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Sample records for radon progeny application

  1. Control of indoor radon and radon progeny concentrations

    International Nuclear Information System (INIS)

    Sextro, R.G.

    1985-05-01

    There are three general categories of techniques for the control of radon and radon progeny concentrations in indoor air - restriction of radon entry, reduction of indoor radon concentrations by ventilation or air cleaning, and removal of airborne radon progeny. The predominant radon entry process in most residences appears to be pressure driven flow of soil gas through cracks or other openings in the basement, slab, or subfloor. Sealing these openings or ventilation of the subslab or subfloor space are methods of reducing radon entry rates. Indoor radon concentrations may be reduced by increased ventilation. The use of charcoal filters for removal of radon gas in the indoor air by adsorption has also been proposed. Concentrations of radon progeny, which are responsible for most of the health risks associated with radon exposures, can be controlled by use of electrostatic or mechanical filtration. Air circulation can also reduce radon progeny concentrations in certain cases. This paper reviews the application and limitations of each of these control measures and discusses recent experimental results

  2. Dosimetry of inhaled radon and thoron progeny

    International Nuclear Information System (INIS)

    James, A.C.

    1994-06-01

    This chapter reviews recent developments in modeling doses received by lung tissues, with particular emphasis on application of ICRP's new dosimetric model of the respiratory tract for extrapolating to other environments the established risks from exposure to radon progeny in underground mines. Factors discussed include: (1) the influence of physical characteristics of radon progeny aerosols on dose per unit exposure, e.g., the unattached fraction, and the activity-size distributions of clustered and attached progeny; (2) the dependence of dose on breathing rate, and on the exposed subject (man, woman or child); (3) the variability of dose per unit exposure in a home when exposure is expressed in terms of potential α energy or radon gas concentration; (4) the comparative dosimetry of thoron progeny; and (5) the effects of air-cleaning on lung dose. Also discussed is the apparent discrepancy between lung cancer risk estimates derived purely from dosimetry and the lung cancer incidence observed in the epidemiological studies of radon-exposed underground miners. Application of ICRP's recommended risk factors appears to overestimate radon lung-cancer risk for miners by a factor of three. ''Normalization'' of the calculated effective dose is therefore needed, at least for α dose from radon and thoron progeny, in order to obtain a realistic estimate of lung cancer risk

  3. 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.

  4. 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.

  5. Radon progeny mitigation using unipolar ion generators

    International Nuclear Information System (INIS)

    Sapra, B.K.; Arun Kumar; Khan, Arshad; Kothalkar, P.S.; Mayya, Y.S.

    2006-01-01

    Unipolar ion generators are often used for reduction of particulate levels in indoor environments. This paper explores the feasibility of their use in reducing radon progeny concentrations in a confined environment. Experiments have been carried out in a 10 m 3 test vessel in which ionizers are suspended in airspace and 226 Ra planchettes are placed as sources of radon. The radon, progeny and aerosol concentrations were estimated prior to and post-ioniser operation in the vessel using standard instruments and techniques. Results showed that the progeny concentrations decreased by a factor of about 10 with a mean life of about 35 min after ioniser was switched on. A mathematical model involving progeny, particle, ion space charge and electric field interaction processes been developed for estimating the various fractions of the progeny concentrations in the presence of the ionizer. The results of the model compared well with the experimental results. This study has a possible application for reducing progeny concentrations in U mines at local scales and specific working areas. (author)

  6. Microdosimetry of radon progeny: Application to risk assessment

    International Nuclear Information System (INIS)

    Fisher, D.R.; Hui, T.E.; James, A.C.; Bond, V.P.

    1990-01-01

    We developed methods for calculating radiation doses to individual cells and cell nuclei of human bronchial epithelium from radon and progeny for specified levels of exposure, breathing rates, equilibrium factors, unattached fraction of progeny, and other factors that are important in radon dosimetry. If we also know which cells are likely precursors for cancer, and we also know their locations in the respiratory tract, we then may calculate the statistical probability that these cells are irradiated by alpha particles, the number of single alpha-particle hits, and the spectrum of doses delivered as a probability density in specific energy

  7. Measurements of indoor radon and radon progeny in Mexico City

    International Nuclear Information System (INIS)

    Cheng, Y.S.; Rodriguez, G.P.

    1996-01-01

    Indoor radon has been a public concern associated with increased lung cancer risks. Radon decay products interact with indoor aerosols to form progeny with different size distributions, which may influence the lung dosimetry when the progeny are inhaled. Air pollution in Mexico City is a serious problems with high particulate concentrations, but there are few reports of indoor radon measurement. The purposes of this study were to measure the aerosol concentration, radon concentration, and radon activity size distribution in the living area of three houses in Mexico City. The radon concentration was monitored by a RGM-3 radon gas monitor (Eberline, Inc., Santa Fe, NM). A graded diffusion battery was used to determine the progeny concentration and activity size distribution. The concentration and size distribution of the indoor aerosols were monitored by a quartz, crystal microbalance cascade impactor. Our measurements showed high concentrations of indoor aerosols (20-180 gg m -3 ). However, the radon concentrations-were low ( -1 ), but showed a clear diurnal pattern with peak concentrations from 2-10 AM. The activity size distributions of radon progeny were trimodal, with peaks of 0.6 nm, 4-5 nm, and 100 rim. Most activities were associated with large particle sizes. Our results indicated that indoor radon concentration was not high, due in part to a relatively high air exchange with outdoor air. The high aerosol concentration may also play an important part in the activity size distribution of radon progeny

  8. Interaction of radon progeny with atmospheric aerosols

    International Nuclear Information System (INIS)

    Morawska, Lidia

    1994-01-01

    The radiological health hazard due to the airborne radon progeny depends on three factors (i) radon concentration in the air, (ii) radon progeny concentration, and (iii) active particle size distribution. Conclusions as to the health hazard cannot be drawn without full understanding of the interaction mechanisms between radon progeny and atmospheric aerosols. The aim of this work was to study the interaction mechanisms between radon progeny, natural environmental aerosols and environmental tobacco smoke (ETS). The experiments were performed under controlled laboratory conditions of radon concentration (1.85 and 3.70 Bq m -3 ), relative humidity (35, 50, 75 and 95%) and ETS generation. The size distribution of radioactivity carrying aerosols was measured using a wire screen diffusion battery system and size distribution of all airborne aerosols using a differential mobility particle sizer. The paper presents and discusses the results of activity size distribution and radon progeny concentration measurements for different environmental conditions. 7 refs., 2 tabs

  9. Development of a portable radon progeny monitor

    International Nuclear Information System (INIS)

    Iimoto, Takeshi; Kosako, Toshiso; Sugiura, Nobuyuki

    2000-01-01

    Important nuclides in the radon family contributing to the effective dose are the members of the radon short-life progeny, 218 Po and 214 Po and direct measurement of these progenies is suitable for dosimetry. Survey of the radon progeny concentrations in a number of dwellings and offices is very difficult because we have no convenient instrument for the measurement. At present, radon dosimetry is carried out based on the concentration of the parent radon itself. Therefore, for accurate estimation of public or personal effective dose, it is necessary to develop a facile and portable radon progeny monitor. In this study, a portable radon progeny monitor (PRPM) was designed and developed to automatically estimate the individual progeny concentration in the natural environment. The properties of PRPM were investigated. The dimensions of the entire instrument were 65 x 145 x 170 mm and the total weight was 780 g. The portability of PRPM was much superior to the conventional instrument. The PRPM can operate automatically to estimate individual progeny concentration. All component materials of the monitor were selected based on the data of specified performance, cost performance and availability bon the market. The concentration of individual radon progeny was estimated by the build-up decay. It was concluded that PRPM is much suitable for outdoor study and personal dose estimation, as well as indoor measurement. In the field survey, especially in mines and caverns, PRPM is found as a valuable and convenient instrument. (M.N.)

  10. Bronchial dosimeter for radon progeny

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, T.K.; Yu, K.N.; Nikezic, D.; Haque, A.K.M.M. [City University of Hong Kong, Hong Kong (China); Vucic, D. [Faculty of Technology, University of Nis, Lescovac (Yugoslavia)

    2000-05-01

    Traditionally, assessments of the bronchial dose from radon progeny were carried out by measuring the unattached fraction (f{sub p}) of potential alpha energy concentration (PAEC), the total PAEC, activity median diameters (AMDs) and equilibrium factor, and then using dosimetric lung models. A breakthrough was proposed by Hopke et al. (1990) to use multiple metal wire screens to mimic the deposition properties of radon progeny in the nasal (N) and tracheobronchial (T-B) regions directly. In particular, they were successful in using four layers of 400-mesh wire screens with a face velocity of 12 cm s{sup -1} for the simulation of radon progeny deposition in the T-B region. Oberstedt and Vanmarcke (1995) carried out precise calibrations for the system, and named the system as the 'bronchial dosimeter'. Based on these, Yu and Guan (1998) proposed a portable bronchial dosimeter similar to a normal measurement system for radon progeny or PAEC and consisted of only a single sampler and employed only one 400-mesh wire screen and one filter. However, all these 'bronchial dosimeters' in fact only determined the fraction of potential alpha energy from radon progeny deposited in the T-B region, which required certain assumptions and calculations to further give the final bronchial dose. In the present work, a true 'bronchial dosimeter' was designed, which consisted of three 400-mesh wire screens and a filter. With a face velocity of 11 cm s{sup -1}, the deposition pattern on the wire screens was found to satisfactorily match the variation of the dose conversion factor (in the unit of mSv/WLM) with the size of radon progeny from 1 to 1000 nm. In this way, this bronchial dosimeter directly gave the bronchial dose from the alpha counts recorded on the wire-screens and the filter paper. With the development of this bronchial dosimeter, the present practice of 'dose estimation' from large-scale radon surveys can be replaced by large

  11. Health effects of inhaled radon progeny

    International Nuclear Information System (INIS)

    Monchaux, G.

    1997-01-01

    The relationship between an increased risk of lung cancer and exposure to radon progeny has been studied in eleven cohorts of underground workers, both in uranium and non uranium mines as well as in experimental animals. Risk estimates derived from miners studies are used to assess the risk of lung cancer in relation to exposure to indoor radon progeny. Human and animal experimental data are reviewed in the perspective of risk assessment for low exposure to radon progeny, in the conditions of the contemporary working environment as well as the indoor domestic environment. (authors)

  12. 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)

  13. Utilisation of an Air-conditioning System to Control the Levels of Radon and Radon Progeny in a Workplace Environment

    International Nuclear Information System (INIS)

    Marley, F.

    2000-01-01

    From long-term real-time radon and radon progeny measurements taken in a relatively large retail store, cyclical patterns were evident, which were found to relate to the overriding influence of the timed air-conditioning system. Concentration of radon, radon progeny and the variability of F factor were found to depend significantly on the intermittent operation of this ventilation-air-conditioning system. After pressure equalisation remedial measures proved ineffective, the air-movement system was utilised to reduce the levels of radon and radon progeny to well within established norms applicable during working hours. It is demonstrated that the average levels for radon and radon progeny are reduced in absolute terms. This amounted to less than 12% of the general level, during designated work periods. Where air movement systems are already installed, as well as other circumstances, their regulation provides an economical solution to meeting legal and other standards for radon in the workplace. (author)

  14. Attachment of radon progeny to cigarette-smoke aerosols

    International Nuclear Information System (INIS)

    Biermann, A.H.; Sawyer, S.R.

    1995-05-01

    The daughter products of radon gas are now recognized as a significant contributor to radiation exposure to the general public. It is also suspected that a synergistic effect exists with the combination cigarette smoking and radon exposure. We have conducted an experimental investigation to determine the physical nature of radon progeny interactions with cigarette smoke aerosols. The size distributions of the aerosols are characterized and attachment rates of radon progeny to cigarette-smoke aerosols are determined. Both the mainstream and sidestream portions of the smoke aerosol are investigated. Unattached radon progeny are very mobile and, in the presence of aerosols, readily attach to the particle surfaces. In this study, an aerosol chamber is used to contain the radon gas, progeny and aerosol mixture while allowing the attachment process to occur. The rate of attachment is dependent on the size distribution, or diffusion coefficient, of the radon progeny as well as the aerosol size distribution. The size distribution of the radon daughter products is monitored using a graded-screen diffusion battery. The diffusion battery also enables separation of the unattached radon progeny from those attached to the aerosol particles. Analysis of the radon decay products is accomplished using alpha spectrometry. The aerosols of interest are size fractionated with the aid of a differential mobility analyzer and cascade impactor. The measured attachment rates of progeny to the cigarette smoke are compared to those found in similar experiments using an ambient aerosol. The lowest attachment coefficients observed, ∼10 -6 cm 3 /s, occurred for the ambient aerosol. The sidestream and mainstream smoke aerosols exhibited higher attachment rates in that order. The results compared favorably with theories describing the coagulation process of aerosols

  15. Intercomparison of active and passive instruments for radon and radon progeny in North America

    International Nuclear Information System (INIS)

    George, A.C.; Tu, Keng-Wu; Knutson, E.O.

    1995-02-01

    An intercomparison exercise for radon and radon progeny instruments and methods was held at the Environmental Measurements Laboratory (EML) from April 22--May 2, 1994. The exercise was conducted in the new EML radon test and calibration facility in which conditions of exposure are very well controlled. The detection systems of the intercompared instruments consisted of. (1) pulse ionization chambers, (2) electret ionization chambers, (3) scintillation detectors, (4) alpha particle spectrometers with silicon diodes, surface barrier or diffused junction detectors, (5) registration of nuclear tracks in solid-state materials, and (6) activated carbon collectors counted by gamma-ray spectrometry or by alpha- and beta-liquid scintillation counting. 23 private firms, government laboratories and universities participated with a 165 passive integrating devices consisting of: Activated carbon collectors, nuclear alpha track detectors and electret ionization chambers, and 11 active and passive continuous radon monitors. Five portable integrating and continuous instruments were intercompared for radon progeny. Forty grab samples for radon progeny were taken by five groups that participated in person to test and evaluate their primary instruments and methods that measure individual radon progeny and the potential alpha energy concentration (PAEC) in indoor air. Results indicate that more than 80% of the measurements for radon performed with a variety of instruments, are within ±10% of actual value. The majority of the instruments that measure individual radon progeny and the PAEC gave results that are in good agreement with the EML reference value. Radon progeny measurements made with continuous and integrating instruments are satisfactory with room for improvement

  16. Radon: Chemical and physical states of radon progeny. Final technical report

    International Nuclear Information System (INIS)

    Castleman, A.W. Jr.

    1996-01-01

    The evolving chemical and physical form of radon progeny influence their transport to the bioreceptor and the extent to which that receptor can take up these species into various tissues. When first born following radioactive decay processes, the potentially deleterious radon progeny undergo various physical and chemical transformations as they transcend from a highly charged to a neutral state, and interact with various constituents of the environment. These transformations impact on the extent to which the radon progeny become associated with aerosol particles on the one hand, and their ultimate chemical form that is available for uptake in the biosystem, on the other. The program, which originally commenced in 1987, dealt with the basic chemistry and physics of radon progeny and hence impacted on several themes of importance to the DOE/OHER radon program. One of these is dose response, which is governed by the physical forms of the radon progeny, their transport to the bioreceptor and the chemical forms that govern their uptake. The second theme had to do with cellular responses, one of the major issues motivating the work. It is well known that various sizes of ions and molecules are selectively transported across cell membrane to differing degrees. This ultimately has to do with their chemical and physical forms, charge and size. The overall objective of the work was threefold: (1) quantifying the mechanisms and rates of the chemical and physical transformation; (2) ascertaining the ultimate chemical forms, and (3) determining the potential interactions of these chemical species with biological functional groups to ascertain their ultimate transport and incorporation within cells

  17. Field investigation of surface-deposited radon progeny as a possible predictor of the airborne radon progeny dose rate.

    Science.gov (United States)

    Sun, Kainan; Steck, Daniel J; Field, R William

    2009-08-01

    The quantitative relationships between radon gas concentration, the surface-deposited activities of various radon progeny, the airborne radon progeny dose rate, and various residential environmental factors were investigated through actual field measurements in 38 selected Iowa houses occupied by either smokers or nonsmokers. Airborne dose rate was calculated from unattached and attached potential alpha energy concentrations (PAECs) using two dosimetric models with different activity-size weighting factors. These models are labeled Pdose and Jdose, respectively. Surface-deposited 218Po and 214Po were found significantly correlated to radon, unattached PAEC, and both airborne dose rates (p fireplace, or usage of a ceiling fan significantly, or marginally significantly, reduced the Pdose to 0.65 (90% CI 0.42-0.996), 0.54 (90% CI 0.28-1.02), and 0.66 (90% CI 0.45-0.96), respectively. For Jdose, only the usage of a ceiling fan significantly reduced the dose rate to 0.57 (90% CI 0.39-0.85). In smoking environments, deposited 218Po was a significant negative predictor for Pdose (RR 0.68, 90% CI 0.55-0.84) after adjusting for long-term 222Rn and environmental factors. A significant decrease of 0.72 (90% CI 0.64-0.83) in the mean Pdose was noted, after adjusting for the radon and radon progeny effects and other environmental factors, for every 10 additional cigarettes smoked in the room. A significant increase of 1.71 in the mean Pdose was found for large room size relative to small room size (90% CI 1.08-2.79) after adjusting for the radon and radon progeny effects as well as other environmental factors. Fireplace usage was found to significantly increase the mean Pdose to 1.71 (90% CI 1.20-2.45) after adjusting for other factors.

  18. Field applications of a radon barrier to reduce indoor airborne progeny

    International Nuclear Information System (INIS)

    Culot, M.V.J.; Olson, H.G.; Schiager, K.J.

    1978-01-01

    The use of uranium mill tailings in the foundations of dwellings has resulted in indoor radon progeny concentrations and gamma exposures in excess of levels presently allowed for the general public. An account is given of the applications of an epoxy coating on the indoor faces of the concrete foundations of three buildings in Grand Junction, Colorado. Epoxy barriers were shown to be effective for preventing radon influx into structures. Gamma exposure rates must be analyzed to ensure that buildup behind the barrier will not introduce an unacceptable gamma exposure level. The use of a sealant is especially economical in situations where structural integrity may be jeopardized by physical removal of uranium mill tailings. (author)

  19. Control of respirable particles and radon progeny with portable air cleaners

    International Nuclear Information System (INIS)

    Offermann, F.J.; Sextro, R.G.; Fisk, W.J.; Nazaroff, W.W.; Nero, A.V.; Revzan, K.L.; Yater, J.

    1984-02-01

    Eleven portable air cleaning devices have been evaluated for control of indoor concentrations of respirable particles and radon progeny. Following injection of cigarette smoke and radon in a room-size chamber, decay rates for particles and radon progeny concentrations were measured with and without air cleaner operation. Particle concentrations were obtained for total number concentration and for number concentration by particle size. In tests with no air cleaner the natural decay rate for cigarette smoke was observed to be 0.2 hr -1 . Air cleaning rates for particles were found to be negligible for several small panel-filters, a residential ion-generator, and a pair of mixing fans. The electrostatic precipitators and extended surface filters tested had significant particle removal rates, and a HEPA-type filter was the most efficient air cleaner. The evaluation of radon progeny control produced similar results; the air cleaners which were effective in removing particles were also effective in removing radon progeny. At low particle concentrations plateout of the unattached radon progeny is an important removal mechanism. Based on data from these tests, the plateout rate for unattached progeny was found to be 15 hr -1 . The unattached fraction and the overall removal rate due to deposition of attached and unattached nuclides have been estimated for each radon decay product as a function of particle concentration. While air cleaning can be effective in reducing total radon progeny, concentrations of unattached radon progeny can increase with increasing air cleaning. 39 references, 26 figures, 9 tables

  20. Field Investigation of the Surface-deposited Radon Progeny as a Possible Predictor of the Airborne Radon Progeny Dose Rate

    Science.gov (United States)

    Sun, Kainan; Steck, Daniel J.; Field, R. William

    2009-01-01

    The quantitative relationships between radon gas concentration, the surface-deposited activities of various radon progeny, the airborne radon progeny dose rate, and various residential environmental factors were investigated through actual field measurements in 38 selected Iowa houses occupied by either smokers or nonsmokers. Airborne dose rate was calculated from unattached and attached potential alpha energy concentrations (PAECs) using two dosimetric models with different activity-size weighting factors. These models are labeled Pdose and Jdose, respectively. Surface-deposited 218Po and 214Po were found significantly correlated to radon, unattached PAEC, and both airborne dose rates (p fireplace, or usage of a ceiling fan significantly, or marginal significantly, reduced the Pdose to 0.65 (90% CI 0.42–0.996), 0.54 (90% CI 0.28–1.02) and 0.66 (90% CI 0.45–0.96), respectively. For Jdose, only the usage of a ceiling fan significantly reduced the dose rate to 0.57 (90% CI 0.39–0.85). In smoking environments, deposited 218Po was a significant negative predictor for Pdose (RR 0.68, 90% CI 0.55–0.84) after adjusting for long-term 222Rn and environmental factors. A significant decrease of 0.72 (90% CI 0.64–0.83) in the mean Pdose was noted, after adjusting for the radon and radon progeny effects and other environmental factors, for every 10 increasing cigarettes smoked in the room. A significant increase of 1.71 in the mean Pdose was found for large room size relative to small room size (90% CI 1.08–2.79) after adjusting for the radon and radon progeny effects as well as other environmental factors. Fireplace usage was found to significantly increase the mean Pdose to 1.71 (90% CI 1.20–2.45) after adjusting for other factors. PMID:19590273

  1. Wind direction correlated measurements of radon and radon progeny in atmosphere: a method for radon source identification

    International Nuclear Information System (INIS)

    Akber, R.A.; Pfitzner, J.; Johnston, A.

    1994-01-01

    This paper describes the basic principles and methodology of a wind direction correlated measurement technique which is used to distinguish the mine-related and background components of radon and radon progeny concentrations in the vicinity of the ERA Ranger Uranium Mine. Simultaneous measurements of atmospheric radon and radon progeny concentrations and wind speed and direction were conducted using automatic sampling stations. The data were recorded as a time series of half hourly averages and grouped into sixteen 22.5 degrees wind sectors. The sampling interval and the wind sector width were chosen considering wind direction variability (σ θ ) over the sampling time interval. The data were then analysed for radon and radon progeny concentrations in each wind sector. Information about the wind frequency wind speed seasonal and diurnal variations in wind direction and radon concentrations was required for proper data analysis and interpretation of results. A comparison with model-based estimates for an identical time period shows agreement within about a factor of two between the two methods. 15 refs., 1 tab., 5 figs

  2. Concentration ratio of radon progeny in air

    International Nuclear Information System (INIS)

    Kobayashi, Tsuneo

    2000-01-01

    Investigations have been made on the concentration ratio of radon progeny in air. Data have been acquired intermittently since 1988 using alpha spectroscopic method around the author's office that is located in the northeastern part of Japan. Clarifying the behavior of radon progeny is an issue of wide importance to radiation protection, predicting earthquakes, etc. Let Rabc=ECRn(RaA)/{ECRn(RaB) + ECRn(RaC)}; the concentration ratio, Rabc, is relevant to the stability of the air. Statistical and time series analyses indicated several interesting results. To examine the log-normal distribution, Lilliefors test was made for logarithm of outdoor data every one year. Rabc passed the test 6 times for 9 years, while Radon progeny passed 8 times. Outdoor data indicated that the value of Rabc was lower in the morning, in other world, the air was more stable in the morning than in the afternoon. To see the seasonal variation, one-way layout analysis was made for four groups of data, i.e., spring (March to May), summer (June to August), autumn (September to November), and winter (December to February). Rabc indicated significantly higher level in spring and winter, in other word, air was stable in summer and autumn. Time series analysis was made for various variables; power spectra were estimated with autoregressive model that is equivalent to maximum entropy method. Power spectrum for Rabc was most similar to that of wind speed. One-year period, that is always remarkable for radon progeny, was not significant for Rabc. Three- to nine-day periods were often seen for Rabc, radon progeny, wind speed, and atmospheric pressure. These several-day periods are probably attributed to the passage of air masses. Twenty-day to thirty-day peak may be attributed to meteorological phenomena corresponding to the rotation period of the sun. Temperature indicated no significant periodicity except overwhelming one-year period. Wind speed is well known to affect the radon progeny concentration

  3. Cellular lung dosimetry for inhaled thoron progeny: comparison with radon progeny

    International Nuclear Information System (INIS)

    Abd El-Hady, M.; Hofmann, W.; Balashazy, I.

    1998-01-01

    Recently an analytical method was developed to compute radiation doses deposited by 222 Rn progeny alpha particles in 1 μm spheres located at different depths in bronchial epithelium. The same method was now applied to alpha particles emitted from 220 Rn progeny deposited in bronchial airway surfaces. Results of the computations are presented in graphs. The mean cellular doses imparted by 220 Rn progeny to basal and secretory cell nuclei were compared with those produced by 222 Rn progeny; due to differences in alpha energies, radon progeny doses were found to be generally higher than those for thoron progeny. (A.K.)

  4. Distribution characteristics of radon and its progeny in blind roadway with forced ventilation

    International Nuclear Information System (INIS)

    Ye Yongjun; Zhou Xinghuo; Li Xiangyang; Zhong Yongming; Liu Dong; Ding Dexin

    2012-01-01

    The blind roadway is not only the important workplaces, but also is important site of radon and its progeny generating and gathering, it is an important guiding significance for ventilation protection design to study distribution characteristics of radon and its progeny in blind roadway. Therefore, at first, the paper expounded the mathematical relationship between radon activity concentration with alpha potential concentration of radon progeny. Then, analyzed the sources of radon and its progeny, and established mathematical calculation model of Distribution characteristics of radon and its progeny in blind roadway with forced ventilation, respectively. Finally, using mathematical calculation models to analyze the influence law of multiple factors. (authors)

  5. The study of thoron and radon progeny concentrations in dwellings in Japan

    International Nuclear Information System (INIS)

    Guo, Q.; Shimo, M.; Ikebe, Y.

    1992-01-01

    Ths paper aims to make a comparison of different concentrations of thoron ( 220 Rn) progeny and radon ( 222 Rn) progeny in different kinds of dwellings. The potential alpha energy concentrations and the effective dose equivalent caused by thoron and radon progeny, respectively, have also been estimated. The measurements were carried out in 23 dwellings. The results indicate that thoron progeny concentrations indoors might be strongly affected by the type of building material used. Traditional Japanese buildings made with mud may have high thoron progeny concentrations of about 3.52 Bq.m -3 and a concentration ratio of thoron progeny to radon progeny of about 0.5, whereas in concrete dwellings thoron progeny concentrations are about 0.72 Bq.m -3 and the concentration ratio of thoron progeny to radon progeny is about 0.1. The annual effective dose equivalent of thoron progeny is 1.23 mSv in mud dwellings and 0.25 mSv in concrete dwellings. (author)

  6. Measurements of thoron and radon progeny concentrations in Beijing, China

    International Nuclear Information System (INIS)

    Zhang Lei; Liu Cuihong; Guo Qiuju

    2008-01-01

    It has been reported that thoron levels in China are above the world average and may therefore make a significant contribution to the natural background radiation dose. We therefore conducted a pilot study of concentrations of both thoron and radon progeny during the spring of 2006 in the Beijing area, China. A new type of portable 24 h integrating monitor with a CR-39 detector was used during the survey. Seventy dwellings and eight outdoor sites were measured during the survey. For country houses built of red bricks and slurry, the average equilibrium equivalent concentrations (EEC) of thoron and radon were 1.02 ± 0.48 and 16.41 ± 9.02 Bq m -3 , respectively, whereas for city dwellings built of cement blocks and floor slabs, the results were 0.48 ± 0.47 and 11.50 ± 6.99 Bq m -3 for thoron and radon, respectively. For outdoor air, concentrations of thoron and radon progeny were 0.29 ± 0.28 and 7.05 ± 2.68 Bq m -3 , respectively. Radiation exposures from thoron and radon progeny were also evaluated; the ratio of dose contribution from thoron progeny to that of radon progeny was evaluated to be 28% and 17% in country houses and city dwellings, respectively. (note)

  7. 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

  8. Study on radon and thoron progeny levels in Gudalore in South India

    International Nuclear Information System (INIS)

    Selvasekarapandian, S.; Sivakumar, R.; Mugunthamanikandan, N.; Meenakshisundaram, V.; Santhanam, R.

    2000-01-01

    One of the important route of radiation exposure to man is through inhalation of air containing radioisotopes. A major contribution to inhalation dose comes from radon, thoron and its progenies. The indoor radon and thoron progeny levels are determined by two count method. In this method the radon and thoron progenies are collected on a glass fiber filter paper using volume air sampler (Staplex) and counted for alpha activity in ZnS (Ag) alpha counting system. It is observed that thoron working level is higher than the radon working level in all houses except few houses with stone walls and mosaic floor. Behavior of indoor radon and thoron working levels for different seasons at different houses are determined and discussed in detail. Radon and thoron working levels are measured high in winter, autumn, and low in summer and rainy seasons. Among all seasons highest value is measured in winter and low in summer and rainy seasons. Radon progeny working level varies from 1.659 to 6.675 mWL, whereas thoron progeny working level varies from 1.670 to 12.671 mWL. The geometric mean values of radon and thoron progeny concentration in the present study are 2.836 and 4.133 mWL. The high thoron progeny level observed in this is attributed to the high thorium content observed in soils of this area. (author)

  9. Studies of Radon and Radon Progeny in Air Conditioned Rooms in Hospitals

    International Nuclear Information System (INIS)

    Marley, F.; Denman, A.R.; Phillips, P.S.

    1998-01-01

    A series of continuous real-time radon and radon progeny measurements together with passive etched track detector measurements were performed in hospital premises during 1996. In one small room, detailed measurements over several weeks showed that both the radon concentration and the Equilibrium Factor depended on the intermittent operation of a filtered positive pressure displacement air-conditioning system, which was designed to conform to operating theatre standards. The average radon level measured while the air-conditioning was off was almost four times higher than that recorded whilst it was on. The progeny level was over five times higher than that whilst it was on. Thus, the Equilibrium Factor (F), was significantly lower when the air-conditioning was on. Measurements in similar rooms in two hospitals, confirmed that the reduction in radon level was a general finding. Thus staff working in such environments receive significantly lower radiation dose from radon than staff working in nearby normally ventilated rooms. (author)

  10. 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)

    George, A.C.; Knutson, E.O.; Tu, K.W.; Fisenne, I.M.

    1995-12-01

    The results from the May 1995 Intercomparison of Active, Passive and Continuous Instruments for Radon and Radon Progeny Measurement conducted in the EML radon exposure and test facility are presented. Represented were 13 participants that measure radon with open faced and diffusion barrier activated carbon collectors, 10 with nuclear alpha track detectors, 9 with short-term and long-term electret/ionization chambers, and 13 with active and passive commercial electronic continuous monitors. For radon progeny, there were four participants that came in person to take part in the grab sampling methodology for measuring individual radon progeny and the potential alpha energy concentration (PAEC). There were 11 participants with continuous and integrating commercial electronic instruments that are used for measuring the PAEC. The results indicate that all the tested instruments that measure radon fulfill their intended purpose. All instruments and methods used for grab sampling for radon progeny did very well. However, most of the continuous and integrating electronic instruments used for measuring the PAEC or working level appear to underestimate the potential risk from radon progeny when the concentration of particles onto which the radon progeny are attached is -3

  11. Control of radon and its progeny concentration in indoor atmosphere

    International Nuclear Information System (INIS)

    Ramachandran, T.V.; Subbaramu, M.C.

    1986-01-01

    Exposure to radon daughter concentration in indoor atmosphere can result in a significant risk to the general public. There are two generally used methods for the control of radon and progeny concentration in the indoor atmosphere, namely restriction of radon entry and reduction of indoor radon and its progeny concentration by ventilation or by air cleaning. Predominant radon entry process in most of the dwellings appears to be by pressure driven flow of soil gas through cracks or other openings in the basement slab or subfloors. Sealing these openings or ventilation of the subslab or subfloor space are the methods for reducing the radon entry rates. Indoor radon concentration can also be reduced by increasing the ventilation and by using charcoal filters for the removal of radon gas in indoor air by absorption. Concentration of radon progeny, which are responsible for most of the health risks associatd with radon exposure can also be controlled by the use of electrostatic or mechanical filters. This study describes briefly the above control strategies used for reducing the inhalation doses to persons in dwellings. (author). 9 refs., 2 tables

  12. Measurement of radon and thoron progenies in Coimbatore

    International Nuclear Information System (INIS)

    Sivakumar, R.; Selvasekarapandian, S.; Mahendraprasad, M.; Meenakshisundaram, V.; Santhanam, R.; Raghunath, V.M.

    2001-01-01

    The radon and thoron daughter concentrations have been measured in different dwellings of Coimbatore city by grab sampling method and two count. It has been found that the radon daughter concentration varies from 0.5 to 10.5 mWL with mean value of 2.9 mWL and that of thoron progeny is from 0.7 to 16.3 mWL with mean value of 3.8 mWL. The average annual effective dose equivalent due to radon daughters is found to be 1.3 mSv and that of thoron progeny is 3.8 mSv. (author)

  13. Development of calibration facility for radon and its progenies at NIM (China)

    International Nuclear Information System (INIS)

    Liang, J.C.; Liu, H.R.; Zhang, M.; Zheng, P.H.; Guo, Q.J.; Yang, Z.J.; Li, Z.S.; Zhang, L.

    2015-01-01

    Accurate measurement of radon and its progenies is the basis to control the radon dose and reduce the risk of lung cancer caused. The precise calibration of measuring instrument is an important part of the quality control of measurements of the concentration of radon and radon progenies. To establish Chinese national standards and realise reliable calibrations of measuring instrument for radon and its progenies, a radon chamber with regulation capability of environmental parameters, aerosol and radon concentrations was designed and constructed at National Institute of Metrology (NIM). The chamber has a total volume of ∼20 m 3 including an exposure volume of 12.44 m 3 . The radon concentration can be controlled from 12 Bq m -3 to the maximum of 232 kBq m -3 . The regulation range of temperature, relative humidity and aerosol are 0.66-44.39 deg. C, 16.4-95 %RH and 10 2 -10 6 cm -3 , respectively. The main advantages of the NIM radon chamber with respect to maintaining a stable concentration and equilibrium factor of radon progenies in a wide range through automatic regulation and control of radon and aerosol are described. (authors)

  14. Plate-out rates of radon progeny and particles in a spherical chamber

    International Nuclear Information System (INIS)

    Cheng, Y.S.; Chen, B.T.

    1990-01-01

    In indoor and mining environments, deposition or ''plate-out'' of radon progeny onto walls occurs simultaneously with attachment of the radon progeny to airborne particles. Attachment and plate-out processes affect the atmosphere in which radon exposures takes place by reducing concentrations and shifting activity size distributions. Both processes have important consequences in determining the deposition pattern and initial dose of inhaled radon progeny. Theoretical deposition models show that turbulence and natural convection in a room are the major factors that influence plate-out rates. Here we describe plate-out measurements for radon progeny and aerosol particles in a spherical chamber under controlled laboratory conditions. The temperature and velocity profiles in still and turbulent air were monitored. A 161-liter spherical aluminum chamber was used to study the mixing. During mixing, air velocity was detected when rotational speeds were higher than 500 rpm. Monodisperse silver aerosols and polystyrene latex particles in the size range of 5 nm to 2 μm were used in the deposition study. Radon-220 progeny were generated by passing Rn-220 gas into the chamber and letting the gas decay into 212 Pb. The deposition rates of the particles and radon progeny ( 212 Pb) in the chamber were determined by monitoring the concentration decay of the aerosol as a function of time

  15. 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.).

  16. 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.)

  17. 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)

  18. Environmental Concentration of Radon and Radon Progeny in a Nuclear Facility in a Decommissioning Stage

    International Nuclear Information System (INIS)

    Ramirez, M. P.; Correa, E.; Sancho, C.

    1999-01-01

    According to the new European Directive 96/29/EURATOM the radiological risk due to natural radionuclides must be consider and the pertinent periodic control must be realized. During the works performed at CIEMAT an estimation of the effective average doses due to Radon inhalation in work places of the installation have been performed. Radon and Radon progeny concentration has been measured in continuous joint whit the meteorological conditions as temperature, pressure and relative humidity. Two different equipment has been used: Alpha-guard whit ionization chamber detector and Eda-wlm-300 whit a semiconductor detector. A passive Radon detector, E-perm has been simultaneously used in the monitoring system. The results obtained during the measuring of Radon and Radon progeny concentrations indoors and estimation of doses have been analyzed and are presented in the paper. (Author) 11 refs

  19. Evaluation of indoor aerosol control devices and their effects on radon progeny concentrations. Revision

    International Nuclear Information System (INIS)

    Sextro, R.G.; Offermann, F.J.; Nazaroff, W.W.; Nero, A.V.; Revzan, K.L.; Yater, J.

    1984-11-01

    Eleven portable air cleaning devices have been evaluated for control of indoor concentrations of respirable particles, and their concomitant effects on radon progeny concentrations have been investigated. The experiments were conducted in a room-size chamber using cigarette smoke and radon injection from an external source. Of the devices examined the electrostatic precipitators and extended surface filters had significant particle removal rates, while the particle removal rates for several small panel-filters, an ion-generator, and a pair of mixing fans were found to be essentially negligible. The evaluation of radon progeny control produced similar results; the air cleaners which were effective in removing particles were also effective in reducing radon progeny concentrations. At the low particle concentrations, deposition of the unattached radon progeny on room surfaces was found to be a significant removal mechanism. Deposition rates of attached and unattached progeny have been estimated from these data, and were used to calculate the equilibrium factors for total and unattached progeny concentrations as a function of particle concentration. While particle removal reduces total airborne radon progeny concentrations, the relative alpha decay dose to the lungs appears to change very little as the particle concentration decreases due to the greater radiological importance of unattached progeny

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-15

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

  1. Evaluation of indoor aerosol control devices and their effects on radon progeny concentrations

    International Nuclear Information System (INIS)

    Sextro, R.G.; Offermann, F.J.; Nazaroff, W.W.; Nero, A.V.; Revzan, K.L.; Yater, J.

    1984-02-01

    Eleven portable air cleaning devices have been evaluated for control of indoor concentrations of respirable particles, and their concomitant effects on radon progeny concentrations have been investigated. Of the devices we examined the electrostatic precipitators and extended surface filters had significant particle removal rates, while the particle removal rates for several small panel-filters, an ion-generator, and a pair of mixing fans were found to be negligible. The evaluation of radon progeny control produced similar results; the air cleaners which were effective in removing particles were also effective in reducing radon progeny concentrations. Furthermore, at the low particle concentrations, plateout of the unattached radon progeny was found to be a significant removal mechanism. The overall removal rates due to deposition of attached and unattached progeny have been estimated from these data, and the equilibrium factors for total and unattached progeny concentrations have been calculated as a function of particle concentration. 7 references, 2 figures

  2. Evaluation of indoor aerosol control devices and their effects on radon progeny concentrations

    International Nuclear Information System (INIS)

    Sextro, R.G.; Offerman, F.J.; Nazaroff, W.W.; Nero, A.V.; Revzan, K.; Yater, J.

    1984-01-01

    Eleven portable air cleaing devices have been evaluated for control of indoor concentrations of respirable particles, and their concomitant effects on radon progeny concentrations have been investigated. Of the devices we examined the electrostatic precipitators and extended surface filters had significant particle removal rates, while the particle removal rates for several small panel-filters, an ion-generator, and a pair of mixing fans were found to be negligible. The evaluation of radon progeny control produced similar results; the air cleaners which were effective in removing particles were also effective in reducing radon progeny concentrations. Futhermore, at the low particle concentrations, plateout of the unattached radon progeny was found to be a significant removal mechanism. The overall removal rates due to deposition of attached and unattached progeny have been estimated from these data, and the equilibrium factors for total and unattached progeny concentrations have been calculated as a function of particle concentration. (Author)

  3. Measurement of the deposited activity of the short-lived radon progeny in the human respiratory tract

    International Nuclear Information System (INIS)

    Vezzu, G.; Butterweck-Dempewolf, G.; Schuler, C.

    1998-01-01

    Volunteers were exposed in the radon chamber at Paul Scherrer Institut to an atmosphere enriched with highly unattached radon progeny. The deposited radon progeny activity in the respiratory tract of the volunteers was determined using a low level in-vivo counter. The detector arrangement and its calibration for the measurement of deposited radon progeny activity is described and the results for a mouth and a nose breathing volunteer are presented. For the nose breathing volunteer 55% of the deposited radon progeny activity was located in the head and the remaining 45% in the chest whereas for the mouth breathing volunteer 25% was located in the head and the remaining 75% in the chest. A mean clearance half-life for the deposited radon progeny from the respiratory tract of (2±1) h was obtained from the analyses of the temporal behaviour of the deposited radon progeny activity in the head. (orig.)

  4. Radon Progeny In Underground Phosphate Mines and Their Activity Distributions In Human Lung

    International Nuclear Information System (INIS)

    Abd El-Hady, M.; Mohammed, A.; El-Hussein, A.; Ali, A.E.; Ahmed, A.A.

    2001-01-01

    In addition to workers in uranium mines, the staff of other underground mines, such as worker 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 to the workers in those sites. Active techniques are employed to fulfill the objective of measuring individual radon progeny concentrations (C RaA , C RaB and C RaC ). The mean reported values of radon progeny concentrations exceed the action levels recommended by ICRP 65 (1993). Based on the physical properties of attached radon progeny aerosol and physiological parameters for heavy work activity which recommended by ICRP 66 (1994). the deposition fraction for each airway generation was calculated. From the measured individual radon progeny concentrations in these mines and the calculated values of deposition fractions, the surface activity distribution per generation were calculated in human respiratory system (BB and regions). The maximum values of these activities were found in the upper bronchial airway generations. According to the obtained results, some of the corrective actions were recommended in this study

  5. Cellular dosimetry for radon progeny alpha particles in bronchial tissue

    International Nuclear Information System (INIS)

    Mohamed, A.; Hofmann, W.; Balashazy, I.

    1996-01-01

    Inhaled radon progeny are deposited in different regions of the human bronchial tree as functions of particle size and flow rate. Following deposition and mucociliary clearance, the sensitive bronchial basal and secretory cells are irradiated by two different alpha particle sources: (i) radon progeny in the sol and/or gel phase of the mucous layer, and (ii) radon progeny within the bronchial epithelium. In the case of internally deposited radionuclides, direct measurement of the energy absorbed from the ionizing radiation emitted by the decaying radionuclides is rarely, if ever, possible. Therefore, one must rely on dosimetric models to obtain estimates of the spatial and temporal patterns of energy deposition in tissues and organs of the body. When the radionuclide is uniformly distributed throughout the volume of a tissue of homogeneous composition and when the size of the tissue is large compared to the range of the particulate emissions of the radionuclide, then the dose rate within the tissue is also uniform and the calculation of absorbed dose can proceed without complication. However, if non-uniformities in the spatial and temporal distributions of the radionuclide are coupled with heterogeneous tissue composition, then the calculation of absorbed dose becomes complex and uncertain. Such is the case with the dosimetry of inhaled radon and radon progeny in the respiratory tract. There are increasing demands to obtain a definitive explanation of the role of alpha particles emitted from radon daughters in the induction of lung cancer. Various authors have attempted to evaluate the dose to the bronchial region of the respiratory tract due to the inhalation of radon daughters

  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. Proceedings of radon and radon progeny measurements in Australia symposium

    International Nuclear Information System (INIS)

    Akber, R.A.; Harris, F.

    1994-01-01

    This publication contain papers presented at a symposium on radon and radon progeny measurements in Australia, held in Canberra on 18 February 1994. The emphasis was on results of measurements in different exposure situations, however information on methodology and techniques was also included. The scope of the symposium expanded through participation by scientists from China, French Polynesia and New Zealand. A list of participants and their organizations is included at the end of the proceedings. refs., tabs., figs

  8. Assessment of dose due to exposure to indoor radon and thoron progeny

    Directory of Open Access Journals (Sweden)

    Prasad Ganesh

    2010-01-01

    Full Text Available The components of the effective dose through inhalation from radon and its progeny are important for human health since they contribute to more than 50% of the total radiation dose from natural sources. As a consequence, radon has been identified as the second leading cause of lung cancer after smoking. Radon and its short lived decay products (218Po, 214Pb, 214Bi, 214Po present in dwellings are a radiation hazard, particularly if such sources are concentrated in the enclosed areas like poorly ventilated houses and underground mines. The indoor radon, thoron, and progeny concentrations were measured in a small hilly town of Budhakedar and the surrounding area of Tehri Garhwal, India, by using LR-115 Type II plastic track detector in a twin cup radon dosimeter. The concentrations of radon progeny were measured as the highest in winter and the lowest in summer while the thoron progeny concentration was found maximum in rainy season and minimum in autumn. The annual exposure to the potential alpha energy of radon and thoron were found to vary from 0.04 WLM to 0.69 WLM with an average value of 0.29 WLM, and 0.03 WLM to 0.37 WLM with an aver- age value of 0.16 WLM, respectively. The annual effective dose due to the exposure to indoor radon and progeny in Budhakedar homes was found to vary from 0.16 mSv to 2.72 mSv with an average value of 1.14 mSv and the effective dose due to the exposure to thoron and progeny was found to vary from 0.18 mSv to 2.49 mSv with an average value of 1.05 mSv. The results of systematic study have been obtained by considering the room as a space in which the radon and thoron levels are directly related to the dynamic and static parameters.

  9. Study of radon progeny distribution and radiation dose rate in the atmosphere

    International Nuclear Information System (INIS)

    Fujinami, Naoto

    2009-01-01

    The absorbed dose rate in air of airborne gamma-ray and the concentration of radon progeny in surface air have been observed continuously in Maizuru, Japan. When data observed on fine days were plotted, with dose rate as ordinate and contraction as abscissa, these points traced with a lapse of time illustrated an anticlockwise looping for each day. This result suggests that the variation of absorbed dose rate lags behind that of concentration of radon progeny; this is due to the delay time incurred as the concentration level gradually varies from ground surface to upper air. Radon progeny concentrations in precipitation and in surface air have been observed there in order to study the relationship between the two concentrations and the influence of precipitation patterns on the concentration in precipitation. Results obtained from analysis of the observed data suggest that radon progeny in precipitation originate mainly from scavenging within the cloud (rainout) and not from that below the cloud (washout). (author)

  10. Effect of ventilation rate on concentrations of indoor radon and its progenies

    International Nuclear Information System (INIS)

    Wang Chunhong; Liu Yanyang; Liu Fudong; Liu Senlin; Chen Ling

    2012-01-01

    To study concentrations of indoor radon and its progenies, ventilation rates and their corresponding concentrations of indoor radon and its progenies were measured using tracer-gas dilution method. Results show that both ventilation rates and concentrations of indoor radon varied insignificantly and radon concentration were higher than the outdoor environment while doors and windows were all closed with air-conditioner on and off respectively; the concentrations declined and close to the outdoor level when doors and windows were all open with ventilators in operation. Accordingly, in modern life, especially in summer, people's preference for air-conditioners but natural ventilation would result in an increase of indoor radon concentration. (authors)

  11. External gamma exposure to radon progeny in indoor air

    International Nuclear Information System (INIS)

    Fujimoto, Kenzo

    1985-01-01

    The external γ-exposure from radon progeny uniformly distributed in indoor air was estimated by a computer program that was developed. This program can calculate the fluence rate, exposure rate and average energy for any given point in a room of any given size. As numerical example, the exposure rate normalized to unit airborne activity is presented, together with the fluence-weighted and exposure-weighted average photon energies, for a room of representative geometry containing radon progeny in equilibrium. To cover other conditions encountered in practice, quantitative evaluations are additionally presented of the effect on the exposure brought by changes in certain parameters, such as equilibrium factor, wall thickness, room size and receptor position. The study has quantitatively substantiated the prevailing postulate that the effective dose equivalent due to external exposure resulting from normal indoor concentrations of airborne radon progeny in the room of representative geometry should only amount to 0.04 % of that from the internal exposure from the same sources, and that it should be of similarly negligible order compared with internal exposure also in the case of other room geometries. (author)

  12. Temporal and vertical variations radon and its progeny related to atmospheric electrical conductivity

    International Nuclear Information System (INIS)

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

    2015-01-01

    Atmospheric radon, its progeny, electrical conductivity and meteorological parameters such as wind, temperature, humidity, pressure and rainfall were continuously monitored during 2012 to 2014 at one location in Mysuru city. The annual mean atmospheric radon concentration at the study location was found to be 16.4 Bqm -3 . The diurnal cycle of radon and its progeny show a peak in the early morning hours followed by a drastic decrease after sunrise and rising to a second peak in the afternoon. It was found that the stability of the atmosphere and ambient temperature played a major role in the diurnal variations. Higher concentrations of radon and its progeny were observed in winter and lower values in summer. This may due to the variations in origin of air mass and meteorological parameters. Wind direction analyses reveal that in sectors with air which has spent a longer period over the granitic region and low wind speeds will lead to higher concentrations of radon. Atmospheric electrical conductivity near the ground is mainly due to the ionization from radon and its progeny. The diurnal variations of conductivity and ionization rate due to radon and its individual progeny were of similar trend. In addition its significant dependence on meteorological parameters is confirmed. The vertical variations of atmospheric electrical conductivity were studied at different heights up to 250 m from the ground level. Higher values were observed close to the ground surface, there was a rapid reduction up to about 10 m and beyond that the conductivity gradually decreases. The diurnal conductivity cycle is studied at 10 m and 100 m showed the expected similar trend at both the heights but early morning maxima were considerably different, this confirms the accumulation of radon gas close to the ground surface during night time leading to increase of conductivity values. (author)

  13. Experimental determination of the absorption rate of unattached radon progeny from respiratory tract to blood

    International Nuclear Information System (INIS)

    Butterweck, G.; Schuler, Ch.; Vessl, G.; Mueller, R.; Marsh, J.W.; Thrift, S.; Birchall, A.

    2002-01-01

    An exposure methodology was developed for the determination of the absorption rate of unattached radon progeny deposited in the human respiratory tract to blood. Twenty-one volunteers were exposed in a radon chamber during well-controlled aerosol and radon progeny conditions, with predominantly unattached radon daughters. Special efforts were made to restrict the dose to the volunteers to an absolute maximum of 0.08 mSv. Measurements of radon gas and radon progeny in blood samples of these volunteers indicated absorption half times of 20 min to 60 min. Former determinations, mainly performed with much larger aerosol particles of diameters between 100 nm and 1000 nm, implied absorption half times around 10 h. This indicates that the absorption of radon decay products from ciliated airways into blood is dependent upon particle size and particle composition. (author)

  14. Local deposition patterns of inhaled radon progeny in human bronchial airways

    International Nuclear Information System (INIS)

    Heistracher, T.; Hofmann, W.; Balashazy, I.

    1996-01-01

    The local distribution of radon decay products deposited within bronchial bifurcations, particularly the formation of hot spots, may be more relevant for the determination of cellular doses in bronchial tissue than the commonly computed deposition efficiency, which is conceptually equivalent to the assumption of a uniform nuclide distribution. It is well known that the initial states of lung cancer in humans preferably occur in upper airways close to the cardinal location. In this study we use a recently developed geometric approach of a physiologically realistic bifurcation to demonstrate the site sensitivity of radon progeny deposition for two particle sizes, which are representative of the unattached and attached fraction of radon progeny

  15. 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

  16. 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)

  17. Measurements of radon progeny activity on typical indoor surfaces

    International Nuclear Information System (INIS)

    Knutson, E.O.; Gogolak, C.V.; Klemic, G.

    1992-01-01

    A number of studies aimed at defining how well radon progeny on surfaces can be measured, information that is needed in order to test physical/mathematical models governing indoor radon progeny behaviour, are described. One experiment compared the decomposition on to different surfaces. Only relatively small differences were found among metal, filter paper, broadcloth, corduroy fabric, vinyl wallpaper, glass, and latex paint, but polyethylene film collected two to four times as much as the others, due most likely to electrostatic charge on the plastic surface. Another experiment compared the gamma and gross alpha count methods of measuring surface activity for metal, filter paper, broadcloth and corduroy surfaces. No difference for the surfaces tested was found from which it is concluded that, even for rougher surfaces, progeny atoms deposit mainly on the outer layers. A final experiment compared in situ and surrogate-surface methods for measuring surface deposition. For most tests, the two methods agreed within 30%, and the average ratio was not significantly different from unity. 210 Po is a complication in the in situ method. An unexpected location effect was found in the experiments conducted in houses with high radon concentrations: the deposition on the ceiling was higher than on the surfaces. (author)

  18. Indoor radon progeny aerosol size measurements in urban, suburban, and rural regions

    International Nuclear Information System (INIS)

    Tu, K.W.; Knutson, E.O.; George, A.C.

    1991-01-01

    By using direct and indirect methods, the authors conducted size distribution measurements of radon progeny particles in a variety of indoor environments in urban, suburban, and rural areas. The radon progeny particle size distribution owing to indoor activities has two definable source categories: (1) gas combustion from stoves and kerosene heaters - particles were found to be smaller than 0.1 μm in diameter, mostly in the range 0.02-0.08 μm; and (2) cigarette smoking and food frying - particles were found to be larger, in the size range 0.1-0.2 μm. The radon progeny particle size distribution, without significant indoor activities, such as cooking, was found to be larger in rural areas than in urban or suburban areas. The modal diameters of the size spectra in the rural areas were two to three times larger than those in urban or suburban areas, around 0.3-0.4 bs. 0.1-0.2 μm. Results obtained by applying the attachment theory to the measured number-weighted size spectra from an electrical aerosol size analyzer support this finding. These results, if confirmed by more extensive studies, will be useful for the assessment of the risk from the inhalation of radon progeny in various indoor environments

  19. Portable monitors for measuring radon and its progenies air by intergrated sampling method

    International Nuclear Information System (INIS)

    Zhang Huaiqin; Su Jingling; Yao Wanyuan; Liu Jinhua

    1989-01-01

    Two kinds of portable monitors have been developed, which can be used to measure the concentration of radon or potential energy concentration of radon or potential energy concentration of radon progenies in air. The thermoluminescent material CaSO 4 (Tm) is used as a detecting element for both of them. The lowest detectable limit of the passive radon monitor is about 1.5 Bq/m 3 for radon in air, as the exposure time being one week. Its main advantages are high reliability and convenient manipulation. The working level monitor for radon progenies in air consists of a mini membrane pump and an integrating probe. The lowest detectable limit is about 6.2 x 10 -9 J/m 3 , as the sampling time being 6 hours. It weights only about 0.35 kg

  20. Effect of ventilation on concentrations of indoor radon- and thoron-progeny: Experimental verification of a simple model

    International Nuclear Information System (INIS)

    Sheets, R.W.; Thompson, C.C.

    1993-01-01

    Different models relating the dependence of radon ( 222 Rn)- and thoron ( 220 Rn)-progeny activities on room ventilation rates are presented in the literature. Some of these models predict that, as the rate of ventilation increases, activities of thoron progeny decrease more rapidly than those of radon progeny. Other models predict the opposite trend. In this study alpha activities of the radon progeny, 218 Po, 214 Pb, and 214 Bi, together with the thoron progeny 212 Pb, were measured over periods of several days in two rooms of a closed, heated house. Effective ventilation rates were calculated from measured 214 Pb/ 214 Bi ratios. A simple model in which progeny concentrations decrease by radioactive decay and by dilution with outside air has been used to calculate 212 Pb/ 214 Pb ratios as a function of ventilation rate. Calculated ratios are found to correlate significantly with experimentally-determined ratios (R 2 ∼ 0.5--0.8 at p < 0.005) confirming that, for this house, thoron progeny activities decrease faster than radon progeny activities with increasing rates of ventilation

  1. Indoor radon and its progeny levels in new type houses in rural area of Hubei

    International Nuclear Information System (INIS)

    He Quan; Xiong Zhaoxing; He Zuan; Zheng Youqing

    1993-01-01

    Using Cluster Sampling method, indoor radon of 54 rooms and radon progeny potential alpha-energy concentrations of 200 rooms were measured in the new type brick-concrete 2-storey flats and old type brick-wood single-storey residences in the rural area. Instant and cumulative samplings and measurements were made. The average per capita residential area of the surveyed houses was 28.1 m 2 , clear height 3.6 m. The geometric means of indoor radon concentration were 18.22 Bq.m -3 and 15.93 Bq.m -3 for storied and single-storey buildings, respectively; radon progeny potential alpha-energy concentrations were 2.62 mWL and 2.54 mWL, correspondingly. In storied buildings, the arithmetic mean of indoor cumulative radon concentration was 25.56 Bq.m -3 in summer, and 37.94 Bq.m -3 in winter. The annual effective dose equivalent of radon progeny inhaled indoors and outdoors was 0.80 mSv. (orig.). (6 refs., 1 fig., 5 tabs.)

  2. Radon and radon progeny in 70 houses in the Tennessee Valley area: study design and measurement methods

    International Nuclear Information System (INIS)

    Dudney, C.S.; Hawthorne, A.R.; Monar, K.P.; Quillen, J.L.; Clark, C. Jr.; Doane, R.W.; Wallace, R.G.; Reed, R.P.

    1986-01-01

    Levels of radon and its short-lived airborne progeny are being measured in a year-long study of 70 houses in four states in the Tennessee Valley. Various methods were used to solicit volunteers with differing degrees of success. Criteria for selection of houses in the study included presence of a lower level with cement floor and one or more block walls in contact with the soil, absence of obvious indications of technologically enhanced sources of radium, and proximity to one of four cities, (Knoxville, Chattanooga, Birmingham, or Florence). By design, most houses in the study are in the same neighborhood as at least one other house in the study. Houses range in age from newly constructed to about 40 years old. Most of the houses have more than 2000 square feet of finished floor space. The lower level encompasses a garage in most cases. More complete information pertaining to house characteristics will be gathered in the course of the study. Measurements are being made to obtain information on both location- and season-dependent variation of radon and radon progeny. Simultaneous measurements are made quarterly on both upper and lower levels of each house. Grab samples of air are collected and analyzed for radon using a modified Lucas cell technique. Short-term (10-minute) samples of airborne particulate material are collected and analyzed for radon progeny. One-week integrated measurements of working levels are made once each quarter using modified thermoluminescent dosimeters. Both three- and twelve-month integrated measurements of radon using track-etch monitors are being made. 19 references, 1 figures

  3. Wire screens as a tool for survey measurements of the unattached radon progeny in mines

    International Nuclear Information System (INIS)

    Janica, R.

    1996-07-01

    The radon hazard in mines is assessed by measuring the radioactivity accumulated on filters through which air is forced to flow. The filter collects both forms of the short-lived radon progeny, attached and unattached, and, therefore, the assessment is based on the measurement of the total radon progeny. Because of the special radiological significance of the unattached fraction of the short-lived radon progeny, the estimation of the radiation hazard to miners would be improved if the unattached fraction could be measured. This report describes two methods of measurement for the simultaneous determination of the unattached and the total radon progeny. The proposed methods comply with the criterion of practicality (imposed by the working conditions in the mine environment), that is, they are implemented using standard survey equipment and simple procedures. Both methods use wire screens to collect, preferentially, the unattached fraction. According to the first method, air is sampled through a wire screen and a backup filter, and the radioactivity accumulated on both the filter and the wire screen are measured separately using standard counting protocols (e.g. the Kusnetz protocol). The wire screen's efficiency for collecting the unattached radon progeny is determined, in advance, under laboratory conditions. The method assumes the validity of the collection efficiencies when the screens are used under field conditions. To avoid the uncertainty of the lab-determined collection efficiency, a new measuring method was proposed based on the sampling of air through two screens in series and a backup filter. The measurement of the ratio of the activities deposited on both screens allows an estimation of the screen collection efficiency under field conditions. Once this is done, the 'unattached fraction' and total radon progeny are determined by counting only one of the screens and the backup filter as described in the previous method. (author). 73 refs., 8 tabs., 21 figs

  4. Diurnal variations of indoor radon progeny for Bangalore metropolitan, India

    International Nuclear Information System (INIS)

    Nagesh, V.; Sathish, L.A.; Nagaraja, K.; Sundareshan, S.

    2010-01-01

    Radon progenies are identified as major causes of the lung cancer if the activity is above its normal. It has not been clear whether radon poses a similar risk of causing lung cancer in humans exposed at generally lower levels found in homes, but a number of indoor radon survey have been carried out in recent years around the world. In view of this an attempt has been made for the measurement of diurnal variation of indoor radon levels for the environment of Bangalore metropolitan, India. The Radon progeny concentrations in terms of working level were measured using Kusnetz's method. The patterns of daily and annual changes in indoor Radon concentration have been observed in a general way for many years. However, understanding of the physical basis for these changes had to await the development of continuous monitors and a more complete knowledge of transport processes in the atmosphere. Over a continent, heating of the ground surface by the Sun during the day and cooling by radiation during the night causes a marked diurnal change in temperature near the surface. As a result cool air near the ground will accumulate radon isotopes from surface flux during the night; while during the day the warm air will be transported upward carrying radon with it. Many buildings show diurnal radon variations. Concentrations are relatively higher during night than daytime. This is influenced by the outdoor-indoor temperature contrast. This effect can be enhanced in buildings with strong diurnal use patterns. Buildings that have high average radon concentrations, but are only occupied for part of the day, may need to be measured during occupied periods to determine if there is significant diurnal radon variation. The results are discussed in detail. (author)

  5. Measurement of radon, thoron and their progeny concentrations in the dwellings of Pauri Garhwal, Uttarakhand, India

    International Nuclear Information System (INIS)

    Joshi, Veena; Bijalwan, Pramesh; Rawat, Jasbir; Yadav, Manjulata; Ramola, R.C.; Mishra, Rosaline

    2015-01-01

    It is well known that inhalation of radon, thoron and their progeny contribute more than 50% of natural background radiation dose to human being. The time integrated passive measurements of radon, thoron and their progeny concentrations were carried out in the dwellings of Pauri Garhwal, Uttarakhand, India. The measurements of radon and thoron concentrations were performed by LR-115 detector based single entry Pin-Hole dosimeter while for the measurement of progeny concentrations, LR-115 deposition based DTPS/DRPS technique was used. The experimental techniques and results obtained are discussed in detail. (author)

  6. Assessment of nanoparticle surface area by measuring unattached fraction of radon progeny

    Energy Technology Data Exchange (ETDEWEB)

    Ruzer, Lev S. [Ernest Orlando Lawrence Berkeley National Laboratory, Indoor Environment Department (United States)], E-mail: LSRuzer@lbl.gov

    2008-05-15

    A number of studies on the exposure of nanometer aerosols have indicated that health effects associated with low-solubility inhaled particles in the range of 1-100 nm may be more appropriately associated with particulate surface area than mass concentration. Such data on correlation between number, surface area and mass concentration are needed for exposure investigations, but the means for measuring aerosol surface area are not readily available. In this paper we propose a method for particle surface area assessment based on a new approach, deposition of the 'unattached fraction of radon progeny' onto nanometer aerosols.The proposed approach represents a synthesis of:(1) Derived direct analytical correlation between the 'unattached fraction' of radon progeny and surface area particle concentration in the range of 1-100 nm particle diameter;(2) Experimental data on correlation between the unattached fraction of radon progeny and particle surface area for particles with diameter in the range of 44 nm-2.1 {mu}m.

  7. Study on calculation models and distribution rules of the radon concentration and its progenies concentration in blind roadway with forced-exhaust ventilation

    International Nuclear Information System (INIS)

    Ye Yongjun; Wang Liheng; Zhou Xinghuo; Li Xiangyang; Zhong Yongming; Wang Shuyun; Ding Dexin

    2014-01-01

    The forced-exhaust ventilation is an important way to control the concentration of radon and its progenies in long-distance blind driving roadway. It is of great significance for guiding the design of ventilation and radiation protection to study distribution characteristics of the concentration of radon and its progenies in the wind of roadway adopting the forced-exhaust ventilation. Therefore, according to the decay relationship of radon and its progenies, a simplified mathematical calculation model was built, which relates to the radon activity concentration and the potential alpha concentration of radon progenies. The paper also analyzed the sources of radon and its progenies in the limited space of the blind roadway. Then, based on the turbulence mass transfer theory of ventilation air flow, the paper established mathematical calculation models of distribution characteristics of the radon activity concentration and the potential alpha concentration of radon progenies in blind roadway with forced-exhaust ventilation, respectively. Finally, the paper applied the calculation models to a special blind roadway, and discussed the influence of the ventilation air inflow and the radon exhalation rate of rock wall on the distribution of radon concentration and the potential alpha concentration of radon progenies in the roadway. Meanwhile, some protective measurements were put forward to reduce the radiation dose of worker caused by radon and its progenies in the blind roadway. (authors)

  8. Dose-dependent in vivo cell-cycle changes following radon progeny exposure

    International Nuclear Information System (INIS)

    Johnson, N.F.; Carpenter, T.R.; Hickman, A.W.; Jaramillo, R.J.; Gurule, D.M.

    1994-01-01

    Exposures to low concentrations of alpha-emitting radon progeny are reported by the U.S. Environmental Protection Agency to be the second leading cause of lung cancer. Current risk estimates for lung cancer from the inhalation of radon progeny are based on data from underground uranium miners. To produce such risk estimates, calculations are based on several assumptions concerning exposure-response relationships rather than dose-response relationships. A better understanding of the mechanisms of interactions between alpha particles, the cells of the respiratory tract, and the progression toward cancer may validate the mathematical models used to derive risk estimates

  9. Intercomparison and intercalibration of passive/active radon and active radon progeny instruments and methods in North America

    International Nuclear Information System (INIS)

    George, A.C.; Tu, Keng W.

    1993-06-01

    An intercomparison and intercalibration exercise for radon and radon progeny measurements made with active and passive instruments was held at EML from October 22--30,1992. Twenty-five participants submitted 96 passive integrating devices, eight active devices for radon, and seven integrating devices for potential alpha energy concentration (PAEC). In addition, 40 grab samples for radon progeny analysis were taken by five groups that participated in person during the intercomparison. The results reported to EML indicate that the majority of the participants (70%) obtained mean results within 10% of the EML reference value. Although the instruments used in this exercise are based on different principles of collection and detection, they all appear reliable. However, in some instances there seemed to be some minor problems with quality control and calibration bias. Also, the large counting errors for the PAEC experienced by some of the participants can be minimized by using higher sampling air flow rates without sacrificing instrument portability

  10. Radon and thoron progeny levels in air samples at Udagamandalam region of Nilgiris in India

    International Nuclear Information System (INIS)

    Manikandan, N.M.; Selvasekarapandian, S.; Sivakumar, R.; Raghunath, V.M.; Sundaram, V.M.; Santhanam, S.

