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Sample records for radon progeny exposure

  1. Exposure to radon and radon progeny in the indoor environment

    SciTech Connect

    Socolow, R.H.

    1991-01-01

    The objective of this work is to measure experimentally the activity-weighted particle size distribution in conjunction with other relevant house parameters in occupied houses in order to improve the estimate of exposure to radon and radon progeny indoors. Our methodology requires that building construction and operation be studied and understood both experimentally and theoretically in a small number of buildings and that results of side applicability be inferred from the particular case studies. Results are discussed.

  2. Variation of the unattached fraction of radon progeny and its contribution to radon exposure.

    PubMed

    Guo, Lu; Zhang, Lei; Guo, Qiuju

    2016-06-01

    The unattached fraction of radon progeny is one of the most important factors for radon exposure evaluation through the dosimetric approach. To better understand its level and variation in the real environment, a series of field measurements were carried out indoors and outdoors, and radon equilibrium equivalent concentration was also measured. The dose contribution of unattached radon progeny was evaluated in addition. The results show that no clear variation trend of the unattached fraction of radon progeny is observed in an indoor or outdoor environment. The average unattached fraction of radon progeny for the indoors and outdoors are (8.7  ±  1.6)% and (9.7  ±  2.1)%, respectively. The dose contribution of unattached radon progeny to total radon exposure is some 38.8% in an indoor environment, suggesting the importance of the evaluation on unattached radon progeny. PMID:27171653

  3. Exposure to radon and radon progeny in the indoor environment. Final report

    SciTech Connect

    Socolow, R.H.

    1994-10-01

    This report discusses the work done by the Center for Energy and Environmental Studies at Princeton University as part of the radon research program. It involves radon measurements in various buildings, as well as the use of natural ventilation to mitigate radon levels. The report is divided into four chapters: The use of radon entry rate measurements to understand radon concentration in buildings; Use of natural basement ventilation to control radon in single family dwellings; The effect of natural ventilation on radon and radon progeny levels in houses; and Comparison of natural and forced ventilation for radon mitigation in houses.

  4. Dose estimation derived from the exposure to radon, thoron and their progeny in the indoor environment.

    PubMed

    Ramola, R C; Prasad, Mukesh; Kandari, Tushar; Pant, Preeti; Bossew, Peter; Mishra, Rosaline; Tokonami, S

    2016-01-01

    The annual exposure to indoor radon, thoron and their progeny imparts a major contribution to inhalation doses received by the public. In this study, we report results of time integrated passive measurements of indoor radon, thoron and their progeny concentrations that were carried out in Garhwal Himalaya with the aim of investigating significant health risk to the dwellers in the region. The measurements were performed using recently developed LR-115 detector based techniques. The experimentally determined values of radon, thoron and their progeny concentrations were used to estimate total annual inhalation dose and annual effective doses. The equilibrium factors for radon and thoron were also determined from the observed data. The estimated value of total annual inhalation dose was found to be 1.8 ± 0.7 mSv/y. The estimated values of the annual effective dose were found to be 1.2 ± 0.5 mSv/y and 0.5 ± 0.3 mSv/y, respectively. The estimated values of radiation doses suggest no important health risk due to exposure of radon, thoron and progeny in the study area. The contribution of indoor thoron and its progeny to total inhalation dose ranges between 13-52% with mean value of 30%. Thus thoron cannot be neglected when assessing radiation doses. PMID:27499492

  5. Dose estimation derived from the exposure to radon, thoron and their progeny in the indoor environment

    PubMed Central

    Ramola, R. C.; Prasad, Mukesh; Kandari, Tushar; Pant, Preeti; Bossew, Peter; Mishra, Rosaline; Tokonami, S.

    2016-01-01

    The annual exposure to indoor radon, thoron and their progeny imparts a major contribution to inhalation doses received by the public. In this study, we report results of time integrated passive measurements of indoor radon, thoron and their progeny concentrations that were carried out in Garhwal Himalaya with the aim of investigating significant health risk to the dwellers in the region. The measurements were performed using recently developed LR-115 detector based techniques. The experimentally determined values of radon, thoron and their progeny concentrations were used to estimate total annual inhalation dose and annual effective doses. The equilibrium factors for radon and thoron were also determined from the observed data. The estimated value of total annual inhalation dose was found to be 1.8 ± 0.7 mSv/y. The estimated values of the annual effective dose were found to be 1.2 ± 0.5 mSv/y and 0.5 ± 0.3 mSv/y, respectively. The estimated values of radiation doses suggest no important health risk due to exposure of radon, thoron and progeny in the study area. The contribution of indoor thoron and its progeny to total inhalation dose ranges between 13–52% with mean value of 30%. Thus thoron cannot be neglected when assessing radiation doses. PMID:27499492

  6. Dose estimation derived from the exposure to radon, thoron and their progeny in the indoor environment

    NASA Astrophysics Data System (ADS)

    Ramola, R. C.; Prasad, Mukesh; Kandari, Tushar; Pant, Preeti; Bossew, Peter; Mishra, Rosaline; Tokonami, S.

    2016-08-01

    The annual exposure to indoor radon, thoron and their progeny imparts a major contribution to inhalation doses received by the public. In this study, we report results of time integrated passive measurements of indoor radon, thoron and their progeny concentrations that were carried out in Garhwal Himalaya with the aim of investigating significant health risk to the dwellers in the region. The measurements were performed using recently developed LR-115 detector based techniques. The experimentally determined values of radon, thoron and their progeny concentrations were used to estimate total annual inhalation dose and annual effective doses. The equilibrium factors for radon and thoron were also determined from the observed data. The estimated value of total annual inhalation dose was found to be 1.8 ± 0.7 mSv/y. The estimated values of the annual effective dose were found to be 1.2 ± 0.5 mSv/y and 0.5 ± 0.3 mSv/y, respectively. The estimated values of radiation doses suggest no important health risk due to exposure of radon, thoron and progeny in the study area. The contribution of indoor thoron and its progeny to total inhalation dose ranges between 13–52% with mean value of 30%. Thus thoron cannot be neglected when assessing radiation doses.

  7. Exposure to radon and radon progeny in the indoor environment. Technical progress report, January 1, 1990--December 30, 1991

    SciTech Connect

    Socolow, R.H.

    1991-12-31

    The objective of this work is to measure experimentally the activity-weighted particle size distribution in conjunction with other relevant house parameters in occupied houses in order to improve the estimate of exposure to radon and radon progeny indoors. Our methodology requires that building construction and operation be studied and understood both experimentally and theoretically in a small number of buildings and that results of side applicability be inferred from the particular case studies. Results are discussed.

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

    SciTech Connect

    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.

  9. Effects of acute radon progeny exposure on rat alveolar macrophage number and function

    SciTech Connect

    Johnson, N.F.; Newton, G.J.; Guilmette, R.A.

    1992-12-31

    Alveolar macrophages play a key role in removal and translocation of inhaled particles and have been shown to influence proliferation of Alveolar Type II cells and fibroblasts. The effect of radon progeny on alveolar macrophage number and function is not documented. Functional impairment of alveolar macrophages may be an ancillary event in the induction of pulmonary lesions and may also indicate dose to the peripheral lung. In our study, rats were exposed to 1000 working level months (WLM) of radon progeny over a 3- to 5-h period, with a vector aerosol of environmental tobacco smoke. Groups of animals were sacrificed, and the lungs were lavaged immediately after exposure and on days 2, 18, 16, 21 and 29 after exposure. The numbers and viabilities of the lavaged macrophages were determined. Cytological preparations were made to determine the number of binucleated/multinucleated macrophages and macrophages containing micronuclei. The DNA content was measured flow-cytometrically using Hoechst 33342, and phagocytosis was assayed by determining the uptake of fluorescent microspheres. The numbers and viabilities of macrophages recovered from exposed animals were similar to the values measured for control animals. There was no evidence of an inflammatory reaction during any period after radon progeny exposure. Nuclear atypia, evidenced by increases in the number of binucleated cells and cells with micronuclei, occurred in animals 8 days after exposure, and this response peaked at 21 days after exposure. The phagocytic capability of the alveolar macrophages was not significantly affected at any time point after exposure. These results show that there was little functional impairment of alveolar macrophages in rats after acute radon-progeny exposure; however, there was long-standing interference with cell division, resulting in binucleated and micronucleated macrophages.

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

    SciTech Connect

    Mishra, Rosaline E-mail: rosaline.mishra@gmail.com; Sapra, B. K.; Mayya, Y. S.

    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.

  11. A radon progeny deposition model

    SciTech Connect

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

    2010-12-01

    The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly {sup 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 {sup 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.

  12. A Radon Progeny Deposition Model

    SciTech Connect

    Guiseppe, V. E.; Elliott, S. R.; Hime, A.; Rielage, K.; Westerdale, S.

    2011-04-27

    The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly {sup 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 {sup 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.

  13. Control of indoor radon and radon progeny concentrations

    SciTech Connect

    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.

  14. Dosimetry of inhaled radon and thoron progeny

    SciTech Connect

    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 {alpha} 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 {alpha} dose from radon and thoron progeny, in order to obtain a realistic estimate of lung cancer risk.

  15. Modifiers of exposure-response estimates for lung cancer among miners exposed to radon progeny.

    PubMed Central

    Hornung, R W; Deddens, J; Roscoe, R

    1995-01-01

    The association between lung cancer and exposure to radon decay products has been well established. Despite agreement on this point, there is still some degree of uncertainty regarding characteristics of the exposure-response relationship. The use of studies of underground miners to estimate lung cancer risks due to residential radon exposure depends upon a better understanding of factors potentially modifying the exposure-response relationship. Given the diversity in study populations regarding smoking status, mining conditions, risk analysis methodology, and referent populations, the risk estimates across studies are quite similar. However, several factors partially contributing to differences in risk estimates are modified by attained age, time since last exposure, exposure rate, and cigarette smoking patterns. There is growing agreement across studies that relative risk decreases with attained age and time since last exposure. Several studies have also found an inverse exposure-rate effect, i.e., low exposure rates for protracted duration of exposure are more hazardous than equivalent cumulative exposures received at higher rates for shorter periods of time. Additionally, the interaction between radon exposure and cigarette smoking appears to be intermediate between additive and multiplicative in a growing number of studies. Quantitative estimates of these modifying factors are given using a new analysis of data from the latest update of the Colorado Plateau uranium miners cohort. PMID:7614947

  16. Exposure to atmospheric radon.

    PubMed Central

    Steck, D J; Field, R W; Lynch, C F

    1999-01-01

    We measured radon (222Rn) concentrations in Iowa and Minnesota and found that unusually high annual average radon concentrations occur outdoors in portions of central North America. In some areas, outdoor concentrations exceed the national average indoor radon concentration. The general spatial patterns of outdoor radon and indoor radon are similar to the spatial distribution of radon progeny in the soil. Outdoor radon exposure in this region can be a substantial fraction of an individual's total radon exposure and is highly variable across the population. Estimated lifetime effective dose equivalents for the women participants in a radon-related lung cancer study varied by a factor of two at the median dose, 8 mSv, and ranged up to 60 mSv (6 rem). Failure to include these doses can reduce the statistical power of epidemiologic studies that examine the lung cancer risk associated with residential radon exposure. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:9924007

  17. Attachment of radon progeny to cigarette-smoke aerosols

    SciTech Connect

    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, {approximately}10{sup {minus}6} cm{sup 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.

  18. Microdosimetry of radon progeny: Application to risk assessment

    SciTech Connect

    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.

  19. Method for determining individual deposition velocities of radon progeny.

    PubMed

    Angell, C T; Pedretti, M; Norman, E B

    2015-04-01

    The deposition velocity of radon progeny is used to model the removal of progeny from the air by surfaces in assessing indoor air quality. It can also be used to assess radon-induced background in sensitive, low-background experiments. A single value of the deposition velocity is typically used for all radon progeny for modeling purposes. This paper presents a method for uniquely determining the individual deposition velocities of radon progeny. Measurements demonstrating the method were carried out. PMID:25618737

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

    SciTech Connect

    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 {plus_minus}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.

  1. Impact of energy conservation measures on radon and radon progeny concentrations: A controlled study

    SciTech Connect

    Rector, H.E.; Koontz, M.D.; Cade, D.R.; Nagda, N.L.

    1985-01-01

    The effects of retrofitting for building tightness, air-to-air heat exchangers, and HVAC circulation fans on radon and radon progeny levels were investigated using two matched test houses. One test house was retrofitted for tightness and outfitted with an air-to-air heat exchanger. The two houses were unoccupied; selected occupant-related activities were simulated in a controlled manner. Retrofit for tightness reduced the annual average air infiltration rate by 24% and increased radon and radon progeny concentrations by a similar amount. The air-to-air heat exchanger reduced radon and radon progeny concentrations commensurate with mechanical ventilation. Increased mixing from the furnace circulation fan equalized the upstairs/downstairs concentrations. Extended use of the circulation fan reduced radon progeny levels similar to those obtained with the heat exchanger (about 50% reduction). Seasons had considerable impact on indoor radon and radon progeny; higher levels were found in the summer and fall seasons.

  2. Radiometric Meteorology: radon progeny as tracers

    NASA Astrophysics Data System (ADS)

    Greenfield, Mark; Iwata, Atsushi; Ito, Nahoko; Kubo, Kenya; Komura, Kazu; Ishizaki, Miho

    2008-10-01

    In-situ measurement of atmospheric γ radiation from radon progeny determine rain and snow rates to better accuracy than standard rain gauges and gives a handle on how droplets are formed. The measured γ ray rates (GRR) have been shown to be proportional to a power of radiometric precipitation rates (RPR)^α, α giving a handle on the extent to which radon progeny are surface adsorbed or volume absorbed.ootnotetextM. B. Greenfield et al., J. Appl. Phys. 93, (2003) pp 5733-5741. More recently time dependent ratios of GRR from ^214Pb and ^214Bi, concentrated from collected rainwater, have been used to determine the elapsed time since activity from RPR, adhered to rain droplets, was removed from secular equilibrium. Ion exchange resins precipitate out the ^214Pb and ^214Bi ions, which are then filtered from 10s of liters of rainwater or snowmelt. A portable Ge detector is used to integrate the resulting activity over 5-10 min intervals. The measured evolution of these two activities from secular equilibrium to transient equilibrium has meteorological applications enabling both the determination of average elapsed times between the formation of raindrops and the time they reach the ground, as well as an estimate of the initial activity at the source of droplet formation.

  3. Comparative analysis of radon, thoron and thoron progeny concentration measurements

    PubMed Central

    Janik, Miroslaw; Tokonami, Shinji; Kranrod, Chutima; Sorimachi, Atsuyuki; Ishikawa, Tetsuo; Hosoda, Masahiro; Mclaughlin, James; Chang, Byung-Uck; Kim, Yong Jae

    2013-01-01

    This study examined correlations between radon, thoron and thoron progeny concentrations based on surveys conducted in several different countries. For this purpose, passive detectors developed or modified by the National Institute of Radiological Sciences (NIRS) were used. Radon and thoron concentrations were measured using passive discriminative radon-thoron detectors. Thoron progeny measurements were conducted using the NIRS-modified detector, originally developed by Zhuo and Iida. Weak correlations were found between radon and thoron as well as between thoron and thoron progeny. The statistical evaluation showed that attention should be paid to the thoron equilibrium factor for calculation of thoron progeny concentrations based on thoron measurements. In addition, this evaluation indicated that radon, thoron and thoron progeny were independent parameters, so it would be difficult to estimate the concentration of one from those of the others. PMID:23297318

  4. The Effect of Ultrafine Aerosol (0.5 to 50 NM (0.05 Micrometers)) on the Deposition of Radon Progeny in Human Lungs and Implications for the Measurement of Exposure.

    NASA Astrophysics Data System (ADS)

    Schmalbeck, Linda Michaels

    1995-01-01

    Despite a generally acknowledged public health risk from indoor exposure to airborne radon progeny, measurement techniques in current use do not provide sufficient information to assess risk from exposures in the home. By contrast, a simple, direct, measurement (the working level month) is a reliable starting point for the evaluation of miners' risks from radon progeny exposure. Ultrafine particles (0.5 to 50 nm in diameter) are frequently present in room air, especially during high occupancy times when activities like cooking and cleaning are taking place; but they are virtually absent from mine air. Measurement techniques used to evaluate mine and indoor air exposures do not supply any size-based data. Few studies of ultrafine aerosol deposition in humans have been undertaken, and none of these has specifically examined ultrafine particle deposition in the radiosensitive bronchial region of the respiratory tract. In this research, the effect of ultrafine aerosol on radon progeny deposition in the bronchial airways was studied using: (1) a unique human exposure data base involving 8 men and 4 women volunteers, (2) a mathematical model describing the attachment behavior of radon progeny in the presence of aerosol developed as part of this work, and (3) a human respiratory-tract deposition model. The addition of ultrafine aerosol to the air breathed by human subjects more than doubled the amount of radon progeny activity deposited in the bronchial region of the subjects' lungs, although radon gas concentration was held constant during all exposure experiments. The gamma activity measured in vivo remained higher at all times after exposure to ultrafine aerosol, while the rate of gamma activity clearance from the region was, on average, about 40 percent faster following ultrafine aerosol exposure. The human exposure data demonstrated that some aerosol size information is crucial to the determination of regional lung deposition and, consequently, the calculation of

  5. Deposition of radon progeny in nonhuman primate nasal airways

    SciTech Connect

    Yeh, H.C.; Cheng, Y.S.; Su, Y.F. . Inhalation Toxicology Research Inst.); Morgan, K.T. )

    1991-01-01

    Information on aerosol deposition patterns in the human respiratory tract is needed to improve health risk estimates for exposure to airborne radon progeny. To investigate this, deposition of {sup 220}Rn progeny in Rhesus monkey nasal casts was examined. A substantial fraction of the inhaled ultrafine particles are deposited in the nasal cast. Deposition efficiency increases with decreasing particle size, reaching a maximum value of 80% for particles 1.7 nm in diameter. Breathing flow rate has a minimal effect on deposition efficiency. Deposition efficiencies for particles smaller than 100 nm in diameter are similar for monkey and human nasal casts. Equations based on turbulent diffusion can be fitted to these data for either inspirational or expirational flow. These mathematical expressions will be useful for modifying the inhaled particle deposition and dosimetry models. 20 refs., 9 figs., 1 tab (MHB)

  6. An historical overview of radon and its progeny: applications and health effects.

    PubMed

    Mc Laughlin, J

    2012-11-01

    Since its discovery by Dorn in 1900, studies of radon and its progeny have contributed to such diverse scientific fields as meteorology, geophysics, mineral exploration and radiation health effects. In addition to terrestrial scientific studies of radon, NASA missions in recent decades have yielded data on the behaviour of radon and its progeny on the Moon and on Mars. Radon has been used therapeutically for ∼100 y in the form of radon seeds for the irradiation of malignant tumours. It is, however, for its negative health effects that radon is better and more justifiably known. The causal role of radon and, in particular, its progeny in the elevated incidence of lung cancer in underground uranium miners was established in the 1950s. It is of historical interest to note that the fatal lung disease of silver miners in Saxony and Bohemia in the 16th century, was undoubtedly lung cancer caused by the high levels of radon in the mines. In recent decades there has been an ever-growing interest in the public health effects of exposure to radon in homes. Extensive radon epidemiological studies both of underground miners and of the general public in recent decades have quantified the lung cancer risks from radon exposure. Radon was classified in 1988 by International Agency for Research on Cancer as a human carcinogen and in 2009 the World Health Organization identified radon as the second cause of lung cancer globally after smoking. Radon control strategies are used by many governments to control and reduce the risk to public health from radon. PMID:22914338

  7. 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

    SciTech Connect

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

    1994-08-01

    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.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  10. Morphology of respiratory tract lesions in rats exposed to radon progeny

    SciTech Connect

    Dagle, G.E.; Cross, F.T.; Gies, R.A.

    1992-12-31

    We will discuss the morphologic features of lesions in the respiratory tract of rats exposed to radon and radon progeny. Groups of male Wister rats were exposed to from 10 to 1000 working levels (WL) of radon progeny in the presence of less than 1 to about 15 mg m{sup {minus}3} uranium ore dust. Cumulative exposures ranged from 20 to approximately 10,000 working level months (WLM). Higher exposure levels produced radiation pneumonitis characterized by interstitial fibrosis, associated with alveolar epithelial cell hyperplasia and accumulations of alveolar macrophages containing phagocytosed uranium ore dust. Nodular fibrosis and alveolar proteinosis were correlated with deposits of uranium ore dust. Vesicular emphysema also occurred at higher exposure levels. Pulmonary adenomatosis appeared to be a preneoplastic lesion; it was composed of nodular proliferation of bronchioloalveolar epithelium without disruption of the general architecture of the parenchyma. At exposure levels where rats lived longer than 1 y, lung tumors and a few tumors of the nasal cavity developed. The principal lung tumors were pulmonary adenomas, bronchioloalveolar carcinomas, papillary adenocarcinomas, epidermoid carcinomas, and adenosquamous carcinomas. Occasionally, malignant mesotheliomas and sarcomas were also present. The malignant lung tumors were characterized by invasion and occasionally metastasized to regional lymph nodes. Lower exposure rates produced more tumors, generally of different histologic types, and more fatal tumors than higher exposure rates. The similarity to relationships of human radon progeny exposure as far as incidence and types of lung tumors establish the validity of this animal model for studying radon carcinogenesis in humans.

  11. Deposition of radon progeny in nonhuman primate nasal airways

    SciTech Connect

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

    1992-12-31

    Radon progeny are usually associated with ultrafine particles ranging in diameter from 0.001 to 0.005 {mu}m for {open_quotes}unattached{close_quotes} progeny and from 0.005 to 0.2 {mu}m 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 {mu}m in the nasal passages of laboratory animals is available; however, there is little information on the deposition of particles smaller than 0.2 {mu}m. In this report, we describe the use of nasal casts of a rhesus monkey to measure total deposition of ultrafine aerosols, including unattached {sup 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 {mu}m, 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 {sup 22-}Rn progeny, at particle sizes from 0.001 to 0.003 {mu}m. 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{sup b}Q{sup c}) for d{sub p} {<=} 0.2 {mu}m, was derived, where E is the deposition efficiency, d{sub 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.

  12. Modeling surface backgrounds from radon progeny plate-out

    SciTech Connect

    Perumpilly, G.; Guiseppe, V. E.; Snyder, N.

    2013-08-08

    The next generation low-background detectors operating deep underground aim for unprecedented low levels of radioactive backgrounds. The surface deposition and subsequent implantation of radon progeny in detector materials will be a source of energetic background events. We investigate Monte Carlo and model-based simulations to understand the surface implantation profile of radon progeny. Depending on the material and region of interest of a rare event search, these partial energy depositions can be problematic. Motivated by the use of Ge crystals for the detection of neutrinoless double-beta decay, we wish to understand the detector response of surface backgrounds from radon progeny. We look at the simulation of surface decays using a validated implantation distribution based on nuclear recoils and a realistic surface texture. Results of the simulations and measured α spectra are presented.

  13. Behaviour of radon, radon progenies and particle levels during room depressurisation

    NASA Astrophysics Data System (ADS)

    Korhonen, Pirjo; Kokotti, Helmi; Kalliokoski, Pentti

    The aim of the study was to investigate the effect of room depressurisation (up to -28 Pa) on indoor radon, radon progenies and particle concentrations in a wooden school building (A) and in a wooden double-family house (B). The airborne concentrations of particles, radon, and radon progenies decreased with increased depressurisation. At the same time, the air exchange rates increased by a factor of 9.5 (house A) and 13 (house B). The calculated radon entry rates thus rose almost in the same ratio, 6.3 and 12, respectively. The equilibrium factors between radon progenies and radon were the same before and after the depressurisation being 0.04 in house A and 0.16 in house B. When the pressure was the lowest, radon concentrations decreased by a factor of 0.7 in house A and 0.9 in house B, and the radon progeny levels fell by a factor of 0.6 in both houses. The particle levels (particles exceeding 0.01 μm) decreased by a factor of 10 (house A) and of 1.2 (house B). The dilution by outdoor air was more effective in house A, which was less tight.

  14. Study on peak shape fitting method in radon progeny measurement.

    PubMed

    Yang, Jinmin; Zhang, Lei; Abdumomin, Kadir; Tang, Yushi; Guo, Qiuju

    2015-11-01

    Alpha spectrum measurement is one of the most important methods to measure radon progeny concentration in environment. However, the accuracy of this method is affected by the peak tailing due to the energy losses of alpha particles. This article presents a peak shape fitting method that can overcome the peak tailing problem in most situations. On a typical measured alpha spectrum curve, consecutive peaks overlap even their energies are not close to each other, and it is difficult to calculate the exact count of each peak. The peak shape fitting method uses combination of Gaussian and exponential functions, which can depict features of those peaks, to fit the measured curve. It can provide net counts of each peak explicitly, which was used in the Kerr method of calculation procedure for radon progeny concentration measurement. The results show that the fitting curve fits well with the measured curve, and the influence of the peak tailing is reduced. The method was further validated by the agreement between radon equilibrium equivalent concentration based on this method and the measured values of some commercial radon monitors, such as EQF3220 and WLx. In addition, this method improves the accuracy of individual radon progeny concentration measurement. Especially for the (218)Po peak, after eliminating the peak tailing influence, the calculated result of (218)Po concentration has been reduced by 21 %. PMID:25920795

  15. Measurement of the equilibrium factor between radon and its progeny in the underground mining environment.

    PubMed

    Ntwaeaborwa, O M; Kgwadi, N D; Taole, S H; Strydom, R

    2004-04-01

    A scintillation cell and a portable radiation spectrometer for radon progeny were respectively employed to measure the concentration of radon and that of its progeny in the underground gold mine environment. The measured concentrations were subsequently used to calculate the equilibrium factor between radon and its progeny. The results obtained indicate that various locations underground have different values of radon concentration and ratios of radon concentration to its progeny concentration. The differences can be ascribed to variations in grades of uranium at different locations and to some environmental factors such as ventilation, particle concentration, and the deposition of the progeny on surfaces or on the atmospheric aerosol. PMID:15057058

  16. Study on radon and radon progeny in some living rooms.

    PubMed

    Mohamed, A

    2005-01-01

    In the first part of this work, the potential alpha energy concentration (PAEC) of radon progeny, the equilibrium factor (F), the activity concentration of 222Rn gas (Co) and the unattached fraction (fp), were determined in 15 living rooms at El-Minia City, Egypt. The activity size distribution of (214)Pb was measured by using a low pressure Berner impactor. Based on the parameters of that distribution the total effective dose through the human lung was evaluated by using a dosimetric model calculation of ICRP. An electrostatic precipitation method was used for the determination of 222Rn gas concentration. The mean activity concentration of 222Rn gas (Co) was found to be 123 +/- 22 Bq m(-3). A mean unattached fraction (fp) of 0.11 +/- 0.02 was obtained at a mean aerosol particle concentration (Z) of (3.0 +/- 0.21) x 10(3) cm(-3). The mean equilibrium factor (F) was determined to be 0.35 +/- 0.03. The mean PAEC was found to be 37 +/- 8.1 Bq m(-3). The activity size distribution of (214)Pb shows mean activity median diameter of 290 nm with mean geometric standard deviation (sigma) of 2.45. At a total deposition fraction of approximately 23% the total effective dose to the lung was determined to be approximately 1.2 mSv. The second part of this paper deals with a study of natural radionuclide contents of samples collected from the building materials of those rooms under investigation given in part one of this paper. Analyses were performed in Marinelli beakers with a gamma multichannel analyser provided with a NaI(Tl) detector. The samples have revealed the presence of the uranium-radium and thorium radioisotopes as well as (40)K. Nine gamma-lines of the natural radioisotopes that correspond to 212Pb, 214Pb, 214Bi, 228Ac, 40K and 208Tl were detected and measured. The activity concentrations of 226Ra, 232Th and 40K were determined with mean specific activities of 65 +/- 22, 35 +/- 12 and 150 +/- 60 Bq kg(-1), respectively. These activities amount to a radium equivalent

  17. Impact of haze-fog days to radon progeny equilibrium factor and discussion of related factors.

    PubMed

    Hou, Changsong; Shang, Bing; Zhang, Qingzhao; Cui, Hongxing; Wu, Yunyun; Deng, Jun

    2015-11-01

    The equilibrium factor F between radon and its short-lived progenies is an important parameter to estimate radon exposure of humans. Therefore, indoor and outdoor concentrations of radon and its short-lived radon progeny were measured in Beijing area using a continuously measuring device, in an effort to obtain information on the F value. The results showed that the mean values of F were 0.58 ± 0.13 (0.25-0.95, n = 305) and 0.52 ± 0.12 (0.31-0.91, n = 64) for indoor and outdoor, respectively. The indoor F value during haze-fog days was higher than the typical value of 0.4 recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation, and it was also higher than the values of 0.47 and 0.49 reported in the literature. A positive correlation was observed between indoor F values and PM2.5 concentrations (R (2) = 0.71). Since 2013, owing to frequent heavy haze-fog events in Beijing and surrounding areas, the number of the days with severe pollution remains at a high level. Future studies on the impact of the ambient fine particulate matter on indoor radon progeny equilibrium factor F could be important. PMID:26143065

  18. Optimization of the Timepix chip to measurement of radon, thoron and their progenies.

    PubMed

    Janik, Miroslaw; Ploc, Ondrej; Fiederle, Michael; Procz, Simon; Kavasi, Norbert

    2016-01-01

    Radon and thoron as well as their short-lived progenies are decay products of the radium and thorium series decays. They are the most important radionuclide elements with respect to public exposure. To utilize the semiconductor pixel radiation Timepix chip for the measurement of active and real-time alpha particles from radon, thoron and their progenies, it is necessary to check the registration and visualization of the chip. An energy check for radon, thoron and their progenies, as well as for (241)Am and(210)Po sources, was performed using the radon and thoron chambers at NIRS (National Institute of Radiological Sciences). The check found an energy resolution of 200 keV with a 14% efficiency as well as a linear dependency between the channel number (cluster volume) and the energy. The coefficient of determination r(2) of 0.99 for the range of 5 to 9 MeV was calculated. In addition, an offset for specific Timepix configurations between pre-calibration for low energy from 6 to 60 keV, and the actual calibration for alpha particles with energies from 4000 to 9000 keV, was detected. PMID:26547560

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

    SciTech Connect

    Castleman, A.W. Jr.

    1996-12-31

    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.

  20. RADON AND PROGENY ALPHA-PARTICLE ENERGY ANALYSIS USING NUCLEAR TRACK METHODOLOGY

    SciTech Connect

    Espinosa Garcia, Guillermo; Golzarri y Moreno, Dr. Jose Ignacio; Bogard, James S

    2008-01-01

    A preliminary procedure for alpha energy analysis of radon and progeny using Nuclear Track Methodology (NTM) is described in this paper. The method is based on the relationship between alpha-particle energies deposited in polycarbonate material (CR-39) and the track size developed after a well-established chemical etching process. Track geometry, defined by parameters such as major or minor diameters, track area and overall track length, is shown to correlate with alpha-particle energy over the range 6.00 MeV (218Po) to 7.69 MeV (214Po). Track features are measured and the data analyzed automatically using a digital imaging system and commercial PC software. Examination of particle track diameters in CR-39 exposed to environmental radon reveals a multi-modal distribution. Locations of the maxima in this distribution are highly correlated with alpha particle energies of radon daughters, and the distributions are sufficiently resolved to identify the radioisotopes. This method can be useful for estimating the radiation dose from indoor exposure to radon and its progeny.

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

    SciTech Connect

    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. Carcinogenic risk of non-uniform alpha-particle irradiation in the lungs: Radon progeny effects at bronchial bifurcations

    SciTech Connect

    Hoffmann, W.; Crawford-Brown, D.J.; Menache, M.G.; Martonen, T.B.

    1992-01-01

    The combined effect of enhanced deposition and reduced clearance at bronchial bifurcations leads to increased radon progeny doses within branching sites compared to uniformly distributed activity within a given airway generation. A multi-stage carcinogenesis model was used to predict the probability of lung cancer induction at different sites of the bronchial region. For relatively low radon progeny exposures, lung cancer risk is significantly higher in bifurcation zones, particularly at carinal ridges, than along tubular segments. At sufficiently high exposures, however, lung cancer risk is highest in the tubular portions of a generation. This suggests that the common assumption of a uniform dose distribution provides realistic risk estimates for high uranium miner exposures, but may underestimate lung cancer risk at low, environmental exposures. If concomitant exposure to cigarette smoke is factored into the risk analysis in a multiplicative fashion, then the effect related to risk inhomogeneity becomes even more pronounced.

  3. Age-dependent inhalation doses to members of the public from indoor short-lived radon progeny.

    PubMed

    Brudecki, K; Li, W B; Meisenberg, O; Tschiersch, J; Hoeschen, C; Oeh, U

    2014-08-01

    The main contribution of radiation dose to the human lungs from natural exposure originates from short-lived radon progeny. In the present work, the inhalation doses from indoor short-lived radon progeny, i.e., (218)Po, (214)Pb, (214)Bi, and (214)Po, to different age groups of members of the public were calculated. In the calculations, the age-dependent systemic biokinetic models of polonium, bismuth, and lead published by the International Commission on Radiological Protection (ICRP) were adopted. In addition, the ICRP human respiratory tract and gastrointestinal tract models were applied to determine the deposition fractions in different regions of the lungs during inhalation and exhalation, and the absorption fractions of radon progeny in the alimentary tract. Based on the calculated contribution of each progeny to equivalent dose and effective dose, the dose conversion factor was estimated, taking into account the unattached fraction of aerosols, attached aerosols in the nucleation, accumulation and coarse modes, and the potential alpha energy concentration fraction in indoor air. It turned out that for each progeny, the equivalent doses to extrathoracic airways and the lungs are greater than those to other organs. The contribution of (214)Po to effective dose is much smaller compared to that of the other short-lived radon progeny and can thus be neglected in the dose assessment. In fact, 90 % of the effective dose from short-lived radon progeny arises from (214)Pb and (214)Bi, while the rest is from (218)Po. The dose conversion factors obtained in the present study are 17 and 18 mSv per working level month (WLM) for adult female and male, respectively. This compares to values ranging from 6 to 20 mSv WLM(-1) calculated by other investigators. The dose coefficients of each radon progeny calculated in the present study can be used to estimate the radiation doses for the population, especially for small children and women, in specific regions of the world

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  7. RADON EXPOSURE ASSESSMENT AND DOSIMETRY APPLIED TO EPIDEMIOLOGY AND RISK ESTIMATION

    EPA Science Inventory

    Epidemiological studies of underground miners provide the primary basis for radon risk estimates for indoor exposures as well as mine exposures. A major source of uncertainty in these risk estimates is the uncertainty in radon progeny exposure estimates for the miners. In addit...

  8. Acute Exposure from RADON-222 and Aerosols in Drinking Water

    NASA Astrophysics Data System (ADS)

    Bernhardt, George Paul, IV

    Radon-222 in water is released when the water is aerated, such as during showering. As a result, a temporary burst of radon-222 can appear as a short term, or acute, exposure. This study looked at homes with radon-222 concentrations in water from 800 picocuries per liter (pCi/l) to 53,000 pCi/l to determine the buildup of radon gas in a bathroom during showering. Samples from the tap and drain, compared to determine the percentage of radon-222 released, showed that between 58% and 88% of radon-222 in the water was released. The resultant radon-222 increase in air, measured with a flow-through detector, ranged from 2 pCi/l to 114 pCi/l in bathrooms due to a 10 to 15 minute shower with water flow rates ranging from 3 l/min to 6 l/min. Significantly, these rates did not fall rapidly but stayed approximately the same for up to 15 minutes after the water flow ceased. In examining exposures, the true danger is in the radon-222 progeny rather than the radon itself. The progeny can be inhaled and deposited in the tracheobronchial passages in the lung. Filter samples of bathroom air measured in a portable alpha spectrometer showed an increase in radon-222 progeny, notably polonium-218 and -214, in the air after showering. These increases were gradual and were on the order of 0.5 pCi/l at the highest level. Tap samples measured in a portable liquid scintillator showed that the progeny are present in the water but are not in true secular equilibrium with the radon-222 in the water. Therefore, the radon-222 does not have to decay to produce progeny since the progeny are already present in the water. A two stage sampler was used to examine the percentage of radiation available in aerosols smaller than 7 microns. Repeated trials showed that up to 85% of the radiation available in the aerosols is contained in the smaller, more respirable particles.

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

    SciTech Connect

    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/sup -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/sup -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.

  10. CARCINOGENIC RISK OF NONUNIFORM ALPHA PARTICLE IRRADIATION IN THE LUNGS: RADON PROGENY EFFECTS AT BRONCHIAL BIFURCATIONS

    EPA Science Inventory

    The combined effect of enhanced deposition and reduced clearance at bronchial bifurcations leads to increased radon progeny doses within branching sites compared to uniformly distributed activity within a given airway generation. ulti-stage carcinogenesis model was used to predic...

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

    SciTech Connect

    Hopke, P.K.

    1996-09-01

    This report completes Clarkson University`s study of 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 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{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; (3) Measure the rate of ion-induced nucleation using a thermal diffusion cloud chamber, and (4) Measure the neutralization rate of {sup 218}PoO{sub x}{sup +} in O{sub 2} at low radon concentrations.

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

    NASA Astrophysics Data System (ADS)

    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

  13. Cost evaluation of control measures for indoor radon progeny.

    PubMed

    Moeller, D W; Fujimoto, K

    1984-06-01

    Based on assumed conditions within a typical U.S. home, annualized costs for reducing indoor airborne radon progeny concentrations have been calculated for a variety of methods of control. These analyses were limited to methods for control in existing homes. Control through modified construction techniques was not evaluated. Methods assessed included increased air circulation, increased ventilation, particle removal using electrostatic precipitation and unipolar ion generation, and the application of sealants to room surfaces. Although surface sealants proved to be reasonably cost-effective per person- sievert dose reduction, such sealants are prone to cracking and the durability of their effectiveness is questionable. Use of ceiling fans for increased air circulation and particle deposition appears to be least cost-effective, but this method may be attractive in some cases for reasons of comfort. The use of unipolar ion generators appears to be the best approach from the standpoint of cost effectiveness. These devices are also easy to install and are esthetically readily acceptable. PMID:6427137

  14. The Scavenging of Radon Progeny by Snow and Rain

    NASA Astrophysics Data System (ADS)

    Austin, G.; Greenfield, M.; Henson, W.; Peace, A.; Stow, D.

    2003-03-01

    In the previous paper Greenfield et al. show that changes in atmospheric gamma radiation rates due to radon progeny adsorbed by rain measured at 6-20 m above ground can be used as a real-time monitor of rain and snow precipitation rates in several locations around the world. In New Zealand, at the Ardmore Field Station operated by the University of Auckland, a gamma ray detection system of the sort described earlier was installed 6 m up a meteorological tower carrying the usual wind speed, wind direction, temperature, humidity and rainfall measuring equipment and attached to a data logger. In addition, a vertically pointing X Band meteorological radar was deployed together with three rain-drop size spectrum measuring devices (disdrometers) at the ground. The microphysical data obtained, particularly from the radar and the disdrometers, allows the construction of a case by case one-dimensional cloud physics model so that the hydrometeor size spectrum, surface area and fall speeds can be depicted in a reasonably realistic way. This then allows modeling of the scavenging processes by the snow and rain in a more quantitative way thus enabling a program of detailed investigation of the microphysical processes involved in the hypothesis presented in the earlier paper: that this mechanism allows gamma ray count rates to be used as a surrogate for rainfall rates. Interesting questions related to the spatial representativeness of various rainfall data sets can also be pursued.

  15. Radon progeny size distributions and enhanced deposition effects from high radon concentrations in an enclosed chamber.

    PubMed

    Leonard, Bobby E

    2004-01-01

    Prior work studying radon progeny in a small enclosed chamber found that at high (222)Rn concentrations an enhanced surface deposition was observed. Subsequent measurements for unfiltered air showed minimal charged particle mobility influence. Progeny particle size measurements reported here, performed at the US Department of Energy Environmental Measurement Laboratory (now with Home Security Department), using the EML graded screen array (GSA) system show in unfiltered air that the high (222)Rn levels causes a reduction in the attached (218)Po progeny airborne particulates and formation of additional normal sized unattached ( approximately 0.80 nm) and also even smaller (218)Po below 0.50 nm. At a (222)Rn level of 51 kBq m(-3), 73% of all (218)Po are of a mean particle diameter of about 0.40 +/- 0.02 nm. At this (222)Rn level, the ratio of (218)Po to (222)Rn airborne concentrations is reduced significantly from the concentration ratio at low (222)Rn levels. Similar reductions and size reformations were observed for the (214)Pb and (214)Bi/Po progeny. The particle size changes are further confirmed using the plateout rates and corresponding deposition velocities. The Crump and Seinfeld deposition theory provides the corresponding particle diffusion coefficients. With the diffusion coefficient to ultrafine clustered particle diameter correlation of Ramamurthi and Hopke, good agreement is obtained between EML GSA and deposition velocity data down to 0.40 nm. Strong evidence is presented that the progeny size reduction is due to, as a result of air ionization, the increased neutralization rate (primarily from electron scavenging of OH molecules) of the initially charged progeny. This is shown to increase with the (1/2) power of (222)Rn concentration and relative humidity as well as increased air change rate in the chamber. These results imply that at (222)Rn levels above 50 kBq m(-3), at relative humidity of 52%, a considerable reduction in lung dose could occur from

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

    SciTech Connect

    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.

  17. Filter for on-line air monitor unaffected by radon progeny and method of using same

    DOEpatents

    Phillips, Terrance D.; Edwards, Howard D.

    1999-01-01

    An apparatus for testing air having contaminants and radon progeny therein. The apparatus includes a sampling box having an inlet for receiving the air and an outlet for discharging the air. The sampling box includes a filter made of a plate of sintered stainless steel. The filter traps the contaminants, yet allows at least a portion of the radon progeny to pass therethrough. A method of testing air having contaminants and radon progeny therein. The method includes providing a testing apparatus that has a sampling box with an inlet for receiving the air and an outlet for discharging the air, and has a sintered stainless steel filter disposed within said sampling box; drawing air from a source into the sampling box using a vacuum pump; passing the air through the filter; monitoring the contaminants trapped by the filter; and providing an alarm when a selected level of contaminants is reached. The filter traps the contaminants, yet allows at least a portion of the radon progeny to pass therethrough.

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

    NASA Astrophysics Data System (ADS)

    Pereira, L. A.; Hadler, J. C.; Lixandrão F., A. L.; Guedes, S.; Takizawa, R. H.

    2014-11-01

    It is well known that radon daughters up to 214Po 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.

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

    SciTech Connect

    Pereira, L. A.; Hadler, J. C.; Lixandrão F, A. L.; Guedes, S.; Takizawa, R. H.

    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.

  20. Retrospective assessment of indoor radon exposure by measurements of embedded 210Po activity in glass objects

    NASA Astrophysics Data System (ADS)

    Ramola, R. C.; Gusain, G. S.; Prasad, Ganesh

    In most of the epidemiological studies contemporary radon measurements have been used as surrogates for radon concentrations in past decades even though changes in radon levels and residence may have occurred. Short-lived radon progeny may deposit on available surfaces in dwellings thus giving rise over time to a build up of long-lived progeny. Airborne radon decay products can be deposited and implanted through alpha recoil into the glass surfaces. On glass surface, activities of 210Po may arise as a result of the decay of recoil implanted activity following the alpha decay of surface deposited 218Po or 214Po. Measurement of 210Po implanted on a household glass is a method that can be employed to retrospectively determine the historic level of radon in dwellings. This method is based on the assumption that levels of recoil implanted 210Po in the glass provide a measure of time integrated radon concentration in the environment in which the glass has been located. The surface deposited activity of the radon progenies, which then become implanted in the glass by alpha recoil, is believed to reflect past exposure to airborne activity. Such retrospective measurements on glass are valuable in estimating the human dose derived from radon during the time of exposure. In this paper an account is given of the principles and some field applications of a retrospective technique, using the alpha track detectors, CR-39 and LR-115, to measure 210Po implanted in glass surfaces (surface traps). By using this CR-LR difference technique, the cumulative radon exposure in a dwelling in past decades may be estimated. This method provides reliable radon exposure data as a support to epidemiological studies concerning the health effects of radon exposure in the living environment.

  1. RADON AND PROGENY SOURCED DOSE ASSESSMENT OF SPA EMPLOYEES IN BALNEOLOGICAL SITES.

    PubMed

    Uzun, Sefa Kemal; Demiröz, Işık

    2016-09-01

    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 Sarayköy 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(®) 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 questionary 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. PMID:26424134

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

    PubMed

    Trassierra, C Vargas; Stabile, L; Cardellini, F; Morawska, L; Buonanno, G

    2016-08-15

    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. PMID:27131455

  3. Dosimetry of localized accumulations of cigarette smoke and radon progeny at bifurcations

    SciTech Connect

    Martonen, T.B.; Hofmann, W.

    1991-01-01

    The work focuses upon deposition and clearance processes affecting cigarette smoke particles and radon progeny within surrogate airway models, replica casts and the human lung. As shall be demonstrated, 'cloud motion' for mainstream cigarette smoke can produce locations of enhanced deposition not experienced with dilute aerosols composed of like-sized particles. These sites of concentrated deposits occur at airway bifurcations, especially at the inclusive carinal ridges.

  4. Reanalysis of data on particle size distribution of radon progeny in uranium mines

    SciTech Connect

    Knutson, E.O.; George, A.C.

    1992-12-31

    We reanalyzed 26 samples from radon progeny particle-size measurements made in 1971 in four New Mexico uranium mines. These data were obtained with parallel disk diffusion batteries (still in use at our laboratory), together with a Mercer-type diffusion sampler. Seventeen additional samples taken with a cascade impactor were not reanalyzed. The original data analysis, reported in two separate publications, was based on the assumption that the progeny consist of distinct attached and unattached species that can be sampled and analyzed separately. In the new analysis, we treated the progeny as a continuous spectrum of particle sizes, ranging from 1 to 1000 nm, covering both attached and unattached progeny. This was achieved by combining the diffusion battery and diffusion sampler data, and making one calculation. In the new analysis, the assumption of a unimodal lognormal size distribution was dropped. The new calculations showed that 9 of the 26 distributions were unimodal, agreeing closely with the original analyses. Eleven of the new distributions had a bimodal structure, with widely separated modes evoking the classical idea of attached and unattached radon progeny. The remaining six cases had bimodal structures that were not distinct and were therefore not consistent with the classical picture. A dose conversion factor has been computed for each particle size spectrum, yielding values from 1.6 to 7.8 Gy m{sup 3} J{sup -1} h{sup -1}, generally higher than the previously cited values. The highest values correspond to mine locations with low equilibrium factors (<0.1) and severe disequilibrium among progeny nuclides.

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

    PubMed

    Marsh, J W; Bailey, M R

    2013-12-01

    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. PMID:23887272

  6. Radon exposure and oropharyngeal cancer risk.

    PubMed

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

    2015-12-01

    Oropharyngeal cancer is a multifactorial disease. Alcohol and tobacco are the main risk factors. Radon is a human carcinogen linked to lung cancer risk, but its influence in other cancers is not well known. We aim to assess the effect of radon exposure on the risk of oral and pharyngeal cancer through a systematic review of the scientific literature. This review performs a qualitative analysis of the available studies. 13 cohort studies were included, most of them mortality studies, which analysed the relationship between occupational or residential radon exposure with oropharyngeal cancer mortality or incidence. Most of the included studies found no association between radon exposure and oral and pharyngeal cancer. This lack of effect was observed in miners studies and in general population studies. Further research is necessary to quantify if this association really exists and its magnitude, specially performing studies in general population, preferably living in areas with high radon levels. PMID:26335172

  7. Analysis of radon and radon progeny in residences: factors that affect their amounts and methods of reduction. Master's thesis

    SciTech Connect

    Little, D.R.

    1985-03-01

    The effectiveness of using an electrostatic precipitator as a means for reducing harmful levels of radon progeny in the home was evaluated. A commercially available precipitator, manufactured by the Honeywell Corporation, was used during the course of the study. The specific model used was the Honeywell Electronic Air Cleaner model number F50A1009. Daughter concentrations were measured by the modified Tsivoglou method. Samples were collected on a 2-inch millipore filter and alpha emissions were measured with a ZnS(Ag) scintillator. A sample collection time of 5 minutes was used. Sample counting intervals of 2-5, 6-20, and 21-30 minutes after sample collection were used. During this study air samples were made using the blower fan and filters alone with no power to the electrostatic precipitator, and with the electrostatic precipitator energized. The reduction in the working level as a result of using the blower fans and filters only was 75%. With the electrostatic precipitator energized, the reduction level rose to 90%. It is therefore concluded that the electrostatic precipitator is an effective means for reducing radon progeny concentrations in the home.

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

    SciTech Connect

    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.

  9. Determination of rain age via {gamma} rays from accreted radon progeny

    SciTech Connect

    Greenfield, M. B.; Ito, N.; Iwata, A.; Kubo, K.; Ishigaki, M.; Komura, K.

    2008-10-01

    The relative {gamma} ray activities from {sup 214}Pb and {sup 214}Bi condensed from precipitation are used to determine its 'age', the average time the accreted activity has been removed from secular equilibrium. A verifiable assumption that radon progeny on/in the surface/volume of droplets mostly remains in secular equilibrium until they begin their descent, enables estimates of their transit times to ground of typically a few tens of minutes. This agrees well with the time expected for the activity on the surface of droplets to reach the ground from heights of a few kilometers. The half lives of {gamma} activities from {sup 214}Bi and {sup 214}Pb, 19.7 and 26.9 min, respectively, are on the same scale as transit time to ground and close enough to each other to measure ratios of activities from secular equilibrium (1.00) to transient equilibrium (3.88) within a few hundreds of minutes. The ratio of {gamma} count rates is independent of knowledge of either initial activity or any systematic errors and thus limited only by the uncertainty from counting statistics, which from condensates of 5-30 l of rain viewed with 2{pi} solid angle by a 50% efficient, high-resolution Ge detector is only a few percent. These ratios fit extremely well to known theoretical curves, which cannot only be used to date rain but can also be extrapolated backward to determine radon progeny activities in rain prior to its descent, knowledge of which may facilitate further studies using radon progeny as tracers.

  10. Indoor radon exposure and lung cancer: a review of ecological studies.

    PubMed

    Yoon, Ji Young; Lee, Jung-Dong; Joo, So Won; Kang, Dae Ryong

    2016-01-01

    Lung cancer has high mortality and incidence rates. The leading causes of lung cancer are smoking and radon exposure. Indeed, the World Health Organization (WHO) has categorized radon as a carcinogenic substance causing lung cancer. Radon is a natural, radioactive substance; it is an inert gas that mainly exists in soil or rock. The gas decays into radioactive particles called radon progeny that can enter the human body through breathing. Upon entering the body, these radioactive elements release α-rays that affect lung tissue, causing lung cancer upon long-term exposure thereto. Epidemiological studies first outlined a high correlation between the incidence rate of lung cancer and exposure to radon progeny among miners in Europe. Thereafter, data and research on radon exposure and lung cancer incidence in homes have continued to accumulate. Many international studies have reported increases in the risk ratio of lung cancer when indoor radon concentrations inside the home are high. Although research into indoor radon concentrations and lung cancer incidence is actively conducted throughout North America and Europe, similar research is lacking in Korea. Recently, however, studies have begun to accumulate and report important data on indoor radon concentrations across the nation. In this study, we aimed to review domestic and foreign research into indoor radon concentrations and to outline correlations between indoor radon concentrations in homes and lung cancer incidence, as reported in ecological studies thereof. Herein, we noted large differences in radon concentrations between and within individual countries. For Korea, we observed tremendous differences in indoor radon concentrations according to region and year of study, even within the same region. In correlation analysis, lung cancer incidence was not found to be higher in areas with high indoor radon concentrations in Korea. Through our review, we identified a need to implement a greater variety of

  11. Comparative risk assessment of residential radon exposures in two radon-prone areas, Stei (Romania) and Torrelodones (Spain).

    PubMed

    Sainz, Carlos; Dinu, Alexandra; Dicu, Tiberius; Szacsvai, Kinga; Cosma, Constantin; Quindós, Luis Santiago

    2009-07-15

    Radon and radon progeny are present indoors, in houses and others dwellings, representing the most important contribution to dose from natural sources of radiation. Most studies have demonstrated an increased risk of lung cancer at high concentration of radon for both smokers and nonsmokers. The work presents a comparative analysis of the radon exposure data in the two radon-prone areas, Stei, Transylvania, (Romania), in the near of old Romanian uranium mines and in the granitic area of Torrelodones town, Sierra de Guadarrama (Spain). Measurements of indoor radon were performed in 280 dwellings (Romania) and 91 dwellings (Spain) by using nuclear track detectors, CR 39. The highest value measured in Stei area was 2650 Bq m(-3) and 366 Bq m(-3) in the Spanish region. The results are computed with the BEIR VI report estimates using the age-duration model at an exposure rate below 2650 Bq m(-3). We used the EC Radon Software to calculate the lifetime lung cancer death risks for individuals groups in function of attained age, radon exposures and tobacco consumption. A total of 233 lung cancer deaths were observed in the Stei area for a period of 13 years (1994-2006), which is 116.82% higher than expected from the national statistics. In addition, the number of deaths estimated for the year 2005 is 28, which is worth more than 2.21 times the amount expected by authorities. In comparison, for Torrelodones was rated a number of 276 deaths caused by lung cancer for a period of 13 years, which is 2.09 times higher than the number expected by authorities. For the year 2005 in the Spanish region were reported 32 deaths caused by pulmonary cancer, the number of deaths exceeding seen again with a factor of 2.10 statistical expectations. This represents a significantly evidence that elevated risk can strongly be associated with cumulated radon exposure. PMID:19428051

  12. An optimized system for measurement of radon levels in buildings by spectroscopic measurement of radon progeny

    NASA Astrophysics Data System (ADS)

    Fröjdh, A.; Thungström, G.; Fröjdh, C.; Petersson, S.

    2011-12-01

    Radon gas, 222Rn, is a problem in many buildings. The radon gas is not harmful in itself, but the decay chain contains charged elements such as 218Po, and 214Po ions which have a tendency to stick to the lungs when inhaled. Alpha particles from the decay of these ions cause damages to the lungs and increase the risk of lung cancer. The recent reduction in the limits for radon levels in buildings call for new simple and efficient measurement tools [1]. The system has been optimized through modifications of the detector size, changes to the filters and the design of the chamber. These changes increase the electric field in the chamber and the detection efficiency.

  13. Radon Sources and Associated Risk in Terms of Exposure and Dose

    PubMed Central

    Vogiannis, Efstratios G.; Nikolopoulos, Dimitrios

    2015-01-01

    Radon concerns the international scientific community from the early twentieth century, initially as radium emanation and nearly the second half of the century as a significant hazard to human health. The initial brilliant period of its use as medicine was followed by a period of intense concern for its health effects. Miners in Europe and later in the U.S were the primary target groups surveyed. Nowadays, there is a concrete evidence that radon and its progeny can cause lung cancer (1). 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 (2). Indoor radon and its short-lived progeny either attached on aerosol particles or free, compose an air mixture that carries a significant energy amount [Potential Alpha-Energy Concentration (PAEC)]. Prior research at that topic focused on the exposure on PAEC and the dose delivered by the human body or tissues. Special mention was made to the case of water workers due to inadequate data. Furthermore, radon risk assessment and relevant legislation for the dose delivered by man from radon and its progeny has been also reviewed. PMID:25601905

  14. Quantitative Interpretation of Air Radon Progeny Fluctuations in Terms of Stability Conditions in the Atmospheric Boundary Layer

    NASA Astrophysics Data System (ADS)

    Salzano, Roberto; Pasini, Antonello; Casasanta, Giampietro; Cacciani, Marco; Perrino, Cinzia

    2016-03-01

    Determining the mixing height using a tracer can improve the information obtained using traditional techniques. Here we provide an improved box model based on radon progeny measurements, which considers the vertical entrainment of residual layers and the variability in the soil radon exhalation rate. The potential issues in using progeny instead of radon have been solved from both a theoretical and experimental perspective; furthermore, the instrumental efficiency and the counting scheme have been included in the model. The applicability range of the box model has been defined by comparing radon-derived estimates with sodar and lidar data. Three intervals have been analyzed ("near-stable", "transition" and "turbulent"), and different processes have been characterized. We describe a preliminary application case performed in Rome, Italy, while case studies will be required to determine the range limits that can be applied in any circumstances.

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

    NASA Astrophysics Data System (ADS)

    Papp, Z.

    2006-03-01

    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 ( 222Rn) 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 218Po, 214Pb, 214Bi and 212Pb) 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 218Po, 214Pb, 214Bi, EEDC 222 (Equilibrium-Equivalent Decay-product Concentration of radon progeny) and 212Pb 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±0.03, where the

  16. Enhancement of radon exposure in smoking areas.

    PubMed

    Abdel Ghany, Hayam A

    2007-06-01

    Radium-226 is a significant source of radon-222 which enters buildings through soil, construction materials or water supply. When cigarette smoke is present, the radon daughters attach to smoke particles. Thus, the alpha radiation to a smoker's lungs from the natural radon daughters is increased because of smoking. To investigate whether the cigarette tobacco itself is a potential source of indoor radon, the alpha potential energy exposure level contents of radon ((222)Rn, 3.82d) and Thoron ((220)Rn, 55.60s) were measured in 10 different cigarette tobacco samples using CR-39 solid-state nuclear track detectors (SSNTDs). The results showed that the (222, 220)Rn concentrations in these samples ranged from 128 to 266 and 49 to 148 Bqm(-3), respectively. The radon concentrations emerged from all investigated samples were significantly higher than the background level. Also, the annual equivalent doses from the samples were determined. The mean values of the equivalent dose were 3.51 (0.89) and 1.44 (0.08) mSvy(-1), respectively. Measurement of the average indoor radon concentrations in 20 café rooms was, significantly, higher than 20 smoking-free residential houses. The result refers to the dual (chemical and radioactive) effect of smoking as a risk factor for lung cancer. PMID:17342428

  17. Lung Cancer Attributable to Indoor Radon Exposures in Two Radon--Prone Areas, Stei (Romania) and Torrelodones (Spain)

    SciTech Connect

    Dinu, Alexandra; Cosma, Constantin; Vasiliniuc, Stefan; Sainz, Carlos; Poncela, Luis Santiago Quindos

    2009-05-22

    Radon and radon progeny are present indoors, in houses and others dwellings, representing the most important contribution to dose from natural sources of radiation. Most studies have demonstrated an increased risk of lung cancer at high concentration of radon for both smokers and nonsmokers. For medium and low concentrations which are the typical residential radon levels, recent researches have also demonstrated increased risks of lung cancer for people exposed. The work presents a comparative analysis of the radon exposure data in the two radon--prone areas, Stei, Transylvania, (Romania), in the near of old Romanian uranium mines and in the granitic area of Torrelodones town, Sierra de Guadarrama (Spain). One important difference between the two studied areas is related to the houses built using uranium waste as construction material in Stei area. Measurements of indoor radon were performed in 280 dwellings (Romania) and 91 dwellings (Spain) by using nuclear track detectors, CR 39. The highest value measured in Stei area was 2650 Bq{center_dot}m{sup -3}. and 366 Bq{center_dot}m{sup -3} in the Spanish region. The results are compute with the BEIR VI report estimates using the age-duration model at an exposure rate below 2650 Bq{center_dot}m{sup -3}. A total of 233 lung cancer deaths were calculated in the Stei area for a period of 13 years (1994-2006), which is 116.82% higher than observed from the national statistics. In comparison, in Torrelodones area, a number of 276 deaths caused by lung cancer were estimated along a period of 13 years, which is 2.09 times higher than the number observed by authorities. This represents a significantly evidence that elevated risk can strongly be associated with cumulated radon exposure.

