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Sample records for affect radon entry

  1. An investigation of factors affecting the entry of radon into structures on the Island of Guam

    SciTech Connect

    Kladder, D.L.; Burkhart, J.F.; Thorburn, M.S.

    1995-12-31

    Factors affecting the entry of radon-222 gas into structures on the Island of Guam were investigated during the summer of 1993. Research findings indicated that radon transport into buildings on Guam, and perhaps in other tropical areas, is driven by sub-grade soil pressure (positive with respect to atmospheric pressure) rather than interior buildings vacuums. Immediate and substantive increases in indoor radon concentrations were associated with environmental effects of wind and rain. Radon entry, and hence indoor radon concentrations, is significantly greater during the rainy season as opposed to the dry season. In the absence of mechanically induced interior vacuums in buildings, external environmental forces creating sub-slab pressures are the predominant factor in affecting radon entry in Guam. Indoor radon potentials can be correlated to the locations where the underlying geology is limestone. Furthermore, the radon source appears to be within the first few feet of the surface of these limestones rather than uniformly distributed throughout the limestone. The effects of seismic activity on radon entry are short-lived unless significant damage occurs to a structure. Radon entry during calm weather conditions may also be a function of the rising and falling of ocean tides.

  2. Determination of mechanisms and parameters which affect radon entry into a room.

    PubMed

    Vasilyev, A V; Zhukovsky, M V

    2013-10-01

    There are practically no direct techniques for measuring radon entry rate in the rooms. The suggested technique allows estimating such parameter under real conditions. The technique for radon diagnostic procedures including radon entry rate and air change rate assessment was proposed and tested in the field under various experimental conditions. The method consists of the continuous measurement of radon concentration, temperature and pressure difference between indoor and outdoor atmosphere. It was demonstrated that the study of dependence of radon entry rate on temperature difference ΔT between indoor and outdoor atmosphere allows to estimate the dominant radon entry mechanism - diffusion mechanism (absence of the dependence on ΔT) or convective (radon entry rate increase at ΔT increase). It was shown that simultaneous measurements of time series of radon concentration and pressure difference between building envelope and outdoor atmosphere allow assessing such room parameter as Effective Leakage Area. The approach applied in this paper to estimate the air change rate practically is not differing from tracer gas techniques when the constant gas entry rate is used. It was shown that radon could be used as kind of tracer gas to estimate the air change rate. Obtained measurement results for all buildings confirmed the seasonal variations of radon concentrations. A correlation of radon concentration and air change rate with outside temperature occurred in general.

  3. 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.

  4. TEST CELL STUDIES OF RADON ENTRY

    EPA Science Inventory

    The report gives results of a study to contrast the effectiveness of slab-in-stem wall (SSW) with floating slab (FS) construction practices, to measure radon transport and entry for model testing, to develop protocols relevant to depressurized radon measurements, and to determine...

  5. Radon entry control in new house construction.

    PubMed

    Najafi, F T; Lalwani, L; Li, W G

    1995-07-01

    People exposed to high concentration levels of radon face an increased risk of developing lung cancer. The risk is directly proportional to the length and level of radon exposure. Because of health reasons, it is safer to build new houses with radon mitigation systems installed in slab-on-grade houses. However, the interrelationships between parameters and factors governing radon entry and control are highly complex. A study performed by the University of Florida has examined the effectiveness of different radon entry control approaches. The analysis was based on 47 houses from three research projects conducted by the University of Florida (14 houses), Florida Solar Energy Center (13 houses), and GEOMET Technologies (20 houses). The evaluation of the performance and effectiveness of improved floor slabs, space conditioning, and ventilating systems were analyzed. Statistical analyses of the interrelationship between various parameters were also performed. Study findings such as the important factors in reducing radon entry and the effectiveness of passive construction approach and active subslab depressurization systems are presented in this paper.

  6. Models of radon entry: A review

    SciTech Connect

    Gadgil, A.J.

    1991-08-01

    This paper reviews existing models of radon entry into houses. The primary mechanism of radon entry in houses with high indoor concentrations is, in most cases, convective entry of radon bearing soil-gas from the surrounding soil. The driving force for this convective entry is the small indoor-outdoor pressure difference arising from the stack effect and other causes. Entry points for the soil-gas generally are the cracks or gaps in the building substructure, or though other parts of the building shell in direct contact with the soil, although entry may also occur by flow though permeable concrete or cinder block walls of the substructure. Models using analytical solutions to idealized geometrical configurations with simplified boundary conditions obtain analytical tractability of equations to be solved at the cost of severe approximations; their strength is in the insights they offer with their solutions. Models based on lumped parameters attempt to characterize the significant physical behavioral characteristics of the soil-gas and radon flow. When realistic approximations are desired for the boundary conditions and terms in the governing equations, numerical models must be used; these are usually based on finite difference or finite element solutions to the governing equations. Limited data are now available for experimental verification of model predictions. The models are briefly reviewed and their strengths and limitations are discussed.

  7. Radon entry into basements: Approach, experimental structures, and instrumentation of the small structures research project

    SciTech Connect

    Fisk, W.J.; Modera, M.P.; Sextro, R.G.; Garbesi, K.; Wollenberg, H.A.; Narasimhan, T.N.; Nuzum, T.; Tsang, Y.W.

    1992-02-01

    We describe the experimental approach, structures, and instrumentation of a research project on radon generation and transport in soil and entry into basements. The overall approach is to construct small precisely-fabricated basements in areas of different geology and climate, to control the pressures and ventilation rates in the structures, and to monitor radon concentrations and other relevant parameters over a period of one year or more. Two nearly air-tight structures have been constructed at the first site. The floor of each structure contains adjustable-width slots that serve as the only significant pathway for advective entry of radon. A layer of gravel underlays the floor of one structure; otherwise they are identical. The structures are instrumented for continuous or periodic monitoring of soil, structural, and meteorological parameters that affect radon entry. The pressure difference that drives advective radon entry can be maintained constant or varied over time. Soil gas and radon entry rates and associated parameters, such as soil gas pressures and radon concentrations, have been monitored for a range of steady-state and time-varying pressure differences between the interior of the structure and the soil. Examples of the experimentally-measured pressure and permeability fields in the soil around a structure are presented and discussed.

  8. Indoor and soil gas radon simultaneous measurements for the purpose of detail analysis of radon entry pathways into houses.

    PubMed

    Froňka, A

    2011-05-01

    Detailed knowledge of radon transport mechanisms from the subsoil into the indoor environment is essential for the correct interpretation of results of short-term indoor radon measurements and for proper and effective design of radon mitigation systems. Radon transfer factor time variations have been studied based on simultaneous continuous indoor and soil gas radon measurements within the framework of complex radon diagnosis of individual buildings. In this context, the key influencing factors have been identified and analysed in order to provide satisfactory explanation on radon entry variations under different measurement conditions. Moreover, a new significant manner of radon entry into the indoor environment has been identified and will be discussed in detail.

  9. The Effect of Steady Winds on Radon-222 Entry from soil into houses

    SciTech Connect

    Riley, W.J.; Gadgil, A.J.; Bonnefous, Y.C.; Nazaroff, W.W.

    1994-10-01

    Wind affects the radon-222 entry rate from soil into buildings and the resulting indoor concentrations. To investigate this phenomenon, we employ a previously tested three-dimensional numerical model of soil-gas Bow around houses, a commercial computational fluid dynamics code, an established model for determining ventilation rates in the presence of wind, and new wind tunnel results for the ground-surface pressure field caused by wind. These tools and data, applied under steady-state conditions to a prototypical residential building, allow us (1) to determine the complex soil-gas flow patterns that result from the presence of wind-generated ground-surface pressures, (2) to evaluate the effect of these flows on the radon concentration in the soil, and (3) to calculate the effect of wind on the radon entry rate and indoor concentration. For a broad range of soil permeabilities, two wind speeds, and two wind directions, we quantify the"flushing" effect of wind on the radon in the soil surrounding a house, and the consequent sharp decrease in radon entry rates. Experimental measurements of the time-dependent radon concentration in soil gas beneath houses confirm the existence of wind-induced flushing. Comparisons are made to modeling predictions obtained while ignoring the effect of the wind-generated ground-surface pressures. These investigations lead to the conclusion that wind-generated ground-surface pressures play a significant role in determining radon entry rates into residential buildings. [References: 26

  10. Radon transport and entry in hilly karst terrains

    SciTech Connect

    Gammage, R.B.; Dudney, C.S.; Wilson, D.L.

    1991-08-01

    This report consists of copies of the view graphs used for the talk Radon Transport and Entry in Hilly Karst Terrains,'' presented at the DOE-OHER Radon Contractors' Meeting held in Albuquerque in August, 1991. The report describes how aerostatic effects can alter indoor radon concentrations, using houses in Oak Ridge and Huntsville as examples. Due to differing terrain topologies, houses in Huntsville have peak radon concentrations in the summer, roughly twice as high as winter values; Oak Ridge houses have peak radon concentrations in the winter, up to 50 times higher than summer values. A critical parameter for subsurface aerostatic transport of radon is the temperature differential between outside air and air in the underground solution cavities. The transport mechanism identified here should operate in other hilly region with karst or fractured/porous bedrock; some of the 100,000 hottest'' houses in the US are in karst regions. 3 figs., 1 tab. (MHB)

  11. Modeling radon entry into Florida slab-on-grade houses.

    PubMed

    Revzan, K L; Fisk, W J; Sextro, R G

    1993-10-01

    Radon entry into a Florida house whose concrete slab is supported by a permeable concrete-block stem wall and a concrete footer is modeled. The slab rests on backfill material; the same material is used to fill the footer trench. A region of undisturbed soil is assumed to extend 10 m beyond and below the footer. The soil is assumed homogeneous and isotropic except for certain simulations in which soil layers of high permeability or radium content are introduced. Depressurization of the house induces a pressure field in the soil and backfill. The Laplace equation, resulting from Darcy's law and the continuity equation, is solved using a steady-state finite-difference model to determine this field. The mass-transport equation is then solved to obtain the diffusive and advective radon entry rates through the slab; the permeable stem wall; gaps at the intersections of the slab, stem wall, and footer; and gaps in the slab. These rates are determined for variable soil, backfill, and stem-wall permeability and radium content, slab-opening width and position, slab and stem-wall diffusivity, and water table depth. The variations in soil permeability and radium content include cases of horizontally stratified soil. We also consider the effect of a gap between the edge of the slab and the stem wall that restricts the passage of soil gas from the stem wall into the house. Calculations indicate that the total radon entry rate is relatively low unless the soil or backfill permeability or radium content is high. Variations in most of the factors, other than the soil permeability and radium content, have only a small effect on the total radon entry rate. However, for a fixed soil permeability, the total radon entry rate may be reduced by a factor of 2 or more by decreasing the backfill permeability, by making the stem wall impermeable and gap-free, (possibly by constructing a one-piece slab/stem-wall/footer), or by increasing the pressure in the interior of the stem wall (by

  12. MODELNG RADON ENTRY INTO FLORIDA HOUSES WITH CONCRETE SLABS AND CONCRETE-BLOCK STEM WALLS, FLORIDA RADON RESEARCH PROGRAM

    EPA Science Inventory

    The report discusses results of modeling radon entry into a typical Florida house whose interior is slightly depressurized. he model predicts that the total radon entry rate is relatively low unless the soil or backfill permeability or radium content is high. ost of the factors c...

  13. Wind-induced contaminant transport in near-surface soils with application to radon entry into buildings

    SciTech Connect

    Riley, William Jowett

    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.

  14. Modeling radon entry into Florida slab-on-grade houses

    SciTech Connect

    Revzan, K.L.; Fisk, W.J.; Sextro, R.G. )

    1993-10-01

    Radon entry into a Florida house whose concrete slab is supported by a permeable concrete-block stem wall and a concrete footer is modeled. The slab rests on backfill material; the same material is used to fill the footer trench. A region of undisturbed soil is assumed to extend 10 m beyond and below the footer. The soil is assumed homogeneous and isotropic except for certain simulations in which soil layers of high permeability or radium content are introduced. Depressurization of the house induces a pressure field in the soil and backfill. The Laplace equation, resulting from Darcy's law and the continuity equation, is solved using a steady-state finite-difference model to determine this field. The mass-transport equation is then solved to obtain the diffusive and advective radon entry rates through the slab; the permeable stem wall; gaps at the intersections of the slab, stem wall, and footer; and gaps in the slab. These rates are determined for variable soil, backfill, and stem-wall permeability and radium content, slab-opening width and position, slab and stem-wall diffusivity, and water table depth. The variations in soil permeability and radium content include cases of horizontally stratified soil. We also consider the effect of a gap between the edge of the slab and the stem wall that restricts the passage of soil gas from the stem wall into the house. Calculations indicate that the total radon entry rate is relatively low unless the soil or backfill permeability or radium content is high. Variations in most of the factors, other than the soil permeability and radium content, have only a small effect on the total radon entry rate. However, for a fixed soil permeability, the total radon entry rate may be reduced by a factor of 2 or more by decreasing the backfill permeability, by making the stem wall impermeable and gap-free, (possibly by constructing a one-piece slab/stem-wall/footer), or by increasing the pressure in the interior of the stem wall.

  15. Radon entry into buildings: Effects of atmospheric pressure fluctuations and building structural factors

    SciTech Connect

    Robinson, Allen Lantham

    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.

  16. Characterization of radon entry rates and indoor concentrations in underground structures

    SciTech Connect

    Borak, T.B.; Whicker, F.W.; Fraley, L.; Gadd, M.S.; Ibrahim, S.A.; Monette, F.A.; Morris, R.; Ward, D.C.

    1992-12-31

    An experimental facility has been designed to comprehensively determine the influence of soil and meterological conditions on the transport of radon into underground structures. Two identical basements are equipped to continuously monitor pressure differentials, temperatures, soil moisture, precipitation, barometric pressure, wind speed, wind direction, natural ventiliation rates, and radon concentrations. A computerized data acquisition system accumulates and processes data at the rate of 6000 points per day. The experimental design is based on performing experiments in one structure, with the other used as a control. Indoor radon concentrations have temporal variations ranging from 150 to 1400 Bq m{sup -3}. The corresponding entry rate of radon ranges from 300 to 10,000 Bq h{sup -1}. When the radon entry rate is high, the indoor radon concentration decreases, whereas elevated radon concentrations seem to be associated with slow but persistent radon entry rates. This inverse relationship is partially due to compensation from enhanced natural ventilation during periods when the radon entry rate is high. Correlations between measured variables in the soil and indoor-outdoor atmospheres are used to interpret these data. This laboratory has the capability to generate essential data required for developing and testing radon transport models.

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

    EPA Science Inventory

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

  18. Factors affecting atmospheric radon concentration, human health.

    PubMed

    Tchorz-Trzeciakiewicz, D E; Kłos, M

    2017-04-15

    We studied the influence of terrain, geology and weather condition on radon concentration in the atmosphere and occurrence of radon density currents. The survey was carried out in Kowary (SW Poland) and in the spoil tip formed during uranium mining. The measurements of radon concentration were performed using SSNTD LR-115. The measurements of uranium thorium and potassium content in soil were carried out using gamma ray spectrometer Exploranium RS-230. We noticed that terrain and stability of weather condition had significant impact on atmospheric radon concentration. The seasonal variations of radon concentrations in Kowary differ from those usually registered in temperate climate. Based on our analyses, the increase of radon concentration in winter and spring was caused by inversion occurring in that area during these seasons. The observed seasonal variations of radon concentrations in the spoil tip were consistent with those characteristic for temperate climate (the highest radon concentration registered in spring and summer and the lowest in winter and autumn). The spoil tip is located above 900m a.s.l. and is not cover by grass or trees. These circumstances promoted radon exhalation. The air movement above the spoil tip area is intensive, even in winter time. The average atmospheric radon concentration in the spoil tip was 318Bqm(-3). The performed research did not reveal occurrence of radon density currents and flow of radon from the spoil tip to lower lying areas in Kowary. We noticed interdependence of atmospheric radon concentration measured at the height of 1.5 above the ground and uranium content in soil and no correlation between thorium content and radon concentration. The lung cancer in residents of Kowary which is more common than in Poland can be associated with increased concentrations of radon. The average radon concentration in the atmosphere in Kowary was 79Bq m(-3).

  19. Radon entry rate analyses using in situ tracer gas method application.

    PubMed

    Froňka, A; Jílek, K

    2014-07-01

    Recently, the role of energy savings in indoor air quality deterioration has been extensively emphasised, predominantly in the context of significant air exchange rate reduction as a result of home energy retrofits. In case of refurbishment of existing buildings, the effect of energy-efficient technologies on indoor radon concentration is considerably complex and has to be carefully evaluated with respect to radon entry rate (RER) and air exchange rate alteration. For the purpose of detailed analysis of radon entry pathways, the unique infiltration experiment has been carried out using the tracer gas (N2O) method application in field conditions. Significant amount of experimental works has been done to provide an independent assessment of RER and air-exchange rate facilitating the analysis of fundamental factors influencing the indoor radon variations (e.g. indoor-outdoor pressure difference induced by wind, stack effect, heating, ventilation and operation of air-conditioning systems).

  20. Mechanisms and sources of radon entry in buildings constructed with modern technologies.

    PubMed

    Zhukovsky, M V; Vasilyev, A V

    2014-07-01

    To investigate the influence of modern building construction technologies on the accumulation of radon indoor, 20 rooms in buildings constructed using mostly monolithic concrete or aerated concrete blocks have been studied. Dominance of the diffusion mechanism of radon entry in buildings constructed with modern technologies has been established. As a result of computer simulations it was found that the main contribution to the variability of radon concentration was made by changes in the ventilation rate. At a low ventilation rate (<0.2 h(-1)) radon concentration above 200 Bq m(-3) can be observed for residential buildings. There is a need for the regulation of the radium-specific activity in building materials. According to the estimates of this study, the content of 226Ra in building materials should not exceed the value of 100 Bq kg(-1).

  1. A study of the influence of a gravel subslab layer on radon entry rate using two basement structures

    SciTech Connect

    Robinson, A.L.; Sextro, R.G.; Fisk, W.J.; Garbesi, K.; Wooley, J.; Wollenberg, H.A.

    1993-01-01

    In buildings with elevated radon concentrations, the dominant transport mechanism of radon is advective flow of soil gas into the building substructure. However, the building-soil system is often complex, making detailed studies of the radon source term difficult. In order to examine radon entry into buildings, the authors have constructed two room-size, precisely-fabricated basement structures at a site with relatively homogeneous, moderately permeable soil. The basements are identical except that one lies directly on native soil whereas the other lies on a high permeability aggregate layer. The soil pressure field and radon entry rate have been measured for different basement pressures and environmental conditions. The subslab gravel layer greatly enhances the advective entry of radon into the structure; when the structures are depressurized, the radon entry rate into the structure with the subslab gravel layer is more than a factor of 3 times the radon entry rate into the other structure for the same depressurization. The gravel subslab layer also spreads the pressure field around the structure, extending the field of influence of the structure and the region from which it draws radon.

  2. RADON REMOVAL USING POINT-OF-ENTRY WATER TREATMENT TECHNIQUES

    EPA Science Inventory

    The purpose of the EPA Cooperative Agreement was to evaluate the performance of POE granular activated carbon (GAC), and diffused bubble and bubble place aeration systems treating a ground water supply containing radon (35,620 ±6,717 pCi/L). The pattern of loading to the uni...

  3. Monitoring and modeling for radon entry into basements: A status report for the small structures project

    SciTech Connect

    Fisk, W.J.; Flexser, S.; Gadgil, A.J.; Holman, H.Y.; Modera, M.P.; Narasimhan, T.N.; Nuzum, T.; Revzan, K.L.; Sextro, R.G.; Smith, A.R.

    1989-09-01

    The approach, status, and initial findings of a research project on radon transport through soil and entry into buildings are described. We have constructed two room-size precisely-fabricated basements at a site with relatively homogeneous soil. The structures have adjustable-size openings to the soil, are otherwise very air-tight, and are mechanically ventilated using a system that also controls the indoor-outdoor pressure difference. Numerous probes have been installed in the soil surrounding the structures to permit multipoint measurement of soil moisture content, soil temperature, permeability of soil to air, soil-gas pressure and radon concentration. State-of-the-art instrumentation is being installed for real-time monitoring of these parameters plus structure ventilation rate, indoor and entering soil-gas radon concentrations, and meteorologic parameters for a period of at least one year. Many of the factors that control or influence radon entry will be modified intentionally or by changes in environmental parameters during the course of the measurements. We have found it necessary to design and fabricate a new type of probe for more accurate measurements of soil permeability. We have also verified and improved procedures for more accurate, rapid, multipoint measurements of radon concentrations using a continuous radon monitor. Identical structures, with the same instrumentation, will be constructed at additional sites with difference soil characteristics and climates. Core samples of the soil from each site are analyzed to determine density, porosity, permeability, radium content, and radon emmanation coefficient. The research project also includes steady-state and transient numerical modeling efforts that complement the experimental research and that will use the experimental data for model validation. 32 refs., 12 figs., 5 tabs.

  4. Radon

    MedlinePlus

    ... Action Plan: A Strategy for Saving Lives . Indoor Air Quality Home Page Frequent Questions about Radon Find Local ... Radon can have a big impact on indoor air quality . Individuals and Families Health Risk of Radon Citizen's ...

  5. Modeling radon entry into houses with basements: Model description and verification

    SciTech Connect

    Revzan, K.L.; Fisk, W.J.; Gadgil, A.J.

    1991-01-01

    We model radon entry into basements using a previously developed three-dimensional steady-state finite difference model that has been modified in the following ways: first, cylindrical coordinates are used to take advantage of the symmetry of the problem in the horizontal plant; second, the configuration of the basement has been made more realistic by incorporating the concrete footer; third, a quadratic relationship between the pressure and flow in the L-shaped gap between slab, footer, and wall has been employed; fourth, the natural convection of the soil gas which follows from the heating of the basement in winter has been taken into account. The temperature field in the soil is determined from the equation of energy conservation, using the basement, surface, and deep-soil temperatures as boundary conditions. The pressure field is determined from Darcy's law and the equation of mass conservation (continuity), assuming that there is no flow across any boundary except the soil surface (atmospheric pressure) and the opening in the basement shell (fixed pressure). After the pressure and temperatures field have been obtained the velocity field is found from Darcy's law. Finally, the radon concentration field is found from the equation of mass-transport. The convective radon entry rate through the opening or openings is then calculated. In this paper we describe the modified model, compare the predicted radon entry rates with and without the consideration of thermal convection, and compare the predicted rates with determined from data from 7 houses in the Spokane River valley of Washington and Idaho. Although the predicted rate is much lower than the mean of the rates determined from measurements, errors in the measurement of soil permeability and variations in the permeability of the area immediately under the basement slab, which has a significant influence on the pressure field, can account for the range of entry rates inferred from the data. 25 refs., 8 figs.

  6. Toward resolving model-measurement discrepancies of radon entry into houses

    SciTech Connect

    Garbesi, Karina

    1993-06-01

    Analysis of the literature indicated that radon transport models significantly and consistently underpredict the advective entry into houses of soil-gas borne radon. Advective entry is the dominant mechanism resulting in high concentrations of radon indoors. My dissertation research investigated the source of the model-measurement discrepancy via carefully controlled field experiments conducted at an experimental basement located in natural soil in Ben Lomond, California. Early experiments at the structure confirmed the existence and magnitude of the model-measurement discrepancy, ensuring that it was not merely an artifact of inherently complex and poorly understood field sites. The measured soil-gas entry rate during structure depressurization was found to be an order of magnitude larger than predicted by a current three-dimensional numerical model of radon transport. The exact magnitude of the discrepancy depends on whether the arithmetic or geometric mean of the small-scale measurements of permeability is used to estimate the effective permeability of the soil. This factor is a critical empirical input to the model and was determined for the Ben Lomond site in the typical fashion using single-probe static depressorization measurements at multiple locations. The remainder of the dissertation research tests a hypothesis to explain the observed discrepancy: That soil permeability assessed using relatively small-scale probe measurements (0.1--0.5 m) does not reflect bulk soil permeability for flows that is likely to occur at larger scales of several meters or more in real houses and in the test structure. The idea is that soil heterogeneity is of a nature that, as flows occur over larger scales, larger scales of heterogeneity are encountered that facilitate larger flux rates, resulting in a scale dependence of effective soil permeability.

  7. Toward resolving model-measurement discrepancies of radon entry into houses

    SciTech Connect

    Garbesi, Karina

    1994-10-01

    Analysis of the literature indicated that radon transport models significantly and consistently underpredict the advective entry into houses of soil-gas borne radon. Advective entry is the dominant mechanism resulting in high concentrations of radon indoors. The author investigated the source of the model-measurement discrepancy via carefully controlled field experiments conducted at an experimental basement located in natural soil in Ben Lomond, California. Early experiments at the structure confirmed the existence and magnitude of the model-measurement discrepancy, ensuring that it was not merely an artifact of inherently complex and poorly understood field sites. The measured soil-gas entry rate during structure depressurization was found to be an order of magnitude larger than predicted by a current three-dimensional numerical model of radon transport. The exact magnitude of the discrepancy depends on whether the arithmetic or geometric mean of the small-scale measurements of permeability is used to estimate the effective permeability of the soil. This factor is a critical empirical input to the model and was determined for the Ben Lomond site in the typical fashion using single-probe static depressurization measurements at multiple locations. The remainder of the dissertation research tests a hypothesis to explain the observed discrepancy: that soil permeability assessed using relatively small-scale probe measurements does not reflect bulk soil permeability for flows that is likely to occur at larger scales of several meters or more in real houses and in the test structure. The idea is that soil heterogeneity is of a nature that, as flows occur over larger scales, larger scales of heterogeneity are encountered that facilitate larger flux rates, resulting in a scale dependence of effective soil permeability.

  8. 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 ...

  9. Foil coverage of a crawl-space floor: measurements and modeling of radon entry.

    PubMed

    van der Spoel, W H; van der Graaf, E R; de Meijer, R J

    1998-05-01

    The mitigative impact of covering the floor of a crawl space with a membrane has been studied under well-defined and controlled conditions. The measurements have been done with a homogeneous column of dry sand covered with a sheet of polyethylene foil. An air-filled volume on top of the column simulates a crawl space. The experiments mainly concern long-term measurements of the crawl-space radon concentration in combination with steady-state diffusive and combined advective and diffusive transport through the sand column and crawl space. The experimental data are analyzed with both simplified mass-balance models for radon entry into the crawl space and with a two-dimensional numerical model based on a finite-difference approach. In all experiments the influence of atmospheric pressure variations is clearly present. For most experiments the agreement between calculations, which make use of independently measured transport parameters for both sand and foil, and measurements is within 10%. However, the discrepancy is larger for experiments with continuous advective transport from the crawl space to the sand. With undamaged foil, the calculations overestimate the measurements by 20%. Reversely, with an opening in the center of the foil, the calculations underestimate the measurements by 20-40%. The results show that under controlled conditions radon transport from a foil-covered sand column into a crawl-space can be described within 40% on basis of separately measured parameters.

  10. On the potential importance of transient air flow in advective radon entry into buildings

    SciTech Connect

    Narasimhan, T.N.; Tsang, Y.W.; Holman, H.Y. )

    1990-05-01

    The authors have investigated, using a mathematical model, the temporal variations of air flux within the soil mass surrounding a basement in the presence of time dependent periodic variations of barometric pressure and a persistent under-pressure at the basement. The results of transient air flow show that for a homogeneous soil medium, the effects of barometric fluctuations are most significant in the cases where soil permeability to air is low and the fluctuation frequency is high. In these cases, the barometric fluctuation can greatly enhance the magnitude of fluxes as well as introduce flow direction reversals from surrounding soil into the basement. These large fluxes with direction reversals have strong implications in regard to advective transport of radon. The results suggest that the transient oscillations have to be accounted for in quantifying radon entry into buildings. In the actual field set up, the transient behavior will be further influenced by soil permeability heterogeneity, by soil moisture variations, and by the effects of multiple periodic components in the barometric pressure fluctuations.

  11. 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.

  12. Effect of Cognitive Entry Behaviors and Affective Entry Characteristics on Learning Level

    ERIC Educational Resources Information Center

    Çaliskan, Muhittin

    2014-01-01

    In this study, the effect of cognitive entry behaviors and affective entry characteristics on learning level was investigated. The study was conducted on 258 first year students attending the Faculty of Education in the autumn semester of the 2011-2012 academic year. The study was conducted using the relational survey model and data was collected…

  13. Factors affecting yearly variations of indoor radon concentrations

    SciTech Connect

    Steck, D.J.; Baynes, S.A.

    1996-06-01

    Since indoor radon exposures take place over many years while radon measurement periods are shorter, we are studying the yearly variation of indoor radon concentrations in approximately 100 houses located throughout Minnesota. Most houses were initially measured for one or more years in the late 1980`s and for 5 consecutive years starting in 1990. Two houses have been monitored for 12 y. Each year, two alpha track detectors were placed on the two lowest livable levels. The year-to-year variations averaged about 35% (corrected for instrumental uncertainties) in both basements and first floors. The minimum observed variation was 5% and the maximum was 130%. Some homes have shown substantial variation associated with Structural modifications. While most homes show no obvious systematic trends, a few houses have shown temporal trends that may be associated with aging or climate. We are studying possible correlation between year-to-year radon variation, climatic variables (yearly-average and seasonal such as heating/cooling degree days, precipitation, soil moisture), and structural changes.

  14. The Influence of a Subslab Gravel Layer and Open Area on Soil-Gas and Radon Entry into Two Experimental Basements

    SciTech Connect

    Robinson, Allen L.; Sextro, R.G.

    1995-03-01

    Measurements of steady-state soil-gas and {sup 222}Rn entry rates into two room-sized, experimental basement structures were made for a range of structure depressurizations (0-40 Pa) and open floor areas (0-165 x 10{sup -4} m{sup 2}). The 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 subslab gravel layer greatly enhances the soil-gas and radon entry rate into the structure. The radon entry rate into the structure with the subslab gravel layer is four times greater than the entry rate into the structure without the gravel layer with an open floor area of 165 x 10{sup -4}m{sup 2}; however the ratio increases to 30 for an open floor area of 5.0 x 10{sup -4} m{sup 2}. The relationship between open area and soil-gas entry rate is complex. It depends on both the amount and distribution of the open area as well as the permeability of the soil near the opening. The entry rate into the experimental structures is largely determined by the presence or absence of a subslab gravel layer. Therefore open area is a poor indicator of radon and soil-gas entry into the structures. The extension of the soil-gas pressure field created by structure depressurization is a good measure of the radon entry. The measured normalized radon entry rate into both structures has the same linear relationship with the average subslab pressure coupling regardless of open area or the presence or absence of a subslab gravel layer. The average subslab pressure coupling is an estimate of the extension of the soil-gas pressure field. A three-dimensional finite-difference model correctly predicts the effect of a subslab gravel layer and different open area configurations on radon and soil-gas entry rate; however, the model underpredicts the absolute entry rate into each structure by a factor of 1.5.

  15. 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.

  16. A critical evaluation of the cost-effectiveness of radon protection methods in new homes in a radon affected area of England.

    PubMed

    Coskeran, Thomas; Denman, Antony; Phillips, Paul; Tornberg, Roger

    2009-08-01

    In the UK, building new homes in areas prone to radon gas is currently subject to regulations that require installation of radon-proof membranes. These membranes are not, however, the only way to protect residents of new homes against radon's potential to cause lung cancer. Alternative regulatory regimes can be constructed that would achieve the same end. The purpose of this paper is to examine the cost-effectiveness of four alternative regimes and so determine if building regulations for new homes could be altered to protect residents from the effects of radon more cost-effectively than at present. In addressing this question, the paper also contributes to the wider debate on how best to reduce the effect on public health of exposure to radon. The measure of cost-effectiveness used, cost per quality-adjusted life-year gained, is determined from radon test results obtained in properties in Brixworth, England, UK, a radon Affected Area. Confidence intervals for the cost-effectiveness estimates are also derived using bootstrap techniques. The central estimates of cost-effectiveness range from 2870 pounds per quality-adjusted life-year gained for the most cost-effective of the alternative regimes to 6182 pounds for the current regime. These results suggest that alternative regimes may be more cost-effective in tackling the radon problem. A definitive assessment of the most suitable to adopt will require extensive negotiation between government departments, the construction industry, and other interested parties to ensure acceptance of any new regime. The paper offers suggestions for future research that should help in the process of identifying the key features of a new regulatory approach.