    2002-01-01

    Measurement of concentration of radon and thoron daughter products in various indoor environment covering four seasons of a year in Udagamandalam Taluk of Nilgiris biosphere has been carried out using a high volume air sampler to assess the inhalation dose to the population which delivers higher dose than the radon and thoron gas alone. The potential alpha-energy concentrations of the radon and thoron progeny ranged from 0.97 to 12.72 mWL and from 1.63 to 15.83 mWL with a geometric mean of 6.02 and 7.89 mWL, respectively, taking all seasons into account. These measurements have yielded a wealth of data on the variation among the indoor radon and thoron progeny in various places during different seasons. The radon and thoron progeny levels are higher in winter seasons and are less in summer season with autumn and spring data lie in between winter and summer. Using the dose conversion factor for indoor exposures given in UNSCEAR 93 report the internal equivalent dose to the inhalation of radon progeny is evaluated to be 1357 μSv x y -1 and the corresponding annual effective dose equivalent value has been found to be 2.13 mSv x y -1 . It can be observed that the mean value of radon is higher than the Indian average. Also it is found the radon and thoron progeny levels are higher in the case of houses built with rock and granite and in tiled type houses of nearly 100 years old. The levels are less in the case of houses built with brick and cement. The observed results for different types of houses and seasons are discussed in this paper. (author)

  11. Characteristics of radon and its progeny concentrations in air-conditioned office buildings in Tokyo

    International Nuclear Information System (INIS)

    Tokonami, S.; Furukawa, M.; Shicchi, Y.; Sanada, T.; Yamada, Y.

    2003-01-01

    A series of measurements were carried out to understand the characteristics of radon and its progeny in air-conditioned office buildings. Long-term measurements of radon were made with etched track detectors. Continuous measurements of radon and its progeny concentrations were also conducted in some buildings to study their temporal variations. The results show that radon and its progeny concentrations routinely varied along with working activities. They are generally low while people are working, due to air conditioning, whereas they rise steadily after the air conditioning stops. When considering action levels not only in homes but also workplaces, attention should be paid to annual doses from the viewpoint of radiation protection. The annual dose is generally estimated with a long-term measurement of radon concentration using a passive device such as an etched track detector. Since its reading corresponds to a long-term average concentration regardless of working hours, the annual dose will be overestimated. When comparing a real dose after considering the working hours, they differ by a factor of more than 2. (author)

  12. A radon progeny sampler for the determination of effective dose

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, S.B. [Australian Radiation Laboratory, Victoria (Australia)

    1997-12-01

    The design and simulated performance is described of a two-stage sampler (HE-Sampler) for {sup 222}Rn progeny. This HE-Sampler has a collection efficiency optimised to match the particle size dependency of the radon progeny dose conversion factor (DCF), derived from the latest Respiratory Tract Model of the International Commission on Radiological Protection, as implemented in the computer code RADEP. The He-Sampler comprises a wire screen pre-separator, matched to the nasal deposition, and a wire screen collector, matched to the respiratory tract collection. This HE-Sampler allows for the estimation of the radiation dose from the inhalation of {sup 222}Rn progeny, derived from two concurrent alpha particle activity measurements, one on the HE-Sampler screen collector and one on a reference filter sample. As a first approximation, the DCF is proportional to the collected fraction. The HE-Sampler response was simulated for a range of radon progeny size distributions to determine the error in the estimated DCF values. The simulation results show that the HE-Sampler is relatively insensitive to variations in sampling rate and in the screen parameters, particularly for environmental exposure. (Author).

  13. Measurement of unattached radon progeny based in electrostatic deposition method

    International Nuclear Information System (INIS)

    Canoba, A.C.; Lopez, F.O.

    1999-01-01

    A method for the measurement of unattached radon progeny based on its electrostatic deposition onto wire screens, using only one pump, has been implemented and calibrated. The importance of being able of making use of this method is related with the special radiological significance that has the unattached fraction of the short-lived radon progeny. Because of this, the assessment of exposure could be directly related to dose with far greater accuracy than before. The advantages of this method are its simplicity, even with the tools needed for the sample collection, as well as the measurement instruments used. Also, the suitability of this method is enhanced by the fact that it can effectively be used with a simple measuring procedure such as the Kusnetz method. (author)

  14. Internal microdosimetry of inhaled radon progeny in bronchial airways: advantages and limitations

    International Nuclear Information System (INIS)

    Hofmann, Werner; Fakir, Hatim; Pihet, Pascal

    2007-01-01

    The objective of the present study was to identify advantages and limitations of the application of microdosimetric concepts for inhaled radon progeny activities in the lungs. The methods employed for this analysis were a recently developed Monte- Carlo microdosimetry code for the calculation of energy deposition in bronchial target cells and the Probability Per Unit Track Length (PPUTL) model, which relates these microdosimetric parameters to cellular radiation effects. The major advantages of internal microdosimetry of radon progeny in bronchial airways are: (i) quantitative characterisation of non-uniform dose distributions and identification of target sites with enhanced carcinogenic potential, (ii) quantification of low doses of alpha particles by the number of cells hit and the dose received by those cells, (iii) illustration of the random variations of cellular doses by specific energy distributions and (iv) establishment of a direct link to cellular radiobiological effects. At present, a major limitation of microdosimetry is the extrapolation of the response of individual cells to the resulting tissue response, which is still not fully explored. (authors)

  15. STUDY OF RADIATION EXPOSURE DUE TO RADON, THORON AND THEIR PROGENY IN THE INDOOR ENVIRONMENT OF RAJPUR REGION OF UTTARAKHAND HIMALAYA.

    Science.gov (United States)

    Kandari, Tushar; Aswal, Sunita; Prasad, Mukesh; Pant, Preeti; Bourai, A A; Ramola, R C

    2016-10-01

    In the present study, the measurements of indoor radon, thoron and their progeny concentrations have been carried out in the Rajpur region of Uttarakhand, Himalaya, India by using LR-115 solid-state nuclear track detector-based time-integrated techniques. The gas concentrations have been measured by single-entry pin-hole dosemeter technique, while for the progeny concentrations, deposition-based Direct Thoron and Radon Progeny Sensor technique has been used. The radiation doses due to the inhalation of radon, thoron and progeny have also been determined by using obtained concentrations of radon, thoron and their progeny in the study area. The average radon concentration varies from 75 to 123 Bq m -3 with an overall average of 89 Bq m -3 The average thoron concentration varies from 29 to 55 Bq m -3 with an overall average of 38 Bq m -3 The total annual effective dose received due to radon, thoron and their progeny varies from 2.4 to 4.1 mSv y -1 with an average of 2.9 mSv y -1 While the average equilibrium factor for radon and its progeny was found to be 0.39, for thoron and its progeny, it was 0.06. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Assessment of radiological effect of the indoor radon and its progeny

    International Nuclear Information System (INIS)

    Ramachandran, T.V.; Subbaramu, M.C.; Mishra, U.C.

    1988-01-01

    Of all the sources of environmental radiation, radon and its progeny are considered to be responsible for a significant dose to man, especially when they are in enclosed areas like underground mines, caves, cellars, poorly designed and badly ventilated houses. Linear extrapolation from the dose response value of the uranium miners exposed to higher levels of radon and its daughters also suggest that the majority of the lung cancer incidence could be due to radon. Higher indoor radon levels and shift in the disequilibrium of the progeny concentration in dwellings caused by the lower ventilation rate leads to severalfold increase of lung cancer incidence from radon. The large risk which is anticipated calls for further studies in this field and may also lead to the conclusion that the slight, but much feared, burden due to man-made radioactivity could be more than compensated by controlling critical segments of the environmental radioactivity. In this report the study of risk due to breathing of indoor radon is briefly reviewed. Dose equivalent to the exposed tissue of the respiratory tract of the people living in dwellings are evaluated. Like most of the risk assessment of low level radiation, the effort to quantify the effect of radon in terms of death rate dose due to lung cancer attributable to radon levels indoors, has to rely on the extrapolation from the effects of the higher exposure rate. In situations where soil or building materials contain elevated radium levels, living in energy efficient houses may be as dangerous as heavy smoking. (author). 8 tabs., 5 figs., 41 refs

  17. The use of track registration detectors to reconstruct contemporary and historical airborne radon ( sup 2 sup 2 sup 2 Rn) and radon progeny concentrations for a radon-lung cancer epidemiologic study

    CERN Document Server

    Steck, D J

    1999-01-01

    Epidemiologic studies that investigate the relationship between radon and lung cancer require accurate estimates for the long-term average concentrations of radon progeny in dwellings. Year-to-year and home-to-home variations of radon in domestic environments pose serious difficulties for reconstructing an individual's long-term radon-related exposure. The use of contemporary radon gas concentrations as a surrogate for radon-related dose introduces additional uncertainty in dose assessment. Studies of glass exposed in radon chambers and in a home show that radon progeny deposited on, and implanted in, glass hold promise for reconstructing past radon concentrations in a variety of atmospheres. We developed an inexpensive track registration detector for the Iowa Radon Lung Cancer Study (IRLCS) that simultaneously measures contemporary airborne radon concentrations, surface deposited alpha activity density, and implanted sup 2 sup 1 sup 0 Po activity density. The implanted activity is used to reconstruct the cum...

  18. Measurement of radon and thoron progeny size distributions and dose assessments at the mineral treatment industry in Thailand

    International Nuclear Information System (INIS)

    Chutima Kranrod; Supitcha Chanyotha; Nares Chankow

    2013-01-01

    A new portable type cascade impactor has been developed to determine the activity size distribution of radon and thoron progeny in a natural environment more efficiently. The modified impactor consists of 4 stages with a back up filter stage for the collection of aerosol samples. The aerosol cut points in the impactor are set for 10, 2.5, 1 and 0.5 μm at a flow rate of 4 L min -1 . Five CR-39 chips were used as alpha detectors for each stage. In order to separate α particles emitted from radon and thoron progeny, CR-39 detectors are covered with aluminum-vaporized Mylar films. The thickness of each film is adjusted to allow α particles emitted from radon and thoron progeny to reach the CR-39 detectors. The technique has been successfully tested in field studies, particularly inside a mineral treatment industry in Thailand to estimate doses in the working environment. The dose calculations by lung dose evaluation program showed that activity median aerodynamic diameters played a significant role in determining the particle size distributions of the attached radon and thoron progeny. The dose conversion factor determined from short term measurements due to exposure from the inhalation of thoron and its progeny was found to be 4 times higher than comparable values for radon and its progeny. The effective dose for workers exposed to radon is about 4-6 times higher than thoron. (author)

  19. Examination of the influence of water-heated central heating systems on the levels of radon and radon progeny in the workplace

    International Nuclear Information System (INIS)

    Marley, F.; Denman, A.R.; Phillips, P.S.

    2000-01-01

    A series of continuous real-time radon and progeny measurements, together with passive etched-track detector measurements returning average values, were undertaken in commercial premises in Northamptonshire. Detailed measurements over several months in two separate buildings show that the level of both radon and progeny are determined to a major extent by the influence of the operation and timing of the central heating systems in place. Both buildings studied are similar in construction to many single-storey domestic properties. The operative heating system reduced the radon and progeny levels relative to the non-operating mode by over 40% during the heating period of a normal working day. The variation in temperature during this time was generally less than 3 deg. C, indicative of a heat retentive building. Because the equilibrium (F) fraction is reduced during the heating period, the reductions in radon and progeny are not uniform. In the workplaces studied, the work-cycle was normally limited to 0900-1700 hours Monday to Friday, the period when the lowest values were recorded. Average daily values would therefore overstate by more than 50% the maximum potential dose during normal attendance hours. The corollary is that living under similar circumstances in domestic environments, the operation and timing of this type of heating regime may well result in higher exposure in the home than at work

  20. Determination of radon and progeny concentrations in Brazilian underground mines

    International Nuclear Information System (INIS)

    Fraenkel, Mario O.; Gouvea, Vandir de Azevedo; Macacini, Jose F.; Cardozo, Katia; Carvalho Filho, Carlos A. de; Lima, Carlos E.

    2008-01-01

    The aim of this work is to present the activities related to the determination of radon and progeny concentrations in underground mines in Brazil. Radon is originated from decay of radium-226 and radium-228 present in rocks. Radon and its short-lived progeny can be retained in the workers pulmonary alveoli, and this way they bring about cancer risk to these mining professionals. The occurrence of high radon concentrations in underground coal and copper mines and the lack of systematic survey motivated CNEN, the regulatory agency, to develop the Radon Project, aiming to aid the formulation of a specific regulation with occupational dose limits consistent with international standards recommended by the International Atomic Energy Agency (IAEA). Dozens of underground mines are currently in operation in the national. It had to be noted that about 50% of these mines are located in Minas Gerais province, and for this reason it was chosen to start the Project. In each underground mine it is installed in selected points passive nuclear track etch radon detectors, type LEXAN and Cr-39, for periods from three to five months. It was also made local measurements with Dose Man Pro detectors from SARAD. The points are chosen according to geological features, radiometric activity and characteristics of prospect development. The determination of radon present in mines has been made in IEN (Nuclear Engineering Institute)/Rio de Janeiro-RJ, LAPOC (Pocos de Caldas Laboratory)/Pocos de Caldas-MG e ESPOA (Porto Alegre Office)/Porto Alegre-RS. Until now it was visited about 35 mines in a universe of about 50 mines, from which 20% showed concentration values higher than international limits (ICRP 65), between 500 and 1500 Bq.m -3 . (author)

  1. Lung Deposition And Biological Effects Of Inhaled Radon Progenies

    International Nuclear Information System (INIS)

    Balashazy, I.; Farkas, A.; Szoke, I.; Moustafa, M.; Kudela, G.

    2010-01-01

    Inhaled radon progenies provide more than the half of natural radiation exposure. There is increasing evidence that the cellular distribution of radiation burden is an important factor regarding the biological response to ionisation radiation, thus, one of our tasks was the characterisation of the distribution of cellular exposure. Histological studies of former uranium miners presented strong correlation between primer deposition hot spots and neoplastic lesions. Most of these lesions were located along the carinal regions of the large bronchial airways. In the present work, computational fluid dynamics (CFD) approaches have been applied to simulate the deposition distribution of inhaled radon progenies along central human airways. The geometry and the cellular structure of epithelial lung tissue were numerically reconstructed based on anatomical and histological data. Single and multiple ha-hit and cellular dose distributions have been computed applying Monte Carlo modelling techniques at different breathing conditions. Figure 1. Deposition enhancement factor (EF) of inhaled radon progenies on a central airway bifurcation in airway generations 4-5 during light physical activity breathing condition. Size of scanning surface element is a 45μm side triangle. Left panel: EF max=1400,Dp=200 nm (attached). Right panel: EF max1290, Dp= 1 nm (unattached). Values of local per average deposition densities, that is, enhancement factors (Figure 1), hit probabilities and doses may be up to two-three orders of magnitude higher in the deposition hot spots than the average values. Dose calculations revealed that some cell clusters may receive high doses even at low exposure conditions. Applying the model to different radiation exposure conditions useful relations can be received regarding the linear-non threshold hypothesis

  2. Study on the influence of CR-39 detector size on radon progeny detection in indoor environments

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, L. A.; Hadler, J. C.; Lixandrão F, A. L.; Guedes, S.; Takizawa, R. H. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, UNICAMP, 13083-970 Campinas, SP (Brazil)

    2014-11-11

    It is well known that radon daughters up to {sup 214}Po are the real contaminants to be considered in case of indoor radon contamination. Assemblies consisting of 6 circular bare sheets of CR-39, a nuclear track detector, with radius varying from 0.15 to 1.2 cm were exposed far from any material surface for periods of approximately 6 months in 13 different indoor rooms (7 workplaces and 6 dwellings), where ventilation was moderate or poor. It was observed that track density was as greater as smaller was the detector radius. Track density data were fitted using an equation deduced based on the assumption that the behavior of radon and its progeny in the air was described by Fick's Law, i.e., when the main mechanism of transport of radon progeny in the air is diffusion. As many people spend great part of their time in closed or poorly ventilated environments, the confirmation they present equilibrium between radon and its progeny is an interesting start for dosimetric calculations concerning this contamination.

  3. Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Hopke, P.K.

    1992-07-01

    This report covers the second year of the 28 month grant current grant to Clarkson University to study the chemical and physical behavior of the polonium 218 atom immediately following its formation by the alpha decay of radon. Because small changes in size for activity result in large changes in the delivered dose per unit exposure, this behavior must be understood if the exposure to radon progeny and it dose to the cells in the respiratory tract are to be fully assessed. Two areas of radon progeny behavior are being pursued; laboratory studies under controlled conditions to better understand the fundamental physical and chemical process that affect the progeny's atmospheric behavior and studies in actual indoor environments to develop a better assessment of the exposure of the occupants of that space to the size and concentration of the indoor radioactive aerosol. This report describes the progress toward achieving these objectives.

  4. Lung dosimetry for inhaled radon progeny in smokers

    International Nuclear Information System (INIS)

    Baias, P. F.; Hofmann, W.; Winkler-Heil, R.; Cosma, C.; Duliu, O. G.

    2010-01-01

    Cigarette smoking may change the morphological and physiological parameters of the lung. Thus the primary objective of the present study was to investigate to what extent these smoke-induced changes can modify deposition, clearance and resulting doses of inhaled radon progeny relative to healthy non-smokers (NSs). Doses to sensitive bronchial target cells were computed for four categories of smokers: (1) Light, short-term (LST) smokers, (2) light, long-term (LLT) smokers, (3) heavy, short-term (HST) smokers and (4) heavy, long-term (HLT) smokers. Because of only small changes of morphological and physiological parameters, doses for the LST smokers hardly differed from those for NSs. For LLT and HST smokers, even a protective effect could be observed, caused by a thicker mucus layer and increased mucus velocities. Only in the case of HLT smokers were doses higher by about a factor of 2 than those for NSs, caused primarily by impaired mucociliary clearance, higher breathing frequency, reduced lung volume and airway obstructions. These higher doses suggest that the contribution of inhaled radon progeny to the risk of lung cancer in smokers may be higher than currently assumed on the basis of NS doses. (authors)

  5. Characteristics of indoor radon and its progeny in a Japanese dwelling while using air appliances

    International Nuclear Information System (INIS)

    Pornnumpa, C.; Tokonami, S.; Sorimachi, A.; Kranrod, C.

    2015-01-01

    Characteristics of radon and its progeny were investigated in different air conditions by turning four types of indoor air appliances on and off in a two-story concrete Japanese dwelling. The four appliances were air conditioner, air cleaner, gas heater and cooker hood. The measurements were done using two devices: (1) a Si-based semiconductor detector for continuous measurement of indoor radon concentration and (2) a ZnS(Ag) scintillation counting system for equilibrium-equivalent radon concentration. Throughout the entire experiment, the cooker hood was the most effective in decreasing indoor radon concentration over a long period of time and the less effective was the air conditioner, while the air cleaner and gas heater did not affect the concentration of radon. However, the results measured in each air condition will differ according to the lifestyles and activities of the inhabitants. In this study, indoor radon and its progeny in a Japanese dwelling will be characterised by the different air conditions. (authors)

  6. Multi-parametric approach towards the assessment of radon and thoron progeny exposures

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Rosaline, E-mail: rosaline@barc.gov.in, E-mail: rosaline.mishra@gmail.com; Sapra, B. K. [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Mayya, Y. S. [Indian Institute of Technology, Mumbai (India)

    2014-02-15

    Conventionally, the dosimetry is carried out using radon and thoron gas concentration measurements and doses have been assigned using assumed equilibrium factors for the progeny species, which is inadequate pertaining to the variations in equilibrium factors and possibly due to significant thoron. In fact, since the true exposures depend upon the intricate mechanisms of progeny deposition in the lung, therefore an integrated approach for the assessment of progeny is essential. In this context, the recently developed deposition based progeny concentration measurement techniques (DTPS: Direct Thoron progeny sensors and DRPS: Direct Radon progeny sensors) appear to be best suited for radiological risk assessments both among occupational workers and general study populations. DTPS and DRPS consist of aluminized mylar mounted LR115 type passive detectors, which essentially detects the alpha particles emitted from the deposited progeny atoms on the detector surface. It gives direct measure of progeny activity concentrations in air. DTPS has a lower limit of detection limit of 0.1 Bq/m{sup 3} whereas that for DRPS is 1 Bq/m{sup 3}, hence are perfectly suitable for indoor environments. These DTPS and DRPS can be capped with 200-mesh type wire-screen to measure the coarse fraction of the progeny concentration and the corresponding coarse fraction deposition velocities as well as the time integrated fine fraction. DTPS and DRPS can also be lodged in an integrated sampler wherein the wire-mesh and filter-paper are arranged in an array in flow-mode, to measure the fine and coarse fraction concentration separately and simultaneously. The details are further discussed in the paper.

  7. Concentration of Radon Progeny in Air by Alpha Spectrometry Measurement

    International Nuclear Information System (INIS)

    Acena, M. L.; Crespo, M. T.

    1989-01-01

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of 214 Po and 318 Po. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter. (Author) 15 refs

  8. An Alpha spectrometer for measuring radon daughter individual activity concentration; Spettrometro Alfa per la misura delle concentrazioni individuali in attivita' della progenie del radon

    Energy Technology Data Exchange (ETDEWEB)

    Berico, M.; Formignani, M. [ENEA, Div. Protezione dell' Uomo e degli Ecosistemi, Centro Ricerche E. Clementel, Bologna (Italy); Mariotti, F. [Bologna Univ., Bologna (Italy). Dipt. di Fisica

    2001-07-01

    In the frame of the program of the Institute for Radiation Protection of ENEA, related to the evaluation of dose from radon and thoron progeny, an alpha spectrometer for the continuous air monitoring (CAM type) of radon and thoron has been realized. The constructive characteristics of the device are here presented together with energy and efficiency calibration. The device allows, by means of a screen type diffusion battery and a filter, to determinate the single radioactivity of each radionuclide of the progeny selecting them in relation to their diffusive behaviour (dichotomous particle size selection). The three-count filter method has been employed to measure the concentrations of {sup 218}Po, {sup 214}Pb and {sup 214}Bi in air. Radon and thoron effective doses using a dosimetric, instead of an epidemiologic approach, will be then evaluated. [Italian] Presso l'Istituto per la Radioprotezione, nell'ambito del programma di valutazione di dose da radon e' stato progettato e realizzato uno spettrometro alfa per il monitoraggio continuo in aria (CAM) della progenie del radon e del toron. Le caratteristiche costruttive dello strumento permettono, tramite l'utilizzo di batterie a diffusione a reti, di determinare l'attivita' individuale della progenie per diverse dimensioni granulometriche in particolare per la frazione attaccata e non al particolato amosferico con un taglio granulometrico di qualche nanometro. E' stato inoltre applicato un metodo spettrometrico a tre conteggi per il calcolo delle concentrazioni individuali della progenie del radon, {sup 218}Po, {sup 214}Pb and {sup 214}Bi, effettuando un conteggio alfa di {sup 218}Po e due conteggi alfa di {sup 214}Po. Tale informazione consentira' una valutazione della dose di radon utilizzando il modello dosimetrico in alternativa a quello epidemiologico.

  9. Particle size distribution of the radon progeny and ambient aerosols in the Underground Tourist Route "Liczyrzepa" Mine in Kowary Adit

    Science.gov (United States)

    Wołoszczuk, Katarzyna; Skubacz, Krystian

    2018-01-01

    Central Laboratory for Radiological Protection, in cooperation with Central Mining Institute performed measurements of radon concentration in air, potential alpha energy concentration (PAEC), particle size distribution of the radon progeny and ambient aerosols in the Underground Tourist-Educational Route "Liczyrzepa" Mine in Kowary Adit. A research study was developed to investigate the appropriate dose conversion factors for short-lived radon progeny. The particle size distribution of radon progeny was determined using Radon Progeny Particle Size Spectrometer (RPPSS). The device allows to receive the distribution of PAEC in the particle size range from 0.6 nm to 2494 nm, based on their activity measured on 8 stages composed of impaction plates or diffusion screens. The measurements of the ambient airborne particle size distribution were performed in the range from a few nanometres to about 20 micrometres using Aerodynamic Particle Sizer (APS) spectrometer and the Scanning Mobility Particle Sizer Spectrometer (SMPS).

  10. Estimation of radon progeny equilibrium factors and their uncertainty bounds using solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Eappen, K.P.; Mayya, Y.S.; Patnaik, R.L.; Kushwaha, H.S.

    2006-01-01

    For the assessment of inhalation doses due to radon and its progeny to uranium mine workers, it is necessary to have information on the time integrated gas concentrations and equilibrium factors. Passive single cup dosimeters using solid state nuclear track detectors (SSNTD) are best suited for this purpose. These generally contain two SSNTDs, one placed inside the cup to measure only the radon gas concentration and other outside the cup for recording tracks due to both radon gas and the progeny species. However, since one obtains only two numbers by this method whereas information on four quantities is required for an unambiguous estimation of dose, there is a need for developing an optimal methodology for extracting information on the equilibrium factors. Several techniques proposed earlier have essentially been based on deterministic approaches, which do not fully take into account all the possible uncertainties in the environmental parameters. Keeping this in view, a simple 'mean of bounds' methodology is proposed to extract equilibrium factors based on their absolute bounds and the associated uncertainties as obtained from general arguments of radon progeny disequilibrium. This may be considered as reasonable estimates of the equilibrium factors in the absence of a knowledge of fluctuation in the environmental variables. The results are compared with those from direct measurements both in the laboratory and in real field situations. In view of the good agreement found between these, it is proposed that the simple mean of bounds estimate may be useful for practical applications in inhalation dosimetry of mine workers

  11. Prediction of lung cells oncogenic transformation for induced radon progeny alpha particles using sugarscape cellular automata.

    Science.gov (United States)

    Baradaran, Samaneh; Maleknasr, Niaz; Setayeshi, Saeed; Akbari, Mohammad Esmaeil

    2014-01-01

    Alpha particle irradiation from radon progeny is one of the major natural sources of effective dose in the public population. Oncogenic transformation is a biological effectiveness of radon progeny alpha particle hits. The biological effects which has caused by exposure to radon, were the main result of a complex series of physical, chemical, biological and physiological interactions. The cellular and molecular mechanisms for radon-induced carcinogenesis have not been clear yet. Various biological models, including cultured cells and animals, have been found useful for studying the carcinogenesis effects of radon progeny alpha particles. In this paper, sugars cape cellular automata have been presented for computational study of complex biological effect of radon progeny alpha particles in lung bronchial airways. The model has included mechanism of DNA damage, which has been induced alpha particles hits, and then formation of transformation in the lung cells. Biomarkers were an objective measure or evaluation of normal or abnormal biological processes. In the model, the metabolism rate of infected cell has been induced alpha particles traversals, as a biomarker, has been followed to reach oncogenic transformation. The model results have successfully validated in comparison with "in vitro oncogenic transformation data" for C3H 10T1/2 cells. This model has provided an opportunity to study the cellular and molecular changes, at the various stages in radiation carcinogenesis, involving human cells. It has become well known that simulation could be used to investigate complex biomedical systems, in situations where traditional methodologies were difficult or too costly to employ.

  12. Unattached fraction of radon progeny in Polish coal mines

    International Nuclear Information System (INIS)

    Skubacz, K.; Michalik, B.

    2002-01-01

    The system of the monitoring of the radiation hazard in Polish coal mines is based on the monitoring of the workplaces. This system works since 1989 in all coal mines. It gives a very good basis for further epidemiological investigation and assessment of the health detriment within the population of the mines as a result of the exposure for natural radiation. It is very important problem, due to the fact of the presence in the mines another factors, which probably have a synergetic effects on the respiratory tracts. As the routine instrument, a device called ALFA-31 sampling probe was developed in our laboratory. This device was accomplished to regular dust sampler and simultaneous measurements of dust content and potential alpha energy concentration of radon progeny are obligatory in all underground mines in Poland. But the microcyclone used a separator of the respirable fraction which causes the cut-off of unattached fraction of radon progeny, On the other hand measurements of the unattached fraction of short lived radon progeny play a very important role in the investigations of the adequate dose from this source of radiation hazard. During field experiments the use of the alpha spectroscopy system is necessary, while measurements are done not in the vacuum chambers but under normal pressure. It leads to situation, when particular peaks in alpha spectrum are very wide and interfere with other peaks of another alpha-emitting radionuclides. Such instrumentation was designed and completed, and a survey in several underground mines was performed. The analysis of the obtained results must be done very carefully; in other case it may cause a very big uncertainty of the result. In this paper a new approach to the analysis of the alpha spectra has been described. This approach can be used also in other applications of alpha spectroscopy, in which the analysis of energy of alpha peaks in spectrum is needed. The method of the analysis is based on a non-linear regression

  13. Characteristics of indoor radon and its progeny in a Japanese dwelling while using air appliances.

    Science.gov (United States)

    Pornnumpa, C; Tokonami, S; Sorimachi, A; Kranrod, C

    2015-11-01

    Characteristics of radon and its progeny were investigated in different air conditions by turning four types of indoor air appliances on and off in a two-story concrete Japanese dwelling. The four appliances were air conditioner, air cleaner, gas heater and cooker hood. The measurements were done using two devices: (1) a Si-based semiconductor detector for continuous measurement of indoor radon concentration and (2) a ZnS(Ag) scintillation counting system for equilibrium-equivalent radon concentration. Throughout the entire experiment, the cooker hood was the most effective in decreasing indoor radon concentration over a long period of time and the less effective was the air conditioner, while the air cleaner and gas heater did not affect the concentration of radon. However, the results measured in each air condition will differ according to the lifestyles and activities of the inhabitants. In this study, indoor radon and its progeny in a Japanese dwelling will be characterised by the different air conditions. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. A review of lung-to-blood absorption rates for radon progeny

    International Nuclear Information System (INIS)

    Marsh, J. W.; Bailey, M. R.

    2013-01-01

    The International Commission on Radiological Protection (ICRP) Publication 66 Human Respiratory Tract Model (HRTM) treats clearance of materials from the respiratory tract as a competitive process between absorption into blood and particle transport to the alimentary tract and lymphatics. The ICRP recommended default absorption rates for lead and polonium (Type M) in ICRP Publication 71 but stated that the values were not appropriate for short-lived radon progeny. This paper reviews and evaluates published data from volunteer and laboratory animal experiments to estimate the HRTM absorption parameter values for short-lived radon progeny. Animal studies showed that lead ions have two phases of absorption: ∼10 % absorbed with a half-time of ∼15 min, the rest with a half-time of ∼10 h. The studies also indicated that some of the lead ions were bound to respiratory tract components. Bound fractions, f b , for lead were estimated from volunteer and animal studies and ranged from 0.2 to 0.8. Based on the evaluations of published data, the following HRTM absorption parameter values were derived for lead as a decay product of radon: f r = 0.1, s r = 100 d -1 , s s = 1.7 d -1 , f b = 0.5 and s b = 1.7 d -1 . Effective doses calculated assuming these absorption parameter values instead of a single absorption half-time of 10 h with no binding (as has generally been assumed) are only a few per cent higher. However, as there is some conflicting evidence on the absorption kinetics for radon progeny, dose calculations have been carried out for different sets of absorption parameter values derived from different studies. The results of these calculations are discussed. (authors)

  15. Diurnal Variations of Equilibrium Factor and Unattached fraction of Radon Progeny in Some Houses and Laboratories

    International Nuclear Information System (INIS)

    Lee, Seung Chan; Kang, Hee Dong; Kim, Chang Kyu; Lee, Dong Myung

    2001-01-01

    The variation characteristics of radon concentration, equilibrium equivalent concentration and equilibrium factor in some house and laboratory buildings have been studied. The variation of equilibrium factor and the unattached fraction of radon progeny with ventilation condition have been also estimated. The averages of radon concentration, equilibrium equivalent concentration and equilibrium factor were 30 Bq m -3 , 19.6 Bq m -3 and 0.65 in seven houses, while 55.0 Bq m -3 , 31.9 Bq m -3 and 0.58 in three laboratory buildings, respectively. The diurnal variation of radon concentration, equilibrium equivalent concentration and equilibrium factor in indoor showed a typical pattern that the radon concentration, equilibrium equivalent concentration and equilibrium factor increased at dawn and morning, while decreased at midday and evening. While the equilibrium factor rate deceased in the indoor environment which was well ventilated, the unattached fraction of radon progeny increased. The equilibrium factor was in proportion to air pressure and humidity of indoor, whereas in inverse proportion to temperature

  16. An intercomparison between gross α counting and gross β counting for grab-sampling determination of airborne radon progeny and thoron progeny

    International Nuclear Information System (INIS)

    Papp, Z.

    2006-01-01

    The instantaneous values of the airborne activity concentrations of radon progeny and thoron progeny have been determined 34 times in a closed and windowless room in a cellar using two independent grab-sampling methods in order to compare the performance of the methods. The activity concentration of radon ( 222 Rn) was also measured and it varied between 200 and 650 Bq m -3 . Two samples of radon and thoron progeny were collected simultaneously from roughly the same air volume by filtering. For the first method, the isotopes were collected on membrane filter and gross α counting was applied over several successive time intervals. This method was a slightly improved version of the methods that are applied generally for this reason for decades. For the second method, the isotopes were collected on glass-fibre filter and gross β counts were registered over several time intervals. This other method was developed a few years ago and the above series of measurements was the first opportunity to make an intercomparison between it and another similar method based on α counting. Individual radon progeny and thoron progeny activity concentrations (for the isotopes 218 Po, 214 Pb, 214 Bi and 212 Pb) were evaluated by both methods. The detailed investigation of the results showed that the systematic deviation of the methods is small but significant and isotope-dependent. The weighted averages of the β/α activity concentration ratios for 218 Po, 214 Pb, 214 Bi, EEDC 222 (Equilibrium-Equivalent Decay-product Concentration of radon progeny) and 212 Pb were 0.99±0.03, 0.90±0.02, 1.03±0.02, 0.96±0.02 and 0.80±0.03, respectively. The source of the systematic deviation is probably the inaccurate knowledge of the counting efficiencies mainly in the case of the α-counting method. A significant random-type difference between the results obtained with the two methods has also been revealed. For example, the β/α ratio for EEDC 222 varied between 0.81±0.01 and 1.22±0

  17. Deposition of radon progeny in nonhuman primate nasal airways

    International Nuclear Information System (INIS)

    Yeh, H.C.; Cheng, Y.S.; Morgan, K.T.

    1992-01-01

    Radon progeny are usually associated with ultrafine particles ranging in diameter from 0.001 to 0.005 μm for open-quotes unattachedclose quotes progeny and from 0.005 to 0.2 μm for those attached to indoor aerosols. To assess the health effects of inhaling indoor radon progeny, it is necessary to study the regional deposition of these inhaled ultrafine particles. Laboratory animals are often used in studies of the toxicity of inhaled particles and vapors. Information on the deposition of particles larger than 0.2 μm in the nasal passages of laboratory animals is available; however, there is little information on the deposition of particles smaller than 0.2 μm. In this report, we describe the use of nasal casts of a rhesus monkey to measure total deposition of ultrafine aerosols, including unattached 220 Rn progeny, in a unidirectional-flow inhalation exposure system. Deposition data were obtained for monodisperse silver aerosols with particle sizes ranging from 0.005 to 0.2 μm, at several inspiratory and expiratory flow rates that represented normal breathing as well as hypo- and hyperventiliation. In addition, we studied the deposition of unattached 22- Rn progeny, at particle sizes from 0.001 to 0.003 μm. The deposition efficiency decreased with increasing particle size, indicating that diffusion was the dominant deposition mechanism. The effect of flow rate was essentially negligible. Based on assumptions that turbulent flow and complete mixing of aerosols occur in the nasal airways, a general equation E = 1-exp (-a D b Q c ) for d p ≤ 0.2 μm, was derived, where E is the deposition efficiency, d p is the particle diameter, D is the diffusion coefficient, and Q is the flow rate. Constants a, b, and c are estimated from experimental data, for either inspiration or expiration. This mathematical expression will be useful for making modifications to both deposition and dosimetry models

  18. Particle size distribution of the radon progeny and ambient aerosols in the Underground Tourist Route “Liczyrzepa” Mine in Kowary Adit

    Directory of Open Access Journals (Sweden)

    Wołoszczuk Katarzyna

    2018-01-01

    Full Text Available Central Laboratory for Radiological Protection, in cooperation with Central Mining Institute performed measurements of radon concentration in air, potential alpha energy concentration (PAEC, particle size distribution of the radon progeny and ambient aerosols in the Underground Tourist-Educational Route “Liczyrzepa” Mine in Kowary Adit. A research study was developed to investigate the appropriate dose conversion factors for short-lived radon progeny. The particle size distribution of radon progeny was determined using Radon Progeny Particle Size Spectrometer (RPPSS. The device allows to receive the distribution of PAEC in the particle size range from 0.6 nm to 2494 nm, based on their activity measured on 8 stages composed of impaction plates or diffusion screens. The measurements of the ambient airborne particle size distribution were performed in the range from a few nanometres to about 20 micrometres using Aerodynamic Particle Sizer (APS spectrometer and the Scanning Mobility Particle Sizer Spectrometer (SMPS.

  19. Study on seasonal variation of indoor radon, thoron and their progeny levels in Hassan District of Karnataka, India

    International Nuclear Information System (INIS)

    Srinivasa, E.; Rangswamy, D.R.; Sannappa, J.

    2015-01-01

    Radon, thoron and their progeny concentrations have been measured in different types of buildings at different locations for different seasons in Hassan city using time-integrated passive radon dosimeters containing LR-115 Type II solid state nuclear track detector exposed for four seasons of 3 months each covering a period of one year from October 2012 to September 2013. The radon and thoron activity concentration in summer season in the corresponding dwellings has been found to vary from 7.4 to 45.7 Bq m -3 and 5.4 to 34.9 Bqm -3 with a median of 23.59±11 Bqm -3 and 1447±8 Bq -3 respectively. The radon progeny concentrations varies from 0.4 to 4.1 mWL with an average value of 1.83±1 mWL, while thoron progeny concentrations vary from 0.3 to 3.2 mWL with an average value of 1.12±0.7 mWL respectively. The annual effective dose received due to radon, thoron and its progeny by the inhabitants in the dwellings under study has also been calculated which is found to vary from 0.320±0.4 to 1.860 ±1.1 mSv y -1 with an average value of 0.9576 ± 0.8 mSv y -1 . In general, the level of radon-thoron was observed highest in winter and lowest in summer. A detail analysis of radon and thoron distribution in different houses with seasonal variation is presented in this paper. From this study it is observed that, bathrooms and kitchens have significantly higher radon concentrations as compared to other rooms in the dwellings. (author)

  20. Experimental verification of the attachment theory of radon progeny onto ambient aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Tokonami, Shinji

    2000-01-01

    The attachment theory of radon progeny onto ambient aerosols was experimentally verified with a cascade impactor and a graded screen array at the EML environmental chamber. Monodisperse aerosols in the size range of 70 to 500 nm were generated with Carnauba wax by means of the evaporation-condensation method. The temperature and the relative humidity in the chamber were set at 20 C and 20%, respectively, throughout the entire experiment. When the aerosols were being injected into the chamber, both the number size distribution and the activity-weighted size distribution of attached radon progeny were stable. The activity-weighted size distribution was compared with the attachment rate distribution obtained by measuring the number size distribution with the SMPS and multiplying the size-dependent attachment coefficient. There was a relatively good agreement between the two distributions.

  1. Enhancement of exposure to radon progeny as a consequence of passive smoking

    International Nuclear Information System (INIS)

    Moghissi, A.A.; Seiler, M.C.

    1989-01-01

    Among indoor air pollutants, radon and tobacco smoke take dominant positions. Because radon decay products have a relatively short residence time in air, the extent of the equilibrium between radon and its daughter products is linearly proportional to the carcinogenic risk, at least at low exposure levels. The relevant factor is the equilibrium factor F. This paper discusses the enhancement of radon exposure as a result of the presence of particulate matter originating from tobacco smoke. The presence of tobacco smoke provides a mechanism for radon progeny to be attached to inhalable particles and to remain in indoor air for a prolonged time. The results of our study indicate a significant increase in F as a consequence of passive smoking. These modeling efforts are consistent with the experimental data reported previously

  2. Investigation of the exposure to radon and progeny in the thermal spas of Loutraki (Attica-Greece): Results from measurements and modelling

    International Nuclear Information System (INIS)

    Nikolopoulos, Dimitrios; Vogiannis, Efstratios; Petraki, Ermioni; Zisos, Athanasios; Louizi, Anna

    2010-01-01

    Radon and progeny ( 218 Po, 214 Pb, 214 Bi and 214 Po) in thermal spas are well known radioactive pollutants identified for additional radiation burden of patients due to the activity concentration peaks which appear during bath treatment or due to drinking of waters of high radon content. This burden affects additionally the working personnel of the spas. The present paper has focused on the thermal spas of Loutraki (Attica-Greece). The aim was the investigation of the health impact for patients and working personnel due to radon and progeny. Attention has been paid to radon and progeny transient concentration peaks (for bath treatment) and to radon of thermal waters (both for bath treatment and drinking therapy). Designed experiments have been carried out, which included radon and progeny activity concentration measurements in thermal waters and ambient air. Additionally, published models for description of radon and progeny transient concentration peaks were employed. The models were based on physicochemical processes involved and employed non linear first order derivative mass balance differential equations which were solved numerically with the aid of specially developed computer codes. The collected measurements were analysed incorporating these models. Results were checked via non linear statistical tests. Predictions and measurements were found in close agreement. Non linear parameters were estimated. The models were employed for dosimetric estimations of patients and working personnel. The effective doses of patients receiving bath treatment were found low but not negligible. The corresponding doses to patients receiving potable treatment were found high but below the proposed international limits. It was found that the working personnel are exposed to considerable effective doses, however well below the acceptable limits for workers. It was concluded that treatment and working in the Loutraki spas leads to intense variations of radon and progeny and

  3. Radon, thoron and their progeny levels in some dwellings of Union Territory Chandigarh, India using SSNTDs

    International Nuclear Information System (INIS)

    Mehta, Vimal; Kumar, Amit; Chauhan, R.P.; Mudahar, G.S.

    2013-01-01

    Indoor air quality is an important issue for protection against adverse health effects caused by the inhalation of pollutants because most individuals spend 90% of their time indoors and that indoor air quality is deteriorated by a large variety of sources. Out of these sources radon is a major pollutant and is an important global problem of radiation hygiene. Radon and its progeny are the major contributors in the radiation dose received by general population of the world. Next to cigarette smoking, the inhalation of radon gas and the products of its radioactive disintegration are considered the most significant cause of lung cancer. Due to the potentially serious public health implications of exposure to high levels of radon, the environmental monitoring of radon, thoron and their progeny in some dwellings of Chandigarh, union territory of India has been carried out. The radon-thoron twin dosimeter cups were used for the study. The aim of the study is the possible health risk assessment in the dwellings under consideration. (author)

  4. Effect of natural ventilation on radon and radon progeny levels in houses. Rept. for Apr 90-Sep 91

    International Nuclear Information System (INIS)

    Cavallo, A.; Gadsby, K.; Reddy, T.A.; Socolow, R.

    1991-01-01

    The paper discusses the effect of natural ventilation on radon and radon progeny levels in houses. Contradicting the widely held assumption that ventilation is ineffective in reducing indoor radon concentrations, experiments in a research house have shown that the basement radon level can be reduced by a factor of 5 to 10 using only natural ventilation. Measurement of the outdoor-basement pressure differential and the radon entry rate shows that this unexpectedly large reduction in indoor radon levels is caused by two complementary physical processes: (1) the obvious one, dilution, which lowers radon concentrations by adding uncontaminated outdoor air; and (2) although less evident, introducing a pressure break in the system through an open basement window which, in turn, reduces the outdoor-basement pressure differential and the rate at which radon-laden soil gas is drawn into the house. The radon entry rate was found to be a linear function of basement depressurization up to a differential pressure of about 4 Pa, as would be expected for laminar soil gas flow; opening two basement windows approximately doubled the building air exchange rate and reduced the radon entry rate by up to a factor of 5

  5. Thoron and radon progeny concentration measurements using direct progeny sensors in HLNRAs of Kerala

    International Nuclear Information System (INIS)

    Mishra, R.; Prajith, R.; Gole, A.C.; Kanse, S.D.; Chougaonkar, M.P.; Sapra, B.K.; Mayya, Y.S.; Jayalekshmi, P.; Nair, Raghu Ram K.

    2010-01-01

    Passive Progeny Dosimeters (PPDs) were deployed in 500 houses in 3 villages namely Allapad, Chavara and Neendakara villages of Karunagapally Taluk of Kollam district of Kerala. Each PPD unit is a combination of a DTPS and a DRPS placed side-by-side for time integrated thoron and radon progeny concentration estimation respectively. The PPDs were suspended vertically in the rooms, such that the nearest distance from any wall or surface was at least 30 cm. These are, as of now, being exposed for a period of 3 months, after which they will be retrieved and analysed by chemical etching and track counting. Simultaneously, external gamma radiation measurements have also been made using a survey meter; these showed a variation from 13 to 118 μR/h in indoors and 21 to 213 μR/h in the outdoor environments. Spot measurements of thoron progeny concentrations were also made in 7 selected houses using the conventional grab filter-paper sampling technique at a flow-rate of 21 min -1 for 30 minutes, followed by alpha counting. The average thoron progeny concentration was found to be 2.0 ± 0.7 Bq m -3 . In the outdoor environment, filter-paper sampling was carried out for 2 hours at 21 min -1 and the thoron progeny concentration was measured as 2.96 Bq m -3 . To corroborate these measurements, a flow mode integrated sampler which uses the DTPS and DRPS elements was used

  6. Application of nuclear track detectors for radon related measurments

    International Nuclear Information System (INIS)

    Abu-Jarad, F.A.

    1988-01-01

    The application of nuclear track detectors for radon related measurements is discussed. The ''Can Technique'', used for measuring radon emanation from building materials, walls and soil; the ''Working Level Monitor'', used for measuring short period working levels of radon daughters in houses; and ''Passive Radon Dosimeters'', used to measure radon levels in houses for long term (few months) periods are described. Application of nuclear track detectors for measuring the radon daughters plate-out on the surface of mixing fan blades and walls are discussed. The uranium content of some wall papers was found to be 6 ppm. The variation of radon progeny concentration in the same room was measured and supported by another study through Gas Chromatograph measurements. The independence of radon concentration on room level in high-rise buildings was established. The effect of sub-floor radon emanation on radon concentration in houses is dependent on whether there is sub-floor ventilation or not. (author)

  7. Portable devices for monitoring radon and its progeny in air

    International Nuclear Information System (INIS)

    Zhang Huaiqin; Yao Wanyuan; Su Jingling; Liu Jinhua

    1990-01-01

    We have developed two kinds of portable monitoring devices to measure the concentration and potential energy concentration of radon and its progeny in air. The thermoluminescence material CaSO4 (Tm) is used as the detection element. One of the devices is called passive radon monitor. The lowest detectable limit for radon in air is about 1.5 Bq/m 3 , as a sampling time being one week. Good reliability and ease to operate are its main advantages. The second kind of device is called a working level monitor which consists of a miniature remembrane pump and an integrating sampling probe. The lowest detectable limit is about 0.00043 WL (9x10 -9 J/m 3 ) for a sampling time of 6 hours. It weighs only 0.35 kg, but maintenance is necessary sometimes. (author). 6 refs, 2 figs, 4 tabs

  8. Radon and progeny sourced dose assessment of spa employees in balneological sites

    International Nuclear Information System (INIS)

    Kemal Uzun, Sefa; Demiroez, Isik

    2016-01-01

    This study was conducted in the scope of IAEA project with the name 'Establishing a Systematic Radioactivity Survey and Total Effective Dose Assessment in Natural Balneological Sites' (TUR/9/018), at the Health Physics department of Saraykoey Nuclear Research and Training Center (SANAEM). The aim of this study is estimation of radon and progeny sourced effective dose for the people who are working at the spa facilities by measuring radon activity concentration (RAC) at the ambient air of indoor spa pools and dressing rooms. As it is known, the source of the radon gas is the radium content of the earth crust. Therefore, thermal waters coming from ground may contain dissolved radon and the radon can diffuse water to air. So the ambient air of spa pools can contain serious RAC that depends on a lot of parameters. In this regard, RAC measurements were executed at the 70 spa facilities in Turkey. The measurements were done with both active and passive methods at ambient air of spa pools and dressing rooms. Thus, active measurements were carried out by using the Alphaguard R with diffusion mode during half an hour, and passive measurements were carried out by using the humidity resistive CR-39 radon detectors during 2 months. Results show that RAC values at ambient air of spa pools varies between 13 Bq m -3 and 10 kBq m -3 . Because long-term measurements are more reliable, if it is available, for dose calculations passive radon measurements (with CR-39 detectors) at ambient air of spa pools and dressing rooms were used, otherwise active measurement results were used. With the measurement by the conversion coefficients of ICRP 65 and occupational data of the employees has got from questionnaire forms, effective dose values were calculated. According to the calculations, spa employees are exposed to annual average dose between 0.05 and 29 mSv because of radon and progeny. (authors)

  9. Study of radiation exposure due to radon, thoron and progeny in the indoor environment of Yamuna and Tons valleys of Garhwal Himalaya

    International Nuclear Information System (INIS)

    Prasad, Mukesh; Rawat, Mukesh; Dangwal, Anoop; Ramola, R.C.; Prasad, Ganesh; Mishra, Rosaline

    2016-01-01

    Long-term measurements of indoor radon, thoron and their progeny concentrations have been carried out in dwellings of Yamuna and Tons Valleys of Uttarkashi, Garhwal Himalaya to investigate the health risk associated with inhalation of radon, thoron and progeny. The experimentally determined values of radon, thoron and progeny concentrations were used to estimate the annual inhalation doses and annual effective doses. The annual inhalation dose has been found to vary from 0.8 to 3.9 mSv y -1 with an average of 1.8 mSv y -1 . The annual effective dose from the exposure to radon and its progeny in the study area has been found to vary from 0.1 to 2.4 mSv with an average of 1.2±0.6 mSv. Similarly, the annual effective dose due to thoron and its progeny has been found to vary from 0.2 to 1.5 mSv with an average of 0.6±0.4. The measurement techniques and results obtained are discussed in detail. (authors)

  10. Exposure of workers to radon progeny in the Baradla cave at Aggtelek

    International Nuclear Information System (INIS)

    Dezsoe, Z.

    2004-01-01

    By measuring the radon concentration using active technique in all parts of the cave visited in a tour and furthermore by assessing also the time spent at these locations, it is possible to determine the radon level averaged over a tour. The time averaged radon concentration along the route of the cave investigated has been estimated to 970 Bq/m 3 in summer and 410 Bq/m 3 in winter. We concluded that in 62 % of the year cave climate shows warm season and only in 38 % cold season Rn-levels. On this basis the yearly mean radon concentration averaged over the tour comes to 750 Bq/m3. This figure, however, should not be used to estimate exposure because the number of visitors is substantially higher in summer than in winter, so that the tour guides work much more in summer (about 750 tours) than in winter (about 270 tours). Taking this into account, the yearly mean Rn concentration is to 820 Bq/m 3 . Since the dose is delivered by radon progeny and not radon itself, one has to also assess the equilibrium factor representative in the cave. The data available in the literature show that F is always larger than under normal ambient conditions. Published values are between 0.5 - 0.8. As part of this work, several radon progeny concentration measurements have also been made in the Baradla cave at different locations. The results confirm the occurrence of high F-values in caves. Furthermore, the equilibrium factor is increased by the presence of humans (visitors or cavers). In the Virgin Cave, F = 0.5 - 0.6, which increases steadily to about 0.8 due to the activity of man. In this work, F = 0.8 has been used for the dose assessment. Using the ICRP 65 dosimetry model, exposure was calculated to be 4.04 mJhm 3 , which corresponds to an effective dose of 5.8 mSv. (P.A.)

  11. Measurment of radon, thoron and their progeny in indoor environment of Mohali, Punjab, Northern India, using pinhole dosimeters

    Directory of Open Access Journals (Sweden)

    Mehta Vimal

    2016-01-01

    Full Text Available The health hazards of radon and its decay products above certain levels are well known. However, for any preventive measures to be taken, we have to be aware of radon levels of that particular area. Measurement of radon and its decay products in indoor environments is an important aspect of assessing indoor air quality and health conditions associated with it. Keeping this in mind, measurements of radon, thoron and their progeny concentrations were carried out in Mohali, Northern India, using pinhole-based twin cup dosimeters. Radon exhalation rates of soil samples in the dwellings/areas were measured via an active technique of a continuous radon monitor. The indoor radon concentration in Mohali varied from 15.03 ± 0.61 Bq/m3 to 39.21 ± 1.46 Bq/m3 with an average of 26.95 Bq/m3 ,while thoron concentration in the same dwellings varied from 9.62 ± 0.54 Bq/m3 to 52.84 ± 2.77 Bq/m3 with an average of 31.09 Bq/m3. Radon progeny levels in dwellings under study varied from 1.63 to 4.24 mWL, with an average of 2.94 mWL, while thoron progeny levels varied from 0.26 to 1.43 mWL , with an average of 0.84 mWL. The annual dose received by the inhabitants of dwellings under study varied from 0.78 to 2.36 mSv, with an average of 1.61 mSv. The in situ gamma dose rate varied from 0.12 to 0.32 mSv/h.

  12. STUDY OF RADIATION EXPOSURE DUE TO RADON, THORON AND PROGENY IN THE INDOOR ENVIRONMENT OF YAMUNA AND TONS VALLEYS OF GARHWAL HIMALAYA.

    Science.gov (United States)

    Prasad, Mukesh; Rawat, Mukesh; Dangwal, Anoop; Prasad, Ganesh; Mishra, Rosaline; Ramola, R C

    2016-10-01

    Long-term measurements of indoor radon, thoron and their progeny concentrations have been carried out in dwellings of Yamuna and Tons Valleys of Uttarkashi, Garhwal Himalaya to investigate the health risk associated with inhalation of radon, thoron and progeny. The experimentally determined values of radon, thoron and progeny concentrations were used to estimate the annual inhalation doses and annual effective doses. The annual inhalation dose has been found to vary from 0.8 to 3.9 mSv y -1 with an average of 1.8 mSv y -1 The annual effective dose from the exposure to radon and its progeny in the study area has been found to vary from 0.1 to 2.4 mSv with an average of 1.2±0.6 mSv. Similarly, the annual effective dose due to thoron and its progeny has been found to vary from 0.2 to 1.5 mSv with an average of 0.6±0.4. The measurement techniques and results obtained are discussed in detail. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Long-term determination of airborne concentrations of unattached and attached radon progeny using stacked LR 115 detector with multi-step etching

    International Nuclear Information System (INIS)

    Nikezic, D.; Yu, K.N.

    2010-01-01

    We developed the theoretical basis for long-term determination of airborne concentrations of unattached and attached radon progeny. The work was separated into two parts. First, we showed that (stacked and multiply etched) LR 115 detectors could be used to determine airborne concentrations of the short-lived radon progeny, 218 Po and 214 Bi. The equilibrium factor F between radon and its progeny could then be determined through the use of the reduced equilibrium factor F red . The airborne concentrations of 214 Pb could then be determined. Second, we developed a method based on the airborne concentrations of 218 Po, 214 Pb and 214 Bi to determine the parameters of the Jacobi room model, viz., the ventilation rate λ v , aerosol attachment rate λ a , deposition rate of unattached progeny λ d u and the deposition rate of attached progeny λ d u . With these parameters, the unattached fraction f p of the potential alpha energy concentration could also be determined. Knowledge of f p , together with F, would enable more accurate determination of the effective dose in the human lung.

  14. Microclimatic effects on outdoor radon and its progeny in a long-term study

    International Nuclear Information System (INIS)

    Schuetz, M.; Keller, G.; Kappel, R.J.A.

    1994-01-01

    The dose due to the long term radon exposure is estimated from the radon concentration and from an equilibrium factor that in the literature is reported with a wide uncertainty. Therefore the radon equilibrium factor outdoors and its dependence on climatic effects should be investigated in a long-term study. Both the outdoor concentrations of radon and of its progeny near Ellweiler/Hunsrueck were measured continuously during 12 months and the resulting equilibrium factors were determined. Simultaneously to the every 2 hour's radon data many meterological parameters as temperature and relative to humidity of the air, barometric pressure and duration and amount of rainfall were recorded. At a height of 6 meters above ground and in 10 minute intervals the local wind direction and velocity were registered. By that a set of more than 3000 single measurements of the equilibrium factor and of the corresponding weather conditions was collected

  15. Concentration of Radon, thoron and their progeny levels in different types of floorings, walls, rooms and building materials

    International Nuclear Information System (INIS)

    Sathish, L. A.; Nagaraja, K.; Ramanna, H. C.; Nagesh, V.; Sundareshan, S.

    2009-01-01

    Radon, thoron and their progenies are the most important contributions to human exposure from natural sources. Radon exists in soil gas, building materials, Indoor atmosphere etc. Among all the natural sources of radiation dose to human beings, inhalation of radon contributes a lot. The work presented here emphasizes the long term measurements of radon, thoron and their progeny concentrations in about 100 dwellings using solid state nuclear track detectors. Materials and Methods: Measurements were made using dosimeters and the concentrations were estimated by knowing the track density of films through spark counter, and sensitivity factor for bare, filter and membrane films. Results: Presence of radon and thoron in houses is the effect of several aspects such as the activity concentrations of uranium, radium and thorium in the local soil, building materials, ventilation of houses and also entry of radon into houses through the cracks in floor/wall. Conclusion: The observations reveal that the concentrations of radon and/or thoron are relatively higher in granite than in concrete, cement and bricks. In continuation to this the concentration observed in bathrooms is more compared to kitchen bedroom and living rooms. This study discloses that the residential rooms of good ventilation will avoid the health hazards due to radon and its rich materials.

  16. Detection of 210Po on filter papers 16 years after use for the collection of short-lived radon progeny in a room

    International Nuclear Information System (INIS)

    Abu-Jarad, F.; Fazal-ur-Rehman

    2003-01-01

    Radon gas was allowed to accumulate in its radium source and then injected into a 36 m 3 test room, resulting in an initial radon concentration of 15 kBq m -3 . Filter papers were used to collect the short-lived radon progeny and thus to measure the Potential Alpha Energy Concentration (PAEC) in-situ in the year 1984 at different times and conditions according to the experimental design. The radon progeny collected on the filter papers were studied as a function of aerosol particle concentration ranging from 10 2 -10 5 particles cm -3 in three different experiments. The highest aerosol particle concentration was generated by indoor cigarette smoking. Those filters were stored after the experiment, and were used after 16 years to study the activity of the radon long-lived alpha emitter progeny, 210 Po (T 1/2 =138 days). This isotope is separated from the short-lived progeny by 210 Pb beta emitter with 22.3 years half-life. After 16 years' storage of these filters, each filter paper was sandwiched and wrapped between two CR-39 nuclear track detectors, to put the detectors in contact with the surfaces of different filters, for 337 days. Correlation between the PAEC measured using filter papers in the year 1984 and the activity of long-lived alpha emitter 210 Po on the same filter papers measured in the year 2000 were studied. The results of the 210 Po activity showed a very good correlation of 0.92 with the PAEC 16 years ago. The results also depict that the PAEC and 210 Po activity in indoor air increased with the increase of aerosol particle concentration, which shows the attachment of short-lived radon progeny with the aerosol particles. The experiment proves that indoor cigarette smoking is a major source of aerosol particles carrying radon progeny and, thus, indoor cigarette smoking is an additional source of internal radiation hazard to the occupants whether smoker or non-smoker

  17. RADON PROGENY AS AN EXPERIMENTAL TOOL FOR DOSIMETRY OF NANOAEROSOLS

    Energy Technology Data Exchange (ETDEWEB)

    Ruzer, Lev; Ruzer, Lev S.; Apte, Michael G.

    2008-02-25

    The study of aerosol exposure and dosimetry measurements and related quantitation of health effects are important to the understanding of the consequences of air pollution, and are discussed widely in the scientific literature. During the last 10 years the need to correlate aerosol exposure and biological effects has become especially important due to rapid development of a new, revolutionary industry ?-- nanotechnology. Nanoproduct commerce is predicted to top $1 trillion by 2015. Quantitative assessment of aerosol particle behavior in air and in lung deposition, and dosimetry in different parts of the lung, particularly for nanoaerosols, remains poor despite several decades of study. Direct measurements on humans are still needed in order to validate the hollow cast, animal studies, and lung deposition modeling. We discuss here the use of nanoscale radon decay products as an experimental tool in the study of local deposition and lung dosimetry for nanoaerosols. The issue of the safe use of radon progeny in such measurements is discussed based on a comparison of measured exposure in 3 settings: general population, miners, and in a human experiment conducted at the Paul Scherer Institute (PSI) in Switzerland. One of the properties of radon progeny is that they consist partly of 1 nm radioactive particles called unattached activity; having extremely small size and high diffusion coefficients, these particles can be potentially useful as radioactive tracers in the study of nanometer-sized aerosols. We present a theoretical and experimental study of the correlation between the unattached activity and aerosol particle surface area, together with a description of its calibration and method for measurement of the unattached fraction.

  18. Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres. Progress report, July 1, 1991--June 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Hopke, P.K.

    1992-07-01

    This report covers the second year of the 28 month grant current grant to Clarkson University to study the chemical and physical behavior of the polonium 218 atom immediately following its formation by the alpha decay of radon. Because small changes in size for activity result in large changes in the delivered dose per unit exposure, this behavior must be understood if the exposure to radon progeny and it dose to the cells in the respiratory tract are to be fully assessed. Two areas of radon progeny behavior are being pursued; laboratory studies under controlled conditions to better understand the fundamental physical and chemical process that affect the progeny`s atmospheric behavior and studies in actual indoor environments to develop a better assessment of the exposure of the occupants of that space to the size and concentration of the indoor radioactive aerosol. This report describes the progress toward achieving these objectives.

  19. Radon Progenies as a Source of Gross Alpha-beta Activities in Drinking Water in Vinaninkarena, Antsirabe-Madagascar

    International Nuclear Information System (INIS)

    Raoelina Andriambololona; Rabesiranana, N.; Rasolonirina, M.; Rakotomanga, H.

    2004-01-01

    The village of Vinaninkarena, Antsirabe, Madagascar is located in a high radioactivity area. With the aim of assessing the health impact of radioactivity pollution, a survey was conducted around an abandoned radium mining. Waters from 24 sampling points, including 5 wells and 13 springs were sampled. The water radioactivity was measured using a portable Triathler LSC, model 425-034 from Hidex Turku. Each sample is counted more than 3 times: less than 2h after sampling, 4h to few days and more than 3 weeks after when 226 Ra attains equilibrium with 222 Rn and its short-lived daughters. Combination of water non miscible, radon extractive LS cocktail and water miscible one is used to reveal contribution of radium, radon and its short lived progenies to the gross alpha-beta activities. Maximum activity values found are : 3.6±0.3 Bq.L -1 for 226 Ra, 554±9 Bq.L -1 for the excess of radon, and 408±8 Bq.L -1 for the excess of radon progenies. Based on these data, a daily consumption of 2 L of these waters by a standard person would produce an annual 226 Ra ingestion well above the annual intake limit for 226 Ra. Moreover, the increasing gross alpha-beta activity resulting from radon progenies raises the issue of health effects. The potential for rapid spring-to-mouth delivery, which is frequent in rural area, may expose the water consumer to the short-lived alpha particle emitters.

  20. Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres. Final project report

    International Nuclear Information System (INIS)

    Hopke, P.K.

    1996-09-01

    This report completes Clarkson University's study of the chemical and physical behavior of the 218 Po atom immediately following its formation by the alpha decay of radon. Because small changes in size for activity in the sub-10 nm size range result in large changes in the delivered dose per unit exposure, this behavior must be understood if the exposure to radon progeny and it dose to the cells in the respiratory tract are to be fully assessed. In order to pursue this general goal, two areas of radon progeny behavior are being pursued; laboratory studies under controlled conditions to better understand the fundamental physical and chemical processes that affect the progeny's atmospheric behavior and studies in actual indoor environments to develop a better assessment of the exposure of the occupants of that space to the size and concentration of the indoor radioactive aerosol. Thus, two sets of specific goals have been established for this project. The specific tasks of the controlled laboratory studies are (1) Determine the formation rates of circ OH radicals formed by the radiolysis of air following radon decay; (2) Examine the formation of particles by the radiolytic oxidation of substances like SO 2 , ethylene, and H 2 S to lower vapor pressure compounds and determine the role of gas phase additives such as H 2 O and NH 3 in determining the particle size; (3) Measure the rate of ion-induced nucleation using a thermal diffusion cloud chamber, and (4) Measure the neutralization rate of 218 PoO x + in O 2 at low radon concentrations

  1. The protective effect of propolis on damage to lung and blood in rats by inhaled radioactive radon and its progeny

    International Nuclear Information System (INIS)

    Ding Jiansong; Nie Jihua; Tong Jian

    2006-01-01

    Twenty-eight male wistar rats were randomly divided into seven groups, i.e. the radon groups (3), the propolis+radon groups (3) and the control (1). The propolis+radon groups were fed intragastrically with propolis 0.2 g/kg, before exposing them, together with the radon groups, to radon and its progeny with the cumulative dose up to 30, 67 and 111 working level month (WLM), respectively. The levels of SOD (superoxide dismutase) and MDA (Malonic dialdehyde) in blood and lung tissue were determined. The SOD level of in blood and lung tissues of the radon groups decreased significantly and the MDA level increased. The MDA level in lung tissue of the 30 WLM propolis+radon group was significantly higher than the 30 WLM radon group. The SOD level in lung tissue of the 67 WLM propolis+radon group was significantly higher, but the MDA level was significantly lower, than the 67 WLM radon group. Both the SOD and MDA levels in blood and lung tissue of the 111 WLM propolis+radon group were significantly higher than the 111 WLM radon group. In conclusion, the inhalation of radon and its progeny can lead to persistent disturbance of the redox state in rats. Propolis show some protective effects on the redox damage under the experimental conditions. (authors)

  2. Detection of {sup 210}Po on filter papers 16 years after use for the collection of short-lived radon progeny in a room

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Jarad, F. E-mail: falah.abujarad@aramco.com; Fazal-ur-Rehman

    2003-07-01

    Radon gas was allowed to accumulate in its radium source and then injected into a 36 m{sup 3} test room, resulting in an initial radon concentration of 15 kBq m{sup -3}. Filter papers were used to collect the short-lived radon progeny and thus to measure the Potential Alpha Energy Concentration (PAEC) in-situ in the year 1984 at different times and conditions according to the experimental design. The radon progeny collected on the filter papers were studied as a function of aerosol particle concentration ranging from 10{sup 2}-10{sup 5} particles cm{sup -3} in three different experiments. The highest aerosol particle concentration was generated by indoor cigarette smoking. Those filters were stored after the experiment, and were used after 16 years to study the activity of the radon long-lived alpha emitter progeny, {sup 210}Po (T{sub 1/2}=138 days). This isotope is separated from the short-lived progeny by {sup 210}Pb beta emitter with 22.3 years half-life. After 16 years' storage of these filters, each filter paper was sandwiched and wrapped between two CR-39 nuclear track detectors, to put the detectors in contact with the surfaces of different filters, for 337 days. Correlation between the PAEC measured using filter papers in the year 1984 and the activity of long-lived alpha emitter {sup 210}Po on the same filter papers measured in the year 2000 were studied. The results of the {sup 210}Po activity showed a very good correlation of 0.92 with the PAEC 16 years ago. The results also depict that the PAEC and {sup 210}Po activity in indoor air increased with the increase of aerosol particle concentration, which shows the attachment of short-lived radon progeny with the aerosol particles. The experiment proves that indoor cigarette smoking is a major source of aerosol particles carrying radon progeny and, thus, indoor cigarette smoking is an additional source of internal radiation hazard to the occupants whether smoker or non-smoker.

