure recommended by the U.S. Environmental Protection Agency (EPA) and was found to give excellent agreement. An E-perm is an electret ion chamber that consists of a small chamber constructed from a conducting plastic and having an electret at its base and a filtered air inlet at the top. The technique described in this paper takes advantages of E-Perm's insensitivity to high humidity

  16. Persistence of radon-222 flux during monsoon at a geothermal zone in Nepal

    International Nuclear Information System (INIS)

    Girault, Frederic; Koirala, Bharat Prasad; Perrier, Frederic; Richon, Patrick; Rajaure, Sudhir

    2009-01-01

    The Syabru-Bensi hydrothermal zone, Langtang region (Nepal), is characterized by high radon-222 and CO 2 discharge. Seasonal variations of gas fluxes were studied on a reference transect in a newly discovered gas discharge zone. Radon-222 and CO 2 fluxes were measured with the accumulation chamber technique, coupled with the scintillation flask method for radon. In the reference transect, fluxes reach exceptional mean values, as high as 8700 ± 1500 g m -2 d -1 for CO 2 and 3400 ± 100 x 10 -3 Bq m -2 s -1 for radon. Gases fluxes were measured in September 2007 during the monsoon and during the dry winter season, in December 2007 to January 2008 and in December 2008 to January 2009. Contrary to expectations, radon and its carrier gas fluxes were similar during both seasons. The integrated flux along this transect was approximately the same for radon, with a small increase of 11 ± 4% during the wet season, whereas it was reduced by 38 ± 5% during the monsoon for CO 2 . In order to account for the persistence of the high gas emissions during monsoon, watering experiments have been performed at selected radon measurement points. After watering, radon flux decreased within 5 min by a factor of 2-7 depending on the point. Subsequently, it returned to its original value, firstly, by an initial partial recovery within 3-4 h, followed by a slow relaxation, lasting around 10 h and possibly superimposed by diurnal variations. Monsoon, in this part of the Himalayas, proceeds generally by brutal rainfall events separated by two- or three-day lapses. Thus, the recovery ability shown in the watering experiments accounts for the observed long-term persistence of gas discharge. This persistence is an important asset for long-term monitoring, for example to study possible temporal variations associated with stress accumulation and release.

  17. Investigation of the concentrations of radon-222 and its daughter products in Loutraki spas (Peloponnese, Greece)

    International Nuclear Information System (INIS)

    Kritidis, Panaiotis; Angelou, Panaiotis.

    1984-07-01

    An express variant of the three-interval total alpha-counting filter method being suitable for the determination of elevated concentrations of 222 Rn decay products in air of increased humidity is described. The method has been used for the determination of radon daughters in air in the major radon spas of Loutraki. Concentrations of 222 Rn and 226 Ra in spa water have been determined as well. Annual effective dose equivalents for the personnel and the patients have been estimated. The need of certain radiation protection measures is pointed out. (author)

  18. Paloma-radon: atmospheric radon 222 as a geochemical probe for water in the martian subsoil

    International Nuclear Information System (INIS)

    Sabroux, J.Ch.; Michielsen, N.; Voisin, V.

    2003-01-01

    Radon exhalation from a porous soil is known to depend strongly on the soil moisture content: a minute amount of water, or water ice, in the pore space increases dramatically the possibility for radon to migrate far from its parent mineral. We propose to take advantage of this characteristic by using atmospheric radon 222 as a geochemical probe for water in the Martian soil, at least one order of magnitude deeper than the current Mars Odyssey neutron data. Strong thermal inversions during the Martian night will accumulate radon in the lowest atmospheric boundary layer, up to measurable levels despite the comparatively high environmental (cosmic and solar) background radiation and the assumed low uranium content of the upper crust of the planet. Preliminary studies and development of an instrument for the measurement of the Martian atmospheric alpha radioactivity is part of the CNES supported PALOMA experiment. Two test benches have been implemented, one of them allowing differential measurements of the diffusion of radon in the Martian soil simulant NASA JSC Mars-1, under relevant temperatures and pressures. The other, a 1 m3 radon-dedicated test bench, aims to characterize the instrument that will measure radon in the Mars environment (7 mb CO 2 ). Tests on several nuclear radiation detectors show that semiconductor alpha-particle detectors (PIPS) are the best option. In addition, the detection volume is left open in order to capitalize upon the long (ca. 4 m) alpha track at this low pressure. A stationary diffusion model was developed in order to assess the radon flux at the Mars soil surface. Diffusion of gas in Martian soil is governed by Knudsen diffusion. The radon Knudsen diffusion coefficient was estimated, depending on the soil moisture and relevant structural properties, leading to a radon diffusion length of the order of 20 m. The landed platform PALOMA-Radon instrument will consist of a set of alpha detectors connected to an electronic spectrometer, a

  19. Paloma-radon: atmospheric radon 222 as a geochemical probe for water in the martian subsoil

    Energy Technology Data Exchange (ETDEWEB)

    Sabroux, J.Ch.; Michielsen, N.; Voisin, V

    2003-07-01

    Radon exhalation from a porous soil is known to depend strongly on the soil moisture content: a minute amount of water, or water ice, in the pore space increases dramatically the possibility for radon to migrate far from its parent mineral. We propose to take advantage of this characteristic by using atmospheric radon 222 as a geochemical probe for water in the Martian soil, at least one order of magnitude deeper than the current Mars Odyssey neutron data. Strong thermal inversions during the Martian night will accumulate radon in the lowest atmospheric boundary layer, up to measurable levels despite the comparatively high environmental (cosmic and solar) background radiation and the assumed low uranium content of the upper crust of the planet. Preliminary studies and development of an instrument for the measurement of the Martian atmospheric alpha radioactivity is part of the CNES supported PALOMA experiment. Two test benches have been implemented, one of them allowing differential measurements of the diffusion of radon in the Martian soil simulant NASA JSC Mars-1, under relevant temperatures and pressures. The other, a 1 m3 radon-dedicated test bench, aims to characterize the instrument that will measure radon in the Mars environment (7 mb CO{sub 2}). Tests on several nuclear radiation detectors show that semiconductor alpha-particle detectors (PIPS) are the best option. In addition, the detection volume is left open in order to capitalize upon the long (ca. 4 m) alpha track at this low pressure. A stationary diffusion model was developed in order to assess the radon flux at the Mars soil surface. Diffusion of gas in Martian soil is governed by Knudsen diffusion. The radon Knudsen diffusion coefficient was estimated, depending on the soil moisture and relevant structural properties, leading to a radon diffusion length of the order of 20 m. The landed platform PALOMA-Radon instrument will consist of a set of alpha detectors connected to an electronic spectrometer

  20. Measurement of radon 222 in drinking water and air by liquid scintillation

    International Nuclear Information System (INIS)

    Schoenhofer, F.

    1991-01-01

    This is a brief description of the liquid scintillation measuring method for determining radon 222 in drinking water and air. Discussed are the advantages of this method and its reliability or accuracy, as well as some conclusions from the results. (orig.) [de

  1. Measurements of environmental radon - 222 concentrations in indoors and outdoors in Egypt

    International Nuclear Information System (INIS)

    Kenawy, M.A.; Morsey, A.A.; Kotb, M.A.; Osman, A.; El-Haag, A.

    1990-01-01

    The major contribution to population exposure from natural radiation arises from the inhalation of the decay products of radon. Substantial surveys are being conducted by several investigators to estimate the indoor and outdoor exposure nationally and to discover regional variations. In this work, radon concentration in the indoors and outdoor air was determined using the can technique and employing CR-39 solid state nuclear track detector for lengthy exposures. The range of radon - 222 activity in this survey was 54 -299 PCi.m -3 in Cairo, 22 - 171 PCi.m -3 in Alexandria and 89 - 370 PCi.m -3 in Asiut. Measurements carried out in Aswan and Sinai ranged between 98 - 411 PCi.m -3 . Values of indoors and outdoors radon concentrations were found to vary with time of day, geographic location, season and height above ground. Further work is going on to study the different parameters affecting the levels of the environmental radon. The national survey and associated studies is expected to yield data that may correlate radon activity with some respiratory diseases, particularly lung cancer. (author). 7 refs, 5 figs

  2. Alpha radioactivity monitoring related to Radon-222 in water from wells in metropolitan area of Curitiba (PR), Brazil; Monitoramento da radioatividade alfa relacionada ao radonio-222 em aguas de pocos da regiao metropolitana de Curitiba (PR)

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Janine Nicolosi; Paschuk, Sergei Anatolyevich; Kappke, Jaqueline; Claro, Flavia Del; Perna, Allan Felipe Nunes; Reque, Marilson, E-mail: janine_nicolosi@hotmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Denyak, Valeriy; Schelin, Hugo Reuters [Instituto de Pesquisa Pele Pequeno Principe (IPPPP), Curitiba, PR (Brazil); Rocha, Zildete; Santos, Talita Oliveira [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-04-15

    This research objective was to assess the level of randon-222 concentration in well water of the metropolitan region of Curitiba, Parana. Current work presents the results of indoor {sup 222}Rn activity ground water samples from artesian wells from aquifers of the region. The studies of radon activity in water were performed using the radon detector AlphaGUARD. The calculations of initial radon activity in water were done considering the {sup 222}Rn decay correction as well as equilibrium level of {sup 222}Rn and {sup 226}Ra observed after 30 days of measurements. Obtained results show that about 70% of measured activity levels of {sup 222}Rn are higher than the recommended value of 11.1 Bq.L{sup -1}, which represent the risk for the human health associated with this radionuclide. The case study showed that previous measurements of radon are recommended for a construction project is implemented. In this case, it is observed that the radon concentrations decrease about 56% in the first water tank and 83% in the second water tank over the well. This fact shows that the actions for mitigation of radon are viable and do not require major modifications to the usual systems of construction. (author)

  3. Evaluation of radon-222 concentration in air of workplaces at Curitiba/PR, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Del Claro, Flavia; Correa, Janine N.; Paschuk, Sergei A.; Kappke, Jaqueline; Perna, Allan F.N.; Reque, Marilson, E-mail: flaviadelclaro@gmail.com, E-mail: spaschuk@gmail.com, E-mail: janine_nicolosi@hotmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Denyak, Valeriy, E-mail: denyak@gmail.com [Instituto de Pesquisa Pele Pequeno Principe (IPPP), Curitiba, PR (Brazil); Rocha, Zildete; Santos, Talita O., E-mail: rocha@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    The isotope Rn-222 is a noble gas that is responsible for approximately half of the effective annual dose received by the world population, and has very high probability to induce the lung cancer. The goal of present research is to evaluate the activity concentration of Rn-222 in the air of workplaces at Curitiba, Parana State. Simultaneously there were performed the measurements of Rn-222 emanation from soil and building materials occurred at evaluated workplaces. Indoor measurements of Rn-222 activity were performed using CR-39 detectors. The instant radon detector AlphaGUARD (Saphymo GmbH) was used in the measurements of the average concentrations of Rn-222 in soil gas and building materials. The average concentration of indoor Rn-222 obtained in the measurements of workplaces vary between 36+/-49 Bq/m³ and 164+/-51 Bq/m³. These values are considered within the reference limit of 200 Bq/m³ established by international agencies such as the United Nations Scientific Committee on the Effects of Atomic Radiation and the International Commission on Radiological Protection, but slightly above the limit of 148 Bq/m³ established by the United States Environmental Protection Agency. The measurements involving building materials presented the concentration values of Rn-222 in a range from 427+/-310 Bq/m³ to 2053+/-700 Bq/m³. The Rn-222 concentrations in soil ranged from 31+/-2 kBq/m³ to 35+/-4 kBq/m³ and the average values of Rn-220 are found in a range of 41+/-6 kBq/m³ and 25+/-11 kBq/m³, thus the concentrations of radon gas soil are below the swedish criterion of 50 kBq/m³ that represent the minimum value for high-risk situation. (author)

  4. Evaluation of radon-222 concentration in air of workplaces at Curitiba/PR, Brazil

    International Nuclear Information System (INIS)

    Del Claro, Flavia; Correa, Janine N.; Paschuk, Sergei A.; Kappke, Jaqueline; Perna, Allan F.N.; Reque, Marilson; Denyak, Valeriy; Rocha, Zildete; Santos, Talita O.

    2013-01-01

    The isotope Rn-222 is a noble gas that is responsible for approximately half of the effective annual dose received by the world population, and has very high probability to induce the lung cancer. The goal of present research is to evaluate the activity concentration of Rn-222 in the air of workplaces at Curitiba, Parana State. Simultaneously there were performed the measurements of Rn-222 emanation from soil and building materials occurred at evaluated workplaces. Indoor measurements of Rn-222 activity were performed using CR-39 detectors. The instant radon detector AlphaGUARD (Saphymo GmbH) was used in the measurements of the average concentrations of Rn-222 in soil gas and building materials. The average concentration of indoor Rn-222 obtained in the measurements of workplaces vary between 36+/-49 Bq/m³ and 164+/-51 Bq/m³. These values are considered within the reference limit of 200 Bq/m³ established by international agencies such as the United Nations Scientific Committee on the Effects of Atomic Radiation and the International Commission on Radiological Protection, but slightly above the limit of 148 Bq/m³ established by the United States Environmental Protection Agency. The measurements involving building materials presented the concentration values of Rn-222 in a range from 427+/-310 Bq/m³ to 2053+/-700 Bq/m³. The Rn-222 concentrations in soil ranged from 31+/-2 kBq/m³ to 35+/-4 kBq/m³ and the average values of Rn-220 are found in a range of 41+/-6 kBq/m³ and 25+/-11 kBq/m³, thus the concentrations of radon gas soil are below the swedish criterion of 50 kBq/m³ that represent the minimum value for high-risk situation. (author)

  5. Contribution of 222Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China

    International Nuclear Information System (INIS)

    Song Gang; Wang Xinming; Chen Diyun; Chen Yongheng

    2011-01-01

    This study investigates the contribution of radon ( 222 Rn)-bearing water to indoor 222 Rn in thermal baths. The 222 Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM 10 and PM 2.5 ) and carbon dioxide (CO 2 ) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m -3 of 222 Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which 222 Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average 222 Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor 222 Rn levels were influenced by the 222 Rn concentrations in the hot spring water and the bathing times. The average 222 Rn transfer coefficients from water to air were 6.2 x 10 -4 -4.1 x 10 -3 . The 24-h average levels of CO 2 and PM 10 in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM 2.5 . Radon and PM 10 levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. - Highlights: → 222 Rn-bearing water is the main contributor to indoor radon in hot spring hotel. → The PM 2.5 and CO 2 are also the main indoor pollutants in the hotel rooms. → Higher radon and PM levels might have significant negative health effects to human. → The radon transfer coefficients are consistent with the published data.

  6. A study of radon-222 concentrations in North Carolina groundwater

    International Nuclear Information System (INIS)

    Evans, J.P.

    1992-01-01

    The groundwater of 400 North Carolina homes was sampled to ascertain the distribution and extent of 222 Rn in North Carolina groundwater. Arithmetic mean (AM) and geometric mean (GM) concentrations of 1,816 pCi L -1 and 656 pCi L -1 were found for the state. These results indicate that two-thirds of 114 degree C. homes served by groundwater exceed the EPA proposed 300 pCi L -1 maximum contaminant level (MCL). Only 2% of NC homes exceeded 10,000 pCi L-1. The Eastern region had the lowest radon concentrations by far, with a GM of 2-)0 pCi L -1 . The Central region and Western region had GM's of 794 pCi L -1 and 1,032 pCi L -1 respectively. The groundwater data approached a log normal distribution. No consistent trends were noted in the relationship between indoor radon concentrations and groundwater radon concentrations. A correlation coefficient of 0.00921 revealed a very weak linear relationship

  7. Development of a PIN diode based on-line measurement system for Radon (222Rn) and Thoron (220Rn) in environment

    International Nuclear Information System (INIS)

    Ashokkumar, P.; Chaudhury, Probal; Sumesh, C.G.; Sahoo, B.K.; Gaware, J.J.; Mayya, Y.S.

    2014-01-01

    Radon, thoron and their progenies are universally present in outdoor air, and can reach higher levels in indoor air due to poor ventilation. Several instruments have been developed for accurate measurement of radon and thoron in the environment. Semiconductor detector based system employing spectroscopic method has been proved to be the best among them. A PIN diode based electrostatic collection type online real-time instrument has been developed in Bhabha Atomic Research Centre for simultaneous measurement of radon and thoron in an environment while both 222 Rn and 220 Rn are present. This system can be used for determination of radon and thoron concentrations at residence or workplace. Furthermore, since the 222 Rn and 220 Rn are differentiated from each other through spectroscopy, this monitor can be used even in a mixed radon/thoron environment

  8. Estimating the dynamics of groundwater input into the coastal zone via continuous radon-222 measurements

    International Nuclear Information System (INIS)

    Burnett, William C.; Dulaiova, Henrieta

    2003-01-01

    Submarine groundwater discharge (SGD) into the coastal zone has received increased attention in the last few years as it is now recognized that this process represents an important pathway for material transport. Assessing these material fluxes is difficult, as there is no simple means to gauge the water flux. To meet this challenge, we have explored the use of a continuous radon monitor to measure radon concentrations in coastal zone waters over time periods from hours to days. Changes in the radon inventories over time can be converted to fluxes after one makes allowances for tidal effects, losses to the atmosphere, and mixing with offshore waters. If one assumes that advective flow of radon-enriched groundwater (pore waters) represent the main input of 222 Rn in the coastal zone, the calculated radon fluxes may be converted to water fluxes by dividing by the estimated or measured 222 Rn pore water activity. We have also used short-lived radium isotopes ( 223 Ra and 224 Ra) to assess mixing between near-shore and offshore waters in the manner pioneered by . During an experiment in the coastal Gulf of Mexico, we showed that the mixing loss derived from the 223 Ra gradient agreed very favorably to the estimated range based on the calculated radon fluxes. This allowed an independent constraint on the mixing loss of radon--an important parameter in the mass balance approach. Groundwater discharge was also estimated independently by the radium isotopic approach and was within a factor of two of that determined by the continuous radon measurements and an automated seepage meter deployed at the same site

  9. Relevance of air conditioning for 222Radon concentration in shops of the Savona Province, Italy

    International Nuclear Information System (INIS)

    Panatto, Donatella; Ferrari, Paola; Lai, Piero; Gallelli, Giovanni

    2006-01-01

    Radon ( 222 Rn) concentration was evaluated in shops of the Savona Province, Italy, between summer 2002 and winter 2002-2003. The main characteristics of each shops were recorded through a questionnaire investigating the ventilation rate and factors related to 222 Rn precursors in the soil and the construction materials. The main variables that were related to radon concentration were the following: age of the building, level of the shop above ground, season of the year, wind exposure, active windows, and type of heating system. Shops equipped with individual air heating/conditioning systems exhibited radon concentrations that were three times higher than those of shops heated by centralized furnaces. Our data indicate that the level of pollution in the shops was of medium level, with an expected low impact on the salespersons' health. Only in wintertime, the action level of 200 Bq m -3 for the confined environment was reached in 10 shops equipped with individual air heating/conditioning systems

  10. Paloma-radon: Atmospheric radon-222 as a geochemical probe for water in the Martian subsoil.

    Science.gov (United States)

    Sabroux, J.-C.; Michielsen, N.; Voisin, V.; Ferry, C.; Richon, P.; Pineau, J.-F.; Le Roulley, J.-C.; Chassefière, E.

    2003-04-01

    Radon exhalation from a porous soil is known to depend strongly on the soil moisture content: a minute amount of water, or water ice, in the pore space increases dramatically the possibility for radon to migrate far from its parent mineral. We propose to take advantage of this characteristic by using atmospheric radon-222 as a geochemical probe for water in the Martian soil, at least one order of magnitude deeper than the current Mars Odyssey neutron data. Strong thermal inversions during the Martian night will accumulate radon in the lowest atmospheric boundary layer, up to measurable levels despite the comparatively high environmental (cosmic and solar) background radiation and the assumed low uranium content of the upper crust of the planet. Preliminary studies and development of an instrument for the measurement of the Martian atmospheric alpha radioactivity is part of the CNES-supported PALOMA experiment. Two test benches have been implemented, one of them allowing differential measurements of the diffusion of radon in the Martian soil simulant NASA JSC Mars-1, under relevant temperatures and pressures. The other, a 1 m^3 radon-dedicated test bench, aims to characterize the instrument that will measure radon in the Mars environment (7 mb CO_2). Tests on several nuclear radiation detectors show that semiconductor alpha-particle detectors (PIPS) are the best option (already on board the Mars Pathfinder Rover and other platforms). In addition, the detection volume is left open in order to capitalize upon the long (ca. 4 m) alpha track at this low pressure. A stationary diffusion model was developed in order to assess the radon flux at the Mars soil surface. Diffusion of gas in Martian soil is governed by Knudsen diffusion. The radon Knudsen diffusion coefficient was estimated, depending on the soil moisture and relevant structural properties, leading to a radon diffusion length of the order of 20 m. The landed platform PALOMA-Radon instrument will consist of a

  11. Emanation of radon-222 in uraniferous phosphorite from Pernambuco, Brazil

    International Nuclear Information System (INIS)

    Santos, M.L.O.; França, E.J.; Amaral, D.S.; Silva, K.E.M.; Hazin, C.A.; Farias, E.E.G.

    2017-01-01

    The concentration of radon-222 activity available for transport to the surface through the pore space can be defined as radon emanation. From the decay of radium-226, whose half-life is 1850 years, it is associated with the development of neoplasia, such as lung cancer. In the Metropolitan Region of Recife, sedimentary rocks known as phosphorites have been known since 1959, so, from the radiometric characterization of the Paulista and Igarassu Municipality, in Pernambuco, emanation tests were carried out, aiming to determine the emanation power of radon in samples of uraniferous phosphorite from the Recife Metropolitan Region. Initially, 6 independent samples of phosphorites with activity concentration of 226 Ra> 400 Bq kg -1 were comminuted. Portions of 5g were conditioned in a radon chamber with 500 mL volume for measurements. The linear fit of the model converged after 200 interactions with selection of the best fit by the Chi-Square test, through the Origin® 8.0 program. After analysis of the samples, radon emanation power was estimated in the range of 7% to 15%, with a mean value of 10.8%. The methodology used to determine the emanation parameters in samples of uraniferous phosphorite was adequate, observing an inversely proportional relation between the concentration of the radium-226 and the emanation power

  12. Tracing and quantifying groundwater inflow into lakes using a simple method for radon-222 analysis

    Directory of Open Access Journals (Sweden)

    T. Kluge

    2007-09-01

    Full Text Available Due to its high activities in groundwater, the radionuclide 222Rn is a sensitive natural tracer to detect and quantify groundwater inflow into lakes, provided the comparatively low activities in the lakes can be measured accurately. Here we present a simple method for radon measurements in the low-level range down to 3 Bq m−3, appropriate for groundwater-influenced lakes, together with a concept to derive inflow rates from the radon budget in lakes. The analytical method is based on a commercially available radon detector and combines the advantages of established procedures with regard to efficient sampling and sensitive analysis. Large volume (12 l water samples are taken in the field and analyzed in the laboratory by equilibration with a closed air loop and alpha spectrometry of radon in the gas phase. After successful laboratory tests, the method has been applied to a small dredging lake without surface in- or outflow in order to estimate the groundwater contribution to the hydrological budget. The inflow rate calculated from a 222Rn balance for the lake is around 530 m³ per day, which is comparable to the results of previous studies. In addition to the inflow rate, the vertical and horizontal radon distribution in the lake provides information on the spatial distribution of groundwater inflow to the lake. The simple measurement and sampling technique encourages further use of radon to examine groundwater-lake water interaction.

  13. Evaluation of radon-222 concentrations levels at workplaces of Curitiba, PR, Brazil

    International Nuclear Information System (INIS)

    Del Claro, Flavia; Paschuk, Sergei A.; Correa, Janine N.; Kappke, Jaqueline; Perna, Allan F.N.; Reque, Marilson; Martins Neto, Manoel R.; Denyak, Valeriy

    2013-01-01

    The radon is noble radioactive gas, which when inhaled and undergoing spontaneous decay emits alpha particles that interacting with the cells of biological tissue stimulates the development of lung cancer. The isotope 222 Rn is responsible for approximately half of the effective dose received by the population from natural radiation sources. Current work is focused at the evaluation of the radon concentration levels in air of different workplaces at Curitiba-PR. For this purpose 126 track-etched detectors CR-39 were mounted inside the diffusion chambers that were distributed at workplaces of three enterprises environments for a period of three months approximately. The diffusion chambers were protected by a borosilicate glass fiber filters. After the exposition in air the detectors were submitted to chemical etching using a solution of 6.25M NaOH at 70°C during 14 hours. Such chemical treatment enables to count alpha particle track using an optical microscope with 100x objective magnification. The density of alpha particle tracks in CR-39 was converted to the radon activity concentration in air using the results of previous calibration performed at the National Institute of Radiological Sciences (NIRS) in Japan. Obtained results show that the concentration of 222 Rn in air at studied workplaces varied from 16±2 Bq/m³ to 78±9 Bq/m³. These values are considered within the limits established by international regulatory agencies such as EPA and ICRP, which consider as normal the radon activity up to 200 Bq/m³ and 148 Bq/m³, respectively. (author)

  14. Evaluation of radon-222 concentrations levels at workplaces of Curitiba, PR, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Del Claro, Flavia; Paschuk, Sergei A.; Correa, Janine N.; Kappke, Jaqueline; Perna, Allan F.N.; Reque, Marilson; Martins Neto, Manoel R., E-mail: flavia_delclaro@yahoo.com.br, E-mail: spaschuk@gmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba - PR (Brazil); Denyak, Valeriy, E-mail: denyak@gmail.com [Instituto de Pesquisa Pele Pequeno Principe (FPP), Curitiba - PR (Brazil)

    2013-07-01

    The radon is noble radioactive gas, which when inhaled and undergoing spontaneous decay emits alpha particles that interacting with the cells of biological tissue stimulates the development of lung cancer. The isotope {sup 222}Rn is responsible for approximately half of the effective dose received by the population from natural radiation sources. Current work is focused at the evaluation of the radon concentration levels in air of different workplaces at Curitiba-PR. For this purpose 126 track-etched detectors CR-39 were mounted inside the diffusion chambers that were distributed at workplaces of three enterprises environments for a period of three months approximately. The diffusion chambers were protected by a borosilicate glass fiber filters. After the exposition in air the detectors were submitted to chemical etching using a solution of 6.25M NaOH at 70°C during 14 hours. Such chemical treatment enables to count alpha particle track using an optical microscope with 100x objective magnification. The density of alpha particle tracks in CR-39 was converted to the radon activity concentration in air using the results of previous calibration performed at the National Institute of Radiological Sciences (NIRS) in Japan. Obtained results show that the concentration of {sup 222}Rn in air at studied workplaces varied from 16±2 Bq/m³ to 78±9 Bq/m³. These values are considered within the limits established by international regulatory agencies such as EPA and ICRP, which consider as normal the radon activity up to 200 Bq/m³ and 148 Bq/m³, respectively. (author)

  15. Sampling and analysis for radon-222 dissolved in ground water and surface water

    Science.gov (United States)

    DeWayne, Cecil L.; Gesell, T.F.

    1992-01-01

    Radon-222 is a naturally occurring radioactive gas in the uranium-238 decay series that has traditionally been called, simply, radon. The lung cancer risks associated with the inhalation of radon decay products have been well documented by epidemiological studies on populations of uranium miners. The realization that radon is a public health hazard has raised the need for sampling and analytical guidelines for field personnel. Several sampling and analytical methods are being used to document radon concentrations in ground water and surface water worldwide but no convenient, single set of guidelines is available. Three different sampling and analytical methods - bubbler, liquid scintillation, and field screening - are discussed in this paper. The bubbler and liquid scintillation methods have high accuracy and precision, and small analytical method detection limits of 0.2 and 10 pCi/l (picocuries per liter), respectively. The field screening method generally is used as a qualitative reconnaissance tool.

  16. Roles of Radon-222 and other natural radionuclides in earthquake prediction

    International Nuclear Information System (INIS)

    Smith, A.R.; Wollenberg, H.A.; Mosier, D.F.

    1980-01-01

    The concentration of 222 Rn in subsurface waters is one of the natural parameters being investigated to help develop the capability to predict destructive earthquakes. Since 1966, scientists in several nations have sought to link radon variations with ongoing seismic activity, primarily through the dilatancy model for earthquake occurrences. Within the range of these studies, alpha-, beta-, and gamma-radiation detection techniques have been used in both discrete-sampling and continiuous-monitoring programs. These measured techniques are reviewed in terms of instrumentation adapted to seismic-monitoring purposes. A recent Lawrence Berkeley Laboratory study conducted in central California incorporated discrete sampling of wells in the aftershock area of the 1975 Oroville earthquake and continuous monitoring of water radon in a well on the San Andreas Fault. The results presented show short-term radon variations that may be associated with aftershocks and diurnal changes that may reflect earth tidal forces

  17. Indoor Radon-222 concentration measurements during the summer season of year 2000 in some houses in the western part of Yatta City

    International Nuclear Information System (INIS)

    Abu-Samreh, Mohammad M.

    2005-01-01

    Radon, as a natural noble gas, has three main natural isotopes; namely, radon 222 (Rn), a decay product of 238U, radon-220(220Rn, known as thoron), produced in the decay series of thorium-232(232Th), and radon-219 (219Rn), a decay product from the chain originating with 235U [1]. Both 238U and 232th occur naturally in soil and rocks at variable concentrations of about 1pCi/g and also 226Ra, the parent of 222Rn [2]. The 222Rn isotope has half-life of 3.82 days; while 220Rn isotope has a half-life of 55 seconds and 219Rn isotope has a half-life of about 3.96 seconds. 222Rn decays into polonium-218(218Po), which in turn decays within minutes to lead-214 (214Pb), bismuth-214 (214Bi), and polonium-218 (218Po), which in turn decays within minutes to lead-214 (214Pb), bismuth 214 (214Bi), and polonium-214 (214Po)[3]. In particular, 222Rn poses a major concern in regard to radiation pollution and human health hazard [4, 5]. The radon gas can diffuse easily out of the soil surface into air or houses; it can be trapped in poorly ventilated houses and so its concentration can build up to higher levels. Although soil is considered to be the main source of indoor radon concentration, raw building materials (especially quartz, cement, etc.) can make a significant contribution to the level of natural radioactivity in closed spaces such as stores and badly-ventilated dwelling [6]. Moreover, the production rate of radon in dwellings depends on the concentration of radium content in the subsoil, building materials, and porosity as well as the density of the wall material [7, 8]. The emission of radon from building materials is found to be a function of ventilation as well as of the radium content in building materials. The nongaseous 222 Rn decay products are partially suspended in air as mixture of attached and unattached fractions and partially deposited on walls and furniture [9]. Over the past four decades, natural radiation exposure due to 222Rn and its progeny inside houses

  18. Characterizing the sources, range, and environmental influences of radon 222 and its decay products

    International Nuclear Information System (INIS)

    Nero, A.V.; Sextro, R.G.; Doyle, S.M.; Moed, B.A.; Nazaroff, W.W.; Revzan, K.L.; Schwehr, M.B.

    1985-06-01

    Recent results from our group directly assist efforts to identify and control excessive concentrations of radon 222 and its decay products in residential environments. We have demonstrated directly the importance of pressure-induced flow of soil gas for transport of radon from the ground into houses. Analysis of available information from measurements of concentration in US homes has resulted in a quantitative appreciation of the distribution of indoor levels, including the degree of dependence on geographic location. Experiments on the effectiveness of air cleaning devices for removal of particles and radon decay products indicate the potential and limitations of this approach to control. 30 refs., 3 figs

  19. Improved automated analysis of radon (222Rn) and thoron (220Rn) in natural waters.

    Science.gov (United States)

    Dimova, Natasha; Burnett, William C; Lane-Smith, Derek

    2009-11-15

    Natural radon ((222)Rn) and thoron ((220)Rn) can be used as tracers of various chemical and physical processes in the environment. We present here results from an extended series of laboratory experiments intended to improve the automated analysis of (222)Rn and (220)Rn in water using a modified RAD AQUA (Durridge Inc.) system. Previous experience with similar equipment showed that it takes about 30-40 min for the system to equilibrate to radon-in-water concentration increases and even longer for the response to return to baseline after a sharp spike. While the original water/gas exchanger setup was built only for radon-in-water measurement, our goal here is to provide an automated system capable of high resolution and good sensitivity for both radon- and thoron-in-water detections. We found that faster water flow rates substantially improved the response for both isotopes while thoron is detected most efficiently at airflow rates of 3 L/min. Our results show that the optimum conditions for fastest response and sensitivity for both isotopes are at water flow rates up to 17 L/min and an airflow rate of 3 L/min through the detector. Applications for such measurements include prospecting for naturally occurring radioactive material (NORM) in pipelines and locating points of groundwater/surface water interaction.

  20. Measurement of radon-222 concentration in environment sampled within short time using charcoal detector

    International Nuclear Information System (INIS)

    Yamasaki, Tadashi; Sekiyama, Shigenobu; Tokin, Mina; Nakayasu, Yumiko; Watanabe, Tamaki.

    1994-01-01

    The concentration of 222 Rn in air sampled within a very short period of time was measured using activated charcoal as the adsorber. The detector is the plastic canister containing mixture of the activated charcoal and the silica gel. The radon gas was adsorbed in the charcoal in the radon chamber at the temperature of 25degC. A little amount of liquid scintillation cocktail was added into the vial of liquid scintillation counter with the canister. The radon in the charcoal was extracted in the liquid scintillation cocktail. Alpha particles emitted from radon and its daughter nuclei in the cocktail were detected using the liquid scintillation counter. Present method has advantages of not only short sampling time of air but also adsorption of radon in charcoal under a constant temperature. The concentration of radon in air down to 2 Bq/m 3 could be detected. A kinetic model for adsorption of radon in the charcoal is also presented. The ratio of radon concentration in the charcoal to that in air under the equilibrium state of adsorption was estimated to be from 6.1 to 6.8 m 3 /kg at the temperature of 25degC. (author)

  1. Using radon-222 to distinguish between vertical transport processes at Jungfraujoch

    Science.gov (United States)

    Griffiths, Alan; Chambers, Scott; Conen, Franz; Weingartner, Ernest; Zimmermann, Lukas; Williams, Alastair; Steinbacher, Martin

    2015-04-01

    Trace gases measured at Jungfrajoch, a key baseline monitoring station in the Swiss Alps, are tranported from the surface to the alpine ridge by several different processes. On clear days with weak synoptic forcing, thermally-driven upslope mountain winds (anabatic winds) are prevalent. Using hourly radon--222 observations, which are often used to identify air of terrestrial origin, we used the shape of the diurnal cycle to sort days according to the strength of anabatic winds. Radon is ideal as an airmass tracer because it is emitted from soil at a relatively constant rate, it is chemically inert, and decays with a half-life of 3.8 days. Because of its short half-life, radon concentrations are much lower in the free troposphere than in boundary-layer air over land. For comparable radon concentrations, anabatic wind days at Jungfraujoch are different from non-anabatic days in terms of the average wind speed, humidity, air temperature anomalies, and trace species. As a consequence, future studies could be devised which focus on a subset of days, e.g. by excluding anabatic days, with the intention of choosing a set of days which can be more accurately simulated by a transport model.

  2. Contribution of {sup 222}Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China

    Energy Technology Data Exchange (ETDEWEB)

    Song Gang, E-mail: songg2005@126.co [School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006 (China); Wang Xinming [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Diyun; Chen Yongheng [School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006 (China)

    2011-04-15

    This study investigates the contribution of radon ({sup 222}Rn)-bearing water to indoor {sup 222}Rn in thermal baths. The {sup 222}Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM{sub 10} and PM{sub 2.5}) and carbon dioxide (CO{sub 2}) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m{sup -3} of {sup 222}Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which {sup 222}Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average {sup 222}Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor {sup 222}Rn levels were influenced by the {sup 222}Rn concentrations in the hot spring water and the bathing times. The average {sup 222}Rn transfer coefficients from water to air were 6.2 x 10{sup -4}-4.1 x 10{sup -3}. The 24-h average levels of CO{sub 2} and PM{sub 10} in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM{sub 2.5}. Radon and PM{sub 10} levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. - Highlights: {yields} {sup 222}Rn-bearing water is the main contributor to indoor radon in hot spring hotel. {yields} The PM{sub 2.5} and CO{sub 2} are also the main indoor pollutants in the hotel rooms. {yields} Higher radon and PM levels might have significant negative health effects to human. {yields} The radon transfer coefficients are consistent with the published data.

  3. Radon-222 as an indicator of continental air masses and air mass boundaries over ocean areas

    International Nuclear Information System (INIS)

    Larson, R.E.; Bressan, D.J.

    1980-01-01

    Radon ( 222 Rn) has proven to be an excellent indicator of the continental nature of over-ocean air and air mass boundaries. Radon is almost exclusively of continental origin, and low-level real-time monitoring is possible with our improved radon measurement techniques. The transition from continental to maritime air in offshore and onshore winds is rather obvious and can easily be established near large islands or continents as an order-of-magnitude change in radon concentration from a few tens of picocuries per cubic meter or more to a few picocuries per cubic meter or less. Sharply changing radon concentrations are usually associated with frontal areas. Our data have offered insights into air movements, and hence transport of continental materials and pollutants over oceanic areas

  4. Quantification of Groundwater Discharge in a Subalpine Stream Using Radon-222

    Directory of Open Access Journals (Sweden)

    Elizabeth Avery

    2018-01-01

    Full Text Available During the dry months of the water year in Mediterranean climates, groundwater influx is essential to perennial streams for sustaining ecosystem health and regulating water temperature. Predicted earlier peak flow due to climate change may result in decreased baseflow and the transformation of perennial streams to intermittent streams. In this study, naturally occurring radon-222 (222Rn was used as a tracer of groundwater influx to Martis Creek, a subalpine stream near Lake Tahoe, CA. Groundwater 222Rn is estimated based on measurements of 222Rn activity in nearby deep wells and springs. To determine the degassing constant (needed for quantification of water and gas flux, an extrinsic tracer, xenon (Xe, was introduced to the stream and monitored at eight downstream locations. The degassing constant for 222Rn is based on the degassing constant for Xe, and was determined to be 1.9–9.0 m/day. Applying a simple model in which stream 222Rn activity is a balance between the main 222Rn source (groundwater and sink (volatilization, the influx in reaches of the upstream portion of Martis Creek was calculated to be <1 to 15 m3/day/m, which cumulatively constitutes a significant portion of the stream discharge. Experiments constraining 222Rn emanation from hyporheic zone sediments suggest that this should be considered a maximum rate of influx. Groundwater influx is typically difficult to identify and quantify, and the method employed here is useful for identifying locations for focused stream flow measurements, for formulating a water budget, and for quantifying streamwater–groundwater interaction.

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

    International Nuclear Information System (INIS)

    Davis, Brian M.; Semprini, Lewis; Istok, Jonathan

    2003-01-01

    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

  6. Seasonal and diurnal variation of outdoor radon (222Rn) concentrations in urban and rural area with reference to meteorological conditions

    International Nuclear Information System (INIS)

    Podstawczynska, A.; Pawlak, W.; Kozak, K.; Mazur, J.

    2010-01-01

    The objective of the study was to investigate temporal variability of outdoor radon ( 222 Rn) concentration registered in the center of Lodz (urban station), at Ciosny (rural station) and Krakow (suburban station) in relation to meteorological parameters (i.e. air temperature, temperature vertical gradient, wind speed, soil heat flux, volumetric water content in soil) with special consideration of urban-rural differences. Continuous measurements of 222 Rn concentration (at 60 min intervals) were performed at a height of 2 m above the ground using AlphaGUARD PQ2000PRO (ionization chamber) from January 2008 to May 2009. 222 Rn levels were characterized by a diurnal cycle with an early morning maximum and a minimum in the afternoon. The well-marked 24 h pattern of radon concentration occurred in summer at anticyclonic weather with cloudless sky, light wind and large diurnal temperature ranges. The urban measurement site was characterized by the lowest atmospheric 222 Rn concentration and an urban-rural differences of radon levels increased from winter to summer and during the nighttime periods. The maximum contrasts of 222 Rn levels between Lodz and Ciosny, reaching - 30 Bq m -3 , were registered in June and July during the urban heat island (UHI) phenomenon (a positive thermal anomaly of a city if compared to rural area) and strong thermal inversion near the ground in the rural area. (authors)

  7. A process-based 222radon flux map for Europe and its comparison to long-term observations

    Science.gov (United States)

    Karstens, U.; Schwingshackl, C.; Schmithüsen, D.; Levin, I.

    2015-11-01

    Detailed 222radon (222Rn) flux maps are an essential pre-requisite for the use of radon in atmospheric transport studies. Here we present a high-resolution 222Rn flux map for Europe, based on a parameterization of 222Rn production and transport in the soil. The 222Rn exhalation rate is parameterized based on soil properties, uranium content, and modelled soil moisture from two different land-surface reanalysis data sets. Spatial variations in exhalation rates are primarily determined by the uranium content of the soil, but also influenced by soil texture and local water-table depth. Temporal variations are related to soil moisture variations as the molecular diffusion in the unsaturated soil zone depends on available air-filled pore space. The implemented diffusion parameterization was tested against campaign-based 222Rn soil profile measurements. Monthly 222Rn exhalation rates from European soils were calculated with a nominal spatial resolution of 0.083° × 0.083° and compared to long-term direct measurements of 222Rn exhalation rates in different areas of Europe. The two realizations of the 222Rn flux map, based on the different soil moisture data sets, both realistically reproduce the observed seasonality in the fluxes but yield considerable differences for absolute flux values. The mean 222Rn flux from soils in Europe is estimated to be 10 mBq m-2 s-1 (ERA-Interim/Land soil moisture) or 15 mBq m-2 s-1 (GLDAS (Global Land Data Assimilation System) Noah soil moisture) for the period 2006-2010. The corresponding seasonal variations with low fluxes in winter and high fluxes in summer range in the two realizations from ca. 7 to ca. 14 mBq m-2 s-1 and from ca. 11 to ca. 20 mBq m-2 s-1, respectively. These systematic differences highlight the importance of realistic soil moisture data for a reliable estimation of 222Rn exhalation rates. Comparison with observations suggests that the flux estimates based on the GLDAS Noah soil moisture model on average better

  8. A process-based 222radon flux map for Europe and its comparison to long-term observations

    International Nuclear Information System (INIS)

    Karstens, U.; Schwingshackl, C.; Schmithuesen, D.; Levin, I.

    2015-01-01

    Detailed 222 radon ( 222 Rn) flux maps are an essential pre-requisite for the use of radon in atmospheric transport studies. Here we present a high-resolution 222 Rn flux map for Europe, based on a parameterization of 222 Rn production and transport in the soil. The 222 Rn exhalation rate is parameterized based on soil properties, uranium content, and modelled soil moisture from two different land-surface reanalysis data sets. Spatial variations in exhalation rates are primarily determined by the uranium content of the soil, but also influenced by soil texture and local water-table depth. Temporal variations are related to soil moisture variations as the molecular diffusion in the unsaturated soil zone depends on available air-filled pore space. The implemented diffusion parameterization was tested against campaign-based 222 Rn soil profile measurements. Monthly 222 Rn exhalation rates from European soils were calculated with a nominal spatial resolution of 0.083 x 0.083 and compared to long-term direct measurements of 222 Rn exhalation rates in different areas of Europe. The two realizations of the 222 Rn flux map, based on the different soil moisture data sets, both realistically reproduce the observed seasonality in the fluxes but yield considerable differences for absolute flux values. The mean 222 Rn flux from soils in Europe is estimated to be 10 mBq m -2 s -1 (ERA-Interim/Land soil moisture) or 15 mBq m -2 s -1 (GLDAS (Global Land Data Assimilation System) Noah soil moisture) for the period 2006-2010. The corresponding seasonal variations with low fluxes in winter and high fluxes in summer range in the two realizations from ca. 7 to ca. 14 mBq m -2 s -1 and from ca. 11 to ca. 20 mBq m -2 s -1 , respectively. These systematic differences highlight the importance of realistic soil moisture data for a reliable estimation of 222 Rn exhalation rates. Comparison with observations suggests that the flux estimates based on the GLDAS Noah soil moisture model on

  9. Determine concentration radon 222Rn in the air inside and outside the buildings at the summer province of Baghdad

    International Nuclear Information System (INIS)

    Al-Ataby, N.R.; Aisa, B.H.; Jebir, H.M.; Hatem, J.N.

    2010-01-01

    In this study, Was use of solid-state nuclear track detectors in the measurement of concentrations of radon 222 Rn inside and outside of the buildings in the summer and winter of the Baghdad province and because of the high features of the technical sensitivity and efficiency to record track of charged particles (such as protons and alpha particles and fission fragments) . Is the radon of Environmental Pollutions that is caused health problems , that was seemed the concern at the problem of pollution, radon gas 222 Rn and thoron gas 220 Rn and the considerable risk resulting from exposure to these isotopes by alpha particles emitted which have proved the relationship between exposure to emitted alpha particles with the incidence of disease of lung cancer. In this study, measured the concentration of radon 222 Rn inside and outside buildings in the summer and winter in several areas from the Baghdad province and as showed in the attached tables. Been studied the environmental radioactivity and measurement of the concentration of radon gas in the air in different parts of the city of Baghdad. the highest concentration was Found in the second Orf ali (A) (of the Sadr City) for the summer and was (37.973 Bq/m3) outside the building and ((53.400 Bq/m3 inside the building, either for the winter season was (55.773 Bq/m3) outside the building and (Bq/m3 58.148) inside the building for the same region and This is the concentration within the limits allowed

  10. Sediment-water chemical exchange in the coastal zone traced by in situ radon-222 flux measurements

    International Nuclear Information System (INIS)

    Martens, C.S.; Kipphut, G.W.; Klump, J.V.

    1980-01-01

    In situ radon-222 flux experiments conducted in benthic chambers in Cape Lookout Bight, a small marine basin on the North Carolina coast, reveal that enhanced chemical transport across the sediment-water interface during summer months is caused by abiogenic bubble tube structures. Transport rates for dissolved radon, methane, and ammonium more than three times greater than those predicted on the basis of molecular diffusion occur when open tubes are maintained by semidiurnal low-tide bubbling

  11. Investigation of some factors affecting on release of radon-222 from phosphogypsum waste associated with phosphate ore processing.

    Science.gov (United States)

    Hilal, M A; El Afifi, E M; Nayl, A A

    2015-07-01

    The aim of this study is oriented to investigate the influence of some physicochemical factors such as radium distribution, grain size, moisture content and chemical constituents on releases of radon-222 from the accumulated phosphogypsum (PG) waste. The emanation fraction, activity concentration in the pore and the surface exhalation rate of radon-222 in the bulk PG waste are 34.5 ± 0.3%, 238.6 ± 7.8 kBq m(-3) and 213 ± 6.9 mBq m(-2) s(-1), respectively. These values were varied and enhanced slightly in the fine grain sizes (F1 factor of 1.05 folds compared to the bulk residue. It was also found that release of radon from residue PG waste was controlled positively by radium (Ra-226), calcium (CaSO4) and strontium (SrO). About 67% of radon release attributed to the grain size below 0.5 mm, while 33% due to the large grain size above 0.5 mm. The emanation fraction of Rn-222 is increased with moisture content and the maximum emanation is ∼43% of moisture of 3-8%. It reduced slowly with the continuous increase in moisture till 20%. Due to PG waste in situ can be enhancing the background to the surround workers and/or public. Therefore, the environmental negative impacts due to release of Rn-222 can be minimized by legislation to restrict its civil uses, or increasing its moisture to ∼10%, or by the particle size separation of the fine fraction containing the high levels of Ra-226 followed by a suitable chemical treatment or disposal; whereas the low release amount can be diluted and used in cement industry, roads or dam construction. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Indoor concentrations of radon 222 and its daughters: sources, range, and environmental influences

    International Nuclear Information System (INIS)

    Nero, A.V. Jr.

    1985-04-01

    The author here reviews what is presently known about factors affecting indoor concentrations of radon 222 and its daughters. In US single-family homes, radon concentrations are found to average about 1.5 pCi/1, but substantially higher concentrations occur frequently: perhaps a million US homes have concentrations exceeding 8 pCi/1 (from which occupants receive radiation doses comparable to those now experienced by uranium miners). The major contributor to indoor radon is ordinary soil underlying homes, with this radon being transported indoors primarily by the slight depressurization that occurs toward the bottom of a house interior (due to indoor-outdoor temperature differences and winds). Water from underground sources contributes significantly in a minority of cases, primarily residences with private wells, with public water supplies contributing only a few percent of indoor radon, even when drawn from wells. The strong variability in indoor concentrations is associated primarily with variability in the amount of radon entering homes from these various sources, and secondarily with differences in ventilation rates. However, for a given entry rate, the ventilation rate is the key determinant of indoor concentrations. Human doses are also influenced strongly by the chemical behavior of the daughters (i.e., decay products of radon), and considerable progress has been made recently in investigating a major aspect of this behavior, i.e., the manner in which daughters attach to airborne particles, to walls, and - indeed - to the lining of the lung itself, where the key radiation dose occurs

  13. Current issues and ways to reduce the negative impact of environment increased concentrations of Radon ({sup 222}Rn); Probleme actuale si tehnologii de reducerea a impactului negative al concentratiilor avansate de radon ({sup 222}Rn) in mediul ambiant

    Energy Technology Data Exchange (ETDEWEB)

    Coretchi, Liubov; Bahnarel, Ion; Apostol, Ion; Virlan, Serghei [Centrul National de Sanatate Publica, Chisinau (Moldova, Republic of)

    2012-10-15

    (This study was conducted to review the latest research in radon problem carried out by scientists of Moldova, the 13 EU countries and the USA, and relevant international organizations. Particular attention was paid to contradictions between energy efficiency measures and these of mitigation of {sup 222}Rn negative impact on human health. The main proposals developed were focused on the need for a National Radon Strategy (NRS) and a National Action Plan (NAP) for NRS implementation. Both NRS and NAP has to be correlated with other national policies, such as Smoking Reducing or Energy Efficiency. Development of a Radon Database including a map of radon concentrations, as well as a set of requirements for new housing construction, would be among the main components of NAP. (authors)

  14. A direct evidence for high carbon dioxide and radon-222 discharge in Central Nepal

    International Nuclear Information System (INIS)

    Perrier, F.; Byrdina, S.; Richon, P.; Bollinger, L.; Bureau, S.; Richon, P.; France-Lanord, Ch.; Rajaure, S.; Koirala, Bharat Prasad; Shrestha, Prithvi Lal; Gautam, Umesh Prasad; Tiwari, Dilli Ram; Sapkota, Soma Nath; Revil, A.; Revil, A.; Contraires, S.

    2009-01-01

    Gas discharges have been identified at the Syabru-Bensi hot springs, located at the front of the High Himalaya in Central Nepal, in the Main Central Thrust zone. The hot spring waters are characterized by a temperature reaching 61 C, high salinity, high alkalinity and δ 13 C varying from +0. 7 parts per thousand to +4. 8 parts per thousand. The gas is mainly dry carbon dioxide, with a δ 13 C of -0. 8 parts per thousand. The diffuse carbon dioxide flux, mapped by the accumulation chamber method, reached a value of 19000 g m -2 day -1 , which is comparable with values measured on active volcanoes. Similar values have been observed over a two-year time interval and the integral around the main gas discharge amounts to 0. 25 ± 0. 07 mol s -1 , or 350 ± 100 ton a -1 . The mean radon-222 concentration in spring water did not exceed 2. 5 Bq L -1 , exponentially decreasing with water temperature. In contrast, in gas bubbles collected in the water or in the dry gas discharges, the radon concentration varied from 16 000 to 41000 Bq m -3 . In the soil, radon concentration varied from 25000 to more than 50000 Bq m -3 . Radon flux, measured at more than fifty points, reached extreme values, larger than 2 Bq m -2 s -1 , correlated to the larger values of the carbon dioxide flux. Our direct observation confirms previous studies which indicated large degassing in the Himalaya. The proposed understanding is that carbon dioxide is released at mid-crustal depth by metamorphic reactions within the Indian basement, transported along pre-existing faults by meteoric hot water circulation, and degassed before reaching surface. This work, first, confirms that further studies should be undertaken to better constrain the carbon budget of the Himalaya, and, more generally, the contribution of mountain building to the global carbon balance. Furthermore, the evidenced gas discharges provide a unique natural laboratory for methodological studies, and appear particularly important to study as

  15. Calibration of detectors type CR-39 for methodology implementation for Radon-222 determination in CRCN-NE, Brazil

    International Nuclear Information System (INIS)

    Silva, Karolayne E.M. da; Santos, Mariana L. de O.; Amaral, Déric S. do; Vilela, Eldice C.; França, Elvis J. de; Hazin, Clovis A.; Farias, Emerson E.G. de

    2017-01-01

    Radon-222 is a radioactive gas, a product of the decay of uranium-238, which emits alpha particles and represents more than 50% of the dose of natural radiation received by the population. Therefore, monitoring of this gas is essential. For indoor measurement, solid state detectors can be used, the most common of which is CR-39. For monitoring using CR-39, alpha particles, generated by radon-222 and the daughter radionuclides, strike the surface of the detector and generate traces. To relate the trace density per exposure area in environments with unknown activity concentration, it is necessary to determine the calibration factor. The objective of this study was to calibrate CR-39 type detectors for the implementation of the radon determination methodology in Centro Regional de Ciencias Nucleares do Nordeste - CRCN-NE of Brazilian Nuclear Energy Commission - CNEN. In order to determine the CR-39 calibration factor, 19 exposures of the detectors were performed in the CRCN-NE calibration chamber (RN1-CRCN) at an activity of 5.00 kBq m -3 , with the exposure time varying from 24 to 850 hours. For the detection of the detectors, sodium hydroxide was used in a thermostat bath at 90 ° C for 5 hours. The count of number of traits per unit of field was performed with the aid of optical microscopy with an increase of 100 times, being read 30 fields per dosimeters. As a result, the calibration factor was obtained, and the linear response of the trace density as a function of exposure was observed. The results allow the use of CR-39 in the determination of radon-222 by CRCN-NE

  16. Numerical modelling of radon-222 entry into houses: An outline of techniques and results

    DEFF Research Database (Denmark)

    Andersen, C.E.

    2001-01-01

    Numerical modelling is a powerful tool for studies of soil gas and radon-222 entry into houses. It is the purpose of this paper to review some main techniques and results. In the past, modelling has focused on Darcy flow of soil gas (driven by indoor–outdoor pressure differences) and combined...... diffusive and advective transport of radon. Models of different complexity have been used. The simpler ones are finite-difference models with one or two spatial dimensions. The more complex models allow for full three-dimensional and time dependency. Advanced features include: soil heterogeneity, anisotropy......, fractures, moisture, non-uniform soil temperature, non-Darcy flow of gas, and flow caused by changes in the atmospheric pressure. Numerical models can be used to estimate the importance of specific factors for radon entry. Models are also helpful when results obtained in special laboratory or test structure...

  17. Current issues and ways to reduce the negative impact of environment increased concentrations of Radon (222Rn)

    International Nuclear Information System (INIS)

    Coretchi, Liubov; Bahnarel, Ion; Apostol, Ion; Virlan, Serghei

    2012-01-01

    (This study was conducted to review the latest research in radon problem carried out by scientists of Moldova, the 13 EU countries and the USA, and relevant international organizations. Particular attention was paid to contradictions between energy efficiency measures and these of mitigation of 222 Rn negative impact on human health. The main proposals developed were focused on the need for a National Radon Strategy (NRS) and a National Action Plan (NAP) for NRS implementation. Both NRS and NAP has to be correlated with other national policies, such as Smoking Reducing or Energy Efficiency. Development of a Radon Database including a map of radon concentrations, as well as a set of requirements for new housing construction, would be among the main components of NAP. (authors)

  18. Use of radon-222 as tracer to estimate groundwater infiltration velocity in a river bank area

    International Nuclear Information System (INIS)

    Trinh Van Giap

    2003-01-01

    Naturally occurring isotope Rn-222 has been used as a natural tracer to determine the residence time of groundwater infiltrated from river into an aquifer in a riverbank area. The applied method is based on the increasing radon concentration in infiltrating water during it passes through the riverbank and reaches an equilibrium value. Solid-state nuclear track detector technique is used to measure directly radon concentration in water of a well. In order to confirm the relationship between radon concentration and it's residence time, a model was constructed in the laboratory. Experiment carried out in Nam Dinh are showed that mean infiltrating velocity of groundwater in the studied area as high as 5.1 m/day. (author)

  19. Measurement of radon (222Rn) in thermal water of Cerro Pacho, Coatepeque Caldera, El Salvador

    International Nuclear Information System (INIS)

    Rodriguez, Ramiro; Olmos, Rodolfo; Payes, Julio

    2014-01-01

    Radon ( 222 Rn) concentrations and radio ( 226 Ra) evaluation dissolved in thermal spring water are presented to contribute to volcanic monitoring, adapting and validating analytical methodology. Sampling was discreet and monthly type, from June 2011 to March 2013. Radon levels was vary from 0,48 ± 0,1 to 1,54 ± 0,13 Bq/L (average 1,24 Bq/L). Radio concentrations were evaluated from January to December 2012. The values found do not show radio detection confidence level of 95% with respect to the detection limit (4,2 mBq/L). A decrease in radon was observed possibly related to subduction anomalies with epicenter at 143 km from Cerro Pacho, in November 2012, volcanic seismicity was also recorded 40 days before with increments of microearthquakes and volcano-tectonic activity. The first measurements of radon in thermal water have been generated, establishing the baseline to evaluate the behavior of these radionuclides with seismic activity. (author) [es

  20. Studies on 222Rn concentration in ground water using smart radon monitor and assessment of the radiation dose to the population of Mysuru city

    International Nuclear Information System (INIS)

    Chandrashekara, M.S.; Pruthvi Rani, K.S.

    2017-01-01

    Radioactive elements originate from the earth's crust and make their way into air, water, food and eventually in to the living system. Even though 75% of the Earth's surface is covered by water, only about 0.3 % of the total water on the Earth is available for public use. The ground water contains trace amounts of radioactive elements and these radionuclides contribute significant amount of dose to living beings, through intake of water into the human body. Radon dissolved in water is released into air when it is used for cooking, drinking, bathing and washing purposes. Exposure of population to higher concentrations of radon and its progeny for a long time causes occurrence of lung cancer and pathological effects like respiratory functional changes. Radon is a main source of ionizing radiation of natural origin and the studies on radon concentrations in drinking water are of importance. A systematic study of 226 Ra and 222 Rn concentration in the drinking water samples was carried out in Mysuru city. The concentration of 226 Ra and 222 Rn was estimated in water samples using emanometry method employing scintillation cells and alpha counting system. The 222 Rn concentration in water was also measured using a Smart Radon Monitor (SRM) for comparison of the results. SRM is a technologically advanced real time, portable, radon monitor developed at BARC, Mumbai

  1. A Radon Chamber without Radium Source for Detector Calibration and Radon Measurements

    International Nuclear Information System (INIS)

    Al-Azmi, D.; Karunakara, N.

    2008-01-01

    A radon chamber of volume 216 liters was designed and constructed for calibration of radon detectors and radon test measurements. The main feature of this chamber is that the active 226 Ra source, to generate the 222 Rn inside the chamber volume, is not required. Instead, 222 Rn from soil gas is utilized for this purpose. The supply of radon comes from the soil gas. Soil gas is drawn from the soil to fill the chamber with high radon concentration levels (∼ 80 kBq/m3). Desired radon concentration levels can be obtained by drawing the soil gas for different time durations and/or flow rate (author)

  2. Radon-222 in ground water in the German Rhine-Nahe-Area

    International Nuclear Information System (INIS)

    Raff, O.; Haberer, K.

    1998-01-01

    Investigations of the radon-222 activity concentrations of 129 raw water samples from wells, springs and galeries used by public water supply in the surrounding areas of Mainz and Wiesbaden showed a clear dependence on the lithology of the aquifers. Whereas the arithmetic mean value of 27 samples from alluvial aquifers was 0.9 Bq/l (maximum values 3.5 Bq/l) and of 90 samples from different sedimentary rock aquifers approximately 17 Bq/l (maximum value 93 Bq/l), the mean value of 12 samples from rhyolitic aquifers of the Saar-Nahe-Basin was 141 Bq/l (461 Bq/l in maximum). The values of all 129 samples show roughly a lognormal distribution with a geometric mean value of 6.4 Bq/l and a median of 10 Bq/l. The determined values are compared with values from other investigations in Europe and the USA. Reasons for the big differences of the water radon concentrations are explained on the basis of the geological situation. (orig.) [de

  3. A simple bubbling system for measuring radon (222Rn) gas concentrations in water samples based on the high solubility of radon in olive oil.

    Science.gov (United States)

    Al-Azmi, D; Snopek, B; Sayed, A M; Domanski, T

    2004-01-01

    Based on the different levels of solubility of radon gas in organic solvents and water, a bubbling system has been developed to transfer radon gas, dissolving naturally in water samples, to an organic solvent, i.e. olive oil, which is known to be a good solvent of radon gas. The system features the application of a fixed volume of bubbling air by introducing a fixed volume of water into a flask mounted above the system, to displace an identical volume of air from an air cylinder. Thus a gravitational flow of water is provided without the need for pumping. Then, the flushing air (radon-enriched air) is directed through a vial containing olive oil, to achieve deposition of the radon gas by another bubbling process. Following this, the vial (containing olive oil) is measured by direct use of gamma ray spectrometry, without the need of any chemical or physical processing of the samples. Using a standard solution of 226Ra/222Rn, a lowest measurable concentration (LMC) of radon in water samples of 9.4 Bq L(-1) has been achieved (below the maximum contaminant level of 11 Bq L(-1)).

  4. Radon: Not so Noble

    Indian Academy of Sciences (India)

    Radon in the Environment and Associated Health Problems ... is presently working on emission of ... Radon isotope 222 has a half-life of 3.8 days, long enough to ..... 222Rn concentration of one WL for 170 working hours in one month.

  5. A process-based {sup 222}radon flux map for Europe and its comparison to long-term observations

    Energy Technology Data Exchange (ETDEWEB)

    Karstens, U. [Max-Planck-Instistut fuer Biogeochemie, Jena (Germany); Schwingshackl, C.; Schmithuesen, D.; Levin, I. [Heidelberg Univ. (Germany). Inst. fuer Umweltphysik

    2015-07-01

    Detailed {sup 222}radon ({sup 222}Rn) flux maps are an essential pre-requisite for the use of radon in atmospheric transport studies. Here we present a high-resolution {sup 222}Rn flux map for Europe, based on a parameterization of {sup 222}Rn production and transport in the soil. The {sup 222}Rn exhalation rate is parameterized based on soil properties, uranium content, and modelled soil moisture from two different land-surface reanalysis data sets. Spatial variations in exhalation rates are primarily determined by the uranium content of the soil, but also influenced by soil texture and local water-table depth. Temporal variations are related to soil moisture variations as the molecular diffusion in the unsaturated soil zone depends on available air-filled pore space. The implemented diffusion parameterization was tested against campaign-based {sup 222}Rn soil profile measurements. Monthly {sup 222}Rn exhalation rates from European soils were calculated with a nominal spatial resolution of 0.083 x 0.083 and compared to long-term direct measurements of {sup 222}Rn exhalation rates in different areas of Europe. The two realizations of the {sup 222}Rn flux map, based on the different soil moisture data sets, both realistically reproduce the observed seasonality in the fluxes but yield considerable differences for absolute flux values. The mean {sup 222}Rn flux from soils in Europe is estimated to be 10 mBq m{sup -2} s{sup -1} (ERA-Interim/Land soil moisture) or 15 mBq m{sup -2} s{sup -1} (GLDAS (Global Land Data Assimilation System) Noah soil moisture) for the period 2006-2010. The corresponding seasonal variations with low fluxes in winter and high fluxes in summer range in the two realizations from ca. 7 to ca. 14 mBq m{sup -2} s{sup -1} and from ca. 11 to ca. 20 mBq m{sup -2} s{sup -1}, respectively. These systematic differences highlight the importance of realistic soil moisture data for a reliable estimation of {sup 222}Rn exhalation rates. Comparison with

  6. The use of radon (Rn-222) and volatile organic compounds in monitoring soil gas to localize NAPL contamination at a gas station in Rio Claro, São Paulo State, Brazil

    International Nuclear Information System (INIS)

    Barbosa, E.Q.; Galhardi, J.A.; Bonotto, D.M.

    2014-01-01

    This study focuses on the presence of radon ( 222 Rn) and volatile organic compounds (VOCs) in soil gases at a gas station located in the city of Rio Claro, São Paulo, Brazil, where a fossil fuel leak occurred. The spatial distribution results show a correlation between 222 Rn and VOCs, consistent with the fact that radon gas has a greater chemical affinity with organic phases than with water. This finding demonstrates that the presence of a residual hydrocarbon phase in an aquifer can retain radon, leading to a reduced radon content in the soil gas. The data in this study confirm the results of previous investigations, in which the method used in this study provided a preliminary fingerprint of a contaminated area. Furthermore, the data analysis time is brief, and only simple equipment is required. - Highlights: • 222 Rn in soil gases. • Correlation between 222 Rn and VOCs. • Useful method as a preliminary fingerprint of a contaminated area

  7. Experimental study of the combined effect of cigarette smoke and an active burden of radon-222

    International Nuclear Information System (INIS)

    Chameaud, J.; Perraud, R.; Chretien, J.; Masse, R.; Lafuma, J.