  17. 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...

  18. Underground air returns as active transportation pathways for radon gas entry into homes.

    PubMed

    Kearfott, K J; Metzger, R L; Holbert, K E

    1992-12-01

    Levels of elevated 222Rn in homes can fail to correlate with measured radium concentrations in soils and surrounding rocks for reasons which can include water sources, building materials, and unusual variations in climate or building construction. Several homes were identified in the Phoenix, AZ metropolitan area with soil radium concentrations of < 0.074 Bq g-1 (2.0 pCi g-1) which had elevated radon concentrations unexplained by geological sources alone. Continuous monitoring of eight houses under different conditions of cooling system usage revealed a definite role of the underground air returns as active transport pathways contributing to the enhancement of the indoor concentration of 222Rn in six of the houses. The ratio of indoor 222Rn concentrations on days when the cooling system was operated continuously compared to days the system was off ranged from essentially one up to a factor exceeding 10.

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

    PubMed

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

    2017-05-01

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

  20. Setting radon-specific release criteria and demonstrating compliance for land affected by NORM.

    PubMed

    García-Talavera, M; Martínez, M; Matarranz, J L M; Ramos, L

    2008-11-01

    Residues from industrial activities involving naturally occurring radioactive materials (NORMs) may cause radiation exposures to members of the public, particularly when NORM-affected land is brought into residential use. To provide an adequate protection against radiation in such situations, the following limiting criteria are currently required in Spain for releasing NORM-affected land: (i) no more than a 300 microSv yr(-1) increase (excluding radon doses) over the natural background; (ii) (222)Rn concentrations in hypothetical future dwellings lower than 200 Bq m(-3); and (iii) reduction of all radiation exposures to as low as reasonable achievable. This paper addresses some of the problems encountered in translating the (222)Rn criterion into site-specific release limits and in demonstrating compliance with them.

  1. 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.

  2. 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...

  3. 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.

  4. 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.

  5. Radon-Induced Health Effects

    NASA Astrophysics Data System (ADS)

    Muirhead, C. R.

    The following sections are included: * Lung Cancer * Studies of miners * Estimates of lifetime risk associated with indoor radon exposure * Factors that may affect risk estimates * Sex and age at exposure * Joint effect of radon and smoking * Exposure rate * Epidemiological studies of lung cancer and indoor radon exposure * Cancers Other Than Lung * Dosimetry * Epidemiological studies * Studies of miners * Indoor radon exposure * Concluding Remarks * References

  6. Radon levels and doses in dwellings in two villages in Kosovo, affected by depleted uranium.

    PubMed

    Nafezi, G; Gregoric, A; Vaupotic, J; Bahtijari, M; Kuqali, M

    2014-01-01

    The radon ((222)Rn) activity concentration in 15 dwellings in the Planej village and 10 dwellings in the Gorozhup village has been measured with the aim to complement the national radon survey and to compare the results of two different measurement techniques. The radon concentration has been measured in winter and spring using alpha scintillation cells and in winter, spring and summer by exposing solid-state nuclear track detectors. Both methods gave similar results. Radon concentrations in both villages were similar, ranging from 82 to 432 Bq m(-3); the value of 400 Bq m(-3) was exceeded only in two dwellings. The resulting annual effective doses ranged from 1.78 to 6.40 mSv, with the average values of 3.28 mSv in the Planej village and 3.87 mSv in the Gorozhup village.

  7. Effect of soil moisture on seasonal variation in indoor radon concentration: modelling and measurements in 326 Finnish houses.

    PubMed

    Arvela, H; Holmgren, O; Hänninen, P

    2016-02-01

    The effect of soil moisture on seasonal variation in soil air and indoor radon is studied. A brief review of the theory of the effect of soil moisture on soil air radon has been presented. The theoretical estimates, together with soil moisture measurements over a period of 10 y, indicate that variation in soil moisture evidently is an important factor affecting the seasonal variation in soil air radon concentration. Partitioning of radon gas between the water and air fractions of soil pores is the main factor increasing soil air radon concentration. On two example test sites, the relative standard deviation of the calculated monthly average soil air radon concentration was 17 and 26%. Increased soil moisture in autumn and spring, after the snowmelt, increases soil gas radon concentrations by 10-20 %. In February and March, the soil gas radon concentration is in its minimum. Soil temperature is also an important factor. High soil temperature in summer increased the calculated soil gas radon concentration by 14%, compared with winter values. The monthly indoor radon measurements over period of 1 y in 326 Finnish houses are presented and compared with the modelling results. The model takes into account radon entry, climate and air exchange. The measured radon concentrations in autumn and spring were higher than expected and it can be explained by the seasonal variation in the soil moisture. The variation in soil moisture is a potential factor affecting markedly to the high year-to-year variation in the annual or seasonal average radon concentrations, observed in many radon studies.

  8. Effect of soil moisture on seasonal variation in indoor radon concentration: modelling and measurements in 326 Finnish houses

    PubMed Central

    Arvela, H.; Holmgren, O.; Hänninen, P.

    2016-01-01

    The effect of soil moisture on seasonal variation in soil air and indoor radon is studied. A brief review of the theory of the effect of soil moisture on soil air radon has been presented. The theoretical estimates, together with soil moisture measurements over a period of 10 y, indicate that variation in soil moisture evidently is an important factor affecting the seasonal variation in soil air radon concentration. Partitioning of radon gas between the water and air fractions of soil pores is the main factor increasing soil air radon concentration. On two example test sites, the relative standard deviation of the calculated monthly average soil air radon concentration was 17 and 26 %. Increased soil moisture in autumn and spring, after the snowmelt, increases soil gas radon concentrations by 10–20 %. In February and March, the soil gas radon concentration is in its minimum. Soil temperature is also an important factor. High soil temperature in summer increased the calculated soil gas radon concentration by 14 %, compared with winter values. The monthly indoor radon measurements over period of 1 y in 326 Finnish houses are presented and compared with the modelling results. The model takes into account radon entry, climate and air exchange. The measured radon concentrations in autumn and spring were higher than expected and it can be explained by the seasonal variation in the soil moisture. The variation in soil moisture is a potential factor affecting markedly to the high year-to-year variation in the annual or seasonal average radon concentrations, observed in many radon studies. PMID:25899611

  9. Is environmental radon gas associated with the incidence of neurodegenerative conditions? A retrospective study of multiple sclerosis in radon affected areas in England and Wales.

    PubMed

    Groves-Kirkby, Christopher J; Denman, Antony R; Campbell, Jackie; Crockett, Robin G M; Phillips, Paul S; Rogers, Stephen

    2016-04-01

    To test whether an association exists between radon gas concentration in the home and increased multiple sclerosis (MS) incidence, a retrospective study was undertaken of MS incidence in known areas of raised domestic radon concentration in England and Wales, using The Health Improvement Network (THIN) clinical research database. The study population comprised 20,140,498 person-years of clinical monitoring (males: 10,056,628: 49.93%; females: 10,083,870: 50.07%), representing a mean annual population of 2.5 million individuals. To allow for the possible latency of MS initiation following exposure, data extraction was limited to patients with at least five years registration history with the same GP practice before first diagnosis. Patient records were allocated to one of nine radon concentration bands depending on the average radon level in their postcode sector. MS incidence was analysed by searching for patients with first MS diagnosis over the eight calendar years 2005-2012 inclusive. 1512 new MS cases were diagnosed, 1070 females, 442 males, equivalent to raw incidence rates of 7.51, 10.61 and 4.40 per 10(5) person-years respectively, comparable to previously reported results. Of these new cases, 115 could be allocated to one of the radon bands representing high radon areas. Standardising to the UK 2010 population, excess relative risk (ERR) figures for MS were calculated for each radon band. Linear regression of ERR against mean band radon concentration shows a positive gradient of 0.22 per 100 Bq·m(-3) (R(2) = 0.25, p = 0.0961) when forced through the origin to represent a linear-no-threshold response. The null hypothesis falls inside the 95% confidence interval for the linear fit and therefore this fit is not statistically significant. We conclude that, despite THIN sampling around 5% of the population, insufficient data was available to confirm or refute the hypothesised association between MS incidence and radon concentration.

  10. RADON MITIGATION IN SCHOOLS: CASE STUDIES OF RADON MITIGATION SYSTEMS INSTALLED BY EPA IN FOUR MARYLAND SCHOOLS ARE PRESENTED

    EPA Science Inventory

    The first part of this two-part paper discusses radon entry into schools, radon mitigation approaches for schools, and school characteristics (e.g., heating, ventilation, and air-conditioning -- HVAC-- system design and operation) that influence radon entry and mitigation system ...

  11. Automatically processed alpha-track radon monitor

    DOEpatents

    Langner, G.H. Jr.

    1993-01-12

    An automatically processed alpha-track radon monitor is provided which includes a housing having an aperture allowing radon entry, and a filter that excludes the entry of radon daughters into the housing. A flexible track registration material is located within the housing that records alpha-particle emissions from the decay of radon and radon daughters inside the housing. The flexible track registration material is capable of being spliced such that the registration material from a plurality of monitors can be spliced into a single strip to facilitate automatic processing of the registration material from the plurality of monitors. A process for the automatic counting of radon registered by a radon monitor is also provided.

  12. Automatically processed alpha-track radon monitor

    DOEpatents

    Langner, Jr., G. Harold

    1993-01-01

    An automatically processed alpha-track radon monitor is provided which includes a housing having an aperture allowing radon entry, and a filter that excludes the entry of radon daughters into the housing. A flexible track registration material is located within the housing that records alpha-particle emissions from the decay of radon and radon daughters inside the housing. The flexible track registration material is capable of being spliced such that the registration material from a plurality of monitors can be spliced into a single strip to facilitate automatic processing of the registration material from the plurality of monitors. A process for the automatic counting of radon registered by a radon monitor is also provided.

  13. Automatically processed alpha-track radon monitor

    SciTech Connect

    Langner, G.H. Jr.

    1991-05-02

    An automatically processed alpha-track radon monitor is provided which includes a housing having an aperture allowing radon entry, and a filter that excludes the entry of radon daughters into the housing. A flexible track registration material is located within the housing that records alpha-particle emissions from the decay of radon and radon daughters inside the housing. The flexible track registration material is capable of being spliced such that the registration material from a plurality of monitors can be spliced into a single strip to facilitate automatic processing of the registration material from the plurality of monitors. A process for the automatic counting of radon registered by a radon monitor is also provided.

  14. 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

  15. The Influence of Student's Affective Entry on Instructor and Course Evaluations.

    ERIC Educational Resources Information Center

    Ory, John C.; Pieper, David M.

    A study was undertaken in six fall 1978 courses at a large midwestern university to examine possible biasing influences on student ratings of instruction brought about by pre-course expectations of the course. Student and course demographic variables were analyzed as possible determiners of affective entry into the course. These data were examined…

  16. RADON MITIGATION IN SCHOOLS: HVAC SYTEMS IN SCHOOLS TEND TO HAVE A GREATER IMPACT ON RADON LEVELS THAN HVAC SYSTEMS IN HOMES

    EPA Science Inventory

    The first part of this two-part paper discusses radon entry into schools, radon mitigation approaches for schools, and school characteristics (e.g., heating, ventilation, and air conditioing -- HVAC-- system design and operationg) that influence radon entry and mitigation system ...

  17. Environmental factors affecting long-term stabilization of radon suppression covers for uranium mill tailings

    SciTech Connect

    Young, J.K.; Long, L.W.; Reis, J.W.

    1982-04-01

    Pacific Northwest Laboratory is investigating the use of a rock armoring blanket (riprap) to mitigate wind and water erosion of an earthen radon suppression cover applied to uranium mill tailings. To help determine design stresses for the tailings piles, environmental parameters are characterized for the five active uranium-producing regions on a site-specific basis. Only conventional uranium mills that are currently operating or that are scheduled to open in the mid 1980s are considered. Available data indicate that flooding has the most potential for disrupting a tailings pile. The arid regions of the Wyoming Basins and the Colorado Plateau are subject to brief storms of high intensity. The Texas Gulf Coast has the highest potential for extreme precipitation from hurricane-related storms. Wind data indicate average wind speeds from 3 to 6 m/sec for the sites, but extremes of 40 m/sec can be expected. Tornado risks range from low to moderate. The Colorado Plateau has the highest seismic potential, with maximum acceleration caused by earthquakes ranging from 0.2 to 0.4 g. Any direct effect from volcanic eruption is negligible, as all mills are located 90 km or more from an igneous or hydrothermal system.

  18. 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)

  19. 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.

  20. 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.

  1. Radon levels inside residences in Mexico City

    SciTech Connect

    Espinoza, G. . Inst. de Fisica); Gammage, R.B. )

    1989-01-01

    Levels of radon were measured during winter and spring seasons inside 55 colonial and modern houses and 30 multifamily apartment buildings representative of middle and upper income families. The modern houses and apartment buildings in the southern section of the city had average radon levels exceeding 150 Bq m{sup {minus}3} with a maximum single measurement of 458 Bq m{sup {minus}3}. The colonial houses in the central downtown section had radon levels nearly all averaging below 100 Bq m{sup {minus}3}. Between the ground and third floor of the apartment buildings, radon levels diminished by tenfold indicating that entry of radon-bearing soil gas was largely responsible for the elevated concentrations of radon. The radon levels in winter exceeded by about 30% the radon levels during spring. The potentially adverse health effects of these radon levels may be exacerbated by the quality of air in Mexico City which during winter is often highly polluted. 7 refs., 2 figs.

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

    PubMed

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

    2015-07-01

    The aim of this study is oriented to investigate the influence of some physicochemical factors such as radium distribution, grain size, moisture content and chemical constituents on releases of radon-222 from the accumulated phosphogypsum (PG) waste. The emanation fraction, activity concentration in the pore and the surface exhalation rate of radon-222 in the bulk PG waste are 34.5 ± 0.3%, 238.6 ± 7.8 kBq m(-3) and 213 ± 6.9 mBq m(-2) s(-1), respectively. These values were varied and enhanced slightly in the fine grain sizes (F1 < 0.125 mm) by a factor of 1.05 folds compared to the bulk residue. It was also found that release of radon from residue PG waste was controlled positively by radium (Ra-226), calcium (CaSO4) and strontium (SrO). About 67% of radon release attributed to the grain size below 0.5 mm, while 33% due to the large grain size above 0.5 mm. The emanation fraction of Rn-222 is increased with moisture content and the maximum emanation is ∼43% of moisture of 3-8%. It reduced slowly with the continuous increase in moisture till 20%. Due to PG waste in situ can be enhancing the background to the surround workers and/or public. Therefore, the environmental negative impacts due to release of Rn-222 can be minimized by legislation to restrict its civil uses, or increasing its moisture to ∼10%, or by the particle size separation of the fine fraction containing the high levels of Ra-226 followed by a suitable chemical treatment or disposal; whereas the low release amount can be diluted and used in cement industry, roads or dam construction.

  3. 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

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

    EPA Science Inventory

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

  5. EFFECTS OF NATURAL AND FORCED BASEMENT VENTILATION ON RADON LEVELS IN SINGLE FAMILY DWELLINGS

    EPA Science Inventory

    The report gives, for the first time, results of an extensive study of the effect of ventilation on radon concentrations and radon entry rate in a single-family dwelling. Measurements of radon concentrations, building dynamics, and environmental parameters made in Princeton Unive...

  6. 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.

  7. 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.

  8. A review on mathematical models for estimating indoor radon concentrations.

    PubMed

    Park, Ji Hyun; Kang, Dae Ryong; Kim, Jinheum

    2016-01-01

    Radiation from natural sources is one of causes of the environmental diseases. Radon is the leading environmental cause of lung cancer next to smoking. To investigate the relationship between indoor radon concentrations and lung cancer, researchers must be able to estimate an individual's cumulative level of indoor radon exposure and to do so, one must first be able to assess indoor radon concentrations. In this article, we outline factors affecting indoor radon concentrations and review related mathematical models based on the mass balance equation and the differential equations. Furthermore, we suggest the necessities of applying time-dependent functions for indoor radon concentrations and developing stochastic models.

  9. RADON DIAGNOSTIC MEASUREMENT GUIDANCE FOR LARGE BUILDINGS - VOLUME 2. APPENDICES

    EPA Science Inventory

    The report discusses the development of radon diagnostic procedures and mitigation strategies applicable to a variety of large non-residential buildings commonly found in Florida. The investigations document and evaluate the nature of radon occurrence and entry mechanisms for rad...

  10. Effects of vegetation on radon transport processes in soil

    SciTech Connect

    Borak, T.B.

    1991-01-01

    This research was conducted to measure radon concentrations. Radon concentrations in soil gas were measured on a weekly schedule. Samples were extracted through the tubes used for measuring pressure differentials at depths of 30, 100, 180 cm. The average soil moisture content was measured with the neutron gauge. Other soil parameters such as soil temperature and meteorological data were analyzed in order to determine their influence on soil radon concentrations. For indoor radon concentrations, 15 minute measurements were used to obtain a monthly average for one structure from January 1989--August 1990. Also measured were wind speed and pressure differential correlations with radon concentration. The salient features of the data obtained thus far are as follows: radon gas concentrations in the silty clay surrounding the structures increased with depth; monthly averaged radon concentrations in the underground structures do not exhibit obvious seasonal variations; indoor radon concentrations are not correlation with pressure differences between the structure and surrounding soil; for these structures the radon entry rate has two components; one that is constant and the other that changes with time; and the wind speeds that increase the radon entry rate, also increase the ventilation rate. 11 figs.

  11. Comparative dosimetry of radon in mines and homes. Panel of dosimetric assumptions affecting the application of radon risk estimates, Board on Radiation Effects Research, Commission on Life Sciences, National Research Council

    SciTech Connect

    Not Available

    1991-01-01

    The National Academy study addresses a topic of widespread attention since the discovery in 1984 of a worker found to be contaminated with radon in his home. Scientists have long understood the dangers of exposure to radon and its progeny and have analyzed the effects of exposure of these radionuclides in underground miner populations. However, extensive analyses on effects of radon exposure in the home are only now being performed. This study evaluates available data, describes uncertainties and attempts to translate dosimetric information related mine worker exposure to risk information regarding home radon exposures. The Academy's compilation and evaluation of the data are, as usual, pain-staking and thorough. Their discussions of uncertainties is helpful and careful to describe the boundaries and limitations of their results. The dosimetric model which resulted from their comparative evaluation is clearly presented. Risk assessors concerned about residential exposures to radionuclides will find this study useful.

  12. 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

  13. Radon in Schools

    MedlinePlus

    ... is a critical component of any comprehensive indoor air quality (IAQ) management program, l earn how to manage ... provide feedback, or report a problem. Radon Indoor Air Quality Home Page Radon Home Local Radon Zones and ...

  14. Managing Radon in Schools

    EPA Pesticide Factsheets

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

  15. 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)

  16. 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)

  17. School-Entry Policies and Skill Accumulation across Directly and Indirectly Affected Individuals

    ERIC Educational Resources Information Center

    Bedard, Kelly; Dhuey, Elizabeth

    2012-01-01

    During the past half-century, there has been a trend toward increasing the minimum age a child must reach before entering school in the United States. States have accomplished this by moving the school-entry cutoff date earlier in the school year. The evidence presented in this paper shows that these law changes increased human capital…

  18. Potential health effects of indoor radon exposure.

    PubMed Central

    Radford, E P

    1985-01-01

    Radon-222 is a ubiquitous noble gas arising from decay of radium-226 normally present in the earth's crust. Alpha radiation from inhaled short-lived daughters of radon readily irradiates human bronchial epithelium, and there is now good evidence of excess risk of lung cancer in underground miners exposed to higher concentrations. In homes, radon levels are highly variable, showing approximately log-normal distributions and often a small fraction of homes with high concentrations of radon and radon daughters. Factors affecting indoor concentrations include type of bedrock under dwellings, house foundation characteristics, radon dissolved in artesian water, and ventilation and degree of air movement in living spaces. Despite much recent work, exposures to radon daughters by the general public are not well defined. From application of risk assessments in miners to home conditions, it appears that about 25% or more of lung cancers among nonsmokers over the age of 60, and about 5% in smokers, may be attributable to exposure to radon daughters at home. It may be necessary to take remedial action to reduce this hazard in those dwellings with elevated levels of radon, and new construction should take account of this problem. PMID:4085431

  19. Potential health effects of indoor radon exposure.

    PubMed

    Radford, E P

    1985-10-01

    Radon-222 is a ubiquitous noble gas arising from decay of radium-226 normally present in the earth's crust. Alpha radiation from inhaled short-lived daughters of radon readily irradiates human bronchial epithelium, and there is now good evidence of excess risk of lung cancer in underground miners exposed to higher concentrations. In homes, radon levels are highly variable, showing approximately log-normal distributions and often a small fraction of homes with high concentrations of radon and radon daughters. Factors affecting indoor concentrations include type of bedrock under dwellings, house foundation characteristics, radon dissolved in artesian water, and ventilation and degree of air movement in living spaces. Despite much recent work, exposures to radon daughters by the general public are not well defined. From application of risk assessments in miners to home conditions, it appears that about 25% or more of lung cancers among nonsmokers over the age of 60, and about 5% in smokers, may be attributable to exposure to radon daughters at home. It may be necessary to take remedial action to reduce this hazard in those dwellings with elevated levels of radon, and new construction should take account of this problem.

  20. Indoor radon and decay products: Concentrations, causes, and control strategies

    SciTech Connect

    Nero, A.V.; Gadgil, A.J.; Nazaroff, W.W.; Revzan, K.L.

    1990-11-01

    This report is another in the on going technical report series that addresses various aspects of the DOE Radon Research Program. It provides an overview of what is known about the behavior of radon and its decay products in the indoor environment and examines the manner in which several important classes of factors -- structural, geological, and meteorological -- affect indoor radon concentrations. Information on US indoor radon concentrations, currently available monitoring methods and novel radon control strategies are also explored. 238 refs., 22 figs., 9 tabs.

  1. New-construction techniques and HVAC (heating, venting and air conditioning) overpressurization for radon reduction in schools

    SciTech Connect

    Witter, K.A.; Craig, A.B.; Saum, D.

    1988-04-01

    Construction of a school in Fairfax County, Virginia, is being carefully monitored since elevated indoor radon levels have been identified in many existing houses near the site. Soil-gas radon concentrations measured prior to pouring of the slabs were also indicative of a potential radon problem should the soil gas enter the school; however, subslab radon measurements collected thus far are lower than anticipated. In addition, the school's heating, ventilating, and air-conditioning (HVAC) system has been designed to operate continously in overpressurization to help reduce pressure-driven entry of radon-containing soil gas into the building. Following completion, indoor radon levels in the school will be monitored to determine the effectiveness of these radon-resistant new-construction techniques and HVAC overpressurization in limiting radon entry into the school.

  2. Naturally Occurring Radon and 120(h) transfers

    EPA Pesticide Factsheets

    This page contains a discussion regarding how the presence of naturally occurring radon on closing military bases affects the United States' ability to transfer parcels under §120(h) (3) and §120(h) (4).

  3. From the similarities between neutrons and radon to advanced radon-detection and improved cold fusion neutron-measurements

    NASA Astrophysics Data System (ADS)

    Tommasino, L.; Espinosa, G.

    2014-07-01

    Neutrons and radon are both ubiquitous in the earth's crust. The neutrons of terrestrial origin are strongly related to radon since they originate mainly from the interactions between the alpha particles from the decays of radioactive-gas (namely Radon and Thoron) and the light nuclei. Since the early studies in the field of neutrons, the radon gas was used to produce neutrons by (α, n) reactions in beryllium. Another important similarity between radon and neutrons is that they can be detected only through the radiations produced respectively by decays or by nuclear reactions. These charged particles from the two distinct nuclear processes are often the same (namely alpha-particles). A typical neutron detector is based on a radiator facing a alpha-particle detector, such as in the case of a neutron film badge. Based on the similarity between neutrons and radon, a film badge for radon has been recently proposed. The radon film badge, in addition to be similar, may be even identical to the neutron film badge. For these reasons, neutron measurements can be easily affected by the presence of unpredictable large radon concentration. In several cold fusion experiments, the CR-39 plastic films (typically used in radon and neutron film-badges), have been the detectors of choice for measuring neutrons. In this paper, attempts will be made to prove that most of these neutron-measurements might have been affected by the presence of large radon concentrations.

  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. 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.

  6. Nde1-mediated inhibition of ciliogenesis affects cell cycle re-entry

    PubMed Central

    Kim, Sehyun; Zaghloul, Norann A.; Bubenshchikova, Ekaterina; Oh, Edwin C.; Rankin, Susannah; Katsanis, Nicholas; Obara, Tomoko; Tsiokas, Leonidas

    2011-01-01

    The primary cilium is an antenna-like organelle that is dynamically regulated during the cell cycle. Ciliogenesis is initiated as cells enter quiescence, while cilium resorption precedes mitosis. The mechanisms coordinating ciliogenesis with the cell cycle are unknown. Here we identify the centrosomal protein, Nde1, as a negative regulator of ciliary length. Nde1 is expressed at high levels in mitosis, low levels in quiescence and localizes at the mother centriole, which nucleates the primary cilium. Cells depleted of Nde1 show longer cilia and a delay in cell cycle re-entry that correlates with ciliary length. Knockdown of Nde1 in zebrafish embryos results in increased ciliary length, suppression of cell division, reduction of the number of cells forming the Kupffer’s vesicle, and left-right patterning defects. These data suggest that Nde1 is an integral component of a network coordinating ciliary length with cell cycle progression and have implications in the transition from quiescence to a proliferative state. PMID:21394081

  7. Modeled atmospheric radon concentrations from uranium mines

    SciTech Connect

    Droppo, J.G.

    1985-04-01

    Uranium mining and milling operations result in the release of radon from numerous sources of various types and strengths. The US Environmental Protection Agency (EPA) under the Clean Air Act, is assessing the health impact of air emissions of radon from underground uranium mines. In this case, the radon emissions may impact workers and residents in the mine vicinity. To aid in this assessment, the EPA needs to know how mine releases can affect the radon concentrations at populated locations. To obtain this type of information, Pacific Northwest Laboratory used the radon emissions, release characteristics and local meterological conditions for a number of mines to model incremental radon concentrations. Long-term, average, incremental radon concentrations were computed based on the best available information on release rates, plume rise parameters, number and locations of vents, and local dispersion climatology. Calculations are made for a model mine, individual mines, and multiple mines. Our approach was to start with a general case and then consider specific cases for comparison. A model underground uranium mine was used to provide definition of the order of magnitude of typical impacts. Then computations were made for specific mines using the best mine-specific information available for each mine. These case study results are expressed as predicted incremental radon concentration contours plotted on maps with local population data from a previous study. Finally, the effect of possible overlap of radon releases from nearby mines was studied by calculating cumulative radon concentrations for multiple mines in a region with many mines. The dispersion model, modeling assumptions, data sources, computational procedures, and results are documented in this report. 7 refs., 27 figs., 18 tabs.

  8. Radon: A health problem

    SciTech Connect

    Pucci, J.; Gaston, S.

    1990-01-01

    Nurses can and should function as effective teachers about the potential hazards to health of radon contamination in the home as well as become activists in the development of health care policy on radon.

  9. Radon and climatic multiparameter analysis: A one-year study on radon dynamics in a house

    SciTech Connect

    Genrich, V.

    1995-12-31

    Radon-reduction in private and public buildings is a current issue. Research has opened our eyes for the enormous fluctuations of the indoor radon level over longer observation periods. For generalizing the behavior radon in a building, care must be taken that the observation period is long enough, to mediate the pronounced climatic changes in the course of a year. The author has started a one-year observations, precisely logging up the radon level in a single family home. Six portable multiparameter-monitors, each equipped with a 0.6 liter PIC-detector (PIC = pulse ionization chamber), have been installed at different locations within the building and outdoors (incl. two soil-gas probes). Besides the radon concentration, in the same instruments the following parameters are logged cotinuously: relative humidity, differential pressure between basement and sub-slab area, soil impendance (indication water saturation) and wind speed on the roof. In the basement, the radon concentration varies between 61 Bq/m{sup 3} and 5408 Bq/m{sup 3} (mean: 1092 Bq/m{sup 3}.) By analyzing these records, the time sequence of the radon concentration can be characterized as a {open_quotes}mixture{close_quotes} of (periodic) circadian variations overlayed with (aperiodic) seasonal fluctuations. In this building, it turns out, that the pressure difference across the base plate is an important factor for radon entry as well as ventilation rate. It can be shown, that the pressure is closely related to the indoor-outdoor temperature difference. This relation was found to be non-linear. Other factors are attributed to the activities of the inhabitants. The paper points out correlations between radon and different climatic parameters mainly by using scatterplots and classical regression methods.

  10. Peripheral tissue homing receptors enable T cell entry into lymph nodes and affect the anatomical distribution of memory cells

    PubMed Central

    Brinkman, C. Colin; Rouhani, Sherin J.; Srinivasan, Nithya; Engelhard, Victor H.

    2013-01-01

    Peripheral tissue homing receptors enable T cells to access inflamed non-lymphoid tissues. Here we show that two such molecules, E-selectin ligand and α4β1 integrin, enable activated and memory T cells to enter lymph nodes as well. This affects the quantitative and qualitative distribution of these cells among regional lymph node beds. CD8 memory T cells in lymph nodes that express these molecules were mostly CD62Llo, and would normally be classified as effector memory cells. However, similar to central memory cells, they expanded upon antigen re-encounter. This led to differences in the magnitude of the recall response that depended on the route of immunization. These novel cells share properties of both central and effector memory cells, and reside in lymph nodes based on previously undescribed mechanisms of entry. PMID:23926324

  11. BmNHR96 participate BV entry of BmN-SWU1 cells via affecting the cellular cholesterol level.

    PubMed

    Dong, Xiao-Long; Liu, Tai-Hang; Wang, Wei; Pan, Cai-Xia; Du, Guo-Yu; Wu, Yun-Fei; Pan, Min-Hui; Lu, Cheng

    2017-01-22

    B.mori nucleopolyhedrovirus (BmNPV), which produces BV and ODV two virion phenotypes in its life cycle, caused the amount of economic loss in sericulture. But the mechanism of its infection was still unclear. In this study we characterized B.mori nuclear hormone receptor 96 (BmNHR96) as a NHR96 family member, which was localized in the nucleus. We also found BmNHR96 over-expression could enhance the entry of BV as well as cellular cholesterol level. Furthermore, we validated that BmNHR96 increased membrane fusion mediated by GP64, which could probably promote BV-infection. In summary, our study suggested that BmNHR96 plays an important role in BV infection and this function probably actualized by affecting cellular cholesterol level, and our results provided insights to the mechanisms of BV-infection of B.mori.

  12. 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%.

  13. Measurement and apportionment of radon source terms for modeling indoor environments

    SciTech Connect

    Harley, N.H.

    1992-01-01

    This research has two main goals; (1) to quantify mechanisms for radon entry into homes of different types and to determine the fraction of indoor radon attributable to each source and (2) to model and calculate the dose (and therefore alpha particle fluence) to cells in the human and animal tracheobronchial tree that is pertinent to induction of bronchogenic carcinoma from inhaled radon daughters. The dosimetry has been extended to include organs other than the lung.

  14. 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.

  15. Evaluation of building design, construction, and performance for the control of radon in florida houses. Evaluation of radon resistant construction techniques in eight new houses. Final report, January 1993-April 1994

    SciTech Connect

    Hintenlang, D.E.; Shanker, A.; Najafi, F.T.; Roessler, E.C.

    1995-07-01

    The report gives results of a study of eight houses throughout their construction in North Central Florida. Each house was built in compliance with the proposed radon resistant construction standard being developed by the Florida Department of Community Affairs. Each house was monitored for at least 6 days after construction, operating in three different heating, ventilation, and air-conditioning (HVAC) system configurations. Continuous measurements of indoor radon concentrations, house ventilation rates, across-slab differential pressures, and interzone differential pressures provided time-resolved radon entry rates and a performance index for passive radon barriers. Radon entry rates were found to be relatively constant throughout the measurement periods and for the different house operating conditions, implying that the passive radon barrier eliminates most convective entry.

  16. Radon reduction and radon-resistant construction demonstrations in New York. Volume 1. Technical report. Final report, March 1987-February 1991

    SciTech Connect

    Nitschke, I.; Clarkin, M.; Clark, W.; Hough, R.E.