  3. Concentration of Radon Progeny in Air by Alpha Spectrometry Measurement; Medida de los descendientes del radon en aire por Espectrometria Alfa

    Energy Technology Data Exchange (ETDEWEB)

    Acena, M L; Crespo, M T

    1989-07-01

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of 214 Po and 318 Po. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter. (Author) 15 refs.

  4. A method for determining an indicator of effective dose calculation due to inhalation of Radon and its progeny from in vivo measurements

    International Nuclear Information System (INIS)

    Estrada, Julio Jose da Silva

    1994-01-01

    Direct measurement of the absolved dose to lung tissue from inhalation of radon and its progeny is not possible and must be calculated using dosimetric models, taking into consideration the several parameters upon which the dose calculation depends. To asses the dose due to inhalation of radon and its progeny, it is necessary to estimate the cumulative exposure. Historically, this has been done using WLM values estimated with measurements of radon concentration in air. The radon concentration in air varies significantly, however, in space with time, and the exposed individual is also constantly moving around. This makes it almost impossible to obtain a precise estimate of an individual's inhalation exposure. This work describes a pilot study to calculate lung dose from the deposition of radon progeny, via estimates of cumulative exposure derived from in vivo measurements of 210 Pb, in subjects exposed to above-average radon and its progeny concentrations in their home environments. The measurements were performed in a whole body counter. With this technique, the exposed individuals become, in affect, their own samplers and dosimeters and the estimate of cumulative exposure is not affected by the variation of the atmospheric concentration of radon and its progeny in time and space. Forty individuals identified as living in homes with radon levels ranging from about 740 Bq/m 3 to 150.000 Bq/m 3 were measured. Also, additional 34 measurements were made on personnel from NYUMC/NIEM who live in a residential area surrounding the laboratory in which the levels of radon have been shown to be at below average values. To realize these measurements a methodology was developed to determine the subject's background, using a head phantom made with a cubic plastic container containing known amounts of potassium and calcium dissolved in four liters of water. The effective doses calculated from the in vivo measurements are compared to effective doses estimated, for the same

  5. Underground measurements of aerosol in radon and thoron progeny activity distributions

    International Nuclear Information System (INIS)

    Khan, A.; Bandi, F.; Phillips, C.R.; Duport, P.

    1990-01-01

    Aerosol and activity distributions of 218 Polonium, 214 Lead, 214 Bismuth, and 212 Lead were determined in two different underground mining environments by means of an optimized time-delay counting scheme and diffusion batteries. In one environment, diesel equipment was operating; and in the other, electrically powered equipment. The two environments differed significantly in total aerosol concentration. In the diesel environment, in particular, aerosol concentrations were unsteady, and fluctuated with vehicular traffic and mining activities. As measured by radon progeny disequilibrium, the age of the air ranged from about 25 to 60 minutes. Thoron working levels were of the same order as radon working levels. In this paper, comparisons are made between the aerosol and activity size distributions in both the diesel and electric mine

  6. Lung dosimetry for inhaled radon progeny

    International Nuclear Information System (INIS)

    Hofmann, W.

    1986-01-01

    Lung cancer risk assessment for inhaled radon progeny requires a detailed knowledge of the dose distribution pattern throughout the human respiratory tract. Current lung dosimetry models take into acocunt aerosol deposition in a formalized airway structrue, modification of the initial deposition pattern by clearance mechanisms, and the energy deposited by alpha particles in sensitive cells of the bronchial epithelium. The resulting dose distribution pattern depends on the characteristics of the inhaled aerosol and the breathing pattern. Special emphasis has been laid on the age dependency of the anatomical structure of the human lung and the resulting doses, as well as on the rediological significance of enhanced aerosol deposition at bronchial bifuraction. The biological variability inherent in all morphometric, physiological and histological parameters involved in lung dosimetry suggests the application of stochastic modelling techniques. Examples for the use of Monte Carlo methods presented here are the random walk of inhaled particles through a random airway geometry, and the influence of the intra-subject variability of radiation doses on radiation protection standards. At the cellular level the concept of absorbed dose loses its significance and has to be replaced by microdosimetric concepts, such as internal microdosimtry or track structure theory. An image-analysis model allows us to construct specific energy distributions in sensitive lung cells. Application of a track structure model of alpha particle interaction with bronchial epithelial cells permits the calculation of probabilities for inactivation, transformation, and tumor induction. The latter has been used to analyse lung cancer risk at low doses in Chinese high background areas

  7. Estimation of equilibrium factors of radon and its progeny using SSNTDs in the various dwellings of Hyderabad, Andhra Pradesh, India

    International Nuclear Information System (INIS)

    Yadagiri Reddy, P.; Rama Reddy, K.; Sreenath Reddy, M.

    2013-01-01

    In the estimation of effective dose in the indoor environment due to Radon and its progeny the equilibrium factor (F) plays a significant role. It is the radioactive equilibrium between radon and its short-lived decay products. Generally in the dose estimation is made taking the equilibrium factor 0.4 (UNSCEAR value) for the radon and its progeny. But in practice the concentration of radon and its progeny vary significantly with local environmental conditions and time, subsequently the equilibrium factor F also changes and hence affects the effective dose estimation of a particular dwelling. Therefore the UNSCEAR F value does not reflect the actual effective doses. Therefore, the present study is carried out to estimate the equilibrium factors in different types of dwellings in the urban Hyderabad using SSNTDs. It is found that, the equilibrium factors in the urban Hyderabad vary from 0.01 to 0.71 with an average 0.32 ± 0.23. The average F values of urban Hyderabad relatively lower than Indian average and global average. The reasons for the lower equilibrium factor values in the study area have been discussed in this paper. (author)

  8. Role of radon and its progeny in the origin and evolution of life on earth

    International Nuclear Information System (INIS)

    Subba Ramu, M.C.; Vohra, K.G.

    1980-01-01

    The role of natural ionising radiations from radon and its progeny in catalysing certain chemical reactions and aiding certain biological phenomena leading to the formation and evolution of life on earth is explained with illustrations. (M.G.B.)

  9. Attached and Unattached Activity Size Distribution of Short-Lived Radon Progeny (214Pb) and Evaluation of Deposition Fraction

    International Nuclear Information System (INIS)

    Mohamed, A.; Ahmed, A.A.; Ali, A.E.; Yuness, M.

    2009-01-01

    Inhalation of 2 '2 2 Rn progeny in the domestic environment contributes the greatest fraction of the natural radiation exposure to the public. Dosimetric models are most often used in the assessment of human lung doses due to inhaled radioactivity because of the difficulty in making direct measurements. These models require information about the parameters of activity size distributions of radon progeny. The current study presents measured data on the attached and unattached activity size distributions of radon progeny in indoor air in El-Minia, Egypt. The attached fraction was collected using a low pressure Berner cascade impactor technique. A screen diffusion battery was used for collecting the unattached fraction. Most of the attached activities for 222 Rn progeny were associated with aerosol particles of the accumulation mode. The mean activity median aerodynamic diameter (AMAD) of this mode for 21 4 P b was determined to be 401 nm with relative mean geometric standard deviation of 2.96. The mean value of specific air activity concentration of 214 Pb associated with that mode was determined to be 4.74 %0.44 Bq m -3 . The relative mean geometric standard deviations of unattached 214 Pb was determined to be 1.21 with the mean activity thermodynamic diameter (AMTD) of 1.2 nm. The mean unattached activity concentration of 214 Pb was found to be 0.44%0.14 Bq m-3. Based on the obtained results of radon progeny size distributions (unattached and attached), the deposition fractions in each airway generation of the human lung were evaluated by using a lung deposition model

  10. 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.

  11. DOSEmanPRO - active electronic online personal air sampler for detection of radon progeny long lived alpha nuclides

    International Nuclear Information System (INIS)

    Streil, T.; Oeser, V.

    2002-01-01

    Full text: Using the micro system - technology we developed a online personal air sampler not bigger than a mobile phone, to open a new dimension in personal dosimetry of inhaled radioactive aerosols. The DOSEman PRO containing an internal pump with a continuous air flow of 0.15 I/min sample the radon progeny or other nuclides on a millipore filter with excellent spectroscopic resolution. A 1.5 cm 2 light protected ion-implanted silicon detector analyses the alpha radiation at the filter. This small detector head contains also the pre amplification and pulse processing. The alpha radiation of the radon progeny and the long lived alpha nuclides is analyzed by a 60 channel spectrometer. The energy resolution of the online analyzed filter spectra is in the order of 150 keV. Mechanical and electronic design enables one to distinguish the long lived alpha nuclides from the radon and thoron progeny very easily. Using a special algorithm we correct the influence of the tailing of the radon progeny to the long lived alpha nuclides and take into consideration possible interference in determining the long lived alpha nuclides. Because of the air sampling volume of nearly 10 I/h, the system has a high efficiency. The detection limit by 2 hours sampling time is 0.05 Bq/m 3 alpha nuclide concentration. In a modified device for air sampling especially of long-lived alpha nuclides like uranium, radium or plutonium, the flow rate is increased to 0,3 1/min e.g. during a 10 h sampling period we can detect 0.005 Bq/m 3 in a low radon atmosphere. Assuming increased radon progeny concentration, the statistical error for the long lived alpha nuclides will be higher, but in most of the cases for use in nuclear facilities low radon concentrations are ambient conditions. This concept of an electronic personal air sampler with an alpha spectroscopy offers some outstanding advantages compared to passive dosimeters or off-line alpha air filters: The dose value and the nuclide concentration is

  12. Levels of radon gas concentration and progeny in homes of Potosi City, Bolivia to 4000 m; Niveles de concentracion de gas radon y progenie en viviendas de la Ciudad de Potosi, Bolivia a 4000 msnm

    Energy Technology Data Exchange (ETDEWEB)

    Mamani M, R. [Universidad Autonoma Tomas Frias, Carrera de Fisica, Av. del maestro s/n, Edif. Central Potosi, Villa Imperial de Potosi (Bolivia, Plurinational State of); Claros J, J. [Universidad Autonoma Tomas Frias, Facultad de Minas Potosi, Centro de Investigacion, Av. Serrudo y Arce s/n, Villa Imperial de Potosi (Bolivia, Plurinational State of); Vasquez A, R., E-mail: raulm2k13@hotmail.com [Instituto Boliviano de Biologia de Altura, Calle Hoyos 953, La Paz (Bolivia, Plurinational State of)

    2015-10-15

    Full text: In this work the presence of radon gas was determined, which is a radioactive contaminant that comes from underground, able to penetrate the houses. The danger is that when mixed air and when inhaled can cause serious damage to the lungs, for the short life time that has radon and progeny for decay, damaging the pulmonary alveoli and reducing breathing capacity of the habitants, then causing polycythemia in some cases. The study was carried out in homes in the city of Potosi, Bolivia located at 4000 m. The quantification of radon gas and progeny was performed with the equipment Alpha-Zaeller-2 (Az-2), quantification was realized in 6 zones of the city of Potosi, chosen randomly. In each zone were carried out measurements in 40 homes (2 rooms more permanent), both day and night, for a period of 3 days in two different seasons and with concentrations of average humidity of 20, 50 and 80%. The values obtained for each period vary depending on the season and 30 to 50% of the allowable values given by the EPA and Who for housing. (Author)

  13. Unattached fraction and the aerosol size distribution of the radon progeny in a natural cave and mine atmospheres

    International Nuclear Information System (INIS)

    Butterweck, G.; Porstendoerfer, J.; Reineking, A.; Kesten, J.

    1992-01-01

    Measurements of the activity size distribution of aerosol-attached radon progeny and the amount of unattached radon daughters have been performed in mine atmospheres and a tourist cave. During working hours a large number (10 5 -10 6 cm -3 ) of aerosol particles is generated in mines, mainly by diesel engines. The activity size distribution of these aerosol particles has smaller median diameters (AMAD about 200 nm) than the aged aerosol existing in the mine during non-working hours (AMAD about 350 nm). Strictly correlated to the aerosol concentration, the unattached fraction of the radon progeny, f p , in the tourist cave (3000 particles per cm 3 ) is higher (f p = 0.1) than in mines (f p 0.01) during working hours. This yields 1.4-2.5 times higher radiation dose conversion factors in the natural cave than in mines under working conditions. (author)

  14. Mass spectrometric studies of the cluster formation of radon progeny

    Energy Technology Data Exchange (ETDEWEB)

    Gong, S L [Toronto Univ., ON (Canada). Dept. of Chemical Engineering and Applied Chemistry

    1994-12-31

    A new experimental system is developed to study the cluster formation of radon progeny with neutral molecules in the environment, which includes a modified mass spectrometer and a surface barrier detector. With the system, the cluster research is carried out at molecular level at which the mass of individual cluster formed is measured. A theory is also proposed to treat the cluster formation as a discrete process based on the ion-dipole and dipole-dipole interactions. Comparison between the theory and experiment is given. (author). 16 refs., 6 figs.

  15. Mass spectrometric studies of the cluster formation of radon progeny

    International Nuclear Information System (INIS)

    Gong, S.L.

    1993-01-01

    A new experimental system is developed to study the cluster formation of radon progeny with neutral molecules in the environment, which includes a modified mass spectrometer and a surface barrier detector. With the system, the cluster research is carried out at molecular level at which the mass of individual cluster formed is measured. A theory is also proposed to treat the cluster formation as a discrete process based on the ion-dipole and dipole-dipole interactions. Comparison between the theory and experiment is given. (author). 16 refs., 6 figs

  16. Inversion of the Jacobi-Porstendorfer room model for the radon progeny

    International Nuclear Information System (INIS)

    Thomas, J.; Jilek, K.; Brabec, M.

    2010-01-01

    The Jacobi-Porstendoerfer (J-P) room model describes the behaviour of radon progeny in the atmosphere of a room. It distinguishes between free and attached radon progeny in air. It has been successfully used without substantial changes for nearly 40 years. There have been several attempts to invert the model approximately to determine the parameters describing the physical processes. Here, an exact solution is aimed at as an algebraic inversion of the system of six linear equations for the five unknown physical parameters k, X, R, q f , q a of the room model. Two strong linear dependencies in this system, unfortunately do not allow to obtain a general solution (especially not for the ventilation coefficient k), but only a parameterized one or for reduced sets of unknown parameters. More, the impossibility to eliminate one of the two linear dependencies and the departures of the measured concentrations forces to solve a set of allowed combinations of equations of the algebraic system and to accept its mean values (therefore with variances) as a result of the algebraic inversion. These results are in agreement with results of the least squares method as well as of a sophisticated modern statistical approach. The algebraic approach provides, of course, a lot of analytical relations to study the mutual dependencies between the model parameters and the measurable quantities. (authors)

  17. Estimation of radiological dose from radon, thoron and their progeny levels in the dwellings of Shivamogga district, Karnataka, India

    International Nuclear Information System (INIS)

    Rangaswamvi, D.R.; Sannappa, J.; Srinivasa, E.

    2018-01-01

    Among all natural radiation exposure to man, inhalation of radon, thoron and their progenies are the major contributor (50 %) to the dose from ionizing radiation received by the general population. Based on the results of epidemiological studies in Europe and North America, the World Health Organization (WHO) has recommended reducing the indoor radon reference level from 200 to 100 Bq.m -3 . In view of this, focus has now been given for simultaneous measurement of radon, thoron and their progeny concentration in indoor air and also to estimate radiological dose in the dwellings of the Shivamogga district. The geology of the Shivamogga district comprises different types of rock formation such as granites, schists, magnetites and gneisses, Meta basalt, laterites, quartz and chlorite schist, Graywacke etc. Present study was concentrating more in granite bed rock regions along with their surrounding regions

  18. Evaluation of room air cleaners for the reduction of exposure and dose to indoor radon progeny

    International Nuclear Information System (INIS)

    Hopke, P.K.; Jensen, B.; Wasiolek, P.

    1994-01-01

    Since the proximate source of dose to the cells of the bronchial epithelium is the deposited radon progeny, the exposure and resulting dose could be reduced if the radon decay products were effectively removed from the indoor atmosphere. Thus, room air cleaners could be effective in reducing the risks associated with indoor radon. However, because of the short half-life of 218 Po, it grows back quickly and in the altered aerosol conditions that are produced by the presence of an air cleaner, the exposure/dose conditions as well as the magnitude of the dose can be substantially changed. To examine the nature of the exposure of individuals in normally occupied homes and to determine the effect of various types of room air cleaners on the exposure to and dose from the indoor radon progeny, a series of measurements have been made using an automated graded screen array system. Two extended experiments were performed in homes in Arnprior, Ontario and Parishville, NY, in which filtration systems, a positive ion electrostatic precipitator, and ioniser/fan systems have been tested for their ability to remove both airborne radioactivity and particles. In both experiments, measurements were made over one week periods with an air cleaner operating and the distributions of exposure are compared with measurements of the background conditions when no cleaner is functioning. The doses to both basal and secretory cells of the bronchial epithelium in the first eight generations of the bronchus were calculated using the model developed by James and their distributions are compared among the various exposure conditions. In most cases the presence of the air cleaner reduced the exposure to radon progeny. However, the reductions in dose were generally substantially smaller than the reductions in exposure. In the intercomparisons of the two filtration units and the two identical ioniser/fan systems, the units generally behaved in a similar manner. The results of this substantial set of

  19. Occupational exposure to radon progeny: Importance, experience with control, regulatory approaches

    International Nuclear Information System (INIS)

    Kraus, W.; Schwedt, J.

    2002-01-01

    An overview of possible occupational exposures to enhanced natural radiation in Germany is given, based on an analysis of the German Radiological Protection Commission. So far, the most significant exposure source is radon at underground and above ground workplaces. As a result of relevant regulations, in East Germany since the 70's a systematic monitoring of exposures to radon progeny has been introduced step by step in the uranium industry, in conventional ore mining, in show caves and mines, in enterprises for securing mining areas against subsidence, in radon spas and in water works in radon affected areas. Individual exposures have been assessed. The monitoring results for the period 1975-1998 are presented. Successful protection measures leading to a significant reduction of the exposures are discussed. using workplace monitoring results and registered occupancy times. In West Germany no regulations in this area were in force. Nevertheless, voluntary measuring programmes at similar workplaces were carried out. In case of unacceptable exposures successful protection measures were implemented. At present a systematic approach to control occupational exposures to radon is laid down in the European Directive 96/29/Euratom which has to be taken over in the national legislation to come. The expected number of workplaces to be included in the radiation protection system in Germany, the recommendable way of including different workplace types taking into account appropriate reference levels, and possible approaches to a graded system of workplace and individual monitoring are discussed in detail. (author)

  20. Need for an integrated approach towards the assessment of radon, thoron and their progeny exposures

    International Nuclear Information System (INIS)

    Mayya, Y.S.

    2008-01-01

    Recent publications dealing with epidemiological studies on North American and European populations have indicated statistically significant lung cancer risk coefficients attributable to residential radon exposures. These are essentially based on radon gas itself as the quantitative measure of exposures. However, considering that true exposures depend upon the intricate mechanisms of decay product deposition in the lung, it is necessary to go for the assessment of decay products including their size distributions and deposition velocities. This approach is essential for assessing the risks of thoron and its decay products which is of considerable importance in the public domain and in the thorium fuel cycle. The recent development of deposition based progeny concentration measurement techniques appear to be best suited for radiological risk assessments both among occupational workers and general study populations. These provide an easy to wear alternative for radon inhalation dosimetry similar to TLDs for external gamma radiations. It is urgently required to characterize their performance under a variety of residential indoor and workplace conditions. This may be achieved through an integrated multi-parametric study programme involving measurements of radon, thoron and their progeny concentrations along with fine and coarse fractions and indoor source terms. This will not only in delineate the true exposure profiles and indoor parameters (e.g. deposition velocities and air exchange rates) in the country, but also will help in establishing deposition dosimetry as a basic technique for inhalation exposure estimations for occupational workers and subjects living in high background radiation areas

  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. Effect of radon and its progeny on the expression and mutation of p53 in lung tissues of mice

    International Nuclear Information System (INIS)

    Piao Chunnan; Tian Mei; Liu Jianxiang; Ruan Jianlei; Su Xu

    2010-01-01

    Objective: To explore the effect of radon and its progeny on the expression and mutations of p53 in lung tissue of mouse model. Methods: Apoptosis was detected by terminal deoxynucleotidy transferase-mediated dUTP-biotin nick end labeling. The expression of p53 gene was analyzed by immunohistochemistry, Western blot and realtime-PCR. PCR-SSCP was used to detect the mutation of p53 in lung tissues. Results: Compared with those in the control group, the apoptotic index were increased significantly in 30 WLM and 60 WLM groups (t=18.11, -10.30, P<0.05). The p53 protein was increased significantly (t=-11.08, P<0.05; t=-7.00, P<0.05) in 30 WLM and 60 WLM groups. The mutation of p53 gene was not detected in lungs of radon-exposure mice. Conclusions: Lung and bronchus might be the targets of radon and its progeny, and p53 gene plays an important role in the progression of radon-induced lung injury. (authors)

  3. Levels of radon gas concentration and progeny in homes of Potosi City, Bolivia to 4000 m

    International Nuclear Information System (INIS)

    Mamani M, R.; Claros J, J.; Vasquez A, R.

    2015-10-01

    Full text: In this work the presence of radon gas was determined, which is a radioactive contaminant that comes from underground, able to penetrate the houses. The danger is that when mixed air and when inhaled can cause serious damage to the lungs, for the short life time that has radon and progeny for decay, damaging the pulmonary alveoli and reducing breathing capacity of the habitants, then causing polycythemia in some cases. The study was carried out in homes in the city of Potosi, Bolivia located at 4000 m. The quantification of radon gas and progeny was performed with the equipment Alpha-Zaeller-2 (Az-2), quantification was realized in 6 zones of the city of Potosi, chosen randomly. In each zone were carried out measurements in 40 homes (2 rooms more permanent), both day and night, for a period of 3 days in two different seasons and with concentrations of average humidity of 20, 50 and 80%. The values obtained for each period vary depending on the season and 30 to 50% of the allowable values given by the EPA and Who for housing. (Author)

  4. Probing the application of Fourier Transform Infrared (FTIR) spectroscopy for assessment of deposited flux of Radon and Thoron progeny in high exposure conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, R., E-mail: rosaline@barc.gov.in; Sapra, B.K.; Rout, R.P.; Prajith, R.

    2016-12-01

    Direct measurement of Radon and Thoron progeny in the atmosphere and occupational environments such as Uranium mines, Uranium and Thorium handling facilities has gained importance because of its radiological significance in inhalation dose assessment. In this regard, Radon and Thoron Progeny sensors (DTPS and DRPS) are the only passive solid state nuclear track detector (SSNTD, LR115) based devices which are being extensively used for time integrated direct progeny measurements. An essential component of the analysis is the chemical etching of the detectors, followed by spark counting of tracks and then estimation of the inhalation dose using appropriate calibration factors. Alternatively, the tracks may be counted using image analysis techniques. However, under high exposure conditions, both these methods have inherent limitations and errors arising due to increased frequency of tracks. In the present work, we probe the use of Fourier Transform Infra Red (FTIR) spectroscopy to analyse the deposited fluence of the progeny particulates based on change in transmittance of the nitric group vibrational bands of the LR115. A linear relationship between the transmittance and the deposited fluence was observed, which can be used to estimate the deposited fluence rate and the inhalation dose. This alternative method of analysis will provide a faster and non-destructive technique for inhalation dose assessment, specially for routine large scale measurements. - Highlights: • An alternative method of inhalation dose assessment. • Linearity between the transmittance of nitric goup bands and the deposited fluence. • Faster and non-destructive technique for high exposure scenarios.

  5. Numerical modelling of local deposition patients, activity distributions and cellular hit probabilities of inhaled radon progenies in human airways

    International Nuclear Information System (INIS)

    Farkas, A.; Balashazy, I.; Szoeke, I.

    2003-01-01

    The general objective of our research is modelling the biophysical processes of the effects of inhaled radon progenies. This effort is related to the rejection or support of the linear no threshold (LNT) dose-effect hypothesis, which seems to be one of the most challenging tasks of current radiation protection. Our approximation and results may also serve as a useful tool for lung cancer models. In this study, deposition patterns, activity distributions and alpha-hit probabilities of inhaled radon progenies in the large airways of the human tracheobronchial tree are computed. The airflow fields and related particle deposition patterns strongly depend on the shape of airway geometry and breathing pattern. Computed deposition patterns of attached an unattached radon progenies are strongly inhomogeneous creating hot spots at the carinal regions and downstream of the inner sides of the daughter airways. The results suggest that in the vicinity of the carinal regions the multiple hit probabilities are quite high even at low average doses and increase exponentially in the low-dose range. Thus, even the so-called low doses may present high doses for large clusters of cells. The cell transformation probabilities are much higher in these regions and this phenomenon cannot be modeled with average burdens. (authors)

  6. Submicron-sized aerosol and radon progeny measurements in an uranium mine

    International Nuclear Information System (INIS)

    Boulaud, D.; Chouard, J.C.

    1992-01-01

    Submicron-sized aerosol was studied in an uranium mine using an Electrical Aerosol Analyzer and a Differential Mobility Particle Sizer. In addition radon progeny particle size distributions were measured using a prototype instrument developed by us (SDI 2000). With cascade impactor the number weighted mean electrical mobility diameters and the geometric standard deviations ranged respectively from 0.05 to 0.1 μm and 1.8 to 2. The gross alpha activity weighted mean thermodynamic diameters ranged typically from 0.1 to 0.2 μm. 6 refs., 3 figs

  7. Measurement of the size distributions of radon progeny in indoor air

    International Nuclear Information System (INIS)

    Hopke, P.K.; Ramamurthi, M.; Li, C.S.

    1990-01-01

    A major problem in evaluating the health risk posed by airborne radon progeny in indoor atmospheres is the lack of available information on the activity-weighted size distributions that occur in the domestic environment. With an automated, semicontinuous, graded screen array system, we made a series of measurements of activity-weighted size distributions in several houses in the northeastern United States. Measurements were made in an unoccupied house, in which human aerosol-generating activities were simulated. The time evolution of the aerosol size distribution was measured in each situation. Results of these measurements are presented

  8. Study of indoor radon, thoron and their progeny concentration levels in the surrounding areas of Mangaldoi, Assam

    International Nuclear Information System (INIS)

    Deka, P.C.; Sarkar, S.; Goswami, T.D.; Sarma, B.K.

    2006-01-01

    Natural sources contribute a significant percentage of radiation towards the total radiation exposure that humans receive. The majority of this natural radiation is harmless to humans in the ambient environment. However, radon, a major component of the natural radiation that humans are exposed to (greater than sixty percent), can pose a threat to the public health when radon gas accumulates in poorly ventilated residential and occupational settings. Measurements of concentration of radon, thoron and their decay products in various indoor environment covering four seasons of a year were carried out using the passive time-integrated method by employing LR-15 type II detectors in plastic twin-chamber dosimeter cups. The estimated indoor radon levels for well ventilated houses varied from a minimum value of 25.2 Bq.m -3 to a maximum of 80J Bq.m -3 with an annual geometric mean of 46.9 Bq.m -3 and that for poorly ventilated houses varied from a minimum value of 46.8 Bq.m -3 to a maximum of 146.8 Bq.m -3 with the annual geometric mean of 82 .2 Bq.m -3 . The thoron levels in well ventilated houses were also varied from a minimum value of 4.9 Bq.m -3 to a maximum of 21.5 Bq.m -3 with an annual geometric mean of 10.5 Bq.m -3 and that for poorly ventilated houses varied from a minimum of 6.3 Bq.m -3 to a maximum value of 29.2 Bq.m -3 with the annual geometric mean of 14.1 Bq.m -3 . Thus it is seen that both radon and thoron levels are higher in poorly ventilated houses than in well-ventilated houses. The ranges of radon and thoron progeny levels for well ventilated houses were 0.10 mWL to 0.58 mWL with an annual geometric mean of 0.21 mWL and 0.01 mWL to 0.06 mWL with an annual geometric mean of 0.03 mWL respectively. Similar variation was also observed in poorly ventilated houses. In poorly ventilated houses, the radon and thoron progeny levels varied between 0.16 mWL and 1.61 mWL with an annual geometric mean of 0.41 mWL and 0.02 to 029 mWL with the annual geometric mean

  9. Determination of Lung-to-Blood Absorption Rates for Lead and Bismuth which are Appropriate for Radon Progeny

    International Nuclear Information System (INIS)

    Marsh, J.W.; Birchall, A.

    1999-01-01

    The ICRP Publication 66 Human Respiratory Tract Model (HRTM) treats clearance as a competitive process between absorption into blood and particle transport to the gastrointestinal tract and lymphatics. The ICRP recommends default absorption rates for lead and bismuth in ICRP Publication 71 but states that the values are not appropriate for short-lived radon progeny. This paper describes an evaluation of published data from volunteer experiments to estimate the absorption half-times of lead and bismuth that are appropriate for short-lived radon progeny. The absorption half-time for lead was determined to be 10±2 h, based on 212 Pb lung and blood retention data from several studies. The absorption half-time for bismuth was estimated to be about 13 h, based on 212 Bi urinary excretion data from one experiment and the ICRP biokinetic model for bismuth as a decay product of lead. (author)

  10. Direct progeny detection techniques and random epidemiology

    International Nuclear Information System (INIS)

    Mayya, Y.S.; Mishra, Rosaline; Sapra, B.K.

    2015-01-01

    Over the past 40 years, there has been considerable progress in the measurements methods and their application to the estimates of risks due to radon among general populations. The previous decade saw major development in this regard. It was the direct estimate of indoor radon risk from epidemiological studies in Europe and North America. These were important findings that demonstrated the presence of lung cancer risks at residential radon levels supplementing the generally used risks estimates at high exposures obtained from uranium miner's data. The residential radon epidemiological studies largely used radon concentration as a measure of exposure. The exposure to decay products, which are primarily the dose givers, are assumed to be proportional to the measured gas concentrations. Also, the presence of thoron was neglected in these studies. Although several corrections have appeared to these assessments, the question of variability of actual decay product exposures has largely remained unaddressed. In order to circumvent this limitation, passive techniques were developed to estimate the decay product concentrations directly using deposition monitors. These are based on detecting the alpha particles from decay products deposited on an absorber mounted LR-115 detectors. Known as Direct radon, and Thoron Progeny sensors (DRPS/DTPS), these have been further refined to separate fine fraction from the coarse fraction by wire-mesh capping techniques. Large number environmental calibration exercises and field data generation has been carried out on the progeny concentrations in Indian and some European environments. The development of progeny sensors offers a new tool for future epidemiology. Since in the Indian context, there exist no radon related epidemiological estimates of risk, it is time one conducts large scale studies to seek possible correlations between DRPS/DTPS data and lung cancer risks. While epidemiological studies in High background radiation areas

  11. Measurement of unattached radon progeny based in electrostatic deposition method; Medicion de la fraccion no unida a aerosoles de la progenie de {sup 222}Rn mediante un metodo de deposicion electrostatica

    Energy Technology Data Exchange (ETDEWEB)

    Canoba, A C; Lopez, F O

    1999-07-01

    A method for the measurement of unattached radon progeny based on its electrostatic deposition onto wire screens, using only one pump, has been implemented and calibrated. The importance of being able of making use of this method is related with the special radiological significance that has the unattached fraction of the short-lived radon progeny. Because of this, the assessment of exposure could be directly related to dose with far greater accuracy than before. The advantages of this method are its simplicity, even with the tools needed for the sample collection, as well as the measurement instruments used. Also, the suitability of this method is enhanced by the fact that it can effectively be used with a simple measuring procedure such as the Kusnetz method. (author)

  12. Radon in workplaces

    International Nuclear Information System (INIS)

    Reichelt, A.; Lehmann, K.-H.; Reineking, A.; Porstendoerfer, J.; Schwedt, J.; Streil, T.

    2000-01-01

    The radiological assessment of the results of radon measurements in dwellings is not automatically applicable to workplaces due to different forms of utilization, constructional conditions, time of exposure, heating and ventilation conditions, additional aerosol sources, aerosol parameters, chemical substances, etc. In order to investigate the peculiarities of the radon situation in workplaces located inside buildings compared with that in dwellings, long-time recordings of radon, attached radon progeny and unattached radon progeny concentrations ( 218 Po, 214 Pb, 214 Bi) are carried out at several categories of workplaces (e.g. offices, social establishments, schools, production rooms, workshops, kitchens, agricultural facilities). 36 workplaces have been investigated. There have been carried out at least 2-3 long-time recordings for each workplace during different seasons. At the same time the gamma dose rate, meteorological conditions, aerosol particle concentrations have been registered. Many special dates from the workplaces and the buildings have been recorded. Activity size distribution of the aerosol-attached and unattached fraction of short-lived radon decay products have been determinated in 20 workplaces. Mainly the following measurement systems were used: Radon- and Radon Progeny Monitor EQF 3020, SARAD GmbH, Germany. Alpha-Track Radon Detectors, BfS Berlin, Germany. Screen Diffusion Batteries with Different Screens, University of Goettingen, Germany. Low-Pressure Cascade Impactor, Type BERNER. Condensation Nuclei Counter, General Electric, USA. PAEC-f p -Rn-Monitor, University of Goettingen, Germany. Through the measurements, many peculiarities in the course of the radon-concentration, the equilibrium factor F, the unattached fraction f p and the activity size distribution have been determined. These amounts are influenced mainly by the working conditions and the working intervals. The influence of these peculiarities in workplaces on the dose have

  13. Variation of indoor radon progeny concentration and its role in dose assessment

    International Nuclear Information System (INIS)

    Singh, Manmohan; Singh, Kulwant; Singh, Surinder; Papp, Z.

    2008-01-01

    Instantaneous measurements of equilibrium equivalent concentration of radon (EEC Rn ) were taken over a period of 1 year in 2004 in a typical house at Amritsar city, located in the northwest part of India. A method based on absolute beta counting subsequent to grab aerosol sampling was used. During that year, EEC Rn varied between 1.56 Bq m -3 and 22.77 Bq m -3 with average value of 8.76 Bq m -3 . EEC Rn decreased with the transition from winter to summer and vice versa, having a negative correlation with outdoor temperature. The use of mechanical ventilation, under normal living conditions during summer, caused an extra decrease in the concentrations. The variations with temperature and mechanical ventilation are discussed. Some major issues related to the uncertainties in dose calculations caused by the lack of knowledge of equilibrium factor and ignoring the effect of life style on the radon and its progeny concentrations are discussed

  14. Aerosol properties of indoor radon decay products

    International Nuclear Information System (INIS)

    Martell, E.A.

    1984-01-01

    Lung cancer risks attributable to indoor radon are highly dependent on the properties of radon progeny aerosols which, in turn, are dependent on the nature and concentration of small particles in indoor air. In clean filtered air, radon progeny are attached to small hygroscopic particles of high mobility which are rapidly deposited on surfaces. By contrast, radon progeny attached to cigarette smoke are on large particles of low mobility which persist in air. Radon progeny ingaled by smokers are largely associated with smoke particles from 0.5 to 4.0 μm diameter. Such particles are selectively deposited at bronchial bifurcations and are highly resistant to dissolution. The attached radon progeny undergo a substantial degree of radioactive decay at deposition sites before clearance which gives rise to large alpha radiation doses in small volumes of bronchial epithelium. These processes provide new insights on mechanisms of bronchial cancer induction and on relative risks of lung cancer in smokers, passive smokers, and other non-smokers. (Author)

  15. Dose assessment from exposure to radon, thoron and their progeny concentrations in the dwellings of sub-mountainous region of Jammu and Kashmir, India

    International Nuclear Information System (INIS)

    Kaur, M.; Dr. B. R. Ambedkar National Institute of Technology, Jalandhar, Punjab; Kumar, A.; Mehra, R.; Mishra, R.

    2018-01-01

    The present work deals with the assessment of annual inhalation dose due to exposure of indoor radon, thoron and their progeny concentrations in the villages situated in sub-mountainous region of Jammu and Kashmir, India. The distribution of the data and the homogeneity of medians among different seasons and dwellings were assessed with the Shapiro-Wilk test and the Mann-Whitney test. The estimated total annual inhalation dose in these villages varied from 0.5 to 1.9 mSv year -1 which is less than the prescribed limit by ICRP (2008). Thus, the investigated area is safe from irradiation of radon, thoron and their progeny. (author)

  16. SARAD EQF 3020 - A new microsystem based monitoring system for the continuous measurement of radon and the attached and unattached fraction of the radon progeny

    International Nuclear Information System (INIS)

    Streil, T.; Holfeld, G.; Oeser, V.; Feddersen, C.; Schoenefeld, K.

    1996-01-01

    Due to the large differences in the dose factors for radon and radon daughters it's recommended to measure both, but monitors for the continuous and simultaneous measurement of radon and radon progeny concentrations are too expensive to be widely used if they are built from individual components. Integrating detector, readout electronics, memory and an A/D converter on a single chip offers far lower prices at least if this silicon microsystem can be produced in large quantities. It is known that dRAM cells of commercial available memories are sensitive to alpha particles, but even if one accepts unstable operating conditions (Ucc 2 . Further development with special PMOS-transistors in a floating n-well as sensor cells has resulted in an alpha particle spectrometric microsystem with an effective sensor array of 40 mm 2 . Alternative for higher resolution we developed PiN -structures with more than 100 mm 2 sensor area with integrated preamplification

  17. Radon Research Program, FY 1992

    International Nuclear Information System (INIS)

    1993-04-01

    The United States Department of Energy, Office of Health and Environmental Research (DOE/OHER) is the principal federal agency conducting basic research related to indoor radon. The scientific information being sought in this program encompasses research designed to determine radon availability and transport outdoors, modeling transport into and within buildings, physics and chemistry of radon and radon progeny, dose response relationships, lung cancer risk, and mechanisms of radon carcinogenesis. There still remains a significant number of uncertainties in the currently available knowledge that is used to estimate lung cancer risk from exposure to environmental levels of radon and its progeny. The main goal of the DOE/OHER Radon Research Program is to develop information to reduce these uncertainties and thereby provide an improved health risk estimate of exposure to radon and its progeny and to identify and understand biological mechanisms of lung cancer development and required copollutants at low levels of exposure. Information useful in radon control strategies is also provided by the basic science undertaken in this program

  18. Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres. Progress report, May 1, 1993--January 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Hopke, P.K.

    1993-01-01

    Progress is reported on the chemical and physical behavior of the {sup 218}Po atom immediately following its formation by the alpha decay of radon. Two areas of radon progeny behavior are being pursued; laboratory studies under controlled conditions to better understand the fundamental physical and chemical processes that affect the progeny`s atmospheric behavior and studies in actual indoor environments to develop a better assessment of the exposure of the occupants of that space to the size and concentration of the indoor radioactive aerosol. The specific tasks addressed were to determine the formation rates of {center_dot}OH radicals formed by the radiolysis of air following radon decay, to examine the formation of particles by the radiolytic oxidation of substances like SO{sub 2}, ethylene, and H{sub 2}S to lower vapor pressure compounds and determine the role of gas phase additives such as H{sub 2}O and NH{sub 3} in determining the particle size, to measure the rate of ion-induced nucleation using a thermal diffusion cloud chamber, and to measure the neutralization rate of {sup 218}PoO{sub x}{sup +} in O{sub 2} at low radon concentrations. Initial measurements were conducted of the activity size distributions in actual homes with occupants present so that the variability of the indoor activity size distributions can be assessed with respect to indoor aerosol sources and general lifestyle variations of the occupants. A prospective study of the utility of measurement of deposited {sup 210}Pb embedded in glass surfaces as a measure of the long-term, integrated exposure of the population to radon are described. Methodology was developed to determine the hygroscopicity of the indoor aerosol so that the changes in deposition efficiency of the radioactive indoor aerosol with hygroscopic growth in the respiratory tract can be assessed.

  19. Assessing the deposition of radon progeny from a uranium glass necklace

    International Nuclear Information System (INIS)

    Hanse, M.F.; Moss, G.R.

    2015-01-01

    Could jewellery made from uranium glass beads pose an increased risk to skin cancer? The literature Eatough (Alpha-particle dosimetry for the basal layer of the skin and the radon progeny 218 Po and 214 Po. Phys. Med. Biol. 1997;42:1899-1911.) suggests that the alphas from the short-lived radon daughters, 218 Po and 214 Po, may reach the basal layer of the epidermis, which is believed to be important in the induction of skin cancers. The deposition of the alphas from the 218 Po and 214 Po daughters was investigated using PADC detector material. The expectation would be that no alpha particles would penetrate through the dead skin layer, assuming the average of 70 microns used in radiation protection, but the skin around the collar bone could potentially be thinner than the assumed average. It should be noticed that by inserting a slice of pig skin in between the necklace and the PADC, no great excess of alpha tracks were seen after 1 week of exposure in the freezer. There was, however, a clear signal through the pig skin from beta particles, confirming the potential of a uranium bead necklace posing a health risk. (authors)

  20. Unattached fraction and the size distribution of the radon progeny in indoor air

    International Nuclear Information System (INIS)

    Yamasaki, K.; Shimo, M.

    1992-01-01

    The size-distribution of the aerosol-attached radon progeny and the unattached (cluster) fraction were measured by using a low pressure cascade impactor and a single wire screen in a building of the nuclear facility. The radon concentration at the condition of ventilation 'ON' was about 50 Bq m -3 , but it increased exponentially after ventilation 'OFF' and reached to the saturated concentration of about 600 Bq m -3 . At the condition of low aerosol concentration without additional aerosol, the activity median aerodynamic diameter, the geometric standard deviation and the unattached fraction were, respectively, 0.4 μm, 2.7-2.9 and 0.3-0.5. On the other hand, at the condition of high aerosol concentration with burning a mosquito coil, these were, 0.4 μm, 2.1 and 0.02-0.03. These yield 2.5 times higher radiation dose conversion factors at the low aerosol condition than the high aerosol condition. (author)

  1. 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)

  2. 220Radon (Thoron) and progeny exposures in the front-end of nuclear fuel cycle activities with special reference to radioactive minerals, thorium and rare earths processing

    International Nuclear Information System (INIS)

    Pillai, P.M.B.

    2008-01-01

    Radon is a major Source of radiation exposure both at home and work places due to its universal presence. The International Commission on Radiological Protection has always treated the radioactive noble gas radon ( 222 Rn) and its isotope thoron ( 220 Rn) as a separate subject. ICRP Publication 65 (ICRP, 1993) summarizes the current knowledge of health effects of inhaled radon and its decay products and gives recommendations/guidelines for the control of exposures due to high radon levels encountered in dwellings and work places. A major departure from earlier publications on the subject is the entirely epidemiological considerations for developing the recommendations. In work place monitoring the progeny concentrations are of primary concern than the gases themselves. However radon/thoron gas measurements may also be used provided reliable information on the equilibrium factors are available. Though many developments have taken place and many options are available for individual monitoring for radon (mainly progeny) exposures of occupational workers, a viable personal dosimeter for individual monitoring for thoron daughters is yet to materialize. The doses are mostly estimated by making use of work place monitoring data in combination with occupancy factors

  3. Instrumentation for radon measurement and diagnosis

    International Nuclear Information System (INIS)

    Whyte, N.; Ellacott, K.; Brabant, L.

    1990-01-01

    Knowledge of existing protocols and guidelines, coupled with equipment acumen can make for a successful endeavor in the radon field. But where do you collect a users perspective on radon equipment? Obtaining a first hand understanding of how radon detection equipment may be applied can be a lengthy and expensive process. In this paper first principals of progeny collection, and counting, are covered. Use of Thomson and Nielsen equipment to screen, and diagnose radon will e presented. Equipment performance in a wide variety of field applications and in calibration chambers will be brought to light. The distinctive nature and versatility of the equipment will e outlined with applications information, system performance, and unique configurations

  4. The field measurements of the activity-weighted size distributions of radon decay products

    International Nuclear Information System (INIS)

    Wasiolek, P.; Montassier, N.; Hopke, P.K.

    1991-01-01

    Because of the importance of particle size in the calculations of dose deposited in the respiratory tract by radon progeny, the determination of the size distribution of radon decay products in indoor air had increased in interest in recent years. A system for the measurement of the activity-weighted size distribution of radon decay products at environmental levels has been developed. The system (ASC-GSA) utilizes a combination of six multiple wire screens (Graded Screen Array) sampler detector units operated in parallel. The cut off points of the samplers and the data deconvolution procedure allow to obtain the activity fractions of radon progeny in the size range 0.5-500 mn. The computer control of sampling, alpha counting and data storage permits the operation of the system on the semi-continuous basis. The primary application of the ASC-GSA system has been to collect data of activity-weighted size distributions of radon progeny in real house environments. The results of field measurements in several houses with elevated radon levels are presented

  5. On the interaction between radon progeny and particles generated by electronic and traditional cigarettes

    Science.gov (United States)

    Vargas Trassierra, C.; Cardellini, F.; Buonanno, G.; De Felice, P.

    2015-04-01

    During their entire lives, people are exposed to the pollutants present in indoor air. Recently, Electronic Nicotine Delivery Systems, mainly known as electronic cigarettes, have been widely commercialized: they deliver particles into the lungs of the users but a "second-hand smoke" has yet to be associated to this indoor source. On the other hand, the naturally-occurring radioactive gas, i.e. radon, represents a significant risk for lung cancer, and the cumulative action of these two agents could be worse than the agents separately would. In order to deepen the interaction between radon progeny and second-hand aerosol from different types of cigarettes, a designed experimental study was carried out by generating aerosol from e-cigarette vaping as well as from second-hand traditional smoke inside a walk-in radon chamber at the National Institute of Ionizing Radiation Metrology (INMRI) of Italy. In this chamber, the radon present in air comes naturally from the floor and ambient conditions are controlled. To characterize the sidestream smoke emitted by cigarettes, condensation particle counters and scanning mobility particle sizer were used. Radon concentration in the air was measured through an Alphaguard ionization chamber, whereas the measurement of radon decay product in the air was performed with the Tracelab BWLM Plus-2S Radon daughter Monitor. It was found an increase of the Potential Alpha-Energy Concentration (PAEC) due to the radon decay products attached to aerosol for higher particle number concentrations. This varied from 7.47 ± 0.34 MeV L-1 to 12.6 ± 0.26 MeV L-1 (69%) for the e-cigarette. In the case of traditional cigarette and at the same radon concentration, the increase was from 14.1 ± 0.43 MeV L-1 to 18.6 ± 0.19 MeV L-1 (31%). The equilibrium factor increases, varying from 23.4% ± 1.11% to 29.5% ± 0.26% and from 30.9% ± 1.0% to 38.1 ± 0.88 for the e-cigarette and traditional cigarette, respectively. These growths still continue for long

  6. Radon Research Program, FY 1991

    International Nuclear Information System (INIS)

    1992-03-01

    The scientific information being sought in this program encompasses research designed to determine radon availability and transport outdoors, modeling transport into and within buildings, physics and chemistry of radon and radon progeny, dose response relationships, lung cancer risk, and mechanisms of radon carcinogenesis. The main goal of the DOE/OHER Radon Research Program is to develop information to reduce these uncertainties and thereby provide an improved health risk estimate of exposure to radon and its progeny as well as to provide information useful in radon control strategies. Results generated under the Program were highlighted in a National Research Council report on radon dosimetry. The study concluded that the risk of radon exposure is 30% less in homes than in mines. This program summary of book describes the OHER FY-1991 Radon Research Program. It is the fifth in an annual series of program books designed to provide scientific and research information to the public and to other government agencies on the DOE Radon Research Program

  7. Radon studies in selected workplaces

    International Nuclear Information System (INIS)

    Randle, M.W.

    2000-01-01

    Radon progeny levels were measured in coal mines, a hard rock mine and two underground hydro power stations, to indicate if there is a health problem associated with exposure to radon and radon progeny in these workplaces. The average alpha concentrations ranged from 37 to 276 Bq m -3 , with the highest levels being found in a mine with no ventillation that was being decommissioned. Average dosages were calculated to be 0.1 - 0.7 mSv y -1 . Radon progeny levels in coal mines measured in the return air circuit are indicative of levels to which a worker at the face would be exposed. They were well below international guidelines for intervention in New Zealand mines, as were the slightly higher levels in two underground hydro power stations. These results confirm that radon levels in New Zealand are low. Even in the extreme situation represented by the Sullivan mine with no ventillation the levels do not warrant concern. 11 refs., 2 tabs

  8. Measurement of radon progeny concentrations in air by alpha-particle spectrometey

    International Nuclear Information System (INIS)

    Kerr, G.D.

    1975-07-01

    A technique is presented for measuring air concentrations of the short-lived progeny of radon-222 by the use of alpha spectrometry. In this technique, the concentration of RaA, RaB, and RaC are calculated from one integral count of the RaA and two integral counts of the RaC' alpha-particle activity collected on a filter with an air sampling device. The influence of air sampling and counting intervals of time on the accuracy of the calculated concentrations is discussed in the report. A computer program is presented for use with this technique. It is written in the BASIC language. The program will calculate the air concentrations of RaA, RaB, and RaC, and will estimate the accuracy in these calculated concentrations. (U.S.)

  9. Validation of the abbreviated Radon Progeny Integrating Sampling Unit (RPISU) method for Mesa County, Colorado

    International Nuclear Information System (INIS)

    Langner, G.H. Jr.

    1987-06-01

    The US Department of Energy (DOE) Office of Remedial Action and Waste Technology established the Technical Measurements Center at the DOE Grand Junction, Colorado, Projects Office to standardize, calibrate, and compare measurements made in support of DOE remedial action programs. Indoor radon-daughter concentration measurements are made to determine whether a structure is in need of remedial action. The Technical Measurements Center conducted this study to validate an abbreviated Radon Progeny Integrated Sampling Unit (RPISU) method of making indoor radon-daughter measurements to determine whether a structure has a radon-daughter concentration (RDC) below the levels specified in various program standards. The Technical Measurements Center established a criterion against which RDC measurements made using the RPISU sampling method are evaluated to determine if sampling can be terminated or whether further measurements are required. This abbreviated RPISU criterion was tested against 317 actual sets of RPISU data from measurements made over an eight-year period in Mesa County, Colorado. The data from each location were tested against a standard that was assumed to be the same as the actual annual average RDC from that location. At only two locations was the criterion found to fail. Using the abbreviated RPISU method, only 0.6% of locations sampled can be expected to be falsely indicated as having annual average RDC levels below a given standard

  10. Environmental radon dosimetry in Indian dwellings and workplaces

    Energy Technology Data Exchange (ETDEWEB)

    Kant, K. [K.L.Mehta Dayanand College for Women, Dept. of Physics, Haryana (India); Upadhyay, S.B. [B.S.A. College, Dept. of Physics, Mathura, (India)

    2006-07-01

    Measurements of radon and its progeny in the dwellings and environment of workplaces are important because the radiation dose to human population due to inhalation of radon and its progeny contribute more than 50% of the total dose from natural sources and is the second leading cause of lung cancer after smoking. Recent experimental and epidemiological studies suggest that inhalation of radon progeny, which are the most important source of irradiation of the human respiratory track in workplace and domestic environment could be a cause of lung cancer. The quantification of iidual radon exposure over a long time period is one of the main issues. In the present study, we will report the results of radon monitoring carried out in the environment of workplaces of an oil refinery, LPG bottling plant, thermal power plant and gas power plant, besides the typical and modern Indian dwellings using alpha sensitive L.R.-115 type II solid-state nuclear track detectors in order to quantify the dose to the workers and the inhabitants. For comparison, the radon and its progeny levels were also measured in dwellings far away from the plants. Radon and its progeny levels were found higher in the environment of workplaces and dwellings in the vicinity of the plants. The details of the results obtained will be reported in the full paper. (authors)

  11. Environmental radon dosimetry in Indian dwellings and workplaces

    International Nuclear Information System (INIS)

    Kant, K.; Upadhyay, S.B.

    2006-01-01

    Measurements of radon and its progeny in the dwellings and environment of workplaces are important because the radiation dose to human population due to inhalation of radon and its progeny contribute more than 50% of the total dose from natural sources and is the second leading cause of lung cancer after smoking. Recent experimental and epidemiological studies suggest that inhalation of radon progeny, which are the most important source of irradiation of the human respiratory track in workplace and domestic environment could be a cause of lung cancer. The quantification of individual radon exposure over a long time period is one of the main issues. In the present study, we will report the results of radon monitoring carried out in the environment of workplaces of an oil refinery, LPG bottling plant, thermal power plant and gas power plant, besides the typical and modern Indian dwellings using alpha sensitive L.R.-115 type II solid-state nuclear track detectors in order to quantify the dose to the workers and the inhabitants. For comparison, the radon and its progeny levels were also measured in dwellings far away from the plants. Radon and its progeny levels were found higher in the environment of workplaces and dwellings in the vicinity of the plants. The details of the results obtained will be reported in the full paper. (authors)

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

    Science.gov (United States)

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

    2016-04-01

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

  13. Radon in uranium mining industry and application of SSNTD in monitoring and dose evaluation

    International Nuclear Information System (INIS)

    Khan, A.H.

    2006-01-01

    Radon is present everywhere and accounts for a globally major share of natural radiation exposure of the population. Though it is present in most of the underground workings it is a source of concern in uranium mining and ore processing industry as well as in many other operations carried out in confined spaces below the ground, like railway tunnels and non-uranium underground mines. Many monitoring techniques are available for evaluation of radon and its short-lived progeny concentrations. Scintillation cell techniques, also called Lucas cell, is one of the earliest developed methods of radon monitoring still widely used in mines where appreciable concentrations of radon above about 40-50 Bq.m -3 are expected. For low concentration of radon as observed in the atmosphere, dwellings and other workplaces, the radon absorption in charcoal followed by gamma counting, two filter method and electrostatic techniques are available. Solid state nuclear track detectors (SSNTD) are now widely used for a variety of situations for monitoring of low level of radon over an extended period of time. It is now extensively used in radon monitoring in dwellings and also in radon dosimetry in mines. Radon daughters being the more important contributors to the internal radiation exposure are also being monitored using conventional techniques as well as SSNTD. Various monitoring techniques for radon and its progeny and the concentrations observed at different stages of uranium mining, ore processing and tailings management are discussed in this presentation. (author)

  14. Optimization of filtration for control of exposure to radon progeny

    International Nuclear Information System (INIS)

    Curling, C.A.; Rudnick, S.N.; Ryan, P.B.; Moeller, D.W.

    1989-01-01

    The theoretical optimization of filter characteristics that minimize an individual's dose from the inhalation of radon progeny is described. The computer simulation presented combines models for a well-mixed room, lung deposition, and lung dose equivalent. A modified form of the Jacobi-Porstendorfer room model and the Jacobi-Eisfeld lung dosimetry model are used for the simulation. The parameters of the filter that are optimized include the filter's solidity, thickness, and fiber diameter. Room ventilation, particle size distribution and concentration, and other factors are specified. The theoretical model is used to determine optimal filter characteristics for reducing the lung dose equivalent under specified room conditions. The resulting optimal design is a thin filter (0.1 - 0.7 mm) of low solidity (0.5 - 1.0%) and relatively large diameter fibers (30 - 100 μm). This model indicates that a significant reduction in the dose-equivalent rate can be achieved through the use of a properly designed recirculating filter system

  15. Measurement of indoor radon-thoron and their progeny levels in dwellings and radon concentrations in ground water of Hassan city, Karnataka, India

    International Nuclear Information System (INIS)

    Srinivasa, E.; Rangaswamy, D.R.; Sannappa, J.

    2014-01-01

    The indoor radon and thoron concentrations in dwellings of Hassan city have been measured by using LR-115 type-Il Solid State Nuclear Tracks Detectors (SSNTDs). Measurements were carried in summer season from March to May-2013. The radon and thoron activity concentration in the corresponding dwellings has been found to vary from 7.4 to 45.7 Bqm -3 and 5.4 to 34.9 Bqm -3 with a median of 23.59±11 Bqm -3 and 14.47±8 Bqm -3 respectively. The overall average radon concentrations are found to be less than the lower reference level of 200 Bq m -3 of the International Commission on Radiological Protection. The annual effective dose received due to radon and its progeny by the inhabitants in the dwellings under study has also been calculated which found to vary from 0.320 ±0.4 to 1.86 ±1.1 mSv y -1 with an average value of 0.957±0.8 mSv -1 . The obtained results are much lower than the upper reference level of 10 mSv y -1 (ICRP 2007). Radon in bore well water at different locations of Hassan city was determined using the emanometry technique and exposure dose from ingestion of drinking water was estimated. The radon concentration in ground water was found to vary from 19.49 to 60.74 Bq l -1 with an average value of 47.16±14Bq l -1 . From this study it is evident that, the recorded ground water radon concentration values are higher than MCL of 11 Bq l -1 proposed by USEPA. The total dose due to inhalation and ingestion of 222 Rn in ground water ranges from 0.053 mSv y -1 to 0.165mSv y -1 with an average value of 0.127±0.038mSv y -1 . (author)

  16. Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Hopke, P.K.

    1992-07-01

    This report describes studies on the chemical and physical behavior of the [sup 218]Po atom immediately following its formation by the alpha decay of radon. Because small changes in size for activity in the sub-10 nm size range result in large changes in the delivered dose per unit exposure, this behavior must be understood if the exposure to radon progeny and its dose to the cells in the respiratory tract are to be fully assessed. The specific tasks of the controlled laboratory studies are to determine the formation rates of [center dot]OH radicals formed by the radiolysis of air following radon decay, to examine the formation of particles by the radiolytic oxidation of substances like SO[sub 2] ethylene, and H[sub 2]S to lower vapor pressure compounds and determine the role of gas phase additives such as H[sub 2]O and NH[sub 3] in determining the particle size, to measure the rate of ion-induced nucleation using a thermal diffusion cloud chamber, and to measure the neutralization rate of [sup 218]Po[sub x][sup +] in O[sub 2] at low radon concentrations. Tasks of the exposure studies in occupied indoor spaces are to initiate measurements of the activity size distributions in actual homes with occupants present so that the variability of the indoor activity size distributions can be assessed with respect to indoor aerosol sources and general lifestyle variations of the occupants, to initiate a prospective study of the utility of measurement of deposited [sup 210]Pb embedded in glass surfaces as a measure of the long-term, integrated exposure of the population to radon, and to develop the methodology to determine the hygroscopicity of the indoor aerosol so that the changes in deposition efficiency of the radioactive indoor aerosol with hygroscopic growth in the respiratory tract can be assessed.

  17. Radon progeny distribution in cylindrical diffusion chambers

    International Nuclear Information System (INIS)

    Pressyanov, Dobromir S.

    2008-01-01

    An algorithm to model the diffusion of radioactive decay chain atoms is presented. Exact mathematical solutions in cylindrical geometry are given. They are used to obtain expressions for the concentrations of 222 Rn progeny atoms in the volume and deposited on the wall surface in cylindrical diffusion chambers. The dependence of volume fractions of 222 Rn progeny and chamber sensitivity on the coefficient of diffusion of 222 Rn progeny atoms in air is modeled.

  18. Naturally occurring radionuclides in drinking water before and after radon removal

    International Nuclear Information System (INIS)

    Swedjemark, G.A.; Linden, A.

    1998-06-01

    Radon removal can, with a good effect, be used to remove radon from well water. The short-lived radon progeny have been investigated in the raw and cleaned water from six private wells where radon removal based on aeration and recirculation of the water have been installed. The results from this pilot study indicate that the short-lived radon progeny in some cases follow the water to the tap for consumption to such an extent that the problem should be considered. The extent of the study is not sufficient for general conclusions. However, it is important to stress that the effective dose from the short-lived progeny is always lower than it would have been from the radon, when no radon is removed

  19. Cigarette use and the estimation of lung cancer attributable to radon in the United States

    International Nuclear Information System (INIS)

    Lubin, J.H.; Steindorf, K.

    1995-01-01

    Residential exposure to radioactive radon and its decay products has been estimated to account for 10-12% of all lung cancer deaths in the US. It has been difficult to evaluate fully the impact of cigarette smoking, the most important cause of lung cancer, on this estimate, because factors for patterns of tobacco use have not been included in the risk models, since risk models are derived from studies of underground miners exposed to radon and detailed data on smoking are limited. Lung cancer risk estimates for exposure to radon progeny in smoker and non-smoker populations are obtained by applying the same risk model to each population group, thereby assuming the joint effects of smoking and exposure to radon progeny are multiplicative. However, in miners, joint relative risks (RR) for the two exposures are most consistent with an intermediate relationship between multiplicative and additive, so that the present approach likely results in an overestimate of risk in smokers and an underestimate of risk in nonsmokers. One approach for adjusting risk models to incorporate smoking status is based on the relative magnitude of the effects of radon progeny in smokers and nonsmokers and therefore may not be applicable to non-miner populations if the proportion of smokers and the RR for smoking differ. We show that the modification can be derived explicitly by assuming an arithmetic mixture model for the joint RR for smoking and exposure to radon progeny. In this way, smoking parameters in the population of interest (the proportion of smokers and the RR of smoking) can be used directly to adjust radon progeny risk models and obtain risk estimates that are specific for smokers and nonsmokers. With an intermediate RR relationship for smoking and radon progeny, the attributable percentage of lung cancer deaths from residential radon may be twofold greater in nonsmokers than in smokers. 20 refs., 1 fig., 3 tabs

  20. Calculating CR-39 Response to Radon in Water Using Monte Carlo Simulation

    International Nuclear Information System (INIS)

    Razaie Rayeni Nejad, M. R.

    2012-01-01

    CR-39 detectors are widely used for Radon and progeny measurement in the air. In this paper, using the Monte Carlo simulation, the possibility of using the CR-39 for direct measurement of Radon and progeny in water is investigated. Assuming the random position and angle of alpha particle emitted by Radon and progeny, alpha energy and angular spectrum that arrive at CR-39, the calibration factor, and the suitable depth of chemical etching of CR-39 in air and water was calculated. In this simulation, a range of data were obtained from SRIM2008 software. Calibration factor of CR-39 in water is calculated as 6.6 (kBq.d/m 3 )/(track/cm 2 ) that is corresponding with EPA standard level of Radon concentration in water (10-11 kBq/m 3 ). With replacing the skin instead of CR-39, the volume affected by Radon and progeny was determined to be 2.51 mm 3 for one m 2 of skin area. The annual dose conversion factor for Radon and progeny was calculated to be between 8.8-58.8 nSv/(Bq.h/m 3 ). Using the CR-39 for Radon measurement in water can be beneficial. The annual dose conversion factor for Radon and progeny was calculated to be between 8.8-58.8 nSv/ (Bq.h/m 3 ).

  1. Radon dosimetry for workers: ICRP's approach

    International Nuclear Information System (INIS)

    Marsh, James W.; Laurier, Dominique; Tirmarche, Margot

    2017-01-01

    The International Commission on Radiological Protection (ICRP) has recently published two reports on radon exposure; Publication 115 on lung cancer risks from radon and radon progeny and Publication 126 on radiological protection against radon exposure. A specific graded approach for the control of radon in workplaces is recommended where a dose assessment is required in certain situations. In its forthcoming publication on Occupational Intakes of Radionuclides (OIR) document, Part 3, effective dose coefficients for radon and thoron will be provided. These will be calculated using ICRP reference biokinetic and dosimetric models. Sufficient information and dosimetric data will be given so that site-specific dose coefficients can be calculated based on measured aerosol parameter values. However, ICRP will recommend a single dose coefficient of 12 mSv per working level month (WLM) for inhaled radon progeny to be used in most circumstances. This chosen reference value was based on both dosimetry and epidemiological data. In this paper, the application and use of dose coefficients for workplaces are discussed including the reasons for the choice of the reference value. Preliminary results of dose calculations for indoor workplaces and mines are presented. The paper also briefly describes the general approach for the management of radon exposure in workplaces based both on ICRP recommendations and the European directive (2013/59/EURATOM). (authors)

  2. The effect of natural ventilation on radon and radon progeny levels in houses

    International Nuclear Information System (INIS)

    Cavallo, A.; Gadsby, K.; Reddy, T.A.; Socolow, R.

    1992-01-01

    In contradiction to the widely held assumption that ventilation is ineffective as a means of reducing indoor radon concentrations, experiments in a research house have shown that the basement radon level can be reduced by a factor of 5-10 using only natural ventilation. Measurements of the outdoor-basement pressure differential and the radon entry rate show that this unexpectedly large reduction in indoor radon levels is caused by two complementary physical processes. The first mechanism is the obvious one: dilution. Radon concentrations are lowered by the addition of uncontaminated outdoor air. The second mechanism is less evident: an open basement window reduces basement depressurisation. This decreases the rate at which radon-laden soil gas is drawn into the house. It was also found that the radon entry rate is a linear function of basement depressurisation up to a differential pressure of about 4 Pa, as would be expected for laminar soil gas flow; opening two basement windows approximately doubles the building air exchange rate and reduces the radon entry rate by up to a factor of 5. (author)

  3. Modelling the effect of non-uniform radon progeny activities on transformation frequencies in human bronchial airways

    International Nuclear Information System (INIS)

    Fakir, H.; Hofmann, W.; Aubineau-Laniece, I.