  18. Radon exposures in a Jerusalem public school.

    PubMed

    Richter, E D; Neeman, E; Fischer, I; Berdugo, M; Westin, J B; Kleinstern, J; Margaliot, M

    1997-12-01

    In December 1995, ambient radon levels exceeding 10,000 Bq/m3 were measured in a basement shelter workroom of a multilevel East Talpiot, Jerusalem, public elementary school (six grades, 600 students). The measurements were taken after cancers (breast and multiple myeloma) were diagnosed in two workers who spent their workdays in basement rooms. The school was located on a hill that geologic maps show to be rich in phosphate deposits, which are a recognized source for radon gas and its daughter products. Levels exceeding 1000,000 Bq/m3 were measured at the mouth of a pipe in the basement shelter workroom, the major point of radon entry. The school was closed and charcoal and electret ion chamber detectors were used to carry out repeated 5-day measurements in all rooms in the multilevel building over a period of several months. Radon concentrations were generally higher in rooms in the four levels of the building that were below ground level. There were some ground-level rooms in the building in which levels reached up to 1300 Bq/m3. In rooms above ground level, however, peak levels did not exceed 300 Bq/m3. Exposure control based on sealing and positive pressure ventilation was inadequate. These findings suggested that radon diffused from highly contaminated basement and ground-floor rooms to other areas of the building and that sealing off the source may have led to reaccumulation of radon beneath the building. Later, subslab venting of below-ground radon pockets to the outside air was followed by more sustained reductions in indoor radon levels to levels below 75 Bq/m3. Even so, radon accumulated in certain rooms when the building was closed. This sentinel episode called attention to the need for a national radon policy requiring threshold exposure levels for response and control. A uniform nationwide standard for school buildings below 75 Bq/m3 level was suggested after considering prudent avoidance, the controversies over risk assessment of prolonged low

  19. Radon exposures in a Jerusalem public school.

    PubMed Central

    Richter, E D; Neeman, E; Fischer, I; Berdugo, M; Westin, J B; Kleinstern, J; Margaliot, M

    1997-01-01

    In December 1995, ambient radon levels exceeding 10,000 Bq/m3 were measured in a basement shelter workroom of a multilevel East Talpiot, Jerusalem, public elementary school (six grades, 600 students). The measurements were taken after cancers (breast and multiple myeloma) were diagnosed in two workers who spent their workdays in basement rooms. The school was located on a hill that geologic maps show to be rich in phosphate deposits, which are a recognized source for radon gas and its daughter products. Levels exceeding 1000,000 Bq/m3 were measured at the mouth of a pipe in the basement shelter workroom, the major point of radon entry. The school was closed and charcoal and electret ion chamber detectors were used to carry out repeated 5-day measurements in all rooms in the multilevel building over a period of several months. Radon concentrations were generally higher in rooms in the four levels of the building that were below ground level. There were some ground-level rooms in the building in which levels reached up to 1300 Bq/m3. In rooms above ground level, however, peak levels did not exceed 300 Bq/m3. Exposure control based on sealing and positive pressure ventilation was inadequate. These findings suggested that radon diffused from highly contaminated basement and ground-floor rooms to other areas of the building and that sealing off the source may have led to reaccumulation of radon beneath the building. Later, subslab venting of below-ground radon pockets to the outside air was followed by more sustained reductions in indoor radon levels to levels below 75 Bq/m3. Even so, radon accumulated in certain rooms when the building was closed. This sentinel episode called attention to the need for a national radon policy requiring threshold exposure levels for response and control. A uniform nationwide standard for school buildings below 75 Bq/m3 level was suggested after considering prudent avoidance, the controversies over risk assessment of prolonged low

  20. Long-term measurements of radon, thoron and their airborne progeny in 25 schools in Republic of Srpska.

    PubMed

    Ćurguz, Z; Stojanovska, Z; Žunić, Z S; Kolarž, P; Ischikawa, T; Omori, Y; Mishra, R; Sapra, B K; Vaupotič, J; Ujić, P; Bossew, P

    2015-10-01

    This article reports results of the first investigations on indoor radon, thoron and their decay products concentration in 25 primary schools of Banja Luka, capital city of Republic Srpska. The measurements have been carried out in the period from May 2011 to April 2012 using 3 types of commercially available nuclear track detectors, named: long-term radon monitor (GAMMA 1)- for radon concentration measurements (C(Rn)); radon-thoron discriminative monitor (RADUET) for thoron concentration measurements (C(Tn)); while equilibrium equivalent radon concentration (EERC) and equilibrium equivalent thoron concentrations (EETC) measured by Direct Radon Progeny Sensors/Direct Thoron Progeny Sensors (DRPS/DTPS) were exposed in the period November 2011 to April 2012. In each school the detectors were deployed at 10 cm distance from the wall. The obtained geometric mean concentrations were C(Rn) = 99 Bq m(-3) and C(Tn) = 51 Bq m(-3) for radon and thoron gases respectively. Those for equilibrium equivalent radon concentration (EERC) and equilibrium equivalent thoron concentrations (EETC) were 11.2 Bq m(-3) and 0.4 Bq m(-3), respectively. The correlation analyses showed weak relation only between C(Rn) and C(Tn) as well as between C(Tn) and EETC. The influence of the school geographical locations and factors linked to buildings characteristic in relation to measured concentrations were tested. The geographical location and floor level significantly influence C(Rn) while C(Tn) depend only from building materials (ANOVA, p ≤ 0.05). The obtained geometric mean values of the equilibrium factors were 0.123 for radon and 0.008 for thoron. PMID:26171822

  1. Occupant radon exposure in houses with basements

    SciTech Connect

    Franklin, E.M.; Fuoss, S.

    1995-12-31

    This study compares basement and main-level radon exposure based on bi-level week-long radon measurements, occupancy and activity data collected in normal use during heating and non-heating seasons in a geographically-stratified random sample of about 600 Minnesota homes, in response to critiques of radon measurement protocol. Basement radon (RN1) (M=4.5, SD=4.5) and main level (Rn2)(M=2.9, SD=3.4) correlation was 0.8 (p=.00), including seasonal variation. In a 101-house subsample where Rn1 >=4.0 pCi/L and Rn2 <=3.9 pCi/L, maximum household exposure in basements was 1162 pCiHrs (M=120, Sd=207), main-level 2486 pCiHrs (M-434, SD=421). In same households, persons with most basement-time maxed 100 hrs (M=13,SD=23), persons with most main-level time maxed 160 hrs (M=79, SD=39). Basement activities show two patterns, (1) member used it for personal domain, e.g. sleeping, and (2) household used it for general activities, e.g. TV or children`s play. Basement occupancy justifies measurement of radon in the lowest livable housing level.

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

    SciTech Connect

    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.

  3. 30 CFR 57.5037 - Radon daughter exposure monitoring.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Radon daughter exposure monitoring. 57.5037... Radon daughter exposure monitoring. (a) In all mines at least one sample shall be taken in exhaust mine air by a competent person to determine if concentrations of radon daughters are present....

  4. 30 CFR 57.5037 - Radon daughter exposure monitoring.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Radon daughter exposure monitoring. 57.5037... Radon daughter exposure monitoring. (a) In all mines at least one sample shall be taken in exhaust mine air by a competent person to determine if concentrations of radon daughters are present....

  5. 30 CFR 57.5037 - Radon daughter exposure monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Radon daughter exposure monitoring. 57.5037... Radon daughter exposure monitoring. (a) In all mines at least one sample shall be taken in exhaust mine air by a competent person to determine if concentrations of radon daughters are present....

  6. Evaluation of radon progeny from Mount St. Helens eruptions. Final report

    SciTech Connect

    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. The Distribution of Exposure to Radon: Effects of Population Mobility

    SciTech Connect

    Gadgil, A.J.; Rein, S.; Nero, A.V.; Wollenberg Jr., H.A.

    1993-01-01

    The distribution of population exposures to radon, rather than the distribution of indoor radon concentrations, determines the fraction of population exposed to exceptionally high risk from radon exposures. Since this fraction at high risk has prompted the development of public policies on radon, it is important to first determine the magnitude of this fraction, and then how it much would decrease with different implementation program options for radon mitigation. This papers presents an approach to determining the distribution of population exposures to radon from public domain data, and illustrates it with application to the state of Minnesota. During this work, we are led to define a radon entry potential index which appears useful in the search for regions with high radon houses.

  8. In-vivo measurements of Pb-210 to determine cumulative exposure to radon daughters: A pilot study

    SciTech Connect

    Laurer, G.R.; Cohen, N. . Dept. of Environmental Medicine); Stark, A.; Ju, C. . Bureau of Environmental and Occupational Epidemiology)

    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.

  9. Cancer mortality among a group of fluorspar miners exposed to radon progeny

    SciTech Connect

    Morrison, H.I.; Semenciw, R.M.; Mao, Y.; Wigle, D.T.

    1988-12-01

    A cohort study of the mortality experience (1950-1984) of 1,772 Newfoundland underground fluorspar miners occupationally exposed to high levels of radon daughters (mean dose = 382.8 working levels months) has been conducted. Observed numbers of cancers of the lung, salivary gland, and buccal cavity and pharynx were significantly elevated among these miners. A highly significant relation was noted between radon daughter exposure and risk of dying of lung cancer; the small numbers of salivary gland (n = 2) and buccal cavity and pharynx (n = 6) cancers precluded meaningful analysis of dose response. Attributable and relative risk coefficients for lung cancer were estimated as 6.3 deaths per working level month per million person-years and 0.9% per working level month, respectively. Relative risk coefficients were highest for those first exposed before age 20 years. Cigarette smokers had relative and attributable risk coefficients comparable to those of nonsmokers. Relative risks fell sharply with age, whereas attributable risks were lowest in the youngest and oldest age groups. The results suggest that efforts to raise existing occupational exposure standards may be inappropriate.

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

    NASA Astrophysics Data System (ADS)

    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

  11. Coronary heart disease mortality and radon exposure in the Newfoundland fluorspar miners' cohort, 1950-2001.

    PubMed

    Villeneuve, Paul J; Lane, Rachel S D; Morrison, Howard I

    2007-08-01

    Kreuzer and coworkers recently reported no association between cumulative exposure to radiation and death from cardiovascular disease in a cohort of German uranium miners. Here, we report on the relationship between cumulative exposure to radon progeny and coronary heart disease among Newfoundland fluorspar miners. Previous analyses in this cohort found elevated death rates from coronary heart disease among those with higher cumulative radon exposure. However, this finding was based on a relatively small number of deaths and was not statistically significant. Since then, the follow-up of this cohort has been extended by 10 years until the end of 2001. Among the 2,070 miners in our study, 267 died from coronary heart disease. There was no trend evident between cumulative exposure to radon and the relative risk of death from coronary heart disease (P = 0.63). This finding was unchanged after adjusting for the lifetime smoking status that was available for approximately 54% of the cohort. Similarly, the cumulative radon exposure was found to be unrelated to deaths of the circulatory system, acute myocardial infarction, and cerebrovascular disease. These findings are consistent with those recently reported by Kreuzer and colleagues. We share their view that uncontrolled confounding for other coronary heart disease risk factors hinders the interpretation of the risk estimates. PMID:17453229

  12. 30 CFR 57.5037 - Radon daughter exposure monitoring.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Radon daughter exposure monitoring. 57.5037... Quality, Radiation, Physical Agents, and Diesel Particulate Matter Radiation-Underground Only § 57.5037 Radon daughter exposure monitoring. (a) In all mines at least one sample shall be taken in exhaust...

  13. Does long term exposure to radon gas influence the properties of polymeric waterproof materials?

    NASA Astrophysics Data System (ADS)

    Navratilova Rovenska, Katerina; Jiranek, Martin; Kokes, Pavel; Wasserbauer, Richard; Kacmarikova, Veronika

    2014-01-01

    The technical state of buildings and the quality of the indoor environment depend on the quality of the waterproofing course and on the properties of the insulating materials that are applied, in particular on their durability, long-term functional reliability and resistance to corrosive effects of the subsoil. Underground water chemistry and soil bacteria are well-known corrosive agents. Our investigations indicate that the ageing process of waterproof materials can be significantly accelerated by alpha particles emitted by radon and radon progenies which are present in soil gas. Materials commonly available on the building market, e.g. LDPE and HDPE of various densities, PVC, TPO (thermoplastic polyolefin), PP (polypropylene) and EPDM were selected for our experimental study. The preliminary results for 3-year exposure to radon gas show a decrease in tensile strength to 60%, elongation to 80% and hardness to 95% for samples based on PE. The diffusion coefficient of radon for samples based on PVC decreased to 20% of the initial value after 1-year exposure to radon and soil bacteria.

  14. CFD as a tool in risk assessment of inhaled radon progenies.

    PubMed

    Farkas, Arpád; Hofmann, Werner; Balásházy, Imre; Szoke, István

    2006-01-01

    During the last decade, computational fluid dynamics techniques proved to be a powerful tool in the modelling of biological processes and the design of biomedical devices. In this work, a computational fluid dynamics method was applied to model the transport of inhaled air and radioactive particles within the human respiratory tract. A finite volume numerical approach was used to compute the flow field characteristics and particle trajectories in the lumen of the first five airway generations of the human tracheobronchial tree, leading to the right upper lobe. The computations were performed for breathing and exposure conditions characteristic of uranium mines and homes. Primary radon daughter deposition patterns and energy distributions were computed, exhibiting highly inhomogeneous particle and energy deposition patterns. The results of the present modelling effort can serve as input data in lung cancer risk analysis. PMID:17132667

  15. The Cellular and Molecular Carcinogenic Effects of Radon Exposure: A Review

    PubMed Central

    Robertson, Aaron; Allen, James; Laney, Robin; Curnow, Alison

    2013-01-01

    Radon-222 is a naturally occurring radioactive gas that is responsible for approximately half of the human annual background radiation exposure globally. Chronic exposure to radon and its decay products is estimated to be the second leading cause of lung cancer behind smoking, and links to other forms of neoplasms have been postulated. Ionizing radiation emitted during the radioactive decay of radon and its progeny can induce a variety of cytogenetic effects that can be biologically damaging and result in an increased risk of carcinogenesis. Suggested effects produced as a result of alpha particle exposure from radon include mutations, chromosome aberrations, generation of reactive oxygen species, modification of the cell cycle, up or down regulation of cytokines and the increased production of proteins associated with cell-cycle regulation and carcinogenesis. A number of potential biomarkers of exposure, including translocations at codon 249 of TP53 in addition to HPRT mutations, have been suggested although, in conclusion, the evidence for such hotspots is insufficient. There is also substantial evidence of bystander effects, which may provide complications when calculating risk estimates as a result of exposure, particularly at low doses where cellular responses often appear to deviate from the linear, no-threshold hypothesis. At low doses, effects may also be dependent on cellular conditions as opposed to dose. The cellular and molecular carcinogenic effects of radon exposure have been observed to be both numerous and complex and the elevated chronic exposure of man may therefore pose a significant public health risk that may extend beyond the association with lung carcinogenesis. PMID:23880854

  16. In vivo measurements of lead-210 for assessing cumulative radon exposure in uranium miners

    SciTech Connect

    Guilmette, R.A.; Laurer, G.R.; Lambert, W.E.; Gilliland, F.D.

    1995-12-01

    It has long been recognized that a major contributor to the uncertainty in risk analysis of lung cancer in uranium and other hard rock miners is the estimation of total radon progeny exposure of individual miners under study. These uncertainties arise from the fact that only a limited number of measurements of airborne {sup 222}Rn progeny concentrations were made in the mines during the times that the miners were being exposed, and that dosimeters capable of integrating the Rn progeny exposures of the miners did not exist. Historically, the cumulative exposures for individual uranium and other hard rock miners have been calculated by combining the employee`s work history, which may or may not have included time spent at different jobs within the mines and at different locations within the mines, with whatever periodic measurements of Rn and Rn progeny were available. The amount and quality of the measurement data varied enormously from mine to mine and from population to population. Because the quality of the exposure data collected during the period of active mining in the United STates cannot now be altered substantially, significant improvement in individual miner exposure estimates is only likely to be achieved if a new cumulative exposure metric is developed and implemented. The decay chain of Rn includes the production of {sup 210}Pb, which can accumulate in the skeleton in amounts proportional to the intake of Rn progeny. We hypothesize that the in vivo measurement of {sup 210}Pb in the skulls of miners will provide such a metric. In summary, the primary purpose of this pilot study to demonstrate the feasibility of measuring {sup 210}Pb in the heads of former uranium miners has been accomplished.

  17. Indoor radon.

    PubMed

    Polpong, P; Bovornkitti, S

    1998-01-01

    The naturally radioactive but chemically inert gas, radon, is formed from the radioactive decay of radium which is part of the uranium series. Radon gas, which has a half life of 3.8 days, must escape from soil particles through air-filled pores in order to enter the atmosphere following the decay of radium. The concentration of radon in the atmosphere varies, depending on the place, time, height above the ground and meteorological conditions. It is thus an inescapable source of radiation exposure, both at home and at work. The potential hazards posed by exposure to radiation from indoor radon gas and its daughter products are of great concern worldwide. Noting of an excessive lung cancer risk among several groups of underground miners exposed to radon and its daughter products, studies on radon concentrations in the workplace and in dwellings have been conducted in many countries. The results have shown that the distribution of radon concentrations are approximately lognormal from which population weighted; the arithmetic mean of radon concentration of 40 Bq.m-3 has been adopted worldwide for dwellings and workplaces. The principal methods for reducing a high indoor radon concentration are: reducing the radon supply by reversing the pressure difference between the building and the soil; raising the resistance of the foundations to soil gas entry; removing the radon sources such as water or underlying soil; diluting the concentration by increasing the ventilation rate; and reducing the concentration of radon progeny by filtering and increasing the circulation of indoor air. Buildings which have a radon concentration higher than 200 Bq.m-3 should be investigated by the national authorities concerned; meanwhile, householders should be advised to take simple temporary precautions, such as increasing ventilation, until a permanent remedy can be effected. PMID:9470322

  18. Residential Radon Exposure and Risk of Lung Cancer in Missouri

    Cancer.gov

    A case-control study of lung cancer and residential radon exposure in which investigators carried out both standard year-long air measurements and CR-39 alpha detector measurements (call surface monitors)

  19. In-vivo measurements of Pb-210 to determine cumulative exposure to radon daughters: A pilot study. Final report, 1 March, 1990--May 31, 1991

    SciTech Connect

    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. Cancer risks from exposure to radon in homes.

    PubMed Central

    Axelson, O

    1995-01-01

    Exposure to radon and its decay products in mines is a well recognized risk of lung cancer in miners. A large number of epidemiologic studies from various countries are quite consistent in this respect even it the magnitude of the risk differs according to exposure levels. Indoor radon became a concern in the 1970s and about a dozen studies have been conducted since 1979, mainly of the case-control design. From first being of a simple pilot character, the designs have become increasingly sophisticated, especially with regard to exposure assessment. Crude exposure estimates based on type of house, building material and geological features have been supplemented or replaced by quite extensive measurements. Still, exposure assessment remains a difficult and uncertain issue in these studies, most of which indicate a lung cancer risk from indoor radon. Also a recent large scale study has confirmed a lung cancer risk from indoor radon. More recently there are also some studies, mainly of the correlation type, suggesting other cancers also to be related to indoor radon, especially leukemia, kidney cancer, and malignant melanoma, and some other cancers as well. The data are less consistent and much more uncertain than for indoor radon and lung cancer, however; and there is no clear support from studies of miners in this respect. PMID:7614945

  1. A macroscopic and microscopic study of radon exposure using Geant4 and MCNPX to estimate dose rates and DNA damage

    NASA Astrophysics Data System (ADS)

    van den Akker, Mary Evelyn

    Radon is considered the second-leading cause of lung cancer after smoking. Epidemiological studies have been conducted in miner cohorts as well as general populations to estimate the risks associated with high and low dose exposures. There are problems with extrapolating risk estimates to low dose exposures, mainly that the dose-response curve at low doses is not well understood. Calculated dosimetric quantities give average energy depositions in an organ or a whole body, but morphological features of an individual can affect these values. As opposed to human phantom models, Computed Tomography (CT) scans provide unique, patient-specific geometries that are valuable in modeling the radiological effects of the short-lived radon progeny sources. Monte Carlo particle transport code Geant4 was used with the CT scan data to model radon inhalation in the main bronchial bifurcation. The equivalent dose rates are near the lower bounds of estimates found in the literature, depending on source volume. To complement the macroscopic study, simulations were run in a small tissue volume in Geant4-DNA toolkit. As an expansion of Geant4 meant to simulate direct physical interactions at the cellular level, the particle track structure of the radon progeny alphas can be analyzed to estimate the damage that can occur in sensitive cellular structures like the DNA molecule. These estimates of DNA double strand breaks are lower than those found in Geant4-DNA studies. Further refinements of the microscopic model are at the cutting edge of nanodosimetry research.

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

    PubMed

    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. PMID:12633999

  3. Radon exposures from the use of natural gas in buildings.

    PubMed

    Dixon, D W

    2001-01-01

    Low levels of natural radioactivity in the ground produce radon-222 and its decay products which can be entrained with gas streams and become distributed with gas supplies to commercial and domestic users. Levels of radon in blended gas received by most users are comparable with the levels that are present naturally in buildings as a result of ingress from the ground and this is further diluted during the combustion process. For typical rates of gas usage with an average radon level of about 200 Bq x m(-3), the estimated dose from the use of natural gas is estimated at 4 microSv, less than 1% of the dose from radon exposure at the average level in UK homes. Commercial users may receive somewhat higher doses, and the estimate for a critical group is a few tens of microsievert. The total radon emission to the environment is estimated at about 10(13) Bq x y(-1) which represents less than 10(-4) of the natural emission rate from the ground. There is some variability of radon levels in gas from different sources and it would be prudent to keep this source of exposure under review. A standard sampling and measurement protocol has been developed in conjunction with a technical group representing the industry. PMID:11843341

  4. Lung Cancer Attributable to Indoor Radon Exposures in Two Radon—Prone Areas, Ştei (Romania) and Torrelodones (Spain)

    NASA Astrophysics Data System (ADS)

    Dinu, Alexandra; Cosma, Constantin; Sainz, Carlos; Poncela, Luis Santiago Quindós; Vasiliniuc, Ştefan

    2009-05-01

    Radon and radon progeny are present indoors, in houses and others dwellings, representing the most important contribution to dose from natural sources of radiation. Most studies have demonstrated an increased risk of lung cancer at high concentration of radon for both smokers and nonsmokers. For medium and low concentrations which are the typical residential radon levels, recent researches have also demonstrated increased risks of lung cancer for people exposed. The work presents a comparative analysis of the radon exposure data in the two radon—prone areas, Ştei, Transylvania, (Romania), in the near of old Romanian uranium mines and in the granitic area of Torrelodones town, Sierra de Guadarrama (Spain). One important difference between the two studied areas is related to the houses built using uranium waste as construction material in Ştei area. Measurements of indoor radon were performed in 280 dwellings (Romania) and 91 dwellings (Spain) by using nuclear track detectors, CR 39. The highest value measured in Ştei area was 2650 Bqṡm-3. and 366 Bqṡm-3 in the Spanish region. The results are compute with the BEIR VI report estimates using the age-duration model at an exposure rate below 2650 Bqṡm-3. A total of 233 lung cancer deaths were calculated in the Ştei area for a period of 13 years (1994-2006), which is 116.82% higher than observed from the national statistics. In comparison, in Torrelodones area, a number of 276 deaths caused by lung cancer were estimated along a period of 13 years, which is 2.09 times higher than the number observed by authorities. This represents a significantly evidence that elevated risk can strongly be associated with cumulated radon exposure.

  5. Estimated effective dose rates from radon exposure in workplaces and residences within Los Alamos county in New Mexico

    SciTech Connect

    Whicker, Jeffrey J; Mcnaughton, Michael

    2009-01-01

    Many millions of office workers are exposed to radon while at work and at home. Though there has been a multitude of studies reporting the measurements of radon concentrations and potential lung and effective doses associated with radon and progeny exposure in homes, similar studies on the concentrations and subsequent effective dose rates in the workplace are lacking. The purposes of this study were to measure radon concentrations in office and residential spaces in the same county and explore the radiation dose implications. Sixty-five track-etch detectors were deployed in office spaces and 47 were deployed in residences, all within Los Alamos County, New Mexico, USA. The sampling periods for these measurements were generally about three months. The measured concentrations were then used to calculate and compare effective dose rates resulting from exposure while at work and at home. Results showed that full-time office workers receive on average about nine times greater exposure at home than while in the office (691 mrem yr{sup -1} versus 78 mrem yr{sup -1}). The estimated effective dose rate for a more homebound person was 896 mrem yr{sup -1}. These effective dose rates are contrasted against the 100 mrem yr{sup -1} threshold for regulation of a 'radiological worker' defined in the Department of Energy regulations occupational exposure and the 10 mrem yr{sup -1} air pathway effective public dose limit regulated by the Environmental Protection Agency.

  6. International intercalibration and intercomparison measurements of radon progeny particle size distribution

    SciTech Connect

    Tu, Keng-Wu

    1997-07-01

    Because there is no standard method for {sup 222}Rn progeny size measurements, verifying the performance of various measurement techniques is important. This report describes results of an international intercomparison and calibration of {sup 222}Rn progeny size measurements involving low pressure impactors (MOUDI and Berner) and diffusion battery systems, as well as both alpha- and gamma- counting methods. The intercomparison was at EML on June 12-15, 1995. 5 different particle sizes (80, 90, 165, 395, 1200 nm) of near monodisperse condensation Carbauba wax aerosol and 2 bimodal size spectra (160 and 365 nm, and 70 and 400 nm) were used. 20 tests were completed, covering both low and high concentrations of {sup 222}Rn and test aerosols. For the single-mode test aerosol, the measurements agreed within the size range. Best agreement was found between the two low pressure impactors. Some differences between the impactor and diffusion battery methods were observed in the specific peak locations and the resultant geometric mean diameters. For the two bimodal size distribution aerosols, the MOUDI measurements showed two modes, while the other 3 devices showed a single mode size distribution.

  7. Children's Exposure to Radon in Nursery and Primary Schools.

    PubMed

    Branco, Pedro T B S; Nunes, Rafael A O; Alvim-Ferraz, Maria C M; Martins, Fernando G; Sousa, Sofia I V

    2016-04-01

    The literature proves an evident association between indoor radon exposure and lung cancer, even at low doses. This study brings a new approach to the study of children's exposure to radon by aiming to evaluate exposure to indoor radon concentrations in nursery and primary schools from two districts in Portugal (Porto and Bragança), considering different influencing factors (occupation patterns, classroom floor level, year of the buildings' construction and soil composition of the building site), as well as the comparison with IAQ standard values for health protection. Fifteen nursery and primary schools in the Porto and Bragança districts were considered: five nursery schools for infants and twelve for pre-schoolers (seven different buildings), as well as eight primary schools. Radon measurements were performed continuously. The measured concentrations depended on the building occupation, classroom floor level and year of the buildings' construction. Although they were in general within the Portuguese legislation for IAQ, exceedances to international standards were found. These results point out the need of assessing indoor radon concentrations not only in primary schools, but also in nursery schools, never performed in Portugal before this study. It is important to extend the study to other microenvironments like homes, and in time to estimate the annual effective dose and to assess lifetime health risks. PMID:27043596

  8. Characterization of Radon Progeny in EXO-200 Using Machine Learning Algorithms

    NASA Astrophysics Data System (ADS)

    Smith, Erica

    Neutrinoless double beta decay (0nubetabeta) is a rare, second-order process that occurs in certain isotopes for which beta decay is energetically forbidden. EXO-200 is a 0nubetabeta experiment with 110 kg of active liquid xenon (LXe) isotopically enriched in 136Xe. EXO-200 detects events using a combination of scintillation and ionization signals, which allows for excellent particle discrimination. However, events with a low ionization signal cannot be fully characterized with the current analysis framework. To fill in these gaps, we introduce a boosted decision tree regressor as a new tool to characterize events in the detector. We focus on alpha decays of 222Rn and its progeny, which have low ionization signals that often fall below the threshold for position reconstruction. Using information gained from this technique, we confirm previous results for the 218Po ion velocity and improve previous results for the 218Po ionization fraction. We also investigate events that occur near the walls of the vessel. These events have no ionization signal and therefore cannot be characterized with any existing technique in the analysis framework. By investigating these events we determine that they are not distributed uniformly throughout the detector, which may point to charging up of the plastics inside the LXe vessel or a "hot spot'' on the plastic due to contamination during cleaning and installation.

  9. Worldwide studies of household radon exposure and lung cancer

    SciTech Connect

    Neuberger, J.S.

    1989-06-01

    The purpose of this paper is to summarize the ongoing studies of household radon exposure and lung cancer. To accomplish the above objective, a registry of ongoing epidemiologic studies was consulted. A questionnaire was sent to all known investigators. Principal investigators reviewed their listing and provided copies of their questionnaires. Ongoing studies are larger in size and provide more complete information on radon exposures and various confounders (e.g., cigarette smoking and occupation) than do most previously published studies. For example, out of 17 case/control studies in progress, almost all will collect information on active and passive smoking, occupation, and residential history. Ten of the studies will collect information on family history of cancer and diet. However, although the ongoing studies are more sophisticated, they generally are not standardized in protocol design or questionnaire development. Hence it may prove somewhat difficult to combine a number of studies. The feasibility of pooling data from these studies should be examined by experts in meta-analysis. If results from these studies are inconsistent or negative with respect to radon exposure and lung cancer, then a further study or studies should be considered. Such a study could be in a high radon area, use standardized protocols and questionnaires and be a multi-center, collaborative effort. A feasibility study for such an expanded epidemiologic effort is recommended. 44 refs., 9 tabs.

  10. Air cleaning and radon decay product mitigation

    SciTech Connect

    Hopke, P.K. ); Li, C.S. . John B. Pierce Foundation Lab.); Ramamurthi, M. )

    1990-01-01

    We evaluated air cleaning as a means to mitigate risks arising from exposure to indoor radon progeny in several single-family houses in the northeastern United States, using a new, automated, semi-continuous activity-weighted size distribution measurement system. Measurements included radon concentration, condensation nuclei count, and activity-weighted size distribution of radon decay products. Measurements were made with and without the air cleaning system operating. The influence of particles generated by various sources common to normal indoor activities on radon progeny behavior was evaluated. Aerosols were generated by running water in a shower, burning candles, smoking cigarettes, vacuuming, opening doors, and cooking. Both a filtration unit and an electrostatic precipitator were evaluated. Using a room model, the changes in attachment rates, average attachment diameters, and deposition rates of the unattached'' fraction with and without the air cleaning systems were calculated. The air cleaner typically reduced the radon progeny concentrations by 50 to 60%.

  11. Air cleaning and radon decay product mitigation

    SciTech Connect

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

    1990-12-31

    We evaluated air cleaning as a means to mitigate risks arising from exposure to indoor radon progeny in several single-family houses in the northeastern United States, using a new, automated, semi-continuous activity-weighted size distribution measurement system. Measurements included radon concentration, condensation nuclei count, and activity-weighted size distribution of radon decay products. Measurements were made with and without the air cleaning system operating. The influence of particles generated by various sources common to normal indoor activities on radon progeny behavior was evaluated. Aerosols were generated by running water in a shower, burning candles, smoking cigarettes, vacuuming, opening doors, and cooking. Both a filtration unit and an electrostatic precipitator were evaluated. Using a room model, the changes in attachment rates, average attachment diameters, and deposition rates of the ``unattached`` fraction with and without the air cleaning systems were calculated. The air cleaner typically reduced the radon progeny concentrations by 50 to 60%.

  12. Radon

    MedlinePlus

    ... with elevated radon underwent changes to reduce radon pollution. 1 How Can Radon Be Detected? The only ... Association Applauds EPA’s Update to Cross-State Air Pollution Rule News: New Truck Efficiency Standards Expected to ...

  13. Predicted reduction in lung cancer risk following cessation of smoking and radon exposure

    SciTech Connect

    Ennever, F.K. )

    1990-03-01

    Recently there has been considerable public and regulatory concern that radon, produced by the decay of naturally occurring uranium, can accumulate in homes, offices, and schools at levels that may substantially increase the risk of lung cancer. The major cause of lung cancer is smoking, and radon appears to interact multiplicatively with smoking in causing lung cancer. Thus, the most effective way to reduce the increased risk of lung cancer resulting from radon exposure is to cease smoking. In this paper, a model for the risks associated with radon exposure that was developed by a committee of the National Academy of Sciences is used to calculate the benefits, in terms of reduction in lifetime risk of lung cancer, of ceasing to smoke, ceasing radon exposure, or ceasing both. Ceasing to smoke is considerably more beneficial than ceasing radon exposure, and thus policymakers addressing the health effects of radon should place priority on encouraging individuals to stop smoking.

  14. Residential Radon Exposure and Lung Cancer: Evidence of an Inverse Association in Washington State.

    ERIC Educational Resources Information Center

    Neuberger, John S.; And Others

    1992-01-01

    Presents results of a descriptive study of lung cancer death rates compared to county levels of radon in Washington State. Age-specific death rates were computed for white female smokers according to radon exposure. A significant lung cancer excess was found in lowest radon counties. No significant difference was found between the proportion of…

  15. Coagulation effect on the activity size distributions of long lived radon progeny aerosols and its application to atmospheric residence time estimation techniques.

    PubMed

    Anand, S; Mayya, Y S

    2015-03-01

    The long lived naturally occurring radon progeny species in the atmosphere, namely (210)Pb, (210)Bi and (210)Po, have been used as important tracers for understanding the atmospheric mixing processes and estimating aerosol residence times. Several observations in the past have shown that the activity size distribution of these species peaks at larger particle sizes as compared to the short lived radon progeny species - an effect that has been attributed to the process of coagulation of the background aerosols to which they are attached. To address this issue, a mathematical equation is derived for the activity-size distribution of tracer species by formulating a generalized distribution function for the number of tracer atoms present in coagulating background particles in the presence of radioactive decay and removal. A set of these equations is numerically solved for the progeny chain using Fuchs coagulation kernel combined with a realistic steady-state aerosol size spectrum that includes nucleation, accumulation and coarse mode components. The important findings are: (i) larger shifts in the modal sizes of (210)Pb and (210)Po at higher aerosol concentrations such as that found in certain Asian urban regions (ii) enrichment of tracer specific activity on particles as compared to that predicted by pure attachment laws (iii) sharp decline of daughter-to-parent activity ratios for decreasing particle sizes. The implication of the results to size-fractionated residence time estimation techniques is highlighted. A coagulation corrected graphical approach is presented for estimating the residence times from the size-segregated activity ratios of (210)Bi and (210)Po with respect to (210)Pb. The discrepancy between the residence times predicted by conventional formula and the coagulation corrected approach for specified activity ratios increases at higher atmospheric aerosol number concentrations (>10(10) #/m(3)) for smaller sizes (<1 μm). The results are further

  16. Radon

    MedlinePlus

    You can't see radon. And you can't smell it or taste it. But it may be a problem in your home. Radon comes from the natural breakdown of uranium in soil, rock, and water. Radon is the second leading cause of lung cancer ...

  17. Indoor air radon.

    PubMed

    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. The major and almost universal problem is in estimating exposure

  18. Daily variation of radon gas and its short-lived progeny concentration near ground level and estimation of aerosol residence time

    NASA Astrophysics Data System (ADS)

    M, Mohery; A, M. Abdallah; A, Ali; S, S. Baz

    2016-05-01

    Atmospheric concentrations of radon (222Rn) gas and its short-lived progenies 218Po, 214Pb, and 214Po were continuously monitored every four hours at the ground level in Jeddah city, Kingdom of Saudi Arabia. The measurements were performed three times every week, starting from November 2014 to October 2015. A method of electrostatic precipitation of positively charged 218Po and 214Po by a positive voltage was applied for determining 222Rn gas concentration. The short-lived 222Rn progeny concentration was determined by using a filter holder connected with the alpha-spectrometric technique. The meteorological parameters (relative air humidity, air temperature, and wind speed) were determined during the measurements of 222Rn and its progeny concentrations. 222Rn gas as well as its short-lived progeny concentration display a daily and seasonal variation with high values in the night and early morning hours as compared to low values at noon and in the afternoon. The observed monthly atmospheric concentrations showed a seasonal trend with the highest values in the autumn/winter season and the lowest values in the spring/summer season. Moreover, and in parallel with alpha-spectrometric measurements, a single filter-holder was used to collect air samples. The deposited activities of 214Pb and the long-lived 222Rn daughter 210Pb on the filter were measured with the gamma spectrometric technique. The measured activity concentrations of 214Pb by both techniques were found to be relatively equal largely. The highest mean seasonally activity concentrations of 210Pb were observed in the autumn/winter season while the lowest mean were observed in the spring/summer season. The mean residence time (MRT) of aerosol particles in the atmospheric air could be estimated from the activity ratios of 210Pb/214Pb. Project supported by the Deanship of Scientific Research (DSR), King Abdulaziz University, Jeddah (Grant No. 291/965/1434).

  19. The usability of wood as a volume trap for the purpose of retrospective radon exposure assessment

    SciTech Connect

    Paridaens, J.; Vanmarcke, H. )

    1999-06-01

    The possibility of using wood samples as a retrospective radon monitor was investigated. Retrospective radon monitors are based on the analysis of the enhanced [sup 210]Po content of the bulk of the sample as a result of radon exposure. Several wood samples in different sizes and shapes were tested for their radon penetrability and the speed at which radon can diffuse throughout the material. Also, the volume ratio of air to solid material and the natural occurring [sup 210]Po background were determined. It was seen that only in fairly exceptional cases wood can be used as an acceptable volume trap. This is mostly due to the high and variably occurring natural [sup 210]Po background in wood samples with respect to the expected increase in radon-related [sup 210]Po due to common radon concentrations in dwellings.

  20. Work to save dose: contrasting effective dose rates from radon exposure in workplaces and residences against the backdrop of public and occupational limits

    SciTech Connect

    Whicker, Jeffrey J; Mcnaughton, Michael W

    2009-01-01

    Office workers are exposed to radon while at work and at home. Though there has been a multitude of studies reporting the measurements of radon concentrations and potential lung and effective doses associated with radon and progeny exposure in homes, similar studies on the concentrations and subsequent effective dose rates in the non-mine workplaces are lacking. Additionally, there are few, if any, comparative analyses of radon exposures at more 'typical' workplace with residential exposures within the same county. The purposes of this study were to measure radon concentrations in office and residential spaces in the same county and explore the radiation dose implications. Sixty-five track-etch detectors were deployed in office spaces and 47 were deployed in residences, all within Los Alamos County, New Mexico, USA. The sampling periods for these measurements were generally about three months. The measured concentrations were used to calculate and compare effective dose rates resulting from exposure while at work and at home. Results showed that full-time office workers receive on average about 8 times greater exposure at home than while in the office (2.3 mSv yr-! versus 0.3 mSv yr-!). The estimated effective dose rate for a more homebound person was about 3 mSv yr-!. Estimating effective doses from background radon exposure in the same county as Los Alamos National Laboratory, with thousands of'radiological workers,' highlights interesting contrasts in radiation protection standards that span public and occupational settings. For example, the effective dose rate from background radon exposure in unregulated office spaces ranged up to 1.1 mSv yr-!, which is similar to the 1 mSv yr-! threshold for regulation ofa 'radiological worker,' as defined in the Department of Energy regulations for occupational exposure. Additionally, the estimated average effective dose total of> 3 mSv yf! from radon background exposure in homes stands in contrast to the 0.1 mSv yr-! air

  1. Protection from radon exposure at home and at work in the directive 2013/59/Euratom.

    PubMed

    Bochicchio, F

    2014-07-01

    In recent years, international organisations involved in radiation protection and public health have produced new guidance, recommendations and requirements aiming better protection from radon exposure. These organisations have often worked in close collaboration in order to facilitate the establishment of harmonised standards. This paper deals with such standards and specifically with the new European Council Directive of 5 December 2013 on basic safety standards for protection against the dangers arising from exposure to ionising radiation (2013/59/Euratom). This new Directive has established a harmonised framework for the protection against ionising radiations, including protection from radon exposure. Requirements for radon in workplace are much more tightening than in previous Directive, and exposures to radon in dwellings are regulated for the first time in a Directive. Radon-related articles of this Directive are presented and discussed in this paper, along with some comparisons with other relevant international standards. PMID:24729590

  2. Using geographic information systems for radon exposure assessment in dwellings in the Oslo region, Norway

    NASA Astrophysics Data System (ADS)

    Kollerud, R.; Blaasaas, K.; Ganerød, G.; Daviknes, H. K.; Aune, E.; Claussen, B.

    2014-04-01

    Radon exposures were assigned to each residential address in the Oslo region using a geographic information system (GIS) that included indoor radon measurements. The results will be used in an epidemiologic study regarding leukemia and brain cancer. The model is based on 6% of measured residential buildings. High density of indoor radon measurements allowed us to develop a buffer model where indoor radon measurements found around each dwelling were used to assign a radon value for homes lacking radon measurement. Intraclass correlation coefficients (ICCs) were used to study the agreement between radon values from the buffer method, from indoor radon values of measured houses, and from a regression model constructed with radiometric data (eTh, eU) and bedrock geology. We obtained good agreement for both comparisons with ICC values between 0.54 and 0.68. GIS offers a useful variety of tools to study the indoor-radon exposure assessment. By using the buffer method it is more likely that geological conditions are similar within the buffer and this may take more into account the variation of radon over short distances. It is also probable that short-distance-scale correlation patterns express similarities in building styles and living habits. Although the method has certain limitations, we regard it as acceptable for use in epidemiological studies.

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

    SciTech Connect

    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.

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

    PubMed

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

    2014-11-01

    According to Austrian Law, dose assessments in workplaces with potentially enhanced radon exposures are mandatory since 2008, including tourist mines and caves. A pilot study was carried out to evaluate the situation to test the measurement methods and to specify the main parameters controlling the radon concentration in tourist mines and caves. Radon was measured in six mines and three caves for 1 y, along with determining thoron and equilibrium factors and taking into account climatic, geological and site-related effects. The radon concentrations have a seasonal dependence with maximum in summer and minimum in winter, related to natural ventilation. Radon concentrations in the karst caves were quite low, as it was in the salt mine, whereas radon concentrations in copper and silver mines were high. The dose assessment of the employees yielded doses above 6 mSv a(-1) only in the copper mine. PMID:25013031

  5. Quality assurance for radon exposure chambers at the National Air and Radiation Environmental Laboratory, Montgomery, Alabama

    SciTech Connect

    Semler, M.O.; Sensintaffar, E.L.

    1993-12-31

    The Office of Radiation and Indoor Air, U.S. Environmental Protection Agency (EPA), operates six radon exposure chambers in its two laboratories, the National Air and Radiation Environmental Laboratory (NAREL) in Montgomery, Alabama, and the Las Vegas Facility, Las Vegas, Nevada. These radon exposure chambers are used to calibrate and test portable radon measuring instruments, test commercial suppliers of radon measurement services through the Radon Measurement Proficiency Program, and expose passive measurement devices to known radon concentrations as part of a quality assurance plan for federal and state studies measuring indoor radon concentrations. Both laboratories participate in national and international intercomparisons for the measurement of radon and are presently working with the National Institute of Standards and Technology (NIST) to receive a certificate of traceability for radon measurements. NAREL has developed an estimate of the total error in its calibration of each chamber`s continuous monitors as part of an internal quality assurance program. This paper discusses the continuous monitors and their calibration for the three chambers located in Montgomery, Alabama, as well as the results of the authors intercomparisons and total error analysis.

  6. MEASUREMENTS OF RADON, THORON, ISOTOPIC URANIUM AND THORIUM TO DETERMINE OCCUPATIONAL & ENVIRONMENTAL EXPOSURE & RISK AT FERNALD FEED MATERIALS PRODUCTION CENTER.

    EPA Science Inventory

    The research at the Fernald Environmental Restoration Management Corporation (FERMCO) site will provide radionuclide data, and realistic risk evaluation for isotopic radon, thorium, uranium and lead exposure.We have developed and tested a passive radon monitor with proven accur...

  7. Calculation of lifetime lung cancer risks associated with radon exposure, based on various models and exposure scenarios.

    PubMed

    Hunter, Nezahat; Muirhead, Colin R; Bochicchio, Francesco; Haylock, Richard G E

    2015-09-01

    The risk of lung cancer mortality up to 75 years of age due to radon exposure has been estimated for both male and female continuing, ex- and never-smokers, based on various radon risk models and exposure scenarios. We used risk models derived from (i) the BEIR VI analysis of cohorts of radon-exposed miners, (ii) cohort and nested case-control analyses of a European cohort of uranium miners and (iii) the joint analysis of European residential radon case-control studies. Estimates of the lifetime lung cancer risk due to radon varied between these models by just over a factor of 2 and risk estimates based on models from analyses of European uranium miners exposed at comparatively low rates and of people exposed to radon in homes were broadly compatible. For a given smoking category, there was not much difference in lifetime lung cancer risk between males and females. The estimated lifetime risk of radon-induced lung cancer for exposure to a concentration of 200 Bq m(-3) was in the range 2.98-6.55% for male continuing smokers and 0.19-0.42% for male never-smokers, depending on the model used and assuming a multiplicative relationship for the joint effect of radon and smoking. Stopping smoking at age 50 years decreases the lifetime risk due to radon by around a half relative to continuing smoking, but the risk for ex-smokers remains about a factor of 5-7 higher than that for never-smokers. Under a sub-multiplicative model for the joint effect of radon and smoking, the lifetime risk of radon-induced lung cancer was still estimated to be substantially higher for continuing smokers than for never smokers. Radon mitigation-used to reduce radon concentrations at homes-can also have a substantial impact on lung cancer risk, even for persons in their 50 s; for each of continuing smokers, ex-smokers and never-smokers, radon mitigation at age 50 would lower the lifetime risk of radon-induced lung cancer by about one-third. To maximise risk reductions, smokers in high-radon

  8. Radon Exposure and the Definition of Low Doses-The Problem of Spatial Dose Distribution.

    PubMed

    Madas, Balázs G

    2016-07-01

    Investigating the health effects of low doses of ionizing radiation is considered to be one of the most important fields in radiological protection research. Although the definition of low dose given by a dose range seems to be clear, it leaves some open questions. For example, the time frame and the target volume in which absorbed dose is measured have to be defined. While dose rate is considered in the current system of radiological protection, the same cancer risk is associated with all exposures, resulting in a given amount of energy absorbed by a single target cell or distributed among all the target cells of a given organ. However, the biological effects and so the health consequences of these extreme exposure scenarios are unlikely to be the same. Due to the heterogeneous deposition of radon progeny within the lungs, heterogeneous radiation exposure becomes a practical issue in radiological protection. While the macroscopic dose is still within the low dose range, local tissue doses on the order of Grays can be reached in the most exposed parts of the bronchial airways. It can be concluded that progress in low dose research needs not only low dose but also high dose experiments where small parts of a biological sample receive doses on the order of Grays, while the average dose over the whole sample remains low. A narrow interpretation of low dose research might exclude investigations with high relevance to radiological protection. Therefore, studies important to radiological protection should be performed in the frame of low dose research even if the applied doses do not fit in the dose range used for the definition of low doses. PMID:27218294

  9. Characterisation of an electronic radon gas personal dosemeter.

    PubMed

    Gründel, M; Postendörfer, J

    2003-01-01

    The monitoring of radon exposure at workplaces is of great importance. Up to now passive measurement systems have been used for the registration of radon gas. Recently an electronic radon gas personal dosemeter came onto the market as an active measurement system for the registration of radon exposure (DOSEman; Sarad GmbH, Dresden, Germany). In this personal monitor, the radon gas diffuses through a membrane into a measurement chamber. A silicon detector system records spectroscopically the alpha decays of the radon gas and of the short-lived progeny 218Po and 214Po gathered onto the detector by an electrical field. In this work the calibration was tested and a proficiency test of this equipment was made. The diffusion behaviour of the radon gas into the measurement chamber, susceptibility to thoron, efficiency, influence of humidity, accuracy and the detection limit were checked. PMID:14756187

  10. A Systematic Review of Radon Investigations Related to Public Exposure in Iran

    PubMed Central

    Pirsaheb, Meghdad; Najafi, Farid; Khosravi, Touba; Hemati, Lida

    2013-01-01

    Background The main sources of radiation exposure of all living organisms including humans are natural. In fact, radon and its decay products are the cause of 50% of the total dose that is derived from natural sources. Because of the significant health hazards of radon gas, its levels are widely monitored throughout the world. Accordingly, considerable researches have also been carried out in Iran. Objectives The aim of this research is a systematic review of the most recent studies associated with evaluation of radon gas levels in Iran. The main emphasis of this study was on public exposure to radon gas. Materials and Methods The most important route of exposure to such radiation is indoor places. In this investigation measurement of radon in water resources, tap water, indoor places and exhalation of radon from building material, the major sources of indoor radon gas emission, were considered. Results Significantly high levels of radon gas were found mostly in water and residenvial buildings. Conclusions It conclusion with regard to the study of building materials, granite stone and adobe coverings cannot be recommended for construction purposes. PMID:24719680

  11. Residential Radon Exposure and Incidence of Childhood Lymphoma in Texas, 1995–2011

    PubMed Central

    Peckham, Erin C.; Scheurer, Michael E.; Danysh, Heather E.; Lubega, Joseph; Langlois, Peter H.; Lupo, Philip J.

    2015-01-01

    There is warranted interest in assessing the association between residential radon exposure and the risk of childhood cancer. We sought to evaluate the association between residential radon exposure and the incidence of childhood lymphoma in Texas. The Texas Cancer Registry (n = 2147) provided case information for the period 1995–2011. Denominator data were obtained from the United States Census. Regional arithmetic mean radon concentrations were obtained from the Texas Indoor Radon Survey and linked to residence at diagnosis. Exposure was assessed categorically: ≤25th percentile (reference), >25th to ≤50th percentile, >50th to ≤75th percentile, and >75th percentile. Negative binomial regression generated adjusted incidence rate ratios (aIRR) and 95% confidence intervals (CI). We evaluated lymphoma overall and by subtype: Hodgkin (HL; n = 1248), Non-Hodgkin excluding Burkitt (non-BL NHL; n = 658), Burkitt (BL; n = 241), and Diffuse Large B-cell (DLBCL; n = 315). There was no evidence that residential radon exposure was positively associated with lymphoma overall, HL, or BL. Areas with radon concentrations >75th percentile had a marginal increase in DLBCL incidence (aIRR = 1.73, 95% CI: 1.03–2.91). In one of the largest studies of residential radon exposure and the incidence of childhood lymphoma, we found little evidence to suggest a positive or negative association; an observation consistent with previous studies. PMID:26404336

  12. Residential Radon Exposure and Incidence of Childhood Lymphoma in Texas, 1995-2011.

    PubMed

    Peckham, Erin C; Scheurer, Michael E; Danysh, Heather E; Lubega, Joseph; Langlois, Peter H; Lupo, Philip J

    2015-10-01

    There is warranted interest in assessing the association between residential radon exposure and the risk of childhood cancer. We sought to evaluate the association between residential radon exposure and the incidence of childhood lymphoma in Texas. The Texas Cancer Registry (n = 2147) provided case information for the period 1995-2011. Denominator data were obtained from the United States Census. Regional arithmetic mean radon concentrations were obtained from the Texas Indoor Radon Survey and linked to residence at diagnosis. Exposure was assessed categorically: ≤25th percentile (reference), >25th to ≤50th percentile, >50th to ≤75th percentile, and >75th percentile. Negative binomial regression generated adjusted incidence rate ratios (aIRR) and 95% confidence intervals (CI). We evaluated lymphoma overall and by subtype: Hodgkin (HL; n = 1248), Non-Hodgkin excluding Burkitt (non-BL NHL; n = 658), Burkitt (BL; n = 241), and Diffuse Large B-cell (DLBCL; n = 315). There was no evidence that residential radon exposure was positively associated with lymphoma overall, HL, or BL. Areas with radon concentrations >75th percentile had a marginal increase in DLBCL incidence (aIRR = 1.73, 95% CI: 1.03-2.91). In one of the largest studies of residential radon exposure and the incidence of childhood lymphoma, we found little evidence to suggest a positive or negative association; an observation consistent with previous studies. PMID:26404336

  13. Modeling Joint Exposures and Health Outcomes for Cumulative Risk Assessment: the Case of Radon and Smoking

    EPA Science Inventory

    Community-based cumulative risk assessment requires characterization of exposures to multiple chemical and non-chemical stressors, with consideration of how the non-chemical stressors may influence risks from chemical stressors. Residential radon provides an interesting case exam...

  14. Levels of thoron and progeny in high background radiation area of southeastern coast of Odisha, India.

    PubMed

    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

    2012-11-01

    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. PMID:22908359

  15. Residental radon exposure and lung cancer: Evidence of an urban factor in Iowa

    SciTech Connect

    Neuberger, J.S.; Lynch, C.F.; Kross, B.C.

    1994-03-01

    An ecological study of lung cancer, cigarette smoking, and radon exposure was conducted in 20 Iowa counties. County-based lung cancer incidence data for white female residents of Iowa were stratified according to radon level and smoking status. Cancer incidence data for the period 1973-1990 were obtained from the State Health Registry of Iowa. Smoking level was determined from a randomly mailed survey. Radon level was determined according to an EPA supported charcoal canister survey. Within low smoking counties, rates for all lung cancer and small cell carcinoma were significantly lower (p < 0.05) in the high radon counties relative to the medium and low radon counties. However, within high smoking counties, rates for all lung cancer, adenocarcinoma, and small cell carcinoma were significantly higher (p < 0.05) in the high radon counties relative to the low radon counties. Variations in socioeconomic data for these counties, available through the 1980 and 1990 census, did not explain these results. Lung cancer rates also were significantly increased in urban counties even after holding smoking status constant. Multivariate analyses revealed significant interactions between smoking, urbanization, radon levels, and lung cancer. The results of this hypothesis generating study will be tested in a case/control study now ongoing in Iowa. Analysis will need to include separate evaluations by smoking status, radon level, and residence in urban or rural areas for the major morphologic types of lung cancer. 24 refs., 3 figs., 5 tabs.

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

    SciTech Connect

    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.

  17. Residential Radon Exposure and Skin Cancer Incidence in a Prospective Danish Cohort

    PubMed Central

    Bräuner, Elvira Vaclavik; Loft, Steffen; Sørensen, Mette; Jensen, Allan; Andersen, Claus Erik; Ulbak, Kaare; Hertel, Ole; Pedersen, Camilla; Tjønneland, Anne; Krüger Kjær, Susanne; Raaschou-Nielsen, Ole

    2015-01-01

    Background Although exposure to UV radiation is the major risk factor for skin cancer, theoretical models suggest that radon exposure can contribute to risk, and this is supported by ecological studies. We sought to confirm or refute an association between long-term exposure to residential radon and the risk for malignant melanoma (MM) and non-melanoma skin cancer (NMSC) using a prospective cohort design and long-term residential radon exposure. Methods During 1993–1997, we recruited 57,053 Danish persons and collected baseline information. We traced and geocoded all residential addresses of the cohort members and calculated radon concentrations at each address lived in from 1 January 1971 until censor date. Cox proportional hazards models were used to estimate incidence rate-ratios (IRR) and confidence intervals (CI) for the risk associated with radon exposure for NMSC and MM, and effect modification was assessed. Results Over a mean follow-up of 13.6 years of 51,445 subjects, there were 3,243 cases of basal cell carcinoma (BCC), 317 cases of squamous cell carcinoma (SCC) and 329 cases of MM. The adjusted IRRs per 100 Bq/m3 increase in residential radon levels for BCC, SCC and MM were 1.14 (95% CI: 1.03, 1.27), 0.90 (95% CI: 0.70, 1.37) and 1.08 (95% CI: 0.77, 1.50), respectively. The association between radon exposure and BCC was stronger among those with higher socio-economic status and those living in apartments at enrollment. Conclusion and Impact Long-term residential radon exposure may contribute to development of basal cell carcinoma of the skin. We cannot exclude confounding from sunlight and cannot conclude on causality, as the relationship was stronger amongst persons living in apartments and non-existent amongst those living in single detached homes. PMID:26274607

  18. 30 CFR 57.5037 - Radon daughter exposure monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... every two weeks at random times in all active working areas such as stopes, drift headings, travelways..., travel, or congregate. However, if concentrations of radon daughters are found in excess of 0.3 WL in an active working area, radon daughter concentrations thereafter shall be determined weekly in that...

  19. Environmental Assessment for moving the Pacific Northwest Laboratory radon generators from Life Sciences Laboratory II, Richland North Area, to Life Sciences Laboratory I, 300 Area, and their continued use in physical and biological research

    SciTech Connect

    Nelson, I.C.

    1993-09-01

    The Pacific Northwest Laboratory (PNL) radon generators are a core resource of the overall U. S. Department of Energy`s (DOE) Radon Research Program and are administratively controlled within the ``Radon Hazards in Homes`` project. This project primarily focuses on radon exposures of animals and addresses the major biologic effects and factors influencing risks of indoor radon exposures. For example, the ``Mechanisms of Radon Injury`` and ``In vivo/In vitro Radon-Induced Cellular Damage`` projects specifically address the cytogenetic and DNA damage produced by radon exposure as part of a larger effort to understand radon carcinogenesis. Several other ongoing PNL projects, namely: ``Biological Effectiveness of Radon Alpha Particles: A Microbeam Study of Dose Rate Effects,`` ``Laser Measurements of Pb-210,`` ``Radon Transport Modeling in Soils,`` ``Oncogenes in Radiation Carcinogenesis,`` ``Mutation of DNA Targets,`` ``Dosimetry of Radon Progeny,`` and ``Aerosol Technology Development`` also use the radon exposure facilities in the conduct of their work. While most, but not all, studies in the PNL Radon Research Program are funded through DOE`s Office of Health and Environmental Research, PNL also has ongoing collaborative radon studies with investigators worldwide; many of these use the radon exposure facilities. The purpose of the proposed action is to provide for relocation of the radon generators to a DOE-owned facility and to continue to provide a controlled source of radon-222 for continued use in physical and biological research.

  20. Effectiveness Analysis of Filters Used with Radon Detectors under Extreme Environmental Conditions for Long-term Exposures

    NASA Astrophysics Data System (ADS)

    Moreno, V.; Font, Ll.; Baixeras, C.; Garcia-Orellana, J.; Bach, J.; Grossi, C.; Vargas, A.

    Active and passive radon detectors have been exposed with different filter configurations at the INTE radon chamber controlled conditions. Correction factors and delay times of the radon diffusion through each filter have been determined. Additionally, some of the studied filter/detector configurations have been used to measure radon in several workplaces and outdoor sites under real extreme environmental conditions. Analysis of these detectors showed partial degradation, so used filters seem not to be protective enough for long-term exposures.

  1. Caves, mines and subterranean spaces: hazard and risk from exposure to radon.

    NASA Astrophysics Data System (ADS)

    Crockett, R. G. M.; Gillmore, G. K.