    1978-01-01

    Previous studies on the carcinogenic effect of radon-222 derivatives have yielded accurate relationships, for each radon dose, between the dose value and the frequencies and latency times of lung cancers. In the present work, one hundred rats were subjected, over one-and-a-half months, to a total dose of 3600 WLM, chosen because it corresponds to a 30% occurrence of cancers. Fifty of these animals then inhaled cigarette smoke during 50 ten-minute sessions per week. The total time for these inhalations was 350 hours spread over about six months. In the 'radon' group (50 rats), 17 animals were found to have lung cancer. In the 'radon + tobacco' group (50 rats), 32 cancers were observed; moreover, the tumours in this group were much more extensive, multifocal and invasive. Animals subjected to cigarette smoke alone have never shown lung cancer. The effect of tobacco as a co-factor in carcinogenesis has thus been varified experimentally, although inhaled cigarette smoke alone is not carcinogenic in rats. (author)

  8. Study and development of an airborne instrument for collecting aerosols and for measuring radon 222 by its active deposition

    International Nuclear Information System (INIS)

    Filippi, Dominique

    2000-01-01

    The study and development of an airborne instrument designed to collect aerosols and measure radon 222 is detailed in this thesis. Having discussed the context of radon and introduced the methods of the measurement of radon 222 by its natural active deposition, the measurement of aerosols with the Sextant Avionique/LSCE dynamic iso-kinetic probe is quantified. These estimations of the efficiency of the probe were obtained during iso-axial simulations of the flow around the probe at different sub-sonic speeds, then by the calculation of trajectories of particles at the entrance to the probe for several debit coefficients. The effect of the attack angle is discussed along with the iso-kinetic criteria of pressure necessary for the functioning of this probe. To conclude this theoretical study, the author has estimated the deposits during aerosol transport in pipes. The instrument once constructed, (dubbed A VIRAD), is then itself presented, along with the technological aspects adopted for its use. The instrument was validated during an experimental aerial study STAAARTE 99. The measures obtained during these flights are presented in the conclusions. (author) [fr

  9. Calibration of detectors type CR-39 for methodology implementation for Radon-222 determination in CRCN-NE, Brazil; Calibração de detectores do tipo CR-39 para implementação da metodologia de determinação de radônio-222 no CRCN-NE

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Karolayne E.M. da; Santos, Mariana L. de O.; Amaral, Déric S. do; Vilela, Eldice C.; França, Elvis J. de; Hazin, Clovis A.; Farias, Emerson E.G. de, E-mail: keesthefany@gmail.com, E-mail: marianasantos_ufpe@hotmail.com, E-mail: dericsoares@gmail.com, E-mail: ecvilela@cnen.gov.br, E-mail: ejfrana@cnen.gov.br, E-mail: chazin@cnen.gov.br, E-mail: emersonemiliamo@yahoo.com.br [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2017-07-01

    Radon-222 is a radioactive gas, a product of the decay of uranium-238, which emits alpha particles and represents more than 50% of the dose of natural radiation received by the population. Therefore, monitoring of this gas is essential. For indoor measurement, solid state detectors can be used, the most common of which is CR-39. For monitoring using CR-39, alpha particles, generated by radon-222 and the daughter radionuclides, strike the surface of the detector and generate traces. To relate the trace density per exposure area in environments with unknown activity concentration, it is necessary to determine the calibration factor. The objective of this study was to calibrate CR-39 type detectors for the implementation of the radon determination methodology in Centro Regional de Ciencias Nucleares do Nordeste - CRCN-NE of Brazilian Nuclear Energy Commission - CNEN. In order to determine the CR-39 calibration factor, 19 exposures of the detectors were performed in the CRCN-NE calibration chamber (RN1-CRCN) at an activity of 5.00 kBq m{sup -3}, with the exposure time varying from 24 to 850 hours. For the detection of the detectors, sodium hydroxide was used in a thermostat bath at 90 ° C for 5 hours. The count of number of traits per unit of field was performed with the aid of optical microscopy with an increase of 100 times, being read 30 fields per dosimeters. As a result, the calibration factor was obtained, and the linear response of the trace density as a function of exposure was observed. The results allow the use of CR-39 in the determination of radon-222 by CRCN-NE.

  10. Investigation of natural levels of radon-222 in groundwater in Maine for assessment of related health effects

    International Nuclear Information System (INIS)

    Hess, C.T.; Casparius, R.E.; Norton, S.A.; Brutsaert, W.F.

    1980-01-01

    We have used an inexpensive radon ( 222 Rn) measurement method using liquid scintillation counting to remeasure potable water from 10 sites near Raymond, Maine, to determine the accuracy and reproducibility of earlier measurements. Duplication or triplication of samples shows a high degree of reproducibility for the liquid scintillation method. A hypothesis emerged from analysis of the measured values of 222 Rn near Raymond, Maine, that high values (50,000 to 200,000 pCi/liter) are associated with granite. This was shown to be correct for several large areas of granite such as the Sebago, Lucern, Waldo, and Waldoboro granites. The presence of high 222 Rn concentrations in granite areas hundreds of kilometers from the Raymond area shows that the high 222 Rn levels in water are a statewide and perhaps a regional problem rather than a western Maine problem

  11. The radon 222 transport in soils. The case of the storage of residues coming from uranium ores processing; La migration du radon 222 dans un sol. Application aux stockages de residus issus du traitement des minerais d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Ferry, C

    2000-07-01

    Uranium Mill Tailings (UMT) contain comparatively large quantities of radium-226. This radionuclide yields, by radioactive decay, the radioactive gas radon-222. Tailing piles are routinely covered to reduce the radon release-rate into the atmosphere. In order to assess the long term environmental impact of a UMT repository, mechanisms governing radon exhalation at the soil surface must be deciphered and understood. A model of radon transport in the unsaturated zone is developed for this purpose: water- and air-flow in the porous material are determined, as well as radon transport by diffusion in the pore space and advection by the gas phase. The radon transport model in the unsaturated zone - TRACI (which stands, in French, for Radon Transport within the Unsaturated Layer) - calculates moisture contents in the soil, Darcy's velocities of the liquid and gas phases, radon concentrations in the gas phase and radon flux at the soil surface. TRACI's results are compared with observations carried out on a UMT and a cover layer. Input parameters are derived from the textural analysis of the material under study, whereas upper boundary conditions are given by meteorological data. If we consider measurement errors and uncertainties on the porous medium characterisation, model's results are generally in good agreement with observations, at least on the long run. Moreover, data analysis shows hat transient phenomena are understood as well, in most situations. (author)

  12. Genetic effects of radon 222 in a population of Drosophila melanogaster chronically exposed; Efectos geneticos del radon 222 en una poblacion de Drosophila melanogaster cronicamente expuesta

    Energy Technology Data Exchange (ETDEWEB)

    Salceda, V M [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico). Dept. de Biologia

    1997-07-01

    It was investigated the mutagenic effect of Radon 222 during a experimental period of 11 generations. In this lapse Drosophila melanogaster larvae line Canton-S were maintained in a radon atmosphere. In each test generation had been extracted males, consequently exposed to radiation which were subjected to a crossing series with a bearer marker genes of according to the Wallace experimental design (1956). Due to the experimental conditions it only was determined the recessive lethal mutations frequency for the second chromosome in the 1,4,7 and 11 generations. Of all study it was conduced in parallel way a non-treated witness population. The concentrations at which was subjected the experimental population varied of generation to generation from 12 {+-} 2 to 43 {+-} 5 kBq/m{sup 3}. Our analysis correspond to lethality determination in 1182 second chromosomes distributed between two populations and the different exposition generations. The study allow to determine the respective frequencies of recessive lethal genes varying according to the population and/or generation between 10.53 and 22.02%. The statistical analysis of data did not show significant differences among the different populations. (Author)

  13. Design and construction of a system for determining Radon-222 through Alpha spectroscopy

    International Nuclear Information System (INIS)

    Bonifacio, J.; Iturbe, J.L.

    1992-02-01

    The study of the present work consists on designing a system to measure gas 222 Rn, using a surface barrier detector, in order to obtaining a more accuracy measure of this isotope by means of an alpha particle spectra and thus to try to avoid the influence of the radioactivity of the isotope descendants of short half life, which are also emitting of alpha particles, since by other methods its should make a series of corrections to obtain the real value of the radon activity. (Author)

  14. Evaluation of 222Rn concentration of the internal and external environments of residences at Monte Alegre municipality, Para, Brazil

    International Nuclear Information System (INIS)

    Melo, Vicente de Paula

    1999-01-01

    The human being is constantly exposed to the natural radioactivity in the environment where he lives. This radioactivity comes mainly from materials present in the terrestrial crust that possess in their constitution chemical elements belonging to the radioactive families of uranium and thorium. The use of such materials for the construction of houses constitutes an important exposure form to the natural radiation, above all to the radioactive gas 222 Rn, that it is exhaled from them. The Brazilian soil is composed, among other, of minerals that contain appreciable concentrations of these elements. The inhabitants of Monte Alegre town in Para, located at 2 deg 00' 24,9 'S ; 54 deg 04 ' 13,5 W , used in the construction of their houses stones obtained from an area 20 km distant of Monte Alegre, denominated Ingles de Souza, located at 01 deg 56' 4 0,1 S; 54 deg 12 149,7 W, where a small residential village, denominated National Agricultural Colony of Para (CANP), is located. The objective of this work was to evaluate the indoor concentration of 222 Rn in the residences of Monte Alegre and CANP. Determinations of the 238 U and 226 Ra concentrations, measurements of the radon flux in samples of stones and soils of the two regions, as well as measurements to the gamma dose close of the soil and inside the residences, were also carried out. The average results of the radon concentration in the air of the investigated residences did not exceed the limits of 200 Bq. m 3 (action level) and 600 Bq. m 3 (intervention level) recommended by the International Commission on Radiological Protection (ICRP). The concentrations of natural radionuclides and the radon flux determined at the village showed values 17 times higher than those found at the urban area of Monte Alegre, while the average indoor gamma dose rate in the village residences was 0.86 mSv/a. (author)

  15. Exhalation velocity of radon-222 of Dutch building materials and the influence of paint systems

    International Nuclear Information System (INIS)

    Dijk, W. van; Jong, P. de

    1989-02-01

    In order to achieve a better insight concerning the source terms of radon in the Dutch dwelling in the framework of the RENA-programme an investigation has been performed into the exhalation velocity of radon-222 from building materials. From this investigation it turned out that the ventilation factor does not have any influence upon the exhalation velocity, neither an influence of alteration of air pressure could be demonstrated. The influence of air humidity upon the exhalation velocity showed a twofold picture; for gypsum a linear increase of the exhalation velocity with vapour pressure was found, while for concrete a linear decrease with vapour pressure was observed. Further it has been investigated in how far paint systems diminish the exhalation velocity of the Rn-222 from gypsum and concrete. Acryl paints, mostly used in the Dutch dwelling, did not show a decrease of the exhalation velocity and structure paints did even cause an increase of the exhalation velocity. Other types of paint based on chlorous rubber, epoxy resins and poly-urethane, in contrast, showed a clear reduction. From these those based on poly-urethane showed the largest reduction (60-75%) at a double sided treatment of the wall. With the help of a mathematical modelling of the exhalation estimations have been made of the exhalation velocity of Rn-222 at single sided treatment of a wall and for the exhalation velocity of Rn-220. For the fore mentioned poly-urethane-paints this yelds, at an estimate, a reduction of respectively 90-95% and 100%. (author). 40 refs.; 15 figs.; 8 tabs

  16. Radon

    Energy Technology Data Exchange (ETDEWEB)

    Weigel, F [Muenchen Univ. (Germany, F.R.). Inst. fuer Anorganische Chemie

    1978-09-01

    The noble gas radon, formerly called emanation, was discovered a few years after radium. /sup 222/Rn, the longest-lived isotope, has a half-life of 3,82 days. This half life is so short that the experimental techniques available at present (1978) are not sufficient for a characterization of defined radon compounds, even though there are definite indications for the existence of such compounds, and one may expect such radon compounds to be even more stable than the numerous known xenon compounds. - The radon isotopes /sup 219/Rn (Actinon), /sup 220/Rn (Thoron), and /sup 222/Rn (Radon) occur in nature despite their rather short half-lives, because they are continously generated from their mothers /sup 223/Ra, /sup 224/Ra, and /sup 226/Ra, which are in secular equilibrium with long-lived isotopes /sup 235/U, /sup 238/U, and /sup 232/Th, and are in turn continously formed from these long-lived isotopes. Since the radon isotopes are gases, they enter the atmosphere and are carried for long distances with air currents. - Because radon is so short-lived, its practical applications are rather limited. For medical applications, small sealed glass tubes filled with radon are used as radiation sources after the radon has decayed, because the whole series of Po-, Bi-, and Pb-isotopes of the radium decay chain are formed, whose penetrating radiation is useful for therapy. When solids are spiked with Ra isotopes, radon is evolved at a constant rate. On heating such solids, phase transitions show up by sudden increased radon evolution (Hahn's emanation method). - On the basis of nuclear theoretical calculations, there is hardly a chance for the discovery of a long-lived radon species. Therefore, major progress in radon chemistry is hardly to be expected in the near future.

  17. Contribution of (222)Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China.

    Science.gov (United States)

    Song, Gang; Wang, Xinming; Chen, Diyun; Chen, Yongheng

    2011-04-01

    This study investigates the contribution of radon ((222)Rn)-bearing water to indoor (222)Rn in thermal baths. The (222)Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM(10) and PM(2.5)) and carbon dioxide (CO(2)) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m(-3) of (222)Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which (222)Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average (222)Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor (222)Rn levels were influenced by the (222)Rn concentrations in the hot spring water and the bathing times. The average (222)Rn transfer coefficients from water to air were 6.2 × 10(-4)-4.1 × 10(-3). The 24-h average levels of CO(2) and PM(10) in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM(2.5). Radon and PM(10) levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Contribution of 222Rn in domestic water supplies to 222Rn in indoor air in Colorado homes

    International Nuclear Information System (INIS)

    Lawrence, E.P.; Wanty, R.B.; Nyberg, P.

    1992-01-01

    The contribution of 222Rn from domestic water wells to indoor air was investigated in a study of 28 houses near Conifer, CO. Air concentrations determined by alpha-track detectors (ATDs) and continuous radon monitors were compared with the predictions of a single-cell model. In many of the houses, the water supply was shown to contribute significantly to levels of indoor 222Rn. The data from the ATD study were augmented with a continuous monitoring study of a house near Lyons, CO. The well water in that house has the highest known concentration of 222Rn in water yet reported (93 MBq m-3). The temporal pattern in the indoor 222Rn concentration corresponds to water-use records. In general, it is difficult to quantify the proportion of indoor radon attributable to water use. Several lines of evidence suggest that the single-cell model underestimates this proportion. Continuous-monitoring data, although useful, are impractical due to the cost of the equipment. We propose a protocol for 222Rn measurement based on three simultaneous integrating radon detectors that may help estimate the proportion of indoor 222Rn derived from the water supply

  19. 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+.

  20. Measurement of Radon (222Rn) in the High School of Medicine 'Dr.Ali Sokoli' in Prishtina

    International Nuclear Information System (INIS)

    Kadiri, S.; Hodolli, G.; Pllana, X.; Dumani, S.; Hasani, F.

    2011-01-01

    Measurements of radon concentration (222Rn) were performed in the largest High School of Medicine ''Dr. Ali Sokoli'' in Prishtina. We choose four locations (classrooms) at ground level, three at first and three on the second floor. In the same premises, the measurements were performed with two methods: using a scintillation cell and a continuous method. The maximum value of radon concentration, measurements with scintillation cells, were obtained by the ground level moving to (573 ± 26) Bq m -3 , while the minimum value of (176 ± 11) Bq m -3 was obtained in the second floor. The maximum value of radon concentration measurements with the continuous method was 116 Bq m -3 in ground level, and the minimum value was 70 Bq m -3 . Based on these results, we calculated annual effective dose, which ranges between (0.76 ± 0.06) mSv and (2.48 ± 0.11) mSv, by scintillation cells. Whereas, the annual effective dose measuring by continuous method was between 0.30 mSv and 0.50 mSv. Based on those results, we conclude that radon concentration and annual effective doses were within accepted international standards. (author)

  1. Optimized measurement of radium-226 concentration in liquid samples with radon-222 emanation

    International Nuclear Information System (INIS)

    Perrier, Frédéric; Aupiais, Jean; Girault, Frédéric; Przylibski, Tadeusz A.; Bouquerel, Hélène

    2016-01-01

    Measuring radium-226 concentration in liquid samples using radon-222 emanation remains competitive with techniques such as liquid scintillation, alpha or mass spectrometry. Indeed, we show that high-precision can be obtained without air circulation, using an optimal air to liquid volume ratio and moderate heating. Cost-effective and efficient measurement of radon concentration is achieved by scintillation flasks and sufficiently long counting times for signal and background. More than 400 such measurements were performed, including 39 dilution experiments, a successful blind measurement of six reference test solutions, and more than 110 repeated measurements. Under optimal conditions, uncertainties reach 5% for an activity concentration of 100 mBq L"−"1 and 10% for 10 mBq L"−"1. While the theoretical detection limit predicted by Monte Carlo simulation is around 3 mBq L"−"1, a conservative experimental estimate is rather 5 mBq L"−"1, corresponding to 0.14 fg g"−"1. The method was applied to 47 natural waters, 51 commercial waters, and 17 wine samples, illustrating that it could be an option for liquids that cannot be easily measured by other methods. Counting of scintillation flasks can be done in remote locations in absence of electricity supply, using a solar panel. Thus, this portable method, which has demonstrated sufficient accuracy for numerous natural liquids, could be useful in geological and environmental problems, with the additional benefit that it can be applied in isolated locations and in circumstances when samples cannot be transported. - Highlights: • Radium-226 concentration measured with optimized accumulation in a container. • Radon-222 in air measured precisely with scintillation flasks and long countings. • Method tested by repetition tests, dilution experiments, and successful blind tests. • Estimated conservative detection limit without pre-concentration is 5 mBq L"−"1. • Method is portable, cost

  2. Spatial and time variations of radon-222 concentration in the atmosphere of a dead-end horizontal tunnel

    International Nuclear Information System (INIS)

    Richon, Patrick; Perrier, Frederic; Sabroux, Jean-Christophe; Trique, Michaeel; Ferry, Cecile; Voisin, Vincent; Pili, Eric

    2004-01-01

    The concentration of radon-222 has been monitored since 1995 in the atmosphere of a 2 m transverse dimension, 128 m long, dead-end horizontal tunnel located in the French Alps, at an altitude of 1600 m. Most of the time, the radon concentration is stable, with an average value ranging from 200 Bq m -3 near the entrance to about 1000 Bq m -3 in the most confined section, with an equilibrium factor between radon and its short-lived decay products varying from 0.61 to 0.78. However, radon bursts are repeatedly observed, with amplitudes reaching up to 36 x 10 3 Bq m -3 and durations varying from one to several weeks, with similar spatial variations along the tunnel as the background concentration. These spatial variations are qualitatively interpreted in terms of natural ventilation. Comparing the radon background concentration with the measured radon exhalation flux at the wall yields an estimate of 8 ± 2 x 10 -6 s -1 (0.03 ± 0.007 h -1 ) for the ventilation rate. The hypothesis that the bursts could be due to transient changes in ventilation can be ruled out. Thus, the bursts are the results of transient increased radon exhalation at the walls, that could be due to meteorological effects or possibly combined hydrological and mechanical forcing associated with the water level variations of the nearby Roselend reservoir lake. Such studies are of interest for radiation protection in poorly ventilated underground settings, and, ultimately, for a better understanding of radon exhalation associated with tectonic or volcanic processes

  3. A study of radon 222 transfer indoors

    International Nuclear Information System (INIS)

    Maximilien, R.; Robe, M.C.; Archimbaud, M.

    1985-01-01

    Indoor exposure can vary considerably depending upon the natural environment (geology, climate), man-made arrangements (building materials, insulation and ventilation systems...) or way of living. In order to specify the sources and assess their respective contribution in a given dwelling, a good knowledge of radon transfer and dispersion processes is required as well as a heavy experimental device (continuous radon and ventilation monitoring...). The study must be limited to some cases selected by a systematic measurement program either because they are representative of dwelling conditions, or preferably on account of their high radon level, the origin of which will be investigated. As a consequence, countermeasures can be developed. A pilot study has been carried out on radon transport in two houses of the Rhone river valley. The two houses -selected among 131 other ones for their high radon levels- are built with the same architectural approach and located very close to each other, yet the factors accounting for domestic exposure are quite different. Indoor parameters are at the origin of various radon concentrations in the case of low natural ventilation; conversely, outdoor parameters only seem to act in the case of high ventilation. For a larger part, however, radon seems to emanate from under the foundations of both houses [fr

  4. Analyses of atmospheric radon 222 / canisters exposed by Greenpeace in Niger (Arlit / Akokan sector)

    International Nuclear Information System (INIS)

    Chareyron, B.

    2010-01-01

    The companies SOMAIR and COMINAK, subsidiaries of the AREVA group, are mining uranium deposits in northern Niger. In the course of a field mission carried out in November 2009, a Greenpeace International team deposited detectors (canisters of activated charcoal) to measure radon 222, a radioactive gas formed by the decay of the radium 226 present in the uranium ore. This report includes the results of the analysis of the activated charcoal canisters conducted in CRIIRAD's laboratory, and a brief commentary on the interpretation of the results. (authors)

  5. Comparison of techniques active and passive in measurement of radon concentration ("2"2"2Ra) in the air

    International Nuclear Information System (INIS)

    Oliveira, Evaldo Paulo de

    2017-01-01

    The purpose of this work was to perform a study comparing radon concentration measurements between two techniques used to measure radon gas in the air: one using LEXAN polycarbonate plastic detectors and the other the continuous monitor in AlphaGUARD passive mode. The concentrations of radon gas within radon emanation chambers were measured using calibrated / traceable sources generating "2"2"2Rn through "2"2"6Ra. In calibration the 'calibration factor' or 'sensitivity' was determined for the LEXAN plastic detector. The calibration work of the dosimeters was carried out at the Radon Laboratory of the Environmental Analysis Division - DIRAD IRD/CNEN and at the Natural Radioactivity Laboratory (LRN) of the Center for the Development of Nuclear Technology (CDTN/CNEN). The 'calibration factor' or 'sensitivity' was found to be 32.34 (traits.cm"-"2)/(kBq.d.m"-"3). This factor was used to determine the radon concentration measured by the LEXAN plastic detectors. Also in the calibration, the efficiencies for LEXAN (94.1% ± 9.7%) and AlphaGUARD (92.5% ± 7.2%) were determined. The statistical analysis used showed good parity in the results of the measurements. It was concluded that the results were satisfactory and will serve as a good reference for studies related to the radon air meters used in this work. (author)

  6. Measurement of radon permeability through polyethylene membrane using scintillation detector

    Energy Technology Data Exchange (ETDEWEB)

    Ashry, A.H.; Abou-Leila, M. [Department of Physics, Faculty of Education, Ain Shams University, Cairo (Egypt); Abdalla, A.M., E-mail: aymanabdalla62@hotmail.co [Department of Physics, Faculty of Education, Ain Shams University, Cairo (Egypt); Department of Physics, Faculty of Sciences and Arts, Najran University, Najran, P.O. Box. 11001 (Saudi Arabia); Advanced Materials and Nano-Engineering Laboratory (AMNEL), Centre for Advanced Materials and Nano-Engineering (CAMNE), Najran University, Najran, P.O. Box. 11001 (Saudi Arabia)

    2011-01-15

    The permeability of Radon 222 through polyethylene membranes has been studied using activated charcoal technique. The permeability constant of Radon 222 through low-density polyethylene, linear low-density Polyethylene and high density polyethylene samples has been measured. There is a considerable agreement between the values obtained by our method and the method suggested by W. Arafa [2002. Permeability of radon 222 through some materials. Radiat. Meas. 35, 207-211], and SSNTD technique suggested by A. Hafez and G. Somogyi [1986. Determination of radon and thoron permeability through some plastics by track technique. Int. J. Radiat. Appl. Instrum. Nucl. Track Radiat. Meas. 12 (1-6), 697-700]. In this work Radon permeability through different polyethylene membranes has been measured using three different methods, i.e. solid state nuclear track technique, W. Arafa [2002. Permeability of radon 222 through some materials. Radiat. Meas. 35, 207-211]method and our proposed method. In addition to this, in this study, the diffusion coefficient of radon in charcoal as well as solubility of Radon in polyethylene membrane has been taken into consideration.

  7. Measurement of radon permeability through polyethylene membrane using scintillation detector

    International Nuclear Information System (INIS)

    Ashry, A.H.; Abou-Leila, M.; Abdalla, A.M.

    2011-01-01

    The permeability of Radon 222 through polyethylene membranes has been studied using activated charcoal technique. The permeability constant of Radon 222 through low-density polyethylene, linear low-density Polyethylene and high density polyethylene samples has been measured. There is a considerable agreement between the values obtained by our method and the method suggested by W. Arafa [2002. Permeability of radon 222 through some materials. Radiat. Meas. 35, 207-211], and SSNTD technique suggested by A. Hafez and G. Somogyi [1986. Determination of radon and thoron permeability through some plastics by track technique. Int. J. Radiat. Appl. Instrum. Nucl. Track Radiat. Meas. 12 (1-6), 697-700]. In this work Radon permeability through different polyethylene membranes has been measured using three different methods, i.e. solid state nuclear track technique, W. Arafa [2002. Permeability of radon 222 through some materials. Radiat. Meas. 35, 207-211] method and our proposed method. In addition to this, in this study, the diffusion coefficient of radon in charcoal as well as solubility of Radon in polyethylene membrane has been taken into consideration.

  8. Seismo-volcanic monitoring at Furnas Volcano (Azores): radon (222Rn) concentration in groundwater

    Science.gov (United States)

    Silva, Catarina; Virgílio Cruz, José; Ferreira, Teresa; Viveiros, Fátima; Freire, Pedro; Allard, Patrick

    2017-04-01

    The Azores archipelago, located in the middle of the North Atlantic Ocean, is composed of nine volcanic islands that formed at the triple junction of the North American, Eurasian and African (Nubian) tectonic plates. These volcanic islands were the sites of several eruptions and destructive earthquakes since human settlement in the 15th century. S. Miguel Island, the largest and most densely populated island of the Azores, hosts three active strato-volcanoes with calderas. Furnas Volcano is one of these. Its eruptive activity has been essentially explosive, involving magmas with trachytic (s.l.) composition. In the last 5000 years at least 10 explosive eruptions occurred inside the caldera of Furnas. The last one occurred in 1630 and was subplinian in character. Since then an intense hydrothermal activity has persisted, involving four main fumarolic fields, thermal springs, CO2-rich springs, several soil diffuse degassing areas (CO2 and 222Rn), as well as occasional hydrothermal explosions. In the past decade we have developed a radon survey of Furnas hydrothermal manifestations. Here we report on the radon survey of twelve water springs, located inside the caldera, and representative of the different water types encountered at the volcano (orthothermal, thermal and CO2-rich springs). Bimonthly sampling and determination of radon activity and water temperature was performed in the selected springs between years 2007 and 2011. At each sampling point two water samples were collected for radon dosing in laboratory with the RAD7 equipment. A decay correction was applied to each sample. The average radon activities were found to vary between 1.15 Bq/L and 29.77 Bq/L, while water temperatures ranged between 16.5 °C and 76.2 °C. As a whole radon activities inversely correlate with water temperature, with orthothermal springs showing higher radon activity than thermal springs. Temporal variations in both parameters appear to be mainly determined by seasonal variations of

  9. Temporal variability of atmospheric radon-222 concentration at Gosan Station, Jeju Island, Korea, during 2009-2013

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jung Min; Kim, Won Hyung; Kang, Chang Hee [Dept. of Chemistry, Jeju National University, Jeju (Korea, Republic of); Lee, Hae Young; Lee, Chul Kyu [Korea Global Atmosphere Watch Center, Korea Meteorological Administration, ChungNam (Korea, Republic of); Chambers, S.; Williams, A. G. [Australian Nuclear Science and Technology Organisation, Kirrawee DC (Australia)

    2015-02-15

    Atmospheric radon-222 (radon) measurements were made from 2009 to 2013 at the Gosan station of Jeju Island, one of the cleanest regions in Korea, in order to characterize the temporal variability (on diurnal, seasonal, and annual scales) and analyze the influence of changing air mass transport pathways on observed radon concentrations. The mean hourly radon concentration over the whole period was 2441 ± 1037 mBq/m{sup 3}. The seasonal cycle of radon at the Gosan station was characterized by a fall maximum and summer minimum, consistent with a reduction in nonfrozen terrestrial fetch from fall to summer. In order, the seasonal mean radon concentrations were 2962 mBq/m{sup 3} (fall) >2907 mBq/m{sup 3} (winter) >2219 mBq/m{sup 3} (spring) >1756 mBq/m{sup 3} (summer). Based on a 5-year composite, the maximum mean monthly radon concentration in October (3100 mBq/m{sup 3}) was more than twice the July minimum (1471 mBq/m{sup 3}). Diurnal composite radon concentrations for the whole period increased throughout the night to a maximum of 2788 mBq/m{sup 3} at around 7 a.m., and then gradually decreased to a minimum of 2050 mBq/m{sup 3} at around 3 p.m. The winter diurnal cycle had a small amplitude due to the low variability in atmospheric mixing depth associated with recent air mass fetch over the Yellow Sea. The diurnal cycle in summer, however, exhibited a relatively large amplitude due to changes in atmospheric mixing depth associated with recent fetch over Jeju Island. Back trajectory analysis showed that high radon events were typically associated with long-term air mass fetch over continental Asia. Specifically, the average radon concentration of air masses originating from China was about 2.4 times higher than that of air masses originating from the North Pacific Ocean.

  10. Temporal variability of atmospheric radon-222 concentration at Gosan Station, Jeju Island, Korea, during 2009-2013

    International Nuclear Information System (INIS)

    Song, Jung Min; Kim, Won Hyung; Kang, Chang Hee; Lee, Hae Young; Lee, Chul Kyu; Chambers, S.; Williams, A. G.

    2015-01-01

    Atmospheric radon-222 (radon) measurements were made from 2009 to 2013 at the Gosan station of Jeju Island, one of the cleanest regions in Korea, in order to characterize the temporal variability (on diurnal, seasonal, and annual scales) and analyze the influence of changing air mass transport pathways on observed radon concentrations. The mean hourly radon concentration over the whole period was 2441 ± 1037 mBq/m"3. The seasonal cycle of radon at the Gosan station was characterized by a fall maximum and summer minimum, consistent with a reduction in nonfrozen terrestrial fetch from fall to summer. In order, the seasonal mean radon concentrations were 2962 mBq/m"3 (fall) >2907 mBq/m"3 (winter) >2219 mBq/m"3 (spring) >1756 mBq/m"3 (summer). Based on a 5-year composite, the maximum mean monthly radon concentration in October (3100 mBq/m"3) was more than twice the July minimum (1471 mBq/m"3). Diurnal composite radon concentrations for the whole period increased throughout the night to a maximum of 2788 mBq/m"3 at around 7 a.m., and then gradually decreased to a minimum of 2050 mBq/m"3 at around 3 p.m. The winter diurnal cycle had a small amplitude due to the low variability in atmospheric mixing depth associated with recent air mass fetch over the Yellow Sea. The diurnal cycle in summer, however, exhibited a relatively large amplitude due to changes in atmospheric mixing depth associated with recent fetch over Jeju Island. Back trajectory analysis showed that high radon events were typically associated with long-term air mass fetch over continental Asia. Specifically, the average radon concentration of air masses originating from China was about 2.4 times higher than that of air masses originating from the North Pacific Ocean

  11. Seasonal and spatial variations in Rn-222 and Rn-220 in soil gas, and implications for indoor radon levels

    International Nuclear Information System (INIS)

    Sharman, G.

    1992-01-01

    Rn-222 enters dwellings as a component of soil gas drawn from the soil by mass flow driven by the pressure difference between the house and soil beneath. In a site on Northampton Sand Ironstone (Aalenian), a preferred path of emanation (hotspot) was found. A difference of 63 Bq L -1 Rn-222 was recorded in July between this point and another 3 m away. Rn-222 in this hotspot shows 12% less variation annually than the surrounding rock. During winter, Rn-222 values within 1.6 m of the house were 44% lower than those at more than 4 m away. Rn-222 showed a 99.5% negative correlation with wind run, showing that on this soil wind pressure can significantly reduce radon in the soil at 500 mm depth. Rn-220 in soil gas correlated positively at the 99.5% level with grass and air temperatures. Rn-220 was not associated with the hotspot. (Author)

  12. Radon level and radon effective dose rate determination in Moroccan dwellings using SSNTDs

    International Nuclear Information System (INIS)

    Oufni, L.; Misdaq, M.A.; Amrane, M.

    2005-01-01

    Inhalation of radon ( 222 Rn) and its daughter product are a major source of natural radiation exposure. The measurement of radon activity in dwelling is assuming ever increasing importance. It is known from recent surveys in many countries that radon and its progeny contribute significantly to total inhalation dose and it is fairly established that radon when inhaled in large quantity causes lung disorder. Keeping this in view, the indoor radon activity level and radon effective dose rate were carried out in the dwellings of Beni-Mellal, Khouribgra and Ben Guerir cities, Morocco, using the solid state nuclear track detectors (SSNTD) technique. Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, we found that the 222 Rn effective dose rate in the studied dwellings ranges from 1.01 to 7.90mSvy -1 . The radon activity in the corresponding dwellings was found to vary from 40 to 532Bqm -3 . The radon activity has not only been found to vary with seasonal changes, but also with the age, the construction mode of houses, the ventilation conditions and with specific sites and geological materials

  13. Evaluation of groundwater discharge into small lakes based on the temporal distribution of radon-222

    Science.gov (United States)

    Dimova, N.T.; Burnett, W.C.

    2011-01-01

    In order to evaluate groundwater discharge into small lakes we constructed a model that is based on the budget of 222Rn (radon t1/2 5 3.8 d) as a tracer. The main assumptions in our model are that the lake's waters are wellmixed horizontally and vertically; the only significant 222Rn source is via groundwater discharge; and the only losses are due to decay and atmospheric evasion. In order to evaluate the groundwater-derived 222Rn flux, we monitored the 222Rn concentration in lake water over periods long enough (usually 1-3 d) to observe changes likely caused by variations in atmospheric exchange (primarily a function of wind speed and temperature). We then attempt to reproduce the observed record by accounting for decay and atmospheric losses and by estimating the total 222Rn input flux using an iterative approach. Our methodology was tested in two lakes in central Florida: one of which is thought to have significant groundwater inputs (Lake Haines) and another that is known not to have any groundwater inflows but requires daily groundwater augmentation from a deep aquifer (Round Lake). Model results were consistent with independent seepage meter data at both Lake Haines (positive seepage of ??? 1.6 ?? 104 m3 d-1 in Mar 2008) and at Round Lake (no net groundwater seepage). ?? 2011, by the American Society of Limnology and Oceanography, Inc.

  14. Seasonal variations of natural ventilation and radon-222 exhalation in a slightly rising dead-end tunnel.

    Science.gov (United States)

    Perrier, Frédéric; Richon, Patrick; Gautam, Umesh; Tiwari, Dilli Ram; Shrestha, Prithvi; Sapkota, Soma Nath

    2007-01-01

    The concentration activity of radon-222 has been monitored, with some interruptions, from 1997 to 2005 in the end section of a slightly rising, dead-end, 38-m long tunnel located in the Phulchoki hill, near Kathmandu, Nepal. While a high concentration varying from 6 x 10(3) Bq m(-3) to 10 x 10(3) Bq m(-3) is observed from May to September (rainy summer season), the concentration remains at a low level of about 200 Bq m(-3) from October to March (dry winter season). This reduction of radon concentration is associated with natural ventilation of the tunnel, which, contrary to expectations for a rising tunnel, takes place mainly from October to March when the outside air temperature drops below the average tunnel temperature. This interpretation is supported by temperature measurements in the atmosphere of the tunnel, a few meters away from the entrance. The temporal variations of the diurnal amplitude of this temperature indeed follow the ventilation rate deduced from the radon measurements. In the absence of significant ventilation (summer season), the radon exhalation flux at the rock surface into the tunnel atmosphere can be inferred; it exhibits a yearly variation with additional transient reductions associated with heavy rainfall, likely to be due to water infiltration. No effect of atmospheric pressure variations on the radon concentration is observed in this tunnel. This experiment illustrates how small differences in the location and geometry of a tunnel can lead to vastly different behaviours of the radon concentration versus time. This observation has consequences for the estimation of the dose rate and the practicability of radon monitoring for tectonic purposes in underground environments.

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

    International Nuclear Information System (INIS)

    Stieglitz, Thomas C.; Cook, Peter G.; Burnett, William C.

    2010-01-01

    The radon isotope 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.

  16. MODELO PARA DETERMINAR FUNÇÕES TRANSFERÊNCIA PARA ANÁLISE DE ESTABILIDADE DE VANTS

    Directory of Open Access Journals (Sweden)

    Igor Mayer Soares

    2017-01-01

    Full Text Available Neste trabalho foi apresentado um modelo para determinar as funções de transferência para análise da estabilidade longitudinal de Veículos Aéreos Não Tripulados (VANT através do desenvolvimento simplificado das equações do movimento de aeronaves. O sistema foi simplificado considerando que o motor e o arrasto na superfície de comando não influenciam na dinâmica do veículo, pois o mesmo é significativamente menor que um avião. Analisamos também a resposta em função do tempo para as deflexões das superfícies de comando. Nos resultados apresentados é possível perceber que mesmo simples, o modelo oferece uma boa aproximação para análise dinâmica de VANTs e predizer sua estabilidade e qualidade de voo.

  17. 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...

  18. Estimation of the radiological risk related to the presence of radon 222 in a hydrotherapy centre in Tunisia

    International Nuclear Information System (INIS)

    Labidi, S; Essafi, F; Mahjoubi, H

    2006-01-01

    The 222 Rn concentration in air was measured in a thermal water spa used as a hydrotherapy centre in Tunisia. The associated health risk for employees and patients due to the inhalation of 222 Rn and its progeny was estimated. A protection scheme for the employees of the spas has been designed. Results show that the 222 Rn concentration varies in the range 33-589 Bq m -3 . The 222 Rn concentrations measured in the present study show lower values in comparison to those reported for thermal spas in other countries. The 222 Rn concentration in different rooms of the spa depends mainly on the ventilation rate. A model based on a dosimetric approach was adopted to estimate the radon risk considering the 222 Rn concentration, the time spent in the spa, and the radioactive equilibrium factor F. The annual effective dose was found to vary between 0.2 and 1.7 mSv for workers while the range for patients was from 2.8 x 10 -4 to 1.1 x 10 -4 mSv. These values are within the ICRP recommended values. (note)

  19. Estimation of the radiological risk related to the presence of radon 222 in a hydrotherapy centre in Tunisia

    Energy Technology Data Exchange (ETDEWEB)

    Labidi, S [Institut Superieur des Technologies Medicales de Tunis (Tunisia); Essafi, F [Faculte de Medecine de Tunis, Section de Biophysique, Tunis (Tunisia); Mahjoubi, H [Institut Superieur des Technologies Medicales de Tunis (Tunisia)

    2006-09-15

    The {sup 222}Rn concentration in air was measured in a thermal water spa used as a hydrotherapy centre in Tunisia. The associated health risk for employees and patients due to the inhalation of {sup 222}Rn and its progeny was estimated. A protection scheme for the employees of the spas has been designed. Results show that the {sup 222}Rn concentration varies in the range 33-589 Bq m{sup -3}. The {sup 222}Rn concentrations measured in the present study show lower values in comparison to those reported for thermal spas in other countries. The {sup 222}Rn concentration in different rooms of the spa depends mainly on the ventilation rate. A model based on a dosimetric approach was adopted to estimate the radon risk considering the {sup 222}Rn concentration, the time spent in the spa, and the radioactive equilibrium factor F. The annual effective dose was found to vary between 0.2 and 1.7 mSv for workers while the range for patients was from 2.8 x 10{sup -4} to 1.1 x 10{sup -4} mSv. These values are within the ICRP recommended values. (note)

  20. Measurement of airborne concentrations of radon-220 daughter products by alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Kerr, G.D.; Ryan, M.T.; Perdue, P.T.

    1978-01-01

    The decay of naturally occurring uranium-238 and thorium-232 produces radon-222 and radon-220 isotopes which can escape into the atmosphere. If these radon gases become concentrated in air, their daughter products may present an inhalation hazard to man. The airborne concentrations of radon-222 can usually be measured very accurately in the presence of normal airborne concentrations of radon-220 and its daughters. In contrast, the measurements of the airborne concentrations of radon-220 daughters are usually complicated by the presence of radon-222 and its daughters even at normally occurring airborne concentrations. The complications involved in these measurements can be overcome in most situations by using an alpha particle spectrometer to distinguish the activity of radon-222 daughters from that due to radon-220 daughters collected on a filter. A practical spectrometer for field measurements of alpha particle activity on a filter is discussed

  1. Emanation of radon-222 in uraniferous phosphorite from Pernambuco, Brazil; Emanação de radônio-222 em fosforito uranífero de Pernambuco

    Energy Technology Data Exchange (ETDEWEB)

    Santos, M.L.O.; França, E.J.; Amaral, D.S.; Silva, K.E.M.; Hazin, C.A.; Farias, E.E.G., E-mail: emersonemiliano@yahoo.com.br [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2017-07-01

    The concentration of radon-222 activity available for transport to the surface through the pore space can be defined as radon emanation. From the decay of radium-226, whose half-life is 1850 years, it is associated with the development of neoplasia, such as lung cancer. In the Metropolitan Region of Recife, sedimentary rocks known as phosphorites have been known since 1959, so, from the radiometric characterization of the Paulista and Igarassu Municipality, in Pernambuco, emanation tests were carried out, aiming to determine the emanation power of radon in samples of uraniferous phosphorite from the Recife Metropolitan Region. Initially, 6 independent samples of phosphorites with activity concentration of {sup 226}Ra> 400 Bq kg{sup -1} were comminuted. Portions of 5g were conditioned in a radon chamber with 500 mL volume for measurements. The linear fit of the model converged after 200 interactions with selection of the best fit by the Chi-Square test, through the Origin® 8.0 program. After analysis of the samples, radon emanation power was estimated in the range of 7% to 15%, with a mean value of 10.8%. The methodology used to determine the emanation parameters in samples of uraniferous phosphorite was adequate, observing an inversely proportional relation between the concentration of the radium-226 and the emanation power.

  2. Radon-222 in boundary layer and free tropospheric continental outflow events at three ACE-Asia sites

    OpenAIRE

    Zahorowski, Wlodek; Chambers, Scott; Wang, Tao; Kang, Chang-Hee; Uno, Itsushi; Poon, Steven; Oh, Sung-Nam; Werczynski, Sylvester; Kim, Jiyoung; Henderson-Sellers, Ann

    2011-01-01

    A 1-year record of hourly atmospheric radon-222 concentration observations at three ACE-Asia network sites—Hok Tsui (Hong Kong), Gosan (Jeju Island) and Mauna Loa Observatory (Hawaii)—is presented and discussed. The observations include the spring 2001 ACE-Asia intensive operation period. Site locations were chosen for the experimental characterization of both boundary layer (Hok Tsui, Gosan) and free tropospheric (Mauna Loa) continental outflow to the Pacific. A significant seasonal variabil...

  3. The therapeutic use of radon; Radon als Heilmittel

    Energy Technology Data Exchange (ETDEWEB)

    Deetjen, P [Innsbruck Univ. (Austria). Inst. fuer Physiologie und Balneologie

    1995-09-01

    Spas with a somewhat elevated concentration of Radon{sup 222} (between 300 and 3000 Bq/l) are described to achieve good clinical results in the treatment of chronic rheumatic diseases. Recently a prospective randomized doubel-blind-study proved the pain reducing efficacy of Radon therapy in patients with cervical pain. Studies in experimental animal models have accumulated remarkable data in tissues and organs that provide a rationale to explain the observed effects of Radon therapy in patients. (orig.) [Deutsch] In verschiedenen europaeischen und asiatischen Laendern werden oft schon seit vielen Jahrhunderten Quellen als besonders heilkraeftig beschrieben, die eine etwas erhoehte Aktivitaet an Radon{sup 222} aufweisen (etwas zwischen 300 und 3000 Bq/l). Neuerdings liegt auch eine prospektive randomisierte Doppelblind-Studie vor, die den klinischen Nachweis der Schmerzlinderung durch eine Radonkur erbringt. In tierexperimentellen Untersuchungen wurden unter Radonexposition zahlreiche stimulierende Effekte auf Zellstoffwechsel, Immunabwehr, Abbau toxischer Radikale, DNA-Reparatur-Systeme oder Synthese von Mediatorsubstanzen gemessen, die rationale Ansaetze fuer das Verstaendnis der Wirkung einer Radonexposition im niedrigen Dosisbereich ergeben. (orig.)

  4. Analyses of atmospheric radon 222 / canisters exposed by Greenpeace in Niger (Arlit / Akokan sector); Analyses du radon 222 dans l'air ambiant / Capteurs exposes par Greenpeace au Niger (secteur Arlit et Akokan)

    Energy Technology Data Exchange (ETDEWEB)

    Chareyron, B.

    2010-07-01

    The companies SOMAIR and COMINAK, subsidiaries of the AREVA group, are mining uranium deposits in northern Niger. In the course of a field mission carried out in November 2009, a Greenpeace International team deposited detectors (canisters of activated charcoal) to measure radon 222, a radioactive gas formed by the decay of the radium 226 present in the uranium ore. This report includes the results of the analysis of the activated charcoal canisters conducted in CRIIRAD's laboratory, and a brief commentary on the interpretation of the results. (authors)

  5. 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.

  6. Online {sup 222}Rn removal by cryogenic distillation in the XENON100 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Messina, M.; Plante, G.; Rizzo, A.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Orrigo, S.E.A.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L.; Franco, D.; Galloway, M.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wei, Y.; Wulf, J. [University of Zurich, Physik-Institut, Zurich (Switzerland); Bauermeister, B. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Stockholm University, AlbaNova, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Undagoitia, T.M.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G.; Gallo Rosso, A.; Molinario, A. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); Budnik, R.; Duchovni, E.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. v. [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Calven, J.; Conrad, J.; Ferella, A.D.; Pelssers, B. [Stockholm University, AlbaNova, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Cervantes, M.; Lang, R.F.; Masson, D.; Pienaar, J.; Reichard, S.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Cussonneau, J.P.; Diglio, S.; Le Calloch, M.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [Universite de Nantes, SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (France); Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN, Bologna (Italy); Fei, J.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Murra, M.; Rosendahl, S.; Weinheimer, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Grandi, L.; Saldanha, R.; Shockley, E.; Upole, N. [University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Lindemann, S. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Meng, Y.; Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Miguez, B.; Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Lavina, L.S. [LPNHE, Universite Pierre et Marie Curie, Universite Paris Diderot, CNRS/IN2P3, Paris (France); Tunnell, C. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Cristescu, I. [Karlsruhe Institute of Technology, Tritium Laboratory Karlsruhe, Eggenstein-Leopoldshafen (Germany); Collaboration: XENON Collaboration

    2017-06-15

    We describe the purification of xenon from traces of the radioactive noble gas radon using a cryogenic distillation column. The distillation column was integrated into the gas purification loop of the XENON100 detector for online radon removal. This enabled us to significantly reduce the constant {sup 222}Rn background originating from radon emanation. After inserting an auxiliary {sup 222}Rn emanation source in the gas loop, we determined a radon reduction factor of R > 27 (95% C.L.) for the distillation column by monitoring the {sup 222}Rn activity concentration inside the XENON100 detector. (orig.)

  7. Radon-222 in boundary layer and free tropospheric continental outflow events at three ACE-Asia sites

    International Nuclear Information System (INIS)

    Zahorowski, Wlodek; Chambers, Scott; Wang Tao

    2005-01-01

    A 1-year record of hourly atmospheric radon-222 concentration observations at three ACE-Asia network sites Hok Tsui (Hong Kong), Gosan (Jeju Island) and Mauna Loa Observatory (Hawaii) is presented and discussed. The observations include the spring 2001 ACE-Asia intensive operation period. Site locations were chosen for the experimental characterization of both boundary layer (Hok Tsui, Gosan) and free tropospheric (Mauna Loa) continental outflow to the Pacific. A significant seasonal variability in background radon concentration is quantified at each site with the ratios of winter maximum to summer minimum background of 96, 15 and 3 for Hok Tsui, Gosan and Mauna Loa, respectively. Only during summer were background radon concentrations directly comparable with unperturbed marine values (20 mBq/m 3 ). The variability in radon signal was characterized at each site on diurnal to seasonal timescales. The seasonal variability in fetch regions for air masses experiencing the greatest and smallest terrestrial influence was characterized using 10-day back trajectories of air masses corresponding to radon concentrations higher (lower) than the 90th (10th) percentile value. The trajectory analyses for Hok Tsui and Gosan, as well as a direct analysis of the experimental results, further supports the previously postulated existence of a strong spatial heterogeneity in the radon source strength in East Asia. Back trajectories of free tropospheric air masses reaching Mauna Loa indicated source regions deep within the Asian continent primarily between 20 and 40 deg N. This fetch region is different from that influencing the Hok Tsui and Gosan sites. The radon concentration of air masses reaching Mauna Loa was shown to vary seasonally as well as with latitude of the predominant fetch region. Possible mechanisms of this phenomenon have been identified and include (a) seasonal variation in the radon source, (b) seasonal variation in the strength, frequency and/or efficiency of

  8. Mapping of 222Rn and 4He in soil gas over a karstic limestone-granite boundary: correlation of high indoor 222Rn with zones of enhanced permeability

    International Nuclear Information System (INIS)

    O'Connor, P.J.; Gallagher, V.; Van den Boom, G.

    1992-01-01

    Recent indoor radon reconnaissance surveys in Ireland have identified buildings with high radon concentrations (up to 1700 Bq.m -3 ) overlying Carboniferous karstic limestone sequences in the western part of the country. A detailed investigation of indoor 222 Rn and soil gas 222 Rn and 4 He concentrations has been carried out over a karstic limestone-uraniferous granite boundary in County Galway. High indoor 222 Rn concentrations occur in dwellings over both lithologies. Radon migratory routes in bedrock and overburden appear to be controlled by zones of enhanced permeability, e.g. fractures, faults, etc. which are defined by linear arrays of elevated 4 He soil gas values. While the ultimate source of radon remains conjectural, the greatly enhanced permeability of karstified limestone is thought to be of fundamental importance in providing a means of rapid radon transport into overlying soils and buildings. (author)

  9. Rapid determination of radon daughter concentrations

    International Nuclear Information System (INIS)

    Bigu, J.

    1990-08-01

    A technical evaluation of four radon 222 progeny measuring instruments has been conducted. The evaluation has been carried out under laboratory controlled conditions and at several locations in an underground uranium mine. The laboratory evaluation consisted of a thorough study of the behaviour and performance of the instruments under a wide variety of environmental conditions such as radon 222 gas concentration, radon 222 progeny concentration, temperature, relative humidity, aerosol concentration, and gamma-field exposure. The four instruments tested were: the Pylon WL-1000C, the MDA IWLM-811, the MIMIL IIM, and the EDA WLM-30. The readings of the instruments were compared with a widely accepted radon 222 progeny concentration measuring method, namely, the Thomas-Tsivoglou method. Two variables affected two instruments significantly, namely, under high aerosol concentration conditions, one of the instruments (EDA WLM-30) ceased to operate because of filter loading. The other variable was gamma-field exposure which affected another instrument (MDA-811) adversely. The instruments were rated according to several criteria. The overall best performer was the MIMIL IIM, although other instruments also fared quite well under a variety of experimental conditions

  10. Temporal behavior of 222Radon, 226Radium and 238Uranium in deep water wells which provide Valle de Toluca with drinking water

    International Nuclear Information System (INIS)

    Pena, P.; Tamez, E.; Iturbe, J.L.; Acosta, A.; Segovia, N.; Carrillo, J.; Armienta, M.

    1994-01-01

    The presence of radionuclides in underground waters may be an indication of its origin and also the sign of the hydraulic properties of the aquifers layers where circulate. Additionally, the ingestion by human beings of water with radioactive elements (Radon 222, Radium 226, Uranium 238) can give as a result the accumulation of such elements in several organs of the body producing then health damages. In this work, the concentrations of Radon 222, Radium 226 and Uranium 238, in waters coming from deep wells which provide with drinking water the Toluca Valley, were determined. For this purpose, during a year (june 1991 to August 1992) ten wells were sampled with a tracking of the radionuclides concentration as well as the physical-chemical components of water; it was established the relationship presented by the analyzed waters with the local geology and the local and regional systems. (Author)

  11. Radon-222 and beryllium-7 as natural tracer; Radon-222 und Beryllium-7 als natuerliche Tracer

    Energy Technology Data Exchange (ETDEWEB)

    Frank, G.; Steinkopff, T. [Deutscher Wetterdienst, Offenbach (Germany). Radioaktivitaetsueberwachung; Salvamoser, J. [Institut fuer Angewandte Isotopen-, Gas- und Umweltuntersuchungen (IGU), Woerthsee (Germany)

    2016-07-01

    The Global Atmosphere Watch Program (GAW) is intended to analyse worldwide the influence of anthropogenic emissions to the atmosphere. Data are continuously transferred to the ''World Data Centre for Green House Gases'' of the WMO. For the study of atmospheric transports the natural radionuclides Rn-222, Be-7, Pb-210, Pb- 214 and Bi-214 are continuously measured at the Umweltforschungsstation Schneefernerhaus (2650 m) and at the Zugspitze (2962 m) by the Deutscher Wetterdienst (DWD, German Weather Service). The measurements support the classification of atmospheric transport, atmospheric dilution and dispersion models of gaseous and aerosol bond micro pollutants. Results are carried out in combination with meteorological data. It is shown the optimization and effect of a new sampling site for the measurement of Rn-222 activity at the Zugspitze. Results of Rn-222 and Be-7 concentrations are shown in relation to horizontal and vertical dispersion of air masses. The origin of natural Rn-222 and Be-7 are known, therefore both nuclides are well suited for the research of atmospheric transport. Rn-222 is an ideal tracer, because there is no influence by atmospheric processes (chemical processes, wash out effects).

  12. A continuous monitor for the measurement of environmental radon

    International Nuclear Information System (INIS)

    Chittaporn, P.; Eisenbud, M.; Harley, N.H.

    1981-01-01

    Although inhaled short-lived 222 Rn daughters deliver the pertinent α dose for assessing human health effects, radon daughters do not of themselves exist in any atmosphere for more than 2-3 hr. Their long-lived parent (3.82 day) 222 Rn supports the daughter activity and it is the transport of 222 Rn which ultimately determines dose. Without an understanding of the long and short-term temporal patterns of indoor and outdoor 222 Rn it is impossible to understand the factors which are important in establishing any human health hazard from the daughters. This work describes a new continuous environmental radon monitor which measures radon alone without interference from radon daughters. The detector is a cylinder (13 cm diameter x 14 cm high), is lined with alpha scintillation phospor on a Mylar substrate and is portable and easily constructed from inexpensive and commercially available materials. (author)

  13. Genetic effects of radon 222 in a population of Drosophila melanogaster chronically exposed

    International Nuclear Information System (INIS)

    Salceda, V.M.

    1997-01-01

    It was investigated the mutagenic effect of Radon 222 during a experimental period of 11 generations. In this lapse Drosophila melanogaster larvae line Canton-S were maintained in a radon atmosphere. In each test generation had been extracted males, consequently exposed to radiation which were subjected to a crossing series with a bearer marker genes of according to the Wallace experimental design (1956). Due to the experimental conditions it only was determined the recessive lethal mutations frequency for the second chromosome in the 1,4,7 and 11 generations. Of all study it was conduced in parallel way a non-treated witness population. The concentrations at which was subjected the experimental population varied of generation to generation from 12 ± 2 to 43 ± 5 kBq/m 3 . Our analysis correspond to lethality determination in 1182 second chromosomes distributed between two populations and the different exposition generations. The study allow to determine the respective frequencies of recessive lethal genes varying according to the population and/or generation between 10.53 and 22.02%. The statistical analysis of data did not show significant differences among the different populations. (Author)

  14. Radon depletion in xenon boil-off gas

    Energy Technology Data Exchange (ETDEWEB)

    Bruenner, S.; Cichon, D.; Lindemann, S.; Undagoitia, T.M.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2017-03-15

    An important background in detectors using liquid xenon for rare event searches arises from the decays of radon and its daughters. We report for the first time a reduction of {sup 222}Rn in the gas phase above a liquid xenon reservoir. We show a reduction factor of >or similar 4 for the {sup 222}Rn concentration in boil-off xenon gas compared to the radon enriched liquid phase. A semiconductor-based α-detector and miniaturized proportional counters are used to detect the radon. As the radon depletion in the boil-off gas is understood as a single-stage distillation process, this result establishes the suitability of cryogenic distillation to separate radon from xenon down to the 10{sup -15} mol/mol level. (orig.)

  15. 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.

  16. Temporal behavior of {sup 222}Radon, {sup 226}Radium and {sup 238}Uranium in deep water wells which provide Valle de Toluca with drinking water; Comportamiento temporal de {sup 222}Radon, {sup 226}Radio y {sup 238}Uranio en pozos profundos que abastecen de agua potable al Valle de Toluca

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P; Tamez, E; Iturbe, J L; Acosta, A; Segovia, N [Instituto Nacional de Investigaciones Nucleares, Mexico City (Mexico); Carrillo, J; Armienta, M [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Geofisica

    1994-12-31

    The presence of radionuclides in underground waters may be an indication of its origin and also the sign of the hydraulic properties of the aquifers layers where circulate. Additionally, the ingestion by human beings of water with radioactive elements (Radon 222, Radium 226, Uranium 238) can give as a result the accumulation of such elements in several organs of the body producing then health damages. In this work, the concentrations of Radon 222, Radium 226 and Uranium 238, in waters coming from deep wells which provide with drinking water the Toluca Valley, were determined. For this purpose, during a year (june 1991 to August 1992) ten wells were sampled with a tracking of the radionuclides concentration as well as the physical-chemical components of water; it was established the relationship presented by the analyzed waters with the local geology and the local and regional systems. (Author).

  17. A long range transport model of Rn-222

    International Nuclear Information System (INIS)

    Ikebe, Y.; Kojima, S.; Shimo, M.

    1993-01-01

    In this report, we propose an analytical treatment about temporal variation of 222 Rn concentration in the atmosphere with an aim to clarify origin and transport of 222 Rn. Based on the results of numerical simulation of radon, we separate the 222 Re concentration measured at Nagoya into the following two components : (1) 222 Rn atom originated near from the measuring site, which is denoted by 'diurnal variation component'. From numerical simulation of radon, it has been shown that the measured diurnal variation can be explained by this component. (2) 222 Rn atoms originated far from the measuring site (including Chinese Continent), which is denoted by 'background component'. For this component, we propose here a one layer transport model using air mass trajectory technique. By this model we can explain the temporal variation of background component and seasonal variation of 222 Rn at Nagoya. (3 figs.)

  18. Evaluation of {sup 222}Rn concentration of the internal and external environments of residences at Monte Alegre municipality, Para, Brazil; Avaliacao da concentracao do {sup 222}Rn nos ambientes internos e externos de residencias do municipio de Monte Alegre, PA

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Vicente de Paula

    1999-07-01

    The human being is constantly exposed to the natural radioactivity in the environment where he lives. This radioactivity comes mainly from materials present in the terrestrial crust that possess in their constitution chemical elements belonging to the radioactive families of uranium and thorium. The use of such materials for the construction of houses constitutes an important exposure form to the natural radiation, above all to the radioactive gas {sup 222}Rn, that it is exhaled from them. The Brazilian soil is composed, among other, of minerals that contain appreciable concentrations of these elements. The inhabitants of Monte Alegre town in Para, located at 2 deg 00' 24,9 'S ; 54 deg 04 ' 13,5 {sup W}, used in the construction of their houses stones obtained from an area 20 km distant of Monte Alegre, denominated Ingles de Souza, located at 01 deg 56' 4 0,1 S; 54 deg 12 149,7 W, where a small residential village, denominated National Agricultural Colony of Para (CANP), is located. The objective of this work was to evaluate the indoor concentration of {sup 222}Rn in the residences of Monte Alegre and CANP. Determinations of the {sup 238}U and {sup 226}Ra concentrations, measurements of the radon flux in samples of stones and soils of the two regions, as well as measurements to the gamma dose close of the soil and inside the residences, were also carried out. The average results of the radon concentration in the air of the investigated residences did not exceed the limits of 200 Bq. m{sup 3} (action level) and 600 Bq. m{sup 3} (intervention level) recommended by the International Commission on Radiological Protection (ICRP). The concentrations of natural radionuclides and the radon flux determined at the village showed values 17 times higher than those found at the urban area of Monte Alegre, while the average indoor gamma dose rate in the village residences was 0.86 mSv/a. (author)

  19. Evaluation of {sup 222}Rn concentration of the internal and external environments of residences at Monte Alegre municipality, Para, Brazil; Avaliacao da concentracao do {sup 222}Rn nos ambientes internos e externos de residencias do municipio de Monte Alegre, PA

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Vicente de Paula

    1999-07-01

    The human being is constantly exposed to the natural radioactivity in the environment where he lives. This radioactivity comes mainly from materials present in the terrestrial crust that possess in their constitution chemical elements belonging to the radioactive families of uranium and thorium. The use of such materials for the construction of houses constitutes an important exposure form to the natural radiation, above all to the radioactive gas {sup 222}Rn, that it is exhaled from them. The Brazilian soil is composed, among other, of minerals that contain appreciable concentrations of these elements. The inhabitants of Monte Alegre town in Para, located at 2 deg 00' 24,9 'S ; 54 deg 04 ' 13,5 {sup W}, used in the construction of their houses stones obtained from an area 20 km distant of Monte Alegre, denominated Ingles de Souza, located at 01 deg 56' 4 0,1 S; 54 deg 12 149,7 W, where a small residential village, denominated National Agricultural Colony of Para (CANP), is located. The objective of this work was to evaluate the indoor concentration of {sup 222}Rn in the residences of Monte Alegre and CANP. Determinations of the {sup 238}U and {sup 226}Ra concentrations, measurements of the radon flux in samples of stones and soils of the two regions, as well as measurements to the gamma dose close of the soil and inside the residences, were also carried out. The average results of the radon concentration in the air of the investigated residences did not exceed the limits of 200 Bq. m{sup 3} (action level) and 600 Bq. m{sup 3} (intervention level) recommended by the International Commission on Radiological Protection (ICRP). The concentrations of natural radionuclides and the radon flux determined at the village showed values 17 times higher than those found at the urban area of Monte Alegre, while the average indoor gamma dose rate in the village residences was 0.86 mSv/a. (author)

  20. Some basic facts about radioactive radon

    International Nuclear Information System (INIS)

    Duval, J.S.; Tanner, A.B.

    1990-01-01

    This article presents some basic facts about 222 Rn. These facts include: half-life; diffusion patterns; how radon enters a house; health risks; and means of definition and estimation of radon hazard potential

  1. Using radon-222 for tracing groundwater discharge into an open-pit lignite mining lake--a case study.

    Science.gov (United States)

    Schmidt, Axel; Schubert, Michael

    2007-12-01

    Groundwater discharge into an open pit lignite mining lake was investigated using radon-222 as a naturally occurring environmental tracer. The chosen study site was a meromictic lake, i.e., a water body that is divided horizontally into two separate layers--the upper mixolimnion (with seasonal mixing) and the lower monimolimnion (without seasonal mixing). For the estimation of groundwater discharge rates into the lake, a simple box model including all radon sinks and sources related to each layer was applied. Two field investigations were performed. During the October campaign, the total groundwater discharge into the lake was found to be 18.9 and 0.7 m(3) d(-1) for the mixolimnion and monimolimnion, respectively. During the December campaign, the groundwater discharge into the mixolimnion was 15.0 m(3) d(-1), whereas no discharge at all was observed into the monimolimnion. Based on the given water volumes, the residence time of lake water was 5.3 years for the monimolimnion and varies between 0.9 and 1.1 years for the mixolimnion. The investigation confirmed radon to be a useful environmental tracer for groundwater and surface water interactions in meromictic lake environments.

  2. Contribution to the characterization of 222-radon concentrations variability in water to the understanding of an aquifer behaviour in fractured medium: example of the Ploemeur site, Morbihan

    International Nuclear Information System (INIS)

    Le Druillennec, Th.