    2006-01-01

    The effects of radiological and morphological source heterogeneities in straight and Y-shaped bronchial airways on hit frequencies and Micro-dosimetric quantities in epithelial cells have been investigated previously. The goal of the present study is to relate these physical quantities to transformation frequencies in sensitive target cells and to radon-induced lung cancer risk. Based on an effect-specific track length model, computed linear energy transfer (LET) spectra were converted to corresponding transformation frequencies for different activity distributions and source - target configurations. Average transformation probabilities were considerably enhanced for radon progeny accumulations and target cells at the carinal ridge, relative to uniform activity distributions and target cells located along the curved and straight airway portions at the same exposure level. Although uncorrelated transformation probabilities produce a linear dose - effect relationship, correlated transformations first increase depending on the LET, but then decrease significantly when exceeding a defined number of hits or cumulative exposure level. (authors)

  4. Radon and radon progeny in 70 houses in the Tennessee Valley area: study design and measurement methods

    International Nuclear Information System (INIS)

    Dudney, C.S.; Hawthorne, A.R.; Monar, K.P.; Quillen, J.L.; Clark, C. Jr.; Doane, R.W.; Wallace, R.G.; Reed, R.P.

    1986-01-01

    Levels of radon and its short-lived airborne progeny are being measured in a year-long study of 70 houses in four states in the Tennessee Valley. Various methods were used to solicit volunteers with differing degrees of success. Criteria for selection of houses in the study included presence of a lower level with cement floor and one or more block walls in contact with the soil, absence of obvious indications of technologically enhanced sources of radium, and proximity to one of four cities (Knoxville, Chattanooga, Birmingham, or Florence). By design, most houses in the study are in the same neighborhood as at least one other house in the study. Houses range in age from newly constructed to about 40 years old. Most of the houses have more than 2000 square feet of finished floor space. The lower level encompasses a garage in most cases. More complete information pertaining to house characteristics will be gathered in the course of the study. 19 refs., 1 fig

  5. Radon parameters in outdoor air

    International Nuclear Information System (INIS)

    Porstendoerfer, J.; Zock, Ch.; Wendt, J.; Reineking, A.

    2002-01-01

    For dose estimation by inhalation of the short lived radon progeny in outdoor air, the equilibrium factor (F), the unattached fraction (f p ), and the activity size distribution of the radon progeny were measured. Besides the radon parameter the meteorological parameter like temperature, wind speed, and rainfall intensity were registered. The measurements were carried out continuously for several weeks to find out the variation with time (day/night) and for different weather conditions. The radon gas, the unattached and aerosol-attached radon progenies were measured with an monitor developed for continuous measurements in outdoor air with low activity concentrations. For the determination of the activity size distribution a low pressure online alpha cascade impactor was used. The measured values of the equilibrium factor varied between 0.5-0.8 depending on weather conditions and time of the day. For high pressure weather conditions a diurnal variation of the F-factor was obtained. A lower average value (F=0.25) was registered during rainy days. The obtained f p -values varied between 0.04 and 0.12. They were higher than expected. The measured activity size distribution of the radon progeny averaged over a measurement period of three weeks can be approximated by a sum of three log-normal distributions. The greatest activity fraction is adsorbed on aerosol particles in the accumulation size range (100-1000 nm) with activity median diameters and geometric standard deviation values between 250-450 nm and 1.5-3.0, respectively. The activity median diameter of this accumulation mode in outdoor air was significantly greater than in indoor air (150-250 nm). An influence of the weather conditions on the activity of the accumulation particles was not significant. In contrast to the results of measurements in houses a small but significant fraction of the radon progeny (average value: 2%) is attached on coarse particles (>1000 nm). This fraction varied between 0-10%. 20

  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. Changes of indoor aerosol characteristics and their associated variation on the dose conversion factor due to radon progeny inhalation

    International Nuclear Information System (INIS)

    Tokonami, Shinji; Ishikawa, Tetsuo; Yonehara, Hidenori; Yamada, Yuji; Matsuzawa, Takao; Iimoto, Takeshi

    2003-01-01

    Since the dose conversion factor (hereafter called DCF) due to radon progeny inhalation is strongly dominated by aerosol characteristics in the environment, it is important to understand the air quality for accurate dose assessment. Thus temporal variations on aerosol concentration, its particle size and its related airborne radioactivities were continuously measured in an actual indoor environment with a relatively high radon concentration. The following human activities were added during the observation period: air-conditioning, removal of aerosol with an air cleaner and ventilation. DCFs based on these activities were evaluated with the latest International Commission of Radiological Protection (ICRP) respiratory tract model and were compared among them. Consequently, the present study has shown that operation of air cleaner enhanced the DCF critically because the unattached fraction increased significantly due to removal of aerosols. (author)

  8. Development of a standard for indoor radon measurements in Australia

    International Nuclear Information System (INIS)

    O'Brien, R.S.; Solomon, S.B.

    1994-01-01

    A standard covering methodologies for the measurement of indoor radon and radon progeny concentrations in air in Australian buildings is currently under preparation as part of a set of standards covering total indoor air quality. This paper outlines the suggested methodology for radon and discusses some of the problems associated with the development of the standard. The draft standard recommends measurement of the radon concentration in air using scintillation cells, charcoal cups and solid state nuclear track detectors, and measurement of radon progeny concentration in air using the Rolle method or the Nazaroff method. 14 refs., 1 tab

  9. Effects of aerosol polydispersity on theoretical calculations of unattached fractions of radon progeny

    International Nuclear Information System (INIS)

    Bandi, F.; Khan, A.; Phillips, C.R.

    1987-01-01

    Theoretical calculations of unattached fractions of radon progeny require prediction of an attachment coefficient. Average attachment coefficients for aerosols of various count median diameters, CMD, and geometric standard deviations, σ/sub g/, are calculated using four different theories. These theories are: (1) the kinetic theory, (2) the diffusion theory, (3) the hybrid theory and (4) the kinetic-diffusion theory. Comparisons of the various calculated attachment coefficients are made and the implications of using either the kinetic or the diffusion theory to calculate unattached fractions for aerosols of various CMD and σg are discussed. Significant errors may arise in use of either the kinetic theory or the diffusion theory. Large and unacceptable errors arise in calculating unattached fractions of a polydisperse aerosol by characterizing the aerosol as monodisperse. Unattached fractions of RaA are calculated for two mine aerosols and a room aerosol

  10. Stochastic rat lung dosimetry for inhaled radon progeny: a surrogate for the human lung for lung cancer risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Winkler-Heil, R.; Hofmann, W. [University of Salzburg, Division of Physics and Biophysics, Department of Materials Research and Physics, Salzburg (Austria); Hussain, M. [University of Salzburg, Division of Physics and Biophysics, Department of Materials Research and Physics, Salzburg (Austria); Higher Education Commission of Pakistan, Islamabad (Pakistan)

    2015-05-15

    Laboratory rats are frequently used in inhalation studies as a surrogate for human exposures. The objective of the present study was therefore to develop a stochastic dosimetry model for inhaled radon progeny in the rat lung, to predict bronchial dose distributions and to compare them with corresponding dose distributions in the human lung. The most significant difference between human and rat lungs is the branching structure of the bronchial tree, which is relatively symmetric in the human lung, but monopodial in the rat lung. Radon progeny aerosol characteristics used in the present study encompass conditions typical for PNNL and COGEMA rat inhalation studies, as well as uranium miners and human indoor exposure conditions. It is shown here that depending on exposure conditions and modeling assumptions, average bronchial doses in the rat lung ranged from 5.4 to 7.3 mGy WLM{sup -1}. If plotted as a function of airway generation, bronchial dose distributions exhibit a significant maximum in large bronchial airways. If, however, plotted as a function of airway diameter, then bronchial doses are much more uniformly distributed throughout the bronchial tree. Comparisons between human and rat exposures indicate that rat bronchial doses are slightly higher than human bronchial doses by about a factor of 1.3, while lung doses, averaged over the bronchial (BB), bronchiolar (bb) and alveolar-interstitial (AI) regions, are higher by about a factor of about 1.6. This supports the current view that the rat lung is indeed an appropriate surrogate for the human lung in case of radon-induced lung cancers. Furthermore, airway diameter seems to be a more appropriate morphometric parameter than airway generations to relate bronchial doses to bronchial carcinomas. (orig.)

  11. Mitigation of the effective dose of radon decay products through the use of an air cleaner in a dwelling in Okinawa, Japan

    International Nuclear Information System (INIS)

    Kranrod, Chutima; Tokonami, Shinji; Ishikawa, Tetsuo; Sorimachi, Atsuyuki; Janik, Miroslaw; Shingaki, Reina; Furukawa, Masahide; Chanyotha, Supitcha; Chankow, Nares

    2009-01-01

    Field measurements were conducted to assess the effects of an air cleaner on radon mitigation in a dwelling with a high radon concentration in Okinawa, Japan. The measurements included indoor radon concentration, individual radon progeny concentration, equilibrium equivalent concentration of radon (EECRn), unattached fraction, and size distribution of aerosol-attached radon progeny. These measurements were conducted in a 74 m 3 room with/without the use of an air cleaner. The results showed that the mean radon concentration during the measurement was quite high (301 Bq m -3 ). The operation of air cleaner decreased the radon progeny activity concentration, EECRn and equilibrium factor by 33%, 57% and 71%, respectively, whereas the unattached fraction increased by 174%. In addition, the activity concentration of attached radon progeny in the accumulation mode (50-2000 nm) was obviously deceased by 42%, when the air cleaner was operated. According to dosimetric calculations, the operation of air cleaner reduced the effective dose due to radon progeny by about 50%.

  12. Radon Sources and Associated Risk in terms of Exposure and Dose

    Directory of Open Access Journals (Sweden)

    Efstratios Gregory Vogiannis

    2015-01-01

    Full Text Available Radon concern the international scientific community from early 20th century. Initially as radium emanation, almost the second half of the century as severe harmful to human health. Initial brilliant period of use as medicine, followed by a period of intense concern for its health effects. Primary target groups surveyed were miners early in Europe later in U.S. There is now compelling evidence that radon and its progeny can cause lung cancer. Human activities may create or modify pathways increasing indoor radon concentration compared to outdoor background. These pathways can be controlled by preventive and corrective actions. Indoor Radon and its short-lived progeny attached on aerosol particles or free compose an air mixture that carry a significant energy amount (PAEC. Exposure on PAEC and dose delivered reviewed in detail. Special attention was paid to the case of water workers because lack of adequate data. Radon risk assessment and current legislation regulates dose from radon and its progeny, also were reviewed.

  13. Study on radon and thoron levels in different types of granitic work industries around Tumkur city

    International Nuclear Information System (INIS)

    Nagabhushan, S.R.; Ujjinappa; Srilatha; Sannappa, J.

    2013-01-01

    Radon, Thoron and its progeny monitoring has become a global phenomenon due to its health hazards on human being. The concentration of radon, thoron and their progeny levels have been measured in different types of Granite and brick work industries around Tumkur city by using LR-115 type II Solid State Nuclear Track Detectors (SSNTDs) have been used for the measurement of these gases. The higher concentration of radon, thoron and their progeny were observed in the dwellings near brick industries compared to Granite cutting and polishing industries. The inhalation dose due to Radon, Thoron and their progeny to the workers and public living near these industries have been estimated. (author)

  14. Radon in the indoor environment

    International Nuclear Information System (INIS)

    Vanmarcke, H.

    1998-01-01

    A precise retrospective assessment of long-term radon exposures in dwellings is essential for estimating lung-cancer risks. The objectives of this research are (1) to investigate the deposition of radon progeny in the human respiratory tract by means of direct measurements as a function of aerosol conditions, (2) to assess the radon concentrations in buildings retrospectively with volume traps

  15. Radon in the indoor environment

    International Nuclear Information System (INIS)

    Vanmarcke, H.

    1998-01-01

    The objectives of R and D on radon in the indoor environment at SCK-CEN is to (1) to investigate the deposition of radon progeny in the human respiratory tract by means of direct measurements as a function of aerosol conditions; to assess the radon concentrations in buildings retrospectively with volume traps. Progress and main achievements in 1997 are reported on

  16. Air radon equilibrium factor measurement in a Waste Water Pre-Treatment Plant

    International Nuclear Information System (INIS)

    Martinez, J.E.; Juste, B.; Ortiz, J.; Martorell, S.; Verdu, G.

    2017-01-01

    We analyze in this paper a Waste Water Pre-Treatment Plant (WWTP) located at the Mediterranean coast with air radon concentration above Spanish action level (600 Bq per cubic meter). This paper presents a method for radon equilibrium determination by gamma spectrometry measuring of the radon progeny concentrations in the air, in order to estimate WWTP workers effective dose more exactly. The method is based on simultaneous sampling of air through a filter paper and alpha spectrometry measurement of radon activity concentration in the air. According to the measured radon activity concentration in the air of 368±45 Bq/m 3 the equilibrium factor between radon and progenies is estimated to be F=0.27, which is in good agreement with expected values. - Highlights: • High levels of Radon in a workplace can increase health risks in the employees. • Using the typical equilibrium factor 0.4 could lead to an error in the estimation of radon doses. • We present a method for radon equilibrium determination. • Equilibrium factor is calculated by gamma spectrometry measuring of radon progeny concentrations in the air.

  17. Radon and its short-lived decay nuclides in the living environment

    International Nuclear Information System (INIS)

    Abe, Siro

    1988-01-01

    The problem about radon and its shortlived decay nuclides in the living environment has been frequently closed-up. The problem is focused on the exposure of human being due to radon and its progeny. This paper reports the reason to the occurrence of the problem. Radon source as well as its pathway into our rooms are outlined here. The behavior of radon and its progeny indoors is also shown in this paper in comparison with outdoor situation and from the persons' activity's point of view. (author)

  18. Radiation doses from radon and progeny in Irish houses

    International Nuclear Information System (INIS)

    McLaughlin, J.P.

    1985-08-01

    In the United Kingdom, the estimated average annual effective dose equivalent to members of the public from all sources is 2.4 mSv (240 mrem). 40% of this dose is contributed by exposure to radon, and it is not unreasonable to assume that the situation in Ireland is very similar. During 1982-84 a preliminary study of radon and penetrating radiation on 300 Irish houses showed seasonally averaged indoor radon concentrations in the range 3 Bq/m 3 of air to 700 bq/m 3 , with a median value of about 40 bq/m 3 . A national survey of indoor radon has now been undertaken; 3000 households, randomly selected from the electoral register are to be monitored and the result correlated with energy conservation practices. The final part of this document deals with the regulatory aspects of radon control and reviews the practices for reduction of indoor radon daughter doses presently in hand in Scandinavia. An appendix of radiation units and terms is also given

  19. 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

  20. 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)

  1. Changes in the rat lung after exposure to radon and its progeny: Effects on incorporation of bromodeoxyuridine in epithelial cells and on the incidence of nuclear aberrations in Alveolar macrophages

    International Nuclear Information System (INIS)

    Taya, A.; Morgan, A.; Baker, S.T.; Humphreys, J.A.H.; Collier, C.G.; Bisson, M.

    1994-01-01

    The aim of this study was to investigate some responses of cells in the rat respiratory tract as a function of time after inhalation exposure to various levels of radon and its progeny. Rats were exposed to a constant concentration of radon and its progeny to give cumulative exposure levels of 120, 225, 440 and 990 working level months (WLM). An additional unexposed group of rats served as controls. The end points selected for investigation were (a) the incorporation of bromodeoxyuridine (BrdU) in epithelial cells of the conducting airways and of the alveolar region of the respiratory tract and (b) the incidence of alveolar macrophages with nuclear aberrations. After exposure, the incidence of epithelial cells incorporating BrdU-the labeling index-increased in all regions of the respiratory tract examined, but the increase occurred later in alveolar than in airway epithelial cells. The highest labeling index was found in bronchial epithelial cells, which probably received the highest radiation dose. After an initial induction period, the incidence of alveolar macrophages with nuclear aberrations also increased. The possibility of using the labeling index of alveolar and airway epithelial cells, and/or the incidence of nuclear aberrations in alveolar macrophages, to estimate the radiation dose to various regions of the respiratory tract after exposure of rats to radon and its progeny is discussed. 22 refs., 3 figs., 1 tab

  2. 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

  3. Short- and long-term variability of radon progeny concentration in dwellings in the Czech Republic.

    Science.gov (United States)

    Slezáková, M; Navrátilová Rovenská, K; Tomásek, L; Holecek, J

    2013-03-01

    In this paper, repeated measurements of radon progeny concentration in dwellings in the Czech Republic are described. Two distinct data sets are available: one based on present measurements in 170 selected dwellings in the Central Bohemian Pluton with a primary measurement carried out in the 1990s and the other based on 1920 annual measurements in 960 single-family houses in the Czech Republic in 1992 and repeatedly in 1993. The analysis of variance model with random effects is applied to data to evaluate the variability of measurements. The calculated variability attributable to repeated measurements is compared with results from other countries. In epidemiological studies, ignoring the variability of measurements may lead to biased estimates of risk of lung cancer.

  4. A study of radon variation in dwelling during 1988

    International Nuclear Information System (INIS)

    Shaikh, A.N.; Ramachandran, T.V.; Muraleedharan, T.S.; Subbaramu, M.C.

    1989-01-01

    Natural radioactivity due to radon and its progeny levels indoors contributes significantly to the total radiation to man. The main source of radon and its progeny in a dwelling is the emanation of radon gas from soil. The temperature and ventilation vary in a dwelling during the year. These parameters influence the indoor radon levels. The seasonal variation of radon was studied in a dwelling as well as in the outside air. The filter paper method and alpha counting, and the solid state track detector technique and track counting were used to study the radon levels. The geometric mean of radon daughters concentrations were 0.5 mWL and 0.8 mWL measured by filter-paper method and SSNTD method respectively. The geometric mean of radon concentrations were 6.2 Bqm -3 and 10.0 Bqm -3 by filter-paper method and SSNTD method respectively. (author). 3 figs., 3 tabs., 13 refs

  5. A method for determining an indicator of effective dose calculation due to inhalation of Radon and its progeny from in vivo measurements; Um metodo para determinar um indicador para calcular dose efetiva devida a inalacao de Radonio e seus descendentes utilizando medicoes in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, Julio Jose da Silva

    1994-07-01

    Direct measurement of the absolved dose to lung tissue from inhalation of radon and its progeny is not possible and must be calculated using dosimetric models, taking into consideration the several parameters upon which the dose calculation depends. To asses the dose due to inhalation of radon and its progeny, it is necessary to estimate the cumulative exposure. Historically, this has been done using WLM values estimated with measurements of radon concentration in air. The radon concentration in air varies significantly, however, in space with time, and the exposed individual is also constantly moving around. This makes it almost impossible to obtain a precise estimate of an individual's inhalation exposure. This work describes a pilot study to calculate lung dose from the deposition of radon progeny, via estimates of cumulative exposure derived from in vivo measurements of {sup 210} Pb, in subjects exposed to above-average radon and its progeny concentrations in their home environments. The measurements were performed in a whole body counter. With this technique, the exposed individuals become, in affect, their own samplers and dosimeters and the estimate of cumulative exposure is not affected by the variation of the atmospheric concentration of radon and its progeny in time and space. Forty individuals identified as living in homes with radon levels ranging from about 740 Bq/m{sup 3} to 150.000 Bq/m{sup 3} were measured. Also, additional 34 measurements were made on personnel from NYUMC/NIEM who live in a residential area surrounding the laboratory in which the levels of radon have been shown to be at below average values. To realize these measurements a methodology was developed to determine the subject's background, using a head phantom made with a cubic plastic container containing known amounts of potassium and calcium dissolved in four liters of water. The effective doses calculated from the in vivo measurements are compared to effective doses estimated, for

  6. A method for determining an indicator of effective dose calculation due to inhalation of Radon and its progeny from in vivo measurements; Um metodo para determinar um indicador para calcular dose efetiva devida a inalacao de Radonio e seus descendentes utilizando medicoes in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, Julio Jose da Silva

    1994-07-01

    Direct measurement of the absolved dose to lung tissue from inhalation of radon and its progeny is not possible and must be calculated using dosimetric models, taking into consideration the several parameters upon which the dose calculation depends. To asses the dose due to inhalation of radon and its progeny, it is necessary to estimate the cumulative exposure. Historically, this has been done using WLM values estimated with measurements of radon concentration in air. The radon concentration in air varies significantly, however, in space with time, and the exposed individual is also constantly moving around. This makes it almost impossible to obtain a precise estimate of an individual's inhalation exposure. This work describes a pilot study to calculate lung dose from the deposition of radon progeny, via estimates of cumulative exposure derived from in vivo measurements of {sup 210} Pb, in subjects exposed to above-average radon and its progeny concentrations in their home environments. The measurements were performed in a whole body counter. With this technique, the exposed individuals become, in affect, their own samplers and dosimeters and the estimate of cumulative exposure is not affected by the variation of the atmospheric concentration of radon and its progeny in time and space. Forty individuals identified as living in homes with radon levels ranging from about 740 Bq/m{sup 3} to 150.000 Bq/m{sup 3} were measured. Also, additional 34 measurements were made on personnel from NYUMC/NIEM who live in a residential area surrounding the laboratory in which the levels of radon have been shown to be at below average values. To realize these measurements a methodology was developed to determine the subject's background, using a head phantom made with a cubic plastic container containing known amounts of potassium and calcium dissolved in four liters of water. The effective doses calculated from the in vivo measurements are compared to effective doses

  7. Personal dosimetry and area monitoring for neutrons and radon in workplaces

    International Nuclear Information System (INIS)

    Tommasino, L.

    2001-01-01

    The first successful applications of damage track detectors in radiation protection have been made in the early 1970s in personal dosimetry of neutrons, radon and its progenies. Most of the scientists actively engaged in the solution of the complex problem of personal neutron dosimetry by damage track detectors-SSNTD, have attempted to develop individual radon monitoring for exposure in mines by using the same SSNTDs. In late 1970s and the early 1980s, new radon monitoring devices based on SSNTDs have been developed to measure radon in soil, mainly for applications in uranium prospecting or more generally in earth sciences. Most of the radon monitors, developed since then for completely different applications in mind, have been used later for large scale survey of indoor radon. With the current implementation within Europe of the European Union Directive 96/29, applications of damage track detectors will increase drastically, specially for the assessment of the exposure of the workers to natural sources of radiation. In this case, the early work on personal neutron/radon dosimetry, is highly valuable to tackle these new problems of individual monitoring

  8. Measurements of size distributions of radon progeny for improved quantification of the lung cancer risk emanating from exposure to radon decay products; Messungen der Groessenverteilungen von Radon-Folgeprodukten zur Verbesserung der Quantifizierung des durch Radonexposition verursachten Lungenkrebsrisikos

    Energy Technology Data Exchange (ETDEWEB)

    Haninger, T

    1998-12-31

    A major issue in radiation protection is to protect the population from the harmful effects of exposure to radon and radon progeny. Quantification of the lung cancer risk emanating from exposure to radon decay products in residential and working environments poses problems, as epidemiologic studies yield information deviating from the results obtained by the indirect method of assessment based on dosimetric respiratory tract models. One important task of the publication here was to characterize the various exposure conditions and to quantify uncertainties that may result from application of the ``dose conversion convention``. A special aerosol spectrometer was therefore designed and built in order to measure the size distributions of the short-lived radon decay products in the range between 0.5 nm and 10 000 nm. The aerosol spectrometer consists of a three-step diffusion battery with wire nets, an 11-step BERNER impactor, and a detector system with twelve large-surface proportional detectors. From the measured size distributions, dose conversion coefficients, E/P{sup eq}, were calculated using the PC software RADEP; the RADEP program was developed by BIRCHALL and JAMES and is based on the respiratory tract model of the ICRP. The E/P{sup eq} coefficients indicate the effective dose E per unit exposure P{sup eq} to radon decay products. (orig./CB) [Deutsch] Eines der groessten Probleme des Strahlenschutzes ist der Schutz der Bevoelkerung vor einer Strahlenexposition durch Radon und seine Folgeprodukte. Die Quantifizierung des Lungenkrebsrisikos, das durch Radonexpositionen in Wohnungen und an Arbeitsplaetzen verursacht wird, ist ein grosses Problem, weil epidemiologische Studien ein anderes Ergebnis liefern, als die indirekte Methode der Abschaetzung mit dosimetrischen Atemtrakt-Modellen. Eine wichtige Aufgabe der vorliegenden Arbeit war es, unterschiedliche Expositionsbedingungen zu charakterisieren und die Unsicherheiten zu quantifizieren, die sich aus der

  9. Measurements of size distributions of radon progeny for improved quantification of the lung cancer risk emanating from exposure to radon decay products; Messungen der Groessenverteilungen von Radon-Folgeprodukten zur Verbesserung der Quantifizierung des durch Radonexposition verursachten Lungenkrebsrisikos

    Energy Technology Data Exchange (ETDEWEB)

    Haninger, T.

    1997-12-31

    A major issue in radiation protection is to protect the population from the harmful effects of exposure to radon and radon progeny. Quantification of the lung cancer risk emanating from exposure to radon decay products in residential and working environments poses problems, as epidemiologic studies yield information deviating from the results obtained by the indirect method of assessment based on dosimetric respiratory tract models. One important task of the publication here was to characterize the various exposure conditions and to quantify uncertainties that may result from application of the ``dose conversion convention``. A special aerosol spectrometer was therefore designed and built in order to measure the size distributions of the short-lived radon decay products in the range between 0.5 nm and 10 000 nm. The aerosol spectrometer consists of a three-step diffusion battery with wire nets, an 11-step BERNER impactor, and a detector system with twelve large-surface proportional detectors. From the measured size distributions, dose conversion coefficients, E/P{sup eq}, were calculated using the PC software RADEP; the RADEP program was developed by BIRCHALL and JAMES and is based on the respiratory tract model of the ICRP. The E/P{sup eq} coefficients indicate the effective dose E per unit exposure P{sup eq} to radon decay products. (orig./CB) [Deutsch] Eines der groessten Probleme des Strahlenschutzes ist der Schutz der Bevoelkerung vor einer Strahlenexposition durch Radon und seine Folgeprodukte. Die Quantifizierung des Lungenkrebsrisikos, das durch Radonexpositionen in Wohnungen und an Arbeitsplaetzen verursacht wird, ist ein grosses Problem, weil epidemiologische Studien ein anderes Ergebnis liefern, als die indirekte Methode der Abschaetzung mit dosimetrischen Atemtrakt-Modellen. Eine wichtige Aufgabe der vorliegenden Arbeit war es, unterschiedliche Expositionsbedingungen zu charakterisieren und die Unsicherheiten zu quantifizieren, die sich aus der

  10. Development and application of a complex numerical model and software for the computation of dose conversion factors for radon progenies.

    Science.gov (United States)

    Farkas, Árpád; Balásházy, Imre

    2015-04-01

    A more exact determination of dose conversion factors associated with radon progeny inhalation was possible due to the advancements in epidemiological health risk estimates in the last years. The enhancement of computational power and the development of numerical techniques allow computing dose conversion factors with increasing reliability. The objective of this study was to develop an integrated model and software based on a self-developed airway deposition code, an own bronchial dosimetry model and the computational methods accepted by International Commission on Radiological Protection (ICRP) to calculate dose conversion coefficients for different exposure conditions. The model was tested by its application for exposure and breathing conditions characteristic of mines and homes. The dose conversion factors were 8 and 16 mSv WLM(-1) for homes and mines when applying a stochastic deposition model combined with the ICRP dosimetry model (named PM-A model), and 9 and 17 mSv WLM(-1) when applying the same deposition model combined with authors' bronchial dosimetry model and the ICRP bronchiolar and alveolar-interstitial dosimetry model (called PM-B model). User friendly software for the computation of dose conversion factors has also been developed. The software allows one to compute conversion factors for a large range of exposure and breathing parameters and to perform sensitivity analyses. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. The effect of increase in humidity on the size and activity distributions of radon progeny laden aerosols from hydrocarbon combustion

    International Nuclear Information System (INIS)

    Khan, Atika; Phillips, C.R.

    1988-01-01

    The effects of a humidity increase on the distributions of aerosol size and activity for hydrocarbon combustion aerosols laden with radon progeny were determined. Pre-humidification aerosol conditions were 20 0 C and 35% RH. Post-humidification aerosol conditions were 37 0 C and 100% RH, intended to simulate conditions in the human respiratory tract. Using kerosene combustion aerosols, a growth factor of 1.3 ± 0.2 (standard deviation) was found for both the aerosol median diameter and the activity median diameter. (author)

  12. Variability of radon and thoron equilibrium factors in indoor environment of Garhwal Himalaya

    International Nuclear Information System (INIS)

    Prasad, Mukesh; Rawat, Mukesh; Dangwal, Anoop; Kandari, Tushar; Gusain, G.S.; Mishra, Rosaline; Ramola, R.C.

    2016-01-01

    The measurements of radon, thoron and their progeny concentrations have been carried out in the dwellings of Uttarkashi and Tehri districts of Garhwal Himalaya, India using LR-115 detector based pin-hole dosimeter and DRPS/DTPS techniques. The equilibrium factors for radon, thoron and their progeny were calculated by using the values measured with these techniques. The average values of equilibrium factor between radon and its progeny have been found to be 0.44, 0.39, 0.39 and 0.28 for rainy, autumn, winter and summer seasons, respectively. For thoron and its progeny, the average values of equilibrium factor have been found to be 0.04, 0.04, 0.04 and 0.03 for rainy, autumn, winter and summer seasons, respectively. The equilibrium factor between radon and its progeny has been found to be dependent on the seasonal changes. However, the equilibrium factor for thoron and progeny has been found to be same for rainy, autumn and winter seasons but slightly different for summer season. The annual average equilibrium factors for radon and thoron have been found to vary from 0.23 to 0.80 with an average of 0.42 and from 0.01 to 0.29 with an average of 0.07, respectively. The detailed discussion of the measurement techniques and the explanation for the results obtained is given in the paper. - Highlights: • Equilibrium factors for indoor radon, thoron and their progeny were measured. • Recently developed passive detector techniques were used for measurements. • The values of equilibrium factors are comparable with world's average values. • Equilibrium factor should be measured separately for individual dwelling. • Separate values of equilibrium factors are useful to produce actual radiation dose.

  13. Use of a Radon Stripping Algorithm for Retrospective Assessment of Air Filter Samples

    International Nuclear Information System (INIS)

    Hayes, Robert

    2009-01-01

    An evaluation of a large number of air sample filters was undertaken using a commercial alpha and beta spectroscopy system employing a passive implanted planar silicon (PIPS) detector. Samples were only measured after air flow through the filters had ceased. Use of a commercial radon stripping algorithm was implemented to discriminate anthropogenic alpha and beta activity on the filters from the radon progeny. When uncontaminated air filters were evaluated, the results showed that there was a time-dependent bias in both average estimates and measurement dispersion with the relative bias being small compared to the dispersion. By also measuring environmental air sample filters simultaneously with electroplated alpha and beta sources, use of the radon stripping algorithm demonstrated a number of substantial unexpected deviations. Use of the current algorithm is therefore not recommended for assay applications and so use of the PIPS detector should only be utilized for gross counting without appropriate modifications to the curve fitting algorithm. As a screening method, the radon stripping algorithm might be expected to see elevated alpha and beta activities on air sample filters (not due to radon progeny) around the 200 dpm level

  14. Annual effective dose due to residential radon progeny in Sweden: Evaluations based on current risk projections models and on risk estimates from a nation-wide Swedish epidemiological study

    Energy Technology Data Exchange (ETDEWEB)

    Doi, M [National Inst. of Radiological Sciences, Chiba (Japan); Lagarde, F [Karolinska Inst., Stockholm (Sweden). Inst. of Environmental Medicine; Falk, R; Swedjemark, G A [Swedish Radiation Protection Inst., Stockholm (Sweden)

    1996-12-01

    Effective dose per unit radon progeny exposure to Swedish population in 1992 is estimated by the risk projection model based on the Swedish epidemiological study of radon and lung cancer. The resulting values range from 1.29 - 3.00 mSv/WLM and 2.58 - 5.99 mSv/WLM, respectively. Assuming a radon concentration of 100 Bq/m{sup 3}, an equilibrium factor of 0.4 and an occupancy factor of 0.6 in Swedish houses, the annual effective dose for the Swedish population is estimated to be 0.43 - 1.98 mSv/year, which should be compared to the value of 1.9 mSv/year, according to the UNSCEAR 1993 report. 27 refs, tabs, figs.

  15. Annual effective dose due to residential radon progeny in Sweden: Evaluations based on current risk projections models and on risk estimates from a nation-wide Swedish epidemiological study

    International Nuclear Information System (INIS)

    Doi, M.; Lagarde, F.

    1996-12-01

    Effective dose per unit radon progeny exposure to Swedish population in 1992 is estimated by the risk projection model based on the Swedish epidemiological study of radon and lung cancer. The resulting values range from 1.29 - 3.00 mSv/WLM and 2.58 - 5.99 mSv/WLM, respectively. Assuming a radon concentration of 100 Bq/m 3 , an equilibrium factor of 0.4 and an occupancy factor of 0.6 in Swedish houses, the annual effective dose for the Swedish population is estimated to be 0.43 - 1.98 mSv/year, which should be compared to the value of 1.9 mSv/year, according to the UNSCEAR 1993 report. 27 refs, tabs, figs

  16. Radon in Africa: South African Lessons Learnt

    International Nuclear Information System (INIS)

    Simanga, A.T.

    2010-01-01

    Radon remained a chemical curiosity for decades, promoted at some stage as a health giving gas. Mining related history: (based on ICRP 65) dating back to 15 Century when high mortality from lung cancer was observed among miners in Schneeberg. After the Curies had extracted Radium from Jachymov ores (1898), radon was identified. When measurements were done in Schneeberger and Jachymov mines high concentrations of radon were found. Initially a link was assumed between lung cancer and high radon concentration based on the measurements. (The assumption was not generally accepted).In 1953 William F. Bale indicated that the causative agents of lung cancer was the radon progeny and not radon gas. A possible lung cancer risk to members of the public was discovered very recently (first published results were based on the indoor measurements done in Sweden in a study initiated by Rolf Sievert) Much attention has been given to radon as a radiological health hazard: Recently human exposure to radon progeny in buildings has emerged as an important issue. Lung cancer is the principal concern associated with Rn exposure. The principal concern is associated with radon progeny. These species are chemically reactive, and may be deposited on respiratory tract tissues when inhaled. Subsequent alpha particle decay may damage cells near the deposition site, contributing to increased risk of lung cancer Radon: In Occupational Exposure Protection against Rn Exposure is a Techno-Legal Legal Aspects: There has to be a national legislative framework for the protection of workers against radon The legal framework should entail, inter alia: - Set up of regulator, development of regulations and standards to enable compliance assurance and other protection issues, training of technical people. 10 Legislative Framework in South Africa National Nuclear Regulatory Act (1999) Enables the regulator (NNR) to exercise oversight for Rn protection Occupational Exposure is mainly in Mining and Mineral

  17. Variability of radon and thoron equilibrium factors in indoor environment of Garhwal Himalaya.

    Science.gov (United States)

    Prasad, Mukesh; Rawat, Mukesh; Dangwal, Anoop; Kandari, Tushar; Gusain, G S; Mishra, Rosaline; Ramola, R C

    2016-01-01

    The measurements of radon, thoron and their progeny concentrations have been carried out in the dwellings of Uttarkashi and Tehri districts of Garhwal Himalaya, India using LR-115 detector based pin-hole dosimeter and DRPS/DTPS techniques. The equilibrium factors for radon, thoron and their progeny were calculated by using the values measured with these techniques. The average values of equilibrium factor between radon and its progeny have been found to be 0.44, 0.39, 0.39 and 0.28 for rainy, autumn, winter and summer seasons, respectively. For thoron and its progeny, the average values of equilibrium factor have been found to be 0.04, 0.04, 0.04 and 0.03 for rainy, autumn, winter and summer seasons, respectively. The equilibrium factor between radon and its progeny has been found to be dependent on the seasonal changes. However, the equilibrium factor for thoron and progeny has been found to be same for rainy, autumn and winter seasons but slightly different for summer season. The annual average equilibrium factors for radon and thoron have been found to vary from 0.23 to 0.80 with an average of 0.42 and from 0.01 to 0.29 with an average of 0.07, respectively. The detailed discussion of the measurement techniques and the explanation for the results obtained is given in the paper. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Health effects of radon

    International Nuclear Information System (INIS)

    Easterly, C.

    1994-01-01

    Exposure of people to radon has taken on increased interest during the last decade because of the understanding that buildings can serve to trap radon and its daughters, and thereby build up undesirable concentrations of these radioactive elements. Numerous studies of underground miners (often uranium miners) have shown an increased risk of lung cancer in comparison with nonexposed populations. Laboratory animals exposed to radon daughters also develop lung cancer. The abundant epidemiological and experimental data have established the carcinogenicity of radon progeny. Those observations are of considerable importance, because uranium, from which radon and its progeny arise, is ubiquitous in the earth's crust, including coal mines. Risk estimates of the health effects of long-term exposures at relatively low levels require continued development, especially to address the potential health effects of radon and radon daughters in homes and occupational settings where the exposure levels are less than levels in underground uranium and other metal mines that have been the subject of epidemiological studies. Two approaches can be used to characterize the lung-cancer risks associated with radon-daughter exposure: mathematical representations of the respiratory tract that model radiation doses to target cells and epidemiological investigation of exposed populations, mainly underground uranium miners. The mathematically-based dosimetric approach provides an estimate of lung cancer risk related to radon-daughter exposure based specifically on modeling of the dose to target cells. The various dosimetric models all require assumptions, some of which are not subject to direct verification, as to breathing rates; the deposition of radon daughters in the respiratory tract; and the type, nature, and location of the target cells for cancer induction. The most recent large committee effort drawn together to evaluate this issue was sponsored by the National Research Council

  19. Application of single-chip microcomputer to portable radon and radon daughters monitor

    International Nuclear Information System (INIS)

    Meng Yecheng; Huang Zhanyun; She Chengye

    1992-01-01

    Application of single-chip microcomputer to portable radon and radon daughters monitor is introduced in this paper. With the single-chip microcomputer automation comes into effect in the process from sampling to measuring of radon and radon daughters. The concentrations of radon and radon daughters can be easily shown when the conversion coefficients are pre-settled before the measurement. Moreover, the principle and design are briefly discussed according to the characteristics of the monitor

  20. Inhalation dose due to indoor radon and thoron concentrations in the surrounding villages of Hyderabad, Andhra Pradesh, India

    International Nuclear Information System (INIS)

    Sreenath Reddy, M.; Sreenivasa Reddy, B.; Yadagiri Reddy, P.; Gopal Reddy, Ch.; Rama Reddy, K.

    2006-01-01

    Inhalation of radon, thoron and their decay products is the major contribution to the total radioactive dose received by the human population from the natural radiation. The indoor inhalation doses due to radon, thoron and their progenies in the surrounding villages of Hyderabad, India are evaluated. The average inhalation dose due to radon and its progeny is found to be 0.26 ± 0.21 mSv y -1 and due to thoron and its progeny is 0.35 ± 0.38 mSv y -1 . The inhalation dose is also analyzed based on the types of floor, roof and walls of the dwellings and it is found that the dwellings with mud type construction materials have higher inhalation dose. Generally, the contribution of thoron and its progeny to the total dose is neglected but in the present study area the fractional dose of thoron and its progeny is found to be comparable to that of radon and its progeny. (author)

  1. Indoor radon distribution in metropolitan region of Belo Horizonte, Brazil

    International Nuclear Information System (INIS)

    Santos, Talita O.; Oliveira, Arno H. de

    2009-01-01

    Human beings are exposed to ionizing radiation from many natural sources. Radon and its progeny have been recognized as the most important contributors to the natural radioactivity dose, accounting for about half of all human exposure to ionizing radiation. Radon ( 222 Rn) is a α-radioactive noble gas derived from the natural series of uranium (2 38 U), which occurs in a wide concentration range in all geological materials, especially, in rocks, soils and waters. By diffusion and convection, radon migrates from the rocks and soils to atmosphere and through fissures, pipes and holes it may enter the dwellings and other buildings. Another important radon source in dwellings is its emanation from the construction material. The radon progeny concentration in dwellings has been receiving considerable global attention due to its potential effect in causing lung cancer if it deposited in upper respiratory tract when inhaled. This paper presents radon concentration distribution in dwellings in Metropolitan Region of Belo Horizonte - RMBH. The effective dose estimate is also presented for the RMBH inhabitants. The geological settings of the area are Archean rocks of Granitic Gnaissic Complex and of metasediments sequences of the great Precambrian unit of the Iron Quadrangle of Minas Gerais, Brazil. Radon concentration measurements were carried out with continuous detector AlphaGUARD PQ200PRO (Genitron), in passive mode and with passive detectors E-PERM R Eletret Ion Chamber-EIC. The radon progeny concentration was carried out with a solid state alpha spectroscope, the DOSEman PRO (Sarad). It was found an indoor radon concentration varying in a large range from 18.5 to 2671.4 Bq/m -3 , with an average value of 148.0 Bqm -3 and geometric mean equal to 128.2 Bqm -3 . The variable results are due mainly to region geological factors and building material composition of dwellings. The equilibrium factor between radon and its progeny were determined in dwellings, as 0.3 in

  2. Point-of-entry removal of radon from drinking water

    International Nuclear Information System (INIS)

    Lowry, J.D.; Brutsaert, W.F.; Mc Enerney, T.; Molk, C.

    1987-01-01

    Two processes were investigated in the laboratory to determine their efficiency for removing radon from household water supplies. Granular activated carbon (GAC) adsorption was found to be extremely effective as a result of an adsorption-decay steady state that is established quickly and continues for years. The GAC bed, however, adsorbs radon progeny as the radon decays, and it becomes a source of gamma radiation. This problem is believed to be manageable for the vast majority of potential applications. Diffused bubble aeration was found to be as effective as GAC, with removals of greater than 99 percent being practical. Although more costly than GAC, aeration does not have the problem of gamma activity buildup

  3. Radioactivity on the surfaces of computer monitors and television screens due to progeny palatal

    International Nuclear Information System (INIS)

    Abdel-Nady, A.; Morsy, A.A.

    2002-01-01

    Computer monitors and television screens can collect radon progeny. Radon decay forming meta-stable progeny, namely, Po-218, Po-214, and Po-210, which are found mostly in positively, charged aerosol particles. These particles are attract by the large negative field of a video display terminals (VDT) leading to buildup of radioactivity on the VDT screen. The charged aerosol particles might drift in the electric field between the VDT and the operator and be accelerated into the operator's face. The aim of this work is to measure these phenomena set of ultra-sensitive TASTRAK detectors used to measure the plate out of positively charged radioactive radon progeny. The track detectors were fixed on the outer monitor screen. For an occupational computer worker spending 200 days per year for 6 hours a day. It was found that the mean dose equivalent was 1.77 mSv, 0.25 mSv/year for normal CRT and LCD monitors respectively

  4. The influence of the cigarette smoke pollution and ventilation rate on alpha-activities per unit volume due to radon and its progeny

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Flata, K.

    2003-01-01

    Alpha and beta activities per unit volume air due to radon, thoron and their decay products were evaluated in the air of various cafe rooms polluted by cigarette smoke. Both CR-39 and LR-115 type II solid state nuclear track detectors (SSNTD) were used. Equilibrium factors between radon and its progeny and thoron and its daughters have been evaluated in the air of the studied cafe rooms. The committed equivalent doses due to short-lived radon decay products were determined in different regions of the respiratory tract of non-smoker members of the public. The influence of cigarette smoke pollution, ventilation rate and exposure time on committed equivalent dose in the respiratory systems of non-smokers was investigated. Committed equivalent doses ranged from 1.15x10 -11 -2.7x10 -7 Sv.y -1 /h of exposure in the extrathoracic region and from 0.8x10 -12 -1.7x10 -8 Sv.y -1 /h of exposure in the thoracic region of the respiratory tract of non-smokers

  5. Radon dose and aerosols

    International Nuclear Information System (INIS)

    Planinic, J.; Radolic, V.; Faj, Z.; Vukovic, B.

    2000-01-01

    The equilibrium factor value (F) was measured in the NRPB radon chamber and the corresponding track density ratio (r = D/D 0 ) of bare (D) and diffusion (D 0 ) LR-115 nuclear track detectors was determined, as well as the regression equation F(r). Experiments with LR-115 nuclear track detectors and aerosol sources (burning candle and cigarette) were carried out in the Osijek University radon chamber and afterwards an empirical relationship between the equilibrium factor and aerosol concentration was derived. For the purpose of radon dose equivalent assessment, procedures for determining the unattached fraction of radon progeny were introduced using two nuclear track detectors. (author)

  6. Studying the response of CR-39 to radon in non-polar liquids above water by Monte Carlo simulation and measurement

    International Nuclear Information System (INIS)

    Rezaie, Mohammad Reza; Sohrabi, Mehdi; Negarestani, Ali

    2013-01-01

    The application of CR-39 has been extensive for measurement of radon and progeny in air of dwellings, but limited as regards to measurements of radon in water. In this paper, a new method is introduced for efficient measurement of radon in water by registering alpha particle tracks in a CR-39 detector placed in a non-polar medium such as cyclohexane, hexane and olive oil when each mixed with water, then separated and fixed above water, as a two-phase media. The method introduced here is however different from the widely used liquid - liquid extraction technique by liquid scintillation spectrometry since it is a passive detection method (CR-39) in a non-polar liquid with enhanced absorption of radon in the liquid, it has a capability for long sample counting to decrease the minimum detection limit (MDL), it does not require sophisticated low light counting systems, and it has the potential for simultaneous measurements of large number of samples for large-scale applications. It also has a low cost and is readily available. A new Monte Carlo calculation of energy-distance travelled by alphas from radon and progeny in a medium was also investigated. The sensitivity of CR-39 detector to radon and progeny in water was determined under two conditions; in a single-phase and two-phase media. In a single-phase medium, CR-39 is directly placed either in air, water, cyclohexane, hexane or olive oil. When CR-39 is placed directly in water, its sensitivity is (2.4 ± 0.1) × 10 −4 (track/cm 2 )/(Bq.d/m 3 ). In the two-phase media, CR-39 is placed either in cyclohexane, hexane or olive oil when each is fixed above water. The sensitivities in the two-phase media are significantly enhanced and are respectively (1.98 ± 0.10) × 10 −2 , (2.8 ± 0.15) × 10 −2 and (2.86 ± 0.15) × 10 −2 (track/cm 2 )/(Bq.d/m 3 ). The sensitivies are about 76, 82 and 110 times more than that of when CR-39 is directly placed in water. The new method is a novel alternative for radon

  7. Risk Assessment from Radon Gas in the Greenhouses

    International Nuclear Information System (INIS)

    Fahmi, N.M.; El-Khatib, A.M.; Abd El-Zaher, M

    2009-01-01

    Radon is a naturally occurring radioactive gas found in varying amounts in all soils. Therefore, it is very important to study radon emanation from different soils in different circumstances; especially, in green houses which widely used to propagate and cultivate of plants. In greenhouses radon comes from either soil or the substances which make suitable flooring in the greenhouse. Radon and its progeny are accumulated in the air and on the plants themselves, which causes hazard for workers and customers in a later stage. Radon gas is measured in two kinds of greenhouses, one of them is constructed from plastic sheet and the other from glass (Agriculture Research Center - Horticulture Research Institute) using CR-39 NTDs as a passive technique. It based on the production of track in the detector due to alpha-particles emitted from radon and its progeny. The observed track densities are then converted to annual radon dose to be 12.36 mSv and 8.3 mSv for the plastic and glass greenhouses under investigation, respectively. It is also found that the workers have been subject to regulatory control

  8. Levels of thoron and progeny in high background radiation area of southeastern coast of Odisha (India))

    International Nuclear Information System (INIS)

    Ramola, R. C.; Gusain, G. S.; Rautela, B. S.; Sagar, D. V.; Prasad, G.; Shahoo, S. K.; Ishikawa, T.; Omori, Y.; Janik, M.; Sorimachi, A.; Tokonami, S.

    2012-01-01

    Exposure to radon, 222 Rn, is assumed to be the most significant source of natural radiation to human beings in most cases. It is thought that radon and its progeny are major factors that cause cancer. The presence of thoron, 220 Rn, was often neglected because it was considered that the quantity of thoron in the environment is less than that of radon. However, recent studies have shown that a high thoron concentration was found in some regions and the exposure to 220 Rn and its progeny can equal or several time exceed that of 220 Rn and its progeny. The results of thoron and its progeny measurements in the houses of high background radiation area (HBRA) of the southeastern coast of Odisha (India)) presented here. This area is one of the high background radiation areas in India with a large deposit of monazite sand which is the probable source of thoron. Both active and passive methods were employed for the measurement of thoron and its progeny in cement, brick and mud houses in the study area. Thoron concentration was measured using RAD-7 and Raduet. A CR-39 track detector was employed for the measurement of environmental thoron progeny, both in active and passive modes. Thoron and its progeny concentrations were found to be comparatively high in the area. A comparison between the results obtained with various techniques is presented in this paper. (authors)

  9. Levels of thoron and progeny in high background radiation area of southeastern coast of Odisha (India))

    Energy Technology Data Exchange (ETDEWEB)

    Ramola, R C; Gusain, G S; Rautela, B S [Dept. of Physics, H.N.B. Garhwal Univ., Badshahi Thaul Campus, Tehri Garhwal 249199 (India); Sagar, D V [Health Physics Unit EAD, BARC, IRE, OSCOM, Matikhalo, Ganjam, Odisha 761 045 (India); Prasad, G; Shahoo, S K; Ishikawa, T; Omori, Y; Janik, M [National Inst. of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan); Sorimachi, A; Tokonami, S [Inst. of Radiation Emergency Medicine, Hirosaki Univ., Aomori 036-8564 (Japan)

    2012-07-01

    Exposure to radon, {sup 222}Rn, is assumed to be the most significant source of natural radiation to human beings in most cases. It is thought that radon and its progeny are major factors that cause cancer. The presence of thoron, {sup 220}Rn, was often neglected because it was considered that the quantity of thoron in the environment is less than that of radon. However, recent studies have shown that a high thoron concentration was found in some regions and the exposure to {sup 220}Rn and its progeny can equal or several time exceed that of {sup 220}Rn and its progeny. The results of thoron and its progeny measurements in the houses of high background radiation area (HBRA) of the southeastern coast of Odisha (India)) presented here. This area is one of the high background radiation areas in India with a large deposit of monazite sand which is the probable source of thoron. Both active and passive methods were employed for the measurement of thoron and its progeny in cement, brick and mud houses in the study area. Thoron concentration was measured using RAD-7 and Raduet. A CR-39 track detector was employed for the measurement of environmental thoron progeny, both in active and passive modes. Thoron and its progeny concentrations were found to be comparatively high in the area. A comparison between the results obtained with various techniques is presented in this paper. (authors)

  10. Prototype exposure chamber of radon for animal experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Yuji; Koizumi, Akira; Yonehara, Hidenori; Shimo, Michikuni; Inaba, Jiro [National Institute of Radiological Sciences, Chiba (Japan)

    1998-12-31

    To evaluate a dose conversion factor from the `Working Level of Month` (WLM) of radon to the absorbed dose (mGy), the quality of radon and its progeny was assessed, and exposures controlled for each deposition region were planed as follows: 1) exposure of radon gas to the entire respiratory tract, 2) exposure of `unattached` fractions to the upper respiratory tract, 3) exposure of `attached` fractions onto ultrafine particles to the deep lung, 4) exposure of `attached` fractions onto fine particles to the lower respiratory tract, 5) exposure of `attached` fractions onto coarse particles to the upper respiratory tract. In this preliminary study, a prototype exposure system of radon and its progeny for small rodents was designed. A whole body exposure chamber with a volume of about 0.5 m{sup 3} was used, which it held 20 rats. The aging and mixing chamber separated by the exposure chamber had a volume of about 1 m{sup 3}. As career aerosols of radon progeny, carnauba wax aerosols as solid particles, DOS aerosols as liquid particles and NaCl aerosols as hygroscopic particles were selected. These aerosols generated using a vaporization-condensation method and/or an electrical classification method were almost monodisperse with {sigma}{sub g} of <1.2. The monitoring data on biologically related gases showed an importance in the oxygen injection system and the carbon dioxide absorption system. (author)

  11. Indoor air radon

    International Nuclear Information System (INIS)

    Cothern, C.R.

    1990-01-01

    This review concerns primarily the health effects that result from indoor air exposure to radon gas and its progeny. Radon enters homes mainly from the soil through cracks in the foundation and other holes to the geologic deposits beneath these structures. Once inside the home the gas decays (half-life 3.8 d) and the ionized atoms adsorb to dust particles and are inhaled. These particles lodge in the lung and can cause lung cancer. The introduction to this review gives some background properties of radon and its progeny that are important to understanding this public health problem as well as a discussion of the units used to describe its concentrations. The data describing the health effects of inhaled radon and its progeny come both from epidemiological and animal studies. The estimates of risk from these two data bases are consistent within a factor of two. The epidemiological studies are primarily for hard rock miners, although some data exist for environmental exposures. The most complete studies are those of the US, Canadian, and Czechoslovakian uranium miners. Although all studies have some deficiencies, those of major importance include uranium miners in Saskatchewan, Canada, Swedish iron miners, and Newfoundland fluorspar miners. These six studies provide varying degrees of detail in the form of dose-response curves. Other epidemiological studies that do not provide quantitative dose-response information, but are useful in describing the health effects, include coal, iron ore and tin miners in the UK, iron ore miners in the Grangesburg and Kiruna, Sweden, metal miners in the US, Navajo uranium miners in the US, Norwegian niobian and magnitite miners, South African gold and uranium miners, French uranium miners, zinc-lead miners in Sweden and a variety of small studies of environmental exposure. An analysis of the epidemiological studies reveals a variety of interpretation problem areas.172 references

  12. A study of environmental radon levels in rammed earth dwellings in the south west of Western Australia

    International Nuclear Information System (INIS)

    Walsh, M.; Jennings, P.

    2002-01-01

    Indoor radon and thoron progeny Equilibrium Equivalent Concentrations (EEC) were measured with a portable 'Radon Sniffer' in 10 rammed earth dwellings and 10 conventional dwellings in Margaret River in the South West of Western Australia. Natural background gamma radiation was also measured within the dwellings. The results of this study show that the mean indoor radon progeny concentrations in rammed earth and non-rammed earth dwellings was 24 Bq m -3 EEC and 9.3 Bq m -3 EEC respectively. The mean indoor thoron progeny concentrations in rammed earth and non-rammed earth dwellings was 3.9 Bq m -3 EEC and 0.8 Bq m -3 EEC respectively. The ranges of combined indoor radon and thoron progeny concentrations in rammed earth and non-rammed earth dwellings were between 2.1 and 76 Bq m -3 EEC and 2.0 and 27 Bq m -3 EEC respectively. The mean annual effective radiation dose equivalents from combined indoor radon and thoron progeny concentrations EEC using UNSCEAR's (1982) conversion factors in rammed earth and non-rammed earth dwellings were 4.1 mSv y -1 and 2.2 mSv y -1 respectively. Copyright (2002) Australasian Radiation Protection Society Inc

  13. Application of underwater radon measurements in geology

    Energy Technology Data Exchange (ETDEWEB)

    Varhegyi, A.; Baranyi, I.; Gerzson, I. (Mecsek Ore Mining Enterprise, Pecs (Hungary)); Somogyi, G.; Hakl, J.; Hunyadi, I. (Magyar Tudomanyos Akademia, Debrecen (Hungary). Atommag Kutato Intezete)

    1988-01-01

    Based on the observed phenomenon of geogas migration in microbubble form from deeper regions, the authors have developed a new model for the vertical transport of radon released from deeper sources. The physical properties of the rock relating to the upflow of microbubbles below the groundwater level are considered and the radon transport parameter of rocks is introduced. The vertical distribution of radon concentration in the case of a multi-layered geological model is given and the penetration depth of underwater radon measurements is examined. Aspects of underwater radon detection by the nuclear track detector technique are analyzed. The radon transport model gives a new theoretical basis for several applications of radon measurements in geology. The advantages of underwater radon detection have already been proved in uranium exploration. Further geological applications are proposed in earthquake prediction, in volcanology, in the survey of active faults and thermal waters. (author).

  14. Influence of Meteorological Conditions in the Annual Variation of Environmental Radon Activity

    International Nuclear Information System (INIS)

    Márquez, J.L.; Sáez, J.C.; Álvarez, A.; Quiñones, J.

    2015-01-01

    The aim of this study is to determine the correlations that exist between Rn gas, the Rn progeny and the meteorological variables. Also it takes part from the study to observe which variables are responsible of ambient dose equivalent rate variations. The study of correlations between different variables was performed using two methodologies; the first of them is a graphical representation of all variables to observe the temporal evolution of each variable and the second is the application of a Principal Component Analysis. The study of variables behavior has been divided into three periods (day, month and year), considering the presence and absence of rainfall for daily and monthly period. Several correlations have been identified between the Rn gas, Rn progeny and meteorological variables. It has also identified the influence of rainfall on the ambient dose equivalent rate due to the radon progeny. To complete the study, a theoretical model based on an adjustment by the least-squares has been performed to estimate the levels of exhaled radon in atmosphere for any day of the year.

  15. Radon dose assessment in underground mines in Brazil

    International Nuclear Information System (INIS)

    Santos, T.O.; Rocha, Z.; Cruz, P.; Gouvea, V.A.; Siqueira, J.B.; Oliveira, A.H.

    2014-01-01

    Underground miners are internally exposed to radon, thoron and their short-lived decay products during the mineral processing. There is also an external exposure due to the gamma emitters present in the rock and dust of the mine. However, the short-lived radon decay products are recognised as the main radiation health risk. When inhaled, they are deposited in the respiratory system and may cause lung cancer. To address this concern, concentration measurements of radon and its progeny were performed, the equilibrium factor was determined and the effective dose received was estimated in six Brazilian underground mines. The radon concentration was measured by using E-PERM, AlphaGUARD and CR-39 detectors. The radon progeny was determined by using DOSEman. The annual effective dose for the miners was estimated according to United Nations Scientific Committee on the Effects of Atomic Radiation methodologies. The mean value of the equilibrium factor was 0.4. The workers' estimated effective dose ranged from 1 to 21 mSv a -1 (mean 9 mSv a -1 ). (authors)

  16. Risk assessment of exposure to radon decay products

    Energy Technology Data Exchange (ETDEWEB)

    Monchaux, G

    1999-07-01

    The aim of this project was to assess the risk due to inhalation of radon and its decay products using an horizontal approach across a large scale research programme. The central objective was the assessment of human risk which requires combination of several topics involving a multidisciplinary approach. In the Aerosol Studies Group, progress was achieved in improvement, calibration and automation of experimental techniques for continuous and integrated measurements of the unattached fraction f{sub p}- and equilibrium factor F- values. Measurements were performed to determine the variation of size distributions of unattached and aerosol-associated radon decay products under typical living conditions. All aerosol groups performed controlled chamber studies to understand the basic behaviour of airborne activity concentrations. Measurements were performed to determine neutralisation rates of {sup 218}Po, to understand the cluster growth with residence time and to understand the hygroscopic growth of aerosol particles. In the Modelling Group, the programme RADEP has been developed to calculate the weighted committed equivalent lung dose per unit exposure of radon progeny (H{sub w}/P{sub p}) which implements the ICRP Publication 66 Human Respiratory Tract Model (HRTM). The stochastic deposition model (IDEAL) has been compared with the deposition model used by the HRTM, and the agreement between the two deposition models was excellent. A deterministic radon progeny dosimetry model (RADOS) has been developed. This model includes all bronchial airway generations compared with the HRTM that groups the 16 airway generations into three regions. Initial calculations with RADOS show that the basal and secretory cell doses are slightly smaller compared with that of the HRTM. A sensitivity analysis has been performed that has identified those HRTM model parameters that most affect the Hw/Pp. A stochastic rat deposition model (RALMO) and a clearance model for the rat based on the

  17. Risk assessment of exposure to radon decay products

    International Nuclear Information System (INIS)

    Monchaux, G.

    1999-01-01

    The aim of this project was to assess the risk due to inhalation of radon and its decay products using an horizontal approach across a large scale research programme. The central objective was the assessment of human risk which requires combination of several topics involving a multidisciplinary approach. In the Aerosol Studies Group, progress was achieved in improvement, calibration and automation of experimental techniques for continuous and integrated measurements of the unattached fraction f p - and equilibrium factor F- values. Measurements were performed to determine the variation of size distributions of unattached and aerosol-associated radon decay products under typical living conditions. All aerosol groups performed controlled chamber studies to understand the basic behaviour of airborne activity concentrations. Measurements were performed to determine neutralisation rates of 218 Po, to understand the cluster growth with residence time and to understand the hygroscopic growth of aerosol particles. In the Modelling Group, the programme RADEP has been developed to calculate the weighted committed equivalent lung dose per unit exposure of radon progeny (H w /P p ) which implements the ICRP Publication 66 Human Respiratory Tract Model (HRTM). The stochastic deposition model (IDEAL) has been compared with the deposition model used by the HRTM, and the agreement between the two deposition models was excellent. A deterministic radon progeny dosimetry model (RADOS) has been developed. This model includes all bronchial airway generations compared with the HRTM that groups the 16 airway generations into three regions. Initial calculations with RADOS show that the basal and secretory cell doses are slightly smaller compared with that of the HRTM. A sensitivity analysis has been performed that has identified those HRTM model parameters that most affect the Hw/Pp. A stochastic rat deposition model (RALMO) and a clearance model for the rat based on the HRTM have been

  18. Indoor-atmospheric radon-related radioactivity affected by a change of ventilation strategy

    International Nuclear Information System (INIS)

    Kobayashi, Tuneo

    2006-01-01

    The present author has kept observation for concentrations of atmospheric radon, radon progeny and thoron progeny for several years at the campus of Fukushima Medical University. Accidentally, in the midst of an observation term, i.e., February 2005, the facility management group of the university changed a strategy for the manner of ventilation, probably because of a recession: tidy everyday ventilation of 7:30-24:00 into shortened weekday ventilation of 8:00-21:00 with weekend halts. This change of ventilation manner brought a clear alteration for the concentrations of radon-related natural radioactivity in indoor air. The present paper concerns an investigation of the effect of the ventilation strategy on the indoor-atmospheric radon-related radioactivity. (author)

  19. Uncertainties of estimating average radon and radon decay product concentrations in occupied houses

    International Nuclear Information System (INIS)

    Ronca-Battista, M.; Magno, P.; Windham, S.

    1986-01-01

    Radon and radon decay product measurements made in up to 68 Butte, Montana homes over a period of 18 months were used to estimate the uncertainty in estimating long-term average radon and radon decay product concentrations from a short-term measurement. This analysis was performed in support of the development of radon and radon decay product measurement protocols by the Environmental Protection Agency (EPA). The results of six measurement methods were analyzed: continuous radon and working level monitors, radon progeny integrating sampling units, alpha-track detectors, and grab radon and radon decay product techniques. Uncertainties were found to decrease with increasing sampling time and to be smaller when measurements were conducted during the winter months. In general, radon measurements had a smaller uncertainty than radon decay product measurements. As a result of this analysis, the EPA measurements protocols specify that all measurements be made under closed-house (winter) conditions, and that sampling times of at least a 24 hour period be used when the measurement will be the basis for a decision about remedial action or long-term health risks. 13 references, 3 tables

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

    International Nuclear Information System (INIS)

    Yu, K.N.; Young, E.C.M.; Stokes, M.J.; Lo, C.H.

    1997-01-01

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

  1. A nationwide survey of radon concentration in Japan. Indoor, outdoor and workplace

    International Nuclear Information System (INIS)

    Sanada, Tetsuya; Oikawa, Shinji; Kanno, Nobuyuki; Abukawa, Johji; Higuchi, Hideo

    2004-01-01

    The nationwide indoor, outdoor and workplace radon concentrations were surveyed in Japan. These surveys were conducted to estimate the natural radiation dose due to radon and its progeny for the general public. The radon concentration was measured using passive type radon monitor. The number of radon monitors were installed at indoor, outdoor and workplace for 940 houses, 705 points and 705 sites, respectively. The radon concentration was measured for one year at each measurement site. Annual mean radon concentration was obtained from four quarters measurements of 47 prefectures in Japan. The nationwide indoor, outdoor and workplace annual mean radon concentration were 15.5 Bq m -3 , 6.1 Bq m -3 and 20.8 Bq m -3 , respectively. Their radon concentration shows approximately a logarithmic normal distribution. Workplace showed relatively high radon concentration compared with other environments, may be due to construction materials and low ventilation rate. The indoor radon concentration found to be seasonal variation and architectural dependences. Seasonal variation and regional distribution of outdoor radon concentration was also observed. From the results of these radon surveys, the annual effective dose to the general public due to radon and its progeny was estimated to be 0.49 mSv y -1 in Japan. (author)

  2. Radon in an underground cave system in Victoria

    International Nuclear Information System (INIS)

    Hedt, J.C.; Boal, T.J.

    1998-01-01

    Radon levels in a cave system in Victoria have been measured. The variation of radon and radon progeny levels with time, position throughout the cave and season have been determined. The radiation exposure of tour guides were estimated. The data is being used to develop a radiation management plan for the tour guides. Radon concentration within a cave system was proven to be dependent to a large extent upon the rate of air exchange with outside. Cave ventilation is the single most important factor in determining if there is diurnal variation in the radon concentration

  3. Establishment of a radon test chamber

    International Nuclear Information System (INIS)

    Chen Chingjiang; Liu Chichang; Lin Yuming

    1993-01-01

    A walk-in type radon test chamber of 23 m 3 has been built for testing and calibration of radon measurement instruments. The environmental conditions of the test chamber can be varied within a wide range of values. The design objectives specification, monitoring instruments and testing results of this chamber are discussed. This test chamber is available for domestic radon researchers and its accuracy can be traced to the international standard. A routine intercomparison study will be held annually by using this chamber. Other tests like radon progeny and thoron standard may also be performed in this chamber. (1 fig.)

  4. Evaluation of indoor radon equilibrium factor using CFD modeling and resulting annual effective dose

    Science.gov (United States)

    Rabi, R.; Oufni, L.

    2018-04-01

    The equilibrium factor is an important parameter for reasonably estimating the population dose from radon. However, the equilibrium factor value depended mainly on the ventilation rate and the meteorological factors. Therefore, this study focuses on investigating numerically the influence of the ventilation rate, temperature and humidity on equilibrium factor between radon and its progeny. The numerical results showed that ventilation rate, temperature and humidity have significant impacts on indoor equilibrium factor. The variations of equilibrium factor with the ventilation, temperature and relative humidity are discussed. Moreover, the committed equivalent doses due to 218Po and 214Po radon short-lived progeny were evaluated in different tissues of the respiratory tract of the members of the public from the inhalation of indoor air. The annual effective dose due to radon short lived progeny from the inhalation of indoor air by the members of the public was investigated.

  5. 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)

  6. Standardization of radon measurements

    International Nuclear Information System (INIS)

    Matuszek, J.M.; Hutchinson, J.A.; Lance, B.H.; Virgil, M.G.; Mahoney, R.J.