    2009-04-01

    Radon is a naturally occurring radioactive gas. It is colourless, odourless and chemically inert. The most hazardous isotope is 222Rn. Radon is formed in the natural environment by the radioactive decay of the element uranium (238U) and is a daughter product of daughter product of radium (226Ra). Uranium and radium are found, in differing degrees, in a wide range of rocks, soils (and building materials that are made from these). Radon concentrations in caves, e.g. limestone caves such as the Great Cave of Niah, Borneo, and caves in the Mendips and Peak District in the UK, has been documented and reveal that both (prehistoric) cave-dwellers and other users such as archaeologists are at risk from exposure to radon a naturally occurring radioactive gas. In general, but dependent on cave geometry and ventilation, radon concentration increases with increasing distance from the entrance, implying that the hazard also increases with distance from the entrance. With regard to mines and mining operations, as well as modern extraction of uranium and radium ores, both ores commonly occur alongside other metallic ores, e.g. silver at Schneeberg and Joachimsthal, and tin in Cornwall, and in some instances, waste from earlier metalliferious mining activity has itself been ‘mined' for uranium and/or radium ores. It is not solely the miners and other subterranean workers which are at risk, other workers and local inhabitants are also at risk. Also, that risk is not eliminated by protection against dust/airborne particulates: the risk from inhalation of radon is only reduced by reducing the inhalation of radon, i.e. use of breathing apparatus. Amongst the general population, radon is the second most significant cause of lung cancer behind tobacco smoking. Estimates vary but 6-9% of lung-cancers are attributable to radon and approximately 2% all cancer deaths are attributable to radon. These proportions will increase in higher-radon environments such as caves, mines and mining

  2. Indoor air radon

    SciTech Connect

    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.

  3. Hypoxia Treatment of Callosobruchus maculatus Females and Its Effects on Reproductive Output and Development of Progeny Following Exposure.

    PubMed

    Yan, Yan; Williams, Scott B; Baributsa, Dieudonne; Murdock, Larry L

    2016-01-01

    Modified atmospheres present a residue-free alternative to fumigants for controlling postharvest pests of grain during storage. How sub-lethal applications of this method affects the reproductive fitness of target pests, however, is still not fully understood. We examined how low levels of ambient oxygen influence the reproduction of the female cowpea bruchid (Callosobruchus maculatus), a pest of cowpea. We used three low-oxygen atmospheres-2%, 5% and 10% (v/v) oxygen-and observed their effects on: (1) the number of eggs laid by bruchids compared to insects held in normoxic (~20% oxygen) conditions; (2) the total number of eggs laid; and (3) the number of progeny that reached maturity. Low oxygen did not significantly affect the number of eggs laid during 48 or 72 h of exposure, but 2% and 5% oxygen did negatively affected total egg production. Increasing the exposure time from 48 to 72 h further depressed lifetime reproductive output. Maternal and egg exposure to hypoxia reduced the number of progeny that reached adulthood. Lower adult emergence was observed from eggs laid under low oxygen and longer exposure times. These data demonstrate that hermetic conditions depress the egg-laying behavior of cowpea bruchids and the successful development of their progeny. PMID:27322332

  4. Hypoxia Treatment of Callosobruchus maculatus Females and Its Effects on Reproductive Output and Development of Progeny Following Exposure

    PubMed Central

    Yan, Yan; Williams, Scott B.; Baributsa, Dieudonne; Murdock, Larry L.

    2016-01-01

    Modified atmospheres present a residue-free alternative to fumigants for controlling postharvest pests of grain during storage. How sub-lethal applications of this method affects the reproductive fitness of target pests, however, is still not fully understood. We examined how low levels of ambient oxygen influence the reproduction of the female cowpea bruchid (Callosobruchus maculatus), a pest of cowpea. We used three low-oxygen atmospheres—2%, 5% and 10% (v/v) oxygen—and observed their effects on: (1) the number of eggs laid by bruchids compared to insects held in normoxic (~20% oxygen) conditions; (2) the total number of eggs laid; and (3) the number of progeny that reached maturity. Low oxygen did not significantly affect the number of eggs laid during 48 or 72 h of exposure, but 2% and 5% oxygen did negatively affected total egg production. Increasing the exposure time from 48 to 72 h further depressed lifetime reproductive output. Maternal and egg exposure to hypoxia reduced the number of progeny that reached adulthood. Lower adult emergence was observed from eggs laid under low oxygen and longer exposure times. These data demonstrate that hermetic conditions depress the egg-laying behavior of cowpea bruchids and the successful development of their progeny. PMID:27322332

  5. Health effects of radon exposure. Report of the Council on Scientific Affairs, American Medical Association

    SciTech Connect

    Not Available

    1991-04-01

    The consensus of scientists is that exposure to radon is hazardous, but disagreement exists about the effects of lower radon concentrations. Studies of underground miners have indicated that the risk of lung cancer increases in proportion to the intensity and duration of exposure to radon, and a recent authoritative report (BEIR IV) has concluded that estimates based on those studies are appropriate for estimating risks for occupants of homes. The BEIR IV report concluded that smoking cigarettes increases the risk of lung cancer associated with radon. Average radon levels in US homes range from 0.055 to 0.148 Bq/L (1.5 to 4 pCi/L), depending on the circumstances of measurement. Few studies have investigated health outcomes in occupants of homes with high radon levels. In advising patients about reducing the risks associated with radon, physicians should consider the costs, as well as the benefits, of remedial actions, and they should emphasize that, by far, the best way to avoid lung cancer is to stop smoking.

  6. Radon exposure mediated changes in lung macrophage morphology and function, in vitro

    SciTech Connect

    Seed, T.M.; Niiro, G.K.; Kretz, N.D.

    1990-01-01

    Bronchopulmonary macrophages play a key role in the normal physiology of the respiratory system. Potential respiratory dysfunctions due to radon/radon daughter exposure-mediated damage of the macrophage lung cell population has been explored via in vitro technology. In this study, macrophages were isolated from lungs of normal healthy dogs by saline lavage, cultured for varying periods (0-96 h) in the presence or absence of radon gas, and assessed for radon dose-dependent changes in cell morphology and function. The in vitro culture procedure and the cell exposing system allowed for detailed alpha particle dosimetry, in relation to the assessed biological end points; i.e. (1) exposure-dependent changes in macrophage surface topography, (2) capacity to elaborate specific growth factor (CSF) essential for self maintenance, and (3) alterations in cell viability. Highlights of the morphologic assessment indicate that relatively low alpha particle doses arising from protracted radon/radon daughter exposure elicites pronounced topographic alterations of the exposed macrophage's cell surface. 27 refs., 7 figs., 1 tab.

  7. Radon exhalation and natural radiation exposure in low ventilated rooms

    NASA Astrophysics Data System (ADS)

    Abdallah, A. M.; Mohery, M.; Yaghmour, Saud J.; Alddin, S. H.

    2012-11-01

    In the first part of this paper, the influence of radon (222Rn) exhalation rate from walls and air exchange upon its concentration in room air was considered using a simple mathematical room model. The exhalation rates have been determined in ten low ventilated rooms of ten villas in Jeddah city (Western Province) of Saudi Arabia. An electroprecipitation method has been applied for the determination of the 222Rn gas concentration in these rooms. The mean 222Rn gas concentration was found to be 46.80±8.80 Bq m-3. The mean 222Rn exhalation rate was estimated to be 20.11±6.90 Bq m-2 h-1. The mean inhalation dose due to the exposure to 222Rn gas was calculated to be 1.18±2.30 mSv y-1. The second part of this paper deals with a study of natural radionuclide contents of samples collected from the building materials of these rooms under investigations in part one. Analyses were performed in Marinelli beakers with a gamma spectroscopy system to quantify radioactivity concentrations. The collected samples revealed the presence of the uranium-radium (226Ra) and thorium (232Th) radioisotopes as well as 40K. The mean activity concentration of 226Ra, 232Th and 40K was determined to be 48.30±5.08, 43.90±5.63 and 223.90±7.55 Bq kg-1, respectively. These activities amount to a radium equivalent (Raeq) of 125.96±15.90 Bq kg-1 and to a mean value of external hazard index (Hex) of 0.34±0.04.

  8. Occupational radon exposure and lung cancer mortality: estimating intervention effects using the parametric G formula

    PubMed Central

    Edwards, Jessie K.; McGrath, Leah J.; Buckley, Jessie P.; Schubauer-Berigan, Mary K.; Cole, Stephen R.; Richardson, David B.

    2015-01-01

    Background Traditional regression analysis techniques used to estimate associations between occupational radon exposure and lung cancer focus on estimating the effect of cumulative radon exposure on lung cancer, while public health interventions are typically based on regulating radon concentration rather than workers’ cumulative exposure. Moreover, estimating the direct effect of cumulative occupational exposure on lung cancer may be difficult in situations vulnerable to the healthy worker survivor bias. Methods Workers in the Colorado Plateau Uranium Miners cohort (N=4,134) entered the study between 1950 and 1964 and were followed for lung cancer mortality through 2005. We use the parametric g-formula to compare the observed lung cancer mortality to the potential lung cancer mortality had each of 3 policies to limit monthly radon exposure been in place throughout follow-up. Results There were 617 lung cancer deaths over 135,275 person-years of follow-up. With no intervention on radon exposure, estimated lung cancer mortality by age 90 was 16%. Lung cancer mortality was reduced for all interventions considered, and larger reductions in lung cancer mortality were seen for interventions with lower monthly radon exposure limits. The most stringent guideline, the Mine Safety and Health Administration standard of 0.33 working level months, reduced lung cancer mortality from 16% to 10% (risk ratio 0.67; 95% confidence interval 0.61, 0.73). Conclusions This work illustrates the utility of the parametric g-formula for estimating the effects of policies regarding occupational exposures, particularly in situations vulnerable to the healthy worker survivor bias. PMID:25192403

  9. Thoron and thoron progeny measurements in German clay houses.

    PubMed

    Gierl, S; Meisenberg, O; Feistenauer, P; Tschiersch, J

    2014-07-01

    In recent years, elevated thoron concentrations were found in houses built of unfired clay. In this study experiments were carried out in 17 traditional and modern clay houses in Germany to obtain an overview of indoor thoron in such houses. Long-term measurements over an 8-week period were performed using a newly developed Unattended Battery-Operated Progeny Measurement Device (UBPM) for measuring thoron progeny. This instrument uses a high-voltage electric field to precipitate radon and thoron progeny on nuclear track detectors. Additional active and passive measurements of radon, thoron and their progeny were performed. The equilibrium equivalent thoron concentration was found to be between 2 and 10 Bq m(-3). Gas concentrations were found to be between 20 and 160 Bq m(-3) for radon and between 10 and 90 Bq m(-3) for thoron 20 cm from the wall. The thoron exposure contributes significantly to the inhalation dose of the dwellers (0.6-4 mSv a(-1)). PMID:24743764

  10. Radon exposure at a radioactive waste storage facility.

    PubMed

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

    2014-06-01

    The Waste Management Department of Nuclear and Energy Research Institute (IPEN) is responsible for the safety management of the waste generated at all internal research centers and that of other waste producers such as industry, medical facilities, and universities in Brazil. These waste materials, after treatment, are placed in an interim storage facility. Among them are (226)Ra needles used in radiotherapy, siliceous cake arising from conversion processes, and several other classes of waste from the nuclear fuel cycle, which contain Ra-226 producing (222)Rn gas daughter.In order to estimate the effective dose for workers due to radon inhalation, the radon concentration at the storage facility has been assessed within this study. Radon measurements have been carried out through the passive method with solid-state nuclear track detectors (CR-39) over a period of nine months, changing detectors every month in order to determine the long-term average levels of indoor radon concentrations. The radon concentration results, covering the period from June 2012 to March 2013, varied from 0.55 ± 0.05 to 5.19 ± 0.45 kBq m(-3). The effective dose due to (222)Rn inhalation was further assessed following ICRP Publication 65. PMID:24705248

  11. Meta-analysis of residential exposure to radon gas and lung cancer.

    PubMed Central

    Pavia, Maria; Bianco, Aida; Pileggi, Claudia; Angelillo, Italo F.

    2003-01-01

    OBJECTIVES: To investigate the relation between residential exposure to radon and lung cancer. METHODS: A literature search was performed using Medline and other sources. The quality of studies was assessed. Adjusted odds ratios with 95% confidence intervals (CI) for the risk of lung cancer among categories of levels of exposure to radon were extracted. For each study, a weighted log-linear regression analysis of the adjusted odds ratios was performed according to radon concentration. The random effect model was used to combine values from single studies. Separate meta-analyses were performed on results from studies grouped with similar characteristics or with quality scores above or equal to the median. FINDINGS: Seventeen case-control studies were included in the meta-analysis. Quality scoring for individual studies ranged from 0.45 to 0.77 (median, 0.64). Meta-analysis based on exposure at 150 Bq/m3 gave a pooled odds ratio estimate of 1.24 (95% CI, 1.11-1.38), which indicated a potential effect of residential exposure to radon on the risk of lung cancer. Pooled estimates of fitted odds ratios at several levels of randon exposure were all significantly different from unity--ranging from 1.07 at 50 Bq/m3 to 1.43 at 250 Bq/m3. No remarkable differences from the baseline analysis were found for odds ratios from sensitivity analyses of studies in which > 75% of eligible cases were recruited (1.12, 1.00-1.25) and studies that included only women (1.29, 1.04-1.60). CONCLUSION: Although no definitive conclusions may be drawn, our results suggest a dose-response relation between residential exposure to radon and the risk of lung cancer. They support the need to develop strategies to reduce human exposure to radon. PMID:14758433

  12. Field experience with volume traps for assessing retrospective radon exposures.

    PubMed

    Paridaens, J; Vanmarcke, H; Zunic, Z S; McLaughlin, J P

    2001-05-14

    Approximately 200 volume traps were retrieved from dwellings in various radon prone areas in Europe. They were analysed for the purpose of retrospective radon assessment. Emphasis is put on specific problems encountered when using field samples as opposed to laboratory exposed samples. It was seen that in very dusty circumstances, direct penetration of radon decay products from the outside to the centre of the volume traps calls for extra caution. Rinsing the samples is proposed as a solution and was tested in field and laboratory conditions, showing good results. An attempt was made to give an assessment of the achievable accuracy of the method. Where possible, the volume trap retrospective results were compared with contemporary measurements or to retrospective results from surface traps. The overall impression is that although volume traps are sometimes hard to find in the field, the high reliability of the results makes it well worth the effort. PMID:11379924

  13. Passive Measurements of Thoron and its Progeny in some Dwellings in Ireland

    SciTech Connect

    Choncubhair, Orlaith Ni; Laughlin, James Mc; Tokonami, Shinji

    2008-08-07

    In this paper, an account is given of the development, calibration and field use of a passive alpha track detector sensitive to thoron as well as to radon. No database of thoron and thoron progeny concentrations in dwellings in Ireland exists and, as a result, the level of exposure of the Irish population to thoron and its progeny is unknown. As an initial or pilot stage in establishing such a data base measurements of thoron and thoron progeny concentrations (the latter expressed in Equilibrium Equivalent Thoron Concentration (EETC)) were made in 40 randomly chosen Irish dwellings. The EETC measurements were made using a passive thoron progeny deposition rate monitor designed and supplied by NIRS (Japan). In addition standard unmodified SSI passive radon detectors were used to measure radon in these dwellings. The measured thoron concentrations ranged from below the level of detection to 154 Bq/m{sup 3} while the radon gas ranged from 15 to 179 Bq/m{sup 3}. The thoron progeny EETC values for these dwellings ranged from 0.03 to 7.7 Bq/m{sup 3}. An account is also given of the dosimetric implications of these measurements.

  14. Children’s Exposure to Radon in Nursery and Primary Schools

    PubMed Central

    Branco, Pedro T. B. S.; Nunes, Rafael A. O.; Alvim-Ferraz, Maria C. M.; Martins, Fernando G.; Sousa, Sofia I. V.

    2016-01-01

    The literature proves an evident association between indoor radon exposure and lung cancer, even at low doses. This study brings a new approach to the study of children’s exposure to radon by aiming to evaluate exposure to indoor radon concentrations in nursery and primary schools from two districts in Portugal (Porto and Bragança), considering different influencing factors (occupation patterns, classroom floor level, year of the buildings’ construction and soil composition of the building site), as well as the comparison with IAQ standard values for health protection. Fifteen nursery and primary schools in the Porto and Bragança districts were considered: five nursery schools for infants and twelve for pre-schoolers (seven different buildings), as well as eight primary schools. Radon measurements were performed continuously. The measured concentrations depended on the building occupation, classroom floor level and year of the buildings’ construction. Although they were in general within the Portuguese legislation for IAQ, exceedances to international standards were found. These results point out the need of assessing indoor radon concentrations not only in primary schools, but also in nursery schools, never performed in Portugal before this study. It is important to extend the study to other microenvironments like homes, and in time to estimate the annual effective dose and to assess lifetime health risks. PMID:27043596

  15. Lung cancer in women and type of dwelling in relation to radon exposure

    SciTech Connect

    Svensson, C.; Pershagen, G.; Klominek, J.

    1989-04-01

    A case-control study based on interviews with 210 incident female lung cancer patients, 209 age-matched population controls, and 191 hospital controls was carried out in Stockholm county, Sweden. Radon measurements made in a sample of 303 dwellings, in which the study subjects had lived, showed that dwellings with ground contact had an average concentration of approximately 160 Bqm-3, twice the average concentration of other dwellings. A cumulated radon exposure index was calculated for each subject based on data from the interviews and the measurements. For the total group of lung cancer a relative risk (RR), adjusted for smoking, age, and degree of urbanization, of 1.8 (95% confidence interval: 1.2-2.9) and 1.7 (0.9-3.3) associated with ''intermediate'' and ''high'' exposure to radon was found. There was also a significant trend to a positive dose-response relationship (Ptrend = 0.03). For small cell cancer the corresponding figures for RRs were 1.9 (0.6-4.5) and 4.7 (1.5-14.2), respectively (Ptrend = 0.01). There seemed to be a positive interaction between radon exposure and smoking in relation to lung cancer. The findings indicate that domestic radon may be of importance for the induction of lung cancer, particularly for some histological types.

  16. Thoron detection with an active Radon exposure meter—First results

    NASA Astrophysics Data System (ADS)

    Irlinger, J.; Wielunski, M.; Rühm, W.

    2014-02-01

    For state-of-the-art discrimination of Radon and Thoron several measurement techniques can be used, such as active sampling, electrostatic collection, delayed coincidence method, and alpha-particle-spectroscopy. However, most of the devices available are bulky and show high power consumption, rendering them unfeasible for personal exposition monitoring. Based on a Radon exposure meter previously realized at the Helmholtz Center Munich (HMGU), a new electronic prototype for Radon/Thoron monitoring is currently being developed, which features small size and weight. Operating with pin-diode detectors, the low-power passive-sampling device can be used for continuous concentration measurements, employing alpha-particle-spectroscopy and coincidence event registration to distinguish decays originating either from Radon or Thoron isotopes and their decay products. In open geometry, preliminary calibration measurements suggest that one count per hour is produced by a 11 Bq m-3 Radon atmosphere or by a 15 Bq m-3 Thoron atmosphere. Future efforts will concentrate on measurements in mixed Radon/Thoron atmospheres.

  17. Thoron detection with an active Radon exposure meter—First results

    SciTech Connect

    Irlinger, J. Wielunski, M.; Rühm, W.

    2014-02-15

    For state-of-the-art discrimination of Radon and Thoron several measurement techniques can be used, such as active sampling, electrostatic collection, delayed coincidence method, and alpha-particle-spectroscopy. However, most of the devices available are bulky and show high power consumption, rendering them unfeasible for personal exposition monitoring. Based on a Radon exposure meter previously realized at the Helmholtz Center Munich (HMGU), a new electronic prototype for Radon/Thoron monitoring is currently being developed, which features small size and weight. Operating with pin-diode detectors, the low-power passive-sampling device can be used for continuous concentration measurements, employing alpha-particle-spectroscopy and coincidence event registration to distinguish decays originating either from Radon or Thoron isotopes and their decay products. In open geometry, preliminary calibration measurements suggest that one count per hour is produced by a 11 Bq m{sup −3} Radon atmosphere or by a 15 Bq m{sup −3} Thoron atmosphere. Future efforts will concentrate on measurements in mixed Radon/Thoron atmospheres.

  18. Thoron detection with an active Radon exposure meter--first results.

    PubMed

    Irlinger, J; Wielunski, M; Rühm, W

    2014-02-01

    For state-of-the-art discrimination of Radon and Thoron several measurement techniques can be used, such as active sampling, electrostatic collection, delayed coincidence method, and alpha-particle-spectroscopy. However, most of the devices available are bulky and show high power consumption, rendering them unfeasible for personal exposition monitoring. Based on a Radon exposure meter previously realized at the Helmholtz Center Munich (HMGU), a new electronic prototype for Radon/Thoron monitoring is currently being developed, which features small size and weight. Operating with pin-diode detectors, the low-power passive-sampling device can be used for continuous concentration measurements, employing alpha-particle-spectroscopy and coincidence event registration to distinguish decays originating either from Radon or Thoron isotopes and their decay products. In open geometry, preliminary calibration measurements suggest that one count per hour is produced by a 11 Bq m(-3) Radon atmosphere or by a 15 Bq m(-3) Thoron atmosphere. Future efforts will concentrate on measurements in mixed Radon/Thoron atmospheres. PMID:24593342

  19. Intercomparison of Retrospective Radon Detectors

    SciTech Connect

    Field, R W.; Steck, D J.; Parkhurst, Maryann ); Mahaffey, Judith A. ); Alavanja, M C.

    1998-11-01

    We performed both a laboratory and field intercomparison of two novel glass-based retrospective radon detectors previously used in major radon case-control studies performed in Missouri and Iowa. The new detectors estimate retrospective residential radon exposure from the accumulation of a long-lived radon decay product, Pb-210, in glass. The detectors use track registration material in direct contact with glass surfaces to measure the alpha emission of a Pb-210 decay product, Po-210. The detector's track density generation rate (tracks cm{sup -2} hr{sup -1}) is proportional to the surface alpha activity. In the absence of other strong sources of alpha emission in the glass, the implanted surface alpha activity should be proportional to the accumulated Po-210 and hence, the cumulative radon gas exposure. The goals of the intercomparison were to: (1) perform collocated measurements using two different glass-based retrospective radon detectors in a controlled laboratory environment to compare their relative response to implanted polonium in the absence of environmental variation, (2) perform collocated measurements using two different retrospective radon progeny detectors in a variety of residential settings to compare their detection of glass implanted polonium activities, and (3) examine the correlation between track density rates and contemporary radon gas concentrations. The laboratory results suggested that the materials and methods used by the studies produced similar track densities in detectors exposed to the same implanted Po-210 activity. The field phase of the intercomparison found excellent agreement between the track density rates for the two types of retrospective detectors. The correlation between the track density rates and direct contemporary radon concentration measurements was relatively high, considering that no adjustments were performed to account for either the residential depositional environment or glass surface type.

  20. Lung cancer in French and Czech uranium miners: Radon-associated risk at low exposure rates and modifying effects of time since exposure and age at exposure.

    PubMed

    Tomasek, Ladislav; Rogel, Agnès; Tirmarche, Margot; Mitton, Nicolas; Laurier, Dominique

    2008-02-01

    Radon is recognized as a public health concern for indoor exposure. Precise quantification derived from occupational exposure in miners is still needed for estimating the risk and the factors that modify the dependence on cumulated exposure. The present paper reports on relationship between radon exposure and lung cancer risk in French and Czech cohorts of uranium miners (n = 10,100). Miners from these two cohorts are characterized by low levels of exposure (average cumulated exposure of less than 60 WLM) protracted over a long period (mean duration of exposure of 10 years) and by a good quality of individual exposure estimates (95% of annual exposures based on radon measurements). The modifying effect of the quality of exposure on the risk is analyzed. A total of 574 lung cancer deaths were observed, which is 187% higher than expected from the national statistics. This significantly elevated risk is strongly associated with cumulated radon exposure. The estimated overall excess relative risk per WLM is 0.027 (95% CI: 0.017-0.043, related to measured exposures). For age at exposure of 30 and 20 years since exposure, the ERR/WLM is 0.042, and this value decreases by approximately 50% for each 10-year increase in age at exposure and time since exposure. The present study emphasizes that the quality of exposure estimates is an important factor that may substantially influence results. Time since exposure and simultaneously age at exposure were the most important effect modifiers. No inverse exposure-rate effect below 4 WL was observed. The results are consistent with estimates of the BEIR VI report using the concentration model at an exposure rate below 0.5 WL. PMID:18220460

  1. Exposure to radon in dwellings in the Sharri community, Kosovo.

    PubMed

    Bahtijari, M; Vaupotic, J; Gregoric, A; Stegnar, P; Kobal, I

    2008-01-01

    Indoor air radon concentration was measured by exposing etched track detectors in the sleeping and living rooms of 18 houses in 6 villages of the Sharri community in Kosovo. Values ranged from 24 to 209 Bq m(-3), with only one exceeding 200 Bq m(-3), with a geometric mean and geometric standard deviation of 95.4 Bq m(-3) and 1.6, respectively. On the basis of the assumption that the spring radon concentrations obtained in this survey represent the yearly average, annual effective doses of residents were calculated; they range from 0.89 to 4.7 mSv y(-1), with the geometric mean and geometric standard deviation of 1.5 mSv y(-1) and 2.2, respectively. No mitigation measures are planned to be undertaken. PMID:18083721

  2. Physical factors affecting lung deposition of cigarette smoke (with syncarcinogenic radon progeny effects), and mineral-fiber particulate matter

    SciTech Connect

    Martonen, T.B.; Hofmann, W.; Balashazy, I.

    1988-11-01

    Unusual dynamic factors affecting the behavior and fate of inhaled cigarette-smoke particles and mineral fibers within the human lung are addressed. The actions of interception, for fiber particles, and cloud-settling, for concentrated cigarette smoke, can enhance focal deposition in locations that would not have been anticipated for dilute aerosols or for more-regularly shaped, sphere-like particles. It is important to quantitate the efficiencies of these deposition mechanisms because it is after deposition that deleterious biological effects can occur. Theoretical deposition models are presented that simulate the actions of the interception and cloud-settling processes, which are validated by comparisons with in vitro and in vivo data. The sites of preferential deposition are regions whose cells receive increased doses of hazardous substances associated with smokes and fibers. They must, therefore, be considered in risk-assessment analyses of human inhalation exposures to airborne toxicants. Incorporation of these mechanisms in aerosol-therapy protocols could conceivably lead to improved therapeutic procedures.

  3. Estimation of radon exposures to workers at the Fernald Feed Materials Production Center 1952-1988.

    PubMed

    Hornung, Richard W; Pinney, Susan M; Lodwick, Jeffrey; Killough, George G; Brewer, David E; Nasuta, James

    2008-09-01

    The Feed Materials Production Center (FMPC) at Fernald, Ohio produced uranium metal products for use in Department of Energy defense programs. Radium-contaminated waste material was stored on-site in two K-65 silos on the west side of the facility and provided a source of 222Ra. The initial objective of this study was to estimate radon exposures to employees at FMPC working from 1952 to 1988. A modified Gaussian plume model was used to estimate exposures to workers. In an effort to validate these model-based estimates, we used 138 CR-39 film assays from window glass sampled in buildings throughout the site. Results from the CR-39 assays indicated a second substantial source of radon, the smaller Q-11 silos located in the production area. A response-surface regression analysis using a cubic spline model was fit to the CR-39 data to estimate 210Po surface activity levels at geographic coordinates throughout the facility. Knowledge of the age of the glass, the amount of contaminated waste in the Q-11 silos, and 210Po decay rates were used to estimate annual exposures to radon decay products (WLM: working level months). Estimated WLM levels associated with the Q-11 source term indicated that employees working in the vicinity during the period when they were filled with radium-contaminated waste (1952-1958) received substantially higher radon exposures than those from the K-65 source during this period. Results of the two models, corresponding to the K-65 and Q-11 sources, were combined to estimate WLM levels by year for each of the 7143 Fernald workers during the period 1952-1988. Estimated cumulative exposures to individual workers ranged from <0.5 to 751 WLM. Estimated radon exposures from this newly discovered source have important implications for future epidemiologic studies of lung cancer in workers at the Fernald facility. PMID:18183043

  4. ASSESSMENT OF THE EXPOSURE TO AND DOSE FROM RADON DECAY PRODUCTS IN NORMALLY OCCUPIED HOMES

    EPA Science Inventory

    The paper gives results of an assessment of the exposure to radon decay products in seven houses in northeastern U.S. and southeastern Canada. n two houses, a single individual smoked cigarettes. ariety of heating and cooking appliances were in the houses. hese studies provided 5...

  5. Estimating the distribution of lifetime cumulative radon exposures for California residents: A brief summary

    SciTech Connect

    Liu, K.S.; Chang, Y.L.; Hayward, S.B.; Gadgil, A.J.; Nero, A.V. Jr.

    1992-04-01

    We have used data on residential radon concentrations in California, together with information on California residents` moving histories and time-activity patterns, to estimate the distribution of lifetime cumulative exposures to radon 222. This distribution was constructed using Monte Carlo techniques to simulate the lifetime occupancy histories -- and associated radon exposures -- of 10,000 California residents. For standard male and female lifespans, the simulation sampled from transition probability matrices representing changes of residence within and between six regions of California, as well as into and out of the other United States, and then sampled from the appropriate regional (or national) distribution of indoor concentrations. The resulting distribution of lifetime cumulative exposures has a significantly narrower relative width than the distribution of California indoor concentrations, with only a small fraction -- less than 0.2% -- of the population having lifetime exposures equivalent to living during their lifetimes in a single home with a radon concentration of 148 Bq/m{sup 3} or more.

  6. Exposure assessment of radon in the drinking water supplies: a descriptive study in Palestine

    PubMed Central

    2012-01-01

    Background Radon gas is considered as a main risk factor for lung cancer and found naturally in rock, soil, and water. The objective of this study was to determine the radon level in the drinking water sources in Nablus city in order to set up a sound policy on water management in Palestine. Methods This was a descriptive study carried out in two phases with a random sampling technique in the second phase. Primarily, samples were taken from 4 wells and 5 springs that supplied Nablus city residents. For each source, 3 samples were taken and each was analyzed in 4 cycles by RAD 7 device manufactured by Durridge Company. Secondly, from the seven regions of the Nablus city, three samples were taken from the residential tap water of each region. Regarding the old city, ten samples were taken. Finally, the mean radon concentration value for each source was calculated. Results The mean (range) concentration of radon in the main sources were 6.9 (1.5-23.4) Becquerel/liter (Bq/L). Separately, springs and wells' means were 4.6 Bq/L and 9.5 Bq/L; respectively. For the residential tap water in the 7 regions, the results of the mean (range) concentration values were found to be 1.0 (0.9-1.3) Bq/L. For the old city, the mean (range) concentration values were 2.3 (0.9-3.9) Bq/L. Conclusions Except for Al-Badan well, radon concentrations in the wells and springs were below the United State Environmental Protection Agency maximum contaminated level (U.S EPA MCL). The level was much lower for tap water. Although the concentration of radon in the tap water of old city were below the MCL, it was higher than other regions in the city. Preventive measures and population awareness on radon's exposure are recommended. PMID:22243625

  7. Radon: The Invisible Invader.

    ERIC Educational Resources Information Center

    School Leader, 1987

    1987-01-01

    A brief background on indoor radon and the health risks associated with radon exposure, with special emphasis on nonresidential buildings. One school district's experience in radon testing and monitoring is included. (MLF)

  8. Radon Testing in Schools.

    ERIC Educational Resources Information Center

    Wheeler, Robert

    1989-01-01

    Schools may be a significant source of radon exposure for children and staff. Describes radon detection kits and technologies, when to use them, and what action to take given the results of a radon test. (MLF)

  9. Assessment of the exposure to and dose from radon decay products in normally occupied homes

    SciTech Connect

    Hopke, P.K.; Jensen, B.; Li, C.S.; Montassier, N.; Wasiolek, P.; Cavallo, A.J.; Gatsby, K.; Socolow, R.H.; James, A.C.

    1995-05-01

    The exposure to radon decay products has been assessed in seven homes in the northeastern United States and southeastern Canada. In two of the houses, there was a single individual who smoked cigarettes. There were a variety of heating and cooking appliances among these homes. These studies have provide 565 measurements of the activity-weighted size distributions in these houses. The median value for the equilibrium factor was 0.408 as compared with the previously employed value of 0.50. Using the recently adopted ICRP lung deposition and dosimetry model, the hourly equivalent lung dose rate per unit, radon exposure was estimated for each measured size distribution. Differences between houses with smokers present and absent were noted in the exposure conditions, but the resulting dose rate per unit of radon gas concentration was essentially the same for the two groups. Expressed in terms of ICRP`s unit of effective dose for members of the public, the mean dose rate conversion coefficient with respect to radon gas concentration found in this study was 3.8 nSv h{sup -} Bq{sup -} m{sup -3}. 26 refs., 8 figs., 3 tabs.

  10. A generic biokinetic model for noble gases with application to radon

    SciTech Connect

    Leggett, Richard Wayne; Marsh, James; Gregoratto, Demetrio; Blanchardon, Eric

    2013-01-01

    The International Commission for Radiological Protection (ICRP) currently uses a dose conversion coefficient to calculate effective dose per unit exposure to radon and its progeny. The coefficient is derived by dividing the detriment associated with unit exposure to radon, as estimated from epidemiological studies, by the detriment per unit effective dose, as estimated mainly from atomic bomb survivor data and animal studies. In a recent statement the ICRP indicated that future guidance on exposure to radon and its progeny will be developed in the same way as guidance for any other radionuclide. That is, intake of radon and progeny will be limited on the basis of effective dose coefficients derived from biokinetic and dosimetric models. This paper proposes a biokinetic model for systemic (absorbed) radon for use in the calculation of dose coefficients for inhaled or ingested radon. The model is based largely on physical laws governing transfer of a non-reactive and soluble gas between materials. Model predictions are shown to be consistent with results of controlled studies of the fate of internally deposited radon in human subjects.

  11. Relation of radon exposure and tobacco use to lung cancer among tin miners in Yunnan Province, China

    SciTech Connect

    Qiao, Y.L.; Taylor, P.R.; Yao, S.X.; Schatzkin, A.; Mao, B.L.; Lubin, J.; Rao, J.Y.; McAdams, M.; Xuan, X.Z.; Li, J.Y. )

    1989-01-01

    We studied the relation of radon exposure and tobacco use to lung cancer among tin miners in Yunnan Province in the People's Republic of China. Interviews were conducted in 1985 with 107 living tin miners with lung cancer and an equal number of age-matched controls from among tin miners without lung cancer to obtain information on lung cancer risk factors including a detailed history of employment and tobacco use. Occupational history was combined with extensive industrial hygiene data to estimate cumulative working level months (WLM) of radon daughter exposure. Similar data were also used to estimate arsenic exposure for control in the analysis. Results indicate an increased risk of lung cancer for water pipe smoking, a traditional form of tobacco use practiced in 91% of cases and 85% of controls. The use of water pipes was associated with a twofold elevation in risk when compared with tobacco abstainers, and a dose-response relation was observed with increasing categories of pipe-year (dose times duration) usage. Estimated WLM of radon exposure varied from 0 to 1,761 among subjects but averaged 515 in cases versus only 244 in controls. Analyses indicated that the persons in the highest quarter of the radon exposure distribution had an odds ratio (OR) = 9.5 (95% confidence interval = 2.7-33.1) compared to persons without radon exposure after controlling for arsenic exposure and other potential confounders. Examination of duration and rate of radon exposure indicated higher risk associated with long duration as opposed to high rate of exposure. Cross-categorizations of radon exposure and tobacco use suggest greater risk associated with radon exposure than tobacco in these workers.

  12. Intercomparison of retrospective radon detectors.

    PubMed Central

    Field, R W; Steck, D J; Parkhurst, M A; Mahaffey, J A; Alavanja, M C

    1999-01-01

    We performed both a laboratory and a field intercomparison of two novel glass-based retrospective radon detectors previously used in major radon case-control studies performed in Missouri and Iowa. The new detectors estimate retrospective residential radon exposure from the accumulation of a long-lived radon decay product, (210)Pb, in glass. The detectors use track registration material in direct contact with glass surfaces to measure the alpha-emission of a (210)Pb-decay product, (210)Po. The detector's track density generation rate (tracks per square centimeter per hour) is proportional to the surface alpha-activity. In the absence of other strong sources of alpha-emission in the glass, the implanted surface alpha-activity should be proportional to the accumulated (210)Po, and hence to the cumulative radon gas exposure. The goals of the intercomparison were to a) perform collocated measurements using two different glass-based retrospective radon detectors in a controlled laboratory environment to compare their relative response to implanted polonium in the absence of environmental variation, b) perform collocated measurements using two different retrospective radon progeny detectors in a variety of residential settings to compare their detection of glass-implanted polonium activities, and c) examine the correlation between track density rates and contemporary radon gas concentrations. The laboratory results suggested that the materials and methods used by the studies produced similar track densities in detectors exposed to the same implanted (210)Po activity. The field phase of the intercomparison found excellent agreement between the track density rates for the two types of retrospective detectors. The correlation between the track density rates and direct contemporary radon concentration measurements was relatively high, considering that no adjustments were performed to account for either the residential depositional environment or glass surface type

  13. Comparison of radon fluxes with gamma-radiation exposure rates and soil /sup 226/Ra concentrations

    SciTech Connect

    Young, J.A.; Thomas, V.W.

    1984-04-01

    Radon fluxes and contact gamma-radiation-exposure rates were measured at the grid points of rectangular grids on three properties in Edgemont, South Dakota that were known to have deposits of residual radioactivity relatively near to the surface. The coefficient of determination, r/sup 2/, between the radon fluxes and the contact gamma-radiation-exposure rates varied from 0.89 to 0.31 for the three properties. The property having the highest fluxes and residual radioactivity of relatively uniform depth showed the highest correlation between fluxes and exposure rates, and the property having residual radioactivity that varied considerably in depth showed the lowest. Correlations between fluxes and /sup 226/Ra concentrations measured in boreholes that varied in depth from 60 to 195 cm were lower than those between fluxes and exposure rates, indicating that exposure rates are better than /sup 226/Ra measurements for detecting elevated radon fluxes from near-surface deposits. Measurements made on one property at two different times indicated that if the average flux were determined from a large number (40) of measurements at one time, the average flux at a later time could be estimated from a few measurements using the assumption that the change in the flux at individual locations will be equal to the change in the average flux. Flux measurements around two buildings showing elevated indoor radon-daughter concentrations, but around which no residual radioactivity had been discovered by /sup 226/Ra and gamma-radiation measurements, provided no clear indication of the presence of such material, possibly because none was present.

  14. Gestational exposure to diethylstilbestrol alters cardiac structure/function, protein expression and DNA methylation in adult male mice progeny.

    PubMed

    Haddad, Rami; Kasneci, Amanda; Mepham, Kathryn; Sebag, Igal A; Chalifour, Lorraine E

    2013-01-01

    Pregnant women, and thus their fetuses, are exposed to many endocrine disruptor compounds (EDCs). Fetal cardiomyocytes express sex hormone receptors making them potentially susceptible to re-programming by estrogenizing EDCs. Diethylstilbestrol (DES) is a proto-typical, non-steroidal estrogen. We hypothesized that changes in adult cardiac structure/function after gestational exposure to the test compound DES would be a proof in principle for the possibility of estrogenizing environmental EDCs to also alter the fetal heart. Vehicle (peanut oil) or DES (0.1, 1.0 and 10.0μg/kg/da.) was orally delivered to pregnant C57bl/6n dams on gestation days 11.5-14.5. At 3months, male progeny were left sedentary or were swim trained for 4weeks. Echocardiography of isoflurane anesthetized mice revealed similar cardiac structure/function in all sedentary mice, but evidence of systolic dysfunction and increased diastolic relaxation after swim training at higher DES doses. The calcium homeostasis proteins, SERCA2a, phospholamban, phospho-serine 16 phospholamban and calsequestrin 2, are important for cardiac contraction and relaxation. Immunoblot analyses of ventricle homogenates showed increased expression of SERCA2a and calsequestrin 2 in DES mice and greater molecular remodeling of these proteins and phospho-serine 16 phospholamban in swim trained DES mice. DES increased cardiac DNA methyltransferase 3a expression and DNA methylation in the CpG island within the calsequestrin 2 promoter in heart. Thus, gestational DES epigenetically altered ventricular DNA, altered cardiac function and expression, and reduced the ability of adult progeny to cardiac remodel when physically challenged. We conclude that gestational exposure to estrogenizing EDCs may impact cardiac structure/function in adult males. PMID:23142472

  15. Residential radon exposure and risk of incident hematologic malignancies in the Cancer Prevention Study-II Nutrition Cohort.

    PubMed

    Teras, Lauren R; Diver, W Ryan; Turner, Michelle C; Krewski, Daniel; Sahar, Liora; Ward, Elizabeth; Gapstur, Susan M

    2016-07-01

    Dosimetric models show that radon, an established cause of lung cancer, delivers a non-negligible dose of alpha radiation to the bone marrow, as well as to lymphocytes in the tracheobronchial epithelium, and therefore could be related to risk of hematologic cancers. Studies of radon and hematologic cancer risk, however, have produced inconsistent results. To date there is no published prospective, population-based study of residential radon exposure and hematologic malignancy incidence. We used data from the American Cancer Society Cancer Prevention Study-II Nutrition Cohort established in 1992, to examine the association between county-level residential radon exposure and risk of hematologic cancer. The analytic cohort included 140,652 participants (66,572 men, 74,080 women) among which 3019 incident hematologic cancer cases (1711 men, 1308 women) were identified during 19 years of follow-up. Cox proportional hazard regression was used to calculate multivariable-adjusted hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) for radon exposure and hematologic cancer risk. Women living in counties with the highest mean radon concentrations (>148Bq/m(3)) had a statistically significant higher risk of hematologic cancer compared to those living in counties with the lowest (<74Bq/m(3)) radon levels (HR=1.63, 95% CI:1.23-2.18), and there was evidence of a dose-response relationship (HRcontinuous=1.38, 95% CI:1.15-1.65 per 100Bq/m(3); p-trend=0.001). There was no association between county-level radon and hematologic cancer risk among men. The findings of this large, prospective study suggest residential radon may be a risk factor for lymphoid malignancies among women. Further study is needed to confirm these findings. PMID:27015563

  16. Real-time measurement of individual occupational radon exposures in tombs of the Valley of the Kings, Egypt.

    PubMed

    Gruber, E; Salama, E; Rühm, W

    2011-03-01

    The active radon exposure meter developed recently at the German Research Center for Environmental Health (Helmholtz Zentrum München) was used to measure radon concentrations in 12 tombs located in the Valley of the Kings, Egypt. Radon concentrations in air between 50 ± 7 and 12 100 ± 600 Bq m(-3) were obtained. The device was also used to measure individual radon exposures of those persons working as safeguards inside the tombs. For a measurement time of 2-3 d, typical individual radon exposures ranged from 1800 ± 400 to 240 000 ± 13 000 Bq h m(-3), depending on the duration of measurement and radon concentration in the different tombs. Based on current ICRP dose conversion conventions for workers and on equilibrium factors published in the literature for these tombs, individual effective dose rates that range from 1.5 ± 0.3 to 860 ± 50 µSv d(-1) were estimated. If it is assumed that the climatic conditions present at the measurement campaign persist for about half a year, in this area, then effective doses up to ∼ 66 mSv could be estimated for half a year, for some of the safeguards of tombs where F-values were known. To reduce the exposure of the safeguards, some recommendations are proposed. PMID:21183552

  17. Biology Based Lung Cancer Model for Chronic Low Radon Exposures

    SciTech Connect

    Truta-Popa, Lucia-Adina; Hofmann, Werner; Fakir, Hatim; Cosma, Constantin

    2008-08-07

    Low dose effects of alpha particles at the tissue level are characterized by the interaction of single alpha particles, affecting only a small fraction of the cells within that tissue. Alpha particle intersections of bronchial target cells during a given exposure period were simulated by an initiation-promotion model, formulated in terms of cellular hits within the cycle time of the cell (dose-rate) and then integrated over the whole exposure period (dose). For a given average number of cellular hits during the lifetime of bronchial cells, the actual number of single and multiple hits was selected from a Poisson distribution. While oncogenic transformation is interpreted as the primary initiation step, stimulated mitosis by killing adjacent cells is assumed to be the primary radiological promotion event. Analytical initiation and promotion functions were derived from experimental in vitro data on oncogenic transformation and cellular survival.To investigate the shape of the lung cancer risk function at chronic, low level exposures in more detail, additional biological factors describing the tissue response and operating specifically at low doses were incorporated into the initiation-promotion model. These mechanisms modifying the initial response at the cellular level were: adaptive response, genomic instability, induction of apoptosis by surrounding cells, and detrimental as well as protective bystander mechanisms. To quantify the effects of these mechanisms as functions of dose, analytical functions were derived from the experimental evidence presently available. Predictions of lung cancer risk, including these mechanisms, exhibit a distinct sublinear dose-response relationship at low exposures, particularly for very low exposure rates.

  18. Biology Based Lung Cancer Model for Chronic Low Radon Exposures

    NASA Astrophysics Data System (ADS)

    TruÅ£ǎ-Popa, Lucia-Adina; Hofmann, Werner; Fakir, Hatim; Cosma, Constantin

    2008-08-01

    Low dose effects of alpha particles at the tissue level are characterized by the interaction of single alpha particles, affecting only a small fraction of the cells within that tissue. Alpha particle intersections of bronchial target cells during a given exposure period were simulated by an initiation-promotion model, formulated in terms of cellular hits within the cycle time of the cell (dose-rate) and then integrated over the whole exposure period (dose). For a given average number of cellular hits during the lifetime of bronchial cells, the actual number of single and multiple hits was selected from a Poisson distribution. While oncogenic transformation is interpreted as the primary initiation step, stimulated mitosis by killing adjacent cells is assumed to be the primary radiological promotion event. Analytical initiation and promotion functions were derived from experimental in vitro data on oncogenic transformation and cellular survival. To investigate the shape of the lung cancer risk function at chronic, low level exposures in more detail, additional biological factors describing the tissue response and operating specifically at low doses were incorporated into the initiation-promotion model. These mechanisms modifying the initial response at the cellular level were: adaptive response, genomic instability, induction of apoptosis by surrounding cells, and detrimental as well as protective bystander mechanisms. To quantify the effects of these mechanisms as functions of dose, analytical functions were derived from the experimental evidence presently available. Predictions of lung cancer risk, including these mechanisms, exhibit a distinct sublinear dose-response relationship at low exposures, particularly for very low exposure rates.

  19. 76 FR 72006 - Draft Interim Staff Guidance: Evaluations of Uranium Recovery Facility Surveys of Radon and Radon...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-21

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

  20. Gestational exposure to diethylstilbestrol alters cardiac structure/function, protein expression and DNA methylation in adult male mice progeny

    SciTech Connect

    Haddad, Rami; Kasneci, Amanda; Mepham, Kathryn; Sebag, Igal A.; and others

    2013-01-01

    Pregnant women, and thus their fetuses, are exposed to many endocrine disruptor compounds (EDCs). Fetal cardiomyocytes express sex hormone receptors making them potentially susceptible to re-programming by estrogenizing EDCs. Diethylstilbestrol (DES) is a proto-typical, non-steroidal estrogen. We hypothesized that changes in adult cardiac structure/function after gestational exposure to the test compound DES would be a proof in principle for the possibility of estrogenizing environmental EDCs to also alter the fetal heart. Vehicle (peanut oil) or DES (0.1, 1.0 and 10.0 μg/kg/da.) was orally delivered to pregnant C57bl/6n dams on gestation days 11.5–14.5. At 3 months, male progeny were left sedentary or were swim trained for 4 weeks. Echocardiography of isoflurane anesthetized mice revealed similar cardiac structure/function in all sedentary mice, but evidence of systolic dysfunction and increased diastolic relaxation after swim training at higher DES doses. The calcium homeostasis proteins, SERCA2a, phospholamban, phospho-serine 16 phospholamban and calsequestrin 2, are important for cardiac contraction and relaxation. Immunoblot analyses of ventricle homogenates showed increased expression of SERCA2a and calsequestrin 2 in DES mice and greater molecular remodeling of these proteins and phospho-serine 16 phospholamban in swim trained DES mice. DES increased cardiac DNA methyltransferase 3a expression and DNA methylation in the CpG island within the calsequestrin 2 promoter in heart. Thus, gestational DES epigenetically altered ventricular DNA, altered cardiac function and expression, and reduced the ability of adult progeny to cardiac remodel when physically challenged. We conclude that gestational exposure to estrogenizing EDCs may impact cardiac structure/function in adult males. -- Highlights: ► Gestational DES changes cardiac SERCA2a and CASQ2 expression. ► Echocardiography identified systolic dysfunction and increased diastolic relaxation. ► DES

  1. Radon Exposure, IL-6 Promoter Variants, and Lung Squamous Cell Carcinoma in Former Uranium Miners

    PubMed Central

    Leng, Shuguang; Thomas, Cynthia L.; Snider, Amanda M.; Picchi, Maria A.; Chen, Wenshu; Willis, Derall G.; Carr, Teara G.; Krzeminski, Jacek; Desai, Dhimant; Shantu, Amin; Lin, Yong; Jacobson, Marty R.; Belinsky, Steven A.

    2015-01-01

    Background: High radon exposure is a risk factor for squamous cell carcinoma, a major lung cancer histology observed in former uranium miners. Radon exposure can cause oxidative stress, leading to pulmonary inflammation. Interleukin-6 (IL-6) is a pro-carcinogenic inflammatory cytokine that plays a pivotal role in lung cancer development. Objectives: We assessed whether single nucleotide polymorphisms (SNPs) in the IL6 promoter are associated with lung cancer in former uranium miners with high occupational exposure to radon gas. Methods: Genetic associations were assessed in a case–control study of former uranium miners (242 cases and 336 controls). A replication study was performed using data from the Gene Environment Association Studies (GENEVA) Genome Wide Association Study (GWAS) of Lung Cancer and Smoking. Functional relevance of the SNPs was characterized using in vitro approaches. Results: We found that rs1800797 was associated with squamous cell carcinoma in miners and with a shorter time between the midpoint of the period of substantial exposure and diagnosis among the cases. Furthermore, rs1800797 was also associated with lung cancer among never smokers in the GENEVA dataset. Functional studies identified that the risk allele was associated with increased basal IL-6 mRNA level and greater promoter activity. Furthermore, fibroblasts with the risk allele showed greater induction of IL-6 secretion by hydrogen peroxide or benzo[a]pyrene diolepoxide treatments. Conclusions: An IL6 promoter variant was associated with lung cancer in uranium miners and never smokers in two external study populations. The associations are strongly supported by the functional relevance that the IL6 promoter SNP affects basal expression and carcinogen-induced IL-6 secretion. Citation: Leng S, Thomas CL, Snider AM, Picchi MA, Chen W, Willis DG, Carr TG, Krzeminski J, Desai D, Shantu A, Lin Y, Jacobson MR, Belinsky SA. 2016. Radon exposure, IL-6 promoter variants, and lung squamous

  2. Measurement of Radon, Thoron, Isotopic Uranium and Thorium to Determine Occupational and Environmental Exposure and Risk at Fernald Feed Material Production Center

    SciTech Connect

    Naomi H. Harley, Ph.D.

    2004-07-01

    To develop a new and novel area and personal radon/thoron detector for both radon isotopes to better measure the exposure to low airborne concentrations of these gases at Fernald. These measurements are to be used to determine atmospheric dispersion and exposure to radon and thoron prior to and during retrieval and removal of the 4000 Ci of radium in the two silos at Fernald.

  3. In utero exposure to phthalate downregulates critical genes in Leydig cells of F1 male progeny.

    PubMed

    Sekaran, Suganya; Jagadeesan, Arunakaran

    2015-07-01

    Phthalates are the largest group of environmental pollutants and are considered toxicant to the endocrine system. The present study was aimed to test the effect of in utero exposure of di(2-ethylhexyl)phthalate (DEHP) on Leydig cell steroidogenesis in F1 male offspring's. Pregnant dams were oral gavaged with different doses (1, 10, and 100 mg/kg/day) of DEHP or olive oil during gestational Day 9-21. Serum testosterone (T) and estradiol (E2) levels were significantly reduced in male offspring at 60 days of age. Our results also demonstrate a coordinate, dose-dependent disruption of genes involved in steroidogenesis. The gene expression of StAR, Cyp11a1, 3β-HSD, 17β-HSD, 5α-reductase and cytochrome P450 19a1 (or) aromatase (Cyp-19) were significantly decreased. The transcription factors like steroidogenic factor-1 (SF-1) and specific protein-1 (Sp-1) showed a significant decrease in 10 and 100 mg DEHP treatment group. DNA methylation analysis using bisulfite specific-methylation PCR shows hypermethylation in the SF-1 and Sp-1 promoter regions. Further to determine whether the DEHP-induced methylation changes were associated with increased DNA methyltransferase (Dnmt) levels, we measured the expression levels of Dnmt3a, Dnmt3b, Dnmt1, and Dnmt3l using real-time PCR and Western blot method. The mRNA and protein expressions of Dnmt3a, Dnmt3b, and Dnmt1 were stimulated in 10 and 100 mg DEHP treatment groups, whereas no significant change was seen in Dnmt3l expression, suggesting that increased Dnmt3a/b, Dnmt1 may cause DNA hypermethylation in testicular Leydig cells. Overall, these data suggest that gestational exposure to DEHP affects adult testicular function via altered methylation patterns. PMID:25649163

  4. Indoor Radon: The Deadliest Pollutant.

    ERIC Educational Resources Information Center

    Kerr, Richard A.

    1988-01-01

    Describes the origin, occurrence, and effects of radon gas. Cites studies which attribute 5,000 to 20,000 deaths per year to radon exposure and the synergistic effect between radon and smoking. Explains ways to reduce risks. (RT)

  5. Development of a new thoron progeny detector based on SSNTD and the collection by an electric field.

    PubMed

    Bi, L; Tschiersch, J; Meisenberg, O; Wielunski, M; Li, J L; Shang, B

    2011-05-01

    The importance of (220)Rn (thoron) progeny for human exposure has been widely recognised in the past decades. Since no stable equilibrium factor was found between indoor thoron and its progeny, and the concentration of thoron progeny varies with time, it is necessary to develop detectors for long-term measurement that directly sample and detect thoron progeny. However, power supply of this kind of detectors has always been a problem. In this study, a set of device that is suitable for long-term measurement is introduced. A high-voltage electric field was formed for the collection of charged aerosols attached by (222)Rn (radon) and thoron progenies on solid-state nuclear track detector. Impact from radon progeny could be eliminated with a shield of Al foil of appropriate thickness. Tests were made both in an experimental house and in a thoron chamber in Helmholtz Zentrum München to determine the parameters and to verify the universality under different conditions. PMID:21493610

  6. Study of epidemiological risk of lung cancer in Mexico due indoor radon exposure

    NASA Astrophysics Data System (ADS)

    Ángeles, A.; Espinosa, G.

    2014-07-01

    In this work the lifetime relative risks (LRR) of lung cancer due to exposure to indoor 222Rn on the Mexican population is calculated. Cigarette smoking is the number one risk factor for lung cancer (LC), because that, to calculate the number of cases of LC due to exposure to 222Rn is necessary considers the number of cases of LC for smoking cigarette. The lung cancer mortality rates published by the "Secretaría de Salud" (SSA), the mexican population data published by the "Consejo Nacional de Población" (CONAPO), smoking data in the mexican population, published by the "Comisión Nacional Contra las Adicciones" (CONADIC), the "Organización Panamericana de la Salud" (OPS) and indoor 222Rn concentrations in Mexico published in several recent studies are used. To calculate the lifetime relative risks (LRR) for different segments of the Mexican population, firstly the Excess Relative Risk (ERR) is calculated using the method developed by the BEIR VI committee and subsequently modified by the USEPA and published in the report "EPA Assessment of Risks from Radon in Homes". The excess relative risks were then used to calculate the corresponding lifetime relative risks, again using the method developed by the BEIR VI committee. The lifetime relative risks for Mexican male and female eversmokers and Mexican male and female never-smokers were calculated for radon concentrations spanning the range found in recent studies of indoor radon concentrations in Mexico. The lifetime relative risks of lung cancer induced by lifetime exposure to the mexican average indoor radon concentration were estimated to be 1.44 and 1.40 for never-smokers mexican females and males respectively, and 1.19 and 1.17 for ever-smokers Mexican females and males respectively. The Mexican population LRR values obtained in relation to the USA and Canada LRR published values in ever-smokers for both gender are similar with differences less than 4%, in case of never-smokers in relation with Canada

  7. Evaluation of the intake of radon through skin from thermal water

    PubMed Central

    Sakoda, Akihiro; Ishimori, Yuu; Tschiersch, Jochen

    2016-01-01

    The biokinetics of radon in the body has previously been studied with the assumption that its absorption through the skin is negligibly small. This assumption would be acceptable except in specific situations, such as bathing in a radon hot spring where the radon concentration in thermal water is far higher than that in air. The present study focused on such a situation in order to better understand the biokinetics of radon. To mathematically express the entry of radon through the skin into the body, we first modified the latest sophisticated biokinetic model for noble gases. Values of an important parameter for the model—the skin permeability coefficient K (m s−1)—were derived using data from previous human studies. The analysis of such empirical data, which corresponded to radon concentrations in the air exhaled by subjects during and following bathing in radon-rich thermal water, revealed that the estimated K values had a log-normal distribution. The validity of the K values and the characteristics of the present model are then discussed. Furthermore, the impact of the intake of radon or its progeny via inhalation or skin absorption on radiation dose was also assessed for possible exposure scenarios in a radon hot spring. It was concluded that, depending on the radon concentration in thermal water, there might be situations in which the dose contribution resulting from skin absorption of radon is comparable to that resulting from inhalation of radon and its progeny. This conclusion can also apply to other therapeutic situations (e.g. staying in the pool for a longer period). PMID:26983980

  8. Evaluation of the intake of radon through skin from thermal water.

    PubMed

    Sakoda, Akihiro; Ishimori, Yuu; Tschiersch, Jochen

    2016-07-01

    The biokinetics of radon in the body has previously been studied with the assumption that its absorption through the skin is negligibly small. This assumption would be acceptable except in specific situations, such as bathing in a radon hot spring where the radon concentration in thermal water is far higher than that in air. The present study focused on such a situation in order to better understand the biokinetics of radon. To mathematically express the entry of radon through the skin into the body, we first modified the latest sophisticated biokinetic model for noble gases. Values of an important parameter for the model-the skin permeability coefficient K (m s(-1))-were derived using data from previous human studies. The analysis of such empirical data, which corresponded to radon concentrations in the air exhaled by subjects during and following bathing in radon-rich thermal water, revealed that the estimated K values had a log-normal distribution. The validity of the K values and the characteristics of the present model are then discussed. Furthermore, the impact of the intake of radon or its progeny via inhalation or skin absorption on radiation dose was also assessed for possible exposure scenarios in a radon hot spring. It was concluded that, depending on the radon concentration in thermal water, there might be situations in which the dose contribution resulting from skin absorption of radon is comparable to that resulting from inhalation of radon and its progeny. This conclusion can also apply to other therapeutic situations (e.g. staying in the pool for a longer period). PMID:26983980

  9. Simultaneous measurement of Rn and its progeny in cave air by liquid scintillation techniques and. cap alpha. -ray spectrometry

    SciTech Connect

    Amano, H.; Kasai, A.; Matsunaga, T.

    1985-09-01

    To estimate the internal dose from Rn and its progeny, the working level month which is defined as exposure at one working level concentration for 170 h has been used traditionally. But concerning dose calculated for the inhalation of Rn and its progeny to the public, dose factors from individual nuclides were recommended. The approach using individual dose factors requires determination of the concentration of these individual nuclides. Thus a simultaneous measurement of Rn and its progeny was made in an enclosed cave, which is used for seismological observation, since the problem is most acute in an enclosed environment and the situation is not so complicated under such circumstances. Radon sampling by adsorption in organic solvent and in-situ ..cap alpha..-ray spectrometry of Rn progeny have been carried out in this cave. The internal dose by inhalation is estimated for the workers in this cave.