    2007-06-01

    Heterogeneous fractured aquifers which developed in crystalline rocks, such as schist or granite, supply 20% of tap water production of Brittany. These fractured media present a large range of permeability. In these aquifers, fluid flow and transport of elements dissolved in water are strongly related on the geometry of the fractured network. Increasing the knowledge of the hydrogeological behaviour of the aquifer is fundamental for the management and the protection of the groundwater resources. Radon-222 is a radioactive noble gas produced from radium-226 further to the radioactive decay of uranium-238; it occurs naturally in ground waters and derives primarily from U-rich rocks and minerals that have been in contact with water. Radon-222 concentrations in waters are liable to provide significant and relevant information on both the geometry of a fracture network and the flow distribution. Furthermore, radon may also be used as a tracer in the aquifer of water exchanges between zones of variable permeability. Three main results were obtained in this study: 1. An accurate characterisation of the radon concentrations in water was carried out in the Ploemeur aquifer (Brittany, France). These results highlight the variability in the spatial and vertical distributions of 222 Rn activity in groundwater together with a wide range of concentrations extending from 0 to 1 500 Bq.L -1 . 2. The influence of fracture aperture on radon content in groundwater has been demonstrated with the modelling of radon concentration. Indeed, the satisfactory results obtained with a simple crack model highlight that the geometry of the fracture network controls the radon activity in groundwater. 3. Thus, the results of pumping tests performed in the boreholes improved our understanding of the system. After the pumping test, an increase of the radon content in groundwater occurred and evidenced a contribution of a radon-rich water to supply the flow rate that seems to come from the low

  3. Determination of 222Rn levels in houses, schools and hotels of Ramsar by AEOI passive radon diffusion dosimeters

    International Nuclear Information System (INIS)

    Sohrabi, M.; Zainali, H.; Mahdi, Sh.; Solaymanian, A.R.; Salehi, M.

    1993-01-01

    Radon-222 levels were determined in 473 rooms of about 350 houses, 16 schools in Ramsar and its high-level natural radiation areas (HLNRAs) as well as in 89 rooms and many locations of old and new Ramsar Hotels. The AEOI (Atomic Energy Organization of Iran) Radon Diffusion Dosimeters applying electrochemical etching of polycarbonate detectors were used indoors during different seasons. The levels measured ranged from 20 to 3700 Bq.m -3 , detected in Talesh Mahalleh which has the highest natural radiation level in the area, corresponding to effective dose equivalents (H e ) up to 98.5 mSv.a -1 . The mean radon levels determined in different regions were 615 Bq.m -3 in Talesh Mahalleh, 326 Bq.m -3 in Chaparsar, 258 Bq.m -3 in schools of Ramsar and its HLNRAs, 246 Bq.m -3 in Ramak, 111 Bq.m -3 in Rasmar city, 50 Bq.m -3 in Sadat Mahalleh and Katalom, 49 Bq.m -3 Tonekabon and 27 Bq.m -3 in Talesh Mahalleh of Katalom; and 90 Be.m -3 in old and 50 Bq.m -3 in new Ramsar Hotels. It was found that houses built at a higher level above the ground even in the areas with the highest gamma exposures have lower radon levels compared to those built directly on the ground. The results of the radon levels determined in the above regions indoors are presented. (author). 10 refs, 9 figs, 3 tabs

  4. Radon-222 as communication and information tool about natural radioactivity

    International Nuclear Information System (INIS)

    Pelliccione, Nina Beatriz B.; Gouvea, Rita de Cassia S.; Kelecom, Alphonse; Gouvea, Vandir A.

    2005-01-01

    The nuclear area still suffers from the psychological impact caused by the atomic bombs detonated at Hiroshima and Nagasaki, and also from the Chernobyl plant explosion. This situation results from two main reasons: manipulation of public opinion and lack of suitable information. In general, knowledge about radioactivity is very superficial, impregnated by preconceived notions transmitted by the media or by pacific organizations and ecologic groups. Rejection attitudes are observed among most of the general public that expresses an opinion although it does not know the subject. To change this situation has been the major challenge of the nuclear sector and needs to better communication with people at large. To teach is fundamental. This work reports on a didactic experiment carried out with 130 under graduating and graduating students in Biology and Environmental Science from the Fluminense Federal University. The goal was to try to perceive the existence of a natural radioactivity, hence not related to human activities, through radon-222 dosage. This practice complements the theoretical lessons, as it illustrates properties of ionizing radiation, and can easily be transposed to the general public. The monitoring equipment works detecting nuclear tracks. It is an easy to handle small and light device - hence friendly, to be put in the most used room of each one's house. It is taught how to use it and how to give correct information to interested people. Radon measurements are discussed with the students, and at the same time they perceive the existence of natural radioactivity, present everywhere, they start to change their own perception of radioactivity, which turns to be very different from their original nuclear imaginary. (author)

  5. Investigations into the long-distance atmospheric transport in Central Europe using Rn-222

    International Nuclear Information System (INIS)

    Volpp, H.J.

    1984-01-01

    An measuring network was used to determine the atmospheric Rn-222 content in Central Europe (Northern and Southern Germany, Poland). Rn-222 is to serve as tracer for the long-distance atmospheric transport in central Europe. For several areas, an average Rn-222 flux density was found. The radon source 'continent' and the soil as radon source have been taken into account. (DG) [de

  6. Relation between "terra rossa" from the Apulia aquifer of Italy and the radon content of groundwater: Experimental results and their applicability to radon occurrence in the aquifer

    Science.gov (United States)

    Tadolini, T.; Spizzico, M.

    The radon-222 (222Rn) activity in groundwater of the Apulian karstic aquifer in southern Italy is as great as 500 Becquerel per liter (Bq/L) locally. Normal radium-226 (226Ra) activity in the limestone and calcareous dolomites of the aquifer is not enough to explain such a high level. Laboratory investigations identified high 226Ra activity in the "terra rossa," the residuum occupying fissures and cavities in the bedrock, and also the relation between (1) 226Ra-bearing bedrock and "terra rossa" and (2) 222Rn in water. The "terra rossa" is the primary source of the radon in the groundwater. The experimental results show the need to characterize the "terra rossa" of Apulia on the basis of 226Ra activity and also to study the distribution and variations in 222Rn activity over time in the aquifer. Résumé L'activité du radon-222 (222Rn) dans les eaux souterraines de l'aquifère karstique des Pouilles, dans le sud de l'Italie, atteint localement 500 Becquerel par litre (Bq/L). L'activité normale du radium-226 (226Ra) dans les calcaires et dans les calcaires dolomitiques de l'aquifère n'est pas assez élevée pour expliquer des valeurs aussi élevées. Des analyses de laboratoire ont mis en évidence une forte activité en 226Ra dans la terra rossa, remplissage de fissures et de cavités de la roche, ainsi qu'une relation entre (1) la roche et la terra rossa contenant du 226Ra et (2) le 222Rn dans l'eau. La terra rossa est la source primaire de radon dans l'eau souterraine. Les résultats expérimentaux montrent qu'il est nécessaire de caractériser la terra rossa des Pouilles par son activité en 226Ra et d'étudier la distribution et les variations de l'activité en 222Rn au cours du temps dans l'aquifère. Resumen La actividad del radon-222 (222Rn) en el agua subterránea del acuífero cárstico de Apulia, al sur de Italia, alcanza localmente los 500Bq/L. La actividad normal del radio-226 (226Ra) en las calcitas y dolomitas del acuífero no es suficiente para

  7. Radon quantification in dwellings of different construction located in Pichincha Province

    International Nuclear Information System (INIS)

    Ayala, Maria Mercedes

    1992-01-01

    The desintegration of uranium-238 yields radon-222 present in most dwellings and buildings. Radon-222 gets into them, accumulatively, through floors and walls, domestic fuel-gas and drinking water pipes. Upon inhalation radon is cancer's causes, death-rate being about 5000 deaths per year in USA. This fact evidences the necessity to quantifying radon in dwellings in Ecuador. This research involves data from dwellings built up with different types of raw materials found spread in Pichincha province. The SSNTD method using a cellulose nitrate sensible film LR-115 was used for the research. The incidence of temperature, altitude, ventilation on the concentration gas Rn 222 were also subject of a qualitative study. Eventually, the results shows that the adobe dwellings and/or poorly ventilated dwellings produce maximum concentration of Rn 222 . Some cases show that ground floors have higher rate of Rn 222 than the first or second floors, meaning that the gas is also coming up from the ground. in any case the level of Rn 222 concentration is less than accepted limit 200 Bq/m 3 by UNCEAR only places, such as Mindo and Calderon, surpass the limit

  8. MODEL RADIOACTIVE RADON DECAY

    Directory of Open Access Journals (Sweden)

    R.I. Parovik

    2012-06-01

    Full Text Available In a model of radioactive decay of radon in the sample (222Rn. The model assumes that the probability of the decay of radon and its half-life depends on the fractal properties of the geological environment. The dependencies of the decay parameters of the fractal dimension of the medium.

  9. Contribution to the characterization of 222-radon concentrations variability in water to the understanding of an aquifer behaviour in fractured medium: example of the Ploemeur site, Morbihan; Apport de la caracterisation de la variabilite des concentrations en radon-222 dans l'eau a la comprehension du fonctionnement d'un aquifere en milieu fracture de socle: exemple du site de Ploemeur, Morbihan

    Energy Technology Data Exchange (ETDEWEB)

    Le Druillennec, Th

    2007-06-15

    Heterogeneous fractured aquifers which developed in crystalline rocks, such as schist or granite, supply 20% of tap water production of Brittany. These fractured media present a large range of permeability. In these aquifers, fluid flow and transport of elements dissolved in water are strongly related on the geometry of the fractured network. Increasing the knowledge of the hydrogeological behaviour of the aquifer is fundamental for the management and the protection of the groundwater resources. Radon-222 is a radioactive noble gas produced from radium-226 further to the radioactive decay of uranium-238; it occurs naturally in ground waters and derives primarily from U-rich rocks and minerals that have been in contact with water. Radon-222 concentrations in waters are liable to provide significant and relevant information on both the geometry of a fracture network and the flow distribution. Furthermore, radon may also be used as a tracer in the aquifer of water exchanges between zones of variable permeability. Three main results were obtained in this study: 1. An accurate characterisation of the radon concentrations in water was carried out in the Ploemeur aquifer (Brittany, France). These results highlight the variability in the spatial and vertical distributions of {sup 222}Rn activity in groundwater together with a wide range of concentrations extending from 0 to 1 500 Bq.L{sup -1}. 2. The influence of fracture aperture on radon content in groundwater has been demonstrated with the modelling of radon concentration. Indeed, the satisfactory results obtained with a simple crack model highlight that the geometry of the fracture network controls the radon activity in groundwater. 3. Thus, the results of pumping tests performed in the boreholes improved our understanding of the system. After the pumping test, an increase of the radon content in groundwater occurred and evidenced a contribution of a radon-rich water to supply the flow rate that seems to come from the

  10. Comparison of techniques active and passive in measurement of radon concentration ({sup 222}Ra) in the air; Comparacao de tecnicas ativa e passiva na medicao de concentracao de radonio ({sup 222}Rn) no ar

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Evaldo Paulo de

    2017-11-01

    The purpose of this work was to perform a study comparing radon concentration measurements between two techniques used to measure radon gas in the air: one using LEXAN polycarbonate plastic detectors and the other the continuous monitor in AlphaGUARD passive mode. The concentrations of radon gas within radon emanation chambers were measured using calibrated / traceable sources generating {sup 222}Rn through {sup 226}Ra. In calibration the 'calibration factor' or 'sensitivity' was determined for the LEXAN plastic detector. The calibration work of the dosimeters was carried out at the Radon Laboratory of the Environmental Analysis Division - DIRAD IRD/CNEN and at the Natural Radioactivity Laboratory (LRN) of the Center for the Development of Nuclear Technology (CDTN/CNEN). The 'calibration factor' or 'sensitivity' was found to be 32.34 (traits.cm{sup -2})/(kBq.d.m{sup -3}). This factor was used to determine the radon concentration measured by the LEXAN plastic detectors. Also in the calibration, the efficiencies for LEXAN (94.1% ± 9.7%) and AlphaGUARD (92.5% ± 7.2%) were determined. The statistical analysis used showed good parity in the results of the measurements. It was concluded that the results were satisfactory and will serve as a good reference for studies related to the radon air meters used in this work. (author)

  11. Estimation of the molecular hydrogen soil uptake and traffic emissions at a suburban site near Paris through hydrogen, carbon monoxide, and radon-222 semicontinuous measurements

    International Nuclear Information System (INIS)

    Yver, C.; Schmidt, M.; Bousquet, P.; Ramonet, M.; Bousquet, P.; Zahorowski, W.

    2009-01-01

    Since June 2006, simultaneous semicontinuous measurements of tropospheric molecular hydrogen (H 2 ), carbon monoxide (CO), and radon-222 ( 222 Rn) have been performed at Gif-sur-Yvette (Paris region), a suburban atmospheric measurement site in France. Molecular hydrogen mixing ratios range from 500 to 1000 ppb, CO mixing ratios vary from 100 to 1400 ppb, and 222 Rn concentrations fluctuate from 0 to 20 Bq m -3 . The H 2 seasonal cycle shows the expected pattern for the Northern Hemisphere with a maximum in spring and a minimum in autumn. We inferred a mean baseline value of 533 ppb with a peak-to-peak amplitude of 30 ppb. Carbon monoxide exhibits a seasonal cycle with a maximum in winter and a minimum in summer. The mean baseline value reaches 132 ppb with a peak-to-peak amplitude of 40 ppb. Radon-222 presents weak seasonal variations with a maximum in autumn/winter and a minimum in spring/summer. The diurnal cycles of H 2 and CO are dominated by emissions from nearby traffic with two peaks during morning and evening rush hours. The typical H 2 /CO emission ratio from traffic is found to be 0.47 ± 0.08 on a molar basis (ppb/ppb). The radon tracer method is applied to nighttime H 2 observations to estimate the H 2 soil uptake of the nocturnal catchment area of our sampling site. The influences from nocturnal local anthropogenic combustion sources are estimated by parallel measurements of CO at 0.14 * 10 -5 g(H 2 ) m -2 h -1 . The mean inferred dry deposition velocity is 0.024 ± 0.013 cm s -1 with a seasonal amplitude of 40% at Gif-sur-Yvette.

  12. Behaviors of radon in indoor environment

    International Nuclear Information System (INIS)

    Mochizuki, Sadamu; Shimo, Michikuni.

    1987-01-01

    The source of radon ( 222 Rn) in the atmosphere is radioactive nuclide, uranium ( 238 U), which exists fairly common throughout the earth's crust. Radium ( 226 Ra) descended from uranium produce radon ( 222 Rn) of noble gas by decay. After formation in the ground, radon diffuses into the atmosphere. Without exception radon decay products are heavy metals which soon become attached to natural aerosols. Therefore, radon and its daughters (decay products) appear also in indoor environment, and generally, their concentration levels become higher than that of outdoor air due to build-up effects in the closed indoor environments. With the progress of the study on the influence of radon and its daughers on human health, it has become clear that they act effectively as an exciting cause of lung cancer. So, the study on the risk evaluation of them in room air has become to be very important. Concequently, the behaviors of radon and its daughters in indoor environment, first of all, should be studied in detail for the accurate estimation of the risk caused by them. In this special edition, fundamental characteristics of radon and its daughters, some measuring methods, theoretical considerations and some observational evidences obtained from various circumstances of indoor environment are described inorder to grasp and understand the behaviors of radon and its daughters in the indoor environment. (author)

  13. Radon-222 Study in Ceramics and Indoor Air

    International Nuclear Information System (INIS)

    Moussa, N.L.A.A.

    2011-01-01

    A total 50 samples of 13 different ceramic tiles companies collected from the Egyptian market for the measurements of radon exhalation rate. Three homes include twenty rooms were selected. The period of the survey was in range 2-3 months for homes for each season while it was about 15 days for ceramic tiles. The radon exhalation rate of ceramic tiles (clay and glaze) and indoor radon activity concentration were measured by alpha tracks technique. The average radon exhalation rate in three homes was observed to be in the range 2.2-5.2 mBq.m -2 .h -1 . The average of Ra-226 activity for all ceramic tiles either the floor or wall tile is in the range 16-64 Bq.kg -1 . The porosity of ceramic tiles is found in the range 0.19-0.29. The effective dose in all rooms is found in the range 0.9- 1.3 mSv.y -1 .

  14. A multi-detector continuous monitor for assessment of 222Rn in the coastal ocean

    International Nuclear Information System (INIS)

    Dulaiova, H.; Peterson, R.; Burnett, W.C.

    2005-01-01

    Radon-222 is a good natural tracer of groundwater discharge and other physical processes in the coastal ocean. Unfortunately, its usefulness is limited by the time consuming nature of collecting individual samples and traditional analysis schemes. An automated multi-detector system is demonstrated that can be used in a continuous survey basis to assess radon activities in coastal ocean waters. The system analyses 222 Rn from a constant stream of water delivered by a submersible pump to an air-water exchanger where radon in the water phase equilibrates with radon in a closed air loop. The air stream is fed to 3 commercial radon-in-air monitors connected in parallel to determine the activity of 222 Rn. By running the detectors out of phase, it is possible to obtain as many as 6 readings per hour with a precision of approximately ±5-15% for typical coastal seawater concentrations. (author)

  15. Radon as a natural geochemical tracer for study of groundwater discharge into lakes

    International Nuclear Information System (INIS)

    Schmidt, Axel

    2008-01-01

    In the presented work the suitability of the naturally occurring radioactive noble gas isotope radon-222 for qualitative and quantitative description of groundwater discharge into lakes was studied. Basis of these investigations was the development of two innovative techniques for the on-site determination of radon in water. In the ex-situ radon measurement procedure, water from the source concerned is taken up in an exchange cell used for this purpose. Inside this cell, the radon dissolved in water is transferred via diffusion into a closed counter-flow of air and subsequently detected by a radon-in-air monitor. Where the in-situ radon determination is concerned, a module composed of a semipermeable membrane is introduced into a water column. Subsequently, the radon dissolved in the water body diffuses through the membrane into the corresponding air flow, by means of which it is transferred into a radon-in-air monitor and is detected. Combination of the developed mobile radon extraction techniques with a suitable and portable radon monitor allow the detection of radon-222 with sufficient accuracy (smaller 20 %) in groundwater as well as in surface waters, i.e., within a broad range of concentrations. Radon-222 was subsequently used to characterize groundwater discharge into a meromictic and a dimictic lake, i.e. two types of lake basically distinct from each other with respect to their water circulation properties were investigated. The use of the noble gas isotope radon-222 as a geochemical tracer makes the application of on-site detection techniques possible and that this in turn permits a rapid, reliable, and cost-effective assessment of groundwater discharge rates into lake water bodies

  16. Radon as a natural geochemical tracer for study of groundwater discharge into lakes

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Axel

    2008-06-27

    In the presented work the suitability of the naturally occurring radioactive noble gas isotope radon-222 for qualitative and quantitative description of groundwater discharge into lakes was studied. Basis of these investigations was the development of two innovative techniques for the on-site determination of radon in water. In the ex-situ radon measurement procedure, water from the source concerned is taken up in an exchange cell used for this purpose. Inside this cell, the radon dissolved in water is transferred via diffusion into a closed counter-flow of air and subsequently detected by a radon-in-air monitor. Where the in-situ radon determination is concerned, a module composed of a semipermeable membrane is introduced into a water column. Subsequently, the radon dissolved in the water body diffuses through the membrane into the corresponding air flow, by means of which it is transferred into a radon-in-air monitor and is detected. Combination of the developed mobile radon extraction techniques with a suitable and portable radon monitor allow the detection of radon-222 with sufficient accuracy (smaller 20 %) in groundwater as well as in surface waters, i.e., within a broad range of concentrations. Radon-222 was subsequently used to characterize groundwater discharge into a meromictic and a dimictic lake, i.e. two types of lake basically distinct from each other with respect to their water circulation properties were investigated. The use of the noble gas isotope radon-222 as a geochemical tracer makes the application of on-site detection techniques possible and that this in turn permits a rapid, reliable, and cost-effective assessment of groundwater discharge rates into lake water bodies.

  17. Uranium, radon-222 and polonium-210 in drinking waters from metropolitan area of Recife, PE, Brazil

    International Nuclear Information System (INIS)

    Silva, Cleomacio Miguel da

    2000-04-01

    There is only scarce information on the presence of radionuclides in water for public consumption in Brazil. A recently issued federal regulation requires that waters from public supplies be screened to determine their content of alpha and beta emitters. In order to comply with this requirement the present work was carried out with the purpose of determining the concentration of natural uranium, 222 Rn and 210 Po in water supplies in the metropolitan region of Recife, Brazil. The analyses were performed in 17 points of supply of superficial water and 94 points of groundwater supply. The concentrations of uranium were determined by the fluorimetric method, whereas the liquid scintillation method was used to determine the concentration of 222 Rn. Polonium-210, on the other hand, was determined by alpha spectrometry, following its spontaneous deposition on copper disks. The water analyzer presented uranium concentrations varying from 35.3 to 1146.5 mBq/L for superficial resources and from 20.2 to 919.15 mBq/L for underground sources. The concentration of uranium in superficial water showed significant correlation with some parameters such as conductivity, alkalinity and total hardness, as well as, with the concentrations of Ca, Mg, Cl, K, SO 4 and Mn. No correlation, however, was shown with the concentrations of Fe, NO 2 and NO 3 . The concentrations of 222 Rn varied from 5.3 to 83.7 Bq/L in the groundwater analyzer. Radon concentration was not measured in superficial water due to the high emanation rate of radon in open air conditions. As far as 210 Po is concerned, the analyses showed concentrations ranging from 210 Po did not show and correlation with physico-chemical parameters. The average concentrations of uranium and 210 Po in superficial water were of 44.7 mBq/L, respectively. These values correspond to effective doses of 5.8 x 10 -4 mSv/yr and 4.5 x 10 -2 mSv/yr, for uranium and 210 Po, respectively. The average values for the concentrations of uranium, 222

  18. Survey of radon concentrations in three Italian towns

    International Nuclear Information System (INIS)

    Malanca, A.; Pessina, V.; Dallara, G.

    1992-01-01

    Radon-222 was measured in 187 dwellings in Parma, Reggio Emilia, and Orvieto. Samples were collected using activated carbon canisters, placed in basements and on the upper floors for at least 48 h in the period starting from January 1989 to July 1990. Gamma spectroscopy was used for the measurement of 222 Rn and its progeny. The data for the three towns show a lognormal distribution. Owing to the high radium concentration in building materials and underlying soil, high radon concentrations were observed in Orvieto's dwellings. Additional measurements carried out in 22 public schools of Parma and Reggio Emilia showed moderate radon concentrations, while significant radon levels were recorded in 37 castles and ancient buildings in Parma and Reggio Emilia provinces

  19. Biological effects of radon in Drosophila; Efectos biologicos del radon en Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel P, A E; Tavera D, L; Cruces M, M P; Arceo M, C; Rosa D, M.E. de la

    1992-04-15

    The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

  20. Biological effects of radon in Drosophila; Efectos biologicos del radon en Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel P, A.E.; Tavera D, L.; Cruces M, M.P.; Arceo M, C.; Rosa D, M.E. de la

    1992-04-15

    The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

  1. Radon in soil gas survey in Curitiba (Brazil)

    International Nuclear Information System (INIS)

    Paschuk, Sergei A.; Correa, Janine Nicolosi; Schelin, Hugo R.; Barbosa, Laercio; Sadula, Tatyana; Matsuzaki, Cristiana A.

    2009-01-01

    This work describes the radon in soil gas measurements performed during the last two years in cooperation between the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR), the Nuclear Technology Development Center (CDTN) and the Institute of Radiation Protection and Dosimetry (IRD) from the Brazilian Nuclear Energy Commission (CNEN). Following previously concluded measurements of radon concentration in dwellings and the measurements of 222 Rn activity in drinking water collected at artesian bores of Curitiba urban area, present step of activities has been dedicated to measurements of radon concentration in soil gas. Experimental setup was based on the Professional Radon Monitor (ALPHA GUARD) connected to specially developed for such measurements Soil Gas Probe through the air pump and filter system. After the Probe was inserted, the ground has been tamped down around the probe, to prevent air from moving vertically along the outside of the shaft. The equipment was adjusted with air flow of 0.03 L/min and the measurements were performed during 90 min approximately. The 222 Rn concentration levels were detected and analyzed by the computer every 5 minutes using the software DataEXPERT by GENITRON Instruments. Collected average levels of 222 Rn concentration were processed taking into account the internal volume of Soil Probe and connection vessels. Radon sampling was performed at a depth of 50 - 70 cm. Obtained experimental data of radon concentration present rather big variation but correlates perfectly with previously obtained results for 222 Rn activity in drinking water. Further measurements are planned to be performed at other regions of Parana State and will involve the mineral analysis of soil samples. (author)''

  2. 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.

  3. Radiation and Radon Survey of Akchatau (Khazakstan) and Experience with Radon Remedial Measures

    International Nuclear Information System (INIS)

    Soroka, Y.; Molchanov, A.

    1998-01-01

    A radiation survey of the territory of Akchatau settlement has been carried out. The main factors affecting the high content of radon in dwelling houses were revealed. The experiment on isolation of under floor spaces was carried out to prevent the entry of radon-containing soil gas into living rooms. The repair works efficiency for decreasing of the radon content in hazardous houses was analysed. The survey showed a need for regulation of the value of 222 Rn exhalation on the territories planned for construction works. (author)

  4. Concept for a primary Romanian radon standard

    International Nuclear Information System (INIS)

    Sahagia, M.; Stanga, D.; Waetjen, A.C.; Luca, A.; Toro, L.; Varlam, C.; Cassette, P.

    2008-01-01

    The paper presents the concept of a complex system, aimed to assure the traceability of 222 Rn measurements, from the absolute (primary) standardization to the preparation and delivery of secondary standards, gas vials. The system will contain a solid 226 Ra source, a gas radon circuit, connections with a liquid scintillator vial and with glass vials. The absolute standardization of the 222 Rn, in equilibrium with all the short half life daughters, will be performed by the method of the Liquid Scintillation Counting (LSC). The system, and method, will allow our laboratory to take part in future international 222 Rn comparisons. The transfer of activity unit from the primary to the secondary standardization will be performed by the preparation of vials with 222 Rn gas, comparative measurements by LSC and a GeHP gamma-ray spectrometry system, or a well type NaI(Tl) crystal, and their link. The secondary standards will be used for the calibration of measurement instruments, for assurance of controlled radon atmosphere in 'radon chambers', and for the validation of some calculation models for various detectors efficiency. The range of activities for secondary standards is in agreement with the national measurement necessities. (author)

  5. Long term population dose due to radon (Rn-222) released from uranium mill tailings

    International Nuclear Information System (INIS)

    Chambers, D.B.; Lower, L.M.; Stager, R.H.

    2001-01-01

    The results of a study undertaken by the European Commission on the external costs (environmental and social) of various energy production systems is likely to be influential in determining how the European Union will develop its energy supply systems. The estimated costs for nuclear power from the study will be based on the findings of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), with the costs being dominated by the estimated long term (10,000 y) population doses due to radon (Rn-222) released from mill tailings. UNSCEAR developed a central estimate of 150 person-Sv per GW y and a range of 1 to 1,000 person-Sv per GW y. However, the generic data available to and being used by UNSCEAR are dated and are not appropriate for the current and planned future conditions in the uranium production industry, with the result that the estimated external costs of nuclear power (specifically, the doses due to radon emitted from mill tailings) are overestimated. The Uranium Institute sponsored a study to estimate long term population doses based on the most recent 1993 UNSCEAR methodology, but using data that would be more appropriate to the current major uranium production facilities. Site-specific information obtained from the owners/operators and the Uranium Institute included: present and proposed tailings management plans; tailings volumes and areas; ore grades and reserves; measurements and estimates of radon emission rates; and population densities. Tailings at closed facilities that no longer contribute to uranium production were not evaluated since it was assumed that these radon sources need not be considered in evaluating the external costs of current and future nuclear power production. Based on the same approach as UNSCEAR, but using a more sophisticated air dispersion model, and more site-specific data relative to existing sites and proposed tailings management practices, radon emission rates and population densities (that

  6. Measurements of radon in soil gas

    International Nuclear Information System (INIS)

    Paschuk, Sergei A.; Correa, Janine Nicolosi; Schelin, Hugo R.; Barbosa, Laercio; Sadula, Tatyana; Matsuzaki, Cristiana A.

    2009-01-01

    Full text: After the decades of systematic and numerous studies performed at different countries of the World, it has been concluded that radon as well as its progeny is the main cause of lung cancer. It is well known that more than 50% of the effective annual radiation dose received by a human being is related to the radon and its progenies. Among the principle mechanisms that bring the radon inside the dwelling is the soil exhalation as well as exhalation and release from the water. Radon concentration in the soil and its transport (emanation, diffusion, advection and adsorption) to the surface depends on different physical, geological and ambient parameters such as the geology of the area, geochemical composition of the soil, its porosity and permeability, grain size, soil humidity, bottom sediments and inputs from streams, temperature, atmospheric pressure, etc. Since the main part of indoor radon originates in the soil, the measurements of radon concentration in soil gas have to be considered as an important tool and indicator of probable high levels of radon inside the dwellings. Present work describes the radon in soil gas measurements performed during the last two years in cooperation between the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR), the Nuclear Technology Development Center (CDTN) and the Institute of Radiation Protection and Dosimetry (IRD) from the Brazilian Nuclear Energy Commission (CNEN). Following previously concluded measurements of radon concentration in dwellings and the measurements of 222 Rn activity in drinking water collected at artesian bores of Curitiba urban area, present step of activities has been dedicated to measurements of radon concentration in soil gas. Experimental setup was based on the Professional Radon Monitor (ALPHA GUARD) connected to specially developed for such measurements Soil Gas Probe through the air pump and filter system. The equipment was adjusted with air flow of 0

  7. Modeling dynamic behavior of Radon-222 in the planetary boundary layer

    International Nuclear Information System (INIS)

    Yuan, Y.C.; Stunder, M.J.

    1983-01-01

    A model has been used to simulate the dynamic behavior of radon concentration in the lower atmosphere from naturally occurring sources. The model includes prediction of radon exhalation rate from the surface of the ground due to convection and diffusion processes and the radon concentration profile in the planetary boundary layer. A time-dependent radon exhalation rate, variable mixing height, and altitude-dependent diffusivity are incorporated into the diffusion model by transforming the governing equation. The Galerkin finite-element technique and Crank-Nicholson finite different time marching are used in solving the discretized differential equations. The model-simulated time-varying radon concentrations near the ground agree well with measurements made over a period of seven days. It has been demonstrated that the model provides a reasonably good prediction of ambient radon concentration. As a general tool, with the input of actual radon concentration measurements, the model is also capable of estimating average radon exhalation rate from the ground surface. With current techniques, radon flux measurement is still a time-consuming and difficult task

  8. Radon-222 exhalation and its variation in soil air

    International Nuclear Information System (INIS)

    Mochizuki, S.; Sekikawa, T.

    1980-01-01

    A new method has been designed and developed for measuring the concentration of radon in soil air without disturbing the natural condition of the soil. By this method, radon concentrations in the soil air at various points down to a depth of 1 m below the ground are obtained from the concentrations of radium A ( 218 Po) measured in the same air. The radium A concentration is measured by spectrometry of alpha particles from radioactive ions in the soil air. The basic experiments and preliminary observations made in the soil air below the ground confirmed the usefulness of the newly constructed apparatus for measuring the radon concentration in the soil air. Our preliminary observations showed that the radon concentration in the soil air near the surface of the earth varied remarkably before heavy thunderstorms

  9. Inhalation exposures due to radon and thoron ((222)Rn and (220)Rn): Do they differ in high and normal background radiation areas in India?

    Science.gov (United States)

    Mishra, Rosaline; Sapra, B K; Prajith, R; Rout, R P; Jalaluddin, S; Mayya, Y S

    2015-09-01

    In India, High Background Radiation Areas (HBRAs) due to enhanced levels of naturally occurring radionuclides in soil (thorium and, to a lesser extent, uranium), are located along some parts of the coastal tracts viz. the coastal belt of Kerala, Tamilnadu and Odisha. It is conjectured that these deposits will result in higher emissions of radon isotopes ((222)Rn and (220)Rn) and their daughter products as compared to Normal Background Radiation Areas (NBRAs). While the annual external dose rates contributed by gamma radiations in these areas are about 5-10 times higher, the extent of increase in the inhalation dose rates attributable to (222)Rn and (220)Rn and their decay products is not well quantified. Towards this, systematic indoor surveys were conducted wherein simultaneous measurements of time integrated (222)Rn and (220)Rn gas and their decay product concentrations was carried out in around 800 houses in the HBRAs of Kerala and Odisha to estimate the inhalation doses. All gas measurements were carried out using pin-hole cup dosimeters while the progeny measurements were with samplers and systems based on the Direct radon/thoron Progeny sensors (DRPS/DTPS). To corroborate these passive measurements of decay products concentrations, active sampling was also carried out in a few houses. The results of the surveys provide a strong evidence to conclude that the inhalation doses due to (222)Rn and (220)Rn gas and their decay products in these HBRAs are in the same range as observed in the NBRAs in India. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. 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

    Results from 1,041 groundwater samples collected during 1986‒2015 from 16 geologic units in Pennsylvania, associated with 25 or more groundwater samples with concentrations of radon-222, were evaluated in an effort to identify variations in radon-222 activities or concentrations and to classify potential radon-222 exposure from groundwater and indoor air. Radon-222 is hereafter referred to as “radon.” Radon concentrations in groundwater greater than or equal to the proposed U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) for public-water supply systems of 300 picocuries per liter (pCi/L) were present in about 87 percent of the water samples, whereas concentrations greater than or equal to the proposed alternative MCL (AMCL) for public water-supply systems of 4,000 pCi/L were present in 14 percent. The highest radon concentrations were measured in groundwater from the schists, gneisses, and quartzites of the Piedmont Physiographic Province.In this study, conducted by the U.S. Geological Survey in cooperation with the Pennsylvania Department of Health and the Pennsylvania Department of Environmental Protection, groundwater samples were aggregated among 16 geologic units in Pennsylvania to identify units with high median radon concentrations in groundwater. Graphical plots and statistical tests were used to determine variations in radon concentrations in groundwater and indoor air. Median radon concentrations in groundwater samples and median radon concentrations in indoor air samples within the 16 geologic units were classified according to proposed and recommended regulatory limits to explore potential radon exposure from groundwater and indoor air. All of the geologic units, except for the Allegheny (Pa) and Glenshaw (Pcg) Formations in the Appalachian Plateaus Physiographic Province, had median radon concentrations greater than the proposed EPA MCL of 300 pCi/L, and the Peters Creek Schist (Xpc), which is in the Piedmont

  11. COOMET.RI(II)-S1.Rn-222 (169/UA/98): Rn-222 volume activity comparison

    International Nuclear Information System (INIS)

    Skliarov, V.; Rottger, A.; Honig, A.; Korostin, S.; Kuznetsov, S.; Lapenas, A.; Milevsky, V.; Ivaniukovich, A.; Kharitonov, I.; Sepman, S.

    2009-01-01

    According to a first program, a supplementary comparison of Rn-222 volume activity was drawn up as a bilateral supplementary comparison between NSC 'Institute of Metrology', Ukraine, and VNIIFTRI, Russia. It took place in March 2005. In April 2005, at the 5. meeting of COOMET held in Braunschweig (Germany), representatives of these institutes exchanged data which showed the comparability of the national standards of Ukraine and Russia for the check points. During the discussion of the procedure some other institutes decided to join the comparison program, which was extended to BelGIM (Belarus), PTB (Germany), VNIIM (Russia) and RMTC (Latvia). The national standards of volume activity of radon-222 were thus calibrated using one standard radon radiometer as the transfer standard. Results are shown in the Final Report of the comparison. (authors)

  12. COOMET.RI(II)-S1.Rn-222 (169/UA/98): Rn-222 volume activity comparison

    Energy Technology Data Exchange (ETDEWEB)

    Skliarov, V. [National Scientific Centre, Institute of Metrology (NSC IM), Kharkiv (Ukraine); Rottger, A.; Honig, A. [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany); Korostin, S.; Kuznetsov, S. [All-Russian Scientific Research Institute of Physical, Technical and Radio Measurements (VNIIFTRI), Moscow Region, Mendeleyevo (Russian Federation); Lapenas, A. [Latvian National Metrology Centre Ltd, Radiation Metrology and Testing Centre (RMTC), Salaspils (Latvia); Milevsky, V.; Ivaniukovich, A. [Belarussian State Institute of Metrology (BelGIM), Minsk (Belarus); Kharitonov, I.; Sepman, S. [D I Mendeleyev Institute of metrology (VNIIM), Saint Petersburg (Russian Federation)

    2009-06-15

    According to a first program, a supplementary comparison of Rn-222 volume activity was drawn up as a bilateral supplementary comparison between NSC 'Institute of Metrology', Ukraine, and VNIIFTRI, Russia. It took place in March 2005. In April 2005, at the 5. meeting of COOMET held in Braunschweig (Germany), representatives of these institutes exchanged data which showed the comparability of the national standards of Ukraine and Russia for the check points. During the discussion of the procedure some other institutes decided to join the comparison program, which was extended to BelGIM (Belarus), PTB (Germany), VNIIM (Russia) and RMTC (Latvia). The national standards of volume activity of radon-222 were thus calibrated using one standard radon radiometer as the transfer standard. Results are shown in the Final Report of the comparison. (authors)

  13. Radon chamber for soil gas detectors

    International Nuclear Information System (INIS)

    Andersson, P.

    1987-01-01

    Swedish Geological Co (SGAB) has designed and constructed a chamber for the calibration of detectors and instruments intended for the measurement of radon-222 in soil gas. In the chamber radon detectors may be exposed in a model environment which simulates ground conditions with respect to radon concentration, temperature and humidity. Also included in the research project is the development of methods for calibration procedures, together with test measurements. In general, these measurements indicate that the radon detectors tested are sufficiently accurate and reliable for radon measurements in Swedish soils if they are calibrated in an environment which simulates ground conditions. (orig./HP)

  14. 222Rn activity concentration differences in groundwaters of three Variscan granitoid massifs in the Sudetes (NE Bohemian Massif, SW Poland)

    International Nuclear Information System (INIS)

    Przylibski, Tadeusz A.; Gorecka, Joanna

    2014-01-01

    Based on research conducted in three Variscan granitoid massifs located within the crystalline Bohemian Massif, the authors confirmed that the higher the degree of their erosional dissection, the smaller the concentration of 222 Rn in groundwaters circulating in these massifs. This notion implies that radon waters and high-radon waters, from which at least some of the dissolved radon should be removed before feeding them as drinking water to the water-supply system, could be expected in granitoid massifs which have been poorly exposed by erosion. At the same time, such massifs must be taken into account as the areas of possible occurrence of radon medicinal waters, which in some countries can be used for balneotherapy in health resorts. Slightly eroded granitoid massifs should be also regarded as very probable radon prone areas or areas of high radon potential. - Highlights: • The concentration of 222 Rn in groundwater depends on the zone of the granitoid massif which is exposed on the ground surface. • The highest 222 Rn concentrations occur in the least eroded granitoid massifs, the lowest in massifs with exposed root parts. • The stronger the erosional dissection of a granitoid massif, the lower 222 Rn concentration in groundwaters in this massif. • Not all granitoid massifs are areas with groundwaters containing high concentrations of 222 Rn. • The least eroded granitoid massifs are radon prone areas with the occurrence of high-radon and radon groundwaters

  15. Evaluation of 222radon occupational exposure in underground workplaces: tunnels used for mushroom cultivation in Italy

    International Nuclear Information System (INIS)

    Fontana, C.; Vecchiariello, S.; Angeloni, U.; Trevisi, R.; Tonnarini, S.

    2006-01-01

    The mushroom cultivation in tunnels represents a working activity with interesting characteristics from a radiological protection point of view. The practice of using tunnels or caves for the cultivation of mushrooms is diffused in many countries as well as in several Italian regions. These places are characterized by micro climate conditions (temperature, humidity, etc.) particularly adapted for the growth of mushrooms in every period of the year. This practice, like every working activity carried out in underground workplaces, is regulated by the Italian implementation of the European Union Basic Safety Standards (E.U. B.S.S., 1996). With the aim to evaluate the 222 Rn exposure of workers in tunnels used for mushroom cultivation, a study has been undertaken. In particular, hygienic and micro climatic characteristics (depth, temperature, relative humidity, barometric pressure, ventilation, etc.) and radiometric parameters (indoor radon concentration, radon decay products concentration, equilibrium factor F) have been investigated. In the present paper, the results of the two steps of the study are reported. In the first step, an operative protocol has been defined: the protocol was put through a series of measurements in two tuff tunnels in the area of Rome. In the second step, several tunnels used for mushroom cultivation, located in different Italian regions, have been monitored and experimental data have been used to estimate annual effective doses of workers due to radon inhalation.The experimental results have been analyzed in the context of the E.U. B.S.S

  16. Evaluation of radon concentration in dwellings and well water of Parana State-Brazil

    International Nuclear Information System (INIS)

    Correa, Janine Nicolosi

    2011-01-01

    Considering the growing interest of International Agencies and national Governmental organs in studies and measurements of radon activity in air, soil gas and ground water (mainly from artesian wells) as well as scarceness of such measurements at Brazilian territory, present studies were initiated by the Laboratory of Applied Nuclear Physics of Federal University of Technology - Parana (UTFPR) in collaboration with the Institute of Radiation Protection and Dosimetry (IRD) and the Center of Nuclear Technology Development (CDTN) of Brazilian Commission on Nuclear Energy (CNEN). This Collaboration started in 2003. Radon monitoring program is based mainly on use of Solid State Nuclear Track Detectors for radon activity measurements in air. Continuous electronic radon detectors are used for radon measurements in soil gas and water. Current work presents the results of indoor 222 Rn activity of dwellings and working places of Curitiba-PR and radon concentration in ground water samples from artesian wells from aquifers of the same area. The indoor measurements of radon activity were performed using Solid State Nuclear Track Detectors CR-39. After the exposition, CR-39 detectors were submitted to chemical development which permitted to make alpha particle tracks counting. The results of calibration of CR-39 together with efficiency of used exhalation chambers as well as alpha particle tracks chemical development procedure were performed in cooperation with CDTN and collaboration with the National Institute of Radiological Sciences (NIRS). The major part of indoor 222 Rn concentration in residences was found below 100 Bq/m3. In the case of working places, all measurements present 222 Rn concentration bellow 100 Bq/m3. The studies of radon activity in water were performed using the samples of water from artesian wells submitted to recursive measurements by instant radon detector AlphaGUARD PQ2000 PRO during few weeks with intervals of about 4 days between each measurement

  17. Variation of radon exposure in Damascus dwellings

    International Nuclear Information System (INIS)

    Shweikani, R.

    2012-01-01

    In the present work, activity concentrations of 222 Rn in air and 222 Rn and 226 Ra in drinking water were measured in Damascus city covering its old and modern parts. It was found that the average air radon activity concentration in the old part was higher than in the modern part, and in drinking water, radon was found to be 60±3 Bq/l, and less than 0.13 Bq/l for radium, which were lower than the recommended levels set by WHO. - Highlights: ► This work presents screening of natural radioactivity in dwellings in Damascus city. ► Radon, 226 Rn and total alpha/beta in air and drinking water were measured. ► Most of the obtained results were within the recommended levels set by WHO. ► In general radon in the old part was higher than the modern part of the city.

  18. Radon distribution in a gasoline-contaminated aquifer

    International Nuclear Information System (INIS)

    Fan, K.; Kuo, T.; Han, Y.; Chen, C.; Lin, C.; Lee, C.

    2007-01-01

    Naturally occurring radon-222 gas in groundwater was investigated as a partitioning tracer to detect non-aqueous phase liquid (NAPL) in a gasoline-contaminated aquifer. The radon-222 activity of groundwater decreased significantly from an average of 7.38+/-1.68BqL -1 measured in monitoring wells located upgradient in the uncontaminated zone to an average of 2.30+/-0.60BqL -1 measured in monitoring wells inside the NAPL source zone. Meanwhile, the radium-226 concentrations measured in aquifer matrix were virtually homogeneous at several locations both upgradient of and inside the NAPL source zone. Furthermore, the NAPL concentration obtained from the Radon Deficit Factor agrees reasonably with the results derived from direct sampling and chemical analysis of soil samples taken from the residual NAPL source zone. The field results of this study confirmed the general applicability of groundwater radon to detect residual NAPL source zone

  19. Radon -- an environmental hazard

    International Nuclear Information System (INIS)

    Faheem, M.; Rahman, R.; Rahman, S.; Matiullah

    2005-01-01

    Humans have always been exposed throughout its period of experience to naturally occurring sources of ionizing radiation or natural background radiation, It is an established fact that even these low background doses are harmful to man and cause increased cancer risk. About half of our radiation comes from radon, a radioactive gas coming from normal materials in the ground. Several building materials such as granite, bricks, sand, cement etc., contain uranium in various amounts. The radioactive gas /sup 222/Rn produced in these materials due to decay of 226Ra is transported to indoor air through diffusion and convective flow. It seeps out of soil and rocks, well water, building materials and other sources at a varied rate. Amongst the naturally occurring radioisotopes, radon is the most harmful one that can be a cause of lung cancer. Radon isotopes are born by the decay of radium and radium production in turns comes from uranium or thorium decay. For humans the greatest importance among Radon isotopes is attributed to /sup 222/Rn because it is the longest lived of the three naturally produced isotopes. Drinking water also poses a threat. Radon gas is dissolved in water and is released into the air via water faucets, showerheads, etc. the lack of understanding has so far lead to speculative estimates of pollutant related health hazards. (author)

  20. Radon in Antarctica

    International Nuclear Information System (INIS)

    Ilic, R.; Rusov, V.D.; Pavlovych, V.N.; Vaschenko, V.M.; Hanzic, L.; Bondarchuk, Y.A.

    2005-01-01

    The paper reviews results of radon measurements obtained in Antarctic research stations in the last 40 years by both active and passive radon monitors. A brief description of the radon laboratory set-up in the Ukrainian Academician Vernadsky station on the Antarctic Peninsula (W 64 o 16 ' , S 65 o 15 ' ), where radon is measured by two types of etched track Rn dosimeter and 4 types of continuous radon monitoring devices is presented. Some selected results of research work are described related to: (i) analysis of radon storms, defined as an abrupt increase of 222 Rn during the occurrence of a cyclone, and its applicability for the study of the transport of air masses of continental origin to Antarctica; (ii) a study of the correlation of changes of radon concentration and geomagnetic field induced by tectonic activity and its application to predicting tectonomagnetic anomalies, and (iii) verification of a newly developed theoretical model based on noise analysis of the measured radon signal for earthquake prediction. Suggestions for future utilization of radon for basic research in Antarctica (and not only in Antarctica) conclude the contribution. conclude the contribution

  1. Indoor radon measurements in Athens, Greece

    International Nuclear Information System (INIS)

    Proukakis, C.; Molfetas, M.; Ntalles, K.; Georgiou, E.; Serefoglou, A.

    1987-01-01

    A pilot study was carried out in order to measure air concentrations of radon 222 and 220 isotopes in Athenian houses, as a first step of a national survey in Greece. In this paper the authors deal with radon concentration in air and water and will rely on measurements conducted in Greece. (author)

  2. Radon emanation from soils

    International Nuclear Information System (INIS)

    Markkanen, M.; Arvela, H.

    1992-01-01

    The results of gamma spectrometric sample measurements of radon ( 222 Rn) emanation coefficients and radium concentrations ( 226 Ra) from about 800 Finnish soil samples are presented. The radon emanation rate was measured in about 400 soil samples, using radon-tight cans and Lucas cells. The effects of water content and temperature on radon emanation were investigated, using various samples of different soil types. Radon emanation and the effect of water content on radon emanation were investigated separately for different grain sizes (samples of till). The results provide some information on radon emanation in different soil types and relate emanation in laboratory conditions to conditions in ground soil. In routine measurements of radon emanation from soil samples, use of a 5% water content was considered advisable. The correction coefficients of radon emanation varied between 0.3 and 1.5, depending on the water content and soil type. At 5% water content, hardly any difference was found between radon emanation at temperatures of 20 and 1 o C. Radon emanation was found to be an inverse function of grain sizes larger than 0.5 mm in diameter. (author)

  3. Radon: risk to health? El radón: ¿riesgo para la salud?

    Directory of Open Access Journals (Sweden)

    Juan Miguel Barros Dios

    2011-12-01

    Full Text Available Radon (Rn222 is a radioactive noble gas whose origin is Radium (Ra226 when it emits an alpha particle (two protons and two neutrons or a helium nucleus. Rn222 transforms in another radioactive element (Po218 when an alpha particle is emitted. Its carcinogenic effect on the lung was discovered various decades ago, first on uranium miners and later on general population exposed at home to residential radon. The main factor influencing radon concentration in dwellings is the uranium content of the subsoil, since uranium is the first element of the radioactive disintegration chain where radon appears. Geological risk areas of Spain due to their granite and therefore uranium content are Galicia, the Northwest and the West of Spain. Numerous countries of Europe and America have enforced legislation focused to protect population and reduce radon concentration in order to prevent lung cancer appearance. These laws comprise public buildings and private homes. Since the late 80s, alpha radiation generated by radon and its short-life descendents has been classified as carcinogenic agents by the International Agency for Research on Cancer (Lyon, 1988 and the National Research Council (BEIR IV, 1988.El radón (Rn222 es un gas noble radiactivo que procede directamente del radio (Ra226 cuando este emite una partícula alfa (dos protones y dos neutrones o núcleo de helio, y que a su vez se transforma en otro elemento radiactivo (Po218 al desprenderse de otra partícula alfa. Desde hace varias décadas se conoce su efecto como factor de riesgo del cáncer primario pulmonar, primero en mineros del uranio y posteriormente en la población general expuesta al radón residencial en hogares construidos sobre suelos de rocas ricas en uranio (U238, elemento inicial de la cadena de degradación radiactiva de la que procede el radón. Áreas geológicamente constituidas por granitos o pizarras, como son las de gran parte de Galicia y todo el noroeste y oeste de la pen

  4. Kinetics of ingested 222Rn in humans determined from measurements with 133Xe. Project summary report

    International Nuclear Information System (INIS)

    Correia, J.A.; Weise, S.B.; Callahan, R.J.; Strauss, H.W.

    1987-12-01

    The problem of naturally occurring 222-radon contamination has received a great deal of public and scientific attention over the past several years, and has become a major public health issue worldwide. The purpose of the work reported in this document was to provide information about the behavior of ingested 222-radon in the digestive system and other organs of the human body. 133-Xenon, an element which behaves in the same manner as 222-radon in tissue and differs only in tissue solubility, was used in studies on human subjects. The tissue solubility differences were accounted for by using the tissue/blood partition coefficients of the two gases

  5. Construction of growth curve of Rn-222 activity for use as a calibration factor for determination of Rn-222 in water by LSC; Construção de curva de crescimento da atividade do Rn-222 para utilização como fator de calibração para determinação de Rn-222 em água por LSC

    Energy Technology Data Exchange (ETDEWEB)

    Santos, M.L.O.; Farias, E.E.G.; Amaral, D.S.; Hazin, C.A.; França, E.J., E-mail: emersonemiliano@yahoo.com.br [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Souza Neto, J.A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2017-07-01

    Liquid Scintillation Spectrometry (LSC) is one of the most used techniques for quantification of alpha and beta particles in aqueous medium, being used to determine the concentration of Radon-222 in water. The counting efficiency of this methodology depends on the good extraction of the radionuclide and the definition of the most appropriate scintillator cocktail. The study aimed to construct a growth curve of Rn-222 activity in aqueous medium and to test the counting efficiency of this method. For this, samples containing 12 mL Ra-226 standard solution and 12 mL scintillator cocktail were prepared in triplicate. The cocktail was prepared using 1 L of p-xylene, 7 g of 2,5-diphenyloxazole (PPO) and 0.75 g of 1,4-bis- [2- (5-diphenyloxazol)] benzene (POPOP). Subsequently, the containers were sealed and agitated for five minutes, seeking an efficient transfer of the radon to the organic phase. Analytical white was prepared using deionized water and the scintillation cocktail. After 3 hours, the concentrations of this radionuclide were determined by the LSC technique, using QUANTULUS 1220 equipment, Perkin Elmer. Analyzes were performed on nine different days, making a total of 21 days between the first and last analysis. The results obtained allowed to make an analytical curve with good fit (r{sup 2} = 0.98), which could be used as a calibration factor for this method. The method used showed a counting efficiency of 78%. A suitable analytical protocol for determination of Rn-222 in water samples was established.

  6. Radon and lung cancer in Bangalore Metropolitan, India

    International Nuclear Information System (INIS)

    Sathish, L.A.; Nethravathi, K.S.; Ramachandran, T.V.

    2012-01-01

    Radon is a radioactive gas released from the normal decay of 238 U in rocks and soil. It is an invisible, odorless, tasteless gas that seeps up through the ground and diffuses into the air. In a few areas, depending on local geology, radon dissolves into ground water and can be released into the air when the water is used. Radon gas usually exists at very low levels outdoors. However, in areas without adequate ventilation, such as underground mines, radon can accumulate to levels that substantially increase the risk of lung cancer. Radon decays quickly, giving off tiny radioactive particles. When inhaled, these radioactive particles can damage the cells that line the lung. Long-term exposure to radon can lead to lung cancer, the only cancer proven to be associated with inhaling radon. Public interest in radon has been occasionally piqued by articles in the general press. Considerable attention has been given to the high radon levels that were uncovered in the Reading Prong region of Pennsylvania, following the discovery in late 1984 of extremely high levels in one home. Several epidemiological study programmes in different countries are in progress to estimate the population exposures due to natural radiation with a view to obtain the radiation risk coefficients at low dose rate levels. In this regard, radiation surveys in high background areas (HBRAs) can provide excellent settings for epidemiological studies relating to the effects of low doses of radiation. In view of these, a comprehensive estimate of the natural inhalation dose requires both 222 Rn and 220 Rn levels in the indoor atmosphere. In this outlook an attempt is made to investigate the 222 Rn and 220 Rn levels in dwellings of Bangalore Metropolitan, India. Three year results shows that the activity concentrations of 226 Ra, 232 Th, radon in ground water, the concentrations 222 Rn and 220 Rn and the dose rate (mSvy -1 ) are at alarming levels for the environment of Bangalore Metropolitan, India. The

  7. Evaluación de un proyecto de inversión para determinar hasta cuanto deben invertir los productores para diferenciar el chile habanero.

    OpenAIRE

    Pérez Martín, Alberto Orlando

    2012-01-01

    El chile habanero es un cultivo básico para la península de Yucatán ya que se abre paso, en la industria agroalimentaria del mundo por su sabor y pungencia, además, que en torno a este producto giran innumerables actividades económicas del campo y de la industria por sus altos contenidos de capsaicinoides. El presente trabajo se desarrolló para determinar hasta cuánto deben invertir los productores del estado de Yucatán para diferenciar el chile habanero (capsicum chínense) de la forma trad...

  8. Estimate of lifetime excess lung cancer risk due to indoor exposure to natural radon-222 daughters in Korea

    International Nuclear Information System (INIS)

    Si-Young Chang; Jeong-Ho Lee; Chung-Woo Ha

    1993-01-01

    Lifetime excess lung cancer risk due to indoor 222 Rn daughters exposure in Korea was quantitatively estimated by a modified relative risk projection model proposed by the U.S. National Academy of Science and the recent Korean life table data. The lifetime excess risk of lung cancer death attributable to annual constant exposure to Korean indoor radon daughters was estimated to be about 230/10 6 per WLM, which seemed to be nearly in the median of the range of 150-450/10 6 per WLM reported by the UNSCEAR in 1988. (1 fig., 2 tabs.)

  9. Development and evaluation of global radon transport model

    International Nuclear Information System (INIS)

    Kojima, H.; Nagano, K.

    2003-01-01

    The radioactive noble gas Radon-222 ( 222 Rn) is chemically inert and is removed only by radioactive decay (T1/2=3.8 d). Its primary source is uniformly distributed over the continents and the ocean represents a secondary source of atmospheric 222 Rn. The strong contrast in source strength between continents and the ocean makes 222 Rn an ideal marker of continental air masses. Because of its simple properties, the temporal and spatial distribution of 222 Rn in the troposphere is straightforward to simulate by means of atmospheric transport models. The simulation provides an intuitive visualization of the complex transport characteristics and more definite proof of phenomenon. In this paper, we present the results of an exploratory study, in which we investigated the performance of a three-dimensional transport model of the global troposphere in simulating the long range transport of 222 Rn. The transport equation has been solved by a numerical procedure based on some boundary conditions. The model structure which we have originally developed, has a horizontal resolution of 2.5deg in latitude and 2.5deg in longitude, and 10 layers in the vertical dimension. The basic computational time step used in the model runs was set to 5 min. The simulations described in this article were performed by means of a transport model driven by global objective analytical data of a time resolution of 6 h, supplied by the Japan Meteorological Agency. We focus on the west of North Pacific Ocean, were the influence of air pollution from an Asian Continent and the Japan Islands was received. For simulation experiments, radon data from some shipboard measurements on the North Pacific Ocean have been used in the present study. Figure shows time series of model prediction with different latitude distributions of radon exhalation rate and measured radon data. We find that our model consistently produce the observation. We will discuss the characteristics of the temporal and special

  10. Studies of radon mitigation in well water by aeration

    International Nuclear Information System (INIS)

    Mafra, Karina Cristina; Paschuk, Sergei A.; Denyak, Valeriy; Reque, Marilson; Correa, Janine Nicolosi; Barbosa, Laercio

    2011-01-01

    The 222 Rn concentration in natural water in different countries usually is about few Bq/L and is the subject of the National legislation as well as International norms and recommendations. The United States Environmental Protection Agency (USEPA) established a limit of 11.1 Bq/L for the radon level in drinking water and this limit is considered as guideline in Canada and many countries of the European Union. This work presents the results of study of radon ( 222 Rn) concentration reduction in well water using the aeration process developed at the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR). The water samples were collected from a well at Pinheirinho region of Curitiba in 2011. Experimental setup was based on the Radon Monitor (AlphaGUARD). The 222 Rn concentration was analyzed using the software DataEXPERT by Genitron Instruments, taking into account the volume of water sample, its temperature, atmospheric pressure and the total volume of the air in the vessels. Initial concentration of radon in water samples was 28,67 Bq/L which is bigger than maximum concentration recommended by USEPA. The mitigation was performed by means of diffusion aeration of water samples of 15L during the time interval of 24 hours following a period of 4 days. The efficiency of aeration mitigation was controlled by comparing the activity of radon in aerated water with reference water samples that were not aerated. Obtained results show very satisfactory decrease of 222 Rn activity in water samples even after few hours of intense aeration. (author)

  11. Radon in houses - identification of sources and pathways of transfer

    International Nuclear Information System (INIS)

    Robe, M.C.; Rannou, A.; Le Bronec, J.

    1992-01-01

    The Institut de Protection et de Surete Nucleaire (IPSN) is studying the remedial actions to reduce high concentration of radon in houses. The first step to know how to modify houses is to identify radon sources and pathways of transfer to upper floors. A pilot study in Brittany was designed to develop a simple method of diagnosis. This investigation was based on indoor and outdoor measurements of 222 Rn activity concentration in the air and 222 Rn area exhalation rate from the soils and walls, measurements of the potential alpha energy concentration of 222 Rn daughters and the ventilation rate. The structural characteristics of houses and the influence of the life style of the inhabitants were examined. Analysis of the results showed that a limited number of parameters can be selected for use in a rapid radon diagnosis. (author)

  12. 222Rn Determination In Drinking Waters - RAD7 And LSC Technique Comparison

    International Nuclear Information System (INIS)

    Todorovic, N.; Stojkovic, I.; Nikolov, J.; Tenjovic, B.

    2015-01-01

    A procedure for the determination of 222Rn in environmental water samples using liquid scintillation counting (LSC) was applied and optimized. For radon determination in drinking water from groundwater and surface water sources by LSC, the EPA Method 913.0 was used. A minimum detectable activity of 0.029 Bq L-1 in a 20 mL glass vial (10 mL water sample mixed with 10 mL of liquid scintillation cocktail) has been achieved during 300 minutes of measurement time. The procedure was compared with RAD7 radon detector measurements. Factors that affect the measurement accuracy and precision of RAD7 radon detector are the sampling technique, sample concentration, sample size, counting time, temperature, relative humidity and background effects. The minimal detectable activity (MDA) for RAD7 technique was found to be 0.1 Bq/L. From obtained results of 222Rn measurements in 15 water samples with different 222Rn activities, correlation between the two techniques applied for measurements of 222Rn in water samples (A less than 400 Bq/L) was determined. There is reasonable agreement (within statistical uncertainties) between the various techniques in most cases, while disagreements most likely come from systematic uncertainties associated with sampling procedures. Discrepancy in determined activities between the two techniques becomes more evident with increased 222Rn activities in water. LSC technique gives in general higher activity concentrations for about 30 percent than RAD7 spectrometer. The interpretation of shown results could be that RAD7 is not properly calibrated for higher activities, since USA reference level of 222Rn concentrations in water is only 11.1 Bq/L (US EPA, Proposed Radon in Drinking Water Regulation). (author).

  13. Effect of source and environmental factors on Rn-222 air concentration

    International Nuclear Information System (INIS)

    Mamoon, A.

    2005-01-01

    Rn-222(radon) air concentration depends on several factors. Some of the factors are source related and other factors are environmentally related. Because high levels of radon concentrations in air have potential health effects, it is important to study the impact of the various factors affecting radon air concentration. Laboratory scale investigations of the various factors affecting radon air concentration were carried out under controlled conditions that allow variation of the various variables

  14. Measurements of indoor 222RN activity in dwellings and workplaces of Curitiba (Brazil)

    International Nuclear Information System (INIS)

    Corrêa, Janine N.; Paschuk, Sergei A.; Del Claro, Flávia; Kappke, Jaqueline; Perna, Allan F.N.; Schelin, Hugo R.; Denyak, Valeriy

    2014-01-01

    The present work describes the results of systematic measurements of radon ( 222 Rn) in residential environments and workplaces in the Metropolitan Region of Curitiba (Paraná State, Brazil) during the period 2004–2012. For radon in air activity measurements, polycarbonate Track Etch Detectors CR-39, mounted in diffusion chambers protected by borosilicate glass fiber filters, were used. After being exposed in air, the CR-39 detectors were submitted to a chemical etching in a 6.25 M NaOH solution at 70 °C for 14 h. The alpha particle tracks were identified and manually counted with an optical microscope, and with the results of previously performed calibrations, the indoor activity concentration of 222 Rn was calculated. The calibration of CR-39 and the alpha particle tracks chemical development procedures were performed in collaboration the National Institute of Radiological Sciences (NIRS, Japan). The major part of indoor 222 Rn concentration in residences was found to be below 100 Bq/m 3 . In the case of working places, all measurements of 222 Rn concentrations were below 100 Bq/m 3 . These values are considered within the limits set by international regulatory agencies, such as the US EPA and ICRP, which adopt up to 148 and 300 Bq/m 3 as upper values for the reference levels for radon gas activity in dwellings, respectively. The latest value of 300 Bq/m 3 for radon activity in air is proposed by ICRP considering the upper value for the individual dose reference level for radon exposure of 10 mSv/yr. - Highlights: • Radon activity in air of dwellings was measured. • Radon activity in air of workplaces was measured. • Obtained experimental results are compared with International Norms and Regulations

  15. Evaluation of {sup 222}radon occupational exposure in underground workplaces: tunnels used for mushroom cultivation in Italy

    Energy Technology Data Exchange (ETDEWEB)

    Fontana, C.; Vecchiariello, S.; Angeloni, U. [Laboratory of Environmental Radioactivity - Central Laboratory, ITALIAN RED CROSS, Rome (Italy); Trevisi, R.; Tonnarini, S. [Radon Measurement Laboratory - Department of Occupational Hygiene, ISPESL, Rome (Italy)

    2006-07-01

    The mushroom cultivation in tunnels represents a working activity with interesting characteristics from a radiological protection point of view. The practice of using tunnels or caves for the cultivation of mushrooms is diffused in many countries as well as in several Italian regions. These places are characterized by micro climate conditions (temperature, humidity, etc.) particularly adapted for the growth of mushrooms in every period of the year. This practice, like every working activity carried out in underground workplaces, is regulated by the Italian implementation of the European Union Basic Safety Standards (E.U. B.S.S., 1996). With the aim to evaluate the {sup 222}Rn exposure of workers in tunnels used for mushroom cultivation, a study has been undertaken. In particular, hygienic and micro climatic characteristics (depth, temperature, relative humidity, barometric pressure, ventilation, etc.) and radiometric parameters (indoor radon concentration, radon decay products concentration, equilibrium factor F) have been investigated. In the present paper, the results of the two steps of the study are reported. In the first step, an operative protocol has been defined: the protocol was put through a series of measurements in two tuff tunnels in the area of Rome. In the second step, several tunnels used for mushroom cultivation, located in different Italian regions, have been monitored and experimental data have been used to estimate annual effective doses of workers due to radon inhalation.The experimental results have been analyzed in the context of the E.U. B.S.S.