    1988-01-01

    Radon escaping from soil into homes appears to present the single greatest source of radiation exposure that most people will ever face. Measurement protocols for the relatively inert gas inextricably link the method of collection with the counting of the specimen. The most commonly used methods depend on the measurement of dislocation sites on plastic α-track detectors or on the adsorption of radon onto activated charcoal for subsequent counting of the γ-rays produced by decay of the radon progeny. The uncertainties inherent to the radon-measurement methods used commercially in the United States are far greater than those for measurements of other environmental radionuclides. The results of this preliminary study raise doubts as to whether existing proficiency-testing programs can provide assurance that radon-measurement methods are representative of actual conditions in any dwelling. 17 refs., 1 figs., 4 tabs

  7. Seasonal behavior of radon decay products in indoor air and resulting radiation dose to human respiratory tract

    Directory of Open Access Journals (Sweden)

    A.M.A. Mostafa

    2015-01-01

    Full Text Available Most of radiation hazard of indoor radon is largely due to the radon progenies, which are inhaled and deposited in the human respiratory tract. It is essential to evaluate aerodynamic characteristics of the radon progenies, which are either attached or unattached to aerosol particles, because the dose is strongly dependent on the location of deposition in respiratory tract and hence on the aerodynamic characteristics of the aerosol particles. This paper presents the seasonal behavior of radon decay products in indoor air under domestic conditions at Nagoya University, Japan. A low pressure cascade impactor as an instrument for classifying aerosol sizes and imaging plate as a radiation detector have been employed to characterize the activity size distribution of short-lived radon decay products. In parallel, radon and its progenies concentrations were measured. Taking into account the progeny characteristics, the inhalation dose in the different seasons was also estimated based on a lung dose model with the structure that is related to the ICRP66 respiratory tract model. The result evident that, the highest dose 0.22 mSvy−1 was observed during the winter where the highest value of equilibrium equivalent concentration of radon (EEC and lowest value of the activity median aerodynamic diameter (AMAD were found in this season; whereas, the dose in spring appeared to be lowest 0.02 mSvy−1.

  8. Studies on thoron progeny implantation in different materials

    International Nuclear Information System (INIS)

    Cosma, C.; Flore, A.; Pop, I.

    2003-01-01

    The purpose of this work is to obtain the alpha spectra for thoron daughters implanted at the surface of different materials and to show the possibility of this method to simulate the radon progeny implantation and thus to find some parameters used in the Jacobi model

  9. The effect of RTP (Radon Thoron Progeny) and dust loading on the design of an alarm system for airborne plutonium particulates

    International Nuclear Information System (INIS)

    Pai, H.L.; Sun, L.C.

    2004-01-01

    If the alpha method is adopted, the main problem for determining airborne plutonium particulates is the overlapping of the alpha spectrum between Pu and RTF (radon thoron progeny). The order of magnitude estimation establishes that RTP is more than 20 times higher than Pu. Therefore a method of discriminating RTP is required. The primary methods of discrimination are the aerosol size and the alpha spectrum methods. If the alpha spectrum method is adopted, the formation of the low energy tail of RTP should be investigated. Preliminary study indicates that the low energy tail is related to the air gap and dust loading. (author)

  10. Study on collaborative optimization control of ventilation and radon reduction system based on multi-agent technology

    International Nuclear Information System (INIS)

    Dai Jianyong; Meng Lingcong; Zou Shuliang

    2015-01-01

    According to the radioactive safety features such as radon and its progeny, combined with the theory of ventilation system, structure of multi-agent system for ventilation and radon reduction system is constructed with the application of multi agent technology. The function attribute of the key agent and the connection between the nodes in the multi-agent system are analyzed to establish the distributed autonomous logic structure and negotiation mechanism of multi agent system of ventilation and radon reduction system, and thus to implement the coordination optimization control of the multi-agent system. The example analysis shows that the system structure of the multi-agent system of ventilation and reducing radon system and its collaborative mechanism can improve and optimize the radioactive pollutants control, which provides a theoretical basis and important application prospect. (authors)

  11. A combined method for evaluating radon and progeny in waters and its use at Guarani aquifer, Sao Paulo State, Brazil

    International Nuclear Information System (INIS)

    Bonotto, D.M.; Mello, C.B.

    2006-01-01

    A combined method for evaluating radon ( 222 Rn) and progeny ( 214 Pb and 214 Bi) in water was developed by using inexpensive alpha scintillation counting and gamma ray spectrometry through NaI(Tl) scintillation detectors. A groundwater sample collected at the Pocos de Caldas alkaline massif in Brazil was submitted to the technique in order to assure its applicability by comparing the volumetric activities by different methods. Similar volumetric activity was determined for 214 Pb and 214 Bi in the sample analyzed that is compatible with the expected condition of radioactive equilibrium between these nuclides. The combined method was successfully used to analyze groundwater samples from Guarani aquifer in Sao Paulo State, Brazil, and the results of the measurements indicated that 214 Pb and 214 Bi provide useful information concerning the evaluation of the drinking water quality in terms of radiological aspects. This is because they are directly identified in the water samples, without the need of requiring the assumption of the establishment of the transient equilibrium condition with its parent 222 Rn

  12. A combined method for evaluating radon and progeny in waters and its use at Guarani aquifer, Sao Paulo State, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Bonotto, D.M. [Departamento de Petrologia e Metalogenia, Universidade Estadual Paulista (UNESP), IGCE-Instituto de Geociencias e Ciencias Exatas, Av. 24-A, No. 1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil)]. E-mail: dbonotto@rc.unesp.br; Mello, C.B. [Departamento de Petrologia e Metalogenia, Universidade Estadual Paulista (UNESP), IGCE-Instituto de Geociencias e Ciencias Exatas, Av. 24-A, No. 1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil)

    2006-07-01

    A combined method for evaluating radon ({sup 222}Rn) and progeny ({sup 214}Pb and {sup 214}Bi) in water was developed by using inexpensive alpha scintillation counting and gamma ray spectrometry through NaI(Tl) scintillation detectors. A groundwater sample collected at the Pocos de Caldas alkaline massif in Brazil was submitted to the technique in order to assure its applicability by comparing the volumetric activities by different methods. Similar volumetric activity was determined for {sup 214}Pb and {sup 214}Bi in the sample analyzed that is compatible with the expected condition of radioactive equilibrium between these nuclides. The combined method was successfully used to analyze groundwater samples from Guarani aquifer in Sao Paulo State, Brazil, and the results of the measurements indicated that {sup 214}Pb and {sup 214}Bi provide useful information concerning the evaluation of the drinking water quality in terms of radiological aspects. This is because they are directly identified in the water samples, without the need of requiring the assumption of the establishment of the transient equilibrium condition with its parent {sup 222}Rn.

  13. Men and radon - a noble gas of many disguise - Part I and Part II

    International Nuclear Information System (INIS)

    Momcilovic, B.; Lykken, G. I.

    2005-01-01

    Radon-induced lung cancer can be traced back to the 16th century miners in Europe, but recently there has been a world wide concern that elevated radon progeny levels in dwellings may also be implicated in lung cancer. Historical and experimental evidence is presented to document how inhaled radon is distributed throughout the body and stored in fats and lipids. Background counts in a steel room using a human whole-body counter (HWBC) progressively decreased throughout the day, which is attributed to a lowering of radon as subjects entered the steel room. The observed increases in potassium-40 (4 0K ) counts in marathon runners was attributed to inhalation of environmental radon, and radon progeny was verified by measuring contributions to the 4 0K photopeak by 2 14B i in cyclists and an untrained subject who exercised in a room with radon-laden air. Effective half-lives and regional 2 14B i emissions were found to be the highest in the areas of the head (brain) and stomach (omentum) when filtered radon-laden air was inhaled. These observations prompted analyses for radon progeny (2 10B i and 2 10P o) from brain tissues of persons who suffered from Alzheimer's and Parkinson's Diseases (AD and PD). Protein in AD and lipids in PD were high in these progeny relative to the control tissues. Whole body counts (2 14B i emissions) of subjects over a period of 24 years were analysed for radon body content (Rn-conc). Statistically significant correlations were found between total body fat and Rn-conc in women and between seasonal home radon concentrations and seasonal Rn-conc in subjects participating in community-based studies. It is concluded that environmental radon is indeed stored in the body, that body concentration correlates with body fat in women, and that these reflect seasonal concentrations in their dwellings. Radon decay products include a number of alpha and beta particle emitters. These emissions produce a radiation risk and may play a role in multiple

  14. Risk assessment of exposure to radon concentration in indoor atmosphere and drinking water of Shimoga city, Karnataka, India

    International Nuclear Information System (INIS)

    Rangaswamy, D.R.; Sannappa, J.; Srinivasa, E.

    2016-01-01

    The exposure of population to natural sources of radiation has become an important issue in terms of radiological protection. The major contribution of dose from natural radiation in normal background regions arises due to inhalation of alpha-emitting radon and thoron, and their progenies, which are ubiquitous in both indoor and outdoor environs. The aim of the present study is to measure indoor radon, thoron and their progeny levels in the dwellings of Shimoga city and radon concentration in drinking water and to estimate the annual effective dose. The indoor concentration of radon, thoron and their progeny was measured using Solid-State Nuclear Track Detectors (SSNTDs) based twin chamber dosimeter cups. The 222 Rn concentration in drinking water was estimated by the Emanometry technique

  15. Radon concentration levels in Fatima Jinnah women university Pakistan

    International Nuclear Information System (INIS)

    Khan, S.A.; Ali, S.; Tufail, A.; Qureshi, A.A.

    2005-01-01

    Public exposure to radioactive gas radon and its progeny present in the air results in the largest contribution to total effective dose received by human beings. It is therefore of great concern to monitor radon concentration in energy conserved air tight buildings. Measurements of radon in the Fatima Jinnah Women University (FJWU) have been carried out for investigation and comparison of radon concentration in the new and old buildings of the campus at Rawalpindi, Pakistan. The study was done because according to the international guidelines concerning environmental problems, it is necessary to evaluate and know the radon levels, especially since most of the natural radiation dose to human beings comes from radon gas and its progeny. Solid State Nuclear Track Detectors (SSNTDs) being efficient, therefore, the measurements were carried out by passive, time integrated method, using CR-39 detector in polythene bags. The detectors were exposed for more than six month in various locations indoors and outdoors. The detectors were etched using NaOH, the tracks were counted manually, and the track density was converted to radon concentration. Radon concentration varied from 31 to 213 Bq.m -3 in old building and from 27 to 143 Bq.m -3 in new buildings, showing slight elevated values in the old buildings. Radon concentration values were found to be less than the values quoted by radiation protection agencies. Radiation dose due to radon varied in the university campus depending on occupancy factor. (author)

  16. 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

  17. Assessing the risks from exposure to radon in dwellings

    International Nuclear Information System (INIS)

    Walsh, P.J.; Lowder, W.M.

    1983-07-01

    The factors used to assess the radiation dose and health risks from human exposure to radon in dwellings are critically reviewed in this summary. Sources of indoor radon and determinants of air concentrations and exposure levels are given as well as the uncertainties that exist in their formulation. Methods of assessing health effects from inhalation of radon and its progeny are discussed with emphasis on dosimetry of radon daughters and formulation of risk per dose values. Finally, methods of assessing risks for general population exposures to indoor radon concentrations are treated

  18. 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

  19. A self-calibrating radon monitor with statistical discrimination

    International Nuclear Information System (INIS)

    Valcov, N.; Purghel, L.

    2002-01-01

    A radon monitor, able to perform the measurement of the radon and its progeny volumic activity, in a gamma-ray or natural radiation background field, was developed. The instrument consists of a 10 l ionization chamber, a high voltage source, an integrating preamplifier, a data acquisition system and a personal computer. A new method for self-calibration of Radon volumic activity measurements, based on the alpha counting with an ionization chamber is also presented

  20. Studies on radon concentration at the work places of Mysuru, Bengaluru, Tumkuru and Kolar Districts of Karnataka State, South India

    International Nuclear Information System (INIS)

    Ningappa, C.; Reddy, K. Umesha; Rangaswamy, D.R.; Sannappa, J.

    2015-01-01

    Radon is a radioactive noble gas and is the decay product of naturally occurring uranium. It decays into radioactive metal ions polonium-218 and polonium-214 by alpha radiation, which are harmful to the human health. The concentrations of radon and its progeny inside a given working place depends on activity of radium both in the soil surrounding the workplace and in the building materials, atmospheric conditions, design of the workplace, porosity of the surrounding soil, building layout, and the ventilation habits of the inhabitants of the building. The estimation of dose due to radon and its progeny to the general public and workers at work places are very important. Thus, concentration of radon and its progeny and dose due to radon and its progeny to the public and workers were measured at sixty workplaces of Mysuru, Bengaluru, Tumkur and Kolar districts based on geology and willingness of the workplace owner using twin cup dosimeter based on Solid State Nuclear Track Detectors (SSNTDs) and results are discussed in the present study. The values measured indoor radon in the area of study ranged from a 11.6 to 284.8 Bq.m -3 . (author)

  1. Measurement of the radon concentration in an underground public facility and dose assessment. Fukuoka Tenjin Shopping Center

    International Nuclear Information System (INIS)

    Narazaki, Yukinori; Tokonami, Shinji; Sanada, Tetsuya; Kanno, Nobuyuki; Yamada, Yuji

    2000-01-01

    Radon concentrations were measured with a passive radon detector from April 1998 through June 1999 in the Fukuoka Tenjin Underground Shopping Center to assess the dose affecting workers because of radon progeny inhalation. The radon concentration during the period was distributed from a range of 1.9 to 13.6 Bq/m 3 . The arithmetic average concentration was estimated to be 6.9±2.4 Bq/ 3 . The radon level was lower than that in dwellings in Japan and other countries. No spatial distribution of radon concentration was found in that area. From continuous measurement, the radon concentration was found to be high from midnight to noon and low in the afternoon. Little difference was noted between the daily average radon concentration and that during working hours. There was no seasonal variation. The equilibrium factor of 0.21±0.10 was obtained during working hours. The activity-weighted size distribution of radon progeny was evaluated by using the number distribution of ambient aerosols and the classical attachment theory. Consequently, the activity median diameter was 150 nm. The unattached fraction of radon progeny was estimated to be 0.025 with an empirical equation. The annual effective dose of workers at the Tenjin center was calculated with the dose conversion factor from the UNSCEAR 1993 report and estimated to be 0.024 mSv/y. (author)

  2. Development of electret technology to measure indoor radon-daughter concentrations: Final report (Phase 1)

    International Nuclear Information System (INIS)

    Kotrappa, P.; Dempsey, J.C.; Stieff, L.R.

    1989-05-01

    A new type of radon progeny monitor called an electret radon progeny integrating sampling unit (E-RPISU) was developed and demonstrated which uses an electret ion chamber to measure the progeny concentration. A conventional 1 LPM particulate air sampling system is used to collect the progeny on a 35 cm 2 filter which is mounted on the side of the electret ion chamber such that the collected progeny are exposed to the inside of the chamber. The alpha radiation emitted by the progeny collected on the filter ionizes the air in the 220 ml chamber. The ions of opposite polarity collect on the surface of the 127 μm thick electret and reduce its surface voltage. A specially built surface voltmeter is used to measure the electret voltage before and after sampling. The electret voltage drop which occurs during the sampling period is shown to be proportional to the time integrated progeny concentration. Two prototype systems were fabricated and tested in homes and in calibrated radon chambers. The resulting data are presented and analyzed. The calibration factor for the E-RPISU ranged from 1.5 to 2.0 V/mWL-day depending on the electret voltage. Two of the E-RPISUs were delivered to UNC Geotech for further testing. 32 refs., 11 figs., 5 tabs

  3. 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

  4. Analysis of radon reduction and ventilation systems in uranium mines in China.

    Science.gov (United States)

    Hu, Peng-hua; Li, Xian-jie

    2012-09-01

    Mine ventilation is the most important way of reducing radon in uranium mines. At present, the radon and radon progeny levels in Chinese uranium mines where the cut and fill stoping method is used are 3-5 times higher than those in foreign uranium mines, as there is not much difference in the investments for ventilation protection between Chinese uranium mines and international advanced uranium mines with compaction methodology. In this paper, through the analysis of radon reduction and ventilation systems in Chinese uranium mines and the comparison of advantages and disadvantages between a variety of ventilation systems in terms of radon control, the authors try to illustrate the reasons for the higher radon and radon progeny levels in Chinese uranium mines and put forward some problems in three areas, namely the theory of radon control and ventilation systems, radon reduction ventilation measures and ventilation management. For these problems, this paper puts forward some proposals regarding some aspects, such as strengthening scrutiny, verifying and monitoring the practical situation, making clear ventilation plans, strictly following the mining sequence, promoting training of ventilation staff, enhancing ventilation system management, developing radon reduction ventilation technology, purchasing ventilation equipment as soon as possible in the future, and so on.

  5. Analysis of radon reduction and ventilation systems in uranium mines in China

    International Nuclear Information System (INIS)

    Hu Penghua; Li Xianjie

    2012-01-01

    Mine ventilation is the most important way of reducing radon in uranium mines. At present, the radon and radon progeny levels in Chinese uranium mines where the cut and fill stoping method is used are 3–5 times higher than those in foreign uranium mines, as there is not much difference in the investments for ventilation protection between Chinese uranium mines and international advanced uranium mines with compaction methodology. In this paper, through the analysis of radon reduction and ventilation systems in Chinese uranium mines and the comparison of advantages and disadvantages between a variety of ventilation systems in terms of radon control, the authors try to illustrate the reasons for the higher radon and radon progeny levels in Chinese uranium mines and put forward some problems in three areas, namely the theory of radon control and ventilation systems, radon reduction ventilation measures and ventilation management. For these problems, this paper puts forward some proposals regarding some aspects, such as strengthening scrutiny, verifying and monitoring the practical situation, making clear ventilation plans, strictly following the mining sequence, promoting training of ventilation staff, enhancing ventilation system management, developing radon reduction ventilation technology, purchasing ventilation equipment as soon as possible in the future, and so on.

  6. Biological indicators of exposure to radon

    International Nuclear Information System (INIS)

    Beno, M.

    1998-01-01

    A review is given of recent investigations into mutagenesis and carcinogenesis due to alpha irradiation by the radon progeny. Studies of the occurrence of chromosomal aberrations after alpha irradiation are given particular attention. In the author's opinion, up to now no useful biological indicator of response to high and low doses of alpha particles has been found, including those of radon on the molecular and cellular level. (A.K.)

  7. Ethanol as radon storage: applications for measurement

    International Nuclear Information System (INIS)

    Winter, I.; Philipsborn, H. von

    1997-01-01

    Ethanol as Radon Storage: Applications for Measurement Ethanol has a solubility for radon of 6 Bq/l per kBq/m 3 air, 24 times higher than water. On filtration of ethanol, radon decay products are completely adsorbed on glass fiber filters, as previously reported for water. Hence: 1. A new simple method for measuring radon in soil air, without expensive equipment. 2. The production of mailable radon calibration sources ('radonol') with 50-100 kBq/l in PET-bottles with 3.8 days half-life, using uraniferous rocks as primary source. (orig.) [de

  8. A combined method for evaluating radon and progeny in waters and its use at Guarani aquifer, São Paulo State, Brazil.

    Science.gov (United States)

    Bonotto, D M; Mello, C B

    2006-01-01

    A combined method for evaluating radon (222Rn) and progeny (214Pb and 214Bi) in water was developed by using inexpensive alpha scintillation counting and gamma ray spectrometry through NaI(Tl) scintillation detectors. A groundwater sample collected at the Poços de Caldas alkaline massif in Brazil was submitted to the technique in order to assure its applicability by comparing the volumetric activities by different methods. Similar volumetric activity was determined for 214Pb and 214Bi in the sample analyzed that is compatible with the expected condition of radioactive equilibrium between these nuclides. The combined method was successfully used to analyze groundwater samples from Guarani aquifer in São Paulo State, Brazil, and the results of the measurements indicated that 214Pb and 214Bi provide useful information concerning the evaluation of the drinking water quality in terms of radiological aspects. This is because they are directly identified in the water samples, without the need of requiring the assumption of the establishment of the transient equilibrium condition with its parent 222Rn.

  9. An overview of thoron and its progeny in the indoor environment

    International Nuclear Information System (INIS)

    McLaughlin, J.

    2010-01-01

    An account is given of the behaviour of thoron and its progeny in the indoor environment. Emphasis is placed on the spatial distribution of these radionuclides in room air and on their interactions with indoor aerosols. How these aspects of thoron and progeny behaviour give rise to special problems for measuring them and assessing their radiological impact are described. Descriptions and comparisons are given of a range of thoron and progeny measurement techniques both passive and active. Recent progress in thoron dosimetry is described as well as compared with radon dosimetry. The results of some indoor thoron and progeny surveys carried out in different countries in recent years are given. As an example of this a summary account is presented of a recently concluded survey of thoron and its airborne progeny in over 200 houses in Ireland. (authors)

  10. An Alpha spectrometer for measuring radon daughter individual activity concentration

    International Nuclear Information System (INIS)

    Berico, M.; Formignani, M.; Mariotti, F.

    2001-01-01

    In the frame of the program of the Institute for Radiation Protection of ENEA, related to the evaluation of dose from radon and thoron progeny, an alpha spectrometer for the continuous air monitoring (CAM type) of radon and thoron has been realized. The constructive characteristics of the device are here presented together with energy and efficiency calibration. The device allows, by means of a screen type diffusion battery and a filter, to determinate the single radioactivity of each radionuclide of the progeny selecting them in relation to their diffusive behaviour (dichotomous particle size selection). The three-count filter method has been employed to measure the concentrations of 218 Po, 214 Pb and 214 Bi in air. Radon and thoron effective doses using a dosimetric, instead of an epidemiologic approach, will be then evaluated [it

  11. Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres. Progress report, July 1, 1992--March 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Hopke, P.K.

    1992-07-01

    This report describes studies on the chemical and physical behavior of the {sup 218}Po atom immediately following its formation by the alpha decay of radon. Because small changes in size for activity in the sub-10 nm size range result in large changes in the delivered dose per unit exposure, this behavior must be understood if the exposure to radon progeny and its dose to the cells in the respiratory tract are to be fully assessed. The specific tasks of the controlled laboratory studies are to determine the formation rates of {center_dot}OH radicals formed by the radiolysis of air following radon decay, to examine the formation of particles by the radiolytic oxidation of substances like SO{sub 2} ethylene, and H{sub 2}S to lower vapor pressure compounds and determine the role of gas phase additives such as H{sub 2}O and NH{sub 3} in determining the particle size, to measure the rate of ion-induced nucleation using a thermal diffusion cloud chamber, and to measure the neutralization rate of {sup 218}Po{sub x}{sup +} in O{sub 2} at low radon concentrations. Tasks of the exposure studies in occupied indoor spaces are to initiate measurements of the activity size distributions in actual homes with occupants present so that the variability of the indoor activity size distributions can be assessed with respect to indoor aerosol sources and general lifestyle variations of the occupants, to initiate a prospective study of the utility of measurement of deposited {sup 210}Pb embedded in glass surfaces as a measure of the long-term, integrated exposure of the population to radon, and to develop the methodology to determine the hygroscopicity of the indoor aerosol so that the changes in deposition efficiency of the radioactive indoor aerosol with hygroscopic growth in the respiratory tract can be assessed.

  12. Radon Measurements In Preschool And School Facilities In The Municipality Of Bank's Kapur

    International Nuclear Information System (INIS)

    Kadic, I.; Deljkic, D.; Ilic, Z.

    2015-01-01

    Radon is a radioactive noble gas, chemically inert and motile at room temperature. It is a colorless and odorless gas, but the characteristic of radioactivity enables us to detect it and measure it by two methods - the passive and the active one. The results of a research on concentration of radon activity in the air of preschool's and school's indoors in the area of the municipality of Bosanska Krupa in 2013 is shown in this work. To determine radon concentration, passive measuring method was used, canisters of radon with active carbon, with correction for the air humidity. The active carbon is placed into a canister that is opened during measurements and placed on the wanted location. Radon from the air arrives into the canister and is adsorbed on the active carbon which has high affinity towards few gases and steams, including 222Rn. Adsorbed radon in granules of active carbon is decomposed to short-living progeny: 218Po, 214Pb, 214Bi, 214Po and 210Pb. Radon's progeny 214Pb and 214Bi emit gamma-rays, it permits determination of the radon concentration via gamma-spectrometry through mentioned transitions, because three hours later the equilibrium between radon and its progeny in the carbon has already been established. The measurements have been conducted on high-resolution gamma spectrometer Ortec with 30 percent relative efficiency, integrated electronic system (Ortec) and GAMMA VISION (Ortec) software for spectra processing, analysis and evaluation of the results of measurements. The purpose of this work was to detect the levels of radon, targeting the protection of the youngest population in case of high radon concentrations in residential areas. (author).

  13. Modeling of indoor radon

    International Nuclear Information System (INIS)

    Paschoa, A.S.

    1990-01-01

    This paper reports on models for radon, which are developed not only to describe the behavior of radon and daughters since the moment that radon is created in natural sources by the alpha decay of 226 Ra up to the point that doses to humans are estimated based on the inhalation of radon and its progeny. The objective of a model should be determinant in defining the model structure and boundaries. Modeling indoors radon is particularly useful when the 226 Ra concentration in building materials and soils can be known before a house will be built with such 226 Ra bearing materials and over 226 Ra rich soils. The reported concentrations of 226 Ra in building materials range from 0.3 Bq · kg -1 in wood to about 2.6 x 10 3 Bq · kg -1 in aerated concrete based on alum shale. 30 In addition, when a house is built on a soil containing a high 226 Ra concentration, radon exhalation from the soil contributes to increase radon concentration indoors. The reported radon exhalation from soils range from 3.4 Bq · m -2 · s -1 in latosolic soil from Osaka, Japan to about 53 mBq · m -2 · s -1 in chernozemic soil from Illinois

  14. Estimation of radon concentration in dwellings in and around ...

    Indian Academy of Sciences (India)

    Besides, it is also known that out of the total radiation dose received from natural and man-made sources, 60% of the dose is due to radon and its progeny. Taking this into account, an attempt has been made to estimate radon concentration in dwellings in and around Guwahati using aluminium dosimeter cups with CR-39 ...

  15. Radon-thoron levels and inhalation dose distribution patterns in India dwellings

    International Nuclear Information System (INIS)

    Ramachandran, T.V.; Eappen, K.P.; Nair, R.N.; Mayya, Y.S.; Sadasivan, S.

    2003-09-01

    A countrywide survey on radon and thoron levels has been carried out in Indian dwellings under a Coordinated Research Project sponsored by the Board of Research in Nuclear Sciences (BRNS), Department of Atomic Energy (DAE). Eight universities and a few research institutions from different parts of the country participated in this project. Under this project, radon and thoron levels were measured using Solid State Nuclear Track Detector (SSNTD) -spark counter based passive technique. A plastic twin chamber radon -thoron dosimeter was developed and standardized for the survey. This radon-thoron discriminating dosimeter uses three SSNTDs; two of which are exposed in cup modes and the third one is exposed in bare mode. Calibration factors (CF) are obtained for cup and bare mode SSNTDs through controlled experiments in a calibration facility. Calibration factors obtained from experiments showed very good agreement with the calibration factors derived from theoretical models. Four nodal centres were set up each at Kalpakkam, Jodhpur, Jaduguda and Mumbai for calibration and standardization of the dosimeter system. Inter calibration of the dosimeters were also carried out for comparison purpose. Nearly 4500 measurements in about 1400 dwellings were made during the survey period. An analysis of the data shows that the indoor radon gas concentrations at different locations vary between 4.6 and 147.0 Bq.m -3 with a geometric mean of 23.0 Bq.m -3 (GSD 2.61). Indoor thoron gas concentrations, in general, are found to be less than the radon concentrations and vary from 3.6 to 42.8 Bq.m -3 with a geometric mean of 12.2 Bq.m -3 (GSD 3.22). The mean annual inhalation dose rate due to radon, thoron and their progeny in the dwellings is estimated to be 0.97 mSv.y -1 (GSD 2.49). It is observed that the major contribution to the indoor inhalation dose is due to radon and its progeny. However, the contribution due to thoron and its progeny is not trivial as it is about 20 % of the total

  16. Radon progeny dose conversion coefficients for Chinese males and females

    Energy Technology Data Exchange (ETDEWEB)

    Yu, K.N. E-mail: peter.yu@city.edu.hk; Cheung, T.T.K.; Haque, A.K.M.M.; Nikezic, D.; Lau, B.M.F.; Vucic, D

    2001-07-01

    The airway dimensions for Caucasian males have been scaled by multiplying by factors 0.95 and 0.88 to give those for Chinese males and females, respectively. Employing the most recent data on physical and biological parameters, the radiation doses to the basal and secretory cells due to {alpha} particles from {sup 218}Po and {sup 214}Po, homogeneously distributed in the mucous layer, have been calculated. The emission of {alpha} particles has been simulated by a Monte Carlo method. For both basal and secretory cells, the dose conversion coefficients (DCCs) for physical conditions of sleep, rest, light and heavy exercise, have been obtained for Chinese males and females for unattached progeny, and for attached progeny of diameters 0.02, 0.15, 0.25, 0.30 and 0.50 {mu}m. For basal cells, the coefficients lie in the range 0.69-6.82 mGy/(J s/m{sup 3}) or 8.7-86 mGy/WLM for unattached progeny and in the range 0.045-1.98 mGy/(J s/m{sup 3}) or 0.57-25 mGy/WLM for attached progeny. The corresponding ranges for Caucasian males are 1.27-8.81 mGy/(J s/m{sup 3}) or 16-111 mGy/WLM{sup -1} and 0.05-2.30 mGy/(J s/m{sup 3}) or 0.64-29 mGy/WLM. For secretory cells, the coefficients lie in the range 0.095-16.82 mGy/(J s/m{sup 3}) (1.2-212 mGy/WLM) for unattached progeny and in the range 0.095-6.67 mGy/(J s/m{sup 3}) (1.2-84 mGy/WLM) for attached progeny. The corresponding ranges for Caucasian males are 0.34-21.51 mGy/(J s/m{sup 3}) (4.3-271 mGy/WLM) and 0.1-7.78 mGy/(J s/m{sup 3}) (1.3-98 mGy/WLM). The overall DCCs calculated for a typical home environment are 0.59 and 0.52 mSv/(J s/m{sup 3}) (7.4 and 6.5 mSv/WLM) for Chinese males and females, respectively, which are 80 and 70% of the value, 0.73 mSv/(J s/m{sup 3}) (9.2 mSv/WLM), for Caucasian males.

  17. Distribution of radon concentration in residences and others buildings of Belo Horizonte city, MG, Brazil

    International Nuclear Information System (INIS)

    Santos, Talita de Oliveira

    2010-01-01

    Human beings are exposed to ionizing radiation from many natural sources. Radon and its progeny have been recognized as the most important contributors to the natural radioactivity dose, accounting for about half of all human exposure to ionizing radiation. Radon is a α-radioactive noble gas derived from the natural series of uranium and thorium, which occurs in a wide concentration range in all geological materials, especially, in rocks, soils and waters. By diffusion and convection, radon migrates from the rocks and soils to atmosphere and through fissures, pipes and holes it may enter the dwellings and other buildings. Another important radon source in dwellings is its emanation from the construction material. The radon progeny concentration in dwellings has been receiving considerable global attention due to its potential effect in causing lung cancer if it deposited in upper respiratory tract when inhaled. This work presents radon concentration distribution in dwellings in Metropolitan Region of Belo Horizonte - RMBH. The geological settings of the area are Archean rocks of Granitic Gneissic Complex and of metasediments sequences of the great Precambrian unit of the Iron Quadrangle of Minas Gerais, Brazil. Radon concentration measurements were carried out with continuous detector AlphaGUARD PQ200PRO (Genitron), in passive mode and with passive detectors E-PERM Electrets Ion Chamber-EIC. The radon progeny concentration was carried out with a solid state alpha spectroscope, the DOSEman PRO (Sarad). It was found an indoor radon concentration varying in a large range from 4 to 2664,0 Bq.m"-"3, with an average value of 108.0 Bq.m"-"3, median of 70 Bq.m"-"3, geometric mean equal to 76 Bq.m"-"3 and standard deviation of 170 Bq.m"-"3. About 15% of the results are over the United States Environmental Protection Agency (U.S. EPA) actions level, which is 148 Bq.m"-"3.The equilibrium factor between radon and its progeny were determined in dwellings, as 0.3 in average

  18. 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

  19. Radon in Croatian spas

    International Nuclear Information System (INIS)

    Radolic, V.; Vukovic, B.; Planinic, J.

    2004-01-01

    There are ten thermal spas in Croatia and all of them provide health services for patients and visitors. Radon measurements were performed since there is a lack of data concerning natural radioactivity originated from radon and its short-lived progenies in such environments. The thermal water at two different sites (the indoor swimming pool with geothermal water and the spring) in each spa was sampled and radon concentrations were measured by AlphaGUARD radon measuring system. The obtained values were in the range of 0.7 to 19 Bq.dm -3 and 2 to 94 Bq.dm -3 for indoor swimming pools and springs, respectively. Integrated measurements of radon concentration in air were performed by two solid state nuclear track detectors LR-115 II (open and diffusion one) thus enabling estimation of equilibrium factor between radon and its daughters. The annual effective doses received by spa workers were found to be about 1 mSv/y (below the lower limit value of 3 mSv/y recommended by ICRP 65). The doses of patients and visitors were one or two order of magnitude lower than that of the personnel. (author)

  20. Use of static and ac field techniques for measuring mobility and charge lifetimes of radon progeny with a simple device

    International Nuclear Information System (INIS)

    Sapra, B.K.; Mayya, Y.S.

    1998-01-01

    A simple device, based on a modification of the scintillation cell, has been developed for the measurement of radon daughter mobility and charge lifetimes by employing AC and static electric fields. It has a central electrode coated with ZnS and the scintillations are recorded by a PMT unit. The coating is made on the wire, instead of on the inner walls, to improve the relative response of the device with respect to the zero field situation. Radon is drawn into the cell by evacuation techniques. Theoretical formulae, relating the observed count rates to the system parameters and progeny mobilities and charge lifetimes, have been derived under zero field, static and AC field situations. Measurements indicate that the device has very low leak rate (T 1/2 ∼38 days) and the initial environment if maintained for long time. Results of experiments carried out with static and AC fields in most air yielded 218 Po mobilities (1.89 cm 2 /V/s) and charge lifetimes (0.08s) are comparable to those reported in the literature. This demonstrates the feasibility of this technique for future studies with different trace gases. A major advantage of this device as opposed to the conventional spectrometric methods is its simplicity. (author)

  1. Analysis of errors in the measurement of unattached fractions of radon and thoron progeny in a Canadian uranium mine using wire screen methods

    International Nuclear Information System (INIS)

    Khan, A.; Phillips, C.R.

    1987-01-01

    The unattached fraction of radon/thoron progeny in uranium mines is generally small and therefore difficult to measure accurately. The simple wire screen method provides a direct estimate of the unattached fraction from the screen count, or an indirect estimate from the difference between the reference and back-up filter counts. Wire screen method results are often difficult to analyse, especially when the unattached activity is small. Experimental data obtained in Canadian uranium mines are presented here, together with a detailed error analysis. The method consisting of counting the wire screen and the back-up filter is found to be the most precise method for unattached fraction determination. (author)

  2. An improved model for the reconstruction of past radon exposure.

    Science.gov (United States)

    Cauwels, P; Poffijn, A

    2000-05-01

    If the behavior of long-lived radon progeny was well understood, measurements of these could be used in epidemiological studies to estimate past radon exposure. Field measurements were done in a radon-prone area in the Ardennes (Belgium). The surface activity of several glass sheets was measured using detectors that were fixed on indoor glass surfaces. Simultaneously the indoor radon concentration was measured using diffusion chambers. By using Monte Carlo techniques, it could be proven that there is a discrepancy between this data set and the room model calculations, which are normally used to correlate surface activity and past radon exposure. To solve this, a modification of the model is proposed.

  3. Radon measurement works in Dhaka city and central part of Bangladesh

    International Nuclear Information System (INIS)

    Talukder, S.R.; Hamid Khan, M.A.

    2011-01-01

    The major source of natural radiation that irradiates the human body is primarily due to inhalation of Radon and its short-lived progeny nuclides. It is well known that exposure of population to high concentration of Radon and its daughters for a long period leads to pathological effects like the respiratory functional changes and the occurrence of lung cancer. Solid State Nuclear Track Detectors (CR-39) are being used for detection and measurement works of radon and its progeny in Bangladesh. Dhaka the capital of Bangladesh and some areas of the central region of Bangladesh are chosen for the present study to measure the Radon concentration level of the country. Dhaka is one of the most populous cities in Bangladesh as well as in the world. High working levels (WL) were found in some locations of Dhaka city specially in the old part of the city where so many ancient building are established and in some villages of the central part of the country. The aim of the study is to prepare a Radon Map of Bangladesh and the results so far obtained have been presented in the paper. (author)

  4. Radon applications in geosciences - Progress & perspectives

    Science.gov (United States)

    Barbosa, S. M.; Donner, R. V.; Steinitz, G.

    2015-05-01

    During the last decades, the radioactive noble gas radon has found a variety of geoscientific applications, ranging from its utilization as a potential earthquake precursor and proxy of tectonic stress over its specific role in volcanic environments to a wide range of applications as a tracer in marine and hydrological settings. This topical issue summarizes the current state of research as exemplified by some original research articles covering the aforementioned as well as other closely related aspects and points to some important future directions of radon application in geosciences. This editorial provides a more detailed overview of the contents of this volume, a brief summary of the rationale underlying the diverse applications, and outlines some important perspectives.

  5. 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)

  6. Calibration of SSNDT detectors for radon measurements

    International Nuclear Information System (INIS)

    Takahashi, Laura C.; Santos, Talita O.; Pinheiro, Rose Mary M.; Rocha, Zildete

    2017-01-01

    The methods and instrumentation used to measure the concentration of radon need to be calibrated to obtain accurate results. The Nuclear Track Detector is considered the main method of analysis of radon research. Thus, the Natural Radioactivity Laboratory of the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG, Brazil) uses the detector CR-39 (Landauer) to measure the concentration of radon in homes, workplaces, underground mines, soils and in environment. Epidemiological studies reveal the strong relationship between lung cancer and radon exposure. Therefore, it is important to monitor this gas and its progeny in order to assess the radiological risk. The alpha particles emitted by radon and its progeny leave traces on CR-39 due to Coulombian interactions with the atoms of the material. The liquid density of traces is converted to radon concentration by means of a calibration factor obtained in calibrated systems. This work aims to determine the LRN / CDTN calibration factor. To do so, the CR-39 detectors were placed inside the calibration chambers, along with two AlphaGUARD (Saphymo GmbH) detectors and Ra-266 sources with activities of 3,379 kBq or 0.483 kBq, referenced by NIST. From this, six levels of exposure were obtained, which were: 44 kBq.d.m 3 , 4 kBq.d.m 3 , 3 kBq.d.m 3 , 15 kBq.d.m 3 , 30 kBq.d.m 3 , 26 kBq.d.m 3 . The conversion factor between the liquid density of traces and the total exposure time obtained was K = 52.028 ± 0.752 [(trace density.cm -2 ) / (kBq.d.m -3 )]. After the determination of the conversion factor, it was used to measure the concentration of radon in underground mines, obtaining concentration results between 122 ± 24 and 7384 ± 517 kBq.m -3

  7. Measurement of unattached aerosols of 222 Rn progeny by means of an electrostatic deposition method

    International Nuclear Information System (INIS)

    Canoba, Analia C.; Lopez, Fabio O.

    2001-01-01

    A method for the measurement of unattached radon progeny based on its electrostatic deposition onto wire screens, using only one pump, has been implemented and calibrated. The importance of being able of making use of this method is related with the special radiological significance that has the unattached fraction of the short-lived radon progeny. Because of this, the assesment of exposure could be directly related to dose with far greater accuracy than before.The advantages of this method are its simplicity, even with the tools needed for the sample collection, as well as the measurement instruments used. Also, the suitability of this method is enhanced by the fact that it can effectively be used with a simple measuring procedure such as the Kusnetz method. (author)

  8. Investigation of radon, thoron, and their progeny near the earth's surface. Final report, 1 January 1994 - 31 December 1997

    International Nuclear Information System (INIS)

    Schery, S.D.; Wasiolek, P.T.

    1998-01-01

    This is the final report for DOE Grant DE-FG03-94ER6178, covering a performance period of 1 January 1994 through 31 December 1997. The DOE award amount for this period was $547,495. The objective of the project as stated in its proposal was open-quotes to improve our understanding of the physical processes controlling the concentration of radon, thoron, and their progeny in the atmospheric environment.close quotes The original project was directed at developing underlying science that would help with evaluation of the health hazard from indoor radon in the United States and implementation of corrective measures that might be employed to reduce the health hazard. As priorities within the Office of Health and Environment (OHER) changed, and the radon research program was phased out, emphasis of the project was shifted somewhat to be also relevant to other interests of the OHER, namely global pollution and climate change and pollution resulting from energy production. This final report is brief, since by reference it can direct the reader to the comprehensive research publications that have been generated by the project. In section 2, we summarize the main accomplishments of the project and reference the primary publications. There were seven students who received support from the project and their names are listed in section 3. One of these students (Fred Yarger, Ph.D. candidate) continues to work on research initiated through this project. No post-docs received support from the project, although one of the co-principal investigators (Dr. Piotr Wasiolek) received the majority of his salary from the project. The project also provided part-time support for a laboratory manager (Dr. Maryla Wasiolek). Section 4 lists chronologically the reports and publications resulting from the project (references 1 through 12), and the Appendix provides abstracts of major publications and reports

  9. 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.)

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

    Science.gov (United States)

    Mudd, Gavin M

    2008-02-01

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

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

    International Nuclear Information System (INIS)

    Mudd, Gavin M.

    2008-01-01

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

  12. Radon risks in animals with reference to man

    International Nuclear Information System (INIS)

    Gilbert, E.S.; Cross, F.T.

    1988-10-01

    Radon inhalation studies in animals provide important supplementary information to human data. Because the measurement of exposure characteristics in experimental studies is more accurate than in epidemiological studies, animal studies may provide a more reliable assessment of the dependence of risks on radon-daughter cumulative exposure. Experimental data have also provided information on the dependence of risks on radon-progeny exposure rate, unattached fraction, and disequilibrium, as well as on concomitant exposures to cigarette smoke. A summary of radon studies in animals has been published. Two examples of results from these studies are included; in both cases, results were based on the percent of animals with lung tumors. 8 refs., 4 figs., 3 tabs

  13. Cardiovascular Mortality Caused by Exposure to Radon

    International Nuclear Information System (INIS)

    Johnson, J. R.; Duport, P.

    2004-01-01

    Cardiovascular diseases (CVD) are reported as the cause of morbidity and mortality in humans exposed to (high) therapeutic doses of radiation, A-bomb explosions, accidental (Chernobyl liquidators) and occupational level of radiation while CVD risk does not appear to be elevated in other populations exposed to radiation CVD mortality also appears to be elevated, proportionally with radon progeny exposure in Newfoundland fluorspar miners. In addition, radiation exposure does not seem to increase and may indeed decrease CVD mortality or morbidity in mammals exposed to radiation in the laboratory. We have calculated the doses to blood and coronary artery wall from radon and progeny, and have concluded radon exposure may indeed increase the incidence of cardiovascular diseases and that a thorough investigation of that risk is justified, even at environmental and occupational levels. These contradictory observations suggest that radiation may be considered as one of many risk factors for cardiovascular diseases. As such, it may be necessary to reduce not only other risk factors as far as possible, but also to minimize exposures to radiation to further reduce the burden of cardiovascular diseases in the population. (Author) 27 refs

  14. Exposures to 222Rn and its progeny derived from implanted 210Po activity

    International Nuclear Information System (INIS)

    Nikezic, D.; Yu, K.N.

    2006-01-01

    The Jacobi room model was applied to study the relative contributions from the unattached and attached fractions to the implanted activity of 210 Po. It was found that under normal conditions, about 85% of the implantation was due to the unattached fraction. Sensitivity analysis was performed to identify the most important factors that influence the deposition and implantation of radon progeny. The main factors affecting the incorporation of 210 Po are the attachment rate, deposition rate of unattached progeny and the surface to volume ratio of the room. The calibration curves, which related the 210 Po activity per unit surface area to the concentrations of 222 Rn and of the radon progeny, were determined as functions of exposure times. The implanted activity is found to distribute close to a lognormal distribution. For an exposure of 20 years, the distribution has a geometric standard deviation of 2.2 and a geometric mean of 0.023Bq/m 2 /(Bq/m 3 ). The last value is considered as the calibration coefficient of the glass response in terms of the implanted 210 Po activity per unit surface area per unit concentration of 222 Rn for an exposure period of 20 years

  15. Fluid-based radon mitigation technology development for industrial applications

    International Nuclear Information System (INIS)

    Liu, K.V.; Gabor, J.D.; Holtz, R.E.; Gross, K.C.

    1996-01-01

    The objective of the radon mitigation technology development effort is to develop an efficient and economical radon gas removal technology based on a fluid absorption process. The technology must be capable of cleaning up a wide range of radon gas stream concentrations to a level that meets EPA gas emission standards for residential and industrial applications. Argonne has recently identified a phenomenon that offers the possibility of radon recovery from the atmosphere with high efficiency at room temperature, and radon release at slightly elevated temperatures (50-60 degrees C.) such a device would offer numerous substantial advantages over conventional cryogenic charcoal systems for the removal of radon. Controlled sources of radon in Argonne's radon research facility are being used to quantitatively assess the performance of a selected class of absorbing fluids over a range of radon concentrations. This paper will discuss the design of laboratory- and engineering-scale radon absorption units and present some preliminary experimental test results

  16. Study on radon and thoron levels in different types of granitic work industries around Tumkur city

    International Nuclear Information System (INIS)

    Nagabhushan, S.R.; Ningappa, C.; Srilatha; Shekar, Usha; Sannappa, J.

    2011-01-01

    Radon is a naturally occurring radioactive noble gas generated by the decay of uranium and thorium bearing minerals in rocks, soils and building materials. Radon and decay products are the major contributors to human exposure from natural radiation sources. Epidemiological evidence indicates that indoor radon and thoron were responsible for a substantial number of lung cancer in publics. UNSCEAR reported recently indicates that there is a remarkable coherence between the risk estimates developed from epidemiological studies from miners and residential case-control radon studies. Hence to select the study area for the estimation of dose due to radon and thoron to the publics and workers, concentration of radon, thoron and their progeny were measured by using SSNTD. Since, activity concentration in granite more, higher concentrations of radon and thoron have been observed in the dwellings near to granite industry and lesser concentration of radon and thoron have been observed in the dwellings near brick industries of Tumkur city. From the study, the concentration of radon and thoron varied from 31 to 70.4 Bq.m 3 and 11.6 to 46.3 Bq.m 3 , respectively. Corresponding progeny level varied from 0.11 to 2.5 mWL and 1.1 to 3.4 mWL, respectively. (author)

  17. Measurement of unattached aerosols of {sup 222} Rn progeny by means of an electrostatic deposition method; Medicion de la fraccion no unida a aerosoles de la progenie de {sup 222} Rn mediante un metodo de deposicion electrostatica

    Energy Technology Data Exchange (ETDEWEB)

    Canoba, Analia C; Lopez, Fabio O [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina)

    2001-07-01

    A method for the measurement of unattached radon progeny based on its electrostatic deposition onto wire screens, using only one pump, has been implemented and calibrated. The importance of being able of making use of this method is related with the special radiological significance that has the unattached fraction of the short-lived radon progeny. Because of this, the assesment of exposure could be directly related to dose with far greater accuracy than before.The advantages of this method are its simplicity, even with the tools needed for the sample collection, as well as the measurement instruments used. Also, the suitability of this method is enhanced by the fact that it can effectively be used with a simple measuring procedure such as the Kusnetz method. (author)

  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. Diseases of uranium miners and other underground miners exposed to radon

    International Nuclear Information System (INIS)

    Samet, J.M.

    1991-01-01

    Excess lung cancer has been demonstrated in many groups of underground miners exposed to radon, including uranium miners and those mining other substances in radon-contaminated mines. In the United States, most underground uranium mines had shut down by the late 1980s, but occupational exposure to radon progeny remains a concern for many other types of underground miners and other underground workers. Worldwide, uranium mining continues, with documented production in Canada, South Africa and other African countries, and Australia. Thus, radon in underground mines remains a significant occupational hazard as the end of the twentieth century approaches.39 references

  20. 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)

  1. Exposure due to radon in homes - an IAEA perspective

    International Nuclear Information System (INIS)

    Navratilova-Rovenska, K.; Boal, T.; Colgan, T.

    2014-01-01

    The results of miner and residential epidemiology studies provide statistically strong evidence of harmful effects of exposure due to radon and its progeny. With the publication of the fifth edition of the International Basic Safety Standards, of the World Health Organizations Handbook on Indoor Radon and new ICRP statement on radon, there is increased interest from the public health and radiation protection authorities on controlling exposure due to radon and its progeny.The IAEA Safety Requirements publication 'Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards' sets out requirements on governments for control of existing exposure situations, which includes exposure due to radon. The types of situation that are included in the scope of existing exposure situations include exposure in workplaces for which the exposure due to radon is not required by or directly related to the work and for which annual average activity concentrations due to 222 Rn must not exceed a maximum reference level of 1000 Bq/m 3 annual activity concentration, as well as exposure in dwellings and in other buildings with high occupancy factors for members of the public for which the reference level must not exceed a maximum value of 300 Bq/m 3 . These requirements include: collecting data on the activity concentrations of radon in dwellings and other buildings with high occupancy by the public; providing information on exposure due to radon and the associated health risks; and if necessary, to develop an action plan for controlling public exposure to radon. The IAEA has developed a Safety Guide to provide guidance on developing the radon action plan: 'Protection of the Public against Exposure Indoors due to Radon and Other Natural Sources of Radiation'. This presentation will summarize the information on the assistance that the IAEA is currently providing to IAEA Member States to develop radon action plans. These activities include

  2. Comparison of outdoor activity size distributions of 220 Rn and 222 Rn progeny and their Influences on lung dosimetry distributions

    International Nuclear Information System (INIS)

    Mohamed, A.; El-Hussein, A.; Ahmed, A.

    2005-01-01

    In the case of internally deposited radionuclides, direct measurement of the energy absorbed from ionizing radiation emitted by the decaying radionuclides is rarely, if ever, possible. Therefore, one must rely on dosimetric models to obtain estimates of the spatial and temporal patterns of energy deposition in human lung. T These models always need some information about the parameters of activity size distributions of thoron and radon progeny. In the present work, the attached and unattached activity size distributions of thoron and radon progeny were measured in outdoor air of El-Minia, Egypt. The attached samples were collected using a low pressure Berner cascade impactor technique, while a constructed screen diffusion b attery was used for collecting the unattached samples. Most of the attached activities for 222 Rn and 220 Rn progeny were associated with the aerosol particles of the accumulation mode. The activity size distribution of thoron progeny was found to be shifted to slightly smaller particle size, compared to radon progeny. An analytical method has been developed to compute the local energy deposition of 2l2 Bi alpha particles in a target volume of 1 jam spheres located at different depths in bronchial epithelium. In order to reach the target, alpha particles travel either through tissue alone (near-wall dose) or through air and tissue (far-wall dose). It was found that the contribution of near-wall dose is higher than that of the far wall dose. While the depth-dose distributions for nuclides uniformly distributed within the epithelium are practically constant with

  3. A Monte Carlo study of radon detection in cylindrical diffusion chambers

    Energy Technology Data Exchange (ETDEWEB)

    Rickards, Jorge, E-mail: rickards@fisica.unam.m [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito de la Investigacion Cientifica, Ciudad Universitaria, Delegacion Coyoacan, 04520 Mexico, D.F. (Mexico); Golzarri, Jose-Ignacio, E-mail: golzarri@fisica.unam.m [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito de la Investigacion Cientifica, Ciudad Universitaria, Delegacion Coyoacan, 04520 Mexico, D.F. (Mexico); Espinosa, Guillermo, E-mail: espinosa@fisica.unam.m [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito de la Investigacion Cientifica, Ciudad Universitaria, Delegacion Coyoacan, 04520 Mexico, D.F. (Mexico)

    2010-05-15

    The functioning of radon diffusion chambers was studied using the Monte Carlo code RAMMX developed here. The alpha particles from radon are assumed randomly produced in the volume of the cylinder, and those from the progeny are assumed to originate randomly at the cylindrical surface. The energy spectrum, the distribution of incident angles, and the distribution of path lengths of the alpha particles on the detector were obtained. These quantities vary depending on input parameters such as initial alpha particle energy, radius and depth of the diffusion chamber, detector size and atmospheric pressure. The calculated energy spectrum for both {sup 222}Rn and {sup 220}Rn was compared with experiment, permitting the identification of each peak and its origin, and a better understanding of radon monitoring. Three aspects not considered in previous calculations are progeny alphas coming from surfaces of the monitor, taking into account the atmospheric pressure, and including the isotope {sup 220}Rn.

  4. Epidemiological potentials of radon- and thoron-prone area in China

    International Nuclear Information System (INIS)

    Sun, Quanfu; Hou, Changsong; Tokonami, Shinji

    2004-01-01

    In order to explore the feasibility of an epidemiological study on lung cancer in areas with elevated indoor radon and thoron exposures, 202 residences including loess caves, brick caves, stone caves, and ordinary houses in twenty villages were selected from Yan'an and Luliang areas in the Chinese loess plateau, and indoor levels of thoron and its progeny as well as radon were determined with passive radon-thoron discriminative detectors and thoron progeny deposition rate devices. The indoor radon concentration in loess cave ranged from 17 to 179 Bq m -3 , with geometric means of 73 Bq m -3 and 71 Bq m -3 in Luliang and Yan'an, respectively. Geometric mean of EEC Tn was estimated to be 1.6 Bq m -3 in Luliang and 2.2 Bq m -3 in Yan'an. The study also revealed that the air pollution in Yan'an was small compared with that in Luliang. Residential migration was very low in Yan'an area: 86% of the subjects had no migration, mean number of houses for the family master was estimated to be 1, ranged from 1 to 3. It would be expected to have several hundreds of lung cancer cases diagnosed with pathological evidences in 3-5 years. Yan'an and surrounding area are suitable for conducting an epidemiological study on residential exposure to radon, thoron and lung cancer risk. (author)

  5. Indoor radon measurements and methodologies in Latin American countries

    International Nuclear Information System (INIS)

    Canoba, A.; Lopez, F.O.; Arnaud, M.I.; Oliveira, A.A.; Neman, R.S.; Hadler, J.C.; Iunes, P.J.; Paulo, S.R.; Osorio, A.M.; Aparecido, R.; Rodriguez, C.; Moreno, V.; Vasquez, R.; Espinosa, G.; Golzarri, J.I.; Martinez, T.; Navarrete, M.; Cabrera, I.; Segovia, N.; Pena, P.; Tamez, E.; Pereyra, P.; Lopez-Herrera, M.E.; Sajo-Bohus, L.

    2001-01-01

    According to the current international guidelines concerning environmental problems, it is necessary to evaluate and to know the indoor radon levels, specially since most of the natural radiation dose to man comes from radon gas and its progeny. Several countries have established National Institutions and National Programs for the study of radon and its connection with lung cancer risk and public health. The aim of this work is to present the indoor radon measurements and the detection methods used for different regions of Latin America (LA) in countries such as Argentina, Brazil, Ecuador, Mexico, Peru and Venezuela. This study shows that the passive radon devices based on alpha particle nuclear track methodology (NTM) is one of the more generalized methods in LA for long term indoor radon measurements, CR-39, LR-115 and Makrofol being the more commonly used detector materials. The participating institutions and the radon level measurements in the different countries are presented in this contribution

  6. Exposure to radon in Australian tourist caves

    International Nuclear Information System (INIS)

    Solomon, S.B.; Langroo, R.; Lyons, R.G.

    1994-01-01

    In 1991 the International Commission on Radiological Protection(ICRP) produced guidelines and recommendations dealing with workplace exposure to elevated background radiation, in particular, the risk associated with the inhalation of radon and radon progeny. An intervention level of 1000 Bq m -3 has been proposed. Australia has over 40 tourist caves, under the management of the various State Departments or private groups. The limited data available on radon levels in Australian caves would suggest that some of these caves may be in excess of the proposed intervention level, thus presenting a potential health risk for the cave guides. This paper summarises the current information on radon in Australian caves and describes the proposed methodologies to be used for a Worksafe Australia-funded survey of radon levels in Tourist caves within Australia. This survey is to be carried out jointly by researchers at the Australian Radiation Laboratory, University of Auckland and the University of Sydney, during 1994 and 1995. 7 refs., 3 tabs

  7. MODERN APPROACHES TO PUBLIC PROTECTION AGAINST INDOOR RADON. INTERNATIONAL REGULATORY EXPERIENCE

    Directory of Open Access Journals (Sweden)

    S. M. Kiselev

    2014-01-01

    Full Text Available Intensive worldwide researches of the public exposure to radon are carried out for over 30 years. According to numerous studies being performed in many countries, radon and its progenies contribute significantly in total dose to the public. At that, dose due to inhalation of radon and its progenies is higher than that induced by other radiation sources, including sources used in medicine and those occurring in the environment due to the nuclear fuel cycle activities. Prolonged internal exposure to the human‘s body induced by the radon decay products is one of the key factors in the development of the lung cancer pathology. The recent results of global epidemiological studies, aimed at the risk assessment of indoor radon-induced lung cancer, have initiated the need to improve approaches to the regulation of this problem. International organizations (such as WHO, IAEA, ICRP proposed a strategy of the public radiation protection against radon exposure and adapted this strategy to the up-to-date realities. The recent recommendations not only correct the radon activity concentration being limited in dwellings, but also change its status through converting the action level to the reference one. The strategies for limitation of the public exposure due to this component of natural radiation should be revised at the national level and an action plan for their implementation in the long term perspective should be developed. This paper deals with the key provisions of the recent international recommendations including approaches to regulate the public protection against radon exposure.

  8. Radon Measurements in Egypt using passive etched track detectors. A Review

    Energy Technology Data Exchange (ETDEWEB)

    Gomaa, M A [National Network of Radiation Physics. Atomic Energy Authority (Egypt); Hussein, A S [Radiation Protection Department, Nuclear Power Plants Authority, (Egypt); El-Arabi, A M [Physics Department, Faculty of Science, South Valley University, Qena, (Egypt)

    2005-04-01

    Radon and its progeny may cause serious radiation harm to human health such as lung cancer and other types. Radon measurements based on alpha particles etched track detectors (LR-115, CR-39) are very attractive for assessment of radon exposure. This is due to their high sensitivity, low cost, easy to handle and retain a permanent record of data. Also these detectors can incorporate the effects of seasonal and diurnal fluctuation of radon activity concentrations due to physical, geological and meteorological factors. The present review is based mainly on the topic of passive etched track detectors for the measurements of radon in Egypt in the recent years. Published papers includes the measurements of radon in dwellings, working places, Cairo Metro stations, ancient Pharaonic places and uranium exploration galleries as well as assessment of radon in drinking water.

  9. Radon Measurements in Egypt using passive etched track detectors. A Review

    International Nuclear Information System (INIS)

    Gomaa, M.A.; Hussein, A.S.; El-Arabi, A.M.

    2005-01-01

    Radon and its progeny may cause serious radiation harm to human health such as lung cancer and other types. Radon measurements based on alpha particles etched track detectors (LR-115, CR-39) are very attractive for assessment of radon exposure. This is due to their high sensitivity, low cost, easy to handle and retain a permanent record of data. Also these detectors can incorporate the effects of seasonal and diurnal fluctuation of radon activity concentrations due to physical, geological and meteorological factors. The present review is based mainly on the topic of passive etched track detectors for the measurements of radon in Egypt in the recent years. Published papers includes the measurements of radon in dwellings, working places, Cairo Metro stations, ancient Pharaonic places and uranium exploration galleries as well as assessment of radon in drinking water

  10. Properties of radioactive aerosols produced by interactions of indoor radon decay products with cigarette smoke and burning cigarettes

    International Nuclear Information System (INIS)

    Martell, E.A.; Sweder, K.S.

    1984-01-01

    Risks of lung cancer to smokers, attributable in part to exposure to indoor radon decay products, are dependent on properties of radon progeny-tagged smoke particles. The authors have investigated the properties and interactions of radon progeny-tagged smoke particles as they pass through burning cigarettes into mainstream smoke, using /sup 212/Pb-tagged smoke particles as tracers, cascade impactors for particle size determinations, and low-level β/sup -/ counting techniques. /sup 212/Pb-tagged particles of submicron size are destroyed in the burning zone of cigarettes. However, /sup 212/Pb-tagged smoke particles exceeding 1.0 μm diameter pass readily through the burning zone and tobacco rod into mainstream smoke. /sup 212/ Pb- tagged particles in mainstream smoke have an activity median aerodynamic diameter between 1.0 and 2.0 μm diameter. Particles > 2.0 μm diameter carry about 10 percent of the total activity, are selectively deposited at the carina of bifurcations, and are resistant to dissolution in lung fluid. These results indicate that indoor radon progeny on large particles in mainstream smoke can contribute substantially to the cumulative alpha radiation dose at ''hot spots'' in the bronchi of smokers

  11. 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.

  12. Cleaners in reducing the hazards of indoor radon decay products

    International Nuclear Information System (INIS)

    Montassier, N.; Hopke, P.K.; Shi, Y.; Wasiolek, P.; McCallum, B.

    1992-01-01

    The objective of this study was to evaluate the influence of three types of air cleaners on the concentration and size distribution of radon progeny in a normally occupied house. Using an automated, semi-continuous, graded-screen array system and a radon monitor, the activity size distribution and radon concentration was measured and the exposure of the occupants of the home to radon could be assessed. The dose model developed as part of the recently released U.S. National Academy of Sciences report was used to related the exposure to deposited dose in the tissue of the bronchial epithelium. Thus, the effectiveness of the air cleaners in reducing both exposure and dose were evaluated. (author)

  13. Radon in elementary schools in Tunisia

    International Nuclear Information System (INIS)

    Labidi, S.; Mahjoubi, H.; Al-Azmi, D.; Ben Salah, R.

    2010-01-01

    Indoor radon measurements were carried out in 30 elementary schools in Tunis, the capital city of Tunisia, during the winter months of December 2008 to early March 2009. Two classrooms, one each from ground floor and first floor were chosen from each school making a total of 60 classrooms. In some of the classrooms, two detectors (open and closed) were used to measure the concentrations of radon as well as radon and its progeny to allow the calculations of the equilibrium factors. Nuclear track detectors type LR-115 (Kodalpha) were used for the measurements. The results show that the radon concentration levels are low in the range of 6-169 Bq m-3 with a mean value of 26.9 Bq m-3. The annual effective dose was found to vary between 0.025-0.715 mSv y-1 for teachers while the range for pupils was from 0.019-0.525 mSv y-1. These values are within the ICRP recommended values. (authors)

  14. Concentrations of indoor radon and thoron in cave-dwellings with discussions on risk estimation of lung cancer

    International Nuclear Information System (INIS)

    Sun Quanfu; Hou Changsong; Zhang Shouzhi; Nie Xiaoqian; Shang Bing

    2005-01-01

    Objective: To explore a residential area with elevated indoor radon exposure for conducting epidemiological studies on indoor radon and lung cancer. Methods: Two hundred and two cave-dwellings (CD) including loess CD, brick CD, stone CD, and ordinary house in twenty villages were selected from Yan'an and Lvliang in the Chinese loess plateau. Indoor levels of thoron and its progeny as well as radon were measured with passive radon-thoron discriminative detectors and thoron progeny deposition rate devices. The exposure period covered from August 2001 through August 2002. Results: Loess CD was one of the most common type of dwelling caves in both areas. The indoor radon concentrations in loess CD ranged from 17 to 179 Bq/m 3 ; thoron varied sub-stantially depending upon the distance from the device to the wall, ranged from 10 to 760 Bq/m 3 . Geometric means of indoor radon, thoron and thoron's progeny (EEC Tn ) of loess caves in Yan'an area were estimated to be 71, 185 and 2.2 Bq/m 3 , respectively, and the corresponding figures were 73, 145 and 116 Bq/m 3 in Lvliang area. Possible contamination of thoron on radon measurement in a previous case-control study on lung caner was discussed. The study revealed that the indoor air pollution in Yan'an area was slight compared with that in Lvliang area. Migration was very low. Eighty-six percent of the investigated persons have had no migration in Yan'an area, and 90 percent of the cave-dwellings where the subjects once resided were available to our measurements. Two million people have been living in cave-dwellings over several generations. Conclusion: The investigated cave-dwelling area in Yan'an is suitable for conducting epidemiological study on residential thoron and radon exposure and lung cancer.(authors)

  15. 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

  16. Analysis of data on radon monitoring and dose estimates for uranium mines

    International Nuclear Information System (INIS)

    Khan, A.H.; Srivastava, G.K.; Jha, Shankar; Sagar, D.V.

    1994-01-01

    Radon progeny are the major contributors to the radiation dose to uranium miners. Monitoring for radon and gamma radiation is an integral part of radiation protection in such mines. Data for equilibrium equivalent radon and the estimated mean annual doses are presented in this paper for Jaduguda uranium mine from 1986 to 1992. The 1992 data for Jaduguda and Bhatin mines are compared. The average annual effective dose for uranium miners is estimated at around 15.5 mSv. (author). 1 ref., 2 figs

  17. Development of a portable instantaneous soil radon measurement instrument

    International Nuclear Information System (INIS)

    Wang Yushuang; Ge Liangquan; Jiang Haijing; Lin Yanchang

    2007-01-01

    A dual-channel instantaneous soil radon measurement instrument based on the method of electrostatic collection is designed. It has the features of small size, low cost, and high sensitivity, etc. A single chip microcomputer is adopted as the data processing and control unit. The concentration of radon can be reported in field. The result is also corrected by the pressure sensing system. A double channel discriminator is used so that the detector can eliminate the interference from the progenies of radon except RaA. LCD and MCU based encoding keyboard are used to give users a friendly interface. Operating and function setting is easy. (authors)

  18. Indoor radon in Tunisian spas

    International Nuclear Information System (INIS)

    Labidi, S.; Al-Azmi, Darwish; Ben Salah, R.