  10. The Spanish indoor radon mapping strategy.

    PubMed

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

    2014-11-01

    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 1980s. A significant proportion of them resulted from the last campaign performed from 2009 to 12. This campaign completed the first version of a map based on a grid 10 × 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. PMID:25013034

  11. In-vivo measurements of Pb-210 to determine cumulative exposure to radon daughters: A pilot study

    SciTech Connect

    Laurer, G.R.; Cohen, N. . Inst. of Environmental Medicine); Stark, A.; Ju, C. . Bureau of Environmental and Occupational Epidemiology)

    1990-10-01

    The feasibility of measuring Pb-210 in vivo in the skulls of those individuals who have resided in homes with above average levels of radon/radon daughters, has now been successfully demonstrated. These values, when incorporated into metabolic models of Pb-210 in the body including other related physical parameters, can be used for the calculation of a realistic estimate of a resident's cumulative exposure to radon and its' decay products. Data are presented for 26 subjects exposed to higher than average concentrations of radon i.e. ranging from 10 to 120 pCi/l, for various periods of time. Their skeletal Pb-210 burdens are compared to measurement results of a population of individuals presumed to have been exposed to values which are more representative of average levels i.e. <1pCi/1. Results of a study to determine the biological retention of Pb-210 in the human skeleton for use in the metabolic model relating skull burdens of this nuclide to cumulative radon/daughter exposure, are also described. At the present time, our measurements, made over a period of 10 years, of an individual with a significant Pb-210 burden, indicate a biological half-time of approximately 57 years and an effective half-life of 16 years. 4 refs., 11 figs.

  12. Maternal low-dose estradiol-17β exposure during pregnancy impairs postnatal progeny weight development and body composition

    SciTech Connect

    Werner Fürst, Rainer; Pistek, Veronika Leopoldine; Kliem, Heike; Skurk, Thomas; Hauner, Hans; Meyer, Heinrich Herman Dietrich; Ulbrich, Susanne Ernestine

    2012-09-15

    Endocrine disrupting chemicals with estrogenic activity play an important role as obesogens. However, studies investigating the most potent natural estrogen, estradiol-17β (E2), at low dose are lacking. We examined endocrine and physiological parameters in gilts receiving distinct concentrations of E2 during pregnancy. We then investigated whether adverse effects prevail in progeny due to a potential endocrine disruption. E2 was orally applied to gilts during the entire period of pregnancy. The concentrations represented a daily consumption at the recommended ADI level (0.05 μg/kg body weight/day), at the NOEL (10 μg/kg body weight/day) and at a high dosage (1000 μg/kg body weight/day). Plasma hormone concentrations were determined using enzyme immuno assays. Offspring body fat was assessed by dual-energy X-ray absorptiometry scanning. In treated gilts receiving 1000 μg E2/kg body weight/day we found significantly elevated plasma E2 levels during pregnancy, paralleled by an increased weight gain. While offspring showed similar weight at birth, piglets exhibited a significant reduction in weight at weaning even though their mothers had only received 0.05 μg E2/kg body weight/day. At 8 weeks of age, specifically males showed a significant increase in overall body fat percentage. In conclusion, prenatal exposure to low doses of E2 affected pig offspring development in terms of body weight and composition. In line with findings from other obesogens, our data suggest a programming effect during pregnancy for E2 causative for the depicted phenotypes. Therefore, E2 exposure may imply a possible contribution to childhood obesity. -- Highlights: ► We investigate the potential role of estradiol-17β (E2) as an obesogen. ► We orally apply E2 at the ADI, NOEL and a high dose to gilts during pregnancy. ► Offspring weight is similar at birth but reduced at weaning even after ADI treatment. ► Male offspring only exhibit an increase in overall body fat percentage

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

    PubMed

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

    2016-09-01

    Radon activity concentrations (in water and in air) were measured at 13 selected locations at the Avalon Springs thermal spa resort in Montagu (Western Cape, South Africa) to estimate the associated effective dose received by employees and visitors. A RAD-7 detector (DURRIDGE), based on alpha spectrometry, and electret detectors (E-PERM®Radelec) were used for these radon measurements. The primary source of radon was natural thermal waters from the hot spring, which were pumped to various locations on the resort, and consequently a range of radon in-water analyses were performed. Radon in-water activity concentration as a function of time (short term and long term measurements) and spatial distributions (different bathing pools, etc.) were studied. The mean radon in-water activity concentrations were found to be 205 ± 6 Bq L (source), 112 ± 5 Bq L (outdoor pool) and 79 ± 4 Bq L (indoor pool). Radon in-air activity concentrations were found to range between 33 ± 4 Bq m (at the outside bar) to 523 ± 26 Bq m (building enclosing the hot spring's source). The most significant potential radiation exposure identified is that due to inhalation of air rich in radon and its progeny by the resort employees. The annual occupational effective dose due to the inhalation of radon progeny ranges from 0.16 ± 0.01 mSv to 0.40 ± 0.02 mSv. For the water samples collected, the Ra in-water activity concentrations from samples collected were below the lower detection limit (~0.7 Bq L) of the γ-ray detector system used. No significant radiological health risk can be associated with radon and progeny from the hot spring at the Avalon Springs resort. PMID:27472753

  14. Maternal Exposure to Cadmium and Manganese Impairs Reproduction and Progeny Fitness in the Sea Urchin Paracentrotus lividus.

    PubMed

    Migliaccio, Oriana; Castellano, Immacolata; Cirino, Paola; Romano, Giovanna; Palumbo, Anna

    2015-01-01

    Metal contamination represents one of the major sources of pollution in marine environments. In this study we investigated the short-term effects of ecologically relevant cadmium and manganese concentrations (10(-6) and 3.6 x 10(-5) M, respectively) on females of the sea urchin Paracentrotus lividus and their progeny, reared in the absence or presence of the metal. Cadmium is a well-known heavy metal, whereas manganese represents a potential emerging contaminant, resulting from an increased production of manganese-containing compounds. The effects of these agents were examined on both P. lividus adults and their offspring following reproductive state, morphology of embryos, nitric oxide (NO) production and differential gene expression. Here, we demonstrated that both metals differentially impaired the fertilization processes of the treated female sea urchins, causing modifications in the reproductive state and also affecting NO production in the ovaries. A detailed analysis of the progeny showed a high percentage of abnormal embryos, associated to an increase in the endogenous NO levels and variations in the transcriptional expression of several genes involved in stress response, skeletogenesis, detoxification, multi drug efflux processes and NO production. Moreover, we found significant differences in the progeny from females exposed to metals and reared in metal-containing sea water compared to embryos reared in non-contaminated sea water. Overall, these results greatly expanded previous studies on the toxic effects of metals on P. lividus and provided new insights into the molecular events induced in the progeny of sea urchins exposed to metals. PMID:26125595

  15. Maternal Exposure to Cadmium and Manganese Impairs Reproduction and Progeny Fitness in the Sea Urchin Paracentrotus lividus

    PubMed Central

    Migliaccio, Oriana; Castellano, Immacolata; Cirino, Paola; Romano, Giovanna; Palumbo, Anna

    2015-01-01

    Metal contamination represents one of the major sources of pollution in marine environments. In this study we investigated the short-term effects of ecologically relevant cadmium and manganese concentrations (10-6 and 3.6 x 10-5 M, respectively) on females of the sea urchin Paracentrotus lividus and their progeny, reared in the absence or presence of the metal. Cadmium is a well-known heavy metal, whereas manganese represents a potential emerging contaminant, resulting from an increased production of manganese-containing compounds. The effects of these agents were examined on both P. lividus adults and their offspring following reproductive state, morphology of embryos, nitric oxide (NO) production and differential gene expression. Here, we demonstrated that both metals differentially impaired the fertilization processes of the treated female sea urchins, causing modifications in the reproductive state and also affecting NO production in the ovaries. A detailed analysis of the progeny showed a high percentage of abnormal embryos, associated to an increase in the endogenous NO levels and variations in the transcriptional expression of several genes involved in stress response, skeletogenesis, detoxification, multi drug efflux processes and NO production. Moreover, we found significant differences in the progeny from females exposed to metals and reared in metal-containing sea water compared to embryos reared in non-contaminated sea water. Overall, these results greatly expanded previous studies on the toxic effects of metals on P. lividus and provided new insights into the molecular events induced in the progeny of sea urchins exposed to metals. PMID:26125595

  16. Measurement of differential pressures and radon entry in research houses and evaluation of radon control methods: Final report

    SciTech Connect

    Fortmann, R.C.; Rector, H.E.; Nagda, N.L.

    1988-12-01

    Experimental testing was conducted in two well-insulated bilevel research houses to evaluate the effectiveness of selected radon and radon progeny control methods and to develop a fuller understanding of the relationship between indoor-outdoor pressure differences and radon entry. Radon, radon progeny, indoor and outdoor temperatures, air infiltration rates, pressure differences, and meteorological conditions were measured continuously with an automated system. Radon and radon progeny control methods were tested in one house; the other house served as a reference to avoid the confounding effects of natural radon variation on calculations of control effectiveness. Differences in pressure between indoors and outdoors or indoors and the subslab airspace averaged less than 2 pascals throughout the year. Pressure differences were consistent with indoor-outdoor temperature differences; the downstairs of the houses were depressurized with respect to outdoors during the winter and pressurized during the summer. Seasonal differences in radon entry rates were consistent with general patterns of indoor-outdoor pressure differences, but regression techniques did not show strong correlation between pressure differences and radon entry rates. The subslab suction system was the most effective of the radon control methods tested. Radon progeny control devices tested, including common household appliances, such as ceiling fans, portable air cleaners, and electronic precipitators, reduced radon progeny levels by as much as 70 percent. 26 refs., 21 figs., 12 tabs.

  17. Radiation exposure and dose to small mammals in radon-rich soils.

    PubMed

    Macdonald, C R; Laverock, M J

    1998-07-01

    Protection of the environment from radionuclide releases requires knowledge of the normal background levels of radiation exposure in the exposed biotic community and an estimate of the detriment caused by additional exposure. This study modeled the background exposure and dose to the lungs of small burrowing mammals from 222Rn in artificial burrows in radon-rich soils at a site in southeastern Manitoba. E-PERM chambers used to measure 222Rn in soil showed good reproducibility of measurement, with an average coefficient of variance (CV) of about 10%. Geometric mean (GM) 222Rn concentrations at nine randomly selected sites ranged from 5,490 Bq/m3 (GSD = 1.57, n = 7) to 41,000 Bq/m3 (GSD = 1.02, n = 5). Long-term monitoring of 222Rn concentrations in artificial burrows showed large variation within and between burrows and did not show consistent variation with season, orientation of the burrow opening, or levels of 226Ra in the soil. Annual GM concentrations in individual burrows ranged from 7,480 Bq/m3 (GSD = 1.60) to 18,930 Bq/m3 (GSD = 1.81) in burrows several meters apart. A grand GM of 9,990 Bq/m3 (GSD = 1.81, n = 214) was measured over the site for the year. An exposure model was constructed for five small mammal species based on their respiration rates and the number of hours spent in the burrow, active or hibernating, exposed to soil gas 222Rn, and the time spent out of the burrow exposed to atmospheric 222Rn. A background dose of 0.9 mGy/a from atmospheric 222Rn (40 Bq/m3) was estimated for a large-bodied (80 kg), nonburrowing animal living on the soil surface. The highest exposures (mJ/a) in burrowing mammals occurred in those species with the highest respiration rates. Hibernation accounted for a small fraction of total annual exposure (<5%) because of very low respiration rates during this period. Absorbed dose to lung (mGy/a) was highest in the pocket gopher and decreased in the larger animals because of larger lung mass. Using mean 222Rn concentrations

  18. [The radon exposure in mine: risk evaluation, risk assessment and health effects].

    PubMed

    Coggiola, M; Scielzo, G; Baracco, A; Perrelli, F; Pribytkova, Z

    2011-01-01

    In mining sector, the natural presence of radon determines an exposition which deserves substantive consideration. The results of radon measure from '90 years in a talc mining show levels of radon below to the threshold limit of 400 Bq/m3, values influenced from air forced systems. The epidemiologic studies updated in a cohort of talc workers between 1946 and 1995 showed no excess for lung cancer mortality. No excess was found for lung cancer mortality in miners exposed to low dose of radon. PMID:23393887

  19. Estimated risk from exposure to radon decay products in US homes

    SciTech Connect

    Nero, A.V. Jr.

    1986-05-01

    Recent analyses now permit direct estimation of the risks of lung cancer from radon decay products in US homes. Analysis of data from indoor monitoring in single-family homes yields a tentative frequency distribution of annual-average /sup 222/Rn concentrations averaging 55 Bq m/sup -3/ and having 2% of homes exceeding 300 Bq m/sup -3/. Application of the results of occupational epidemiological studies, either directly or using recent advances in lung dosimetry, to indoor exposures suggests that the average indoor concentration entails a lifetime risk of lung cancer of 0.3% or about 10% of the total risk of lung cancer. The risk to individuals occupying the homes with 300 Bq m/sup -3/ or more for their lifetimes is estimated to exceed 2%, with risks from the homes with thousands of Bq m/sup -3/ correspondingly higher, even exceeding the total risk of premature death due to cigarette smoking. The potential for such average and high-level risks in ordinary homes forces development of a new perspective on environmental exposures.

  20. A review of exposures to radon, long-lived radionuclides and external gamma at the Czech uranium mine.

    PubMed

    Marušiaková, M; Gregor, Z; Tomášek, L

    2011-05-01

    This paper presents the results of the personal exposure monitoring conducted in the RoŽná uranium mine in the Czech Republic. In this mine, which has been operated since the late 1950s, personal ALGADE dosemeters have been used since 1998. A group of 600 miners employed during the period 2000-09 has been analysed. Annual exposures to radon decay products, long-lived alpha emitters and external gamma radiation are described. These components play an essential role in the estimation of the total effective dose. The dependence of the exposures on the type of mining job is also assessed. PMID:21471123

  1. USACE FUSRAP Maywood Team Develops a Mechanism to Evaluate Residual Radon Exposure Potential at Vicinity Properties Where Remediation of Accessible Contamination has been Completed

    SciTech Connect

    Winters, M.; Walnicki, S.; Hays, D.

    2008-07-01

    The Maywood FUSRAP Team is obligated, under its approved remedy selection decision document, to demonstrate substantive compliance with New Jersey Administrative Code 7:28- 12(a)2, establishing an indoor limit of three Pico-Curies per liter above background for radon-222 (Rn-222). The Maywood Team explores various avenues for dealing with the radon issue and provides an alternative for demonstrating substantive compliance with the radon remediation standard by answering the question: 'In certain conservative situations, can compliance with the radon standard be demonstrated without performing monitoring?' While monitoring may be the most definitive method for demonstrating compliance, a logical argument can be made that when radiological remediation removes the potential source for Rn-222 above background, monitoring is unnecessary. This position is defended through the use of historical physical radon measurements which illustrate that indoor radon was not a pre-remediation problem, and post-remediation soil sampling data which demonstrate that the source of the potentially elevated Rn- 222 levels have been successfully mitigated. Monitoring recommendations are made for situations where insufficient data exists to make definitive determinations or when un-remediated sources affecting habitable structures remain on a given property. Additional information regarding recommended techniques and references for effective monitoring of indoor radon are included in this paper. This paper may benefit teams that have similar regulatory commitments and/or have need to make assessments of radon exposure potential based upon historical monitoring data and available soils concentration data. (authors)

  2. Is thoron a problem in Swedish dwellings? Results of measurements of concentrations of thoron and its progeny.

    PubMed

    Skeppström, K; Wåhlin, E

    2015-11-01

    Long-term measurements of thoron progeny concentrations (equilibrium-equivalent thoron concentration) have been carried out in Swedish dwellings with the aim of investigating if thoron and its progeny pose a health risk. Measurements were performed in 93 houses and 25 apartments. In addition to thoron progeny concentration, thoron gas concentration near the wall surface, ambient dose equivalent rate of gamma radiation and radon gas concentration were also measured. The results show that the mean value of thoron progeny was 2.2 Bq m(-3) in houses and 1.6 Bq m(-3) in apartments. Ten per cent of the dwellings (both houses and apartments) had thoron progeny concentrations exceeding 10 Bq m(-3). Thoron progeny concentration is not significantly different in dwellings built of alum shale-based aerated concrete ('blue concrete') than dwellings built of other construction materials. For the dwellings in this study (not representative of the Swedish population), the mean dose estimated due to exposure to thoron was found to be 0.4 mSv y(-1). PMID:25904697

  3. Radon: Detection and treatment

    SciTech Connect

    Loken, S.; Loken, T. )

    1989-11-01

    Within the last few years, natural radon exposure in non-industrial settings, primarily homes, has become a health concern. Research has demonstrated that many homes throughout the United States have radon concentrations much higher than the legal federal limits set for miners. Thousands of unsuspecting people are being exposed to high levels of radiation. It is estimated that up to 15 percent of lung cancers are caused from radon. This is a significant health risk. With basic knowledge of the current information on radon, a primary health care provider can address patients' radon concerns and make appropriate referrals.

  4. Genetic effects of chronic radon exposure in northern pocket gophers (Thomomys talpoides)

    SciTech Connect

    McMillen, C.C.; McBee, K.; Hafner, D.J.

    1995-12-31

    This study examined effects on genetic organization of a chronic stressor, radon, in a population of Thomomys talpoides living in radon-rich soils in the Jemez Mountains of New Mexico compared to five populations living in soils with no measurable amounts of radon. Karyology showed no differences in standard metaphase chromosomal structure among populations. Flow cytometric analyses showed significant populational differences in mean G1 peak position but these differences were less than intraspecific differences previously described for gophers. Allozymic studies revealed lower mean heterozygosity levels in all populations than have been previously reported in the same geographic area. Cluster analysis using Roger`s genetic similarity coefficients separated the radon-exposed population from the unexposed populations; however, this suggests the possibility of adaptive biochemical differentiation in this population.

  5. Comparison of active and passive methods for radon exhalation from a high-exposure building material.

    PubMed

    Abbasi, A; Mirekhtiary, F

    2013-12-01

    The radon exhalation rates and radon concentrations in granite stones used in Iran were measured by means of a high-resolution high purity Germanium gamma-spectroscopy system (passive method) and an AlphaGUARD model PQ 2000 (active method). For standard rooms (4.0 × 5.0 m area × 2.8 height) where ground and walls have been covered by granite stones, the radon concentration and the radon exhalation rate by two methods were calculated. The activity concentrations of (226)Ra in the selected granite samples ranged from 3.8 to 94.2 Bq kg(-1). The radon exhalation rate from the calculation of the (226)Ra activity concentration was obtained. The radon exhalation rates were 1.31-7.86 Bq m(-2)h(-1). The direction measurements using an AlphaGUARD were from 218 to 1306 Bq m(-3) with a mean of 625 Bq m(-3). Also, the exhalation rates measured by the passive and active methods were compared and the results of this study were the same, with the active method being 22 % higher than the passive method. PMID:23798709

  6. Continuous measurements of bronchial exposure induced by radon decay products during inhalation

    NASA Astrophysics Data System (ADS)

    Iwaoka, Kazuki; Tokonami, Shinji; Yonehara, Hidenori; Ishikawa, Tetsuo; Doi, Masahiro; Kobayashi, Yosuke; Yatabe, Yoshinori; Takahashi, Hiroyuki; Yamada, Yuji

    2007-09-01

    The deposition of radon decay products is not equal in each of the respiratory regions and as the presence of radon has been linked with an increase in lung cancer risk, it is important to calculate the deposition of radon decay products in each of the respiratory regions. Recently, many studies on the deposition of radon in respiratory regions have been simulated using wire screens. The systems and equipment used in those studies are not suitable for field measurements as their dimensions are relatively massive, nor can they measure continuously. We developed a continuous bronchial dosimeter (CBD) which is suitable for field measurements. It was designed with specifications that allow it to be remain compact. The CBD simulates the deposition of radon decay products in the different respiratory regions by the use of a combination of wire screens. Deposition in the simulated regions of the lung can be continuously estimated in various environments. The ratio of activities deposited in a simulated nasal cavity (N) and tracheobronchial (TB) regions was calculated from the results of simultaneous measurements using CBD-R (reference), CBD-N (nasal), and CBD-TB (tracheobronchial) measurement units. After aerosols were injected into the radon chamber, the ratio of N and TB depositions decreased. This results indicate that the CBD gave a good response to changes in the environment. It was found that the ratio of N and TB deposition also varied with time in each actual environment.

  7. Continuous measurements of bronchial exposure induced by radon decay products during inhalation

    SciTech Connect

    Iwaoka, Kazuki; Tokonami, Shinji; Yonehara, Hidenori; Ishikawa, Tetsuo; Doi, Masahiro; Kobayashi, Yosuke; Yatabe, Yoshinori; Takahashi, Hiroyuki; Yamada, Yuji

    2007-09-15

    The deposition of radon decay products is not equal in each of the respiratory regions and as the presence of radon has been linked with an increase in lung cancer risk, it is important to calculate the deposition of radon decay products in each of the respiratory regions. Recently, many studies on the deposition of radon in respiratory regions have been simulated using wire screens. The systems and equipment used in those studies are not suitable for field measurements as their dimensions are relatively massive, nor can they measure continuously. We developed a continuous bronchial dosimeter (CBD) which is suitable for field measurements. It was designed with specifications that allow it to be remain compact. The CBD simulates the deposition of radon decay products in the different respiratory regions by the use of a combination of wire screens. Deposition in the simulated regions of the lung can be continuously estimated in various environments. The ratio of activities deposited in a simulated nasal cavity (N) and tracheobronchial (TB) regions was calculated from the results of simultaneous measurements using CBD-R (reference), CBD-N (nasal), and CBD-TB (tracheobronchial) measurement units. After aerosols were injected into the radon chamber, the ratio of N and TB depositions decreased. This results indicate that the CBD gave a good response to changes in the environment. It was found that the ratio of N and TB deposition also varied with time in each actual environment.

  8. Awareness and perceptions of the risks of exposure to indoor radon: a population-based approach to evaluate a radon awareness and testing campaign in England and Wales.

    PubMed

    Poortinga, Wouter; Bronstering, Karin; Lannon, Simon

    2011-11-01

    The current study aimed to evaluate the locally directed radon roll-out program that was conducted between 2001 and 2005 in England and Wales to increase radon awareness and testing rates. A representative sample of 1,578 residents aged 16 and older were interviewed who lived in radon-affected areas of 15 local authorities in England and Wales that were eligible for participation in the program. The study systematically sampled across participating and nonparticipating local authorities, "actionable" and "nonactionable" radon-affected areas, and geographic regions with different campaign histories (Wales, Southwest England, and the rest of England). As a multistage sampling strategy was used, the data were analyzed from a multilevel perspective. This study found that participants living in participating local authorities had higher levels of awareness and were more likely to have tested their home for radon than participants living in nonparticipating local authorities. Similar results were found for participants living in "actionable" areas as compared to those living in "nonactionable" radon-affected areas. The study further found that radon awareness and testing rates were the highest in Southwest England and the lowest in Wales. This study suggests that the radon roll-out program has been effective in raising awareness and testing rates, and that ongoing domestic radon campaigns in Southwest England may have raised radon awareness and testing in these areas, showing important reinforcement effects of multiple risk communication campaigns. PMID:21477087

  9. Adult myeloid leukaemia, geology, and domestic exposure to radon and gamma radiation: a case control study in central Italy

    PubMed Central

    Forastiere, F.; Sperati, A.; Cherubini, G.; Miceli, M.; Biggeri, A.; Axelson, O.

    1998-01-01

    OBJECTIVES: To investigate whether indoor randon or gamma radiation might play a part in myeloid leukaemia as suggested by studies based on crude geographical or geological data for exposure assessment. METHODS: For six months randon and gamma radiation was measured with solid state nuclear track detectors and thermoluminescent dosimeters in dwellings of 44 adult male cases of acute myeloid leukaemia and 211 controls (all subjects deceased). Conditional logistic regression ORs (ORs) and 95% confidence intervals (95% CIs) were estimated for quartiles of radon and gamma radiation and for municipality and dwelling characteristics. RESULTS: The risk of leukaemia was associated with an increasing urbanisation index (p value for trend = 0.008). An increased OR was found among those living in more modern houses (OR 3.0, 95% CI 1.4 to 6.6). Confirming the findings of a previous study in the same area, geological features bore a positive association with myeloid leukemia, even by adjusting for level of urbanisation. Contrary to expectations from the previous study, however, no association appeared between myeloid leukaemia and radon and gamma radiation; for the highest quartiles of exposure, ORs were 0.56 (95% CI 0.2 to 1.4) and 0.52 (95% CI 0.2 to 1.4), respectively. Considering only subjects who had lived > or = 20 years in the monitored home and adjusting for urbanisation, there was still no effect of exposure to radiation. CONCLUSIONS: In view of the limited numbers, the results do not in general refute a possible risk of myeloid leukaemia from exposure to indoor radon or gamma radiation, but decrease the credibility of such a relation in the area studied and also of other studies suggesting an effect without monitoring indoor radiation. Some other fairly strong determinants have appeared--that is, level of urbanisation and living in modern houses-- that might need further consideration.   PMID:9614394

  10. Radon Exposure Assessment and Relative Effective Dose Estimation to Inhabitants of Puglia Region, South Italy

    PubMed Central

    Quarto, Maria; Pugliese, Mariagabriella; La Verde, Giuseppe; Loffredo, Filomena; Roca, Vincenzo

    2015-01-01

    Indoor radon concentrations were measured in dwellings of the Puglia region in Southern Italy using LR-115 passive detectors. The results show that the radon concentrations varied from 15 ± 2 to 2166 ± 133 Bq/m3 with a geometric mean of 114 Bq/m3 and a geometric standard deviation of 2.3. An analysis on the factors affecting radon concentration such as age of the dwellings, floors, and stories, was performed. The mean effective dose to inhabitants has been calculated and found to be 8.2 mSv/y. Finally, for estimation of cancer risks, the lifetime risk and lung cancer cases per years per million have been calculated. PMID:26610543

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

    PubMed

    Zunić, Z S; Celiković, I; Tokonami, S; Ishikawa, T; Ujić, P; Onischenko, A; Zhukovsky, M; Milić, G; Jakupi, B; Cuknić, O; Veselinović, N; Fujimoto, K; Sahoo, S K; Yarmoshenko, I

    2010-10-01

    This paper deals with the results of the first-field use in the Balkans, i.e. Serbia and Republic of Srpska (Bosnia and Hercegovina), of a passive polycarbonate Mark II type and poliallyldiglycol 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 Institute 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. PMID:20966203

  12. Laboratory measurements on Radon exposure effects on local environmental temperature: implications for satellite TIR measurements

    NASA Astrophysics Data System (ADS)

    Martinelli, Giovanni; Tomasz Solecki, Andrzej; Eulalia Tchorz-Trzeciakiewicz, Dagmara; Karolina Grudzinska, Katarzyna

    2014-05-01

    Surface latent heat flux (SLHF) is proportional to the heat released by phase changes during solidification or evaporation or melting. Effects of SLHF on earth's surface have also been measured by satellite techniques able to measure thermal infrared radiation (TIR). Recent studies found a possible correlation between SLHF and earthquakes thus satellite techniques are widely utilized in researches on the possible link between SLHF and earthquakes. Possible fluctuations on SLHF values during seismic periods have been attributed to different causes like the expulsion from the ground of greenhouse gases or by Radon. In particular ionization processes due to Radon decay could lead to changes in air temperature. Laboratory experiments have been carried out to highlight the possible role of Radon in thermal environmental conditions of a laboratory controlled atmospheric volume. Samples of highly radioactive granite powder containing 600 Bq/kg of Radium that is 20 times higher than the average continental lithosphere content has been stored in a desiccator of 0,005 m3 volume for 30 days to accumulate radon 222Rn in the desiccator air. After radon accumulation the desiccator was placed inside a styrofoam chamber of 1x0.5x0.5 m size and the cover removed. The relative humidity of chamber air was 72% and temperature 24 oC. Experiment was monitored by an infrared camera Flir Therma CAM PM695 operating in the spectrum band 7,5-13 µm with thermal resolution 0,01ºC and a RadStar RS300-I Radon Detector/Monitor with 1 hour time resolution. Air temperature and humidity were monitored by a digital Terdens thermohygrometer. No significant thermal or humidity effects were observed.

  13. Mechanistic study on lung cancer mortality after radon exposure in the Wismut cohort supports important role of clonal expansion in lung carcinogenesis.

    PubMed

    Zaballa, I; Eidemüller, M

    2016-08-01

    Lung cancer mortality after radon exposure in the Wismut cohort was analyzed using the two-stage clonal expansion (TSCE) model. A total of 2996 lung cancer deaths among the 58,695 male workers were observed during the follow-up period between 1946 and 2003. Adjustment to silica exposure was performed to find a more accurate estimation of the risk of radon exposure. An additional analysis with the descriptive excess relative risk (ERR) model was carried out for comparison. The TSCE model that best describes the data is nonlinear in the clonal expansion with radon exposure and has a saturation level at an exposure rate of [Formula: see text]. The excess relative risk decreases with age and shows an inverse exposure rate effect. In comparison with the ERR model, the TSCE model predicts a considerably larger risk for low exposures rates below [Formula: see text]. Comparison to other mechanistic studies of lung cancer after exposure to alpha particles using the TSCE model reveals an extraordinary consistency in the main features of the exposure response, given the diversity in the characteristics of the cohorts and the exposure across different studies. This suggests that a nonlinear response mechanism in the clonal expansion, with some level of saturation at large exposure rates, may be playing a crucial role in the development of lung cancer after alpha particle irradiation. PMID:27334643

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

    SciTech Connect

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

    1992-12-31

    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.

  15. Radon dosimetry for a lung cancer study in Missouri

    SciTech Connect

    Alavanja, M.C.R.; Wood, M.; Hrubec, Z.; Boice, J.D. Jr.; Brownson, R.; Mahaffey, J.

    1992-12-31

    The power of any study to detect and quantify an association between lung cancer and residential radon exposure depends critically on the quality, completeness, and reliability of exposure data. To evaluate the adequacy of radon dosimetry in an ongoing case-control study of lung cancer in nonsmoking white women in Missouri, residential histories from 798 telephone interviews and year-long radon measurements from 250 study subjects were examined. An attempt was made to place alpha-track detectors in the bedroom and kitchen of every dwelling occupied by those subjects for the past 30 y (mean = 2.6 homes). The length of residence in current homes was 22 y on average. However, the proportion of women exceeding a 30-y, time-weighted, average concentration of 4 pCi L{sup {minus}1} significantly decreased with an increased number of residences. For those living in 1,2, and 3+ homes during the last 30 y, the percentages greater than 4 pCi L{sup {minus}1} were 11.3%, 5.6%, and 0%, respectively. These findings support recent theoretical modeling that points to a substantial reduction in statistical power to detect a radon-related lung-cancer risk in populations with high residential mobility. Statistical power is further reduced as the number of missing radon measurements increases. Missing data result when owners refuse measurements, when the dwelling has been torn down, or when structural changes are so severe that a current measurement has little relevance to past radon concentrations. Estimates of missing exposure data must then be based on assumptions of uncertain validity. A novel approach to estimating cumulative residential radon exposure involves affixing CR-39 detectors to glass objects, such as mirrors, that have been in the possession of the study subject for at least 20 y. Measurements of alpha-particle emissions from long-lived radon progeny that accumulated in the surfaces of these glass objects might reflect long-term radon exposures.

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

    PubMed

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

    2015-09-01

    In India, High Background Radiation Areas (HBRAs) due to enhanced levels of naturally occurring radionuclides in soil (thorium and, to a lesser extent, uranium), are located along some parts of the coastal tracts viz. the coastal belt of Kerala, Tamilnadu and Odisha. It is conjectured that these deposits will result in higher emissions of radon isotopes ((222)Rn and (220)Rn) and their daughter products as compared to Normal Background Radiation Areas (NBRAs). While the annual external dose rates contributed by gamma radiations in these areas are about 5-10 times higher, the extent of increase in the inhalation dose rates attributable to (222)Rn and (220)Rn and their decay products is not well quantified. Towards this, systematic indoor surveys were conducted wherein simultaneous measurements of time integrated (222)Rn and (220)Rn gas and their decay product concentrations was carried out in around 800 houses in the HBRAs of Kerala and Odisha to estimate the inhalation doses. All gas measurements were carried out using pin-hole cup dosimeters while the progeny measurements were with samplers and systems based on the Direct radon/thoron Progeny sensors (DRPS/DTPS). To corroborate these passive measurements of decay products concentrations, active sampling was also carried out in a few houses. The results of the surveys provide a strong evidence to conclude that the inhalation doses due to (222)Rn and (220)Rn gas and their decay products in these HBRAs are in the same range as observed in the NBRAs in India. PMID:26065929

  17. Additional contamination when radon is in excess.

    PubMed

    Martín Sánchez, A; de la Torre Pérez, J; Ruano Sánchez, A B; Naranjo Correa, F L

    2013-11-01

    A study of the behavior of the (222)Rn progeny on clothes, skin and hair has been performed in a place with very high radon concentration. In the past, radon concentration was established to be about 32 kBq/m(3) in a very high humidity environment inside a tourist cave in Extremadura (Spain). The results show that (222)Rn daughters are adhered on clothes, skin and hair, adding some radioactive concentration to that due to radon and its progeny existing in the breathable air. PMID:23548693

  18. Exposure to indoor radon and natural gamma radiation in some workplaces at Algiers, Algeria.

    PubMed

    Aït Ziane, M; Lounis-Mokrani, Z; Allab, M

    2014-07-01

    Radon activity concentrations have been measured in 34 workplaces throughout Algiers nuclear research centre, in Algeria, during some periods between March 2007 and June 2013 using Electret ion chambers, nuclear tracks detectors and an AlphaGuard system. The indoor radon levels range from 2 to 628 Bq m(-3) with an average indoor concentration equals to 92 Bq m(-3), whereas the estimated outdoor radon concentrations range from 2 to 14 Bq m(-3) with an average value of 6 Bq m(-3). This study also focused on parameters affecting radon concentration levels such as floor number, ventilation and atmospheric parameters. Furthermore, the mean gamma rates have been measured in the different investigated locations and have been found to be varying between 33 and 3300 nSv h(-1). The annual effective dose for workers calculated using the appropriate equilibrium and occupancy factors is lower than the value recommended by International Commission on Radiological Protection in its Publication 103. PMID:24711531

  19. Assessing the level of chromosome aberrations in peripheral blood lymphocytes in long-term resident children under conditions of high exposure to radon and its decay products.

    PubMed

    Druzhinin, Vladimir G; Sinitsky, Maxim Yu; Larionov, Aleksey V; Volobaev, Valentin P; Minina, Varvara I; Golovina, Tatiana A

    2015-09-01

    In this study, the frequency and spectrum of chromosomal aberrations were analysed in samples of peripheral blood from 372 (mean age = 12.24 ± 2.60 years old) long-term resident children in a boarding school (Tashtagol city, Kemerovo Region, Russian Federation) under conditions of high exposure to radon and its decay products. As a control group, we used blood samples from people living in Zarubino village (Kemerovo Region, Russian Federation). We discovered that the average frequencies of single and double fragments, chromosomal exchanges, total number of aberrations, chromatid type, chromosome type and all types of aberrations were significantly increased in the exposed group. This is evidence of considerable genotoxicity to children living under conditions of high exposure to radon compared to children living under ecological conditions without increased radon radiation. PMID:25904585

  20. Radon: The Silent Danger.

    ERIC Educational Resources Information Center

    Stoffel, Jennifer

    1989-01-01

    This article discusses the public health dangers associated with radon exposure in homes and schools. In addition, testing and corrective efforts by federal and state agencies are discussed. A map indicating areas in the U.S. with potentially high radon levels is included. (IAH)

  1. Radon emanation from low-grade uranium ore.

    PubMed

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

    2013-12-01

    Estimation of radon emanation in uranium mines is given top priority to minimize the risk of inhalation exposure due to short-lived radon progeny. This paper describes the radon emanation studies conducted in the laboratory as well as inside an operating underground uranium mine at Jaduguda, India. Some of the important parameters, such as grade/(226)Ra activity, moisture content, bulk density, porosity and emanation fraction of ore, governing the migration of radon through the ore were determined. Emanation from the ore samples in terms of emanation rate and emanation fraction was measured in the laboratory under airtight condition in glass jar. The in situ radon emanation rate inside the mine was measured from drill holes made in the ore body. The in situ(222)Rn emanation rate from the mine walls varied in the range of 0.22-51.84 × 10(-3) Bq m(-2) s(-1) with the geometric mean of 8.68 × 10(-3) Bq m(-2) s(-1). A significant positive linear correlation (r = 0.99, p < 0.001) between in situ(222)Rn emanation rate and the ore grade was observed. The emanation fraction of the ore samples, which varied in the range of 0.004-0.089 with mean value of 0.025 ± 0.02, showed poor correlation with ore grade and porosity. Empirical relationships between radon emanation rate and the ore grade/(226)Ra were also established for quick prediction of radon emanation rate from the ore body. PMID:23974076

  2. Radon exposure assessment for underground workers: a case of Seoul Subway Police officers in Korea.

    PubMed

    Song, Myeong Han; Chang, Byung-Uck; Kim, Yongjae; Cho, Kun-Woo

    2011-11-01

    The objective of this study is the systematic and individual assessment of the annual effective dose due to inhaled radon for the Seoul Subway Police officers, Korea. The annual average radon concentrations were found to be in the range of 18.9-114 Bq·m(-3) in their workplaces. The total annual effective doses which may likely to be received on duty were assessed to be in the range of 0.41-1.64 mSv·y(-1). These were well below the recommended action level 10 mSv·y(-1) by ICRP. However, the effective doses were higher than subway station staff in Seoul, Korea. PMID:21242168

  3. Analysis of lung tumor risks in rats exposed to radon.

    PubMed

    Gilbert, E S; Cross, F T; Dagle, G E

    1996-03-01

    Using data on 3117 rats exposed by inhalation to radon, radon progeny and uranium ore dust, the hazard function (or age-specific risk) for lung tumor incidence was modeled as a function of exposure, exposure rate and other factors. The overall estimate of lifetime risk was 237 cases per 10(6) rats per WLM (237 per 10(6) WLM), reasonably comparable to estimates obtained from data for humans. The data below 1000 WLM (20-640 WLM) were consistent with linearity with positive excess risks at all levels; however, evidence of statistically significant excess risk was limited to exposures of 80 WLM or greater. Evidence for an inverse exposure-rate effect was limited primarily to cumulative exposures exceeding 1000 WLM (1280-10,240 WLM) and to comparison of results at 100 and 1000 WL. Even at these levels, the possibility that the effect might be explained by time since last exposure or by heterogeneity across experiments could not be entirely excluded. The inverse exposure-rate effect was strongest for epidermoid and adenosquamous tumors, and the only indication of such an effect at exposures below 1000 WLM was modest evidence (P=0.024) in analyses limited to these tumors. When all lung tumors, or all malignant lung tumors, were included, there was no evidence of such an effect below 1000 WLM. These data support the viewpoint that the inverse exposure-rate effect is primarily a high-dose phenomenon. PMID:8927704

  4. Radon 222 permeation through different polymers (PVC, EVA, PE and PP) after exposure to gamma radiation or surface treatment by cold plasma

    NASA Astrophysics Data System (ADS)

    Klein, D.; Tomasella, E.; Labed, V.; Meunier, C.; Cetier, Ph.; Robé, M. C.; Chambaudet, A.

    1997-08-01

    In order to limit radon emission during the storage of radioactive wastes and to comply with the different regulations in the storage facility, the packaging used for these types of wastes should include intermediate enclosures, such as polymer membranes used as radon barriers. However, the membrane would be subjected to different types of radiation during long periods of storage, it would have to be regularly monitored for damage. The first aim of this study is to check the efficiency and the continuity of such polymer membranes subjected to different accelerated ageing processes by exposure to gamma radiation. PolyVinyl Chloride (PVC) and Ethylene Vinyl Acetate (EVA) membranes were studied after gamma exposures. Thus, we evaluated the effects of the gamma radiations on the radon permeation coefficient, and the degradation of these polymers due to this exposure. The second objective of this study is to evaluate the modifications of the polymer surface by cold plasma. PolyEthylene (PE) and PolyPropylene (PP) membranes were studied. Exposure of a polymer to a plasma creates reactive sites on the polymer's surface. Different modifications in the surface composition (chemical composition, molecular weight, etc.) can be obtained. The advantage of the plasma process is that it acts within seconds and does not produce any noticeable effects on the bulk properties. The obtained results show that this treatment increases the polymer's efficiency as a radon barrier.

  5. PROGRESS REPORT. MEASUREMENTS OF RADON, THORON, ISOTOPIC URANIUM AND THORIUM TO DETERMINE OCCUPATIONAL & ENVIRONMENTAL EXPOSURE & RISK AT FERNALD FEED MATERIALS PRODUCTION CENTER

    EPA Science Inventory

    There are three basic research objectives: (1) To develop an accurate personal and area radon/thoron (222Rn/220Rn) detector for accurate measurement of the exposure to low airborne concentrations of these gases during remediation at Fernald. These are to be used to determine atmo...

  6. Carcinogenesis and low-level ionizing radiation with special reference to lung cancer and exposure to radon daughters

    SciTech Connect

    Fabrikant, J.I.

    1982-06-01

    The quantitative estimation of the carcinogenic risk of low-dose, high-LET radiation in the case of exposure to radon daughters and lung-cancer is subject to numerous uncertainties. The greatest of these concerns the parametric values of the dose-response curve. We lack knowledge and an understanding of the dosimetry and the distribution of aggregates of radioactivity that remain localized as hot spots in specific regions of the lungs and the influence on greater or lesser risk of lung cancer per average lung dose than uniformly deposited radiation (NRC76). We have only a limited understanding of the response to exposure to high-LET radiations, such as alpha particles, for which linear risk estimates for low doses are less likely to overestimate the risk, and may, in fact, underestimate the risk (BEIR80). Other uncertainties include the length of the latency period, the RBE for alpha radiation relative to gamma radiation, the period during which the radiation risk is expressed, the risk projection model used - whether absolute or relative - for projecting risk beyond the period of observation, the effect of dose rate and protraction of dose, and the influence of differences in the natural incidence of lung cancer in different populations. In addition, uncertainties are introduced by the biological and life-style risk characteristics of humans, for example, the effect of sex, the effect of age at the time of irradiation and at the time of appearance of the cancer, the influence of length of observation or follow-up of the study populations, and the influence of perhaps the most important confounding bias, cigarette-smoking. The collective influence of these uncertainties is such as to deny great credibility to any estimate of human lung cancer risk and other cancer risk that can be made for low-dose, high-LET radon daughter radiation exposure.

  7. A complete low cost radon detection system.

    PubMed

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

    2013-08-01

    Monitoring the (222)Rn activity through the 1200 km long Northern Anatolian fault line, for the purpose of earthquake precursory, requires large number of cost effective radon detectors. We have designed, produced and successfully tested a low cost radon detection system (a radon monitor). In the detector circuit of this monitor, First Sensor PS100-7-CER-2 windowless PIN photodiode and a custom made transempedence/shaping amplifier were used. In order to collect the naturally ionized radon progeny to the surface of the PIN photodiode, a potential of 3500 V was applied between the conductive hemi-spherical shell and the PIN photodiode. In addition to the count rate of the radon progeny, absolute pressure, humidity and temperature were logged during the measurements. A GSM modem was integrated to the system for transferring the measurements from the remote locations to the data process center. PMID:23583920

  8. An overview of the North American residential radon and lung cancer case-control studies.

    PubMed

    Field, R William; Krewski, Daniel; Lubin, Jay H; Zielinski, Jan M; Alavanja, Michael; Catalan, Vanessa S; Klotz, Judith B; Létourneau, Ernest G; Lynch, Charles F; Lyon, Joseph L; Sandler, Dale P; Schoenberg, Janet B; Steck, Daniel J; Stolwijk, Jan A; Weinberg, Clarice; Wilcox, Homer B

    2006-04-01

    Lung cancer has held the distinction as the most common cancer type worldwide since 1985 (Parkin et al., 1993). Recent estimates suggest that lung cancer accounted for 1.2 million deaths worldwide in 2002, which represents 17.6% of the global cancer deaths (Parkin et al., 2005). During 2002, the highest lung cancer rates for men worldwide reportedly occurred in North America and Eastern Europe, whereas the highest rates in females occurred in North America and Northern Europe (Parkin et al., 2005). While tobacco smoking is the leading risk factor for lung cancer, because of the magnitude of lung cancer mortality, even secondary causes of lung cancer present a major public health concern (Field, 2001). Extrapolations from epidemiologic studies of radon-exposed miners project that approximately 18,600 lung cancer deaths per year (range 3000 to 41,000) in the United States alone are attributable to residential radon progeny exposure (National Research Council, 1999). Because of differences between the mines and the home environment, as well as differences (such as breathing rates) between miners and the general public, there was a need to directly evaluate effects of radon in homes. Seven major residential case-control radon studies have been conducted in North America to directly examine the association between prolonged radon progeny (radon) exposure and lung cancer. Six of the studies were performed in the United States including studies in New Jersey, Missouri (two studies), Iowa, and the combined states study (Connecticut, Utah, and southern Idaho). The seventh study was performed in Winnipeg, Manitoba, Canada. The residential case-control studies performed in the United States were previously reviewed elsewhere (Field, 2001). The goal of this review is to provide additional details regarding the methodologies and findings for the individual studies. Radon concentration units presented in this review adhere to the types (pCi/L or Bq/m3) presented in the

  9. Contribution of radon and radon daughters to respiratory cancer.

    PubMed Central

    Harley, N; Samet, J M; Cross, F T; Hess, T; Muller, J; Thomas, D

    1986-01-01

    This article reviews studies on the contribution of radon and radon daughters to respiratory cancer and proposes recommendations for further research, particularly a national radon survey. The steady-state outdoor radon concentration averages 200 pCi/m3, and indoor levels are about 4 times higher. The primary source of radon in homes is the underlying soil; entry depends on multiple variables and reduced ventilation for energy conservation increases indoor radon levels. Occupational exposures are expressed in units of radon daughter potential energy concentration or working level (WL). Cumulative exposure is the product of the working level and the time exposed. The unit for cumulative exposure is the working level month (WLM). The occupational standard for radon exposure is 4 WLM/year, and 2 WLM/year has been suggested as a guideline for remedial action in homes. Epidemiologic studies show that miners with cumulative radon daughter exposures somewhat below 100 WLM have excess lung cancer mortality. Some 3% to 8% of miners studied have developed lung cancer attributable to radon daughters. All of the underground mining studies show an increased risk of lung cancer with radon daughter exposure. All cell types of lung cancer increased with radon exposure. If radon and smoking act in a multiplicative manner, then the risk for smokers could be 10 times that for nonsmokers. The potential risk of lung cancer appears to be between 1 and 2 per 10,000/WLM, which yields a significant number of lung cancers as some 220 million persons in the United States are exposed on average to 10 to 20 WLM/lifetime. PMID:3830103

  10. Estimate of the annual per capita surplus dose due to the elevated indoor exposure to 222Rn progeny caused by the use of slag and spoil of uranium rich coal for building purposes in Ajka Town, Hungary.

    PubMed

    Papp, Z

    1998-03-01

    Ajka is a mining and industrial town in Hungary. Brown coal rich in uranium (300 to 900 Bq kg(-1)) has been mined by the town since 1865. Slag and spoil of the coal were frequently used in the town for building purposes before 1960. Screening measurements of 222Rn progeny in indoor air were performed in 86 Ajka buildings. Elevated 222Rn progeny levels were found in houses that used the above by-products as building materials or foundations. Annual per capita surplus effective doses due to the exposure to elevated 222Rn progeny levels were estimated from the results of the screening measurements. The possibility of estimating the mean of the annual averages of 222Rn or 222Rn progeny concentration for a group of houses from the results of screening measurements is discussed in detail. The estimated annual surplus dose is 0.64 mSv for the population of the whole town and 1.86 mSv for the 7,000 occupants of family houses built before 1960. PMID:9482606

  11. Radon and lung cancer.

    PubMed

    Sethi, Tarsheen K; El-Ghamry, Moataz N; Kloecker, Goetz H

    2012-03-01

    Lung cancer is the leading cause of cancer-related deaths worldwide. Radon exposure is the second leading cause of lung cancer, following tobacco smoke. Radon is not only an independent risk factor; it also increases the risk of lung cancer in smokers. Numerous cohort, case-control, and experimental studies have established the carcinogenic potential of radon. The possibility of radon having a causative effect on other cancers has been explored but not yet proven. One of the postulated mechanisms of carcinogenesis is DNA damage by alpha particles mediated by the production of reactive oxygen species. The latter are also thought to constitute one of the common mechanisms underlying the synergistic effect of radon and tobacco smoke. With an estimated 21,000 lung cancer deaths attributable to radon in the United States annually, the need for radon mitigation is well acknowledged. The Environmental Protection Agency (EPA) has established an indoor limit of 4 picocuries (pCi)/L, and various methods are available for indoor radon reduction when testing shows higher levels. Radon mitigation should accompany smoking cessation measures in lung cancer prevention efforts. PMID:22402423

  12. Radon programmes and health marketing.

    PubMed

    Fojtikova, Ivana; Rovenska, Katerina

    2011-05-01

    Being aware of negative health effects of radon exposure, many countries aim for the reduction of the radon exposure of their population. The Czech radon programme was commenced >20 y ago. Since then experts have gathered a lot of knowledge, necessary legislation has been enacted, tens of thousands of inhabitants have been offered free measurement and subsidy for the mitigation. Despite the effort, the effectiveness of the radon programme seems to be poor. Newly built houses still exhibit elevated radon concentrations and the number of houses mitigated is very low. Is it possible to enhance the effectivity of radon programme while keeping it on a voluntary basis? One possible way is to employ health marketing that draws together traditional marketing theories and science-based strategies to prevention. The potential of using marketing principles in communication and delivery of radon information will be discussed. PMID:21498864

  13. Gene mutation discovery research of non-smoking lung cancer patients due to indoor radon exposure.

    PubMed

    Choi, Jung Ran; Park, Seong Yong; Noh, O Kyu; Koh, Young Wha; Kang, Dae Ryong

    2016-01-01

    Although the incidence and mortality for most cancers such as lung and colon are decreasing in several countries, they are increasing in several developed countries because of an unhealthy western lifestyles including smoking, physical inactivity and consumption of calorie-dense food. The incidences for lung and colon cancers in a few of these countries have already exceeded those in the United States and other western countries. Among them, lung cancer is the main cause of cancer death in worldwide. The cumulative survival rate at five years differs between 13 and 21 % in several countries. Although the most important risk factors are smoking for lung cancer, however, the increased incidence of lung cancer in never smokers(LCINS) is necessary to improve knowledge concerning other risk factors. Environmental factors and genetic susceptibility are also thought to contribute to lung cancer risk. Patients with lung adenocarcinoma who have never smoking frequently contain mutation within tyrosine kinase domain of the epidermal growth factor receptor(EGFR) gene. Also, K-ras mutations are more common in individuals with a history of smoking use and are related with resistance to EFGR-tyrosine kinase inhibitors. Recently, radon(Rn), natural and noble gas, has been recognized as second common reason of lung cancer. In this review, we aim to know whether residential radon is associated with an increased risk for developing lung cancer and regulated by several genetic polymorphisms. PMID:26985396

  14. Indoor radon and lung cancer in the radium dial workers

    SciTech Connect

    Neuberger, J.S.; Rundo, J.

    1996-12-31

    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.

  15. Radon: Counseling patients about risk

    SciTech Connect

    Birrer, R.B. )

    1990-09-01

    Exposure to radon and its decay products has increased as the United States has changed from an outdoor society to a largely indoor society. Radon, which is found primarily in the soil, enters houses and buildings through cracks, holes and pipes in foundation walls and floors. Although radon is suspected of being a significant cause of lung cancer, comparisons with other risk factors cannot yet be made. Radon levels in the home can be measured with commercially available kits. Guidelines for reducing the amount of radon in a home are provided by the U.S. Environmental Protection Agency.18 references.

  16. Radon: counseling patients about risk.

    PubMed

    Birrer, R B

    1990-09-01

    Exposure to radon and its decay products has increased as the United States has changed from an outdoor society to a largely indoor society. Radon, which is found primarily in the soil, enters houses and buildings through cracks, holes and pipes in foundation walls and floors. Although radon is suspected of being a significant cause of lung cancer, comparisons with other risk factors cannot yet be made. Radon levels in the home can be measured with commercially available kits. Guidelines for reducing the amount of radon in a home are provided by the U.S. Environmental Protection Agency. PMID:2203238

  17. The role of the implementation of policies for the prevention of exposure to Radon in Brazil-a strategy for controlling the risk of developing lung cancer.

    PubMed

    Lino, Aline da Rocha; Abrahão, Carina Meira; Amarante, Marcus Paulo Fernandes; de Sousa Cruz, Marcelo Rocha

    2015-01-01

    Lung cancer is the leading cause of cancer death in the United States and other industrialised countries. The most important risk factor is active smoking. However, given the increased incidence of lung cancer in non-smokers, it is necessary to improve knowledge regarding other risk factors. Radon (Rn) is a noble gas and is the most important natural source of human exposure to ionizing radiation. Exposure to high levels of this radioactive gas is related to an increased risk of developing lung cancer. The objective of this work is to highlight the importance of measuring indoor concentration of this gas and identify which steps should be taken for achieving radiological protection. A survey was conducted on the websites of the National Health Surveillance Agency (ANVISA), LAMIN (Mineral Analysis Laboratory), CPRM (Geological Survey of Brazil), Ministry of Health and PubMed. Using the words 'radon', 'lung', 'cancer', and PubMed®, 1,371 results were obtained; when using the words 'radon', 'lung', 'cancer', and with 'Brazil' or 'Brazilians', only six results were obtained. We emphasise that lung cancer is a major public health problem and the exposure to Rn indoors should be considered as a risk factor for lung cancer in non-smokers. Buildings or houses with high concentrations of Rn should be identified. However, currently in Brazil-a country with great potential for mineral extraction-there are no specific regulated recommendations to control indoor exposure to Rn. PMID:26435745

  18. Estimated risk of lung cancer from exposure to radon decay products in U.S. homes: A brief review

    NASA Astrophysics Data System (ADS)

    Nero, Anthony V.

    Recent analyses now permit direct estimation of the risks of lung cancer from radon decay products in U.S. homes. Analysis of data from indoor monitoring in single-family homes yields a tentative frequency distribution of annual-average 222Rn concentrations with an arithmetic mean of 55 Bq m -3 and approximately 2% of homes having 300 Bq m -3 or more. Application of the results of occupational epidemiological studies to indoor exposures, either directly or using recent advances in lung dosimetry, suggests that the average indoor concentration entails a lifetime risk of lung cancer of about 0.4%, contributing about 10% of the total risk of lung cancer. The risk to individuals occupying the homes with 300 Bq m -3 or more for their lifetimes is estimated to exceed 2%, with risks from the homes with thousands of Bq m -3 correspondingly higher, even exceeding the total risk of premature death due to cigarette smoking. Such average and high-level risks greatly exceed ordinarily-considered environmental risks, forcing development of a new perspective on environmental exposures.

  19. Radiological risk of building materials using homemade airtight radon chamber

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    Soil based building materials known to contain various amounts of natural radionuclide mainly 238U and 232Th series and 40K. 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 222Radon and its progenies which arise from the decay of 226Ra. 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.

  20. Radiological risk of building materials using homemade airtight radon chamber

    SciTech Connect

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

    2014-02-12

    Soil based building materials known to contain various amounts of natural radionuclide mainly {sup 238}U and {sup 232}Th series and {sup 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 {sup 222}Radon and its progenies which arise from the decay of {sup 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{sup −3}, 192 Bq m{sup −3}, 176 Bq m{sup −3} and 28 Bq m{sup −3}, respectively. The result indicates that the radon concentration in the studied building materials have more than 100 Bq m{sup −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{sup −1}, 4.85 mSv y{sup −1}, 4.44 mSv y{sup −1} and 0.72 mSv y{sup −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{sup −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.

  1. Radon concentrations in residential housing in Hiroshima and Nagasaki

    SciTech Connect

    Yonehara, Hidenori; Aoyama, Takashi; Radford, E.P.

    1995-05-01

    A measurement of indoor radon ({sup 222}Rn) concentrations in Hiroshima and Nagasaki was carried out to assess the variability of exposure expected among atomic bomb survivors. Two hundred dwellings, mostly belonging to members of the fixed cohort of atomic bomb survivors under study by the Radiation Effects Research Foundations, were selected for this measurement. The geometric mean values of the radon concentrations for 100 dwellings in Hiroshima and 99 dwellings in Nagasaki measured by Track-Etcho Type SF detectors were 56.8 Bq m{sup {minus}3} and 28.5 Bq m{sup {minus}3}, respectively. No statistically significant difference was observed between lung cancer mortalities in the low-dose range in the two cities. However, apparent values of the mortality rate for low dose range in Hiroshima are consistently greater than those in Nagasaki. The exposure to radon and its progeny and the atomic bomb radiation effect might have some cooperative effects on the lung cancer incidence.

  2. Radon and smoking status

    SciTech Connect

    Roscoe, R.J.; Steenland, K. )

    1989-12-01

    The authors of two letters to the editor regarding an article entitled, Lung cancer mortality among non-smoking uranium miners exposed to radon daughters, disagree with the risk analysis regarding nonsmokers and the conclusions drawn by the original authors. In a reply letter, the authors comment on each point raised in the letters, and reaffirm their original conclusion that the common exposure for all miners was radon daughters, which is the most likely explanation for the high observed lung cancer risk.

  3. Radon testing behavior in a sample of individuals with high home radon screening measurements

    SciTech Connect

    Field, R.W.; Kross, B.C.; Vust, L.J. )

    1993-08-01

    Although radon exposure has been identified as the second leading cause of lung cancer, fewer than 6% of US homeowners test their homes for radon. This report examines participants' follow-up radon testing behavior subsequent to receiving an initial screening radon level greater than 20 pCi/L. Sixty-two participants in the Iowa State-Wide Rural Radon Screening Survey who had radon screening measurements over 20 pCi/L were questioned by phone survey 3 months after receipt of their radon screening result to assess: whether participants were aware of radon's health risk; if participants recalled the radon screening results; how participants perceived the relative health risk of radon and whether participants planned follow-up radon testing. Only 19% of the respondents specifically identified lung cancer as the possible adverse health outcome of high radon exposure, and the majority of participants underestimated the health risks high radon levels pose when compared to cigarettes and x-rays. In addition, less than one third (29%) of the participants actually remembered their radon screening level within 10 pCi/L 3 months after receiving their screening results. Only 53% of the individuals correctly interpreted their screening radon level as being in the high range, and only 39% of the participants planned follow-up radon measurements. Receipt of radon screening test results indicating high radon levels was not an adequate motivational factor in itself to stimulate further radon assessment or mitigation. The findings suggest that free radon screening will not result in a dramatic increase in subsequent homeowner initiated remediation or further recommended radon testing. 13 refs., 1 fig., 5 tabs.

  4. High-LET alpha-emitters: Radon, lung cancer and smoking

    SciTech Connect

    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.