    1993-03-01

    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 foundation penetrations in the basement effectively reduced the radon concentration, although not below 4 pCi/L, and that sealing aids the effectiveness of an active depressurization system. Active depressurization systems were usually successful in achieving 4 pCi/L. The footing drain, sub-slab, and basement walls were all successfully depressurized using a standard technique after grab samples or radon 'sniffing' techniques were used to identify the radon entry sources. Basement pressurization also effectively reduced the radon level below the EPA guideline at one site. Water aeration systems effectively mitigated radon from residential water supplies, although the system tested was large and noisy. Activated charcoal filters adsorbed the radon in water, but eventually became an unacceptable source of gamma radiation. The inspection of houses where radon mitigation systems were installed in 1984 revealed that new systems and techniques, such as in-line centrifugal fans, were generally superior to the earlier methods using axial computer-type fans.

  17. MEASUREMENT AND REPORTING OF RADON EXPOSURES.

    PubMed

    2012-12-01

    measured radon activity concentrations exhibit significant spatial variations (i.e., local and areal), and temporal variations (i.e., diurnal, seasonal, and annual). Consequently,estimates of the average annual radon activity concentrations are typically used for radon surveys and are compared with reference levels for radiation protection purposes. Other factors that may affect the interpretation of radon measurement results and the related dose estimates include thoron (220Rn) interference on radon detection systems, variations of aerosol parameters, equilibrium factor, duration of exposure (i.e., occupancy times in a building or location) and breathing rates. Often encountered problems are the uncertainties in extrapolating short-term measurements carried out at different locations within a building, or at different times during a year or in different years to statistically reasonable average values.Finally, the third objective of this report is to provide recommendations on optimal measurement strategies,measurement techniques, recording and reporting of measurements for different measurement objectives,such as individual exposure, average population exposure in a region or country, epidemiological studies or compliance with reference levels in radiation protection.

  18. The radon indicator

    NASA Astrophysics Data System (ADS)

    Samuelsson, L.

    2005-11-01

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

  19. Geologic controls on radon

    SciTech Connect

    Gates, A.E.; Gundersen, L.C.S.

    1992-01-01

    This text provides a review of recent research on geological controls of [sup 222]Rn concentrations in soil gas in relation to the problem of high indoor radon concentrations in houses. The importance of the subject matter is highlighted in the preface by the observation that the US Environmental Protection Agency (EPA) estimates that 15,000 to 25,000 deaths result from radon-induced lung cancer each year in the United States. The text contains 8 Chapters: (1) Geology of radon in the United States; (2) Sensitivity of soil radon to geology and the distribution of radon and uranium in the Hylas Zone Area, Virginia; (3) Geologic and environmental implications of high soil-gas radon concentrations in The Great Valley, Jefferson and Berkeley Counties, West Virginia; (4) Soil radon distribution in glaciated areas: an example from the New Jersey Highlands; (5) Radon in the coastal plain of Texas, Alabama, and New Jersey; (6) Effects of weather and soil characteristics on temporal variations in soil-gas radon concentrations; (7) A theoretical model for the flux of radon from rock to ground water; (8) The influence of season, bedrock, overburden, and house construction on airborne levels of radon in Maine homes. The individual chapters are written by different authors in the form of self-contained research papers, each of which is followed by a comprehensive list of references.

  20. Indoor radon: deadliest pollutant

    SciTech Connect

    Pool, R.

    1988-04-29

    Radon in individual homes may be the greatest source of radiation that people are exposed to during a lifetime. In areas where radon concentrations in homes are high, people may be exposed to more radiation than were the Russian people living in the vicinity of Chernobyl Nuclear Power Plant. Studies indicate that the radon exposure contributes to 5000 to 20,000 deaths per year from lung cancer and that smoking may have a lethal interaction with the radon exposure. One study found an average annual concentration of radon in living spaces of 1.5 picocuries per liter. 7% of U.S. homes were found to have a radon concentration above the 4 picocuries per liter level set by the Environmental Protection Agency, and 1 - 3% of the homes have levels above 8 picocuries. Some ways are described for changing the air pressure in a house so that air is not constantly drawn from the permeable soil where the radon originates.

  1. Radon is out

    SciTech Connect

    Harley, J.H.

    1992-12-31

    This paper discusses some facets of outdoor radon. There is only one source of radon - the decay of radium. Radium is everywhere but the bulk is in soil, rock, and ocean sediments. Soil porosity is a prime factor in radon movement. Exhalation from soil is fed by the high concentrations of radon in soil gas. Because the surface soil is losing radon to the atmosphere, soil gas concentration would be expected to increase with depth. There is a wide range of air radon concentrations, with marked seasonal and diurnal variations. Atmospheric stability is certainly a major factor - radon increases during inversions and decreases when the inversion breaks up. In addition, temperature, soil moisture, snow cover, and wind direction all play a part. Different investigators sometimes come to contrary conclusions on the effects of these factors. They are probably all correct - for the conditions in effect at the time - since no simple generalities exist for most factors.

  2. RADON DIAGNOSTIC MEASUREMENT GUIDANCE FOR LARGE BUILDINGS - VOLUME 1. TECHNICAL REPORT

    EPA Science Inventory

    The report discusses the development of radon diagnostic procedures and mitigation strategies applicable to a variety of large non-residential buildings commonly found in Florida. The investigations document and evaluate the nature of radon occurrence and entry mechanisms for rad...

  3. LARGE BUILDINGS CHARACTERISTICS AS RELATED TO RADON RESISTANCE: A LITERATURE REVIEW

    EPA Science Inventory

    The report gives results of a literature review to determine to what useful extent buildings have been characterized and a data base developed in relation to radon entry and mitigation. Prior to 1993, most radon research in large buildings was focused on developing diagnostic and...

  4. 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

  5. Partitioning of 222Rn entry into a structure surrounded by soil.

    PubMed

    Gadd, M S; Borak, T B

    1994-07-01

    This paper describes the entry rate of 222Rn into a basement structure surrounded by a sandy clay loam soil. The highest indoor radon concentrations occurred when the rate of entry was lowest. Data from in-situ measurements were used to identify the entry pathways and also the origins of the radon during periods when the entry rate was low. Results indicated that 25% of the radon entered through the floor-wall joint and 75% through the floor and walls. About 30% of the radon originated in the concrete. Diffusion was the primary transport mechanism. However, radon entry through the floor-wall joint was a combination of diffusion and a convective flow between the subslab region and the interior of the structure.

  6. Overview of current radon and radon daughter research at LBL

    SciTech Connect

    Not Available

    1983-01-01

    This report provides a brief summary of radon and radon daughter research at Lawrence Berkeley Laboratory. The radon and radon daughter research program has two broad goals: (1) the study of sources of radon and its subsequent transport into houses, and (2) research on the behavior of radon daughters in indoor environments. Additional research effort is directed to several auxiliary areas, including development of instrumentation and monitoring techniques, studies of indoor air movement, and measurement and control of indoor particulate concentrations.

  7. 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)

  8. Design of new schools and other large buildings which are radon resistant and easy to mitigate. Report for September 1990-August 1991

    SciTech Connect

    Craig, A.B.; Leovic, K.W.; Harris, D.B.

    1992-01-01

    The paper discusses the recent incorporation of radon mitigation design recommendations in the construction of a hospital in Johnson City, TN. The recommendations resulted in the mitigation of a 5,500 square meter building with only one suction point at an incremental cost of $1.03 per square meter. Extrapolation of the pressure field extension (PFE) measurements indicates that a much larger building could have been mitigated with the system used. A search is underway for larger buildings to be built in radon prone areas of the U.S. in order to determine the effectiveness of the mitigation system in reducing radon in even larger buildings. As a prelude to the preparation of a new construction technical guidance document for schools, architectural drawings of all schools research by EPA, to date, were carefully studied to determine which building characteristics affect radon entry and ease of mitigation. Results of the study were presented at an international symposium on radon in Philadelphia, PA, in April 1991.

  9. ANALYSIS OF RADON MITIGATION TECHNIQUES USED IN EXISTING U.S. HOUSES

    EPA Science Inventory

    This paper reviews the full range of techniques that have been installed in existing US houses for the purpose of reducing indoor radon concentrations resulting from soil gas entry. The review addresses the performance, installation and operating costs, applicability, mechanisms,...

  10. [Radon and domestic exposure].

    PubMed

    Melloni, B; Vergnenègre, A; Lagrange, P; Bonnaud, F

    2000-12-01

    Radon is a noble gas derived from the decay of radium, which itself is a decay product of uranium. The decay products of radon can collect electrostatically on dust particles in the air and, if these particles are inhaled and attach to bronchial epithelium, produce a high local radiation dose. Alpha particles can induce DNA double-strand breaks and the development of cancer. A causal relation between lung cancer and radon exposure and its progeny has been demonstrated in epidemiological studies of miners. Radon exposure became a public health issue almost 15 years ago. Most radon exposure occurs indoors, predominantly in the home. There is however, a wide range of radon concentration values in different countries. The highest level occurs in areas with granite and permeable soils. The risk for smoking, the leading cause of lung cancer, is far greater than for radon, the second leading cause. The estimates obtained from case-control studies of indoor radon are very contradictory. Scientific knowledge of effects of low levels of exposure to radon and the role of cigarette smoking, as a combined factor, must be studied. Smoking and radon probably interact in a multiplicative fashion.

  11. 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)

  12. Normal seasonal variations for atmospheric radon concentration: a sinusoidal model.

    PubMed

    Hayashi, Koseki; Yasuoka, Yumi; Nagahama, Hiroyuki; Muto, Jun; Ishikawa, Tetsuo; Omori, Yasutaka; Suzuki, Toshiyuki; Homma, Yoshimi; Mukai, Takahiro

    2015-01-01

    Anomalous radon readings in air have been reported before an earthquake activity. However, careful measurements of atmospheric radon concentrations during a normal period are required to identify anomalous variations in a precursor period. In this study, we obtained radon concentration data for 5 years (2003-2007) that can be considered a normal period and compared it with data from the precursory period of 2008 until March 2011, when the 2011 Tohoku-Oki Earthquake occurred. Then, we established a model for seasonal variation by fitting a sinusoidal model to the radon concentration data during the normal period, considering that the seasonal variation was affected by atmospheric turbulence. By determining the amplitude in the sinusoidal model, the normal variation of the radon concentration can be estimated. Thus, the results of this method can be applied to identify anomalous radon variations before an earthquake.

  13. 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.

  14. State Policies Affecting the "Adult Re-Entry Pipeline" in Postsecondary Education: Results of a Fifty-State Inventory

    ERIC Educational Resources Information Center

    Boeke, Marianne; Zis, Stacey; Ewell, Peter

    2011-01-01

    With support from the Bill and Melinda Gates Foundation, the National Center for Higher Education Management Systems (NCHEMS) is engaged in a two year project centered on state policies that foster student progression and success in the "adult re-entry pipeline." The adult re-entry pipeline consists of the many alternative pathways to…

  15. Testing, time limits, and English learners: does age of school entry affect how quickly students can learn English?

    PubMed

    Conger, Dylan

    2009-06-01

    Using data on young English learners (EL) who enroll in the New York City public school system, I examine how long it takes students to become minimally proficient in English and how the time to proficiency differs for students by their age of school entry. Specifically, I follow four recent entry cohorts of ELs ages 5-10 and use discrete-time survival analysis to model the rate at which different age groups acquire proficiency. I find that approximately half of the students become proficient within three years after school entry and that younger students learn more quickly than older students. Age of entry differences are robust to controls for observed differences between age of entry groups in their economic and demographic characteristics, their disabilities, and the schools they attend. The results lend support to the theory that older students face developmental barriers to learning new languages quickly.

  16. Consumer's Guide to Radon Reduction

    MedlinePlus

    ... EPA United States Environmental Protection Agency Search Search Radon Share Facebook Twitter Google+ Pinterest Contact Us Consumer's Guide to Radon Reduction: How to Fix Your Home Contains information ...

  17. MEASUREMENT OF RADON, THORON AND THEIR PROGENY CONCENTRATIONS IN THE DWELLINGS OF PAURI GARHWAL, UTTARAKHAND, INDIA.

    PubMed

    Joshi, Veena; Dutt, Sanjay; Yadav, Manjulata; Mishra, Rosaline; Ramola, R C

    2016-10-01

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

  18. Ethanolic Extract of Melia Fructus Has Anti-influenza A Virus Activity by Affecting Viral Entry and Viral RNA Polymerase

    PubMed Central

    Jin, Young-Hee; Choi, Jang-Gi; Cho, Won-Kyung; Ma, Jin Yeul

    2017-01-01

    Meliae Fructus (MF) is the dried ripe fruit of Melia toosendan Siebold et Zuccarini, Meliaceae family. MF is widely used in traditional medicine to treat inflammation and helminthic infection and has anti-bacterial, anti-oxidant, anti-cancer, anti-inflammatory, and analgesic activities. However, potential anti-influenza properties of MF have yet to be investigated. We determined whether an ethanolic extract of MF (EMF) has anti-viral activity via an EMF pre-, co-, and post-treatment assay, using the Influenza A/PR/8/34 and H3N2 virus on Madin-Darby canine kidney (MDCK) cells. The EMF had anti-influenza virus activity in pre- and co-treated cells in a dose-dependent manner, but not in post-treated cell. EMF inhibited the activity of hemagglutinin (HA) and neuraminidase (NA) of influenza virus. EMF inhibited viral HA, nucleoprotein (NP), matrix protein 2 (M2), non-structural protein 1 (NS1), polymerase acidic protein (PA), polymerase basic protein 1 (PB1), and polymerase basic protein 2 (PB2) mRNA synthesis at 5 h post infection (hpi), however, the levels of PA, PB1, and PB2 mRNA were increased in pre- and co-EMF treated cells compared with control virus-infected and EMF post-treated cells at 18 hpi. The level of M2 protein expression was also decreased upon pre- and co-treatment with EMF. The PA protein was accumulated and localized in not only the nucleus but also the cytoplasm of virus-infected MDCK cells at 18 hpi. Pre-EMF treatment inhibited the expression of pAKT, which is induced by influenza virus infection, at the stage of virus entry. We also found that treatment of EMF up-regulated the antiviral protein Mx1, which may play a partial role in inhibiting influenza virus infection in pre- and co-EMF treated MDCK cells. In summary, these results strongly suggested that an ethanolic extract of Meliae Fructus inhibited influenza A virus infection by affecting viral entry, PA proteins of the RNA polymerase complex, and Mx1 induction and may be a potential and

  19. Generation and mobility of radon in soil

    SciTech Connect

    Rose, A.W.

    1990-01-01

    This research generation and mobility of radon in soil evaluates the extent and nature of uranium and radium depletion and/or enrichment in soil horizons as a function of climate and other factors affecting soil character; evaluates the relation of radon emanation coefficient to soil type, soil properties, soil-forming factors, and radon levels in soil gas; and evaluate the relations of fragipans, soil moisture and soil permeability to radon concentration and radon flux in soil profiles. The approach has been to investigate in detail 13 soil profiles selected to represent distinct differences in parent material (limestone, sandstone, shale, granite), major soil groups (Alfisols, Ultisol, Inceptisol, Mollisol, Spodosol), and moisture regimes (well-drained to somewhat poorly drained with fragipan). The nine profiles investigated in the first 2 years are in Pennsylvania and North Carolina. Four profiles currently being sampled are in New York, Tennessee, Illinois and Pennsylvania. Samples from five profiles in Georgia have also been analyzed in less detail. A combination of pedologic, geochemical and radiometric methods have been applied to understanding radon at these sites (Table 2). An important feature of the project has been the collaboration of a geochemist, a soil scientist and a nuclear engineer as Co-PI's. 4 refs., 12 figs., 4 tabs.

  20. Preliminary assessment of radon potential of the Pacific coast states

    SciTech Connect

    Otton, J.K. )

    1993-04-01

    The US Geological Survey has recently released preliminary assessments of the radon potential in Washington, Oregon, and California. These assessments, funded by the Environmental Protection Agency, are based on geology, soils, aeroradiometric data, indoor radon data, and housing characteristics. Coastal mountain areas with low-uranium basaltic rocks and high soil moisture, and drier inland areas of low-uranium basaltic rocks in the northern part of the three-stage area have low round potential (<10 percent of homes with >4 pCi/L). Areas with highly permeable, uraniferous glacial outwash deposits in central and northeastern Washington; local areas with uraniferous marine shales in southern and south-central California; areas of granites, acidic volcanic rocks and alluvium derived from then in southeastern Oregon and central California; and steep soils developed on volcanic rocks in the Columbia River Gorge all have moderate (10-25 percent of homes with >4 pCi/L) radon potential. Extreme levels of indoor radon are possible in the northern Spokane, Wash. suburbs where homes may be sited on uranium occurrences. the radon potential of Mojave-Desert areas with high-uranium soils and rocks seems to be lowered by low radon entry rates, probably caused by slab-on-grade construction, use of evaporative coolers, and lifestyle factors. With the uranium-rich soils and rocks present, however, high indoor radon levels are possible where unusual housing conditions are present.

  1. 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)

  2. 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 ...

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

    MedlinePlus

    ... Radon: The Guide to Protecting Yourself and Your Family from Radon Contains basic information about Radon in ... Radon Zones and State Contact Information Individuals and Families Radon Publications Home Buyers and Sellers Builders and ...

  4. 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)

  5. Statistical uncertainty analysis of radon transport in nonisothermal, unsaturated soils

    SciTech Connect

    Holford, D.J.; Owczarski, P.C.; Gee, G.W.; Freeman, H.D.

    1990-10-01

    To accurately predict radon fluxes soils to the atmosphere, we must know more than the radium content of the soil. Radon flux from soil is affected not only by soil properties, but also by meteorological factors such as air pressure and temperature changes at the soil surface, as well as the infiltration of rainwater. Natural variations in meteorological factors and soil properties contribute to uncertainty in subsurface model predictions of radon flux, which, when coupled with a building transport model, will also add uncertainty to predictions of radon concentrations in homes. A statistical uncertainty analysis using our Rn3D finite-element numerical model was conducted to assess the relative importance of these meteorological factors and the soil properties affecting radon transport. 10 refs., 10 figs., 3 tabs.

  6. Measurement and apportionment of radon source terms for modeling indoor environments. Annual progress report, March 1991--February 1992

    SciTech Connect

    Harley, N.H.

    1992-02-01

    This research has two main goals; (1) to quantify mechanisms for radon entry into homes of different types and to determine the fraction of indoor radon attributable to each source and (2) to model and calculate the dose (and therefore alpha particle fluence) to cells in the human and animal tracheobronchial tree that is pertinent to induction of bronchogenic carcinoma from inhaled radon daughters. The dosimetry has been extended to include organs other than the lung.

  7. Mutagenicity of radon and radon daughters

    NASA Astrophysics Data System (ADS)

    Evans, H. H.

    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(-) mutants. Eleven radon-induced HPRT(-) mutants have been isolated, and will be analyzed in a similar fashion.

  8. High radon areas in the Walloon region of Belgium.

    PubMed

    Tondeur, F; Cinelli, G; Dehandschutter, B

    2015-06-01

    Indoor radon data from Southern Belgium are organised in 35 geological units (GUs), most of which are homogeneous with respect to the radon risk. The percentage of cases above the reference level (400 Bq m(-3); 300 Bq m(-3) in the future) is calculated for these GUs from the observations and from the log-normal distribution fitted to the data. Affected areas are defined as areas with more than 1 % of houses above the reference level. In the north of the region, the old Palaeozoic basement is generally covered by Silesian, Cretaceous and Tertiary rocks, which are unaffected. The affected areas here are hot spots associated with specific Palaeozoic outcrops. In the south, there is generally no cover above Palaeozoic formations, which are often radon affected. The affected areas of Ardenne and Condroz dominate this part, but unaffected areas occur like Famenne and Gaume. About 48 % of the Walloon region is expected to be radon affected.

  9. Factors affecting curriculum content and the integration of evidence-based practice in entry-level physiotherapy programs.

    PubMed

    Chipchase, Lucy S; Williams, Marie T; Robertson, Val J

    2007-01-01

    Decisions about curricular content in entry-level health professional programs are influenced by a variety of external and internal factors. However, little is known about how lecturers make decisions about the curricular content to be included or excluded from entry-level programs. This study aimed to explore the factors influencing such decision making regarding curricular content in entry-level Australian and New Zealand programs for physiotherapy, as well as how evidence-based practice (EBP) is integrated into the teaching and learning framework. Thirteen lecturers from 13 institutions (100% response rate) responsible for teaching a core part of physiotherapy practice, electrophysical agents, participated in a semistructured telephone interview. Decision making for curricular content involved an overall democratic process with the program team, but the day-to-day content was determined by the lecturer. Factors that lecturers reported as impacting on the choice of curriculum were current clinical practice, evidence, and accreditation or registration requirements. Thematic analysis of open-ended questions identified four main themes relating to the integration of the EBP paradigm within teaching: resource materials, use of broad definitions of evidence, inclusion of specific instructional strategies, and context of curriculum. Lecturers used a variety of research methodologies as a backdrop for the presentation of techniques and interventions that are used commonly in clinical practice despite limitations in the evidence base. The results highlighted tensions that exist when designing entry-level curricula with the need to prepare competent and safe practitioners while working within an EBP paradigm.

  10. 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.

  11. Radon Optical Processing in Radon Space.

    DTIC Science & Technology

    1986-06-15

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

  12. Annual variation in the atmospheric radon concentration in Japan.

    PubMed

    Kobayashi, Yuka; Yasuoka, Yumi; Omori, Yasutaka; Nagahama, Hiroyuki; Sanada, Tetsuya; Muto, Jun; Suzuki, Toshiyuki; Homma, Yoshimi; Ihara, Hayato; Kubota, Kazuhito; Mukai, Takahiro

    2015-08-01

    Anomalous atmospheric variations in radon related to earthquakes have been observed in hourly exhaust-monitoring data from radioisotope institutes in Japan. The extraction of seismic anomalous radon variations would be greatly aided by understanding the normal pattern of variation in radon concentrations. Using atmospheric daily minimum radon concentration data from five sampling sites, we show that a sinusoidal regression curve can be fitted to the data. In addition, we identify areas where the atmospheric radon variation is significantly affected by the variation in atmospheric turbulence and the onshore-offshore pattern of Asian monsoons. Furthermore, by comparing the sinusoidal regression curve for the normal annual (seasonal) variations at the five sites to the sinusoidal regression curve for a previously published dataset of radon values at the five Japanese prefectures, we can estimate the normal annual variation pattern. By fitting sinusoidal regression curves to the previously published dataset containing sites in all Japanese prefectures, we find that 72% of the Japanese prefectures satisfy the requirements of the sinusoidal regression curve pattern. Using the normal annual variation pattern of atmospheric daily minimum radon concentration data, these prefectures are suitable areas for obtaining anomalous radon variations related to earthquakes.

  13. Study of indoor radon distribution using measurements and CFD modeling.

    PubMed

    Chauhan, Neetika; Chauhan, R P; Joshi, M; Agarwal, T K; Aggarwal, Praveen; Sahoo, B K

    2014-10-01

    Measurement and/or prediction of indoor radon ((222)Rn) concentration are important due to the impact of radon on indoor air quality and consequent inhalation hazard. In recent times, computational fluid dynamics (CFD) based modeling has become the cost effective replacement of experimental methods for the prediction and visualization of indoor pollutant distribution. The aim of this study is to implement CFD based modeling for studying indoor radon gas distribution. This study focuses on comparison of experimentally measured and CFD modeling predicted spatial distribution of radon concentration for a model test room. The key inputs for simulation viz. radon exhalation rate and ventilation rate were measured as a part of this study. Validation experiments were performed by measuring radon concentration at different locations of test room using active (continuous radon monitor) and passive (pin-hole dosimeters) techniques. Modeling predictions have been found to be reasonably matching with the measurement results. The validated model can be used to understand and study factors affecting indoor radon distribution for more realistic indoor environment.

  14. Generation and mobility of radon in soil

    SciTech Connect

    Rose, A.W.

    1990-04-25

    This report discusses progress from March 1987--June 1990. Objectives of this project are to: evaluate the extent and nature of uranium and radium depletion and/or enrichment in soil horizons as a function of climate and other factors affecting soil character; evaluate the relation of radon emanation coefficient to soil type, soil properties, soil-forming factors, and radon levels in soil gas; and evaluate the relations of fragipans, soil moisture and soil permeability to radon concentration and radon flux in soil profiles. The approach has been to investigate in detail 13 soil profiles selected to represent distinct differences in parent material (limestone, sandstone, shale, granite), major soil groups (Alfisols, Ultisol, Inceptisol, Mollisol, Spodosol), and moisture regimes (well-drained to somewhat poorly drained with fragipan). The 13 profiles investigated in the past 3 years are in Pennsylvania, North Carolina, New York, Tennessee, Illinois, and represent highly varied soil types. Samples from five profiles in Georgia have also been analyzed in less detail. A combination of pedologic, geochemical and radiometric methods have been applied to understanding radon at these sites. 12 refs., 14 figs., 5 tabs.

  15. Protect Your Family from Lung Cancer Caused by Radon

    EPA Pesticide Factsheets

    DALLAS - (Jan. 15, 2014) One in 15 homes is affected by elevated radon levels, so this month the U.S. Environmental Protection Agency is encouraging Americans around the country to test their homes for this naturally occurring radioactive gas.

  16. Generation and mobility of radon in soil

    SciTech Connect

    Not Available

    1992-01-01

    Objectives of this research include: (1) To determine the processes that cause large seasonal and short-term changes in the radon (Rn) content of soil gases, and to develop methods of predicting and modeling these variations; (2) to evaluate the relation of Rn emanation coefficients to form of radium (Ra) and other U-series decay products, particularly the role of Ra in organic matter and Fe-oxides; (3) to evaluate the conditions in which convection of gas in soil and bedrock may affect soil gas radon availability in houses; and, (4) to collaborate with other DOE researchers on evaluation of Rn flux into houses, using our well characterized soil sites.

  17. Health Risk of Radon

    MedlinePlus

    ... and Control Reports. Top of Page Studies Find Direct Evidence Linking Radon in Homes to Lung Cancer ( ... VI)". This report by the National Academy of Sciences (NAS) is the most definitive accumulation of scientific ...

  18. 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.

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

    PubMed

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

    2015-11-01

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

  20. 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).

  1. 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

  2. Radon: Is it a problem

    SciTech Connect

    Hart, B.L.; Mettler, F.A.; Harley, N.H. )

    1989-09-01

    Radon gas is a major source of radiation exposure to the general public. Radon-222 is a product of uranium-238, present in varying concentrations in all soils. Radon enters buildings from soil, water, natural gas, and building materials. Its short-lived breakdown products, termed radon daughters, include alpha-emitting solids that can deposit in the lungs. Firm evidence links lung cancer risk in miners with high exposure to radon daughters. The amount of risk associated with the much lower but chronic doses received in buildings is difficult to establish. By some extrapolations, radon daughters may be responsible for a significant number of lung cancer deaths. The existence or extent of synergism with smoking is unresolved. Local conditions can cause high levels of radon in some buildings, and measures that reduce indoor radon are of potential value. 39 references.

  3. Factors affecting the entry of for-profit providers into a price regulated market for formal long-term care services: a case study from Japan.

    PubMed

    Tokunaga, Mutsumi; Hashimoto, Hideki

    2013-01-01

    While the distinct behaviors of for-profit and non-profit providers in the healthcare market have been compared in the economic literature, their choices regarding market entry and exit have only recently been debated. Since 2000, when public Long-Term Care Insurance was introduced in Japan, for-profit providers have been able to provide formal long-term homecare services. The aim of this study is to determine which factors have affected market entry of for-profit providers under price regulation and in competition with existing non-profit providers. We used nation-wide panel data from 2002 to 2010, aggregated at the level of local public insurers (n = 1557), a basic area unit of service provision. The number of for-profit providers per elderly population in the area unit was regressed against factors related to local demand and service costs using first-difference linear regression, a fixed effects model, and Tobit regression for robustness checking. Results showed that demand (the number of eligible care recipients) and cost factors (population density and minimum wage) significantly influenced for-profit providers' choice of market entry. These findings indicate that for-profit providers will strategically choose a local market for maximizing profit. We believe that price regulation should be redesigned to incorporate quality of care and market conditions, regardless of the profit status of the providers, to ensure equal access to efficient delivery of long-term care across all regions.

  4. 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.

  5. Understanding the origin of radon indoors: Building a predictive capability

    SciTech Connect

    Sextro, R.G.

    1985-12-01

    Indoor radon concentrations one to two orders of magnitude higher than the US average of approx.60 Bq m/sup -3/ (approx.1.5 pCi L/sup -1/) are not uncommon, and concentrations greater than 4000 Bq m/sup -3/ have been observed in houses in areas with no known artificially-enhanced radon sources. In general, source categories for indoor radon are well known: soil, domestic water, building materials, outdoor air, and natural gas. Soil is thought to be a major source of indoor radon, either through molecular diffusion (usually a minor component) or convective flow of soil gas. While soil gas flow into residences has been demonstrated, no detailed understanding of the important factors affecting the source strength of radon from soil has yet emerged. Preliminary work in this area has identified a number of likely issues, including the concentration of radium in the soil, the emanating fraction, soil type, soil moisture content, and other factors that would influence soil permeability and soil gas transport. Because a significant number of dwellings are expected to have indoor radon concentrations above guideline levels, a predictive capability is needed that would help identify geographical areas having the potential for high indoor concentrations. This paper reviews the preliminary work that has been done to identify important soil and building characteristics that influence the migration of radon and outlines the areas of further research necessary for development of a predictive method. 32 refs., 4 figs.

  6. Alirocumab, a Therapeutic Human Antibody to PCSK9, Does Not Affect CD81 Levels or Hepatitis C Virus Entry and Replication into Hepatocytes

    PubMed Central

    Ramanathan, Aarti; Gusarova, Viktoria; Stahl, Neil; Gurnett-Bander, Anne; Kyratsous, Christos A.

    2016-01-01

    Background Proprotein convertase subtilisin/kexin type 9 (PSCK9) is secreted mainly from the liver and binds to the low-density lipoprotein receptor (LDLR), reducing LDLR availability and thus resulting in an increase in LDL-cholesterol. While the LDLR has been implicated in the cell entry process of the hepatitis C virus (HCV), overexpression of an artificial non-secreted, cell membrane-bound form of PCSK9 has also been shown to reduce surface expression of CD81, a major component of the HCV entry complex, leading to concerns that pharmacological inhibition of PCSK9 may increase susceptibility to HCV infection by increasing either CD81 or LDLR availability. Here, we evaluated effects of PCSK9 and PCSK9 blockade on CD81 levels and HCV entry with a physiologically relevant model using native secreted PCSK9 and a monoclonal antibody to PCSK9, alirocumab. Methods and Results Flow cytometry and Western blotting of human hepatocyte Huh-7 cells showed that, although LDLR levels were reduced when cells were exposed to increasing PCSK9 concentrations, there was no correlation between total or surface CD81 levels and the presence and amount of soluble PCSK9. Moreover, inhibiting PCSK9 with the monoclonal antibody alirocumab did not affect expression levels of CD81. In an in vitro model of HCV entry, addition of soluble PCSK9 or treatment with alirocumab had no effect on the ability of either lentiviral particles bearing the HCV glycoproteins or JFH-1 based cell culture virus to enter hepatocytes. Consistent with these in vitro findings, no differences were observed in hepatic CD81 levels using in vivo mouse models, including Pcsk9-/- mice compared with wild-type controls and hyperlipidemic mice homozygous for human Pcsk9 and heterozygous for Ldlr deletion, treated with either alirocumab or isotype control antibody. Conclusion These results suggest that inhibition of PCSK9 with alirocumab has no effect on CD81 and does not result in increased susceptibility to HCV entry

  7. The radon EDM apparatus

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  8. 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.

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

    USGS Publications Warehouse

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

    1988-01-01

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

  10. 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.

  11. 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+.

  12. 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+.