    2012-01-01

    Indoor radon concentrations were measured in four well-known spas of Tunisia using nuclear track detectors. The radon concentrations in these spas were found to be in the range of 19 - 870 Bq.m -3 . The equilibrium factor F between radon and its progeny was found to vary in the range of 0.2 - 0.5, depending upon the ventilation rates within the buildings of the spas. Using the exposure-dose conversion factor, the effective doses to patients and workers were estimated and the dose was found to vary in the range 3.7 x 10 -3 - 12.5 x 10 -3 mSv.y -1 and 0.45 - 1.5 mSv.y -1 for patients and workers, respectively. These values are well inside the limit recommended for the annual dose limit of 20 mSv.y -1 for an occupational worker. The radium content in the groundwater of all four spas was measured and the results showed no correlation between the 226 Ra concentration in water and radon concentration in indoor air of the investigated spas. (authors)

  19. Detailed analysis of radon flux studies at Australian uranium projects

    International Nuclear Information System (INIS)

    Mudd, Gavin M.

    2005-01-01

    The release of radon gas and radon progeny from uranium projects is a major issue during operation as well as for the design of rehabilitation works. In Australia, there have been a number of premining radon flux studies as part of the environmental investigation and potential development of recent uranium projects. There is also an increasing amount of operational data on radon fluxes and loads from various aspects of projects, such as tailings, waste rock and mills. Thus there exists much useful measured data which can be used to assess the design radon flux and load targets for rehabilitation. The main projects for which radon data exists includes Ranger, Olympic Dam, Beverley, Honeymoon, Jabiluka, Yeelirrie, Lake Way, Koongarra, Moline, Coronation Hill, Rockhole, Nabarlek, Rum Jungle, Port Pirie and Ben Lomond. To date, much of this data has not been systematically evaluated. The need to compile and assess this data is twofold. Firstly, to assess the loads released from uranium production as an input into life-cycle analyses of the nuclear fuel cycle, such as those undertaken by UNSCEAR and industry groups. Secondly, there is a need to set suitable design standards for radon flux for the rehabilitation of former and current uranium projects. This paper will present such a detailed compilation of radon fluxes and loads which can then be used as the basis for both life-cycle analyses as well as setting appropriate site-specific rehabilitation criteria for radon. The implications for former and current projects is then discussed as well as future data needs. Ultimately, there is a critical need for thorough baseline surveys prior to mining to ensure accurate assessments of changes to radon fluxes and loads. The data and analysis presented is considered applicable to all uranium projects in Australia, as well as being a useful model for considering such issues internationally

  20. Study of a Greek area with enhanced indoor radon concentrations

    International Nuclear Information System (INIS)

    Louizi, A.; Nikolopoulos, D.; Koukouliou, V.; Kehagia, K.

    2003-01-01

    In this paper the focus is on Arnea Chalkidikis, an area in Greece with granitic geological background and indications of possible elevated radon concentration indoors. Data are reported of indoor radon measurements with etched track detectors and those used for dosimetric estimations. Moreover, data are reported on soil gas and soil radon concentrations in Arnea, as well as radon and uranium concentrations in water samples. From the measured radon concentrations in water samples the contribution to the overall dose has been calculated. For a period of 1 month, indoor radon and progeny activity has also been monitored in the dwelling that has the maximum indoor radon concentration in Greece. This dwelling is in Arnea and the dose delivered to the inhabitants has been calculated. Mean annual effective dose due to indoor radon was 4.5 mSv and about 11% of this was due to the use of water. Mean soil gas concentration and soil radon concentration were (90 ± 30) kBq m -3 (P -3 (P -1 (P<0.05). (author)

  1. The radon monitoring system in Daya Bay Reactor Neutrino Experiment

    International Nuclear Information System (INIS)

    Chu, M.C.; Kwan, K.K.; Kwok, M.W.; Kwok, T.; Leung, J.K.C.; Leung, K.Y.; Lin, Y.C.; Luk, K.B.; Pun, C.S.J.

    2016-01-01

    We developed a highly sensitive, reliable and portable automatic system (H 3 ) to monitor the radon concentration of the underground experimental halls of the Daya Bay Reactor Neutrino Experiment. H 3 is able to measure radon concentration with a statistical error less than 10% in a 1-h measurement of dehumidified air (R.H. 5% at 25 °C) with radon concentration as low as 50 Bq/m 3 . This is achieved by using a large radon progeny collection chamber, semiconductor α-particle detector with high energy resolution, improved electronics and software. The integrated radon monitoring system is highly customizable to operate in different run modes at scheduled times and can be controlled remotely to sample radon in ambient air or in water from the water pools where the antineutrino detectors are being housed. The radon monitoring system has been running in the three experimental halls of the Daya Bay Reactor Neutrino Experiment since November 2013.

  2. Estimation of radon concentration in dwellings in and around ...

    Indian Academy of Sciences (India)

    of the total radiation dose received from natural and man-made sources, 60% of the dose is due to radon and its progeny. ... The perforated opening at the other end of the cup .... Cancer among uranium miners in United States; Health. Phys.

  3. Radon exposure during treatment in some thermal spa centers in Greece

    International Nuclear Information System (INIS)

    Nikolopoulos, D.; Louizi, A.; Serefoglou, A.; Georgiou, E.; Vogiannis, E.; Halvadakis, C.

    2004-01-01

    peaks both for radon, radon daughter and coarse particles, were found to appear during filling of baths in the treatment process. According to the bath filling and pouring out procedure followed, these peaks presented variations. The peaks were attributed to radon degassing. Peaks were also detected for coarse particle concentration (droplets) at the same time periods which were related to peaks in radon and daughter activity. A time delay which reaches up to 4 hours between radon peak and daughter peak concentration has been systematically observed for each progeny nuclei. The unattached fraction of radon progenies found to be below 0.1 % for each daughter nuclei. Thus, almost all progeny nuclei attach to coarse particles at their generation. Doses were estimated using proposed models. The doses delivered to the bathers during treatment were in the range of 0.00670 mSv per year to 0.1279 mSv per year, while the doses delivered to personnel were in the range 0.4 and 4.5 mSv per year. The peaks in concentrations measurements were related with an additional short term health impact both for bathers and working personnel. (author)

  4. Radon: Chemical and physical processes associated with its distribution

    International Nuclear Information System (INIS)

    Castleman, A.W. Jr.

    1992-01-01

    Assessing the mechanisms which govern the distribution, fate, and pathways of entry into biological systems, as well as the ultimate hazards associated with the radon progeny and their secondary reaction products, depends on knowledge of their chemistry. Our studies are directed toward developing fundamental information which will provide a basis for modeling studies that are requisite in obtaining a complete picture of growth, attachment to aerosols, and transport to the bioreceptor and ultimate incorporation within. Our program is divided into three major areas of research. These include measurement of the determination of their mobilities, study of the role of radon progeny ions in affecting reactions, including study of the influence of the degree of solvation (clustering), and examination of the important secondary reaction products, with particular attention to processes leading to chemical conversion of either the core ions or the ligands as a function of the degree of clustering

  5. A charcoal canister survey of radon emanation at the rehabilitated uranium mine site at Nabarlek

    International Nuclear Information System (INIS)

    Storm, J.R.; Patterson, J.R.

    1999-01-01

    This paper describes a recent survey of radon emanation measurements from the rehabilitated Nabarlek mine site. It was mined out in 1979, decommissioned in 1995 and provided a good test bed for assessment of rehabilitation in terms of radon flux attenuation. Measurements have been made with charcoal canisters. Studies to measure the radon-220 flux by observing Tl-208 progeny of thoron the effectiveness of trial covers and meteorological considerations will be reported

  6. A charcoal canister survey of radon emanation at the rehabilitated uranium mine site at Nabarlek

    Energy Technology Data Exchange (ETDEWEB)

    Storm, J R; Patterson, J R [University of Adelaide, Adelaide, SA (Australia). Department of Physics and Mathematical Physics

    1999-07-01

    This paper describes a recent survey of radon emanation measurements from the rehabilitated Nabarlek mine site. It was mined out in 1979, decommissioned in 1995 and provided a good test bed for assessment of rehabilitation in terms of radon flux attenuation. Measurements have been made with charcoal canisters. Studies to measure the radon-220 flux by observing Tl-208 progeny of thoron the effectiveness of trial covers and meteorological considerations will be reported.

  7. Radiological impact of exposure to radon-thoron and their progeny present in the environment of fly ash dumping site in Faridabad (Haryana)

    International Nuclear Information System (INIS)

    Gupta, Nitin; Kant, Krishan; Garg, Maneesha

    2013-01-01

    Radon-Thoron and their Progeny monitoring was carried out in dwellings near fly ash dumping sites in Faridabad (Haryana), as it is very important from health and hygiene point of view of the occupants. For the measurements, the track etch technique was used. The dosimeter employed for the measurement consisted of twin chamber systems with LR-115 Type II SSNTDs placed on the two sides of the central partition inside the cup and a bare film placed outside it. The detectors were exposed in the mixed field of radon-thoron in the environment of dwellings. The detectors were placed in about 100 dwellings and the choice of the dwelling was random. The value of PAEC, radon concentration, annual exposure, annual effective dose in the dwellings near fly ash dumping sites in District Faridabad (Haryana) varied from 1.34 mWL to 14.05 mWL with an average value of (4.95 0.85) mWL, 12.41 Bqm -3 to 129.91 Bqm -3 with an average value of (45.77 7.87) Bqm -3 , 0.55 10 -1 WLM to 5.83 10 -1 WLM with an average value of (2.04 0.28) 10 -1 WLM and 0.21 mSv to 2.23 mSv with an average value of (0.79 0.13) mSv. The value of PAEC, thoron concentration, annual exposure, annual effective dose in the dwellings near fly ash dumping sites in District Faridabad (Haryana) varied from 1.34 mWL to 14.0 SmWL with an average value of (4.95 0.85) mWL, 1.16 Bq/m 3 to 65.08 Bq/m 3 with an average value of (32.77 7.87) Bqm -3 , 0.55 10 -1 WLM to 5.83 10 -1 WLM with an average value of (2.04 0.28) 10 -1 WLM and 0.21 mSv to 2.23 mSv with an average value of (0.79 0.13) mSv. The measurements indicate that the radon concentration was below the safety levels (action levels) as recommended by various regulatory bodies. The maximum value of 129.91 Bqm -3 was found in a cave inside a temple, where there was no ventilation. The different values of radon concentrations are due to different ventilation conditions and house structures. The radon concentration was found to decrease with the increase in distance of the

  8. Energy deposition and radiation quality of radon and radon daughters. Final report

    International Nuclear Information System (INIS)

    Karam, L.R.; Caswell, R.S.

    1996-01-01

    This program was aimed at creating a quantitative physical description, at the micrometer and nanometer levels, of the physical interactions of the alpha particles from radon and its daughters with cells at risk in the bronchial epithelium. The authors calculated alpha-particle energy spectra incident upon the cells and also energy deposition spectra in micrometer- and nanometer-sized sites as a function of cell depth, site size, airway diameter, activities of 218 Po and 214 Po, and other parameters. These data are now being applied, using biophysical models of radiation effects, to predict cell killing, mutations, and cell transformation. The model predictions are then compared to experimental biophysical, biochemical, and biological information. These studies contribute to a detailed understanding of the mechanisms of the biological effectiveness of the radiations emitted by radon and its progeny

  9. Seasonal variation of radon concentration in different rooms of dwellings

    International Nuclear Information System (INIS)

    Jayasheelan, A.; Manjunatha, S.; Chandrashekaraiah, G.; Shankar, P.; Umeshareddy, K.; Ningappa, C.

    2016-01-01

    Indoor air is a dominant exposure for humans, where more than half of the body's intake during a lifetime. The main natural sources of indoor radon are soil, building materials like sand, rocks, cement, marble, bricks, ceramics, natural gas and the underground-derived water supply. In the present research, dwellings with similar building style (similar floorings and dimensions) from Tumkur city were studied for indoor radon, thoron and their progeny measurements for various seasons

  10. The design and realization of calibration apparatus for measuring the concentration of radon in three models

    Energy Technology Data Exchange (ETDEWEB)

    Huiping, Guo [The Second Artillery Engineering College, Xi' an (China)

    2007-06-15

    For satisfying calibration request of radon measure in the laboratory, the calibration apparatus for radon activity measure is designed and realized. The calibration apparatus can auto-control and auto-measure in three models. sequent mode, pulse mode and constant mode. The stability and reliability of the calibration apparatus was tested under the three models. The experimental result shows that the apparatus can provides an adjustable and steady radon activity concentration environment for the research of radon and its progeny and for the calibration of its measure. (authors)

  11. Measurement of radon daughters in air samples by alpha spectroscopy

    International Nuclear Information System (INIS)

    Acena, M.L.; Crespo, M.T.

    1989-01-01

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of polonium 214 and polonium 218. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter (Author)

  12. The Spanish indoor radon mapping strategy

    International Nuclear Information System (INIS)

    Sainz-Fernandez, C.; Fernandez-Villar, A.; Fuente-Merino, I.; Gutierrez-Villanueva, J.L.; Casal-Ordas, S.; Quindos-Poncela, L.S.; Martin-Matarranz, J.L.; Garcia-Talavera, M.

    2014-01-01

    Indoor radon mapping still represents a valuable tool for drawing the picture of the exposure of general public due to radon and radon progeny inhalation in a residential context. The information provided by means of a map is useful not only as awareness and strategic element for authorities and policy-makers, but also as a scientific start-up point in the design of epidemiological and other specific studies on exposure to natural radiation. The requirements for a good mapping are related to harmonisation criteria coming from European recommendations, as well as to national/local characteristics and necessities. Around 12 000 indoor radon measurements have been made since the Spanish national radon programme began at the end of the 1980's. A significant proportion of them resulted from the last campaign performed from 2009 to 12. This campaign completed the first version of a map based on a grid 10 x 10 km 2 . In this paper, the authors present the main results of a new map together with the criteria adopted to improve the number of measurements and the statistical significance of them. (authors)

  13. Radon measurements with a PIN photodiode

    International Nuclear Information System (INIS)

    Martin-Martin, A.; Gutierrez-Villanueva, J.L.; Munoz, J.M.; Garcia-Talavera, M.; Adamiec, G.; Iniguez, M.P.

    2006-01-01

    Silicon photodiodes are well suited to detect alphas coming from different sources as neutron reactions or radon daughters. In this work a radon in air detecting device, using an 18x18 mm silicon PIN photodiode is studied. The ionized airborne decay products formed during radon diffusion were focused by an accelerating high voltage to the PIN surface. Several conducting rings were disposed inside a cylindrical PVC vessel in such a way that they reproduced the electric field created by a punctual charge located behind PIN position. Alpha spectra coming from the neutral and ionized species deposited on the PIN surface, dominated by 218 Po and 214 Po progeny peaks, were recorded for varying conditions. Those include radon concentration from a Pylon source, high voltage (thousands of volts) and PIN inverse bias voltage. Different parameters such as temperature and humidity were also registered during data acquisition. The increase in the particle collection efficiency with respect to zero electric field was compared with the corresponding to a parallel plates configuration. A discussion is made in terms of the most appropriate voltages for different radon concentrations

  14. 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

  15. Review of radon and lung cancer risk

    International Nuclear Information System (INIS)

    Samet, J.M.; Hornung, R.W.

    1990-01-01

    Radon, a long-established cause of lung cancer in uranium and other underground miners, has recently emerged as a potentially important cause of lung cancer in the general population. The evidence for widespread exposure of the population to radon and the well-documented excess of lung cancer among underground miners exposed to radon decay products have raised concern that exposure to radon progeny might also be a cause of lung cancer in the general population. To date, epidemiological data on the lung cancer risk associated with environmental exposure to radon have been limited. Consequently, the lung cancer hazard posed by radon exposure in indoor air has been addressed primarily through risk estimation procedures. The quantitative risks of lung cancer have been estimated using exposure-response relations derived from the epidemiological investigations of uranium and other underground miners. We review five of the more informative studies of miners and recent risk projection models for excess lung cancer associated with radon. The principal models differ substantially in their underlying assumptions and consequently in the resulting risk projections. The resulting diversity illustrates the substantial uncertainty that remains concerning the most appropriate model of the temporal pattern of radon-related lung cancer. Animal experiments, further follow-up of the miner cohorts, and well-designed epidemiological studies of indoor exposure should reduce this uncertainty. 18 references

  16. 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

  17. Collaborative investigations on thoron and radon in some rural communities of Balkans

    International Nuclear Information System (INIS)

    Zunic, Z. S.; Celikovic, I.; Tokonami, S.; Ishikawa, T.; Ujic, P.; Onischenko, A.; Zhukovsky, M.; Milic, G.; Jakupi, B.; Cuknic, O.; Veselinovic, N.; Fujimoto, K.; Sahoo, S. K.; Yarmoshenko, I.

    2010-01-01

    This paper deals with the results of the first-field use in the Balkans, i.e. Serbia and Republic of Srpska (Bosnia and Herzegovina), of a passive polycarbonate Mark II type and poli-allyl-diglycol carbonate (Cr-39) alpha track detectors sensitive to thoron as well as to radon. Both types of solid state nuclear track detectors were designed and supplied by National Inst. of Radiological Sciences (NIRS), Chiba (Japan). The commercial names for these detectors which all have been field tested in Balkan rural communities are known as: UFO and RADUET passive discriminative radon/thoron detectors. No database of thoron and thoron progeny concentrations in dwellings in Serbia or Balkans region exist, and as a result, the level of exposure of the Serbian population to thoron and its progeny is unknown so far. (authors)

  18. Relationship of 220Rn and 222Rn progeny levels in Canadian underground U mines

    International Nuclear Information System (INIS)

    Bigu, J.

    1988-01-01

    Radon-222 and 220 Rn progeny are found in some Canadian underground U mines. Because both can contribute to lung dose, their experimental determinations are important. The relationship between 222 Rn progeny Working Level [WL(Rn)] and 220 Rn progeny Working Level [WL(Tn)] has been investigated in U mines. Experimental measurements extended from 1981 to 1986 and consisted of about 700 measurements of each WL(Rn) and WL(Tn). The data were analyzed by standard linear and power-function regression analysis. A power-function relationship between WL(Rn) and WL(Tn) seemed to fit the experimental data best. The relationship obtained permits the calculation of WL(Tn) from experimental values of WL(Rn). The relationship is useful for lung-dose-calculation purposes and in mine-ventilation-engineering calculations

  19. Diurnal measurement of equilibrium equivalent radon/thoron concentration using time integrated flow mode grab sampler

    International Nuclear Information System (INIS)

    Pant, P.; Kandari, T.; Ramola, R.C.; Semwal, C.P.; Prasad, M.

    2018-01-01

    The basic processes which influenced the concentration of radon and thoron decay products are- attachment, recoil and deposition and by the room specific parameters of radon exhalation and ventilation. The freshly formed decay products have a high diffusivities (especially in air) and ability to stick to surfaces. According to UNSCEAR 1977, radon daughters may be combined as the so called equilibrium equivalent concentration which is related to the potential alpha energy distribution concentration. In the present study an effort has been made to see the diurnal variation of radon and thoron progeny concentration using time integrated flow mode sampler

  20. Orphan radon daughters at Denver Radium site

    International Nuclear Information System (INIS)

    Holub, R.F.; Droullard, R.F.; Davis, T.H.

    1992-01-01

    During 18 mo of sampling airborne radioactively at a National Priority List (open-quotes Superfundclose quotes) site in metroPOlitan Denver, Bureau of mines personnel discovered radon daughters that are not supported by the parent radon gas. We refer to them as open-quotes orphanclose quotes daughters because the parent, radon, is not present in sufficient concentration to support the measured daughter products. Measurements of the open-quotes orphanclose quotes daughters were made continuously, using the Bureau-developed radon and working-level (radon-daughter) monitors. The data showed high equilibrium ratios, ranging from 0.7 to 3.5, for long periods of time. Repeated, high-volume, 15-min grab samples were made, using the modified Tsivoglou method, to measure radon daughters, to which thoron daughters contributed 26 ± 12%. On average 28 ± 6% of the particulate activity was contributed by thoron daughters. Most samples were mixtures in which the 218 Po concentration was lower than that of 214 Pb and 214 Bi, in agreement with the high-equilibrium factors obtained from the continuous sampling data. In view of the short half-life of radon progeny, we conclude that the source of the orphan daughters is not far from the Superfund sites. The mechanism of this phenomenon is not understood at this time, but we will discuss its possible significance in evaluating population doses

  1. 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

  2. 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.

  3. QA/QC For Radon Concentration Measurement With Charcoal Canister

    International Nuclear Information System (INIS)

    Pantelic, G.; Zivanovic, M.; Rajacic, M.; Krneta Nikolic, J.; Todorovic, D.

    2015-01-01

    The primary concern of any measuring of radon or radon progeny must be the quality of the results. A good quality assurance program, when properly designed and diligently followed, ensures that laboratory staff will be able to produce the type and quality of measurement results which is needed and expected. Active charcoal detectors are used for testing the concentration of radon in dwellings. The method of measurement is based on radon adsorption on coal and measurement of gamma radiation of radon daughters. Upon closing the detectors, the measurement was carried out after achieving the equilibrium between radon and its daughters (at least 3 hours) using NaI or HPGe detector. Radon concentrations as well as measurement uncertainties were calculated according to US EPA protocol 520/5-87-005. Detectors used for the measurements were calibrated by 226Ra standard of known activity in the same geometry. Standard and background canisters are used for QA and QC, as well as for the calibration of the measurement equipment. Standard canister is a sealed canister with the same matrix and geometry as the canisters used for measurements, but with the known activity of radon. Background canister is a regular radon measurement canister, which has never been exposed. The detector background and detector efficiency are measured to ascertain whether they are within the warning and acceptance limits. (author).

  4. Performance of the first Japanese large-scale facility for radon inhalation experiments with small animals

    International Nuclear Information System (INIS)

    Ishimori, Y.; Mitsunobu, F.; Yamaoka, K.; Tanaka, H.; Kataoka, T.; Sakoda, A.

    2011-01-01

    A radon test facility for small animals was developed in order to increase the statistical validity of differences of the biological response in various radon environments. This paper illustrates the performances of that facility, the first large-scale facility of its kind in Japan. The facility has a capability to conduct approximately 150 mouse-scale tests at the same time. The apparatus for exposing small animals to radon has six animal chamber groups with five independent cages each. Different radon concentrations in each animal chamber group are available. Because the first target of this study is to examine the in vivo behaviour of radon and its effects, the major functions to control radon and to eliminate thoron were examined experimentally. Additionally, radon progeny concentrations and their particle size distributions in the cages were also examined experimentally to be considered in future projects. (authors)

  5. Radon in the Houses of Slavonski Brod-Posavina County

    International Nuclear Information System (INIS)

    Poleto, Z.; Varga, M.; Radolic, V.; Poje, M.; Vukovic, B.

    2008-01-01

    Radon is a noble alpha-emitting radioactive gas produced by the decay od radium. The aim of this study was to measure radon concentrations in the houses of Slavonski Brod-Posavina county. The measurements were performed by means of the passive track etching method with strippable LR-115 SSNDT film, type II (Kodak-Pathe, France). The cylindrical plastic vessel of detector, with the diameter and the length of 11 and 7 cm, respectively, was covered with a paper filter of 0.078 kg/m 3 surface density. Inside, of the bottom of the vessel, a LR-115 film that presented a diffusion detector was fixed.Outside, on the cylindrical shell of the vessel, another film, that presented the open detector was fixed. The open LR-115 detector registers the total number of alpha-particles of radon and its short-lived progeny, while the diffusion detector registers tracks only of alpha particles emitted by radon. Measurements gave radon concentrations in the range of 14-404 Bq m -3 . Average annual effective radon dose for population of Slavonski Brod-Posavina county is 2.91 mSv

  6. Measurement of size distribution for 220Rn progeny attached aerosols

    International Nuclear Information System (INIS)

    Zhang Lei; Guo Qiuju; Zhuo Weihai

    2008-01-01

    The size distribution of radioactive aerosols is a very important factor for evaluating the inner exposure dose contributed by radon and thoron progeny in environments. In order to measure the size distribution of thoron progeny attached radioactive aerosols, a device was developed using wire screens. The count median diameter (CMD) and the geometric standard deviation (GSD) of attached radioactive aerosols were calculated by collecting ThB and using CR-39 as detector. Field measurement results at Yangjiang City in Guangdong Province show that the CMDs distribute between 30 and 130 nm, and the GSDs are between 1.9 and 3.3. It also shows that the more humid country, the smaller CMDs, and the ventilation has great influence on the size distribution of aerosols. The CMDs of adobe house are smaller than that of the concrete houses. (authors)

  7. Evaluation of several air cleaners for reducing indoor radon progeny

    International Nuclear Information System (INIS)

    Hopke, P.K.; Jensen, B.; Montassier, N.

    1994-01-01

    Over the past several years, studies have been made of the effectiveness of several kinds of air cleaners in removing radon decay products from indoor air using a recently developed automated, semi-continuous measurement system that can determine the activity-weighted size distributions in occupied homes. Measurements of activity-weighted size distributions and radon concentrations were made every 90 min in a home with a high air exchange rate. A week-long series of measurements was made for the home with no cleaner operating and a similar set of measurements were made for each of the air cleaners. Two different types of air cleaners were tested in this study; filtration units (two different designs from two different manufacturers) and two ion generator/fan systems (identical design NO-RAD systems, but from two different manufacturers). It was found that the filtration units resulted in a median reduction in exposure of 15% and 36% for the two units and corresponding dose reductions of 32% and 53%. The two NO-RAD systems produced 37% and 10% reductions in the median exposure, but the reductions in the median dose were 49% and 46%. (author)

  8. Passive and Active Measurements of Radon related parameters inside ancient Egyptian Tombs in Luxor

    International Nuclear Information System (INIS)

    Abo-Elmagd, M.; Eissa, H.M.; Metwally, S.M.; Fiki, S.A.; Salama, E.

    2005-01-01

    Radon concentration and its exhalation rate were measured using active (Alpha-Guard analyzer) and passive (CR-39) techniques inside seven ancient Egyptian tombs of the Kings valley in Luxor. The measurements were performed during the winter season of tourism (15/10/2003 up to 09/02/2004). The real radium content was determine for all examined tombs by HPGe detector, while the effective radium content was obtained by Alpha-Guard and sealed cup techniques. The average radon concentration inside the tombs based on the active technique ranges from 116 42 to 362 115 Bq m-3 and the exhalation rate ranges from 0.68 to 1.47 Bq m-2 h-1. For passive measurements, the average radon concentrations inside the tombs vary from 88 5 to 517 8 Bq m-3 while the exhalation rate ranges from 0.60 to 1.42 0.05 Bq m-2 h-1. Because of the variations of tombs dimensions and their ventilation systems, the equilibrium factor between radon and its progeny ranges from 0.10 0.04 to 0.99 0.14 based on Can and Bare measurement method. The effective dose rate inside the tombs varies from 0.11 0.04 to 4.28 0.68 Sv/h, based on UNSCEAR 2000 dose conversion factors for radon and its progeny. Radon exhalation rate was correlated with the real radium content. Moreover, a good correlation was found between active and passive measurements. So it may be useful to use passive technique in large scale instead of the active one

  9. Passive and Active Measurements of Radon related parameters inside ancient Egyptian Tombs in Luxor

    Energy Technology Data Exchange (ETDEWEB)

    Abo-Elmagd, M; Eissa, H M [National institute for standerd, radiation Measurements department, Giza (Egypt); Metwally, S M; Fiki, S A; Salama, E [Faculty of Science Department of physics, Ain Shams University, Cairo (Egypt)

    2005-04-01

    Radon concentration and its exhalation rate were measured using active (Alpha-Guard analyzer) and passive (CR-39) techniques inside seven ancient Egyptian tombs of the Kings valley in Luxor. The measurements were performed during the winter season of tourism (15/10/2003 up to 09/02/2004). The real radium content was determine for all examined tombs by HPGe detector, while the effective radium content was obtained by Alpha-Guard and sealed cup techniques. The average radon concentration inside the tombs based on the active technique ranges from 116 42 to 362 115 Bq m-3 and the exhalation rate ranges from 0.68 to 1.47 Bq m-2 h-1. For passive measurements, the average radon concentrations inside the tombs vary from 88 5 to 517 8 Bq m-3 while the exhalation rate ranges from 0.60 to 1.42 0.05 Bq m-2 h-1. Because of the variations of tombs dimensions and their ventilation systems, the equilibrium factor between radon and its progeny ranges from 0.10 0.04 to 0.99 0.14 based on Can and Bare measurement method. The effective dose rate inside the tombs varies from 0.11 0.04 to 4.28 0.68 Sv/h, based on UNSCEAR 2000 dose conversion factors for radon and its progeny. Radon exhalation rate was correlated with the real radium content. Moreover, a good correlation was found between active and passive measurements. So it may be useful to use passive technique in large scale instead of the active one.

  10. Radon impact at a remediated uranium mine site in Japan

    International Nuclear Information System (INIS)

    Ishimori, Yuu

    2011-01-01

    This paper mainly illustrates the radon impact of the closed uranium mine site remediated in 2007. The site remediated is the waste rock site located on the steep slope of a hill about 1.5 km upstream from a residential area along a main ravine. Major remedial action was to cover these waste rock yards with weathering granite soil. The radon flux density after remediation was intended to be 0.1 Bqm -2 s -1 in consideration with the natural background level around Ningyo-toge because there is no value of radon flux density regulated in Japan. Our action decreased the radon concentration in the site to natural background level, approximately from 10 to 40 Bqm -3 , although relatively high concentration in excess of 100 Bqm -3 was observed before remediation. On the other hand, our action did not decrease the radon concentrations around the site in general. This fact proved that the limited source such as waste rocks affected the radon concentrations at neighboring area only. The similar tendencies were also observed in other environmental data such as radon progeny concentrations. In conclusion, these findings proved that our remedial action was successful against radon. This fact will lead to more reasonable action plans for other closed mine sites. (author)

  11. A further study of the (CR-LR) difference technique for retrospective radon exposure assessment

    International Nuclear Information System (INIS)

    Nikezic, D.; Yip, C.W.Y.; Leung, S.Y.Y.; Leung, J.K.C.; Yu, K.N.

    2006-01-01

    The (CR-LR) difference technique, based on the CR-39 and LR 115 detectors, for the determination of implanted 210 Po in glass after deposition of short-lived radon progeny, was analyzed in details in this paper. The sensitivities of both detectors were calculated using the Monte Carlo method with V functions particularly derived in our previous works for the detectors used in the present experiments. The dependency of the sensitivity ratio on the removed layer of both detectors was determined and verified experimentally. The simulated sensitivity ratios correlate well with the experimental ones. A major finding of the present work is that the sensitivity ratio between the CR-39 and LR 115 detectors depends only weakly on the ratio between the 238 U and 232 Th concentrations in the glass samples. This is crucial for the application of the (CR-LR) difference technique for retrospective radon exposure assessments, since measurements of the 238 U and 232 Th concentrations in the relatively small real-life glass samples will make the retrospective radon exposure assessments impractical

  12. Measurement of concentration and size distribution of radon decay products in homes using air cleaners

    International Nuclear Information System (INIS)

    Montassier, N.; Hopke, P.K.; Shi, Y.; McCallum, B.

    1992-01-01

    By removing particles, air cleaners can also eliminate radon decay products. However, by removing the particles, the open-quotes unattachedclose quotes fraction of the radon progeny is increased leading to a higher dose per unit exposure. Thus, both the concentration and size distributions of the radon decay products are needed to evaluate air cleaners. Three types of room air cleaners, NO-RAD Radon Removal System, Electronic Air Cleaner and PUREFLOW Air Treatment System were tested in a single family home in Arnprior, Ontario (Canada). Semi-continuous measurements of radon gas concentration and radon decay product activity weighted size distribution were performed in the kitchen/dining room under real living conditions. The effects of air cleaners on both the concentration and size distribution of the radon decay products were measured, and their impact on the dose of radiation given to the lung tissue were examined

  13. Uranium-bearing wastes and their radon emanation

    International Nuclear Information System (INIS)

    Sasaki, Tomozo; Imamura, Mitsutaka; Gunji, Yasuyoshi

    2007-01-01

    There are no data available with regard to radon emanation coefficients for uranium-bearing wastes; such data are needed for the assessment of radiation exposure from radon that will be generated in the distant future as one uranium progeny at shallow land disposal sites for uranium-bearing wastes. There are many kinds of uranium-bearing wastes. However, it is not necessary to measure the radon emanation coefficients for all of them for two reasons. First, the radon emanation coefficients for uranium-bearing wastes contaminated by dissolved uranium are determined by the uranium chemical form, the manner of uranium deposition on the waste matrix, and the size of the particles which constitute the waste matrix. Therefore, only a few representative measurements are sufficient for such uranium-bearing wastes. Second, it is possible to make theoretical calculations of radon emanation coefficients for uranium-bearing wastes contaminated by UO 2 particles before sintering. In the present study, simulated uranium-bearing wastes contaminated by dissolved uranium were prepared, their radon emanation coefficients were measured and radon emanation coefficients were calculated theoretically for uranium-bearing wastes contaminated by UO 2 particles before sintering. The obtained radon emanation coefficients are distributed at higher values than those for ubiquitous soils and rocks in the natural environment. Therefore, it is not correct to just compare uranium concentrations among uranium-bearing wastes, ubiquitous soils and rocks in terms of radiation exposure. The radon emanation coefficients obtained in the present study have to be employed together with the uranium concentration in uranium-bearing wastes in order to achieve proper assessment of radiation exposure. (author)

  14. Radon mitigation in a typical underground car park in Hong Kong

    International Nuclear Information System (INIS)

    Leung, J.K.C.; Tso, M.-Y.W.; Ho, C.W.; Hung, L.C.

    1997-01-01

    Experiments were conducted to investigate the equivalent dose to the lung (lung dose) due to radon in an underground car park with four levels. Size distribution of aerosols and activity size distribution of radon progeny loaded aerosols from 9 nm to 10 μm were measured and their relations to car movement and emission were investigated. Unattached fraction, equilibrium factor and PAEC of radon progeny were monitored and were used to predict the lung dose by adopting the ICRP Human Respiratory Tract Model. The mean annual (i.e. 2000 h) lung doses at the four levels, B1, B2, B3 and B4 during daytime were 1.5 , 2.4, 2.0 and 2.8 mSv respectively. The lung dose for each car park level at night were 2 times higher. Mitigation methods were investigated and it was found that increasing the ventilation rate only resulted in a few per cent reduction in the lung dose rate during daytime though a larger reduction in PAEC (50% at B1 and 38% at B4) was observed at night. Cleaning the fresh air filters and washing the car park floor with water also resulted in a 21% and 12% reduction in the lung dose rate respectively during daytime. (Author)

  15. Experimental and Monte Carlo simulation studies of open cylindrical radon monitoring device using CR-39 detector

    Energy Technology Data Exchange (ETDEWEB)

    Rehman, Fazal-ur- E-mail: fazalr@kfupm.edu.sa; Jamil, K.; Zakaullah, M.; Abu-Jarad, F.; Mujahid, S.A

    2003-07-01

    There are several methods of measuring radon concentrations but nuclear track detector cylindrical dosimeters are widely employed. In this investigation, the consequence of effective volumes of the dosimeters on the registration of alpha tracks in a CR-39 detector was studied. In a series of experiments an optimum radius for a CR-39-based open cylindrical radon dosimeter was found to be about 3 cm. Monte Carlo simulation techniques hav been employed to verify the experimental results. In this context, a computer code Monte Carlo simulation dosimetry (MOCSID) was developed. Monte Carlo simulation experiments gave the optimum radius of the dosimeters as 3.0 cm. The experimental results are in good agreement with those obtained by Monte Carlo design calculations. In addition to this, plate-out effects of radon progeny were also studied. It was observed that the contribution of radon progeny ({sup 218}Po and {sup 214}Po) plated-out on the wall of the dosimeters increases with an increase of dosimeter radii and then decrease to 0 at a radius of about 3 cm if a point detector has been installed at the center of the dosimeter base. In the code MOCSID different types of random number generators were employed. The results of this research are very useful for designing an optimum size of radon dosimeters.

  16. Experimental and Monte Carlo simulation studies of open cylindrical radon monitoring device using CR-39 detector

    International Nuclear Information System (INIS)

    Rehman, Fazal-ur-; Jamil, K.; Zakaullah, M.; Abu-Jarad, F.; Mujahid, S.A.

    2003-01-01

    There are several methods of measuring radon concentrations but nuclear track detector cylindrical dosimeters are widely employed. In this investigation, the consequence of effective volumes of the dosimeters on the registration of alpha tracks in a CR-39 detector was studied. In a series of experiments an optimum radius for a CR-39-based open cylindrical radon dosimeter was found to be about 3 cm. Monte Carlo simulation techniques hav been employed to verify the experimental results. In this context, a computer code Monte Carlo simulation dosimetry (MOCSID) was developed. Monte Carlo simulation experiments gave the optimum radius of the dosimeters as 3.0 cm. The experimental results are in good agreement with those obtained by Monte Carlo design calculations. In addition to this, plate-out effects of radon progeny were also studied. It was observed that the contribution of radon progeny ( 218 Po and 214 Po) plated-out on the wall of the dosimeters increases with an increase of dosimeter radii and then decrease to 0 at a radius of about 3 cm if a point detector has been installed at the center of the dosimeter base. In the code MOCSID different types of random number generators were employed. The results of this research are very useful for designing an optimum size of radon dosimeters

  17. The detection and measurement of the electrical mobility size distributions associated with radon decay products

    International Nuclear Information System (INIS)

    Fei, Lin.

    1996-04-01

    The potential risk of lung cancer has evoked interest in the properties of radon decay products. There are two forms of this progeny: either attached to ambient aerosols, or still in the status of ions/molecules/small clusters. This ''unattached'' activity would give a higher dose per unit of airborne activity than the ''attached'' progeny that are rather poorly deposited. In this thesis, a system for determining unattached radon decay products electrical mobility size distribution by measuring their electrical mobilities was developed, based on the fact that about 88% of 218 Po atoms have unit charge at the end of their recoil after decay from 222 Rn, while the remainder are neutral. Essential part of the setup is the radon-aerosol chamber with the Circular Electrical Mobility Spectrometer (CEMS) inside. CEMS is used for sampling and classifying the charged radioactive clusters produced in the chamber. An alpha- sensitive plastic, CR-39 disk, is placed in CEMS as an inlaid disk electrode and the alpha particle detector. CEMS showed good performance in fine inactive particles' classification. If it also works well for radon decay products, it can offer a convenient size distribution measurement for radioactive ultrafine particles. However, the experiments did not obtain an acceptable resolution. Suggestions are made for solving this problem

  18. Developmental toxicology of radon exposures

    International Nuclear Information System (INIS)

    Sikov, M.R.; Cross, F.T.; Mast, T.J.; Palmer, H.E.; James, A.C.; Thrall, K.D.

    1992-01-01

    Concerns about hazards associated with radon exposure in dwellings may be especially relevant to pregnant women, many of whom spend substantial amounts of time in their homes. There are few data concerning the placental transfer and fetoplacental distribution of inhaled radon and decay products or their effects on the conceptus. We performed a study in rats to determine if prenatal effects could be produced by prolonged inhalation exposures to high concentrations of radon throughout gestation. A group of 43 pregnant rats was exposed 18 h d -1 , at a rate of 124 working level months (WLM) per day, from 6 to 19 days of gestation (dg), of radon and daughters adsorbed onto ore dust. A group of 26 pregnant rats from the same shipment was exposed to a filtered-air atmosphere as controls. At 20 dg, the rats were removed from the chambers, killed, and necropsied. The fetuses were evaluated for the presence of toxic effects, which included detailed teratology protocols. These exposures did not produce detectable reproductive toxicity nor teratogenic change. Two other rats were removed from the radon chambers during the last day of exposure, and their tissues were analyzed to determine the distribution of radioactivity and for dosimetry. Samples from these rats suggested that the dose rates to the placenta were roughly threefold those to the fetus but were similar to those to the liver and femur of the pregnant rats. These data indicate that the dose to the conceptus from the decay of placentally transferred radon and its progeny is more important than the contribution of translocated decay products. Translocated radon decay products are an important source of radiation doses to placental structures, however, and may have most of the radioactivity content at birth

  19. Analysis of the main factors affecting the evaluation of the radon dose in workplaces: The case of tourist caves

    International Nuclear Information System (INIS)

    Sainz, Carlos; Quindos, Luis Santiago; Fuente, Ismael; Nicolas, Jorge; Quindos, Luis

    2007-01-01

    High concentrations of radon exist in several workplaces like tourist caves mainly because of the low ventilation rates existing at these enclosures. In this sense, in its 1990 publication, the ICRP recommended that high exposures of radon in workplaces should be considered as occupational exposure. In developed caves in which guides provide tours for the general public great care is needed for taking remedial actions concerning radon, because in some circumstances forced ventilation may alter the humidity inside the cave affecting some of the formations or paintings that attract tourists. Tourist guides can work about 1900 h per year, so the only option to protect them and other cave workers from radon exposure is to apply an appropriate system of radiation protection mainly based on limitation of exposure by restricting the amount of time spent in the cave. Because of the typical environmental conditions inside the caves, the application of these protecting actions requires to know some indoor air characteristics like particle concentration, as well as radon progeny behaviour in order to get more realistic effective dose values In this work the results of the first two set of radon measurements program carried out in 10 caves located in the region of Cantabria (Spain) are presented

  20. Developing an interactive computational system to simulate radon concentration inside ancient egyptian tombs

    Energy Technology Data Exchange (ETDEWEB)

    Metwally, S M; Salama, E; El-Fikia, S A [Faculty of Science, Department of Physics, Ain Shams University, P. O. Box 11566, Cairo (Egypt); Abo-EImagd, M; Eissa, H M [National Institute for Standard, Radiation Measurements Department, P. O. Box 136Giza code no. 12211 RSSP (Egypt)

    2007-06-15

    RSSP (Radon Scale Software Package) is an interactive support system that simulates the radon concentration inside ancient Egyptian tombs and the consequences on the population in terms of internal and external exposure. RSSP consists of three interconnected modules: the first one simulates the radon concentration inside ancient Egyptian tombs using a developed mathematical model. This model introduces the possibility of controlling the rate of radon accumulation via additional artificial ventilation systems. The source of inputs is an editable database for the tombs includes the geometrical dimensions and some environmental parameters like temperature and outdoor radon concentration at the tombs locations. The second module simulates the absorbed dose due to internal exposure of radon and its progeny. The third module simulates the absorbed dose due to external exposure of Gamma rays emitted from the tomb wall rocks. RSSP introduces the facility of following the progress of radon concentration as well as Internal and external absorbed dose in a wide range of time (seconds, minutes, hours and days) via numerical data and the corresponding graphical interface.

  1. Developing an interactive computational system to simulate radon concentration inside ancient egyptian tombs

    International Nuclear Information System (INIS)

    Metwally, S. M.; Salama, E.; El-Fikia, S. A.; Abo-EImagd, M.; Eissa, H. M.

    2007-01-01

    RSSP (Radon Scale Software Package) is an interactive support system that simulates the radon concentration inside ancient Egyptian tombs and the consequences on the population in terms of internal and external exposure. RSSP consists of three interconnected modules: the first one simulates the radon concentration inside ancient Egyptian tombs using a developed mathematical model. This model introduces the possibility of controlling the rate of radon accumulation via additional artificial ventilation systems. The source of inputs is an editable database for the tombs includes the geometrical dimensions and some environmental parameters like temperature and outdoor radon concentration at the tombs locations. The second module simulates the absorbed dose due to internal exposure of radon and its progeny. The third module simulates the absorbed dose due to external exposure of Gamma rays emitted from the tomb wall rocks. RSSP introduces the facility of following the progress of radon concentration as well as Internal and external absorbed dose in a wide range of time (seconds, minutes, hours and days) via numerical data and the corresponding graphical interface

  2. Comparison of five-minute radon-daughter measurements with long-term radon and radon-daughter concentrations

    International Nuclear Information System (INIS)

    Young, J.A.; Jackson, P.O.; Thomas, V.W.

    1983-01-01

    Five-minute air filter radon daughter measurements were made in 84 buildings in Edgemont, South Dakota, in which annual average radon daughter concentrations have been determined from six 100-hour Radon Progeny Integrating Sampling Unit (RPISU) measurements. Averaging radon concentrations were also determined in 50 of these buildings using Terradex Track Etch detectors. The standard deviation of the difference between the (natural) logarithms of the RPISU annual averages and the logarithms of the air filter measurements (SD-ln) was found to be 0.52. This SD-ln is considerably smaller than the SD-ln of 0.71 between the RPISU annual averages and the air filter measurements reported by ALARA at Grand Junction, Colorado; presumably because a considerable number of air filter measurements in Edgemont were disregarded because of short turnover times or high wind speeds. Using the SD-ln of 0.52 it can be calculated that there would only be a 5% probability in Edgemont that the RPISU annual average would be greater than 0.015 WL if the five-minute measurement were equal to 0.010 WL. This indicates that the procedure used in Edgemont of clearing buildings from remedial action if the five-minute measurement were less than 0.010 WL was reasonable. There was about a 28% probability that the RPISU annual average would be less than 0.015 WL if the five-minute measurement were 0.033 WL, indicating that the procedure of performing an engineering assessment if the average of two five-minute measurements was greater than 0.033 WL was also reasonable. Comparison indicates that the average of two RPISU measurements taken six months apart would provide a dependable estimate of the annual average

  3. Design, characterization and use of replicate human upper airways for radon dosimetry studies

    International Nuclear Information System (INIS)

    Swift, D.L.; Cheng, Y.S.; Su, Y.F.; Yeh, H.C.

    1992-01-01

    The size distribution of inhaled radon progeny aerosols is a significant factor in dosimetry. The role of the airways above the trachea is an important determinant of the respiratory distribution of both attached and unattached progeny aerosols. In order to provide information on the effect of particle size and breathing conditions on the overall and local deposition, we have developed a method to produce a replicate airway model from an in vivo magnetic resonance imaging coronal scan. The model consists of a sandwich of methacrylate elements, each element having the thickness of the scan interval. The transition between successive scan outlines traced on the front and back surfaces of each element is handsculpted in the plastic. The hollow model of the nasal passages thus produced has been characterized both morphologically and fluid-mechanically and has a flow resistance typical of a normal adult. The model has several distinct advantages for studies of radon progeny aerosol deposition. After exposure to a radioaerosol (or to an aerosol of an otherwise measurable substance) the individual elements can be separated to determine local deposition. The dimensions of specific upper-airway regions can be changed by replacing a small number of elements. The model has been incorporated in an exposure system for determining overall nandregional deposition of aerosols whose median diameter is approximately 1.7 nm. Measurements at several flow rates are presented to demonstrate use of the model in radon dosimetry. The model should also be useful for determining the airway deposition of other environmental aerosols

  4. Underwater in situ measurements of radionuclides in selected submarine groundwater springs, Mediterranean sea

    International Nuclear Information System (INIS)

    Tsabaris, C.; Scholten, J.; Karageorgis, A. P.; Comanducci, J. F.; Georgopoulos, D.; Liong Wee Kwong, L.; Patiris, D. L.; Papathanassiou, E.

    2010-01-01

    The application of the in situ measurement system 'KATERINA' for monitoring of radon progenies in submarine groundwater discharge (SGD) was investigated at different locations in the Mediterranean Sea (Chalkida, Stoupa, Korfos and Cabbe). At Chalkida and Stoupa radon progenies concentration exhibited almost constant values of 1.2±0.1 and 2.5±0.2 Bq l -1 , respectively. At Korfos these activities ranged between 1.4±0.1 and 2.3±0.2 Bq l -1 exhibiting inverse relationship with salinity. At Cabbe the in situ measured data were compared with radon measurements obtained by liquid scintillation counter. The system also resolved radon progeny variations of SGD on time scales above 1 h. The radioactivity levels of radon progenies from all sites were found considerably lower (approximately 2 orders of magnitude) than the commonly accepted limits for radon in drinking water. (authors)

  5. Field monitoring versus individual miner dosimetry of radon daughter products in mines.

    Science.gov (United States)

    Domański, T; Kluszczyński, D; Olszewski, J; Chruscielewski, W

    1989-01-01

    The paper presents the results realised simultaneously by two different and independent systems of measurement of an assessment of miners' exposure to radon daughter products which naturally occur in the air of mines. The first one, called the Air Sampling System (ASS), was based on the field monitoring of radon progeny in air, the second one, called the Individual Dosimetry System (IDS), was based on the individual dosimeters worn by miners. Experimental comparison of these two systems has been conducted for six years in eleven Polish underground metal-ore mines. This study reveals that no correlation exists between the concentration and annual miners' exposures evaluated by the ASS and IDS. The ratio ASS/IDS for mine population varies from 11.0 to 0.14 in respect of annual concentration means, and in respect to annual exposures, this ratio varies from 4.5 to 0.14. The conclusion to be drawn from six years' observation and comparison of both systems is that correct and true evaluation of miners' exposure to radon progeny can be made only by the use of the Individual Dosimetry System, since the Air Sampling System is too sensitive and too dependent on the Strategy of sampling and its radiation.

  6. Comparison of indoor radon and thoron concentrations in the urban and rural dwellings of Chhattisgarh state of India

    International Nuclear Information System (INIS)

    Khokhar, M.S.K.; Kher, R.S.; Rathore, V.B.; Pandey, S.; Ramachandran, T.V.

    2008-01-01

    In the frame of nationwide radon/thoron monitoring program, indoor radon/thoron and their progeny concentrations have been estimated for 210 dwellings situated in 8 towns (urban) and 9 villages (rural) of Chhattisgarh state of India. The measurement has been made on quarterly integrating cycle for one full year in each dwelling. Twin chamber dosimeter cup with LR-115 Type-II Solid State Nuclear Track Detector was used for the measurement of indoor radon/thoron concentration. The results show that the geometric mean of indoor thoron concentration in urban dwellings varies from 11.57 to 25.88Bqm -3 with an overall geometric mean value of 16.65Bqm -3 , while in rural dwellings it varies from 12.50 to 30.08Bqm -3 with an overall geometric mean value of 19.00Bqm -3 . The potential alpha energy concentration (PAEC) levels of thoron in the urban and rural dwellings are found to be 2.58 and 4.57 mWL, respectively. Similarly, the geometric mean of indoor radon concentrations in urban dwellings is found to vary from 20.20 to 30.13Bqm -3 with an overall geometric mean value of 25.28Bqm -3 , while in rural dwellings it varies from 15.50 to 36.05Bqm -3 with an overall geometric mean value of 27.32Bqm -3 . The PAEC levels of radon in the urban and rural dwellings are found to be 1.50 and 1.87 mWL, respectively. The dose contribution of thoron and progeny in total inhalation dose has been found to be more than 20% in all the surveyed places that show the necessity to pay attention to the presence of thoron and progeny from public health point of view

  7. Assessment of indoor radon, thoron concentrations, and their relationship with seasonal variation and geology of Udhampur district, Jammu & Kashmir, India.

    Science.gov (United States)

    Kumar, Ajay; Sharma, Sumit; Mehra, Rohit; Narang, Saurabh; Mishra, Rosaline

    2017-07-01

    Background The inhalation doses resulting from the exposure to radon, thoron, and their progeny are important quantities in estimating the radiation risk for epidemiological studies as the average global annual effective dose due to radon and its progeny is 1.3 mSv as compared to that of 2.4 mSv due to all other natural sources of ionizing radiation. Objectives The annual inhalation dose has been assessed with an aim of investigating the health risk to the inhabitants of the studied region. Methods Time integrated deposition based 222 Rn/ 220 Rn sensors have been used to measure concentrations in 146 dwellings of Udhampur district, Jammu and Kashmir. An active smart RnDuo monitor has also been used for comparison purposes. Results The range of indoor radon/thoron concentrations is found to vary from 11 to 58 Bqm -3 with an average value of 29 ± 9 Bqm -3 and from 25 to 185 Bqm -3 with an average value of 83 ± 32 Bqm -3 , respectively. About 10.7% dwellings have higher values than world average of 40 Bqm -3 prescribed by UNSCEAR. The relationship of indoor radon and thoron levels with different seasons, ventilation conditions, and different geological formations have been discussed. Conclusions The observed values of concentrations and average annual effective dose due to radon, thoron, and its progeny in the study area have been found to be below the recommended level of ICRP. The observed concentrations of 222 Rn and 220 Rn measured with active and passive techniques are found to be in good agreement.

  8. Age and sex dependent inhalation doses to members of the public from indoor thoron progeny

    Energy Technology Data Exchange (ETDEWEB)

    Bi, L; Tschiersch, J [Helmholtz Zentrum Muenchen-German Research Center for Environmental Health, Institute of Radiation Protection, D-85764, Neuherberg (Germany); Li, W B [Helmholtz Zentrum Muenchen-German Research Center for Environmental Health, Department of Medical Radiation Physics and Diagnostics, D-85764, Neuherberg (Germany); Li, J L, E-mail: bilei1983@gmail.com [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)

    2010-12-01

    The increased indoor thoron level in Europe, North America and Asia has shown that the exposure to thoron and its decay products cannot be ignored in some environments. The contribution of thoron and its progeny can be a significant component of the total exposure from radon and thoron. In the present paper, radiation dose assessment of members of the public of different age and sex exposed to {sup 220}Rn progeny under different daily life activities is performed through a dosimetric approach. Dose conversion coefficients under typical indoor conditions were estimated to be in the range of 107 nSv (Bq h m{sup -3}){sup -1} for infant to 81.7 nSv (Bq h m{sup -3}){sup -1} for adult. The results of this work emphasized that small children receive a radiation dose of 25% more than adults under the same conditions, and people performing exercise receive a radiation dose 100% more than when sleeping. The results of this work are appropriate to the risk assessment of thoron exposure to members of the public who live in areas with high radon and thoron concentrations.

  9. Radon diffusion coefficients for soils. Previous studies and their application to uranium-bearing wastes

    International Nuclear Information System (INIS)

    Sasaki, Tomozo; Gunji, Yasuyoshi; Iida, Takao

    2008-01-01

    Radon diffusion in soils has been studied over the years by many researchers. The application of such studies to the evaluation of radiation exposure caused by radon from uranium-bearing wastes disposed in a shallow land site is very important. The present paper surveyed closely relevant studies and elucidated the inherent nature of radon diffusion in terms of the definition of radon diffusion coefficients. Then, basic features of measurement methods for determining radon diffusion coefficients in soils were explained. Furthermore, theoretical aspects of radon diffusion in soils were discussed in terms of microscopic radon diffusion in soils and large-scale radon diffusion through cover soil defects for uranium mill tailings. Finally, in order to apply the radon diffusion studies to uranium-bearing waste disposal in shallow land sites, new challenges were presented: elucidation of radon diffusion in uranium-bearing wastes and cover-soil cracks, and demonstration of the validity of applying only radon diffusion in the evaluation of radiation exposure caused by radon, which would come through Japanese cover soils for uranium-bearing waste disposal. (author)

  10. 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

  11. Indigenous development and networking of online radon monitors in the underground uranium mine

    International Nuclear Information System (INIS)

    Gaware, J.J.; Sahoo, B.K.; Sapra, B.K.; Mayya, Y.S.

    2010-01-01

    low as 8 Bqm -3 . This monitor overcomes many limitations of commercially available radon monitors and is very much cost effective for networking of required numbers of monitors in an occupational environment like underground uranium mine. This monitor also finds application in monitoring of ambient radon concentration and surface exhalation of radon from soil matrix. Different test and measurement were carried out and compared with commercial instruments. It was found to be an excellent matching with the results of commercial instruments. Since the ZnS:Ag is sensitive to the alpha emission from radon and its progenies in the volume of detector, this detector can be operated without any electrostatic collection. Although the sensitivity of the instrument is low in the absence of electric field, this mode of operation is very useful for online measurements of high radon concentration in the presence of very high humidity and trace gases. A few such instruments have installed in different locations of uranium mine at Turamdih and connected to a common network system as a requirement of the department

  12. Radon concentrations in houses around the Plomin coal-fired power plant

    International Nuclear Information System (INIS)

    Lokobauer, N.; Franic, Z.; Sencar, J.; Bauman, A.; Sokolovic, E.

    1997-01-01

    Investigation of radon activity concentration in houses around the Plomin coal-fired power plant (Istrian Peninsula) started in the winter of 1990 upon the assumption that certain old houses in this region were built using mortar and plaster prepared from slag and ash. This paper presents the results of a preliminary investigation carried out in the winter of 1990 and spring of 1991, when the difference between radon levels in old and newly built houses was first noted, and the subsequent data obtained by radon measurements in 40 selected houses in the period from 1992 to 1994. The average annual radon activity concentrations in the old houses ranged from 55 Bqm -3 to 426 Bqm -3 (mean value 146 ± 91 Bqm -3 ) and in more recently built houses from 16 Bqm -3 to 67 Bqm -3 (mean value 36 ± 13 Bqm -3 ). The average annual effective doses from inhalation of radon progeny for the inhabitants living in the old and newly built houses were estimated to be 2.7 mSv and 0.7 mSv, respectively. (Author)

  13. Study of radon dispersion in typical dwelling using CFD modeling combined with passive-active measurements

    Science.gov (United States)

    Rabi, R.; Oufni, L.

    2017-10-01

    Inhalation of radon (222Rn) and its decay products are a major source of natural radiation exposure. 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. Indoor air conditions and ventilation systems strongly influence the indoor radon concentration. This study focuses on investigating both numerically and experimentally the influence of environmental conditions on the indoor radon concentration and spatial distribution. The numerical results showed that ventilation rate, temperature and humidity have significant impacts on both radon content and distribution. The variations of radon concentration with the ventilation, temperature and relative humidity are discussed. The measurement results show the diurnal variations of the indoor radon concentration are found to exhibit a positive correlation with relative humidity and negatively correlate with the air temperature. The analytic solution is used to validate the numeric results. The comparison amongst analytical, numerical and measurement results shows close agreement.

  14. Application of CR-39 to radon measurement

    International Nuclear Information System (INIS)

    Miyake, Hiroshi

    1988-01-01

    CR-39, an ally diglycol carbonate, has recently come into wider use as material for solid-state track detector. Etching with NaOH or KOH solution allow CR-39 to develop extremely clear etch pits attributed to alpha rays. The most widely used method for measuring radon concentration employs a plastic cup with a solid-state track detector mounted at its bottom to detect alpha rays resulting from radon or its daughters that disintegrate within or on the wall of the cup. Simple in mechanism and low in cost, this method is suitable for such a case where the radon concentration distribution over a wide area has to be measured by using a large number of devices. The concentration of radon alone can be measured with the aid of a filter attached to the mouth of the cup to remove the daughters of radon and thoron. The simplest and most effective way of improving the sensitivity of a solid-state track detector for radon concentration measurement is to electrostatically collect daughters resulting from decay of radon onto the surface of the detector. Another method widely used to determine the radon concentration is to measure the concentration of the radon daughters instead of direct measurement of the concentration of radon itself. (Nogami, K.)

  15. Project Radon

    International Nuclear Information System (INIS)

    Ekholm, S.

    1988-01-01

    The project started in March 1987. The objective is to perform radon monitoring in 2000 dwellings occupied by people employed by State Power Board and to continue to contribute to the development of radon filters. The project participates in developing methods for radon measurement and decontamination and in adapting the methods to large scale application. About 400 so called radon trace measurements (coarse measurement) and about 10 action measurements (decontamination measurement) have been made so far. Experience shows that methods are fully applicable and that the decontamination measures recommended give perfectly satisfactory results. It is also established that most of the houses with high radon levels have poor ventilation Many of them suffer from moisture and mould problems. The work planned for 1988 and 1989 will in addition to measurements be directed towards improvement of the measuring methods. An activity catalogue will be prepared in cooperation with ventilation enterprises. (O.S.)

  16. Radon measurements in underground and ground constructions in Tashkent city

    International Nuclear Information System (INIS)

    Akimov, V.A.; Yafasov, A.Y.; Vasidov, A.; En, Z.; Tillaev, T.; Tsipin, V.Z.

    2002-01-01

    More than half of the dose of the natural radioactivity received by population is related to radon and its progeny. Investigations of scientists all over the world have shown that excessive radon and its progeny exposure dose is associated with a risk of lung cancer. Short-lived radon daughters (Po-218 and Po-214) are considered to be of the most dangers. At a relaxation process resulting from an earthquake, the radon gas can release from the accumulators and get indoors, that enhances greatly the radon level there. According to seismologists data, as a result of the strong Tashkent earthquake in 1966, extensive breaks and faults have been formed along the city and its neighborhoods. The aim of our work was evaluation of radon concentration level and its variation in Tashkent subway stations and related underground offices and also in apartments of multi story buildings and detached houses. The measurements were conducted by two different techniques-with ionization chamber radiometer 'Alpha GUARD' and with solid state nuclear track detectors. The Alpha GUARD radiometer operates either in the mode of passive sampling, or by pumping air through the ionization camera being of 0.6 l in volume. The radiometer is capable of measuring a volumetric activity of radon-222 in air (Bq/m3), and it is equipped with the devices that measure some environmental parameters such as temperature, relative humidity and air pressure. The range of V A of 222 Rn in air the device is able to measure is 10 to 2x10 6 Bq/m 3 , sensitivity is 1 pulse/min for 20 Bq/m 3 , and its self-background is less than 1 Bq/m 3 . The radon measurements in Tashkent subway stations and underground offices have shown that daily mean radon values were in the range of 14-65 Bq/m 3 , except for the Pushkin Station, where the daily mean V A was 137 Bq/m3. Such a high radon level is connected with availability near the station of one of the numerous faults and fractures of the terrestrial crust responsible for the

  17. 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%

  18. Study on radon concentration monitoring using activated charcoal canisters in high humidity environments

    International Nuclear Information System (INIS)

    Wang Yuexing; Wang Haijun; Yang Yifang; Qin Sichang; Wang Zhentao; Zhang Zhenjiang

    2009-01-01

    The effects of humidity on the sensitivity using activated charcoal canisters for measuring radon concentrations in high humidity environments were studied. Every canister filled with 80 g of activated charcoal, and they were exposed to 48 h or 72 h in the relative humidity of 68%, 80%, 88% and 96% (28 degree C), respectively. The amount of radon absorbed in the canisters was determined by counting the gamma rays from 214 Pb and 214 Bi (radon progeny). The results showed that counts decreased with the increase of relative humidity. There was a negative linear relationship between count and humidity. In the relative humidity range of 68%-96%, the sensitivity of radon absorption decreased about 2.4% for every 1% (degree)rise in humidity. The results also showed that the exposure time of the activated charcoal canisters should be less than 3 days. (authors)

  19. New three-count technique for short-lived radon decay products in air

    International Nuclear Information System (INIS)

    Tian Deyuan; Lu Zhizhao

    1998-01-01

    Up to the present, radon and its short-lived decay products in air are usually monitored by means of a detection. But radon progeny, including RaB ( 214 Pb) and RaC ( 214 Bi) which are β and γ emitters, contribute about 90% to the equilibrium equivalent radon concentration (EECRn). Therefore, this paper introduces a new three-count technique by a β detector in the light of radioactive decay law and its boundary conditions during sampling and counting times to solve the Bateman equation. β (even low level β) instruments have been fairly popularized domestically and internationally. It can be used not only as an instrument for radon and its daughters in air, but also as a monitor for β airborne activity in the environment. This new method taps further the latent power of the present instrument and realizes various uses for a unit. (author)

  20. Radon and hydrotherapy: application to French spas

    International Nuclear Information System (INIS)

    Ameon, R.

    2004-01-01

    Owing to the use of thermal water for treatments, the dissolved radon ends up, through degassing, in the atmosphere of the various spa premises. According to the type of treatments, the radon activity concentration in the air is very variable; it depends on two factors, the supply of thermal water, and therefore of radon, and the ventilation of the various premises. In unfavourable, even non-existent, ventilation conditions, it is not uncommon to measure radon concentration reaching several thousands of becquerels per air cubic meter. These high values of radon activity concentration, with or without its short-lived daughters, may lead to a staff exposure of approximately ten or several tens of mSv per year. A French spa was subject to a radon 'expertise' during which the radon source terms, 'ground in contact with the buildings' and 'thermal water' were characterized. The radon mapping in the internal atmosphere of the various spa premises and the workstations' analysis resulted in an assessment of the exposure due to radon inhalation. This study showed that on workstations, notably linked to hydrotherapy, the staff exposure to radon is in the same range as the dose assessments from foreign studies. The implementation of an appropriate ventilation of the treatment rooms and a better management of the thermal water in the spa resulted in a significant reduction of staff exposure

  1. Application of a radon model to explain indoor radon levels in a Swedish house

    International Nuclear Information System (INIS)

    Font, LL.; Baixeras, C.; Joensson, G.; Enge, W.; Ghose, R.

    1999-01-01

    Radon entry from soil into indoor air and its accumulation indoors depends on several parameters, the values of which normally depend on the specific characteristics of the site. The effect of a specific parameter is often difficult to explain from the result of indoor radon measurements only. The adaptation of the RAGENA (RAdon Generation, ENtry and Accumulation indoors) model to a Swedish house to characterise indoor radon levels and the relative importance of the different radon sources and entry mechanisms is presented. The building is a single-zone house with a naturally-ventilated crawl space in one part and a concrete floor in another part, leading to different radon levels in the two parts of the building. The soil under the house is moraine, which is relatively permeable to radon gas. The house is naturally-ventilated. The mean indoor radon concentration values measured with nuclear track detectors in the crawl-space and concrete parts of the house are respectively 75±30 and 200±80 Bq m -3 . Results of the model adaptation to the house indicate that soil constitutes the most relevant radon source in both parts of the house. The radon concentration values predicted by the model indoors fall into the same range as the experimental results

  2. 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

  3. The application of air pressure difference in reducing indoor radon concentration

    International Nuclear Information System (INIS)

    Leung, J.K.C.; Tso, M.Y.W.