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

    PubMed

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

    2013-12-01

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

  6. Experimental setup for radon exposure and first diffusion studies using gamma spectroscopy

    NASA Astrophysics Data System (ADS)

    Maier, Andreas; van Beek, Patrick; Hellmund, Johannes; Durante, Marco; Schardt, Dieter; Kraft, Gerhard; Fournier, Claudia

    2015-11-01

    In order to measure the uptake and diffusion of 222Rn in biological material, an exposure chamber was constructed where cell cultures, biological tissues and mice can be exposed to 222Rn-activities similar to therapy conditions. After exposure, the material is transferred to a gamma spectrometer and the decay of 214Pb and 214Bi is analyzed. From the time kinetics of these decays the total amount of the initial 222Rn concentration can be calculated. In this paper the design and construction as well as first test measurements are reported.

  7. Measurements of radon concentrations in the lunar atmosphere

    NASA Technical Reports Server (NTRS)

    Brodzinski, R. L.; Jackson, P. O.; Langford, J. C.

    1977-01-01

    The radon concentrations in the lunar atmosphere were determined by measuring the Po-210 progeny activity in artifacts returned from the moon. Experiments performed on a section of the polished aluminum strut from Surveyor 3 and data obtained from the Apollo 16 Cosmic Ray Detector Experiment Teflon thermal shield are compared with other values of the lunar radon concentration obtained at different times and different locations and by various techniques. Possible sources and release mechanisms compatible with all of the data are discussed. An experimental procedure to determine the relative retention coefficients of various types of material for radon progeny in a simulated lunar environment is described. The results of several experiments are given, and their effect on lunar radon progeny measurements is discussed. An analytical procedure is given for the analysis of a Teflon matrix for trace constituents.

  8. The effect on the radon diffusion coefficient of long-term exposure of waterproof membranes to various degradation agents.

    PubMed

    Navrátilová Rovenská, Katerina

    2014-07-01

    Waterproofing, usually made of bitumen or polymers with various additives, is used to protect buildings mainly against dampness, but also against radon transported from the soil beneath the building. The radon diffusion coefficient is a material property which is considered to be strongly influenced by the inner structure (chemical composition, crystallinity) of a measured sample. We have used this parameter together with measurements of mechanical properties (hardness, tensile strength, elongation at break, etc.) and FTIR spectroscopy has been used in order to describe the changes in material properties induced by long-term degradation. This paper summarizes the results of radon diffusion coefficient measurements of waterproof materials exposed to radon, soil bacteria, high temperature and combinations of these factors. We have discovered changes as high as 83 % have been discovered compared to virgin samples. PMID:24748486

  9. Radon exposure, cigarette smoking, and other mining experience in the beaverlodge uranium miners cohort

    SciTech Connect

    L'Abbe, K.A.; Howe, G.R.; Burch, J.D.; Miller, A.B.; Abbatt, J.; Band, P.; Choi, W.; Du, J.; Feather, J.; Gallagher, R. )

    1991-04-01

    A nested case-control study within the Beaverlodge Uranium Miners Cohort was undertaken to assess any possible contribution of confounding by smoking and other mining experience to the risk estimate derived from the original cohort study. Next of kin have been interviewed for 46 lung cancer cases and 95 controls enrolled in the Beaverlodge Uranium Miners Cohort Study who died between 1950 and 1980. Confounding by cigarette smoking and other mining experience appears unlikely to have contributed to the relative risk coefficient for exposure to Rn decay products derived in the parent study. Data for smoking and exposure to Rn decay products are consistent with a multiplicative model, although considerable caution must be applied to this interpretation.

  10. Mutagenicity of radon and radon daughters

    SciTech Connect

    Evans, H.H.

    1991-01-01

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

  11. Radon in outdoor air in Nevada.

    PubMed

    Price, J G; Rigby, J G; Christensen, L; Hess, R; LaPointe, D D; Ramelli, A R; Desilets, M; Hopper, R D; Kluesner, T; Marshall, S

    1994-04-01

    Measurements of radon at 50 sites with varying geology indicate that outdoor air in Nevada is comparable to that measured nationwide by Hopper et al. (1991). The statewide median of 15 Bq m-3 (0.4 pCi L-1) is essentially the same as the nationwide median. The range is considerable: from 2.6-52 Bq m-3 (0.07-1.40 pCi L-1). Variations in these measurements can generally be correlated with different concentrations of radon in soils and uranium and its progeny in rocks. Silica-rich igneous rocks (rhyolites and granites) appear to be the main sources of high levels of radon in outdoor air in Nevada. Concentrations of radon in outdoor air generally correlate with levels of radon in soil gas. Measurements taken from heights of 0.5, 1.0, and 2.0 m above the ground suggest that radon in outdoor air reflects the local geology throughout this range of heights. Towns for which > 20% of the homes have indoor-air radon concentrations > 48 Bq m-3 (4 pCi L-1) generally have relatively high soil-gas radon, relatively high outdoor-air radon, or both. PMID:8138410

  12. Problems with Estimating Annual Mean Indoor Radon Concentrations

    SciTech Connect

    Marusiakova, Miriam; Hulka, Jiri

    2010-09-30

    Radon and its progeny in dwellings is responsible for the majority of the total radiation dose among the general population. The indoor radon concentration varies considerably during the daytime, individual days, seasons and even years. It is affected by many factors such as ventilation, soil concentration, quality of house insulation and others.The annual mean value of the radon concentration in buildings is important in order to estimate the effective dose to inhabitants. However, it is not always possible to perform radon measurements over a period of one year. Thus estimates based on short-term continuous measurements are suggested.We analyse hourly radon measurements obtained from one uninhabited rural house in Teleci in the Czech Republic. We study the behaviour of the radon concentration with time and its relationship to meteorological variables such as outdoor temperature, wind speed or pressure. Further we discuss various estimates of the annual mean radon concentration and their properties.

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

    NASA Astrophysics Data System (ADS)

    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.

    2016-02-01

    We developed a highly sensitive, reliable and portable automatic system (H3) to monitor the radon concentration of the underground experimental halls of the Daya Bay Reactor Neutrino Experiment. H3 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/m3. 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.

  14. Design and Fabrication of A Modern Radon-Tight Chamber for Radon Concentration Measurements

    NASA Astrophysics Data System (ADS)

    Alhalemi, Ahmed; Jaafar, M. S.

    2010-07-01

    A modern radon-tight chamber (RTC) has been designed and fabricated to meet the request and requirements for both the Professional Continuous Radon Monitor (PCRM), and the RAD7 radon detector. The chamber is cubic shaped, made of Perspex with a volume of about 0.125 m3. The RTC was also equipped with a thermometer and a humidity sensor. A pair of gloves was attached on one side of the chamber's lateral opening for operating the PCRM. In addition, a fan was installed to circulate the air, and to distribute the radon gas to ensure homogeneity after the air inside the chamber is evacuated with nitrogen gas. At the end of the monitoring period, the results of the concentration of the radon emanated from a sample placed inside the chamber will then be available in any of three forms: numerical display on the control panel of the radon detector, printed report on the accessory printer, or transferred into a file on a personal computer via the RS-232 Serial port without disturbing the radon concentration inside the chamber. Computer software is provided by the manufacturer for this purpose. The result of analysis was presented in a one-way ANOVA that indicated that the radon concentration means are not difference for the three different positions of the PCRM (P > 0.05). Thus, this RTC can be used to measure the radon concentration and its progeny; in addition, it can be used for research and useful studies on radon exhalation from building materials.

  15. Radon in homes

    SciTech Connect

    Not Available

    1987-08-07

    Radon 222 and its radioactive decay products can enter buildings and, through inhalation, expose the inhabitants' pulmonary tissues to ionizing radiation. Studies of radon levels in the US indicate that variations of 100-fold or greater exist among private dwellings. In one region, 55% of homes had levels exceeding 4 pCi/L (0.15 Bq/L), which is the guidance level recommended by the US Environmental Protection Agency. Ventilation and tightness of construction are important determinants of radon levels. In some instances, fans or heat exchangers can reduce excessive concentrations, but in others more elaborate remedial measures may be required. Physicians may obtain information about radon through Environmental Protection Agency regional offices and state radiation control programs. The risk of radiogenic cancer is believed to increase with exposure to ionizing radiation. According to some estimates, concentrations of radon decay products in US homes could be responsible for several thousand cases of lung cancer per year. Studies of radon levels in representative buildings and guidelines are needed to ensure safe, effective, and cost-effective counter-measures. Architects, contractors, designers, building code administrators, health physicists, and biomedical investigators can help with solutions.

  16. Assessment of inhalation and ingestion doses from exposure to radon gas using passive and active detecting techniques

    SciTech Connect

    Ismail, A. H.; Jafaar, M. S.

    2011-07-01

    The aim of this study was to assess an environmental hazard of radon exhalation rate from the samples of soil and drinking water in selected locations in Iraqi Kurdistan, passive (CR-39NTDs) and active (RAD7) detecting techniques has been employed. Long and short term measurements of emitted radon concentrations were estimated for 124 houses. High and lower radon concentration in soil samples was in the cities of Hajyawa and Er. Tyrawa, respectively. Moreover, for drinking water, high and low radon concentration was in the cities of Similan and Kelak, respectively. A comparison between our results with that mentioned in international reports had been done. Average annual dose equivalent to the bronchial epithelium, stomach and whole body in the cities of Kelak and Similan are estimated, and it was varied from 0.04{+-}0.01 mSv to 0.547{+-}0.018 mSv, (2.832{+-}0.22)x10{sup -5} to (11.972{+-}2.09)x10{sup -5} mSv, and (0.056 {+-}0.01) x10{sup -5} to (0.239{+-}0.01)x10{sup -5} mSv, respectively. This indicated that the effects of dissolved radon on the bronchial epithelium are much than on the stomach and whole body. (authors)

  17. Air conditioning impact on the dynamics of radon and its daughters concentration.

    PubMed

    Kozak, Krzysztof; Grządziel, Dominik; Połednik, Bernard; Mazur, Jadwiga; Dudzińska, Marzenna R; Mroczek, Mariusz

    2014-12-01

    Radon and its decay products are harmful pollutants present in indoor air and are responsible for the majority of the effective dose due to ionising radiation that people are naturally exposed to. The paper presents the results of the series of measurements of radon and its progeny (in unattached and attached fractions) as well as indoor air parameters: temperature, relative humidity, number and mass concentrations of fine aerosol particles. The measurements were carried out in the auditorium (lecture hall), which is an indoor air quality laboratory, in controlled conditions during two periods of time: when air conditioning (AC) was switched off (unoccupied auditorium) and when it was switched on (auditorium in normal use). The significant influence of AC and of students' presence on the dynamics of radon and its progeny was confirmed. A decrease in the mean value of radon and its attached progeny was found when AC was working. The mean value of radon equilibrium factor F was also lower when AC was working (0.49) than when it was off (0.61). The linear correlations were found between attached radon progeny concentration and particle number and mass concentration only when the AC was switched off. This research is being conducted with the aim to study the variability of radon equilibrium factor F which is essential to determine the effective dose due to radon and its progeny inhalation. PMID:24375376

  18. Nonlinear dose-response relationship between radon exposure and the risk of lung cancer: evidence from a meta-analysis of published observational studies.

    PubMed

    Duan, Peng; Quan, Chao; Hu, Chunhui; Zhang, Jicai; Xie, Fei; Hu, Xiuxue; Yu, Zongtao; Gao, Bo; Liu, Zhixiang; Zheng, Hong; Liu, Changjiang; Wang, Chengmin; Yu, Tingting; Qi, Suqin; Fu, Wenjuan; Kourouma, Ansoumane; Yang, Kedi

    2015-07-01

    Although radon exposure (RE) has been confirmed to increase the risk of lung cancer (LC), questions remain about the shape of the dose-response relationship between RE and the risk of LC. We carried out a dose-response meta-analysis to investigate and quantify the potential dose-response association between residential and occupational exposure to radon and the risk of LC. All cohort and case-control studies published in English and Chinese on Embase, PubMed, and China National Knowledge Infrastructure (CNKI) digital databases through November 2013 were identified systematically. We extracted effect measures (relative risk, odds ratio, standardized mortality ratio, standardized incidence ratio, or standardized rate ratio) from individual studies to generate pooled results using meta-analysis approaches. We derived meta-analytic estimates using random-effects models taking into account the correlation between estimates. Restricted cubic splines and generalized least-squares regression methods were used to model a potential curvilinear relationship and to carry out a dose-response meta-analysis. Stratified analysis, sensitivity analysis, and assessment of bias were performed in our meta-analysis. Sixty publications fulfilling the inclusion criteria for this meta-analysis were finally included. Occupational RE was associated with LC [risk ratio 1.86, 95% confidence interval (CI)=1.67-2.09; I²=92.2%; 27 prospective studies], for pooled risk estimate of the: standardized mortality ratio [2.00 (95% CI=1.82-2.32)]; standardized incidence ratio [1.45 (95% CI=1.20-1.74)]; relative risk [2.10 (95% CI=1.64-2.69)]. In a subgroup analysis of uranium miners and residents exposed to occupational uranium, the summary risk was 2.23 (95% CI=1.86-2.68) and 1.23 (95% CI=1.05-1.44). The overall meta-analysis showed evidence of a nonlinear association between RE and the risk of LC (P(nonlinearity)<0.014); in addition, the point value of residential radon also improved the results

  19. Neutralization of thoron progeny in gases.

    PubMed

    Cheng, Y S; Yu, C C; Tung, C J; Hopke, P K

    1994-08-01

    This paper reports charge neutralization phenomena of 212Pb particles in nitrogen or oxygen atmospheres with trace amounts of other gases. Newly produced thoron or radon progeny are positively charged, stable molecular clusters that are subsequently neutralized by several mechanisms. The charged clusters have a smaller diffusion coefficient than neutral clusters of the same size due to the interaction of the charge with the surrounding gas molecules. In this study, we have found that the diffusion coefficients of 212Pb in O2, N2, NH3/O2, NH3/N2, and C6H12/N2 (IPs between 15.58 and 9.8 eV) ranged between 0.015 and 0.030 cm2 s-1. In the case of C6H12/O2, NO2/O2, NO/O2, and dimethylamine/O2 (ionization potential between 9.8 and 8.23 eV), the diffusion coefficients have increased to between 0.046 and 0.69 cm2 s-1. These results are consistent with previous results of 218Po, indicating that charged progeny are neutralized by electron transfer from a gas molecule with a lower ionization potential than lead oxide. We estimate the ionization potential of lead oxide to range between 9.8 and 10.2 eV. 212Pb was also neutralized by an electron scavenging mechanism in NO2/nitrogen. PMID:8026969

  20. Researching Radon.

    ERIC Educational Resources Information Center

    Lucidi, Louis; Mecca, Peter M.

    2001-01-01

    Introduces a project in which students examined the physics, chemistry, and geology of radon and used available technology to measure radon concentrations in their homes. Uses the inquiry process, analytical skills, communication skills, content knowledge, and production of authentic products for student assessment. (YDS)

  1. Estimate of the dose-increment due to outdoor exposure to gamma rays from uranium progeny deposited on the soil around a coal-fired power plant in Ajka Town, Hungary.

    PubMed

    Papp, Z; Dezsö, Z

    2003-06-01

    Brown coal unusually rich in uranium is burnt in a coal-fired power plant that lies inside the confines of a small industrial town named Ajka, Hungary, and has been operational since 1943. The 238U (226Ra) activity discharged to the atmosphere per unit electrical energy produced was about 330-400 GBq (GW y)(-1), which is 66-80 times more than that was estimated by UNSCEAR (1988) as a characteristic value for old type coal-fired power plants [5 GBq (GW y)(-1)]. The objective of this study was the experimentally established assessment of the artificial increment in the dose from external exposure to gamma rays of terrestrial radionuclides outdoors. Soil samples were collected in and near Ajka from 81 locations. The samples were investigated by Ge(Li) gamma spectrometry. Considerably elevated concentrations of uranium and its progeny have been measured in most of the samples that were collected near to the plant. Concentrations of 238U and 226Ra in the top (0-5 cm depth) layer of undisturbed soil at public areas inside town were 4.7 times higher, on average, than those in the uncontaminated deeper layers. Dose rate in air (air kerma) from external exposure to terrestrial gamma rays outdoors at a height of 1 m and effective doses were estimated from the measured activity concentrations using some relevant literature data. The estimated artificial increment in the dose rate in air was, on average, 32.8, 10.3, and 102.1 nGy h(-1) at public areas, vegetable gardens, and backyards, respectively. The mean artificial increment in the annual per caput effective dose from external exposure to terrestrial radionuclides outdoors is 21.8 microSv y(-1). The collective dose commitment per unit energy generated from outdoor exposure to the deposited uranium progeny is about 8.0-9.1 person Sv (GW y)(-1), which is 67-76 times more than that evaluated by UNSCEAR (1988) for a typical "old" coal-fired power plant [0.12 person Sv (GW y)(-1)]. Ajka is a suitable place for studying the

  2. Lack of evidence for an association between the frequency of mutants or translocations in circulating lymphocytes and exposure to radon gas in the home

    SciTech Connect

    Cole, J.; Green, M.H.L.; Bridges, B.A.

    1996-01-01

    Radon measurements in the living room and main bedroom of 41 houses in the town of Street, Somerset, England have been made. Exposure levels, weighted using the formula of the UK National Radiological Protection Board, of 19-484 Bq m{sup -3} (about half >100 Bq m{sup -3}) were found. Blood samples were obtained from a total of 66 occupants in these homes, and the frequency of genetic alterations in lymphocytes was estimated using two different end points. Gene mutations at the hypoxanthine guanine phosphoribosyl transferase locus were determined in T lymphocytes for 65 subjects using a clonal assay, and the frequency of the BCL-2 t(14;18) translocation, a chromosomal event associated with leukemia/lymphoma, was estimated in lymphocytes using a polymerase chain reaction-based technique for 64 subjects. In neither case was a significant correlation with radon levels in the home found, in contrast to our earlier observation with a smaller series. 52 refs., 5 figs., 2 tabs.

  3. Radon permeability and radon exhalation of building materials.

    PubMed

    Keller, G; Hoffmann, B; Feigenspan, T

    2001-05-14

    High radon concentrations indoors usually depend on the possibilities of radon penetration from the surrounding soil into the buildings. Radon concentrations in dwellings up to 100 kBq/m3 were found in some special regions (i.e. Schneeberg/Saxony, Umhausen/Tyrol), where the soil shows a high uranium content and additionally, a fast radon transport in the soil is possible. To reduce the radon exposure of the inhabitants in these 'radon prone areas' it is necessary to look for building and insulating materials with low radon permeability. We examined several building materials, like cements, concretes and bricks of different constitutions for their diffusion coefficients and their exhalation rates. The insulating materials, like foils and bitumen were tested also on their radon tightness. The measurements were performed with an online radon measuring device, using electrostatic deposition of 218Po ions onto a surface barrier detector and subsequent alpha spectroscopy. The mean diffusion lengths for the investigated building materials range from lower than 0.7 mm (i.e. for plastic foil), up to 1.1 m for gypsum. The diffusion length R was calculated from the diffusion coefficient D with R = square root(D/lambda). If the thickness of the material is more than 3 times the diffusion length, then it is called radon-tight. The mean 222Rn exhalation rates for the building materials varied between 0.05 and 0.4 mBq/m2s. The samples were investigated as stones, plates, blocks, foils, coatings, powders etc., no statement can be made about working at the construction site of a building. Also the fabrication and processing of the materials has to be considered, because the material characteristics may have changed. PMID:11379942

  4. Effects of Radon Inhalation on Some Biophysical Properties of Blood in Rats

    NASA Astrophysics Data System (ADS)

    Essa, M. F.; Shahin, Fayez M.; Ahmed, Ashour M.; Abdel-Salam, Omar

    2013-03-01

    The major source of human exposure to natural radiation arises from the inhalation of radon (222Rn) gas. Exposure to high concentrations of radon 222Rn and its daughters for long period leads to pathological effects like lung cancer, leukaemia, skin cancer and kidney diseases. The present study was performed on rats to investigate the effect of radon exposure on the absorption spectra of hemoglobin. Measurements have been performed in a radon chamber where rats were exposed to radon for 1, 5 or 7 weeks. The inhalation of radon resulted in decrease in intensity of the absorption bands characterizing the hemoglobin molecular structure with increased radon doses.

  5. Thoron ( 220Rn) progeny reduction by an air cleaner of the polarized media filter type

    NASA Astrophysics Data System (ADS)

    Bigu, J.

    1993-02-01

    The effect of an air cleaner on 220Rn progeny atmospheres has been studied in a Radon/Thoron Test Facility (RTTF) of the walk-in type. The air cleaner consists basically of a fan and a special filter material sandwiched between two metal screens, to which an electric field is applied. The filter is of the polarized media type and uses fibreglass as material. The fan and filter system are housed in a metal case. Air is drawn from the back of the case by means of the fan and forced through the "electrical" filter where removal of the 220Rn progeny occurs. Radon-220 progeny "depleted" air is discharged at the top of the device. Tests were conducted in 220Rn/ 220Rn progeny atmospheres when the air cleaner was operating, and when it was turned off. Very pronounced effects were observed during the operation of the device, namely: a dramatic decrease in the 220Rn progeny concentrations and the total aerosol concentration, as well as a large increase in the 220Rn progeny unattached fractions and the plate-out of these radionuclides on the walls of the RTTF. The air cleaner has potential in industrial applications, which should be explored.

  6. Radon potential, geologic formations, and lung cancer risk

    PubMed Central

    Hahn, Ellen J.; Gokun, Yevgeniya; Andrews, William M.; Overfield, Bethany L.; Robertson, Heather; Wiggins, Amanda; Rayens, Mary Kay

    2015-01-01

    Objective Exposure to radon is associated with approximately 10% of U.S. lung cancer cases. Geologic rock units have varying concentrations of uranium, producing fluctuating amounts of radon. This exploratory study examined the spatial and statistical associations between radon values and geological formations to illustrate potential population-level lung cancer risk from radon exposure. Method This was a secondary data analysis of observed radon values collected in 1987 from homes (N = 309) in Kentucky and geologic rock formation data from the Kentucky Geological Survey. Radon value locations were plotted on digital geologic maps using ArcGIS and linked to specific geologic map units. Each map unit represented a package of different types of rock (e.g., limestone and/or shale). Log-transformed radon values and geologic formation categories were compared using one-way analysis of variance. Results Observed radon levels varied significantly by geologic formation category. Of the 14 geologic formation categories in north central Kentucky, four were associated with median radon levels, ranging from 8.10 to 2.75 pCi/L. Conclusion Radon potential maps that account for geologic factors and observed radon values may be superior to using observed radon values only. Knowing radon-prone areas could help target population-based lung cancer prevention interventions given the inequities that exist related to radon. PMID:26844090

  7. Radon monitoring and hazard prediction in Ireland

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  8. Radon reduction

    SciTech Connect

    Hamilton, M.A. )

    1990-11-01

    During a radon gas screening program, elevated levels of radon gas were detected in homes on Mackinac Island, Mich. Six homes on foundations with crawl spaces were selected for a research project aimed at reducing radon gas concentrations, which ranged from 12.9 to 82.3 pCi/l. Using isolation and ventilation techniques, and variations thereof, radon concentrations were reduced to less than 1 pCi/l. This paper reports that these reductions were achieved using 3.5 mil cross laminated or 10 mil high density polyethylene plastic as a barrier without sealing to the foundation or support piers, solid and/or perforated plastic pipe and mechanical fans. Wind turbines were found to be ineffective at reducing concentrations to acceptable levels. Homeowners themselves installed all materials.

  9. Epidemiological analysis of the relationship between exposure to Rn progeny, smoking and bronchogenic carcinoma in the U-mining population of the Colorado Plateau--1960-1980

    SciTech Connect

    Saccomanno, G.; Yale, C.; Dixon, W.; Auerbach, O.; Huth, G.C.

    1986-05-01

    This study investigates the relationship between exposure to radioactive Rn decay products during U mining and milling operations, cigarette smoking and age, on the incidence and mortality rates of lung cancer among U workers of the Colorado Plateau during the 20-yr period from 1960-1980. A case control sample was taken from an extensive data base of 9,817 men accumulated by one author (Saccomanno). A preliminary hypothesis had been made that a possible synergistic or at least additive effect might exist when the risk factors of exposure to Rn decay products and smoking were simultaneously present. This study would seem to indicate that a synergistic effect is not present. In this work, a total of 489 cases, defined as men having a cytological diagnosis of moderate or worse atypical squamous-cell metaplasia, and a random sample of 992 ''non-cases'' were selected retrospectively from the dynamic cohort of workers. These data analyzed from three different perspectives indicate significant effects due to Rn-decay-product exposure in excess of the expected incidence due to age and smoking history. The data also indicate that Rn-decay-product accumulations of less than 300 working level months (WLM) is not carcinogenic in non-cigarette smokers.

  10. [The radon risk in Lombardy].

    PubMed

    Facchini, U; Sesana, L; Agostoni, G; Testa, V

    1997-10-01

    We investigated the geographical distribution of lung cancer mortality rates in some Italian regions, Lombardy and Emilia-Romagna in particular, where the investigation was mainly focused on the risk related to the presence of radon inside dwelling-houses. We referred to the death certificates provided by the Central Institute of Statistics (ISTAT) relative to the years 1980-1988 to calculate the relevant mortality rates. Mortality rates appear higher in some northern than in southern regions and in the islands and also (> a factor of 10) in the male than in the female population; the mortality rates in the male population exhibit a linear correlation with past cigarette smoking. The death rates in the male population (age range: 35-64 years) in northern Italy average 100 events/100,000 inhabitants, but several local health centers in Lombardy at the foot of the Alpine range, north of the Po River, have mortality rates over 50% higher than estimated rates. We considered radon exposure in Lombardy dwelling-houses. The Alps are rich in granite rocks, with 50-150 Bq/kg uranium concentrations, which produce the sediments, sands and gravels making the ground of the Lombardy plain. A recent survey of indoor radon exposure levels showed average values around 100 Bq/m3. The National Academy of Sciences (Washington, DC) has presented a formula to calculate the relative risk of lung cancer related to radon exposure during a lifetime. When this model was applied to excess events in Lombardy, acceptable agreement was found with the assumption that excess deaths are ascribable to higher radon exposure levels. We also compared Lombardy with Emilia-Romagna where the sediments and soil in the plain come from the Apennine range where calcareous rocks have low uranium content. Radon exposure levels in Emilia-Romagna were around 50 Bq/m3 and the radon risk factor in this region is therefore not particularly significant. PMID:9465246

  11. Geogenic and anthropogenic impacts on indoor radon in the Techa River region.

    PubMed

    Yarmoshenko, I; Malinovsky, G; Vasilyev, A; Onischenko, A; Seleznev, A

    2016-11-15

    Indoor radon concentration was studied in the 14 settlements located near the Techa River, which was contaminated by radioactive wastes in 1950-s. Results of the radon survey were used for analysis of the relationship between the indoor radon and main geologic factors (Pre-Jurassic formations, Quaternary sediments and faults), local geogenic radon potential and anthropogenic factors. Main influencing factors explain 58% of the standard deviation of indoor radon concentration. Association of the air exchange influence over radon concentration with underlying geological media was related to different contributions of geogenic advective and diffusive radon entries. The properties of geological formation to transfer radon gas in interaction with the house can be considered within the radon geogenic potential concept. The study of the radon exposure of the Techa River population can be used to estimate the contribution of natural radon to the overall radiation exposure of the local population during the period of radioactive waste discharges. PMID:27474991

  12. [Radon and internal contamination].

    PubMed

    Stanga, A; Trenta, F

    2008-01-01

    Because of hits everywhere presence in air and in water needful mediums for life, radon is a omnipresent risk for every person. Therefore, in relation to those vital functions, lungs and gastro-enteric tract represent the principal target organs of this noble radioactive gas (and mainly of hits radioactive daughters). International organisms evaluated the effective dose coefficients for both target organs, so it is possible e quantitative assessment of the exposure risk related to this noble gas. PMID:19288807

  13. Radon Measurements in Schools: An Interim Report.

    ERIC Educational Resources Information Center

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

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

  14. Concentration en radon dans une maison du Calvados

    NASA Astrophysics Data System (ADS)

    Leleyter, Lydia; Riffault, Benoit; Mazenc, Bernard

    2010-03-01

    Recent studies indicate a link between the risk of lung cancer and residential radon exposure. However, in France, awareness of this problem was made relatively late. Accordingly this study examines the radon concentration in a private home in Calvados. Findings show that the presence of a fireplace in a house can accelerate radon convective transfer, and that simple adjustments to interior and exterior accommodation can significantly reduce radon concentrations in the home.

  15. Exposure to non-nutritive sweeteners during pregnancy and lactation: Impact in programming of metabolic diseases in the progeny later in life.

    PubMed

    Araújo, João Ricardo; Martel, Fátima; Keating, Elisa

    2014-11-01

    The nutritional environment during embryonic, fetal and neonatal development plays a crucial role in the offspring's risk of developing diseases later in life. Although non-nutritive sweeteners (NNS) provide sweet taste without contributing to energy intake, animal studies showed that long-term consumption of NSS, particularly aspartame, starting during the perigestational period may predispose the offspring to develop obesity and metabolic syndrome later in life. In this paper, we review the impact of NNS exposure during the perigestational period on the long-term disease risk of the offspring, with a particular focus on metabolic diseases. Some mechanisms underlying NNS adverse metabolic effects have been proposed, such as an increase in intestinal glucose absorption, alterations in intestinal microbiota, induction of oxidative stress and a dysregulation of appetite and reward responses. The data reviewed herein suggest that NNS consumption by pregnant and lactating women should be looked with particular caution and requires further research. PMID:25263228

  16. Activation of oncogenes by radon progeny and x-rays

    SciTech Connect

    Ling, C.C.

    1990-01-01

    The overall goal of this proposal is to study the carcinogenic effect of both high and low LET radiation at the molecular level, utilizing techniques developed in molecular biology, cancer cell biology and radiation biology. The underlying assumption is that malignant transformation of normal cells is a multistep process requiring two or more molecular events in the genomic DNA. We hypothesize that radiation may induce such events in one or more steps of the multistep process. We will use in vitro models of transformation that reproduce the stepwise progression of normal cells toward the transformed phenotype and ask whether radiation can provide the necessary activating function at discrete steps along this path. Our strategy involves transfecting into normal primary cells a variety of cloned oncogenes that are known to supply only some of the functions necessary for full transformation. These partially transformed'' cells will be the targets for irradiation by x-rays and alpha particles. The results will provide the basis for assessing the ability of ionizing radiation to activate oncogenic functions that complement'' the oncogene already present in the transfected cells and produce the fully transformed phenotype. Progress is described. 121 refs.

  17. AGE-DEPENDENT LUNG DOSIMETRY OF RADON PROGENY

    EPA Science Inventory

    Two morphometric models differing in the tracheobronchial region, were compared in the present paper: Model 1 is based on the adult morphology of Weibel, assuming that all bronchial airways grow in equal proportion; while Model 2 adopts the adult structure proposed by Yeh and Sch...

  18. Age-dependent lung dosimetry of radon progeny

    SciTech Connect

    Hofmann, W.; Martonen, T.B.; Menache, M.G.

    1988-02-01

    Two morphometric models differing in the tracheobronchial region, were compared in the present paper: Model 1 is based on the adult morphology of Weibel, assuming that all bronchial airways grow in equal proportion; while Model 2 adopts the adult structure proposed by Yeh and Schum, using measured airway dimensions in the right upper lobe as a function of age. Tidal volume and respiratory frequency also vary with age: while the breathing frequency decreases with rising age, tidal volume increases. Radiation doses in each bronchial airway generation were computed for the deep lying basal cells as well as for the more uniformly distributed serous (SMGS) cells, which are currently assumed to be the progenitor cells for bronchial carcinomas. Radiation doses to both target cells were significantly higher in the newborn than in the adult, for all simulated breathing patterns, showing the highest relative increase in upper bronchial airways. Comparing both tracheobronchial growth models, Model 1 predicts higher doses at early ages, but produced lower doses in the adult lung.

  19. Elimination of radon from the body

    SciTech Connect

    Harley, J.H.; Jetter, E.S.; Nelson, N.

    1994-01-01

    A series of experiments were run on the retention of inhaled radon. The radon absorbed by the body is present in a multiphase system, showing five distinct elimination coefficients. After high-level radon exposure for a normal working day, an appreciable breath radon output is found 72 h after removal from exposure. This is a practical consideration in breath radon sampling, and it must be realized that the breath measurement may indicate a higher body radium content than that actually present. Another valuable result is that the radon retention figures allow us to reconcile the results of breath radon analyses and total body radium analyses on unexposed persons. The results of our breath measurements averaged 6[times]10[sup [minus]9] g on ten unexposed individuals. It is apparent that the breath radon measurement is not capable of measuring normal body radium, due both to the small quantity present, and to the interference of radon absorbed by the body from the normal environment. 2 refs., 3 figs., 4 tab.

  20. The use of radon as tracer in environmental sciences

    NASA Astrophysics Data System (ADS)

    Quindos Poncela, Luis; Sainz Fernandez, Carlos; Fuente Merino, Ismael; Gutierrez Villanueva, Jose; Gonzalez Diez, Alberto

    2013-08-01

    Radon can be used as a naturally occurring tracer for environmental processes. By means of grab-sampling or continuous monitoring of radon concentration, it is possible to assess several types of dynamic phenomena in air and water. We present a review of the use of radon and its progeny at the University of Cantabria. Radon can be an atmospheric dynamics indicator related with air mass interchange near land-sea discontinuities as well as for the study of vertical variations of air parameters (average values of different types of stability: 131-580 Bq m-3). Concerning indoor gas, we present some results obtained at Altamira Cave (Spain): from 222 to 6549 Bq m-3 (Hall) and from 999 to 6697 Bq m-3 (Paintings Room). Finally, variations of radon concentration in soil (0.3 to 9.1 kBq m-3) and underground water (values up to 500 Bq l-1) provide relevant information about different geophysical phenomena.

  1. Federal programs on indoor radon

    SciTech Connect

    1988-04-01

    The CIRRPC Science Panel Report No. 4, ``Radon Protection and Health Effects,`` identified five major issues and made specific recommendations in regard to each issue. These issues and recommendations involved: Needs for research on the effects of radon exposure; the need for guidance on remedial actions; the need for methods to predict high risk locations; the need for a national survey of population exposures; and the need for adequate remedial and mitigation measures. Reviews of each of these, in terms of the extent that the needs are being addressed by the various Federal agencies, follow. Each review is preceded by excerpts from Report No. 4 on the issue and related recommendation.

  2. Radon detection

    DOEpatents

    MacArthur, D.W.; Allander, K.S.; Bounds, J.A.

    1994-01-25

    A detector for atmospheric radon using a long range alpha detector as its sensing element is described. An electrostatic filter removes ions from ambient air, while allowing radon atoms to pass into a decay cavity. Here, radon atoms are allowed to decay, creating air ions. These air ions are drawn by a fan through a second electrostatic filter which can be activated or deactivated, and into the long range alpha detector. With the second electrostatic filter activated, no air ions are allowed to pass, and the signal output from the long range alpha detector consists of only the electronic background. With the second electrostatic filter deactivated, air ions and cosmic rays will be detected. The cosmic ray contribution can be minimized by shielding. 3 figures.

  3. Radon detection

    DOEpatents

    MacArthur, Duncan W.; Allander, Krag S.; Bounds, John A.

    1994-01-01

    A detector for atmospheric radon using a long range alpha detector as its sensing element. An electrostatic filter removes ions from ambient air, while allowing radon atoms to pass into a decay cavity. Here, radon atoms are allowed to decay, creating air ions. These air ions are drawn by a fan through a second electrostatic filter which can be activated or deactivated, and into the long range alpha detector. With the second electrostatic filter activated, no air ions are allowed to pass, and the signal output from the long range alpha detector consists of only the electronic background. With the second electrostatic filter deactivated, air ions and cosmic rays will be detected. The cosmic ray contribution can be minimized by shielding.

  4. Radon exhalation rates from some soil samples of Kharar, Punjab

    SciTech Connect

    Mehta, Vimal; Singh, Tejinder Pal; Chauhan, R. P.; Mudahar, G. S.

    2015-08-28

    Radon and its progeny are major contributors in the radiation dose received by general population of the world. Because radon is a noble gas, a large portion of it is free to migrate away from radium. The primary sources of radon in the houses are soils and rocks source emanations, emanation from building materials, and entry of radon into a structure from outdoor air. Keeping this in mind the study of radon exhalation rate from some soil samples of the Kharar, Punjab has been carried out using Can Technique. The equilibrium radon concentration in various soil samples of Kharar area of district Mohali varied from 12.7 Bqm{sup −3} to 82.9 Bqm{sup −3} with an average of 37.5 ± 27.0 Bqm{sup −3}. The radon mass exhalation rates from the soil samples varied from 0.45 to 2.9 mBq/kg/h with an average of 1.4 ± 0.9 mBq/kg/h and radon surface exhalation rates varied from 10.4 to 67.2 mBq/m{sup 2}/h with an average of 30.6 ± 21.8 mBq/m{sup 2}/h. The radon mass and surface exhalation rates of the soil samples of Kharar, Punjab were lower than that of the world wide average.

  5. Integrated measurements of short-lived 222Rn progeny by rotating filters.

    PubMed

    Pressyanov, D S; Guelev, M G; Pentchev, O J

    1993-05-01

    The dependence of the risk from inhalation of radon progeny on their disequilibrium suggests that the measurements of the time-integrated concentrations of each of the short-lived radon progeny are necessary for complete risk estimations. This paper presents a method that, in principle, allows the determination of the integrated specific volume activities in air of each of the radionuclides 218Po, 214Pb, 214Bi, 212Pb, and 212Bi. The method employs thermoluminescence detectors positioned around uniformly rotating filters. Two prototypes that are suitable for practical applications are described and mathematical expressions for data processing are given. Experiments with these "rotating filter dosimeters" were conducted in atmospheres radiologically dominated by 222Rn progeny. The comparison between the results obtained by the proposed method and those given by simultaneously conducted series of instantaneous grab-sampling measurements support the conclusion that the method works for 222Rn progeny. The method can be experimentally extended for 220Rn progeny as well as for unattached fractions. PMID:8387983

  6. A comparative study of the indoor radon level with the radon exhalation rate from soil in Alexandria city.

    PubMed

    Abd El-Zaher, Mohamed

    2013-05-01

    The assessment of the radiological risk related to the inhalation of radon and radon its progeny is based mainly on the integrated measurement of radon in both indoor and outdoor environments. The exhalation of radon from the earth's crust and building materials forms the main source of radon in the indoor environment. This study has been undertaken for the purpose of health risk assessment. In this comparative study, the indoor radon level, radium content, radon exhalation rate and concentration of soil radon are measured using the Can Technique. Soil samples were collected simultaneously from different geological formations of the same area for laboratory measurement of the radon exhalation rate. The radon exhalation rate was measured in the laboratory using LR-115 type II plastic track detectors. The indoor radon concentrations in this study area were found to vary from 44±9 to 132±31 Bq m(-3) with an average of 72±29 Bq m(-3). The seasonal variations of the indoor radon reveal the maximum values in the winter and in summer in different dwellings of Alexandria city. The annual effective dose varies from 0.75 to 2.2 mSv with an average value of 1.34 mSv. The radon exhalation rate was found to vary in the ranges 8.31-233.70×10(-3) Bq kg(-1) h(-1), 0.48-15.37 Bq m(-2) h(-1) with an average 47.97×10(-3) Bq kg(-1) h(-1), (3.14 Bq m(-2) h(-1)). The radium content in soil varies from 3.14 to 39.60 Bq kg(-1) with an average of 11.55 Bq kg(-1). The significance of this study is discussed in details from the point of view of radiation protection. PMID:23070484

  7. The role of the implementation of policies for the prevention of exposure to Radon in Brazil—a strategy for controlling the risk of developing lung cancer

    PubMed Central

    Lino, Aline da Rocha; Abrahão, Carina Meira; Amarante, Marcus Paulo Fernandes; de Sousa Cruz, Marcelo Rocha

    2015-01-01

    Lung cancer is the leading cause of cancer death in the United States and other industrialised countries. The most important risk factor is active smoking. However, given the increased incidence of lung cancer in non-smokers, it is necessary to improve knowledge regarding other risk factors. Radon (Rn) is a noble gas and is the most important natural source of human exposure to ionizing radiation. Exposure to high levels of this radioactive gas is related to an increased risk of developing lung cancer. The objective of this work is to highlight the importance of measuring indoor concentration of this gas and identify which steps should be taken for achieving radiological protection. A survey was conducted on the websites of the National Health Surveillance Agency (ANVISA), LAMIN (Mineral Analysis Laboratory), CPRM (Geological Survey of Brazil), Ministry of Health and PubMed. Using the words ‘radon’, ‘lung’, ‘cancer’, and PubMed®, 1,371 results were obtained; when using the words ‘radon’, ‘lung’, ‘cancer’, and with ‘Brazil’ or ‘Brazilians’, only six results were obtained. We emphasise that lung cancer is a major public health problem and the exposure to Rn indoors should be considered as a risk factor for lung cancer in non-smokers. Buildings or houses with high concentrations of Rn should be identified. However, currently in Brazil—a country with great potential for mineral extraction—there are no specific regulated recommendations to control indoor exposure to Rn. PMID:26435745

  8. Optical image sensors and their application in radon detection

    NASA Astrophysics Data System (ADS)

    Griffin, Ryan H.; Tarr, N. Garry

    2013-10-01

    This paper reports on the development and testing of a direct reading radon detector assembled from consumer electronics at very low cost. An electrostatic concentrator constructed by metalizing a plastic funnel is used to focus charged radon progeny onto the exposed surface of an optical image sensor from a webcam. Alpha particles emitted by the collected progeny strike the image sensor, generating sufficient charge to completely saturate one or more pixels The high voltage required by the concentrator is generated using a simple Cockcroft-Walton charge pump. A personal computer is used to analyze the webcam data. Alpha particles were counted at a rate of 5.2 counts/ hour at a radon concentration of 159 Bq/ m3.

  9. On the exhalation rate of radon by man

    SciTech Connect

    Rundo, J.; Markun, F.; Plondke, N.J.

    1990-01-01

    This paper describes some aspects of the exhalation rate of radon by man which may be relevant to its internal dosimetry and, therefore, to possible radiobiological consequences. Prolonged exposure of a person to radon results in a reservoir or radon dissolved in body fat and fluids. If the person then moves to an environment with a lower radon concentration, there is a net exhalation of radon and the initial exhalation rate depends on the radon concentration in the first environment. This is demonstrated for seven persons whose houses contained radon at concentrations varying from 10 Bq m{sup {minus}3} to almost 1000 Bq m{sup {minus}3}. About one hour after leaving the house, the subjects' average exhalation rate of radon, expressed as the equivalent volume of house air per unit time, was 236 mL min{sup {minus}1}. 4 refs., 4 figs., 2 tabs.

  10. Radon 222

    Integrated Risk Information System (IRIS)

    Radon 222 ; CASRN 14859 - 67 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effec

  11. Mapping the geogenic radon potential of the eastern Canary Islands.

    NASA Astrophysics Data System (ADS)

    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

  12. (Mutagenicity of radon and radon daughters)

    SciTech Connect

    Not Available

    1990-01-01

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

  13. Development and management of a radon assessment strategy suitable for underground railway tunnelling projects.

    PubMed

    Purnell, C J; Frommer, G; Chan, K; Auch, A A

    2004-01-01

    The construction of underground tunnels through radon-bearing rock poses a radiation health risk to tunnelling workers from exposure to radon gas and its radioactive decay products. This paper presents the development and practical application of a radon assessment strategy suitable for the measurement of radon in tunnelling work environments in Hong Kong. The assessment strategy was successfully evaluated on a number of underground railway tunnelling projects over a 3 y period. Radon measurements were undertaken using a combination of portable radon measurement equipment and track etch detectors (TEDs) deployed throughout the tunnels. The radon gas monitoring results were used to confirm that ventilation rates were adequate or identified, at an early stage, when further action to reduce radon levels was required. Exposure dose estimates based on the TED results showed that the exposure of tunnel workers to radon did not exceed 3 mSv per annum for the duration of each project. PMID:15103065

  14. Influence of indoor air conditions on radon concentration in a detached house.

    PubMed

    Akbari, Keramatollah; Mahmoudi, Jafar; Ghanbari, Mahdi

    2013-02-01

    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%. PMID:23159846

  15. DNA damage-inducible genes as biomarkers for exposures to environmental agents.

    PubMed Central

    Johnson, N F; Carpenter, T R; Jaramillo, R J; Liberati, T A

    1997-01-01

    A biodosimetric approach to determine alpha-particle dose to the respiratory tract epithelium from known exposures to radon has been developed in the rat. Cytotoxicity assays have been used to obtain dose-conversion factors for cumulative exposures typical of those encountered by underground uranium miners. However, this approach is not sensitive enough to derive dose-conversion factors for indoor radon exposures. The expression of DNA damage-inducible genes is being investigated as a biomarker of exposure to radon progeny. Exposure of cultures of A549 cells to alpha particles resulted in an increase in the protein levels of the DNA damage-inducible genes, p53, Cip1, and Gadd45. These protein changes were associated with a transient arrest of cells passing through the cell cycle. This arrest was typified by an increase in the number of cells in the G1 and G2 phases and a decrease in the number of cells in the S phase. The effect of inhaled alpha particles (radon progeny) in rats was examined in the epithelial cells of the lateral well of the anterior nasal cavity. Exposures to radon progeny resulted in a significant increase in the number of cells in the G1 phase and a decrease in the number of cells in the S phase. These cell-cycle changes were concomitant with an increase in the number of cells containing DNA strand breaks. These results suggest a commonality between cell-cycle events in vitro and in vivo following exposure to ionizing radiation. In addition to ionizing radiation, A549 cells were exposed to 4-nitroquinoline-1-oxide, methyl methanesulphonate, crocidolite asbestos, and glass microfiber. These studies showed that physical and chemical agents induce different expression patterns of p53, Cip1, and Gadd153 proteins and they could be used to discriminate between toxic and nontoxic materials such as asbestos and glass microfiber. The measurement of gene expression in A549 cells may provide a means to identify a broad spectrum of physical and chemical

  16. Measurements of radon, thoron, isotopic uranium and thorium to determine occupational and environmental exposure and risk at Fernald Feed Materials Production Center. 1998 annual progress report

    SciTech Connect

    Harley, N.H.

    1998-06-01

    'The research objectives of this report are: (1) To develop an accurate personal radon/thoron monitor to quantitate exposure during remediation. This personal monitor is a miniaturization and modification of the area {sup 222}Rn monitor that has proven accuracy and precision. (2) To develop a personal aerosol particle size sampler, based on the principles of the novel sampler the author has developed. The sampler measures not only {sup 222}Rn decay product aerosol size but long lived nuclides. There are, as yet, no size distribution data on the aerosol particle size distribution of these nuclides during remediation, yet the aerosol particle size is the major determinant of lung dose. (3) To develop the sequential radiochemistry necessary to measure any environmental sample for {sup 228,230,232}Th, {sup 226,228}Ra, {sup 234,235,238}U and {sup 210}Pb. To utilize the radiochemistry to accurately trace and delineate these nuclides in the environment. To obtain historic and present radiochemical data to understand the need for supplemental soil/water etc. measurements.'

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

    PubMed Central

    Mendez, David; Philbert, Martin A.

    2013-01-01

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

  18. Regional deposition of thoron progeny in models of the human tracheobronchial tree

    SciTech Connect

    Smith, S.M.; Cheng, Yung-Sung; Yeh, Hsu-Chi

    1995-12-01

    Models of the human tracheobronchial tree have been used to determine total and regional aerosol deposition of inhaled particles. Particle sizes measured in these studies have all been > 40 nm in diameter. The deposition of aerosols < 40 nm in diameter has not been measured. Particles in the ultrafine aerosol size range include some combustion aerosols and indoor radon progeny. Also, the influence of reduced lung size and airflow rates on particle deposition in young children has not been determined. With their smaller lung size and smaller minute volumes, children may be at increased risk from ultrafine pollutants. In order to accurately determine dose of inhaled aerosols, the effects of particle size, minute volume, and age at exposure must be quantified. The purpose of this study was to determine the deposition efficiency of ultrafine aerosols smaller than 40 nm in diameter in models of the human tracheobronchia tree. This study demonstrates that the deposition efficiency of aerosols in the model of the child`s tracheobronchial tree may be slightly higher than in the adult models.

  19. Indoor radon and lung cancer. Estimating the risks.

    PubMed Central

    Samet, J. M.

    1992-01-01

    Radon is ubiquitous in indoor environments. Epidemiologic studies of underground miners with exposure to radon and experimental evidence have established that radon causes lung cancer. The finding that this naturally occurring carcinogen is present in the air of homes and other buildings has raised concern about the lung cancer risk to the general population from radon. I review current approaches for assessing the risk of indoor radon, emphasizing the extrapolation of the risks for miners to the general population. Although uncertainties are inherent in this risk assessment, the present evidence warrants identifying homes that have unacceptably high concentrations. PMID:1734594

  20. Daily and seasonal variations of radon activity measured in Mystery Cave

    SciTech Connect

    Lively, R.S. ); Krafthefer, B. ); Netherton, W. )

    1993-03-01

    Mystery Cave, southeastern Minnesota, is the site of an ongoing study of how radon and radon progeny are affected by meteorological changes in and about the dave. Data on radon, radon progeny, temperature, relative humidity, barometric pressure, wind speed and direction, and rainfall are collected at 4-hour intervals at different locations within and just outside the cave. During winter months, average ambient radon levels ranged from 5 to 200 pCi/L. Transient levels above 500 pCi/L tended to correlate with failing barometric pressure, but not with the magnitude of [Delta]P. In summer, average ambient radon increased to around 300 pCi/L with short-term levels exceeding 500 pCi/L. Fluctuations related to temperature were also noted. Radon progeny generally correlate with radon and both showed rates of change faster than ingrowth or decay. In addition to the time variations in the radon activity levels, pulses were observed between monitoring locations. The probable correlation of radon-activity transport with aboveground meteorological changes and preliminary data on cave airflow is being studied. Previous grab sampling with Lucas cells and integrating alpha-track devices did not show either the 10- to 100-fold daily fluctuations or the pulses. As more continuous data become available, it is increasingly evident that radon fluctuates on time scales that range from hours to years, in response to conditions both inside and outside the cave system. Funding for this project was approved by the Minnesota legislature ML 1991, Chapter 264, Art. 1, Sec. 14, subd. 3 (I) as recommended by the Legislative Commission on Minnesota Resources from the Minnesota Future Resources Fund.

  1. Experimental, statistical, and biological models of radon carcinogenesis

    SciTech Connect

    Cross, F.T.

    1991-09-01

    Risk models developed for underground miners have not been consistently validated in studies of populations exposed to indoor radon. Imprecision in risk estimates results principally from differences between exposures in mines as compared to domestic environments and from uncertainties about the interaction between cigarette-smoking and exposure to radon decay products. Uncertainties in extrapolating miner data to domestic exposures can be reduced by means of a broad-based health effects research program that addresses the interrelated issues of exposure, respiratory tract dose, carcinogenesis (molecular/cellular and animal studies, plus developing biological and statistical models), and the relationship of radon to smoking and other copollutant exposures. This article reviews experimental animal data on radon carcinogenesis observed primarily in rats at Pacific Northwest Laboratory. Recent experimental and mechanistic carcinogenesis models of exposures to radon, uranium ore dust, and cigarette smoke are presented with statistical analyses of animal data. 20 refs., 1 fig.

  2. Radon Treatment Controversy

    PubMed Central

    Zdrojewicz, Zygmunt; Strzelczyk, Jadwiga (Jodi)

    2006-01-01

    In spite of long traditions, treatments utilizing radon-rich air or water have not been unequivocally embraced by modern medicine. The objective of this work is to examine factors that contribute to this continuing controversy. While the exact mechanism of radon's effect on human body is not completely understood, recent advances in radiobiology offer new insights into biochemical processes occurring at low-level exposures to ionizing radiation. Medical evidence and patients' testimonials regarding effectiveness of radon spa treatments of various ailments, most notably rheumatoid arthritis are accumulating worldwide. They challenge the premise of the Linear-No-Threshold (LNT) theory that the dose-effect response is the same per unit dose regardless of the total dose. Historically, such inference overshadowed scientific inquiries into the low-dose region and lead to a popular belief that no amount of radiation can be good. Fortunately, the LNT theory, which lacks any scientific basis, did not remain unchallenged. As the reviewed literature suggests, a paradigm shift, reflected in the consideration of hormetic effects at low-doses, is gaining momentum in the scientific community worldwide. The impetus comes from significant evidence of adaptive and stimulatory effects of low-levels of radiation on human immune system. PMID:18648641

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

    SciTech Connect

    Evans, H.H.

    1991-12-01

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

  4. Radon in The Home May Be Linked to Blood Cancers in Women

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_158632.html Radon in the Home May Be Linked to Blood ... strong link between exposure to high levels of radon in the home and women's risk of blood ...

  5. Management of radon: a review of ICRP recommendations.

    PubMed

    Vaillant, Ludovic; Bataille, Céline

    2012-09-01

    This article proposes a review of past and current ICRP publications dealing with the management of radon exposures. Its main objective is to identify and discuss the driving factors that have been used by the Commission during the last 50 years so as to better appreciate current issues regarding radon exposure management. The analysis shows that major evolutions took place in very recent years. As far as the management of radon exposures is concerned, ICRP recommended, until ICRP Publication 103 (ICRP 2007 ICRP Publication 103; Ann. ICRP 37), to use action levels and to consider only exposures above these levels. The Commission has reviewed its approach and now proposes to manage any radon exposure through the application of the optimisation principle and associated reference levels. As far as the assessment of the radon risk is concerned, it appears that the successive changes made by ICRP did not have a strong impact on the values of radon gas concentration recommended as action levels either in dwellings or in workplaces. The major change occurred in late 2009 with the publication of the ICRP Statement on Radon, which acknowledged that the radon risk has been underestimated by a factor of 2, thus inducing a major revision of radon reference levels. PMID:22809956

  6. Radon Risk Communication Strategies: A Regional Story.

    PubMed

    Cheng, Winnie

    2016-01-01

    Risk communication on the health effects of radon encounters many challenges and requires a variety of risk communication strategies and approaches. The concern over radon exposure and its health effects may vary according to people's level of knowledge and receptivity. Homeowners in radon-prone areas are usually more informed and have greater concern over those not living in radon-prone areas. The latter group is often found to be resistant to testing. In British Columbia as well as many other parts of the country, some homes have been lying outside of the radon-prone areas have radon levels above the Canadian guideline, which is the reason Health Canada recommends that all homes should be tested. Over the last five years, the Environment Health Program (EHP) of Health Canada in the British Columbia region has been using a variety of different approaches in their radon risk communications through social media, workshops, webinars, public forums, poster contests, radon distribution maps, public inquiries, tradeshows and conference events, and partnership with different jurisdictions and nongovernmental organizations. The valuable lessons learned from these approaches are discussed in this special report. PMID:26867298

  7. Carcinogenic and Cocarcinogenic Effects of Radon and Radon Daughters in Rats.

    PubMed Central

    Monchaux, G; Morlier, JP; Morin, M; Chameaud, J; Lafuma, J; Masse, R

    1994-01-01

    It has been previously established that lung cancer could be induced in rats by exposure to radon and radon daughters. Although the oat-cell carcinomas that are common in humans were not found in rats, other histological types of lung carcinomas, especially squamous cell carcinomas and primitive lung adenocarcinomas, were similar to those observed in humans. A dose-effect relationship was established for cumulative doses varying from 25 to 3000 working-level-months (WLM), which was similar for medium and high cumulative doses to that observed in uranium miners. This experimental protocol was also used to study the potential cocarcinogenic effects of other environmental or industrial airborne pollutants such as tobacco smoke, mineral fibers, diesel exhausts, or minerals from metallic mine ores that may act synergistically with radon exposure. In rats exposed to radon and tobacco smoke combined, the incidence of lung cancers was higher by a factor of 2-4 according to the cumulative radon exposure and the duration of tobacco smoke exposure. When mineral fibers were injected intrapleurally, an increased incidence of malignant thoracic tumors was observed in rats exposed to radon and fibers combined, but synergistic effects resulted in additivity. With diesel exhausts or minerals from metallic ores, a slight, nonsignificant increase in the incidence of lung carcinomas was observed compared with rats exposed to radon alone. These results demonstrated that it is possible to establish the potential cocarcinogenic action, showing either multiplicative, additive, or no effect of various environmental or industrial airborne pollutants combined with radon exposure. This radon model is valid for investigating possible interactions between two occupational exposures. Images p64-a Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. PMID:9719670

  8. Comparisons between soil radon and indoor radon

    SciTech Connect

    Mose, D.G.; Mushrush, G.W.

    1999-10-01

    Several thousand indoor radon measurements have been obtained for homes in northern Virginia. Compilations of these data according to the geologic units under the homes show that some units have relatively high or relatively low medium indoor radon levels, and that these differences persist through all four seasons. An attempt to determine if soil radon and soil permeability could yield similar results, in terms of relative indoor radon, was not successful. Care should be taken in using such measurements to characterize the potential for radon problems in established communities and in areas of as-yet undeveloped property.

  9. On-line continuous monitoring of groundwater radon levels at L’Aquila fault, Italy

    NASA Astrophysics Data System (ADS)

    Tsabaris, C.; Lampousis, A.

    2009-12-01

    This work describes in situ radon progeny measurements in the Gran Sasso National Laboratory (LNGS) of L’Aquila region, located 60 miles north-east of Rome, Italy, conducted in December 2007. The marine radon progeny monitor KATERINA (i.e., Hellenic Centre for Marine Research patent July 2008) was submerged inside a tank filled with groundwater from the Gran Sasso Mountain. The measured spectra obtained through KATERINA exhibited photopeaks of the main gamma emitters (214Pb and 214Bi) of the primordial nucleus 238U (222Rn). High background levels of radionuclides (i.e., inside the mountain) emitting high energy gamma rays affected the measurement. In order to correct and deduce the final volumetric activities of radon progenies (214Pb and 214Bi) the system was calibrated using the simulation tool GEANT4. The first day of deployment an averaged value of radon progenies amounted to a value of (3.1 ± 0.3) Bq/l. The second day the averaged values of radon progenies were reduced by 30% due to the loss of noble gas radon from the tank. Additional spectra were recorded successfully after removing background airborne radon present in the LNGS laboratory. KATERINA operated reliably during its in situ radon monitoring. This was confirmed by further calibration using off line measurements performed in collaboration with the Marine Environmental Laboratory of the International Atomic Energy Agency (IAEA). Future work includes the development of a continuous radon monitoring tool to further study the L’Aquila fault. By implementing a continuous inflow and outflow system and by controlling the radon levels both inside and outside the water tank, radon variations will be correlated with other geophysical/geochemical parameters like microseismicity, slip rates, pH, H2S, CO2, and He. Additional contributions include an increased understanding of the correlations between radon levels in the proximity of active faults and regional seismic activity. If indeed this proves to be an

  10. Simplified modeling for infiltration and radon entry

    SciTech Connect

    Sherman, M.H.

    1992-08-01

    Air leakage in the envelopes of residential buildings is the primary mechanism for provided ventilation to those buildings. For radon the same mechanisms that drive the ventilation, drive the radon entry This paper attempts to provide a simplified physical model that can be used to understand the interactions between the building leakage distribution, the forces that drive infiltration and ventilation, and indoor radon concentrations, Combining both ventilation and entry modeling together allows an estimation of Radon concentration and exposure to be made and demonstrates how changes in the envelope or ventilation system would affect it. This paper will develop simplified modeling approaches for estimating both ventilation rate and radon entry rate based on the air tightness of the envelope and the driving forces. These approaches will use conventional leakage values (i.e. effective leakage area ) to quantify the air tightness and include natural and mechanical driving forces. This paper will introduce a simplified parameter, the Radon Leakage Area, that quantifies the resistance to radon entry. To be practical for dwellings, modeling of the occupant exposures to indoor pollutants must be simple to use and not require unreasonable input data. This paper presents the derivation of the simplified physical model, and applies that model to representative situations to explore the tendencies to be expected under different circumstances.