  13. 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)

  14. A Comparative Study of Indoor Radon Contributed by Diffusive and Advective Transport through Intact Concrete

    NASA Astrophysics Data System (ADS)

    Chauhan, R. P.; Kumar, Amit

    The present work is aimed that out of diffusive and advective transport which is dominant process for indoor radon entry under normal room conditions. For this purpose the radon diffusion coefficient and permeability of concrete were measured by specially designed experimental set up. The radon diffusion coefficient of concrete was measured by continuous radon monitor. The measured value was (3.78 ± 0.39)×10-8 m2/s and found independent of the radon gas concentration in source chamber. The radon permeability of concrete varied between 1.85×10-17 to 1.36×10-15 m2 for the bulk pressure difference fewer than 20 Pa to 73.3 kPa. From the measured diffusion coefficient and absolute permeability, the radon flux from the concrete surface having concentrations gradient 12-40 kBq/m3 and typical floor thickness 0.1 m was calculated by the application of Fick and Darcy laws. Using the measured flux attributable to diffusive and advective transport, the indoor radon concentration for a typical Indian model room having dimension (5×6×7) m3 was calculated under average room ventilation (0.63 h-1). The results showed that the contribution of diffusive transport through intact concrete is dominant over the advective transport, as expected from the low values of concrete permeability.

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

    PubMed

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

    2014-04-01

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

  16. Furin cleavage of the SARS coronavirus spike glycoprotein enhances cell-cell fusion but does not affect virion entry

    SciTech Connect

    Follis, Kathryn E.; York, Joanne; Nunberg, Jack H. . E-mail: jack.nunberg@umontana.edu

    2006-07-05

    The fusogenic potential of Class I viral envelope glycoproteins is activated by proteloytic cleavage of the precursor glycoprotein to generate the mature receptor-binding and transmembrane fusion subunits. Although the coronavirus (CoV) S glycoproteins share membership in this class of envelope glycoproteins, cleavage to generate the respective S1 and S2 subunits appears absent in a subset of CoV species, including that responsible for the severe acute respiratory syndrome (SARS). To determine whether proteolytic cleavage of the S glycoprotein might be important for the newly emerged SARS-CoV, we introduced a furin recognition site at single basic residues within the putative S1-S2 junctional region. We show that furin cleavage at the modified R667 position generates discrete S1 and S2 subunits and potentiates membrane fusion activity. This effect on the cell-cell fusion activity by the S glycoprotein is not, however, reflected in the infectivity of pseudotyped lentiviruses bearing the cleaved glycoprotein. The lack of effect of furin cleavage on virion infectivity mirrors that observed in the normally cleaved S glycoprotein of the murine coronavirus and highlights an additional level of complexity in coronavirus entry.

  17. Time-dependent response of a charcoal bed to radon and water vapor in flowing air

    SciTech Connect

    Henkel, J.A.; Fentiman, A.W.; Blue, T.E.

    1995-12-31

    Extremely high airborne concentrations of radon gas may be encountered during the remediation of uranium mill tailings storage facilities. Radon is also a constituent of the off-gas of mill-tailing vitrification. An effective way to remove radon from either gas is to pass the gas through a packed bed containing activated charcoal. Measurements of radon concentrations in the environment using charcoal canisters were first described by George. Canisters similar to those used by George in his first experiments have become the U.S. Environmental Protection Agency`s (EPA`s) standard for measuring environmental radon and were described in the EPA protocol for environmental radon measurement. The dynamic behavior of EPA charcoal canisters has been previously described with a mathematical model for the kinetics of radon gas adsorption in air in the presence of water vapor. This model for charcoal canisters has been extended to large charcoal beds with flowing air containing radon and water vapor. The mathematical model for large charcoal beds can be used to evaluate proposed bed designs or to model existing beds. Parameters that affect the radon distribution within a charcoal bed that can be studied using the mathematical model include carrier gas relative humidity and flow velocity, and input radon concentration. In addition, the relative performances of several different charcoals can be studied, provided sufficient information about their adsorption, desorption, and diffusion constants is known.

  18. Preliminary study on the variation of radon-222 inside greenhouse of Shouguang county, China.

    PubMed

    Li, Xiaohong; Xu, Xianqin; Li, Wanwei; Wang, Fei; Hai, Chunxu

    2016-03-01

    Studies on radon have become the focus of indoor radiation. In this study, we chose greenhouse to be the study field, the research aims to: (1) explore the diurnal variation of radon concentration inside greenhouse in Shouguang county, China; (2) pre-analyze the relationship between radon concentration, temperature and relative humidity, and shed light on the radon behavior characteristic inside greenhouse; (3) verify the feasibility of calculating radon radiation dose by using short-period detected radon concentrations in typical months in Shouguang county. The following conclusions were drawn. Firstly, the average radon levels in typical months in Shouguang county are all much higher than that in ordinary dwellings in China, diurnal and seasonal variations in radon levels are observed inside greenhouse. Secondly, temperature and relative humidity may play a role indirectly through affecting soil moisture and other factors. The mechanism need to be further studied. Thirdly, radon concentrations detected in typical months are still useful in preliminary estimation of radon radiation dose for vegetable-plant farmers in Shouguang county.

  19. A creeping suspicion about radon

    SciTech Connect

    Alderson, L.

    1994-10-01

    Who would expect an odorless, invisible gas that occurs nearly everywhere on earth to cause such trouble Yet radon, the gas emitted by decay of uranium in the earth's crust, is one of America's most significant environmental risks, according to the EPA, which estimates that residential radon levels lead to approximately 13,600 lung cancer deaths each year. A new National Cancer Institute analysis of multiple studies of miners confirms early estimates, putting the number at 15,000. No other risk comes close, not even environmental tobacco smoke, which is estimates to cause some 3,000 deaths each year. Hot debate surrounds the assessment of risk from radon exposure to Americans via indoor air and water supplies. The primary culprit is not radon gas itself, but its decay products, including polonium-214 and polonium-218, which have long half-lives and emit alpha particles - positively charged particles - and lung cancer when inhaled. Radon seeps into homes from the ground or is present in water supplies. Waterborne radon may be inhaled as radon or its progeny during household use - cooking or showering - or it may be ingested. But the EPA estimates that water sources contribute only about 5% of total airborne radon exposure, leaving indoor air as the worst offender. While the EPA estimates that approximately 200 cancer cases per year result from exposure to radon from public groundwater systems, estimates of annual lung cancer deaths from indoor air radon range from 7,000 to 30,000.

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

    PubMed

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

    2017-01-01

    but suffers from low sensitivities for radon affected areas. We investigate an alternative classification method based on a Naïve Bayes classifier which results in similar overall performance. The work forms part of an ongoing study which will eventually incorporate airborne equivalent uranium data, as and when new airborne data become available.

  1. Multi-Level Factors Affecting Entry into and Engagement in the HIV Continuum of Care in Iringa, Tanzania

    PubMed Central

    Layer, Erica H.; Kennedy, Caitlin E.; Beckham, Sarah W.; Mbwambo, Jessie K.; Likindikoki, Samuel; Davis, Wendy W.; Kerrigan, Deanna L.; Brahmbhatt, Heena

    2014-01-01

    Progression through the HIV continuum of care, from HIV testing to lifelong retention in antiretroviral therapy (ART) care and treatment programs, is critical to the success of HIV treatment and prevention efforts. However, significant losses occur at each stage of the continuum and little is known about contextual factors contributing to disengagement at these stages. This study sought to explore multi-level barriers and facilitators influencing entry into and engagement in the continuum of care in Iringa, Tanzania. We used a mixed-methods study design including facility-based assessments and interviews with providers and clients of HIV testing and treatment services; interviews, focus group discussions and observations with community-based providers and clients of HIV care and support services; and longitudinal interviews with men and women living with HIV to understand their trajectories in care. Data were analyzed using narrative analysis to identify key themes across levels and stages in the continuum of care. Participants identified multiple compounding barriers to progression through the continuum of care at the individual, facility, community and structural levels. Key barriers included the reluctance to engage in HIV services while healthy, rigid clinic policies, disrespectful treatment from service providers, stock-outs of supplies, stigma and discrimination, alternate healing systems, distance to health facilities and poverty. Social support from family, friends or support groups, home-based care providers, income generating opportunities and community mobilization activities facilitated engagement throughout the HIV continuum. Findings highlight the complex, multi-dimensional dynamics that individuals experience throughout the continuum of care and underscore the importance of a holistic and multi-level perspective to understand this process. Addressing barriers at each level is important to promoting increased engagement throughout the continuum. PMID

  2. Multi-level factors affecting entry into and engagement in the HIV continuum of care in Iringa, Tanzania.

    PubMed

    Layer, Erica H; Kennedy, Caitlin E; Beckham, Sarah W; Mbwambo, Jessie K; Likindikoki, Samuel; Davis, Wendy W; Kerrigan, Deanna L; Brahmbhatt, Heena

    2014-01-01

    Progression through the HIV continuum of care, from HIV testing to lifelong retention in antiretroviral therapy (ART) care and treatment programs, is critical to the success of HIV treatment and prevention efforts. However, significant losses occur at each stage of the continuum and little is known about contextual factors contributing to disengagement at these stages. This study sought to explore multi-level barriers and facilitators influencing entry into and engagement in the continuum of care in Iringa, Tanzania. We used a mixed-methods study design including facility-based assessments and interviews with providers and clients of HIV testing and treatment services; interviews, focus group discussions and observations with community-based providers and clients of HIV care and support services; and longitudinal interviews with men and women living with HIV to understand their trajectories in care. Data were analyzed using narrative analysis to identify key themes across levels and stages in the continuum of care. Participants identified multiple compounding barriers to progression through the continuum of care at the individual, facility, community and structural levels. Key barriers included the reluctance to engage in HIV services while healthy, rigid clinic policies, disrespectful treatment from service providers, stock-outs of supplies, stigma and discrimination, alternate healing systems, distance to health facilities and poverty. Social support from family, friends or support groups, home-based care providers, income generating opportunities and community mobilization activities facilitated engagement throughout the HIV continuum. Findings highlight the complex, multi-dimensional dynamics that individuals experience throughout the continuum of care and underscore the importance of a holistic and multi-level perspective to understand this process. Addressing barriers at each level is important to promoting increased engagement throughout the continuum.

  3. Predicting indoor radon-222 concentration

    SciTech Connect

    Stowe, M.H.

    1994-12-31

    Radon, a cause of lung cancer among miners, is being investigated as a source of lung cancer in the general population due to long-term low-level exposures in residences. Assessment of cumulative residential radon exposure entails measurements in past residences, some of which no longer exist or are not accessible. Estimates of radon concentrations in these missing homes are necessary for analysis of the radon-lung cancer association. Various approaches have been used by researchers attempting to predict the distribution of radon measurements in homes from specified geological and building characteristics. This study has modelled the set of basement radon measurements of 3788 Connecticut homes with several of these approaches, in addition to a descriptive tree method not previously utilized, and compared their validity on a random subset of homes not used in model construction. Each geographical and geological variable was more predictive of radon concentration than any of the housing characteristics. The single variable which explained the largest fraction of the variability in radon readings was the mean radon concentration for the zipcode area in which the house was located (R{sup 2} = .157). Soil characteristics at individual housing sites were not available for these analyses. They would be expected to increase the predictive power of the models. Multiple regression models, both additive and multiplicative, were not able to explain more than 22% of the variation in radon readings. Variables found to be significant in these models were zipcode mean, residential radon mean of bedrock unit, building age, type of foundation walls, type of water supply, aeroradioactivity reading, and lithology of the bedrock. A site potential index, based upon a classification of the bedrock underlying the house, was a better predictor of indoor radon level than other single geological variables, yet only explained 8% of the radon variability.

  4. Measurement of indoor and outdoor radon concentrations during Superstorm Sandy.

    PubMed

    Kotrappa, Payasada; Paul, Prateek; Stieff, Alex; Stieff, Frederick

    2013-12-01

    Superstorm Sandy affected much of the US East Coast extending over 1800 km. It passed over the test location in the State of Maryland on 29 October 2012. Being 350 km away from the regions of highest intensity the storm was of lower intensity at the test location. Continuous radon monitors and passive radon monitors were used for the measurement. The test location was the basement of a single family home representing the indoor concentration. A partially opened garage of the same test home represented the outdoor radon concentration. In 24 h, the atmospheric pressure dropped from 990 to 960 mbar and the indoor radon concentration increased from 70 to 1500 Bq m(-3) and returned to the normal of 70 Bq m(-3) at the end of the storm. Throughout the storm, the outdoor radon concentration was not significantly affected. Probable reasons for such surprisingly large changes are discussed. However, the outdoor temperature dropped from 13°C to 7°C during the radon peak.

  5. High indoor radon variations and the thermal behavior of eskers.

    PubMed

    Arvela, H; Voutilainen, A; Honkamaa, T; Rosenberg, A

    1994-09-01

    Measurements of indoor radon concentrations in houses built on the Pispala esker in the city of Tampere were taken. The objective was to find connections between indoor radon concentrations, esker topography, and meteorological factors. The results show that not only the permeable soil but also subterranean air-flows in the esker strongly affect the indoor radon concentrations. The difference in temperature between the soil air inside the esker and the outdoor air compels the subterranean air to stream between the upper and lower esker areas. In winter, the radon concentrations are amplified in the upper esker areas where air flows out from the esker. In summer, concentrations are amplified in certain slope zones. In addition, wind direction affects the soil air and indoor radon concentrations when hitting the slopes at right angles. Winter-summer concentration ratios are typically in the range of 3-20 in areas with amplified winter concentration, and 0.1-0.5 in areas with amplified summer concentrations. A combination of winter and summer measurements provides the best basis for making mitigation decisions. On eskers special attention must be paid to building technology because of radon.

  6. High indoor radon variations and the thermal behavior of eskers

    SciTech Connect

    Arvela, H.; Voutilainen, A.; Honkamaa, T.; Rosenberg, A.

    1994-09-01

    Measurements of indoor radon concentrations in houses built on the Pispala esker in the city of Tampere were taken. The objective was to find connections between indoor radon concentrations, esker topography, and meteorological factors. The results show that not only the permeable soil but also subterranean air-flows in the esker strongly affect the indoor radon concentrations. The difference in temperature between the soil air inside the esker and the outdoor air compels the subterranean air to stream between the upper and lower esker areas. In winter, the radon concentrations are amplified in the upper esker areas where air flows out from the esker. In summer, concentrations are amplified in certain slope zones. In addition, wind direction affects the soil air and indoor radon concentrations when hitting the slopes at right angles. Winter-summer concentration ratios are typically in the range of 3-20 in areas with amplified winter concentration, and 0.1-0.5 in areas with amplified summer concentrations. A combination of winter and summer measurements provides the best basis for making mitigation decisions. On eskers special attention must be paid to building technology because of radon. 9 refs., 7 figs., 1 tab.

  7. Radon in soil gas and its relationship with some major faults of SW England.

    PubMed

    Varley, N R; Flowers, A G

    1993-09-01

    The south-west of England was designated by the National Radiological Protection Board (NRPB) as the first 'Radon Affected Area', as over 1% of the housing stock is estimated to have an indoor radon concentration in excess of the 200 Bq m(-3) Action Level. The situation is even worse for houses situated above uraniferous granite intrusions, where over 30% are thought to be above the Action Level.The aim of this study is to investigate the relationship between the level of radon in soil gas and the local geology. Particularly high radon levels were measured along major fault zones. This could be explained by: increased rate of migration of the radon due to the permeable fault, the presence of radium or radon-bearing ground water within the fault, or secondary uranium mineralisation. Seasonal variations are also considered.

  8. Residential construction code impacts on radon

    SciTech Connect

    Galbraith, S.; Brennan, T.; Osborne, M.C.

    1988-04-01

    The paper discusses residential construction-code impacts on radon. It references existing residential construction codes that pertain to the elements of construction that impact either the ability to seal radon out of houses or the ability to achieve good soil ventilation for radon control. Several inconsistencies in the codes that will impact radon resistant construction are identified. Resolution of these resulting radon issues is necessary before specification-style building codes can be developed to achieve radon-resistant construction.

  9. 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.

  10. 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.

  11. The cost effectiveness of radon reduction programmes in domestic housing in England and Wales: the impact of improved radon mapping and housing trends.

    PubMed

    Denman, A R; Sinclair, J; Phillips, P S; Crockett, R G M; Groves-Kirkby, C J

    2013-09-01

    In the UK, excessive levels of radon gas have been detected in domestic housing. Areas where 1% of existing homes were found to be over the Action Level of 200Bq·m(-3) were declared to be Radon Affected Areas. Building Regulations have been introduced which require that, for areas where between 3% and 10% of existing houses are above the Action Level, new homes should be built with basic radon protection using a membrane, and that, where 10% or more of existing homes exceed this level, new homes should be built with full radon protection. Initially these affected areas followed administrative boundaries, known as Counties. However, with increasing numbers of measurements of radon levels in domestic homes recorded in the national database, these areas have been successively refined into smaller units - 5km grid squares in 1999, down to 1km grid squares in 2007. One result is the identification of small areas with raised radon levels within regions where previously no problem had been identified. In addition, some parts of areas that were previously considered radon affected are now considered low, or no, risk. Our analysis suggests that the net result of improved mapping is to increase the number of affected houses. Further, the process is more complex for local builders, and inspectors, who need to work out whether radon protection in new homes is appropriate. Our group has assessed the cost-effectiveness of radon remediation programmes, and has applied this analysis to consider the cost-effectiveness of providing radon protection in both new and existing homes. This includes modelling the potential failure rate of membranes, and whether testing radon levels in new homes is appropriate. The analysis concludes that it is more cost effective to provide targeted radon protection in high radon areas, although this introduces more complexity. The paper also considers the trend in housing to a greater proportion of apartments, the regional variations in types of housing

  12. The health risk of radon

    SciTech Connect

    Conrath, S.M.; Kolb, L.

    1995-10-01

    Although radon is the second leading cause of lung cancer in the United States, second only to cigarette smoking, many members of the public are not aware that radon is one of the most serious environmental cancer risks in the US. Based on extensive data from epidemiological studies of underground miners, radon has been classified as a known human carcinogen. In contrast to most pollutants, the assessment of human risk from radon is based on human occupational exposure data rather than animal data. That radon causes lung cancer has been well established by the scientific community. More is known about radon than most other cancer causing environmental carcinogens. While there are some uncertainties involved when estimating radon risk to the public, it is important to recognize that the risk information is based on human data and that the uncertainties have been addressed in the risk assessment. The US Environmental Protection Agency (EPA) estimates that the number of annual US lung cancer deaths due to residential radon exposures is approximately 14,000 with an uncertainty range of 7,000 to 30,000. The abundant information on radon health risks that supports EPA`s risk assessment indicates that recommendations for public action by the federal government and other public health organizations constitute prudent public policy.

  13. EVALUATION OF RADON EMANATION FROM SOIL WITH VARYING MOISTURE CONTENT IN A SOIL CHAMBER

    EPA Science Inventory

    The paper describes measurements to quantitatively identify the extent to which moisture affects radon emanation and diffusive transport components of a sandy soil radon concentration gradient obtained in the EPA test chamber. The chamber (2X2X4 m long) was constructed to study t...

  14. 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)

  15. 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

  16. 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

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  18. Low air exchange rate causes high indoor radon concentration in energy-efficient buildings.

    PubMed

    Vasilyev, A V; Yarmoshenko, I V; Zhukovsky, M V

    2015-06-01

    Since 1995, requirements on energy-efficient building construction were established in Russian Building Codes. In the course of time, utilisation of such technologies became prevailing, especially in multi-storey building construction. According to the results of radon survey in buildings constructed meeting new requirements on energy efficiency, radon concentration exceeds the average level in early-constructed buildings. Preponderance of the diffusion mechanism of radon entry in modern multi-storey buildings has been experimentally established. The experimental technique of the assessment of ventilation rate in dwellings under real conditions was developed. Based on estimates of average ventilation rate, it was approved that measures to increase energy efficiency lead to reduction in ventilation rate and accumulation of higher radon concentrations indoors. Obtained ventilation rate values have to be considered as extremely low.

  19. 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

  20. Radon and radon daughter measurements in solar buildings.

    PubMed

    George, A C; Knutson, E O; Franklin, H

    1983-08-01

    Measurements of radon and radon daughters in 11 buildings in five states, using active or passive solar heating, showed no significant excess in concentrations over the levels measured in buildings with conventional heating systems. Radon levels in two buildings using rock storage in their active solar systems exceeded the U.S. Nuclear Regulatory Commission's limit of 3 pCi/l. for continuous exposure in uncontrolled areas. In the remainder of the buildings, radon concentrations were found to be at levels considered to be normal. It appears that the slightly elevated indoor radon concentrations result from the local geological formations and from the tightening of the buildings rather than as a result of the solar heating technology.

  1. Radon: Gas transport in soils and its relation to radon availability: Hot spot identification and flow characteristics near structures. Progress report and request for third year incremental funding

    SciTech Connect

    Reimer, G.M.

    1995-04-14

    There are 3 major objectives being addressed in this research. The first is to participate, by providing ground truth quality assurance, in the DOE/LBL/EPA cooperative study to determine a methodology to predict the areas where indoor radon concentrations have the highest probability of exceeding 20 pCi/L (750 Bq/m{sup 3}). The second is to examine 2 common types of homes (basement and non-basement) for radon entry by monitoring specific parameters under normal living conditions. The third task is to participate with other researchers in their studies using the techniques and experience developed by this principal investigator during previously funded times. Those researchers seek assistance in measuring soil permeability, determining the effect of meteorological parameters on radon entry, determining the diffusion characteristics of standard basement wall materials, developing a GIS (Geographic Information System) data base for predicting regional radon potential, and examining the contribution of regional solution-developed permeability in limestone to the radon potential of an area.

  2. Radon in ground water supplies

    SciTech Connect

    Dixon, K.L.; Lee, R.G.

    1989-06-01

    In September 1986, the System Water Quality Department of the American Water Works Service Co. began conducting a radon survey that was designed to determine the levels of radon in American ground water supplies, and to assess the radon removal efficiency of existing treatment processes such as filtration through granular activated carbon (GAC) and various forms of aeration. The survey found that companies in the northeastern part of the country experienced the highest levels of radon in ground water supplies. The highest concentrations were in individual wells in New Hampshire, Maryland, Connecticut, Rhode Island, New Jersey, Pennsylvania and California. The analytical results from the occurrence phase of the survey seemed to correlate well with the known geology of the aquifer materials from which samples of ground water were drawn. The highest levels were associated with formations of uranium-bearing granitic rocks. GAC can effectively reduce radon concentrations in drinking water supplies to very low levels. However, the amount of contact time within the carbon bed required to do so would be prohibitive to many water utilities from an operational and economic standpoint. Further, disposal of the spent GAC as a low-level radioactive waste may be required. Aeration is very effective in the removal of radon from drinking water. Packed tower aerators achieved > 95% reduction in radon concentrations and conventional cascading tray aerators achieved > 75% reduction in radon concentrations. 7 refs., 6 tabs.

  3. APPLICATION OF RADON REDUCTION METHODS

    EPA Science Inventory

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

  4. INDOOR RADON REDUCTION IN CRAWL-SPACE HOUSES: A REVIEW OF ALTERNATIVE APPROACHES

    EPA Science Inventory

    An analysis has been completed of the performance, mechanisms, and costs of alternative technologies for preventing radon entry into the living areas of houses having crawl-space foundations. Sub-membrane depressurization (SMD) is consistently the most effective technique, often ...

  5. 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.

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

    PubMed

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

    2017-04-01

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

  7. Effects of radon mitigation vs smoking cessation in reducing radon-related risk of lung cancer.

    PubMed Central

    Mendez, D; Warner, K E; Courant, P N

    1998-01-01

    OBJECTIVES: The purpose of this paper is to provide smokers with information on the relative benefits of mitigating radon and quitting smoking in reducing radon-related lung cancer risk. METHODS: The standard radon risk model, linked with models characterizing residential radon exposure and patterns of moving to new homes, was used to estimate the risk reduction produced by remediating high-radon homes, quitting smoking, or both. RESULTS: Quitting smoking reduces lung cancer risk from radon more than does reduction of radon exposure itself. CONCLUSIONS: Smokers should understand that, in addition to producing other health benefits, quitting smoking dominates strategies to deal with the problem posed by radon. PMID:9585753

  8. Modulated Entry

    NASA Technical Reports Server (NTRS)

    Grant, Frederick C.

    1960-01-01

    The technique of modulation, or variable coefficients, is discussed and the analytical formulation is reviewed. Representative numerical results of the use of modulation are shown for the lifting and nonlifting cases. These results include the effects of modulation on peak acceleration, entry corridor, and heat absorption. Results are given for entry at satellite speed and escape speed. The indications are that coefficient modulation on a vehicle with good lifting capability offers the possibility of sizable loading reductions or, alternatively, wider corridors; thus, steep entries become practical from the loading standpoint. The amount of steepness depends on the acceptable heating penalty. The price of sizable fractions of the possible gains does not appear to be excessive.

  9. 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.

  10. 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.

  11. Radon in earthquake prediction research.

    PubMed

    Friedmann, H

    2012-04-01

    The observation of anomalies in the radon concentration in soil gas and ground water before earthquakes initiated systematic investigations on earthquake precursor phenomena. The question what is needed for a meaningful earthquake prediction as well as what types of precursory effects can be expected is shortly discussed. The basic ideas of the dilatancy theory are presented which in principle can explain the occurrence of earthquake forerunners. The reasons for radon anomalies in soil gas and in ground water are clarified and a possible classification of radon anomalies is given.

  12. Indoor Radon and Its Decay Products: Concentrations, Causes, and Control Strategies

    SciTech Connect

    Nero, A.V.; Gadgil, A.J.; Nazaroff, W.W.; Revzan, K.L.

    1990-01-01

    This report is an introduction to the behavior of radon 222 and its decay products in indoor air. This includes review of basic characteristics of radon and its decay products and of features of the indoor environment itself, all of which factors affect behavior in indoor air. The experimental and theoretical evidence on behavior of radon and its decay products is examined, providing a basis for understanding the influence of geological, structural, and meteorological factors on indoor concentrations, as well as the effectiveness of control techniques. We go on to examine three important issues concerning indoor radon. We thus include (1) an appraisal of the concentration distribution in homes, (2) an examination of the utility and limitations of popular monitoring techniques and protocols, and (3) an assessment of the key elements of strategies for controlling radon levels in homes.

  13. Advertising and generic market entry.

    PubMed

    Königbauer, Ingrid

    2007-03-01

    The effect of purely persuasive advertising on generic market entry and social welfare is analysed. An incumbent has the possibility to invest in advertising which affects the prescribing physician's perceived relative qualities of the brand-name and the generic version of the drug. Advertising creates product differentiation and can induce generic market entry which is deterred without differentiation due to strong Bertrand competition. However, over-investment in advertising can deter generic market entry under certain conditions and reduces welfare as compared to accommodated market entry.

  14. Emanation of radon from household granite.

    PubMed

    Kitto, Michael E; Haines, Douglas K; Arauzo, Hernando Diaz

    2009-04-01

    Emanation of radon (222Rn) from granite used for countertops and mantels was measured with continuous and integrating radon monitors. Each of the 24 granite samples emitted a measurable amount of radon. Of the two analytical methods that utilized electret-based detectors, one measured the flux of radon from the granite surfaces, and the other one measured radon levels in a glass jar containing granite cores. Additional methods that were applied utilized alpha-scintillation cells and a continuous radon monitor. Measured radon flux from the granites ranged from 2 to 310 mBq m-2 s-1, with most granites emitting <20 mBq m-2 s-1. Emanation of radon from granites encapsulated in airtight containers produced equilibrium concentrations ranging from <0.01 to 11 Bq kg-1 when alpha-scintillation cells were used, and from <0.01 to 4.0 Bq kg-1 when the continuous radon monitor was used.

  15. Radon Risk and Remediation: A Psychological Perspective

    PubMed Central

    Hevey, David

    2017-01-01

    Although radon exposure in the home increases the risk of lung cancer, this risk can be managed. However, evidence indicates that testing for radon and subsequent home remediation rates are generally low in many countries. The present perspective outlines some key insights from psychological science that might account for sub-optimal radon protection. Psychological aspects of how the health risks posed by radon are perceived and managed are outlined. There is need to consider radon risk perception in terms of the (a) cognitive and emotional responses to radon and (b) social context in which the radon threat occurs. In addition, the nature of the threat itself is integral to the failure for people to act in response to a radon threat. Finally, the challenges arising from defensive processing of radon threat information are outlined.

  16. Radon measurement and mitigation activity in Finland.

    PubMed

    Valmari, T; Arvela, H; Reisbacka, H; Holmgren, O

    2014-07-01

    Radon prevention, measurement and mitigation activities have been increasing in Finland during the 2000s. Nowadays, many municipal authorities, especially those located in high-radon areas, require radon prevention measures. This has activated radon measurements. Owners of new houses having radon piping installed under the floor slab are the most active group to measure and reduce the found high-radon values. Their radon awareness is apparently better than on the average, and the existing piping makes it easier and cheaper to reduce the radon levels. Local campaigns involving invitation flyers mailed to the residents have been a cost-effective means to activate measurements of older houses. So far 116,611 dwellings in low-rise residential buildings have been measured. At least 15% of the 16,860 dwellings found to exceed the reference level of 400 Bq m(-3) had their indoor radon level reduced below that.

  17. Generation and mobility of radon in soil. Annual report

    SciTech Connect

    Not Available

    1992-07-01

    Objectives of this research include: (1) To determine the processes that cause large seasonal and short-term changes in the radon (Rn) content of soil gases, and to develop methods of predicting and modeling these variations; (2) to evaluate the relation of Rn emanation coefficients to form of radium (Ra) and other U-series decay products, particularly the role of Ra in organic matter and Fe-oxides; (3) to evaluate the conditions in which convection of gas in soil and bedrock may affect soil gas radon availability in houses; and, (4) to collaborate with other DOE researchers on evaluation of Rn flux into houses, using our well characterized soil sites.

  18. Radon diffusion coefficients in soils of varying moisture content

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

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

  19. A Physician's Guide to Radon

    EPA Pesticide Factsheets

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

  20. 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.

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

    PubMed Central

    Foster, Stephanie; Everett Jones, Sherry

    2016-01-01

    Radon is a naturally occurring, colorless, odorless, and tasteless radioactive gas. Without testing, its presence is unknown. Using nationally representative data from the 2012 School Health Policies and Practices Study, we examined whether the prevalence of school district policies for radon testing and for radon-resistant new construction practices varied by district location in relation to the U.S. Environmental Protection Agency Map of Radon Zones. Among school districts located in counties with high predicted average indoor radon, 42.4% had policies for radon testing and 37.5% had policies for radon-resistant new construction practices. These findings suggest a critical need for improved awareness among policy makers regarding potential radon exposure for both students and school staff. PMID:27983613

  2. 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.

  3. Soil radon measurements in the Canadian cities.

    PubMed

    Chen, J; Moir, D; MacLellan, K; Leigh, E; Nunez, D; Murphy, S; Ford, K

    2012-08-01

    Radon has been identified as the second leading cause of lung cancer after tobacco smoking. Information on indoor radon concentrations is required to assess the lung cancer burden due to radon exposure. Since radon in soil is believed to be the main source of radon in homes, measurements of soil gas radon concentrations can be used to estimate variations in radon potential of indoor environments. This study reports surveys of natural background variation in soil radon levels in four cities, Montreal, Gatineau, Kingston and the largest Canadian city of Toronto. A total of 212 sites were surveyed. The average soil gas radon concentrations varied significantly from site to site, and ranged from below detection limit to 157 kBq m(-3). For each site, the soil radon potential (SRP) index was determined with the average soil radon concentration and average soil permeability measured. The average SRP indexes are 20±16, 12±11, 8±9 and 12±10 for Montreal, Gatineau, Kingston and Toronto, respectively. The results provide additional data for the validation of an association between indoor and soil radon potentials and for the development of radon potential map of Canada.

  4. Characterizing the occurrence, sources, and variability of radon in Pacific Northwest homes.

    PubMed

    Turk, B H; Prill, R J; Grimsrud, D T; Moed, B A; Sextro, R G

    1990-04-01

    A compilation of data from earlier studies of 172 homes in the Pacific Northwest indicated that approximately 65 percent of the 46 homes tested in the Spokane River Valley/Rathdrum Prairie region of eastern Washington/northern Idaho had heating season indoor radon (222Rn) concentrations above the U. S. EPA guideline of 148 Bq m-3 (4 pCi L-1). A subset of 35 homes was selected for additional study. The primary source of indoor radon in the Spokane River Valley/Rathdrum Prairie was pressure-driven flow of soil gas containing moderate radon concentrations (geometric mean concentration of 16,000 Bq m-3) from the highly permeable soils (geometric mean permeability of 5 x 10(-11) m2) surrounding the house substructures. Estimated soil gas entry rates ranged from 0.4 to 39 m3h-1 and 1 percent to 21 percent of total building air infiltration. Radon from other sources, including domestic water supplies and building materials was negligible. In high radon homes, winter indoor levels averaged 13 times higher than summer concentrations, while in low radon homes winter levels averaged only 2.5 times higher. Short-term variations in indoor radon were observed to be dependent upon indoor-outdoor temperature differences, wind speed, and operation of forced-air furnace fans. Forced-air furnace operation, along with leaky return ducts and plenums, and openings between the substructure and upper floors enhanced mixing of radon-laden substructure air throughout the rest of the building.