    2000-01-01

    In densely populated tropical cities like Hong Kong, people usually live and work inside high-rise buildings. And because of the hot and humid climate, air conditioning systems are used throughout the year, particularly in commercial buildings. Previous territory-wide surveys have shown that over 10% of commercial buildings in Hong Kong have indoor radon concentrations above 200 Bq m -3 . Since the major source of indoor radon in high-rise buildings is the building materials, increasing ventilation and applying radon barriers on wall surfaces seem to be the only ways to reduce the indoor radon concentration. But it was noted that the ventilation rate the many commercial buildings are not efficient enough to remove the radon because of various reasons such as energy saving, lack of maintenance, etc. In this study, radon mitigation was achieved by reducing the rate of radon exhaled from the building materials. A special laboratory, which has the capability of simulating any meteorological conditions that could be faced by high-rise buildings in Hong Kong, was built. The reduction of radon exhalation rate by applying pressure difference and temperature difference across walls was studied in the laboratory. This paper summarizes the results and tactics for applying pressure difference in existing commercial buildings. A new technique of reducing radon exhalation rate in new buildings by depressurizing the interior of walls was also developed. Tunnels can be embedded in the concrete walls of new buildings during construction. By using simple vacuum pumps, radon exhalation rate from the walls can be reduced significantly by depressurizing the tunnels. The feasibility and applicability of the technique is presented in this paper. (author)

  4. Application of the can technique and radon gas analyzer for radon exhalation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Fazal-ur-Rehman E-mail: fazalr@kfupm.edu.sa; Al-Jarallah, M.I.; Musazay, M.S.; Abu-Jarad, F

    2003-12-01

    A passive 'can technique' and an active radon gas analyzer with an emanation container were applied for radon exhalation rate measurements from different construction materials, viz. five marble seven ceramic and 100 granite tiles used in Saudi Arabia. The marble and ceramic tiles did not show detectable radon exhalation using the active radon gas analyzer system. However the granite tiles showed relatively high radon exhalations, indicating a relatively high uranium content. A comparison of the radon exhalation rates measured by the two techniques showed a linear correlation coefficient of 0.57. The radon exhalation rates from the granites varied from 0.02 to 6.58 Bq m{sup -2} h{sup -1} with an average of 1.35{+-}1.40 Bq m{sup -2} h{sup -1}. The geometric mean and the geometric standard deviation of the frequency distribution were found to be 0.80 and 3.1, respectively. The track density found on the nuclear track detectors in the can technique exposed to the granites, having high exhalation rates, varied linearly with exposure time with a linear correlation coefficient of 0.99. This experimental finding agrees with the theoretical prediction. The can technique showed sensitivity to low radon exhalation rates from ceramic, marble and some granite over a period of 2 months, which were not detectable by the active radon gas analyzer system. The reproducibility of data with both measuring techniques was found to be within a 7% deviation.

  5. Integrating measurements of indoor thoron and its progeny concentrations

    International Nuclear Information System (INIS)

    Zhuo, W.H.; Iida, T.; Hashiguchi, Y.

    2000-01-01

    In recent years, indoor surveys in Europe and Asia revealed that the dose contribution from thoron and its progeny can equal or even exceed that of radon and its progeny. For measuring thoron and its progeny, several methods had been reported. However, convenient, low-cost and time-integrating measuring methods which are suitable for large-scale surveys are still unavailable. To solve this problem, three integrating measuring methods with allyl diglycol carbonate plastic (CR-39) as detectors have recently been. The results indicated that they are suitable for estimating the indoor thoron and its progeny concentrations when the public exposure to thoron and its progeny is taken into account. Cup monitor - Former types of passive integrating 222 Rn and 220 Rn cup monitors had been reported. Recently, in order to improve the sensitivity of thoron detection, the air exchange rate between the inner and outer cup was enhanced, and the radius of the hemisphere was reduced to 37.5 mm. Furthermore, the procedure of detector exchange was made to be more convenient. Equilibrium-equivalent 222 Rn and 220 Rn concentrations monitor (EEC monitor) - The measuring system is composed of a monitor head and a diaphragm pump. The total weight of the system is less than 1.5 kg, which makes it portable. The construction of the monitor head and the measuring principle were also reported by the authors. Thoron progeny deposition rate monitor - The monitor is simply constituted a piece of CR-39 covered with thin sheets of absorbers. The thickness of the absorbers are adjusted to let only the α particles emitted from 212 Pb impinge on the detector. The concentrations of thoron progeny are estimated from the deposition rates, assuming that the deposition velocities of thoron progeny are constant in general dwellings. The improved cup monitor has higher sensitivity than former monitors, with a calibration factor of 1.59x10 -3 tracks·cm -2 (Bq·m -3 ·h) -1 for thoron. The accuracy of the ECC

  6. The passive radon-thoron discriminative dosimeter for practical use

    International Nuclear Information System (INIS)

    Doi, Masahiro; Kobayashi, Sadayoshi

    1994-01-01

    A passive radon-thoron discriminative dosimeter for practical use has been developed. The body of the practical R-T dosimeter is made of two hemispheric diffusion chambers of carbonized plastic whose diameters are 110 mm and 70 mm, respectively. These diameters are determined to improve the detection efficiency of radon as well as thoron and also the discrimination ratio of radon to thoron. Inner surface of the detector housing is smooth and free from electrified charge to assure the uniform deposition of radon and thoron progeny, because the detector housing is molded out of carbonized plastic as an anti-static material. In addition, structure of an air inlet has improved to contact more tightly with a glass fiber filter to prevent dust from entering the detector housing. The air inlet of the detector housing is also covered with a half-cutted hemispherical windbreak to protect the glass fiber filter from weathering and to stabilize the influence of convectional air flow on the radon and thoron entry rate into two hemispherical diffusion chambers of the dosimeter. The results of calibration exercises showed that the lower detection limit of radon and thoron concentrations were estimated to be 5.1 Bqm -3 and 7.9 Bqm -3 respectively in 2 months exposure. And an interim measurement in the concrete cellar proved that the practical R-T dosimeter has enough specifications to be used in the large-scale radon-thoron discriminative survey. (author)

  7. Radon: A special case in radiation protection

    International Nuclear Information System (INIS)

    Vanmarcke, H.

    2008-01-01

    The conversion conventions of ICRP 65 are based on equality of detriment, not on dosimetry. They are derived from epidemiological studies on miners by comparing the risk of having fatal lung cancer with the detriment associated with a unit of exposure in ICRP 60. Things have moved on since ICRP 65 and the new scientific evidence (numerator change, denominator change and also the dosimetric approach in ICRP 66) is pointing away from ICRP 65 in the direction of the long-established UNSCEAR conversion factor of 9 (nSv h -1 )/(Bq m -3 ) radon progeny exposure, which is 50% higher than the ICRP 65 conversion convention for members of the public. Anyhow, smoking, by the almost multiplicative relationship with radon, determines to a considerable extent the lung cancer risk. Although there is a fairly general consensus among health physicists that radon exposure constitutes the largest and most variable contribution to the population exposure from natural sources, they are divided between themselves on the numerical value of the risk estimates and on the need and urgency to incite the population to take action. This relaxed attitude to radon exposure is reflected in the regulatory approach, which is very much in line with the perceived risk by the population. (authors)

  8. Radon exhalation in some building construction materials and effect of plastering and paints on the radon exhalation rate using fired bricks

    International Nuclear Information System (INIS)

    Sharma, Anil; Mahur, A.K.; Rajendra Prasad; Sonkawade, R.G.; Sharma, A.C.

    2013-01-01

    The technological endeavors of human beings have modified the levels of radiation exposure slightly. The emanation of radon is primarily associated with radium and its ultimate precursor uranium. The radiation dose received by human beings from indoor radon and its progeny is the largest of all doses received either by natural or man-made sources. In order to investigate the effect of paints available in the market on the radon exhalation rate from building materials, several bricks were collected. These bricks were plastered with a mixture of cement and sand. Before measurements bricks were dried for 24 hours. These plastered bricks were then coated with white wash and again dried for 1- 2 hours. After drying the bricks were coated with different brands and colors of paints. Radon exhalation rates measurements were carried out for these painted bricks using 'Sealed can Technique' cylindrical plastic 'Can' of 7.5 cm height and 7.0 cm diameter was sealed to the individual samples by plastic can. In each 'Can' a LR-115 type II plastic detector (2 cm 2cm) was fixed at the top inside of the 'Can', such that the sensitive surface of the detector faces the material and is freely exposed to the emergent radon. Radon decays in the volume of the can record the alpha particles resulting from the 218 Po and 214 Po deposited on the inner wall of the 'Can'. Radon and its daughters will reach an equilibrium in concentration after one week or more. Hence the equilibrium activity of the emergent radon can be obtained from the geometry of the can and the time of exposure. The results will be discussed. (author)

  9. Influence of indoor air conditions on radon concentration in a detached house

    International Nuclear Information System (INIS)

    Akbari, Keramatollah; Mahmoudi, Jafar; Ghanbari, Mahdi

    2013-01-01

    Radon is released from soil and building materials and can accumulate in residential buildings. Breathing radon and radon progeny for extended periods hazardous to health and can lead to lung cancer. Indoor air conditions and ventilation systems strongly influence indoor radon concentrations. This paper focuses on effects of air change rate, indoor temperature and relative humidity on indoor radon concentrations in a one family detached house in Stockholm, Sweden. In this study a heat recovery ventilation system unit was used to control the ventilation rate and a continuous radon monitor (CRM) was used to measure radon levels. FLUENT, a computational fluid dynamics (CFD) software package was used to simulate radon entry into the building and air change rate, indoor temperature and relative humidity effects using a numerical approach. The results from analytical solution, measurements and numerical simulations showed that air change rate, indoor temperature and moisture had significant effects on indoor radon concentration. Increasing air change rate reduces radon level and for a specific air change rate (in this work Ach = 0.5) there was a range of temperature and relative humidity that minimized radon levels. In this case study minimum radon levels were obtained at temperatures between 20 and 22 °C and a relative humidity of 50–60%. - Highlights: ► We use CFD to simulate indoor radon concentration and distribution. ► The effects of ventilation rate, temperature and moisture are investigated. ► Model validation is performed through analytical solution and measurement results. ► Results show that ventilation rate is inversely proportional to radon level. ► There is a range of temperature and relative humidity that minimize radon level.

  10. Application of a radon model to explain indoor radon levels in a Swedish house

    CERN Document Server

    Font, L; Jönsson, G; Enge, W; Ghose, R

    1999-01-01

    Radon entry from soil into indoor air and its accumulation indoors depends on several parameters, the values of which normally depend on the specific characteristics of the site. The effect of a specific parameter is often difficult to explain from the result of indoor radon measurements only. The adaptation of the RAGENA (RAdon Generation, ENtry and Accumulation indoors) model to a Swedish house to characterise indoor radon levels and the relative importance of the different radon sources and entry mechanisms is presented. The building is a single-zone house with a naturally-ventilated crawl space in one part and a concrete floor in another part, leading to different radon levels in the two parts of the building. The soil under the house is moraine, which is relatively permeable to radon gas. The house is naturally-ventilated. The mean indoor radon concentration values measured with nuclear track detectors in the crawl-space and concrete parts of the house are respectively 75+-30 and 200+-80 Bq m sup - sup 3...

  11. 210Pb in bone in vivo - a biodosimeter for assessing uranium miner radon progeny exposure

    International Nuclear Information System (INIS)

    Guilmette, R.A.; Snipes, M.B.; Hoover, M.D.; Leggett, R.W.; Laurer, G.R.; Lambert, W.E.; Coons, T.A.; Gilliland, F.D.

    2002-01-01

    A joint analysis of the results of 11 epidemiological studies of lung cancer among uranium miners has shown a significant level of variability in the relative risk per unit of exposure - in the range of a factor of 30 (Lubin et al., 1994). A significant fraction of the uncertainty associated with these risk coefficients may be due to differences in the methods and quality of data used in calculating cumulative exposures, in WLM, for the various miner populations. We hypothesize that in vivo measurement of 210 Pb, a long-lived radon decay product that is retained in bone, will provide an improved measure of Rn progeny exposures received by individual miners during their mining careers. To accomplish such in vivo measurements, the lovelace in vivo bioassay facility (LIVBF) was modified to obtain an optimized counting geometry for measuring 210 Pb in the skull. Six 12.7 cm diameter phoswich detectors were positioned about the head of a reclining subject (one in the posterior, and one in the anterior position, and four about the mid-sagittal plane), and photon emission from the skull was measured using anticoincidence multichannel analysis electronics. We analyzed the in vivo data from about 90 former uranium miners from the grants mining district, and compared the recorded WLM exposures for each uranium miner (data from the UNM epidemiological data base) with a WLM exposure calculated using a model developed specifically for this study. This model couples a Pb biokinetic model with the ICRP publication 66 respiratory tract dosimetry model. The analyses show that the independent measurements of exposure are statistically correlated, but with a large degree of variability occurring among individual values, and that a major source of uncertainty in mining exposure estimation is the uncertainty involved in accounting for non-mining sources of 210 Pb. (orig.)

  12. High-LET alpha-emitters: Radon, lung cancer and smoking

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1988-11-01

    The National Academy of Sciences BEIR IV Report deals with the health effects in human populations exposed to internally-deposited alpha-emitting radionuclides and their decay products. Quantitative risk estimates for cancer induction are derived, mainly from analyses of epidemiological data. The Report addresses the health outcomes of exposure to radon and its daughters, primarily lung cancer risks of worker exposure to radon progeny in underground mines and in the general public in indoor domestic environments. An excess relative risk model of lung cancer mortality and exposure to radon progeny is developed; this models the excess risk per Working Level Month in terms of time intervals prior to an attained age, and is dependent on time-since-exposure and age at risk. Risk projections are presented and cover exposure situations of current public health concern. For example, lifetime exposure to 1 WLM y/sup /minus/1/ is estimated to increase the number of deaths due to lung cancer by a factor of about 1.5 over the current rate for both males and females in a population having the current prevalence of cigarette-smoking. Occupational exposure to 4 WLM y/sup /minus/1/ from ages 20 y to 40 y is projected to increase lung cancer deaths by a factor of 1.6 over the current rate of this age cohort in the general population. In all of these cases, most of the increased risk occurs to smokers for whom the risk is up to ten times greater than for non-smokers. 8 refs., 1 tab

  13. Indoor radon and lung cancer in the radium dial workers

    International Nuclear Information System (INIS)

    Neuberger, J.S.; Rundo, J.

    1996-01-01

    Internally deposited radium has long been known to have tumorigenic effects in the form of sarcomas of the bone and carcinomas of the paranasal sinuses and mastoid air cells. However, the radium dial workers were also exposed to radiation hazards other than that occurring from ingestion of the radium paint, viz., external gamma radiation and elevated concentrations of airborne radon. The uranium miners were also exposed to high concentrations of radon in the 1950s and later, and numerous cases of lung cancer have occurred in that population. However, unlike the atmosphere in the uranium mines, the air in the dial painting plants was probably rather clean and perhaps not much different from the air in many houses. In view of the current concern over the possibility of lung cancer fin the general population being caused by radon (progeny) in houses, it is important to examine the mortality due to this usually fatal disease in the dial workers and to attempt to relate it to their exposure to radon, to the extent that this is possible

  14. Optimization of the Timepix chip to measurement of radon, thoron and their progenies

    Czech Academy of Sciences Publication Activity Database

    Janik, M.; Ploc, Ondřej; Fiederle, M.; Proc, S.; Kavasi, N.

    2016-01-01

    Roč. 107, JAN (2016), s. 220-224 ISSN 0969-8043 Institutional support: RVO:61389005 Keywords : Radon * Thoron * Timepix * calibration Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.128, year: 2016

  15. Reducing radon daughter background in alpha continuous air monitors

    International Nuclear Information System (INIS)

    Rodgers, J.C.; McFarland, A.R.

    1991-01-01

    Alpha continuous air monitors are instruments designed to sample aerosols which may contain alpha-emitting radionuclides and, in near-real time, to monitor the sample for alpha emissions. This process is subject to interference from radon decay products. The usual method for overcoming this interference is by signal processing or data processing in such a manner as to accurately subtract a portion of the background from the transuranic count. An innovative alternative approach has been jointly developed in a collaboration between Los Alamos National Laboratory and Texas A ampersand M University. The concept is to attempt to physically remove a portion of the interfering radon daughters from the incoming sample by a diffusion screen before the sample is collected. The results of laboratory tests indicate that a very high removal efficiency for unattached radon progeny can be obtained without excessive loss of efficiency for collection of the contaminant aerosols of concern. 15 refs., 4 figs., 1 tab

  16. Radon in soil and homes of Osijek

    International Nuclear Information System (INIS)

    Planinic, J.; Vukovic, B.; Faj, Z.; Radolic, V.; Stanic, D.

    2002-01-01

    Radon, 2 22R n, is an inert radioactive gas which arises from decay of 2 26R a and ultimately from 2 38U . These parent elements are ubiquitous in the crust of the earth, although with very various concentrations. It has been recognized that Rn gas can accumulate in homes, sometimes to levels that can exceed occupational standards for mines. Enhanced concentrations of indoor radon and its also-emitting progeny 2 14P o and 2 18P o can increase the risk of pulmonary diseases, that was first observed still among underground miners (ICRP, 1987; Lubin et al., 1990; Gilliland et al., 2000). Because of the uncertainty inherent in extrapolating risks from studies of miners to the general population, epidemiological studies have been undertaken to confirm the presumed harm (carcinogenesis) of indoor radon ( Stidley and Samet, 1993; Cohen, 1995). We undertook so called ecologic and case-control studies for inhabitants of the Osijek town (East Croatia, a hundred thousand citizens) to investigate an association between indoor radon exposure and lung cancer rate; some results showed a positive linear regression for the mentioned variables, although the correlation coefficient was not statistically significant, or statistical samples were not large enough (Planinic et al., 2002; further investigation is going on). A particular problem was to determine indoor radon concentrations with a satisfied precision (that reduces sample size), as well as to find a cause of their variation

  17. The German thoron progeny chamber-Concept and application

    International Nuclear Information System (INIS)

    Roettger, Annette; Honig, Anja; Arnold, Dirk

    2009-01-01

    Following completion of the project 'Generation and characterisation of reference atmospheres of thoron decay products for the calibration of measuring devices for thoron decay products', the Physikalisch-Technische Bundesanstalt (PTB) now operates a thoron progeny chamber in which 220 Rn (thoron), 222 Rn and its progenies can be made available under almost all ambient conditions. This allows all measuring systems to be calibrated under realistic climatic conditions with an accuracy unique worldwide.

  18. Electronic instrument for radon daughter dosimetry. Report of investigations

    International Nuclear Information System (INIS)

    Durkin, J.

    1977-01-01

    Due to the daily exposures of uranium mining personnel to 222Rn daughters, a device is needed which will continually monitor the individual's exposure. Such a device has been built and tested and is known as the Radon Daughter Dosimeter. This is an electronic instrument using a solid-state detector and circuitry. The system permits the evaluation of cumulative exposures to airborne radon progeny, expressed in units of Working Level Hours (WL-HRS). The instrument is a personal device worn by the individual throughout the working shift. Since the instrument is in close proximity to the miner and measures continual exposure, it provides an accurate account of total cumulative exposure, thus avoiding the errors caused by the present technique of spot checking of the environment

  19. A reference aerosol for a radon reference chamber

    Science.gov (United States)

    Paul, Annette; Keyser, Uwe

    1996-02-01

    The measurement of radon and radon progenies and the calibration of their detection systems require the production and measurement of aerosols well-defined in size and concentration. In the German radon reference chamber, because of its unique chemical and physical properties, carnauba wax is used to produce standard aerosols. The aerosol size spectra are measured on-line by an aerosol measurement system in the range of 10 nm to 1 μm aerodynamic diameter. The experimental set-ups for the study of adsorption of radioactive ions on aerosols as function of their size and concentration will be described, the results presented and further adaptations for an aerosol jet introduced (for example, for the measurement of short-lived neutron-rich isotopes). Data on the dependence of aerosol radius, ion concentration and element selectivity is collected by using a 252Cf-sf source. The fission products of this source range widely in elements, isotopes and charges. Adsorption and the transport of radioactive ions on aerosols have therefore been studied for various ions for the first time, simultaneously with the aerosol size on-line spectrometry.

  20. A reference aerosol for a radon reference chamber

    Energy Technology Data Exchange (ETDEWEB)

    Paul, A. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Keyser, U. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    1996-01-11

    The measurement of radon and radon progenies and the calibration of their detection systems require the production and measurement of aerosols well-defined in size and concentration. In the German radon reference chamber, because of its unique chemical and physical properties, carnauba wax is used to produce standard aerosols. The aerosol size spectra are measured on-line by an aerosol measurement system in the range of 10 nm to 1 {mu}m aerodynamic diameter. The experimental set-ups for the study of adsorption of radioactive ions on aerosols as function of their size and concentration are described, the results presented and further adaptations for an aerosol jet introduced (for example, for the measurement of short-lived neutron-rich isotopes). Data on the dependence of aerosol radius, ion concentration and element selectivity is collected by using a {sup 252}Cf-sf source. The fission products of this source range widely in elements, isotopes and charges. Adsorption and the transport of radioactive ions on aerosols have therefore been studied for various ions for the first time, simultaneously with the aerosol size on-line spectrometry. (orig.).

  1. Radon in the Houses of Virovitica and Podravina County

    International Nuclear Information System (INIS)

    Varga Pajtler, M.; Miklavcic, I.; Poje, M.; Radolic, V.; Vukovic, B.; Ivkovic, I.; Jurisic, D.

    2011-01-01

    222Ra is the gaseous radioactive product of the decay of radium isotope 226Ra which is present in soil. Radon atoms that are released from the ground are transported by diffusion and then released in the atmosphere. Radon entries into buildings by advection that is driven by the pressure difference between the building and the ground around the foundation. The aim of this study was to measure radon concentrations in the houses of Virovitica and Podravina county. The measurements were performed by means of two passive track detectors LR-115 (Kodak-Pathe, France), one of which (the open detector) detected total number of alpha-particles of radon and its short-lived progeny, while the other (diffusion detector) registerd tracks only of alpha particles emitted by radon. After being exposed to radiation, the LR-115 detectors were etched in 10 % NaOH aqueous solution at 60 degrees of C for 120 minutes and the detector tracks were counted. Radon concentrations in air were determined according to equation (1), where D 0 was the number of tracks per one day of exposure of the open detector and k is the sensitivity coefficient od the person that counted the tracks. For the track densities D and D 0 of the open and diffusion detectors, respectively, the equilibrium factor was calculated according to equation (2), with the parameters a = 0,50, and b = -0,53. Obtained value for the equilibrium factor was 0,85. Measurements gave radon concentrations in the range of 5.7 - 187.7 Bq m -3 . Average annual effective radon dose for population of Virovitica and Podravina county is 1,5 mSv. (author)

  2. 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

  3. Elevated radon levels in buildings: an investigation of potential sources in Region V arising from energy-conserving practices

    International Nuclear Information System (INIS)

    May, H.A.

    1979-01-01

    Some trends in single dwelling construction, and the resulting possibility of increased radiation exposure from radon progeny to the inhabitants, are identified. The number of such dwellings available and convenient for an ANL study is estimated. Preliminary measurements are reported

  4. Radon in Houses of Vukovar-Srijem County

    International Nuclear Information System (INIS)

    Radolic, V.; Novakovic, L.; Jerkovic, G.; Vukovic, B.

    2008-01-01

    During years 2003 and 2004, a long-term indoor radon measurements in some, randomly selected, homes in Croatia were performed by LR-115 track etch detectors. The number of exposed detectors in each of 20 Croatian counties was set according to population criteria (one detector per 4000 inhabitants) and around 40 measurements were performed in Vukovar-Srijem County. Additional measurements are followed in years 2006-07 and these results rapidly improve the knowledge of spatial distribution of indoor radon concentration in this County. Radon was measured by method with two LR-115 type II nuclear track detectors which enable the estimation of equilibrium factor as well as the assessment of the annual effective dose. The obtained values were in range of 18 to 548 Bq m -3 , with the arithmetic and geometric means of 95 Bq m -3 and 74 Bq m -3 , respectively. The municipality with lowest average radon level of 51 Bq m -3 is city of Vukovar while Andrijasevci has the highest average radon concentration of 269 Bq m -3 . The average estimated equilibrium factor in Vukovar-Srijem County is 0.512; the relative error of the estimation is 14.8 percent. The statistical χ 2 -test, applied on the empirical and theoretical frequencies, show that the empirical frequency distribution for the radon in houses of Vukovar-Srijem County belonged to the log-normal distribution (calculated parameter, χ 2 = 7.39, was lower than the theoretical one, χ 2 0.05 = 9.49, for 4 degrees of freedom and significance level of 0.05). The percentage of houses with radon concentrations above 200 or 400 Bq/m 3 was 8.7 percent and 1.4 percent, respectively. The assessment of the annual effective dose from the indoor radon and its short-lived progenies for the inhabitants of Vukovar-Srijem County (for the average equilibrium factor of 0.512 and occupancy factor of 0.6) gave the average effective dose of 2.4 mSv/y.(author)

  5. 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

  6. Evaluation of radon progeny from Mount St. Helens eruptions. Final report

    International Nuclear Information System (INIS)

    Lepel, E.A.; Olsen, K.B.; Thomas, V.W.; Eichner, F.N.

    1982-09-01

    A network of twelve monitoring sites around Mount St. Helens was established to evaluate possible short-lived radioactivity in the fallen ash. Seven sites were located near major population centers of Washington and Oregon, and five sites were located within 80 km of the volcano. Each site monitored the radioactivity present by the use of thermoluminescent dosimeters which recorded the total exposure to radioactivity over the exposure period. Eruptions occurring on July 22, August 7, and October 16 to 18, 1980 were monitored. No statistically significant quantities of measurable radon daughters were observed

  7. AlphaGUARD, the new reference for continuous radon monitoring in air, soil, gas, water and material

    International Nuclear Information System (INIS)

    Roessler, F.; Buerkin, W.; Villert, J.

    2016-01-01

    The company Saphymo GmbH has more than 25 years of experience in the field of radon measurement. More than 20 years ago Saphymo developed the professional and robust radon monitor AlphaGUARD, quickly recognized as a standard for reliable and continuous measurements of the radon concentration. Today AlphaGUARD is internationally established as the reference in radon measurement. Following up on this success story the new generation of AlphaGUARD can now be presented. Based on the excellent measurement characteristics of its predecessor the new AlphaGUARD combines the well-proven principle of the pulse ionisation chamber with new and additional features. The robust housing is oriented on the well-proven design of the predecessor and includes now an integrated flow controlled and powerful pump. The instrument can be operated in flow as well as in diffusion mode (without pump). Via the new large display and the intuitive menu navigation all measurement data can be retrieved. The presentation of time series in charts is possible as well as the parametrisation of the instrument. A wide range of accessories, developed in cooperation with various radon experts of universities and laboratories, enables the user a varied and flexible application of the AlphaGUARD: Measurement of the radon concentration in air (radon, thoron, radon progenies), in water (sampling and time resolved measurements) and in soil (soil gas measurements, exhalation measurements), emanation measurements from material, multi spot measurement, online measurement with remote data transmission via Ethernet/DSL, Bluetooth, Wi-Fi, GPRS/3G or satellite. Due to its high sensitivity and its fast and linear response over a large measuring range the AlphaGUARD is excellently suited for calibration laboratories. Furthermore the AlphaGUARD enables ideal prerequisites for field applications: robust housing for operations under harsh conditions, long battery life for the measurement at any location, low

  8. Sex and smoking sensitive model of radon induced lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zhukovsky, M.; Yarmoshenko, I. [Institute of Industrial Ecology of Ural Branch of Russian Academy of Sciences, Yekaterinburg (Russian Federation)

    2006-07-01

    Radon and radon progeny inhalation exposure are recognized to cause lung cancer. Only strong evidence of radon exposure health effects was results of epidemiological studies among underground miners. Any single epidemiological study among population failed to find reliable lung cancer risk due to indoor radon exposure. Indoor radon induced lung cancer risk models were developed exclusively basing on extrapolation of miners data. Meta analyses of indoor radon and lung cancer case control studies allowed only little improvements in approaches to radon induced lung cancer risk projections. Valuable data on characteristics of indoor radon health effects could be obtained after systematic analysis of pooled data from single residential radon studies. Two such analyses are recently published. Available new and previous data of epidemiological studies of workers and general population exposed to radon and other sources of ionizing radiation allow filling gaps in knowledge of lung cancer association with indoor radon exposure. The model of lung cancer induced by indoor radon exposure is suggested. The key point of this model is the assumption that excess relative risk depends on both sex and smoking habits of individual. This assumption based on data on occupational exposure by radon and plutonium and also on the data on external radiation exposure in Hiroshima and Nagasaki and the data on external exposure in Mayak nuclear facility. For non-corrected data of pooled European and North American studies the increased sensitivity of females to radon exposure is observed. The mean value of ks for non-corrected data obtained from independent source is in very good agreement with the L.S.S. study and Mayak plutonium workers data. Analysis of corrected data of pooled studies showed little influence of sex on E.R.R. value. The most probable cause of such effect is the change of men/women and smokers/nonsmokers ratios in corrected data sets in North American study. More correct

  9. Sex and smoking sensitive model of radon induced lung cancer

    International Nuclear Information System (INIS)

    Zhukovsky, M.; Yarmoshenko, I.

    2006-01-01

    Radon and radon progeny inhalation exposure are recognized to cause lung cancer. Only strong evidence of radon exposure health effects was results of epidemiological studies among underground miners. Any single epidemiological study among population failed to find reliable lung cancer risk due to indoor radon exposure. Indoor radon induced lung cancer risk models were developed exclusively basing on extrapolation of miners data. Meta analyses of indoor radon and lung cancer case control studies allowed only little improvements in approaches to radon induced lung cancer risk projections. Valuable data on characteristics of indoor radon health effects could be obtained after systematic analysis of pooled data from single residential radon studies. Two such analyses are recently published. Available new and previous data of epidemiological studies of workers and general population exposed to radon and other sources of ionizing radiation allow filling gaps in knowledge of lung cancer association with indoor radon exposure. The model of lung cancer induced by indoor radon exposure is suggested. The key point of this model is the assumption that excess relative risk depends on both sex and smoking habits of individual. This assumption based on data on occupational exposure by radon and plutonium and also on the data on external radiation exposure in Hiroshima and Nagasaki and the data on external exposure in Mayak nuclear facility. For non-corrected data of pooled European and North American studies the increased sensitivity of females to radon exposure is observed. The mean value of ks for non-corrected data obtained from independent source is in very good agreement with the L.S.S. study and Mayak plutonium workers data. Analysis of corrected data of pooled studies showed little influence of sex on E.R.R. value. The most probable cause of such effect is the change of men/women and smokers/nonsmokers ratios in corrected data sets in North American study. More correct

  10. Radon survey techniques

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The report reviews radon measurement surveys in soils and in water. Special applications, and advantages and limitations of the radon measurement techniques are considered. The working group also gives some directions for further research in this field

  11. Radon - from knowledge to action: an all-around cleared issue of radiation protection?

    Energy Technology Data Exchange (ETDEWEB)

    Maringer, F.J. [Vienna Univ. of Natural Resources and Applied Life Science, BEV - Federal Office of Metrology and Surveying (Austria); Vienna Univ. of Technology, Low-Level Counting Laboratory Arsenal, Wien (Austria)

    2006-07-01

    The knowledge about radon is well established in the radiation protection world. After many decades of research work done worldwide by many radiation protection scientists and research teams, the sources and origin, the transport through the soil and into the buildings, and the radiobiological effects of radon progenies in the human respiratory tract are well known. When typing 'radon' in web search engines e.g. www.google.at about 5.1 Million hits are appearing. A countless number of papers have been published in the field of radon research and the ICRP has established radiation protection principles for radon exposure at home and at workplaces. So far, the radon issue seemed well ticked off in the scientific world of radiation protection and the scientists could give more attention to other and more newsworthy problems and questions. But this is only half the truth. The implementation of radon mitigation and precaution standards needs continuously scientific attendance and research networking on an international level. Otherwise the radon issue could degrade easily to a simplified technical and economical exercise without sustainable results in public health. In this paper the radon investigations in Austria which have been carried out in the last 20 years and the applied methods and derived standards for mitigation and precaution in the home and workplace sectors are given. The future strategy and scientific and social necessities in the radon issue are outlined comprehensively. The agreed and proposed research objectives and cooperation which seems necessary are discussed in consideration of the medium-term European radiation protection context. (authors)

  12. Radon - from knowledge to action: an all-around cleared issue of radiation protection?

    International Nuclear Information System (INIS)

    Maringer, F.J.

    2006-01-01

    The knowledge about radon is well established in the radiation protection world. After many decades of research work done worldwide by many radiation protection scientists and research teams, the sources and origin, the transport through the soil and into the buildings, and the radiobiological effects of radon progenies in the human respiratory tract are well known. When typing 'radon' in web search engines e.g. www.google.at about 5.1 Million hits are appearing. A countless number of papers have been published in the field of radon research and the ICRP has established radiation protection principles for radon exposure at home and at workplaces. So far, the radon issue seemed well ticked off in the scientific world of radiation protection and the scientists could give more attention to other and more newsworthy problems and questions. But this is only half the truth. The implementation of radon mitigation and precaution standards needs continuously scientific attendance and research networking on an international level. Otherwise the radon issue could degrade easily to a simplified technical and economical exercise without sustainable results in public health. In this paper the radon investigations in Austria which have been carried out in the last 20 years and the applied methods and derived standards for mitigation and precaution in the home and workplace sectors are given. The future strategy and scientific and social necessities in the radon issue are outlined comprehensively. The agreed and proposed research objectives and cooperation which seems necessary are discussed in consideration of the medium-term European radiation protection context. (authors)

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  14. Extended application of radon as a natural tracer in oil reservoirs

    Directory of Open Access Journals (Sweden)

    Moreira R.M.

    2013-05-01

    Full Text Available In the 80's it was a common practice in the study of contamination by NAPL to incorporate a tracer to the medium to be studied. At that time the first applications focused on the use of 222Rn, a naturally occurring radioactive isotope as a natural tracer, appropriate for thermodynamics studies, geology and transport properties in thermal reservoirs. In 1993 the deficit of radon was used to spot and quantify the contamination by DNAPL under the surface. For the first time these studies showed that radon could be used as a partitioning tracer. A methodology that provides alternatives to quantify the oil volume stored in the porous space of oil reservoirs is under development at CDTN. The methodology here applied, widens up and adapts the knowledge acquired from the use of radon as a tracer to the studies aimed at assessing SOR. It is a postulation of this work that once the radon partition coefficient between oil and water is known, SOR will be determined considering the increased amount of radon in the water phase as compared to the amount initially existent as the reservoir is flooded with water. This paper will present a description of the apparatus used and some preliminary results of the experiments.

  15. Indigenous development and networking of online radon monitors in the underground uranium mine

    International Nuclear Information System (INIS)

    Gaware, J.J.; Sahoo, B.K.; Sapra, B.K.; Mayya, Y.S.

    2011-01-01

    There has been a long standing demand for online monitoring of radon level in various locations of underground Uranium mine for taking care of radiological protection to workers. Nowadays, radon ( 222 Rn) monitors, based on electrostatic collection of charged progeny and subsequent detection by semiconductor detector are increasingly employed for radon monitoring in environment. However, such instruments have some limitations such as (i) requirement of additional dryer since sensitivity is dependent on the humidity (ii) cannot be connected to a network and (iii) not cost effective etc. Hence use of such instruments in underground uranium mine (humidity level >90), may not be reliable. Towards this end, we have indigenously developed radon monitor based on electrostatic collection and scintillation technology for the online monitoring in uranium mine. This instrument overcomes the above mentioned limitation of commercial radon monitors and based on custom made features. Different tests and measurements were carried out and compared with commercial instruments. It was found to be in an excellent agreement with the commercial instruments. A few such instruments have been installed in different locations of uranium mine at Turamdih and connected to a network system for online monitoring and display. (author)

  16. Exposure to Radon in Dwellings in the Area of Zagreb

    International Nuclear Information System (INIS)

    Lokobauer, N.; Franic, Z.; Petroci, Lj.; Sokolovic, E.; Lokner, V.

    1998-01-01

    Until the 1970s radon and its progeny were regarded as radiation health hazards encountered only in the mining and processing of uranium ore. This notion has dramatically changed as a result of increasing efforts made by many countries to measure radon in dwellings. Since it has been assessed that radon constitutes on average about 53% of the human exposure to natural radiation (UNSCEAR 1993), attention to the problem of exposure to radon and associated health risk has been growing in both developed and developing countries. This paper deals with the investigations of indoor radon activity concentrations at selected dwellings in the area of Zagreb. The fact that concentration of indoor radon depends strongly on radium sources in the soil pointed to the possibility that increased radon levels could be measured in the ground floor dwellings. The measurements of indoor radon performed by Honeywell professional radon monitor in the 30 ground floor dwellings, and at same location in 10 dwellings on higher floors. In order to obtain average daily values, radon activity concentrations were measured throughout 24 hours at each dwelling, over the seasons spring-summer and autumn-winter. In the season spring-summer radon activity concentrations in the ground floor dwellings ranged from 22±5 to 133±12 Bqm -3 (mean value 56±31 Bqm -3 ) and in the season autumn-winter ranged from 22±5 to 311±18 Bqm -3 (mean value 94±64 Bqm -3 ). In the dwellings on higher floors radon activity concentrations in the season spring-summer ranged from 11±3 to 78±9 Bqm -3 (mean value 32±21 Bqm -3 ), and in the season autumn-winter ranged from 30±5 to 137±12 Bqm -3 (mean value 60±32 Bqm -3 ). Average annual radon activity concentration for the 30 investigated ground floor dwellings were 75±45 Bqm -3 , and 46±26 Bqm -3 for the 10 dwellings on higher floors. Investigations performed in the dwellings in the area of Zagreb revealed significant differences in radon levels between the ground

  17. Radon exhalation rates corrected for leakage and back diffusion – Evaluation of radon chambers and radon sources with application to ceramic tile

    Directory of Open Access Journals (Sweden)

    M. Abo-Elmagd

    2014-10-01

    Full Text Available The natural radon decay, leakage and back diffusion are the main removal processes of radon from its container. Ignoring these processes leads to underestimate the measured value of radon related parameters like exhalation rate and radium content. This work is aimed to evaluate two different radon chambers through determining their leakage rate λv and evaluation of radon source by determine its back diffusion rate λb inside the evaluated radon chambers as well as a small sealed cup. Two different methods are adapted for measuring both the leakage rate and the back diffusion rate. The leakage rate can be determined from the initial slope of the radon decay curve or from the exponential fitting of the whole decay curve. This can be achieved if a continuous monitoring of radon concentration inside the chamber is available. Also, the back diffusion rate is measured by sealing the radon source in the chamber and used the initial slope of the buildup curve to determine λb and therefore the exhalation rate of the source. This method was compared with simple equation for λb based on the ratio of the source to the chamber volume. The obtained results are applied to ceramic tile as an important radon source in homes. The measurement is targeted the ceramic glaze before and after firing as well as the obtained tile after adhere the glaze on the tile main body. Also, six different tile brands from Egyptian market are subjected to the study for comparison.

  18. Remedial measures in Swedish and Norwegian houses - application of radon and radon decay product measurements

    International Nuclear Information System (INIS)

    Just, G.; Philipsborn, H. von; Matolin, M.; Molzahn, D.

    1998-01-01

    Houses and apartments in Sweden and Norway with excessive indoor radon concentrations were studied in detail with a variety of methods, standard and novel ones recently developed. For suitable remediation it is necessary to distinguish soil radon and exhalation from blue (porous) concrete. Our CARBOTEST-S is a simple, sensitive, in-situ method to quantify radon exhalation from existing walls, as well as radon permeability of different protective foils and final quality control of foils applied to existing walls. (orig.) [de

  19. In-vivo measurements of Pb-210 to determine cumulative exposure to radon daughters: A pilot study

    International Nuclear Information System (INIS)

    Laurer, G.R.; Cohen, N.; Stark, A.; Ju, C.

    1991-05-01

    The objective of this study is to demonstrate the feasibility of estimating cumulative exposure of individuals to low concentrations of radon by measuring the amount of Pb-A-10 in their skeletons. This report presents progress to date establishing the validity of an vivo technique to measure skeletal burdens of Pb-210, accumulated from exposure to radon and radon progeny. With the skeletal content of Pb--210 and a model for Pb metabolism, cumulative exposure to radon and its short-lived daughters (radon/daughters) may be calculated for use in deriving a dose-response relationship between lung cancer and exposure to radon/daughters. Data are presented for 29 subjects exposed to ''above-average'' radon concentrations in their homes, showing the correlation between measured Pb--210 burdens, and measured pCi/l and WLM exposure estimates. Their results are compared to measurements of a population of 24 subject's presumed exposed to average concentrations. Measurements of a Pennsylvania family exposed for a year in a home with an extremely high radon content are also presented. Update of results of an ongoing study of the biological half-time of Pb--210 in man involving measurements, of a retired radiation worker with a 40 year old skeletal burden of Pb-210

  20. Radiation Protection for Radon in Dwellings - Consequences of the ICRP Publication 115

    International Nuclear Information System (INIS)

    Azzam, Jai T.; Breckow, J.; Grimm, V.; Grund, A.

    2013-01-01

    In the last decade several epidemiological studies on risk estimations due to exposure to radon in dwellings revealed higher risks to radon exposure than estimated previously. Thus, in ICRP Publication 115 (ICRP, 2011) a revised nominal probability coefficient for radon and its progeny-induced lung cancer was propounded. Based on the results of the exposure from residential studies and underground miners, the risk of lung cancer was estimated as 5x10 -4 per WLM (lifetime excess absolute risk, LEAR) and 8x10 -1 0 per Bqxh/m 3 , respectively. In the former Publication 65 (ICRP, 1993), the coefficient has been 2.83x10 -4 per WLM and 4x10 -1 0 per Bqxh/m 3 , respectively. Typical radon activity concentration in dwellings is about 60 Bq/m? in many parts of Europe. According to the ICRP Publication 65-dose coefficients, this concentration leads to a mean annual effective dose of 1.2 mSv. If the new nominal risk coefficient from ICRP Publication 115 is applied, the effective dose due to radon in dwellings increases to approximately 2.3 mSv per year. Referring the reference level of 10 mSv/a for radon exposure in dwellings in ICRP Publication 103 (ICRP, 2007) and based on the new recommendations in ICRP Publication 115, actions have to be taken to reduce the upper reference level for radon gas in dwellings from 600 Bq/m 3 to 300 Bq/m 3 .(author)

  1. Radon as a geophysical tracer on Mars: study of its transport, first evidence and development of an instrument for its measurement

    International Nuclear Information System (INIS)

    Meslin, Pierre-Yves

    2008-01-01

    Radon-222, an inert and radioactive gas stemming from the uranium decay series, and its progeny are often used as tracers to study transfers in soils and in the atmosphere. They have also been studied on the surface of the Moon in connection with lunar outgassing. On Mars, where radon has never been studied nor measured so far, we show that their measurement could provide new insight and constraints on the chemical nature of the hydrogen measured in the Martian soil, in surface-atmosphere exchange processes, in atmospheric transport and, finally, in the dust cycle. Our approach is based on a coupled soil-atmosphere transport model implemented into the Global Circulation Model LMDZ. It includes the source term, the diffusion and adsorption of radon within the soil, and its atmospheric transport. The model input parameters are derived either experimentally (emanation factor and adsorption coefficient extrapolated to low temperatures) or by realistic models of porous media (diffusion coefficient at low pressure and as a function of the water saturation level). The model yields predictive maps of the radon exhalation rate as well as 3D fields of concentration in the soil and atmosphere, which will allow direct comparison with bismuth-214 measurements made by the GRS onboard the Mars Odyssey orbiter. We present preliminary results on this subject. An analysis of alpha spectra acquired by the APXS of the rover Opportunity is also presented, which shows evidence of a polonium-210 deposit on atmospheric dust, providing the first indirect proof of the presence of radon in the Martian atmosphere. We propose a simplified dust cycle model that enables us to infer an estimate of the global average radon exhalation rate on Mars. Lastly, we simulate the performance of an alpha spectrometer aimed at measuring radon and its progeny on the surface of the planet. (author)

  2. Concentrations Of Radon In Kindergartens And Schools In Like - Sen And Karlovac Counties

    International Nuclear Information System (INIS)

    Radolic, V.; Stanic, D.; Miklavcic, I.; Poje, M.; Muzevic, M.; Krpan, I.; Vukovic, B.

    2015-01-01

    Measurements of radon concentrations in schools and kindergartens were performed by means of passive, strippable, nuclear track etched detectors LR - 115 type II (Kodak - Pathe, France). The detectors are paired in the way that one detector (open detector), placed on the circumferential side of the plastic detector vessel, registers total number of alpha particles from radon and its short-lived progenies. At the same time, the other detector (diffusion detector) is placed inside the vessel and it registers only alpha particles emitted by radon. The average radon concentrations in kindergartens and schools of Lika-Senj County are 318 and 317 Bq m -3 while for Karlovac County they are 228 and 304 Bq m -3 respectively. Moreover, there are three schools in Karlovac County with the average radon concentration higher than 1000 Bq m -3 , which represents the action level for intervention measures in Croatia. Even more, there are 2.5 percent of rooms in kindergartens and 4 percent of rooms in schools in Lika - Senj County with measured radon concentrations higher than 1000 Bq m -3 . In Karlovac County there are 2.4 percent of such rooms in kindergartens and 7 percent in schools. Maps of spatial distribution of indoor radon concentrations for homes as well as for kindergartens and schools were created by using the Inverse Distance Weighting interpolation method. This is one of the useful methods for identifying radon prone areas. The authors propose a repetition of measurements in those kindergartens, schools and homes with higher radon concentrations in coordination with the local government. (author).

  3. Effective dose to radon considering people's activities

    International Nuclear Information System (INIS)

    Shimo, M.; Seki, K.; Kikuchi, I.

    1992-01-01

    The tidal volume was estimated for evaluating the effective dose due to radon concentration in the atmosphere. In this study regional population was separated to vocation and non-vocation. The occupancy time and the breathing rate for both vocation and non-vocation groups were estimated, and the annual tidal volume for both groups were calculated. Human actions were separated to 18 activities in the process for estimating the breathing rate. It was clear that the breathing rate depended on human activity and that the human activity changed with its age, so the breathing rate varied with age. Finally the effective doses due to radon and radon progeny indoors and outdoors were evaluated. The maximum annual effective dose was estimated to be 1.2 mSv, minimum 0.2 mSv, and mean 0.51 mSv for vocation. For non-vocation, the male maximum value 0.43 mSv was obtained at the 16 age and the minimum 0.12 mSv at the 70 age, whereas female maximum 0.26 mSv was obtained at the 12 age and the minimum 0.11 mSv at the 70 age. In addition in this study objective areas are Aichi, Gifu, and Mie prefectures for vocation and only Aichi prefecture for non-vocation. (author)

  4. Passive and active measurements of radon-related parameters inside ancient Egyptian tombs in Luxor

    Energy Technology Data Exchange (ETDEWEB)

    Abo-Elmagd, M [Radiation Measurements Department, National Institute for Standard, Giza (Egypt); Metwally, S M [Faculty of Science, Department of Physics, Ain Shams University, Cairo (Egypt); El-Fiki, S A [Faculty of Science, Department of Physics, Ain Shams University, Cairo (Egypt); Eissa, H M [Radiation Measurements Department, National Institute for Standard, Giza (Egypt); Salama, E [Faculty of Science, Department of Physics, Ain Shams University, Cairo (Egypt)

    2007-01-15

    Radon and its related parameters were measured using passive (CR-39) and active (Alpha-Guard analyzer) techniques inside seven ancient Egyptian tombs of the Valley of the Kings in Luxor. The measurements were performed throughout the winter and summer seasons. The average radon concentration inside the tombs ranges from 96.9+/-10.8 to 415+/-43Bqm{sup -3} in winter and from 86.4+/-13.8 to 6102.8+/-573.6 in summer. Because of the variations of tombs dimensions and their ventilation systems, the equilibrium factor between radon and its progeny ranges from 0.228+/-0.02 to 0.95+/-0.05. The effective doses for the tomb workers, the tour guide and visitors were calculated. Active measurements show that radon exhalation rates range from 0.68+/-0.30 to 1.47+/-0.27Bqm{sup -2}h{sup -1} and from 0.60+/-0.03 to 1.42+/-0.05Bqm{sup -2}h{sup -1} for passive measurements. The real radium content was determined for all examined tombs by HPGe detector, while the effective radium content was obtained by Alpha-Guard and sealed cup techniques. Radon exhalation rates were correlated with the real radium content. A good correlation was found between active and passive measurements of radon exhalation rate.

  5. Passive and active measurements of radon-related parameters inside ancient Egyptian tombs in Luxor

    International Nuclear Information System (INIS)

    Abo-Elmagd, M.; Metwally, S.M.; El-Fiki, S.A.; Eissa, H.M.; Salama, E.

    2007-01-01

    Radon and its related parameters were measured using passive (CR-39) and active (Alpha-Guard analyzer) techniques inside seven ancient Egyptian tombs of the Valley of the Kings in Luxor. The measurements were performed throughout the winter and summer seasons. The average radon concentration inside the tombs ranges from 96.9+/-10.8 to 415+/-43Bqm -3 in winter and from 86.4+/-13.8 to 6102.8+/-573.6 in summer. Because of the variations of tombs dimensions and their ventilation systems, the equilibrium factor between radon and its progeny ranges from 0.228+/-0.02 to 0.95+/-0.05. The effective doses for the tomb workers, the tour guide and visitors were calculated. Active measurements show that radon exhalation rates range from 0.68+/-0.30 to 1.47+/-0.27Bqm -2 h -1 and from 0.60+/-0.03 to 1.42+/-0.05Bqm -2 h -1 for passive measurements. The real radium content was determined for all examined tombs by HPGe detector, while the effective radium content was obtained by Alpha-Guard and sealed cup techniques. Radon exhalation rates were correlated with the real radium content. A good correlation was found between active and passive measurements of radon exhalation rate

  6. Radon emanation fractions from concretes containing fly ash and metakaolin.

    Science.gov (United States)

    Taylor-Lange, Sarah C; Juenger, Maria C G; Siegel, Jeffrey A

    2014-01-01

    Radon ((222)Rn) and progenies emanate from soil and building components and can create an indoor air quality hazard. In this study, nine concrete constituents, including the supplementary cementitious materials (SCMs) fly ash and metakaolin, were used to create eleven different concrete mixtures. We investigated the effect of constituent radium specific activity, radon effective activity and emanation fraction on the concrete emanation fraction and the radon exhalation rate. Given the serious health effects associated with radionuclide exposure, experimental results were coupled with Monte Carlo simulations to demonstrate predictive differences in the indoor radon concentration due to concrete mixture design. The results from this study show that, on average, fly ash constituents possessed radium specific activities ranging from 100 Bq/kg to 200 Bq/kg and emanation fractions ranging from 1.1% to 2.5%. The lowest emitting concrete mixture containing fly ash resulted in a 3.4% reduction in the concrete emanation fraction, owing to the relatively low emanation that exists when fly ash is part of concrete. On average, the metakaolin constituents contained radium specific activities ranging from 67 Bq/kg to 600 Bq/kg and emanation fractions ranging from 8.4% to 15.5%, and changed the total concrete emanation fraction by roughly ±5% relative to control samples. The results from this study suggest that SCMs can reduce indoor radon exposure from concrete, contingent upon SCM radionucleotide content and emanation fraction. Lastly, the experimental results provide SCM-specific concrete emanation fractions for indoor radon exposure modeling. © 2013.

  7. Long-term Radon Levels and Equilibrium Factor in Some Spanish Workplaces Measured with a Passive Integrating Detector

    International Nuclear Information System (INIS)

    Baixeras, C.; Amgarou, K.; Font, Ll.; Domingo, C.

    1999-01-01

    The measurement of long-term radon levels and equilibrium factor is important to estimate the annual averaged dose due to radon progeny inhalation indoors. According to the European Union directive 96/26/EURATOM it is necessary to control the radon level in workplaces. This paper presents the radon concentration and equilibrium factor values obtained in some workplaces from the Barcelona area with a passive integrating dosemeter exposed for two months. The dosemeter consists of two Makrofol-DE nuclear etched track foils, one within a diffusion chamber and the other one bare, allowing the separated measurement of 222 Rn (C 0 ) and 214 Po (C 4 ) activity concentration respectively. The equilibrium factor is estimated from the disequilibrium degree (k 4 = C 4 /C 0 ). A description of the dosemeter and the methodology used, and an estimation of the annual dose received for the workers at the different workplaces are presented. (author)

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

    Science.gov (United States)

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

    2016-01-01

    Because (222)Rn is a progeny of (238)U, the relative abundance of uranium may be used to predict the areas that have the potential for high indoor radon concentration and therefore determine the best areas to conduct future surveys. Geographic Information System (GIS) mapping software was used to construct maps of South Dakota that included levels of uranium concentrations in soil and stream water and uranium deposits. Maps of existing populations and the types of land were also generated. Existing data about average indoor radon levels by county taken from a databank were included for consideration. Although the soil and stream data and existing recorded average indoor radon levels were sparse, it was determined that the most likely locations of elevated indoor radon would be in the northwest and southwest corners of the state. Indoor radon levels were only available for 9 out of 66 counties in South Dakota. This sparcity of data precluded a study of correlation of radon to geological features, but further motivates the need for more testing in the state. Only actual measurements should be used to determine levels of indoor radon because of the strong roles home construction and localized geology play in radon concentration. However, the data visualization method demonstrated here is potentially useful for directing resources relating to radon screening campaigns. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  9. Radon exposure in uranium mining industry vs. exposure in tourist caves

    International Nuclear Information System (INIS)

    Quindos Poncela, L.; Fernandez Navarro, P.; Sainz Fernandez, C.; Gomez Arozamena, J.; Bordonoba Perez, M.

    2004-01-01

    There is a fairly general consensus among health physicists and radiation professionals that exposure to radon progeny is the largest and most variable contribution to the population's exposure to natural sources of radiation. However, this exposure is the subject of continuing debate concerning the validity of risk assessment and recommendations on how to act in radon-prone areas. The purpose of this contribution is to situate the radon issue in Spain in two very different settings. The first is a uranium mining industry located in Saelices el Chico (Salamanca), which is under strict control of the Spanish Nuclear Safety Council (CSN). We have measured radon concentrations in different workplaces in this mine over a five-year period. The second setting comprises four tourist caves, three of which are located in the province of Cantabria and the fourth on the Canary Island of Lanzarote. These caves are not subject to any administrative control of radiation exposure. Measured air 222 Rn concentrations were used to estimate annual effective doses due to radon inhalation in the two settings, and dose values were found to be from 2 to 10 times lower in the uranium mine than in the tourist caves. These results were analysed in the context of the new European Basic Safety Standards Directive (EU-BSS, 1996). (authors)

  10. Radon concentration measurements for determination of radiation dose and assessment of cancer risk in the premises of some colleges in Lahore, Pakistan

    International Nuclear Information System (INIS)

    Mahmood, A.; Tufail, M.; Iqbal, M.A.

    2010-01-01

    Radon concentration has been measured in campus and hostel buildings of some colleges in the city of Lahore. The technique of passive radon measurements was employed using CN-85 etched track detectors in the box type dosimeters. The observed radon concentration in different parts of monitored buildings was within the range 18-61 Bq m/sup -3/. The cause of radon in college buildings may be the construction materials, drinking water, natural gas, drainage, sewerage pipes, etc. Moving fans, open doors and windows in summer season diluted the radon concentration, while the air tight arrangement in the winter enhanced the radon concentration level. Alpha dose from radon to the students and supporting staff was estimated as 0.34 and 0.91 mSv y/sup -1/ in campus and hostel buildings respectively. The corresponding excess lifetime cancer risk attributed to the students and staff in the college campuses was found to be 0.20 %, while the staff and students residing in the hostels of the colleges received the excess lifetime risk of cancer 0.53 % due to radon progenies. (author)

  11. Attenuated radon transform: theory and application in medicine and biology

    Energy Technology Data Exchange (ETDEWEB)

    Gullberg, G.T.

    1979-06-01

    A detailed analysis is given of the properties of the attenuated Radon transform and of how increases in photon attenuation influence the numerical accuracy and computation efficiency of iterative and convolution algorithms used to determine its inversion. The practical applications for this work involve quantitative assessment of the distribution of injected radiopharmaceuticals and radionuclides in man and animals for basic physiological and biochemical studies as well as clinical studies in nuclear medicine. A mathematical structure is developed using function theory and the theory of linear operators on Hilbert spaces which lends itself to better understanding the spectral properties of the attenuated Radon transform. The continuous attenuated Radon transform reduces to a matrix operator for discrete angular and lateral sampling, and the reconstruction problem reduces to a system of linear equations. For the situation of variable attenuation coefficient frequently found in nuclear medicine applications of imaging the heart and chest, the procedure developed in this thesis involves iterative techniques of performing the generalized inverse. For constant attenuation coefficient less than 0.15 cm/sup -1/, convolution methods can reliably reconstruct a 30 cm object with 0.5 cm resolution. However, for high attenuation coefficients or for the situation where there is variable attenuation such as reconstruction of distribution of isotopes in the heart, iterative techniques developed in this thesis give the best results. (ERB)

  12. 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

  13. Mitigation of radon and thoron decay products by filtration

    International Nuclear Information System (INIS)

    Wang Jin; Meisenberg, Oliver; Chen Yongheng; Karg, Erwin; Tschiersch, Jochen

    2011-01-01

    thoron decay product concentrations. - Highlights: → Indoor radon and thoron decay products are important sources of radiation exposure. → Diminishing ventilation rates in new buildings suggest active mitigation techniques. → Filtration decreases significantly the total effective thoron inhalation dose. → However, the overall effect of filtration on radon dose is small. → Permanent filtration is recommended because of the slow decrease of thoron progeny.

  14. QA Programme for Radon and its Short-Lived Progeny Measuring Instruments in NRPI Prague

    Czech Academy of Sciences Publication Activity Database

    Jílek, K.; Thomas, J.; Brabec, Marek

    2008-01-01

    Roč. 130, č. 1 (2008), s. 43-47 ISSN 0144-8420 Grant - others:GA SÚJB(CZ) JC_11/2006 Institutional research plan: CEZ:AV0Z10300504 Keywords : calibration * quality assurance * radon daughter products * uncertainty estimation Subject RIV: DI - Air Pollution ; Quality Impact factor: 0.951, year: 2008

  15. Radon detectors for continuous environmental monitoring applications

    International Nuclear Information System (INIS)

    Sisoutham, O.; Werczynski, S.; Chambers, S.; Zahorowski, W.

    2003-01-01

    The two-filter method is presently the best technique available for real-time low-level counting of atmospheric 222 Rn. The Australian Nuclear Science and Technology Organisation has developed and deployed a range of dual flow loop, two-filter radon detectors around the world for various applications. The detectors have a response time of 45 minutes, and can be custom built for specific purposes. The largest detectors have a lower limit of detection of ∼10 mBq m -3

  16. Application of solid state nuclear track detectors in radiation protection

    International Nuclear Information System (INIS)

    Ramachandran, T.V.; Subba Ramu, M.C.; Mishra, U.C.

    1989-01-01

    This article reviews the current status of the application of nuclear track detectors with emphasis on recent developments in the field of radiation protection. Track etch detectors have been used for the measurements of low level radiation in the environment, fast neutron and radon daughter inhalation dose. Recent developments in the field of dosimetry seem to be promising. In fast neutron dosimetry, track etch detectors can be used without inclusion of fissile materials by using the electrochemical etching technique. These detectors can provide important information in the energy range upto 250 keV. Survey of this range of energy with TLD is difficult because they are extremely energy dependent and over-respond to low energy neutrons. Measurement of radon using track detectors can help to lower the cost of the radon dosimeters. Certain detectors are sensitive to alpha particles from radon and their progeny. Higher sensitivity permits their use in a passive type of personnel dosimeter, which does not require the troublesome aspects of air sampling for the collection of radon daughter samples. (author), 38 refs., 8 tabs., 12 figs

  17. Inversion of the Jacobi-Porstendörfer Room Model for the Radon Progeny

    Czech Academy of Sciences Publication Activity Database

    Thomas, J.; Jílek, K.; Brabec, Marek

    2010-01-01

    Roč. 55, č. 4 (2010), s. 433-437 ISSN 0029-5922 Institutional research plan: CEZ:AV0Z10300504 Keywords : Jacobi room model * inversion and invariants of the model * unattached radon daughters * attachment rate * deposition rate Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.321, year: 2010 http://www.nukleonika.pl/www/back/full/vol55_2010/v55n4p433f.pdf

  18. Monitoring of radon gas in caves of the Yorkshire Dales, United Kingdom

    International Nuclear Information System (INIS)

    Langridge, D; Stokes, R P; Jackson, C P

    2010-01-01

    A number of vocational training courses are held in caves in the Yorkshire Dales region of the United Kingdom. The instructors and students involved in these courses have the potential to be exposed to enhanced levels of radon ( 222 Rn) and its progeny as a result of their occupations. A prior radiological risk assessment for the training courses recommended that an environmental monitoring programme be carried out to establish the radon concentrations in the caves, and that the caving instructors wear personal radon dosemeters. Radon gas concentrations varied seasonally, being at their highest in summer and their lowest in winter. The lowest result was 40 Bq m -3 recorded in Lower Longchurn cave during winter, whilst the highest result was 4440 Bq m -3 recorded in Crackpot cave during the summer. As the individuals involved in the caving are entering atmospheres with radon gas concentrations in excess of 400 Bq m -3 , the Ionising Radiation Regulations 1999 (GB Parliament 2000 Ionising Radiations Regulations 1999 (London: Stationary Office) SI 1999/3232) apply. A system of work is therefore in place to control exposure to radon. This system of work stipulates an initial dose investigation level of 1 mSv, a second dose investigation level of 2 mSv and an annual dose limit of 6 mSv. The highest annual dose recorded to date is 2.2 mSv, although the average (median) annual dose is only 0.5 mSv.

  19. 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)

  20. The measurement of activity-weighted size distributions of radon progeny: methods and laboratory intercomparison studies

    International Nuclear Information System (INIS)

    Hopke, P.K.; Strydom, R.; Ramamurthi, M.; Knutson, E.O.; Tu, K.W.; Scofield, P.; Holub, R.F.; Cheng, Y.S.; Su, Y.F.; Winklmayr, W.

    1992-01-01

    Over the past 5 y, there have been significant improvements in measurement of activity-weighted size distributions of airborne radon decay products. The modification of screen diffusion batteries to incorporate multiple screens of differing mesh number, called graded screen arrays, have permitted improved size resolution below 10 nm such that the size distributions can now be determined down to molecular sized activities (0.5 nm). In order to ascertain the utility and reliability of such systems, several intercomparison tests have been performed in a 2.4 m3 radon chamber in which particles of varying size have been produced by introducing SO2 and H2O along with the radon to the chamber. In April 1988, intercomparison studies were performed between direct measurements of the activity-weighted size distributions as measured by graded screen arrays and an indirect measurement of the distribution obtained by measuring the number size distribution with a differential mobility analyzer and multiplying by the theoretical attachment rate. Good agreement was obtained in these measurements. A second set of intercomparison studies among a number of groups with graded screen array systems was made in April 1989 with the objective of resolving spectral structure below 10 nm. Again, generally good agreement among the various groups was obtained although some differences were noted. It is thus concluded that such systems can be constructed and can be useful in making routine measurements of activity-weighted size distributions with reasonable confidence in the results obtained

  1. Radon in workplaces - application of new Slovak legislation

    International Nuclear Information System (INIS)

    Futas, M.; Gombala, E.

    1998-01-01

    To carry out the categorization of underground workplaces the work-group comprising workers of State Health Institute of the Slovak Republic in Bratislava and in Banska Bystrica was created. During 1997 this group took the set of radon concentration measurements in four ore mines (Hodrusa Hamre, gold; Talcum - Magnezit Hnusta, talc, magnesite; Zelba Rudnany, barytes, polymetallic ores; Zelba -Siderit Nizna Slana, siderit) and twelve show caves (Belianska, Bystrianska, Demanovska j.Slobody, Demenovska ladova, Dobsinska ladova, Domica, Driny, Gombasecka, Harmanecka, Jasovska, Ochtinska aragonite, Vazecka).The highest radon activity concentration 24470 ± 118 Bq/m 3 in Vazecka cave (location Galeria) was measured According to averaged radon levels the following conclusions were made for show caves: all show caves except two ice caves shall be declared as workplaces with ionizing radiation sources for radon levels high above 1000 Bq/m 3 (the chosen action level 1000 Bq/m 3 corresponds to the annual effective dose 6 mSv providing 2000 working hours spent in such workplace) were detected and no technical mitigation is possible because of preservation of cave decoration. Situation in ore mines ii a bit different. Measured radon levels were found varying in a wide range depending on the position in the mine, work practices and season. The increase of radon gas concentration in summer months was observed as it was expected. In every ore mine workplaces with radon concentration high above the action level were found. Powerful ventilation system is a basic prerequisite and can reduce concentration below the action level. High radon concentration (up to 4200 Bq/m 3 ) in Hodrusa Hereditary Drift (haulage-way from Hodrusa gold mine) were successfully reduced to 200 Bq/m 3 by walling up mouths of the old mine works. In other three mines the current ventilation conditions are not sufficient to ensure radon concentrations below the action level for the time being. This is the

  2. Radon emanation fractions from concretes containing fly ash and metakaolin

    International Nuclear Information System (INIS)

    Taylor-Lange, Sarah C.; Juenger, Maria C.G.; Siegel, Jeffrey A.

    2014-01-01

    Radon ( 222 Rn) and progenies emanate from soil and building components and can create an indoor air quality hazard. In this study, nine concrete constituents, including the supplementary cementitious materials (SCMs) fly ash and metakaolin, were used to create eleven different concrete mixtures. We investigated the effect of constituent radium specific activity, radon effective activity and emanation fraction on the concrete emanation fraction and the radon exhalation rate. Given the serious health effects associated with radionuclide exposure, experimental results were coupled with Monte Carlo simulations to demonstrate predictive differences in the indoor radon concentration due to concrete mixture design. The results from this study show that, on average, fly ash constituents possessed radium specific activities ranging from 100 Bq/kg to 200 Bq/kg and emanation fractions ranging from 1.1% to 2.5%. The lowest emitting concrete mixture containing fly ash resulted in a 3.4% reduction in the concrete emanation fraction, owing to the relatively low emanation that exists when fly ash is part of concrete. On average, the metakaolin constituents contained radium specific activities ranging from 67 Bq/kg to 600 Bq/kg and emanation fractions ranging from 8.4% to 15.5%, and changed the total concrete emanation fraction by roughly ± 5% relative to control samples. The results from this study suggest that SCMs can reduce indoor radon exposure from concrete, contingent upon SCM radionucleotide content and emanation fraction. Lastly, the experimental results provide SCM-specific concrete emanation fractions for indoor radon exposure modeling. - Highlights: • Fly ash or metakaolin SCMs can neutralize or reduce concrete emanation fractions. • The specific activity of constituents is a poor predictor of the concrete emanation fraction. • Exhalation from fly ash concretes represents a small fraction of the total indoor radon concentration

  3. Result of the intercomparison exercise on radon measuring instruments and radon detectors 'bev- radon ring 2005'

    International Nuclear Information System (INIS)

    Baumgartner, A.; Maringer, F.J.; Michai, P.; Kreuziger, M.