  11. Carcinogenesis and low-level ionizing radiation with special reference to lung cancer and exposure to radon daughters

    SciTech Connect

    Fabrikant, J.I.

    1982-04-01

    Of the important health effects of ionizing radiation, three important late effects - carcinogenesis, teratogenesis and mutagenesis are of greatest concern. This is because any exposure, even at low levels, carries some risk of such deleterious effects. As the dose of radiation increases above very low levels, the risk of health effects increases. Cancer-induction is the most important late somatic effect of low-dose ionizing radiation. Solid cancers, rather than leukemia, are principal late effects in exposed individuals. Tissues vary greatly in their susceptibility to radiation carcinogenesis. The most frequently occurring radiation-induced cancers in man include, in decreasing order of susceptibility: the female breast, the thyroid gland, the blood-forming tissues, the lung, certain organs of the gastrointestinal tract, and the bones. A number of biological and physical factors affect the cancer risk, such as age, sex, life-style, LET, and RBE. Despite uncertainty about low-level radiation risks, regulatory and advisory bodies must set standards for exposure, and individuals need information to be able to make informed judgments for themselves. From the point of view of the policy maker, the overriding concern is the fact that small doses of radiation can cause people to have more cancers than would otherwise be expected. While concern for all radiation effects exists, our human experience is limited to cancer-induction in exposed populations. This discussion is limited to cancer risk estimation and decision-making in relation to the health effects on populations of exposure to low levels of ionizing radiation. Here, low-level radiation will refer to yearly whole-body doses up to 5 rems or 0.05 Sv, or to cumulative doses up to 50 rems or 0.5 Sv from low-LET radiation and from high-LET radiation. (ERB)

  12. Estimation of EEC, unattached fraction and equilibrium factor for the assessment of radiological dose using pin-hole cup dosimeters and deposition based progeny sensors.

    PubMed

    Bangotra, Pargin; Mehra, Rohit; Kaur, Kirandeep; Kanse, Sandeep; Mishra, Rosaline; Sahoo, B K

    2015-10-01

    High concentration of radon ((222)Rn), thoron ((220)Rn) and their decay products in environment may increase the risk of radiological exposure to the mankind. The (222)Rn, (220)Rn concentration and their separate attached and unattached progeny concentration in units of EEC have been measured in the dwellings of Muktsar and Mansa districts of Punjab (India), using Pin-hole cup dosimeters and deposition based progeny sensors (DTPS/DRPS). The indoor (222)Rn and (220)Rn concentration was found to vary from 21 Bqm(-3) to 94 Bqm(-3) and 17 Bqm(-3) to 125 Bqm(-3). The average EEC (attached + unattached) of (222)Rn and (220)Rn was 25 Bqm(-3) and 1.8 Bqm(-3). The equilibrium factor for (222)Rn and (220)Rn in studied area was 0.47 ± 0.13 and 0.05 ± 0.03. The equilibrium factor and unattached fraction of (222)Rn and (220)Rn has been calculated separately. Dose conversion factors (DCFs) of different models have been calculated from unattached fraction for the estimation of annual effective dose in the studied area. From the experimental data a correlation relationship has been observed between unattached fraction (f(p)(Rn)) and equilibrium factor (F(Rn)). The present work also aims to evaluate an accurate expression among available expression in literature for the estimation of f(p)(Rn). PMID:26117280

  13. Portable apparatus for the measurement of environmental radon and thoron

    DOEpatents

    Negro, Vincent C.

    2001-01-01

    The radometer is a portable instrument for the measurement of the concentration of atmospheric radon/thoron in a test area. A constant velocity pump pulls the air from the outside at a constant flow rate. If the air is too moist, some or all of the sample is passed through a desiccant filter prior to encountering an electrostatic filter. The electrostatic filter prevents any charged particles from entering the sampling chamber. Once the sample has entered the chamber, the progeny of the decay of radon/thoron are collected on a detector and measured. The measured data is compiled by a computer and displayed.

  14. Transport of radon and thoron at the earth's surface

    SciTech Connect

    Schery, S.D.

    1991-06-15

    This report covers progress under the current funding period Jan. 1, 1991 to Jan. 1, 1992 and presents the continuation proposal for Jan. 1, 1992 to Jan. 1, 1993. The previous progress report was submitted in May 1990, so activities during the last half of 1990 will also be included. Major activities over the last year have centered on the study of disequilibrium of radon progeny near the earth's surface and the sources of thoron in indoor air. In addition, we have carried out supplemental measurements of radon sorption coefficients in porous materials focusing on the physical mechanism of sorption.

  15. Portable Apparatus for the Measurement of Environmental Radon and Thoron

    SciTech Connect

    Negro, Vincent

    1999-08-19

    The radometer is a portable instrument for the measurement of the concentration of atmospheric radon/thoron in a test area. A constant velocity pump pulls the air from the outside at a constant flow rate. If the air is too moist, some or all of the sample is passed through a desiccant filter prior to encountering an electrostatic filter. The electrostatic filter prevents any charged particles from entering the sampling chamber. Once the sample has entered the chamber, the progeny of the decay of radon/thoron are collected on a detector and measured. The measured data is compiled by a computer and displayed.

  16. Radon concentrations in elementary schools in Kuwait.

    PubMed

    Maged, A F

    2006-03-01

    Measurements of indoor radon concentrations were performed in 25 classrooms in the capital city of Kuwait from September 2003 to March 2004 using track etch detectors. The investigation was focused on area, ventilation, windows, air conditioners, fans, and floor number. All the schools have nearly the same design. Mean indoor radon concentration was higher for case subjects (classrooms) than for control subjects (locations in inert gas, p < 0.001). The mean alpha dose equivalent rate for case subjects, 0.97 +/- 0.25 mSv y, was higher than the radiation dose equivalent rate value of control subjects, 0.43 +/- 0.11 mSv y. The average radon concentrations were found to be 16 +/- 4 Bq m for the first floor and 19 +/- 4.8 Bq m for the second floor after subtraction of the control. These values lead to average effective dose equivalent rates of 0.40 +/- 0.10 and 0.48 +/- 0.12 mSv y, respectively. The equilibrium factor between radon and its progeny was found to be 0.6 +/- 0.2. PMID:16505623

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

    SciTech Connect

    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.

  18. Controlling the Radon Threat Needn't Be Another Costly Nightmare.

    ERIC Educational Resources Information Center

    Freije, Matthew R.

    1989-01-01

    After a study of 3,000 classrooms in 130 schools in 16 states, the Environmental Protection Agency urged all schools to conduct tests for radon. Explains a 6-step screening test, methods of reducing radon concentrations, and how the risk from radon exposure compares with other risks. (MLF)

  19. Attached, unattached fraction of progeny concentrations and equilibrium factor for dose assessments from (222)Rn and (220)Rn.

    PubMed

    Singh, Parminder; Saini, Komal; Mishra, Rosaline; Sahoo, Bijay Kumar; Bajwa, Bikramjit Singh

    2016-08-01

    In this study, measurements of indoor radon ((222)Rn), thoron ((220)Rn) and their equilibrium equivalent concentration (EEC) were carried out in 96 dwellings from 22 different villages situated in Hamirpur district, Himachal Pradesh, India, by using LR-115 type II-based pinhole twin cup dosimeters and deposition-based progeny sensors (DRPS/DTPS). The annual average indoor (222)Rn and (220)Rn concentrations observed in these dwellings were 63.82 and 89.59 Bq/m(3), respectively, while the average EEC (attached + unattached) for (222)Rn and (220)Rn was 29.28 and 2.74 Bq/m(3). For (222)Rn (f Rn) and (220)Rn (f Tn), the average values of unattached fraction were 0.11 and 0.09, respectively. The equilibrium factors for radon (F Rn) and thoron (F Tn) varied from 0.12 to 0.77 with an average of 0.50, and from 0.01 to 0.34 with an average of 0.05, respectively. The annual inhalation dose due to mouth and nasal breathing was calculated using dose conversion factors and unattached fractions. The indoor annual effective doses for (222)Rn (AEDR) and (220)Rn (AEDT) were found to be 1.92 and 0.83 mSv a(-1), respectively. The values of (222)Rn/(220)Rn concentrations and annual effective doses obtained in the present study are within the safe limits as recommended by the International Commission on Radiological Protection for indoor dwelling exposure conditions. PMID:27289385

  20. What Is Radon?

    MedlinePlus

    ... Learn About Cancer » What Causes Cancer? » Other Carcinogens » Pollution » Radon Share this Page Close Push escape to ... can move into the air and into underground water and surface water. Radon is present outdoors and ...

  1. Radon removal method

    SciTech Connect

    Lamarre, B.L.

    1989-09-26

    This patent describes a method of removing radon from water without recycling. It comprises: distributing radon-laden water in the upper portion of a vertically oriented hollow column containing mass transfer packing material, forcing air through the column to evaporate radon gas out of the radon-laden water as the water splashes through the packing material, venting air laden with radon evaporated from the radon-laden water out of the column, collecting water significantly purified by removal of radon as the water falls to the lower portion of the column, and pumping the collected water into a water storage container remote from the source of the radon-laden water. Thereby the collected and stored water is available for immediate residential use without recycling through the mass transfer packing material.

  2. Variations in radon concentration in groundwater of Kumaon Himalaya, India.

    PubMed

    Bourai, A A; Gusain, G S; Rautela, B S; Joshi, V; Prasad, G; Ramola, R C

    2012-11-01

    The radon content in groundwater sources depends on the radium concentration in the rock of the aquifer. Radon was measured in water in many parts of the world, mostly for the risk assessment due to consumption of drinking water. The exposure to radon through drinking water is largely by inhalation and ingestion. Airborne radon can be released during normal household activities and can pose a greater potential health risk than radon ingested with water. Transport of radon through soil and bedrock by water depends mainly on the percolation of water through the pores and along fracture planes of bedrock. In this study, the radon concentration in water from springs and hand pumps of Kumaun Himalaya, India was measured using the radon emanometry technique. Radon concentration was found to vary from 1 to 392 Bq l(-1) with a mean of 50 Bq l(-1) in groundwater in different lithotectonic units. The radon level was found to be higher in the area consisting of granite, quartz porphyry, schist, phyllites and lowest in the area having sedimentary rocks, predominantly dominated by quartzite rocks. PMID:22914330

  3. Impact from indoor air mixing on the thoron progeny concentration and attachment fraction.

    PubMed

    de With, G; de Jong, P

    2016-07-01

    Despite the considerable amount of work in the field of indoor thoron exposure, little studies have focussed on mitigation strategies to reduce exposure to thoron and its progeny. For this reason an advanced computer model has been developed that describes the dispersion and aerosol modelling from first principal using Computational Fluid Dynamics. The purpose of this study is to investigate the mitigation effects from air mixing on the progeny concentration and attachment with aerosols. The findings clearly demonstrate a reduction in thoron progeny concentration due to air mixing. The reduction in thoron progeny is up to 60% when maximum air mixing is applied. In addition there is a reduction in the unattached fraction from 1.2% under regular conditions to 0.3% in case of maximum mixing. PMID:27064565

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

    SciTech Connect

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

    2008-06-05

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

  5. Potential for ion-induced nucleation of volatile organic compounds by radon decay in indoor environments

    SciTech Connect

    Daisey, J.M.

    1991-11-01

    There is considerable interest in the ``unattached`` fraction of radon progeny in indoor air because of its significance to the estimation of the risks of radon exposure. Because of its high mobility in air, the unattached fraction is more efficiently deposited in the respiratory tract. Variation in the diameter of the ``unattached`` fraction and in its diffusion coefficient can be due to clustering of other atmospheric species around the {sup 218}PoO{sub 2}{sup +} ion. The purpose of this study was to investigate the potential for the formation of clusters of vapor phase organic compounds, found in indoor air, around the {sup 218}PoO{sub 2}{sup +} ion and to determine which were most likely to form clusters. A secondary purpose was to provide a compilation of measurements of indoor organic compounds for future experiments and theoretical calculations by the radon research community. The classical charged liquid droplet theory (Thomson equation) was used to estimate the Gibbs free energy of ion-induced nucleation and to provide an indication of the indoor organic compounds most likely to undergo ion-induced nucleation. Forty-four volatile and semi-volatile organic compounds out of the more than 300 which have been reported in indoor air were investigated. Water vapor was included for comparison. The results indicate that there is a potential for the formation of clusters of organic compounds around the {sup 218}PoO{sub 2}{sup +} ion. The compounds with the greatest potential for cluster formation are the volatile oxidized hydrocarbons (e.g., n-butanol, phenol, hexanal, nonanal, benzaldehyde, the ketones and the acetates) and the semi-volatile organic compounds (pentachlorophenol, nicotine, chlordane, chlorpyrifos).

  6. Potential for ion-induced nucleation of volatile organic compounds by radon decay in indoor environments

    SciTech Connect

    Daisey, J.M.

    1991-11-01

    There is considerable interest in the unattached'' fraction of radon progeny in indoor air because of its significance to the estimation of the risks of radon exposure. Because of its high mobility in air, the unattached fraction is more efficiently deposited in the respiratory tract. Variation in the diameter of the unattached'' fraction and in its diffusion coefficient can be due to clustering of other atmospheric species around the {sup 218}PoO{sub 2}{sup +} ion. The purpose of this study was to investigate the potential for the formation of clusters of vapor phase organic compounds, found in indoor air, around the {sup 218}PoO{sub 2}{sup +} ion and to determine which were most likely to form clusters. A secondary purpose was to provide a compilation of measurements of indoor organic compounds for future experiments and theoretical calculations by the radon research community. The classical charged liquid droplet theory (Thomson equation) was used to estimate the Gibbs free energy of ion-induced nucleation and to provide an indication of the indoor organic compounds most likely to undergo ion-induced nucleation. Forty-four volatile and semi-volatile organic compounds out of the more than 300 which have been reported in indoor air were investigated. Water vapor was included for comparison. The results indicate that there is a potential for the formation of clusters of organic compounds around the {sup 218}PoO{sub 2}{sup +} ion. The compounds with the greatest potential for cluster formation are the volatile oxidized hydrocarbons (e.g., n-butanol, phenol, hexanal, nonanal, benzaldehyde, the ketones and the acetates) and the semi-volatile organic compounds (pentachlorophenol, nicotine, chlordane, chlorpyrifos).

  7. Radiological risk assessment of environmental radon

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

  8. Radiological risk assessment of environmental radon

    SciTech Connect

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

    2013-11-27

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

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

    SciTech Connect

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

    1996-09-09

    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 {sup 218}Po and {sup 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.

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

    PubMed

    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. PMID:26472478

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

    PubMed Central

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

    2016-01-01

    Because 222Rn is a progeny of 238U, 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. PMID:26472478

  12. Radon in the DRIFT-II directional dark matter TPC: emanation, detection and mitigation

    NASA Astrophysics Data System (ADS)

    Battat, J. B. R.; Brack, J.; Daw, E.; Dorofeev, A.; Ezeribe, A. C.; Fox, J. R.; Gauvreau, J.-L.; Gold, M.; Harmon, L. J.; Harton, J. L.; Landers, J. M.; Lee, E. R.; Loomba, D.; Matthews, J. A. J.; Miller, E. H.; Monte, A.; Murphy, A. StJ.; Paling, S. M.; Phan, N.; Pipe, M.; Robinson, M.; Sadler, S. W.; Scarff, A.; Snowden-Ifft, D. P.; Spooner, N. J. C.; Telfer, S.; Walker, D.; Warner, D.; Yuriev, L.

    2014-11-01

    Radon gas emanating from materials is of interest in environmental science and also a major concern in rare event non-accelerator particle physics experiments such as dark matter and double beta decay searches, where it is a major source of background. Notable for dark matter experiments is the production of radon progeny recoils (RPRs), the low energy (~ 100 keV) recoils of radon daughter isotopes, which can mimic the signal expected from WIMP interactions. Presented here are results of measurements of radon emanation from detector materials in the 1 m3 DRIFT-II directional dark matter gas time projection chamber experiment. Construction and operation of a radon emanation facility for this work is described, along with an analysis to continuously monitor DRIFT data for the presence of internal 222Rn and 218Po. Applying this analysis to historical DRIFT data, we show how systematic substitution of detector materials for alternatives, selected by this device for low radon emanation, has resulted in a factor of ~ 10 reduction in internal radon rates. Levels are found to be consistent with the sum from separate radon emanation measurements of the internal materials and also with direct measurement using an attached alpha spectrometer. The current DRIFT detector, DRIFT-IId, is found to have sensitivity to 222Rn of 2.5 μBql-1 with current analysis efficiency, potentially opening up DRIFT technology as a new tool for sensitive radon assay of materials.

  13. Radon Measurements at the Molten Salt Reactor Experiment (MSRE) Facility from August 1997 through April 1998

    SciTech Connect

    Coleman, R.L.

    1999-04-01

    From August 1997 through April 1998, radon and radon progeny measurements were collected at the Molten Salt Reactor Experiment (MSRE) facility at Oak Ridge National Laboratory. The purpose of the measurements was to determine the baseline concentrations of 222Rn (radon), 220Rn (thoron), and their progeny in the air at selected points with emphasis on the characterization of 220Rn and its daughter products in the high bay area. The daughter product concentrations ranged from the equivalent of approximately 0.001 times the derived air concentration (DAC) of the isotope mixture up to 0.09 DAC, with the highest measurements occurring inside the pit above the equipment drain tank cell. Direct radon measurements in this area indicated a relatively constant 222Rn concentration with an average value of 1.4 pCi/L and a 220Rn concentration that fluctuated from <1 pCi/L up to about 30 pCi/L. Measurements were also collected inside the vent house adjacent to building 7503. The progeny concentrations inside the room ranged from an equivalent of about 0.002 DAC up to 0.01 DAC. The direct radon measurements in the vent house indicated a relatively constant 222Rn concentration with an average value of 0.7 pCi/L while the 220Rn concentration varied appreciably and ranged from <0.5 pCi/L up to almost 200 pCi/L with an average concentration of 18 pCi/L.

  14. Nonhereditary enhancement of progeny growth

    NASA Technical Reports Server (NTRS)

    Khan, Amir S.; Fiorotto, Marta L.; Hill, Leigh-Anne; Malone, P. Brandon; Cummings, Kathleen K.; Parghi, Deena; Schwartz, Robert J.; Smith, Roy G.; Draghia-Akli, Ruxandra

    2002-01-01

    The im electroporated injection of a protease-resistant GH-releasing hormone cDNA into rat dams at 16 d gestation resulted in enhanced long-term growth of the F(1) offspring. The offspring were significantly heavier by 2 wk of age, and the difference was sustained to 10 wk of age. Consistent with their augmented growth, the plasma IGF-I concentration of the F(1) progeny was increased significantly. The pituitary gland of the offspring was significantly heavier and contained an increased number of somatotrophs and PRL-secreting cells, which is indicative of modification of cell lineage differentiation. These unique findings demonstrate that enhanced GH-releasing hormone expression in pregnant dams can result in intergenerational growth promotion by altering development of the pituitary gland in the offspring.

  15. Radon in homes. Council on Scientific Affairs.

    PubMed

    1987-08-01

    Radon 222 and its radioactive decay products can enter buildings and, through inhalation, expose the inhabitants' pulmonary tissues to ionizing radiation. Studies of radon levels in the United States indicate that variations of 100-fold or greater exist among private dwellings. In one region, 55% of homes had levels exceeding 4 pCi/L (0.15 Bq/L), which is the guidance level recommended by the US Environmental Protection Agency. Ventilation and tightness of construction are important determinants of radon levels. In some instances, fans or heat exchangers can reduce excessive concentrations, but in others more elaborate remedial measures may be required. Physicians may obtain information about radon through Environmental Protection Agency regional offices and state radiation control programs. The risk of radiogenic cancer is believed to increase with exposure to ionizing radiation. According to some estimates, concentrations of radon decay products in US homes could be responsible for several thousand cases of lung cancer per year. Studies of radon levels in representative buildings and guidelines are needed to ensure safe, effective, and cost-effective countermeasures. Architects, contractors, designers, building code administrators, health physicists, and biomedical investigators can help with solutions. PMID:3612990

  16. Radon in homes. Council on Scientific Affairs

    SciTech Connect

    Not Available

    1987-08-07

    Radon 222 and its radioactive decay products can enter buildings and, through inhalation, expose the inhabitants' pulmonary tissues to ionizing radiation. Studies of radon levels in the United States indicate that variations of 100-fold or greater exist among private dwellings. In one region, 55% of homes had levels exceeding 4 pCi/L (0.15 Bq/L), which is the guidance level recommended by the US Environmental Protection Agency. Ventilation and tightness of construction are important determinants of radon levels. In some instances, fans or heat exchangers can reduce excessive concentrations, but in others more elaborate remedial measures may be required. Physicians may obtain information about radon through Environmental Protection Agency regional offices and state radiation control programs. The risk of radiogenic cancer is believed to increase with exposure to ionizing radiation. According to some estimates, concentrations of radon decay products in US homes could be responsible for several thousand cases of lung cancer per year. Studies of radon levels in representative buildings and guidelines are needed to ensure safe, effective, and cost-effective countermeasures. Architects, contractors, designers, building code administrators, health physicists, and biomedical investigators can help with solutions.

  17. The performance of functional methods for correcting non-Gaussian measurement error within Poisson regression: corrected excess risk of lung cancer mortality in relation to radon exposure among French uranium miners.

    PubMed

    Allodji, Rodrigue S; Thiébaut, Anne C M; Leuraud, Klervi; Rage, Estelle; Henry, Stéphane; Laurier, Dominique; Bénichou, Jacques

    2012-12-30

    A broad variety of methods for measurement error (ME) correction have been developed, but these methods have rarely been applied possibly because their ability to correct ME is poorly understood. We carried out a simulation study to assess the performance of three error-correction methods: two variants of regression calibration (the substitution method and the estimation calibration method) and the simulation extrapolation (SIMEX) method. Features of the simulated cohorts were borrowed from the French Uranium Miners' Cohort in which exposure to radon had been documented from 1946 to 1999. In the absence of ME correction, we observed a severe attenuation of the true effect of radon exposure, with a negative relative bias of the order of 60% on the excess relative risk of lung cancer death. In the main scenario considered, that is, when ME characteristics previously determined as most plausible from the French Uranium Miners' Cohort were used both to generate exposure data and to correct for ME at the analysis stage, all three error-correction methods showed a noticeable but partial reduction of the attenuation bias, with a slight advantage for the SIMEX method. However, the performance of the three correction methods highly depended on the accurate determination of the characteristics of ME. In particular, we encountered severe overestimation in some scenarios with the SIMEX method, and we observed lack of correction with the three methods in some other scenarios. For illustration, we also applied and compared the proposed methods on the real data set from the French Uranium Miners' Cohort study. PMID:22996087

  18. The influence of thoron on instruments measuring radon activity concentration.

    PubMed

    Michielsen, N; Bondiguel, S

    2015-11-01

    Thoron, the isotope 220 of radon, is a radionuclide whose concentration may influence the measurement of the activity concentration of (222)Rn in the air. If in the case of continuous and active sampling measuring instruments, using a pump for example, the influence of thoron on radon measurement is obvious and is taken into account in the apparatus, it is often assumed that in the case of a passive sampling, by diffusion through a filter for example, this thoron influence is negligible. This is due to the very short radioactive half-life of thoron, 55.6 s (3.82 d for (222)Rn), and the assumption that the diffusion time of thoron in the detection chamber is long enough beside that of the thoron half-life. The objective of this study is to check whether this assumption is true or not for different kinds of commercial electronic apparatus used to measure radon activity concentration from soil to dwellings. First of all, the devices were calibrated in activity concentration of radon, and then they were exposed to a controlled thoron atmosphere. The experiments concerning the thoron aimed to investigate the sensitivity to thoron in the radon measuring mode of the apparatus. Results of these experiments show that all devices have a very quick answer to thoron atmosphere, even though the sensitivities vary from one instrument to another. Results clearly show that this influence on radon measurement due to the thoron is observed also after the exposition because of the decay of (212)Pb and its progenies. In conclusion, the sensitivity to thoron in the radon measuring mode depends strongly on the type of instruments. The results of the present investigation show that for some apparatus, the influence of thoron cannot be disregarded especially when measuring radon in soil. PMID:25953787

  19. Residential Radon and Brain Tumour Incidence in a Danish Cohort

    PubMed Central

    Bräuner, Elvira V.; Andersen, Zorana J.; Andersen, Claus E.; Pedersen, Camilla; Gravesen, Peter; Ulbak, Kaare; Hertel, Ole; Loft, Steffen; Raaschou-Nielsen, Ole

    2013-01-01

    Background Increased brain tumour incidence over recent decades may reflect improved diagnostic methods and clinical practice, but remain unexplained. Although estimated doses are low a relationship between radon and brain tumours may exist. Objective To investigate the long-term effect of exposure to residential radon on the risk of primary brain tumour in a prospective Danish cohort. Methods During 1993–1997 we recruited 57,053 persons. We followed each cohort member for cancer occurrence from enrolment until 31 December 2009, identifying 121 primary brain tumour cases. We traced residential addresses from 1 January 1971 until 31 December 2009 and calculated radon concentrations at each address using information from central databases regarding geology and house construction. Cox proportional hazards models were used to estimate incidence rate-ratios (IRR) and 95% confidence intervals (CI) for the risk of primary brain tumours associated with residential radon exposure with adjustment for age, sex, occupation, fruit and vegetable consumption and traffic-related air pollution. Effect modification by air pollution was assessed. Results Median estimated radon was 40.5 Bq/m3. The adjusted IRR for primary brain tumour associated with each 100 Bq/m3 increment in average residential radon levels was 1.96 (95% CI: 1.07; 3.58) and this was exposure-dependently higher over the four radon exposure quartiles. This association was not modified by air pollution. Conclusions We found significant associations and exposure-response patterns between long-term residential radon exposure radon in a general population and risk of primary brain tumours, adding new knowledge to this field. This finding could be chance and needs to be challenged in future studies. PMID:24066143

  20. Intercomparison of activity size distributions of thoron progeny by alpha- and gamma-counting methods.

    PubMed

    Cheng, Y S; Yu, C C; Tu, K W

    1994-01-01

    It is difficult to calibrate sampling devices using radon or thoron progeny or particles measuring 1-4 nm; therefore, an interlaboratory comparison is important to verify the performance of graded diffusion batteries for the activity size distributions of the "unattached" progeny. This paper describes the results of an interlaboratory comparison of 220Rn progeny size distributions using graded diffusion batteries by alpha- and gamma-counting methods with different data inversion schemes. Graded diffusion batteries designed at the Inhalation Toxicology Research Institute and at the Environmental Measurement Laboratory were used in the study. Screens and backup filters from the Environmental Measurement Laboratory-graded diffusion batteries were counted simultaneously in alpha counters for total alpha activities, and those of the Inhalation Toxicology Research Institute-graded diffusion batteries were counted in a gamma detector for gamma activities from 212Pb. Because of the different counting methods and data analysis procedures used, this interlaboratory study of 220Rn progeny allows a more rigorous way of testing instrument performance. 212Pb particles generated in well-controlled environments of oxygen, nitrogen, or oxygen with 1 ppm of nitrogen oxide were measured. In general, good agreement in activity size distributions was obtained from these two methods. Some differences observed in individual size spectra were attributable to the data inversion programs used in each laboratory. When the data were analyzed by the same computer program, most differences disappeared. PMID:8253581

  1. Atmosphere purification of radon and radon daughter elements

    DOEpatents

    Stein, L.

    1974-01-01

    A method of removing radon and radon daughter elements from an atmosphere containing these elements by passing the atmosphere through a bed of fluorinating compound whereby the radon and radon daughters are oxidized to their respective fluorides is discussed. These fluorides adhere to the fluorinating compound and are thus removed from the atmosphere which may then be recirculated. A method for recovering radon and separating radon from its daughter elements is also described. (Official Gazette)

  2. Individual variation in p53 and Cip1 expression profiles in normal human fibroblast strains following exposure to high-let radiation

    SciTech Connect

    Carpenter, T.R.; Johnson, N.F.; Gilliland, F.D.

    1995-12-01

    Exposure to {alpha}-particles emitted by radon progeny appears to be the second-leading cause of lung cancer mortality. However, individual susceptibility to the carcinogenic effects of {alpha}-particles remains poorly characterized. Variation in susceptibility to cancer produced by certian classes of DNA-damaging chemicals is suspected to involve differences in metabolic activation and detoxication. Susceptibility to {alpha}-particle-induced cancer may involve variations in capacity or opportunity to repair DNA damage. Subtle variations in DNA repair capacity would more likely explain radon-related lung cancer susceptibility. The p53 tumor suppressor protein accumulates as a cellular response to DNA damage from ionizing radiation and regulates arrest in the G{sub 1} portion of the cell cycle. Arrest in G{sub 1} portion of the cell cycle. While upstream regulation of p53 protein stability is poorly understood, variations in the ability to accumulate p53 following DNA damage represent potential variations in lung cancer susceptibility related to radon progeny. Further, transcription of the cell-cycle regulatory gene Cip1 is regulated by p53 and increases following ionizing radiation. Therefore, variations in the expression of Cip1 following {alpha}-particle exposure may also be a susceptibility factor in radon-related lung cancers. The purpose of the present investigation was to measure p53 and Cip1 protein induction following {alpha}-particle exposure of fibroblast lines from nine individuals to determine if there were significant variations. The expression of Cip1 protein indicates the differences in response are biologically relevant.

  3. Potential for bias in epidemiologic studies that rely on glass-based retrospective assessment of radon.

    PubMed Central

    Weinberg, C R

    1995-01-01

    Retrospective assessment of exposure to radon remains the greatest challenge in epidemiologic efforts to assess lung cancer risk associated with residential exposure. An innovative technique based on measurement of alpha-emitting, long-lived daughters embedded by recoil into household glass may one day provide improved radon dosimetry. Particulate air pollution is known, however, to retard the plate-out of radon daughters. This would be expected to result in a differential effect on dosimetry, where the calibration curve relating the actual historical radon exposure to the remaining alpha-activity in the glass would be different in historically smoky and nonsmoky environments. The resulting "measurement confounding" can distort inferences about the effect of radon and can also produce spurious evidence for synergism between radon exposure and cigarette smoking. Images Figure 1. Figure 2. Figure 3. Figure 4. PMID:8605854

  4. Radon-hazard potential the Beaver basin, Utah

    SciTech Connect

    Bishop, C.E.

    1995-06-01

    Indoor-radon levels in the Beaver basin of southwestern Utah are the highest recorded to date in Utah, ranging from 17.5 to 495 picocuries per liter (pCi/L). Because the U.S. Environment Protection Agency considers indoor-radon levels above 4 pCi/L to represent a risk of lung cancer from long-term exposure, the Utah Geological Survey is preparing a radon-hazard-potential map for the area to help prioritize indoor testing and evaluate the need for radon-resistant construction. Radon is a chemically inert radioactive gas derived from the decay of uranium-238, which is commonly found in rocks and soils. Soil permeability, depth to ground water, and uranium/thorium content of source materials control the mobility and concentration of radon in the soil. Once formed, radon diffuses into the pore space of the soil and then to the atmosphere or into buildings by pressure-driven flow of air or additional diffusion. The Beaver basin has been a topographic and structural depression since late Miocene time. Paleocene to Miocene volcanic and igneous rocks border the basin. Uraniferous alluvial-fan, piedmont-slope, flood-plain, and lacustrine sediments derived from the surrounding volcanic rocks fill the basin. A soil-gas radon and ground radioactivity survey in the Beaver basin shows that soils have high levels of radon gas. In this survey, uranium concentrations range from 3 to 13 parts per million (ppm) and thorium concentrations range from 10 to 48 ppm. Radon concentrations in the soil gas ranged from 85 to 3,500 pCi/L. The highest concentrations of uranium, thorium, and radon gas and the highest radon-hazard-potential are in the well-drained permeable soils in the lower flood- plain deposits that underlie the city of Beaver.

  5. Results of simultaneous radon and thoron measurements in 33 metropolitan areas of Canada

    PubMed Central

    Chen, Jing; Bergman, Lauren; Falcomer, Renato; Whyte, Jeff

    2015-01-01

    Radon has been identified as the second leading cause of lung cancer after tobacco smoking. 222Rn (radon gas) and 220Rn (thoron gas) are the most common isotopes of radon. In order to assess thoron contribution to indoor radon and thoron exposure, a survey of residential radon and thoron concentrations was initiated in 2012 with ∼4000 homes in the 33 census metropolitan areas of Canada. The survey confirmed that indoor radon and thoron concentrations are not correlated and that thoron concentrations cannot be predicted from widely available radon information. The results showed that thoron contribution to the radiation dose varied from 0.5 to 6 % geographically. The study indicated that, on average, thoron contributes ∼3 % of the radiation dose due to indoor radon and thoron exposure in Canada. Even though the estimated average thoron concentration of 9 Bq m−3 (population weighted) in Canada is low, the average radon concentration of 96 Bq m−3 (population weighted) is more than double the worldwide average indoor radon concentration. It is clear that continued efforts are needed to further reduce the exposure and effectively reduce the number of lung cancers caused by radon. PMID:24748485

  6. Radon assay and purification techniques

    SciTech Connect

    Simgen, Hardy

    2013-08-08

    Radon is a source of background in many astroparticle physics experiments searching for rare low energy events. In this paper an overview about radon in the field is given including radon detection techniques, radon sources and material screening with respect to radon emanation. Finally, also the problem of long-lived radioactive {sup 222}Rn-daughters and the question of gas purification from radon is addressed.

  7. Risks from Radon: Reconciling Miner and Residential Epidemiology

    SciTech Connect

    Chambers, Douglas B.; Harley, Naomi H.

    2008-08-07

    Everyone is exposed to radon, an inert radioactive gas that occurs naturally and is present everywhere in the atmosphere. The annual dose from radon and its (short-lived) decay products is typically about one-half of the dose received by members of the public from all natural sources of ionizing radiation. Data on exposures and consequent effects have recently been reviewed by the National Council on Radiation Protection and Measurements (NCRP) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Studies of underground miners provides a well-established basis for estimating risks from occupational exposures to radon and for studying factors that may affect the dose response relationship such as the reduction of risk (coefficients) with increasing time since exposure. Miners' studies previously formed the basis for estimating risks to people exposed to radon at home, with downward extrapolation from exposures in mines to residential levels of radon. Presently, the risk estimates from residential studies are adequate to estimate radon risks in homes. Although there are major uncertainties in extrapolating the risks of exposure to radon from the miner studies to assessing risks in the home, there is remarkably good agreement between the average of risk factors derived from miner studies and those from pooled residential case-control studies. There are now over 20 analytical studies of residential radon and lung cancer. These studies typically assess the relative risk from exposure to radon based on estimates of residential exposure over a period of 25 to 30 years prior to diagnosis of lung cancer. Recent pooled analyses of residential case-control studies support a small but detectable lung cancer risk from residential exposure, and this risk increases with increasing concentrations. The excess relative risk of lung cancer from long-term residential exposure is about the same for both smokers and non-smokers; however, because the

  8. Risks from Radon: Reconciling Miner and Residential Epidemiology

    NASA Astrophysics Data System (ADS)

    Chambers, Douglas B.; Harley, Naomi H.

    2008-08-01

    Everyone is exposed to radon, an inert radioactive gas that occurs naturally and is present everywhere in the atmosphere. The annual dose from radon and its (short-lived) decay products is typically about one-half of the dose received by members of the public from all natural sources of ionizing radiation. Data on exposures and consequent effects have recently been reviewed by the National Council on Radiation Protection and Measurements (NCRP) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Studies of underground miners provides a well-established basis for estimating risks from occupational exposures to radon and for studying factors that may affect the dose response relationship such as the reduction of risk (coefficients) with increasing time since exposure. Miners' studies previously formed the basis for estimating risks to people exposed to radon at home, with downward extrapolation from exposures in mines to residential levels of radon. Presently, the risk estimates from residential studies are adequate to estimate radon risks in homes. Although there are major uncertainties in extrapolating the risks of exposure to radon from the miner studies to assessing risks in the home, there is remarkably good agreement between the average of risk factors derived from miner studies and those from pooled residential case-control studies. There are now over 20 analytical studies of residential radon and lung cancer. These studies typically assess the relative risk from exposure to radon based on estimates of residential exposure over a period of 25 to 30 years prior to diagnosis of lung cancer. Recent pooled analyses of residential case-control studies support a small but detectable lung cancer risk from residential exposure, and this risk increases with increasing concentrations. The excess relative risk of lung cancer from long-term residential exposure is about the same for both smokers and non-smokers; however, because the

  9. Radon gas: Health risks and toxicity. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    Not Available

    1993-08-01

    The bibliography contains citations concerning health risks and toxicity associated with indoor and outdoor exposure to radon gas. Citations discuss radon sources from tobacco smoke, fossil fuel combustion, phosphate mining, uranium mining, granitic rocks, building materials, and water supplies. Discussed also are risk assessment, regulations, radon gas monitoring, exposure modeling and control, biological pathways, and occupational exposure. Radionuclides in groundwater, and radon analysis and detection, are examined in separate bibliographies. (Contains a minimum of 125 citations and includes a subject term index and title list.)

  10. Radon diffusion modelling.

    PubMed

    Wilkinson, P; Dimbylow, P J

    1985-10-01

    A mathematical model has been developed that examines the ingress of radon into houses, through a vertical crack in an otherwise impervious concrete floor. Initially, the model considered the diffusive flow of radon from its soil source and this simulation has highlighted the dependency of the flux of radon into the house on the magnitude of various parameters, such as the diffusion coefficient of radon in soil. A preliminary investigation of the modelling of pressure-driven flow into a building is presented, and the potential of this type of analysis is discussed. PMID:4081719

  11. Radon concentration of waters in Greece and Cyprus

    NASA Astrophysics Data System (ADS)

    Nikolopoulos, D.; Vogiannis, E.; Louizi, A.

    2009-04-01

    Radon (222Rn) is a radioactive gas generated by the decay of the naturally occurring 238U series. It is considered very important from radiological point of view, since it is the most significant natural source of human radiation exposure (approximately 50% from all natural sources). Radon is present in soil, rocks, building materials and waters. Through diffusion and convection, radon migrates and emanates to the atmosphere. Outdoors, radon concentrates at low levels (in the order of 10 Bq/m3). However indoors, radon accumulates significantly. It is trivial to observe indoor environments with high radon levels (in the order of 400 Bq/m3 or higher). Radon accumulation indoors, depends on the composition of the underlying soil and rock formation, on building materials, meteorological parameters, ventilation, heating and water use. Although soil and building materials are the most significant radon sources, there have been reported elevated radon concentrations in building structures due to entering water. It is the radon concentrations in the entering water, the volume and the way of water usage, separated or in combination, that result in large amounts of radon in indoor air. Moreover, radon is a factor of stomach radiation burden due to water consumption. This burden is estimated by measurements of radon concentrations in waters. Due to the health impact of radon exposure, the reporting team continuously measures radon. This work focused on the radon concentrations exposure due to water consumption and use in Greece and Cyprus. Various locations in Greece and Cyprus were accessed taking into consideration existing natural radioactivity data (mainly radon in water), however under the restriction of the capability of movement. Radon in water was measured by Alpha Guard (Genitron Ltd) via a special unit (Aqua Kit). This unit consists of a vessel used for forced degassing of radon diluted in water samples, a security vessel used for water drop deposition. Vessels and

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

    PubMed

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

    2016-01-15

    Variance of radon concentration in dwelling atmosphere is analysed with regard to geogenic and anthropogenic influencing factors. Analysis includes review of 81 national and regional indoor radon surveys with varying sampling pattern, sample size and duration of measurements and detailed consideration of two regional surveys (Sverdlovsk oblast, Russia and Niška Banja, Serbia). The analysis of the geometric standard deviation revealed that main factors influencing the dispersion of indoor radon concentration over the territory are as follows: area of territory, sample size, characteristics of measurements technique, the radon geogenic potential, building construction characteristics and living habits. As shown for Sverdlovsk oblast and Niška Banja town the dispersion as quantified by GSD is reduced by restricting to certain levels of control factors. Application of the developed approach to characterization of the world population radon exposure is discussed. PMID:26409145

  13. RADON REDUCTION AND RADON RESISTANT CONSTRUCTION DEMONSTRATIONS IN NEW YORK

    EPA Science Inventory

    The report covers three tasks related to indoor radon: (1) the demonstration of radon reduction techniques in 8 houses in each of two uniquely different radon prone areas of the State of New York; (2) the evaluation and repair of 14 radon mitigation systems in houses mitigated 4 ...

  14. Atmosphere purification of radon and radon daughter elements

    DOEpatents

    Stein, L.

    1973-12-11

    A method for purifying an atmosphere of radon and radon daughter elements which may be contained therein by contacting the atmosphere with a fluorinating solution, whereby the radon and radon daughters are oxidized to their respective fluorides is discussed. The fluorides dissolve in the fluorinating solutlon and are removed from the atmosphere, which may then be recirculated. (Official Gazette)

  15. RADON REDUCTIONAND RADON RESISTANT CONSTRUCTION DEMONSTRATIONS IN NEW YORK

    EPA Science Inventory

    The report covers three tasks related to indoor radon: (1) the demonstration of radon reduction techniques in 8 houses in each of two uniquely different radon prone areas of the State of New York; (2) the evaluation and repair of 14 radon mitigation systems in houses mitigated 4 ...

  16. Assessment of indoor dose from gamma ray emitters and radon daughters in Milan

    NASA Astrophysics Data System (ADS)

    Battaglia, A.; Bazzano, E.; Carioni, T.

    Gamma ray doses were determined by duplicate exposure of dosimeters for two 1 month periods in 100 houses chosen at random and classified a posteriori according to location in the town, age, building materials, air ventilation, etc. Radon and radon daughters long-term determinations were carried out by passive track etch detectors. Gamma spectrometry analysis of typical building materials and spot active analysis of radon and radon daughters were carried out. No relation between house location and indoor gamma ray exposure level is noted. Higher levels are recorded in the oldest houses, and those with brick or hollow tile external walls. The first two stories have the highest radiation levels. There is no correlation between radon concentration and gamma ray exposure rates. The highest radon measures are recorded in dwellings with low occupancy factors.

  17. ESTIMATING THE RISK OF LUNG CANCER FROM INHALATION OF RADON DAUGHTERS INDOORS: REVIEW AND EVALUATION

    EPA Science Inventory

    A review of the dosimetric models and epidemiological studies with regard to the relation between indoor radon exposure and lung cancer indicates that the Working Level is an appropriate unit for indoor radon exposure; that the uncertainty in applying risk estimates derived from ...

  18. Human Lung Cancer Risks from Radon – Part III - Evidence of Influence of Combined Bystander and Adaptive Response Effects on Radon Case-Control Studies - A Microdose Analysis

    PubMed Central

    Leonard, Bobby E.; Thompson, Richard E.; Beecher, Georgia C.

    2012-01-01

    Since the publication of the BEIR VI (1999) report on health risks from radon, a significant amount of new data has been published showing various mechanisms that may affect the ultimate assessment of radon as a carcinogen, in particular the potentially deleterious Bystander Effect (BE) and the potentially beneficial Adaptive Response radio-protection (AR). The case-control radon lung cancer risk data of the pooled 13 European countries radon study (Darby et al 2005, 2006) and the 8 North American pooled study (Krewski et al 2005, 2006) have been evaluated. The large variation in the odds ratios of lung cancer from radon risk is reconciled, based on the large variation in geological and ecological conditions and variation in the degree of adaptive response radio-protection against the bystander effect induced lung damage. The analysis clearly shows Bystander Effect radon lung cancer induction and Adaptive Response reduction in lung cancer in some geographical regions. It is estimated that for radon levels up to about 400 Bq m−3 there is about a 30% probability that no human lung cancer risk from radon will be experienced and a 20% probability that the risk is below the zero-radon, endogenic spontaneous or perhaps even genetically inheritable lung cancer risk rate. The BEIR VI (1999) and EPA (2003) estimates of human lung cancer deaths from radon are most likely significantly excessive. The assumption of linearity of risk, by the Linear No-Threshold Model, with increasing radon exposure is invalid. PMID:22942874

  19. The reliability of radon as seismic precursor

    NASA Astrophysics Data System (ADS)

    Emilian Toader, Victorin; Moldovan, Iren Adelina; Ionescu, Constantin; Marmureanu, Alexandru

    2016-04-01

    Our multidisciplinary network (AeroSolSys) located in Vrancea (Curvature Carpathian Mountains) includes radon concentration monitoring in five stations. We focus on lithosphere and near surface low atmosphere phenomena using real-time information about seismicity, + / - ions, clouds, solar radiation, temperature (air, ground), humidity, atmospheric pressure, wind speed and direction, telluric currents, variations of the local magnetic field, infrasound, variations of the atmospheric electrostatic field, variations in the earth crust with inclinometers, electromagnetic activity, CO2 concentration, ULF radio wave propagation, seismo-acoustic emission, animal behavior. The main purpose is to inform the authorities about risk situation and update hazard scenarios. The radon concentration monitoring is continuously with 1 hour or 3 hours sample rate in locations near to faults in an active seismic zone characterized by intermediate depth earthquakes. Trigger algorithms include standard deviation, mean and derivative methods. We correlate radon concentration measurements with humidity, temperature and atmospheric pressure from the same equipment. In few stations we have meteorological information, too. Sometime the radon concentration has very high variations (maxim 4535 Bq/m3 from 106 Bq/m3) in short time (1 - 2 days) without being accompanied by an important earthquake. Generally the cause is the high humidity that could be generated by tectonic stress. Correlation with seismicity needs information from minimum 6 month in our case. For 10605 hours, 618 earthquakes with maxim magnitude 4.9 R, we have got radon average 38 Bq/m3 and exposure 408111 Bqh/m3 in one station. In two cases we have correlation between seismicity and radon concentration. In other one we recorded high variation because the location was in an area with multiple faults and a river. Radon can be a seismic precursor but only in a multidisciplinary network. The anomalies for short or long period of

  20. LARGE BUILDING RADON MANUAL

    EPA Science Inventory

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

  1. Study of indoor radon concentrations and associated health risks in the five districts of Hazara division, Pakistan.

    PubMed

    Khan, Fayaz; Ali, Nawab; Khan, Ehsan U; Khattak, Nimat U; Raja, Iftikhar A; Baloch, Muzahir A; Rajput, Muhammad U

    2012-11-01

    A total of 200 indoor air samples were collected to measure radon concentration levels and its contribution to the mean effective doses during different seasons of the period 2009-2010 at different sites of the five districts of Hazara division, Pakistan. The major portion of the region is mountainous and is full of thick forests which receives heavy snow fall in winter. The need for conducting the present survey relied on the fact that occupants spend their lives in poorly ventilated indoor environments of the region, especially in the winter season when they use wood fire inside their residences. The measurements of indoor air samples were taken with RAD-7, a solid state α-detector. Radon concentrations in the whole region range from 41 Bq m(-3) to 254 Bq m(-3) with a geometric mean of 128 Bq m(-3). Radon progenies were measured with a surface barrier detector through alpha spectroscopy from which the Equilibrium Factor (EF) for radon and Radon Decay Products (RDPs) for the smoke-bearing as well as smoke-free indoor environments were deduced. The respective mean values of EF were calculated as 0.49 ± 0.08 and 0.40 ± 0.07. The mean effective doses from indoor air of Abbottabad, Mansehra, Haripur, Battgram and Kohistan districts were calculated as 3.5 ± 1.2, 3.7 ± 0.7, 3.9 ± 1.0, 3.6 ± 1.1 and 3.9 ± 0.7 mSv a(-1) respectively, with the maximum value of 5.1 ± 1.8 mSv a(-1) in Kohistan district during winter and the minimum value of 2.9 ± 1.0 mSv a(-1) in Abbottabad district during summer. The annual exposure dose to the inhabitants of the locality lies below the upper bound of 10 mSv a(-1), as recommended by ICRP-65, and may not pose any significant threat to the public health. PMID:23034598

  2. Constraints for Using Radon-in-Water Concentrations as an Indicator for Groundwater Discharge into Surface Water Bodies

    NASA Astrophysics Data System (ADS)

    Petermann, Eric; Schubert, Michael

    2015-04-01

    The radon (222-Rn) activity concentration of surface water is a favourable indicator for the detection of groundwater discharge into surface water bodies since radon is highly enriched in groundwater relative to surface waters. Hence, positive radon-in-water anomalies are interpreted as groundwater discharge locations. For this approach, usually, radon time-series are recorded along transects in near-surface waters. Time-series of radon-in-water concentration are commonly measured by permanent radon extraction from a water pump stream and continuous monitoring of the resulting radon-in-air concentration by means of a suitable radon detector. Radon-in-water concentrations are derived from the recorded radon-in-air signal by making allowances for water/air partitioning of radon. However, several constraints arise for this approach since undesirable factors are influencing the radon-in-water concentration. Consequently, corrections are required to remove the effect of these undesirable factors from the radon signal. First, an instrument inherent response delay between actual changes in the radon-in-water concentration and the related radon-in-air signal was observed during laboratory experiments. The response delay is due to (i) the water/air transfer kinetics of radon and (ii) the delayed decay equilibrium between radon and its progeny polonium (218-Po), which is actually being measured by most radon-in-air monitors. We developed a physical model, which considers all parameters that are responsible for the response delay. This model allows the reconstruction of radon-in-water time-series based on radon-in-air records. Second, on a time-scale of several hours the tidal stage is known as a major driver for groundwater discharge fluctuations due to varying hydraulic gradients between groundwater and surface water during a tidal cycle. Consequently, radon-in-water time-series that are detected on tidal coasts are not comparable among each other without normalization

  3. A simple radon well

    NASA Astrophysics Data System (ADS)

    Lahti, Katariina; Graeffe, Gunnar

    The development of a simple radon well, as effective but less expensive and technically easier to put into practice than is usual, was addressed. The wall was accomplished by a drill well technique. A long plastic tube, partly perforated, is put into the ground. To the top end of the tube an exhaust fan is connected to suck the air from the soil to make an underpressure. By this method radon is prevented from entering dwellings. Measurements were carried out in a one family house in four-day periods by a continuously monitoring radon detector. The radon concentration was usually 3000 to 4000 Bq/cu m without the use of the well. When the fan was turned on it reduced the radon concentration below 200 Bq/cu m.

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

    PubMed

    Collignan, Bernard; Powaga, Emilie

    2014-11-01

    Risk assessment due to radon exposure indoors is based on annual average indoor radon activity concentration. To assess the radon exposure in a building, measurement is generally performed during at least two months during heating period in order to be representative of the annual average value. This is because radon presence indoors could be very variable during time. This measurement protocol is fairly reliable but may be a limiting in the radon risk management, particularly during a real estate transaction due to the duration of the measurement and the limitation of the measurement period. A previous field study defined a rapid methodology to characterize radon entry in dwellings. The objective of this study was at first, to test this methodology in various dwellings to assess its relevance with a daily test. At second, a ventilation model was used to assess numerically the air renewal of a building, the indoor air quality all along the year and the annual average indoor radon activity concentration, based on local meteorological conditions, some building characteristics and in-situ characterization of indoor pollutant emission laws. Experimental results obtained on thirteen individual dwellings showed that it is generally possible to obtain a representative characterization of radon entry into homes. It was also possible to refine the methodology defined in the previous study. In addition, numerical assessments of annual average indoor radon activity concentration showed generally a good agreement with measured values. These results are encouraging to allow a procedure with a short measurement time to be used to characterize long-term radon potential in dwellings. PMID:25011073

  5. Measurement of radon concentration in some water samples belonging to some adjoining areas of Pathankot, Punjab

    SciTech Connect

    Kumar, Ajay Sharma, Sumit

    2015-08-28

    The study of radon concentration was measured in some areas of Pathankot district, Punjab, India, from the health hazard point of view due to radon. The exposure to radon through drinking water is largely by inhalation and ingestion. RAD 7, an electronic solid state silicon detector (Durridgeco., USA) was used to measure the radon concentration in drinking water samples of the study area. The recorded values of radon concentration in these water samples are below the recommended limit by UNSCEAR and European commission. The recommended limit of radon concentration in water samples is 4 to 40 Bq/l given by UNSCEAR [1] and European commission has recommended the safe limit for radon concentration in water sample is 100 Bq/l [2].

  6. Experimental animal studies of radon and cigarette smoke

    SciTech Connect

    Cross, F.T.; Dagle, G.E.; Gies, R.A.; Smith, L.G.; Buschbom, R.L.

    1992-12-31

    Cigarette-smoking is a dominant cause of lung cancer and confounds risk assessment of exposure to radon decay products. Evidence in humans on the interaction between cigarette-smoking and exposure to radon decay products, although limited, indicates a possible synergy. Experimental animal data, in addition to showing synergy, also show a decrease or no change in risk with added cigarette-smoke exposures. This article reviews previous animal data developed at Compagnie Generale des Matieres Nucleaires and Pacific Northwest Laboratory (PNL) on mixed exposures to radon and cigarette smoke, and highlights new initiation-promotion-initiation (IPI) studies at PNL that were designed within the framework of a two-mutation carcinogenesis model. Also presented are the PNL exposure system, experimental protocols, dosimetry, and biological data observed to date in IPI animals.

  7. Photosynthetic Effect in Selenastrum capricornutum Progeny after Carbon-Ion Irradiation

    PubMed Central

    Wang, Jie; Li, Xin; Lu, Dong; Du, Yan; Ma, Liang; Li, Wenjian; Chen, Jihong; Li, Fuli; Fan, Yong; Hu, Guangrong; Wang, Jufang

    2016-01-01

    A large proportion of mutants with altered pigment features have been obtained via exposure to heavy-ion beams, a technique that is efficient for trait improvement in the breeding of plants and algae. However, little is known about the underlying mechanisms by which the photosynthetic pigments are altered by heavy-ion irradiation. In our study, the photosynthetic characteristics of progenies from carbon-ion irradiated Selenastrum capricornutum were investigated. Five progenies deficient in chlorophyll a were isolated after carbon-ion exposure. Photosynthetic characteristics, photoprotection capacity and gene expression of the light-harvesting complex in these progenies were further characterized by the measurement of chlorophyll fluorescence parameters (Fv/Fm, ФPSII, NPQ, ETR), the de-epoxidation state of the xanthophyll cycle, the amount of lutein and quantitative real-time PCR. High maximum quantum yield of photosystem II at day 10 and high thermal dissipation ability were observed in progenies #23 and #37 under normal culture condition. Progenies #18, #19 and #20 showed stronger resistance against high levels of light steps than the control group (612–1077 μmol photons m -2 s -1, p< 0.05). The progenies #20 and #23 exhibited strong photoprotection by thermal dissipation and quenching of 3Chl* after 24 h of high light treatment. The mRNA levels of Lhcb5, Lhcbm5 and Lhcbm1 of the light-harvesting complex revealed markedly differential expression in the five progenies irradiated by carbon-ion beams. This work indicates that photosynthetic efficiency, photoprotection ability and the expression of light-harvesting antennae in unicellular green algae can be markedly influenced by irradiation. To our knowledge, this is the first report on changes in the photosynthetic pigments of green algae after treatment with carbon-ion beams. PMID:26919351

  8. Photosynthetic Effect in Selenastrum capricornutum Progeny after Carbon-Ion Irradiation.

    PubMed

    Wang, Jie; Li, Xin; Lu, Dong; Du, Yan; Ma, Liang; Li, Wenjian; Chen, Jihong; Li, Fuli; Fan, Yong; Hu, Guangrong; Wang, Jufang

    2016-01-01

    A large proportion of mutants with altered pigment features have been obtained via exposure to heavy-ion beams, a technique that is efficient for trait improvement in the breeding of plants and algae. However, little is known about the underlying mechanisms by which the photosynthetic pigments are altered by heavy-ion irradiation. In our study, the photosynthetic characteristics of progenies from carbon-ion irradiated Selenastrum capricornutum were investigated. Five progenies deficient in chlorophyll a were isolated after carbon-ion exposure. Photosynthetic characteristics, photoprotection capacity and gene expression of the light-harvesting complex in these progenies were further characterized by the measurement of chlorophyll fluorescence parameters (Fv/Fm, ФPSII, NPQ, ETR), the de-epoxidation state of the xanthophyll cycle, the amount of lutein and quantitative real-time PCR. High maximum quantum yield of photosystem II at day 10 and high thermal dissipation ability were observed in progenies #23 and #37 under normal culture condition. Progenies #18, #19 and #20 showed stronger resistance against high levels of light steps than the control group (612-1077 μmol photons m -2 s -1, p< 0.05). The progenies #20 and #23 exhibited strong photoprotection by thermal dissipation and quenching of 3Chl* after 24 h of high light treatment. The mRNA levels of Lhcb5, Lhcbm5 and Lhcbm1 of the light-harvesting complex revealed markedly differential expression in the five progenies irradiated by carbon-ion beams. This work indicates that photosynthetic efficiency, photoprotection ability and the expression of light-harvesting antennae in unicellular green algae can be markedly influenced by irradiation. To our knowledge, this is the first report on changes in the photosynthetic pigments of green algae after treatment with carbon-ion beams. PMID:26919351

  9. Correcting for exposure measurement error in a reanalysis of lung cancer mortality for the Colorado Plateau Uranium Miners cohort.

    PubMed

    Stram, D O; Langholz, B; Huberman, M; Thomas, D C

    1999-09-01

    The exposure estimates used to date for the analysis of lung cancer mortality in the Colorado Plateau Uranium Miners cohort were developed from radon progeny measurements taken in mines beginning in 1951. Since uranium miners were often exposed over long periods of time and since mines were not continuously monitored, much extrapolation and/or interpolation of measured dose-rates was needed in order to develop estimates of exposure for each of the miners in the cohort. We have recently re-examined the interpolation scheme used to create the histories in the light of the fit of a statistical model for the radon progeny measurements taken in mines within the Plateau, and we have computed revised exposure estimates for the large majority of miners in the cohort. This report describes the use of these new model-based revised exposure estimates in the analysis of lung cancer mortality, using follow-up data current through 1990. Specific issues addressed here are (1) the strength of the association between exposure and risk of lung cancer mortality; (2) effects of attained age and time since exposure upon risk of lung cancer mortality; and (3) exposure-rate effects upon risk. Results using the revised exposure estimates are compared to those obtained fitting the same models using the original Public Health Service (PHS) exposure estimates. We found evidence that the new exposure histories provide a better fit to the lung cancer mortality data than do the histories based upon the original PHS dose-rate estimates. In general, the new results show a stronger overall relationship (larger slope estimate) between lung cancer mortality and exposure per unit exposure compared to those obtained with the original estimates, while displaying similar age at exposure and time since exposure effects. In the reanalysis the impact of low dose-rate exposure is found to be relatively unchanged before and after exposure error correction, while the estimate of the effect of high dose

  10. Radon and lung cancer risk: taking stock at the millenium.

    PubMed Central

    Samet, J M; Eradze, G R

    2000-01-01

    Radon is a well-established human carcinogen for which extensive data are available, extending into the range of exposures experienced by the general population. Mounting epidemiologic evidence on radon and lung cancer risk, now available from more than 20 different studies of underground miners and complementary laboratory findings, indicates that risks are linear in exposure without threshold. Radon is also a ubiquitous indoor air pollutant in homes, and risk projections imply that radon is the second leading cause of lung cancer after smoking. Recommended control strategies in the United States and other countries, which include testing of most homes and mitigation of those exceeding guideline levels, have been controversial. Further research is needed, drawing on molecular and cellular approaches and continuing the follow-up of the underground miner cohorts, and scientists should work toward constructing mechanistically based models that combine epidemiologic and experimental data to yield risk estimates with enhanced certainty. Images Figure 1 Figure 2 PMID:10931781

  11. Problems Found Using a Radon Stripping Algorithm for Retrospective Assessment of Air Filter Samples

    SciTech Connect

    Robert Hayes

    2008-04-01

    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 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 of anthropogenic activity estimates with the relative bias being small compared to the dispersion, indicating that the system would not give false positive indications for an appropriately set decision level. By also measuring environmental air sample filters simultaneously with electroplated alpha filters, use of the radon stripping algorithm demonstrated a number of substantial unexpected deviations from calibrated values indicating that the system would give false negative indications. Use of the current algorithm is, therefore, not recommended for general assay applications. 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 activities on air sample filters (not due to radon progeny) around the 200 disintegrations per minute level.