  5. 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...

  6. Variation of soil radon concentrations in southern Ontario.

    PubMed

    Chen, J; Ly, J; Bergman, L; Wierdsma, J; Klassen, R A

    2008-01-01

    Radon has been identified as the second leading cause of lung cancer after tobacco smoking. Information on indoor radon concentrations is required to assess the lung cancer burden due to radon exposure. However, radon data in highly populated southern Ontario are very limited. Since radon in soil is believed to be the main source of radon in homes, measurements of soil gas radon concentrations can be used to estimate variations in radon potential of indoor environments. This study reports a transect survey of natural background variation in soil radon levels across southern Ontario. The results indicate that radon risk could be high in some areas of southern Ontario.

  7. Development of a high efficiency personal/environmental radon dosimeter using polycarbonate detectors.

    PubMed

    Taheri, M; Jafarizadeh, M; Baradaran, S; Zainali, Gh

    2006-12-01

    Passive radon dosimeters, based on alpha particle etched track detectors, are widely used for the assessment of radon exposure. These methods are often applied in radon dosimetry for long periods of time. In this research work, we have developed a highly efficient method of personal/environmental radon dosimetry that is based upon the detection of alpha particles from radon daughters, (218)Po and (214)Po, using a polycarbonate detector (PC). The radon daughters are collected on the filter surface by passing a fixed flow of air through it and the PC detector, placed at a specified distance from the filter, is simultaneously exposed to alpha particles. After exposure, the latent tracks on the detector are made to appear by means of an electrochemical etching process; these are proportional to the radon dose. The air flow rate and the detector-filter distance are the major factors that can affect the performance of the dosimeter. The results obtained in our experimental investigations have shown that a distance of 1.5 cm between the detector and the filter, an absorber layer of Al with a thickness of 12 microm and an air flow rate of 4 l min(-1) offer the best design parameters for a high efficiency radon dosimeter. Then, the designed dosimeter was calibrated against different values of radon exposures and the obtained sensitivity was found to be 2.1 (tracks cm(-2)) (kBq h m(-3))(-1). The most important advantages of this method are that it is reliable, fast and convenient when used for radon dose assessment. In this paper, the optimized parameters of the dosimeter structure and its calibration procedure are presented and discussed.

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

    PubMed

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

    2017-01-01

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

  9. The use of volunteer radon measurements for radon mapping purposes: an examination of sampling bias issues.

    PubMed

    Burke, Orlaith; Murphy, Patrick

    2011-09-01

    National and regional radon surveys are used in many nations to produce maps detailing the spatial variation of indoor radon concentrations. National surveys which are designed to be representative use either a geographically-weighted or a population-weighted sampling scheme. Additionally, many countries collect a large number of data on indoor radon concentrations from volunteers who have chosen to have the indoor radon concentration measured in their own dwellings. This work examines the representativeness of volunteer-based samples in radon measurement and explores the effect of potential volunteer bias on radon mapping results. We also investigate the influence that media attention has on volunteer sampling of indoor radon concentrations. The result of our work indicates that volunteer measurements are biased due to over-sampling of high radon areas. Consequently such volunteer radon measurements should not be used for radon mapping purposes.

  10. EPA recommends radon testing in January

    EPA Pesticide Factsheets

    PHILADELPHIA (January 8, 2015) - The U.S. Environmental Protection Agency has designated January as national Radon Action Month, a perfect time for you to protect your family by testing your home for radon.

  11. Final Federal Radon Action Plan Scorecard

    EPA Pesticide Factsheets

    This page provides information and a link to the draft Federal Radon Action Plan. It also contains a Federal Radon Action Plan Scorecard, a tool designed to display the current status of each federal agency commitments and outcomes to date.

  12. 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.

  13. Simulation of the steady-state transport of radon from soil into houses with basements under constant negative pressure

    SciTech Connect

    de Oliveira Loureiro, C.

    1987-05-01

    A theoretical model was developed to simulate this phenomenon, under some specific assumptions. The model simulates: the generation and decay of radon within the soil; its transport throughout the soil due to diffusion and convection induced by the pressure disturbance applied at a crack in the basement; its entrance into the house through the crack; and the resultant indoor radon concentration. The most important assumptions adopted in the model were: a steady-state condition; a house with a basement; a geometrically well-defined crack at the wall-floor joint in the basement; and a constant negative pressure applied at the crack in relation to the outside atmospheric pressure. Two three-dimensional finite-difference computer programs were written to solve the mathematical equations of the model. The first program, called PRESSU, was used to calculate: the pressure distribution within the soil as a result of the applied disturbance pressure at the crack; and the resultant velocity distribution of the soil gas throughout the soil matrix. The second program, called MASTRA, was used to: solve the radon mass-transport equation, and to calculate the concentration distribution of radon in the soil gas within the whole soil; and to calculate the entry rate of radon through the crack into the basement, and the final indoor radon concentration. A parametric sensitivity analysis performed on the model, revealed several features of the mechanisms involved in the transport of radon into the house. 84 refs., 66 figs., 16 tabs.

  14. Testing of indoor radon-reduction techniques in central Ohio houses: Phase 1 (Winter 1987-1988). Report for October 1987-August 1988 (Final)

    SciTech Connect

    Findlay, W.O.; Robertson, A.; Scott, A.G.

    1989-07-01

    The U.S. Environmental Protection Agency (EPA) has a program to demonstrate practical, cost-effective methods to reduce indoor radon concentrations in housing to 150 Bq/cu m (4 pCi/L) or less. The complete program will evaluate the full range of radon-reduction methods, i.e., house ventilation, sealing of entry routes, soil ventilation, radon removal from water, and air cleaning in the full range of housing substructure types and building styles, and geological conditions across the continental United States. The program described in the report demonstrated certain radon-reduction methods in housing and geology typical of southern Ohio in particular, and the central Great Plains States in general. The testing of radon-mitigation systems in Ohio houses is envisioned as taking place in two phases. The report describes Phase 1, which was carried out in 16 existing houses in the Dayton area during the 1987-1988 heating season.

  15. Comparative survey of outdoor, residential and workplace radon concentrations.

    PubMed

    Barros, Nirmalla; Field, Dan W; Steck, Daniel J; Field, R William

    2015-02-01

    This study investigated radon concentrations in above-ground (i.e. first floor) workplace in Missouri and compared them with above-ground radon concentrations in nearby homes and outdoor locations. This study also examined the potential utility of using home and outdoor radon concentrations to predict the radon concentration at a nearby workplace (e.g. county agencies and schools). Even though workplace radon concentrations were not statistically different from home radon concentrations, the radon concentration at a particular home, or outdoor location, was a poor predictor of the radon concentration at a nearby workplace. Overall, 9.6 and 9.9 % of homes and workplace, respectively, exhibited radon concentrations of ≥148 Bq m(-3). Because of the percentage of workplace with elevated radon concentrations, the results suggest that additional surveys of workplace radon concentrations are needed, especially in areas of high radon potential, to assess the contribution of workplace radon exposure to an individual's overall radon exposure.

  16. 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)

  17. 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…

  18. Radon-hazard potential of Utah

    SciTech Connect

    Black, B.D.; Solomon, B.J. )

    1993-04-01

    Radon is a naturally occurring radioactive gas formed by decay of uranium, and occurs in nearly all geologic materials. Although radon has been shown to be a significant cause of lung cancer in miners, the health hazard from accumulation of radon gas in buildings has only recently been recognized. Indoor-radon hazards depend on both geologic and non-geologic factors. Although non-geologic factors such as construction type, weather, and lifestyles are difficult to measure, geologic factors such as uranium concentration, soil permeability, and depth to ground water can be quantified. Uranium-enriched geologic materials, such as black shales, marine sandstones, and certain granitic, metamorphic, and volcanic rocks, are generally associated with a high radon-hazard potential. Impermeable soil or shallow ground water impedes radon movement and is generally associated with a low radon-hazard potential. A numerical rating system based on these geologic factors has been developed to map radon-hazard potential in Utah. A statewide map shows that the radon-hazard potential of Utah is generally moderate. Assessments of hazard potential from detailed field investigations correlate well with areas of this map. Central Utah has the highest radon-hazard potential, primarily due to uranium-enriched Tertiary volcanic rocks. The radon-hazard potential of eastern Utah is moderate to high, but is generally restricted by low uranium levels. Western Utah, where valley basins with impermeable soils and shallow ground water are common, has the lowest radon-hazard potential.

  19. 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...

  20. 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…

  1. Radon reduction systems in the construction of new houses in Gainesville, Florida

    SciTech Connect

    Najafi, F.T.

    1998-11-01

    High radon level exposures increase human risk of lung cancer. The objective of this paper is to present the results of the effectiveness of applying the Enkavent mat method and the suction pit method; as tested by a University of Florida research team; to reduce radon entry in new houses built in the city of Gainesville and the surrounding Alachua County area in Florida. Both of these passive techniques include placement of a barrier under the concrete floor slab right on top of the soil at the new building sites. Passive and active techniques applied in the construction of new houses reduced radon levels to below the minimum requirements of 148 Bq m{sup {minus}3} (4 pCi L{sup {minus}1}). The mitigation systems investigated in this research were adopted by the Florida Legislature to become part of the new building construction code in Florida.

  2. 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.

  3. 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.

  4. Unusually high indoor radon concentrations

    NASA Astrophysics Data System (ADS)

    Ennemoser, O.; Ambach, W.; Brunner, P.; Schneider, P.; Oberaigner, W.; Purtscheller, F.; Stingl, V.

    Measurements of indoor radon concentrations in the village Umhausen (2600 inhabitants, Ötztal valley, Tyrol, Austria) revealed unusually high indoor radon concentrations up to 274,000 Bq m -3. The medians measured on the basements were 3750 Bq m -3 in winter and 361 Bq m -3 in summer, those on the ground floors were 1180 Bq m -3 and 210 Bq m -3, respectively. Seventy-one per cent of the houses showed basement radon concentrations above the Austrian action level of 400 Bq m -3 in winter, 33% in summer. There are indications that the high radon concentrations are due to a giant rock slide about 8700 years ago. The unusually high radon concentrations in Umhausen coincide with a statistically significant increase in lung cancer mortality. For the period 1970-1991 the age and sex standardized mortality rate is 3.85 (95% confidence interval: 2.9 to 5.1). The control population is the total population of Tyrol (630,000 inhabitants).

  5. Physical conditions of a house and their effects on measured radon levels: data from Hillsborough Township, New Jersey, 2010-2011.

    PubMed

    Shendell, Derek G; Carr, Michael

    2013-10-01

    Concentrations of radon in homes are thought to be dependent on several factors, including the presence of certain physical conditions of the house that act as entry points for this colorless, odorless gas. Drains and sump pits are currently sealed as part of radon mitigation, but doing so may cause drainage problems and mold. The authors attempted to determine if specific attributes and physical conditions of homes are associated with measured residential concentrations of radon. Radon tests were conducted in 96 participating homes in rural Hillsborough Township, New Jersey, November 2010-February 2011. Samplers were placed and a walk-through survey was conducted. Test devices were analyzed by a New Jersey certified radon testing laboratory and results compared to survey data. Overall, 50% of houses with a perimeter drain and 30% of houses with a sump pit exceeded the New Jersey and federal radon action level of 4.0 picocuries per liter, and 47% of homes with both a sump and a perimeter "French" drain exceeded this action level. The authors' results suggested certain physical conditions act as pathways allowing radon entry into homes. Results could be used by local and state agencies to start local initiatives, e.g., increased testing or to seal these components as partial mitigation.

  6. Lung-cancer reduction from smoking cessation and radon remediation: a preliminary cost-analysis in Northamptonshire, UK.

    PubMed

    Groves-Kirkby, C J; Timson, K; Shield, G; Denman, A R; Rogers, S; Phillips, P S

    2011-02-01

    Domestic radon levels in parts of the United Kingdom are sufficiently high as to increase the risk of lung-cancer among residents. Public health campaigns in the county of Northamptonshire, a designated radon Affected Area with 6.3% of homes having average radon levels in excess of the UK Action Level of 200 Bq m(-3), have encouraged householders to test for radon and then, if indicated to be necessary, to carry out remediation in their homes. These campaigns have been only partially successful, since to date only 40% of Northamptonshire houses have been tested, and only 15% of those householders finding raised levels have proceeded to remediate. Those who remediate have been shown to have smaller families, to be older, and to include fewer smokers than the average population, suggesting that current strategies to reduce domestic radon exposure are not reaching those most at risk. During 2004-2005, the NHS Stop-Smoking Services in Northamptonshire assisted 2847 smokers to quit to the 4-week stage, the 15% (435) of these 4-week quitters remaining quitters at 1year forming the subjects of a retrospective study considering whether smoking cessation campaigns contribute significantly to radon risk reduction. Quantitative assessment of the risk of lung-cancer among the study population, from knowledge of the individuals' age, gender, and smoking habits, together with the radon levels in their homes, demonstrates that smoking cessation programmes have significant added value in reducing the incidence of lung-cancer in radon Affected Areas, and contribute a substantially greater health benefit at a lower cost than the alternative strategy of reducing radon levels in the smokers' homes, while they remain smokers. Both radon remediation and smoking cessation programmes are very cost effective in Northamptonshire, with smoking cessation being significantly more cost effective, and these are potentially valuable programmes to drive health improvements through promotion of the

  7. Estimation of radon diffusion coefficients in soil using an updated experimental system.

    PubMed

    Prasad, Ganesh; Ishikawa, Tetsuo; Hosoda, Masahiro; Sorimachi, Atsuyuki; Janik, Miroslaw; Sahoo, Sarata Kumar; Tokonami, Shinji; Uchida, Shigeo

    2012-09-01

    Radon diffusion through soil is strongly affected by the degree of water saturation of the soil pores. Methods have been developed by many researchers to measure radon diffusion coefficient. We developed an updated experimental system to estimate radon diffusion coefficients for typical types of soil in Japan and applied it to a typical loam with different water saturation levels (0-0.82). The system consists of a passive-type scintillation cell, soil column, accumulation tank, and radon source. The radon concentration in the accumulation tank is kept stable, and radon diffused through the soil column is continuously measured with the passive-type scintillation cell. We found the radon diffusion coefficients vary from 9.60 × 10(-6) m(2) s(-1) to 1.27 × 10(-7) m(2) s(-1) for the loam samples. Generally, the diffusion coefficients are almost constant for a water saturation range of 0-0.4 and decrease with increasing water saturation from 0.4 to 0.82.

  8. Indoor radon measurements in Turkey dwellings.

    PubMed

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

    2015-12-01

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

  9. Correlation of soil radon and permeability with indoor radon potential in Ottawa.

    PubMed

    Chen, Jing; Falcomer, Renato; Bergman, Lauren; Wierdsma, Jessica; Ly, Jim

    2009-08-01

    Soil gas radon and soil gas permeability measurements were conducted at 32 sites across the five most populated communities in the city of Ottawa where indoor radon measurements were available for 167 houses. A soil radon index (SRI) determined from the soil radon concentration and the soil gas permeability was used to characterise radon availability from soil to air. This study demonstrated that the average SRI in a community area correlates with the indoor radon potential (the percentage of homes above 200 Bq m(-3)) in that community. Soil gas radon concentrations together with soil gas permeability measurements can be a useful tool for the prediction of the indoor radon potential in the development of a Canadian radon risk map.

  10. Modeling radon transport in dry, cracked soil

    SciTech Connect

    Holford, D.J. ); Schery, S.D.; Wilson, J.L.; Phillips, F.M. )

    1993-01-10

    A two-dimensional finite element code was used to investigate the effect of changes in surface air pressure on radon flux from soil with parallel, partially penetrating cracks. A sensitivity analysis investigates the effects of various crack dimensions, soil characteristics, and surface air pressure on radon flux from the soil surface to the atmosphere. Simulation results indicate that radon flux is most sensitive to soil properties; the diffusion coefficient is most important, followed by permeability and porosity. Radon flux is also sensitive to changes in barometric pressure, which cause variations in radon flux above and below the average diffusive flux. Sinusoidal variations in barometric pressure cause a net increase in the average radon flux from the soil, because increases in flux during periods of decreasing pressure are greater than the decreases in flux during periods of decreasing pressure of equal magnitude. Cracks were found to significantly increase radon flux from soils of low permeability. 33 refs. 19 figs., 1 tab.

  11. New Methods of Energy Efficient Radon Mitigation

    SciTech Connect

    Fisk, W.J.; Prill, R.J.; Wooley, J.; Bonnefous, Y.C.; Gadgil, A.J.; Riley, W.J.

    1994-05-01

    Two new radon mitigation techniques are introduced and their evaluation in a field study complemented by numerical model predictions is described. Based on numerical predictions, installation of a sub gravel membrane at the study site resulted in a factor of two reduction in indoor radon concentrations. Experimental data indicated that installation of 'short-circuit' pipes extending between the subslab gravel and outdoors, caused an additional factor of two decrease in the radon concentration. Consequently, the combination of these two passive radon mitigation features, called the membrane and short-circuit (MASC) technique, was associated with a factor of four reduction in indoor radon concentration. The energy-efficient active radon mitigation method, called efficient active subslab pressurization (EASP), required only 20% of the fan energy of conventional active subslab depressurization and reduced the indoor radon concentration by approximately a factor of 15, including the numerically-predicted impact of the sub-gravel membrane.

  12. 30 CFR 57.5046 - Protection against radon gas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Protection against radon gas. 57.5046 Section... Protection against radon gas. Where radon daughter concentrations exceed 10 WL, respirator protection against radon gas shall be provided in addition to protection against radon daughters. Protection against...

  13. 30 CFR 57.5046 - Protection against radon gas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  14. 30 CFR 57.5046 - Protection against radon gas.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Protection against radon gas. 57.5046 Section... Protection against radon gas. Where radon daughter concentrations exceed 10 WL, respirator protection against radon gas shall be provided in addition to protection against radon daughters. Protection against...

  15. 30 CFR 57.5046 - Protection against radon gas.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Protection against radon gas. 57.5046 Section... Protection against radon gas. Where radon daughter concentrations exceed 10 WL, respirator protection against radon gas shall be provided in addition to protection against radon daughters. Protection against...

  16. 30 CFR 57.5046 - Protection against radon gas.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Protection against radon gas. 57.5046 Section... Protection against radon gas. Where radon daughter concentrations exceed 10 WL, respirator protection against radon gas shall be provided in addition to protection against radon daughters. Protection against...

  17. Local health campaigns to reduce lung cancers induced by radon and smoking--who responds?

    PubMed

    Denman, Antony Roger; Timson, Karen; Shield, George; Groves-Kirkby, Christopher John; Rogers, Stephen; Campbell, Jackie Ann; Phillips, Paul Scott

    2009-12-01

    The greatest risk factor for lung cancer is smoking, the second largest factor being raised radon levels at home. Initiatives to stop smoking and reduce domestic radon levels have met with some success, but in both cases a significant proportion of those affected have not taken action. The two risk factors combine, so that those who smoke and live in a house with high radon levels are at higher risk than if exposed to only one of the two threats. There is the potential for combined public health campaigns to better target those affected. Using postal questionnaires, we collected demographic information of those in Northamptonshire, UK, a radon Affected Area, who participated in Smoking Cessation Programmes, and compared these to a recent study by our group of those who had taken action to reduce radon. The comparison suggests that these two groups are significantly different, and in some cases differ from the general population. In addition, those who continue to quit smoking at 1 year were more likely to have children under 18 at home, and live with a parent or partner compared to those who had relapsed after the previous assessment at 4 weeks. There is merit in extending Smoking Cessation Programmes to include advice on reducing the risks from radon.

  18. 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...

  19. Predictive analysis of shaft station radon concentrations in underground uranium mine: A case study.

    PubMed

    Zhao, Guoyan; Hong, Changshou; Li, Xiangyang; Lin, Chunping; Hu, Penghua

    2016-07-01

    This paper presented a method for predicting shaft station radon concentrations in a uranium mine of China through theoretical analysis, mathematical derivation and Monte-Carlo simulation. Based upon the queuing model for tramcars, the average waiting time of tramcars and average number of waiting tramcars were determined, which were further used in developing the predictive model for calculating shaft station radon concentrations. The results exhibit that the extent of variation of shaft station radon concentration in the case study mine is not significantly affected by the queuing process of tramcars, and is always within the allowable limit of 200 Bq m(-3). Thus, the empirical limit of 100,000 T annual ore-hoisting yields has no value in ensuring radiation safety for this mine. Moreover, the developed model has been validated and proved useful in assessing shaft station radon levels for any uranium mine with similar situations.

  20. Reducing indoor radon levels in a UK test house using different ventilation strategies

    SciTech Connect

    Welsh, P.A.

    1995-12-31

    This paper reports on some of the most recent tests involving a number of studies in an unoccupied radon test house. The house has a suspended timber floor and naturally elevated indoor radon levels, peaking at times above 6000 Bqm{sup -3}. Various sensors monitor how different ventilation strategies affect indoor radon levels and the building environment. Data from five different scenarios is presented. Initially the house was monitored as purchased with poor natural underfloor ventilation. This was followed by testing whole house pressurisation, improved natural underfloor ventilation, and two types of mechanical underfloor ventilation. The results from these and future studies may be used to make a more informed choice of remedy, based on a whole number of aspects, not only radon reduction as is frequently the case.

  1. NEW APPROACHES: Teaching about radon

    NASA Astrophysics Data System (ADS)

    Sang, David; Sutcliffe, Jill

    1997-03-01

    Radon is a major natural hazard and people should know about it. But exactly what needs to be known, how should it be taught and what resources are available to teach it? The answers suggest that a good deal of work needs to be done.

  2. Use of simulink to address key factors for radon mitigation in a Fairbanks home.

    PubMed

    Marsik, Tom; Johnson, Ron

    2008-05-01

    Hilly areas around Fairbanks, Alaska, are known to have elevated soil radon concentrations. Due to geological conditions, cold winters, and the resulting stack effect, houses in these areas are prone to higher indoor radon concentrations. Key variables with respect to radon mitigation were addressed in this paper by using a dynamic model implemented in MATLAB Simulink. These variables included the ventilation rate; the foundation flow resistance, which can be affected by sealing the foundation during the construction of a house; and the differential pressure between the subslab and the house interior, which can be affected by using a subslab depressurization system. The model was used for the scenario of a varying differential pressure and then for the scenario of a varying ventilation rate at a Fairbanks home where real-time radon concentrations were measured. The correlation coefficients between the model-predicted and measured radon concentrations were 0.96 and 0.94, for both scenarios respectively, which verified the feasibility of the model for predicting indoor radon concentrations.

  3. Radon/radon daughter environmental chamber located in the northwest end of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Radon/radon daughter environmental chamber located in the northwest end of building. VIEW LOOKING WEST - Department of Energy, Grand Junction Office, Building No. 32, 2597 B3/4 Road, Grand Junction, Mesa County, CO

  4. Combination of geological data and radon survey results for radon mapping.

    PubMed

    Zhukovsky, Michael; Yarmoshenko, Ilia; Kiselev, Sergey

    2012-10-01

    The typical method of radon mapping usually used in most countries is the presenting of average radon concentrations in dwellings for districts or regions. Sometimes the maps of radon concentrations in the soil or maps of percentage above the reference level also demonstrated. Such approach not always can be used for identification of the regions with high probability of radon exposure above the reference levels where the population density is low. The combination of archive geological data and the results of representative radon survey allow estimating the typical parameters of radon concentration distribution for selected categories of buildings (multi-storey or rural type houses) situated in geological zones with the different radon potential. In this case it is possible to give grounds for the necessary level of radon protection measures in the new buildings constructed in this region. The use of such approach in Ural region of Russia is demonstrated.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    obtained by the radon probe installed along the NE flank of Etna (~1800 m asl), nearby a seismogenic fault that is the westernmost segment of the Pernicana fault system. The probe is located also close to the North-East Rift, an important volcano-tectonic structure of Etna which is site of frequent lateral volcanic eruptions. The collected data (radon, temperature and atmospheric pressure) were statistically analyzed and compared with the main meteorological parameters. In two periods (28/Feb/2010-06/May/2010 and 01/Jan/2011- 18/Feb/2011) we observed major anomalies in the signal of radon. An earthquake swarm has affected the western portion of the Pernicana fault system on 2-3 April 2010. Moreover, the period under investigation was characterized by tree eruptive paroxysms occurred on 11-12 January, 18 February and 10 April 2011, respectively. The maximum release of seismic energy falls almost halfway through the first radon anomaly (28/Feb/2010-06/Maj/2010), after about 33 days from its inception. Regarding the second radon anomaly (01/Jan/2011-18/Feb/2011), two of the three paroxysmal eruptions (11-12 January and 18 February 2011) fall within that timeframe. In this case the radon anomaly begins ~10 days before the 11-12 January paroxysm. The results show the possibility of using the anomalous variations of radon as potential tracers of seismic and volcanic activity.

  6. National radon contractor proficiency program. Proficiency report

    SciTech Connect

    Not Available

    1991-02-01

    The report lists those individual contractors who have met the requirements of the Radon Contractor Proficiency (PCP) Program as of December 15, 1990. These requirements are designed to provide minimum proficiency criteria for individuals who design and supervise the installation of radon mitigation systems in buildings. The RCP Program measures the proficiency of an individual contractor, not their company. The report provides the program requirements, RCP mitigation guidelines, State Radon contacts, and information on how to use the RCP tables.

  7. Radon emanation on the San Andreas Fault

    USGS Publications Warehouse

    King, C. Y.

    1978-01-01

    Radon is a radioactive gas with a half-life of 3.8 days. (Half-life is the time required for the substance to lose half of its radioactivity by decay.) It is itself produced by the decay of uranium. Radon is constantly emanated from the Earth into the atmosphere. Many cases are known where anomalously large amounts of radon have been given off along active faults. THe radon emanation has shown variations with time that are related to changing atmospheric conidtions and possibly to nearby seismic activity. 

  8. Low-Cost Radon Reduction Pilot Study

    SciTech Connect

    Rose, William B.; Francisco, Paul W.; Merrin, Zachary

    2015-09-01

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

  9. The Japanese Radon and Thoron Reference Chambers

    SciTech Connect

    Tokonami, Shinji; Ishikawa, Tetsuo; Sorimachi, Atsuyuki; Takahashi, Hiroyuki; Miyahara, Nobuyuki

    2008-08-07

    Passive detectors used for large-scale and long-term surveys are generally calibrated in a well-controlled environment such as a radon chamber. It has been also pointed out that some of them are sensitive to thoron. Thus it is necessary to check the thoron contribution to the detector response with the proposed or similar test before practical use. The NIRS accommodates radon/aerosol and thoron chambers for quality assurance and quality control of radon measurements. Thus both chambers work so well that they can supply us with the calibration technique and consequently, a good level of knowledge of the radon and thoron issue.

  10. Radon in outdoor air in Nevada

    SciTech Connect

    Price, J.G.; Rigby, J.G.; Christensen, L.

    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. The state-wide median of 15 Bq m{sup -3} (0.4 pCi L{sup -1}) is essentially the same as the nationwide median. The range is considerable: from 2.6-52 Bq m{sup -3} (0.07-1.40 pCi L{sup -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{sup -3} (4 pCi L{sup -1}) generally have relatively high soil-gas radon, relatively high outdoor-air radon, or both. 16 refs., 4 figs., 1 tab.

  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.

  12. siRNA screen for genes that affect Junín virus entry uncovers voltage-gated calcium channels as a therapeutic target

    PubMed Central

    Lavanya, Madakasira; Cuevas, Christian D.; Thomas, Monica; Cherry, Sara; Ross, Susan R.

    2014-01-01

    New world hemorrhagic fever arenaviruses infection of humans results in 15–30% mortality. We performed a high throughput siRNA screen with Junín virus glycoprotein-pseudotyped viruses to find potential host therapeutic targets. Voltage-gated calcium channels (VGCC) subunits, for which there are FDA-approved drugs, were identified in the screen. Knockdown of VGCC subunits or treatment with channel blockers diminished Junín virus-cell fusion and entry into cells and thereby decreased infection. Gabapentin, an FDA-approved drug used to treat neuropathic pain that targets the α2δ2 subunit, inhibited infection of mice by the Candid 1 vaccine strain of the virus. These findings demonstrate that VGCCs play a role in virus infection and have the potential to lead to therapeutic intervention of new world arenavirus infection. PMID:24068738

  13. Nucleotide sequences of Herpes Simplex Virus type 1 (HSV-1) affecting virus entry, cell fusion, and production of glycoprotein gB (VP7)

    SciTech Connect

    DeLuca, N.; Bzik, D.J.; Bond, V.C.; Person, S.; Snipes, W.

    1982-10-30

    The tsB5 strain of Herpes Simplex Virus type 1 (HSV-1) contains at least two mutations; one mutation specifies the syncytial phenotype and the other confers temperature sensitivity for virus growth. These functions are known to be located between the prototypic map coordinates 0.30 and 0.42. In this study it was demonstrated that tsB5 enters human embryonic lung (HEL) cells more rapidly than KOS, another strain of HSV-1. The EcoRI restriction fragment F from the KOS strain (map coordinates 0.315 to 0.421) was mapped with eight restriction endonucleases, and 16 recombinant plasmids were constructed which contained varying portions of the KOS genome. Recombinant viruses were generated by marker-rescue and marker-transfer cotransfection procedures, using intact DNA from one strain and a recombinant plasmid containing DNA from the other strain. The region of the crossover between the two nonisogenic strains was inferred by the identification of restriction sites in the recombinants that were characteristic of the parental strains. The recombinants were subjected to phenotypic analysis. Syncytium formation, rate of virus entry, and the production of gB were all separable by the crossovers that produced the recombinants. The KOS sequences which rescue the syncytial phenotype of tsB5 were localized to 1.5 kb (map coordinates 0.345 to 0.355), and the temperature-sensitive mutation was localized to 1.2 kb (0.360 to 0.368), giving an average separation between the mutations of 2.5 kb on the 150-kb genome. DNA sequences that specify a functional domain for virus entry were localized to the nucleotide sequences between the two mutations. All three functions could be encoded by the virus gene specifying the gB glycoprotein.

  14. Probabilistic Assessment of Radon Transport at the Monticello, Utah Uranium Mill Tailings Disposal Site

    NASA Astrophysics Data System (ADS)

    Arnold, B. W.; Ho, C. K.; Cochran, J. R.; Taira, R. Y.

    2001-12-01

    One objective of the cover design at the Monticello site is attenuation of the radon emanation from the mill tailings to the atmosphere. The landfill cover acts as a diffusion barrier, allowing time for the decay of the relatively short-lived Rn-222 gas during migration through the pore spaces of the cover soil. The conceptual model of radon migration through the landfill cover is one-dimensional upward transport driven by the difference in concentration in the tailings and the atmosphere. The processes affecting transport are molecular diffusion and radioactive decay. Uncertainty in the radon emanation rate from the tailings, as well as uncertainties in the effective diffusion coefficient and moisture content for individual layers in the landfill cover are assessed for both present and future conditions. Transport of radon gas by diffusion is enhanced at higher moisture content because of the reduced air phase volume in the soil under these conditions. In a competing manner, higher moisture content results in a lower effective diffusion coefficient for radon gas. Multiple realizations of the system and simulations of radon transport were performed using the RAECOM and FRAMES computer programs. Results indicate a very low probability of exceeding the regulatory limit of 20 pCi/m2/s under present conditions and a low probability of exceedence for future conditions. Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000.