  16. Thoron (RN-220) interference in the determination of RN-222 exhalation rate of soils

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Déric S.; Farias, Emerson E.G.; Santos, Mariana L.O.; Silva, Karolayne E.M.; Hazin, Clovis A.; França, Elvis J., E-mail: emersonemiliano@yahoo.com [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Souza Neto, João A., E-mail: adauto@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Geologia

    2017-07-01

    The transport of Rn-222 from the soil to the atmosphere known as exhalation is influenced by meteorological conditions and soil geophysical parameters. In closed and poorly ventilated rooms, this radioactive gas can reach high activity concentrations, in which the energy of alpha particles released by this radionuclide and its progeny is the second leading cause of lung cancer. Soil exhalation rate is an important parameter for assessing human health risks associated with radon. For radon determination using an exhalation chamber, an ionization chamber detector is used to count the electrical pulses generated by the interaction between the alpha particles produced by Rn-222 and its progeny and the air inside the chamber. In this work, the interference of thoron (Rn-220) in the determination of soil exhalation rate of Rn-222 was studied. For this, the RadonBOX exhalation chamber and the AlphaGuard ionization chamber detector were utilized for analyzing the same soil during two hours on different days under similar meteorological conditions. From zero up to approximately 2,400 s, the radon activity concentrations decreased. After 40 minutes, the radon concentrations started to increase, thereby allowing the calculation of soil exhalation rate. This initial decreasing could be explained by a high Rn-220 than Rn-222 presence in the soil, in which, because of its short half-life, after 40 minutes, most thoron present in the chamber has undergone so that the main alpha emitter become Rn-222. In order to confirm this, Rn-220 activity was estimated by the Ra-228 concentration in the soil determined after 30 days using High Resolution Gamma-Ray Spectrometry with HPGe detectors. Therefore, the thoron interference in the determination of soil radon exhalation rate was considered negligible after 40 minutes of measurement time for the analyzed soil. (author)

  17. Assessment of radon build up pattern in a closed room with minimal ventilation disturbance

    International Nuclear Information System (INIS)

    Singh, M.K.; Patnaik, R.L.; Jha, V.N.; Ravi, P.M.; Tripathi, R.M.

    2016-01-01

    Radon is ubiquitous in nature. The immediate source of Radon is 226 Ra is present in building materials underneath earth due to presence of natural uranium in terrestrial region. 222 Ra gas continuously diffused out into room atmosphere through the pores, cracks and fissures if any. The buildup of this 222 Rn is anticipated in a closed room lack of proper ventilation. A study was done to see the build up pattern of radon concentration by two different measurement techniques in a closed room of ESL, Jaduguda. Present paper summarizes the result of buildup study of 222 Rn in a closed room of lab for a period of 3 months

  18. Radon-enriched spring waters in the South of Poland

    International Nuclear Information System (INIS)

    Kozlowska, B.; Hetman, A.; Dorda, J.; Zipper, W.

    2001-01-01

    A method for determination of 222 Rn in natural water samples which involves a Wallac 1414 Win Spectral α/β liquid scintillation counter is described. Samples were collected from springs in health resorts in the Sudety Mountains in Poland. Half of the studied water samples were radon enriched with an activity concentration higher then 74 Bq/l. Seasonal variations of 222 Rn in these waters are under investigation. The method introduced is very convenient and elegant for radon activity measurements.

  19. Continuous measurements of outdoor radon concentrations

    International Nuclear Information System (INIS)

    Iida, T.; Ikebe, Y.; Suzuki, K.; Ueno, K.; Komura, K.; Kato, I.; Jin Yihe

    1993-01-01

    The authors studied and developed an electrostatic 222 Rn monitor and have measured continuously outdoor radon ( 222 Rn) concentrations at Nagoya University since 1985. Four 222 Rn monitors were newly constructed to measure outdoor 222 Rn concentrations at other locations. The 222 Rn concentrations at Nagoya and Kasugai show a clear diurnal variation in autumn, and a seasonal pattern of a spring-summer minimum and a autumn-winter maximum. The results at Toki are the same pattern as that at Nagoya except spring. The concentrations at Kanazawa show a slight seasonal variation. A clear diurnal variation is observed in summer. (4 figs.)

  20. The measurement of 222Rn and its relationship to environmental variables: Factors controlling indoor radon: Final report for the contract period June 1, 1982 to May 31, 1985

    International Nuclear Information System (INIS)

    Harley, N.H.

    1985-01-01

    Indoor levels of radon-222 and daughter nuclei were monitored at various locations within a single family dwelling and in an apartment building. Indoor levels were correlated with soil temperature, atmospheric pressure, wind, rain and time of year. 9 refs., 23 figs., 19 tabs

  1. 222Rn Measurements in Dwellings of Argentina

    International Nuclear Information System (INIS)

    Gnoni, G.; Canoba, A.; Czerniczyniec, M.

    2011-01-01

    Radon gas ( 222 Rn) is responsible of about fifty per cent of the world population dose due to natural sources, being the most important pathway the inhalation of radon progeny, specially indoors. Radon concentration has been measured in dwellings at different locations in Argentina. The places selected to be evaluated are representative of the different geologic zones of the country. Near 3000 dwellings have been analyzed since 1983 up today. The measuring methods used in this case were track etched detectors, electrets and detectors based on activated charcoal adsorption. Two different methods with track etched detectors were used: a simple one, which determines only the average radon concentration, and a second one that measures both radon concentration and the equilibrium factor (F) between radon and its daughters. The last one is a method that uses two Makrofol passive track detectors in the same device. The average radon concentration value obtained from all the dwellings evaluated was 44.2 Bq.m-3. The annual effective dose calculated from this average concentration, using a dosimetric factor of 25 μSv.a- 1. (Bq.m -3 ) -1 , which assumes an equilibrium factor of 0.4, was 1.11 mSv. The average value obtained from the 222 dwellings evaluated by the second method was 49.3 Bq.m -3 and 0,37 the equilibrium factor, resulting the annual effective dose estimated 1,44 mSv. The measured equilibrium factor of 0,37 allows us to verify the assumed equilibrium factor of 0,4. Finally, radon levels in dwellings of Argentina are within the acceptable values for population, not being necessary to implement remedial actions, except in isolate cases that are still under study. (authors)

  2. Radon in air calibration procedure: A primary method

    International Nuclear Information System (INIS)

    Lucas, H.F.; Markun, F.

    1988-01-01

    A procedure has been developed for preparing 3- to 9-iota volumes of air under natural conditions with a known concentration of /sup 222/Rn to be used for calibrating radon systems. Air is passed into a plastic bag through a standard /sup 226/Ra solution (prepared by the U.S. National Bureau of Standards) contained in an emanation flask. This plastic bag retains /sup 222/Rn with little loss into or through the bag walls. The mean ratios of the /sup 222/Rn in the air at 2 and 7 days after filling to that immediately after filling were -.992 +- 0.006 and 0.969 +- 0.008, which suggests a rate of radon loss into the bag of 0.4 +- 0.1%/day

  3. Radon exhalation from granitic rocks

    International Nuclear Information System (INIS)

    Del Claro, Flávia; Paschuk, Sergei A.; Corrêa, Janine N.; Mazer, Wellington; Narloch, Danielle Cristine; Martin, Aline Cristina; Denyak, Valeriy

    2017-01-01

    Naturally occurring radionuclides such as radon ( 222 Rn), its decay products and other elements from the radioactive series of uranium ( 238 U and 235 U) and thorium ( 232 Th) are an important source of human exposure to natural radioactivity. The worldwide evaluation of health radiobiological effects and risks from population exposure to natural radionuclides is a growing concern. About 50% of personal radiation annual dose is related to radionuclides such as radon ( 222 Rn), thoron ( 220 Rn), radium ( 226 Ra), thorium ( 232 Th) and potassium ( 40 K), which are present in modern materials commonly used in construction of dwellings and buildings. The radioactivity of marbles and granites is of big concern since under certain conditions the radioactivity levels of these materials can be hazardous to the population and require the implementation of mitigation procedures. Present survey of the 222 Rn and 220 Rn activity concentration liberated in the air was performed using commercialized Brazilian granite rocks at national market as well as exported to other countries. The 222 Rn and 220 Rn measurements were performed using the AlphaGUARD instant monitor and RAD7 detector, respectively. This study was performed at the Applied Nuclear Physics Laboratory of the Federal University of Technology – Paraná (UTFPR). Obtained results of radon concentration activity in air exhaled studied samples of granites varied from 3±1 Bq/m 3 to 2087±19 Bq/m 3 , which shows that some samples of granitic rocks represent rather elevated health risk the population. (author)

  4. Construction materials and Radon

    International Nuclear Information System (INIS)

    Paschuk, Sergei A.; Correa, Janine Nicolosi; Loriane, Fior; Schelin, Hugo R.; Pottker, Fabiana; Paula Melo, Vicente de

    2008-01-01

    Full text: Current studies have been performed with the aim to find the correlation of radon concentration in the air and used construction materials. At the first stage of the measurements different samples of materials used in civil construction were studied as a source of radon in the air and at the second step it was studied the radon infiltration insulation using different samples of finishing materials. For 222 Rn concentration measurements related to different construction materials as well as for the studies of radon emanation and its reduction, the sealed cell chambers, of approximately 60 x 60cm 2 , have been built using the ceramic and concrete blocks. This construction has been performed within protected and isolated laboratory environment to maintain the air humidity and temperature stable. These long term measurements have been performed using polycarbonate alpha track passive detectors. The exposure time was set about 15 days considering previous calibration performed at the Institute of Radiation Protection and Dosimetry (IRD/CNEN), where the efficiency of 70% was obtained for the density of alpha particle tracks about 13.8 cm -2 per exposure day and per kBq/m 3 of radon activity concentration. The chemical development of alpha tracks has been achieved by electrochemical etching. The track identification and counting have been done using a code based on the MATLAB Image Processing Toolbox. The cell chambers have been built following four principle steps: 1) Assembling the walls using the blocks and mortar; 2) Plaster installation; 3) Wall surface finishing using the lime; 4) Wall surface insulation by paint. Making the comparison between three layers installed at the masonry walls from concrete and ceramic blocks, it could be concluded that only wall painting with acrylic varnish attended the expectation and reduced the radon emanation flow by the factor of 2.5 approximately. Studied construction materials have been submitted the instant

  5. Development of model DTY-104 radon measuring meter

    International Nuclear Information System (INIS)

    Shi Zhixia; Zhang Aiming; Li Yachun; Wang Qingheng

    2000-01-01

    Model DTY-104 radon measuring meter is an improvement on Model DTY-103. 'Difference value method' is used, which has been strictly developed and makes the radon exhalation rate more accurate, instead of using 'simplified difference value method'. The electronic circuit is redesigned and 80C31 single chip processor is used, which makes the operation more convenient and the function strengthened. In a more reasonable manner, the humidity sensor is mounted in the collection chamber. The collection efficiency can be automatically corrected. The technique of exchanging the collection mylar reduces the waiting time and improves work efficiency. The apparatus is applied to the measurement of the radon concentration in the environment and the radon exhalation from the surface of the building materials, walls and ground. The lower detection limit is about 4Bq/m 3 for 222 Rn concentration and 5 x 10 -5 Bq/s/m 2 for 222 Rn exhalation rate

  6. 222Rn in the Antarctic Peninsula during 1986

    International Nuclear Information System (INIS)

    Pereira, E.B.; Setzer, A.W.; Cavalcanti, I.F.A.

    1988-01-01

    222 Rn was continuously measured at the Brazilian Antarctic Station (62 0 S, 58 0 W) during the year of 1986. Baseline radon concentration averaged 0.02 Bq.m -3 with surges peaking 0.4 Bq.m -3 . The data exhibited a characteristic periodicity of about 25 days and a strong positive association with short term fluctuations of atmospheric temperature. No seasonal variations of radon were observed. Interpretation of the radon surges with reference to synoptic charts and weather satellite pictures showed that the continental influence of radon at the Antarctic Peninsula is very small and comes only from the tip of the South American cone. (author)

  7. A preliminary investigation of 222Rn and 220Rn levels in non-uranium mines in China

    International Nuclear Information System (INIS)

    Shang Bing; Cui Hongxing; Wu Yunyun; Zhang Qingzhao; Su Xu

    2008-01-01

    Objective: To measure levels of 222 Rn and 220 Rn in typical non-uranium mines, China, and to estimate dose from the occupational radon exposure in the miners. Methods: Using typical sampling scheme, 44 mines were selected in 12 provinces, which can be classified into 4 categories and 17 types of mines. The radon-thoron discriminative detectors were used to measure 222 Rn and 220 Rn concentrations in mines. Result: The concentration of 222 Rn or 220 Rn was log-normally distributed. The arithmetic mean (AM) concentration and geometric mean (GM) concentration of 222 Rn and 220 Rn in 25 metal mines (n=147) were estimated to be (1211 ±2359) Bq/m 3 (AM) and (311 ± 5.5) Bq/m 3 (GM), and (269 ±700) Bq/m 3 (AM) and (71 ± 4.4)Bq/m 3 (GM), respectively. The mean concentrations of 222 Rn and 220 Rn in 18 non-metal mines (n=118) were (98 ± 207) Bq/m 3 (AM) and(55 ± 2.5) Bq/m 3 (GM), and (60 ± 76) Bq/m 3 (AM) and (38 ± 2.4) Bq/m 3 (GM) respectively. In total, we measured 222 Rn concentration in 44 underground mines, 6 of them, accounted for 15%, with the mean radon concentration exceeding 1000 Bqm -3 (limit of workplace in China). Approximately 7% of radon concentration in mines measured were higher than 3700 Bq/m 3 (current limit in uranium mine in China), some points even exceeded 10 000 Bq/m 3 . Based on this typical measurements, the equilibrium factor for 222 Rn was estimated to be 0.33 ± 0.15 in underground mines and 0.47 ±0.18 in nearby houses. Equilibrium factor for 220 Rn ranged from 0.001 to 0.032. Using the data obtained in this typical survey, the average annual effective dose of underground miners exposed to radon and thoron was estimated to be 8.15 mSv/a. Conclusions: High levels of 222 Rn exists in metal mines, such as copper, tin, lead and zinc, gold, and aluminum mines among others. More study and administrative measures are needed to address the radiation protection of workers occupationally exposed to high radon in mines. (authors)

  8. Study of 222Rn variations in the soil air

    International Nuclear Information System (INIS)

    Holy, K.; Boehm, R.; Matos, M.; Polaskova, A.; Hola, O.

    1998-01-01

    A significant source of radon in the indoor atmosphere is represented by 222 Rn in the soil air, ie., by the fraction of radon atoms produced by alpha decay of 226 Ra in soil grains that escaped into soil pores. In the paper the results are presented of a three year monitoring of radon in soil air, using a 125 ml Lucas type scintillation cell. Radon concentration depth profiles in the soil in various seasons of the year were also measured, and saturated concentration of radon in soil air was found at a depth of about 2 m. Monthly variations in the radon concentration were observed over several months and the possible causes of the variations are discussed. Daily courses of radon concentration were also measured and the results are presented. (A.K.)

  9. Survey of radon 222 in Monroe county, Pennsylvania

    International Nuclear Information System (INIS)

    Houle, P.N.; Blick, D.N.

    1990-01-01

    This paper reports on a high density of home radon concentration measurements over one Pennsylvania County that was made. Agreement between these results and larger area but lower density measurements is found to be good. It is concluded that a measurement density of approximately .15 measurements per square mile will yield results in good agreement with a density of 1.39 measurements per square mile. It is also found that Pennsylvania, in part or taken as a whole, has three times as high a percentage of homes with radon concentrations greater than 4.0 Pci/L than present E. P. A. estimates indicate

  10. Biological effects of radon in Drosophila

    International Nuclear Information System (INIS)

    Pimentel P, A.E.; Tavera D, L.; Cruces M, M.P.; Arceo M, C.; Rosa D, M.E. de la

    1992-04-01

    The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

  11. The ratio of long-lived to short-lived radon-222 progeny concentrations in ground-level air

    International Nuclear Information System (INIS)

    Hoetzl, H.; Winkler, R.

    1996-01-01

    The ratio of 210 Pb air concentration to the short-lived radon ( 222 Rn) decay products concentration at ground level was investigated at a semi-rural location 10 km north of Munich, south Germany, for a period of 11 years (1982-1992). The average ratio from 132 monthly mean values has been found to be (7.5±2.2) x 10 -5 (arithmetic mean±S.D.). While the time series of the short-lived radon daughter concentration exhibit a distinct seasonal pattern with maxima mostly in October of each year, the course of 210 Pb air concentration is characterized by high values from October through February. Consequently, high ratios of 210 Pb to short-lived decay product concentration are often observed in the winter months of December-February. To study the influence of meteorological conditions on this behaviour, 210 Pb and 214 Pb concentrations were measured on a short-term basis with sampling intervals of 2-3 days from October 1991 to November 1992. The air concentrations obtained within those intervals were then correlated with actual meteorological parameters. On the base of this investigation the seasonal behaviour can essentially be explained by the more frequent inversion weather conditions in winter than in the summer months. At the same location, the average ratio of 210 Po to 210 Pb concentration in ground level air has been found to be 0.079 from 459 weakly mean values between 1976 and 1985. Hence, the corresponding average ratios of the short-lived radon daughters (EEC) to 210 Pb and 210 Po, were 1:7.5x10 -5 and 1:0.6 x 10 -5 , respectively

  12. Radon Concentrations in Drinking Water in Beijing City, China and Contribution to Radiation Dose

    Science.gov (United States)

    Wu, Yun-Yun; Ma, Yong-Zhong; Cui, Hong-Xing; Liu, Jian-Xiang; Sun, Ya-Ru; Shang, Bing; Su, Xu

    2014-01-01

    222Rn concentrations in drinking water samples from Beijing City, China, were determined based on a simple method for the continuous monitoring of radon using a radon-in-air monitor coupled to an air-water exchanger. A total of 89 water samples were sampled and analyzed for their 222Rn content. The observed radon levels ranged from detection limit up to 49 Bq/L. The calculated arithmetic and geometric means of radon concentrations in all measured samples were equal to 5.87 and 4.63 Bq/L, respectively. The average annual effective dose from ingestion of radon in drinking water was 2.78 μSv, and that of inhalation of water-borne radon was 28.5 μSv. It is concluded that it is not the ingestion of waterborne radon, but inhalation of the radon escaping from water that is a substantial part of the radiological hazard. Radon in water is a big concern for public health, especially for consumers who directly use well water with very high radon concentration. PMID:25350007

  13. Radon Concentrations in Drinking Water in Beijing City, China and Contribution to Radiation Dose

    Directory of Open Access Journals (Sweden)

    Yun-Yun Wu

    2014-10-01

    Full Text Available 222Rn concentrations in drinking water samples from Beijing City, China, were determined based on a simple method for the continuous monitoring of radon using a radon-in-air monitor coupled to an air-water exchanger. A total of 89 water samples were sampled and analyzed for their 222Rn content. The observed radon levels ranged from detection limit up to 49 Bq/L. The calculated arithmetic and geometric means of radon concentrations in all measured samples were equal to 5.87 and 4.63 Bq/L, respectively. The average annual effective dose from ingestion of radon in drinking water was 2.78 μSv, and that of inhalation of water-borne radon was 28.5 μSv. It is concluded that it is not the ingestion of waterborne radon, but inhalation of the radon escaping from water that is a substantial part of the radiological hazard. Radon in water is a big concern for public health, especially for consumers who directly use well water with very high radon concentration.

  14. Metrology of radon and thoron concentrations

    International Nuclear Information System (INIS)

    Durcik, M; Vicanova, M.

    1998-01-01

    The alpha spectrometry measurements of radon (radon-222) and thoron (radon-220) concentrations by ionisation chamber, used only in laboratory conditions are described in this paper. For the measurements of radon and thoron in dwellings and work areas was proposed diffusion double chamber detector with track detector. The described dosimeter is very useful for routine measurement and would be applied in measuring of radon and thoron concentrations in caves and dwellings. Big disadvantage of the dosimeter is small holes in cover and it could not be used in dusty areas. From previous measurements of the equilibrium equivalent thoron concentrations by semiconductor detector the measured values ranged from 0.1 to 5.6 Bq m -3 in the Slovak kindergartens were obtained

  15. RAETRAD MODEL OF RADON GAS GENERATION, TRANSPORT, AND INDOOR ENTRY

    Science.gov (United States)

    The report describes the theoretical basis, implementation, and validation of the Radon Emanation and Transport into Dwellings (RAETRAD) model, a conceptual and mathematical approach for simulating radon (222Rn) gas generation and transport from soils and building foundations to ...

  16. Measurements of radon in drinking water (Curitiba, PR, Brazil)

    International Nuclear Information System (INIS)

    Correa, Janine Nicolosi; Paschuk, Sergei A.; Schelin, Hugo R.; Barbosa, Laercio; Sadula, Tatyana; Matsuzaki, Cristiana A.

    2009-01-01

    Full text: Among the principle mechanisms that bring the radon inside the dwelling is the exhalation and release from the water. It was evaluated that considering the latest mechanism, the exhalation of radon from the water represents about 89% of the cancer risk and the consumption of water with high concentration of radon is related to about 11% of risk cancer. Radon concentration in water could be subject of different factors such as the geology of the area, bottom sediments and inputs from streams, temperature, atmospheric pressure, etc. It is well known that the solubility of radon in water is about 510 cm 3 kg -1 at 0 deg C and decreases at higher temperatures. The 222 Rn concentration in various types of natural water in different countries usually is about few Bq/L and is the subject of the National legislation as well as International norms and recommendations. For example, the United States Environmental Protection Agency (USEPA) established a limit of 11.1 Bq/L for the radon level in drinking water and this limit is considered as guideline in Canada and many countries of the European Union. Current work presents the results of more than 100 measurements of 222 Rn activity in drinking water collected at artesian bores at Curitiba region during the period of 2008 - 2009. The measurements were performed at the Laboratory of Applied Nuclear Physics of the Federal University of Technology in cooperation with the Nuclear Technology Development Center (CDTN) of Brazilian Nuclear Energy Committee (CNEN). Experimental setup was based on the Professional Radon Monitor (ALPHA GUARD) connected to specific kit of glass vessels Aqua KIT through the air pump. The equipment was adjusted with air flow of 0.5 L/min. The 222 Rn concentration levels were detected and analyzed by the computer using the software DataEXPERT by GENITRON Instruments. Collected average levels of 222 Rn concentration were processed taking into account the volume of water sample and its temperature

  17. ''Radon-emanometry'' applied to internal geophysics

    International Nuclear Information System (INIS)

    Seidel, J.L.

    1982-02-01

    An experimental set-up for in ground radon 222 measurements has been realised with solid state track detectors (cellulose nitrates CN85 and LR115). A preliminary study of radon activity variations has been conducted over various sites expecting using radon as one of forerunner geophysical parameters of volcanic eruptions and earthquakes predictions. The first data obtained in the field are presented: Etna (Sicily), Krafla (Iceland), Poas and Arenal (Costa Rica), Colima and Paricutin (Mexico) for active volcanoes, Ech Cheliff (Algeria) and Alsace (France) for sismotectonic areas [fr

  18. Indoor "2"2"2Rn concentration in the exhibition and storage rooms of Polish geological museums

    International Nuclear Information System (INIS)

    Długosz-Lisiecka, Magdalena; Krystek, Marcin; Raczyński, Paweł; Głuszek, Ewa; Kietlińska-Michalik, Barbara; Niechwedowicz, Mariusz

    2017-01-01

    The radon exhaled from radioactive mineral collections exhibited in five Polish geological museums may influence its total indoor concentration. Radon concentrations measured in the exhibition halls do not pose a risk for visitors or museum staff. However, air exceeding the action limit for workers (equal to 300 Bq/m"3) was noted in the storage rooms of two museums. Significant"2"2"2Rn activity concentrations equal to more than ~300 kBq/m"3were measured inside lead containers where radioactive minerals were stored. - Highlights: • In this "2"2"2Rn radionuclide measurements in 5 Polish geological museums have been done. • The review of "2"2"2Rn activity in the air in areas containing radioactive geological collections is not a routine protocol, and is not included in the national radon monitoring program. • Therefore the radiological exposure for museum staff resulting from inhalation of gaseous radon and its products has been including.

  19. Radon concentrations in ground and drinking water in the state of Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Villalba, L.; Colmenero Sujo, L.; Montero Cabrera, M.E.; Cano Jimenez, A.; Renteria Villalobos, M.; Delgado Mendoza, C.J.; Jurado Tenorio, L.A.; Davila Rangel, I.; Herrera Peraza, E.F.

    2005-01-01

    This paper reports 222 Rn concentrations in ground and drinking water of nine cities of Chihuahua State, Mexico. Fifty percent of the 114 sampled wells exhibited 222 Rn concentrations exceeding 11 Bq/L, the maximum contaminant level (MCL) recommended by the USEPA. Furthermore, around 48% (123 samples) of the tap-water samples taken from 255 dwellings showed radon concentrations over the MCL. There is an apparent correlation between total dissolved solids and radon concentration in ground-water. The high levels of 222 Rn found may be entirely attributed to the nature of aquifer rocks

  20. Radon concentrations in ground and drinking water in the state of Chihuahua, Mexico.

    Science.gov (United States)

    Villalba, L; Colmenero Sujo, L; Montero Cabrera, M E; Cano Jiménez, A; Rentería Villalobos, M; Delgado Mendoza, C J; Jurado Tenorio, L A; Dávila Rangel, I; Herrera Peraza, E F

    2005-01-01

    This paper reports (222)Rn concentrations in ground and drinking water of nine cities of Chihuahua State, Mexico. Fifty percent of the 114 sampled wells exhibited (222)Rn concentrations exceeding 11Bq/L, the maximum contaminant level (MCL) recommended by the USEPA. Furthermore, around 48% (123 samples) of the tap-water samples taken from 255 dwellings showed radon concentrations over the MCL. There is an apparent correlation between total dissolved solids and radon concentration in ground-water. The high levels of (222)Rn found may be entirely attributed to the nature of aquifer rocks.

  1. Radon exhalation from granitic rocks

    Energy Technology Data Exchange (ETDEWEB)

    Del Claro, Flávia; Paschuk, Sergei A.; Corrêa, Janine N.; Mazer, Wellington; Narloch, Danielle Cristine; Martin, Aline Cristina [Universidade Tecnológica Federal do Paraná (UTFPR), Curitiba, PR (Brazil); Denyak, Valeriy, E-mail: flaviadelclaro@gmail.com, E-mail: spaschuk@gmail.com, E-mail: janine_nicolosi@hotmail.com, E-mail: denyak@gmail.com [Instituto de Pesquisa Pelé Pequeno Príncipe (IPPP), Curitiba, PR (Brazil)

    2017-07-01

    Naturally occurring radionuclides such as radon ({sup 222}Rn), its decay products and other elements from the radioactive series of uranium ({sup 238}U and {sup 235}U) and thorium ({sup 232}Th) are an important source of human exposure to natural radioactivity. The worldwide evaluation of health radiobiological effects and risks from population exposure to natural radionuclides is a growing concern. About 50% of personal radiation annual dose is related to radionuclides such as radon ({sup 222}Rn), thoron ({sup 220}Rn), radium ({sup 226}Ra), thorium ({sup 232}Th) and potassium ({sup 40}K), which are present in modern materials commonly used in construction of dwellings and buildings. The radioactivity of marbles and granites is of big concern since under certain conditions the radioactivity levels of these materials can be hazardous to the population and require the implementation of mitigation procedures. Present survey of the {sup 222}Rn and {sup 220}Rn activity concentration liberated in the air was performed using commercialized Brazilian granite rocks at national market as well as exported to other countries. The {sup 222}Rn and {sup 220}Rn measurements were performed using the AlphaGUARD instant monitor and RAD7 detector, respectively. This study was performed at the Applied Nuclear Physics Laboratory of the Federal University of Technology – Paraná (UTFPR). Obtained results of radon concentration activity in air exhaled studied samples of granites varied from 3±1 Bq/m{sup 3} to 2087±19 Bq/m{sup 3}, which shows that some samples of granitic rocks represent rather elevated health risk the population. (author)

  2. Radon counting statistics - a Monte Carlo investigation

    International Nuclear Information System (INIS)

    Scott, A.G.

    1996-01-01

    Radioactive decay is a Poisson process, and so the Coefficient of Variation (COV) of open-quotes nclose quotes counts of a single nuclide is usually estimated as 1/√n. This is only true if the count duration is much shorter than the half-life of the nuclide. At longer count durations, the COV is smaller than the Poisson estimate. Most radon measurement methods count the alpha decays of 222 Rn, plus the progeny 218 Po and 214 Po, and estimate the 222 Rn activity from the sum of the counts. At long count durations, the chain decay of these nuclides means that every 222 Rn decay must be followed by two other alpha decays. The total number of decays is open-quotes 3Nclose quotes, where N is the number of radon decays, and the true COV of the radon concentration estimate is 1/√(N), √3 larger than the Poisson total count estimate of 1/√3N. Most count periods are comparable to the half lives of the progeny, so the relationship between COV and count time is complex. A Monte-Carlo estimate of the ratio of true COV to Poisson estimate was carried out for a range of count periods from 1 min to 16 h and three common radon measurement methods: liquid scintillation, scintillation cell, and electrostatic precipitation of progeny. The Poisson approximation underestimates COV by less than 20% for count durations of less than 60 min

  3. Variability of Atmospheric Radon-222 and Secondary Aerosol Components in Accordance with Air Mass Transport Pathways at Jeju Island, Korea, during 2011-2014

    International Nuclear Information System (INIS)

    Bu, Jun-Oh; Song, Jung-Min; Kim, Won-Hyung; Kang, Chang-Hee; Chambers, Scott D.; Williams, Alastair G.; Lee, Chulkyu

    2016-01-01

    Real-time monitoring of hourly atmospheric Radon-222 concentration and three daily monitoring of the secondary aerosol components of PM_1_0 were performed throughout 2011-2014 at Gosan station, Jeju Island, in order to characterize their background levels and temporal variation. The annual mean radon and PM_1_0 mass concentrations were 2326 ± 1198 mBq/m"3 and 37.1 ± 19.5 μg/m"3, respectively. Based on cluster analyses of air mass back trajectories, the frequencies of air masses originating from continental China, the Korean Peninsula, and North Pacific Ocean routes were 53, 28, and 19%, respectively. When the air masses were transported to Jeju Island from continental China, the concentrations of radon and secondary aerosol components (nss-SO_4"2"-, NO_3"-, NH_4"+) were relatively high: 2577 mBq/m"3 and 14.4 μg/m"3, respectively. In cases when the air masses have moved from the Korean Peninsula, the corresponding concentrations were 2247 mBq/m"3 and 11.4 μg/m"3, respectively. On the other hand, when the air masses came from the North Pacific Ocean, their radon and secondary aerosol concentrations decreased much further, 1372 mBq/m"3 and 10.5 μg/m"3, respectively. Consequently, the variability of atmospheric radon concentrations at Gosan station might be characterized by synoptic changes in air mass fetch as well as diurnal changes in atmospheric mixing depth.

  4. The optimation of radon-222 determination in water by Lucas cell technique

    International Nuclear Information System (INIS)

    Andrejkovicova, S.; Kuruc, J.; Kovacsova, A.; Mackova, J.; Rajec, P.

    2003-01-01

    The aim of this work was to determine detection efficiency ε, volume activity a v , low detection limit, minimal detection activity for radon. There were collecting several samples of water: water from tap water, mineral water, thermal water, water from wells and bottled drinking water. As we expected, the lowest values of volume activities of radon were reached in bottled drinking water (0.1 - 4.9 Bq/dm 3 ). Higher values were reached in water from tap water and natural mineral water (2.5 - 14.9 Bq/dm 3 ). The highest volume activities of radon were obtained in thermal water and water from wells (17.2 - 107.9 Bq/dm 3 ). Method for determination of radon in water was verified at Institute of Preventive and Clinical Medicine, Bratislava, Slovakia. Results of radon concentration in waters are in accordance with an uppermost - accepted value of radon in water. The volume activity of radon in our samples has never been higher as a limit value has allowed (300 Bq/dm 3 ). (authors)

  5. Radon in the Underground Workplaces; Assessment of the Annual Effective Dose due to Inhaled Radon for the Seoul Subway Station Staffs

    Energy Technology Data Exchange (ETDEWEB)

    Song, Myeong Han; Chang, Byung Uck; Kim, Yong Jae [University of Science and Technology, Daejeon (Korea, Republic of); Lee, Hwa Yong [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Heo, Dong Hey [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2010-12-15

    The effective dose of the Seoul subway staffs due to inhaled radon ({sup 222}Rn) in their workplace was investigated depended on radon concentration exposed at each workplace, and working hours and working types of the staffs. Annual average radon concentrations ranged from 16.5 to 93.0 Bq·m{sup -3}. The staffs commonly spend 2,304 hours in the underground spaces a year. With the radon concentrations and the working hours of the staffs, estimated annual effective doses ranged from 0.23 to 0.73 mSv·y{sup -1}.

  6. Radon in the Underground Workplaces; Assessment of the Annual Effective Dose due to Inhaled Radon for the Seoul Subway Station Staffs

    International Nuclear Information System (INIS)

    Song, Myeong Han; Chang, Byung Uck; Kim, Yong Jae; Lee, Hwa Yong; Heo, Dong Hey

    2010-01-01

    The effective dose of the Seoul subway staffs due to inhaled radon ( 222 Rn) in their workplace was investigated depended on radon concentration exposed at each workplace, and working hours and working types of the staffs. Annual average radon concentrations ranged from 16.5 to 93.0 Bq·m -3 . The staffs commonly spend 2,304 hours in the underground spaces a year. With the radon concentrations and the working hours of the staffs, estimated annual effective doses ranged from 0.23 to 0.73 mSv·y -1

  7. Contribution to the relation between volume activity of soil and indoor radon

    International Nuclear Information System (INIS)

    Mojzes, A.

    1999-01-01

    There were carried out some repeated manual measurements of volume activity of radon-222 (VAR) in both soil air of subsoil and also indoor air of buildings in two different areas in Bratislava. All measurements were done with a portable scintillation detector based on exchangeable Lucas cells. The measurements were repeated in different day and year intervals. There were repeated 259 measurements of volume activity of radon-222 in soil air with the average valuer 11.95 kBq/m 3 and the standard deviation 1.53 kBq/m 3 in the subsoil of the one-story house and 597 measurements of VAR in soil air of the subsoil of the second study building with the average 9.44 kBq/m 3 and the standard deviation 3.08 kBq/m 3 . Presented results of measurement of radon-222 volume activity in both soil and indoor air demonstrate that also in case of low radon concentrations in soil air of geological basement the level of radon in indoor air could be considerably high. It depends mainly on used technology of laying building foundations, on the distance from subsoil and on regime of ventilation. In case of older buildings the ventilation is very effective way to reduce the presence of radon in indoor air. (author)

  8. Radon and radon daughters indoors, problems in the determination of the annual average

    International Nuclear Information System (INIS)

    Swedjemark, G.A.

    1984-01-01

    The annual average of the concentration of radon and radon daughters in indoor air is required both in studies such as determining the collective dose to a population and at comparing with limits. Measurements are often carried out during a time period shorter than a year for practical reasons. Methods for estimating the uncertainties due to temporal variations in an annual average calculated from measurements carried out during various lengths of the sampling periods. These methods have been applied to the results from long-term measurements of radon-222 in a few houses. The possibilities to use correction factors in order to get a more adequate annual average have also been studied and some examples have been given. (orig.)

  9. A study of indoor radon levels and radon effective dose in dwellings of some cities of Gezira State in Sudan

    Directory of Open Access Journals (Sweden)

    Elzain Abd-Elmoniem Ahmed

    2014-01-01

    Full Text Available Exposure to natural sources of radiation, especially 222Rn and its short-lived daughter products has become an important issue throughout the world because sustained exposure of humans to indoor radon may cause lung cancer. The indoor radon concentration level and radon effective dose rate were carried out in the dwellings of Medani, El Hosh, Elmanagil, Haj Abd Allah, and Wad Almahi cities, Gezira State - Central Sudan, in 393 measurements, using passive integrated solid-state nuclear track devices containing allyl diglycol carbonate plastic detectors. The radon concentration in the corresponding dwellings was found to vary from (57 ± 8 Bq/m3 in Medani to 41 ± 9 Bq/m3 in Wad Almahi, with an average of 49 ± 10 Bq/m3. Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, we found that the annual effective dose rate from 222Rn in the studied dwellings ranges from 1.05 to 1.43 mSv per year and the relative lung cancer risk for radon exposure was 1.044%. In this research, we also correlated the relationship of radon concentration and building age. From our study, it is clear that the annual effective dose rate is larger than the “normal” background level as quoted by UNSCEAR, lower than the recommended action level of ICRP, and less than the maximum permissible dose defined by the International Atomic Energy Agency.

  10. Radon-222 related influence on ambient gamma dose.

    Science.gov (United States)

    Melintescu, A; Chambers, S D; Crawford, J; Williams, A G; Zorila, B; Galeriu, D

    2018-04-03

    Ambient gamma dose, radon, and rainfall have been monitored in southern Bucharest, Romania, from 2010 to 2016. The seasonal cycle of background ambient gamma dose peaked between July and October (100-105 nSv h -1 ), with minimum values in February (75-80 nSv h -1 ), the time of maximum snow cover. Based on 10 m a.g.l. radon concentrations, the ambient gamma dose increased by around 1 nSv h -1 for every 5 Bq m -3 increase in radon. Radon variability attributable to diurnal changes in atmospheric mixing contributed less than 15 nSv h -1 to the overall variability in ambient gamma dose, a factor of 4 more than synoptic timescale changes in air mass fetch. By contrast, precipitation-related enhancements of the ambient gamma dose were 15-80 nSv h -1 . To facilitate routine analysis, and account in part for occasional equipment failure, an automated method for identifying precipitation spikes in the ambient gamma dose was developed. Lastly, a simple model for predicting rainfall-related enhancement of the ambient gamma dose is tested against rainfall observations from events of contrasting duration and intensity. Results are also compared with those from previously published models of simple and complex formulation. Generally, the model performed very well. When simulations underestimated observations the absolute difference was typically less than the natural variability in ambient gamma dose arising from atmospheric mixing influences. Consequently, combined use of the automated event detection method and the simple model of this study could enable the ambient gamma dose "attention limit" (which indicates a potential radiological emergency) to be reduced from 200 to 400% above background to 25-50%. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Factors influencing radon attenuation by tailing covers

    International Nuclear Information System (INIS)

    Silker, W.B.; Rogers, V.C.

    1981-07-01

    The US NRC, in its Generic Environmental Impact Statement on uranium milling has specified that the radon flux escaping a uranium mill tailings pile will be reduced to pCi/m 2 s by application of covering layers of soils and clays. These covers present a radon diffusion barrier, which sufficiently increases the time required for radon passage from the tailings to the atmosphere to allow for decay of 222 Rn within the cover. The depth of cover necessary to reduce the escaping radon flux to the prescribed level is to be determined by calculation, and requires precise knowledge of the radon diffusion coefficient in the covering media. A Radon Attenuation Test Facility was developed to determine rates of radon diffusion through candidate cover materials. This paper describes this facility and its application for determining the influence of physical properties of the soil column on the radon diffusion coefficient

  12. Contribution of waterborne radon to home air quality

    International Nuclear Information System (INIS)

    Deb, A.K.

    1994-01-01

    Radon-222 is a member of the uranium decay chain and is formed from the decay of radium-226. Radon and its decay products emit alpha particles during the decay process. If radon is inhaled, alpha particles emitted from inhaled radon and its daughters increase the risk of lung cancer. Radon is soluble in water; thus when radon comes in contact with groundwater it dissolves. The radon concentration in groundwater may range from 100 pCi/L to 1,000,000 pCi/L. When water with a high radon level is used in the home, radon is released from the water to the air and thus can increase indoor air radon concentration. Considering the estimated health risk from radon in public water supply systems, EPA has proposed a maximum contaminant level (MCL) of 300 pCi/L for radon in public drinking water supplies. To address the health risks of radon in water and the proposed regulations, the American Water Works Association Research Foundation (AWWARF) initiated a study to determine the contribution of waterborne radon to radon levels in indoor household air

  13. The ratio of long-lived to short-lived radon-222 progeny concentrations in ground-level air

    Energy Technology Data Exchange (ETDEWEB)

    Hoetzl, H.; Winkler, R. [Institut fuer Strahlenschutz, GSF-Forschungszentrum fuer Umwelt und Gesundheit, Neuherberg Oberschleissheim (Germany)

    1996-02-09

    The ratio of {sup 210}Pb air concentration to the short-lived radon ({sup 222}Rn) decay products concentration at ground level was investigated at a semi-rural location 10 km north of Munich, south Germany, for a period of 11 years (1982-1992). The average ratio from 132 monthly mean values has been found to be (7.5{+-}2.2) x 10{sup -5} (arithmetic mean{+-}S.D.). While the time series of the short-lived radon daughter concentration exhibit a distinct seasonal pattern with maxima mostly in October of each year, the course of {sup 210}Pb air concentration is characterized by high values from October through February. Consequently, high ratios of {sup 210}Pb to short-lived decay product concentration are often observed in the winter months of December-February. To study the influence of meteorological conditions on this behaviour, {sup 210}Pb and {sup 214}Pb concentrations were measured on a short-term basis with sampling intervals of 2-3 days from October 1991 to November 1992. The air concentrations obtained within those intervals were then correlated with actual meteorological parameters. On the base of this investigation the seasonal behaviour can essentially be explained by the more frequent inversion weather conditions in winter than in the summer months. At the same location, the average ratio of {sup 210}Po to {sup 210}Pb concentration in ground level air has been found to be 0.079 from 459 weakly mean values between 1976 and 1985. Hence, the corresponding average ratios of the short-lived radon daughters (EEC) to {sup 210}Pb and {sup 210}Po, were 1:7.5x10{sup -5} and 1:0.6 x 10{sup -5}, respectively.

  14. Observation and modeling of 222Rn daughters in liquid nitrogen

    International Nuclear Information System (INIS)

    Frodyma, N.; Pelczar, K.; Wójcik, M.

    2014-01-01

    The results of alpha spectrometric measurements of the activity of 222 Rn daughters dissolved in liquefied nitrogen are presented. A direct detection method of ionized alpha-emitters from the 222 Rn decay chain ( 214 Po and 218 Po) in a cryogenic liquid in the presence of an external electric field is shown. Properties of the radioactive ions are derived from a proposed model of ion production and transport in the cryogenic liquid. Ionic life-time of the ions was found to be on the order of 10 s in liquid nitrogen (4.0 purity class). The presence of positive and negative ions was observed. - Highlights: • A direct detection method of the alpha-emitters in a cryogenic liquid is shown. • We examine electrostatic drifting of the radioactive ions in liquid nitrogen. • The ions belong to the Radon-222 decay chain; Radon-222 is dissolved in the liquid. • The model of the ions production and behaviour in the liquid is proposed. • The ion production significantly depends on the nuclear decay type (alpha or beta)

  15. Design of a recirculating radon progeny aerosol generation and animal exposure system

    International Nuclear Information System (INIS)

    Newton, G.J.; Cuddihy, R.G.; Yeh, H.C.; Barr, E.B.; Boecker, B.B.

    1988-01-01

    Inhalation studies are being conducted at ITRI using laboratory animals exposed to radon-222 progeny attached to vector aerosols that are typical of indoor environments. The purpose of these studies is to identify the cells at risk from inhaled radon progeny and their locations within the respiratory tract. These studies require exposures up to 1000 working level months (WLM) within a few hours. Thus, large amounts of radium-226 are needed to produce the gaseous radon-222. A once-through-exposure-system was considered to be impractical because of statutory discharge limitations and the large amounts of radium that would be required. Therefore, a recirculating exposure system was designed and constructed that removes the aerosol after passing through the exposure chambers and recirculates purified air and radon. The purified radon is mixed with freshly evolving radon from a radon generator and passed Into a reaction-aging chamber where attachment of radon progeny to the vector aerosol occurs. The design includes: (1) 50-200 mg radium-226 in a radon generator, (2) 40 L/min total flow rate, (3) CO 2 removal, (4) reconstitution of oxygen tension and water vapor content to atmospheric levels, and (5) a trap for radon gas. A radon progeny exposure concentration in the range of 4,000 to 50,000 WL is being produced. (author)

  16. Radon concentrations in ground and drinking water in the state of Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Villalba, L. [Centro de Investigacion en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, CP 31109 Chihuahua, Chih. (Mexico); Colmenero Sujo, L. [Centro de Investigacion en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, CP 31109 Chihuahua, Chih. (Mexico); Instituto Tecnologico de Chihuahua II, Ave. de las Industrias 11101, Chihuahua, Chih. (Mexico); Montero Cabrera, M.E. [Centro de Investigacion en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, CP 31109 Chihuahua, Chih. (Mexico)]. E-mail: elena.montero@cimav.edu.mx; Cano Jimenez, A. [Centro de Investigacion en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, CP 31109 Chihuahua, Chih. (Mexico); Renteria Villalobos, M. [Centro de Investigacion en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, CP 31109 Chihuahua, Chih. (Mexico); Delgado Mendoza, C.J. [Facultad de Ciencias Quimicas, Universidad Autonoma de Chihuahua, Ciudad Universitaria S/N, Chihuahua, Chih. (Mexico); Jurado Tenorio, L.A. [Facultad de Ciencias Quimicas, Universidad Autonoma de Chihuahua, Ciudad Universitaria S/N, Chihuahua, Chih. (Mexico); Davila Rangel, I. [Centro Regional de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 20, Zacatecas, Zac. (Mexico); Herrera Peraza, E.F. [Centro de Investigacion en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, CP 31109 Chihuahua, Chih. (Mexico)

    2005-07-01

    This paper reports {sup 222}Rn concentrations in ground and drinking water of nine cities of Chihuahua State, Mexico. Fifty percent of the 114 sampled wells exhibited {sup 222}Rn concentrations exceeding 11 Bq/L, the maximum contaminant level (MCL) recommended by the USEPA. Furthermore, around 48% (123 samples) of the tap-water samples taken from 255 dwellings showed radon concentrations over the MCL. There is an apparent correlation between total dissolved solids and radon concentration in ground-water. The high levels of {sup 222}Rn found may be entirely attributed to the nature of aquifer rocks.

  17. Realisation of a calibration chamber for radon in the air and establishment of a system for measuring radon in water

    International Nuclear Information System (INIS)

    Sassi, Nedra

    2011-01-01

    Radon is a radioactive gas that is naturally produced from the decay of radium. The main source of radon found in the earth's crust caused by the presence of a series of uranium (222 isotope of radon) and a series of thorium (220 isotope of radon) therein. We have optimized a new radon calibration chamber by developing an electronic system controlled by a PIC 16F877 microcontroller type to manage the various functions of the room. Several electronic circuits were developed to manage multiple functions such as pressure, temperature and controls motors and solenoids. This system can also be interfaced with a computer through programs such as LabView or Matlab.

  18. Radon measurements in well and spring water in Lebanon

    International Nuclear Information System (INIS)

    Abdallah, Samer M.; Habib, Rima R.; Nuwayhid, Rida Y.; Chatila, Malek; Katul, Gabriel

    2007-01-01

    The variation of dissolved radon ( 222 Rn) levels in water supplies remains of interest because of the radiation-induced public health hazards. A large part of the Lebanese population relies on springs and wells for their drinking water. 222 Rn measurements in spring and well water sources were conducted using the E-PERM method at sites ranging from sea level to 1200m above sea level and across several geologic formations within Lebanon. The dissolved radon concentrations ranged from a low of 0.91BqL -1 in a coastal well source to a high of 49.6BqL -1 for a spring source in a mountainous region. Of the 20 sites sampled, only five had radon levels above 11BqL -1 and these mostly occurred in areas adjacent to well-known geological fault zones. A preliminary national average radon level was determined to be about 11.4BqL -1 . In general, as all determined concentrations were well below the 100 and 146BqL -1 revised reference levels proposed in the European Union and the United States, respectively, it is concluded that there is no reason to believe these water sources pose any radon-related hazard. On the other hand, at locations where water is collected directly from the springhead, it is advisable to have a settling/piping system installed allowing for further radon decay and radon loss into the air to alleviate any possible radon problem

  19. Instruments to measure radon activity concentration or exposure to radon. Interlaboratory comparison 2011

    International Nuclear Information System (INIS)

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

    2011-10-01

    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 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 BfS. A radon measuring service is recognized by the competent authority if it proves its organizational 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 website www.bfs.de/de/ion/radon/fachinfomessung/vergleichspruefungen.html and from the European Information System on Proficiency Testing Schemes (eptis) available in the internet. (orig.)

  20. Field GE gamma spectrometry for on site measurements of some parameters characterizing radon-222 exhalation rates from soils and covers

    International Nuclear Information System (INIS)

    Zettwoog, P.; Kobal, I.; Pineau, J.F.

    1997-01-01

    We describe a new method based on differential gamma spectrometry for on site determination of some of the parameters which are relevant for the production of radon 222 in soil gas and its transfer from soil to indoor and outdoor atmospheres. This method is investigated in the context of a 3-year Slovenian-French cooperation programme, the PROTEUS project. We are currently using a germanium detector of 100 cm 3 . The height of the 20 deg. C collimated detector above the soil surface is from 1.5 to 3 m when using a tripod. This arrangement provides results which are representative of soil areas ranging from 1 to 4 square metres. Routine measurements would require larger detector volumes. The main objective is to provide technology and methodology for an efficient mapping of zones with potential for being the source of a high level of indoor radon, eliminating the need for soil sampling followed by laboratory analysis. The feasibility of an airborne mapping laboratory flying at low altitude will be investigated. Another objective is the rapid measurement of radon profiles across covers used to reduce exhalation rates from the surface of a pile of tailings, with characterisation of the influence of humidity content of the top layer. Airborne survey would allow for measuring exhalations from surfaces of slurries not otherwise accessible. (author)

  1. New devices for radon measurements

    International Nuclear Information System (INIS)

    Sevostyanov, V.N.

    2004-01-01

    This work includes the description of two new devices for radon surveys developed by the authors and produced in Kazakhstan. The first appliance is 'Ramon-Radon-01' used to measure 222 Rn radon in various mediums such as air, water, soil, and radon exhalation. The major advantage of the appliance lies in the absence of radioactive pollution in it after measurements. The appliances widely used in the CIS such as 'RAA-01', 'Alpharad' (produced by 'MTM Zaschita', Russia) and 'Alphaguard' (Germany) take samples directly to the measuring camera. For instance, the activity concentration of samples after they are taken by 'RAA-01' and 'Alpharad' is measured by means of electrostatic precipitation of RaA ( 218 Po) atoms to the square of semiconductor detector with subsequent registration of RaA alpha decay. The obvious disadvantage is that the subsequent measurement of relatively small 222 Rn activity concentration values after great values of 222 Rn activity concentration have been obtained requires a considerable exposure of the appliance sometimes exceeding 10 hours. Therefore, appliances register a relatively low value of the top measurement range of 20 KBq/m 3 . 'Alphaguard' has similar limitation resulting from precipitation of radon daughter decay products on the walls of ionizing chamber where radon activity concentration is measured. The radioactive lag of 'RAA-01', 'Alpharad' and 'Alphaguard' makes them of little use as well for automatic monitoring in the conditions of abruptly time negative derivatives on change of radon activity concentration. The second advantage is that 'Ramon-Radon-01', as opposed to above described appliances, registers almost zero radioactive lag, thanks to its constructive peculiarities which enable an abrupt increase of top range of measured value up to 5x10 5 Bq/m 3 , only limited by velocity of electron units of the appliance. The third advantage is that measurement discontinuity is determined only by time of full measurement cycle

  2. Evaluation of radon in hot spring waters in Zacatecas State, Mexico

    International Nuclear Information System (INIS)

    Favila R, E.; Lopez del Rio, H.; Davila R, I.; Mireles G, F.

    2010-10-01

    It is well know that radon is a potent human carcinogen. Because of the health concern of radon exposure, concentrations of 222 Rn were determined in ten hot spring water samples from the Mexican state of Zacatecas. The thermal water is collected in pools and used mainly for recreational purposes. In addition to radon level, the water samples were characterized for temperature, conductivity, and ph. Liquid scintillation spectrometry was used to measure 222 Rn and its decay products by mixing directly an aliquot of water with a commercial liquid scintillation. All measurements were carried out using a liquid scintillation counter (Wallac 1411). The water temperature ranged from 28 to 59 C, while the ph varied from 7.2 to 9.0, and the water conductivity was between 202.4 and 1072 μS/cm. The 222 Rn concentration varied in the range 3.9-32.6 Bq/L. In addition, the risk to radon exposure was assessed by considering three -real and possible- radon exposure scenarios: 1) ingestion of bottled thermal water, 2) direct ingestion of thermal water; and 3) vapor inhalation. The annual effective dose calculated for ingestion of bottled thermal water was 0.010-0.083 mSv/yr; for ingestion of water was 0.65-5.47 mSv/yr; and for inhalation was 0.28-2.81 mSv/yr. (Author)

  3. Measurements of Rn-222, Rn-220 and their decay products in the environmental air of the high background radiation areas in Yangjiang, China

    International Nuclear Information System (INIS)

    Yuan Yongling; Shen Tong; Morishima, Hiroshige; Koga, Taeko; Wei Luxin; Sugahara, Tsutomu

    2000-01-01

    For the renewal of dose estimation from internal irradiation in the high background radiation areas (HBRA) of Yangjiang, the measurements of radon, thoron and their decay products in the environmental air were conducted, including: integrating measurements of Rn-222 and Rn-220 concentrations; equilibrium factor F for Rn-222 and alpha-potential energy value of Rn-220; external gamma radiation in places where radon measurements were undertaken; cumulative exposure to indoor radon for each family in a case-control study on lung cancer. The Rn-Tn cup monitor method was used for the integrating measurement of Rn-222 and Rn-220 concentration. An alpha track detector was used for the integration measurement of Rn-222 concentration in the case-control study on lung cancer. The results of measurements show that although the investigated areas are located between the Equator and the Tropic of Cancer, and that people live in well-ventilated dwellings, the concentrations of radon, especially of Rn-220 are significantly higher in the indoor air of HBRA than those in the control area. The value of equilibrium factors for Rn-222, the alpha potential energy of decay products from Rn-222 and Rn-220 are determined. (author)

  4. Investigation of radon-222 emissions from underground uranium mines. Progress report No. 2

    International Nuclear Information System (INIS)

    Jackson, P.O.; Glissmeyer, J.A.; Enderlin, W.I.; Schwendiman, L.C.; Wogman, N.A.; Perkins, R.W.

    1980-02-01

    A reliable estimate of radon emissions to the environment from underground uranium mines was obtained through measurements of radon in ventilation exhaust air at 24 uranium mines and estimates of radon release from ore piles and waste piles at mines and in water pumped from mines. Three additional mines sampled in 1978 but not in 1979 were included in the overall results. Total production of U 3 O 8 from the mines thus far sampled represent about 63% of total 1978 US production from underground mines. Wide variation in radon emission per unit of production was shown from mine to mine; hence, it became necessary to sum all radon from all mines measured and divide by the sum of all U 3 O 8 production in 1978 from these mines to arrive at a valid estimate of Ci per ton of U 3 O 8 . This value was found to be 26.7 per ton or 5400 Ci/RRY (182 metric tons). The radon emitted in mine ventilation air was by far the dominant source, with other than ventilation exhaust sources accounting for less than three percent of radon in ventilation exhaust. Other observations of interest in this study were the diurnal fluctuations of radon with barometric pressure and the statistically significant relationship between radon released per year from a mine and the cumulative ore production at the time of radon measurement. The linear relationship between Ci/yr of radon and cumulative ore accounted for about half the variability.Several sources of random errors and possible biases were evaluated using some simple descriptive statistics insofar as the current data permitted. Errors in air flow rate in the vents sampled, fluctuations in radon emission with time of day, counting instrument calibration and production rate were estimated and combined to give an uncertainty of about +- 24 percent at the 95 percent confidence level

  5. 222Rn concentration in the outdoor atmosphere and its relation to the atmospheric stability

    International Nuclear Information System (INIS)

    Holy, K.; Boehm, R.; Bosa, I.; Polaskova, A.; Hola, O.

    1998-01-01

    The radon in the outdoor atmosphere has been monitored continuously since 1991. On the basis of the measured data mainly the average daily and the average annual courses of the 222 Rn concentrations have been studied. The annual courses of 222 Rn concentration are similar for all years. They present the annual variations. The average course of the 222 Rn concentration calculated on the basis of all continual measurements in the years 1991-1997 reaches the maximum value in October and the minimum value in April. The average daily courses of the 222 Rn concentration for the individual months of the year. The average daily courses have a form of waves with a maximum in the morning hours and with a minimum in the afternoon. The maximal amplitudes of daily waves have been reached in the summer months, from June till August. The amplitudes of daily waves are very small at the end of an autumn and during the winter months. The analysis of the daily waves and annual courses of 222 Rn showed that the amplitudes of the daily waves are in proportion to the global solar radiation irradiating the Earth's surface. The day duration influence on the phase of the daily wave and the wind velocity influence mainly on the level of the radon concentration. For the study of the relation of the radon concentration in the outdoor atmosphere to the stability the data of the atmosphere were obtained and they were correlated with the radon concentration. The results indicate that the 222 Rn concentrations int he outdoor atmosphere could be used for determination of the vertical atmospheric stability and these ones could reflect the atmospheric stability more completely than the different classifications based on the knowledge pertinent to the meteorological parameters. (authors)

  6. A complete low cost radon detection system

    International Nuclear Information System (INIS)

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

    2013-01-01

    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. - Author-Highlights: • Low cost radon detection. • Integrated GSM modem for early warning of radon anomalies. • Radon detection in environment

  7. Behaviour of 222Rn and its daughter products in open atmosphere

    International Nuclear Information System (INIS)

    Ondo-Estok, D.; Holy, K.; Stanys, T.; Polaskova, A.; Hola, O.

    2003-01-01

    In this contribution the influence of the meteorological conditions on activity concentrations of the outdoor 222 Rn and its daughter products is discussed in detail. In addition, the correlation between concentrations of measured radionuclides is studied and empirical relations for concentrations of radon daughter products are presented. he courses of the activity concentrations of 222 Rn and its short-lived decay products in the outdoor atmosphere are very similar even in some details. The average equilibrium factor F determined on the basis of our measurements in the outdoor atmosphere is approximately about 20 % lower than the value F recommended by UNSCEAR 1996 for the open air (F = 0,7). The obtained nonlinear relations between radon and its decay products reduce the applications of decay products in the atmospheric studies on one hand but on the other hand they can be useful at the calculation of the equilibrium equivalent radon concentration with the aim to determine the effective radon dose on the basis of the measurements of its activity concentrations only. (authors)

  8. Radon measurement in the Architectonic Assembly of Guapulo

    International Nuclear Information System (INIS)

    Jarrin Cornejo, Andrea

    2001-01-01

    The radon is a radioactive gas that does not have color nor scent. The radon comes from the natural decomposition of uranium, an element that is in almost all the types of ground, even on the rock and the water. In general, the radon moves upwards, through the ground, until the air that you breathe. The radon-222 is considered like the second cause of the pulmonary cancer soon of the cigarette, existing greater probability of that a person acquires the greater disease whichever is the exhibition that she is put under. The radon comes from the natural decay (radioactive) of the radio-226 in the ground, rocks and water entering to any type of construction. Any construction can have a problem of radon; therefore to examine is the only way to know such risk. Of it is in favor reason, has determined the concentration of Radon-222 in the interior of the Architectonic Assembly of Guapulo. For it, the System E P ERM was used like quantification method (System Environmental Monitor of Radon) that finds the measurement from a diminution of voltage in an electrical ion camera; which, goes has to be proportional to the amount of present gas in the room. The monitoring points are the different parts from the Convent, the University, and the Church in which the predominant materials of construction are the brick, block, stone, tile, plank and marinate. Of the results, the found values average do not surpass in the Architectonic Assembly of Guapulo, the 200 Bq/m3 (maximum limit established internationally for the concentration of Radon). On the other hand, for the different materials from construction the walls of adobe have greater amount of radon to be formed almost in their totality by elements of the ground, followed those of brick, block and concrete respectively. (The author)

  9. Radon exposure at a radioactive waste storage facility.

    Science.gov (United States)

    Manocchi, F H; Campos, M P; Dellamano, J C; Silva, G M

    2014-06-01

    The Waste Management Department of Nuclear and Energy Research Institute (IPEN) is responsible for the safety management of the waste generated at all internal research centers and that of other waste producers such as industry, medical facilities, and universities in Brazil. These waste materials, after treatment, are placed in an interim storage facility. Among them are (226)Ra needles used in radiotherapy, siliceous cake arising from conversion processes, and several other classes of waste from the nuclear fuel cycle, which contain Ra-226 producing (222)Rn gas daughter.In order to estimate the effective dose for workers due to radon inhalation, the radon concentration at the storage facility has been assessed within this study. Radon measurements have been carried out through the passive method with solid-state nuclear track detectors (CR-39) over a period of nine months, changing detectors every month in order to determine the long-term average levels of indoor radon concentrations. The radon concentration results, covering the period from June 2012 to March 2013, varied from 0.55 ± 0.05 to 5.19 ± 0.45 kBq m(-3). The effective dose due to (222)Rn inhalation was further assessed following ICRP Publication 65.

  10. Radon measurements of groundwater in Mexico

    International Nuclear Information System (INIS)

    Espinosa, G.; Golzarri, J.I.; Cortes, A.

    1991-01-01

    Radon measurement has important applications in hydrogeological studies. Specifically, radon measurement is used to determine the fluctuations of the piezometric levels in groundwater and, in some cases, the path of the water, which is one of the key parameters for evaluating hydrogeological resources. Water from springs and deep wells in the Basin of Mexico and the valley of San Luis Potosi were sampled, measured and analyzed by previous authors. In this work, a method for measuring 222 Rn in groundwater by using a passive detector is presented and the results are compared with a similar experiment performed at the same time, using a dynamic method. The aim of the work is to develop a method for detecting, evaluating and measuring the 222 Rn in groundwater by using SSNTD technology. (author)

  11. Variability of Atmospheric Radon-222 and Secondary Aerosol Components in Accordance with Air Mass Transport Pathways at Jeju Island, Korea, during 2011-2014

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Jun-Oh; Song, Jung-Min; Kim, Won-Hyung; Kang, Chang-Hee [Jeju National University, Jeju (Korea, Republic of); Chambers, Scott D.; Williams, Alastair G. [Australian Nuclear Science and Technology Organisation, Kirrawee DC (Australia); Lee, Chulkyu [Korea Meteorological Administration, Seoul (Korea, Republic of)

    2016-06-15

    Real-time monitoring of hourly atmospheric Radon-222 concentration and three daily monitoring of the secondary aerosol components of PM{sub 10} were performed throughout 2011-2014 at Gosan station, Jeju Island, in order to characterize their background levels and temporal variation. The annual mean radon and PM{sub 10} mass concentrations were 2326 ± 1198 mBq/m{sup 3} and 37.1 ± 19.5 μg/m{sup 3}, respectively. Based on cluster analyses of air mass back trajectories, the frequencies of air masses originating from continental China, the Korean Peninsula, and North Pacific Ocean routes were 53, 28, and 19%, respectively. When the air masses were transported to Jeju Island from continental China, the concentrations of radon and secondary aerosol components (nss-SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, NH{sub 4}{sup +}) were relatively high: 2577 mBq/m{sup 3} and 14.4 μg/m{sup 3}, respectively. In cases when the air masses have moved from the Korean Peninsula, the corresponding concentrations were 2247 mBq/m{sup 3} and 11.4 μg/m{sup 3}, respectively. On the other hand, when the air masses came from the North Pacific Ocean, their radon and secondary aerosol concentrations decreased much further, 1372 mBq/m{sup 3} and 10.5 μg/m{sup 3}, respectively. Consequently, the variability of atmospheric radon concentrations at Gosan station might be characterized by synoptic changes in air mass fetch as well as diurnal changes in atmospheric mixing depth.

  12. 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)

  13. Metrology of the radon in air volume activity at the italian radon reference chamber

    International Nuclear Information System (INIS)

    Sciocchetti, G.; Cotellessa, G.; Soldano, E.; Pagliari, M.

    2006-01-01

    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 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 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)

  14. Detection system for continuous 222Rn monitoring in waters

    International Nuclear Information System (INIS)

    Holy, K.; Patschova, E.; Bosa, I.; Polaskova, A.; Hola, O.

    2001-01-01

    This contribution presents one of the high-sensitive systems of continuous radon monitoring in waters. The device can be used for the continual control of 222 Rn activity concentration in water sources, for a study of the daily and seasonal variations of radon activity concentration in water systems, for the determination of the infiltration time of surface water into the ground water and for the next untraditional applications. (authors)

  15. 222Rn and decay products in outdoor and indoor environments

    International Nuclear Information System (INIS)

    Samuelsson, C.