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

    SciTech Connect

    Robert Hayes

    2009-01-23

    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.

  13. Real-time setup to measure radon emission during rock deformation: implications for geochemical surveillance

    NASA Astrophysics Data System (ADS)

    Tuccimei, P.; Mollo, S.; Soligo, M.; Scarlato, P.; Castelluccio, M.

    2015-05-01

    Laboratory experiments can represent a valid approach to unravel the complex interplay between the geochemical behaviour of radon and rock deformation mechanisms. In light of this, we present a new real-time experimental setup for analysing in continuum the alpha-emitting 222Rn and 220Rn daughters over variable stress-strain regimes. The most innovative segment of this setup consists of the radon accumulation chamber obtained from a tough and durable material that can host large cylindrical rock samples. The accumulation chamber is connected, in a closed-loop configuration, to a gas-drying unit and to a RAD7 radon monitor. A recirculating pump moves the gas from the rock sample to a solid-state detector for alpha counting of radon and thoron progeny. The measured radon signal is enhanced by surrounding the accumulation chamber with a digitally controlled heating belt. As the temperature is increased, the number of effective collisions of radon atoms increases favouring the diffusion of radon through the material and reducing the analytical uncertainty. The accumulation chamber containing the sample is then placed into a uniaxial testing apparatus where the axial deformation is measured throughout a linear variable displacement transducer. A dedicated software allows obtaining a variety of stress-strain regimes from fast deformation rates to long-term creep tests. Experiments conducted with this new real-time setup have important ramifications for the interpretation of geochemical anomalies recorded prior to volcanic eruptions or earthquakes.

  14. Real-time setup to record radon emission during rock deformation: implications for geochemical surveillance

    NASA Astrophysics Data System (ADS)

    Tuccimei, P.; Mollo, S.; Soligo, M.; Scarlato, P.; Castelluccio, M.

    2015-02-01

    Laboratory experiments can represent a valid approach to unravel the complex interplay between the geochemical behaviour of radon and rock deformation mechanisms. In light of this, we present a new real-time experimental setup for analyzing in continuum the alpha-emitting 222Rn and 220Rn daughters over variable stress-strain regimes. The most innovative segment of this setup consists of the radon accumulation chamber obtained from a tough and durable material that can host large cylindrical rock samples. The accumulation chamber is connected, in a closed-loop configuration, to a gas-drying unit and to a RAD7 radon monitor. A re-circulating pump moves the gas from the rock sample to a solid-state detector for alpha counting of radon and thoron progeny. The measured radon signal is enhanced by surrounding the accumulation chamber with a digitally controlled heating belt. As the temperature is increased, the number of effective collision of radon atoms increases favouring the diffusion of radon through the material and reducing the analytical uncertainty. The accumulation chamber containing the sample is then placed into an uniaxial testing apparatus where the axial deformation is measured throughout a linear variable displacement transducer. A dedicated software allows to obtain a variety of stress-strain regimes from fast deformation rates to long-term creep tests. Experiments conducted with this new real-time setup have important ramifications for the interpretation of geochemical anomalies recorded prior to volcanic eruptions or earthquakes.

  15. Residents in a high radon potential geographic area: Their risk perception and attitude toward testing and mitigation

    SciTech Connect

    Ferng, S.F.; Lawson, J.K.

    1996-01-01

    Boone County, Indiana was identified by the EPA as one of the high radon potential geographic areas. Health education campaigns are needed to prevent resident`s unnecessary radon exposure. In order to design suitable programs, a questionnaire mail survey was conducted to measure socio-demographic characteristics of County resident`s knowledge about radon, attitude toward radon testing and mitigation, support of education campaigns, and the best media to deliver radon education campaigns. A stratified random sampling method was applied for a total of 400 samples. The number of samples from each township/city was a proportion of their taxable parcels. The survey return rate was 39.8%. The data were analyzed by Epi Info and SPSS. The statistical significant level was set at {alpha} = 0.05. The results showed that resident`s knowledge about radon was at a relatively superficial level. There was no association identified between the knowledge of radon and gender, age, family income, or education, except that females more frequently believed in false effects caused by radon. A significant correlation between radon knowledge and home radon tests was observed. Also found in this study was that respondents with better knowledge about diseases caused by radon had more confidence in radon mitigation actions. Newspaper was chosen by respondents as the most favorite media to deliver radon health education campaigns. Health education campaigns for the residents of Boone County might be conducted by local governments and/or other organizations.

  16. Radon reduction and radon monitoring in the NEMO experiment

    SciTech Connect

    Nachab, A.

    2007-03-28

    The first data of the NEMO 3 neutrinoless double beta decay experiment have shown that the radon can be a non negligible component of the background. In order to reduce the radon level in the gas mixture, it has been necessary first to cover the NEMO 3 detector with an airtight tent and then to install a radon-free air factory. With the use of sensitive radon detectors, the level of radon at the exit of the factory and inside the tent is continuously controlled. These radon levels are discussed within the NEMO 3 context.

  17. Repeated in utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure affects male gonads in offspring, leading to sex ratio changes in F{sub 2} progeny

    SciTech Connect

    Ikeda, Masahiko . E-mail: ikedam@ys2.u-shizuoka-ken.ac.jp; Tamura, Masashi; Yamashita, Junko; Suzuki, Chinatsu; Tomita, Takako

    2005-08-15

    The effects of in utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the reproductive system of male rat offspring (F{sub 1}) and the sex ratio of the subsequent generation (F{sub 2}) were examined. Female Holtzman rats were gavaged with an initial loading dose of 400 ng/kg TCDD prior to mating, followed by weekly maintenance doses of 80 ng/kg during mating, pregnancy, and the lactation period. Maternal exposure to TCDD had no significant effects on fetus/pup (F{sub 1}) mortality, litter size, or sex ratio on gestation day (GD) 20 or postnatal day (PND) 2. The TCDD concentration in maternal livers and adipose tissue on GD20 was 1.21 and 1.81 ng/kg, respectively, and decreased at weaning to 0.72 in the liver and 0.84 in the adipose tissue. In contrast, the TCDD concentration in pup livers was 1.32 ng/kg on PND2 and increased to 1.80 ng/kg at weaning. Ventral prostate weight of male offspring was significantly decreased by TCDD exposure on PND28 and 120 compared with that of controls. Weight of the testes, cauda epididymides, and seminal vesicle, and sperm number in the cauda epididymis were not changed by TCDD exposure at PND120. TCDD- or vehicle-exposed male offspring were mated with unexposed females. The sex ratio (percentage of male pups) of F{sub 2} offspring was significantly reduced in the TCDD-exposed group compared with controls. These results suggest that in utero and lactational TCDD exposures affect the development of male gonads in offspring (F{sub 1}), leading to changes in the sex ratio of the subsequent generation (F{sub 2})

  18. Wind-induced contaminant transport in near-surface soils with application to radon entry into buildings

    SciTech Connect

    Riley, W J

    1996-05-01

    Indoor air exposures to gaseous contaminants originating in soil can cause large human health risks. To predict and control these exposures, the mechanisms that affect vapor transport in near-surface soils need to be understood. In particular, radon exposure is a concern since average indoor radon concentrations lead to much higher risks than are generally accepted for exposure to other environmental contaminants. This dissertation examines an important component of the indoor radon problem: the impacts of wind on soil-gas and radon transport and entry into buildings. The research includes experimental and modeling studies of wind`s interactions with a building`s superstructure and the resulting soil-gas and radon flows in the surrounding soil. In addition to exploring the effects of steady winds, a novel modeling technique is developed to examine the impacts of fluctuating winds on soil-gas and radon transport.

  19. Indoor Radon Measurement in Van

    SciTech Connect

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

    2007-04-23

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

  20. Susceptibility of progeny from crosses among three stocks of coho salmon to infection by Ceratomyxa shasta

    USGS Publications Warehouse

    Hemmingsen, A.R.; McIntyre, J.D.; Fryer, J.L.

    1986-01-01

    Crossbred coho salmon Oncorhynchus kisutch were produced from all possible crosses among three stocks. The relative susceptibility of the progeny to infection by the myxosporean parasite Ceratomyxa shasta was determined by exposure of juvenile fish to Willamette River water that contained the infective stage of the parasite. Susceptibility of coho salmon native to the Columbia River basin to the disease ceratomyxosis was relatively low whereas that of coho salmon from remote locations was relatively high. Susceptibility of crossbred progeny nearly always was intermediate between the susceptibilities of fish from the parental stocks.

  1. Surface-deposition and Distribution of the Radon (222Rn and 220Rn) Decay Products Indoors

    NASA Astrophysics Data System (ADS)

    Espinosa, G.; Tommasino, Luigi

    The exposure to radon (222Rn and 220Rn) decay products is of great concern both in dwellings and workplaces. The model to estimate the lung dose refers to the deposition mechanisms and particle sizes. Unfortunately, most of the dose data available are based on the measurement of radon concentration and the concentration of radon decay products. These combined measurements are widely used in spite of the fact that accurate dose assessments require information on the particle deposition mechanisms and the spatial distribution of radon decay products indoors. Most of the airborne particles and/or radon decay products are deposited onto indoor surfaces, which deposition makes the radon decay products unavailable for inhalation. These deposition processes, if properly known, could be successfully exploited to reduce the exposure to radon decay products. In spite of the importance of the surface deposition of the radon decay products, both for the correct evaluation of the dose and for reducing the exposure, little or no efforts have been made to investigate these deposition processes. Recently, two parallel investigations have been carried out in Rome and at Universidad Nacional Autónoma de México (UNAM) in Mexico City respectively, which address the issue of the surface-deposited radon decay products. Even though these investigations have been carried independently, they complement one another. It is with these considerations in mind that it was decided to report both investigations in the same paper.

  2. Radon: Chemical and physical processes associated with its distribution. Annual progress report

    SciTech Connect

    Castleman, A.W. Jr.

    1992-12-01

    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.

  3. An assessment of radon in groundwater in New York state.

    PubMed

    Shaw, Stephen B; Eckhardt, David A V

    2012-09-01

    A set of 317 samples collected from wells throughout New York State (excluding Long Island) from 2003 through 2008 was used to assess the distribution of radon gas in drinking water. Previous studies have documented high concentrations of radon in groundwater from granitic and metamorphic bedrock, but there have been only limited characterizations of radon in water from sedimentary rock and unconsolidated sand-and-gravel deposits in New York. Approximately 8% of the samples from bedrock wells exceed 89 Bq L (eight times the proposed regulatory limit), but only 2% of samples from sand-and-gravel wells exceed 44 Bq L. Specific metamorphic and sedimentary rock formations in New York are associated with the high radon concentrations, indicating that specific areas of New York could be targeted with efforts to reduce the risk of exposure to radon in groundwater. Additionally, radon in groundwater from the sand-and-gravel aquifers was found to be directly correlated to radon in indoor air when assessed by county. PMID:22850237

  4. An assessment of radon in groundwater in New York State

    USGS Publications Warehouse

    Shaw, Stephen B.; Eckhardt, David A.V.

    2012-01-01

    Abstract: A set of 317 samples collected from wells throughout New York State (excluding Long Island) from 2003 through 2008 was used to assess the distribution of radon gas in drinking water. Previous studies have documented high concentrations of radon in groundwater from granitic and metamorphic bedrock, but there have been only limited characterizations of radon in water from sedimentary rock and unconsolidated sand-and-gravel deposits in New York. Approximately 8% of the samples from bedrock wells exceed 89 Bq L-1 (eight times the proposed regulatory limit), but only 2% of samples from sand-and-gravel wells exceed 44 Bq L-1. Specific metamorphic and sedimentary rock formations in New York are associated with the high radon concentrations, indicating that specific areas of New York could be targeted with efforts to reduce the risk of exposure to radon in groundwater. Additionally, radon in groundwater from the sand-and-gravel aquifers was found to be directly correlated to radon in indoor air when assessed by county.

  5. Influence of urbanization on radon potential in Zhongshan City in the southern China

    NASA Astrophysics Data System (ADS)

    Wang, N.

    2015-12-01

    Radon and radon progeny are the most important contribution to dose from natural sources of radiation. Most studies have demonstrated an increased risk of lung cancer at high concentration of radon for the public. Radon potential map is an essential approach for radon risk assessment. The radon potential map is based on the measured data of soil gas radon concentration and soil air permeability, combined with GIS technology, in Zhongshan City in the Southern China. The preliminary radon survey in ZC was conducted using a portable semiconductor radon monitor RAD-7 and soil air permeability instrument Rad-jok, covering a total area of 1800 km2. The sampling depth for soil gas radon measurement in the field was at the depth of 80 cm below the ground. 222Rn activity concentrations varyed between 0.74 and 158 kBq/m3, and 220Rn between 0.02 and 235 kBq/m3 in soil gas. The average value of 222Rn and 220Rn was 67.6 and 74.8 kBq/m3, respectively. The results show that: (1) the characteristics and distributions of 222Rn/220Rn concentration from soil gas in ZC are obviously related with local lithology (the Middle and the Late Jurassic and the Cretaceous biotitic-granite) and geological formation. High 222Rn/220Rn concentrations were observed in soil gas in the outcrops of weathered granite or filled back granite sands. (2) The distribution model of 220Rn is as same as that of 222Rn. The Wuguishan Mountain areas and in the south-east areas of ZC, covering with granite rocks, are high radon risk districts; the central zones in ZC are low radon potential areas, and part of the northern districts are medium radon potential areas. (3) Urbanization has increased local radon risk in some districts in the west and the north of ZC, where now covering several meters depth weathered granite products, but deposited the Quaternary sediments near surface before. The research was supported by National Natural Science Foundation of China (No. 41474107, No.41274133 and 41074096).

  6. Progeny from dedifferentiated adipocytes display protracted adipogenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Progeny of adipofibroblast cells, derived from mature bovine adipocytes, were used to determine their ability to redifferentiate into lipid-assimilating adipocytes. Traditional cell biology methods were used, including the expression of adipogenic markers such as PPAR'. When exposed to medium supple...

  7. The Effect of Grain Size on Radon Exhalation Rate in Natural-dust and Stone-dust Samples

    NASA Astrophysics Data System (ADS)

    Kumari, Raj; Kant, Krishan; Garg, Maneesha

    Radiation dose to human population due to inhalation of radon and its progeny contributes more than 50% of the total dose from the natural sources which is the second leading cause of lung cancer after smoking. In the present work the dependence of radon exhalation rate on the physical sample parameters of stone dust and natural dust were studied. The samples under study were first crushed, grinded, dried and then passed through sieves with different pore sizes to get samples of various grain sizes (μm). The average value of radon mass exhalation rate is 5.95±2.7 mBqkg-1hr-1 and average value of radon surface exhalation rate is 286±36 mBqm-2 hr-1 for stone dust, and the average value of radon mass exhalation rate is 9.02±5.37 mBqkg-1hr-1 and average value of radon surface exhalation rate is 360±67 mBqm-2 hr-1 for natural dust. The exhalation rate was found to increase with the increase in grain size of the sample. The obtained values of radon exhalation rate for all the samples are found to be under the radon exhalation rate limit reported worldwide.

  8. The April 1994 and October 1994 radon intercomparisons at EML

    SciTech Connect

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

    1995-10-01

    Quality assurance/quality control (QA/QC) are the backbone of many commercial and research processes and programs. QA/QC research tests the state of a functioning system, be it the production of manufactured goods or the ability to make accurate and precise measurements. The quality of the radon measurements in the US have been tested under controlled conditions in semi-annual radon gas intercomparison exercises sponsored by the Environmental Measurements Laboratory (EML) since 1981. The two Calendar Year 1994 radon gas intercomparison exercises were conducted in the EML exposure chamber. Thirty-two groups including US Federal facilities, USDOE contractors, national and state laboratories, universities and foreign institutions participated in these exercises. The majority of the participant`s results were within {+-}10% of the EML value at radon concentrations of 570 and 945 Bq m{sup {minus}3}.

  9. Models for the analysis of radon-exposed populations.

    PubMed

    Lubin, J H

    1988-01-01

    Radon-222 is a radioactive decay product of radium-226 and uranium-238, which are found throughout the crust of the earth. Studies of underground miners clearly show that exposure to radon and its decay products increases the risk of developing lung cancer. Data on standardized mortality ratios from eight cohort studies indicate that the radon-lung cancer relationship is statistically homogeneous, even though cohorts are from different types of mines and from different countries. Regression methods for cohort data based on a Poisson probability model permit a thorough consideration of risk patterns. In this report, we review these methods, wherein the disease rate in each cell of a multi-way table is modeled as a function of the cross-classifying variables. The National Academy of Sciences' Committee on the Biological Effects of Ionizing Radiation uses the Poisson regression approach to develop a model for age-specific lung cancer risk which depends on cumulative exposure, age at risk, and time since exposure. This model is reviewed and its implications discussed. The most important determinant of lung cancer is cigarette smoking. This paper discusses relative risk models for analysis of joint exposure to radon and tobacco products. The review of available studies suggests that the joint relationship of radon and smoking with lung cancer is consistent with a multiplicative model, but a submultiplicative relationship is most likely. An additive model is rejected. PMID:3051700

  10. Models for the analysis of radon-exposed populations

    SciTech Connect

    Lubin, J.H.

    1988-05-01

    Radon-222 is a radioactive decay product of radium-226 and uranium-238, which are found throughout the crust of the earth. Studies of underground miners clearly show that exposure to radon and its decay products increases the risk of developing lung cancer. Data on standardized mortality ratios from eight cohort studies indicate that the radon-lung cancer relationship is statistically homogeneous, even though cohorts are from different types of mines and from different countries. Regression methods for cohort data based on a Poisson probability model permit a thorough consideration of risk patterns. In this report, we review these methods, wherein the disease rate in each cell of a multi-way table is modeled as a function of the cross-classifying variables. The National Academy of Sciences' Committee on the Biological Effects of Ionizing Radiation uses the Poisson regression approach to develop a model for age-specific lung cancer risk which depends on cumulative exposure, age at risk, and time since exposure. This model is reviewed and its implications discussed. The most important determinant of lung cancer is cigarette smoking. This paper discusses relative risk models for analysis of joint exposure to radon and tobacco products. The review of available studies suggests that the joint relationship of radon and smoking with lung cancer is consistent with a multiplicative model, but a submultiplicative relationship is most likely. An additive model is rejected. 58 references.

  11. Development of a data base on radon in US homes and applications. Final technical report

    SciTech Connect

    Cohen, B.L.

    1991-12-31

    This research led to the development of the compilation of data on radon in homes which is included in this document. This research also contributed to the development of two papers analyzing the results. These are a case control study test and tests of the liner no-threshold theory for lung cancer induced by exposure to radon in residential buildings.

  12. Development of a data base on radon in US homes and applications

    SciTech Connect

    Cohen, B.L.

    1991-01-01

    This research led to the development of the compilation of data on radon in homes which is included in this document. This research also contributed to the development of two papers analyzing the results. These are a case control study test and tests of the liner no-threshold theory for lung cancer induced by exposure to radon in residential buildings.

  13. Shelter and indoor air in the twenty-first century: Radon, smoking and lung cancer risks

    SciTech Connect

    Fabrikant, J.I.

    1988-04-01

    This document describes the relationship between indoor radon exposure, cigarette smoking, and lung cancer. The author explains the sources of radon, the tissues at risk, the human populations most likely to be affected, and the estimates of lung cancer in the population. 6 refs., 2 tabs. (TEM)

  14. Radon in Ingleborough / Clapham Cave, North Yorkshire, UK.

    NASA Astrophysics Data System (ADS)

    Gillmore, Gavin

    2015-04-01

    Atmospheric radon concentration was measured at Ingleborough Cave, North Yorkshire during the summer of 2004, and the autumn / winter of 2004/5. Significantly, Ingleborough Cave forms part of a larger system which includes the world famous Gaping Gill pothole. This plunges 105 m (334 ft), contains the tallest unbroken waterfall in England and one of the largest known underground chambers in the UK. Measurements were taken to assess the effects of seasonal and spatial variation, elevation and ventilation on radon concentration in Ingleborough. In this study personal dose exposures for three groups of cave user were identified, and the performance of a variety of radon detection systems evaluated. Summer radon concentrations inside the cave peaked at around 7,000 Bq m-3, although average concentrations were less than 5,000 Bq m-3. During the winter measurement period, average concentrations were around 100 Bq m-3, and a winter / summer ration therefore of 47,4. The average annual radon concentration exceeded the legislative limitations for the workplace of 400 Bq m-3 due in part to a failed fan in the ventilation system. When the fan was running we noted an 80% reduction in radon concentrations although reliability of the fan was problematic due to extensive but relatively rare flooding of the cave system. The radon dose experienced by cave workers and guides in this study exceeded the Ionisation Radiation Regulations limit of 5 mSv/annum, and highlighted that for health and safety reasons the ventilation system should be fully operational during the high radon concentration summer months. Keywords: Radon, Cave, Ingleborough, Detection methods

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

    SciTech Connect

    Braeuner, Elvira V.; Andersen, Claus E.; Sorensen, Mette; Jovanovic Andersen, Zorana; Gravesen, Peter; Ulbak, Kaare; Hertel, Ole; Pedersen, Camilla; Overvad, Kim; Tjonneland, Anne; Raaschou-Nielsen, Ole

    2012-10-15

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

  16. Radon adsorbed in activated charcoal—a simple and safe radiation source for teaching practical radioactivity in schools and colleges

    NASA Astrophysics Data System (ADS)

    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.

  17. Seasonal Variation of Indoor Radon Concentration in the Tropics: Comparative studies between Kuala Lumpur, Malaysia and Kerala, India

    SciTech Connect

    Mahat, R. H.; Amin, Y. M.; Jojo, P. J.; Pereira, C. E.

    2011-03-30

    The radiation dose received by man from indoor radon and its progeny is the largest at more than 50% of total dose received. The seasonal variation of indoor radon concentration in Kerala, India and Kuala Lumpur, Malaysia were studied. The Southwest coast of the Kerala state in India is known to have very high levels of natural background radiation owing to the rare earths rich monazite sand available in large amount. Kuala Lumpur, Malaysia used to be a famous tin mining area where it was done using open cast system. One-year measurements of radon concentration in houses were done for these two regions. It was found that there is considerable seasonal variation in the levels of radon in Kerala but the variation in Kuala Lumpur is only less than 10%.

  18. Radon concentration and working level in the Exploratory Studies Facility (ESF)

    SciTech Connect

    Stiver, J.H.; Tung, Chao-Hsiung

    1995-06-01

    Radon-222 ({sup 222}Rn) and {sup 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, {sup 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 {sup 222}Rn and {sup 222}Rn progeny monitoring was initiated. Two systems each were employed for {sup 222}Rn and {sup 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 {sup 222}Rn concentration in the ESF. This was true even during periods of ventilation shutdown.

  19. Towards a Brazilian radon map: consortium radon Brazil.

    PubMed

    Silva, N C; Bossew, P; Ferreira Filho, A L; Campos, T F C; Pereira, A J S C; Yoshimura, E M; Veiga, L H S; Campos, M P; Rocha, Z; Paschuk, S A; Bonotto, D M

    2014-07-01

    Recently, the idea of generating radon map of Brazil has emerged. First attempts of coordinating radon surveys--carried out by different groups across the country--and initial discussions on how to proceed on a larger scale were made at the First Brazilian Radon Seminary, Natal, September 2012. Conventionally, it is believed that indoor radon is no major problem in Brazil, because the overall benign climate usually allows high ventilation rates. Nevertheless, scattered measurements have shown that moderately high indoor radon concentrations (up to a few hundred Bq m⁻³) do occur regionally. Brazilian geology is very diverse and there are regions where an elevated geogenic radon potential exists or is expected to exist. Therefore, a Brazilian Radon Survey is expected to be a challenge, although it appears an important issue, given the rising concern of the public about the quality of its environment. PMID:24743768

  20. A diffusion chamber for passive separated measurements of radon/thoron concentration in dwellings

    NASA Astrophysics Data System (ADS)

    Torabi Nabil, F.; Hosseini Pooya, S. M.; Shamsaie Zafarghandi, M.; Taheri, M.

    2012-12-01

    In this research, a passive diffusion chamber has been developed for separated measurement of radon and thoron. The chamber consists of two volumes which are separated by a fiber glass filter. Two lexan polycarbonate nuclear track detectors (film) are placed inside of the volumes to detect the alpha particles of radon/thorn and/or their progenies. Another lexan polycarbonate detector covered with an optimized thickness of an attenuator is placed outside of the chamber to measure only 212Po which its concentration can be related to that of long-life thoron progeny, 212Pb. The sensitivities have been measured by 2.06 and 0.053 [tracks cm-2(kBq m-3 day)-1] values for radon and thoron respectively inside of the chamber, and 7960 [tracks cm-2(kBq m-3 day)-1] value for thoron outside of the chamber. So the system can be successfully used for separated measurement of an extended range of radon/thoron concentrations in dwellings.

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

    SciTech Connect

    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 {sup 218}Po atoms have unit charge at the end of their recoil after decay from {sup 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.

  2. Radon depth migration

    SciTech Connect

    Hildebrand, S.T. ); Carroll, R.J. )

    1993-02-01

    A depth migration method is presented that used Radon-transformed common-source seismograms as input. It is shown that the Radon depth migration method can be extended to spatially varying velocity depth models by using asymptotic ray theory (ART) to construct wavefield continuation operators. These operators downward continue an incident receiver-array plane wave and an assumed point-source wavefield into the subsurface. The migration velocity model is constrain to have longer characteristic wavelengths than the dominant source wavelength such that the ART approximations for the continuation operators are valid. This method is used successfully to migrate two synthetic data examples: (1) a point diffractor, and (2) a dipping layer and syncline interface model. It is shown that the Radon migration method has a computational advantage over the standard Kirchhoff migration method in that fewer rays are computed in a main memory implementation.

  3. Radon: a bibliography

    SciTech Connect

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

    1981-01-01

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

  4. Evaluation of radon emissions and potential control requirements

    SciTech Connect

    Not Available

    1989-08-01

    This report provides estimates of radon release rates at the Weldon Spring Quarry (WSQ) for existing conditions and conditions which are expected to exist as the bulk waste is excavated. It also estimates radon release rates for the Temporary Storage Area (TSA). In 1989, Rn-222 concentrations at the fence line exceeded DOE guidelines. Data on working level concentrations at one monitoring station indicate an effective whole body dose rate of 0.75 mrem/hr for radon daughters and 0.74 mrem/hr for thoron daughters at one meter above the quarry waste. Since some of the calculations are based on assumptions, they show only the relative difference in radon release between present conditions and either of two excavation scenarios. They can be used in calculations of public exposure and potential health effects to evaluate the relative merits of each excavation scenario in comparison with present release conditions. The model used to make the estimates in this report is useful for estimating the radon release rate for the entire period of excavation, but it is not suitable for estimating worker exposure over short periods of time. Therefore, worker exposure and appropriate requirements for personal protective equipment will be determined as the excavation proceeds. 19 refs., 13 tabs.

  5. The health effects of radon and uranium on the population of Kazakhstan.

    PubMed

    Bersimbaev, Rakmetkazhy I; Bulgakova, Olga

    2015-01-01

    The radioactive contamination is a significant factor affecting the environment and human health. Radon and its decay products are the major contributors to human exposure from natural radiation sources. World Health Organization has identified the chronic residential exposure to radon and its decay products as the second cause of lung cancer after tobacco consumption and also as the main risk-factor in never smokers. The high levels of radon are observed in the North and East areas of Kazakhstan because of the natural radiation sources and the long-term and large-scale mining of uranium. The genotoxic effects of radon on population of Kazakhstan are poorly understood, in spite of the fact that many regions of the country contain the high levels of radon. Studies elucidating potential health risk among population exposed to radon and genotoxic effect of radon in Kazakhstan are very limited or they have never been addressed in some areas. In this review, we are presenting available data on the residential radon exposure of humans in uranium mining and milling areas in the North and East areas of Kazakhstan. PMID:27350814

  6. Radon assay for SNO+

    SciTech Connect

    Rumleskie, Janet

    2015-12-31

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

  7. Radon assay for SNO+

    NASA Astrophysics Data System (ADS)

    Rumleskie, Janet

    2015-12-01

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

  8. What Teachers Should Know about Radon.

    ERIC Educational Resources Information Center

    Bettis, Clifford; Throckmorton, Carl

    1991-01-01

    Attempts to clear up misunderstandings about radon and outlines information teachers can convey to their students. Includes a brief history of radon, health threats posed by radon, methods to measure radon quantities, homeowner risks and preventative actions, and a glossary of radon terms. (MDH)

  9. Long-term radon concentrations estimated from 210Po embedded in glass

    USGS Publications Warehouse

    Lively, R.S.; Steck, D.J.

    1993-01-01

    Measured surface-alpha activity on glass exposed in radon chambers and houses has a linear correlation to the integrated radon exposure. Experimental results in chambers and houses have been obtained on glass exposed to radon concentrations between 100 Bq m-3 and 9 MBq m-3 for periods of a few days to several years. Theoretical calculations support the experimental results through a model that predicts the fractions of airborne activity that deposit and become embedded or adsorbed. The combination of measured activity and calculated embedded fraction for a given deposition environment can be applied to most indoor areas and produces a better estimate for lifetime radon exposure than estimates based on short-term indoor radon measurements.

  10. Radon in Irish Show Caves - Personal Monitoring Data From 2001-2006

    SciTech Connect

    Currivan, L.; Murray, M.; O'Colmain, M.; Pollard, D.

    2008-08-07

    The European Directive 96/29/EURATOM and its transposition into national legislation demands the application of radiation protection measures if the presence of radon and radon decay products leads to significant increase in exposures of workers. Irish legislation further demands that laboratories carrying out radon measurements operate a high level quality assurance programme. As a result of a reconnaissance survey regular measurements of show cave guides have been made in order to assess exposure to radon in such workplaces and to ascertain that the limits set for radon are not exceeded. In 2000, an action level of 400 Bqm{sup -3}, was established. Doses in the range 0.3-12.0 mSv have been estimated for workers for the period 2001-2006.

  11. Radon in Irish Show Caves—Personal Monitoring Data From 2001-2006

    NASA Astrophysics Data System (ADS)

    Currivan, L.; Murray, M.; O'Colmain, M.; Pollard, D.

    2008-08-01

    The European Directive 96/29/EURATOM and its transposition into national legislation demands the application of radiation protection measures if the presence of radon and radon decay products leads to significant increase in exposures of workers. Irish legislation further demands that laboratories carrying out radon measurements operate a high level quality assurance programme. As a result of a reconnaissance survey regular measurements of show cave guides have been made in order to assess exposure to radon in such workplaces and to ascertain that the limits set for radon are not exceeded. In 2000, an action level of 400 Bqm-3, was established. Doses in the range 0.3-12.0 mSv have been estimated for workers for the period 2001-2006.

  12. Lung cancer in never-smokers: a case-control study in a radon-prone area (Galicia, Spain).

    PubMed

    Torres-Durán, María; Ruano-Ravina, Alberto; Parente-Lamelas, Isaura; Leiro-Fernández, Virginia; Abal-Arca, José; Montero-Martínez, Carmen; Pena-Álvarez, Carolina; González-Barcala, Francisco Javier; Castro-Añón, Olalla; Golpe-Gómez, Antonio; Martínez, Cristina; Mejuto-Martí, María José; Fernández-Villar, Alberto; Barros-Dios, Juan Miguel

    2014-10-01

    The aim of the study was to assess the effect of residential radon exposure on the risk of lung cancer in never-smokers and to ascertain if environmental tobacco smoke modifies the effect of residential radon. We designed a multicentre hospital-based case-control study in a radon-prone area (Galicia, Spain). All participants were never-smokers. Cases had an anatomopathologically confirmed primary lung cancer and controls were recruited from individuals undergoing minor, non-oncological surgery. Residential radon was measured using alpha track detectors. We included 521 individuals, 192 cases and 329 controls, 21% were males. We observed an odds ratio of 2.42 (95% CI 1.45-4.06) for individuals exposed to ≥200 Bq·m(-3) compared with those exposed to <100 Bq·m(-3). Environmental tobacco smoke exposure at home increased lung cancer risk in individuals with radon exposure>200 Bq·m(-3). Individuals exposed to environmental tobacco smoke and to radon concentrations>200 Bq·m(-3) had higher lung cancer risk than those exposed to lower radon concentrations and exposed to environmental tobacco smoke. Residential radon increases lung cancer risk in never-smokers. An association between residential radon exposure and environmental tobacco smoke on the risk of lung cancer might exist. PMID:25034571

  13. Correlation of indoor radon concentration to commonly available geologic data

    NASA Astrophysics Data System (ADS)

    Burkhart, James F.; Huber, Thomas P.

    1993-03-01

    Over the last several years, the inhalation of decay products coming from radon-222 has become a national health concern. It is estimated that somewhere between 16,000 and 20,000 people die annually in the United States from lung cancer due to exposure to these decay products. Nationwide, 95% of all homes have not been tested for radon, and so it would seem that any methodology that could give a general idea of indoor radon concentrations (without actually testing the house itself) might be useful. While not intended to replace a radon test, which is both simple and inexpensive, our project attempts to predict indoor radon concentrations based on easily obtainable information from Soil Conservation Service county soil surveys and US Geological Survey surficial geology maps. We have chosen four parameters: soil permeability, surficial geology, soil shrink-swell potential, and distance to the nearest geologic fault. Of these four variables, surficial geology and distance to fault correlated well to winter indoor radon concentrations as measured by short-term (48-h) tests. While it is understood that there are limits to this methodology, primarily because of map scale problems, the correlations mentioned above were very strong and suggest further study would be useful.

  14. A novel detection of radon based on its decay product inducing conformational changes of an aptamer probe.

    PubMed

    Long, Minzhi; Deng, Han; Tian, Gang; Song, Chunli; Liu, Hongwen; Shen, Yi; Lv, Changyin

    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(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. PMID:27566356

  15. Studies on the reduction of radon plate-out

    SciTech Connect

    Bruemmer, M.; Nakib, M.; Calkins, R.; Cooley, J. Sekula, S.

    2015-08-17

    The decay of common radioactive gases, such as radon, produces stable isotopes by a sequence of daughter particles with varied half-lives. These daughter particles are a significant source of gamma, neutron, and alpha (α) particle backgrounds that can mimic desired signals in dark matter and neutrinoless double beta decay experiments. In the LUMINA Laboratory at Southern Methodist University (SMU), studies of radon plate-out onto copper samples are conducted using one of XIA’s first five UltraLo 1800 alpha counters. We present results from investigations into various mitigation approaches. A custom-built copper holder (in either plastic or metal) has been designed and produced to maximize the copper’s exposure to {sup 220}Rn. The {sup 220}Rn source is a collection of camping lantern mantles. We present the current status of control and experimental methods for addressing radon exposure levels.

  16. {sup 210}Po as a long-term integrating radon indicator in the indoor environment. Final report

    SciTech Connect

    Not Available

    1992-12-31

    Exposure to radon (Rn-222) decay products in the indoor environment is suspected of being a significant lung cancer agent in many countries. But quantification of the contemporary lung cancer risk (i.e. probability) on an individual basis is not an easy task. Only past exposures are relevant and assessing individual exposures in retrospect is associated with large uncertainties, if possible at all. One way to extend the validity of contemporary measurements to past decades is to measure long-lived decay products of radon, the long-lived radon daughters. After our laboratory had exemplified the correlation between implanted Po-210 and the estimated radon exposures in six different dwellings, the US Department of Energy and the Swedish Radiation Protection Institute granted funds for a one-year study, ``{sup 210}Po as a Long-Term Integrating Radon Indicator in the Indoor Environment.`` In this report the work performed under these two contracts is reported.

  17. Transport of radon and thoron at the earth`s surface. Progress report, 1 January 1991--1 January 1992

    SciTech Connect

    Schery, S.D.

    1991-06-15

    This report covers progress under the current funding period Jan. 1, 1991 to Jan. 1, 1992 and presents the continuation proposal for Jan. 1, 1992 to Jan. 1, 1993. The previous progress report was submitted in May 1990, so activities during the last half of 1990 will also be included. Major activities over the last year have centered on the study of disequilibrium of radon progeny near the earth`s surface and the sources of thoron in indoor air. In addition, we have carried out supplemental measurements of radon sorption coefficients in porous materials focusing on the physical mechanism of sorption.

  18. RESIDENTIAL RADON RESISTANT CONSTRUCTION FEATURE SELECTION SYSTEM

    EPA Science Inventory

    The report describes a proposed residential radon resistant construction feature selection system. The features consist of engineered barriers to reduce radon entry and accumulation indoors. The proposed Florida standards require radon resistant features in proportion to regional...

  19. Domestic and personal determinants of the contamination of individuals by household radon daughters

    SciTech Connect

    Stebbings, J.H.; Kardatzke, D.R.; Toohey, R.E.; Essling, M.E.; Pagnamenta, A.

    1986-01-01

    Radon daughters were counted by gamma spectroscopy from 180 adult residents of eastern Pennsylvania during the winter of 1983-84. Body radon daughter contamination is an index of relative individual respiratory exposures to radon daughters. These can be related to household radon levels, and to personal risk factors such as sex and tobacco smoking. Over 75% of this Pennsylvania population appeared to have environmentally enhanced radon daughter contamination; 59% had counting rates greater than 2 s.d. above background. House radon levels were the major determinants of radon daughters contamination in the 112 subjects for which both sets of measurements were available (p<.001). Both sex (<.02) and cigarette smoking (p<.005) were found to significantly modify that relationship, after nonlinear adjustment for travel times. Using a logarithmic model, for a given radon level body contamination by radon daughters in females was 2-3.5x higher than in males. Nonsmokers had 2-4x higher levels of contamination than smokers. For female nonsmokers relative to male smokers (which in general corresponds to the population of major concern relative to the population from which risk estimates have been derived), the excesses multiply. These results are for total contamination, both internal and external.

  20. Metaphase chromosome aberrations as markers of radiation exposure and dose

    SciTech Connect

    Brooks, A.L.; Khan, M.A.; Jostes, R.F.; Cross, F.T.

    1992-10-01

    Chromosome aberration frequency provides the most reliable biological marker of dose for detecting acute accidental radiation exposure. Significant radiation-induced changes in the frequency of chromosome aberrations can be detected at very low doses. Our paper provides information on using molecular chromosome probes ``paints`` to score chromosome damage and illustrates how technical advances make it possible to understand mechanisms involved during formation of chromosome aberrations. In animal studies chromosome aberrations provide a method to relate cellular damage to cellular dose. Using an In vivo/In vitro approach aberrations provided a biological marker of dose from radon progeny exposure which was used to convert WLM to dose in rat tracheal epithelial cells. Injection of Chinese hamsters with {sup 144}Ce which produced a low dose rate exposure of bone marrow to either low-LET radiation increased the sensitivity of the cells to subsequent external exposure to {sup 60}Co. These studies demonstrated the usefulness of chromosome damage as a biological marker of dose and cellular responsiveness.

  1. Metaphase chromosome aberrations as markers of radiation exposure and dose

    SciTech Connect

    Brooks, A.L.; Khan, M.A.; Jostes, R.F.; Cross, F.T.

    1992-10-01

    Chromosome aberration frequency provides the most reliable biological marker of dose for detecting acute accidental radiation exposure. Significant radiation-induced changes in the frequency of chromosome aberrations can be detected at very low doses. Our paper provides information on using molecular chromosome probes paints'' to score chromosome damage and illustrates how technical advances make it possible to understand mechanisms involved during formation of chromosome aberrations. In animal studies chromosome aberrations provide a method to relate cellular damage to cellular dose. Using an In vivo/In vitro approach aberrations provided a biological marker of dose from radon progeny exposure which was used to convert WLM to dose in rat tracheal epithelial cells. Injection of Chinese hamsters with [sup 144]Ce which produced a low dose rate exposure of bone marrow to either low-LET radiation increased the sensitivity of the cells to subsequent external exposure to [sup 60]Co. These studies demonstrated the usefulness of chromosome damage as a biological marker of dose and cellular responsiveness.

  2. Predictors of Indoor Radon Concentrations in Pennsylvania, 1989–2013

    PubMed Central

    Casey, Joan A.; Ogburn, Elizabeth L.; Rasmussen, Sara G.; Irving, Jennifer K.; Pollak, Jonathan; Locke, Paul A.

    2015-01-01

    Background Radon is the second-leading cause of lung cancer worldwide. Most indoor exposure occurs by diffusion of soil gas. Radon is also found in well water, natural gas, and ambient air. Pennsylvania has high indoor radon concentrations; buildings are often tested during real estate transactions, with results reported to the Department of Environmental Protection (PADEP). Objectives We evaluated predictors of indoor radon concentrations. Methods Using first-floor and basement indoor radon results reported to the PADEP between 1987 and 2013, we evaluated associations of radon concentrations (natural log transformed) with geology, water source, building characteristics, season, weather, community socioeconomic status, community type, and unconventional natural gas development measures based on drilled and producing wells. Results Primary analysis included 866,735 first measurements by building, with the large majority from homes. The geologic rock layer on which the building sat was strongly associated with radon concentration (e.g., Axemann Formation, median = 365 Bq/m3, IQR = 167–679 vs. Stockton Formation, median = 93 Bq/m3, IQR = 52–178). In adjusted analysis, buildings using well water had 21% higher concentrations (β = 0.191, 95% CI: 0.184, 0.198). Buildings in cities (vs. townships) had lower concentrations (β = –0.323, 95% CI: –0.333, –0.314). When we included multiple tests per building, concentrations declined with repeated measurements over time. Between 2005 and 2013, 7,469 unconventional wells were drilled in Pennsylvania. Basement radon concentrations fluctuated between 1987 and 2003, but began an upward trend from 2004 to 2012 in all county categories (p < 0.001), with higher levels in counties having ≥ 100 drilled wells versus counties with none, and with highest levels in the Reading Prong. Conclusions Geologic unit, well water, community, weather, and unconventional natural gas development were associated with indoor radon

  3. Radon mapping strategies in Austria.

    PubMed

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

    2015-11-01

    According to current European and international recommendations (e.g. by IAEA, WHO and European Union), countries shall identify high radon areas. In Austria, this task was initiated already in the early 1990s, which yielded the first Austrian Radon Potential Map. This map is still in use, updated with recent indoor radon data in 2012. The map is based on radon gas measurements in randomly selected dwellings, normalised to a standard situation. To meet the current (legal) requirements, uncertainties in the existing Austrian radon map should be reduced. A new indoor radon survey with a different sampling strategy was started, and possible mapping methods are studied and tested. In this paper, the methodology for the existing map as well as the planned strategies to improve this map is discussed. PMID:25911411

  4. Compact anti-radon facility

    NASA Astrophysics Data System (ADS)

    Fajt, L.; Kouba, P.; Mamedov, F.; Smolek, K.; Štekl, I.; Fojtík, P.; Hýža, M.; Hůlka, J.; Jílek, K.; Stoček, P.; Veselý, J.; Busto, J.

    2015-08-01

    Suppression of radon background is one of main tasks in ultra-low background experiments. The most promising technique for suppression of radon is its adsorption on charcoal. Within the frame of the NEMO-3 experiment, radon trapping facility (RTF) was installed in Modane underground laboratory in 2004. Based on long-term experience with this facility a new compact transportable anti-radon facility was constructed in cooperation among IEAP CTU, SÚRO and ATEKO company. The device provides 20m3/h of purified air (air radon activity at the output ˜10mBq/m3). The basic features and preliminary results of anti-radon device testing are presented.

  5. Compact anti-radon facility

    SciTech Connect

    Fajt, L.; Kouba, P.; Mamedov, F.; Smolek, K.; Štekl, I.

    2015-08-17

    Suppression of radon background is one of main tasks in ultra-low background experiments. The most promising technique for suppression of radon is its adsorption on charcoal. Within the frame of the NEMO-3 experiment, radon trapping facility (RTF) was installed in Modane underground laboratory in 2004. Based on long-term experience with this facility a new compact transportable anti-radon facility was constructed in cooperation among IEAP CTU, SÚRO and ATEKO company. The device provides 20m{sup 3}/h of purified air (air radon activity at the output ∼10mBq/m{sup 3}). The basic features and preliminary results of anti-radon device testing are presented.

  6. DOSIMETRY OF LOCALIZED ACCUMULATIONS OF CIGARETTE SMOKE AND RADON PROGENY AT BIFURCATIONS

    EPA Science Inventory

    Inhalation risk assessment protocols are frequently based upon assumptions of uniform particle deposition patterns and homogenous clearance processes within human lung airways. owever, experiments conducted with cigarette smoke and surrogate airway systems reveal "hot spots" at u...

  7. Cold storage of the adult stage of Gonatocerus ashmeadi girault: the impact on maternal and progeny quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of storage of adult G. ashmeadi at 2, 5 and 10°C on maternal and the unstored progeny fitness qualities was examined. The maternal generation did not survive 5 d exposure to 2°C and those stored at 10°C survived longer than those held at 5°C. Oviposition of the maternal generation conti...

  8. International comparison of cave radon concentrations identifying the potential alpha radiation risks to British cave users

    SciTech Connect

    Hyland, R.; Gunn, J.

    1994-08-01

    Elevated concentrations of {sup 222}Rn have been recorded in many limestone caves throughout the world. As prolonged exposure to high radon concentrations has been linked to cancer and tumors, particularly of the lung, a national survey of radon in British caves was undertaken. Passive radon detectors were exposed at 250 sites in 47 caves over four 7-d sampling periods. Mean concentrations ranging from 454-8,868 Bq m{sup {minus}3} were recorded. In one system, in the Peak District, radon concentrations of 155,000 Bq m{sup {minus}3} were recorded. The results indicate that the potential radiation dose from a single 4-h trip could exceed the national average annual background radiation dose (for the UK) from radon of 1.25 mSv. 18 refs., 3 tabs.

  9. Implementation of the new international standards in Swiss legislation on radon protection in dwellings.

    PubMed

    Palacios Gruson, Martha; Barazza, Fabio; Murith, Christophe; Ryf, Salome

    2015-04-01

    The current revision of the Swiss Radiological Protection Ordinance aims to bring Swiss legislation in line with new international standards. In future, the control of radon exposure in dwellings will be based on a reference level of 300 Bq m(-3). Since this value is exceeded in >10 % of the buildings so far investigated nationwide, the new strategy requires the development of efficient measures to reduce radon-related health risks at an acceptable cost. The minimisation of radon concentrations in new buildings is therefore of great importance. This can be achieved, for example, through the enforcement of building regulations and the education of construction professionals. With regard to radon mitigation in existing buildings, synergies with the ongoing renewal of the building stock should be exploited. In addition, the dissemination of knowledge about radon and its risks needs to be focused on specific target groups, e.g. notaries, who play an important information role in real estate transactions. PMID:25342610

  10. Determination of indoor radon concentrations at the elementary schools of Fatih district in Istanbul

    NASA Astrophysics Data System (ADS)

    Kurt, A.; Yalcin, L. Sahin; Oktem, Y.; Akkus, B.; Bozkurt, E.; Hafizoglu, N.; Ozturk, F. C.; Aytan, O.; Ertoprak, A.

    2016-03-01

    Radon is an odorless, tasteless, colorless noble radioactive gas which is produced within the radioactive decay chain of Uranium. The Radon forms in rocks, diffuses into soil and then escapes into atmosphere. When human exposure to high concentration of radon gas from inside, risk of developing lung cancer is increased. There are many methods to determine 222Rn concentration in the air. In this study, radon concentration of confined air spaces were measured by using LR-115 solid state nuclear track detectors. 509 LR-115 nuclear trace detectors were placed to 25 schools in Fatih District and they effective dose values were calculated. The results of measurements showed that the radon concentration varies between 40-395 Bq/m3. This results compared with Turkey's limits (400 Bq/m3) are low, conversely higher compared with WHO's limits (100 Bq/m3).

  11. International comparison of cave radon concentrations identifying the potential alpha radiation risks to British cave users.

    PubMed

    Hyland, R; Gunn, J

    1994-08-01

    Elevated concentrations of 222Rn have been recorded in many limestone caves throughout the world. As prolonged exposure to high radon concentrations has been linked to cancer and tumors, particularly of the lung (National Academy of Science 1988; Eatough and Henshaw 1990), a national survey of radon in British caves was undertaken. Passive radon detectors were exposed at 250 sites in 47 caves over four 7-d sampling periods. Mean concentrations ranging from 454-8,868 Bq m-3 were recorded. In one system, in the Peak District, radon concentrations of 155,000 Bq m-3 were recorded. The results indicate that the potential radiation dose from a single 4-h trip could exceed the national average annual background radiation dose (for the UK) from radon of 1.25 mSv. PMID:8026972

  12. Chemical methods for removing radon and radon daughters from air.

    PubMed

    Stein, L

    1972-03-31

    Liquid bromine trifluoride and the solid complexes ClF(2)SbF(6), BrF(2)SbF(6), BrF(4)Sb(2)F(11), IF(4)(SbF(6))(3) and BrF(2)BiF(6) react spontaneously with radon and radon daughters at 25 degrees C, converting the radioelements to nonvolatile ions and compounds. The reagents can be used in gas-scrubbing units to remove radon and radon daughters from air. The halogen fluoride-antimony pentafluoride complexes may be suitable for purifying air in uranium mines and analyzing radon in air, since they have low dissociation pressures at 25 degrees C and are less hazardous to handle than liquid halogen fluorides. PMID:5013675

  13. The cost effectiveness of radon mitigation in existing German dwellings--a decision theoretic analysis.

    PubMed

    Haucke, Florian

    2010-11-01

    Radon is a naturally occurring inert radioactive gas found in soils and rocks that can accumulate in dwellings, and is associated with an increased risk of lung cancer. This study aims to analyze the cost effectiveness of different intervention strategies to reduce radon concentrations in existing German dwellings. The cost effectiveness analysis (CEA) was conducted as a scenario analysis, where each scenario represents a specific regulatory regime. A decision theoretic model was developed, which reflects accepted recommendations for radon screening and mitigation and uses most up-to-date data on radon distribution and relative risks. The model was programmed to account for compliance with respect to the single steps of radon intervention, as well as data on the sensitivity/specificity of radon tests. A societal perspective was adopted to calculate costs and effects. All scenarios were calculated for different action levels. Cost effectiveness was measured in costs per averted case of lung cancer, costs per life year gained and costs per quality adjusted life year (QALY) gained. Univariate and multivariate deterministic and probabilistic sensitivity analyses (SA) were performed. Probabilistic sensitivity analyses were based on Monte Carlo simulations with 5000 model runs. The results show that legal regulations with mandatory screening and mitigation for indoor radon levels >100 Bq/m(3) are most cost effective. Incremental cost effectiveness compared to the no mitigation base case is 25,181 euro (95% CI: 7371 euro-90,593 euro) per QALY gained. Other intervention strategies focussing primarily on the personal responsibility for screening and/or mitigative actions show considerably worse cost effectiveness ratios. However, targeting radon intervention to radon-prone areas is significantly more cost effective. Most of the uncertainty that surrounds the results can be ascribed to the relative risk of radon exposure. It can be concluded that in the light of

  14. Invited Article: Radon and thoron intercomparison experiments for integrated monitors at NIRS, Japan

    SciTech Connect

    Janik, M. Ishikawa, T.; Omori, Y.; Kavasi, N.

    2014-02-15

    Inhalation of radon ({sup 222}Rn) and its short-lived decay products and of products of the thoron ({sup 220}Rn) series accounts for more than half of the effective dose from natural radiation sources. At this time, many countries have begun large-scale radon and thoron surveys and many different measurement methods and instruments are used in these studies. Consequently, it is necessary to improve and standardize technical methods of measurements and to verify quality assurance by intercomparisons between laboratories. Four international intercomparisons for passive integrating radon and thoron monitors were conducted at the NIRS (National Institute of Radiological Sciences, Japan). Radon exercises were carried out in the 24.4 m{sup 3} inner volume walk-in radon chamber that has systems to control radon concentration, temperature, and humidity. Moreover, the NIRS thoron chamber with a 150 dm{sup 3} inner volume was utilized to provide three thoron intercomparisons. At present, the NIRS is the only laboratory world-wide that has carried out periodic thoron intercomparison of passive monitors. Fifty laboratories from 26 countries participated in the radon intercomparison, using six types of detectors (charcoal, CR-39, LR 115, polycarbonate film, electret plate, and silicon photodiode). Eighteen laboratories from 12 countries participated in the thoron intercomparisons, using two etch-track types (CR-39 and polycarbonate) detectors. The tests were made under one to three different exposures to radon and thoron. The data presented in this paper indicated that the performance quality of laboratories for radon measurement has been gradually increasing. Results of thoron exercises showed that the quality for thoron measurements still needs further development and additional studies are needed to improve its measuring methods. The present paper provides a summary of all radon and thoron international intercomparisons done at NIRS from 2007 to date and it describes the

  15. Recoil-deposited Po-210 in radon dwellings

    SciTech Connect

    Samuelsson, C.

    1990-12-31

    Short-lived decay products of Rn-222 plate out on all surfaces in a house containing radon gas. Following the subsequent alpha decays of the mother nuclei, the daughter products Pb-214 and Pb-210 are superficially and permanently absorbed. Due to its long half-life (22 y) the activity of absorbed Pb-210 accumulates in the surface. The activity of Pb-210, or its decay products, can thus reflect the past randon daughter and plate-out history of a house over several decades. Our results and experience from measurements of Po-210 and Rn-222 in 22 dwellings will be presented. In these studies the Po-210 surface activity of one plane glass sheet per dwelling (window panes were not used) has been determined and compared with the period of exposure times the mean radon concentration measured over a two-month period. Considering the large uncertainty in the integrated radon exposure estimate the surface {sup 210}Po correlates well (r=0.73) with the accumulated radon exposure. The {sup 210}Po activity of the glass samples has been measured non-destructively using an open-flow pulse ionization chamber and this detector has also been successfully applied in field exercises.

  16. Factors affecting indoor radon concentrations in the United Kingdom.

    PubMed

    Gunby, J A; Darby, S C; Miles, J C; Green, B M; Cox, D R

    1993-01-01

    Data collected in a nationwide study on natural radiation exposure in UK dwellings (Wrixon et al. 1988) were re-analyzed to investigate the effects of rock type and various building and lifestyle characteristics, taken into account simultaneously, on indoor radon concentrations. A multiplicative model which takes into consideration the outdoor radon concentration is used. Indoor radon concentrations were found to be influenced by type of rock underlying the dwelling, double glazing, house type, floor level of rooms in which measurements were taken, window opening habits in the main bedroom, building materials used in the construction of the walls, floor type, and draught proofing. However, these eight factors together account for only 22% of the variation between dwellings. Estimates of the size of the effect associated with each factor are given. PMID:8416211

  17. RADON MITIGATION STUDIES: NASHVILLE DEMONSTRATION

    EPA Science Inventory

    The report gives results of an EPA radon mitigation demonstration project involving 14 houses in the Nashville, TN, area with indoor radon levels of 5.6-47.6 pCi/L, using a variety of techniques, designed to be the most cost effective methods possible to implement, and yet adequa...

  18. MONITORING BEFORE AND AFTER RADON MITIGATION

    EPA Science Inventory

    The paper discusses a radon reduction demonstration project in 1986 on 10 houses in Clinton, NJ. As part of this effort, radon was measured before and after radon reduction techniques were applied. The purpose of the measurements was to ascertain the effectiveness of the radon co...

  19. Quantifying the influences of atmospheric stability on air pollution in Lanzhou, China, using a radon-based stability monitor

    NASA Astrophysics Data System (ADS)

    Chambers, Scott D.; Wang, Fenjuan; Williams, Alastair G.; Xiaodong, Deng; Zhang, Hua; Lonati, Giovanni; Crawford, Jagoda; Griffiths, Alan D.; Ianniello, Antonietta; Allegrini, Ivo

    2015-04-01

    Commercially-available "stability monitors" based on in situ atmospheric radon progeny measurements remain underutilised as a tool for urban pollution studies, due in part to difficulties experienced in relating their standard output directly to the atmospheric mixing state in a consistent manner. The main confounding factor has been a lack of attention to the fact that the observed near-surface atmospheric radon concentration includes large synoptic and fetch-related components in addition to the local stability influence. Here, a technique recently developed for stability classification using a research-quality dual-flow-loop two-filter radon detector is adapted for use with a commercially-available radon-based stability monitor. Performance of the classification scheme is then tested in Lanzhou, China, a topographically-complex region renowned for low mean annual wind speeds (0.8 m s-1) and winter stagnation episodes. Based on an 11-month composite, a factor of seven difference is estimated between peak NOx concentrations in the city's industrial region and a rural background location under stable conditions. The radon-based scheme is evaluated against the Pasquil-Gifford "radiation" (PGR) scheme, and assigns pollutant concentrations more consistently between defined atmospheric stability states than the PGR scheme. Furthermore, the PGR scheme consistently underestimates all peak pollutant concentrations under stable conditions compared with the radon-based scheme, in some cases (e.g. CO in the industrial region) by 25%.

  20. Dual home screening and tailored environmental feedback to reduce radon and secondhand smoke: an exploratory study.

    PubMed

    Hahn, Ellen J; Rayens, Mary Kay; Kercsmar, Sarah E; Adkins, Sarah M; Wright, Ashton Potter; Robertson, Heather E; Rinker, Gwendolyn

    2014-01-01

    Combined exposure to secondhand smoke (SHS) and radon increases lung cancer risk 10-fold. The authors assessed the feasibility and impact of a brief home screening and environmental feedback intervention to reduce radon and SHS (Freedom from Radon and Smoking in the Home [FRESH]) and measured perceived risk of lung cancer and synergistic risk perception (SHS x radon). Participants (N = 50) received home radon and SHS kits and completed baseline surveys. Test results were shared using an intervention guided by the Teachable Moment Model. Half of the participants completed online surveys two months later. Most (76%) returned the radon test kits; 48% returned SHS kits. Of the returned radon test kits, 26% were >4.0 pCi/L. Of the returned SHS kits, 38% had nicotine > .1 microg/m3. Of those with high radon, more than half had contacted a mitigation specialist or planned contact. Of those with positive air nicotine, 75% had adopted smoke-free homes. A significant increase occurred in perceived risk for lung cancer and synergistic risk perception after FRESH. PMID:24645427

  1. Is Radon Emission in Caves Causing Deletions in Satellite DNA Sequences of Cave-Dwelling Crickets?

    PubMed Central

    Allegrucci, Giuliana; Sbordoni, Valerio; Cesaroni, Donatella

    2015-01-01

    The most stable isotope of radon, 222Rn, represents the major source of natural radioactivity in confined environments such as mines, caves and houses. In this study, we explored the possible radon-related effects on the genome of Dolichopoda cave crickets (Orthoptera, Rhaphidophoridae) sampled in caves with different concentrations of radon. We analyzed specimens from ten populations belonging to two genetically closely related species, D. geniculata and D. laetitiae, and explored the possible association between the radioactivity dose and the level of genetic polymorphism in a specific family of satellite DNA (pDo500 satDNA). Radon concentration in the analyzed caves ranged from 221 to 26000 Bq/m3. Specimens coming from caves with the highest radon concentration showed also the highest variability estimates in both species, and the increased sequence heterogeneity at pDo500 satDNA level can be explained as an effect of the mutation pressure induced by radon in cave. We discovered a specific category of nuclear DNA, the highly repetitive satellite DNA, where the effects of the exposure at high levels of radon-related ionizing radiation are detectable, suggesting that the satDNA sequences might be a valuable tool to disclose harmful effects also in other organisms exposed to high levels of radon concentration. PMID:25822625

  2. Estimation of the indoor radon and the annual effective dose from granite samples

    NASA Astrophysics Data System (ADS)

    Sola, P.; Srinuttrakul, W.; Kewsuwan, P.