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

    PubMed

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

    2015-11-01

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

  16. Active-passive measurements and CFD based modelling for indoor radon dispersion study.

    PubMed

    Chauhan, Neetika; Chauhan, R P

    2015-06-01

    Computational fluid dynamics (CFD) play a significant role in indoor pollutant dispersion study. Radon is an indoor pollutant which is radioactive and inert gas in nature. The concentration level and spatial distribution of radon may be affected by the dwelling's ventilation conditions. Present work focus at the study of indoor radon gas distribution via measurement and CFD modeling in naturally ventilated living room. The need of the study is the prediction of activity level and to study the effect of natural ventilation on indoor radon. Two measurement techniques (Passive measurement using pin-hole dosimeters and active measurement using continuous radon monitor (SRM)) were used for the validation purpose of CFD results. The CFD simulation results were compared with the measurement results at 15 points, 3 XY planes at different heights along with the volumetric average concentration. The simulation results found to be comparable with the measurement results. The future scope of these CFD codes is to study the effect of varying inflow rate of air on the radon concentration level and dispersion pattern.

  17. Measurement of Indoor Radon-222 and Radon-220 Concentrations in Central Japan

    SciTech Connect

    Oka, Mitsuaki; Shimo, Michikuni; Tokonami, Shinji; Sorimachi, Atsuyuki; Takahashi, Hiromichi; Ishikawa, Tetsuo

    2008-08-07

    A passive-type radon/thoron detector was used for measuring indoor radon and thoron concentrations at 90 dwellings in Aichi and Gifu prefectures in central Japan during 90 days from December, 2006 to March, 2007. The radon and thoron concentrations were 21.1 Bq/m3 and 25.1 Bq/m3, respectively. The dose due to radon and thoron in dwellings was roughly evaluated as 0.7 mSv/y and 2.4 mSv/y, respectively. The examination of the geological factor and house condition having an effect on indoor radon concentration was performed.

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

    PubMed

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

    2016-10-01

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

  19. Radon as an Anthropogenic Indoor Air Pollutant

    NASA Astrophysics Data System (ADS)

    Gillmore, Gavin; Crockett, Robin

    2016-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  1. 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

  2. Assessment and management of residential radon health risks: a report from the health Canada radon workshop.

    PubMed

    Tracy, Bliss L; Krewski, Daniel; Chen, Jing; Zielinski, Jan M; Brand, Kevin P; Meyerhof, Dorothy

    2006-04-01

    Epidemiologic studies of uranium miners and other underground miners have consistently shown miners exposed to high levels of radon to be at increased risk of lung cancer. More recently, concern has arisen about lung cancer risks among people exposed to lower levels of radon in homes. The current Canadian guideline for residential radon exposure was set in 1988 at 800 Bq/m(3). Because of the accumulation of a considerable body of new scientific evidence on radon lung cancer risks since that time, Health Canada sponsored a workshop to review the current state-of-the-science on radon health risks. The specific objectives of the workshop were (1) to collect and assess scientific information relevant to setting national radon policy in Canada, and (2) to gather information on social, political, and operational considerations in setting national policy. The workshop, held on 3-4 March 2004, was attended by 38 invited scientists, regulators, and other stakeholders from Canada and the United States. The presentations on the first day dealt primarily with scientific issues. The combined analysis of North American residential radon and lung cancer studies was reviewed. The analysis confirmed a small but detectable increase in lung cancer risk at residential exposure levels. Current estimates suggest that radon in homes is responsible for approximately 10% of all lung cancer deaths in Canada, making radon the second leading cause of lung cancer after tobacco smoking. This was followed by a perspective from an UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) working group on radon. There were two presentations on occupational exposures to radon and two presentations considered the possibility of radon as a causative factor for cardiovascular disease and for cancer in other organs besides the lung. The possible contribution of environmental tobacco smoke to lung cancers in nonsmokers was also considered. Areas for future research were identified

  3. Removal of Radon from Household Water.

    ERIC Educational Resources Information Center

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

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

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

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC.

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

  5. 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…

  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.

  7. Radon Measurement in Schools. Revised Edition.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC.

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

  8. Exposure to unusually high indoor radon levels

    SciTech Connect

    Rasheed, F.N. )

    1993-03-27

    Unusually high indoor radon concentrations were reported in a small village in western Tyrol, Austria. The authors have measured the seasonal course of indoor radon concentrations in 390 houses of this village. 71% of houses in winter and 33% in summer, showed radon values on the ground floor above the Austrian action level of 400 Bq/cm[sup 3]. This proportion results in an unusually high indoor radon exposure of the population. The radon source was an 8,700-year-old rock slide of granite gneiss, the largest of the alpine crystalline rocks. It has a strong emanating power because its rocks are heavily fractured and show a slightly increased uranium content. Previous reports show increased lung cancer mortality, myeloid leukemia, kidney cancer, melanoma, and prostate cancer resulting from indoor radon exposure. However, many studies fail to provide accurate information on indoor radon concentrations, classifying them merely as low, intermediate, and high, or they record only minor increases in indoor radon concentrations. Mortality data for 1970-91 were used to calculate age and sex standardized mortality rates (SMR) for 51 sites of carcinoma. The total population of Tyrol were controls. A significantly higher risk was recorded for lung cancer. The high SMR for lung cancer in female subjects is especially striking. Because the numbers were low for the other cancer sites, these were combined in one group to calculate the SMR. No significant increase in SMR was found for this group.

  9. 40 CFR 61.203 - Radon monitoring and compliance procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 9 2012-07-01 2012-07-01 false Radon monitoring and compliance... for Radon Emissions From Phosphogypsum Stacks § 61.203 Radon monitoring and compliance procedures. (a..., each owner or operator of an inactive phosphogypsum stack shall test the stack for radon-222 flux...

  10. 40 CFR 61.203 - Radon monitoring and compliance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 9 2013-07-01 2013-07-01 false Radon monitoring and compliance... for Radon Emissions From Phosphogypsum Stacks § 61.203 Radon monitoring and compliance procedures. (a..., each owner or operator of an inactive phosphogypsum stack shall test the stack for radon-222 flux...

  11. 40 CFR 61.203 - Radon monitoring and compliance procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 9 2014-07-01 2014-07-01 false Radon monitoring and compliance... for Radon Emissions From Phosphogypsum Stacks § 61.203 Radon monitoring and compliance procedures. (a..., each owner or operator of an inactive phosphogypsum stack shall test the stack for radon-222 flux...

  12. Hidden Hazards of Radon: Scanning the Country for Problem Locations.

    ERIC Educational Resources Information Center

    Gundersen, Linda C. S.

    1992-01-01

    Describes the geology of the radon problem in the United States and suggests how homeowners can cope with the radio active gas. Vignettes illustrate how and where radon is produced beneath the earth's surface, testing sites and procedures for radon in houses, and locations for potential radon problems across the United States. (MCO)

  13. 40 CFR 61.203 - Radon monitoring and compliance procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 8 2011-07-01 2011-07-01 false Radon monitoring and compliance... for Radon Emissions From Phosphogypsum Stacks § 61.203 Radon monitoring and compliance procedures. (a..., each owner or operator of an inactive phosphogypsum stack shall test the stack for radon-222 flux...

  14. 40 CFR 61.203 - Radon monitoring and compliance procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Radon monitoring and compliance... for Radon Emissions From Phosphogypsum Stacks § 61.203 Radon monitoring and compliance procedures. (a..., each owner or operator of an inactive phosphogypsum stack shall test the stack for radon-222 flux...

  15. SITE-SPECIFIC MEASUREMENTS OF RESIDENTIAL RADON PROTECTION CATEGORY

    EPA Science Inventory

    The report describes a series of benchmark measurements of soil radon potential at seven Florida sites and compares the measurements with regional estimates of radon potential from the Florida radon protection map. The measurements and map were developed under the Florida Radon R...

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

    EPA Pesticide Factsheets

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

  17. Methodology issues in risk assessment for radon.

    PubMed Central

    Harley, N H

    1991-01-01

    The alpha dose per unit radon daughter exposure in mines and homes is comparable at about 5 mGy/WLM. This means that excess lung cancer risk determined in follow-up studies of miners should be valid to extrapolating to environmental populations. There are several models currently used for risk projection to estimate lung cancer in the U.S. from indoor radon exposure. The accuracy of the estimates depends upon the quality of the exposure data and the models. Recent miner epidemiology confirms that excess lung cancer risk decreases with time subsequent to cessation of exposure. The most rigorous ecological study, to date, shows a persistent negative relationship between average measured indoor radon in U.S. counties and lung cancer mortality. A model for lung cancer risk is proposed that includes smoking, urbanization, and radon exposure. The model helps to explain the difficulties in observing the direct effects of indoor radon in the environment. PMID:2050058

  18. 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.

  19. Indoor radon risk potential of Hawaii

    USGS Publications Warehouse

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

    2005-01-01

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

  20. Radon: implications for the health professional

    SciTech Connect

    Romano, C.A.

    1990-01-01

    Radon is a colorless, odorless gas formed by radioactive decay of radium and uranium, which are naturally present in the earth's crust. When concentrated indoors, this invisible gas becomes a potential health hazard. The Environmental Protection Agency estimates that up to 20,000 lung cancer deaths annually can be attributed to prolonged radon exposure. Radon is an important health issue that should be understood by all health care professionals. This paper discusses some of the important issues regarding radon, such as the incidences of lung cancer believed to be attributable to radon, the high-risk areas in the United States, federal safety guidelines, and public apathy. These issues and their impact on the health care required by professionals, especially nurse practitioners, are discussed.

  1. 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%.

  2. 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.

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

    SciTech Connect

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

    1996-06-01

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

  4. Silencing of the Charcot-Marie-Tooth disease-associated gene GDAP1 induces abnormal mitochondrial distribution and affects Ca2+ homeostasis by reducing store-operated Ca2+ entry.

    PubMed

    Pla-Martín, David; Rueda, Carlos B; Estela, Anna; Sánchez-Piris, Maribel; González-Sánchez, Paloma; Traba, Javier; de la Fuente, Sergio; Scorrano, Luca; Renau-Piqueras, Jaime; Alvarez, Javier; Satrústegui, Jorgina; Palau, Francesc

    2013-07-01

    GDAP1 is an outer mitochondrial membrane protein that acts as a regulator of mitochondrial dynamics. Mutations of the GDAP1 gene cause Charcot-Marie-Tooth (CMT) neuropathy. We show that GDAP1 interacts with the vesicle-organelle trafficking proteins RAB6B and caytaxin, which suggests that GDAP1 may participate in the mitochondrial movement within the cell. GDAP1 silencing in the SH-SY5Y cell line induces abnormal distribution of the mitochondrial network, reduces the contact between mitochondria and endoplasmic reticulum (ER) and alters the mobilization of mitochondria towards plasma membrane upon depletion of ER-Ca(2+) stores. GDAP1 silencing does not affect mitochondrial Ca(2+) uptake, ER-Ca(2+), or Ca(2+) flow from ER to mitochondria, but reduces Ca(2+) inflow through store-operated Ca(2+) entry (SOCE) following mobilization of ER-Ca(2+) and SOCE-driven Ca(2+) entry in mitochondria. Our studies suggest that the pathophysiology of GDAP1-related CMT neuropathies may be associated with abnormal distribution and movement of mitochondria throughout cytoskeleton towards the ER and subplasmalemmal microdomains, resulting in a decrease in SOCE activity and impaired SOCE-driven Ca(2+) uptake in mitochondria.

  5. Indoor radon and lung cancer in China

    SciTech Connect

    Blot, W.J.; Xu, Z.Y.; Boice, J.D. Jr.; Zhao, D.Z.; Stone, B.J.; Sun, J.; Jing, L.B.; Fraumeni, J.F. Jr. )

    1990-06-20

    Radon has long been known to contribute to risk of lung cancer, especially in undergound miners who are exposed to large amounts of the carcinogen. Recently, however, lower amounts of radon present in living areas have been suggested as an important cause of lung cancer. In an effort to clarify the relationship of low amounts of radon with lung cancer risk, we placed alpha-track radon detectors in the homes of 308 women with newly diagnosed lung cancer and 356 randomly selected female control subjects of similar age. Measurements were taken after 1 year. All study participants were part of the general population of Shenyang, People's Republic of China, an industrial city in the northeast part of the country that has one of the world's highest rates of lung cancer in women. The median time of residence in the homes was 24 years. The median household radon level was 2.3 pCi/L of air; 20% of the levels were greater than 4 pCi/L. Radon levels tended to be higher in single-story houses or on the first floor of multiple-story dwellings, and they were also higher in houses with increased levels of indoor air pollution from coal-burning stoves. However, the levels were not higher in homes of women who developed lung cancer than in homes of controls, nor did lung cancer risk increase with increasing radon level. No association between radon and lung cancer was observed regardless of cigarette-smoking status, except for a nonsignificant trend among heavy smokers. No positive associations of lung cancer cell type with radon were observed, except for a nonsignificant excess risk of small cell cancers among the more heavily exposed residents. Our data suggest that projections from surveys of miners exposed to high radon levels may have overestimated the overall risks of lung cancer associated with levels typically seen in homes in this Chinese city.

  6. 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.

  7. Diffusion of radon through concrete block walls: A significant source of indoor radon

    USGS Publications Warehouse

    Lively, R.S.; Goldberg, L.F.

    1999-01-01

    Basement modules located in southern Minnesota have been the site of continuous radon and environmental measurements during heating seasons since 1993. Concentrations of radon within the basement modules ranged from 70 Bq.m-3 to over 4000 Bq.m-3 between November to April during the three measurement periods. In the soil gas for the same times, concentrations of radon ranged between 25,000 and 70,000 Bq.m-3. Levels of radon within the basement modules changed by factors of five or more within 24 h, in concert with pressure gradients of 4 to 20 Pa that developed between the basement modules and their surroundings. Diffusion is identified as the principal method by which radon is transferred into and out of the basement modules, and appears to be relatively independent of insulating materials and vapour retarders. The variability of radon and correlations with differential pressure gradients may be related to air currents in the block walls and soil that interrupt radon diffusing inward. This yields a net decrease of radon in the basement modules by decay and outward diffusion. Levels of radon within the basement modules increase when the pressure differential is zero and air flow ceases, allowing diffusion gradients to be re-established. Radon levels in both the soil and the basement modules then increase until an equilibrium is achieved.

  8. Evaluation of experiences in long-term radon and radon-daughter measurements

    SciTech Connect

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

    1982-12-01

    Pacific Northwest Laboratory (PNL) is performing side-by-side measurements of radon and radon daughter concentrations using several instruments and techniques, and is comparing these measurements with side-by-side measurements made by other investigators at other locations. The standard deviation of the differences between the (natural) logarithms of the Terradex Track Etch radon concentrations and the logarithms of the Radon Progency Integrating Sampling Units (RPISU) radon daughter concentrations (S.D.-ln) measured in 50 buildings in Edgemont, South Dakota, was 0.37. Using this S.D.-ln, it can be calculated that if the Track Etch radon daughter concentration is 0.010 WL there should be only a 14% probability that the RPISU average would be greater than 0.015 WL, and only a 3% probability tht the RPISU average would be greater than 0.020 WL. If buildings had been cleared from remedial action when the Track Etch averages were less than 0.10 WL, then about 61% of the buildings would have been cleared from remedial action, and only a few percent of these buildings would have actually had average RPISU concentrations greater than 0.015 WL. The S.D.-ln between the Track Etch radon measurements and the RPISU radon daughter measurements made by ALARA at Grand Junction, the PERM radon measurements and the MOD-225 radon daughter measurements made by Mound Facility at Canonsburg and Middlesex, and the PERM and Track Etch radon measurements made by Mound Facility at Salt Lake City were similar to the S.D.-ln between the Track Etch radon measurements and the RPISU radon daughter measurements at Edgemont.

  9. Electret ion chamber-based passive radon-thoron discriminative monitors.

    PubMed

    Kotrappa, P; Steck, D

    2010-10-01

    Electret ion chambers (EICs), commercially available under brand name E-PERM(®), are widely used for measuring indoor and outdoor (222)Rn concentrations in air. These are designed to respond only to (222)Rn and not to (220)Rn by restricting diffusional entry area. Such radon EIC (R EIC) monitors are modified by increasing the entry area to allow (220)Rn, in addition to (222)Rn. Such modified units are called RT EIC. When a set of R and RT EICs are collocated, it is possible to discriminate and measure both radon and thoron concentrations, using appropriate calibration factors (CFs) and algorithms. The EICs come in different volumes, providing different sensitivities. The thoron CFs for 58-, 210- and 960-ml volume R and RT pairs are, respectively, 2.8-, 18.7- and 89-V drop per (kBq m(-3) d ), respectively. These provide much wider sensitivities and ranges compared to alpha track-based passive radon-thoron discriminative monitors.

  10. Temporal variations of radon in soil related to earthquakes.

    PubMed

    Planinić, J; Radolić, V; Lazanin, Z

    2001-08-01

    A radon detector with LR-115 nuclear track film was constructed for radon concentration measurements in soil. Temporal radon variations, as well as the barometric pressure, precipitation and temperature were measured for two years. Negative correlation between radon concentration in soil and barometric pressure was found. For some of the recorded earthquakes that occurred during the observation period, soil radon anomalies may be noticed one month before the quakes.

  11. Radon reduction and radon-resistant construction demonstrations in New York. Final report, September 1986-June 1988

    SciTech Connect

    Nitschke, I.

    1989-01-01

    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 years earlier; and (3) the development and application of radon resistant new construction designs in 15 different houses. In applying radon reduction techniques in existing houses, techniques which were applicable in extremely porous soil were not as easily applied to houses built on granite ledge; combinations of techniques may be required in many difficult houses before an acceptable radon level can be achieved. During the study, basement pressurization was applied as a radon reduction technique for the first time. The radon resistant new construction designs should demonstrate effective methods of sealing out radon during construction; however, quality control problems prevalent in the construction industry may require additional laboratory tests for verification.

  12. High sensitivity radon emanation measurements.

    PubMed

    Zuzel, G; Simgen, H

    2009-05-01

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

  13. Technology for Entry Probes

    NASA Technical Reports Server (NTRS)

    Cutts, James A.; Arnold, James; Venkatapathy, Ethiraj; Kolawa, Elizabeth; Munk, Michelle; Wercinski, Paul; Laub, Bernard

    2005-01-01

    A viewgraph describing technologies for entry probes is presented. The topics include: 1) Entry Phase; 2) Descent Phase; 3) Long duration atmospheric observations; 4) Survivability at high temperatures; and 5) Summary.

  14. 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

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

    PubMed

    Chen, Jing; Ford, Ken L

    2017-01-01

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

  16. Nanomaterial Containing Wall Paints Can Increase Radon Concentration in Houses Located in Radon Prone Areas

    PubMed Central

    Haghani, M.; Mortazavi, S. M. J.; Faghihi, R.; Mehdizadeh, S.; Moradgholi, J.; Darvish, L.; Fathi-Pour, E.; Ansari, L.; Ghanbar-pour, M. R.

    2013-01-01

    Background: Nowadays, extensive technological advancements have made it possible to use nanopaints which show exciting properties. In IR Iran excessive radon levels (up to 3700 Bq m–3) have been reported in homes located in radon prone areas. Over the past decades, concerns have been raised about the risk posed by residential radon exposure. Objective: This study aims at investigating the effect of using nanomaterial containing wall paints on radon concentration in homes. Methods: Two wooden model houses were used in this study. Soil samples from Ramsar high background radiation areas were used for simulating the situation of a typical house in radon-prone areas. Conventional water-soluble wall paint was used for painting the walls of the 1st house model; while the 2nd house model was painted with the same wall paint with montmorillonitenanoclay. Results: Three days after sealing the house models, radon level was measured by using a portable radon survey meter. The mean radon level inside the 1st house model (conventional paint) was 515.3 ± 17.8 Bq/m3 while the mean radon concentration in the 2nd house model (nano-painted house model) was 570.8 ± 18.5 Bq/m3. The difference between these means was statistically significant (P<0.001). Conclusion: To the best of our knowledge, this study is the first investigation on the effect of nano-material containing wall paints on indoor radon concentrations.  It can be concluded that nano-material-containing wall paints should not be used in houses with wooden walls located in radon prone areas. Although the mechanism of this effect is not clearly known, decreased porosity in nano-paints might be a key factor in increasing the radon concentration in homes. PMID:25505754

  17. Mitigation of elevated indoor radon gas resulting from underground air return usage.

    PubMed

    Kearfott, K J; Metzger, R L; Kraft, K R; Holbert, K E

    1992-12-01

    Underground air returns have been found to be active transportation pathways for radon gas entry into homes. Several homes for which underground air returns were contributing to elevated indoor 222Rn concentrations were evaluated for possible mitigation. Two houses with such problems were successfully mitigated by inserting flexible ducts into the returns. In one of these houses, the initial mitigation attempt resulted in an exacerbation of the problem due to leakage of the ducting. This was solved by re-sleeving the returns using a stronger material. Mitigation of elevated indoor radon gas caused by use of underground air returns by inserting flexible ducts is not possible for all situations, especially those for which the returns are small, filled with debris, misaligned, or inaccessible.

  18. Normal and seasonally amplified indoor radon levels

    SciTech Connect

    Gammage, R.B.; Dudney, C.S.; Wilson, D.L.; King, D.

    1995-01-01

    Winter and summer indoor radon measurements are reported for 121 houses in Freehold, New Jersey. When presented as winter:summer ratios of indoor radon, the data closely approximate a lognormal distribution. The geometric mean is 1.49. Freehold is located on the fairly flat coastal plain. The winter:summer ratios are believed to represent the norm for regions of the U.S. with cold winters and hot summers. The Freehold data set can be compared to corresponding data sets from other locations to suggest seasonal perturbations of indoor radon arising from unusual causes.

  19. Application of the can technique and radon gas analyzer for radon exhalation measurements.

    PubMed

    Fazal-ur-Rehman; Al-Jarallah, M I; Musazay, M S; Abu-Jarad, F

    2003-01-01

    A passive "can technique" and an active radon gas analyzer with an emanation container were applied for radon exhalation rate measurements from different construction materials, viz. five marble seven ceramic and 100 granite tiles used in Saudi Arabia. The marble and ceramic tiles did not show detectable radon exhalation using the active radon gas analyzer system. However the granite tiles showed relatively high radon exhalations, indicating a relatively high uranium content. A comparison of the radon exhalation rates measured by the two techniques showed a linear correlation coefficient of 0.57. The radon exhalation rates from the granites varied from 0.02 to 6.58 Bqm(-2)h(-1) with an average of 1.35+/-1.40 Bqm(-2)h(-1). The geometric mean and the geometric standard deviation of the frequency distribution were found to be 0.80 and 3.1, respectively. The track density found on the nuclear track detectors in the can technique exposed to the granites, having high exhalation rates, varied linearly with exposure time with a linear correlation coefficient of 0.99. This experimental finding agrees with the theoretical prediction. The can technique showed sensitivity to low radon exhalation rates from ceramic, marble and some granite over a period of 2 months, which were not detectable by the active radon gas analyzer system. The reproducibility of data with both measuring techniques was found to be within a 7% deviation.

  20. Soil gas radon assessment and development of a radon risk map in Bolsena, Central Italy.

    PubMed

    Cinelli, G; Tositti, L; Capaccioni, B; Brattich, E; Mostacci, D

    2015-04-01

    Vulsini Volcanic district in Northern Latium (Central Italy) is characterized by high natural radiation background resulting from the high concentrations of uranium, thorium and potassium in the volcanic products. In order to estimate the radon radiation risk, a series of soil gas radon measurements were carried out in Bolsena, the principal urban settlement in this area NE of Rome. Soil gas radon concentration ranges between 7 and 176 kBq/m(3) indicating a large degree of variability in the NORM content and behavior of the parent soil material related in particular to the occurrence of two different lithologies. Soil gas radon mapping confirmed the existence of two different areas: one along the shoreline of the Bolsena lake, characterized by low soil radon level, due to a prevailing alluvial lithology; another close to the Bolsena village with high soil radon level due to the presence of the high radioactive volcanic rocks of the Vulsini volcanic district. Radon risk assessment, based on soil gas radon and permeability data, results in a map where the alluvial area is characterized by a probability to be an area with high Radon Index lower than 20 %, while probabilities higher than 30 % and also above 50 % are found close to the Bolsena village.

  1. Effects of sampling technique, storage, cocktails, sources of variation, and extraction on the liquid scintillation technique for radon in water

    SciTech Connect

    Kinner, N.E.; Malley, J.P. Jr.; Clement, J.A.; Quern, P.A.; Schell, G.S.; Lessard, C.E. )

    1991-06-01

    Sampling and analytical procedures used in the liquid scintillation counting technique to determine radon in water were examined in a series of experiments. Factors evaluated included the following: sample collection, length of storage, sources of variability, choice of scintillation cocktail, and extraction procedure. Collection using the direct syringe technique yielded the highest radon activities, but its widespread use may be limited by cost and problems with distribution of syringes. Storage in VOA bottles was primarily affected by radioactive decay; however, leakage also led to decreases in radon activity. Sample preparation and instrumentation caused the majority of the variability observed in this study. An Opti-Fluor O scintillation cocktail yielded significantly higher count rates and was less expensive than toluene and mineral oil based cocktails. The data suggested that while the extraction procedure should not be considered in calculating the efficiency factor, samples should be shaken to maximize the rate of transfer of radon to the cocktail phase.

  2. Radon as a tracer of daily, seasonal and spatial air movements in the Underground Tourist Route "Coal Mine" (SW Poland).

    PubMed

    Tchorz-Trzeciakiewicz, Dagmara Eulalia; Parkitny, Tomasz

    2015-11-01

    The surveys of radon concentrations in the Underground Tourist Route "Coal Mine" were carried out using passive and active measurement techniques. Passive methods with application of Solid State Nuclear Track Detectors LR115 were used at 4 points in years 2004-2007 and at 21 points in year 2011. These detectors were exchanged at the beginning of every season in order to get information about seasonal and spatial changes of radon concentrations. The average radon concentration noted in this facility was 799 Bq m(-3) and is consistent with radon concentrations noted in Polish coal mines. Seasonal variations, observed in this underground tourist route, were as follows: the highest radon concentrations were noted during summers, the lowest during winters, during springs and autumns intermediate but higher in spring than in autumn. The main external factor that affected seasonal changes of radon concentrations was the seasonal variation of outside temperature. No correlation between seasonal variations of radon concentrations and seasonal average atmospheric pressures was found. Spatial variations of radon concentrations corresponded with air movements inside the Underground Tourist Route "Coal Mine". The most vivid air movements were noted along the main tunnel in adit and at the place located near no blinded (in the upper part) shaft. Daily variations of radon concentrations were recorded in May 2012 using RadStar RS-230 as the active measurement technique. Typical daily variations of radon concentrations followed the pattern that the highest radon concentrations were recorded from 8-9 a.m. to 7-8 p.m. and the lowest during nights. The main factor responsible for hourly variations of radon concentrations was the daily variation of outside temperatures. No correlations were found between radon concentration and other meteorological parameters such as atmospheric pressure, wind velocity or precipitation. Additionally, the influence of human factor on radon

  3. Monitoring for radon in water

    SciTech Connect

    Deininger, R.A. . School of Public Health)

    1994-04-01

    This article focuses on radionuclides elements of interest to utilities and consumers alike. Each of these groups may be interested in a low-cost radiation detector that can be connected to a laptop or desktop computer through either the serial or the parallel port. A complete set of software comes with the detector, and a detailed manual describes operation of the program and discusses the various forms of common radiation sources in a home. Computer programs can run in the foreground and display a scrolling bar chart or in the background while the incoming data are logged, so the user can continue to work on the computer. Data are automatically stored on a disk file. Data collection times can be set for minutes, hours, days, or weeks, thus allowing long-term trends to be identified. The detector can be connected to the computer by a modular telephone cable and can be placed as far away as several hundred feet. Utilities that use surface water supplies are unlikely to detect any radon. Only those plants that use groundwater supplies from areas where radioactive materials are in the ground will have some radon in the water.

  4. 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

  5. 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

  6. Carcinogenic risk associated with radon-enriched well water

    SciTech Connect

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

    1997-08-01

    A comparison has been made between radon in drinking water and the incidence of cancer using a set of home occupants in Virginia and Maryland. In a subset of people who drink radon-free but chlorinated drinking water from a reservoir, about 3% develop some type of cancer. In a subset of people who drink low-radon water from private water wells, about 3% develop cancer. In a subset who drink high-radon well water, about 6% develop cancer. A comparison with Environmental Protection Agency (EPA) estimates of cancer related to airborne radon indicates that for the general population, the incidence of radon-related cancer from drinking water is similar to the incidence of cancer from inhaled radon. For the 10% of the population that consumes well water and, in particular, for the 5% of the population that consumes high-radon well water, the drinking water carries a considerably higher cancer risk than inhaling airborne radon.

  7. Variable spacial and seasonal hazards of airborne radon

    NASA Astrophysics Data System (ADS)

    Mose, Douglas G.; Mushrush, George W.

    The concentrations of indoor radon in the basements of homes located in northern Virginia average about 1.4 times the first-floor radon concentration. Basement indoor radon concentrations exhibit seasonal variations which can be related to home use patterns of the occupants. Little indoor radon difference was seen between homes that have concrete block basement walls and poured concrete basement walls, but homes that use oil or gas furnaces for heating have a 25% lower indoor radon than homes that use electrical heating systems. Particular geological units seem to be associated with elevated indoor radon concentrations, and several units are associated with indoor radon concentrations that exceed 4 pCi l-1 (the U.S. Environmental Agency "Action Level") in more than 40% of the homes. Comparative studies between indoor radon and total-gamma aeroradioactivity show that aeroradioactivity can be accurately used to estimate community radon hazards.

  8. Comparative survey of outdoor, residential and workplace radon concentrations

    PubMed Central

    Barros, Nirmalla; Field, Dan W.; Steck, Daniel J.; Field, R. William

    2015-01-01

    This study investigated radon concentrations in above-ground (i.e. first floor) workplace in Missouri and compared them with above-ground radon concentrations in nearby homes and outdoor locations. This study also examined the potential utility of using home and outdoor radon concentrations to predict the radon concentration at a nearby workplace (e.g. county agencies and schools). Even though workplace radon concentrations were not statistically different from home radon concentrations, the radon concentration at a particular home, or outdoor location, was a poor predictor of the radon concentration at a nearby workplace. Overall, 9.6 and 9.9 % of homes and workplace, respectively, exhibited radon concentrations of ≥148 Bq m−3. Because of the percentage of workplace with elevated radon concentrations, the results suggest that additional surveys of workplace radon concentrations are needed, especially in areas of high radon potential, to assess the contribution of workplace radon exposure to an individual's overall radon exposure. PMID:24936021

  9. 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

  10. 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)

  11. The Influence of Internal Wall and Floor Covering Materials and Ventilation Type on Indoor Radon and Thoron Levels in Hospitals of Kermanshah, Iran

    PubMed Central

    Pirsaheb, Meghdad; Najafi, Farid; Haghparast, Abbas; Hemati, Lida; Sharafi, Kiomars; Kurd, Nematullah

    2016-01-01

    Background Building materials and the ventilation rate of a building are two main factors influencing indoor radon and thoron levels (two radioactive gases which have the most important role in human natural radiation exposure within dwellings). Objectives This analytical descriptive study was intended to determine the relationship between indoor radon and thoron concentrations and the building materials used in interior surfaces, as well as between those concentrations and the type of ventilation system (natural or artificial). Materials and Methods 102 measurements of radon and thoron levels were taken from different parts of three hospital buildings in the city of Kermanshah in the west of Iran, using an RTM-1688-2 radon meter. Information on the type of building material and ventilation system in the measurement location was collected and then analyzed using Stata 8 software and multivariate linear regression. Results In terms of radon and thoron emissions, travertine and plaster were found to be the most appropriate and inappropriate covering for walls, respectively. Furthermore, granite and travertine were discovered to be inappropriate materials for flooring, while plastic floor covering was found suitable. Natural ventilation performed better for radon, while artificial ventilation worked better for thoron. Conclusions Internal building materials and ventilation type affect indoor radon and thoron concentrations. Therefore, the use of proper materials and adequate ventilation can reduce the potential human exposure to radon and thoron. This is of utmost importance, particularly in buildings with a high density of residents, including hospitals. PMID:28180013

  12. Radon penetration of concrete slab cracks, joints, pipe penetrations, and sealants.

    PubMed

    Nielson, K K; Rogers, V C; Holt, R B; Pugh, T D; Grondzik, W A; de Meijer, R J

    1997-10-01

    Radon movement through 12 test slabs with different cracks, pipe penetrations, cold joints, masonry blocks, sealants, and tensile stresses characterized the importance of these anomalous structural domains. Diffusive and advective radon transport were measured with steady-state air pressure differences controlled throughout the deltaP = 0 to 60 Pa range. Diffusion coefficients (deltaP = 0) initially averaged 6.5 x 10(-8) m2 s(-1) among nine slabs with only 8% standard deviation, but increased due to drying by 0.16% per day over a 2-y period to an average of 2.0 x 10(-7) m2 s(-1). An asphalt coating reduced diffusion sixfold but an acrylic surface sealant had no effect. Diffusion was 42 times higher in solid masonry blocks than in concrete and was not affected by small cracks. Advective transport (deltaP < or = 60 Pa) was negligible for the slabs (10(-16) m2 permeability), pipe penetrations, and caulked gaps, but was significant for cracks, disturbed pipe penetrations, cold joints, masonry blocks, and concrete under tensile stress. Crack areas calculated to be as small as 10(-7) m2 significantly increased radon advection. Algebraic expressions predict air velocity and effective crack width from enhanced radon transport and air pressures. Masonry blocks, open cracks, and slab cold joints enhance radon penetration but stressed slabs, undisturbed pipe penetrations, and sealed cracks may not.