    2006-01-01

    precautionary measures), should have assured quality of the used measuring systems. In this respect the findings from this intercomparison exercise are used for an actual control, improvement of the calibration and optimization to ensure the correct application of the used radon measuring systems in Austria. (authors)

  4. Study of lung cancer and residential radon in the Czech Republic

    International Nuclear Information System (INIS)

    Tomasek, L.; Mueller, T.; Kunz, E.; Heribanova, A.; Matzner, J.; Placek, V.; Burian, I.; Holecek, J.

    2001-01-01

    The lung cancer mortality study was designed as a follow-up study of the population (N = 12,004) in a radon-prone area in the Czech Republic, covering the 1960-1999 period. Information on the vital status and causes of death was mostly obtained from local authorities and extracted from the national population registry. Exposure estimates were based on one-year measurements of radon progeny in the majority of houses within the study area (74 %). Exposures outside the area (16%) were based on radon mapping of the Czech Republic. The mean concentration, 509 Bq/m 3 , is five-fold higher than the country-wide average. By 1999, a total of 210 lung cancers had been observed, which is somewhat more than the nationally expected value (O/E = 1.10), as compared to the generally low numbers regarding cancer types other than lung cancer (O/E = 0.81). The excess relative risk for the standard radon concentration (100 Bq/m 3 ) was 0.087 (90 % CI: 0.017-0.208), which is consistent with the risk coefficients derived from other indoor studies. The increased lung cancer incidence was found to depend linearly on exposure in terms of the mean radon concentration during the past 5-34 years. The estimate was not affected appreciably by adjustment to smoking; although the risk coefficient was higher for non-smokers than for smokers (0.130 vs 0.069), the difference was not statistically significant

  5. Mapping the geogenic radon potential of the eastern Canary Islands.

    Science.gov (United States)

    Rubiano, Jesús G.; Alonso, Hector; Arnedo, Miguel. A.; Tejera, Alicia; Martel, Pablo; Gil, Juan M.; Rodriguez, Rafael; González, Jonay

    2014-05-01

    The main contribution of indoor radon comes from soils and thus, the knowledge of the concentration of this gas in soils is important for estimating the risk of finding high radon indoor concentrations. To characterize the behavior of radon in soils, it is common to use the a quantity named Radon Potential which results of a combination of properties of the soil itself and from the underlying rock, such as concentration and distribution of radium, porosity, permeability, the moisture content and meteorological parameters, among others. In this work, the results three year of campaigns of measurement radon gas as well as the permeability in soils of the Eastern Canary Islands (Gran Canaria, Fuerteventura and Lanzarote) are presented. By combining these two parameters and through the use of geostatistic interpolation techniques, the radon potential of soils is estimated and it is used to carry on a classification of the territory into hazard zones according to their potential for radon emanation. To measure the radon soil gas a probe equipped with a "lost" sharp tip is inserted to the desired sampling depth. One of the characteristics of the Canary Islands is the absence of developed soils and so the bedrock is found typically at very shallow depth. This fact has led us to adopt a sampling depth of 50 cm at most. The probe is connected to the continuous radon monitor Durridge RAD7 equipped with a solid-state alpha spectrometer to determine concentration radon using the activity its short-lived progeny. Dried soil air is delivered to the RAD7 radon monitor by pumping. A half hour counting time for all sampling points has been taken. In parallel to the radon measurement campaign, the permeability of soils has also been determined at each point using the permeameter RADON-JOK. The principle of operation of this equipment consists of air withdrawal by means of negative pressure. The gas permeability is then calculated using the known flow of air flowing through the probe

  6. Radiological risk of building materials using homemade airtight radon chamber

    International Nuclear Information System (INIS)

    Norafatin Khalid; Amran Abdul Majid; Redzuwan Yahaya; Muhammad Samudi Yasir

    2013-01-01

    Full-text: Soil based building materials known to contain various amounts of natural radionuclide mainly 238 U and 232 Th series and 40 K. In general most individuals spend 80 % of their time indoors and the natural radioactivity in building materials is a main source of indoor radiation exposure. The internal exposure due to building materials in dwellings and workplaces is mainly caused by the activity concentrations of short lived 222 Radon and its progenies which arise from the decay of 226 Ra. In this study, the indoor radon concentration emanating from cement brick, red-clay brick, gravel aggregate and Portland cement samples were measured in a homemade airtight radon chamber using continuous radon monitor 1029 model of Sun Nuclear. Radon monitor were left in the chamber for 96 hours with an hour counting time interval. From the result, the indoor radon concentrations for cement brick, red-clay brick, gravel aggregate and Portland cement samples determined were 396 Bq m -3 , 192 Bq m -3 , 176 Bq m -3 and 28 Bq m -3 , respectively. The result indicates that the radon concentration in the studied building materials have more than 100 Bq m -3 for example higher than the WHO action level except for Portland cement sample. The calculated annual effective dose for cement brick, red-clay brick, gravel aggregate and Portland cement samples were determined to be 10 mSv y -1 , 4.85 mSv y -1 , 4.44 mSv y -1 and 0.72 mSv y -1 , respectively. This study showed that all the calculated effective doses generated from indoor radon to dwellers or workers were in the range of limit recommended ICRP action levels for example 3 - 10 mSv y -1 . As consequences, the radiological risk for the dwellers in terms of fatal lifetime cancer risk per million for cement brick, red-clay brick, gravel aggregate and Portland cement were calculated to be 550, 267, 244 and 40 persons respectively. (author)

  7. Radiological risk of building materials using homemade airtight radon chamber

    International Nuclear Information System (INIS)

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

    2014-01-01

    Soil based building materials known to contain various amounts of natural radionuclide mainly 238 U and 232 Th series and 40 K. In general most individuals spend 80% of their time indoors and the natural radioactivity in building materials is a main source of indoor radiation exposure. The internal exposure due to building materials in dwellings and workplaces is mainly caused by the activity concentrations of short lived 222 Radon and its progenies which arise from the decay of 226 Ra. In this study, the indoor radon concentration emanating from cement brick, red-clay brick, gravel aggregate and Portland cement samples were measured in a homemade airtight radon chamber using continuous radon monitor 1029 model of Sun Nuclear. Radon monitor were left in the chamber for 96 hours with an hour counting time interval. From the result, the indoor radon concentrations for cement brick, red-clay brick, gravel aggregate and Portland cement samples determined were 396 Bq m −3 , 192 Bq m −3 , 176 Bq m −3 and 28 Bq m −3 , respectively. The result indicates that the radon concentration in the studied building materials have more than 100 Bq m −3 i.e. higher than the WHO action level except for Portland cement sample. The calculated annual effective dose for cement brick, red-clay brick, gravel aggregate and Portland cement samples were determined to be 10 mSv y −1 , 4.85 mSv y −1 , 4.44 mSv y −1 and 0.72 mSv y −1 , respectively. This study showed that all the calculated effective doses generated from indoor radon to dwellers or workers were in the range of limit recommended ICRP action levels i.e. 3 - 10 mSv y −1 . As consequences, the radiological risk for the dwellers in terms of fatal lifetime cancer risk per million for cement brick, red-clay brick, gravel aggregate and Portland cement were calculated to be 550, 267, 244 and 40 persons respectively

  8. Suppression of the radon background by a prototype PICASSO emulsion container

    International Nuclear Information System (INIS)

    Bocan, J.; Bocarov, V.; Cermak, P.; Konicek, J.; Pospisil, S.; Stekl, I.; Leroy, C.; Jilek, K.

    2004-01-01

    A new PICASSO droplet detector is under development for its installation at the Sudbury Neutrino Observatory (SNO). The concept of the PICASSO experiment rests on an approach consisting of the detection of Cold Dark Matter (CDM) candidate particles, the neutralino in particular, through the use of large mass superheated droplet modular detectors. The sources of background signal for PICASSO detector are gamma rays, mips's, neutrons, radon and alpha particles due to U/Th contamination of the detector and its environment. Droplet detectors have high efficiency for detecting neutrons while being insensitive to mip's, gamma rays when operated at proper temperature and pressure. As in the case of other low background experiments radon is a very important source of background. Radon can diffuse into the detector during fabrication, storage, operation and induce an alpha background by its disintegration. The purpose of our long-term measurement was to define the tightness and penetrability of the PICASSO emulsion container against radon. The PICASSO box has been placed into a bigger plastic box and a Si detector has been installed in both boxes. The source of radon (pitchblende) has been inserted into an outer plastic box to obtain a high level radon environment. Radon monitoring was based on an electrostatic collection of its progeny 218 Po and 214 Po on the Si detector entrance window with spectroscopic counting of alpha particles (e.g. [2]). The spectrometer TAIP was used for a particle energy measurement. The spectrometer was developed at the Czech Technical University in Prague. The spectrometer contains all the spectrometric modules needed for energy measurement as well as the source of voltage for Si detector. It also includes digital memory to save spectra during measurement (up to 1792 spectra). Two long-time tests (2 months and 2.5 months) were performed. Radon concentrations in both containers (the outer plastic box, the PICASSO container) have been measured

  9. Investigations of outbursts and tremors in Polish collieries with application of radon measurements

    International Nuclear Information System (INIS)

    Wysocka, M.

    2010-01-01

    In the 80's and 90's of the last century some attempts were undertaken to apply specific radiometric methods to support the prediction of outbursts in collieries, located in Lower Silesian Coal Basin (LSCB) in south-western Poland. This idea was developed as an analogy to the application of radon changes in groundwater prior to earthquakes, and on this basis the hypothesis of variations of radon emanation from coal seams, preceding approaching outburst, was formulated. It has been stated, that a certain correlation between temporal and spatial variations of radon level and the level of outburst's hazard existed. Then, new investigations have been started in copper and coal mines with the hope to use radon as a tool for the prediction of another dynamic phenomena - tremors. In the case of these investigations, only weak evidences were found. In the last years the occurrence of outburst was noticed in the collieries of Upper Silesian Coal Basin (USCB). Therefore, we started observations of changes of radon concentration in gas, sampled from headings, driven in endangered coal seams. The goal of the research is an attempt to formulate '' radon index of outburst hazard '' to support other, routinely used, methods of the prediction of dangerous events. In this paper some results of investigations, done in collieries in LSCB and in copper mines are quoted to give the background for preliminary results of new research, ongoing in one of the coal mines in the Upper Silesia region. (authors)

  10. Radon progeny exposure and lung cancer risk: Analyses of a cohort of Newfoundland fluorspar miners

    International Nuclear Information System (INIS)

    Morrison, H.I.; Villeneuve, P.J.

    1995-07-01

    A cohort study of the mortality experience (1950-1990) of 1744 underground miners and 321 millers or surface workers has been conducted. Excess mortality among underground miners was noted for cancers of the lung, buccal cavity, pharynx and mouth, urinary tract and for silicosis and pneumoconioses. A highly statistically significant relationship was noted between radon daughter exposure and risk of dying of lung cancer; the small numbers of buccal cavity/pharynx cancers (n = 6) precluded meaningful analysis of exposure-response. No statistically significant excess was found for any cause of death among surface workers. The exposure-response data for lung cancer were fitted to various mathematical models. The model selected included terms for attained age, cumulative dose, dose rate and time since last exposure. Because risk varies according to each of these factors, a single summary risk estimate was felt to be misleading. The joint effects of radon and smoking could not be adequately assessed using this cohort. (author). 46 refs., 16 tabs., 1 fig

  11. Interaction of radon Exposure and cigarette smoking on cells

    International Nuclear Information System (INIS)

    Zhu, Maoxiang; Wei, Han; Yang, Zhihua; Pan, Xiujie; Cao, Zhenshan

    2008-01-01

    Full text: Environmental radon and its progenies is important lung carcinogen both in occupational underground miners and in the general population. Exposure to radon often occurs combined with smoking, another most important lung carcinogen. The join biological effects of alpha- particle radiation and cigarette smoke condense (CSC) were investigated here in order to provide experimental base for medical protection from lung cancer inducing by joint exposure of radon and smoking. Immortalized human bronchial epithelial cells (BEP2D) were divided into 5 groups, namely normal control group (NC), alpha particles irradiation group (0.25 Gy,α), CSC administration group (1μg/ml, CSC), CSC administration (1μg/ml) before (CSC + α) and after (α + CSC) alpha particles irradiation (0.25 Gy) group. On the 35 th passage after treated by alpha particles irradiation and CSC singly or jointly, only α + CSC cells showed malignant transformation characteristics, representing anchor growing independently, losing contact inhibition, and cell cycle disordering, whereas, there were no distinct difference between cells of other groups and normal cells. Moreover, comparison to the groups treated alone with alpha particles radiation or CSC administration, in the groups of joint exposure to alpha particles radiation and CSC treatment, cell survival fractions markedly decreased, intracellular ROS levels, frequencies of comet cell generation significantly increase, and could found that cell survival fractions of group CSC administration after α particle radiation was significantly higher than that of group CSC administration before alpha particles irradiation, suggesting that interaction of radon and smoking associated with their exposure sequence. In summary, interaction of radon and smoking was synergistic effect, and which was impacted by the order of exposure. (author)

  12. 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

  13. Micronuclei in sputum from uranium workers: Epidemiologic application of an evolving cytogenetic technique

    International Nuclear Information System (INIS)

    Loomis, D.P.

    1989-01-01

    The exfoliated-cell micronucleus assay is a relatively new cytogenetic technique which can provide a measure of the genetic effect of exposure to carcinogens and mutagens in target tissues where tumors arise among exposed populations. It is responsive to the effects of ionizing radiation and tobacco smoke in some in vivo human cell systems, but has not been extensively field tested as an indicator of lung cancer-related effects, despite the public health importance of exposure to occupational and environmental lung carcinogens. In this study the exfoliated-cell micronucleus assay was used to assess effects of exposure to radon progeny and cigarette smoke in a population of uranium industry workers (including employees in underground and open-pit mines, mills, laboratories, and administrative offices); underground uranium miners experience markedly elevated lung cancer risk because of exposure to ionizing radiation from radon progeny. Ninety-nine workers were selected at random from among workers in Colorado Plateau uranium-related facilities who participated in a workplace sputum cytology screening program from 1964-1988. The prevalence of cells with micronuclei was determined by a manual assay of one sputum specimen for each worker under a light microscope. Occupational and smoking data obtained by interview during screening were used to classify exposure and smoking status at the time the sputum specimen was taken and to obtain information on potential confounders and effect modifiers; underground miners were classified as exposed to radon progeny, and others were considered unexposed. Neither radon progeny exposure nor cigarette smoking had any appreciable effect on the prevalence of micronucleated cells. Crude prevalence ratios were 1.0 (95% CI 0.7-1.4) and 0.9 (95% CI 0.6-1.3), respectively, for radon exposure and smoking

  14. Radiological characterisation and radon equilibrium factor in the outdoor air of a post-industrial urban area

    International Nuclear Information System (INIS)

    Rozas, S.; Idoeta, R.; Alegría, N.; Herranz, M.

    2016-01-01

    The radiological characterisation of outdoor air is always a complicated task due to the several radioactive emissions coming from the different radionuclides and also because of the very short half-lives of radionuclides in the natural radioactive series. In some places, this characterisation could result in unusual values because the natural presence of radionuclides with terrestrial origin can be modified by manmade activities. Nonetheless, this characterisation is useful not only for air quality control purposes but also because radon and its progeny in the outdoor air are the main contributors to human exposure from natural sources. In this study, we have carried out air particle sampling, followed by gamma-ray spectrometry, alpha spectrometry and beta counting determinations for this purpose. Subsequently, the outdoor air has been radiologically characterised through the obtained data and using a pre-existing analytical method to take into account the radioactive decays of short half-life radionuclides during sampling, sample preparation and measuring times. Bilbao was chosen to carry out this work. It is a medium-sized town located in northern Spain, close to the Atlantic Ocean and at sea level. This city has a recent industrial past as there were numerous steel mills and other heavy industries, including some quarries, and some open pit mines close to it, which concluded in a remediation program. So, it is a place where the air is potentially modified by manmade activities. The obtained results show that activity concentration values for long-lived radionuclides that precede radon and thoron are in the order of 10 −6  Bq m −3 and long-lived ones after radon are around 10 −4  Bq m −3 . Thoron progeny are around 2 × 10 −2  Bq m −3 and radon progeny are around 1.8 Bq m −3 . The mean radon equilibrium factor was 0.18. All of these values are close to the minimum UNSCEAR values, but show some variability, which highlights the importance

  15. Result of the intercomparison exercise on radon measuring instruments and radon detectors 'bev- radon ring 2005'

    Energy Technology Data Exchange (ETDEWEB)

    Baumgartner, A. [Vienna Univ. of Technology, Atominstitut, Wien (Austria); Maringer, F.J.; Michai, P.; Kreuziger, M. [BEV-Federal Office of Metrology and Surveying, Wien (Austria)

    2006-07-01

    precautionary measures), should have assured quality of the used measuring systems. In this respect the findings from this intercomparison exercise are used for an actual control, improvement of the calibration and optimization to ensure the correct application of the used radon measuring systems in Austria. (authors)

  16. Design and operation of an automated beta-particle counting system for the measurement of 220Rn (and 222Rn) progeny

    International Nuclear Information System (INIS)

    Bigu, J.

    1992-01-01

    A fully automated system of the continuous (active) type has been designed for the unattended quantification of 222 Rn progeny and 220 Rn progeny in calibration and test facilities, as well as working and living environments. The system uses a β-particle detector and associated electronic circuitry, in conjunction with an in-house microprocessor-based processing interface card and a personal computer, operated by specially developed in-house software. The system represents a significant improvement over systems using α-particle detectors because of its enhanced flexibility of design and virtual elimination of plate-out effects in the sampling head, and of self-absorption phenomena in the sampling filter. The β-particle system was tested and calibrated in a Radon and Thoron Test Facility of the walk-in type under a variety of experimental conditions. (author)

  17. Wire-mesh capped deposition sensors: Novel passive tool for coarse fraction flux estimation of radon thoron progeny in indoor environments

    International Nuclear Information System (INIS)

    Mayya, Y.S.; Mishra, Rosaline; Prajith, Rama; Sapra, B.K.; Kushwaha, H.S.

    2010-01-01

    Deposition-based 222 Rn and 220 Rn progeny sensors act as unique, passive tools for determining the long time-averaged progeny deposition fluxes in the environment. The use of these deposition sensors as progeny concentration monitors was demonstrated in typical indoor environments as conceptually superior alternatives to gas-based indirect monitoring methods. In the present work, the dependency of these deposition monitors on various environmental parameters is minimized by capping the deposition sensor with a suitable wire mesh. These wire-mesh capped deposition sensors measure the coarse fraction deposition flux, which is less dependent on the change in environmental parameters like ventilation rate and turbulence. The calibration of these wire-mesh capped coarse fraction progeny sensors was carried out by laboratory controlled experiments. These sensors were deployed both in indoor and in occupational environments having widely different ventilation rates. The obtained coarse fraction deposition velocities were fairly constant in these environments, which further confirmed that the signal on the wire-mesh capped sensors show the least dependency on the change in environmental parameters. This technique has the potential to serve as a passive particle sizer in the general context of nanoparticles using progeny species as surrogates. On the whole, there exists a strong case for developing a passive system that responds only to coarse fraction for providing alternative tools for dosimetry and environmental fine particle research. - Research highlights: → Wire-mesh capped deposition sensor measures the coarse fraction deposition flux → Coarse fraction deposition flux less dependent on environmental conditions → Wire-mesh capped deposition sensor as passive particle sizer

  18. Animal study on biological responses by radon inhalation making use of waste rock which contains feeble activity of uranium (2) (Joint research)

    International Nuclear Information System (INIS)

    Ishimori, Yuu; Sakoda, Akihiro; Tanaka, Hiroshi; Mitsunobu, Fumihiro; Yamaoka, Kiyonori; Kataoka, Takahiro; Etani, Reo

    2016-03-01

    Okayama University and the Japan Atomic Energy Agency (JAEA) have carried out the collaborative study of physiological effects of inhaled radon for the low-dose range. Main assignments were as follows. Based on the clinical knowledge, Misasa Medical Center (Okayama University Hospital) clarified the issues that should be addressed. Graduate School of Health Sciences (Okayama University) supervised the research and studied the biological responses. The JAEA made the development and control of a facility for radon inhalation experiments and the investigation of biokinetics and exposure doses of radon. From 2009 to 2013, the following results were obtained. (1) Literature on drinking effects of radon hot spring water was surveyed to determine the present tasks. (2) Under the present experimental conditions, drinking of hot spring water into which radon was intentionally introduced using the equipment in the facility did not have significant effects on mice. (3) Inhibitory effects of antioxidant pre-supplements (Vitamins C and E) and radon pre-inhalation on hepatic or renal oxidative damage were examined to make the comparison. (4) In order to discuss biological responses quantitatively following radon inhalation, the biokinetics of inhaled radon were studied. (5) Some exposure routes due to inhalation of radon or its progeny were modeled to calculate organ doses in mice. (author)

  19. 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)

  20. Investigation of radon entry and effectiveness of mitigation measures in seven houses in New Jersey: Midproject report

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, T.G.; Dudney, C.S.; Monar, K.P.; Landguth, D.C.; Wilson, D.L.; Hawthorne, A.R.; Hubbard, L.M.; Gadsby, K.J.; Bohac, D.L.; Decker, C.A.

    1987-12-01

    A detailed radon mitigation study is in progress in 14 homes in the New Jersey Piedmont area. The principal goals are the refinement of diagnostic measurements for selection and implementation of mitigation systems, and the reduction of radon concentrations to acceptable levels inside the study houses. Monitoring stations were installed in each home in October, 1986. Instrumented measurements included: basement and upstairs radon; differential pressures across the basement/subslag, basement/upstairs and basement/outdoor interfaces; temperatures at basement, upstairs and outdoor locations; and central air handler usage. A weather station was located at one house, monitoring wind speed and direction; barometric pressure; precipitation; soil temperature; and outdoor temperature and relative humidity. A time-averaged value of all of the above parameters was recorded every 30 min. Several additional parameters were monitored on an intermittent basis in all or selected homes. These include multizone air infiltration rates which have been measured in all homes using passive perfluorocarbon tracers (PFT) and in two homes using a constant concentration tracer gas system (CCTG). Total radon progeny, soil gas radon concentration and permeability characteristics, and gamma radiation levels were also monitored periodically in all study homes. 10 refs., 53 figs.

  1. Investigation of radon entry and effectiveness of mitigation measures in seven houses in New Jersey: Midproject report

    International Nuclear Information System (INIS)

    Matthews, T.G.; Dudney, C.S.; Monar, K.P.

    1987-12-01

    A detailed radon mitigation study is in progress in 14 homes in the New Jersey Piedmont area. The principal goals are the refinement of diagnostic measurements for selection and implementation of mitigation systems, and the reduction of radon concentrations to acceptable levels inside the study houses. Monitoring stations were installed in each home in October, 1986. Instrumented measurements included: basement and upstairs radon; differential pressures across the basement/subslag, basement/upstairs and basement/outdoor interfaces; temperatures at basement, upstairs and outdoor locations; and central air handler usage. A weather station was located at one house, monitoring wind speed and direction; barometric pressure; precipitation; soil temperature; and outdoor temperature and relative humidity. A time-averaged value of all of the above parameters was recorded every 30 min. Several additional parameters were monitored on an intermittent basis in all or selected homes. These include multizone air infiltration rates which have been measured in all homes using passive perfluorocarbon tracers (PFT) and in two homes using a constant concentration tracer gas system (CCTG). Total radon progeny, soil gas radon concentration and permeability characteristics, and gamma radiation levels were also monitored periodically in all study homes. 10 refs., 53 figs

  2. Radon adsorbed in activated charcoal—a simple and safe radiation source for teaching practical radioactivity in schools and colleges

    Science.gov (United States)

    Al-Azmi, Darwish; Mustapha, Amidu O.; Karunakara, N.

    2012-07-01

    Simple procedures for teaching practical radioactivity are presented in a way that attracts students' attention and does not make them apprehensive about their safety. The radiation source is derived from the natural environment. It is based on the radioactivity of radon, a ubiquitous inert gas, and the adsorptive property of activated charcoal. Radon gas from ambient air in the laboratory was adsorbed into about 70 g of activated charcoal inside metallic canisters. Gamma radiation was subsequently emitted from the canisters, following the radioactive decay of radon and its progenies. The intensities of the emitted gamma-rays were measured at suitable intervals using a NaI gamma-ray detector. The counts obtained were analysed and used to demonstrate the radioactive decay law and determine the half-life of radon. In addition to learning the basic properties of radioactivity the students also get practical experience about the existence of natural sources of radiation in the environment.

  3. Radon adsorbed in activated charcoal- a simple and safe radiation source for teaching practical radioactivity in schools and colleges

    International Nuclear Information System (INIS)

    Al-Azmi, D.S.

    2014-01-01

    Simple procedures for teaching practical radioactivity are presented in a way that attracts students' attention and does not make them apprehensive about their safety. The radiation source is derived from the natural environment. It is based on the radioactivity of radon, an ubiquitous inert gas, and the adsorptive property of activated charcoal. Radon gas from ambient air in the laboratory was adsorbed into about 70 gram of activated charcoal inside metallic canisters. Gamma radiation was subsequently emitted from the canisters, following the radioactive decay of radon and its progenies. The intensities of the emitted gamma-rays were measured at suitable intervals using a NaI gamma-ray detector. The counts obtained were analysed and used to demonstrate the radioactive decay law and determine the half-life of radon. In addition to learning the basic properties of radioactivity, the students also get practical experience about the existence of natural sources of radiation in the environment. (author)

  4. Seasonal Variability in European Radon Measurements

    Science.gov (United States)

    Groves-Kirkby, C. J.; Denman, A. R.; Phillips, P. S.; Crockett, R. G. M.; Sinclair, J. M.

    2009-04-01

    In temperate climates, domestic radon concentration levels are generally seasonally dependent, the level in the home reflecting the convolution of two time-dependent functions. These are the source soil-gas radon concentration itself, and the principal force driving radon into the building from the soil, namely the pressure-difference between interior and exterior environment. While the meteorological influence can be regarded as relatively uniform on a European scale, its variability being defined largely by the influence of North-Atlantic weather systems, soil-gas radon is generally more variable as it is essentially geologically dependent. Seasonal variability of domestic radon concentration can therefore be expected to exhibit geographical variability, as is indeed the case. To compensate for the variability of domestic radon levels when assessing the long term radon health risks, the results of individual short-term measurements are generally converted to equivalent mean annual levels by application of a Seasonal Correction Factor (SCF). This is a multiplying factor, typically derived from measurements of a large number of homes, applied to the measured short-term radon concentration to provide a meaningful annual mean concentration for dose-estimation purposes. Following concern as to the universal applicability of a single SCF set, detailed studies in both the UK and France have reported location-specific SCF sets for different regions of each country. Further results indicate that SCFs applicable to the UK differ significantly from those applicable elsewhere in Europe and North America in both amplitude and phase, supporting the thesis that seasonal variability in indoor radon concentration cannot realistically be compensated for by a single national or international SCF scheme. Published data characterising the seasonal variability of European national domestic radon concentrations, has been collated and analysed, with the objective of identifying

  5. Indoor Radon Concentration Related to Different Radon Areas and Indoor Radon Prediction

    Science.gov (United States)

    Juhásová Šenitková, Ingrid; Šál, Jiří

    2017-12-01

    Indoor radon has been observed in the buildings at areas with different radon risk potential. Preventive measures are based on control of main potential radon sources (soil gas, building material and supplied water) to avoid building of new houses above recommended indoor radon level 200 Bq/m3. Radon risk (index) estimation of individual building site bedrock in case of new house siting and building protection according technical building code are obligatory. Remedial actions in buildings built at high radon risk areas were carried out principally by unforced ventilation and anti-radon insulation. Significant differences were found in the level of radon concentration between rooms where radon reduction techniques were designed and those where it was not designed. The mathematical model based on radon exhalation from soil has been developed to describe the physical processes determining indoor radon concentration. The model is focused on combined radon diffusion through the slab and advection through the gap from sub-slab soil. In this model, radon emanated from building materials is considered not having a significant contribution to indoor radon concentration. Dimensional analysis and Gauss-Newton nonlinear least squares parametric regression were used to simplify the problem, identify essential input variables and find parameter values. The presented verification case study is introduced for real buildings with respect to various underground construction types. Presented paper gives picture of possible mathematical approach to indoor radon concentration prediction.

  6. The determination of airborne concentrations of radon and thoron progeny by repetitive alpha counting of filter samples

    International Nuclear Information System (INIS)

    French, Clayton S. Jr.; Skrable, Kenneth W.; Chabot, George E.

    1978-01-01

    Analytical equations have been used to determine the airborne concentrations of the particulate daughters of radon and thoron from five net alpha counts obtained at preset time intervals post sampling. The same expressions were used to propagate the associated standard deviations. These propagated errors were minimized by the selection of optimum sampling and counting intervals. An extensive error analysis examined sources of interference and their influence on the calculated concentrations. This system offers sufficient precision for research applications, yet is simple and inexpensive enough for application in field studies. The radon and thoron daughters measured with this technique are 218 Po, 214 Pb, 214 Bi, 212 Pb, and 212 Bi. Because of the decay kinetics involved, the calculated concentrations of 218 Po and 212 Bi involve the greatest uncertainty. The proper choice of sampling and counting intervals optimizes the system for any one of the above radionuclides or for all five collectively. A sampling time of 15 minutes is best for the simultaneous estimation of all five concentrations. Millipore filter samples were obtained from a large, unventilated sub-basement of the University of Lowell research reactor facility and were counted later in direct contact with the window of a gas flow proportional detector having alpha particle counting efficiencies near 0.4 ca -1 and an alpha background of about 1 c min -1 . A typical 15 minute sample obtained at a flow rate of 2 x 10 4 cm 3 min -1 yielded estimates of the airborne concentrations and relative standard deviations: 218 Po, 4.75 x 10 -9 μCi cm -3 ± 18.9%; 214 Pb, 5.15 x 10 -9 μCi cm -3 ± 2.5%; 214 Bi, 4.86 x 10 -9 μCi cm -3 ± 2.4%; 212 Pb, 1.41 x 10 -10 μCi cm -3 ± 2.0%; and 212 Bi, 2.15 x 10 -10 μCi cm -3 ± 27.0%. (author)

  7. Evaluation of fifteen epidemiologic studies examining the lung cancer mortality of underground miners

    International Nuclear Information System (INIS)

    1985-01-01

    A group of 15 epidemiologic studies was identified in which researchers reported excess lung cancer deaths among underground miners who worked in mines where radon (10043922) progeny were present. Several other studies demonstrated a dose response relationship existing between radon progeny exposure and mortality from lung cancer. Two recent studies indicated excess numbers of cases of lung cancer deaths resulting from mean cumulative radon progeny exposures below 100 Working Level Months (WLM). In the mining environment exposure can also occur to other substances such as arsenic (1332214), diesel exhaust, smoking, chromium (7440473), nickel (7440020), and radiation, which can affect the lung cancer risk resulting from exposure to radon progeny. Not much was available in the literature which deals with the results of these combined exposures except the finding that a combined exposure to radon progeny and cigarette smoke resulted in a higher risk than exposure to either substance alone. X-ray surveillance and sputum cytology appeared to be ineffective in preventing radon progeny induced lung cancers in individual miners. There does not appear to be any particular association between one specific lung cancer cell type and radon progeny exposure

  8. Level of radon and its daughters, and internal exposure doses in Shaanxi province

    International Nuclear Information System (INIS)

    Fan Xin; Zhang Yawei; Yu Huilian

    1992-01-01

    About 4500 indoor and outdoor air samples were collected with FDT-84 sampler throughout Shaanxi Province in various seasons, and the concentrations of radon and its daughters in the air were determined with FD-3016 scintillator. Meanwhile, the diurnal, seasonal and altitudinal variation of radon and its progeny in Xi'an area were observed. The annual effective dose equivalent for individual adult resident was estimated to be 1.73 mSv·a -1 and the annual collective effective dose equivalent for the residents- in the whole province was estimated to be 5.09 ± 10 4 man.Sv·a -1 . The concentration levels and the doses are within the range of the data published in UNSCEAR reports in recent years, and all of them are in the normal range of the natural background

  9. Measurements and statistical analyses of indoor radon concentrations in Tokyo and surrounding areas

    International Nuclear Information System (INIS)

    Sugiura, Shiroharu; Suzuki, Takashi; Inokoshi, Yukio

    1995-01-01

    Since the UNSCEAR report published in 1982, radiation exposure to the respiratory tract due to radon and its progeny has been regarded as the single largest contributor to the natural radiation exposure of the general public. In Japan, the measurement of radon gas concentrations in many types of buildings have been surveyed by national and private institutes. We also carried out the measurement of radon gas concentrations in different types of residential buildings in Tokyo and its adjoining prefectures from October 1988 to September 1991, to evaluate the potential radiation risk of the people living there. One or two simplified passive radon monitors were set up in each of the 34 residential buildings located in the above-mentioned area for an exposure period of 3 months each. Comparing the average concentrations in the buildings of different materials and structures, those in the concrete steel buildings were always higher than those in the wooden and the prefabricated mortared buildings. The radon concentrations were proved to become higher in autumn and winter, and lower in spring and summer. Radon concentrations in an underground room of a concrete steel building showed the highest value throughout our investigation, and statistically significant seasonal variation was detected by the X-11 method developed by the U.S. Bureau of Census. The values measured in a room at the first floor of the same concrete steel building also showed seasonal variation, but the phase of variation was different. Another multivariate analysis suggested that the building material and structure are the most important factors concerning the levels of radon concentration among other factors such as the age of the building and the use of ventilators. (author)

  10. Protocol Implementation for Radon Concentration Measurements in Houses in Croatia - Baranja Case

    International Nuclear Information System (INIS)

    Radolic, V.; Miklavcic, I.; Poje, M.; Stanic, D.; Varga Pajtler, M.; Vukovic, B.

    2011-01-01

    The newly established protocol for radon measurements in homes was implemented on the radon survey in houses of Baranja region which was carried out from July 2009 until July 2010. The radon measurements were performed with passive track etched detectors. The method consists of cylindrical plastic vessel and two strippable LR-115 films type II (Kodak-Path, France). This method with two detector films enables the estimation of equilibrium factor as well.Croatian territory is divided in 10 x 10 km 2 cells which were part of a reference grid map which is used in a preparation of European radon concentration map. Detector locations were randomly chosen inside each grid and their number was determined by the number of inhabitants inside (one locations per 350 inhabitants). Radon detectors were exposed for a year in a living room or a bedroom away from strong ventilation and 30 cm from side walls (usually on closet at height of 2 m). After the exposure, detectors were collected and etched in 10 % NaOH aqueous solution at 50 degrees of C for 180 minutes. The tracks were automatically counted using spark counter AIST-2V. The obtained results were in the range from 6 to 355 Bq m -3 with arithmetic mean of 88 Bq m -3 and standard deviation of 69.0 Bq m -3 . The geometric mean was 67.2 Bq m -3 while the geometric standard deviation was 2.1 Bq m -3 . The statistical χ2 -test showed that the empirical frequency distribution for radon in houses of Baranja region belonged to the log-normal distribution. The percentage of houses with radon concentrations between 200 and 400 Bq m -3 was 6.7% and 1.0% of houses have radon concentration above 400 Bq m -3 . The annual effective dose from the indoor radon and its short-lived progenies for the inhabitants of Baranja region (for the average equilibrium factor of 0.53 and occupancy factor of 0.6) was 1.5 mSv. (author)

  11. Calibration of SSNDT detectors for radon measurements; Calibração de detectores SSNDT para medição de radônio

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Laura C.; Santos, Talita O.; Pinheiro, Rose Mary M.; Rocha, Zildete, E-mail: lauratakahashi@hotmail.com, E-mail: talitaolsantos@yahoo.com.br, E-mail: rosepin@cdtn.br, E-mail: rochaz@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    The methods and instrumentation used to measure the concentration of radon need to be calibrated to obtain accurate results. The Nuclear Track Detector is considered the main method of analysis of radon research. Thus, the Natural Radioactivity Laboratory of the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG, Brazil) uses the detector CR-39 (Landauer) to measure the concentration of radon in homes, workplaces, underground mines, soils and in environment. Epidemiological studies reveal the strong relationship between lung cancer and radon exposure. Therefore, it is important to monitor this gas and its progeny in order to assess the radiological risk. The alpha particles emitted by radon and its progeny leave traces on CR-39 due to Coulombian interactions with the atoms of the material. The liquid density of traces is converted to radon concentration by means of a calibration factor obtained in calibrated systems. This work aims to determine the LRN / CDTN calibration factor. To do so, the CR-39 detectors were placed inside the calibration chambers, along with two AlphaGUARD (Saphymo GmbH) detectors and Ra-266 sources with activities of 3,379 kBq or 0.483 kBq, referenced by NIST. From this, six levels of exposure were obtained, which were: 44 kBq.d.m{sup 3}, 4 kBq.d.m{sup 3}, 3 kBq.d.m{sup 3}, 15 kBq.d.m{sup 3}, 30 kBq.d.m{sup 3} , 26 kBq.d.m {sup 3}. The conversion factor between the liquid density of traces and the total exposure time obtained was K = 52.028 ± 0.752 [(trace density.cm{sup -2}) / (kBq.d.m{sup -3})]. After the determination of the conversion factor, it was used to measure the concentration of radon in underground mines, obtaining concentration results between 122 ± 24 and 7384 ± 517 kBq.m{sup -3}.

  12. Inverse method for determining radon diffusion coefficient and free radon production rate of fragmented uranium ore

    International Nuclear Information System (INIS)

    Ye, Yong-jun; Wang, Li-heng; Ding, De-xin; Zhao, Ya-li; Fan, Nan-bin

    2014-01-01

    The radon diffusion coefficient and the free radon production rate are important parameters for describing radon migration in the fragmented uranium ore. In order to determine the two parameters, the pure diffusion migration equation for radon was firstly established and its analytic solution with the two parameters to be determined was derived. Then, a self manufactured experimental column was used to simulate the pure diffusion of the radon, the improved scintillation cell method was used to measure the pore radon concentrations at different depths of the column loaded with the fragmented uranium ore, and the nonlinear least square algorithm was used to inversely determine the radon diffusion coefficient and the free radon production rate. Finally, the solution with the two inversely determined parameters was used to predict the pore radon concentrations at some depths of the column, and the predicted results were compared with the measured results. The results show that the predicted results are in good agreement with the measured results and the numerical inverse method is applicable to the determination of the radon diffusion coefficient and the free radon production rate for the fragmented uranium ore. - Highlights: • Inverse method for determining two transport parameters of radon is proposed. • A self-made experimental apparatus is used to simulate radon diffusion process. • Sampling volume and position for measuring radon concentration are optimized. • The inverse results of an experimental sample are verified

  13. Developing a method for the retrospective estimation of radon exposure from in vivo measurements of 210Pb activity in bone

    International Nuclear Information System (INIS)

    McKenzie, R.J.; Johnston, P.N.

    1999-01-01

    Radon is a naturally occurring radioactive gas which has been linked to lung cancer in occupationally exposed uranium mine workers. Where monitoring of an individual's exposure to radon and radon progeny has not occurred or is incomplete, it may be possible to determine this exposure retrospectively by the measurement of the long lived decay product 210 Pb which accumulates in the bones of exposed individuals. This paper describes a method being developed at the whole body monitor (WBM) facility of the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) to estimate the time integrated exposure to radon over a period of up to several decades from the in vivo measurements of 210 Pb activity in the knee of human subjects. Initial work has concentrated on characterising the WBM facility for this work using artificial bone phantoms. This project will serve as a test of the feasibility of the method before undertaking further studies on human subjects

  14. RADON CONCENTRATION TIME SERIES MODELING AND APPLICATION DISCUSSION.

    Science.gov (United States)

    Stránský, V; Thinová, L

    2017-11-01

    In the year 2010 a continual radon measurement was established at Mladeč Caves in the Czech Republic using a continual radon monitor RADIM3A. In order to model radon time series in the years 2010-15, the Box-Jenkins Methodology, often used in econometrics, was applied. Because of the behavior of radon concentrations (RCs), a seasonal integrated, autoregressive moving averages model with exogenous variables (SARIMAX) has been chosen to model the measured time series. This model uses the time series seasonality, previously acquired values and delayed atmospheric parameters, to forecast RC. The developed model for RC time series is called regARIMA(5,1,3). Model residuals could be retrospectively compared with seismic evidence of local or global earthquakes, which occurred during the RCs measurement. This technique enables us to asses if continuously measured RC could serve an earthquake precursor. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. On the influence of environmental factors on radon levels in caves of Ribeira valley state parks, SP and evaluation of radioactive equilibrium and equilibrium factor between radon and its progeny

    International Nuclear Information System (INIS)

    Alberigi, Simone

    2011-01-01

    In the present study it was carried out the monitoring of radon in caves distributed among three state parks of Sao Paulo. The radon concentration were determinate in Morro Preto and Santana caves, located at PETAR - Parque Estadual Turistico do Alto Ribeira (High Ribeira River Tourist State Park), Diabo cave, situated in PEJ - Parque Estadual de Jacupiranga (Jacupiranga State Park) and Colorida cave located in PEI - Parque Estadual Intervales (Intervales State Park PEI). The monitoring covered measurements between April 2009 and June 2010. Radon concentrations were carried out by using the technique of passive detection with CR-39 solid state nuclear track detectors and NRPB diffusion chambers. The detectors were exposed in periods ranging from 30 to 150 days. Radon concentrations varied from 132 Bq/m 3 to 9456 Bq/m 3 . The values of radon concentrations were analyzed together with information about rainfall and internal and external temperature values of the Santana cave environment and regional literature values for a possible relationship between radon variations and weather information. Both the determinations of 22 '6Ra in water samples collected in some caves and rivers and radon emanation from a stalactite collected at Santana cave allowed to verify that the radon in the caves comes from the walls rocks. The verification of the radioactive equilibrium between 222 Rn, 218 Po and '2 14 Po in the exposed detectors was prejudiced by the high tracks densities, committing the methodology effectiveness. The annual effective dose was calculated for three values obtained from the literature for the equilibrium factor. Considering the most realistic scenario, with equilibrium factor of 0.5 and 52 working weeks, the annual effective dose was 5.1 mSv/y. Concerning the worst scenario, which simulates an extreme case, adopting an equilibrium factor equal to 1 and 52 weeks of work per year, the annual effective dose is 10.2 mSv/y. Also with information received from a

  16. Applications of commercial liquid scintillation counters to radon-222 and radium-226 analyses

    International Nuclear Information System (INIS)

    Gesell, T.F.; Prichard, H.M.; Haygood, J.R.

    1978-01-01

    The ubiquitous commerical liquid scintillation counter offers automatic sample processing, automatic data recording and the prospect of multiple users. With these features in mind we have explored a number of applications of liquid scintillation counters to environmental and health physics problems. One application, the analysis of radon in water has been described elsewhere and is only briefly reviewed. A method for measuring radon in air, two methods for measuring radium in water, and a technique for leak testing radium needles have also been investigated. An ordinary glass scintillation vial is readily converted into a miniature scintillation flask by coating the inside surface with a thin layer in ZnS:Ag phosphor. The lower limit detection is high, about 2 pCi/1 for a 1 hour count, but these flasks have proved to be useful in situations where a larger number of samples must be taken in environments with relatively high levels of radon. One technique for the detection of radium in water uses liquid-liquid extraction to concentrate radon into an organic scintillation fluid, the other involves passing the water sample through an ion exchange resin and then sealing the resin and scintillation fluid in a vial. Both techniques offer the prospect of easy and inexpensive analyses with limits of detection at or below 0.5 pCi/1. Radium needles can be leak tested by placing them in vials containing toluene for a few minutes, adding fluor to the toluene and counting. Preliminary data regarding these several methods are given

  17. Radon gas sampler for indoor and soil measurements and its applications

    International Nuclear Information System (INIS)

    Azimi-Garakani, D.; Flores, B.; Piermattei, S.; Susanna, A.F.; Seidel, J.L.; Tommasino, L.; Torri, G.

    1988-01-01

    A national large scale survey of indoor radon (based on an optimised sampling strategy) is needed in Italy to obtain average population dose for use in epidemiological studies. Since in the great majority of cases, one of the most important radon sources is the soil and rock beneath the houses, it would be interesting to combine this survey with measurements of bed-soil radon. With these objectives in mind, a new radon monitor device has been developed consisting of two etched track detectors enclosed in a heat-sealed polyethylene bag. When compared with existing techniques, this radon gas sampler presents several advantages for both indoor and outdoor measurements. As a pilot project, radon gas measurements have been carried out in hundreds of different sites and for several locations; measurements have been made for different years. Typical houses with relatively high radon concentrations have also been thoroughly investigated. (author)

  18. Comparison of methods and instruments for 222Rn/220Rn progeny measurement

    International Nuclear Information System (INIS)

    Liu Yanyang; Shang Bing; Wu Yunyun; Zhou Qingzhi

    2012-01-01

    In this paper, comparisons were made among three methods of measurement (grab measurement, continuous measurement and integrating measurement) and also measurement of different instruments for a radon/thoron mixed chamber. Taking the optimized five-segment method as a comparison criterion, for the equilibrium-equivalent concentration of 222 Rn, measured results of Balm and 24 h integrating detectors are 31% and 29% higher than the criterion, the results of Wl x, however, is 20% lower; and for 220 Rn progeny, the results of Fiji-142, Kf-602D, BWLM and 24 h integrating detector are 86%, 18%, 28% and 36% higher than the criterion respectively, except that of WLx, which is 5% lower. For the differences shown, further research is needed. (authors)

  19. Radon concentration and exhalation rates in building material samples from crushing zone in Shivalik Foot Hills

    International Nuclear Information System (INIS)

    Pundir, Anil; Kamboj, Sunil; Bansal, Vakul; Chauhan, R.P.; Rana, Rajinder Singh

    2012-01-01

    Radon ( 222 Rn) is an inert radioactive gas in the decay chain of uranium ( 238 U). It continuously emanates from soil to the atmosphere. Radon and its progeny are the major natural radioactive sources for the ambient radioactivity on Earth. A number of studies on radon were performed in recent decades focusing on its transport and movement in the atmosphere under different meteorological conditions. Building materials are the main source of radon inside buildings. Some construction materials are naturally more radioactive and removal of such material from the earth's crust and their subsequent use in construction of buildings further enhances the radioactivity level. The knowledge of radioactivity level in the building materials makes us aware about the management, guidelines and standards in construction of buildings. The main objective of the present investigations is to measure radon Concentration and exhalation rates in the samples collected from the Crushing zone of Shivalik foot hills. Different types of materials are being used in Northern part of India for construction of dwellings. For the measurement of radon concentration and its exhalation rates in building materials, LR-115 detectors were exposed in closed plastic canisters for three months. At the end of the exposure time, the detectors were subjected to a chemical etching process in 2.5N NaOH solution. The tracks produced by the alpha particles were observed and counted under an optical Olympus microscope at 600X. The measured track density was converted into radon concentration using a calibration factor. The surface and mass exhalation rates of radon have also been calculated using present data. The results indicate that the radon concentration varies appreciably from sample to sample and they were found to satisfy the safety criteria. There are samples in which radon concentration is higher and may enhance the indoor radiation levels when used as building construction materials. (author)

  20. Long-lived 222Rn progeny concentrations in ground level air of Milan

    International Nuclear Information System (INIS)

    Marcazzan, G.M.; Valli, G.; Vecchi, R.; Bocelli, R.

    2002-01-01

    Short-lived (2 18P o, 2 14P b, 2 14B i, 2 14P o) as well as long-lived (2 10P b, 2 10B i, 2 10P o) Radon's decay products in atmosphere are due to the 2 22R n exhalation from the continental Earth's crust, where it is generated in the 2 38U decay series. The measurement of the radionuclides concentration in the atmosphere - in addition to yielding valuable data for radioprotection purposes and for assessing the environmental impact of natural radioactivity - can provide information on atmospheric thermodynamic conditions as well as on atmospheric processes that involve aerosols such as transport, dispersion, removal rates and residence time. In particular, the concentration ratio of 2 10P b with other Radon's daughters can be used to obtain information on mean residence time of aerosols (Poet et al., 1972; Rangarajan, 1992; Gaggeler et al., 1995). Continuous measurements of hourly concentration of Radon and its short-lived progeny are routinely carried out in Milan by our group, and the temporal behaviour comes out a suitable tracer of atmospheric stability conditions and a local index of the evolution of the mixing layer height (Marcazzan et al., 1993; Marcazzan et al., 1997). The aim of this work was to measure the concentration and temporal behaviour of 2 10P b on a weekly and a monthly scale at ground level in the urban area of Milan and to get reliable measurements on the annual average concentration for the implementation of the existing data base (Preiss et al., 1996)

  1. Legal issues in radon affairs

    International Nuclear Information System (INIS)

    Massuelle, M.H.

    1999-01-01

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

  2. Legal issues in radon affairs

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-01

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

  3. Towards the use of small amounts of activated charcoal along with well-type NaI(Tl) detector for indoor radon measurements

    International Nuclear Information System (INIS)

    Al-Azmi, D.

    2006-01-01

    The feasibility of using small quantities of activated charcoal and a 7.6 cm x 7.6 cm NaI(Tl) well-type detector was investigated for indoor radon measurements. Vials, filled with 10 g of charcoal, were exposed for different indoor radon concentration levels typical of Kuwait dwellings. After exposure, the vials were sealed and kept for 3 h to allow radon to come into radioactive equilibrium with its progenies and were then analysed by gamma-ray spectrometry using the well-type NaI(Tl) detector. The variation of radon absorption by the vials filled with charcoal with exposure time was also studied. A comparative study of the present technique with the standard technique of using 70 g charcoal canisters and flat NaI detector was also performed. After establishing the suitability of the technique, the charcoal vials were then used to investigate the effect of air-ventilation on the concentration levels of the indoor radon. Results show that there is a reduction in the radon concentration level (up to 25%) when the air-ventilation system was switched on. The paper presents the results of the study on the feasibility of combining small amounts of activated charcoal with a well-type NaI(Tl) detector in the measurement of indoor radon concentrations. (authors)

  4. Estimating lung cancer risks of indoor radon: applications for prevention

    International Nuclear Information System (INIS)

    Klotz, J.B.

    1986-01-01

    The epidemiologic evidence for a serious lung cancer hazard from radon exposure is very strong, and cumulative exposures accrued in residences may frequently overlap those accrued in underground miners. However, many uncertainties exist in extrapolating from mining to indoor risks because of differences in the populations, in radon exposure variables, and in other exposures. Risks are also considered for indoor radon exposures outside the home. There is already suggestive evidence of an association of lung cancer with radon levels in community settings, and several large-scale investigations are in progress. Some important questions regarding quantifying risk may not be approached, however; some further research needs are outlined including development of techniques for preventing or postponing lung cancer in individuals previously exposed to high radon levels. 31 references, 2 tables

  5. Procedure manual for the estimation of average indoor radon-daughter concentrations using the radon grab-sampling method

    International Nuclear Information System (INIS)

    George, J.L.

    1986-04-01

    The US Department of Energy (DOE) Office of Remedial Action and Waste Technology established the Technical Measurements Center to provide standardization, calibration, comparability, verification of data, quality assurance, and cost-effectiveness for the measurement requirements of DOE remedial action programs. One of the remedial-action measurement needs is the estimation of average indoor radon-daughter concentration. One method for accomplishing such estimations in support of DOE remedial action programs is the radon grab-sampling method. This manual describes procedures for radon grab sampling, with the application specifically directed to the estimation of average indoor radon-daughter concentration (RDC) in highly ventilated structures. This particular application of the measurement method is for cases where RDC estimates derived from long-term integrated measurements under occupied conditions are below the standard and where the structure being evaluated is considered to be highly ventilated. The radon grab-sampling method requires that sampling be conducted under standard maximized conditions. Briefly, the procedure for radon grab sampling involves the following steps: selection of sampling and counting equipment; sample acquisition and processing, including data reduction; calibration of equipment, including provisions to correct for pressure effects when sampling at various elevations; and incorporation of quality-control and assurance measures. This manual describes each of the above steps in detail and presents an example of a step-by-step radon grab-sampling procedure using a scintillation cell

  6. Measurement of Radon-Induced Backgrounds in the NEXT Double Beta Decay Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Novella, P.; et al.

    2018-04-02

    The measurement of the internal 222Rn activity in the NEXT-White detector during the so-called Run-II period with 136Xe-depleted xenon is discussed in detail, together with its implications for double beta decay searches in NEXT. The activity is measured through the alpha production rate induced in the fiducial volume by 222Rn and its alpha-emitting progeny. The specific activity is measured to be $(37.5\\pm 2.3~\\mathrm{(stat.)}\\pm 5.9~\\mathrm{(syst.)})$~mBq/m$^3$. Radon-induced electrons have also been characterized from the decay of the 214Bi daughter ions plating out on the cathode of the time projection chamber. From our studies, we conclude that radon-induced backgrounds are sufficiently low to enable a successful NEXT-100 physics program, as the projected rate contribution should not exceed 0.2~counts/yr in the neutrinoless double beta decay sample.

  7. A novel detection of radon based on its decay product inducing conformational changes of an aptamer probe

    International Nuclear Information System (INIS)

    Long, Minzhi; Deng, Han; Tian, Gang; Song, Chunli; Liu, Hongwen; Shen, Yi; Lv, Changyin

    2016-01-01

    This study proposes a novel method for the detection of inert gas radon using a label-free, specific, fluorescence-sensing aptamer in the context of PW17-OG system. This method utilizes the cyanine dye OliGreen (OG) as a signal reactor and the aptamer PW17 as a fluorescent identification probe. When OG integrates into the free curling PW17, a strong fluorescence signal is generated. After radon decays, the long lived naturally occurring radon progeny Pb being disposed and introduced to the system. Lead ions induce PW17 to form a stable G-quadruplex, thereby inhibiting the interaction between OG and PW17 and resulting in a reduction of the fluorescence intensity. The fluorescence intensity show a good linear relationship with lead ion and the radon concentration (D), thereinto, We fitted linear regression of radon concentration in the range of 0.92–4.22 (×10"4 Bqhm"−"3) to receive a good relationship between ΔF and the concentration of radon with the detection limit of 1963 Bqhm"−"3. This method has been successfully applied for detecting standard cumulative concentration of radon and the detection limit reached the national standard of China. This sensitive method can exclude radiation damage in field testing, furthermore, it explores a new field in biological analysis using an aptamer to detected inorganic, gaseous, and radioactive materials. - Highlights: • The label-free fluorescence sensor for detection of radon. • This microscale experiment without radiation damage to experimenters and with less harm to environment. • It provides a sensitive, low cost and simple strategy for radon accumulated concentration and lead ion detection.

  8. A novel detection of radon based on its decay product inducing conformational changes of an aptamer probe

    Energy Technology Data Exchange (ETDEWEB)

    Long, Minzhi; Deng, Han; Tian, Gang; Song, Chunli; Liu, Hongwen; Shen, Yi; Lv, Changyin, E-mail: Lchy1955@163.com

    2016-09-14

    This study proposes a novel method for the detection of inert gas radon using a label-free, specific, fluorescence-sensing aptamer in the context of PW17-OG system. This method utilizes the cyanine dye OliGreen (OG) as a signal reactor and the aptamer PW17 as a fluorescent identification probe. When OG integrates into the free curling PW17, a strong fluorescence signal is generated. After radon decays, the long lived naturally occurring radon progeny Pb being disposed and introduced to the system. Lead ions induce PW17 to form a stable G-quadruplex, thereby inhibiting the interaction between OG and PW17 and resulting in a reduction of the fluorescence intensity. The fluorescence intensity show a good linear relationship with lead ion and the radon concentration (D), thereinto, We fitted linear regression of radon concentration in the range of 0.92–4.22 (×10{sup 4} Bqhm{sup −3}) to receive a good relationship between ΔF and the concentration of radon with the detection limit of 1963 Bqhm{sup −3}. This method has been successfully applied for detecting standard cumulative concentration of radon and the detection limit reached the national standard of China. This sensitive method can exclude radiation damage in field testing, furthermore, it explores a new field in biological analysis using an aptamer to detected inorganic, gaseous, and radioactive materials. - Highlights: • The label-free fluorescence sensor for detection of radon. • This microscale experiment without radiation damage to experimenters and with less harm to environment. • It provides a sensitive, low cost and simple strategy for radon accumulated concentration and lead ion detection.

  9. 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

  10. Radon reduction in crawl-space houses

    International Nuclear Information System (INIS)

    Osborne, M.C.; Moore, D.G.; Southerlan, R.E.; Brennan, T.; Pyle, B.E.

    1989-01-01

    This paper gives results of an EPA study of radon-mitigation alternatives for crawl space houses in several houses in Nashville, TN. Application of one of these alternative mitigation options, suction under a polyethylene membrane, has been successful in significantly reducing radon levels in both the crawl space and the house. The large radon concentrations measured under unvented plastic ground covers and the moisture barriers found in many crawl spaces can act as radon-rich reservoirs capable of contaminating a crawl space and house during periods of depressurization. With the exhaust components of the mitigation system in place, radon levels below the plastic decreased by more than 95% under both passive and active suction conditions. Based on the study, the design of a cost-effective subplastic suction passive radon mitigation system for crawl spaces seems promising

  11. Calibration comparative results for X - and gamma ray spectrometry with HPGe and BEGe detectors for a radon reference chamber

    International Nuclear Information System (INIS)

    Zoran, Maria; Paul, Annette; Arnold, Dirk

    2002-01-01

    Inhaled decay products of 222 Rn are the dominant components of the natural radiation exposure being responsible for about 30% of the whole human radioactive exposure. Field instruments for 222 Rn and his progeny monitoring are calibrated in 'radon climate rooms', where it is possible to vary and monitor 222 Rn and the indoor air parameters ( temperature, humidity, ventilation rate, aerosol concentration). German radon reference chamber used was developed and installed at the Physikalisch-Technische Bundesanstalt in order to serve as a metrological standard for radon and his progeny calibration of active and passive, indoor and outdoor radon monitoring devices in air climate. The basic parts of experimental setup for this γ and X -ray spectrometry analysis consists of a γ-X ray source in a lead shield/collimator, the detectors, the electronics necessary for pulse-height analysis (PHA) to obtain energy spectra. For calibrating system with 226 Ra standard sources (multienergy X ray and gamma emitters), two germanium detectors HPGe (12.5 nominal efficiency) and BEGe (22.5 nominal efficiency) were used. Germanium detectors are semiconductor diodes having a P-I-N structure in which the Intrinsic (I) region is sensitive to ionizing radiation, particularly X-rays and gamma rays. The BEGe is designed with an electrode structure that enhances low energy resolution and is fabricated from selected germanium having an impurity profile that improves charge collection (thus resolution and peak shape) at high energies which is really important in analysis of the complex spectra for uranium and finally for 226 Ra. MAESTRO MCA software and GNUPLOT program were used for spectra acquisition and spectra analysis, respectively . The main aim of this paper was to do a comparatively analysis of the detector performances for this radon chamber spectrometric chain. The calibration data analysis includes energy calibrations for both detection systems as well as comparative X and gamma

  12. Critical assessment of the deposition based dosimetric technique for radon/thoron decay products

    International Nuclear Information System (INIS)

    Mayya, Y.S.

    2010-01-01

    Inhalation doses due to radon ( 222 Rn) and thoron ( 220 Rn) are predominantly contributed by their decay products and not due to the gases themselves. Decay product measurements are being carried out essentially by either short-term active measurement like by air-sampling on a substrate followed by alpha or beta counting or by continuous active monitoring techniques based on silicon barrier detector. However, due to non-availability of satisfactory passive measurement techniques for the progeny species, it has been a usual practice to estimate the long time averaged progeny concentration from measured gas concentration using an assumed equilibrium factor. To be accurate, one is required to measure the equilibrium factor in situ along with the gas concentration. This being not practical, the assigned equilibrium factor (0.4 for indoor and 0.8 for outdoor for 222 Rn) approach has been an inevitable, though uncertain, part of the dosimetric strategies in both occupational and public domains. Further, in the case of thoron decay products however, equilibrium factor is of far more questionable validity. Thus, there is a need to shift from gas based dosimetric paradigm to that based on direct detection of progeny species

  13. Radon therapy in the Soviet Union

    International Nuclear Information System (INIS)

    Sansoni, B.; Andrejew, S.V.

    1991-08-01

    In the Soviet Union approximately one million courses of radon treatment each lasting three weeks are prescribed every year. The curative application of radon used for cardiovascular diseases, including aftercare in cases of cardiac infarction, disorders of the locomotor system and joints and muscles, the male and female sexual system, diseases of the nervous system, endocrinology and metabolic diseases. Contraindication practice is similar to that in Central Europe. Radon is given to skin stimulation by wet and above all dry baths. The radiation exposure of patients from these three-week radon treatments is relatively low. The radon effect is interpreted as 'radiation flash' stimulating the nervous system. The skin plays a particular role in this process, acting as the stimulus acceptor. (orig./MG) [de

  14. Radon in US workplaces: a review

    International Nuclear Information System (INIS)

    Daniels, Robert D.; Schubauer-Berigan, Mary K.

    2017-01-01

    Exposure to naturally occurring radon is unavoidable and is second only to smoking as a direct cause of lung cancer in the USA. The literature for existing information on US occupations that are prone to increased radon exposures was reviewed. Current recommendations and applicable protective standards against occupational radon exposure that are applicable to US workers are discussed. Exposure varied widely among several working populations, most of whom were employed in industries that were unrelated to the uranium fuel cycle. Radon protection standards differed among agencies and have not changed since the height of domestic uranium production in the 1970's. In contrast, European countries are adopting recommendations by the International Commission on Radiation Protection to set a reference level near a derived annual exposure of about one working level month, which is 25% of the level currently established for US miners. (authors)

  15. 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.

  16. Modelling and experimental study of the behavior of radon and radon decay products in an enclosure. Application to houses

    International Nuclear Information System (INIS)

    Gouronnec, A.M.

    1995-01-01

    Since the eighties, more and more studies were performed about radon and its decay products in houses with one of the aim being the estimation of the dose received by their inhabitants. Then, the principal objective of this work is to describe the behaviour of radon and its decay products within a dwelling. In the first part to the report, a few definitions are given and data from literature give an idea of indoor radon and radon decay products activities and/or size distribution. Aspects of dosimetry are presented too. In the second part of the work, a mathematical model, called 'PRADDO' of Physic of Radon and radon Decay products in Domestic environment is developed on the basis of the classical model written by Jacobi in 1972. On the one hand, it has to predict radon decay products activities in systems consisting in one or more enclosure(s), from radon activity and from ambient aerosol concentration and size distribution. On the other hand, one part of the model is assigned to study the influence of the entry model parameters variation on the calculated quantities. Then, in the third part of the work, two experimental studies are realised in order to compare measurements to modelization. The first experimentation is a laboratory work, made on the test bench ICARE from IPSN, and the second one consists in describing the basement of an occupied house from Brittany. In the two cases, the comparison between experiments and modelling shows a good agreement if particles are present in the air, but any conclusion is made when is no aerosol in the enclosure. (author). 158 refs., 81 figs., 42 tabs

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    Between 2008 and 2011 a survey of radon ( 222 Rn) was performed in schools of several districts of Southern Serbia. Some results have been published previously (Žunić et al., 2010; Carpentieri et al., 2011; Žunić et al., 2013). This article concentrates on the geographical distribution of the measured Rn concentrations. Applying geostatistical methods we generate “school radon maps” of expected concentrations and of estimated probabilities that a concentration threshold is exceeded. The resulting maps show a clearly structured spatial pattern which appears related to the geological background. In particular in areas with vulcanite and granitoid rocks, elevated radon (Rn) concentrations can be expected. The “school radon map” can therefore be considered as proxy to a map of the geogenic radon potential, and allows identification of radon-prone areas, i.e. areas in which higher Rn radon concentrations can be expected for natural reasons. It must be stressed that the “radon hazard”, or potential risk, estimated this way, has to be distinguished from the actual radon risk, which is a function of exposure. This in turn may require (depending on the target variable which is supposed to measure risk) considering demographic and sociological reality, i.e. population density, distribution of building styles and living habits. -- Highlights: • A map of Rn concentrations in primary schools of Southern Serbia. • Application of geostatistical methods. • Correlation with geology found. • Can serve as proxy to identify radon prone areas

  18. Genetic Diversity and Relationships of Neolamarckia cadamba (Roxb. Bosser progenies through cluster analysis

    Directory of Open Access Journals (Sweden)

    M. Preethi Shree

    2018-04-01

    Full Text Available Genetic diversity analysis was conducted for biometric attributes in 20 progenies of Neolamarckia cadamba. The application of D2 clustering technique in Neolamarckia cadamba genetic resources resolved the 20 progenies into five clusters. The maximum intra cluster distance was shown by the cluster II. The maximum inter cluster distance was recorded between cluster III and V which indicated the presence of wider genetic distance between Neolamarckia cadamba progenies. Among the growth attributes, volume (36.84 % contributed maximum towards genetic divergence followed by bole height, basal diameter, tree height, number of branches in Neolamarckia cadamba progenies.

  19. Optimizing the number of progenies and replications in plant breeding experiments

    Directory of Open Access Journals (Sweden)

    João Luís da Silva Filho

    2013-01-01

    Full Text Available A determination criterion was proposed for the number of replications, r, and of evaluated progenies, Nr, given P experimentalplots, with Nr=P/r, and n progenies to be selected; its application was discussed in the selection of progenies of bulk populations,derived from two homozygous parents. For a known heritability at the plot level, h20, there is a critical n below which the gain isgreater with selection evaluating P/(r+1 progenies in r+1 than P/r progenies in r replications. Different h20 scenarios were simulatedin the F2 and F∞ generations, assuming no dominance. It was demonstrated that at any h20 , if n > 18.5% of P, larger gains are obtainedby assuming Nr = P, showing that the augmented block design could be used in the early stages of breeding programs. The higher h20,the higher must be the selection intensity to justify the use of additional replications.

  20. Study of underground radon transport

    International Nuclear Information System (INIS)

    Csige, I.; Hakl, J.; Lenart, L.

    1990-01-01

    The soil gas radon content measurements with solid state nuclear track detectors (SSNTDs) are widely used in geoscience, for instance in uranium exploration and earthquake prediction. In these applications the radon frequently is used as a natural tracer of underground fluid transport processes. Obviously, to get the soil radon measuring method more and more effective the study of these transport processes in deeper part of the Earth is fundamental. The Track Detector Group in the Institute of Nuclear Research of the Hungarian Academy of Sciences in Debrecen has been performing environmental radon activity concentration measurements since 1977 with alpha sensitive SSNTDs. These types of measurements were initiated and widely used by the late head of the group Dr. G. Somogyi, who devoted his life to better understanding of the nature. The measurements in caves, springs and drilled wells proved to be effective to study these underground radon transport processes. We are glad to present some results of our investigations. 7 refs, 7 figs