    1984-05-01

    Radon-222 (radon) and radon daughter (RnD) measurement methodologies are analysed from both theoretical and experimental points of view. It is shown that exhalation from enclosed porous materials can be described in terms of the time-dependent diffusion theory. Deficiencies in the established accumulator method of radon exhalation measurement are shown. By the existing methods, the true free exhalation rate of thin samples may be underestimated by a factor of (1+α- 1 ), in radon-tight accumulators (α is the outer to inner volume ratio of the sample). The term back-diffusion is clarified and shown applicable to steady-state conditions only. The wire-screen technique is utilized to separate aerosol-attached and unattached RnD in a 3 m 3 radon cell. The effect of air-filtration on the RnDs is expressed as individual activity concentrations as well as in terms of effective dose equivalent rate, H. H has been reduced by a factor between 1.3 and 2.5 for the small-sized areosol particles used (surface area median less than 100 nm), at the filtration rate constant 5 h- 1 . The exact reduction value is dependent on initial aerosol load, type of filter, and dose model (Jacobi-Eisfeld and James-Birchall in this investigation). The concentration of radon and Pb-210 in the Arctic summer air averaged 75+-21 and 0.075+-0.028 mBq m- 3 , during the Swedish Ymer-80 expedition. It is shown that steadystate equilibrium models are unsuitable for estimation of the mean aerosol residence time in ocean air. A good qualitative agreement between radon-levels and the time since the air mass left larger land areas was found. The radon-222 and long-lived daughter (Pb-210, Po-210) measurements are insensitive to ship- and local contaminations. (author)

  16. Radon in groundwaters from Guarany aquifer, South America: environmental and exploration implications

    International Nuclear Information System (INIS)

    Bonotto, D.M.; Caprioglio, L.

    2002-01-01

    Groundwater and sandstone samples were analyzed for radon in Guarany aquifer, Parana sedimentary basin, South America. The dissolved radon ranged between 3 and 3303 pCi/l, being lognormally distributed, with a modal value of 1315 pCi/l, and a median value of 330 pCi/l. 222 Rn leakage experiments for sandstones yielded a theoretical value of 1390 pCi/l for 222 Rn in water, showing that theoretical modeling can reliably be used to interpret laboratory and field data

  17. Dot Blot para determinar la identidad antigénica en vacunas conjugadas contra Streptococcus pneumoniae serotipo 19F

    Directory of Open Access Journals (Sweden)

    Osmir Cabrera-Blanco

    2017-04-01

    Full Text Available Las autoridades regulatorias recomiendan el uso de técnicas de Resonancia Magnética Nuclear o técnicas serológicas para la determinación de la identidad de los antígenos presentes en las vacunas conjugadas. Con la aparición de las vacunas conjugadas multivalentes, se ha hecho necesario recurrir a técnicas inmunoquímicas con la utilización de anticuerpos monoclonales para aumentar la sensibilidad en la determinación de la identidad de los antígenos en dichas vacunas conjugadas. El objetivo del presente trabajo fue establecer las condiciones óptimas de trabajo que permitieran utilizar la técnica del Dot Blot para determinar la identidad de los antígenos en vacunas conjugadas de Streptococcus pneumoniae serotipo 19F. Para ello se estudiaron los tiempos de incubación, la influencia del reactivo en la solución de bloqueo; también las concentraciones óptimas del anticuerpo monoclonal y de los ingredientes farmacéuticos activos, así como los volúmenes de aplicación óptimos para estos y vacunas. Se utilizó un anticuerpo monoclonal contra el polisacárido capsular del serotipo 19F de neumococo. Las muestras empleadas en este trabajo fueron lotes de ingredientes farmacéuticos activos de conjugados de polisacárido capsular 19F y lotes de un candidato vacunal cubano conjugado heptavalente contra neumococos. Los resultados mostraron que para la determinación de la identidad antigénica fueron suficientes 10 µL de muestras de los principios activos a una concentración de 125 µg/mL e igual volumen para las vacunas heptavalentes. Quedó demostrado que una concentración de 1 µg/mL para el anticuerpo monoclonal y tiempos de incubación de 30 min a 37 °C fueron suficientes para la determinación. Estos resultados permiten concluir que quedaron establecidas las condiciones óptimas de trabajo para determinar la identidad antigénica por Dot Blot del polisacárido capsular de S. pneumoniae serotipo 19F presente en las vacunas

  18. Long-term temporal variability of the radon-222 exhalation flux from a landform covered by low uranium grade waste rock

    International Nuclear Information System (INIS)

    Bollhöfer, Andreas; Doering, Che

    2016-01-01

    Radon-222 exhalation flux densities from two different substrates of several metres thickness, waste rock and waste rock mixed with approximately 30% lateritic material, were measured over a period of five years in the wet-dry tropics of Northern Australia. Fourteen measurement campaigns using activated charcoal canisters (n > 1000) covered both dry and wet seasons and showed differences in seasonal and long term trends of the "2"2"2Rn exhalation flux densities normalised to the "2"2"6Ra activity concentrations of the substrate. Dry season "2"2"2Rn exhalation was generally higher for the mixed substrate, due to the larger fraction of fines. Seasonality established within the first year of landform construction on the mixed substrate, due to the higher water holding capacity of the lateritic material. In contrast, waste rock only shows no seasonality until years four and five after construction, when average normalised dry season "2"2"2Rn exhalation flux densities from waste rock increase to values (0.47 ± 0.06 mBq m"−"2 s"−"1 per Bq kg"−"1) similar to the mixed substrate (0.64 ± 0.08 mBq m"−"2 s"−"1 per Bq kg"−"1), likely due to an increase in fines from rapid weathering of the schistose waste rock. Volumetric water content has been used to parametrize relative "2"2"2Rn exhalation and we determined that wet season "2"2"2Rn exhalation is about 40% of the dry season exhalation. - Highlights: • We determined "2"2"2Rn exhalation flux densities normalised to "2"2"6Ra activity concentrations (R_E_-_R) for two substrates. • R_E_-_R was lower for waste rock only compared to waste rock blended with 30% fine grained lateritic material. • Seasonality in waste rock "2"2"2Rn exhalation flux densities established 4 years after construction. • Wet season R_E_-_R was about 40% of the dry season R_E_-_R.

  19. (222)Rn activity in groundwater of the St. Lawrence Lowlands, Quebec, eastern Canada: relation with local geology and health hazard.

    Science.gov (United States)

    Pinti, Daniele L; Retailleau, Sophie; Barnetche, Diogo; Moreira, Floriane; Moritz, Anja M; Larocque, Marie; Gélinas, Yves; Lefebvre, René; Hélie, Jean-François; Valadez, Arisai

    2014-10-01

    One hundred ninety-eight groundwater wells were sampled to measure the (222)Rn activity in the region between Montreal and Quebec City, eastern Canada. The aim of this study was to relate the spatial distribution of (222)Rn activity to the geology and the hydrogeology of the study area and to estimate the potential health risks associated with (222)Rn in the most populated area of the Province of Quebec. Most of the groundwater samples show low (222)Rn activities with a median value of 8.6 Bq/L. Ninety percent of samples show (222)Rn activity lower than 100 Bq/L, the exposure limit in groundwater recommended by the World Health Organization. A few higher (222)Rn activities (up to 310 Bq/L) have been measured in wells from the Appalachian Mountains and from the magmatic intrusion of Mont-Saint-Hilaire, known for its high level of indoor radon. The spatial distribution of (222)Rn activity seems to be related mainly to lithology differences between U-richer metasediments of the Appalachian Mountains and magmatic intrusions and the carbonaceous silty shales of the St. Lawrence Platform. Radon is slightly enriched in sodium-chlorine waters that evolved at contact with clay-rich formations. (226)Ra, the parent element of (222)Rn could be easily adsorbed on clays, creating a favorable environment for the production and release of (222)Rn into groundwater. The contribution of groundwater radon to indoor radon or by ingestion is minimal except for specific areas near Mont-Saint-Hilaire or in the Appalachian Mountains where this contribution could reach 45% of the total radioactive annual dose. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Estandarización del método propuesto por la Organización Mundial de la Salud para determinar los niveles de susceptibilidad de los vectores de leishmaniasis a insecticidas

    OpenAIRE

    Erika Santamaría

    2002-01-01

    El objetivo de este estudio fue estandarizar el método OMS para determinar susceptibilidad a insecticidas en algunas especies de Lutzomyia en condiciones de laboratorio y de campo. Los ensayos biológicos se realizaron sin insecticida, únicamente con tratamientos controles para determinar mortalidad por manipulación y otras condiciones desfavorables para cada especie. Se emplearon hembras de tres colonias de laboratorio: dos cepas de Lutzomyia longipalpis y una de Lutzomyia serrana. También se...

  1. Uranium, RADON and radon isotopes in selected brines of Poland

    International Nuclear Information System (INIS)

    Kozlowska, B.; Walencik, A.; Zipper, W.; Dorda, J.; Przylibski, T.A.

    2010-01-01

    Natural radioactive isotopes were studied in nine different types of brines from four locations in Poland. Investigated brines are exploited from various geological structures composed of the rocks of different chemical and mineral composition as well as different age and depth. All investigated brines are used in balneotherapy (i.e. baths, inhalations, showers). The main goal of this study was to obtain some basic knowledge on the activity range of natural elements such as uranium, RADON and radon in different brine types in Poland and their variability depending on their location in certain geological structures. Activities of 234,238 U, 226,228 Ra and 222 Rn isotopes were measured with the use of two nuclear spectrometry techniques: liquid scintillation and alpha spectrometry. The activity concentrations of 222 Rn vary from below 1 to 76.1±3.7 Bq/l, for the 226 Ra isotope from 0.19±0.01 to 85.5±0.4 Bq/l and for 228 Ra from below 0.03 to 2.17±0.09 Bq/l. For uranium isotopes, the concentrations are in the range from below 0.5 to 5.1±0.4 mBq/l for 238 U and from 1.6±0.4 to 45.6±2.0 mBq/l for 2 34U . The obtained results indicate high RADON activity concentrations corresponding to high mineralization of waters. (authors)

  2. Assessment of (222)Rn emanation from ore body and backfill tailings in low-grade underground uranium mine.

    Science.gov (United States)

    Mishra, Devi Prasad; Sahu, Patitapaban; Panigrahi, Durga Charan; Jha, Vivekanand; Patnaik, R Lokeswara

    2014-02-01

    This paper presents a comparative study of (222)Rn emanation from the ore and backfill tailings in an underground uranium mine located at Jaduguda, India. The effects of surface area, porosity, (226)Ra and moisture contents on (222)Rn emanation rate were examined. The study revealed that the bulk porosity of backfill tailings is more than two orders of magnitude than that of the ore. The geometric mean radon emanation rates from the ore body and backfill tailings were found to be 10.01 × 10(-3) and 1.03 Bq m(-2) s(-1), respectively. Significant positive linear correlations between (222)Rn emanation rate and the (226)Ra content of ore and tailings were observed. For normalised (226)Ra content, the (222)Rn emanation rate from tailings was found to be 283 times higher than the ore due to higher bulk porosity and surface area. The relative radon emanation from the tailings with moisture fraction of 0.14 was found to be 2.4 times higher than the oven-dried tailings. The study suggested that the mill tailings used as a backfill material significantly contributes to radon emanation as compared to the ore body itself and the (226)Ra content and bulk porosity are the dominant factors for radon emanation into the mine atmosphere.

  3. {sup 222} Rn determination and physicochemical characteristic and biological in aquifers in the Toluca Valley; Determinacion de {sup 222} Rn y caracteristicas fisicoquimicas y biologicas en acuiferos del Valle de Toluca

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez A, A

    1998-10-01

    Concentration levels of {sup 222} Rn and {sup 226} Rn have been analyzed in water samples from boreholes belonging to the drinking water supply system around Toluca, Mexico. The {sup 222} Rn source is the decay of {sup 226} Rn within the solid matrix of the aquifer. The study was performed during the dry and rainy seasons. {sup 222} Rn concentration was determined by the liquid scintillation technique, {sup 226} Rn was determined by gamma spectrometry, the physicochemical parameters and bacteriological analysis were performed by conventional chemical techniques. Solubilized trace elements were determined by Inductively Coupled Plasma - Mass Spectrometry (Icp-Ms). The radon level fluctuations at the boreholes in Toluca city and Almoloya spring indicated differences in the radon content. At borehole Lodos Prietos 2, the temperature and radon level were systematically the highest in comparison with the other boreholes and the spring indicating a contribution of a regional flow to the water of this particular borehole. The result for {sup 226} Rn, the average {sup 222} Rn observed during the sampling period, no correspondence occurs between the radium and the radon content indicating that, radon is not supported by radium, but is incorporated into the water through fissures in the rocks in contact with the water. The radon levels obtained in house faucets which water is supplied by boreholes decrease as a function of the distance from the source borehole to the house. With the chemical composition of each one of the studied boreholes and spring a Piper diagram was draw indicating the kind of water. The boreholes and spring can be classified as bicarbonate calcium/magnesium. Almost no fluctuation on time was observed in the chemical species and trace elements only a slight increase was observed at the end of the rain season. At Almoloya, spring pollution with coliform bacteria and nitrates showed an anthropogenic contribution to the water deterioration probable and

  4. Design and evaluation of representative indoor radon surveys

    International Nuclear Information System (INIS)

    Csige, I.; Csegzi, S.

    2004-01-01

    We have developed a procedure to design and evaluate representative indoor radon surveys. The procedure is based on random sampling of a population of houses and careful statistical analysis of measured indoor radon concentrations. The method is designed to estimate the fraction of houses in which annual average 222 Rn activity concentration may exceed a certain reference level. Measurements of annual average indoor 222 Rn activity concentration were done in sleeping rooms at pillow level using etched track type radon detectors. We applied the above procedure in an old fashioned village and in a fast developing small city in Transylvania, Romania. In the village almost all houses were single floor wooden made houses without cellar built with traditional technology on a geologically uniform area. The distribution of indoor 222 Rn activity concentration in a sample of 115 houses can almost perfectly be fitted with log-normal probability density function. The correlation coefficient of linear fitting on linearized scales was k = -0.9980. The percentages of houses expected to have annual average 222 Rn activity concentration higher than 400 Bq m -3 is less than 1 %, and of those higher than 600 Bq m -3 can be estimated to be around 0.1 %. The small city, on the other hand lies on a geologically inhomogeneous area, and house construction technology has also changed dramatically in past decades. The resulting distribution of measured indoor 222 Rn activity concentration in a sample of 116 houses cannot be fitted with any simple probability density function. Therefore the prediction of the fraction of houses in which the annual average 222 Rn activity concentration may exceed a certain reference level could not be done adequately. With certain assumptions we estimated that the percentages of houses expected to have annual average 222 Rn activity concentration higher than 400 Bq m -3 is between 3 and 7 %, and of those higher than 600 Bq m -3 can be estimated to be between

  5. 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.)

  6. Mapping radon-prone areas - a geophysical approach

    International Nuclear Information System (INIS)

    Shirav, M.; Vulkan, U.

    1997-01-01

    Radon-prone areas in Israel were mapped on the basis of direct measurements of radon ( 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.)

  7. 1982 radon intercomparison exercises at EML

    International Nuclear Information System (INIS)

    Fisenne, I.M.; George, A.C.; Keller, H.W.

    1983-03-01

    This report summarizes the results of two radon measurement intercomparison exercises held in 1982. Sixteen organizations, including five United States federal departments, two state governments, two national laboratories, three universities, three private sector laboratories and Swedish National Institute participated in these exercises. The results indicate good agreement among the participants at the 30 pCi 222 Rn/L level. With the continued interest and cooperation of groups involved in radon measurements, twp intercomparison exercises are planned during 1983

  8. A nationwide radon concentration survey project in Japan. Outdoor and workplaces

    International Nuclear Information System (INIS)

    Oikawa, S.; Kanno, N.; Ohashi, N.; Abukawa, J.

    2003-01-01

    Nationwide survey for outdoor and workplace radon ( 222 Rn) concentration in Japan were carried out to evaluate the effective dose to the general public due to 222 Rn and its progeny. The 222 Rn concentration was measured by using passive-type radon/thoron discriminative monitor equipped with polycarbonate films. Concentration of 222 Rn was calculated from etch pit counts appeared on the polycarbonate film after chemical and electrochemical etching. For outdoor 222 Rn survey, the monitors were installed at about 700 points throughout Japan on every quarters of the fiscal year 1997 to 1999. The mean concentration of outdoor 222 Rn concentration was 6.1 Bq m -3 from the results of 696 measurement points. Seasonal variation of outdoor 222 Rn was found to be minimal in July to September, and maximal in October to December. For workplace 222 Rn survey, the monitors were installed at about 700 points in four categories (office, factory, school and hospital) on every quarters of the fiscal year 2000 to 2002. Nationwide mean 222 Rn concentration in workplaces was found to be 22.7 Bq m -3 for 2000 and 20.7 Bq m -3 for 2001, respectively. Seasonal variation of 222 Rn concentration measured at office, factory, school and hospital were also found to be minimal in July to September, and maximal in October to December. (author)

  9. Study of Rn-222 exhalation in phosphogypsum through the adsorption technique in activated coal; Estudo da exalacao de Rn-222 em fosfogesso por meio da tecnica de adsorcao em carvao ativado

    Energy Technology Data Exchange (ETDEWEB)

    Nisti, Marcelo Bessa; Campos, Marcia Pires de, E-mail: mbnisti@ipen.b, E-mail: mpcampos@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-10-26

    The radon exhalation was estimated through the adsorption in activated carbon technique. Classified as TENORM, the radon exhalation determination on the phosphogypsum piles was performed through the adsorption ratio of radon in activated carbon, from the concentration of descendants of {sup 222}Rn, {sup 214}Pb and {sup 214}Bi obtained by gamma spectrometry. The results obtained in this work were compatibles with the values found in the literature

  10. Factors influencing indoor concentrations of radon and daughter products

    International Nuclear Information System (INIS)

    Wang Hengde

    1985-01-01

    The correlation between indoor concentrations of 222 Rn and its daughters and some influencing factors is discussed and expressions of concentrations are derived with relation to radon exhalation rate from indoor surfaces, air exchange rate and daughter deposition velocities on indoor surfaces. Experimental methods for determining radon exhalation rate, air exchange rate and daughter deposition velocities are also mentioned

  11. Variations of Rn-222 concentration in the Bratislava air

    International Nuclear Information System (INIS)

    Holy, K.; Bohm, R.; Polaskova, A.

    1996-01-01

    222 Rn is produced by alpha decay of 222 Ra in roil. A small fraction of totally produced 222 Rn escapes from coil particles into soil air. Then 222 Rn is transported predominantly by molecular diffusion into outdoor atmosphere. The radon concentration in the outdoor atmosphere is not stable. It varies irregularly depending on meteorological conditions. However there were found out regular daily and remand variations of 222 Rn concentration in outdoor atmosphere. These variations were measured in numerous works and results are summarized f.e. in work of Gesell. A simple model described the annual variations of 222 Rn concentration war published by Minato. A mathematical analysis of daily course of 222 Rn concentration in outdoor atmosphere was realized by Garzon et al. Some results of our study of 222 Rn variations in outdoor atmosphere of Bratislava are shown in this report. (author)

  12. Radon in air concentrations arising from storage of articles containing radium or thorium

    International Nuclear Information System (INIS)

    Slater, M.; Gooding, M.

    2006-01-01

    A major component of public and occupational radiation exposure worldwide arises from the inhalation of radon and thoron gases, produced during the decay of naturally occurring uranium and thorium respectively. Whilst radon and thoron exposures are normally associated with the natural environment, there may also be a risk associated with sources, manufactured articles and waste produced through refining and concentration of naturally occurring radioactive material. Sources and articles manufactured from refined uranium do not normally give rise to the release of radon as the uranium progeny are largely removed during production and, if removed, will take thousands of years to reach full equilibrium with the uranium parent isotopes. Exposure to radon -222 ( 222 Rn) may, however, arise in areas where the uranium-238 ( 238 U) daughter radium-226 ( 226 Ra) is concentrated, for example in the form of sources, luminous articles or low-specific activity (LSA) scale. Exposure to radon- 220 ( 220 Rn), otherwise known as thoron, may occur in areas where thorium isotopes are concentrated, for example as manufactured laboratory thorium compounds. This paper explores the issues affecting radon and thoron release from manufactured articles containing uranium and thorium and their progeny. A methodology is provided for the calculation of 222 Rn and 220 Rn in air concentrations likely to arise as a result of the storage and use of articles containing radium-226 ( 226 Ra) or thorium-232 ( 232 Th). The methodology provided in the document allows derivation of the equilibrium equivalent radon concentration and the radon exposure rate in circumstances where the ventilation rate and volume of the facility can be reliably estimated and the quantities of 226 Ra or 232 Th held are known. A critical variable in the calculation is the release fraction (i.e. the proportion of radon generated that is release to atmosphere), and this paper considers methods for estimating this parameter

  13. Using 222Rn as a tracer of geodynamical processes in underground environments

    International Nuclear Information System (INIS)

    Valladares, D.L.; Silva, A.A.R. da; o, Gragoatá, 24210-340, Niterói, RJ (Brazil))" data-affiliation=" (Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/no, Gragoatá, 24210-340, Niterói, RJ (Brazil))" >Lacerda, T.; o, Gragoatá, 24210-340, Niterói, RJ (Brazil))" data-affiliation=" (Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/no, Gragoatá, 24210-340, Niterói, RJ (Brazil))" >Anjos, R.M.; Rizzotto, M.; Velasco, H.; Rosas, J.P. de; Tognelli, G.

    2014-01-01

    Radon levels in two old mines in San Luis, Argentina, were measured and analyzed, with the aim to assess the potential use of this radioactive noble gas as a tracer of geological processes in underground environments. La Carolina gold mine and Los Cóndores tungsten mine are today used as tourism mines. CR-39 nuclear track detectors were used for this purpose. Measurements were performed during both winter and summer seasons. The findings show that in these environments, significant radon concentrations are subject to large seasonal fluctuations, due to the strong dependence on natural ventilation with the outside temperature variations. For both mines, higher concentration values of 222 Rn were observed in summer than in winter; with an extreme ratio of 2.5 times between summer and winter seasons for Los Cóndores mine. The pattern of radon transport inside La Carolina mine revealed, contrary to what was believed, that this mine behaves as a system with two entrances located at different levels. However, this feature can only be observed in the winter season, when there is a marked difference between the inside and outside temperatures of the mine. In the case of Los Cóndores mine, the radon concentration pattern distribution is principally established by air current due to chimney-effect in summer and winter seasons. In both cases, the analyses of radon pattern distribution appear as a good method to trace air currents, and then localize unknown ducts, fissures or secondary tunnels in subterranean environments. - Highlights: • 222 Rn levels in two old mines in San Luis, Argentina • CR-39 nuclear track detectors were used for this purpose • higher concentration values of 222 Rn were observed in summer than in winter • radon pattern distribution appear as a good method to trace air currents • it localizes unknown ducts, fissures or secondary tunnels in subterranean environments

  14. Radon and radioactivity at a town overlying Uranium ores in northern Greece.

    Science.gov (United States)

    Kourtidis, K; Georgoulias, A K; Vlahopoulou, M; Tsirliganis, N; Kastelis, N; Ouzounis, K; Kazakis, N

    2015-12-01

    Extensive measurements of (222)Rn in the town of Xanthi in N Greece show that the part of the town overlying granite deposits and the outcrop of a uranium ore has exceptionally high indoor radon levels, with monthly means up to 1500 Bq m(-3). A large number of houses (40%) in this part of the town exhibit radon levels above 200 Bq m(-3) while 11% of the houses had radon levels above 400 Bq m(-3). Substantial interannual variability as well as the highest in Europe winter/summer ratios (up to 12) were observed in this part of the town, which consist of traditional stone masonry buildings of the late 19th-early 20th century. Measurements of (238)U and (232)Th content of building materials from these houses as well as radionuclide measurements in different floors show that the high levels of indoor radon measured in these buildings are not due to high radon emanation rates from the building materials themselves but rather due to high radon flux from the soil because of the underlying geology, high radon penetration rates into the buildings from underground due to the lack of solid concrete foundations in these buildings, or a combination thereof. From the meteorological variables studied, highest correlation with indoor (222)Rn was found with temperature (r(2) = 0.65). An indoor radon prognostic regression model using temperature, pressure and precipitation as input was developed, that reproduced indoor radon with r(2) = 0.69. Hence, meteorology is the main driving factor of indoor radon, with temperature being the most important determinant. Preliminary flux measurements indicate that the soil-atmosphere (222)Rn flux should be in the range 150-250 Bq m(-2) h(-1), which is in the upper 10% of flux values for Europe. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Sources and transport of indoor radon

    International Nuclear Information System (INIS)

    Aldenkamp, F.J.; Stoop, P.

    1994-01-01

    An approach in the investigation was to use a multi-compartment model of a home describing the processes that determine how radon concentrations in dwellings are established. Because the model describes Rn-222 concentrations in terms of airflows and sources, the experimental research was focused on the measurement of these three quantities. Development, calibration and assessment of the instrumentation played a major role. The experiments involved measurements of Rn-222 exhalation of buildings materials and the soil underneath the house, Rn-222 concentrations in air and airflows between various parts of the house and between the inside and outside of the house. (DG)

  16. The correlations between Radon in soil gas and its exhalation and concentration in air in the southern part of Syria

    International Nuclear Information System (INIS)

    Shweikani, R.; Hushari, M.

    2005-01-01

    The aim of this work is to measure the concentration of the radon ( 222 Rn) in soil air, 222 Rn exhalation from soil and 222 Rn in outdoor air which may have great influence on 222 Rn levels in houses. 222 Ra activity concentrations were also determined in soil samples. The studied areas are located in southern part of Syria. The common bed rock of this area is black and massive granite which are poor in uranium content [Jubeli Y.M., 1990. Uranium exploration in Syria. Internal Technical Report, vol. 1 (in English), vol. 2 (in Arabic), SAEC, Damascus; Technoexport (USSR), 1966. In: Ponikarov (Ed.), The Geological Map of Syria Scale: 1:200.000, Ministry of Industry, Damascus, Syria]. Results showed that the maximum measurement in all areas was 32500Bqm -3 in soil air with an exhalation rate of 9Bqm -2 s -1 in Darra region and 66.43Bqm -3 of radon in open air, with 77Bqkg -1 of radium content in soil (Damascus suburb). In addition, correlations between Rn in soil and exhalation of Radon from soil and radon in houses were found in some areas (Sweda and Darra), while, no correlations were found in other studied areas. Moreover, no correlation between radon in houses and radon measurements in soil and in outdoors were found. This was attributed to the methodology used and the influence of building design and inhabitants behavior

  17. Protocolos molecular y celular para elaborar y determinar una cepa vacunal de salmonella enterica serotipo enteriditis 82139 y propuesta de tipos de biorreactores para su produccion

    OpenAIRE

    Villanueva Alva, Liliana Verónica

    2016-01-01

    Se presenta Protocolos Molecular y Celular para Elaborar y Determinar una cepa vacunal de Salmonella entérica Serotipo Enteritidis 82139 y Propuesta de Tipos de Biorreactores para su Producción. El Diseño Factorial permitió en un inicio los diseños y selección para la construcción de cepas mutantes hasta la validación estadística en la determinación de la función génica de dsbA, dle y dlp con respecto a la capacidad de movilidad y de invasión intracelular bacteriana a partir de la determinaci...

  18. Alpha scintillation radon counting

    International Nuclear Information System (INIS)

    Lucas, H.F. Jr.

    1977-01-01

    Radon counting chambers which utilize the alpha-scintillation properties of silver activated zinc sulfide are simple to construct, have a high efficiency, and, with proper design, may be relatively insensitive to variations in the pressure or purity of the counter filling. Chambers which were constructed from glass, metal, or plastic in a wide variety of shapes and sizes were evaluated for the accuracy and the precision of the radon counting. The principles affecting the alpha-scintillation radon counting chamber design and an analytic system suitable for a large scale study of the 222 Rn and 226 Ra content of either air or other environmental samples are described. Particular note is taken of those factors which affect the accuracy and the precision of the method for monitoring radioactivity around uranium mines

  19. Methodology for determination of radon-222 production rate of residential building and experimental verification

    International Nuclear Information System (INIS)

    Tung, Thomas C.W.; Niu, J.L.; Burnett, J.; Lau, Judy O.W.

    2005-01-01

    Indoor radon concentration is mainly associated with the radon production rate of building material, ventilation rate, and the outdoor radon concentrations. Radon production rate of a room is defined as the sum of the products of the radon emanation rates and the exposed areas of the materials. Since the selection of the building materials and the exposed areas are different from room to room, it makes the radon production rate of homes fall in a wide range. Here, the radon production rate of a room is suggested to be quantified by a sealing method, in which the systematic radon growth curve is obtained. The radon production rate of the room can be determined from the initial slope of the growth curve. Three rooms at different homes in Hong Kong were selected in the study for verifying the methodology. The uncertainty characterized by data scatter arisen from the coupling effect of the leakage rate and outdoor radon was also included in the discussion. During the measurements, no occupant was allowed into the home. No mechanical ventilation was involved in the measurement. The indoor and outdoor radon concentrations of the sampled homes were monitored simultaneously and lasted for more than three days. The radon production rates and the uncertainties of three rooms at Homes 1, 2, and 3 were found to be 232.8, 46.0, 414.6, and 20.3, 9.4, 59.2Bqh -1 , respectively. The approach is valid when the air leakage rate of the room is controlled below 0.1h -1

  20. Anomalous radon emanation linked to preseismic electromagnetic phenomena

    Directory of Open Access Journals (Sweden)

    Y. Omori

    2007-10-01

    Full Text Available Anomalous emanation of radon (222Rn was observed preceding large earthquakes and is considered to be linked to preseismic electromagnetic phenomena (e.g. great changes of atmospheric electric field and ionospheric disturbances. Here we analyze atmospheric radon concentration and estimate changes of electrical conditions in atmosphere due to preseismic radon anomaly. The increase of radon emanation obeys crustal damage evolution, following a power-law of time-to-earthquake. Moreover, the radon emanation decreases the atmospheric electric field by 40%, besides influencing the maximum strength of atmospheric electric field by 104–105 V/m enough to trigger ionospheric disturbances. These changes are within the ranges observed or explaining electromagnetic phenomena associated with large earthquakes.

  1. Proposal for the classification of closed indoor spaces according to concentration of {sup 222}Rn and the possible doses involved; Propuesta para la clasificacion de los espacios interiores cerrados por su concentracion de Rn-222 y las posibles dosis involucradas

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, Marco; Leon, Kety; Martinez, Jorge [Direccion de Servicios, Instituto Peruano de Energia Nuclear, Lima (Peru)

    2014-07-01

    Radon causes more than 50 % of total dose from natural background radiation per year. It is widely demonstrated the capacity of radon to induce lung cancer in people exposed to this radioactive gas for long periods. Radon emerges continuously from materials that constitute soils, building materials and minerals present in our natural environment, all over the world. In our country, it is necessary to get better regulations to control the exposition of people to this gas inside buildings, dwellings and facilities where people spend their time. Our country has very simple and scarce regulations on this respect. At present, national regulations about radon are adaptations of recommendations and guides published for international organizations but without national studies or statistics to give realistic support to those rules. This work propose a classification for closed spaces where people live and work in this country taking into consideration their {sup 222}Rn concentration and probable doses involved. (authors).

  2. Measurements of the radon-222 and its daughters concentrations throughout Gaza strip, Palestine

    International Nuclear Information System (INIS)

    Rasas, M.F.; Yassin, S.S.; Shabat, M.M.

    2005-01-01

    High Radon levels are present in the granite and grandiositic rocks that. spread in sand dunes along coast of Gaza. Such materials are rich in uranium and T widely used in the construction of dwelling in the Gaza, and their contribution to high indoor Radon levels is most relevant.The present work aims to investigate approaches, measures and detection of indoor Radon level throughout Gaza Strip. Five hundred CR-39 dosimeters were distributed over six locations in the middle Yv-region of Gaza Strip. Results suggest that Radon concentrations range from l3.36 to 83.82 Bq/m 3 and a maximum value of 97.01 Bq/m 3 .The average Radon concentrations was 37.83 Bq/m 3 with standard deviation of 11.23.The results provide a framework for future studies that include a large, broader survey of Radon concentration in Palestine

  3. Environmental Radon Gas and Degenerative Conditions An Overview

    International Nuclear Information System (INIS)

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

    2006-01-01

    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 222 Rn and its progeny 218 Po and 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)

  4. Contribution to the study of radon risk assessment - Use of Solid State Nuclear Tracks Detectors (SSNTD) for the measurement of radon in buildings

    International Nuclear Information System (INIS)

    RALAIARISOA, H.L

    2004-01-01

    222 Rn is a natural radioactive gas, originating from the decay of 226 Ra. Both of these radionuclides are elements of 238 U series. Uranium is naturally present in the rocks and soils, therefore radon is always present too because it is a soil gas. Radon takes the most important part in man exposure to natural sources of ionizing radiations. Moreover, it causes lung cancer. It can accumulate in confined environments such as buildings, so that its inhalation is a potential risk for human health. Thus radon measurement is necessary for radiation protection. Integrated measurement using Solid State Nuclear Tracks Detector (SSNTD) is a very common method for radon measurement in buildings because of the low cost of the detectors and their easy application. The measurement technics are based on the interaction of alpha particles emitted by radon with a polymer. Alpha particles produce in the polymer latent tracks, which need chemical revelation to be observable with optical microscopy. The number of revealed tracks is proportionnal to the average volumic activity of 222 Rn corresponding to the time exposure of the detectors.The aim of this thesis work is the continuation of previous study on the preliminary investigations of radon levels in the city of Antananarivo, and to extend this study in Antsirabe, which has been shown as a region of interest. The levels of radon measured in buildings in Antananarivo and Antsirabe are typical values of indoor radon concentration. The average values of concentrations are inferior to 60 Bq.m - 3. The health risk is negligible but not nul. A typical protocol of radon level measurement in Malagasy buildings is suggested to allow the implementation of a risk management policy related to radon within the Malagasy context. [fr

  5. Sources and protective measures of indoor radon

    International Nuclear Information System (INIS)

    Gou Quanlu; Wang Hengde

    1993-01-01

    This paper presents the relative contribution to indoor radon 222 Rn of various sources in twenty three rooms of three kinds in Taiyuan area. The results show that the major sources in this area are radon emanation from surfaces of soil and building materials and that from outdoor air, while the contribution of water and gas consumed in the rooms is less important. These results suggest a basis for taking suitable protective measures against indoor radon. Some materials are also recommended which are effective in restraining radon exhalation and low in price, by testing more than ten kinds of materials and comparing them using cost-effectiveness analysis technique, such as painting materials, polyvinyl alcohol (CH 2 :CHOH)n, etc. Their sealing effects on radon exhalation were examined with home-made REM-89 Radon Exhalation Monitor. The deposition effects of negative ion generator and humidifier on radon progeny were also tested. The maximum deposition may reach 70-90%, which proves they are also effective and economical in radon protection. (2 tabs., 3 figs.)

  6. A survey of 222Rn in drinking water in mexico city

    International Nuclear Information System (INIS)

    Vasquez-Lopez, C.; Zendejas-Leal, B. E.; Golzarri, J. I.; Espinosa, G.

    2011-01-01

    In Mexico City there are more than 22 millions of inhabitants (10 in the metropolitan area and 12 in the suburban zone) exposed to drinking water. The local epidemiological authorities recognised that exposure to radon contaminated drinking water is a potential health hazard, as has been considered worldwide. The United States Environmental Protection Agency has proposed a limit of 11.1 Bq l -1 for the radon level in drinking water. In Mexico a maximum contamination level of radon in drinking water has not yet even considered. In this work, a 222 Rn study of drinking water in Mexico City has revealed a range of concentrations from background level to 3.8 Bq l -1 . 222 Rn was calculated using a portable degassing system (AquaKIT) associated with an AlphaGUARD measuring system. Samples from 70 wells of the water system of the south of the Valley Basin of Mexico City and from houses of some other political administrative divisions of Mexico City were taken. (authors)

  7. Doses to LiF :Ti, Mg chips encapsulated in plastic extremity rings as a result of radon gas exposure

    International Nuclear Information System (INIS)

    Kearfott, Kimberlee J; Noon, Evan P; Rafique, Muhammad

    2015-01-01

    Previous studies measured the effects of 222 Rn on various thermoluminescent dosemeters (TLDs). This study quantified the effects of 222 Rn on LiF : Ti,Mg chips encapsulated in plastic extremity rings. For 28 d, one batch of TLDs was left in a chamber with high radon levels, and another batch in a control chamber with normal background radon levels. A few TLDs in each batch were removed from the rings for direct exposure to the ambient air in each chamber. Passive continuous radon monitors (CRMs) recorded the 222 Rn levels. TLDs were processed using a third-party dosimetry company, CRM data were analysed, and the relationship between integrated 222 Rn concentration and TLD response was determined. The batch of TLDs in the experimental chamber showed a weak response to 222 Rn gas, which was in the order of 0.5 nSv Bq −1  m 3  d −1 . (paper)

  8. 222 Rn determination and physicochemical characteristic and biological in aquifers in the Toluca Valley

    International Nuclear Information System (INIS)

    Hernandez A, A.

    1998-01-01

    Concentration levels of 222 Rn and 226 Rn have been analyzed in water samples from boreholes belonging to the drinking water supply system around Toluca, Mexico. The 222 Rn source is the decay of 226 Rn within the solid matrix of the aquifer. The study was performed during the dry and rainy seasons. 222 Rn concentration was determined by the liquid scintillation technique, 226 Rn was determined by gamma spectrometry, the physicochemical parameters and bacteriological analysis were performed by conventional chemical techniques. Solubilized trace elements were determined by Inductively Coupled Plasma - Mass Spectrometry (Icp-Ms). The radon level fluctuations at the boreholes in Toluca city and Almoloya spring indicated differences in the radon content. At borehole Lodos Prietos 2, the temperature and radon level were systematically the highest in comparison with the other boreholes and the spring indicating a contribution of a regional flow to the water of this particular borehole. The result for 226 Rn, the average 222 Rn observed during the sampling period, no correspondence occurs between the radium and the radon content indicating that, radon is not supported by radium, but is incorporated into the water through fissures in the rocks in contact with the water. The radon levels obtained in house faucets which water is supplied by boreholes decrease as a function of the distance from the source borehole to the house. With the chemical composition of each one of the studied boreholes and spring a Piper diagram was draw indicating the kind of water. The boreholes and spring can be classified as bicarbonate calcium/magnesium. Almost no fluctuation on time was observed in the chemical species and trace elements only a slight increase was observed at the end of the rain season. At Almoloya, spring pollution with coliform bacteria and nitrates showed an anthropogenic contribution to the water deterioration probable and fertilizers and detritus. Most of the studied water

  9. The distribution of radon in tunnels with different geological characteristics in China

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaoyan, E-mail: lxyan421@hotmail.co [School of Geographic and Biologic Sciences, Guizhou Normal University, GuiYang 550001 (China); Song Bo [College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541004 (China); Zheng Baoshan [Institute of Geochemistry, Chinese Academy of Sciences, GuiYang 550002 (China); Wang Yan [Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071 (China); Wang Xue [Institute of Geochemistry, Chinese Academy of Sciences, GuiYang 550002 (China)

    2010-05-15

    In China, as the economy is developing and the population is expanding, some underground buildings have been used as supermarkets, restaurants and entertainment places. Tunnels in mountains are one type of underground building, and the radon ({sup 222}Rn) level in tunnels is an important issue. Radon levels in different type tunnels appear to differ, and relatively higher levels of {sup 222}Rn are associated with particular types of bedrock. The {sup 222}Rn levels in tunnels in five different geological characteristics were analyzed. Those built in granite had the highest {sup 222}Rn levels with a geometric mean (GM) of 280 Bq m{sup -3}, while those built in limestone (GM: 100 Bq m{sup -3}) and andesitic porphyry (GM: 96 Bq m{sup -3}) were lower. The sequence of {sup 222}Rn concentrations was: granite > tuff > quartz sandstone > limestone > andesitic porphyry, and the {sup 222}Rn in granite was statistically significantly higher than in limestone and andesitic porphyry. Tunnels built in granite, tuff, quartz sandstone, limestone tended to have higher {sup 222}Rn concentrations in summer than in winter, while the reverse tendency was true in andesitic porphyry tunnels. Only the difference in limestone was statistically significant.

  10. The distribution of radon in tunnels with different geological characteristics in China

    International Nuclear Information System (INIS)

    Li Xiaoyan; Song Bo; Zheng Baoshan; Wang Yan; Wang Xue

    2010-01-01

    In China, as the economy is developing and the population is expanding, some underground buildings have been used as supermarkets, restaurants and entertainment places. Tunnels in mountains are one type of underground building, and the radon ( 222 Rn) level in tunnels is an important issue. Radon levels in different type tunnels appear to differ, and relatively higher levels of 222 Rn are associated with particular types of bedrock. The 222 Rn levels in tunnels in five different geological characteristics were analyzed. Those built in granite had the highest 222 Rn levels with a geometric mean (GM) of 280 Bq m -3 , while those built in limestone (GM: 100 Bq m -3 ) and andesitic porphyry (GM: 96 Bq m -3 ) were lower. The sequence of 222 Rn concentrations was: granite > tuff > quartz sandstone > limestone > andesitic porphyry, and the 222 Rn in granite was statistically significantly higher than in limestone and andesitic porphyry. Tunnels built in granite, tuff, quartz sandstone, limestone tended to have higher 222 Rn concentrations in summer than in winter, while the reverse tendency was true in andesitic porphyry tunnels. Only the difference in limestone was statistically significant.

  11. Airborne radon-222 measurement by active sampling with charcoal adsorption and gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Shizuma, Kiyoshi; Wen, Xiao-qiong; Fukami, Kenji; Iwatani, Kazuo; Hamanaka, Shun-ichi

    1998-01-01

    A simple method for measuring radon concentration in air is presented. Airborne radon is adsorbed in a charcoal bed by an active air sampling. In time, the adsorbed radon comes to attain radioactive equilibrium with its short-lived progeny 214 Pb. Utilizing this fact, radon concentration is derived from γ-ray measurement of 214 Pb. This method is estimated to be capable of detecting radon concentration in air down to 0.79 Bq·m -3 . The adsorption coefficient obtained with the method is compared with what is obtainable with passive sampling. Applications of this method to indoor and outdoor radon measurements are described. (author)

  12. Radon studies in Indian dwellings

    International Nuclear Information System (INIS)

    Khan, A.J.

    2000-01-01

    The indoor radon ( 222 Rn) concentration has been measured by Solid State Nuclear Track Detectors (SSNTDs) in large number of Indian dwellings. Radon concentrations were measured in different parts of the country. In the first study, radon concentrations were measured in 143 dwellings of Udaipur, Bikaner and Banswara towns of Rajasthan province. The distributions of the time-averaged indoor radon concentration in these three towns of the Rajasthan fit an approximately log normal distribution. The geometric mean (GM) values of radon concentrations in these three places were found to be 74 Bq m -3 , 46 Bq m -3 and 66 Bq m -3 with a geometric standard deviation (GSD) of 2.2, 2.2 and 2.5 respectively. In another study, radon concentrations were measured in about 150 dwellings of hilly regions of the country. The measurements were carried out in Kohima (Nagaland), Baijnath and Palampur (Himachal Pradesh). The distribution of radon concentration in Kohima dwellings was found to be approximately log normal, however, the radon distribution in Baijnath and Palampur dwellings seems to be bimodal. The GM values of the radon concentrations for 65 dwellings in Kohima and 43 dwellings in Baijnath and Palampur were 88 Bq m -3 and 134 Bq m -3 with GSD of 1.7 and 2.5 respectively. The results are discussed in detail. (author)

  13. The Noble Gas Radon ({sup 222}Rn) as a Hydrogeologic Tracer of Groundwater Inputs to Rivers and Hyporheic Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Stellato, L. [Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE), Seconda Universita degli Studi di Napoli, Caserta (Italy); Newman, B. D. [Isotope Hydrology Section, International Atomic Energy Agency, Vienna (Austria)

    2013-05-15

    The study of nutrient dynamics in lotic ecosystems often requires background knowledge of the hydrologic processes occurring both at large scales and at small scales in order to adopt effective management practices. In particular, surface water/subsurface water interactions can significantly alter nutrient loading in streams and rivers. Two case studies are reported as examples of large scale and small scale investigations carried out by means of an integrated approach where {sup 222}Rn was used: (i) to determine fractions of groundwater inflow to total discharge of a river and to identify sections with flow-through conditions, applying a degassing corrected, two component mixing model; (ii) to estimate water residence time within the hyporheic zone by applying a solute mass balance equation based on radon disequilibrium between pore water and stream water. The two case studies demonstrate that {sup 222}Rn is an effective tool in the study of interactions between surface and subsurface waters when groundwater inputs to rivers have to be quantified and in estimating the residence time of surface water in the hyporheic zone. However, an integrated approach including other hydrological and biogeochemical measurements is always recommended when complex processes have to be elucidated. (author)

  14. Assessment of Effective Dose Equivalent of Indoor 222Rn Daughters in Inchass

    International Nuclear Information System (INIS)

    Ali, E.M.; Taha, T.M.; Gomaa, M.A.; El-Hussein, A.M.; Ahmad, A.A.

    2000-01-01

    The dominant component of natural radiation dose for the general population comes from the radon gas 222 Rn and its short-lived decay products, Ra A ( 214 Po), Ra B ( 214 Pb), Ra C ( 214 Bi), Ra C( 214 Po) in the breathing air. The objective of the present work is to assess the affective dose equivalent of the inhalation exposure of indoor 222 Rn for occupational workers. Average indon concentrations (Bqm -3 ) were monitored in several departments in Nuclear Research Center by radon monitor. We have calculated the lung dose equivalent and the effective dose equivalent for the Egyptian workers due to inhalation exposure of an equilibrium equivalent concentrations of radon daughters which varies from 0.27 to 2.5 mSvy -1 and 0.016 to 0.152mSvy -1 respectively. The annual effective doses obtained are within the accepted range of ICRP recommendations

  15. Development of a portable radon detection system

    International Nuclear Information System (INIS)

    Allen, J.W.

    1976-09-01

    The presence of radon-222 in soil gas and ground water can indicate the existence of nearby uranium deposits even when heavy overburdens completely absorb the associated gamma radiation. Techniques to detect and measure radon have evolved during the past several years to the point where radon prospecting is routinely employed in a number of countries. A program to develop and field test a prototype system for measuring radon from soil gas and water is described. A prototype system employing a flow through scintillation detector was designed and constructed, utilizing standard commercial components, to provide a fieldworthy unit for testing the system concepts. Laboratory and preliminary field tests of this unit indicate that it can detect anomalous radon levels of less than 10 picoCuries per liter (pCi/l) in soil gas and ground water

  16. Continuous 222Rn measurements in water to perform a hydrograph separation

    International Nuclear Information System (INIS)

    Hofmann, H.; Kies, A.; Tosheva, Z.

    2004-01-01

    To get information about the different components of runoff before, during and after heavy rain events, micro catchments were selected to perform hydrograph separations using the radioactive noble gas 222 Rn and the stable isotope 18 O as natural occurring, conservative tracers. These tracers help to separate 'pre event', 'event', and 'post event' water in the total runoff. The selected micro basins are situated in the western part of Luxembourg and belong to the Attert River catchment area. Our investigations are a part of the project 'Cycleau' which is studying risk assessments in the Attert River area. By combining the databases great opportunities for comparison were realized. So far the catchment areas have been studied for two years. Continuous monitoring radon detectors were installed at selected measuring points, which were important for the different flow regimes. Along with the detectors precision thermometers, conductivity instruments, CO 2 -detectors, flow meter, v-notches, and automatic sampler for chemical analysis were set up. Besides the continuous measurements for 222 Rn, point samples were taken for liquid scintillation analysis (LCS). Single rain events will have been sampled and measured intensively for 222 Rn (LCS) and 18 O in two to three days field campaigns, for a comparison of the continuous method with the 18 O results and to strengthen our data by the end of march 2004. During the first year of this study instrument testing and evaluation was performed. Different radon monitor units were examined to find instruments that work best under field conditions. Additionally, separate units had to be constructed for a degassing of the solved gases out of the water, because the instruments for radon measuring were constructed for radon in air not for radon in water. A 'bubbler' had be developed that performs the degassing process. The techniques will be presented. Through stable results from our instrument developments, we observed different radon

  17. Modelo para determinar as exigências de proteína para poedeiras Modelling protein utilization in laying hens

    Directory of Open Access Journals (Sweden)

    Nilva Kazue Sakomura

    2002-11-01

    Full Text Available O objetivo do trabalho foi elaborar um modelo para estimar as exigências de proteína bruta (PB para poedeiras leves, usando o método fatorial. Para determinar as exigências de proteína bruta (PB para manutenção foi utilizada a técnica do balanço de nitrogênio. A exigência de proteína bruta para o ganho de peso foi determinada em função do conteúdo de nitrogênio na carcaça e a eficiência de utilização do nitrogênio da dieta. A exigência de PB, para produção de ovos, foi determinada considerando o teor de PB determinado nos ovos e a eficiência de deposição do nitrogênio no ovo. A partir dos valores das exigências para manutenção, para o ganho e produção foi elaborada uma equação para predizer as exigências diárias de PB (g/ ave/ dia para poedeiras: PB = 1,94. P0,75 + 0,48.G + 0,301.O, em que P = peso corporal (kg, G = ganho de peso diário (g/dia e O = massa de ovos produzida (g/ave/dia.The objective of this study was to determine a model for crude protein requirements (CP for laying hen by the factorial method. The protein maintenance requirement was determine by the nitrogen balance technique . The crude protein requirement for weight gain was determined based on body nitrogen content and nitrogen efficiency for body deposition. The crude protein requirement for egg production was determined based on the nitrogen content of eggs and nitrogen efficiency for egg deposition. Considering the requirements for maintenance, egg production and weight gain, it was elaborated a protein requirement model for laying hen: PB = 1.94xW.75 + 0.480xG + 0,301x E, where PB = requirement (g/bird/day, W = body weight (kg, G = daily weight gain (g/day and E = egg mass (g/bird/day.

  18. Quality assurance for radon measurements in Germany

    International Nuclear Information System (INIS)

    Beck, T.R.; Buchroeder, H.; Foerster, E.; Schmidt, V.

    2005-01-01

    Full text: Radiation protection regarding work activities at workplaces with naturally occurring radiation has been regulated in the German Radiation Protection Ordinance. Regulations refer only to workplaces where the presence of natural radiation leads to a significant increase in the exposure of workers. These workplaces were identified in the following working areas with enhanced exposures to radon-222: underground mines, including visitor mines and show caves; radon-spas and galleries; water supply and distribution industries. Presently, regulations are being initiated by the German government to limit the exposures to radon in homes. For radon measurements at workplaces passive radon devices for individual monitoring as well as active measuring systems for workplace monitoring can be used. However, passive radon devices are preferred for radon measurements in homes because of low costs and availability in large quantities. To assure the quality of radon measurements the German Federal Office for Radiation Protection (BfS) has established annual interlaboratory comparisons for passive radon devices. The comparisons are carried out in the BfS radon calibration laboratory accredited by the German Calibration Service. Passive radon devices which use solid state track detectors, electrets or activated charcoal can be submitted. Approved radon services which offer radon measurements to determine radon exposure in homes and at workplaces have to pass the comparisons successfully. (author)

  19. Mitigation of {sup 222}Rn induced background in the XENON1T dark matter experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bruenner, Stefan A.

    2017-07-05

    {sup 222}Rn is a major source of background in many rare-event experiments such as the XENON1T dark matter search. The noble gas radon is created by radioactive decay inside all detector materials and emanates into the sensitive liquid xenon target disabling any detector shielding. Subsequent beta-decays of radon progenies are the dominant source of background in the XENON1T experiment. In order to mitigate radon induced background the detector's construction materials have been selected according to dedicated {sup 222}Rn emanation measurements. In the first part of this thesis, we summarize the results of the XENON1T radon screening campaign and present the measurement of the integral radon emanation rate of the fully assembled detector. The development of a radon removal system which continuously purifies the liquid xenon target from the emanated radon is the topic of the second part of this thesis. In order to demonstrate the suitability of cryogenic distillation as a technique to separate radon from xenon, we developed an experimental setup to measure the depletion of radon in xenon boil-off gas after a single distillation step. In the last part of the thesis, we demonstrate the operation of a radon removal system for the XENON100 experiment. For this first test employing a running dark matter detector, we integrated a multiple stage, cryogenic distillation column in the XENON100 gas purification loop. From the evolution of the radon concentration in XENON100, we investigate the distillation column's radon removal capability and discuss the design and application of a radon removal system for XENON1T and the upcoming XENONnT experiment.

  20. A simulation of the transport and fate of radon-222 derived from thorium-230 low-level waste in the near-surface zone of the Radioactive Waste Management Site in Area 5 of the Nevada Test Site

    International Nuclear Information System (INIS)

    Lindstrom, F.T.; Cawlfield, D.E.; Donahue, M.E.; Emer, D.F.; Shott, G.J.

    1993-12-01

    US Department of Energy (DOE) Order 5820.2A (DOE, 1988) requires performance assessments on all new and existing low-level radioactive waste (LLW) disposal sites. An integral part of performance assessment is estimating the fluxes of radioactive gases such as radon-220 and radon-222. Data needs pointed out by mathematical models drive site characterization. They provide a logical means of performing the required flux estimations. Thorium-230 waste, consisting largely of thorium hydroxide and thorium oxides, has been approved for disposal in shallow trenches and pits at the LLW Radioactive Waste Management Site in Area 5 of the Nevada Test Site. A sophisticated gas transport model, CASCADR8 (Lindstrom et al., 1992b), was used to simulate the transport and fate of radon-222 from its source of origin, nine feet below a closure cap of native soil, through the dry alluvial earth, to its point of release into the atmosphere. CASCADR8 is an M-chain gas-phase radionuclide transport and fate model. It has been tailored to the site-specific needs of the dry desert environment of southern Nevada. It is based on the mass balance principle for each radionuclide and uses gas-phase diffusion as well as barometric pressure-induced advection as its main modes of transport. CASCADR8 uses both reversible and irreversible sorption kinetic rules as well as the usual classical Bateman (1910) M-chain decay rules for its kinetic processes. Worst case radon-222 gas-phase concentrations, as well as surface fluxes, were estimated over 40 days. The maximum flux was then used in an exposure assessment model to estimate the total annual dose equivalent received by a person residing in a standard 2500-square-foot house with 10-foot walls. Results are described

  1. Radon in the Environment: Friend or Foe?

    International Nuclear Information System (INIS)

    Hussein, A.S.

    2009-01-01

    Radon 222 is a naturally occurring radioactive gas that is part of the Uranium decay series. Its Presence in the environment is associated mainly with trace amounts of uranium and its immediate parent, radium 226 , in rocks, soil and groundwater. About one-half of the effective doses from natural sources is estimated to be delivered by inhalation of the short lived radon progeny. Owing to this fact, radon is the most popular subject of studies on environmental radioactivity. The presence of high level of radon in indoor environment constitutes a major health hazard for man. The radon progeny is well established as causative agents of lung cancer and other types of caners. Radon unique properties as a naturally radioactive gas have led to its use as a geophysical tracer for locating buried faults and geological structures, in exploring for uranium, and for predicting earthquakes. Radon has been used as a tracer in the study of atmospheric transport process. There have been several other applications of radon in meteorology, water research and medicine. This paper summarizes the health effects and the potential benefits of radon and its progeny.

  2. Initial study on the quantitative determination of radon in varied construction dwllings in the province of Pichincha, Ecuador

    International Nuclear Information System (INIS)

    Ayala, Maria; Penaherrera, Patricio; Munoz, Victor

    1993-01-01

    This research involves data from dwellings built up with different types of raw materials found spread in the province of Pichincha - Ecuador. The SSNTD method using a cellulose nitrate sensible film LR-115 was used for the research. The incidence of temperature, altitude, ventilation on the concentration gas radon-222 were also subject of a qualitative study. Eventually, the results show that the adobe dwellings and/or poorly ventilated dwellings prodece maximum concentration of radon-222 than first or second floor, meaning that, the gas is also coming up from the ground. In any case the level of radon-222 concentration is less than the acceptet limit, 200 Bq/m 3, by UNCEAR. Only places, such as Mindo and Calderon, surpass the limit

  3. Radon in thermal waters and radon risk in chosen thermal water spas in V4 countries - preliminary results

    International Nuclear Information System (INIS)

    Holy, K.; Blahusiak, P.; Muellerova, M.; Grzadziel, D.; Kozak, K.; Mazur, J.; Kovacs, T.; Nagy, E.; Shahrokhi, A.; Neznal, M.; Neznal, M.

    2014-01-01

    The territory of V4 countries is rich in thermal springs. Some boreholes reach a depth of 2000 m and temperatures up to 70 grad C. 222 Rn concentrations in some thermal waters can exceed 1000 Bq/l, however this concentration is not constant. In V4 countries, there is a long tradition in using thermal waters in spa care. In thermal spas, radon is released from the water, and is transported along with its decay products into human respiratory tract, which is potentially harmful to human health. Thus, controlling the levels of radon concentration in thermal waters, homes and workplaces of spas is justified. The aim of this project is the study of radon 222 Rn concentration in thermal waters and in thermal spas in V4 countries. The measurements are carried out a few times during at least one year in order to observe seasonal variability. The obtained results will serve to determine annual effective doses for employees who spend ca. 8 hours a day inside spa buildings. It will be also possible to assess the effective doses for patients (users) of the pools with the highest registered radon concentrations. We carry out measurements in 3 existing thermal water spas in each of the countries: Slovakia, Poland and Hungary, and in 1 thermal water spas in the Czech Republic,according to choice of partners. (authors)

  4. Monitoring network of atmospheric Radon-222 concentration in East Asia and backward trajectory analysis of Radon-222 concentration trend at a small solitary island on pacific ocean

    International Nuclear Information System (INIS)

    Ohkura, Takehisa; Yamazawa, Hiromi; Moriizumi, Jun; Hirao, Shigekazu; Iida, Takao; Guo Qiuju; Tohjima, Yasunori

    2009-01-01

    A monitoring network of atmospheric 222 Rn concentration as a tracer for long-range transport in East Asia was established. Atmospheric 222 Rn concentration at Beijing, which is located on China Continent was 10-20 Bq m -3 , at Nagoya, which is located on edge of terrestrial area was 3-10 Bq m -3 and at Hachijo-jima and Hateruma-jima, which are solitary islands in Pacific Ocean was 0.5-3 Bq m -3 , respectively. The atmospheric 222 Rn concentration variations were different from sites. The 222 Rn concentration was the lowest in the summer and the highest in the winter except Nagoya where the highest was observed in the autumn and the lowest in the spring. Diurnal variations were measured at Beijing and Nagoya. In contrast, diurnal variations were not measured but several-day-cycle variations were measured at Hachijo-jima and Hateruma-jima. It was pointed out by this study that the several-day-cycle variations at Hachijo-jima were dependent on synoptic-scale atmospheric disturbance. 222 Rn concentration increased rapidly after a cold front passed through Hachijo-jima. Backward trajectory analysis of the relationship between atmospheric 222 Rn concentrations at Hachijo-jima and transport pathway of air mass indicates that air mass transported from China and Siberia has high concentration 222 Rn and air mass transported from Pacific Ocean has low concentration 222 Rn. In winter, atmospheric 222 Rn concentrations at Hachijo-jima is dependent on vertical transport pathway rather than horizontal transport pathway. (author)

  5. Correlation between indoor radon and soil gas availability: Results of field studies

    International Nuclear Information System (INIS)

    Kothari, B.K.; Kunz, C.; Lilley, W.

    1990-01-01

    To correlate indoor radon concentrations with soil gas, the authors have carried out a field survey of surficial material in selected regions of New York State. The survey consisted of measurements of gamma radiation, Ra-226, Rn-222 and the permeability for gas flow in surficial material. Based on the data, three areas with a potential for above average indoor radon concentrations have been identified: (1) a black shale region in Onondaga County; (2) a granitic region in Orange County; and (3) a black shale region in Erie County. For an area with potential for below-average indoor radon concentrations, sandy deposits on Long Island with an average concentration of 0.7 pCi Ra-226/g and 160 pCi Rn-222/L at 2-feet depth, have been selected. Fifteen homes from each of these four areas are under test for indoor radon. Measurements of air infiltration rates and soil gas availability parameters are planned for all 60 homes

  6. Parameters that characterize the radon hazard of soils

    International Nuclear Information System (INIS)

    Blue, T.E.; Mervis, J.A.; Jarzemba, M.S.; Carey, W.E.

    1990-01-01

    It has been observed that the radon concentration in homes does not depend solely on the steady-state 222 Rn concentration in the soil. An explanation for the lack of correlation between radon concentrations in the soil and in adjacent homes includes factors such as the construction of the homes, their heating systems, and the habits of their occupants. Another explanation, which is proposed in this paper, is that the steady-state concentration of radon in the pore gas does not fully characterize the soil as a radon hazard. Other soil properties, such as its diffusion length for radon and its porosity, may be important. In this paper, the authors have identified the soil properties important in radon transport into the basement of a home by mathematically modeling ventilated basement air enclosed in basement walls and surrounded by soil and by solving the model equations to determine an expression for the basement air radon concentration as a function of the properties of the soil and basement wall

  7. A radon progeny deposition model

    International Nuclear Information System (INIS)

    Rielage, Keith; Elliott, Steven R.; Hime, Andrew; Guiseppe, Vincent E.; Westerdale, S.

    2010-01-01

    The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly 222 Rn) 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 210 Pb 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 deposit radon progeny on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model are presented.

  8. A Radon Progeny Deposition Model

    International Nuclear Information System (INIS)

    Guiseppe, V. E.; Elliott, S. R.; 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 222 Rn) 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 210 Pb 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 deposit radon progeny on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model are presented.

  9. Evaluation of anthropogenic emissions of carbon monoxide in East Asia derived from the observations of atmospheric radon-222 over the western North Pacific

    International Nuclear Information System (INIS)

    Wada, A.; Matsueda, H.; Tsuboi, K.; Sawa, Y.; Murayama, S.; Taguchi, S.; Kamada, A.; Nosaka, M.

    2012-01-01

    We used the observed CO/"2"2"2Rn ratio in the Asian outflows at Minamitorishima (MNM), Yonagunijima (YON), and Ryori (RYO) in the western North Pacific from 2007 to 2011, together with a three-dimensional chemical transport model (STAG), in order to estimate anthropogenic emissions of CO in East Asia. The measurements captured high-frequency synoptic variations of enhanced "2"2"2Rn (ERN) events associated with the long-range transport of continental air masses. "2"2"2Rn and CO showed high correlation during the ERN events observed at MNM and YON in the winter and spring, but not at RYO. The STAG transport model reproduced well the concentrations of observed "2"2"2Rn when forced with a constant and uniform flux density of 1.0 atom cm"-"2 s"-"1, but underestimated the associated enhancement of synoptically variable CO caused by the underestimated flux values in the EDGAR ver. 4.1 emission database used in the model for East Asia. Better estimates for the East Asian emission were derived using a radon tracer method based on the difference in the enhancement ratio of CO/"2"2"2Rn between the observation and the model. The anthropogenic emissions of CO for China, Japan, and Korea were estimated to be 203 Tg CO yr"-"1, 91% of which originated in China. When compared with other estimated emissions of CO, our estimated result showed consistency with those of the inverse method, whereas the emission database of EDGAR was about 45% smaller than our anthropogenic estimation for China.

  10. Development and testing of the detector for monitoring radon double-filter method

    International Nuclear Information System (INIS)

    Sevcik, P.

    2008-01-01

    Applications of physics in the study of radon transport processes in the atmosphere and of testing of atmospheric transport models require sensitive detection devices with low maintenance requirements. The most precise devices involved in the worldwide monitoring program of the atmosphere (GAW) determine volume activity of radon from a variety of daughter products of 222 Rn, resulting in a working volume of the detector (double-filter method). The purpose of this work was to explore theoretically and experimentally the possibilities and limits of a particular simple implementation of this procedure. Tested apparatus consists of a 200 dm 3 chamber (metal drum), where are developed transformation products of radon and semiconductor detector with surface barrier, which registers α particles from the conversion of daughter products 222 Rn collected on a filter at the outlet of the chamber. Testing of the apparatus takes place in the atmosphere with higher concentrations of radon. The measured variations of volume activities 222 Rn have the same character as the variations of radon concentration in the air in laboratory. Minimum detectable activity at 95% significance level is 16.0 Bq.m -3 at a pumping speed of the air 20 dm 3 .min - 1 and 13.0 Bq.m -3 at a pumping rate 24 dm 3 .min -1 . These values are still too high for using the apparatus for measuring in external atmosphere. The main limit of the apparatus is a capture of transformation products arising on the inner walls of the chamber (plate-out effect). The effectiveness of collecting 218 Po from the chamber on the filter in our measurements was only 2.8%. But we managed to increase it to about 20% by adding aerosol delivery systems into production chamber of transformation products of radon. It turns out that based on this principle can be made sensitive and continuously working monitor of radon. (author)

  11. Radon problem in uranium industry

    International Nuclear Information System (INIS)

    Khan, A.H.; Raghavayya, M.