  13. Indications for solar influence on radon signal in the subsurface of Tenerife (Canary Islands, Spain)

    NASA Astrophysics Data System (ADS)

    Steinitz, G.; Martin-Luis, M. C.; Piatibratova, O.

    2015-05-01

    Radon at two locations in Tenerife is investigated. The MM-0 site is located in a bunker near Teide volcano. Daily radon (DR) signals are dominated by a 12-hour (S2) periodicity. Continuous wavelet transform (CWT) analysis of day-time and night-time series results in a day-night differentiation, which does not occur in the coeval temperature and pressure. This indicates that the radon system is directly affected by rotation of Earth around its axis, and not via the pressure and/or temperature pattern. San Fernando sites are in an underground gallery, located at 2.1 and 3 km from the entrance. Alpha and gamma time series show DR signals having an S1 and a strong S2 periodicity. Sidebands occur around the S1 periodicity. The lower sideband is close to 0.9972696 cycles per day (CPD; = sidereal frequency) and the upper sideband at a symmetric frequency above. They reflect a driver containing two waveforms having periodicities of rotation of Earth around its axis and around the Sun that influences radon in a non-linear fashion, leading to the sidebands around the S1 periodicity. Observation in Tenerife of sidebands and day-night phenomena substantiates the notion that the periodic components in the diurnal and annual frequency band of radon time series are due to the influence of a component in solar radiation.

  14. Generation and mobility of radon in soil: Annual technical progress report

    SciTech Connect

    Rose, A.W.

    1988-01-01

    This research program is designed to evaluate the extent and nature of uranium and radium depletion and/or enrichment in soil horizons, as a function of climate and other factors affecting soil character; evaluate the relation of radon emanation coefficient to soil type, soil properties, soil-forming factors and radon levels in soil gas; and evaluate the relation of fragipans, soil mixture and soil permeability to radon concentration and radon flux in soil profiles. During the first year of this project, five soil profiles in central Pennsylvania (3 over limestone/dolomite, 2 over sandstone) were sampled and described and a variety of analysis, including radium and uranium, conducted on the samples, as summarized on table 1. The radon content of soil gas through the profiles was measured at approximately two week intervals throughout the year, so that we now have essentially a year of data. Cores were collected from four soil profiles at a variety of depths and the permeability, diffusion coefficient and emanation coefficient are being measured over a range of moisture contents and temperatures. Selective chemical extractions were used to determine the form of radium and uranium in the soil. 7 refs., 10 figs., 1 tab.

  15. Review of low-energy construction, air tightness, ventilation strategies and indoor radon: results from Finnish houses and apartments.

    PubMed

    Arvela, H; Holmgren, O; Reisbacka, H; Vinha, J

    2014-12-01

    Low-energy and passive house construction practices are characterised by increased insulation, high air tightness of the building shell and controlled mechanical ventilation with heat recovery. As a result of the interaction of mechanical ventilation and high air tightness, the pressure difference in a building can be markedly enhanced. This may lead to elevated indoor radon levels. Minor leakages in the foundation can affect the radon concentration, even in the case where such leaks do not markedly reduce the total air tightness. The potential for high pressures to affect indoor radon concentrations markedly increases when the air tightness ACH50, i.e. the air change per hour induced by a pressure difference of 50 Pa, is <1.0 h(-1). Pressure differences in Finnish low-rise residential houses having mechanical supply and exhaust ventilation with heat recovery (MSEV) are typically 2-3 Pa, clearly lower than the values of 5-9 Pa in houses with only mechanical exhaust ventilation (MEV). In MSEV houses, radon concentrations are typically 30% lower than in MEV houses. In new MSEV houses with an ACH50 of 0.6 h(-1), the limit for passive construction, the analytical estimates predict an increase of 100% in the radon concentration compared with older houses with an ACH50 of 4.0 h(-1). This poses a challenge for efficient radon prevention in new construction. Radon concentrations are typically 30% lower in houses with two storeys compared with only one storey. The introduction of an MSEV ventilation strategy in typically very airtight apartments has markedly reduced pressure differences and radon concentrations.

  16. Influence of a component of solar irradiance on radon signals at 1 km depth, Gran Sasso, Italy

    PubMed Central

    Steinitz, G.; Piatibratova, O.; Gazit-Yaari, N.

    2013-01-01

    Exploratory monitoring of radon is conducted at one location in the deep underground Gran Sasso National Laboratory (LNGS). Measurements (15-min resolution) are performed over a time span of ca 600 days in the air of the surrounding calcareous country rock. Using both α- and γ-ray detectors, systematic and recurring radon signals are recorded. Two primary signal types are determined: (i) non-periodic multi-day (MD) signals lasting 2–10 days and (ii) daily radon (DR) signals—which are of a periodic nature exhibiting a primary 24-h cycle (θ=0.48). The local ancillary environmental conditions (pressure, temperature) seem not to affect radon in air monitored at the site. Long-term patterns of daytime measurements are different from the pattern of night-time measurements indicating a day–night modulation of γ-radiation from radon in air. The phenomenology of the MD and DR signals is similar to situations encountered at other locations where radon is monitored with a high time resolution in geogas at upper crustal levels. In accordance with recent field and experimental results, it is suggested that a component of solar irradiance is affecting the radiation from radon in air, and this influence is further modulated by the diurnal rotation of the Earth. The occurrence of these radon signals in the 1 km deep low-radiation underground geological environment of LNGS provides new information on the time variation of the local radiation environment. The observations and results place the LNGS facility as a high-priority location for performing advanced investigations of these geophysical phenomena. PMID:24204189

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

    PubMed

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

    2014-03-01

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

  18. Clinical data entry.

    PubMed Central

    van Mulligen, E. M.; Stam, H.; van Ginneken, A. M.

    1998-01-01

    Routine capture of patient data for a computer-based patient record system remains a subject of study. Time constraints that require fast data entry and maximal expression power are in favor of free text data entry. However, using patient data directly for decision support systems, for quality assessment, etc. requires structured data entry, which appears to be more tedious and time consuming. In this paper, a prototype clinical data entry application is described that combines free text and structured data entry in one single application and allows clinicians to smoothly switch between these two different input styles. A knowledge base involving a semantic network of clinical data entry terms and their properties and relationships is used by this application to support structured data entry. From structured data, sentences are generated and shown in a text processor together with the free text. This presentation metaphor allows for easy integrated presentation of structured data and free text. Images Figure 1 Figure 2 PMID:9929186

  19. 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.

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

    PubMed

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

    2015-11-23

    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.

  1. 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

  2. Measurement of Radon in Indoor Air.

    ERIC Educational Resources Information Center

    Downey, Daniel M.; Simolunas, Glenn

    1988-01-01

    Describes a laboratory experiment to teach the principles of air sampling, gamma ray spectroscopy, nuclear decay, and radioactive equilibrium. Analyzes radon by carbon adsorption and gamma ray counting. Provides methodology and rate of decay equations. (MVL)

  3. Radon in private drinking water wells.

    PubMed

    Otahal, P; Merta, J; Burian, I

    2014-07-01

    At least 10% of inhabitants in the Czech Republic are supplied with water from private sources (private wells, boreholes). With the increasing cost of water, the number of people using their own sources of drinking water will be likely to increase. According to the Decree of the State Office for Nuclear Safety about the Radiation Protection 307/2002 as amended by Decree 499/2005, the guideline limit for the supplied drinking water ('drinking water for public supply') for radon concentration is 50 Bq·l(-1). This guideline does not apply to private sources of drinking water. Radon in water influences human health by ingestion and also by inhalation when radon is released from water during showering and cooking. This paper presents results of measurements of radon concentrations in water from private wells in more than 300 cases. The gross concentration of alpha-emitting radionuclides and the concentrations of radium and uranium were also determined.

  4. Long term performance of radon mitigation systems

    SciTech Connect

    Prill, R.; Fisk, W.J.

    2002-03-01

    Researchers installed radon mitigation systems in 12 houses in Spokane, Washington and Coeur d'Alene, Idaho during the heating season 1985--1986 and continued to monitor indoor radon quarterly and annually for ten years. The mitigation systems included active sub-slab ventilation, basement over-pressurization, and crawlspace isolation and ventilation. The occupants reported various operational problems with these early mitigation systems. The long-term radon measurements were essential to track the effectiveness of the mitigation systems over time. All 12 homes were visited during the second year of the study, while a second set 5 homes was visited during the fifth year to determine the cause(s) of increased radon in the homes. During these visits, the mitigation systems were inspected and measurements of system performance were made. Maintenance and modifications were performed to improve system performance in these homes.

  5. Radon in earth-sheltered structures

    USGS Publications Warehouse

    Landa, E.R.

    1984-01-01

    Radon concentration in the indoor air of six residential and three non-residential earth-sheltered buildings in eastern Colorado was monitored quarterly over a nine-month period using passive, integrating detectors. Average radon concentrations during the three-month sampling periods ranged from about 1 to 9 pCi/L, although one building, a poorly ventilated storage bunker, had concentrations as high as 39 pCi/L. These radon concentrations are somewhat greater than those typically reported for conventional buildings (around 1 pCi/L); but they are of the same order of magnitude as radon concentrations reported for energy-efficient buildings which are not earth-sheltered. ?? 1984.

  6. Optical detection of radon decay in air

    PubMed Central

    Sand, Johan; Ihantola, Sakari; Peräjärvi, Kari; Toivonen, Harri; Toivonen, Juha

    2016-01-01

    An optical radon detection method is presented. Radon decay is directly measured by observing the secondary radiolumines cence light that alpha particles excite in air, and the selectivity of coincident photon detection is further enhanced with online pulse-shape analysis. The sensitivity of a demonstration device was 6.5 cps/Bq/l and the minimum detectable concentration was 12 Bq/m3 with a 1 h integration time. The presented technique paves the way for optical approaches in rapid radon detec tion, and it can be applied beyond radon to the analysis of any alpha-active sample which can be placed in the measurement chamber. PMID:26867800

  7. Indoor radon in the region of Brussels

    SciTech Connect

    Tondeur, F.; Gerardy, I.; Christiaens, D.; Hallez, S.; Flemal, J.M.

    1999-12-01

    The indoor radon ({sup 222}Rn) concentration has been measured by charcoal detectors in 278 buildings in the region of Brussels, Belgium. The correlation with the nature of the subsoil can be studied in detail thanks to the available geotechnical map. With a geometrical mean indoor radon concentration of 19 Bq m{sup {minus}3}, Brussels can be considered as generally unaffected by the radon problem. No value higher than 400 Bq m{sup {minus}3} (the EU reference level for existing houses) was measured in an occupied room. However, two factors that may enhance the risk are identified: the absence of a basement or a ventilated crawl space, and the presence of loess, under the house. About one third of the houses without basements or ventilated crawl spaces built on loess show an indoor radon concentration above 200 Bq m{sup {minus}3} (the EU reference level for new houses).

  8. Radon Transform and Light-Cone Distributions

    NASA Astrophysics Data System (ADS)

    Teryaev, O. V.

    2016-08-01

    The relevance of Radon transform for generalized and transverse momentum dependent parton distributions is discussed. The new application for conditional (fracture) parton distributions and dihadron fragmentation functions is suggested.

  9. Optical detection of radon decay in air.

    PubMed

    Sand, Johan; Ihantola, Sakari; Peräjärvi, Kari; Toivonen, Harri; Toivonen, Juha

    2016-02-12

    An optical radon detection method is presented. Radon decay is directly measured by observing the secondary radiolumines cence light that alpha particles excite in air, and the selectivity of coincident photon detection is further enhanced with online pulse-shape analysis. The sensitivity of a demonstration device was 6.5 cps/Bq/l and the minimum detectable concentration was 12 Bq/m(3) with a 1 h integration time. The presented technique paves the way for optical approaches in rapid radon detec tion, and it can be applied beyond radon to the analysis of any alpha-active sample which can be placed in the measurement chamber.

  10. Radon reduction and radon-resistant construction demonstrations in New York State

    SciTech Connect

    Not Available

    1991-02-01

    The United States Environmental Protection Agency (EPA) and the New York Energy Research and Development Authority (NYSERDA) cosponsored a project in New York State to demonstrate radon migration techniques in existing homes with elevated radon concentrations and to test radon-resistant construction techniques in new houses. The first part of the existing home evaluation demonstrated radon migration techniques in homes where the indoor radon concentrations exceeded the EPA guidance of 4 pCi/L. Results demonstrated that sealing all accessible foundation penetrations in the basement was an effective way to reduce the radon concentration, although not below the EPA guideline, and that sealing aids in the effectiveness of an active depressurization system. Basement pressurization also proved to be an effective method. Water aeration systems were effective at mitigating radon from residential water supplied although the system tested was large and noisy. Activated charcoal filters adsorbed the radon and eventually became an unacceptable source of gamma radiation. The second part of the existing home evaluation involved the inspection of homes where radon mitigation systems were installed in 1984 as part of an earlier NYSERDA/Niagara Mohawk Power Corporation (NMPC) project. It was found that new systems and techniques, such as in- line centrifugal fans, were generally superior to the earlier method using axial computer-type fans. Polyurethane caulk was found to be in good condition; butyl caulk, on the other hand, had deteriorated. In the new house task, a radon-resistant system was developed for integration into a house during construction. This system included sealing foundation floors, sealing concrete block foundation walls, and passive sub-slab ventilation. This integrated system reduced the radon concentration in new test houses below that of control houses, but the reduction was not usually sufficient to meet the EPA guideline.

  11. Indoor radon and lung cancer in China.

    PubMed

    Blot, W J; Xu, Z Y; Boice, J D; Zhao, D Z; Stone, B J; Sun, J; Jing, L B; Fraumeni, J F

    1990-06-20

    Radon has long been known to contribute to risk of lung cancer, especially in undergound miners who are exposed to large amounts of the carcinogen. Recently, however, lower amounts of radon present in living areas have been suggested as an important cause of lung cancer. In an effort to clarify the relationship of low amounts of radon with lung cancer risk, we placed alpha-track radon detectors in the homes of 308 women with newly diagnosed lung cancer and 356 randomly selected female control subjects of similar age. Measurements were taken after 1 year. All study participants were part of the general population of Shenyang, People's Republic of China, an industrial city in the northeast part of the country that has one of the world's highest rates of lung cancer in women. The median time of residence in the homes was 24 years. The median household radon level was 2.3 pCi/L of air; 20% of the levels were greater than 4 pCi/L. Radon levels tended to be higher in single-story houses or on the first floor of multiple-story dwellings, and they were also higher in houses with increased levels of indoor air pollution from coal-burning stoves. However, the levels were not higher in homes of women who developed lung cancer than in homes of controls, nor did lung cancer risk increase with increasing radon level. No association between radon and lung cancer was observed regardless of cigarette-smoking status, except for a nonsignificant trend among heavy smokers. No positive associations of lung cancer cell type with radon were observed, except for a nonsignificant excess risk of small cell cancers among the more heavily exposed residents. Our data suggest that projections from surveys of miners exposed to high radon levels may have overestimated the overall risks of lung cancer associated with levels typically seen in homes in this Chinese city. However, further studies in other population groups are needed to clarify the carcinogenic potential of indoor radon.

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

    PubMed

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

    2015-02-01

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

  13. 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.

  14. A model for indoor radon variations

    SciTech Connect

    Arvela, H.; Winqvist, K. )

    1989-01-01

    The model relates radon concentration to variations in source strength, air exchange rate, and meteorological factors. The diffusion source represents radon diffused from building materials or from soil. The pressure-difference driven flow represents radon flowing with soil pore air and driven by the stack effect. In a house with diffusion source, the radon concentration decreases when the air exchange rate increases due to increasing temperature differences, whereas the flow source causes an increasing concentration. This is due to the fact that the effect of the source strength increase is stronger than the decreasing effect of air exchange of concentration. The winter-summer concentration ratio depends on the combination of the two types of source. A pure pressure-difference driven flow gives a winter-summer ratio of 2-3 (winter -5{degree}C, summer +15{degree}C, wind speed 3 m/s). A strong contribution of a diffusion source is needed to cause a summer concentration higher than the winter concentration. The model is in agreement with the winter-summer concentration ratios measured. This ratio increases with the increasing winter concentration. The results indicate that radon concentration must be taken into account in analyses of seasonal variations of indoor radon. In houses with a diffusion source, the diurnal maximum occurs in the afternoon; in houses with a pressure-difference driven flow, the maximum is reached in the early morning.

  15. Indoor radon concentrations in Taiwanese homes

    SciTech Connect

    Hung, I.F.; Yu, C.C.; Tung, C.J. ); Yang, Y.C.; Chou, K.D. )

    1994-10-01

    Many air pollutants may be present in the indoor environment. Commonly reported pollutants are carbon monoxide, nitrogen dioxide, volatile organic compounds, radon and its progeny, asbestos fibers and airborne particles. Among these indoor pollutants, radon and its progeny have been known to increase the risk of lung cancer in the U.S. Various studies also found in general higher concentrations of air pollutants in the indoor environment. It is a serious concern to us because of the long periods of time we spend indoors. In this study, the alpha-track radon monitor was used in the screening of higher risk buildings in Taipei and Hsinchu city. None of the homes in the 32 buildings surveyed in these cities had air concentrations of radon exceeding the action level of 4 pCi/l recommended by the U.S. Environmental Protection Agency. Different sources to indoor radon concentrations are the underlying soil, building materials, outdoor air, water and gaseous fuels. Ventilation of the homes and seasonal variations are major factors of higher radon concentrations. 16 refs., 2 figs., 3 tabs.

  16. Determination of air-loop volume and radon partition coefficient for measuring radon in water sample.

    PubMed

    Lee, Kil Yong; Burnett, William C

    A simple method for the direct determination of the air-loop volume in a RAD7 system as well as the radon partition coefficient was developed allowing for an accurate measurement of the radon activity in any type of water. The air-loop volume may be measured directly using an external radon source and an empty bottle with a precisely measured volume. The partition coefficient and activity of radon in the water sample may then be determined via the RAD7 using the determined air-loop volume. Activity ratios instead of absolute activities were used to measure the air-loop volume and the radon partition coefficient. In order to verify this approach, we measured the radon partition coefficient in deionized water in the temperature range of 10-30 °C and compared the values to those calculated from the well-known Weigel equation. The results were within 5 % variance throughout the temperature range. We also applied the approach for measurement of the radon partition coefficient in synthetic saline water (0-75 ppt salinity) as well as tap water. The radon activity of the tap water sample was determined by this method as well as the standard RAD-H2O and BigBottle RAD-H2O. The results have shown good agreement between this method and the standard methods.

  17. RADON REDUCTION AND RADON-RESISTANT CONSTRUCTION DEMONSTRATIONS IN NEW YORK - VOLUME 2: APPENDICES

    EPA Science Inventory

    Growing concern about health risks associated with exposure to indoor radon, a radioactive gas found in varying amounts in nearly all houses, has underscored the need for dependable radon reduction methods in existing and newly constructed houses. Responding to this need, the U....

  18. Radon and thoron levels, their spatial and seasonal variations in adobe dwellings - a case study at the great Hungarian plain.

    PubMed

    Szabó, Zsuzsanna; Jordan, Gyozo; Szabó, Csaba; Horváth, Ákos; Holm, Óskar; Kocsy, Gábor; Csige, István; Szabó, Péter; Homoki, Zsolt

    2014-06-01

    Radon and thoron isotopes are responsible for approximately half of the average annual effective dose to humans. Although the half-life of thoron is short, it can potentially enter indoor air from adobe walls. Adobe was a traditional construction material in the Great Hungarian Plain. Its major raw materials are the alluvial sediments of the area. Here, seasonal radon and thoron activity concentrations were measured in 53 adobe dwellings in 7 settlements by pairs of etched track detectors. The results show that the annual average radon and thoron activity concentrations are elevated in these dwellings and that the proportions with values higher than 300 Bq m(-3) are 14-17 and 29-32% for radon and thoron, respectively. The calculated radon inhalation dose is significantly higher than the world average value, exceeding 10 mSv y(-1) in 7% of the dwellings of this study. Thoron also can be a significant contributor to the inhalation dose with about 30% in the total inhalation dose. The changes of weather conditions seem to be more relevant in the variation of measurement results than the differences in the local sedimentary geology. Still, the highest values were detected on clay. Through the year, radon follows the average temperature changes and is affected by the ventilation, whereas thoron rather seems to follow the amount of precipitation.

  19. A COMPARATIVE STUDY OF RADIUM CONTENT AND RADON EXHALATION RATE FROM SOIL SAMPLES USING ACTIVE AND PASSIVE TECHNIQUES.

    PubMed

    Yadav, Manjulata; Prasad, Mukesh; Joshi, Veena; Gusain, G S; Ramola, R C

    2016-10-01

    Soil is the most important factor affecting the radon level in the human living environments. It depends not only on uranium and thorium contents but also on the physical and chemical properties of the soil. In this paper, the measurements of radium content and mass exhalation rate of radon from the soil samples collected from Uttarkashi area of Garhwal Himalaya are presented. The correlation between radium content and radon mass exhalation rate from soil has also been obtained. The radium was measured by gamma ray spectrometry, while the mass exhalation rate of radon has been determined by both active and passive methods. The radium activity in the soil of study area was found to vary from 45±7 to 285±29 Bq kg(-1) with an average of 99 Bq kg(-1) The radon mass exhalation rate was found to vary from 0.59 × 10(-5) to 2.2 × 10(-5) Bq kg(-1) h(-1) with an average of 1.4 × 10(-5) Bq kg(-1) h(-1) by passive technique and from 0.8 × 10(-5) to 3.2 × 10(-5) Bq kg(-1) h(-1) with an average of 1.5 × 10(-5) Bq kg(-1) h(-1) by active technique. The results suggest that the measured radium value is positively correlated with the radon mass exhalation rate measured with both the active and passive techniques.

  20. Use of linear regression models to determine influence factors on the concentration levels of radon in occupied houses

    NASA Astrophysics Data System (ADS)

    Buermeyer, Jonas; Gundlach, Matthias; Grund, Anna-Lisa; Grimm, Volker; Spizyn, Alexander; Breckow, Joachim

    2016-09-01

    This work is part of the analysis of the effects of constructional energy-saving measures to radon concentration levels in dwellings performed on behalf of the German Federal Office for Radiation Protection. In parallel to radon measurements for five buildings, both meteorological data outside the buildings and the indoor climate factors were recorded. In order to access effects of inhabited buildings, the amount of carbon dioxide (CO2) was measured. For a statistical linear regression model, the data of one object was chosen as an example. Three dummy variables were extracted from the process of the CO2 concentration to provide information on the usage and ventilation of the room. The analysis revealed a highly autoregressive model for the radon concentration with additional influence by the natural environmental factors. The autoregression implies a strong dependency on a radon source since it reflects a backward dependency in time. At this point of the investigation, it cannot be determined whether the influence by outside factors affects the source of radon or the habitant’s ventilation behavior resulting in variation of the occurring concentration levels. In any case, the regression analysis might provide further information that would help to distinguish these effects. In the next step, the influence factors will be weighted according to their impact on the concentration levels. This might lead to a model that enables the prediction of radon concentration levels based on the measurement of CO2 in combination with environmental parameters, as well as the development of advices for ventilation.

  1. Increasing the accuracy and temporal resolution of two-filter radon-222 measurements by correcting for the instrument response

    NASA Astrophysics Data System (ADS)

    Griffiths, Alan D.; Chambers, Scott D.; Williams, Alastair G.; Werczynski, Sylvester

    2016-06-01

    Dual-flow-loop two-filter radon detectors have a slow time response, which can affect the interpretation of their output when making continuous observations of near-surface atmospheric radon concentrations. While concentrations are routinely reported hourly, a calibrated model of detector performance shows that ˜ 40 % of the signal arrives more than an hour after a radon pulse is delivered. After investigating several possible ways to correct for the detector's slow time response, we show that a Bayesian approach using a Markov chain Monte Carlo sampler is an effective method. After deconvolution, the detector's output is redistributed into the appropriate counting interval and a 10 min temporal resolution can be achieved under test conditions when the radon concentration is controlled. In the case of existing archived observations, collected under less ideal conditions, the data can be retrospectively reprocessed at 30 min resolution. In one case study, we demonstrate that a deconvolved radon time series was consistent with the following: measurements from a fast-response carbon dioxide monitor; grab samples from an aircraft; and a simple mixing height model. In another case study, during a period of stable nights and days with well-developed convective boundary layers, a bias of 18 % in the mean daily minimum radon concentration was eliminated by correcting for the instrument response.

  2. Identifying tropospheric baseline air masses at Mauna Loa Observatory between 2004 and 2010 using Radon-222 and back trajectories

    NASA Astrophysics Data System (ADS)

    Chambers, Scott D.; Zahorowski, Wlodek; Williams, Alastair G.; Crawford, Jagoda; Griffiths, Alan D.

    2013-01-01

    We use 7 years of hourly radon observations at Mauna Loa Observatory (MLO), together with 10-day back trajectories, to identify baseline air masses at the station. The amplitude of the annual MLO radon cycle, based on monthly means, was 98 mBq m-3 (39 -137 mBq m-3), with maximum values in February (90th percentile 330 mBq m-3) and minimum values in August (10th percentile 8.1 mBq m-3). The composite diurnal radon cycle (amplitude 49 mBq m-3) is discussed with reference to the influences of local flow features affecting the site, and a 3-hour diurnal sampling window (0730-1030 HST) is proposed for observing the least terrestrially influenced tropospheric air masses. A set of 763 baseline events is selected, using the proposed sampling window together with trajectory information, and presented along with measured radon concentrations as a supplement. This data set represents a resource for the selection of baseline events at MLO for use with a range of trace species. A reduced set of 196 "deep baseline" events occurring in the July-September window is also presented and discussed. The distribution (10th/50th/90th percentile) of radon in deep-baseline events (8.7/29.2/66.1 mBq m-3) was considerably lower than that for the overall set of 763 baseline events (12.3/40.8/104.1 mBq m-3). Results from a simple budget calculation, using sonde-derived mixing depths and literature-based estimates of oceanic radon flux and radon concentrations in the marine boundary layer, indicate that the main source of residual radon in the lower troposphere under baseline conditions at MLO is downward mixing from aged terrestrial air masses in the upper troposphere.

  3. Maps of Lunar Radon-222 and Polonium-210

    NASA Astrophysics Data System (ADS)

    Lawson, S. L.; Feldman, W. C.; Lawrence, D. J.; Moore, K. R.; Maurice, S.; Belian, R. D.; Binder, A. B.

    2002-03-01

    The LP Alpha Particle Spectrometer radon-222 map indicates that radon gas is presently emanating from the vicinity of craters Aristarchus and Kepler. The polonium-210 map indicates a variability in time and space of lunar gas release events.

  4. Radon remediation and prevention status in 23 European countries.

    PubMed

    Holmgren, O; Arvela, H; Collignan, B; Jiránek, M; Ringer, W

    2013-12-01

    Radon remediation and prevention aim at reducing indoor radon concentrations in the existing and new buildings. This paper gives an estimate of the number of dwellings where remediation or preventive measures have been applied so far in Europe. Questionnaires were sent to contact persons in national radiation protection authorities and radon-related research institutes. Answers from 23 European countries were obtained. Approximately 26 000 dwellings have been remediated in total. Millions of dwellings remain to be remediated and the number is increasing due to the rare use of radon prevention. These facts imply a need for an efficient radon strategy to promote radon remediation. Moreover, the importance of radon prevention in new construction and the regulations concerning radon in the national building codes should be emphasised.

  5. Wound-healing error model for radon carcinogenesis

    SciTech Connect

    Kondo, Sohei

    1995-12-31

    Epidemiological studies of lung cancer in uranium miners exposed to radon suggest that radon is a tumor promoter. I will refine this notion by applying the wound-healing error model proposed for radiation carcinogenesis in general.

  6. 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.

  7. Investigations of enhanced outdoor radon concentration in Johanngeorgenstadt (Saxony).

    PubMed

    Dushe, C; Kümmel, M; Schulz, H

    2003-05-01

    Since the beginning of the nineties, the German Federal Office for Radiation Protection (Bundesamt für Strahlenschutz, BfS) has performed extensive measurements of long-term radon concentration in areas influenced by mining. In the region of Johanngeorgenstadt (Saxony) enhanced long-term radon concentrations were measured in the surrounding area of a waste rock pile. To find the explanation for the enhanced radon concentrations both short- and long-term investigations of radon exhalation were performed. To gain information about the local distribution of the radon level, the radon concentrations were measured at a height of 15 cm above ground level. The radon exhalation rate was continuously measured at the toe and the plateau of the waste rock pile. It has been found that radon is extensively released through both diurnal and pronounced seasonal variations. The exhalation pattern is governed by convection processes triggered by the temperature gradient between the waste rock pile and the atmosphere.

  8. Entry at Venus

    NASA Technical Reports Server (NTRS)

    Venkatapathy, Ethiraj; Smith, Brandon

    2016-01-01

    This is lecture to be given at the IPPW 2016, as part of the 2 day course on Short Course on Destination Venus: Science, Technology and Mission Architectures. The attached presentation material is intended to be introduction to entry aspects of Venus in-situ robotic missions. The presentation introduces the audience to the aerodynamic and aerothermodynamic aspects as well as the loads, both aero and thermal, generated during entry. The course touches upon the system design aspects such as TPS design and both high and low ballistic coefficient entry system concepts that allow the science payload to be protected from the extreme entry environment and yet meet the mission objectives.

  9. Radon

    MedlinePlus

    ... Some PDF files may be electronic conversions from paper copy or other electronic ASCII text files. This ... format errors. Users are referred to the original paper copy of the toxicological profile for the official ...

  10. Radon

    MedlinePlus

    ... title + citystate + eventdate + ' '; } else if (sublist.indexOf(row.cat) > -1 && row.cat.length > 0){ html = ' ' + row.title + citystate + eventdate + ' '; } else { ... title + citystate + eventdate + ' '; } else if (sublist.indexOf(row.cat) > -1 && row.cat.length > 0){ html = ' ' + row.title + ...

  11. Seasonal Variability in European Radon Measurements

    NASA Astrophysics Data System (ADS)

    Groves-Kirkby, C. J.; Denman, A. R.; Phillips, P. S.; Crockett, R. G. M.; Sinclair, J. M.