    2015-05-01

    Inhalation of radon and thoron daughters increases the risk of lung cancer. The main sources of indoor radon are building materials. The aim of this research is to estimate the indoor radon and the annual effective dose from the building materials. Eighteen granite samples bought from the markets in Thailand were measured using an ionization chamber (ATMOS 12 DPX) for the radon concentration in air. Radon exhalation rates were calculated from the radon concentration in chamber. The indoor radon from the granite samples ranged from 10.04 to 55.32 Bq·m-2·h-1 with an average value of 20.30 Bq·m-2·h-1 and the annual effective dose ranged from 0.25 to 1.39 mSv·y-1 with an average value of 0.48 mSv·y-1. The results showed that the annual effective doses of three granite samples were higher than the annual exposure limit for the general public (1 mSv·y-1) recommended by the International Commission on Radiological Protection (ICRP). In addition, the relationship between the colours and radon exhalation rates of granite samples was also explained.

  3. Radon gas: Health risks and toxicity. (Latest citations from the NTIS data base). Published Search

    SciTech Connect

    Not Available

    1992-03-01

    The bibliography contains citations concerning the potential health risks associated with indoor and outdoor exposure to radon gas. Included are sources such as cigarette smoke, fossil fuel combustion, phosphate mining, uranium mining, granitic rocks, building materials, and water supplies. Citations include toxicology studies, risk assessment studies, exposure modeling, exposure pathways, physiological effects, and exposure control. Radionuclides in groundwater, and radon analysis and detection, are presented in separate Published Searches. (Contains a minimum of 129 citations and includes a subject term index and title list.)

  4. Design issues in studies of radon and lung cancer: Implications of the joint effect of smoking and radon

    SciTech Connect

    Upfal, M.; Divine, G.; Siemiatycki, J.

    1995-01-01

    Many case-control studies have been undertaken to assess whether and to what extent residential radon exposure is a risk factor for lung cancer. Nearly all these studies have been conducted in populations including smokers and nonsmokers. In this paper, we show that, depending on the nature of the joint effect of radon and tobacco on lung cancer risk, it may be very difficult to detect a main effect due to radon in mixed smoking and nonsmoking populations. If the joint effect is closer to additive than multiplicative, the most cost-effective way to achieve adequate statistical power may be to conduct a study among never-smokers. Because the underlying joint effect is unknown, and because many studies have been carried out among mixed smoker and nonsmoker populations, it would be desirable to conduct some studies with adequate power among never-smokers only. 30 refs., 4 figs., 2 tabs.

  5. Loss of Telomeres in the Progeny of Human Lymphocytes Exposed to Energetic Heavy Ions

    NASA Technical Reports Server (NTRS)

    Cucinotta, F.A.; George, K.; Durante, M.

    2006-01-01

    We have used cross-species multi-color banding (RxFISH) combined with telomere FISH probes, to measure chromosomal aberrations in the progeny of human peripheral blood lymphocytes exposed to ionizing radiation. Accelerated iron particles (energy 1 GeV/nucleon) induced many more terminal deletions than the same dose of gamma-rays. We found that truncated chromosomes without telomeres could be transmitted for at least three cell cycles following exposure, and represented about 10% of all aberrations observed in the progeny of cells exposed to iron ions. High energy heavy ions generate the most significant health risk for human space exploration and the results suggest that telomere loss may be the leading mechanism for their high efficiency in the induction of late effects.

  6. An equilibrium-based model for measuring environmental radon using charcoal canisters.

    PubMed

    Lehnert, A L; Kearfott, K J

    2010-08-01

    Radon in indoor air is often measured using canisters of activated charcoal that function by adsorbing radon gas. The use of a diffusion barrier charcoal canister (DBCC) minimizes the effects of environmental humidity and extends the useful exposure time by several days. Many DBCC protocols model charcoal canisters as simple integrating detectors, which introduces errors due to the fact that radon uptake changes over the exposure period. Errors are compensated for by calculating a calibration factor that is nonlinear with respect to exposure time. This study involves the development and testing of an equilibrium-based model and corresponding measurement protocol that treats the charcoal canisters as a system coming into equilibrium with the surrounding radon environment. This model applies to both constant and temporally varying radon concentration situations, which was essential, as efforts are currently underway using a temporally varying radon chamber. It was found that the DBCCs equilibrate following the relationship E = (1 - e) where E is a measure of how close the DBCC is to equilibrium, t is exposure time, and q is the equilibration constant. This equilibration constant was empirically determined to be 0.019 h. The proposed model was tested in a blind test as well as compared with the currently accepted U.S. Environmental Protection Agency (U.S. EPA) model. Comparisons between the two methods showed a slight decrease in measurement error when using the equilibrium-based method as compared to the U.S. EPA method. PMID:20622564

  7. Test of the linear-NO threshold theory of radiation carcinogenesis for inhaled radon decay products

    SciTech Connect

    Cohen, B.L.

    1995-02-01

    Data on lung cancer mortality rates vs. average radon concentration in homes for 1,601 U.S. counties are used to test the linear-no threshold theory. The widely recognized problems with ecological studies, as applied to this work, are addressed extensively. With or without corrections for variations in smoking prevalence, there is a strong tendency for lung cancer rates to decrease with increasing radon exposure, in sharp contrast to the increase expected from the theory. The discrepancy in slope is about 20 standard deviations. It is shown that uncertainties in lung cancer rates, radon exposures, and smoking prevalence are not important and that confounding by 54 socioeconomic factors, by geography, and by altitude and climate can explain only a small fraction of the discrepancy. Effects of known radon-smoking prevalence correlations-rural people have higher radon levels and smoke less than urban people, and smokers are exposed to less radon than non-smokers-are calculated and found to be trivial. In spite of extensive efforts, no potential explanation for the discrepancy other than failure of the linear-no threshold theory for carcinogenesis from inhaled radon decay products could be found. 46 refs., 2 figs., 7 tabs.

  8. A means to make open-face charcoal detectors respond correctly to varying concentration radon fields

    SciTech Connect

    Distenfeld, C.H.

    1995-12-31

    Ronca-Battista and D. Gray 87, outlined the poor response of open-face charcoal detectors to varying concentration radon fields. At worst, for two day exposures with open-face charcoal canisters, their Table 4 indicated a 75% under-response for radon concentrations that were 10 times higher during the first day of two, 10:1. TCS has made similar measurements with open-faced and diffusion barrier detectors in 20:1, 1:20, and 1:1 fields. For the worst case 20:1, measurements indicate TCS two day open-face canisters under respond by 50%, while the Cohen and TCS diffusion barrier devices under responded by about 37%. The reasons for the under response are radon diffusion out of the charcoal due to the forces of lower concentration during the second half of the exposure, and uncompensated radioactive decay of radon gas.

  9. Lung cancer mortality among nonsmoking uranium miners exposed to radon daughters

    SciTech Connect

    Roscoe, R.J.; Steenland, K.; Halperin, W.E.; Beaumont, J.J.; Waxweiler, R.J.

    1989-08-04

    Radon daughters, both in the workplace and in the household, are a continuing cause for concern because of the well-documented association between exposure to radon daughters and lung cancer. To estimate the risk of lung cancer mortality among nonsmokers exposed to varying levels of radon daughters, 516 white men who never smoked cigarettes, pipes, or cigars were selected from the US Public Health Service cohort of Colorado Plateau uranium miners and followed up from 1950 through 1984. Age-specific mortality rates for nonsmokers from a study of US veterans were used for comparison. Fourteen deaths from lung cancer were observed among the nonsmoking miners, while 1.1 deaths were expected, yielding a standardized mortality ratio of 12.7 with 95% confidence limits of 8.0 and 20.1. These results confirm that exposure to radon daughters in the absence of cigarette smoking is a potent carcinogen that should be strictly controlled.

  10. Intercomparison of passive radon-detectors under field conditions in epidemiological studies

    SciTech Connect

    Kreienbrock, L. ); Poffijn, A. ); Tirmarche, M. ); Feider, M. ); Kies, A. ); Darby, S.C. )

    1999-05-01

    The Ardennes and Eifel region is a geologically distinct area covering parts of Germany, Belgium, France, and Luxembourg where enhanced concentrations of radon occur in some houses and other buildings. An international case-control study is being conducted to examine the role of radon in the etiology of lung cancer in this area. The radon detectors used are issued by different laboratories involving a variety of detector types and processes. A series of intercomparisons in houses was therefore conducted under similar conditions of exposure in the field. In most situations the different detectors gave similar results. Nevertheless, in some situations open and closed detectors yielded different results. Therefore, estimates of radon exposure have to be adjusted if results are to be pooled.

  11. Navy Radon Assessment and Mitigation Program

    SciTech Connect

    Bertini, H.W.; Dudney, C.S.; Wilson, D.L.; Wright, T.

    1990-12-01

    During the reporting period, June, 1 1989, through May 30, 1990, radon detectors were sent to all Department of the Navy installations that contained housing areas, childcare centers, schools, hospitals, bachelor quarters, and brigs. This action was part of the screening phase of the Navy Radon Assessment and Mitigation Program. Because of detector losses, a few facilities will require rescreening. The length of time the detectors are exposed in the buildings is dependent on the time or year they were placed and the time when the doors and windows are normally closed. A 3-month exposure time is sufficient for facilities that placed detectors in building when they would be closed. Otherwise detectors will be exposed for about 1 year. To date, about 9,000 detectors (out of a total of 27,100 detectors sent to the field) have been returned for a determination of exposure levels. About 2,000 detectors have been analyzed and the information sent to the Navel Facilities Engineering Command Headquarters for forwarding to the installations. Except for the additional installations requiring rescreening, the screening effort results should be available this calendar year. The rescreening results should be available by mid-1991. Assessment will start this calendar year based on the results from screening. Initial emphasis will be on housing, child-care centers, schools, and hospitals. 6 refs., 17 figs., 16 tabs.

  12. Risk of Cancer in relation to Natural Radiation, including Radon: Evidence from Epidemiological Studies

    SciTech Connect

    Baysson, Helene; Tirmarche, Margot; Laurier, Dominique

    2008-08-07

    A review of recently published epidemiological studies on populations exposed to natural background ionizing radiation is proposed. The advantages and disadvantages of different types of epidemiological studies as well as the uncertainty linked to multiple exposures are discussed. As radon is the greatest source of natural radiation, particular attention is given to quantification of risk obtained through cohort studies of uranium miners and after joint analysis of case-control studies on lung cancer and residential radon.

  13. Risk of Cancer in relation to Natural Radiation, including Radon: Evidence from Epidemiological Studies

    NASA Astrophysics Data System (ADS)

    Baysson, Hélène; Tirmarche, Margot; Laurier, Dominique

    2008-08-01

    A review of recently published epidemiological studies on populations exposed to natural background ionizing radiation is proposed. The advantages and disadvantages of different types of epidemiological studies as well as the uncertainty linked to multiple exposures are discussed. As radon is the greatest source of natural radiation, particular attention is given to quantification of risk obtained through cohort studies of uranium miners and after joint analysis of case-control studies on lung cancer and residential radon.

  14. United role of radon decay products and nano-aerosols in radon dosimetry

    NASA Astrophysics Data System (ADS)

    Smerajec, M.; Vaupotič, J.

    2012-04-01

    The major part of human exposure to natural radiation originates from inhalation of radon (Rn) and radon short-lived decay products (RnDP: 218Po, 214Pb, 214Bi and 214Po). RnDP are formed as a result of α-transformation of radon. In the beginning they are positive ions which neutralize and form clusters with air molecules, and later partly attach to background aerosol particles in indoor air. Eventually, they appear as radioactive nano-aerosols with a bimodal size distribution in ranges of 1-10 nm (unattached RnDP) and of 200-800 nm (attached RnDP). When inhaled, they are deposited in the respiratory tract. Deposition is more efficient for smaller particles. Therefore, the fraction (fun) of the unattached RnDP, which appears to be influenced by the number concentration and size distribution of general (background) aerosols in the ambient air, has a crucial role in radon dosimetry. Radon, radon decay products and general aerosols have been monitored simultaneously in the kitchen of a typical rural house under real living conditions, also comprising four human activities generating particular matter: cooking and baking, as two typical activities in kitchen, and cigarette smoking and candle burning. In periods without any human activity, the total number concentration of general aerosol ranged from 1000 to 3000 cm-3,with the geometric mean of particle diameter in the range of 60-68 nm and with 0.1-1 % of particles smaller than 10 nm. Preparation of coffee changed the concentration to 193,000 cm-3, the geometric mean of diameter to 20 nm and fraction of particles smaller than 10 nm to 11 %. The respective changes were for baking cake: 503,000 cm-3, 17 nm and 19 %, for smoking:423,000 cm-3, 83 nm and 0.4 %, and forcandle burning: 945,000 cm-3, 8 nm and 85 %. While, as expected, a reduction of fun was observed during cooking, baking and smoking, when larger particles were emitted, fun did not increase during candle burning with mostly particles smaller than 10 nm

  15. Uranium mill tailings and radon

    SciTech Connect

    Hanchey, L A

    1981-04-01

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

  16. Uranium mill tailings and radon

    SciTech Connect

    Hanchey, L A

    1981-01-01

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

  17. 2014 ICHLNRRA intercomparison of radon/thoron gas and radon short-lived decay products measuring instruments in the NRPI Prague.

    PubMed

    Jílek, K; Timková, J

    2015-06-01

    During the Eighth International Conference on High Levels of Natural Radiation and Radon Areas held in autumn 2014 at Prague, the third intercomparison of radon/thoron gas and radon short-lived decay products measurement instruments was organised by and held at the Natural Radiation Division of the National Radiation Protection Institute (NRPI; SÚRO v.v.i.) in Prague. The intercomparison was newly focussed also on continuous monitors with active sampling adapters capable to distinguish radon/thoron gas in their mix field.The results of radon gas measurements carried out in the big NRPI radon chamber indicated very well an average deviation of up to 5 % from the reference NRPI value for 80 % of all the exposed instruments. The results of equilibrium equivalent concentration continuous monitors indicated an average deviation of up to 5 % from the reference NRPI value for 40 % of all the exposed instruments and their ~8-10 % shift compared with the NRPI. The results of investigated ambient conditions upon response of exposed continuous monitors indicated influence of aerosol changes upon response of radon monitors with an active air sampling adapters through the filter, only. The exposures of both radon/thoron gas discriminative continuous monitors and passive detectors have been indicated inconsistent results: on one hand, their excellent agreement up to several per cent for both the gases, and on the other hand, systematic unsatisfactory differences up to 40 %. Additional radon/thoron exercises are recommended to improve both the instruments themselves and quality of their operators. PMID:25990114

  18. Radon entry into buildings: Effects of atmospheric pressure fluctuations and building structural factors

    SciTech Connect

    Robinson, A.L. |

    1996-05-01

    An improved understanding of the factors that control radon entry into buildings is needed in order to reduce the public health risks caused by exposure to indoor radon. This dissertation examines three issues associated with radon entry into buildings: (1) the influence of a subslab gravel layer and the size of the openings between the soil and the building interior on radon entry; (2) the effect of atmospheric pressure fluctuations on radon entry; and (3) the development and validation of mathematical models which simulate radon and soil-gas entry into houses. Experiments were conducted using two experimental basements to examine the influence of a subslab gravel layer on advective radon entry driven by steady indoor-outdoor pressure differences. These basement structures are identical except that in one the floor slab lies directly on native soil whereas in the other the slab lies on a high-permeability gravel layer. The measurements indicate that a high permeability subslab gravel layer increases the advective radon entry rate into the structure by as much as a factor of 30. The magnitude of the enhancement caused by the subslab gravel layer depends on the area of the openings in the structure floor; the smaller the area of these openings the larger the enhancement in the radon entry rate caused by the subslab gravel layer. A three-dimensional, finite-difference model correctly predicts the effect of a subslab gravel layer and open area configuration on advective radon entry driven by steady indoor-outdoor pressure differences; however, the model underpredicts the absolute entry rate into each structure by a factor of 1.5.

  19. Radiological study of exposure levels in El Maghara underground coal mine.

    PubMed

    Amer, Hany A; Shawky, S; Hussein, Mohamed I; Abd el-Hady, M L

    2002-08-01

    Coal is largely composed of organic matter, but it is the inorganic matter in coal minerals and trace elements that have been cited as possible causes of health, environmental and technological problems associated with the use of coal. Some trace elements in coal are naturally radioactive. These radioactive elements include uranium (U), thorium (Th) and their numerous decay products, including radium (Ra) and radon (Rn). Although these elements are less chemically toxic than other coal constituents, such as arsenic, selenium or mercury, questions have been raised concerning the possible risk from radiation. In order to accurately address these questions and to predict the mobility of radioactive elements during the coal fuel cycle, it is important to determine the specific activity, distribution and form of radioactive elements in coal. The assessment of the radiation exposure from coal burning is critically dependent on the specific activity of radioactive elements in coal and in the fly ash that remains after combustion. The El-Maghara coal mine is the only producing coal mine in Egypt. It is located in the middle of the Sinai desert about 250 km north-east of Cairo, where a coal-fired power plant is intended to be built. In this study, a pre-operational radiological baseline of the site and the occupational radiation exposures due to radon progeny in the mine were determined. The specific activities of 226Ra, 232Th and 40K in soil and coal dust samples collected along the main gallery ranges were found to be 6-22.9, 9.6-47.3 and 77-489 Bq kg-1, respectively. Soil samples collected around the mine showed concentrations of 226Ra, 232Th and 40K in the ranges 2.7-20.2, 3.2-12.6 and 14.6-201 Bq kg-1, respectively. All of the mean values of radon progeny were lower than the action levels for working places recommended in the International Commission on Radiological Protection (ICRP) 65. PMID:12196005

  20. Map showing radon potential of rocks and soils in Fairfax County, Virginia

    USGS Publications Warehouse

    Otton, James K.; Schumann, R. Randall; Owen, Douglass E.; Thurman, Nelson; Duval, Joseph S.

    1988-01-01

    Since 1984, indoor radon has gained national attention as a significant health hazard in the United States. Radon is a colorless, odorless, radioactive gas derived from uranium by radioactive decay. The U.S. Environmental Protection Agency (EPA) now projects that 5,000 to 20,000 lung-cancer deaths per year may be attributed to the long-term exposure to indoor radon and its radioactive decay products. Indoor radon has been previously recognized as a health hazard associated with uranium-bearing mill tailings or building materials, but it was not until December 1984 that some natural soils and rocks were found to be sources of indoor radon at levels comparable to those in uranium mines. It is now suspected that elevated indoor radon levels are far more widespread than initially though. The EPA considers 4 picoCuries of radon per liter of air (pCi/L) as the level (in a year-round measurement) at which actions ought to be taken to lower the concentration of indoor radon. All soils and rocks contain measurable amounts of uranium, which generate measurable amounts of radon. Certain soils and rocks, however, have a greater potential to cause indoor radon problems than others because (1) they have a higher uranium content and thus can generate higher levels of radon in soil gas (gas that occupies the pores of the soil), and (2) the permeability of the sol or rack is sufficiently high that radon-bearing soil gas can flow freely and move indoors through the foundation of the structure. This study was designed to demonstrate the correlation between the geologic environment and indoor radon levels and to demonstrate a method of assessment that could be used by other informed workers in areas of their interest. A parallel study by Gundersen and others (1988) of the radon potential of rocks and soils in Montgomery County, Md., used somewhat different methods of assessment because the data available for and assessment of Montgomery County differed.

  1. Bronchial dysplasia induced by radiation in miners exposed to 222Rn progeny.

    PubMed Central

    Michaylov, M A; Pressyanov, D S; Kalinov, K B

    1995-01-01

    OBJECTIVES--To investigate whether sputum cytology can be used to monitor epithelial cell changes in groups at high risk of lung cancer from exposure to radiation. METHODS--Dysplasia of bronchial cells was investigated by means of sputum cytology in a group of 434 underground miners. 100 of them were not exposed, and 334 were exposed to 222Rn progeny at cumulative exposures < 450 working level months. RESULTS--The frequency of dysplasia in the exposed group was significantly higher than that in the not exposed group (P < 0.0001), and an exposure-response relation was found. This relation was different for smokers and non-smokers. CONCLUSIONS--Possibly the frequencies of dysplasia could be used to assess past exposures of groups of miners. This approach could be applied to cases where data on radiation monitoring are not available or are very scarce. Images p82-a PMID:7757171

  2. The history, development and the present status of the radon measurement programme in the United States of America.

    PubMed

    George, A C

    2015-11-01

    The US radon measurement programme began in the late 1950s by the US Public Health Service in Colorado, New Mexico and Utah during the uranium frenzy. After the 1967 Congressional Hearings on the working conditions in uranium mines, the US Atomic Energy Commission (AEC) was asked to conduct studies in active uranium mines to assess the exposure of the miners on the Colorado Plateau and in New Mexico. From 1967 to 1972, the Health and Safety Laboratory of the US AEC in New York investigated more than 20 uranium mines for radon and radon decay product concentrations and particle size in 4 large uranium mines in New Mexico. In 1970, the US Environmental Protection Agency (EPA) was established and took over some of the AEC radon measurement activities. Between 1975 and 1978, the Environmental Measurements Laboratory of the US Department of Energy conducted the first detailed indoor radon survey in the USA. Later in 1984, the very high concentrations of radon found in Pennsylvania homes set the wheels in motion and gave birth to the US Radon Industry. The US EPA expanded its involvement in radon issues and assumed an active role by establishing the National Radon Proficiency Program to evaluate the effectiveness of radon measurement and mitigation methods. In 1998, due to limited resources EPA privatised the radon programme. This paper presents a personal perspective of past events and current status of the US radon programme. It will present an update on radon health effects, the incidence rate of lung cancer in the USA and the number of radon measurements made from 1988 to 2013 using short-term test methods. More than 23 million measurements were made in the last 25 y and as a result more than 1.24 million homes were mitigated successfully. It is estimated that <2 % of the radon measurements performed in the USA are made using long-term testing devices. The number of homes above the US action level of 148 Bq m(-3) (4 pCi l(-1)) may be ∼8.5 million because ∼50

  3. Lung cancer deaths from indoor radon and the cost effectiveness and potential of policies to reduce them

    PubMed Central

    Read, Simon; McGale, Paul; Darby, Sarah

    2009-01-01

    Objective To determine the number of deaths from lung cancer related to radon in the home and to explore the cost effectiveness of alternative policies to control indoor radon and their potential to reduce lung cancer mortality. Design Cost effectiveness analysis. Setting United Kingdom. Data sources Epidemiological data on risks from indoor radon and from smoking, vital statistics on deaths from lung cancer, survey information on effectiveness and costs of radon prevention and remediation. Main outcome measures Estimated number of deaths from lung cancer related to indoor radon, lifetime risks of death from lung cancer before and after various potential interventions to control radon, the cost per quality adjusted life year (QALY) gained from different policies for control of radon, and the potential of those policies to reduce lung cancer mortality. Results The mean radon concentration in UK homes is 21 becquerels per cubic metre (Bq/m3). Each year around 1100 deaths from lung cancer (3.3% of all deaths from lung cancer) are related to radon in the home. Over 85% of these arise from radon concentrations below 100 Bq/m3 and most are caused jointly by radon and active smoking. Current policy requiring basic measures to prevent radon in new homes in selected areas is highly cost effective, and such measures would remain cost effective if extended to the entire UK, with a cost per QALY gained of £11 400 ( €12 200; $16 913). Current policy identifying and remediating existing homes with high radon levels is, however, neither cost effective (cost per QALY gained £36 800) nor effective in reducing lung cancer mortality. Conclusions Policies requiring basic preventive measures against radon in all new homes throughout the UK would be cost effective and could complement existing policies to reduce smoking. Policies involving remedial work on existing homes with high radon levels cannot prevent most radon related deaths, as these are caused by moderate exposure

  4. Radon gas distribution in natural gas processing facilities and workplace air environment.

    PubMed

    Al-Masri, M S; Shwiekani, R

    2008-04-01

    Evaluation was made of the distribution of radon gas and radiation exposure rates in the four main natural gas treatment facilities in Syria. The results showed that radiation exposure rates at contact of all equipment were within the natural levels (0.09-0.1 microSvh(-1)) except for the reflex pumps where a dose rate value of 3 microSvh(-1) was recorded. Radon concentrations in Syrian natural gas varied between 15.4 Bq m(-3) and 1141 Bq m(-3); natural gas associated with oil production was found to contain higher concentrations than the non-associated natural gas. In addition, radon concentrations were higher in the central processing facilities than the wellheads; these high levels are due to pressurizing and concentrating processes that enhance radon gas and its decay products. Moreover, the lowest 222Rn concentration was in the natural gas fraction used for producing sulfur; a value of 80 Bq m(-3) was observed. On the other hand, maximum radon gas and its decay product concentrations in workplace air environments were found to be relatively high in the gas analysis laboratories; a value of 458 Bq m(-3) was observed. However, all reported levels in the workplaces in the four main stations were below the action level set by IAEA for chronic exposure situations involving radon, which is 1000 Bq m(-3). PMID:17905489

  5. Natural radioactivity and radiation exposure at the Minjingu phosphate mine in Tanzania.

    PubMed

    Banzi, F P; Kifanga, L D; Bundala, F M

    2000-03-01

    In this paper the results of studies on activity and ambient radiation background around the Minjingu phosphate mine in Tanzania are presented. The outdoor dose rate in air and the activity levels of samples from and outside the mine were determined by thermoluminiscent dosimeters and a gamma spectrometer system with a Hyper Pure germanium detector system respectively. The determination of activity was made for the 226Ra, 228Ra, 228Th and 40K radionuclides. High concentrations of radium-226 were observed in phosphate rock (5760+/-107 Bq kg(-1)), waste rock (4250+/-98 Bq kg(-1)), wild leaf vegetation (650+/-11 Bq kg(-1)), edible leaf vegetation (393+/-9 Bq kg(-1)), surface water (4.7+/-0.4 mBq l(-1)) and chicken feed (4+/-0.1 Bq kg(-1)) relative to selected control sites. These findings suggest a radiation health risk particularly when the samples are ingested, because the internal exposure may give rise to an effective dose exceeding 20 mSv which is the annual limit of intake of natural radionuclides recommended by the ICRP. On the other hand, the radiation dose from ambient air over five years at the phosphate mine ranges from 1375 to 1475 nGy h(-1) with an average of 1415 nGy h(-1). The average is about 28 times that of the global average background radiation from terrestrial sources, and about 12 times the allowed average dose limit for public exposure over five consecutive years. Future investigations on the occupancy factor, external dose rate and radon and radon progeny exposure in drinking water, buildings and activity content in the locally grown foodstuffs are proposed, for the realistic quantification of the overall exposure of workers and public at Minjingu, and remedial measures for future radiation safety. PMID:10750954

  6. Radon gas: Health risks and toxicity. March 1974-November 1989 (Citations from the NTIS data base). Report for March 1974-November 1989

    SciTech Connect

    Not Available

    1989-12-01

    This bibliography contains citations concerning the toxicity and risks associated with indoor and outdoor exposure to radon gas. Sources of radon gas discussed include cigarette smoke, fossil-fuel combustion, phosphate mining, uranium mining, granitic rocks, building materials, and water supplies. Toxicology studies, risk assessment studies, exposure modeling, exposure pathways, physiological effects, and control of exposure are discussed. Radionuclides in ground water, and radon analysis and detection, can be found in separate related bibliographies. (Contains 152 citations fully indexed and including a title list.)

  7. Dosimetry of radium-223 and progeny

    SciTech Connect

    Fisher, D.R.; Sgouros, G.

    1999-01-01

    Radium-223 is a short-lived (11.4 d) alpha emitter with potential applications in radioimmunotherapy of cancer. Radium-223 can be complexed and linked to protein delivery molecules for specific tumor-cell targeting. It decays through a cascade of short-lived alpha- and beta-emitting daughters with emission of about 28 MeV of energy through complete decay. The first three alpha particles are essentially instantaneous. Photons associated with Ra-223 and progeny provide the means for tumor and normal-organ imaging and dosimetry. Two beta particles provide additional therapeutic value. Radium-223 may be produced economically and in sufficient amounts for widescale application. Many aspects of the chemistry of carrier-free isotope preparation, complexation, and linkage to the antibody have been developed and are being tested. The radiation dosimetry of a Ra-223-labeled antibody shows favorable tumor to normal tissue dose ratios for therapy. The 11.4-d half-life of Ra-223 allows sufficient time for immunoconjugate preparation, administration, and tumor localization by carrier antibodies before significant radiological decay takes place. If 0.01 percent of a 37 MBq (1 mCi) injection deposits in a one gram tumor mass, and if the activity is retained with a typical effective half-time (75 h), the absorbed dose will be 163 mGy MBq{sup {minus}1} (600 rad mCi{sup {minus}1}) administered. 49 refs., 5 figs., 2 tabs.

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

    PubMed

    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. PMID:24231373

  9. Radiation Protection. Measurement of radioactivity in the environment - Air- radon 222. A proposed ISO standard.

    NASA Astrophysics Data System (ADS)

    Gillmore, G.; Woods, M.

    2009-04-01

    Radon isotopes (222, 220, 219) are radioactive gases produced by the disintegration of radium isotopes 226, 224 and 223, which are decay products of uranium238, thorium232 and uranium235 respectively. All are found in the earth's crust. Solid elements, also radioactive, are produced by radon disintegration. Radon is classed as a rare gas in the periodic table of elements, along with helium, argon, neon, krypton and xenon. When disintegrating, radon emits alpha particles and generates solid decay products, which are also radioactive (polonium, bismuth, lead etc.). The potential danger of radon lies in its solid decay products rather than the gas itself. Whether or not they are attached aerosols, radon decay products can be inhaled and deposited in the bronchopulmonary tree to varying depths according to their size. Radon today is considered to be the main source of human exposure to natural radiation. At the international level, radon accounts for 52% of global average exposure to natural radiation. Isotope 222 (48%) is far more significant than isotope 220 (4%), whilst isotope 219 is considered as negligible. Exposure to radon varies considerably from one region to another, depending on factors such as weather conditions, and underlying geology. Activity concentration can therefore vary by a factor of 10 or even a 100 from one period of time to the next and from one area to another. There are many ways of measuring the radon 222 activity concentration and the potential alpha energy concentration of its short-lived decay products. Measuring techniques fall into three categories: - spot measurement methods; continuous measurement; integrated measurement. The proposed ISO (International Organisation for Standardisation) document suggests guidelines for measuring radon222 activity concentration and the potential alpha energy concentration of its short-lived decay products in a free (environment) and confined (buildings) atmosphere. The target date for availability of

  10. Radon detection in conical diffusion chambers: Monte Carlo calculations and experiment

    SciTech Connect

    Rickards, J.; Golzarri, J. I.; Espinosa, G.; Vázquez-López, C.

    2015-07-23

    The operation of radon detection diffusion chambers of truncated conical shape was studied using Monte Carlo calculations. The efficiency was studied for alpha particles generated randomly in the volume of the chamber, and progeny generated randomly on the interior surface, which reach track detectors placed in different positions within the chamber. Incidence angular distributions, incidence energy spectra and path length distributions are calculated. Cases studied include different positions of the detector within the chamber, varying atmospheric pressure, and introducing a cutoff incidence angle and energy.

  11. Radon in indoor concentrations and indoor concentrations of metal dust particles in museums and other public buildings.

    PubMed

    Carneiro, G L; Braz, D; de Jesus, E F; Santos, S M; Cardoso, K; Hecht, A A; Dias da Cunha, Moore K

    2013-06-01

    The aim of this study was to evaluate the public and occupational exposure to radon and metal-bearing particles in museums and public buildings located in the city of Rio de Janeiro, Brazil. For this study, four buildings were selected: two historic buildings, which currently house an art gallery and an art museum; and two modern buildings, a chapel and a club. Integrated radon concentration measurements were performed using passive radon detectors with solid state nuclear track detector-type Lexan used as nuclear track detector. Air samplers with a cyclone were used to collect the airborne particle samples that were analyzed by the particle-induced X-ray emission technique. The average unattached-radon concentrations in indoor air in the buildings were above 40 Bq/m(3), with the exception of Building D as measured in 2009. The average radon concentrations in indoor air in the four buildings in 2009 were below the recommended reference level by World Health Organization (100 Bq/m(3)); however, in 2011, the average concentrations of radon in Buildings A and C were above this level, though lower than 300 Bq/m(3). The average concentrations of unattached radon were lower than 148 Bq/m(3) (4pCi/L), the USEPA level recommended to take action to reduce the concentrations of radon in indoor air. The unattached-radon average concentrations were also lower than the value recommended by the European Union for new houses. As the unattached-radon concentrations were below the international level recommended to take action to reduce the radon concentration in air, it was concluded that during the period of sampling, there was low risk to human health due to the inhalation of unattached radon in these four buildings. PMID:23124728

  12. AIR AND RADON PATHWAY MODELING FOR THE F AREA TANK FARM

    SciTech Connect

    Dixon, K.; Phifer, M.

    2010-07-30

    An air and radon pathways analysis was conducted for the F-Area Tank Farm (FTF) to estimate the flux of volatile radionuclides and radon at the ground surface due to residual waste remaining in the tanks following closure. This analysis was used as the basis to estimate the dose to the maximally exposed individual (MEI) for the air pathway per Curie (Ci) of each radionuclide remaining in the combined FTF waste tanks. For the air pathway analysis, several gaseous radionuclides were considered. These included carbon-14 (C-14), chlorine-36 (Cl-36), iodine-129 (I-129), selenium-79 (Se-79), antimony-125 (Sb-125), tin-126 (Sn-126), tritium (H-3), and technetium-99 (Tc-99). The dose to the MEI was estimated at the SRS Boundary during the 100 year institutional control period. For the 10,000 year post closure compliance period, the dose to the MEI was estimated at the 100 m compliance point. Additionally, the dose to the MEI was estimated at a seepage outcrop located 1600 m from the facility. For the radon pathway analysis, five parent radionuclides and their progeny were analyzed. These parent radionuclides included uranium-238 (U-238), plutonium-238 (Pu-238), uranium-234 (U-234), thorium-230 (Th-230), and radium-226 (Ra-226). The peak flux of radon-222 due to each parent radionuclide was estimated for the simulation period of 10,100 years.

  13. Radon Policy in Finland, Achievements and Challenges

    SciTech Connect

    Arvela, Hannu; Maekelaeinen, Ilona; Reisbacka, Heikki

    2008-08-07

    Finland is a country of high indoor radon concentrations. Since 1980 the authority regulations, guidance, radon mapping and research work supporting decision making have been developed continuously. Clear regulations directed to citizens and authorities form the basis for radon policy. Active mapping work and measurement ordered by private home owners has resulted in 100.000 houses measured. National indoor radon data base forms a good basis for decision making, communication and research. The number of new houses provided with radon preventive constructions has increased remarkably. New radon campaigns has increased measurement and mitigation activity. Furher increasing of public awareness is the key challenge.

  14. Environmental radon and cancer correlations in Maine.

    PubMed

    Hess, C T; Weiffenbach, C V; Norton, S A

    1983-08-01

    The distribution of 222Rn has been measured in the sixteen counties of Maine, U.S.A. by liquid scintillation counting of water samples from more than two thousand public and private wells. Three hundred and fifty of these wells have been characterized for geology and hydrology. Airborne radon has been measured in seventy houses with grab samples and in eighteen houses for 5-7 days each with continuously recording diffusion-electrostatic radon detectors. Concentrations of radon in water ranged from 20 to 180,000 pCi/l. Granite areas yielded the highest average levels (mean = 22,100 pCi/l.; n = 136), with considerable intra-granite variation. Metasedimentary rocks yielded levels characteristic of the lithology for metamorphic grades ranging from chlorite to andalusite. Sillimanite and higher-grade rocks yielded higher 222Rn levels, probably due to the intrusion of uranium-bearing pegmatites in these terranes. Airborne 222Rn in homes ranged from 0.05 to 210 pCi/l. At the high end of this range, doses will exceed recommended industrial limits. In some homes only a small fraction of the airborne 222Rn was due to the water supply. Average 222Rn levels in domestic water supplies for each of the 16 counties, calculated by areally averaging rock types and their associated 222Rn levels, were found to be significantly correlated with rates for all cancers combined and rates for lung and reproductive cancers in the counties. Although numerous factors other than cancer induction by indoor daughter exposures may be responsible for the observed correlations, these have not been investigated in detail. PMID:6885433

  15. Radon levels in New Jersey

    SciTech Connect

    Cahill, M.K.: Nicholls, G.P. ); Ranney, C.; Machever, R. )

    1988-01-01

    The New Jersey Department of Environmental Protection began to assess the potential for a natural indoor radon problem in the state following the discovery in December 1984 of high radon levels in homes in northeastern Pennsylvania. A geologic feature commonly known as the Reading Prong underlying the affected homes was identified by the Pennsylvania Department of Environmental Resources as the source of elevated indoor radon levels. The Reading Prong, which contains bands of rock bodies associated with high uranium concentrations runs in a northeasterly direction out of Pennsylvania through northern New Jersey and into New York. A review of available geologic and aeroradiometric data conducted by the New Jersey Geological Survey demonstrated that New Jersey had significant potential for a radon problem and it was likely that the problem would not be confined to the Reading Prong region, but would include areas to the north and south as well. To determine the magnitude and extent of the indoor radon problem, the New Jersey Department of Environmental Protection commissioned a statewide radon study. A major component of this study and the primary subject of this paper is a survey of approximately 6,000 dwellings. Objectives of the survey are outlined and the results are presented.

  16. A study of Monitoring and Mapping for Radon-Concentration Distribution in Gyeongju - 12201

    SciTech Connect

    Park, Chan Hee; Lee, Jung Min; Jang, So Young; Kim, Shin Jae; Moon, Joo Hyun

    2012-07-01

    Radon is one of the most important contributors to the radiation exposure in humans. This study measured the indoor radon concentrations at the 17 elementary school auditoriums that were sampled from those in the city of Gyeongju, Korea. The reason that an elementary school was selected as a measurement object is that many students and teachers stay for a long time in a day and it's easy to identify the characteristics of the auditorium building such as the essential building. The measurement shows that most of the indoor radon concentrations at the 17 elementary school auditoriums did not exceed 148 Bq/m{sup 3} that is the action level recommended by U.S. Environmental Protection Agency. This study measured the indoor radon concentrations at the elementary school auditoriums in Gyeongju. The measurements were analyzed according to the bedrock type and the time intervals per day. In this study, it was found that the indoor radon concentrations over off-duty hours were generally higher that those over on-duty hours, and the indoor radon concentration in the area whose bedrock is volcanic rock was higher than those in the area of the other types of bedrock. As mentioned above, attention has to be paid to an elementary school since many young students and teachers stay for more 6 hours a day at it. Hence, it is necessary to continuously monitor and properly manage the indoor radon concentrations in the elementary schools. (authors)

  17. The perceived health risks of indoor radon gas and overhead powerlines: a comparative multilevel approach.

    PubMed

    Poortinga, Wouter; Cox, Patrick; Pidgeon, Nick F

    2008-02-01

    Radon and overhead powerlines are two radiation risk cases that have raised varying levels of concern among the general public and experts. Despite both involving radiation-a typically feared and unseen health hazard-individuals' perceptions of the two risk cases may invoke rather different factors. We examined individual and geographic-contextual factors influencing public perceptions of the health risks of indoor radon gas and overhead powerlines in a comparative research design, utilizing a postal questionnaire with 1,528 members of the general public (response rate 28%) and multilevel modeling techniques. This study found that beliefs about the two risk cases mainly differed according to the level of "exposure"-defined here in terms of spatial proximity. We argue that there are two alternative explanations for this pattern of findings: that risk perception itself varies directly with proximity, or that risk is more salient to concerned people in the exposed areas. We also found that while people living in high radon areas are more concerned about the risks of indoor radon gas, they find these risks more acceptable and have more trust in authorities. These results might reflect the positive effects of successive radon campaigns in high radon areas, which may have raised awareness and concern, and at the same time may have helped to increase trust by showing that the government takes the health risks of indoor radon gas seriously, suggesting that genuine risk communication initiatives may have positive impacts on trust in risk management institutions. PMID:18304120

  18. Risk-Reduction Strategies to Expand Radon Care Planning with Vulnerable Groups

    PubMed Central

    Larsson, Laura S.

    2016-01-01

    Objectives Radon is the second leading cause of lung cancer in the United States and the leading cause of lung cancer among nonsmokers. Residential radon is the cause of approximately 21,000 U.S. lung cancer deaths each year. Dangerous levels of radon are just as likely to be found in low-rise apartments and townhomes as single-family homes in the same area. The preferred radon mitigation strategy can be expensive and requires structural modifications to the home. The public health nurse (PHN) needs a collection of low-cost alternatives when working with low-income families or families who rent their homes. Method A review of the literature was performed to identify evidence-based methods to reduce radon risk with vulnerable populations. Results Fourteen recommendations for radon risk reduction were categorized into four strategies. Nine additional activities for raising awareness and increasing testing were also included. Discussion The results pair the PHN with practical interventions and the underlying rationale to develop radon careplans with vulnerable families across housing types. The PHN has both the competence and the access to help families reduce their exposure to this potent carcinogen. PMID:24547763

  19. RADON REDUCTION AND RADON-RESISTANT CONSTRUCTION DEMONSTRATIONS IN NEW YORK - VOLUME 1: TECHNICAL REPORT

    EPA Science Inventory

    The report gives results of radon reduction and radon-resistant construction demonstrations in New York. The existing house evaluation demonstrated radon mitigation techniques where indoor radon concentrations exceeded 4 pCi/L. Results demonstrated that sealing all accessible fou...

  20. Investigation of radon entry and effectiveness of mitigation measures in seven houses in New Jersey: Midproject report

    SciTech Connect

    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. World History Of Radon Research And Measurement From The Early 1900's To Today

    SciTech Connect

    George, A. C.

    2008-08-07

    In 1900, Dorn discovered the emanation in the uranium series that eventually became the well-known gas {sup 222}Rn. From 1900 through 1908, it was demonstrated that {sup 222}Rn is a radioactive gas found in tap water, highly condensable at low temperatures with a half-life of approximately 3.7 days and can be collected on charcoal by adsorption. Although, radon was discovered in 1900, the effects of prolonged exposure had been suspected and noted 300 years earlier among underground miners who developed lung cancer. During the period from 1924-1932, it was suggested that radon was the cause of high lung cancer incidence. In 1951, researchers at the university of Rochester N.Y. pointed out that the lung cancer health hazard was from the alpha radiation dose delivered by the radon decay products that deposited in the respiratory tract. The findings of the BEIR Committee Report VI, which was based on epidemiological studies in different groups of mines in the 1950's and 1960's and on laboratory studies, showed that from 60,000 miners over 2,600 developed lung cancer where only 750 were expected.Since 1998, the epidemiological study conducted in Iowa US, showed beyond any reasonable doubt that radon decay products cause lung cancer among women who lived at least twenty years in their homes. This paper will cover early radon measurements in soil, building material, ground water and in different air environments such as in the atmosphere, caves spas, underground mines and in residential indoor air environment. Radon measurements were conducted in many areas for diagnostic purposes. Radon was used as natural tracer to study air masses, vertical diffusion, and atmospheric studies, in earthquake prediction, and as a geological indicator for radium and uranium. In the early radon measurements, electroscopes, electrometers and primitive ionization chambers were used for many years. In the 1940's fast pulse ionization chambers replaced total ionization chambers. From the mid

  2. World History Of Radon Research And Measurement From The Early 1900's To Today

    NASA Astrophysics Data System (ADS)

    George, A. C.

    2008-08-01

    In 1900, Dorn discovered the emanation in the uranium series that eventually became the well-known gas 222Rn. From 1900 through 1908, it was demonstrated that 222Rn is a radioactive gas found in tap water, highly condensable at low temperatures with a half-life of approximately 3.7 days and can be collected on charcoal by adsorption. Although, radon was discovered in 1900, the effects of prolonged exposure had been suspected and noted 300 years earlier among underground miners who developed lung cancer. During the period from 1924-1932, it was suggested that radon was the cause of high lung cancer incidence. In 1951, researchers at the university of Rochester N.Y. pointed out that the lung cancer health hazard was from the alpha radiation dose delivered by the radon decay products that deposited in the respiratory tract. The findings of the BEIR Committee Report VI, which was based on epidemiological studies in different groups of mines in the 1950's and 1960's and on laboratory studies, showed that from 60,000 miners over 2,600 developed lung cancer where only 750 were expected. Since 1998, the epidemiological study conducted in Iowa US, showed beyond any reasonable doubt that radon decay products cause lung cancer among women who lived at least twenty years in their homes. This paper will cover early radon measurements in soil, building material, ground water and in different air environments such as in the atmosphere, caves spas, underground mines and in residential indoor air environment. Radon measurements were conducted in many areas for diagnostic purposes. Radon was used as natural tracer to study air masses, vertical diffusion, and atmospheric studies, in earthquake prediction, and as a geological indicator for radium and uranium. In the early radon measurements, electroscopes, electrometers and primitive ionization chambers were used for many years. In the 1940's fast pulse ionization chambers replaced total ionization chambers. From the mid 1950's

  3. Thermo-diffusional radon waves in soils.

    PubMed

    Minkin, Leonid; Shapovalov, Alexander S

    2016-09-15

    A new theoretical framework for diurnal and seasonal oscillations of the concentration of radon in soil and open air is proposed. The theory is based on the existing temperature waves in soils and thermo-diffusional gas flux in porous media. As soil is a non-isothermal porous medium, usually possessing a large fraction of microscopic pores belonging to Knudsen's free molecular field, a thermo-diffusional gas flow in soil has to arise. The radon mass transfer equation in soil for sinusoidal temperature oscillations at the soil-atmosphere boundary is solved, which reveals that radon concentration behaves as a damped harmonic wave. The amplitude of radon concentration oscillations and phase shift between radon concentration oscillations and soil temperature depend on the radon diffusion coefficient in soil, rate of radon production, soil thermal conductivity, average soil temperature, decay constant, and heat of radon transfer. Primarily numerical calculations are presented and comparisons with experimental data are shown. PMID:27155259

  4. SWOT analysis of the Czech Radon programme.

    PubMed

    Fojtíková, I

    2014-07-01

    Since the early 1990s, the Czech Republic has been one of the countries that carry out a radon programme on its territory, with the aim of protecting people from unnecessary long-term exposure in their homes. Since that time, many achievements have been registered, and many unexpected difficulties have cropped up. This may be the right moment to take some time out to analyse the state of the programme and to determine the direction for its future development. An extended SWOT analysis can serve as a useful tool for this purpose. Originally, SWOT analyses were used exclusively by for-profit organisations aiming to evaluate their perspectives, develop strategies and make plans in order to achieve their objectives. More recently, it has been used in a wide range of decision-making situations when a desired end-state is to be defined. Here, an extended SWOT analysis is used to formulate possible beneficial strategies for advancing anti-radon policy in the Czech Republic. PMID:24729595

  5. Radon concentrations in abandoned mines, Cumbria, UK: safety implications for industrial archaeologists

    NASA Astrophysics Data System (ADS)

    Gillmore, G.; Alizadeh Gharib, H.; Denman, A.; Phillips, P.; Bridge, D.

    2011-05-01

    This paper presents a number of surveys performed in a geographical area of the UK, part of which until recently was considered low radon risk. The Cumbrian region was identified by the Building Research Establishment (BRE) in its 1999 guide as an area without a significant radon problem in the built environment. The geology of the region, which includes the Northern Pennine Orefield is varied, but consists of granites, andesites, tuffs, carbonates, sandstones and shales. Mineralisation has taken place (mostly lead and copper ores) primarily along fault and fracture zones, one example being Copper Valley, northwest of Coniston village. This work quantifies the risk of exposure to radon in a number of abandoned mine environments. High radon levels, up to 28 589 Bq m-3, have been measured in parts of one mine. This study demonstrates that industrial archaeologists (such as the Cumbrian Amenity Trust Mining History Society or CATMHS members) and explorers of abandoned mines can be at risk from radon exposure and it proposes a management scheme to allow industrial archaeologists to continue exploration whilst minimising the risk to health from radon.

  6. Experience from Intercomparison Exercises of Radon Gas Detectors in the Years 1996-2006

    NASA Astrophysics Data System (ADS)

    Butterweck, Gernot; Schuler, Christoph

    2008-08-01

    Radon gas measuring services in Switzerland must be approved by the Federal Office for Public Health (FOPH). The maintenance of approval includes the obligation to participate in annual intercomparison exercises performed at the radon gas reference laboratory of the Paul Scherrer Institut (PSI). In eleven intercomparison exercises since 1996 a total of 1,515 radon gas detectors was subjected to radon gas exposures between 300 kBq h m-3 and 2100 kBq h m-3. Preparation and read-out of electret detectors is performed by the measuring services. About one percent of these detectors were observed with false positive results. The quality of results of etched-track detectors is determined by the quality assurance system and calibration of the supplier. In one case, a measuring service lost approval due to quality problems of the detector manufacturer. Double blind tests yielded less good results compared to the detectors of the same measuring service participating officially.

  7. Residence times of fine tropospheric aerosols as determined by {sup 210}Pb progeny.

    SciTech Connect

    Marley, N. A.; Gaffney, J. S.; Drayton, P. J.; Cunningham, M. M.; Mielcarek, C.; Ravelo, R.; Wagner, C.

    1999-10-05

    Fine tropospheric aerosols can play important roles in the radiative balance of the atmosphere. The fine aerosols can act directly to cool the atmosphere by scattering incoming solar radiation, as well as indirectly by serving as cloud condensation nuclei. Fine aerosols, particularly carbonaceous soots, can also warm the atmosphere by absorbing incoming solar radiation. In addition, aerosols smaller than 2.5 {micro}m have recently been implicated in the health effects of air pollution. Aerosol-active radioisotopes are ideal tracers for the study of atmospheric transport processes. The source terms of these radioisotopes are relatively well known, and they are removed from the atmosphere only by radioactive decay or by wet or dry deposition of the host aerosol. The progeny of the primordial radionuclide {sup 238}U are of particular importance to atmospheric studies. Uranium-238 is common throughout Earth's crust and decays to the inert gas {sup 222}Rn, which escapes into the atmosphere. Radon-222 decays by the series of alpha and beta emissions shown in Figure 1 to the long-lived {sup 210}Pb. Once formed, {sup 210}Pb becomes attached to aerosol particles with average attachment times of 40 s to 3 min.

  8. Biokinetic models for radiocesium and its progeny

    SciTech Connect

    Leggett, Richard Wayne

    2013-01-01

    Over the next few years the International Commission on Radiological Protection (ICRP) will publish a series of reports containing updated biokinetic and dosimetric models and dose coefficients for occupational intake of radionuclides. The biokinetic modeling scheme continues a trend in modern ICRP reports toward physiologically realistic descriptions of the time-dependent behavior of absorbed radionuclides and ingrowing chain members. This paper proposes systemic biokinetic models for cesium isotopes and their chain members for use in these ICRP reports and examines dosimetric implications of the proposed models. Comparisons of A = tissue dose per unit input to blood based on current ICRP models for workers (ICRP Publication 68, 1994) with B = corresponding values based on the proposed biokinetic models (but using dosimetry models of Publication 68) yields the following ranges of ratios B:A for tissues addressed in current ICRP documents: 0.5-25 for 130Cs (T1/2 = 29.2 min), 0.6-9.5 for 134mCs (2.9 h), 0.8-2.2 for 129Cs (32.1 h), 0.7-1.7 for 131Cs (9.69 d), 0.8-1.3 for 136Cs (13.2 d), 0.7-1.1 for 134Cs (2.06 y), 0.5-1.9 for 137Cs (30.2 y), and 0.2-3.7 for 135Cs (2.3x106 y). The large differences in estimated tissue dose for some tissues and cesium isotopes, particularly short-lived isotopes, result mainly from differences in model predictions of the time-dependent distributions of cesium in the body. For example, the proposed and current ICRP models for cesium predict peak kidney contents of ~22% and ~0.4%, respectively, following intravenous injection of stable cesium. Based on the proposed models for cesium and its progeny, the only dosimetrically significant chain members of cesium isotopes are 137mBa, which represents 32-85% of the estimated tissue doses from injected 137Cs, and 134Cs, which represents 4-53% of the estimated tissue doses from injected 134mCs.

  9. Reducing Radon in Schools: A Team Approach.

    ERIC Educational Resources Information Center

    Ligman, Bryan K.; Fisher, Eugene J.

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

  10. Radon Risk Perception and Testing: Sociodemographic Correlates.

    ERIC Educational Resources Information Center

    Halpern, Michael T.; Warner, Kenneth E.

    1994-01-01

    Using information from the 1990 National Health Interview Survey, examined beliefs regarding radon and radon-testing activities among different sociodemographic groups. Results suggest relatively superficial knowledge regarding radon, and little testing, within the survey population. Significantly less knowledge was observed among female and…

  11. Is Your School Safe from Radon?

    ERIC Educational Resources Information Center

    Martin, Paul

    1990-01-01

    Radon is a natural, chemically inert, radioactive gas that can seep to the surface from underground rocks. As many as 20,000 lung cancer deaths in the U.S. each year may be radon-caused. Screening a school for radon is not difficult and may be done on weekends. It's safer for students and staff to test and be sure. (MLH)

  12. REENTRY OF RADON FROM MITIGATION SYSTEM OUTLETS

    EPA Science Inventory

    The paper gives results of the measurement of reentry rates for radon released at roof level and at ground level near a house, to determine whether or not exhaust is necessary above the roof. (NOTE: Some radon mitigation systems draw air with a high radon concentration from under...

  13. RADON GENERATION AND TRANSPORT THROUGH CONCRETE FOUNDATIONS

    EPA Science Inventory

    The report gives results of an examination of radon generation and transport through Florida residential concretes for their contribution to indoor radon concentrations. Radium concentrations in the 11 concretes tested were all <2.5 pCi/g and radon emanation coefficients were all...

  14. Radon daughter carousel: An automated instrument for measuring indoor concentrations of 218Po, 214Pb, and 214Bi

    NASA Astrophysics Data System (ADS)

    Nazaroff, William W.

    1983-09-01

    A microprocessor-controlled instrument for measuring the concentrations of radon progeny in indoor air is described. The measurement technique is based on alpha spectroscopy and uses two counting intervals following a sampling period during which radon progeny are collected on a filter. The counting intervals are selected to provide optimal precision for measuring 222Rn progeny for fixed total measurement times ranging from 30 to 60 min: concentrations as low as 0.5 pCi/1 can be measured with less than 20% uncertainty in 45 min. The instrument can also be used to estimate the potential alpha energy concentration of 220Rn decay products. The device operates under the control of a computer or a data terminal and functions for week-long periods between filter changes. The user can specify the sampling- and counting-interval timing over a wide range and select from among several operating modes. A number of performance tests are also described indicating that for typical indoor concentrations the measurement uncertainty is dominated by counting statistics.

  15. Radon levels can be predicted

    NASA Astrophysics Data System (ADS)

    Wainger, Lisa A.

    Scientists doing a yearlong study of radon levels in houses have identified several major factors that affect concentrations and have developed a method for predicting indoor radon levels before a house is built. Douglas Mose and George Mushrush (George Mason University, Fairfax, Va.) studied 1500 homes in northern Virginia and central Maryland near Washington, D.C.Radon is a radioactive decay product of uranium that occurs in many rock types. The gas can accumulate in buildings and pose a serious health hazard. Results from the Washington-area study show that ˜35% of the houses had average yearly radon concentrations above 4 pico-Curies per liter (pCi/L), the level at which the Environmental Protection Agency (EPA) suggests that a homeowner should take steps to reduce radon concentrations. At a level of 4-10 pCi/L an estimated 13-120 lung cancer deaths would be expected for every 1000 people exposed. Such a risk is comparable to having 200 chest X rays per year, according to EPA statistics.

  16. Assigning linkage haplotypes from parent and progeny genotypes

    SciTech Connect

    Nejati-Javaremi, A.; Smith, C.

    1996-04-01

    Given the genotypes of parents and progeny, their haplotypes over several or many linked loci can be easily assigned by listing the allele type at each locus along the haplotype known to be from each parent. Only a small number (5-10) of progeny per family is usually needed to assign the parental and progeny haplotypes. Any gaps left in the haplotypes may be filled in from the assigned haplotypes of relatives. The process is facilitated by having multiple alleles at the loci and by using more linked loci in the haplotype and with more progeny from the mating. Crossover haplotypes in the progeny can be identified by their being unique or uncommon, and the crossover point can often be detected if the locus linkage map order is known. The haplotyping method applies to outbreeding populations in plants, animals, and man, as well as to traditional experimental crosses of inbred lines. The method also applies to half-sib families, whether the genotype of the mates are known or unknown. The haplotyping procedure is already used in linkage analysis but does not seem to have been published. It should be useful in teaching and in genetic applications of haplotypes. 15 refs., 5 tabs.

  17. Indoor radon survey in Visegrad countries.

    PubMed

    Műllerová, Monika; Kozak, Krzysztof; Kovács, Tibor; Smetanová, Iveta; Csordás, Anita; Grzadziel, Dominik; Holý, Karol; Mazur, Jadwiga; Moravcsík, Attila; Neznal, Martin; Neznal, Matej

    2016-04-01

    The indoor radon measurements were carried out in 123 residential buildings and 33 schools in Visegrad countries (Slovakia, Hungary and Poland). In 13.2% of rooms radon concentration exceeded 300Bqm(-3), the reference value recommended in the Council Directive 2013/59/EURATOM. Indoor radon in houses shows the typical radon behavior, with a minimum in the summer and a maximum in the winter season, whereas in 32% of schools the maximum indoor radon was reached in the summer months. PMID:26774389

  18. Radon Reduction Experience at a Former Uranium Processing Facility

    SciTech Connect

    Eger, K. J.; Rutherford, L.; Rickett, K.; Fellman, R.; Hungate, S.

    2004-02-29

    Approximately 6,200 cubic meters of waste containing about 2.0E8 MBq of radium-226 are stored in two large silos at the Fernald Site in southwest Ohio. The material is scheduled for retrieval, packaging, off site shipment and disposal by burial. Air in the silos above the stored material contained radon-222 at a concentration of 7.4 E5 Bq/L. Short-lived daughters formed by decay in these headspaces generated dose rates at contact with the top of the silos up to 1.05 mSv/hr and there complicate the process of retrieval. A Radon Control System (RCS) employing carbon adsorption beds has been designed under contract with the Fluor Fernald to remove most of the radon in the headspaces and maintain lower concentrations during periods when work on or above the domes is needed. Removing the radon also removes the short-lived daughters and reduces the dose rate near the domes to 20 to 30 {mu}Sv/hr. Failing to remove the radon would be costly, in the exposure of personnel needed to work extended peri