    1991-01-01

    Radon emission is invariably associated with the mining and processing of uranium ores. Radon (sup(222)Rn) enters mine atmosphere through diffusion from exposed ore body, fractures and fissures in the rocks and is also brought in by ground water. Being the progenitor of a series of short lived radioisotopes it contributes over 70% of the radiation dose to mine workers and thus accounts for nearly 30% of the total radiation doses received by workers in the whole nuclear industry. This paper summarises the data on radon emanation from the ore body, backfilled sands and mine water. Radon and its progeny concentrations in different haulage levels and stopes of the Jaduguda uranium mine are presented to emphasise the need for a well planned ventilation system to control radiation exposure of miners. Results of radon monitoring from a few exploratory uranium mines are included to indicate the need for a good ventilation system from inception of the mining operations. Relative contribution of mine exhaust and tailings surfaces to the environmental radon are also given. Some instruments developed locally for monitoring of radon and its progeny in mines and in the environment are briefly described to indicate the progress made in this field. (author). 17 refs., 2 figs., 6 tabs

  12. Radon and energy efficient homes

    International Nuclear Information System (INIS)

    Burkart, W.

    1981-09-01

    Radon and its daughters in indoor air are presently responsible for dose equivalents of about 31 mSv/year (3 rem/year) to parts of the respiratory tract. Linear extrapolation from the dose response values of uranium miners heavily exposed to radon and its decay products would suggest that almost all lung cancers in the non-smoking population are caused by environmental 222 Rn. Using epidemiological data on the types of lung cancer found in non-smokers of the general public as compared to the miners, a smaller effect of low level radon exposure is assumed, which would result in a lung cancer mortality rate due to radon of about 10 deaths per year and million or 25% of the non-smoker rate. Higher indoor radon concentrations in energy efficient homes mostly caused by reduced air exchange rates will lead to a several fold increase of the lung cancer incidence from radon. Based on the above assumption, about 100 additional lung cancer deaths/year-million will result both from an increase in radionuclide concentrations in indoor air and a concomitant rise in effectiveness of radiation to cause cancer with higher exposure levels. Possibilities to reduce indoor radon levels in existing buildings and costs involved are discussed. (Auth.)

  13. Radon in schools. An elevation measurement in schools in Baden-Wuerttemberg; Radon in Schulen. Eine Erhebungsmessung in Baden-Wuerttemberg

    Energy Technology Data Exchange (ETDEWEB)

    Fesenbeck, I.; Naber, C.; Frank, G.; Wilhelm, C.; Schaller, M. [Karlsruher Institut fuer Technologie (Germany). Sicherheit und Umwelt

    2016-07-01

    With an effective dose of about 1.1 mSv per year, radon and its secondary products have the biggest share in the population's natural radiation exposure. For implementation of the new EU directive 2013/59/EURATOM dated January 17, 2014, it is now planned to adapt the limit values of the Radiation Protection Ordinance and to extend the scope of validity in the EU member states. The ''Radon at Schools'' project is to cover an area-wide survey of radon concentrations in room air of schools in Baden-Wuerttemberg. Potential hazards caused by radon-222 and secondary products of radon are to be studied. For the project, 1600 schools were selected and requested to participate by an information letter. Half of the schools is distributed over the entire area of Baden-Wuerttemberg. The other half is located in areas of increased radon potential. Radon concentration in room air is determined passively by Karlsruhe radon exposimeters. Subsequently, active radon measurements will be made at conspicuous schools and information events will be offered for municipalities, teachers, interested parents, and pupils.

  14. Radon and radium measurement in well water at Curitiba (PR), Brazil

    International Nuclear Information System (INIS)

    Correa, Janine N.; Paschuk, Sergei A.; Perna, Allan F.N.; Kappke, Jaqueline; Claro, Flavio del; Denyak, Valeriy; Schelin, Hugo R.; Rocha, Zildete

    2011-01-01

    This study presents the results of 226 Ra and 222 Rn activity concentration measurements in well water in the city of Curitiba - Parana State of Brazil. Water samples were collected from 31 wells and submitted to the radioactivity measurements in the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR) in cooperation with CDTN-CNEN. Each water sample was submitted to 4 measurements of radon concentration with interval of three days. After two months the same samples were submitted once again to 222 Rn concentration measurements with an objective to evaluate indirectly the amount of 226 Ra contained in water samples. The 222 Rn concentration measurements were performed using AlphaGUARD radon monitor (Genitron Instruments) and 226 Ra concentration was evaluated using the decay curves of 222 Rn. Within few hours after extraction about 70% of water samples from monitored wells presented 222 Rn concentration values above the limit of 11.1 Bq/L recommended by the USEPA. Obtained activity values varied between 1.57 Bq/L - 215.16 Bq/L for radon concentration, and radium concentrations deviated within an interval of 0.61 Bq/L - 6.76 Bq/L. Obtained results showed that the biggest part of 222 Rn found in water samples was not originated from the 226 Ra compounds soluble in water but from gas exhalation by the soil adjacent to the well. The results of present research show the requirement of radioactivity monitoring of water extracted from artesian wells at Curitiba region and indicate the necessity of mitigation procedure development for better control of global alpha radioactivity in drinking water. (author)

  15. Determination of the diffusion coefficient and solubility of radon in plastics.

    Science.gov (United States)

    Pressyanov, D; Georgiev, S; Dimitrova, I; Mitev, K; Boshkova, T

    2011-05-01

    This paper describes a method for determination of the diffusion coefficient and the solubility of radon in plastics. The method is based on the absorption and desorption of radon in plastics. Firstly, plastic specimens are exposed for controlled time to referent (222)Rn concentrations. After exposure, the activity of the specimens is followed by HPGe gamma spectrometry. Using the mathematical algorithm described in this report and the decrease of activity as a function of time, the diffusion coefficient can be determined. In addition, if the referent (222)Rn concentration during the exposure is known, the solubility of radon can be determined. The algorithm has been experimentally applied for different plastics. The results show that this approach allows the specified quantities to be determined with a rather high accuracy-depending on the quality of the counting equipment, it can be better than 10 %.

  16. Radon and 'King Solomon's Miners'. Faynan Orefield, Jordanian Desert

    International Nuclear Information System (INIS)

    Grattan, J.P.; Gillmore, G.K.; Gilbertson, D.D.; Pyatt, F.B.; Hunt, C.O.; McLaren, S.J.; Phillips, P.S.; Denman, A.

    2004-01-01

    Concentrations of 222 Rn were measured in ancient copper mines which exploited the Faynan Orefield in the South-Western Jordanian Desert. The concentrations of radon gas detected indicate that the ancient metal workers would have been exposed to a significant health risk and indicate that any future attempt to exploit the copper ores must deal with the hazard identified. Seasonal variations in radon concentrations are noted and these are linked to the ventilation of the mines. These modern data are used to explore the differential exposure to radon and the health of ancient mining communities

  17. 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)

  18. Radon thematic days - Conference proceedings

    International Nuclear Information System (INIS)

    2011-03-01

    This document brings together the available presentations given at the Radon thematic days organized by the French society of radiation protection (SFRP). Twenty five presentations (slides) are compiled in the document and deal with: 1 - General introduction about radon (Sebastien Baechler, IRA); 2 - Survey of epidemiological studies (Dominique Laurier, IRSN); 3 - Dosimetric model (Eric Blanchardon, Estelle Davesne, IRSN); 4 - Radon issue in Franche-Comte: measurement of the domestic exposure and evaluation of the associated health impact (Francois Clinard, InVS); 5 - WHO's (World Health Organization) viewpoint in limiting radon exposure in homes (Ferid Shannoun, OMS); 6 - Radon measurement techniques (Roselyne Ameon, IRSN); 7 - Quality of radon measurements (Francois Bochud, IRA); 8 - International recommendations (Jean-Francois Lecomte, IRSN); 9 - Radon management strategy in Switzerland - 1994-2014 (Christophe Murith, OFSP); 10 - 2011-2015 action plan for radon risk management (Jean-Luc Godet, Eric Dechaux, ASN); 11 - Radon at work place in Switzerland (Lisa Pedrazzi, SUVA); 12 - Strategies of radiation protection optimization in radon exposure situations (Cynthia Reaud, CEPN); 13 - Mapping of the radon potential of geologic formations in France (Geraldine Ielsch, IRSN); 14 - Radon database in Switzerland (Martha Gruson, OFSP); 15 - Radon 222 in taps water (Jeanne Loyen, IRSN); 16 - Buildings protection methods (Bernard Collignan, CSTB, Roselyne Ameon, IRSN); 17 - Preventive and sanitation measures in Switzerland (Claudio Valsangiacomo, SUPSI); 18 - Training and support approach for building specialists (Joelle Goyette-Pernot, Fribourg engineers and architects' school); 19 - Status of radon bulk activity measurements performed between 2005-2010 in public areas (Cyril Pineau, ASN); 20 - Neuchatel Canton experiments (Didier Racine, SENE); 21 - Montbeliard region experience in the radon risk management (Isabelle Netillard, Pays de Montbeliard Agglomeration); 22

  19. Monitoring of soil radon by SSNTD in Eastern India in search of possible earthquake precursor.

    Science.gov (United States)

    Deb, Argha; Gazi, Mahasin; Ghosh, Jayita; Chowdhury, Saheli; Barman, Chiranjib

    2018-04-01

    The present paper deals with monitoring soil radon-222 concentration at two different locations, designated Site A and Site B, 200 m apart at Jadavpur University campus, Kolkata, India, with a view to find possible precursors for the earthquakes that occurred within a few hundred kilometers from the monitoring site. The solid state nuclear track detector CR-39 has been used for detection of radon gas coming out from soil. Radon-222 time series at both locations during the period August 2012-December 2013 have been analysed. Distinct anomalies in the soil radon time series have been observed for seven earthquakes of magnitude greater than 4.0 M that occurred during this time. Of these, radon anomalies for two earthquakes have been observed at both locations A and B. Absence of anomalies for some other earthquakes has been discussed, and the observations have been compared with some earthquake precursor models. Copyright © 2018. Published by Elsevier Ltd.

  20. 222Rn and short live progeny in atmospheric environment. Origin and measurement techniques

    International Nuclear Information System (INIS)

    Charuau, J.; Labed, V.; Robe, M.C.; Thevenin, J.C.; Fazileabasse, J.; Klein, D.; Heleschewitz, H.; Tymen, G.; Aubert, C.; Gibaud, C.

    1996-01-01

    Radon is the main source of man's exposure to natural ionizing radiation. This document summarizes the general knowledge of the origin of radon 222 and its development in various air environments. It presents several methods for measuring radon activity concentration and the potential alpha energy from its short life daughters. It has been prepared by the commission M60-3, of the Office for the standardization of nuclear equipments (BNEN in French) under the French association for standardization (AFNOR in French). (author)

  1. Scintillation detectors for radon-222 in air and water

    International Nuclear Information System (INIS)

    Mastinu, G.G.

    1980-01-01

    A scintillation detector and an emanation circuit that enable sensitive measurements of 222 Rn in water, in field practice, and in laboratory routine have been developed. Activities as low as 0.1 pCi per sample can be measured with a very simple procedure. The detector is also well suited to measure 222 Rn in air at concentrations down to 0.001 pCi/liter if a large-size detector is used

  2. Experimental study of radon and thoron diffusion through barriers

    Energy Technology Data Exchange (ETDEWEB)

    Durcik, M; Havlik, F [Inst. of Preventive and Clinical Medicine, 83301 Bratislava (Slovakia)

    1996-12-31

    The measurement results of diffusion parameters for radon (radon-222) and thoron (radon-220) through barriers, experimental equipment and theoretical background of diffusion are presented in this paper. The diffusion barriers are used for measuring radon and thoron by passive detectors in order to test the reduction techniques in houses. Six samples (filter paper, rubber, polyethylene, glass laminate, polypropylene) were studied for radon diffusion. The thickness barriers were from 0.012 mm to 2 mm, the diffusion area was 16 cm{sup 2} and the volume V{sub 2} was 30 dm{sup 3}. The diffusion constants D were obtained using given expressions and the data from measurements. The procedures used in experiments are useful for study of diffusion ability of radon and thoron in barriers and determination diffusion parameters from short term measurements. (J.K.). 2 figs., 1 tab., 3 refs.

  3. Experimental study of radon and thoron diffusion through barriers

    International Nuclear Information System (INIS)

    Durcik, M.; Havlik, F.

    1995-01-01

    The measurement results of diffusion parameters for radon (radon-222) and thoron (radon-220) through barriers, experimental equipment and theoretical background of diffusion are presented in this paper. The diffusion barriers are used for measuring radon and thoron by passive detectors in order to test the reduction techniques in houses. Six samples (filter paper, rubber, polyethylene, glass laminate, polypropylene) were studied for radon diffusion. The thickness barriers were from 0.012 mm to 2 mm, the diffusion area was 16 cm 2 and the volume V 2 was 30 dm 3 . The diffusion constants D were obtained using given expressions and the data from measurements. The procedures used in experiments are useful for study of diffusion ability of radon and thoron in barriers and determination diffusion parameters from short term measurements. (J.K.). 2 figs., 1 tab., 3 refs

  4. Novel determination of radon-222 velocity in deep subsurface rocks, and the feasibility to using radon as an earthquake precursor

    Science.gov (United States)

    Zafrir, Hovav; Benhorin, Yochy; Malik, Uri; Chemo, Chaim

    2016-04-01

    An enhanced radon monitoring system was designed in order to study shallow versus deep subsurface processes affecting the appearance of radon anomalies. The method is based on the assumption that the climatic influence is limited since its energy decreases with the decrease in thickness of the geological cover whereby its effect is reduced to a negligible value at depth. Hence, lowering gamma and alpha detectors into deep boreholes and monitoring their temporal variations relative to a reference couple at shallow depths of 10-40 m eliminates the ambient thermal and pressure-induced contribution from the total radon time series. It allows highlighting the residual portion of the radon signals that might be associated with the geodynamic processes. The primary technological key is the higher sensitivity of the gamma detectors - in comparison to the solid-state alpha detectors, which are also suitable for threading into narrow boreholes in parallel to the narrow gamma detector (Zafrir et al., 2013*). The unique achievements of the novel system that was installed at the Sde Eliezer site close to the Hula Valley western border fault (HWBF) in northern Israel are: a) Determination, for the first time, of the radon movement velocity within rock layers at depths of several tens of meters, namely, 25 m per hour on average; b) Distinguishing between the diurnal periodical effect of the ambient temperature and the semi-diurnal effect of the ambient pressure on the radon temporal spectrum; c) Identification of a radon random pre-seismic anomaly preceding the Nuweiba, M 5.5 earthquake of 27 June 2015 that occurred within Dead Sea Fault Zone. * Zafrir, H., Barbosa, S.M. and Malik, U., 2013. Differentiation between the effect of temperature and pressure on radon within the subsurface geological media, Radiat. Meas., 49, 39-56. doi:10.1016/j.radmeas.2012.11.019.

  5. Allometric methodology for the assessment of radon exposures to terrestrial wildlife

    International Nuclear Information System (INIS)

    Vives i Batlle, J.; Copplestone, D.; Jones, S.R.

    2012-01-01

    A practical approach to calculate 222 Rn daughter dose rates to terrestrial wildlife is presented. The method scales allometrically the relevant parameters for respiration in different species of wildlife, allowing inter-species calculation of the dose per unit radon concentration in air as simple base-and-exponent power functions of the mass. For plants, passive gas exchange through the leaf surface is assumed, also leading to specific power relationships with mass. The model generates conservative predictions in which the main contributor to the dose rate of target tissues of the respiratory system is from α radiation arising from 222 Rn daughters. Tabulated 222 Rn DPURn values are given for 69 species used by the England and Wales Environment Agency for habitats assessments. The approach is then applied to assess the authorised discharges of 222 Rn from sites in England, demonstrating that, from a whole-body dose perspective, the biota considered are protected from effects at the population level. - Highlights: ► Allometric method developed to calculate radon daughter doses to 69 species of terrestrial wildlife. ► Model satisfactorily compared with previous studies of lung dose rates for mammals. ► The main contributor to the dose rate of the respiratory system is internal α-radiation from the 222 Rn daughters. ► Air immersion is the principal contributor to the external dose rate. ► Assessment for 7 authorised sites in England suggests that wildlife populations are adequately protected from the anthropogenic radon emissions considered in this study.

  6. Radon monitoring and its application for earthquake prediction

    International Nuclear Information System (INIS)

    Ramchandran, T.V.; Shaikh, A.N.; Khan, A.H.; Mayya, Y.S.; Puranik, V.D.; Venkat Raj, V.

    2004-12-01

    Concentrations ofa wide range of terrestrial gases containing radionuclides like 222 Rn (Radon), H 2 (Hydrogen), Hg (Mercury), CO 2 (Carbon dioxide) and He 4 (Helium) in ground water and soil air have commonly been found to be anomalously high along active faults, suggesting that these faults may be the path for least resistance for the out gassing processes of the solid earth. Among the naturally occurring radionucludes, the 238 U decay series has received great attention in connection with the earthquake prediction and monitoring research all over the world. Due to its nearly ubiquitous occurrence, appreciable abundance, chemical inactivity and convenient half-life (3.823 d), 222 Rn in the 238 U series is the most extensively studied one in this regard. In this report, a brief account of the application of 222 Rn monitoring carried out all over the world, studies carried out in India, modeling of earthquake predictions, measurement techniques, measuring equipments, its availability in India, Indian radon monitoring programme and its prospects are presented. (author)

  7. Automated radon-thoron monitoring for earthquake prediction research

    International Nuclear Information System (INIS)

    Shapiro, M.H.; Melvin, J.D.; Copping, N.A.; Tombrello, T.A.; Whitcomb, J.H.

    1980-01-01

    This paper describes an automated instrument for earthquake prediction research which monitors the emission of radon ( 222 Rn) and thoron ( 220 Rn) from rock. The instrument uses aerosol filtration techniques and beta counting to determine radon and thoron levels. Data from the first year of operation of a field prototype suggest an annual cycle in the radon level at the site which is related to thermoelastic strains in the crust. Two anomalous increases in the radon level of short duration have been observed during the first year of operation. One anomaly appears to have been a precursor for a nearby earthquake (2.8 magnitude, Richter scale), and the other may have been associated with changing hydrological conditions resulting from heavy rainfall

  8. Determination of equilibrium factor between radon and its progeny using surface barrier detector for various shapes of passive radon dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Jamil, K. [PINSTECH, Islamabad (Pakistan). Environ. Radiat. Group; Fazal-ur-Rehman [PINSTECH, Islamabad (Pakistan). Environ. Radiat. Group; Ali, S. [PINSTECH, Islamabad (Pakistan). Environ. Radiat. Group; Khan, H.A. [PINSTECH, Islamabad (Pakistan). Environ. Radiat. Group

    1997-03-21

    In the field of radon dosimetry, it is customary to measure radon ({sup 222}Rn) concentration while potential health hazard is due to the radon short-lived progeny. When radon is in secular equilibrium, the measured activity of radon equals the activity of radon`s progeny. However, in practical cases an inequilibrium between radon and its progeny exists which is measured in terms of the equilibrium factor. To determine the equilibrium factor between radon and its progeny in a closed environment various shapes of passive dosimeters based upon solid state nuclear track detectors (SSNTDs) are employed. In order to observe the dependence of equilibrium factor upon shapes or effective volumes, experiments have been performed replacing the SSNTDs with a surface barrier detector in Karlsruhe diffusion chamber, pen-type and box-type dosimeters. Using the collected alpha spectra, the equilibrium factor has been determined for a radon-air mixture in a custom designed radon chamber simulating a closed environment of a room. The results show that the radon equilibrium factor is about 0.20 for different shapes of dosimeters studied in this research. It is concluded that the determination of equilibrium factor between radon and its progeny does not depend upon effective volume or shape of the passive dosimeters using alpha spectroscopic data acquired by surface barrier detector. (orig.).

  9. Acid-alkaline state of the blood in chronic combined effect of silicon dioxide, radon and tobacco smoke

    International Nuclear Information System (INIS)

    Ivanov, Z.; Charykchiev, D.

    1987-01-01

    Experimental observations were carried out on rats, subjected to inhalaion of radon-222 and combination of radon-222 with intratracheally introduced free silicon dioxide and tobacco smoke. A special method was used for anaerobic and narcosis-free taking of arterial blood from the left cardiac ventricle, the animals being investigated on the 2nd and the 6th month from the start of the experiment. In all tested animals a tendency to respiratory hypercapneic acidosis was established, particularly to the end of the experiment and in the group treated only with radon-222. In these animals a marked non-respiratory alkalosis with deviation of pH to alkaline direction was added. It is assumed that above-mentioned acid-alkaline disturbances could be due to the found morphological changes in the respiratory system, the liver and kidneys

  10. Radon concentrations in the water of Misasa area (Tottori Pref.)

    Energy Technology Data Exchange (ETDEWEB)

    Morishima, Hiroshige; Koga, Taeko; Inagaki, Masayo [Kinki Univ., Higashi-Osaka, Osaka (Japan); Mifune, Masaaki

    1997-02-01

    UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) Report (1988, 1993) indicated that the internal exposure dose of absorption of radon (Rn-222) and the short-lived decay product nucleus occupied about half of 2.4 m Sv of the global average of annual dose of natural radiation source. It is said to be the largest factor of radiation dose of natural radiation. Sample collection and the method, the elution properties by the concentration of Rn-222 in water and the comparison of characteristics among the different methods are explained. The detection limit of concentration of radon in water by OPTI-FLUOR direct method using the liquid scintillator spectrometer was 1.5 Bq/l for 20 mins counting. The maximum radon concentrations determined by this method showed 1700 Bq/l of the spring water in Misasa area, 400 Bq/l of the small water supply system and well and 18 Bq/l of Mitoku river. (S.Y.)

  11. 222radon and its alpha decay concentration into university in Cluj

    International Nuclear Information System (INIS)

    Neda, T.; Mocsy, I.; Tonk, S.

    2004-01-01

    The Bocskai house is an old building in the middle of Kolozsvar city. It was built in 1550. Now it host the Hungarian University Rector's Office and the Faculty of Science and Art, after many modifications. The building has 3 levels. We determined the radon activity concentration and the concentrations of its short-lived daughters in 12 different rooms used for education and as office rooms. The measurements were done with ionization chambers in different conditions in 24 h cycle in the period of 2003-2004. Simultaneously we measured ambient temperature, pressure and relative humidity of the air. We found that the radon activity concentration had values between 40 - 1800 Bq.m-3. Based on the measurements we estimated the exposure from radon and its short lived daughters of the people who work in this building. (author)

  12. The Reference Laboratory for Radon Gas Activity Concentration Measurements at PSI; Das Referenzlabor fuer Radongas-Konzentrationsmessungen am PSI

    Energy Technology Data Exchange (ETDEWEB)

    Schuler, Christoph

    1998-09-01

    Active or passive radon gas measuring instruments are exposed during intercomparison exercises in the radon chamber of the Reference Laboratory for Radon Gas Concentration Measurements at Paul Scherrer Institut: The traceability of radon gas measurements to nationally and internationally acknowledged standards is inspected in the reference atmosphere of the chamber with calibrated {sup 222}Rn activity concentration. The use of secondary standards guarantees the traceability of the radon chamber reference atmosphere. Besides the principal secondary standard, a radon gas standard (secondary standard I), a {sup 226}Ra standard solution (secondary standard II) and a {sup 222}Rn emanation standard (secondary standard III) are used. The {sup 222}Rn activity delivered by one of these standards is quantitatively transferred into a reference volume and hence converted to an activity concentration serving for the calibration of a measuring instrument transfer standard consisting of scintillation cell and counter. By this way, the transfer standard calibration is related and traceable to the internationally acknowledged primary standard laboratories National Institute of Standards and Technology, Gaithersburg, Maryland (U.S.A.) or National Physical Laboratory, Teddington, Middlesex (UK). The calibrated transfer standard is then used to calibrate the radon gas activity concentration in the radon chamber. For a single grab sampling determination of the {sup 222}Rn activity concentration in the radon chamber with the transfer standard, the estimation of Type A and Type B uncertainties yields a relative expanded uncertainty (95% confidence level) of minimum 3% for high concentration levels (10 kBqm{sup -3}) and maximum 30% for low concentration levels (0.2 kBqm{sup -3}). Extended evaluations of the reproducibility of calibration factor measurements obtained by calibration of the transfer standard with the secondary standards I, II and III show a very good reproducibility quality

  13. Tracing submarine groundwater discharge in the NE Gulf of Mexico by 222Rn

    International Nuclear Information System (INIS)

    Young, J.E.; Burnett, W.C.; Chanton, J.P.; Cable, P.H.; Corbett, D.R.

    1993-01-01

    Inputs of freshwater and dissolved components to the ocean by submarine groundwater discharge (SGD) have been largely neglected as source functions for biogeochemical budgets. In order to locate and quantify groundwater inputs, a tracing technique has been developed using 222 Rn, a member of the natural 238 U decay-series. Because 222 Rn has a short half-life (t 1/2 = 3.84 days), is an inert gas, is relatively easy to measure at low concentrations, and has concentrations in groundwater several orders of magnitude greater than seawater, it should make an excellent tracer. Excess 222 Rn concentrations far above ''normal'' ocean values were found in the bottom waters of the northeastern Gulf of Mexico, which suggests this region has significant groundwater discharge. After measuring high water column inventories of excess 222 Rn in this region, an advection/diffusion model was applied to evaluate potential benthic sources of radon. The model is designed to account for sediment diffusion of radon and includes a groundwater term for advective flow into the overlying water. Flow rates and concentrations are adjusted in the model to balance the large difference in the measured water column inventories and the inventory predicted by sediment diffusion alone. The vertical diffusive/advective transport determines the shape of the concentration gradient and fluxes at the sediment-water interface are calculate based on these terms. The authors work shows that SGD could account for as much as 95% of the radon inventory in these offshore waters

  14. Refinement of a thoron insensitive alpha track detector for environmental radon monitoring

    International Nuclear Information System (INIS)

    Davey, J.F.

    1995-01-01

    Olympic Dam Operations, a Copper/Uranium mine in the north of South Australia, currently monitors environmental radon (Rn 222) concentrations at a total of 17 sites in the area surrounding the mining lease and Roxby Downs township. During 1990 a commercial alpha track radon detector service was replaced with an on-site system resulting in lower costs, greater confidence in detector calibration, and reduction in processing time. Alpha track detectors (ATD's) are placed in triplicate at each of the 17 sites. Flow-through scintillation cell continuous radon monitors are also operated at two of these sites. Comparison of results from the two different types of monitor has raised the question of a possible thoron (Rn 220) contribution in the alpha track detectors. Laboratory experiments revealed that the diffusion membranes used in the ATD's were in fact 'transparent' to thoron. A new membrane was tested which effectively excluded thoron from the detector cup without affecting the sensitivity to radon. Field comparisons of the different membranes revealed that the thoron component was significant. Since there is only a very minor Rn220 emission from the mining operation, it is important that the monitoring be specific only to Rn222, the primary source term. The use of the new membrane will result in more accurate measurements of Rn222. 4 refs., 4 tabs., 5 figs

  15. Investigation of the Radon exhalation potential in the PACA region. Phase II: case of high potential exhalation areas in Medium Champsaur (05) and South Esterel (83). Final report

    International Nuclear Information System (INIS)

    2009-01-01

    After having recalled the results of the first phase of the study and the objectives of the second phase, the authors present the methodology: uranium and thorium analysis on rock, radon-222 activity measurement in soil gases, and gamma radiation measurement. They discuss the influence of rock uranium content on radon exhalation (natural contextual and physical phenomena governing radon transport, radon properties, uranium geochemistry). They report the results obtained in the two considered areas (meteorological conditions, radon 222 content in soils, uranium and thorium contents in geological formations, influence of geological formation type and distribution on radon activity)

  16. Scopingreport radon

    International Nuclear Information System (INIS)

    Blaauboer, R.O.; Vaas, L.H.; Hesse, J.M.; Slooff, W.

    1989-09-01

    This report contains general information on radon concerning the existing standards, sources and emissions, the exposure levels and effect levels. lt serves as a basis for the discussion during the exploratory melting to be held in November/December 1989, aimed at determining the contents of the Integrated Criteria Document Radon. Attention is focussd on Rn-222 (radon) and Rn-220 (thoron), presently of public interest because of radon gas pollution in private homes. In the Netherlands air quality standards nor product standards for the exhalation rate of building materials have been recommended. The major source of radon in the Netherlands is the soil gas (> 97%), minor sources are phosphate residues and building materials (> 2% in total). Hence, the major concern is the transfer through the inhalation of air, the lung being the most critical organ at risk to develop cancer. Compared to risks for humans, the risks of radon and its daughters for aquatic and terrestric organisms, as well as for agricultural crops and livestock, are assumed to be limited. In the Netherlands the average dose for man due to radon and thoron progeny is appr. 1.2 mSv per year, the estimated dose range being 0.1-3.5 mSv per year. This dose contributes for about 50% to rhe total exposure due to all sources of ionizing radiation. Of this dose respectively 80% is caused by radon and about 90% is received indoor. The estimated dose for the general population corresponds to a risk for inducing fatal cancers of about 15 x 10-6 per year, ranging from 1.2 x 10-6 to 44 x 10-6 which exceeds the risk limit of 1 x 10-6 per year -as defined in the standardization policy in the Netherlands for a single source of ionizing radiation-with a factor 15 (1- 44). Reduction of exposure is only possible in the indoor environment. Several techniques have been described to reduce the indoor dose, resulting from exhalation of the soil and building materials. )aut- hor). 37 refs.; 3 figs.; 8 tabs

  17. Natural radioactivity and radon specific exhalation rate of zircon sands

    International Nuclear Information System (INIS)

    Righi, S.; Verita, S.; Bruzzi, L.; Albertazzi, A.

    2006-01-01

    The study focuses on the radon emanation from zircon sands and their derivatives, which are widely used in many sectors of industry. In particular, the results obtained by experimental measurements on samples of zircon sands and zircon flours commonly used in Italian ceramic industries are reported. Zircon sands contain a significant concentration of natural radioactivity because Th and U may substitute zirconium in the zircon crystal lattice. The relevant routes of exposure of workers to T.E.N.O.R.M. from zircon materials are external radiation and internal exposure, either by inhalation of aerosols in dusty working conditions or by inhalation of radon in workplaces. The main objective of this investigation is to provide experimental data able to better calculate the internal exposure of workers due to radon inhalation. Zircon samples were surveyed for natural radioactivity, radon specific exhalation rate and emanation fraction. Measurements of radioactivity concentration were carried out using γ-spectrometry. Methods used for determining radon consisted in determining the 222 Rn activity accumulated in a vessel after a given accumulation build-up time. The average activity concentrations of 238 U and 232 Th in samples result about 2600 and 550 Bq kg-1, respectively; these concentrations are significantly higher than the world average noticed in soils, rocks and Earth crust. The 222 Rn specific exhalation rates result very low probably due to the low porosity of the material and the consequent difficulty for radon to be released from the zircon crystal lattice. (author)

  18. Application of spectral decomposition of 222Rn activity concentration signal series measured in Niedźwiedzia Cave to identification of mechanisms responsible for different time-period variations

    International Nuclear Information System (INIS)

    Przylibski, Tadeusz Andrzej; Wyłomańska, Agnieszka; Zimroz, Radosław; Fijałkowska-Lichwa, Lidia

    2015-01-01

    The authors present an application of spectral decomposition of 222 Rn activity concentration signal series as a mathematical tool used for distinguishing processes determining temporal changes of radon concentration in cave air. The authors demonstrate that decomposition of monitored signal such as 222 Rn activity concentration in cave air facilitates characterizing the processes affecting changes in the measured concentration of this gas. Thanks to this, one can better correlate and characterize the influence of various processes on radon behaviour in cave air. Distinguishing and characterising these processes enables the understanding of radon behaviour in cave environment and it may also enable and facilitate using radon as a precursor of geodynamic phenomena in the lithosphere. Thanks to the conducted analyses, the authors confirmed the unquestionable influence of convective air exchange between the cave and the atmosphere on seasonal and short-term (diurnal) changes in 222 Rn activity concentration in cave air. Thanks to the applied methodology of signal analysis and decomposition, the authors also identified a third process affecting 222 Rn activity concentration changes in cave air. This is a deterministic process causing changes in radon concentration, with a distribution different from the Gaussian one. The authors consider these changes to be the effect of turbulent air movements caused by the movement of visitors in caves. This movement is heterogeneous in terms of the number of visitors per group and the number of groups visiting a cave per day and per year. Such a process perfectly elucidates the observed character of the registered changes in 222 Rn activity concentration in one of the decomposed components of the analysed signal. The obtained results encourage further research into precise relationships between the registered 222 Rn activity concentration changes and factors causing them, as well as into using radon as a precursor of geodynamic

  19. Determination of equilibrium factor between radon and its progeny using surface barrier detector for various shapes of passive radon dosimeters

    International Nuclear Information System (INIS)

    Jamil, K.; Fazal-ur-Rehman; Ali, S.; Khan, H.A.

    1997-01-01

    In the field of radon dosimetry, it is customary to measure radon ( 222 Rn) concentration while potential health hazard is due to the radon short-lived progeny. When radon is in secular equilibrium, the measured activity of radon equals the activity of radon's progeny. However, in practical cases an inequilibrium between radon and its progeny exists which is measured in terms of the equilibrium factor. To determine the equilibrium factor between radon and its progeny in a closed environment various shapes of passive dosimeters based upon solid state nuclear track detectors (SSNTDs) are employed. In order to observe the dependence of equilibrium factor upon shapes or effective volumes, experiments have been performed replacing the SSNTDs with a surface barrier detector in Karlsruhe diffusion chamber, pen-type and box-type dosimeters. Using the collected alpha spectra, the equilibrium factor has been determined for a radon-air mixture in a custom designed radon chamber simulating a closed environment of a room. The results show that the radon equilibrium factor is about 0.20 for different shapes of dosimeters studied in this research. It is concluded that the determination of equilibrium factor between radon and its progeny does not depend upon effective volume or shape of the passive dosimeters using alpha spectroscopic data acquired by surface barrier detector. (orig.)

  20. Radon survey related to construction materials and soils in Zacatecas, Mexico using LR-115

    International Nuclear Information System (INIS)

    Mireles, F.; Garcia, M.L.; Quirino, L.L.; Davila, J.I.; Pinedo, J.L.; Rios, C.; Montero, M.E.; Colmenero, L.; Villalba, L.

    2007-01-01

    Indoor radon gas ( 222 Rn), present in the air inside buildings, is one of the most important sources of radiation exposure to the population. This gas originates in the 238 U radioactive decay chain, which is contained in rock and solid soil particles. Radon accumulation in confined spaces, inside buildings, depends on several factors such as the type of soils, type of constructions, building materials, and ventilation. The aim of this work is to present indoor and outdoor radon concentrations for 202 dwellings and indoor concentrations for 148 public clinics; and the radon concentrations relate to the type of predominant soils, the construction years; and building materials used in the ceilings, walls and floors, for cities and towns of the 57 municipalities in the State of Zacatecas, Mexico. The 222 Rn concentrations were measured with a passive-type radon monitor, with LR-115 as detector material; and the radon survey was made during four stages of three months each throughout Zacatecas from 2001 to 2002. The indoor and outdoor radon concentration averages in dwellings were 55.6±4.9Bqm -3 and 46.5±5.3Bqm -3 , respectively. The indoor radon concentration average in public clinics was 57.8±5.4Bqm -3 . These values were lower than the US EPA action limit of 148Bqm -3

  1. Indoor radon survey in Eastern Sicily

    International Nuclear Information System (INIS)

    Catalano, R.; Immè, G.; Mangano, G.; Morelli, D.; Tazzer, A. Rosselli

    2012-01-01

    Inhalation of radon (Rn-222) and its progeny is one of the most significant sources of natural radiation exposure of the population. Nowadays, high radon exposures have been shown to cause lung cancer and many governments all over the world have therefore recommended that radon exposures in dwellings and indoor workplaces should be limited. Radon levels in buildings vary widely from area to area depending on local geology. This paper presents the results of a long-term survey of radon concentrations carried out from 2005 till 2010 in schools and dwellings of Eastern Sicily, using the solid-state nuclear track detector (SSNTD) technique. The investigated area shows medium-high indoor radon concentrations, higher than the Italian average of about 70 Bq/m 3 , with peaks of 500 Bq/m 3 or more in buildings near active faults. Fortunately, only a small fraction of the measurements, about 1.5% of total, was found greater than EU and Italian action limits for indoor and workplaces. - Highlights: ► In this paper we report radon monitoring survey carried out in the east Sicily in schools and dwellings. ► The detection methodology was the solid-state nuclear track detector one. ► The work was supported by a national projects financed by the National Institute of Nuclear Physics.

  2. Determination of radon-222 concentration in inside environments of the Instituto de Engenharia Nuclear, Brazil

    International Nuclear Information System (INIS)

    Gouvea, Vandir de Azevedo; Cardoso, Domingos d'Oliveira; Castro, Carlos Alberto Carvalho

    2000-01-01

    The gotten concentrations of radon-222 in the installations of the IEN had been determined using the active and passive methods. The active method consisted on the use of the alpha spectrometry with a portable equipment Tracerlab Instruments WLM- Plus. In the determination for the passive method, one used detectors of nuclear strokes of type LEXAN. The raised values had been gotten in the wastes deposit and its annexes, room of the press and laboratory of wastes handling. It was observed, in this sector, an instantaneous measure of alpha spectrometry, concentrations around 1000 Bq.m-3, which had over all to the function of storage, the sector, a great volume of natural radioactive materials, especially of radium-226. This determination was carried through in an extreme situation of ventilation zero, where the gates had been kept closed during the execution of the same one. It was observed, however, a considerable fall, with values ten times inferior, after to submit the environment to a ventilation forced by means of fans and exhaust fans. The results gotten in the alpha spectrometry had been confirmed by the detectors of strokes, over all in that it says respect ace trends of storage of the gas in environments little ventilated. Some suggestions had been made on procedures to be adopted, aiming at the security of the people in these environments. The other places studied in the IEN had been, the room of the Argonauta reactor, laboratories and caves of the Cyclotron, diverse laboratories of the sector of chemistry and rooms of staff. The present study it objectified the establishment of a methodology of inquiry of the radon in occupational areas, besides considering solutions for the minimization of the concentrations of the gas, in similar environments of work to the ones of the IEN

  3. Detection of 222Rn and 226Ra in environmental samples by scintillation method

    International Nuclear Information System (INIS)

    Zafimanjato, J.L.R.; Raoelina Andriambololona; Mobius, S.

    2009-01-01

    222 Rn is considered as the major source of radiological exposure of natural radiations to the population. It represents about the half of exposures of natural radiation sources in the world (UNSCEAR, 1993). 222 Rn gets into human body with inhaled air and sometimes with drinking water. Then, the objective of this work is to know the 222 Rn concentrations in water and in indoor atmosphere, and the risk in order to set up a method of monitoring and to identify high radon level areas. A specific method of detection using liquid scintillation with special emphasis on α/β discrimination, the use of solvent extractive and enrichment of radionuclides have been developed for the determination of both 222 Rn and 226 Ra in water. The method is simple, rapid and sensitive. It was shown that the proposed method was suitable for a large scale monitoring and routine analysis. Considerable concentrations of 222 Rn were found in water and air samples from Vinaninkarena - Antsirabe. 222 Rn concentrations obtained by in situ and in laboratory measurements have been compared to the results of an international intercomparison campaigns organised by the German Society for Liquid Scintillation Spectrometry in 2001. An assesment model of the dose due to ingestion and liberation of radon from water is presented and compared with other models especially to the Crawford Brown's model.

  4. Evaluation of radon concentration in well and tap waters in Bursa (Turkey)

    International Nuclear Information System (INIS)

    Akar Tarim, U.; Gurler, O.; Akkaya, G.; Kilic, N.; Yalcin, S.; Kaynak, G.; Gundogdu, O.

    2012-01-01

    222 Rn measurements in water samples collected from 27 wells and 19 taps that were supplied from the investigated wells were conducted using the AlphaGUARD PQ 2000PRO radon gas analyser at sites across several geologic formations within the city of Bursa (Turkey). The measured radon concentrations ranged from 1.46 to 53.64 Bq l -1 for well water and from 0.91 to 12.58 Bq l -1 for tap water. Of the 27 sites sampled, only 7 had radon levels above the safe limit of 11.1 Bq l -1 recommended by the USEPA. In general, all determined concentrations were well below the 100 Bq l -1 revised reference level proposed by the European Union. These values of radon concentrations in water samples are compared with those reported from other countries. Doses resulting from the consumption of these waters were calculated. The minimum and the maximum annual mean effective doses due to 222 Rn intake through water consumption were 0.02 μSv a -1 and 1.11 μSv a -1 , respectively. (authors)

  5. SUPPLEMENTARY COMPARISON: COOMET.RI(II)-S1.Rn-222 (169/UA/98): Rn-222 volume activity comparison

    Science.gov (United States)

    Skliarov, V.; Röttger, A.; Honig, A.; Korostin, S.; Kuznetsov, S.; Lapenas, A.; Milevsky, V.; Ivaniukovich, A.; Kharitonov, I.; Sepman, S.

    2009-01-01

    According to a first program, a supplementary comparison of Rn-222 volume activity was drawn up as a bilateral supplementary comparison between NSC 'Institute of Metrology', Ukraine, and VNIIFTRI, Russia. It took place in March 2005. In April 2005, at the 5th meeting of COOMET held in Braunschweig (Germany), representatives of these institutes exchanged data which showed the comparability of the national standards of Ukraine and Russia for the check points. During the discussion of the procedure some other institutes decided to join the comparison program, which was extended to BelGIM (Belarus), PTB (Germany), VNIIM (Russia) and RMTC (Latvia). The national standards of volume activity of radon-222 were thus calibrated using one standard radon radiometer as the transfer standard. Results are shown in the Final Report of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by COOMET, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  6. Radon and thoron progeny measurements using a portable radon sniffer

    International Nuclear Information System (INIS)

    Efendi, Z.; Jennings, P.

    1993-01-01

    A flexible version of the two-count method has been developed for use in rapid, inexpensive measurements of radon and thoron progeny working levels in residential and industrial premises in the Perth Metropolitan Area. The Method is adapted for use with a simple radon sniffer based on a low speed pump and an alpha counter. The flexibility of the method derives from the software, where some freedom is permitted in the selection of sampling times and post sampling analysis of the filters. This method has been tested on a variety of radioactive materials and it gives consistent, reliable results over a wide range of working levels. The results of a survey of Rn(222) and Rn(220) progeny levels in dwellings within the Perth Metropolitan Area are reported. This study shows that the mean concentration of indoor Rn(222) progeny was 4.7 mWL (17.4 Bq m -3 EEC) up to 23.3 mWL (86.4 Bq m -3 EEC). The mean thoron progeny concentration was 8.2 mWL (2.25 Bq m -3 EEC) with a range from 1 mWL (0.27 Bq m -3 EEC) to 64.5 mWL (17.74 Bq m -3 EEC). Using conversion factors of 0.061 mSv Bq -1 m -3 for Rn(222) progeny and 0.29 mSv Bq -1 m -3 for Rn(220) progeny respectively (UNSCEAR, 1982), it is estimated the average annual effective dose equivalent is 1.1 mSv for Rn(2220 and 0.6 mSv for Rn(220) respectively. 22 refs., 4 tabs., 1 fig

  7. A study of some factors which are related to indoor radon concentrations in Greece

    International Nuclear Information System (INIS)

    Louizi, A.; Nikolopoulos, D.; Lobotesi, E.; Mavroudaki, E.; Koukouliou, V.K.; Chanioti, M.; Papadimitriou, D.; Yiakoumakis, M.; Proukakis, C.

    1997-01-01

    The Medical Physics Department of the University of Athens is conducting radon-222 measurements in Greek dwellings. It is well known that the concentration of radon gas indoors, are related to various factors. A study of these factors has started and first results are reported. (authors)

  8. Radon migration in the ground: a supplementary review

    International Nuclear Information System (INIS)

    Tanner, A.B.

    1980-01-01

    Water is the most important agent in enabling radon isotopes to escape from solid material: Water absorbs kinetic energy of the recoil atom of radon; it is an active agent in altering and hydrating mineral surfaces, thus enhancing their emanating power; and it decreases the adsorption of radon on mineral surfaces. Once in rock and soil pores, radon atoms migrate by diffusion and by transport in varying proportions. In diffusion and transport calculations, it is desirable to use the radon concentration in the interstitial fluid as the concentration parameter and to include porosity explicity. The transport component is important in dry, permeable soils in the upper layers but is much reduced below depths of several tens of meters. Research in disequilibriums in radionuclides of the uranium and thorium series suggests that much assumed migration of 222 Rn is, in fact, a more general migration of uranium and radium isotopes

  9. Radon in buildings: instrumentation of an experimental house

    International Nuclear Information System (INIS)

    Ameon, R.; Diez, O.; Dupuis, M.; Merle-Szeremeta, A.

    2004-01-01

    IRSN decided to develop a code called RADON 2 for conducting simple and methodical studies of indoor radon concentrations. Since a validity check must be performed of the phenomenological model on which the code is based, an experimental program was initiated in 2002, within which a house in Brittany, located on a well-characterized uranium-bearing geological formation, was fitted with special instruments. After characterizing the soil underlying the house, the instrumentation implemented on site continuously monitors a number of parameters to characterize: the radon source term in the building (exhalation rate of 222 Rn at the ground/building interface and at soil surface, radon concentration in the soil and in outdoor air); radon penetration by advection (differential pressure in the house basement); the driving mechanisms for natural ventilation in the house (weather conditions, indoor temperature and relative humidity); radon distribution throughout the house by air flow and radon diffusion (indoor radon concentration at each floor of the house). Using the experimental data acquired over the past two years, the phenomena governing radon penetration inside the house (wind and stack effect) and radon extraction (fresh air supply rate) have been characterized to lay down the bases for validating the newly developed code

  10. Método práctico para determinar protoporfirina libre eritrocitaria como marcador biológico ante la exposición a plomo inorgánico

    Directory of Open Access Journals (Sweden)

    Gloria Marilé Ávalos Ávalos

    2014-10-01

    Full Text Available Introducción: para la evaluación de la exposición ocupacional a plomo inorgánico se utilizan diversos biomarcadores de exposición, entre ellos la determinación de plomo en sangre y la de protoporfirina libre eritrocitaria. Objetivo: determinar la fiabilidad práctica y comparativa de un método espectrofotométrico sencillo para determinar protoporfirina libre en eritrocitos como marcador biológico de la exposición a plomo inorgánico. Métodos: se estudiaron a 40 trabajadores expuestos a plomo con diferentes niveles, a cada uno de ellos se les tomó una muestra de sangre para determinar protoporfirina libre eritrocitaria y plomo, y una muestra de orina para determinar ácido aminolevulínico. Se seleccionó un grupo control de 20 trabajadores no expuestos, donde se correlacionaron las concentraciones halladas de protoporfirina libre eritrocitaria y de ácido aminolevulínico con las de plomo en sangre. Resultados: la correlación entre las concentraciones de protoporfirina libre eritrocitaria y las de plomo en sangre fue mayor y más significativa estadísticamente en los trabajadores expuestos, que la encontrada entre el ácido aminolevulínico y el plomo en sangre de los no expuestos. La técnica propuesta de determinación de protoporfirina libre eritrocitaria, además de resultar exacta, precisa y sensible, es sencilla de realizar en, prácticamente cualquier laboratorio químico con un mínimo de recursos. Conclusiones: la técnica propuesta es confiable y puede ser utilizada en una primera opción en el control higiénico-sanitario de la exposición ocupacional a plomo inorgánico, acudiéndose solamente, de ser imprescindible, a la determinación de plomo en sangre cuando las concentraciones de protoporfirina libre eritrocitaria resulten significativamente altas.

  11. ERRICCA radon model intercomparison exercise

    International Nuclear Information System (INIS)

    Andersen, C.E.; Albarracin, D.; Csige, I.; Graaf, E.R. van der; Jiranek, M.; Rehs, B.; Svoboda, Z.; Toro, L.

    1999-04-01

    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 more fundamental studies of radon transport. To ascertain that results obtained with these models are of good quality, it is necessary that such models are tested. This document reports on a benchmark test organized by the EU project ERRICCA: European Research into Radon in Construction Concerted Action. The test comprises the following cases: 1) Steady-state diffusive radon profiles in dry and wet soils, 2) steady-state entry of soil gas and radon into a house, 3) time-dependent radon exhalation from a building-material sample. These cases cover features such as: soil heterogeneity, anisotropy, 3D-effects, time dependency, combined advective and diffusive transport of radon, flux calculations, and partitioning of radon between air and water in soil pores. Seven groups participated in the intercomparison. All groups submitted results without knowing the results of others. For these results, relatively large group-to-group discrepancies were observed. Because of this, all groups scrutinized their computations (once more) and engaged in follow-up discussions with others. During this debugging process, problems were indeed identified (and eliminated). The accordingly revised results were in better agreement than those reported initially. Some discrepancies, however, 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 recommended that additional exercises are carried out. (au)

  12. Allometric methodology for the assessment of radon exposures to terrestrial wildlife

    Energy Technology Data Exchange (ETDEWEB)

    Vives i Batlle, J., E-mail: jordi.vives.i.batlle@sckcen.be [Belgian Nuclear Research Centre, Boeretang 200, 2400 Mol (Belgium); Copplestone, D. [School of Biological and Environmental Sciences, University of Stirling (United Kingdom); Jones, S.R. [SJ Scientific Ltd, 13 Fern Bank, Cockermouth, Cumbria (United Kingdom)

    2012-06-15

    A practical approach to calculate {sup 222}Rn daughter dose rates to terrestrial wildlife is presented. The method scales allometrically the relevant parameters for respiration in different species of wildlife, allowing inter-species calculation of the dose per unit radon concentration in air as simple base-and-exponent power functions of the mass. For plants, passive gas exchange through the leaf surface is assumed, also leading to specific power relationships with mass. The model generates conservative predictions in which the main contributor to the dose rate of target tissues of the respiratory system is from {alpha} radiation arising from {sup 222}Rn daughters. Tabulated {sup 222}Rn DPURn values are given for 69 species used by the England and Wales Environment Agency for habitats assessments. The approach is then applied to assess the authorised discharges of {sup 222}Rn from sites in England, demonstrating that, from a whole-body dose perspective, the biota considered are protected from effects at the population level. - Highlights: Black-Right-Pointing-Pointer Allometric method developed to calculate radon daughter doses to 69 species of terrestrial wildlife. Black-Right-Pointing-Pointer Model satisfactorily compared with previous studies of lung dose rates for mammals. Black-Right-Pointing-Pointer The main contributor to the dose rate of the respiratory system is internal {alpha}-radiation from the {sup 222}Rn daughters. Black-Right-Pointing-Pointer Air immersion is the principal contributor to the external dose rate. Black-Right-Pointing-Pointer Assessment for 7 authorised sites in England suggests that wildlife populations are adequately protected from the anthropogenic radon emissions considered in this study.

  13. Using {sup 222}Rn as a tracer of geodynamical processes in underground environments

    Energy Technology Data Exchange (ETDEWEB)

    Valladares, D.L. [GEA, Instituto de Matemática Aplicada San Luis (IMASL), Universidad Nacional de San Luis, Consejo Nacional de Investigaciones Científicas y Técnicas, Ej. de los Andes 950, D5700HHW San Luis (Argentina); Silva, A.A.R. da [Instituto de Física, Universidade de São Paulo, P.O.Box 66318, 05314-970, São Paulo, SP (Brazil); Serviço Especializado em Engenharia de Segurança e Medicina do Trabalho, Departamento de Saúde, Universidade de São Paulo, Rua da Reitoria, 109, 05508-900, São Paulo, SP (Brazil); Lacerda, T. [Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/n" o, Gragoatá, 24210-340, Niterói, RJ (Brazil); Anjos, R.M., E-mail: meigikos@if.uff.br [Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/n" o, Gragoatá, 24210-340, Niterói, RJ (Brazil); Rizzotto, M.; Velasco, H.; Rosas, J.P. de [GEA, Instituto de Matemática Aplicada San Luis (IMASL), Universidad Nacional de San Luis, Consejo Nacional de Investigaciones Científicas y Técnicas, Ej. de los Andes 950, D5700HHW San Luis (Argentina); Tognelli, G. [Departamento de Geología, Universidad Nacional de San Luis, Ej. de los Andes 950, D5700HHW San Luis (Argentina); and others

    2014-01-01

    Radon levels in two old mines in San Luis, Argentina, were measured and analyzed, with the aim to assess the potential use of this radioactive noble gas as a tracer of geological processes in underground environments. La Carolina gold mine and Los Cóndores tungsten mine are today used as tourism mines. CR-39 nuclear track detectors were used for this purpose. Measurements were performed during both winter and summer seasons. The findings show that in these environments, significant radon concentrations are subject to large seasonal fluctuations, due to the strong dependence on natural ventilation with the outside temperature variations. For both mines, higher concentration values of {sup 222}Rn were observed in summer than in winter; with an extreme ratio of 2.5 times between summer and winter seasons for Los Cóndores mine. The pattern of radon transport inside La Carolina mine revealed, contrary to what was believed, that this mine behaves as a system with two entrances located at different levels. However, this feature can only be observed in the winter season, when there is a marked difference between the inside and outside temperatures of the mine. In the case of Los Cóndores mine, the radon concentration pattern distribution is principally established by air current due to chimney-effect in summer and winter seasons. In both cases, the analyses of radon pattern distribution appear as a good method to trace air currents, and then localize unknown ducts, fissures or secondary tunnels in subterranean environments. - Highlights: • {sup 222}Rn levels in two old mines in San Luis, Argentina • CR-39 nuclear track detectors were used for this purpose • higher concentration values of {sup 222}Rn were observed in summer than in winter • radon pattern distribution appear as a good method to trace air currents • it localizes unknown ducts, fissures or secondary tunnels in subterranean environments.

  14. Measurement of radon concentration in water by means of {alpha}, {gamma} spectrometry. Radon concentration in ground and spring water in Hiroshima Prefecture

    Energy Technology Data Exchange (ETDEWEB)

    Shizuma, Kiyoshi [Hiroshima Univ. (Japan)

    1997-02-01

    Radon ({sup 222}Rn, T{sub 1/2}=3.8235{+-}0.0003d) is {alpha}-ray releasing nuclide, so that it can not be detected by {gamma}-ray measurement. But, the daughter nuclides {sup 214}Pb (T{sub 1/2}=26.8 min) and {sup 214}Bi (T{sub 1/2}=19.9 min) release {gamma}-ray, accordingly they are measured by Ge detector. Their radioactive equilibrium is kept in the closed vessel, because their half-lives are shorter than that of radon. We developed a measurement method of radon concentration by means of {gamma}-spectrometry. We applied this method to catch radon in the atmosphere by active carbon. The same principle can be applied to radon in water. Radon concentrations in the ground water were measured in 22 points in the Higashi-Hiroshima city and 82 points in the Hiroshima prefecture. The efficiencies of {gamma}-ray were determined. The radon concentration showed between 11 and 459 Bq/l and the average was 123 Bq/l. The high concentration of radon was distributed in the spring of granitic layer and higher concentration of radon were observed in the ground water of fault. (S.Y.)

  15. Source and distribution of radon-222 and radium-226 within South Atlantic Bight waters

    International Nuclear Information System (INIS)

    Ramsey, E.

    1982-09-01

    Radon and radium concentrations were measured in South Atlantic Bight (SAB) waters during six weeks in the summer of 1981. Sampling was designed to coincide with subsurface intrusions of cold Gulf Stream water onto the continental shelf and was part of a large study of the SAB. The distinct zonation of sediment types within the SAB offered the possibility to use radon to trace advection of intruded bottom water. It was determined that the bottom excess radon concentrations, calculated from radon and radium data, were distributed into three groups. The first group of concentrations ranged from 320 to 732 dpm/100L (n=3) and was associated with water occupying the nearshore zone. The second set was sampled within intruded water in the midshelf region. These values ranged from 25.5 to 151.5 dpm/100L (n=35). The third range describes radon concentrations contained in water that is a potential source of upwelled Gulf Stream water. These shelf break concentrations ranged from -1.0 to 213.0 dpm/100L (n=13), and were found to differ significantly (P < 0.001) from the midshelf range of radon concentrations (Mann-Whitney test). The division of radon concentrations into three distinct zones within the SAB waters may provide an indicator of shelf and Gulf Stream water interactions. 55 references, 24 figures, 4 tables

  16. Measurement of 222Rn flux, 222Rn emanation and 226Ra concentration from injection well pipe scale

    International Nuclear Information System (INIS)

    Rood, A.S.; Kendrick, D.T.

    1996-01-01

    The presence of Naturally Occurring Radioactive Material (NORM) has been recognized since the early 1930s in petroleum reservoirs and in oil and gas production and processing facilities. NORM was typically observed in barite scale that accumulated on the interior of oil production tubing and in storage tank and heater-treater separation sludge. Recent concern has been expressed over the health impacts from the uncontrolled release of NORM to the public. There are several potential exposure pathways to humans from oil-field NORM. Among these is inhalation of radon gas and its daughter products. For this exposure pathway to be of any significance, radon must first be released from the NORM matrix and diffuse in free air. The radon emanation fraction refers to the fraction of radon atoms produced by the decay of radium, that migrate from the bulk material as free gaseous atoms. The purpose of this investigation was to characterize the radon release rates from NORM-scale contaminated production tubing being stored above ground, characterize the radon emanation fraction of the bulk scale material when removed from the tubing, and characterize the radium concentrations of the scale. Accurate characterization of 222 Rn emanation fractions from pipe scale may dictate the type of disposal options available for this waste. Characterization of radon release from stored pipes will assist in determining if controls are needed for workers or members of the public downwind from the source. Due to the sensitive nature of this data, the location of this facility is not disclosed

  17. Applications of environmental radon-222 to some cases of water circulation

    International Nuclear Information System (INIS)

    Kimura, S.; Komae, T.

    1980-01-01

    We have proposed three methods to analyze water circulation and the changes caused by human activities by studying the changing distribution patterns of 222 Rn concentrations in water. We investigated the results by applying the methods to some water circulation problems of Japan. The first method was a detailed analysis of the hydrogeological structure of an area, using the fact that the 222 Rn concentration of water takes a value characteristic of the aquifer. In the second method we analyzed the state of mixing of surface water and groundwater by taking advantage of the fact that the 222 Rn concentrations of the two are quite different. In the third method, we used the differing 222 Rn concentrations in vadose water and in retention water to analyze the pressure acting on the aquifer or the groundwater

  18. Uranium, radon-222 and polonium-210 in drinking waters from metropolitan area of Recife, PE, Brazil; Uranio, radonio-222 e polonio-210 em aguas de abastecimento publico da regiao metropolitana do Recife

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleomacio Miguel da

    2000-04-01

    There is only scarce information on the presence of radionuclides in water for public consumption in Brazil. A recently issued federal regulation requires that waters from public supplies be screened to determine their content of alpha and beta emitters. In order to comply with this requirement the present work was carried out with the purpose of determining the concentration of natural uranium, {sup 222} Rn and {sup 210} Po in water supplies in the metropolitan region of Recife, Brazil. The analyses were performed in 17 points of supply of superficial water and 94 points of groundwater supply. The concentrations of uranium were determined by the fluorimetric method, whereas the liquid scintillation method was used to determine the concentration of {sup 222} Rn. Polonium-210, on the other hand, was determined by alpha spectrometry, following its spontaneous deposition on copper disks. The water analyzer presented uranium concentrations varying from 35.3 to 1146.5 mBq/L for superficial resources and from 20.2 to 919.15 mBq/L for underground sources. The concentration of uranium in superficial water showed significant correlation with some parameters such as conductivity, alkalinity and total hardness, as well as, with the concentrations of Ca, Mg, Cl, K, SO{sub 4} and Mn. No correlation, however, was shown with the concentrations of Fe, NO{sub 2} and NO{sub 3}. The concentrations of {sup 222} Rn varied from 5.3 to 83.7 Bq/L in the groundwater analyzer. Radon concentration was not measured in superficial water due to the high emanation rate of radon in open air conditions. As far as {sup 210} Po is concerned, the analyses showed concentrations ranging from <22 mBq/L (the lowest limit of detection) to 57.4 mBq/L for superficial water and from <22 to 813 mBq/L for ground water samples. The concentrations of {sup 210} Po did not show and correlation with physico-chemical parameters. The average concentrations of uranium and {sup 210} Po in superficial water were of 44

  19. Measurement of radon concentration in Taiz city dwellings-yemen

    International Nuclear Information System (INIS)

    Ali, Taher M.; Ahmed, Hayel A.; Ismail, Rokhsana M.

    2001-01-01

    Radon gas considered being a high part of natural radiation background. Emitting alpha particles; radon daughters may be deposited into the lungs and cause health hazards. For this reason, estimation of radon levels in dwellings was done in many countries. In our country, Radon group in the Department of physics, University of Aden has been studied radon level in Aden dwelling. The present study is about the radon level in Taiz City - Yemen. Passive diffusion dosimeters containing (SSNTD s ) Cr - 39 detectors were used in the present work. 125 dosimeters were distributed into dwellings of ten regions in Taiz City. Results obtained show that Rn 222 levels vary between 4 Bq/m 3 and 99 Bq/m 3 . The average concentration in Al-Hasseb district is 23 Bq/m 3 and in Algumhuri hospital district is 53 Bq/m 3 . In other regions it varies between the two values. Whereas the general average in the Taiz City is 34 Bq/m 3 . (author)

  20. Radon Progeny in Egyptian Underground Phosphate Mines

    International Nuclear Information System (INIS)

    El-Hady, M.A.; Mohammed, A.; El-Hussein, A.; Ali, A.E.; Ahmed, A.A.

    2001-01-01

    In addition to the workers in uranium mines, the staff of other underground mines, such as workers in underground phosphate mines, can be exposed to 222 Rn and its progeny. In this study the individual radon progeny concentrations were measured in three Egyptian underground phosphate mines to estimate the occupational exposure of the workers at those sites. A filter method was used to measure individual radon progeny concentrations ( 218 Po, 214 Pb and 214 Po). The reported mean values of radon progeny concentrations exceed the action levels which are recommended by ICRP 65 (1993). Based on the measured individual radon progeny concentrations ( 218 Po, 214 Pb and 214 Po) in these mines, the annual effective dose for the workers has been calculated using the lung dose model of ICRP 66 (1994). According to the obtained results, some countermeasures were recommended in this study to minimise these exposure levels. (author)

  1. Radon emanometric technique for 226Ra estimation

    International Nuclear Information System (INIS)

    Mandakini Maharana; Sengupta, D.; Eappen, K.P.

    2010-01-01

    Studies on natural background radiation show that the major contribution of radiation dose received by population is through inhalation pathway vis-a-vis contribution from radon ( 222 Rn) gas. The immediate parent of radon being radium ( 226 Ra), it is imperative that radium content is measured in the various matrices that are present in the environment. Among the various methods available for the measurement of radium, gamma spectrometry and radiochemical method are the two extensively used measurement methods. In comparison with these two methods, the radon emanometric technique, described here, is a simple and convenient method. The paper gives details of sample processing, radon bubbler, Lucas cell and the methodology used in the emanometric method. Comparison of emanometric method with gamma spectrometry has also undertaken and the results for a few soil samples are given. The results show a fairly good agreement among the two methods. (author)

  2. Calibration of a degassing-emanation line for 222Rn determination in seawater samples; Calibracao de uma linha de emanacao para determinacao de {sup 222}Rn em amostras de agua do mar

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Luciana Aparecida

    2002-07-01

    The purpose of this study is to calibrate a degassing-emanation line and to determine {sup 222}Rn and {sup 226}Ra activity concentrations in seawater samples. This methodology, also called Lucas method, consists in the extraction of radon (originally dissolved in seawater), collection of the gas in a liquid nitrogen cold trap and transfer from the trap to an alpha scintillation cell. Total extraction efficiencies of the 4 degassing-emanation systems were determined by measuring {sup 226}Ra reference solutions. The efficiencies obtained for these 4 systems varied from 21 % to 62%. This work also presents preliminary results of a study carried out in a series of small embayements of Ubatuba, Sao Paulo State-Brazil: Flamengo Bay, Fortaleza Bay, Mar Virado Bay and Ubatuba Bay. Concentration of Rn in excess varied from 0,011 to 0,317 Bq/L for Flamengo Bay, from 0,009 to 0,130 Bq/L for Fortaleza Bay, from 0,018 to 0,050 Bq/L for Mar Virado Bay and from 0,004 to 0,120 Bq/L for Ubatuba Bay. The results obtained for the concentration of {sup 222}Rn in excess in a transect at Flamengo Bay varied from 0,002 to 0,036 Bq/L. Higher concentrations of {sup 222}Rn in excess were obtained in Flamengo Bay, Fortaleza Bay and Ubatuba bay. It was also observed that the concentration of {sup 222}Rn in excess increases with depth, as expected. (author)

  3. Dosimetry of Rn-222 in the air in environments located above and below ground level; Dosimetria de Rn-222 no ar em ambientes localizados acima e abaixo do nivel do solo

    Energy Technology Data Exchange (ETDEWEB)

    Cazula, Camila Dias

    2015-07-01

    Exposure of the general population to ionizing radiation comes mainly from natural sources. The main contribution is due to inhalation of radon (Rn-222), a gas that occurs naturally (UNSCEAR, 2000). The Rn-222 concentration in the environment is controlled by factors such as soil permeability and water content, the weather variability, materials used in the foundation and the usual positive pressure differential between the soil and the internal environment. Studies indicate that the concentration of radon shows a wide variation in the basement, ground floor and upper floors of buildings. The objective of this study is to determine radon levels in basements, ground floor and floors above ground level, at a university in the city of Sao Paulo and in one residential building in the city of Peruibe. Rn-222 measurements were performed using the method with nuclear track of solid state detectors (CR-39). The studied environments present Rn-222 concentration well below the values recommended by the International Commission on Radiological Protection, published in the 2009 document, of 300 Bq/m{sup 3} for homes and 1000 Bq/m{sup 3} for the workplace. In the residential building, the concentration of Ra-266, Th-232 and K-40 in the materials used in the building construction was also analyzed, by gamma spectrometry. The effective total dose for the resident due to external exposure was 0.8 mSv y{sup -1}, lower than the annual dose limit for the general public of 1 mSv y{sup -1}. (author)

  4. Build up of radon, /sup 218/Po and /sup 214/Po in a Karlsruhe diffusion chamber as a function of time

    International Nuclear Information System (INIS)

    Fazal-ur-Rehman; Jamil, K.; Ali, S.; Khan, H.A.

    1996-01-01

    Passive radon /sup 222/Rn dosimeters employing particle detectors are widely used in concentration (p Ci/l) measurement in houses, mines and other areas of activity. These dosimeters yield track density which is needed to be converted into physically meaningful parameter of radon concentration in either p Ci/l or Bq m/sup -3/. Therefore, it is required to know the separate contributions of /sup 222/Rn and its progeny. In the present study we have measured the concentration of /sup 222/Rn and its daughters (/sup 218/Po and /sup 214/Po) separately in the Karlsruhe diffusion chamber radon dosimeter, with and without a filter, as a function of time by an active method using a surface barrier detector. The build up behavior of radon and its two daughters (/sup 218/Po and /sup 214/Po) as a function of time was studied by plotting the area under each peak versus collection time. The differential curves and the relative concentration of radon daughters as a function of time were also studied. The concentration of radon and its daughters shows a somewhat linear build up as a function of time for the presently studied time periods. The results of this experiment are expected to be useful in converting the integrated alpha track density as measured by a particle track detector, (used in passive radon dosimetry) to radon concentration levels and for determination of equilibrium factor. (author)

  5. Método simples e acessível para determinar amônia liberada pela cama aviária

    Directory of Open Access Journals (Sweden)

    Hernandes Renata

    2001-01-01

    Full Text Available A amônia é um gás altamente irritante e causador de estresse às aves confinadas, o que leva à perda de peso, podendo até causar a morte. Por esse motivo, existe grande interesse em se determinar a quantidade de amônia liberada por diferentes camas aviárias e de diferentes condições, bem como os fatores que influenciam a produção desta substância. Assim, idealizou-se o presente trabalho com o objetivo de desenvolver e padronizar uma metodologia simples, acessível, exeqüível para avaliar camas de frangos submetidas a diferentes condições (diferentes tratamentos, tempos de confinamento e temperatura e capaz de determinar a potencialidade da liberação de amônia pela cama de frangos nos galpões. A metodologia baseou-se na adaptação do método da microdifusão, que consta da incubação da cama em um frasco de vidro com capacidade de 500 mL. Sobre a superfície do material incubado coloca-se um béquer de 50 mL contendo 10 mL de solução de ácido bórico 2% (m/v para fixar a amônia exalada pela cama aviária. Esse sistema é fechado e incubado por 15 horas a 30°C e, após, a solução fixadora é retirada e titulada com ácido sulfúrico 0,05 N, usando como indicador uma mistura de verde de bromocresol e alaranjado de metila. O método proposto apresenta precisão para ser usado em experimentos e utiliza material barato e reagentes facilmente encontrados nos laboratórios.

  6. Effect of ventilation type on radon concentration at places of work

    International Nuclear Information System (INIS)

    Oksanen, E.

    1994-01-01

    Indoor radon ( 222 Rn) concentrations were measured at 76 child care facilities and 36 schools in southern Finland. The buildings had three different types of ventilation systems: mechanical air supply and exhaust, mechanical exhaust, and natural ventilation, the first being most common. The effect of the ventilation type on the long-term radon concentration was studied in child care facilities. The radon concentrations were highest in the naturally ventilated buildings. The mechanical air supply and exhaust system maintained the lowest values in cold wintertime. In school buildings both the long-term radon concentration and short-term radon and daughter concentrations were measured. The correlation of the ventilation type and the radon concentration was not obvious in this group of measurements, but the radon concentrations and the equilibrium factors were highest in buildings with natural ventilation. Radon concentrations were generally lower during the working hours than during the one-month period, as expected. (author)

  7. Current status of radon and radium monitoring at the Federal University of Technology (UTFPR), PR, Brazil

    International Nuclear Information System (INIS)

    Paschuk, Sergei A.; Correa, Janine N.; Kappke, Jaqueline; Schelin, Hugo R.; Denyak, Valeriy; Barbosa, Laercio; Perna, Allan F.N.

    2011-01-01

    Numerous and systematic studies performed in different countries for many decades resulted in the explicit conclusion that radon exposure, as well as its progeny, is the main cause of lung cancer among non-smokers. All three natural radon isotopes ( 222 Rn, 220 Rn and 219 Rn) are produced in the three principal natural radioactive decay chains. Specifically, the 222 Rn is produced by the decay series of 238 U and proceeded from α-decay of 226 Ra. Current work describes the present status and obtained results concerning indoor radon survey in dwellings, radon in water supply and soil gas tests performed by the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR) within Curitiba urban area. For radon in air activity measurements, it was used polycarbonate etched track detectors such as LEXAN (GE) and CR-39, mounted in diffusion chambers. For soil gas measurements, the experimental setup was based on the Professional Radon Monitor (AlphaGUARD, Genitron/SAPHYMO) connected to the air pump with filter vessels and to specially developed in our Laboratory the Soil Gas Probe. In the case of radon tests in drinking water, the experimental setup was based on the AlphaGUARD Radon monitor and Electronic radon detector RAD7 (Durridge Company, Inc.) connected to special kit of glass vessels through the air pump. Obtained results permitted to identify few dwellings where radon concentration in air was found bigger than 600 Bq/m 3 which is considered as the action level by most of the European Community and the World Health Organization (WHO). In the case of studied artesian wells, collected samples of water presented the average 222 Rn activity about 60 Bq/L which is 6 times bigger than maximum level recommended by USEPA. Some artesian wells presented the radon activity of almost 200 Bq/L. More over, it was identified the radioactivity of radium ( 226 Ra) salts which are soluble in water and almost all water samples presented results bigger than

  8. Aplicaci??n de los SIG para determinar la variabilidad espacial de par??metros de calidad del mosto de uva. Experiencia en la D.O. Bierzo

    OpenAIRE

    Rodr??guez P??rez, Jos?? Ram??n, 1968-; ??lvarez Taboada, Mar??a Flor; Peters, Stefan

    2008-01-01

    Los estudios tradicionales sobre par??metros de calidad del mosto abarcan grandes bloques de vi??edo y se centran en determinar la evoluci??n temporal de estas variables para decidir la ??poca de vendimia m??s adecuada. En este trabajo se propone una metodolog??a para el an??lisis de la variabilidad espacial de los par??metros del mosto y se exponen los resultados obtenidos en la DO Bierzo, para cuatro variedades diferentes de vid. Los resultados permiten identificar zonas homogeneas en cuant...

  9. Assessment of {sup 222}Rn occupational exposure at IPEN nuclear materials storage site, SP, Brazil; Avaliacao da exposicao ocupacional ao {sup 222}Rn no galpao da Salvaguardas do IPEN, SP

    Energy Technology Data Exchange (ETDEWEB)

    Caccuri, Lilian Saueia

    2007-07-01

    In this study it was assessed the occupational exposure to {sup 222}Rn at IPEN, SP, Brazil, nuclear materials storage site through the committed effective dose received by workers exposed to this radionuclide. The radiation dose was calculated through the radon concentrations at nuclear materials storage site. Radon concentrations were determined by passive detection method with solid state nuclear detectors (SSNTD). The SSNTD used in this study was the polycarbonate Makrofol E; each detector is a small square plastic of 1 cm{sup 2}, placed into a diffusion chamber type KFK. It was monitored 14 points at nuclear materials storage site and one external point, over a period of 21 months, changing the detectors every three months, from December 2004 to September 2006. The {sup 222}Rn concentrations varied from 196 {+-} 9 and 2048 {+-} 81 Bq{center_dot}m{sup -3}. The committed effective dose due to radon inhalation at IPEN nuclear materials storage site was obtained from radon activity incorporated and dose conversion factor, according to International Commission on Radiological Protection procedures. The effective committed dose received by workers is below 20 mSv{center_dot}y{sup -1}. This value is suggested as an annual effective dose limit for occupational exposure by ICRP 60. (author)

  10. Method for radon measurement in the subsoil in geothermal prospectus; Metodos de medicion de radon en el subsuelo en prospeccion geotermica

    Energy Technology Data Exchange (ETDEWEB)

    Balcazar G, M

    1991-02-15

    The present formless describe the technique for radon measurement in the underground, being able to be used as an additional study in the geothermal prospecting. This methodology has been developed in the National Institute of Nuclear Research of Mexico using a film of cellulose nitrate to detect those emanated alpha particles, by the Rn (222). By means of the trace account in this films its settle down the present radon levels in the underground. The present method thinks about as an alternating one to overcome in it leaves the limitations found in the development of the methodology using a radon emanometer ETR-1, of the trade mark SCINTREX. The radon detected by plastics is also an integral method of measuring in a geothermal field that avoids the problems of variations of radon to pluvial precipitations and barometric variations. These variations affect the results strongly when it is used the punctual sampler as it is the ETR-1. (Author)

  11. Radon in energy-efficient earth-sheltered structures

    International Nuclear Information System (INIS)

    Nero, A.V.

    1983-05-01

    Exposure o the radioactive-decay products of radon 222 that are present in indoor air constitutes the most-significant radiation dose received by the general population in most countries. Indoor concentrations vary from one building to another, ranging from insignificant to very high levels that cause radiation doses higher than those experienced by uranium miners. This wide range of concentrations is attributable to variability in the rate at which radon enters buildings, and differences in the ventilation rate. Earth-sheltered dwellings, because they are more completely surrounded by earth material than other structures, have an as yet unquantified potential for having radon entry rates that are higher than typical for other houses in the region. Moreover, measures that save energy by reducing ventilation rates (for example by reducing infiltration) can also raise indoor radon concentrations. For these reasons a significant effort is needed to determine the potential for ventilation-reducing measures and earth sheltering to increase radon concentrations, especially in regions where they are already high. Where necessary, proper attention to specific design features that affect radon entry rates or residence time indoors should be adequate to avoid undue risk to the public

  12. Indoor radon level in schools of Shillong, Meghalaya

    International Nuclear Information System (INIS)

    Saxena, A.; Sharma, Y.; Maibam, D.; Walia, D.; Diengdoh, E.

    2010-01-01

    Radon ( 222 Rn) in the atmosphere is the most important contributor to human exposure from natural sources. Radon is a noble inert gas; and it decays to radionuclides that are chemically active and relatively short lived. Inhalation of the short lived radon progeny imparts a radiation dose to the lung, to which an increased risk of lung cancer is attributed due to the alpha particle irradiation of the secretory and basal cells of the respiratory tract. The indoor radon concentration is dependent on the texture, porosity, permeability, water content of the soil underlying the structure and the radon behaviour in soils on aspects of geology and climate. The direct cause of high radon entry rates into structures exhibiting high indoor radon concentrations are fractures in bedrock formations, cracks in the soil, and similar inhomogeneities in the materials of the foundation of the structures. Other factors influencing indoor radon concentration includes exhalations from the walls and ceilings, building design and material, cracks and openings in the foundation of the buildings. The geological factors in the study area promote radon accumulation especially in buildings and dwellings. The world average annual effective dose in the indoor environments is 1.01 mSv.y -1 . The importance of radon level measurements in school buildings is of interest as children are more sensitive to radon exposure than adults. Hence, radon measurements in 10 schools have been undertaken in the present study

  13. Radiological risk assessment of environmental radon

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, Norafatin; Majid, Amran Ab; Yahaya, Redzuwan; Yasir, Muhammad Samudi [Nuclear Science Programme, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2013-11-27

    Measurements of radon gas ({sup 222}Rn) 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 {sup 226}Ra 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{sup −3} to 571.1 ± 251.4 Bq m{sup −3}, 101.0 ± 41.0 Bq m{sup −3} to 245.3 ± 100.2 Bq m{sup −3}, 53.1 ± 7.5 Bq m{sup −3} to 181.8 ± 9.7 Bq m{sup −3}, 256.1 ± 59.3 Bq m{sup −3} to 652.2 ± 222.2 Bq m{sup −3} and 164.5 ± 75.9 Bq m{sup −3} to 653.3 ± 240.0 Bq m{sup −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{sup −3}, 192.1 ± 75.4 Bq m{sup −3}, 176.1 ± 85.9 Bq m{sup −3} and 28.4 ± 5.7 Bq m{sup −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

  14. A study of radon activity inside some houses in Bangladesh

    International Nuclear Information System (INIS)

    Islam, G.S.; Islam, M.A.; Farid, S.M.; Rahman, A.

    1988-01-01

    The solid state nuclear track detector CR-39 has been used for long term measurements of the radon-222 emanation from building materials and the resultant activity inside houses in Bangladesh. Particular attention is paid to a special type of house with thick walls made entirely of mud. The radon-exhalation rate of the walls of these mud-built houses is found to be consistently higher than that of brick-built houses. (author)

  15. APLICACIÓN DE LA ESPECTROFOTOMETRÍA ULTRAVIOLETA PARA DETERMINAR EL OXÍGENO DISUELTO EN AGUA POR EL MÉTODO WINKLER

    OpenAIRE

    Ramírez T., Gustavo

    1992-01-01

    Se utilizó la espectrofotometría ultravioleta en reemplazo de la titulación convencional con tiosulfato de sodio para determinar el oxígeno disuelto en aguas naturales por el método Winkler. La determinación del oxígeno en aguas de diferente salinidad (Río Manzanares, Ciénaga Grande y Bahía de Santa Marta) no mostró diferencias estadísticas significativas (p

  16. 222Rn in wine cellars in Hungary

    International Nuclear Information System (INIS)

    Csige, I.; Hunyadi, I.; Szerbin, P.; Juhasz, L.

    2004-01-01

    We measured seasonal average 222 Rn activity concentrations in the air of 60 wine cellars in the Tokajhegyalja and Villany wine regions of Hungary using Radamon type etched track radon detectors. The exposure period was 3 months, matching the seasons of 2003-2004. We also used an ionization chamber-type continuous 222 Rn-monitor (AlphaGUARD PQ222, Genitron Instruments, Germany) to study temporal variations of 222 Rn activity concentration in a selected wine cellar in the Tokajhegyalja wine region. This instruments also recorded temperature, atmospheric pressure and relative humidity data. The etched track detector data revealed that the 222 Rn activity concentrations in the air of wine cellars spread over a wide range, from the ambient outdoor concentration of 6 Bq.m -3 up to 6 kBq.m -3 characteristic of natural caves. The temporal variation of 222 Rn activity concentration in the air of the selected cellar varied inversely with the variation of the atmospheric pressure. Earlier we observed similar phenomena in natural karstic caves connected to the surface with vertical shafts only. This suggests that relatively large volume of pore space of the embedding rock communicates with the volume of the cellar induced by the variation of the atmospheric pressure

  17. A study of indoor radon in greenhouses in Mexico City, Mexico

    International Nuclear Information System (INIS)

    Guillermo Espinosa; Allan Chavarria; Jose-Ignacio Golzarri

    2013-01-01

    Enclosed spaces in contact with soil, the main source of radon, like greenhouses have potentially high radon ( 222 Rn) concentrations. Greenhouses are frequented by visitors and also are workplaces. The study of radon concentrations in greenhouses is, thus, a relevant concern for public health and environmental radiation authorities. For this study, the radon concentrations in 12 greenhouses in different locations within Mexico City were measured using nuclear track methodology. The detectors used for the study consisted of the well-known closed-end cup device, with CR-39 Lantrack R as detector material. The measurements were carried out over a period of one year, divided into four three-month sub-periods. The lowest and highest annual mean radon concentrations found in individual greenhouses were 17.0 and 45.1 Bq/m 3 , respectively. The annual mean averaged over all 12 greenhouses was 27.3 Bq/m 3 . No significant seasonal variation was observed. Using the highest annual mean radon concentration found in an individual greenhouse, and an equilibrium factor of 0.4, the effective dose from 222 Rn and its progenies was calculated to be 339.9 nSv/h. This corresponds to an annual dose rate of 679.8 μSv/y (0.057 WLM/y) for a worker spending 4 h a day, 5 days a week, 50 weeks a year, inside the greenhouse. For a visitor spending 12 h a year inside the greenhouse the annual dose is 2.469 μSv/y. The study of indoor radon concentrations in closed buildings such as greenhouses, which are both workplaces and open to visitors, is an important public health consideration. (author)

  18. Radon in schools. An elevation measurement in schools in Baden-Wuerttemberg

    International Nuclear Information System (INIS)

    Fesenbeck, I.; Naber, C.; Frank, G.; Wilhelm, C.; Schaller, M.

    2016-01-01

    With an effective dose of about 1.1 mSv per year, radon and its secondary products have the biggest share in the population's natural radiation exposure. For implementation of the new EU directive 2013/59/EURATOM dated January 17, 2014, it is now planned to adapt the limit values of the Radiation Protection Ordinance and to extend the scope of validity in the EU member states. The ''Radon at Schools'' project is to cover an area-wide survey of radon concentrations in room air of schools in Baden-Wuerttemberg. Potential hazards caused by radon-222 and secondary products of radon are to be studied. For the project, 1600 schools were selected and requested to participate by an information letter. Half of the schools is distributed over the entire area of Baden-Wuerttemberg. The other half is located in areas of increased radon potential. Radon concentration in room air is determined passively by Karlsruhe radon exposimeters. Subsequently, active radon measurements will be made at conspicuous schools and information events will be offered for municipalities, teachers, interested parents, and pupils.

  19. Use of commercial radon monitors for low level radon measurements in dynamically operated VOC emission test chambers

    International Nuclear Information System (INIS)

    Hofmann, M.; Richter, M.; Jann, O.

    2017-01-01

    Compared to the intended EU reference level of 300 Bq m -3 for indoor radon concentrations, the contribution of building materials appears to be low. Considering the recommended limit of 100 Bq m -3 by WHO, their contribution is supposed to be relevant, especially at low air exchange rates. This study as part of a two-part research project investigated the suitability of direct low level 222 Rn measurement under simulated indoor conditions with commercial radon monitors and dynamically operated emission test chambers. Active measuring devices based on ionisation or scintillation chambers with 1-σ uncertainties below 8.6% at 20 Bq m -3 were found to be best suitable for a practical test procedure for the determination of radon exhalation rates of building materials. For the measurement of such low concentrations, the knowledge of the accurate device background level is essential. (authors)

  20. Accumulation and circulation of gaseous radon between lunar fines

    International Nuclear Information System (INIS)

    Lambert, G.; Bristeau, P.; CEA Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette; Le Roulley, J.C.

    1975-01-01

    During the lunar night, the temperature of the regolith upper layer is lower than the radon freezing point. Thus radon atoms coming from the interior can be trapped at the surface of the cold lunar fines. The 222 Rn daughter products, 210 Pb and 210 Po, are embedded in a very thin layer at the surface of the grains. It is therefore possible, by spectrometry, to distinguish between the continuum due to uranium, thorium (and decay products) homogeneously distributed and the narrow peak at 5.3MeV, due to an excess of 210 Pb. The mean day-and-night concentration was about 3.5x10 3 atoms of intergranular 222 Rn per g of superficial fines, corresponding to a continuous flow of 3 atoms per minute and per cm 2 of soil. To account for such a flow of radon atoms moving in a random walk from a 6 meter source depth, the pore size of the regolith should be 60μ. On the other hand, the involved changes in the isotopic composition of the radiogenic lead remain less than 1% [fr

  1. Radon concentration and working level in the Exploratory Studies Facility (ESF)

    International Nuclear Information System (INIS)

    Stiver, J.H.; Tung, Chao-Hsiung.

    1995-01-01

    Radon-222 ( 222 Rn) and 222 Rn progeny WL monitoring in the Exploratory Studies Facility (ESF) was initiated to support regulatory compliance. Measurements were taken over two periods, in Test Alcove No. 1 of the ESF, about 60 m from the tunnel entrance. For both periods, 222 Rn concentration was less than 10% of the Derived Air Concentration (DAC) set forth in DOE Order 5480.11. Thus, these assessments were sufficient to demonstrate regulatory compliance. Based on these findings, quarterly 222 Rn and 222 Rn progeny monitoring was initiated. Two systems each were employed for 222 Rn and 222 Rn progeny measurement. No significant differences were observed between the respective systems. An interesting finding was that at the time the measurements were taken, barometric pressure appeared to be the predominant factor controlling 222 Rn concentration in the ESF. This was true even during periods of ventilation shutdown

  2. 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

  3. Assessment of potential radiological population health effects from radon in liquefied petroleum gas

    Energy Technology Data Exchange (ETDEWEB)

    Gesell, Thomas F; Johnson, Jr, Raymond H; Bernhardt, David E

    1977-02-01

    Liquefied petroleum gas (LPG) contains varying amounts of radon-222 which becomes dispersed within homes when LPG is used in unvented appliances. Radon-222 decays to alpha-emitting daughter products which are associated with increased lung cancer when inhaled and deposited in the respiratory system. The average dose equivalents to the bronchial epithelium from the use of LPG in unvented kitchen ranges and space heaters are estimated to be about 0.9 and 4.0 mrem/year, respectively. When extrapolated to the United States population at risk, the estimated tracheobronchial dose equivalents are about 20,000 and 10,000 person-rems/year for these appliances, or a total of about 30,000 person-rems/year. These doses are very small compared to other natural and man-made sources of ionizing radiation. It is estimated that these low doses would result in less than one lung cancer a year for the total U.S. population. Consequently, the use of LPG containing radon-222 does not contribute significantly to the incidence of lung cancer in the United States. Furthermore, the cost for control of radon levels in LPG would be over $50 million for reduction of one health effect, therefore it is concluded that a requirement for such controls would not be cost effective on a national basis. This study did indicate that individual dose equivalents could possibly exceed 500 mrem/year. However, existing data are not sufficient to determine the significance of such potentially high individual doses. (author)

  4. Exposures to radon in homes in Adana

    International Nuclear Information System (INIS)

    Yegingil, Z.

    1990-01-01

    Radon escaping from soil into homes appears to present the single greatest source of radiation exposure that most people will ever face. The use of solid state nuclear tracks detectors (SSNTD) is one of the most convenient techniques to assess the average radiation levels of alpha activities in the environment. By using CR-39 and LR-115 detectors long term alpha activities have been investigated to be noticeable the concentrations of natural radionuclides and Rn-222 exhalation rate under different environmental conditions in Adana. The radon distributions have been measured in soils an in single houses and apartment buildings in various floors in the summer and winter time. The seasonal variation of the radon concentration measured by CR-39 and LR-115 displayed a correlation. (author). 25 refs, 2 tabs

  5. Radon movement simulation in overburden by the 'Scattered Packet Method'

    International Nuclear Information System (INIS)

    Marah, H.; Sabir, A.; Hlou, L.; Tayebi, M.

    1998-01-01

    The analysis of Radon ( 222 Rn) movement in overburden needs the resolution of the General Equation of Transport in porous medium, involving diffusion and convection. Generally this equation was derived and solved analytically. The 'Scattered Packed Method' is a recent mathematical method of resolution, initially developed for the electrons movements in the semiconductors studies. In this paper, we have adapted this method to simulate radon emanation in porous medium. The keys parameters are the radon concentration at the source, the diffusion coefficient, and the geometry. To show the efficiency of this method, several cases of increasing complexity are considered. This model allows to follow the migration, in the time and space, of radon produced as a function of the characteristics of the studied site. Forty soil radon measurements were taken from a North Moroccan fault. Forward modeling of the radon anomalies produces satisfactory fits of the observed data and allows the overburden thickness determination. (author)

  6. ¿Cómo determinar su riesgo empresarial?

    Directory of Open Access Journals (Sweden)

    Roberto Celaya Figueroa

    2013-07-01

    Full Text Available Las empresas cambian de manera constante, operativa o estructuralmente, sea para responder a las necesidades del mercado o para adecuarse a los cambios. Cualquier persona interesada en analizar una empresa tiene a su alcance herramientas de análisis que van desde determinar su liquidez, rentabilidad y solvencia o sus niveles de operación y los cambios que se generan en su estructura financiera; pero un análisis muy importante y difícil, por los sesgos que sus resultados pueden generar, es la determinación del riesgo inherente a la empresa, tema al que se aboca el presente trabajo

  7. Simultaneous determination of Rn-220 and Rn-222 concentrations in atmospheres by cellulose nitrate ionographic detectors

    International Nuclear Information System (INIS)

    Lobao, N.

    1977-01-01

    A method for the indoor determination of airborne radon and radon daughters is described, based in the utilization of cellulose nitrate (CN) ionographic detectors (LR-115-Kodak-Pathe) These track-etching detectors are coupled to an air sample and to a difusion chamber respectively. In the first system ambient air is pulled through a fiber glass filter for collection of airborne radon daughters (Flow: 230 ml/min). In the second system, the cellulose nitrate detectors is coupled/min). In the second system, the cellulose nitrate detectors is coupled to a difusion chamber electrostatic precipitator arrangement. Here the CN detector will register only the alpha particles given off by the decay products of Rn-222 formed within the sensitive volume of electrostatic precipitator. The construction of calibration curves for the two systems using adequate steady-state concentrations of Rn-220 and Rn-222 in an exposure chamber (1 cubic meter), will allow the use of the system for measurement of measurement of averaged integrated radon concentrations. The CN attached to the CN attached to the air sampler is exposed in the reference atmosphere with and without a mylar filter for discrimination of alpha particles with different energies Field sampling indicated however, that efficiency of the two systems are still low for the measurement of environmental levels of Rn-220 and Rn-222 within houses of the AENR, recommendations for efficienty improvement of the system are proposed [pt

  8. Time variation of 222Rn concentration and gamma level in a half-basement room

    International Nuclear Information System (INIS)

    Iimoto, Takeshi; Eguchi, Hoshio; Kosako, Toshiso; Sugiura, Nobuyuki

    1998-01-01

    Correlation between 222 Rn (radon) concentration and gamma level in a half-basement has been discussed. In order to decrease the background count of a whole-body counter (WBC), a ventilation blower of 72 m 2 h -1 was installed. The device succeeded in a big reduction of radon concentration in the half-basement and then the background of WBC (NaI(Tl)) decreased to the 76.5% of the saturated value. Through a radon saturation test the exhalation rate of radon from concrete wall was estimated as 2.1 Bqm -2 h -1 by a simple model calculation. In addition, through a ventilation test, the procedure was analyzed by another simple model. (author)

  9. Study of radon-222 emanation from sedimentary phosphates and corresponding phosphogypsum. Temperature effect

    International Nuclear Information System (INIS)

    Boujrhal, F.M.

    1993-01-01

    The aim of this study is to examine the effect of temperature on radon emanation from the phosphates of various regions of Morocco, from corresponding phosphogypsum and from teeth fossilized of Youssoufia phosphate. The interpretation of obtained results was carried out by the physicochemical studies with various approaches; the X-ray diffraction analysis, the measurement of the specific surface area and porousness, the determination of the oxygen content by activation analysis with 14 MeV neutron. The thermal treatment between 100 and 900 degrees C conducted to the following points: - An increase of the radon degassing rate, which is first slow when the temperature increase from 20 to 600 degrees C, then becomes brutal beyond this temperature. We attributed this variation to the training effect ( transport effect ) of radon by the others gas susceptible to be released with thermal effect, particularly the CO sub 2. - The reduction of the radon emanation power versus temperature. We could demonstrate a linear correlation between the power emanation and the specific surface area. 122 refs., 102 figs., 20 tabs. (Author)

  10. Risk of lung cancer in animals following low exposures to Radon-222 progeny

    International Nuclear Information System (INIS)

    Duport, P.; Monchaux, G.; Morlier, J.P.

    1997-01-01

    Owing to the facts that a) large uncertainties affect the epidemiology of radon progeny-induced lung cancer in humans (especially at low exposures), and b) the rat is a good model for studying the carcinogenicity of radon progeny in humans, the risk of lung cancer following low exposures to low concentrations of radon progeny can be estimated from data obtained in the laboratory on rats exposed under controlled conditions. From the limited set of laboratory data on the induction of lung cancer in laboratory rats it appears that, at low exposures, the risk of lung cancer decreases with decreasing concentration, and that exposures of the order of 25 WLM, at an exposure rate of 2 WL do not produce any excess lung cancers. Since 20 WLM is a lifetime exposure comparable to those expected in occupational or indoors conditions and 2 WL is an exposure rate about 20 times higher dm current occupational exposures rates and 100 times higher than indoor ones, these observations may be indicative of threshold conditions for the induction of lung cancer by radon progeny. (author)

  11. Radon measurement waters from different regions of Transylvania

    International Nuclear Information System (INIS)

    Moldovan, M.; Cosma, C.

    2004-01-01

    Radon exposure is still a very current problem in the scientific world. It is well-known that 222 Rn and its short-lived daughters contribute to the effective dose equivalent, through inhalation, in a percent of 50% of the total effective dose equivalent from natural sources [UNSCEAR, 1988]. The radon gas incorporated in water is transferred into the indoor air by simple utilisation of water for domestic purposes. According to the American standards, the waters with concentrations of radon higher than 11.11 Bq/l (300 pCi/l) must not be consumed. Radon studies are very motivated even from the medical and geophysical point of view. Moreover, interesting correlations can be done between the measured concentration indoors and the concentration of those underground waters that supply them. We measured over 135 samples of groundwater. These were collected from wells, at different depths. The samples were measured after 12 hours, in order to prevent the radon loss. For groundwater measurements we used, a device called LUK-3A, manufactured in Czech Republic, which has a standard deviation of ± 10% and a sensibility of 0.56 Bq/l (15 pCi/l).The method is based on the detection of alpha radioactivity of 222 Rn. It can be set to perform measurements of 222 Rn from water. In case of this method a water sample of 0.3 l is collected into a glass container which is intensely stirred and shaken for one minute. The container is then connected to a vacuumed Lucas cell on one side and on the other side connected to a syringe in which distillated water was introduced having an amount equal to the volume of gas left into the collector container. Three successive measurements of 100 s were made for each sample. Before starting the measurements the background of the Lucas cells that were going to be used was determined. The concentration of radon is calculated using the formula: C Rn = k · N [Bq/l] where k - calibration constant, k = 9.85; N - count of pulses recorded in 100 minutes

  12. A study of Radon-Concentration Distribution in Buildings in Gyeong-ju

    Energy Technology Data Exchange (ETDEWEB)

    Park, C. H.; Jang, S. Y.; Jung, O. J.; Moon, J. H. [Dongguk University, Gyeongju (Korea, Republic of)

    2010-10-15

    Radon({sup 222}Rn) gas is the natural radiation generated by radioactive decay of uranium({sup 238}U) nuclide. The radon which exists in ground flows into the inside by the atmospheric temperature, the differential-pressure or a gap of building underground and a ejection by a drywall with a phosphoric In Korea, Korean Institute of Nuclear Safety had been studied about the inside-radon radioactivity investigation over the nation. In the area around the nuclear power plant, it is possible to exist both of a radioactivity nuclide and a natural. Therefore it is necessary to investigate the radon radioactivity in surrounding area of nuclear power plants. In this study, it is purpose to develop the method of establishing the on-line monitoring system to minimize the radiological effect due to radon gas, based on the real state of radon exposure in Gyeong-ju surrounding Nuclear Power Plant

  13. Development of a low-level radon reference chamber; Entwicklung einer Low-Level-Radon-Referenzkammer

    Energy Technology Data Exchange (ETDEWEB)

    Linzmaier, Diana

    2013-01-04

    The naturally occurring, radioactive noble gas radon-222 exists worldwide in different activity concentrations in the air. During the decay of radon-222, decay products are generated which are electrically charged and attach to aerosols in the air. Together with the aerosols, the radon is inhaled and exhaled by humans. While the radon is nearly completely exhaled, ca. 20 % of the inhaled aerosols remain in the lungs in one breath cycle. Due to ionizing radiation, in a chain of events, lung cancer might occur. Consequently, radon and its decay products are according to the current findings the second leading cause of lung cancer. At the workplace and in the home measurements of radon activity concentration are performed to determine the radiation exposition of humans. All measurement devices for the determination of radon activity concentration are calibrated above 1000 Bq/m{sup 3}, even though the mean value of the present investigation in Germany shows only 50 Bq/m{sup 3}. For the calibration of measurement devices in the range below 1000 Bq/m{sup 3} over a long time period, the generation of a stable reference atmosphere is presented in this work. Due to a long term calibration (t>5 days) of the measurement devices, smaller uncertainties result for the calibration factor. For the calibration procedure, a so-called low-level radon reference chamber was set up and started operation. The generation of a stable reference atmosphere is effected by means of emanation sources which consist of a radium-226 activity standard. On the basis of {gamma}-spectrometry, the effective emanation coefficient ofthe emanation sources is determined. The traceability of the activity concentration in the reference volume is realized via the activity ofthe radium-226, the emanation coefficient and the volume. With the emanation sources produced, stable reference atmospheres within the range of 150 Bq/m{sup 3} to 1900 Bq/m{sup 3} are achieved. For the realization, maintenance and

  14. Comparative study on radon effects and thermal effects on humans in radon hot spring therapy

    International Nuclear Information System (INIS)

    Yamaoka, K.; Mitsunobu, F.; Hanamoto, K.; Tanizaki, Y.; Sugita, K.; Kohima, S.

    2003-01-01

    Full text: The radon therapy is used radon ( 222 Rn) gas, which mainly emits alpha-rays, and induces a small amount of active oxygen in the body. Because most of the diseases to which the radon therapy as well as the thermal therapy is applied are related to activated oxygen, in this study the effects of the radioactivity of radon and thermal effects were compared under the room or the hot spring condition with the similar chemical component, using as the parameters which are closely involved in the clinical for radon therapy. In the results, the radon and thermal therapy enhanced the antioxidation function, such as the activities of superoxide dismutase (SOD) and catalase, which inhibit lipid peroxidation and total cholesterol produce in the body. Moreover the therapy enhanced concanavalin A (ConA)-induced mitogen response, and increased the level of CD4, which is the marker of helper T cell, and decreased the level of CD8, which is the common marker of killer T cell and supresser T cell, in the white cell differentiation antigen (CD4/CD8) assay. Furthermore, the therapy increased the levels of alpha atrial natriuretic polypeptide (alpha ANP), beta endorphin, adrenocorticotropic hormone (ACTH), insulin and glucose-phosphate dehydrogenase (G-6-PDH), and decreased the vasopression level. The results were on the whole larger in the radon group than in the thermal group. The findings suggest that the radon therapy more contributes to the prevention of life style-related diseases related to peroxidation reactions and immune depression than thermal therapy. Moreover these indicate what may be a part of the mechanism for the alleviation of hypertension, osteoarthritis (pain) and diabetes mellitus brought about more radon therapy than thermal therapy

  15. Gas exchange in the Pee Dee River based on 222Rn evasion

    International Nuclear Information System (INIS)

    Moore, W.S.; Elsinger, R.J.

    1983-01-01

    Excess 222 Rn concentrations decrease downstream in the fresh water section of the Pee Dee River. Ground water is the primary source of the excess 222 Rn to the River. Using the radon concentration gradients determined during four sampling periods, gas exchange rates based on the stagnant film model are calculated. Stagnant film thicknesses range from 19 μm to 48 μm and mass transfer coefficients range from 2.1 m/d to 4.1 m/d

  16. Exposure to radon and mortality standard in a coal miner cohort in Brazil

    International Nuclear Information System (INIS)

    Veiga, Lene Holanda Sadler; Amaral, Eliana; Koifman, Sergio

    2002-01-01

    High levels of radon and his products have been found at a underground coal mine, at the Southern Brazil, in operation since 1945. The 222 Rn concentration levels measured were 7000 Bq/m 3 and 0.7 WL for the radon sons (7.7 WLM/year), which are values considered higher than the limits for intervention in a working environments (500 to 1500 Bq/m3 of 222 Rn) and the occupational exposure limit (4.0 WLM/year). Due to the unique opportunity found in these miner group, it was decided to construct a cohort with miners from that mining (underground and surface) viewing the evaluation of the possible effects to the health decurrens from that exposure

  17. A modeling study of the effect of depth of burial of depleted uranium and thorium on radon gas flux at a dry desert alluvial soil radioactive waste management site (RWMS)

    International Nuclear Information System (INIS)

    Lindstrom, F.T.; Cawlfield, D.E.; Emer, D.F.; Shott, G.J.

    1993-08-01

    An integral part of designing low-level waste (LLW) disposal pits and their associated closure covers in very dry desert alluvium is the use of a radon gas transport and fate model. Radon-222 has the potential to be a real heath hazard. The production of radon-222 results from the radioactive decay (a particle emission) of radium-226 in the uranium-235 and 238 Bateman chains. It is also produced in the thorium-230 series. Both long lived radionuclides have been proposed for disposal in the shallow land burial pits in Area 5 RWMS compound of Nevada Test Site (NTS). The constructed physics based model includes diffusion and barometric pressure-induced advection of an M-chain of radionuclides. The usual Bateman decay mechanics are included for each radionuclide. Both linear reversible and linear irreversible first order sorption kinetics are assumed for each radionuclide. This report presents the details of using the noble gas transport model, CASCADR9, in an engineering design study mode. Given data on the low-level waste stream, which constitutes the ultimate source of radon-222 in the RWMS, CASCADR9 is used to generate the surface flux (pCi/cm 2 -sec) of radon-222 under the realistic atmospheric and alluvial soil conditions found in the RWMS at Area 5, of the NTS. Specifically, this study examines the surface flux of radon-222 as a function of the depth of burial below the land surface

  18. 222Rn studies and mapping in the city of Curitiba - Brazil

    International Nuclear Information System (INIS)

    Correa, Janine Nicolosi; Fior, Loriane; Paschuk, Sergei A.; Schelin, Hugo R.; Pecequilo, Brigitte R. S.; Paula Melo, Vicente de

    2008-01-01

    This work describes radon monitoring performed in cooperation between the Laboratory of Ionizing Radiations of the Federal University of Technology - Parana (UTFPR), the Institute of Nuclear and Energetic Researches (IPEN) and the Institute of Radiation Protection and Dosimetry (IRD), from the Brazilian Nuclear Energy Commission (CNEN), during the last two years. For 222 Rn concentration measurements related to different construction materials as well as for the studies of radon emanation and its reduction, the sealed cell chambers, of approximately 60 x 60 cm 2 , was built using ceramic and concrete blocks. This construction was performed within a protected and isolated laboratory environment to maintain the air humidity and temperature stable. These long term measurements have been performed using polycarbonate alpha track passive detectors. The exposure time was set to 15 days considering previous calibration performed at IRD, where a efficiency of 70% was obtained for the density of alpha particle tracks about 13.8 cm -2 per exposure day and per kBq/m 3 of radon activity concentration. The chemical development of the alpha tracks was achieved by electrochemical etching. The track identification and counting were done using a code based on the MATLAB Image Processing Toolbox. The cell chambers were built following four main steps: 1) assembling the walls using the blocks and mortar; 2) plaster installation; 3) wall surface finishing using lime; 4) wall surface insulation by paint. By comparison between three layers installed at the masonry walls from concrete and ceramic blocks, it was concluded that only wall painting with acrylic varnish attended the expectation and reduced the radon emanation flow by a factor of approximately 2.5. The construction materials were submitted to the instant measurements of radon concentration using a ALPHA GUARD Professional detector. The samples of the construction materials were stored inside an acrylic container (sealed up

  19. Control methods of radon and its progeny concentration in indoor atmosphere

    International Nuclear Information System (INIS)

    Ramachandran, T.V.; Subba Ramu, M.C.

    1990-01-01

    Exposure to radon-222 and its progeny in indoor atmosphere can result in significant inhalation risk to the population particularly to those living in houses with much higher levels of Rn. There are three methods generally used for the control of Rn and its progeny concentration in the indoor environment: (1) restricting the radon entry, (2) reduction of indoor radon concentration by ventilation or by aircleaning and (3) removal of airborne radon progeny by aerosol reduction. Prominent process of radon entry in most of the residence appears to be the pressure driven flow of soil gas through cracks or through other openings in the basements slab or subfloor. Sealing off these openings or ventilation of the slab or subfloor spaces are the methods of reducing the radon entry rate. Indoor radon progeny levels can also be reduced by decreasing the aerosol load in the dwellings. The results of a few experiments carried out to study the reduction in the working level concentration of radon, by decreasing the aerosol load are discussed in this paper. (author). 9 tabs., 8 figs., 37 refs

  20. Radon inhalation suppresses nephropathy in streptozotocin-induced type-1 diabetic mice

    International Nuclear Information System (INIS)

    Nishiyama, Yuichi; Kataoka, Takahiro; Yamato, Keiko; Etani, Reo; Taguchi, Takehito; Yamaoka, Kiyonori

    2016-01-01

    In this study, we investigated the suppressive effects of radon inhalation against nephropathy in C57BL/6J mice with type-1 diabetes induced by intraperitoneal injection of streptozotocin (50 mg/kg weight, given five times). Four weeks after diabetes induction, the diabetic mice were continuously treated with inhaled radon-222 of 2000 Bq/m3 or air only (sham) for four weeks. The results showed that radon inhalation did not affect type-1 diabetic symptoms such as body weight loss, hyperglycemia, and hypoinsulinemia. However, diabetic mice treated with radon showed lower urinary albumin excretion and fibrotic change in renal glomeruli compared with diabetic mice not treated with radon. Furthermore, renal superoxide dismutase activity and glutathione content were significantly higher in diabetic mice treated with radon than in diabetic mice not treated with radon. These findings suggested that radon inhalation enhanced renal antioxidants activities, resulting in the suppression of diabetic nephropathy. This study may contribute to the development of a novel approach in the treatment of nephropathy for diabetic patients. (author)

  1. Assessment of 222Rn occupational exposure at IPEN nuclear materials storage site, SP, Brazil

    International Nuclear Information System (INIS)

    Caccuri, Lilian Saueia

    2007-01-01

    In this study it was assessed the occupational exposure to 222 Rn at IPEN, SP, Brazil, nuclear materials storage site through the committed effective dose received by workers exposed to this radionuclide. The radiation dose was calculated through the radon concentrations at nuclear materials storage site. Radon concentrations were determined by passive detection method with solid state nuclear detectors (SSNTD). The SSNTD used in this study was the polycarbonate Makrofol E; each detector is a small square plastic of 1 cm 2 , placed into a diffusion chamber type KFK. It was monitored 14 points at nuclear materials storage site and one external point, over a period of 21 months, changing the detectors every three months, from December 2004 to September 2006. The 222 Rn concentrations varied from 196 ± 9 and 2048 ± 81 Bq·m -3 . The committed effective dose due to radon inhalation at IPEN nuclear materials storage site was obtained from radon activity incorporated and dose conversion factor, according to International Commission on Radiological Protection procedures. The effective committed dose received by workers is below 20 mSv·y -1 . This value is suggested as an annual effective dose limit for occupational exposure by ICRP 60. (author)

  2. Glass implanted 210Po as a method of determination of long term exposure to radon: First experiments in Israel

    International Nuclear Information System (INIS)

    Haquin, G.; Lang, B.; Even, O.; Asael, Y.; Shamai, Y.; Margaliot, M.; Shirav, M.

    2002-01-01

    Radon gas ( 222 Rn) is known to be the major contributor of the total exposure of the population to ionizing radiation. Retrospective assessment techniques have been developed to estimate long term exposures to ( 222 Rn and its progeny in epidemiological studies. Measurements of implanted 210 Po on glass panes surfaces characterize room radon concentration or habitant characterization.Various methods for retrospective radon measurement are described in the literature. The surface trap method is based on the 210 Po implanted on glass or other vitreous objects, measured using solid-state nuclear track detectors (SSNTD). The volume trap method is based on measurements of 210 Po in spongy, porous materials ( 210 Po volume traps). Other approach is in-vivo measurements of 210 Pb in the human skeleton. The present study uses the surface trap retrospective technique for the first time in Israel, coupled with an approach to estimate the 210 Po concentration in glasses exposed to 222 Rn using alpha spectrometry

  3. New ICRP recommendations on occupational limits for radon daughters

    International Nuclear Information System (INIS)

    Jacobi, W.

    1981-01-01

    The ICRP has recommended in 1959 for the first time a maximum permissible concentration (MPC) for the occupational exposure to radon and its short-lived daughters. Since this time more realistic dosimetric models for radon daughters have been developed. Taking into account epidemiological and new dosimetric findings the ICRP has adopted in March this year new recommendations on occupational limits for inhalation of 222 Rn, 220 Rn and their short-lived daughters. This report will be published this year as ICRP Publication 32 (ICRP 1981). The recommended limits for radon daughters were derived from the basic dose and risk limits as they were proposed by ICRP in its new basic recommendations (ICRP Publ. 26, 1977). In the following this basic system of dose limitation is shortly outlined before the special recommendations for radon daughters are described

  4. Radon Concentration in Caves of Croatia - Assesing Effective Radon Doses for Occupational Workers and Visitors

    International Nuclear Information System (INIS)

    Radolic, V.; Miklavcic, I.; Poje, M.; Stanic, D.; Vukovic, B.; Paar, D.

    2011-01-01

    Radon monitoring at potentially highly radioactive location such as caves is important to assess the radiological hazards to occupational workers and occasional visitors. In its Publication 65 the ICRP has produced recommendations dealing with exposure to elevated background radiation, in particular, the risk associated with the inhalation of radon and radon progeny. Recommended annual effective dose from radon 222Rn and its short-lived progeny for workers should not exceed 20 mSv and for occasional users (visitors) the same recommendation is 1 mSv. Measurements were performed with series of track etched detectors (LR115 - type II) in several caves in Croatia. The obtained values for the radon concentration ranged from ambient values up to several thousand Bq m -3 . Radon concentration was measured in about 20 caves of Velebit and Zumberak mountains and the highest radon concentration was in Lubuska jama (3.8 kBq m -3 ) and cave Dolaca (21.8 kBq m -3 ), respectively. Djurovica cave is especially interesting because of its huge tourist potential due to its location bellow Dubrovnik airport. Its mean annual radon concentration of 17.6 kBq m -3 classifies Djurovica cave among caves with high radon concentration. A visitor during half an hour visit at summer time would receive an effective dose of 30.6 μSv. Calculated mean dose rate of 44 μSv/h means that workers (mainly tourist guides) should limit their time inside cave to 454 hours per year. Manita pec is the only cave open for tourists on the territory of Paklenica National Park. The preliminary radon measurements performed during summer 2010, gave an average radon concentration of 1.1 kBq m -3 . An exposure to average dose rate of 3.7 μSv/h means that the tourist guides would receive an effective dose of 0.42 mSv during summer period according to their working schedule. A visitor during half an hour visits would receive an effective dose of 1.86 μSv. (author)

  5. Subpart W: National Emission Standards for Radon Emissions From Operating Mill Tailings

    Science.gov (United States)

    Subpart W limits the radon-222 emissions rate from uranium tailings piles to 20 picocuries per square meter per second and requires that new tailings impoundments meet certain work practice standards.

  6. Anomalous soil radon fluctuations – signal of earthquakes in Nepal ...

    Indian Academy of Sciences (India)

    The present paper deals with pre-seismic soil radon-222 recorded at two different locations 200 m apart, at Jadavpur ..... prepared plastic cup is placed within the metallic container in ..... a micro-earthquake event in a stable continental region;.

  7. Dosimetry of Rn-222 in the air in environments located above and below ground level

    International Nuclear Information System (INIS)

    Cazula, Camila Dias

    2015-01-01

    Exposure of the general population to ionizing radiation comes mainly from natural sources. The main contribution is due to inhalation of radon (Rn-222), a gas that occurs naturally (UNSCEAR, 2000). The Rn-222 concentration in the environment is controlled by factors such as soil permeability and water content, the weather variability, materials used in the foundation and the usual positive pressure differential between the soil and the internal environment. Studies indicate that the concentration of radon shows a wide variation in the basement, ground floor and upper floors of buildings. The objective of this study is to determine radon levels in basements, ground floor and floors above ground level, at a university in the city of Sao Paulo and in one residential building in the city of Peruibe. Rn-222 measurements were performed using the method with nuclear track of solid state detectors (CR-39). The studied environments present Rn-222 concentration well below the values recommended by the International Commission on Radiological Protection, published in the 2009 document, of 300 Bq/m 3 for homes and 1000 Bq/m 3 for the workplace. In the residential building, the concentration of Ra-266, Th-232 and K-40 in the materials used in the building construction was also analyzed, by gamma spectrometry. The effective total dose for the resident due to external exposure was 0.8 mSv y -1 , lower than the annual dose limit for the general public of 1 mSv y -1 . (author)

  8. Indoor Radon and Its Decay Products: Concentrations, Causes, and Control Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Nero, A.V.; Gadgil, A.J.; Nazaroff, W.W.; Revzan, K.L.

    1990-01-01

    This report is an introduction to the behavior of radon 222 and its decay products in indoor air. This includes review of basic characteristics of radon and its decay products and of features of the indoor environment itself, all of which factors affect behavior in indoor air. The experimental and theoretical evidence on behavior of radon and its decay products is examined, providing a basis for understanding the influence of geological, structural, and meteorological factors on indoor concentrations, as well as the effectiveness of control techniques. We go on to examine three important issues concerning indoor radon. We thus include (1) an appraisal of the concentration distribution in homes, (2) an examination of the utility and limitations of popular monitoring techniques and protocols, and (3) an assessment of the key elements of strategies for controlling radon levels in homes.

  9. Dynamics of radon-222 near below ground surface

    International Nuclear Information System (INIS)

    Fukui, Masami; Katsurayama, Kousuke; Nishimura, Susumu.

    1986-01-01

    The concentrations and variation of 222 Rn were investigated both in unconfined groundwater and in the aerated zone to obtain information as to the behavior of Rn close to ground surface. The Rn concentrations in unconfined groundwater near the surface were depletive by the extent of about 50 % compared with that of lower part in a borehole, then the continuous extraction of groundwater causes pronounced increase of the concentration. The method, which monitors continuously the Rn concentration in such surroundings, was developed, where the unconfined groundwater extracted was injected into another borehole and sprayed gas was measured using an ionization chamber. The read-out values of this system well followed the variation of concentrations caused by the meteorological parameter, especially infiltrating water. The increase of 222 Rn concentration in the aerated zone above the water level was clearly observed following the ascendant of groundwater level caused by the infiltrating water, whereas the change of concentration in soil air just below the ground surface obeyed mainly to the wetness of soil and unconfined groundwater level rather than atmospheric pressure. (author)

  10. Mitigation of indoor radon using balanced mechanical ventilation

    International Nuclear Information System (INIS)

    Wellford, B.W.

    1986-01-01

    Previous research has shown that, for a given source strength, the concentration of Rn 222 in the home is inversely proportional to the ventilation rate. Further reductions in the concentration of the decay products of radon can be achieved due to the decrease in residence time of the parent gas as well as increased plate-out of the progeny. Natural and mechanical ventilation can affect the distribution of pressure across the building envelope potentially increasing the flow of radon bearing soil gas into the home gas into the home and/or promoting mixing of areas of higher and lower concentration. Balanced heat recovery ventilation systems were installed in ten homes in the Boyertown, Pennsylvania area. Ventilation was restricted initially to the basement area. Five installations were later modified to introduce supply air to upstairs living spaces while continuing to exhaust from the basement. An independent contractor measured Rn 222 concentrations and decay product activity in the basement and first floor living area before and after installation or modification of the heat recovery ventilation system. Additional experiments to evaluate the effect of house tightening techniques and positive pressurization of the basement were conducted. With balanced ventilation of the basement only, the mean reduction in Working Level was 92.8% with a high of 98% and a low of 76%. Mean reduction of radon gas concentration was 79.1%. When modified to supply air upstairs, mean reduction in Working Level in the living area was 90%. House tightening measures to reduce stack effect were observed to reduce radon concentration. Results indicate that balanced ventilation is an effective strategy for radon mitigation and can be expected to achieve recommended levels in a majority of homes. 9 references, 2 figures, 2 tables

  11. Radon and its decay products in housing

    International Nuclear Information System (INIS)

    Swedjemark, G.A.

    1985-01-01

    Methods have been worked out for evaluation of the uncertainties due to temporal variations in the annual averages for the concentrations of radon-222 (radon) and radon daughters (RnD) indoors. These methods have been applied to the results from long-term measurements of radon in a few houses. The possible use of correction factors in order to get a more adequate annual average have also been studied and some examples have been given. On the basis of country-wide investigations carried out during 1955-56 and during 1972-75 averages of the radon concentrations in housing existing in 1950 and 1975 were calculated six years ago to be 29 and 71 Bq m -3 respectively. A new country-wide investigation with the aim of obtaining values representative for the country was carried out during 1980-82. On the basis of these results a new calculation was made of the concentrations in dwelllings existing in 1975 to 101 Bq m -3 and also for the 1980 housing stock to 98 Bq m -3 . These results are discussed and the collective dose equivalents in the Swedish population have been calculated. (author)

  12. Identification of radon anomalies in soil gas using decision trees and neural networks

    International Nuclear Information System (INIS)

    Zmazek, B.; Dzeroski, S.; Torkar, D.; Vaupotic, J.; Kobal, I.

    2010-01-01

    The time series of radon ( 222 Rn) concentration in soil gas at a fault, together with the environmental parameters, have been analysed applying two machine learning techniques: (I) decision trees and (II) neural networks, with the aim at identifying radon anomalies caused by seismic events and not simply ascribed to the effect of the environmental parameters. By applying neural networks, 10 radon anomalies were observed for 12 earthquakes, while with decision trees, the anomaly was found for every earthquake, but, undesirably, some anomalies appeared also during periods without earthquakes. (authors)

  13. Variation in radon exhalation from the ground on the active fault in Kobe

    Energy Technology Data Exchange (ETDEWEB)

    Yasuoka, Y.; Shinogi, M. [Kobe Pharmaceutical Univ., Kobe, Hyogo (Japan)

    1998-12-31

    Since 27 January 1997, the measurements of radon (Rn-222) exhaled from the ground have been made continuously by the use of PICO-RAD detector (Packard instrument Co.) at monitoring stations on Ashiya active fault. The fault may have been slipped by the Kobe earthquake (magnitude 7.2, 17 January 1995). The variation of relative radon exhalation on the fault was large. We guessed the large variation of relative radon exhalation on the fault was caused by not only the influence of meteorology but also the influence of other factors. (author)

  14. Radon emanation coefficients in sandy soils

    International Nuclear Information System (INIS)

    Holy, K.; Polaskova, A.; Baranova, A.; Sykora, I.; Hola, O.

    1998-01-01

    In this contribution the results of the study of an influence of the water content on the emanation coefficient for two sandy soil samples are reported. These samples were chosen on the because of the long-term continual monitoring of the 222 Rn concentration just in such types of soils and this radon concentration showed the significant variations during a year. These variations are chiefly given in connection with the soil moisture. Therefore, the determination of the dependence of the emanation coefficient of radon on the water content can help to evaluate the influence of the soil moisture variations of radon concentrations in the soil air. The presented results show that the emanation coefficient reaches the constant value in the wide interval of the water content for both sandy soil samples. Therefore, in the common range of the soil moisture (5 - 20 %) it is impossible to expect the variations of the radon concentration in the soil air due to the change of the emanation coefficient. The expressive changes of the radon concentration in the soil air can be observed in case of the significant decrease of the emanation coefficient during the soil drying when the water content decreases under 5 % or during the complete filling of the soil pores by the water. (authors)

  15. Direct determination of radon in the marine troposphere

    International Nuclear Information System (INIS)

    Burtner, D.R.; Kay, J.G.

    1990-01-01

    222 Rn concentrations have been determined within and directly above the top of the marine boundary layer over the Eastern Pacific Ocean about 350 miles off the California coast. This was part of a multi-investigator, comprehensive study of the chemistry and dynamics of the marine stratocumulus conducted in July and August, 1985. Samples were collected using an aircraft, the Electra, in cooperation with National Center for Atmospheric Research. Concentrations of radon, determined by the Lucas cell method using charcoal absorption techniques, ranged from a low of about 12 atoms of radon per liter of air to a high of about 430 atoms/l. Entrainment rates across the top of the marine boundary layer have been determined from these measurements. Correlation of radon concentrations with other chemical species is suggested in certain cases

  16. Characterization of the personal dosimeter Rn-disk for monitoring radon exposure

    International Nuclear Information System (INIS)

    Orlando, P.; Arcovito, G.; Amici, M.; Orlando, C.; Cardellini, F.; Fiorentino, A.; Trevisi, R.

    2009-01-01

    Rn-disk is a new passive device for measuring occupational exposure to radon 222, are presented the results of tests for the characterization of the dosimeter as a tool for estimating the individual dose for workers. [it

  17. Radon in houses utilizing stone magazines for heat accumulation

    International Nuclear Information System (INIS)

    Stranden, E.

    1981-01-01

    Measurements of 222 Rn and its daughters in three solar energy houses utilizing stone magazines for heat accumulation are reported. Theoretical calculations of the radon contribution from the stone magazines seem to be in good agreement with the measured values. The survey indicated that this method for heat accumulation could give a significant increase in the indoor radon concentration if the radium concentration of the stone material is high. The theoretical considerations suggest that a radium concentration of 1 pCi/g of the stone material could give an increment of the radon concentration in the indoor air of about 1 pCi/l. during the heating season in a house with air volume of 250 m 3 and a 10 5 -kg stone magazine. (author)

  18. Method for radon measurement in the subsoil in geothermal prospectus

    International Nuclear Information System (INIS)

    Balcazar G, M.

    1991-02-01

    The present formless describe the technique for radon measurement in the underground, being able to be used as an additional study in the geothermal prospecting. This methodology has been developed in the National Institute of Nuclear Research of Mexico using a film of cellulose nitrate to detect those emanated alpha particles, by the Rn (222). By means of the trace account in this films its settle down the present radon levels in the underground. The present method thinks about as an alternating one to overcome in it leaves the limitations found in the development of the methodology using a radon emanometer ETR-1, of the trade mark SCINTREX. The radon detected by plastics is also an integral method of measuring in a geothermal field that avoids the problems of variations of radon to pluvial precipitations and barometric variations. These variations affect the results strongly when it is used the punctual sampler as it is the ETR-1. (Author)

  19. Performance improvements on passive activated charcoal 222Rn samplers

    International Nuclear Information System (INIS)

    Wei Suxia

    1996-01-01

    Improvements have been made on passive activated charcoal 222 Rn samplers with sintered metal filters. Based on the samplers of good adaptability to temperature and humidity developed before, better charcoal was selected to further improve their performance in radon absorption ability and moisture-resistance. And charcoal quantity in samplers was strictly controlled. The integration time constant of the improved samplers was about 4.3 days. As the sampler was combined with gamma spectrometer to measure radon concentration, the calibration factor was 0.518 min -1 ·Bq -1 ·m 3 for samplers of 7 days exposure time, and the minimum detectable concentration 0.28 Bq·m -3 if counting time for both background and sample is 1000 minutes. The improved samplers are suited to accurately determine the indoor and outdoor average radon concentration under conditions of great variation in temperature and humidity

  20. Outdoor radon levels and dose to the members of public residing in and around the new BARC campus, Visakhapatnam, India

    International Nuclear Information System (INIS)

    Vinod Kumar, A.; Sumesh, C.G.; Krishna, N.S.; Sahoo, S.K.; Tripathi, R.M.; Puranik, V.D.

    2010-01-01

    Natural radiation is the largest contributor to the collective radiation dose to the world population. The greatest fraction of the natural radiation exposure to humans results from inhalation of the short-lived decay products of Radon ( 222 Rn) and Thoron ( 220 Rn), which occur in the free atmosphere and in higher concentrations in the room air of buildings. 222 Rn, being the most important radon isotope in terms of radiation exposure contributes about 55% of the annual radiation dose to the general population from natural radiation sources

  1. PO.RA project. An analysis on gas radon concentrations in soil versus fluctuations in the groundwater table; Progetto PO.RA.. Analisi della concentrazione di gas radon nel non saturo in relazione alla soggiacenza della falda freatica

    Energy Technology Data Exchange (ETDEWEB)

    Serentha' , C.; Torretta, M. [Agenzia Regionale per la Protezione dell' Ambiente della Lombardia, Dipartimento di Monza, Monza (Italy)

    2001-09-01

    Man is daily exposed to natural radiation, mainly due to cosmic rays and natural radioactive elements, whose most important radioactive daughters are {sup 222}Rn (radon) and {sup 220}Rn (thoron). Being these ones gaseous, they can spread through the ground, reaching the atmosphere and accumulating in rooms, where their concentrations may be very high. As radon exhalation is strongly connected with the hydrogeological features of the environment, this study tried to find a relationship between fluctuations in the groundwater table and gas radon concentrations in soil, in order to try estimates of indoor radon concentrations. [Italian] L'uomo e' quotidianamente esposto ad una radioattivita' di origine naturale, dovuta principalmente ai raggi cosmici ed alla presenza di alcuni elementi radioattivi naturali, i cui discendenti radioattivi piu' importanti sono il {sup 222}Rn (radon) e il {sup 220}Rn (thoron). Tali elementi, a causa della loro natura gassosa, si possono diffondere attraverso il terreno e raggiungere l'atmosfera sovrastante; cio' puo' provocarne l'accumulo in ambienti chiusi, dando luogo a concentrazioni anche elevate con possibili conseguenze sulla salute. Poiche' l'esalazione del gas radon e' foremente legata alle caratteristiche idrogeologiche dell'ambiente, in questo lavoro si e' cercato di definire una relazione che legasse le variazioni della soggiacenza della falda freatica alle variazioni della concentrazione del gas radon nel non saturo, al fine di verificare se sia possibile effettuare un'attivita' previsionale applicabile ai rilievi di gas radon indoor.

  2. The carrying out of a radiometric analysis method applicable to Moroccan phosphates. Study of the uranium amounts, of the U/Ra equilibrium ratio and of 222-radon emanation rates

    International Nuclear Information System (INIS)

    Choukri, A.

    1987-01-01

    A radiometric analysis method for the determination of the uranium and the radium amounts in Moroccan phosphate has been carried out, using NaI(Tl) scintillator to detect gamma radiation of 238-U and 235-U radioactive daughters. The analysis results permit to calculate the U/Ra equilibrium ratio and the emanation rates of 222-Rn versus temperature. The U/Ra disequilibria permit to detect the secondary contribution of a recent uranium. The 222-Rn emanation rates are useful in the evaluation of the radiological hazards related to the phosphate radioactivity. This method was applied to study the phosphate Ganntour deposit and showed that the uranium content ranges from 25ppm to 350ppm, that the U/Ra ratio ranges from 0.6 to 2.2 with an exceptional value of 4.5. The emanation rate of natural radon is between 0% and 27%. The radon forced emanation by heating or by adding different acids has also been studied. The phosphate attack with H 2 SO 4 and HNO 3 , using the analysis method, showed that a maximum degassing appears at 0.9cc/g for H 2 SO 4 and 1.1cc/g for HNO 3 . By adding H 2 SO 4 , 30% of uranium (without radium) passed in the solution and by adding HNO 3 uranium and radium are divided among the solid and the liquid phases. 22 refs., 49 figs., 25 tabs. (author)

  3. The exposure assessment of Rn-222 gas in the atmosphere(II)

    International Nuclear Information System (INIS)

    Ha, Chung Wo; Chang, Si Young; Seo, Kyung Won; Yoon, Yeo Chang; Kim, Jang Lyul; Yoon, Suk Chul; Chung, Rae Ik; Kim, Jong Soo; Park, Young Woong

    1991-01-01

    Dose assessment to inhalation exposure of indoor 222 Rn daughters in 12 residential areas in Korea has been performed by long term averaged radon concentrations measured with passive CR-39 radon cups. A simple mathematical lung dosimetry model based on the ICRP-30 was derived to estimate the indoor radon daughters exposure. The long term average indoor 222 Rn concentrations and corresponding equilibrium equivalent radon concentrations (EEC Rn ) in 12 areas showed a range of 33.82 ∼ 61.42 Bq.m -3 (median : 48.90 Bq.m -3 ) and of 13.53 ∼ 24.57 Bq.m -3 (median: 19.55 Bq.m -3 ), respectively. Reference dose conversion functions for evaluation of regional lung dose and effective dose equivalent for unit exposure to EEC Rn have been derived for an adult. The effective dose equivalent conversion factor was estimated to be 1.07 x 10 -5 mSv/Bq.h.m -3 and this conversion factor agreed well with that recommended by the ICRP and UNSCEAR report. The annual average dose equivalents(H) to Tracheo-Bronchial and Pulmonary region of the lung, and total lung from exposure to measured EEC Rn were estimated to be 17.52 mSv.y -l , 3.35 mSv.y -l and 20.90 mSv.y -1 , respectively, and the resulting effective dose equivalent(H E ) was estimated to be 1.25 mSv.y -l , which is almost 50% of the natural radiation exposure of 2.40 mSv.y -l reported by the UNSCEAR. (Author)

  4. Radon measurements at the FEMP

    International Nuclear Information System (INIS)

    Tomczak, L.M.; Daniels, R.D.; Dennis, C.; Glassey, H.G.; Lohner, W.G.; Ray, E.C.; Selasky, J.A.

    1993-08-01

    Environmental radon monitoring activities at the DOE Fernald Environmental Management Project (FEMP) have been conducted extensively since the early 1980's. Monitoring has been conducted at ambient concentration levels (< 1 pCi/L Rn-222), inside buildings, and at significantly elevated levels (hundreds of thousands pCi/L Rn-222) within the K-65 silo that store concentrated radium bearing wastes. The purpose of this paper/presentation is to present and discuss some of the difficulties encountered/solutions (e.g. reliability, detection limits, affects of environmental factors, data transfer, etc.) that have been discovered while taking measurements using both alpha track-etch passive integrating detectors and alpha scintillation real-time detectors. A short summary and conclusion section is provided following each topic presented

  5. Results of long-term measurement of 222Rn concentrations in outdoor atmosphere

    International Nuclear Information System (INIS)

    Holy, K.; Boehm, R.; Polaskova, A.; Hola, O.

    1998-01-01

    Results are reported of the authors' long-term measurement of 222 Rn concentrations in the outdoor atmosphere. The measurements started in 1987 and were performed at a height of 1.5 m over a grass-covered ground surface, using till 1991 a Lucas type scintillation chamber and later a large volume scintillation chamber. Graphs are presented and discussed of the course of average monthly radon concentration in 1987-1996 and of annual courses of radon concentration for different time intervals of the day over 1991 to 1995. (A.K.)

  6. Development of an electronic monitor for the determination of individual radon and thoron exposure

    International Nuclear Information System (INIS)

    Irlinger, Josef

    2015-01-01

    The carcinogenic effect of the radio isotope 222 Rn of the noble gas radon and its progeny, as well as its residential distribution, are well studied. In contrast, the knowledge about the effects and average dwelling concentration levels of its radio isotope 220 Rn (thoron) is still limited. Generally, this isotope has been assumed to be a negligible contributor to the effective annual dose. However, only recently it has been pointed out in several international studies, that the dose due to thoron exceeds the one from 222 Rn under certain conditions. Additionally, radon monitors may show a considerable sensitivity towards thoron which was also not accounted for in general. Therefore a reliable, inexpensive exposimeter, which allows to distinguish between decays of either radon and thoron, is required to conduct further studies. The scope of this thesis was to develop an electronic radon/thoron exposimeter which features small size, low weight and minimal power consumption. The design is based on the diffusion chamber principle and employs state-of-the-art alpha particle spectroscopy to measure activity concentrations. The device was optimized via inlet layout and filter selection for high thoron diffusion. Calibration measurements showed a similar sensitivity of the monitor towards radon and thoron, with a calibration factor of cf 222 Rn = 16.2 ± 0.9 Bq m -3 /cph and cf 220 Rn = 14.4 ± 0.8 Bq m -3 /cph, respectively. Thus, the radon sensitivity of the device was enhanced by a factor two compared to a previous prototype. The evaluation method developed in this work, in accordance with ISO 11665 standards, was validated by intercomparison measurements. The detection limits for radon and thoron were determined to be C 2 22 Rn = 44.0 Bq m -3 and C 2 20 Rn = 40.0 Bq m -3 , respectively, in case of a low radon environment, a one-hour measurement interval, and a background count rate of zero. In contrast, in mixed radon/thoron concentrations where the 212 Po peak must

  7. Results of Long-term Measurement of 222Rn Volume Activity in Soil Air

    International Nuclear Information System (INIS)

    Holy, K.; Matos, M.; Boem, R.; Stanys, T.; Hola, O.; Polaskova, A.

    1999-01-01

    Radon in the soil air was continuously monitored for four years. The measured volume activities differ one from another even three times. On the basis of the measured data the annual and average daily courses of the 222 Rn volume activity were studied for individual months. In annual courses the winter and also summer maxima of the 222 Rn volume activity were found out. The study of the average daily courses revealed that the oscillation of the 222 Rn volume activity about its average value during a day is only a few percent. For dry summer months a linear relation was found out between the changes of the 222 Rn volume activity and the changes of the atmospheric pressure in their average daily courses (Authors)

  8. PO.RA project. An analysis on gas radon concentrations in soil versus fluctuations in the groundwater table

    International Nuclear Information System (INIS)

    Serentha', C.; Torretta, M.

    2001-01-01

    Man is daily exposed to natural radiation, mainly due to cosmic rays and natural radioactive elements, whose most important radioactive daughters are 222 Rn (radon) and 220 Rn (thoron). Being these ones gaseous, they can spread through the ground, reaching the atmosphere and accumulating in rooms, where their concentrations may be very high. As radon exhalation is strongly connected with the hydrogeological features of the environment, this study tried to find a relationship between fluctuations in the groundwater table and gas radon concentrations in soil, in order to try estimates of indoor radon concentrations [it

  9. Measurements of indoor 222Rn concentration in two art galleries

    International Nuclear Information System (INIS)

    Carneiro, Luana Gomes; Braz, Delson; Jesus, Edgar Francisco de; Cunha, Kenya Dias da; Medeiros, Geiza; Zouain, Felipe; Pitassi, Gabriel; Leite, Carlos Barros; Cardoso, Katia

    2009-01-01

    It is point out that radon and their decay products in environment give high dose to human lung. Studies indicate that the indoor radon inhalation by humans has been considered probably the second most important cause of lung cancer after of smoking. A passive-type radon detector was used for measuring indoor radon concentration in two art galleries at Rio de Janeiro city during 90 days January to March, 2009. The aim of this study is to evaluate the occupational and public radon exposure in art galleries and museums. This paper shows the preliminary results of samples collected at two art galleries located in Gavea, Rio de Janeiro city. 30 LEXAN (GE) track detectors were exposed in the air (indoor as well as outdoor). The samples were collected in the same building which is a construction of XIX century. The analysis of the results suggests that the 222 Rn concentration levels are different in both sampling site, in closed environmental, demonstrating that, although the construction materials are the same the absence of circulating air is a factor very important to increase the concentration of indoor Rn. (author)

  10. A source of ground water 222Rn around Tachikawa fault

    International Nuclear Information System (INIS)

    Saito, Masaaki; Takata, Sigeru

    1994-01-01

    Radon ( 222 Rn) concentration in ground water was characteristically high on the south-western zone divided by the Tachikawa fault, Tokyo. (1) The concentration did not increase with depth, and alluvium is thick on the zone. The source of radon was not considered as the updraft from base rock through the fault. Comparing the south-western zone with its surrounding zone, the followings were found. (2) The distribution of tritium concentration was supported that water had easily permeated into ground on the zone. (3) As the zone is located beside the Tama River and its alluvial fan center, the river water had likely affected. The source of radon on the zone would be 226 Ra in the aquifer soil. It can be presumed that the water of the Tama River had permeated into ground on the zone and had accumulated 226 Ra. (author)

  11. Determination of radon concentration in soil gas by gamma-ray spectrometry of olive oil

    International Nuclear Information System (INIS)

    Al-Azmi, Darwish; Karunakara, N.

    2007-01-01

    Measurements of radon concentration in soil gas have been carried out using a bubbling system in which the soil gas is drawn through an active pumping to bubble a liquid absorber (olive oil) for the deposition of the soil gas in it. After the bubbling process, the absorber is then taken for gamma-ray measurements. Gamma-ray photopeaks from the 214 Pb and the 214 Bi radon progeny are considered for the detection of the 222 Rn gas to study the concentration levels for radon soil gas. Results for some field measurements were obtained and compared with results obtained using AlphaGuard radon gas monitor. The technique provides a possible approach for the measurements of radon soil gas with gamma-ray spectrometry

  12. Radon transport in fractured soil. Laboratory experiments and modelling

    International Nuclear Information System (INIS)

    Hoff, A.

    1997-10-01

    Radon (Rn-222) transport in fractured soil has been investigated by laboratory experiments and by modelling. Radon transport experiments have been performed with two sand columns (homogeneous and inhomogeneous) and one undisturbed clayey till column containing a net of preferential flow paths (root holes). A numerical model (the finite-element model FRACTRAN) and an analytic model (a pinhole model) have been applied in simulations if soil gas and radon transport in fractured soil. Experiments and model calculations are included in a discussion of radon entry rates into houses placed on fractured soil. The main conclusion is, that fractures does not in general alter transport of internally generated radon out of soil, when the pressure and flow conditions in the soil is comparable to the conditions prevailing under a house. This indicates the important result, that fractures in soil have no impact on radon entry into a house beyond that of an increased gas permeability, but a more thorough investigation of this subject is needed. Only in the case where the soil is exposed to large pressure gradients, relative to gradients induced by a house, may it be possible to observe effects of radon exchange between fractures and matrix. (au) 52 tabs., 60 ill., 5 refs

  13. Radon transport in fractured soil. Laboratory experiments and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Hoff, A

    1997-10-01

    Radon (Rn-222) transport in fractured soil has been investigated by laboratory experiments and by modelling. Radon transport experiments have been performed with two sand columns (homogeneous and inhomogeneous) and one undisturbed clayey till column containing a net of preferential flow paths (root holes). A numerical model (the finite-element model FRACTRAN) and an analytic model (a pinhole model) have been applied in simulations if soil gas and radon transport in fractured soil. Experiments and model calculations are included in a discussion of radon entry rates into houses placed on fractured soil. The main conclusion is, that fractures does not in general alter transport of internally generated radon out of soil, when the pressure and flow conditions in the soil is comparable to the conditions prevailing under a house. This indicates the important result, that fractures in soil have no impact on radon entry into a house beyond that of an increased gas permeability, but a more thorough investigation of this subject is needed. Only in the case where the soil is exposed to large pressure gradients, relative to gradients induced by a house, may it be possible to observe effects of radon exchange between fractures and matrix. (au) 52 tabs., 60 ill., 5 refs.

  14. Dose by {sup 222} Rn in houses of the Chihuahua city; Dosis por {sup 222} Rn en casas-habitacion de la ciudad de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Colmenero S, L.H.; Talamantes F, C. [ITCH II, Ave. de las Industrias 11101, Chihuahua (Mexico); Villalba, M.L. [UACH, Facultad de Ingenieria, Chihuahua (Mexico); Dobson, P.F. [Laboratorio Nacional Lawrence Berkeley, California (United States); Ortalejo M, B. [UACH, Facultad de Enfermeria y Nutriologia, Chihuahua (Mexico)]. e-mail: luis.colmenero@cimav.edu.mx

    2007-07-01

    Full text: The dose equivalent that the population of the Chihuahua city receives due to the radon in air that joined to values of uranium, thorium and potassium due to the floor and radon in water was determined, they give values very above the international and national norms. The state of Chihuahua contains near 56 locations distributed by the whole state. The city of Chihuahua, capital of the state, is surrounded of rocks with great content of uranium, for what their floor also contains to the {sup 226} Ra that generates to the {sup 222} Rn. The construction of the housings of the city of Chihuahua is mainly of brick, block and adobe; the material to elaborate them is take from the rocks and floor of the surroundings, this makes that the radon is presented in a great quantity of houses of this city. As the floor and water they also contain those natural radionuclides, the total dose equivalent that the inhabitants receive is bigger to other cities of the country. Diverse international organizations dedicated to the radioactivity, indicate that the level of the {sup 222} Rn should not surpass the 148 Bq/m{sup 3}, since this gas produces lung cancer. The state of Chihuahua has an index of deaths on the average by lung cancer of double the national average, the capital of the state also has a high index. The radon concentration in a house depends on the construction material with which was made, as well as of the existent climatic conditions. During the day, this concentration depends mainly on the interior temperature, so during the night and dawn increases the radon concentration. The radon is the biggest source of radioactive dose received by the human being and it can generate a problem of public health if the concentration is high during enough time, for what the city of Chihuahua has the geologic and climatic characteristics to have it. This study was carried out in 50 house-room of the city of Chihuahua. Built houses with brick, block and adobe were

  15. Study of temporal variation of radon concentrations in public drinking water supplies

    International Nuclear Information System (INIS)

    York, E.L.

    1995-01-01

    The Environmental Protection Agency (EPA) has proposed a Maximum Contaminant Level (MCL) for radon-222 in public drinking water supplies of 300 pCi/L. Proposed monitoring requirements include collecting quarterly grab samples for the first year, then annual samples for the remainder of the compliance cycle provided first year quarterly samples average below the MCL. The focus of this research was to study the temporal variation of groundwater radon concentrations to investigate how reliably one can predict an annual average radon concentration based on the results of grab samples. Using a open-quotes slow-flowclose quotes collection method and liquid scintillation analysis, biweekly water samples were taken from ten public water supply wells in North Carolina (6 month - 11 month sampling periods). Based on study results, temporal variations exist in groundwater radon concentrations. Statistical analysis performed on the data indicates that grab samples taken from each of the ten wells during the study period would exhibit groundwater radon concentrations within 30% of their average radon concentration

  16. Hydrogeological controls of radon in a few hot springs in the Western Ghats at Ratnagiri district in Maharashtra, India

    International Nuclear Information System (INIS)

    Ansari, Md. Arzoo; Sharma, Suman; Saravana Kumar, U.; Chatterjee, Sitangshu; Diksha; Low, Upananda

    2014-01-01

    Geological structures (faults, fractures and weak zones) and high heat flow in geothermal areas allow easy passage for release of radon gas to the atmosphere. Radon is constantly transported from the Earth's interior and vented out through exhalation points at permeable fault zones. 222 Rn concentrations were measured in a few hot springs and nearby groundwater using RAD7 at Tural and Rajwadi, Ratnagiri district, Maharashtra. The 222 Rn concentrations in the hot springs vary from 1087 ± 132 to 1655 ± 177 Bq/m 3 at Tural and from 152 ± 67 to 350 ± 82 Bq/m 3 at Rajwadi. Groundwaters from wells within a radius of 200 m around the geothermal fields have radon concentration between 1087 ± 132 and 5445 ± 337 Bq/m 3 . We have assessed the radon activity in the vicinity of the hot springs to understand their hydrogeological control, origin of heat source and possible effect on the tourist and the human population residing nearby. (author)

  17. Intercomparison of active, passive and continuous instruments for radon and radon progeny measurements in the EML chamber and test facility

    International Nuclear Information System (INIS)

    Scarpitta, S.C.; Tu, K.W.; Fisenne, I.M.; Cavallo, A.; Perry, P.

    1996-10-01

    Results are presented from the Fifth Intercomparison of Active, Passive and Continuous Instruments for Radon and Radon Progeny Measurements conducted in the EML radon exposure and test facility in May 1996. In total, thirty-four government, private and academic facilities participated in the exercise with over 170 passive and electronic devices exposed in the EML test chamber. During the first week of the exercise, passive and continuous measuring devices were exposed (usually in quadruplicate) to about 1,280 Bq m -3 222 Rn for 1--7 days. Radon progeny measurements were made during the second week of the exercise. The results indicate that all of the tested devices that measure radon gas performed well and fulfill their intended purpose. The grand mean (GM) ratio of the participants' reported values to the EML values, for all four radon device categories, was 0.99 ± 0.08. Eighty-five percent of all the radon measuring devices that were exposed in the EML radon test chamber were within ±1 standard deviation (SD) of the EML reference values. For the most part, radon progeny measurements were also quite good as compared to the EML values. The GM ratio for the 10 continuous PAEC instruments was 0.90 ± 0.12 with 75% of the devices within 1 SD of the EML reference values. Most of the continuous and integrating electronic instruments used for measuring the PAEC underestimated the EML values by about 10--15% probably because the concentration of particles onto which the radon progeny were attached was low (1,200--3,800 particles cm -3 ). The equilibrium factor at that particle concentration level was 0.10--0.22

  18. Low-level radon measurements by nuclear track detectors

    International Nuclear Information System (INIS)

    Koksal, E. M.; Goksel, S. A.; Alkan, H.

    1985-01-01

    In the work to be described here we have developed a passive nuclear track dosimeter to measure the integrated value of indoor radon (Rn-222) over a long period of time. Passive radon dosimeter which we have developed in our laboratories makes use of two small pieces of CR-39 plastic (Allyl diglycol carbonate) as detectors for registering tracks of alpha particles emitted by radon. These CR-39 plastic detectors are fixed on the inside bottom of a cup-shaped polystrene enclosure which is closed at the top by a tissue permeable for gases only. CR-39 detectors exposed to radon gas in the indoor air for a period of six months then are removed and chemically etched to make the alpha particle tracks visible under the microscope. The counts of tracks are evaluated to determine the radon concentration in the air in comparison with the number of tracks produced by a known concentration of radon gas. By using the passive dosimeters developed and the chemical etching procedure descriped here, measurements of indoor radon concentrations were carried out in 45 houses in different districts of the city of Istanbul. In this pilot experiment mean radon concentrations between 0.7 and 3.5 pCi/l have been found in these houses. In order to improve the counting of alpha tracks produced on the detectors a prototype electrochemical etching system in addition to chemical etching, is being developed. (author)

  19. Uranium distribution and radon exhalation from Brazilian dimension stones

    International Nuclear Information System (INIS)

    Amaral, P.G.Q.; Galembeck, T.M.B.; Bonotto, D.M.; Artur, A.C.

    2012-01-01

    This paper provides evaluations of the radiometric behavior and exhalation patterns of radon gas in decorative and dimension stones explored in the Brazilian states of Minas Gerais and Espírito Santo, given the importance of determining radon gas concentrations in human-inhabited environments. A total of 10 silicate rock types were studied, featuring different petrographic/petrophysical characteristics given by seven magmatic rocks (three of which are granitic pegmatites) and three metamorphic rocks. The study, comprising radiometric data of U and monitoring of 222 Rn gas exhalation, shows a strong correlation between petrographic parameters and the physical properties of rocks. U levels ranged between 2.9 and 37 ppm, revealing a good coherence between the presence and the absence of radioactive element-bearing accessory minerals for each rock type. The rate of radon exhalation from the stones is related to the petrographic/petrophysical features of each material. By comparing the 222 Rn level generated by a rock to the amount effectively emanated by it, the rate of emanated gas proves to be insignificant; also, a rock that produces more Rn will not always emanate more. Simulations performed to estimate the radon levels inside residences or any given indoor environment showed that nine samples attained values below the 4 pCi/L EPA limit, whereas one was above that limit. - Highlights: ► Integration of distinct radiometric data acquired in dimension stones. ► Dimension stones are extensively commercialized abroad. ► Rn exhalation above the EPA threshold limit of 4 pCi/L.

  20. Uranium distribution and radon exhalation from Brazilian dimension stones

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, P.G.Q.; Galembeck, T.M.B. [Departamento de Petrologia e Metalogenia, Instituto de Geociencias e Ciencias Exatas, Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil); Bonotto, D.M., E-mail: danielbonotto@yahoo.com.br [Departamento de Petrologia e Metalogenia, Instituto de Geociencias e Ciencias Exatas, Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil); Artur, A.C. [Departamento de Petrologia e Metalogenia, Instituto de Geociencias e Ciencias Exatas, Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil)

    2012-04-15

    This paper provides evaluations of the radiometric behavior and exhalation patterns of radon gas in decorative and dimension stones explored in the Brazilian states of Minas Gerais and Espirito Santo, given the importance of determining radon gas concentrations in human-inhabited environments. A total of 10 silicate rock types were studied, featuring different petrographic/petrophysical characteristics given by seven magmatic rocks (three of which are granitic pegmatites) and three metamorphic rocks. The study, comprising radiometric data of U and monitoring of {sup 222}Rn gas exhalation, shows a strong correlation between petrographic parameters and the physical properties of rocks. U levels ranged between 2.9 and 37 ppm, revealing a good coherence between the presence and the absence of radioactive element-bearing accessory minerals for each rock type. The rate of radon exhalation from the stones is related to the petrographic/petrophysical features of each material. By comparing the {sup 222}Rn level generated by a rock to the amount effectively emanated by it, the rate of emanated gas proves to be insignificant; also, a rock that produces more Rn will not always emanate more. Simulations performed to estimate the radon levels inside residences or any given indoor environment showed that nine samples attained values below the 4 pCi/L EPA limit, whereas one was above that limit. - Highlights: Black-Right-Pointing-Pointer Integration of distinct radiometric data acquired in dimension stones. Black-Right-Pointing-Pointer Dimension stones are extensively commercialized abroad. Black-Right-Pointing-Pointer Rn exhalation above the EPA threshold limit of 4 pCi/L.

  1. Estimates concentrations in bottled 222Rn of the dose due to mineral waters in Iran

    International Nuclear Information System (INIS)

    Assadi, M. R.; Esmaealnejad, M.; Rahmatinejad, Z.

    2006-01-01

    Radon is a radionuclide that has the main role in exposure. Radon in water causes exposure in whole body but the largest dose being received by the stomach, as EPA (Environmental Protection Agency) estimates that radon in drinking water causes about 168 cancer deaths per year: 89 p ercent f rom lung cancer caused by breathing released to the indoor air from water and 11 p ercent f rom stomach cancer caused by consuming water containing radon. Now days the consumption of bottled mineral waters has become very popular. As is known, some kinds of mineral waters contain naturally occurring radionuclides in higher concentration than the usual drinking (tap) water. Surveys and reports on radon in most surface waters is low compared with radon level in groundwater and mineral water. In our work, the concentration of Rn(222) was determined in some bottled mineral waters available in Iran , and in next step the dose contribution ; due to ingestion ; for 1 l d -1 bottled mineral water consumption.

  2. Hourly indoor radon measurements in a research house.

    Science.gov (United States)

    Sesana, Lucia; Begnini, Stefania

    2004-01-01

    This paper reports and discusses the behaviour of radon concentration with time in an uninhabited dwelling. The relationship between variations in radon concentrations and indoor-outdoor temperatures and wind intensity has also been discussed. Radon concentration was measured hourly in a house located at a height of 800 m in the Lombard Prealps, at the top of the Valassina valley. The wind velocity and indoor-outdoor temperatures were measured by means of a meteorological station located on the terrace of the house. The data were analysed using the LBL model for indoor-outdoor air exchange and the models for the indoor accumulation of radon due to exhalation from building materials and pressure-driven infiltrations located underground. The role of wind and indoor-outdoor temperatures were analysed. The agreement of measurements with modelling clearly demonstrates the importance of the different sources of indoor radon. As the investigation was conducted in an uninhabited house, the measurements were not affected by the behaviour of people, e.g. opening and closing of windows. Measurements of the outdoor atmospheric concentrations of (222)Rn provide an index of the atmospheric stability, the formation of thermal inversions and convective turbulence.

  3. Hourly indoor radon measurements in a research house

    International Nuclear Information System (INIS)

    Sesana, L.; Begnini, S.

    2004-01-01

    This paper reports and discusses the behaviour of radon concentration with time in an uninhabited dwelling. The relationship between variations in radon concentrations and indoor-outdoor temperatures and wind intensity has also been discussed. Radon concentration was measured hourly in a house located at a height of 800 m in the Lombard Pre-alps, at the top of the Valassina valley. The wind velocity and indoor-outdoor temperatures were measured by means of a meteorological station located on the terrace of the house. The data were analysed using the LBL model for indoor-outdoor air exchange and the models for the indoor accumulation of radon due to exhalation from building materials and pressure-driven infiltrations located underground. The role of wind and indoor-outdoor temperatures were analysed. The agreement of measurements with modelling clearly demonstrates the importance of the different sources of indoor radon. As the investigation was conducted in an uninhabited house, the measurements were not affected by the behaviour of people, e.g. opening and closing of windows. Measurements of the outdoor atmospheric concentrations of 222 Rn provide an index of the atmospheric stability, the formation of thermal inversions and convective turbulence. (authors)

  4. Radon as a natural tracer for gas transport within uranium waste rock piles

    International Nuclear Information System (INIS)

    Silva, N.C.; Chagas, E.G.L.; Dias, D.C.S.; Guerreiro, E.T.Z.; Alberti, H.L.C.; Braz, M.L.; Abreu, C.B.; Lopez, D.; Branco, O.; Fleming, P.

    2014-01-01

    Acid mine drainage (AMD) has been identified as the main cause for outflow of acid water and radioactive/non-radioactive contaminants. AMD encompasses pyrites oxidation when water and oxygen are available. AMD was identified in uranium waste rock piles (WRPs) of Industrias Nucleares do Brasil-Caldas facility (Brazilian uranium mine), resulting in high costs for water treatment. AMD reduction is the main challenge, and scientific investigation has been conducted to understand oxygen and water transportation within WRPs, where 222 Rn is used as natural tracer for oxygen transportation. The study consists of soil radon gas mapping in the top layer of WRP4 using active soil gas pumping, radon adsorption in active charcoal and 222 Rn determination using high-resolution gamma-ray spectrometry. A sampling network of 71 points was built where samples were collected at a depth of 40 cm. Soil radon gas concentration ranged from 33.7 to 1484.2 kBq m -3 with mean concentration of 320.7±263.3 kBq m -3 . (authors)

  5. Monte Carlo simulation experiments on box-type radon dosimeter

    International Nuclear Information System (INIS)

    Jamil, Khalid; Kamran, Muhammad; Illahi, Ahsan; Manzoor, Shahid

    2014-01-01

    Epidemiological studies show that inhalation of radon gas ( 222 Rn) may be carcinogenic especially to mine workers, people living in closed indoor energy conserved environments and underground dwellers. It is, therefore, of paramount importance to measure the 222 Rn concentrations (Bq/m 3 ) in indoors environments. For this purpose, box-type passive radon dosimeters employing ion track detector like CR-39 are widely used. Fraction of the number of radon alphas emitted in the volume of the box type dosimeter resulting in latent track formation on CR-39 is the latent track registration efficiency. Latent track registration efficiency is ultimately required to evaluate the radon concentration which consequently determines the effective dose and the radiological hazards. In this research, Monte Carlo simulation experiments were carried out to study the alpha latent track registration efficiency for box type radon dosimeter as a function of dosimeter’s dimensions and range of alpha particles in air. Two different self developed Monte Carlo simulation techniques were employed namely: (a) Surface ratio (SURA) method and (b) Ray hitting (RAHI) method. Monte Carlo simulation experiments revealed that there are two types of efficiencies i.e. intrinsic efficiency (η int ) and alpha hit efficiency (η hit ). The η int depends upon only on the dimensions of the dosimeter and η hit depends both upon dimensions of the dosimeter and range of the alpha particles. The total latent track registration efficiency is the product of both intrinsic and hit efficiencies. It has been concluded that if diagonal length of box type dosimeter is kept smaller than the range of alpha particle then hit efficiency is achieved as 100%. Nevertheless the intrinsic efficiency keeps playing its role. The Monte Carlo simulation experimental results have been found helpful to understand the intricate track registration mechanisms in the box type dosimeter. This paper explains that how radon

  6. Monte Carlo simulation experiments on box-type radon dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Jamil, Khalid, E-mail: kjamil@comsats.edu.pk; Kamran, Muhammad; Illahi, Ahsan; Manzoor, Shahid

    2014-11-11

    Epidemiological studies show that inhalation of radon gas ({sup 222}Rn) may be carcinogenic especially to mine workers, people living in closed indoor energy conserved environments and underground dwellers. It is, therefore, of paramount importance to measure the {sup 222}Rn concentrations (Bq/m{sup 3}) in indoors environments. For this purpose, box-type passive radon dosimeters employing ion track detector like CR-39 are widely used. Fraction of the number of radon alphas emitted in the volume of the box type dosimeter resulting in latent track formation on CR-39 is the latent track registration efficiency. Latent track registration efficiency is ultimately required to evaluate the radon concentration which consequently determines the effective dose and the radiological hazards. In this research, Monte Carlo simulation experiments were carried out to study the alpha latent track registration efficiency for box type radon dosimeter as a function of dosimeter’s dimensions and range of alpha particles in air. Two different self developed Monte Carlo simulation techniques were employed namely: (a) Surface ratio (SURA) method and (b) Ray hitting (RAHI) method. Monte Carlo simulation experiments revealed that there are two types of efficiencies i.e. intrinsic efficiency (η{sub int}) and alpha hit efficiency (η{sub hit}). The η{sub int} depends upon only on the dimensions of the dosimeter and η{sub hit} depends both upon dimensions of the dosimeter and range of the alpha particles. The total latent track registration efficiency is the product of both intrinsic and hit efficiencies. It has been concluded that if diagonal length of box type dosimeter is kept smaller than the range of alpha particle then hit efficiency is achieved as 100%. Nevertheless the intrinsic efficiency keeps playing its role. The Monte Carlo simulation experimental results have been found helpful to understand the intricate track registration mechanisms in the box type dosimeter. This paper

  7. Preparation of gaseous CRMs from the primary system for "2"2"2Rn activity measurement

    International Nuclear Information System (INIS)

    Kim, B.J.; Kim, B.C.; Lee, K.B.; Lee, J.M.; Park, T.S.

    2016-01-01

    For disseminating the gaseous radon standard traceable to the KRISS primary system based on the defined solid angle counting method, two kinds of radon CRM (a glass ampule type and a stainless steel cylinder type) were developed. The activity of the CRM was certified by subtracting a residual activity from the measured activity by the primary system. After certification, the ampule CRM was used to calibrate a radon-monitoring instrument and the cylinder CRM to calibrate an HPGe system. We also improved the measurement procedure of the radon primary system. In a typical radon energy spectrum, the radon peak overlaps with the polonium peak. For more reliable and accurate measurement of radon activity, a fitting method was adopted for the evaluation of radon area in the alpha energy spectrum. The result of radon activity evaluated by using the fitting method is in good agreement with that by the previous integration method. - Highlights: • Preparation of gaseous Rn-222 CRMs from primary measurement system. • Convolution of 3 left-handed exponentials with a Gaussian function to count radon. • Calibration of continuous radon monitor using glass ampoule CRM. • Calibration of HPGe system as secondary standard for stainless steel cylinder CRM.

  8. Characterization of the radon source in North-Central Florida. Final report part 1 -- Final project report; Final report part 2 -- Technical report

    International Nuclear Information System (INIS)

    1997-01-01

    This report contains two separate parts: Characterization of the Radon Source in North-Central Florida (final report part 1 -- final project report); and Characterization of the Radon Source in North-Central Florida (technical report). The objectives were to characterize the radon 222 source in a region having a demonstrated elevated indoor radon potential and having geology, lithology, and climate that are different from those in other regions of the U.S. where radon is being studied. Radon availability and transport in this region were described. Approaches for predicting the radon potential of lands in this region were developed

  9. Desarrollo de una metodología de muestreo y análisis mediante captadores pasivos y cromatografía gaseosa para determinar contaminantes hidrocarburos (BTEX) en aire

    OpenAIRE

    Gallego Diéz, Mary Luz

    2014-01-01

    En este trabajo se presenta el proceso para desarrollar una metodología de muestreo y análisis mediante un captador pasivo usando la técnica de cromatografía gaseosa para determinar un grupo de contaminantes hidrocarburos presentes en el aire. Consistió en seleccionar un carbón activado adecuado para la construcción de un captador pasivo económico capaz de adsorber del aire los compuestos orgánico volátiles Benceno (B), Tolueno (T), Etilbenceno (E) y Xilenos (X), compuestos conocidos como BTE...

  10. Radon in coal power plant areas

    International Nuclear Information System (INIS)

    Mauna, Traian; Mauna, Andriesica

    2006-01-01

    Radon, the radioactive colourless and inodorous noble gas, represents more than 55% of the natural average radioactivity. It is permanently released from the soil and majority of building materials, it builds up in the mine galleries, in dwelling houses and in other closed rooms. Radon gained increasingly in importance, particularly after 1990 when was doubtless identified as the second cause of lung cancer if a given concentration threshold is surpassed. This threshold is established differentially by each country as a function of the particular site and generally ranges between 150 Bq.m -3 and 600 Bq.m -3 . The telluric radon consists of two isotopes, 222 Rn, a daughter of radium descending from uranium, which induces 90% of the effects, and 220 Rn from thorium series which have too short a lifetime to count in the risk assessments of radon inhalation. The interest of the authorities and population for diminishing the radon effects was illustrated by specific studies which in USA were managed by the National Counsel of Research, the BEIR VI committee of which has issued a report concerning the lung cancer produced by radon and its descendants. Coal mining, the transport, processing, burning, slag and ash disposal are activities entailing radon release. The miners' dwellings are placed in areas with the high radon potential. The local building materials have a high content of radioactive elements from the uranium or thorium series so that radon can build up in the closed rooms of these buildings. Hence the social responsible authorities in the coal power industry zones should consider this aspect long time ignored in the Balkans macro zone so far. The radon issue must be differentially approached in different areas hence a zonal mapping of the radon emission should be first done. It is worth to underline that the gaseous radioactive emission from operational nuclear power plants amounts up to a few percents of the radon natural emissions what entails a

  11. Joint determination of the concentrations of the 222Rn and 220Rn decay products in air

    International Nuclear Information System (INIS)

    Terent'ev, M.V.

    1987-01-01

    The authors describe a modification of the Kuznets and Markov methods normally employed for the determination of radon 220 and 222 daughter alpha product concentration in air in which an air sample is taken for 10 minutes on a filter at a flow rate of 10-40 liters per minute. After the conclusion of sampling the filter activity is measured for another 10 minutes. In order to then determine the latent energy of the radon 222 daughter products and to bring into account the radon 220 daughter products in the total activity measurements of the filter are taken for a second time for 30 minutes five hours after initial sampling. The level of latent energy of the combined daughter products are calculated by an equation which incorporates alpha particle detection efficiency, aerosol retention efficiency in the filter, and the Kuznets coefficients, and analyzes the separate and combined contributions of both daughter products from both sampling periods. A statistical analysis employing the Markov method is also depicted in modified form and is recommended when a more rapid analysis of air radioactivity is mandated

  12. Determination of Rn{sup 222} in samples of well water and domicile of the cities of Chihuahua and Aldama, Mexico; Determinacion de Rn{sup 222} en muestras de agua de pozos y domicilio de las ciudades de Chihuahua y Aldama, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Villalba, L.; Colmenero S, L.; Montero C, M.E. [Centro de Investigacion en Materiales Avanzados (CIMAV), Av. Miguel de Cervantes Saavedra 120, 31109 Chihuahua (Mexico)]. e-mail: lourdes.villalba@cimav. edu. mx

    2004-07-01

    The study of the content of dissolved Rn{sup 222} is presented in underground water and of domicile of the cities of Chihuahua and Aldama of the State of Chihuahua. The existence of the Rn{sup 222} in the underground waters comes from its constant production in the rocks of the terrestrial bark. It has been determined that the radon is a noble gas of more solubility in the water, this solubility induces high concentrations in underground water, as well as bigger risk to the health in the human body once ingested or inhaled. Of the 32 wells studied in the cities of Chihuahua and Aldama, the content of dissolved Rn{sup 222} in the water of 22 of them is bigger than 11 Bq/l and of 73 studied samples of water of domiciles 47 show bigger values that 11 Bq/l. These radon contents are attributable to the uraniferous rocks present in the aquifers. (Author)

  13. Realization of a simulator for radon-222 underground migration studies

    International Nuclear Information System (INIS)

    Tidjani, A.; Seidel, J.L.; Monnin, M.; Isabelle, D.B.

    1987-01-01

    To study under controlled conditions the underground movements of radon gas a simulator has been built. It was designed in order to vary independently the different geophysical parameters such as pressure, temperature, humidity, type of soil and its granulometry, etc.. The first tests, described in this paper, have demonstrated the usefullness of such a simulator. (orig.)

  14. Dose by 222 Rn in houses of the Chihuahua city

    International Nuclear Information System (INIS)

    Colmenero S, L.H.; Talamantes F, C.; Villalba, M.L.; Dobson, P.F.; Ortalejo M, B.

    2007-01-01

    Full text: The dose equivalent that the population of the Chihuahua city receives due to the radon in air that joined to values of uranium, thorium and potassium due to the floor and radon in water was determined, they give values very above the international and national norms. The state of Chihuahua contains near 56 locations distributed by the whole state. The city of Chihuahua, capital of the state, is surrounded of rocks with great content of uranium, for what their floor also contains to the 226 Ra that generates to the 222 Rn. The construction of the housings of the city of Chihuahua is mainly of brick, block and adobe; the material to elaborate them is take from the rocks and floor of the surroundings, this makes that the radon is presented in a great quantity of houses of this city. As the floor and water they also contain those natural radionuclides, the total dose equivalent that the inhabitants receive is bigger to other cities of the country. Diverse international organizations dedicated to the radioactivity, indicate that the level of the 222 Rn should not surpass the 148 Bq/m 3 , since this gas produces lung cancer. The state of Chihuahua has an index of deaths on the average by lung cancer of double the national average, the capital of the state also has a high index. The radon concentration in a house depends on the construction material with which was made, as well as of the existent climatic conditions. During the day, this concentration depends mainly on the interior temperature, so during the night and dawn increases the radon concentration. The radon is the biggest source of radioactive dose received by the human being and it can generate a problem of public health if the concentration is high during enough time, for what the city of Chihuahua has the geologic and climatic characteristics to have it. This study was carried out in 50 house-room of the city of Chihuahua. Built houses with brick, block and adobe were selected. The quantification

  15. The Radamon radon detector and an example of application

    International Nuclear Information System (INIS)

    Csige, I.; Csegzi, S.

    2001-01-01

    The etched track type Radamon radon detector is presented. As an example of application representative indoor radon survey was performed in Gyergyoremete (Romania) to pilot a study that can be done in other places of the country. Gyergyoremete was selected, because it was built on volcanic rock, where a number of aligning mineral water springs indicates the existence of geological faulting, and therefore, it was suspected that the village could be on a radon prone area. Measurements were done in sleeping rooms at pillow level. Representativity of the sample was ensured by random pull of 120 houses from the stock (hypergeometric statistical model). From the results it can be stated that the percentages of houses expected to have annual average 222 Rn activity concentration higher than 400 Bq m -3 is less than 1%

  16. Animals exposed to radon

    International Nuclear Information System (INIS)

    Masse, R.; Morin, M.; Lafuma, J.; Morlier, J.P.; Chameaud, J.; Bredon, P.

    1992-01-01

    'There is sufficient evidence that 222 Rn is a carcinogen in animals': this statement was important for the classification of radon as carcinogenic to man, outside of uranium mine atmospheres, clearly identified by epidemiology as causing lung cancer. Since recent reviews of animal experiments have been given by NCRP and by IARC, this review will be mainly limited to the recent results which came from two laboratories in the last 20 years. Battelle Pacific Northwest Laboratories (PNL), USA, and COGEMA Laboratoire de Pathologie Professionnelle (LPP) France. (author)

  17. Modelling the distribution of 222Rn concentration in a multi level, general purpose building

    International Nuclear Information System (INIS)

    Toro, Laszlo; Noditi, Mihaela; Gheorghe, Raluca; Gheorghe, Dan

    2008-01-01

    The importance of 222 Rn (radon) in the indoor air related to the exposure form natural sources is relatively well documented. About 30% of the individual effective dose from natural sources is coming from the inhalation of 222 Rn and his short lived daughters. In unfavorable conditions given by the soil porosity and the existence of upward air movement in the soil there is a possibility to have unusually high radon concentration in houses even on soil with 'normal' 226 Ra content. Some construction solutions (high indoor spaces) should generate a significant indoor-outdoor negative pressure differences and consequently upward air currents (stack effect) which will facilitate the entrance of radon in the building. This effect will multiply the possibility of migration of radon in the building. The difficulty of the prediction of radon migration in the soil-building system increase the importance of the mathematical modelling of the behavior of radon-soil emission, infiltration and migration in the building - in areas with high radon potential. For one level simple buildings there are several models in the literature but the information regarding the multilevel building models are relatively scarce. Two different approaches used to describe the behavior of the radon gas in large (mainly high) buildings have been analyzed: Direct approach: computational fluid dynamics, solving the transport equations for the whole building (the domain of the solution of the transport and flow equations is delimited by the building envelope - the external walls); the openings (internal and external) and ventilation are defined by the boundary conditions. This approach is quite complex, the equations are solved (numerically) for highly inhomogeneous medium but is based on the fundamental processes governing the transport. In the same time it gives the possibility to obtain a concentration pattern in every part of the building. Multi-zone approach treating the building as interconnected

  18. Enrichment of radon and carbon dioxide in the open atmosphere of an Australian coal seam gas field.

    Science.gov (United States)

    Tait, Douglas R; Santos, Isaac R; Maher, Damien T; Cyronak, Tyler J; Davis, Rachael J

    2013-04-02

    Atmospheric radon ((222)Rn) and carbon dioxide (CO2) concentrations were used to gain insight into fugitive emissions in an Australian coal seam gas (CSG) field (Surat Basin, Tara region, Queensland). (222)Rn and CO2 concentrations were observed for 24 h within and outside the gas field. Both (222)Rn and CO2 concentrations followed a diurnal cycle with night time concentrations higher than day time concentrations. Average CO2 concentrations over the 24-h period ranged from ~390 ppm at the control site to ~467 ppm near the center of the gas field. A ~3 fold increase in maximum (222)Rn concentration was observed inside the gas field compared to outside of it. There was a significant relationship between maximum and average (222)Rn concentrations and the number of gas wells within a 3 km radius of the sampling sites (n = 5 stations; p gas field related to both point (well heads, pipelines, etc.) and diffuse soil sources. Radon may be useful in monitoring enhanced soil gas fluxes to the atmosphere due to changes in the geological structure associated with wells and hydraulic fracturing in CSG fields.

  19. Radon and thoron emanation from various marble materials: impact on the workers

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Amghar, A.

    2005-01-01

    Uranium ( 238 U) and thorium ( 232 Th) concentrations were measured inside different pulverized marble material samples by using a method based on determining detection efficiencies of the CR-39 and LR-115 II solid state nuclear track detectors for the emitted alpha particles. Radon ( 222 Rn) and thoron ( 220 Rn) alpha-activities per unit volume were evaluated inside and outside the marble samples studied. Radon emanation coefficient was determined for the considered marble samples. Alpha- and beta-activities per unit volume of air due to radon, thoron and their progenies were measured in the atmosphere of a marble factory. Equilibrium factors between radon and its progeny and thoron and its decay products were evaluated in the air of the studied marble factory. The committed equivalent doses due to short-lived radon decay products were determined in different regions of the respiratory tract of workers in the considered marble factory

  20. A study of diurnal variations of radon and thoron concentrations in different indoor environmental conditions

    International Nuclear Information System (INIS)

    Pant, Preeti; Prasad, Mukesh; Ramola, R.C.

    2015-01-01

    The measurements for diurnal variations in radon ( 222 Rn) and thoron ( 220 Rn) concentrations were performed in the different indoor conditions of Tehri Garhwal, Uttarakhand, India by using AlphaGUARD, Portable Radon Monitor and RAD7. While selecting the dwellings, the ventilation conditions, building materials, life style of the inhabitants and their exposure time indoors were also considered. The behavior of indoor radon and thoron concentrations was observed for different type of dwellings with different environmental conditions. The measurement techniques, results obtained and comparison of the results are discussed in details. (author)

  1. Seasonal levels of radon and thoron in the dwellings along southern coastal Orissa, Eastern India

    International Nuclear Information System (INIS)

    Sulekha Rao, N.; Sengupta, D.

    2010-01-01

    Inhalation of radon ( 222 Rn) and thoron ( 220 Rn) are a major source of natural radiation exposure. Indoor radon-thoron study has been carried out in some dwellings of Ganjam district, southern coastal Orissa, India using LR-115 type II plastic track detectors. Seasonal variation of indoor radon and thoron shows high values in winter and low values in both summer and rainy. The inhalation dose lies in the range of 0-0.06 μSv h -1 and is not high from those found elsewhere in India.

  2. Seasonal levels of radon and thoron in the dwellings along southern coastal Orissa, Eastern India

    Energy Technology Data Exchange (ETDEWEB)

    Sulekha Rao, N [Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur, West Bengal 721302 (India); Sengupta, D. [Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur, West Bengal 721302 (India)], E-mail: dsgg@gg.iitkgp.ernet.in

    2010-01-15

    Inhalation of radon ({sup 222}Rn) and thoron ({sup 220}Rn) are a major source of natural radiation exposure. Indoor radon-thoron study has been carried out in some dwellings of Ganjam district, southern coastal Orissa, India using LR-115 type II plastic track detectors. Seasonal variation of indoor radon and thoron shows high values in winter and low values in both summer and rainy. The inhalation dose lies in the range of 0-0.06 {mu}Sv h{sup -1} and is not high from those found elsewhere in India.

  3. A numerical study on the performance evaluation of ventilation systems for indoor radon reduction

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ji Eun; Park, Hoon Chae; Choi, Hang Seok; Cho, Seung Yeon; Jeong, Tae Young; Roh, Sung Cheoul [Yonsei University, Wonju (Korea, Republic of)

    2016-03-15

    Numerical simulations were conducted using computational fluid dynamics to evaluate the effect of ventilation conditions on radon ({sup 222}Rn) reduction performance in a residential building. The results indicate that at the same ventilation rate, a mechanical ventilation system is more effective in reducing indoor radon than a natural ventilation system. For the same ventilation type, the indoor radon concentration decreases as the ventilation rate increases. When the air change per hour (ACH) was 1, the indoor radon concentration was maintained at less than 100 Bq/m{sup 3}. However, when the ACH was lowered to 0.01, the average indoor radon concentration in several rooms exceeded 148 Bq/ m{sup 3}. The angle of the inflow air was found to affect the indoor air stream and consequently the distribution of the radon concentration. Even when the ACH was 1, the radon concentrations of some areas were higher than 100 Bq/m{sup 3} for inflow air angles of 5 .deg. and 175 .deg.

  4. Comparative Measurements of Indoor Radon in Homes and Floating Houses

    International Nuclear Information System (INIS)

    Changmuang, Wirote; Tantawiroon, Malulee; Polphong, Pornsri

    2003-06-01

    A survey of the radon ( 222 Rn) concentrations in 318 homes and 152 floating houses (1410 samples) in Phitsanulok province, using a passive 222 Rn charcoal canister and measurement by gamma spectrometry. Floating houses showed significant lower mean levels (8.22 Bqm -3 ) than homes (21.56 Bqm -3 ) (p 222 Rn concentrations indicated that concrete homes had a higher level than wooden homes and homes lying on ground had a higher level than those built at 1 meter or more above ground. The estimated annual mean effective dose equivalent 0.35 mSvy -1 and the annual lung dose equivalent of 5.94 mSvy -1 were only one-third of the world mean estimates

  5. Evolution of {sup 222} Rn and chemical species related with eruptive processes of the Popocatepetl volcano; Evolucion de {sup 222} Rn y especies quimicas relacionadas con procesos eruptivos del volcan Popocatepetl

    Energy Technology Data Exchange (ETDEWEB)

    Aranda, P.; Ceballos, S.; Cruz, D.; Hernandez, A.; Lopez, R.; Pena, P.; Salazar, S.; Segovia, N.; Tamez, E. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    The {sup 222} Rn monitoring in the Popocatepetl volcano was initiated on 1993. At December 21, 1994 it is initiated an eruptive stage in the volcano with gas emission, ashes and the lava dome formation on the crater at middle 1996. During all this time it has been determined radon concentrations on soils with active and passive detectors. In this work the changes in radon contents are reported also the physicochemical parameters in spring water related with the volcanic building associated to the recent activity of the volcano. (Author)

  6. Indoor thoron and radon progeny measurements

    International Nuclear Information System (INIS)

    Tu, K.W.; George, A.C.; Lowder, W.M.; Gogolak, C.V.

    1992-01-01

    Measurements of indoor thoron ( 220 Rn) and radon ( 222 Rn) progeny activities were conducted in 40 homes and six public buildings in five states. A commercial alpha spectrometer system and four portable alpha integrating sampling monitors using diffused junction silicon detectors were used for sampling and recording of radionuclide data in particular the potential alpha energy concentrations (PAEC). The data were analysed for the ratios of PAEC- 220 Rn to PAEC- 222 Rn, and the correlations between the two quantities, and their estimated annual effective dose equivalent (AEDE). The results show that the PAEC ratios were 0.09, 0.6, 0.55, and 0.47, respectively, for all homes with the PAEC- 222 Rn > 400, between 100 and 400, -3 , and the total of all homes tested; the AEDE ratios were 0.03, 0.21, 0.19 and 0.16, respectively. No strong correlations were found between PAEC- 220 Rn and PAEC- 222 Rn, and between basement and ground floor data for PAEC- 220 Rn, but the PAEC- 222 Rn data showed a strong correlation between the basement and the ground floor values. Simultaneous measurements of PAEC- 220 Rn and PAEC- 222 Rn on the ground floor and in the basement of each of the 23 single-family houses tested suggests that 220 Rn entry from building materials may be as significant as from the underlying soil. (author)

  7. Influence of the precipitation on the concentration of the radon in the soil: simulation in laboratory and comparison with field data

    International Nuclear Information System (INIS)

    Garcia Vindas, J.R.

    2000-01-01

    The relation between seismicity and Radon 222 concentration anomalies has been studied. The changes in the gas concentration are considered as precursors of the seismic events. This study illustrates the before mentioned relation and confirms that aquifers are favorable places for radon monitoring. (Author) [es

  8. AGE-DEPENDENT INHALATION DOSE DUE TO EXPOSURE OF SHORT LIVED PROGENY OF RADON AND THORON FOR DIFFERENT AGE GROUPS IN JAMMU & KASHMIR, HIMALAYAS.

    Science.gov (United States)

    Sharma, Sumit; Kumar, Ajay; Mehra, Rohit

    2018-05-16

    Dosimetric approach is used in this study for the assessment of doses due to inhalation of short lived radon/thoron progeny to the inhabitants of Udhampur district of Jammu & Kashmir. This paper also presents the activity concentrations and unattached fraction of radon and thoron progeny. The observed annual concentration of attached and unattached 222Rn and 220Rn progeny has been found to vary from 8 to 32 and 0.09 to 14 Bq/m3, 0.75 to 3.16 and 0.01 to 1.13 Bq/m3, respectively. The inhalation doses from radon progeny to different body organs of different age groups have been calculated by using the age dependent biokinetic model. The attachment rate of 222Rn and indoor aerosol concentration of 222Rn and 220Rn have been estimated and their relation between them has also been studied. The dose conversion factor for mouth and nasal breathing to different exposure conditions has been obtained from Porstendorfer model.

  9. Numerical and analytical assessment of radon diffusion in various media and potential of charcoal as radon detector

    Science.gov (United States)

    Rybalkin, Andrey

    Numerical assessments of radon diffusion together with analytical estimates for short-time and long-time exposure were the first objective of this thesis with the goal to demonstrate how radon propagates in various media. Theoretical predictions were compared to numerical simulations, and obtained values of total radon activities inside each material match quite well with the analytical estimates. These estimates, for activated and nonactivated charcoal, were then used to evaluate the possibility of designing a charcoal system to be used as a radon detector. Another objective was to use nonactivated charcoal samples and measure the level of radon accumulation, and use these data to estimate radon diffusion and adsorption coefficients. The analytical approach was developed to estimate these values. Radon adsorption coefficient in nonactivated charcoal was found to be from 0.2 to 0.4 m3/kg. Radon diffusion coefficient for nonactivated charcoal is in the range of 1.2×10-11 to 5.1×10-10 m2/s in comparison to activated charcoal with adsorption coefficient of 4 m3/kg and diffusion coefficient of 1.43×10-9 m2/s. The third objective was to use GEANT4 numerical code to simulate decay of 238U series and 222Rn in an arbitrary soil sample. Based on that model, the goal was to provide a guideline for merging GEANT4 radioactive decay modeling with the diffusion of radon in a soil sample. It is known that radon can be used as an earthquake predictor by measuring its concentration in groundwater, or if possible, along the faults. Numerical simulations of radon migration by diffusion only were made to estimate how fast and how far radon can move along the fault strands. Among the known cases of successful correlations between radon concentration anomalies and earthquake are the 1966 Tashkent and 1976 Songpan-Pingwu earthquakes. Thus, an idea of radon monitoring along the Wasatch Fault, using system of activated/nonactivated charcoals together with solid state radon detectors is

  10. 222Rn determination in some thermal baths of a central eastern Italian area

    International Nuclear Information System (INIS)

    Desideri, D.; Bruno, M.R.; Roselli, C.

    2004-01-01

    Some recent Italian laws, based on the Euratom Directive 26/96, introduce the obligation of monitoring the exposition to natural radioactivity in particular worksites (thermal baths, mines, basements, etc.). Results of 222 Rn measurements in some thermal baths of Rimini and Pesaro-Urbino provinces (Central Eastern Italy), by Radosys-2000, a complete set suitable to radon concentration measurements with CR-39 plastic alpha-track detectors are reported. Some areas where radon could accumulate (bathing, reaction, muddy, inhalation, insufflation rooms and swimming pools) were selected for the investigation. The dosimeters have been exposed for 98 days. The results show that 222 Rn concentrations are very low in the considered thermal baths (7-71 Bq x m -3 ). Moreover, no difference was observed between the concentrations measured in the therapy rooms (bathing, muddy, inhalation and insufflation rooms, swimming pools) and in the normal areas (passages, reaction rooms, dressing rooms, etc.). The calculated dose contribution to workers was about one tenth of the legally suggested value. (author)

  11. Using radon-222 to study coastal groundwater/surface-water interaction in the Crau coastal aquifer (southeastern France)

    Science.gov (United States)

    Mayer, Adriano; Nguyen, Bach Thao; Banton, Olivier

    2016-11-01

    Radon has been used to determine groundwater velocity and groundwater discharge into wetlands at the southern downstream boundary of the Crau aquifer, southeastern France. This aquifer constitutes an important high-quality freshwater resource exploited for agriculture, industry and human consumption. An increase in salinity occurs close to the sea, highlighting the need to investigate the water balance and groundwater behavior. Darcy velocity was estimated using radon activities in well waters according to the Hamada "single-well method" (involving comparison with radon in groundwater in the aquifer itself). Measurements done at three depths (7, 15 and 21 m) provided velocity ranging from a few mm/day to more than 20 cm/day, with highest velocities observed at the 15-m depth. Resulting hydraulic conductivities agree with the known geology. Waters showing high radon activity and high salinity were found near the presumed shoreline at 3,000 years BP, highlighting the presence of ancient saltwater. Radon activity has also been measured in canals, rivers and ponds, to trace groundwater discharges and evaluate water balance. A model of the radon spatial evolution explains the observed radon activities. Groundwater discharge to surface water is low in pond waters (4 % of total inputs) but significant in canals (55 l/m2/day).

  12. Estimation of radon concentration in various operating areas of a reprocessing facility

    International Nuclear Information System (INIS)

    Jayan, M.P.; Ashok Kumar, P.; Raman, Anand; Gopalakrishnan, R.K.

    2010-01-01

    This paper reports 222 Rn concentration of various operating areas of a reprocessing facility and also the U-processing area, measured using a microcontroller based Continuous Radon Monitor (CRM) built indigenously by Radiation Safety Systems Division, Bhabha Atomic Research Centre

  13. Method of reducing radon levels in buildings

    International Nuclear Information System (INIS)

    Khajdarov, R.A.; Gapurova, O.U.; Khajdarov, R.R.

    2004-01-01

    Radon concentration can be reduced by using polymeric compositions which fill pores inside building materials and decrease the coefficient of permeation of radon atoms and water molecules in building materials (concrete, gypsum, etc.). Polymeric silico-organic compounds were investigated and selected as the chemicals to prevent radon seeping indoors. Gas (air, Ar, 222 Rn, H 2 O) permeability of concrete and gypsum after treatment with chemicals was examined. The effect of the cement and sand types, preliminary treatment with various chemicals, type of the polymeric silico-organic compounds, time between treatments, moisture of concrete, time between the preparation of chemicals and the treatment of concrete (ageing of chemicals), time between the treatment of concrete and testing (ageing of treated concrete) were examined. Surfaces of the samples were treated by spraying. The experiments gave evidence that the chosen method of treatment of the construction materials allows reducing the coefficient of gas permeability in 200 - 400 times. Treatment of the floor, walls and ceiling of the basement of 5 buildings reduced the radon concentration in the premises of the first floor from 400-600 Bq/m 3 to the background value of 17-20 Bq/m 3

  14. Indoor air radon concentration in schools in Prizren, Kosovo

    International Nuclear Information System (INIS)

    Bahtijari, M.; Stegnar, P.; Shemsidini, Z.; Kobal, I.; Vaupotic, J.

    2006-01-01

    Indoor air radon ( 222 Rn) concentrations were measured in spring and winter in 30 rooms of 9 elementary schools and 19 rooms of 6 high schools in Prizren, Kosovo, using alpha scintillation cells. Only in three rooms of elementary schools and four rooms of high schools did winter concentrations exceed 400 Bq m -3 . (authors)

  15. Protocol proposal for radon concentration mensuration from granitic rocks in marble factory; Proposta de protocolo para medicao de concentracoes de radonio proveniente de rochas graniticas em marmorarias

    Energy Technology Data Exchange (ETDEWEB)

    Del Claro, Flavia

    2016-11-01

    Naturally occurring radionuclides such as radon ({sup 222}Rn), its decay products and other elements from the radioactive series of uranium ({sup 238}U and {sup 235}U) and thorium ({sup 232}Th) are an important source of human exposure to natural radioactivity. The worldwide evaluation of health radiobiological effects and risks from population exposure to natural radionuclides is a growing concern. Radionuclides such as radon ({sup 222}Rn), the thoron ({sup 220}Rn), radio ({sup 2}'2'6Ra), thorium ({sup 23}'2Th) and potassium ({sup 40}K) may occur in materials commonly used in construction of dwellings and buildings. Thus, the radioactivity from marbles and granites is of importance, so that under certain conditions these materials radioactivity levels can be hazardous requiring the implementation of mitigation measurements. This research presents a technical protocol marble factories for the control human exposure to natural radioactivity exhaled from granitic rocks. The protocol was based on measurements of the {sup 222}Rn and {sup 220}Rn concentration in Brazilian granite rocks commonly nationally and exported. The {sup 222}Rn and {sup 220}Rn measurements were done using the AlphaGUARD (Saphymo GmbH) and RAD7 (Durridge Company) apparatus, respectively. The samples of granite were sealed in glass jars for 40 days in to achieve secular equilibrium between {sup 226}Ra and {sup 222}Rn radionuclides. The measurements were performed on Applied Nuclear Physics Laboratory at the Federal Technological University of Parana. Also, solid-state nuclear track detectors CR-39 were installed in a marble factory environments located in Curitiba - Parana for the evaluation of {sup 222}Rn concentrations in workplaces. The CR-39 detectors were exposed for about 90 days and submitted to etching process. The alpha particle tracks were observed using an optical microscope. Some granite samples analyzed presented {sup 222}Rn concentrations of attention, since the average

  16. Determination of Rn222 in samples of well water and domicile of the cities of Chihuahua and Aldama, Mexico

    International Nuclear Information System (INIS)

    Villalba, L.; Colmenero S, L.; Montero C, M.E.

    2004-01-01

    The study of the content of dissolved Rn 222 is presented in underground water and of domicile of the cities of Chihuahua and Aldama of the State of Chihuahua. The existence of the Rn 222 in the underground waters comes from its constant production in the rocks of the terrestrial bark. It has been determined that the radon is a noble gas of more solubility in the water, this solubility induces high concentrations in underground water, as well as bigger risk to the health in the human body once ingested or inhaled. Of the 32 wells studied in the cities of Chihuahua and Aldama, the content of dissolved Rn 222 in the water of 22 of them is bigger than 11 Bq/l and of 73 studied samples of water of domiciles 47 show bigger values that 11 Bq/l. These radon contents are attributable to the uraniferous rocks present in the aquifers. (Author)

  17. Fluxes and exchange rates of radon and oxygen across an air-sea interface

    International Nuclear Information System (INIS)

    Duenas, C.; Fernandez, M.C.; La Torre, M. de

    1986-01-01

    The flux of 222 Rn and O 2 from shallow water off the Bay of Malaga has been measured. The mean value of flux of 222 Rn is evaluated to be 74 atoms/m 2 · s. The Bay is a weak source of oxygen to the atmosphere, where the net production of oxygen is found to be 1.82 mol/m 2 · y. Moreover, the gas exchange rates of 222 Rn and O 2 across the air-sea interface has been determined by the radon method. The gas exchange rates and the wind speed have been estimated. (author)

  18. Continual monitoring of radon decay products concentration in indoor and outdoor air

    International Nuclear Information System (INIS)

    Petruf, P.; Holy, K.; Stanys, T.

    1998-01-01

    The goal of this work was the development of the method and construction and testing of measurement device for continual monitoring of radon daughters concentrations in the indoor and outdoor environment with regard to make possible to determine very low activities in the outdoor air (below % Bq/m 3 ). In this method air sample is drawn through the appropriate filter material. Radon and thoron daughters both attached and unattached on aerosols particles are collected on the filter surface and then the filter activity is counted. The silicon surface barrier detector with the active area of 200 mm 2 in monitor was used. The Millipore AW19-type filter was chosen and sampling rate of 30 l/min for collecting of the air samples. The determination of the individual activity concentrations in three-count method is based on the solution of the simultaneous equations describing the number of atoms of measured nuclides on the filter during and after sampling. The monitor was tested in three different environments (the average values of the activity concentrations of radon and its decay products in Bq/m 3 are given): in the basement of the building: 61.4 ± 5.0 of 222 Rn, 29.5 ± 2.8 of 218 Po, 14.1 ± 1.8 of 214 Pb and 12.1 ± 1.6 of 214 Bi; in the room on the second floor of the same building:22.2 ± 7.9 of 222 Rn, 7.3 ± 2.8 of 218 Po, 4.6 ± 1.9 of 214 Pb and 2.6 ± 1.2 of 214 Bi ; in the outdoor air in front of the building: 4.1 ± 2.7 of 222 Rn, 2.3 ± 0.9 of 218 Po, 1.5 ± 0.8 of 214 Pb and 1.4 ± 0.6 of 214 Bi. The results show a good agreement with expectations of the activity concentrations in three different environments. The monitor enables to determine low activity concentrations in the outdoor with an acceptable precision during one hour counting. The monitor can be used for the research of the correlation between the atmospheric stability and activity concentrations of radon decay products

  19. Radon in outdoor air at various sites in Slovakia

    International Nuclear Information System (INIS)

    Bulko, Martin; Holy, Karol; Muellerova, Monika; Polaskova, Anna; Hola, Olga

    2010-01-01

    Radon 222 was continuously monitored at four sites of Slovakia, viz. at the campus of the Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava (FMPI CU), at the Slovak Metrological Institute in Bratislava (SMI), at Jaslovske Bohunice (with its nuclear power plant), and at Novaky (coal mining area). The minima and maxima of the daily radon waves occurred at different periods of the day. The average radon activity concentration (RAC) in Novaky was more than twice as high as at the remaining sites, presumably due to a higher rate of radon exhalation from soil. By using the 'box' model, the exhalation rate at Novaky was estimated to be 40 mBq.m -2 .s -1 , which is about 2.5 times that at the FMPI CU in Bratislava. This higher exhalation rate in Novaky is probably caused by a different bedrock in this area. The average annual effective dose from radon and its daughters estimated by the UNSCEAR methodology is 0.06 mSv in the atmosphere of Bratislava and Jaslovske Bohunice and 0.13 mSv in the atmosphere of Novaky

  20. Radon monitoring using long-range alpha detector-based technology

    International Nuclear Information System (INIS)

    Bolton, R.D.

    1994-01-01

    Long-Range Alpha Detector (LRAD) technology is being studied for monitoring radon gas concentrations. LRAD-based instruments collect and measure the ionization produced in air by alpha decays. These ions can be moved to a collection grid via electrostatic ion-transport design collected approximately 95% of the radon produced ions, while instruments using an airflow transport design collected from 44% to 77% of these ions, depending on detector geometry. The current produced by collecting this ionization is linear with respect to 222 Rn concentration over the available test range of 0.07 to 820 pCi/L. In the absence of statistical limitations due to low radon concentrations, the speed of response of LRAD-based instruments is determined by the air exchange rate, and therefore changes in radon concentration can be detected in just a few seconds. Recent tests show that at radon concentrations below 20 pCi/L current pulses produced by individual alpha decays can be counted, thus improving detector sensitivity and stability even further. Because these detectors are simple, rugged, and do not consume much power, they are natural candidates for portable, battery operation