    2009-04-01

    In temperate climates, domestic radon concentration levels are generally seasonally dependent, the level in the home reflecting the convolution of two time-dependent functions. These are the source soil-gas radon concentration itself, and the principal force driving radon into the building from the soil, namely the pressure-difference between interior and exterior environment. While the meteorological influence can be regarded as relatively uniform on a European scale, its variability being defined largely by the influence of North-Atlantic weather systems, soil-gas radon is generally more variable as it is essentially geologically dependent. Seasonal variability of domestic radon concentration can therefore be expected to exhibit geographical variability, as is indeed the case. To compensate for the variability of domestic radon levels when assessing the long term radon health risks, the results of individual short-term measurements are generally converted to equivalent mean annual levels by application of a Seasonal Correction Factor (SCF). This is a multiplying factor, typically derived from measurements of a large number of homes, applied to the measured short-term radon concentration to provide a meaningful annual mean concentration for dose-estimation purposes. Following concern as to the universal applicability of a single SCF set, detailed studies in both the UK and France have reported location-specific SCF sets for different regions of each country. Further results indicate that SCFs applicable to the UK differ significantly from those applicable elsewhere in Europe and North America in both amplitude and phase, supporting the thesis that seasonal variability in indoor radon concentration cannot realistically be compensated for by a single national or international SCF scheme. Published data characterising the seasonal variability of European national domestic radon concentrations, has been collated and analysed, with the objective of identifying

  12. Shallow circulation groundwater - the main type of water containing hazardous radon concentration

    NASA Astrophysics Data System (ADS)

    Przylibski, Tadeusz

    2010-05-01

    surface water forming a stream, radon very quickly escapes to the atmosphere. This is the main reason, that even in regions, where the bottoms of streams and rivers are formed by the rocks containing high amounts of radium (and uranium), surface waters very quickly lose radon escaping to the atmosphere. Concluding, surface waters cannot be the source of hazardous radon concentration. One may expect completely different situation in the case of groundwater. When the groundwater is exploited without any contact with the atmosphere, it contains higher concentration of Rn-222, than surface water in the same neighbourhood with regard to geological structure. Concentration of radon dissolved in groundwater depends first of all on the emanation coefficient of the reservoir rock. This coefficient may be calculated taking into account a few parameters, like cancentration of parent Ra-226 isotope in the reservoir rocks, effective porosity of the rock and the density of the grain framework of the rock. The way of radium atoms disposition in crystals or mineral grains of rock with reference to the pores and cracks filled with groundwater is also an important parameter. Calculations made by the author for more than 100 intakes of groundwater proove, that the highest values of emanation coefficient are characteristic for the rocks in the weathering zone - on the depths between surface level and 30 - 50 m below surface level. Groundwater exploited from the rocks of this zone contains the highest concentration of Rn-222. On the greater depths even high Ra-226 content in the reservoir rock does not affect to the Rn-222 concentration in groundwater flowing through this rock. Summing up, potentially the great radon concentration may contain groundwater of shallow circulation (up to ~50 m b.s.l.), flowing through weathered resrvoir rock with high content of parent Ra-226 isotope.

  13. Variations of Radon Risk with Changing Mortality Rates

    NASA Astrophysics Data System (ADS)

    Chen, Jing

    2008-08-01

    This study examines the variation of radon risks with changing mortality rates. The Canadian age-specific mortality rates averaged over five year periods from 1986 to 1990 and from 1996 to 2000 were used in the risk calculations. Because of the synergistic interaction between smoking and radon, the risk of radon induced lung cancer for Canadian men decreased with the declining lung cancer mortality rates while for Canadian women the radon risks increased with the rising lung cancer mortality rates

  14. Variations of Radon Risk with Changing Mortality Rates

    SciTech Connect

    Chen Jing

    2008-08-07

    This study examines the variation of radon risks with changing mortality rates. The Canadian age-specific mortality rates averaged over five year periods from 1986 to 1990 and from 1996 to 2000 were used in the risk calculations. Because of the synergistic interaction between smoking and radon, the risk of radon induced lung cancer for Canadian men decreased with the declining lung cancer mortality rates while for Canadian women the radon risks increased with the rising lung cancer mortality rates.

  15. A Calibration and Quality Assurance Program for Environmental Radon Measurements

    PubMed Central

    Fisenne, Isabel M.; George, Andreas C.; Keller, Helen W.

    1990-01-01

    The ideal facility for assessing the quality of radon measurements at environmental levels consists of: (1) an instrument whose response to radon and its progeny is determined from measurements of a certified or standard 226Ra source, and (2) a calibration room with a known radon concentration. The linkage between these two elements and additional quality control requirements are discussed here for some Environmental Measurements Laboratory radon measurements programs. PMID:28179764

  16. 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

  17. Detection of radon decay products in rainwater

    SciTech Connect

    Baker, S.I.

    1999-11-01

    The Argonne National Laboratory-East (ANL-E) Environmental Radiation Monitoring System measures and records ambient radiation levels and provides detection capability for radon decay products in rain clouds. These decay products in rainwater tracked into a facility on the shoes of workers can cause false alarms from hand and shoe monitors. The monitors at ANL-E can easily detect the radon decay products, and the 19.6 and 26.8 min half-lives of the beta-particle emitters are long enough in many cases for sufficient activity to still be present to initiate a contamination alarm when the shoes are checked for radioactivity. The Environmental Radiation Monitoring System provides a warning when precipitation contains elevated levels of radon decay products. It is based on a prototype developed at the Super Collider Laboratory, During its first year of operation there were nine alarms from radon decay products with an alarm trigger point set at 30% greater than background. The alarms occurred at both monitoring stations, which are approximately 1,000 m apart, indicating large diameter radon clouds. The increases in background were associated with low atmospheric pressure. There was no correlation with radon released from the coal-burning steam plant on the site. Alarms also occurred when short-lived accelerator-produced radioactivity in the exhaust stack plume passed over the NaI(TI) detector in one of the stations. The 450 MeV proton accelerator near the station produced {sup 12}C, {sup 13}N, and {sup 15}O by spallation of air nuclei. The gamma-ray spectrum from the plume from the accelerator exhaust stack was dominated by the 511 keV annihilation gamma rays from decay of these radionuclides. These gamma rays were easily distinguished from the 609 keV, 1,120 keV, and 1,764 keV gamma rays emitted by the radon decay products.

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

    NASA Astrophysics Data System (ADS)

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

    2008-08-01

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

  19. 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... 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....

  20. Outdoor Radon--Sources, Monitoring and Risk Assessment

    SciTech Connect

    Bulko, M.; Holy, K.; Mullerova, M.; Simon, J.

    2007-11-26

    Various sources of atmospheric radon, as well as the results of radon monitoring at the Faculty of Mathematics, Physics and Informatics (FMFI CU) campus are discussed. The evaluation of the risk caused by radon and its decay products in the Bratislava atmosphere is given.

  1. 40 CFR 700.41 - Radon user fees.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Radon user fees. 700.41 Section 700.41 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT GENERAL Fees § 700.41 Radon user fees. User fees relating to radon proficiency programs authorized under...

  2. 40 CFR 700.41 - Radon user fees.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Radon user fees. 700.41 Section 700.41 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT GENERAL Fees § 700.41 Radon user fees. User fees relating to radon proficiency programs authorized under...

  3. 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....

  4. 40 CFR 700.41 - Radon user fees.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Radon user fees. 700.41 Section 700.41 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT GENERAL Fees § 700.41 Radon user fees. User fees relating to radon proficiency programs authorized under...

  5. 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....

  6. RESOLVING THE RADON PROBLEM IN CLINTON, NEW JERSEY HOUSES

    EPA Science Inventory

    The paper discusses the resolution of a radon problem in Clinton, New Jersey, where significantly elevated radon concentrations were found in several adjacent houses. The U.S. EPA screened 56 of the houses and selected 10 for demonstration of radon reduction techniques. Each of t...

  7. 40 CFR 700.41 - Radon user fees.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Radon user fees. 700.41 Section 700.41 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT GENERAL Fees § 700.41 Radon user fees. User fees relating to radon proficiency programs authorized under...

  8. 30 CFR 57.5037 - Radon daughter exposure monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 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....

  9. Radon Q & A. What You Need to Know.

    ERIC Educational Resources Information Center

    Bayham, Chris

    1994-01-01

    Because radon is the second leading cause of lung cancer in this country, the article presents a question and answer sheet on where radon comes from, which buildings are most likely to have radon, how to tell whether there is a problem, and expenses involved in testing and fixing problems. (SM)

  10. 40 CFR 700.41 - Radon user fees.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Radon user fees. 700.41 Section 700.41 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT GENERAL Fees § 700.41 Radon user fees. User fees relating to radon proficiency programs authorized under...

  11. 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....

  12. Comparison study and thoron interference test of different radon monitors.

    PubMed

    Sumesh, C G; Kumar, A Vinod; Tripathi, R M; Puranik, V D

    2013-03-01

    A comparison study and thoron interference test for different continuous radon monitors were carried out. The comparison study includes three passive diffusion monitors [one pulse ionisation chamber based-Alpha Guard and two silicon semi-conductor based-Radon Scout Plus (RSP)] and one silicon semi-conductor-based active radon thoron discriminating monitor--RAD 7. Radon emanation standard, supplied by National Institute of Science and Technology, has been utilised for the comparison study to qualify the calibration of the continuous radon monitors. All the instruments showed good agreement with the estimated radon concentration using (226)Ra/(222)Rn emanation standard. It was found that the active radon monitoring system is having a higher initial response towards the transient radon concentration than the passive radon monitors studied. The instruments measuring radon concentration without energy discrimination are likely to have some sensitivity towards the thoron concentration. Thus, thoron interference study was carried out in the above monitors. Nine percent interference in measured radon concentration in the Alpha Guard monitor and 4 % interference in the semi-conductor-based RSP monitors was observed. Study indicates that the interference of thoron in radon monitors depends on the area of diffusion of gas, volume of detection and sensitivity factor.

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

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  14. Stardust Entry Reconstruction

    NASA Technical Reports Server (NTRS)

    Desai, Prasun N.; Qualls, Garry D.

    2008-01-01

    An overview of the reconstruction analyses performed for the Stardust capsule entry is described. The results indicate that the actual entry was very close to the pre-entry predictions. The capsule landed 8.1 km north-northwest of the desired target at Utah Test and Training Range. Analyses of infrared video footage and radar range data (obtained from tracking stations) during the descent show that drogue parachute deployment was 4.8 s later than the pre-entry prediction, while main parachute deployment was 19.3 s earlier than the pre-set timer indicating that main deployment was actually triggered by the backup baroswitch. Reconstruction of a best estimated trajectory revealed that the aerodynamic drag experienced by the capsule during hypersonic flight was within 1% of pre-entry predications. Observations of the heatshield support the pre-entry estimates of small hypersonic angles of attack, since there was very little, if any, charring of the shoulder region or the aftbody. Through this investigation, an overall assertion can be made that all the data gathered from the Stardust capsule entry were consistent with flight performance close to nominal pre-entry predictions. Consequently, the design principles and methodologies utilized for the flight dynamics, aerodynamics, and aerothermodynamics analyses have been corroborated.

  15. Mineral dusts and radon in uranium mines

    SciTech Connect

    Abelson, P.H.

    1991-11-08

    The Environmental Protection Agency (EPA) continues to assert that radon is a major cause of lung cancer in this country. EPA is fostering a radon program that could entail huge financial and emotional costs while yielding negligible benefits to public health. Justification for the program was the occurrence of lung cancer in men exposed to huge amounts of radon, mineral dusts, and other lung irritants in uranium mines on the Colorado Plateau. Lung cancer has been reported in about 356 cigarette smokers and in about 25 nonsmokers. During the era of high radon levels, monitoring was sporadic. Conditions in only a small fraction of the mines were measured, and that on a few separate occasions. Later, cumulative exposure to radon was calculated on the basis of measurements involving only a tiny fraction of the miners. Some were exposed to more than 15,000 pCi/liter of radon and its products. The level in the average home is about 1.5 pCi/liter. In making extrapolations from mine to home, the assumption is made that residents are in their dwellings most of the time and that miners spend only 170 hours a month in the mine. Two major questionable assumptions are involved in extrapolations from high doses of radon in the mines to low doses in homes. One is that no threshold is involved; that is, that humans have no remediation mechanism for {alpha} particle damages. There is evidence to the contrary. The most unrealistic assumption is that heavy exposure to silica has no effect on inducing lung cancer. Many studies have shown that silica dust causes lung cancer in animals. Exposure of human culture cells to silica has resulted in formation of neoplastic tissue. EPA has no solid evidence that exposures to 4 pCi/liter of radon causes lung cancer in either smokers or nonsmokers. Indeed, there is abundant evidence to the contrary in the fact that in states with high levels of radon, inhabitants have less lung cancer than those in states with low levels.

  16. Radon exhalation rates from building materials using electret ion chamber radon monitors in accumulators.

    PubMed

    Kotrappa, Payasada; Stieff, Frederick

    2009-08-01

    An electret ion chamber (EIC) radon monitor in a sealed accumulator measures the integrated average radon concentration at the end of the accumulation duration. Theoretical equations have been derived to relate such radon concentrations (Bq m(-3) ) to the radon emanation rate (Bq d(-1)) from building materials enclosed in the accumulator. As an illustration, a 4-L sealable glass jar has been used as an accumulator to calculate the radon emanation rate from different granite samples. The radon emanation rate was converted into radon flux (Bq mm(-2) d(-1)) by dividing the emanation rate by surface area of the sample. Fluxes measured on typical, commercially available granites ranged from 20-30 Bq m(-2) d(-1). These results are similar to the results reported in the literature. The lower limit of detection for a 2-d measurement works out to be 7 Bq m(-2) d(-1). Equations derived can also be used for other sealable accumulators and other integrating detectors, such as alpha track detectors.

  17. Radon measurements with a PIN photodiode.

    PubMed

    Martín-Martín, A; Gutiérrez-Villanueva, J L; Muñoz, J M; García-Talavera, M; Adamiec, G; Iñiguez, M P

    2006-01-01

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

  18. 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.

  19. 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.

  20. Radon-immune air monitor for plutonium

    SciTech Connect

    Gupton, E.D.

    1982-08-01

    The gross alpha activity in particulate-associated daughters of radon in the work environments may be many times that of one MPC/sub a/ of /sup 239/Pu or /sup 238/Pu. The daughters of radon emit both alpha and beta particles. The ratio of the alpha-to-beta activity is variable and a function of several factors. In spite of this variability, the ratio changes slowly with time and has upper and lower bounds in buildings that have controlled ventilation. This provides the basis for the development of an air monitor in which the radon interference is virtually eliminated. The radon-immune air monitor has three detectors: one that detects the alpha activity on the filter, one that detects the beta activity on the filter plus gamma background, and one that observes gamma background. The counts from these detectors are fed to a computer that is programmed with an algorithm for computing the non-radon-associated alpha activity.

  1. Radon in soil gas in Kosovo.

    PubMed

    Kikaj, Dafina; Jeran, Zvonka; Bahtijari, Meleq; Stegnar, Peter

    2016-11-01

    An assessment of the radiological situation due to exposure to radon and gamma emitting radionuclides was conducted in southern Kosovo. This study deals with sources of radon in soil gas. A long-term study of radon concentrations in the soil gas was carried out using the SSNTDs (CR-39) at 21 different locations in the Sharr-Korabi zone. The detectors were exposed for an extended period of time, including at least three seasonal periods in a year and the sampling locations were chosen with respect to lithology. In order to determine the concentration of the natural radioactive elements (238)U and (226)Ra, as a precursor of (222)Rn, soil samples were collected from each measuring point from a depth of 0.8 m, and measured by gamma spectrometry. The levels (Bq kg(-1)) of naturally occurring radionuclides and levels (kBq m(-3)) of radon in soil gas obtained at a depth 0.8 m of soil were: 21-53 for (226)Ra, 22-160 for (238)U and 0.295-32 for (222)Rn. With respect to lithology, the highest value for (238)U and (226)Ra were found in limestone and the highest value for (222)Rn was found in metamorphic rocks. In addition, the results showed seasonal variations of the measured soil gas radon concentrations with maximum concentration in the spring months.

  2. 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

  3. Standardised Radon Index: a normalisation of radon data-sets in terms of standard normal variables.

    NASA Astrophysics Data System (ADS)

    Crockett, Robin; Holt, Christopher

    2010-05-01

    There is an increasing body of evidence which indicates that radon emissions from rocks, soils and groundater can provide a diagnostic tool for some geophysical phenomena, e.g. tidal deformations and earthquakes. In this context, it is often informative to compare two radon data-sets, e.g. variations in radon concentrations in different locations. However, this can be complicated, e.g. by the use of different detectors, radon concentrations being orders of magnitude different or different non-linear responses of radon emissions to common or similar stimuli. Some of these factors can be taken into account by moving-averages and other de-noising techniques and normalisation of data sets to, e.g. unit mean. However, such techniques do not address different non-linearities. We propose a Standardised Radon Index (SRI), an adaptation of Standardised Precipitation Index (SPI) methodologies under development at the University of Northampton to radon-data. SPIs were first proposed by McKee et al. in 1993, and can be summarised as a normalisation of precipitation data in terms of standard normal random variables. In effect, variations in the data are presented in terms of probabilities thereby revealing periods of relative drought or anti-drought and the same SPI in different data-sets represents the same relative drought/anti-drought across different precipitation regimes. In the case of radon, this normalisation in terms of standard normal variables allows variations in different data-sets to be compared in terms of probability of occurrence: if two different non-linear radon responses to some stimulus are equally probable, this is revealed directly by the SRIs. This facilitates some types of analysis and comparison, and initial results will be presented.

  4. Modulation of the peripheral immune system after low-dose radon spa therapy: Detailed longitudinal immune monitoring of patients within the RAD-ON01 study.

    PubMed

    Rühle, Paul F; Wunderlich, Roland; Deloch, Lisa; Fournier, Claudia; Maier, Andreas; Klein, Gerhart; Fietkau, Rainer; Gaipl, Udo S; Frey, Benjamin

    2017-03-01

    The pain-relieving effects of low-dose radon therapies on patients suffering from chronic painful inflammatory diseases have been described for centuries. Even though it has been suggested that low doses of radiation may attenuate chronic inflammation, the underlying mechanisms remain elusive. Thus, the RAD-ON01 study was initiated to examine the effects of radon spa therapy and its low doses of alpha radiation on the human immune system. In addition to an evaluation of pain parameters, blood was drawn from 100 patients suffering from chronic painful degenerative musculoskeletal diseases before as well as 6, 12, 18, and 30 weeks after the start of therapy. We verified significant long-term pain reduction for the majority of patients which was accompanied by modulations of the peripheral immune cells. Detailed immune monitoring was performed using a multicolor flow cytometry-based whole blood assay. After therapy, the major immune cells were only marginally affected. Nevertheless, a small but long-lasting increase in T cells and monocytes was observed. Moreover, neutrophils, eosinophils and, in particular, dendritic cells were temporarily modulated after therapy. Regarding the immune cell subsets, cytotoxic T and NK cells, in particular, were altered. However, the most prominent effects were identified in a strong reduction of the activation marker CD69 on T, B, and NK cells. Simultaneously, the percentage of HLA-DR(+) T cells was elevated after therapy. The RAD-ON01 study showed for the first time a modulation of the peripheral immune cells following standard radon spa therapy. These modulations are in line with attenuation of inflammation.

  5. Multagenicity of radon and radon daughters. Final technical report, January 1, 1993--December 31, 1996

    SciTech Connect

    Evans, H.H.

    1997-06-01

    The objective of this research was to investigate the dose-response relationship with regard to the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose-rate dependence was studied, as well as the nature of the DNA lesions. The effect of DNA repair on the lethal and mutagenic effects of exposure and on the character of the DNA lesions was investigated by comparing the response of L5178Y strains that differ in their ability to rejoin X radiation-induced DNA double strand breaks. The nature of radon/radon daughter-induced mutational lesions in human lymphoblasts was also investigated.

  6. The relation of seismic activity and radon concentration

    SciTech Connect

    Kulali, Feride E-mail: iskender@fef.sdu.edu.tr; Akkurt, İskender E-mail: iskender@fef.sdu.edu.tr; Vogiannis, Efstratios

    2014-10-06

    Radon, which is the largest source of natural ionizing radiation, reaches to surface as gas or dissolved form in the ground water. Emanation of radon can has a profile is disposed to increasing or decreasing depending on the effects of meteorological events or crust movements. In this work, the radon concentration in soil gas, which is transported from soil to AlphaGUARD, is continuously measured in Mytilene (Greece). A graph of radon concentration is prepared for comparison with simultaneous earthquake data. As a consequence of comparison, we determined that the radon concentration indicates anomalies before the earthquakes.

  7. Radon Diffusion Measurement in Polyethylene based on Alpha Detection

    SciTech Connect

    Rau, Wolfgang

    2011-04-27

    We present a method to measure the diffusion of Radon in solid materials based on the alpha decay of the radon daughter products. In contrast to usual diffusion measurements which detect the radon that penetrates a thin barrier, we let the radon diffuse into the material and then measure the alpha decays of the radon daughter products in the material. We applied this method to regular and ultra high molecular weight poly ethylene and find diffusion lengths of order of mm as expected. However, the preliminary analysis shows significant differences between two different approaches we have chosen. These differences may be explained by the different experimental conditions.

  8. Measurement and determination of radon source potential: A literature review

    SciTech Connect

    Tanner, A.B.

    1994-04-01

    Radon source potential may be estimated for areas of a nation, state, county, housing development, or building lot. The critical characteristics of the soil are its radium concentration, emanation coefficient, permeability to gas, and diffusion coefficient for radon under typical conditions. This report summarizes and evaluates available information on radon potential mapping and site-specific characterization. More than 100 reports have been found that bear on radon potential mapping, and indicate fair to good agreement with indoor radon results where correlations have been possible.

  9. Radon daughter considerations in a nuclear power plant

    SciTech Connect

    VanderMey, T.J.

    1987-07-01

    A boiling water reactor in the start-up phase experienced a significant number of personnel contamination monitor alarms caused by radon daughter plateout on hard hats, clothing, and shoes. Alarm frequencies were compared to environmental conditions and ventilation system operations to determine the effects of various factors on radon plateout. High normal ventilation, radon daughter concentrations in the plant were found to be similar to outdoor concentrations, and alarm frequencies were inversely related to relative humidity. When ventilation systems were shutdown, indoor radon levels and personnel contamination monitor alarm rates increased significantly. In this paper some suggestions for accounting for radon daughter contamination in monitoring and training programs are presented.

  10. An electrical circuit model for simulation of indoor radon concentration.

    PubMed

    Musavi Nasab, S M; Negarestani, A

    2013-01-01

    In this study, a new model based on electric circuit theory was introduced to simulate the behaviour of indoor radon concentration. In this model, a voltage source simulates radon generation in walls, conductivity simulates migration through walls and voltage across a capacitor simulates radon concentration in a room. This simulation considers migration of radon through walls by diffusion mechanism in one-dimensional geometry. Data reported in a typical Greek house were employed to examine the application of this technique of simulation to the behaviour of radon.

  11. The measurement accuracy of passive radon instruments.

    PubMed

    Beck, T R; Foerster, E; Buchröder, H; Schmidt, V; Döring, J

    2014-01-01

    This paper analyses the data having been gathered from interlaboratory comparisons of passive radon instruments over 10 y with respect to the measurement accuracy. The measurement accuracy is discussed in terms of the systematic and the random measurement error. The analysis shows that the systematic measurement error of the most instruments issued by professional laboratory services can be within a range of ±10 % from the true value. A single radon measurement has an additional random measurement error, which is in the range of up to ±15 % for high exposures to radon (>2000 kBq h m(-3)). The random measurement error increases for lower exposures. The analysis especially applies to instruments with solid-state nuclear track detectors and results in proposing criteria for testing the measurement accuracy. Instruments with electrets and charcoal have also been considered, but the low stock of data enables only a qualitative discussion.

  12. Radon measurements aboard the Kuiper Airborne Observatory

    NASA Technical Reports Server (NTRS)

    Kritz, Mark A.; Rosner, Stefan W.

    1995-01-01

    We have carried out three (piggyback) radon-related projects aboard the KAO. The first, which was limited to upper tropospheric measurements while in level flight, revealed the systematic occurrence of unexpectedly high radon concentrations in this region of the atmosphere. The second project was an instrument development project, which led to the installation of an automatic radon measurement system aboard the NASA ER-2 High Altitude Research Aircraft. In the third, we installed a new system capable of collecting samples during the normal climb and descent of the KAO. The results obtained in these projects have resulted in significant contributions to our knowledge of atmospheric transport processes, and are currently playing a key role in the validation of global circulation and transport models.

  13. Variation in residential radon levels in new Danish homes.

    PubMed

    Bräuner, E V; Rasmussen, T V; Gunnarsen, L

    2013-08-01

    Radon-222 gas arises from the radioactive decay of radium-226 and has a half-life of 3.8 days. This gas percolates up through soil into buildings, and if it is not evacuated, there can be much higher exposure levels indoors than outdoors, which is where human exposure occurs. Radon exposure is classified as a human carcinogen, and new Danish homes must be constructed to ensure indoor radon levels below 100 Bq/m(3). Our purpose was to assess how well 200 newly constructed single detached homes perform according to building regulations pertaining to radon and identify the association between indoor radon in these homes and municipality, home age, floor area, floor level, basement, and outer wall and roof construction. Median (5-95 percentile) indoor radon levels were 36.8 (9.0-118) Bq/m(3) , but indoor radon exceeded 100 Bq/m(3) in 14 of these new homes. The investigated variables explained nine percent of the variation in indoor radon levels, and although associations were positive, none of these were statistically significant. In this study, radon levels were generally low, but we found that 14 (7%) of the 200 new homes had indoor radon levels over 100 Bq/m(3). More work is needed to determine the determinants of indoor radon.

  14. Contamination of individuals by radon daughters: a preliminary study

    SciTech Connect

    Stebbings, J.H.; Dignam, J.J.

    1988-03-01

    Body radon daughter contamination reflects relative individual respiratory exposures to radon daughters; counts can be related both to household radon levels and to lung cancer risk factors such as sex and tobacco smoking. Radon daughters were counted by gamma spectroscopy from 180 adult residents of eastern Pennsylvania. A seven-position, 35-min scan was conducted in a mobile body counter, generally during afternoon or evening hours. Track-etch detectors for household radon were distributed, and were recovered from 80% of the subjects. Over 75% of the population had environmentally enhanced radon daughter contamination. House radon levels were strongly related, as anticipated, to radon daughter contamination in the 112 subjects for whom both sets of measurements were available (p less than .001); basement measurements were as strongly related to personal contamination as were living area measurements; bedroom measurements were slightly more strongly correlated. Both sex (p less than .02) and cigarette smoking (p less than .01) significantly modified the relationships, after nonlinear adjustment for travel times. Using a logarithmic model, a given house living-area radon level was associated in females with body contamination by radon daughters 2-3 times that in males. Nonsmokers had 2-4 times higher levels of contamination than smokers. Results are for the total of internal and external contamination, these being highly correlated in preliminary experiments. Time usage and activity patterns of the subjects are believed to be important in explaining these findings, and may become important variables in radon risk assessment.

  15. Radon concentration in houses over a closed Hungarian uranium mine.

    PubMed

    Somlai, János; Gorjánácz, Zorán; Várhegyi, András; Kovács, Tibor

    2006-08-31

    High radon concentration (average 410 kBq m-3) has been measured in a tunnel of a uranium mine, located 15-55 m below the village of Kovágószolos, Hungary. The mine was closed in 1997; the artificial ventilation of the tunnel was then terminated and recultivation works begun. In this paper, a study has been made as to whether the tunnel has an influence on the radon concentration of surface dwellings over the mining tunnel. At different distances from the surface projection of the mining tunnel, radon concentration, the gamma dose, radon exhalation and radon concentration of soil gas were measured. The average radon concentration in the dwellings was 483 Bq m-3. Significantly higher radon concentrations (average 667 Bq m-3) were measured in houses within +/-150 m from the surface projection of the mining tunnel +50 m, compared with the houses further than the 300-m belt (average 291 Bq m-3). The average radon concentration of the soil gas was 88.8 kBq m-3, the average radon exhalation was 71.4 Bq m-2 s-1 and higher values were measured over the passage as well. Frequent fissures crossing the passage and running up to the surface and the high radon concentration generated in the passage (average 410 kBq m-3) may influence the radon concentration of the houses over the mining tunnel.

  16. Preliminary results of indoor radon survey in V4 countries.

    PubMed

    Muűllerová, M; Kozak, K; Kovács, T; Csordás, A; Grzadziel, D; Holý, K; Mazur, J; Moravcsík, A; Neznal, M; Neznal, M; Smetanová, I

    2014-07-01

    The measurements of radon activity concentration carried out in residential houses of V4 countries (Hungary, Poland and Slovakia) show that radon levels in these countries considerably exceed the world average. Therefore, the new radon data and statistical analysis are required from these four countries. Each partner chose a region in their own country, where radon concentration in residential buildings was expected to be higher. The results of the survey carried out in the period from March 2012 to May 2012 show that radon concentrations are <200 Bq m(-3) in ∼87% of cases. However, dwellings with radon concentration ∼800 Bq m(-3) were found in Poland and Slovakia. It was also found that the distribution of radon frequency follows that of houses according to the year of their construction.

  17. Calibration system for measuring the radon flux density.

    PubMed

    Onishchenko, A; Zhukovsky, M; Bastrikov, V

    2015-06-01

    The measurement of radon flux from soil surface is the useful tool for the assessment of radon-prone areas and monitoring of radon releases from uranium mining and milling residues. The accumulation chambers with hollow headspace and chambers with activated charcoal are the most used devices for these purposes. Systematic errors of the measurements strongly depend on the geometry of the chamber and diffusion coefficient of the radon in soil. The calibration system for the attestation of devices for radon flux measurements was constructed. The calibration measurements of accumulation chambers and chambers with activated charcoal were conducted. The good agreement between the results of 2D modelling of radon flux and measurements results was observed. It was demonstrated that reliable measurements of radon flux can be obtained by chambers with activated charcoal (equivalent volume ~75 l) or by accumulation chambers with hollow headspace of ~7-10 l and volume/surface ratio (height) of >15 cm.

  18. Study of the radon released from open drill holes

    SciTech Connect

    Pacer, J C

    1981-06-01

    The radon emanating from three open drill holes was measured at a site of known uranium mineralization in the Red Desert of south central Wyoming. The radon flux from the soil and drill holes was measured by the accumulator method with activated charcoal cartridges. The surface soil was found to release radon at an average rate of 0.41 atoms/cm/sup 2//sec; the radon emanating from the holes was more variable than that from the soil. The three holes studied released an average of 47 atoms/cm/sup 2//sec of radon. This average is equivalent to the radon released to the atmosphere by 14.5 ft/sup 2/ of soil. The data indicate that the radon emanated from an open drill hole is not as significant as other possible activities at a drill site (i.e. digging a trench or drilling a hole) or from household activities involving the usage of water.

  19. Feasibility study of low angle planetary entry. [probe design for Jovian entry

    NASA Technical Reports Server (NTRS)

    Defrees, R. E.

    1975-01-01

    The feasibility of a Jovian entry by a probe originally designed for Saturn and Uranus entries is examined. An entry probe is described which is capable of release near an outer planet's sphere of influence and descent to a predetermined target entry point in the planet's atmosphere. The probe is designed so as to survive the trapped particle radiation belts and an entry heating pulse. Data is gathered and relayed to an overflying spacecraft bus during descent. Probe variations for two similar missions are described. In the first flyby of Jupiter by a Pioneer spacecraft launched during the 1979 opportunity is examined parametrically. In the second mission an orbiter based on Pioneer and launched in 1980 is defined in specific terms. The differences rest in the science payloads and directly affected wiring and electronics packages.

  20. Radon as a Tracer for Lunar Volatiles

    NASA Technical Reports Server (NTRS)

    Friesen, Larry Jay

    1992-01-01

    Radon and its decay product polonium can be used as tracers to search for lunar volatiles. One effective technique to look for them would be by using alpha-particle spectrometers from lunar orbit. Alpha spectrometers were flown in the Apollo Service Modules during the Apollo 15 and 16 missions, and did observe Rn-222 and its decay product Po-210 on the lunar surface from orbit. This demonstrates that radon and polonium can be observed from orbit; what must next be shown is that such observations can reveal something about the locations of volatiles on the Moon.

  1. Radon as a tracer for lunar volatiles

    NASA Astrophysics Data System (ADS)

    Friesen, Larry Jay

    Radon and its decay product polonium can be used as tracers to search for lunar volatiles. One effective technique to look for them would be by using alpha-particle spectrometers from lunar orbit. Alpha spectrometers were flown in the Apollo Service Modules during the Apollo 15 and 16 missions, and did observe Rn-222 and its decay product Po-210 on the lunar surface from orbit. This demonstrates that radon and polonium can be observed from orbit; what must next be shown is that such observations can reveal something about the locations of volatiles on the Moon.

  2. Overview of radon, lead and asbestos exposure

    SciTech Connect

    Demers, R. )

    1991-11-01

    Reducing the incidence of diseases caused by exposure to radon, lead and asbestos is a major public health challenge. Radon gas, which usually enters a home through the foundation, can cause lung cancer. Exposure to lead through paint, auto emissions and other sources can cause neurologic deficits, as well as anemia, abnormal vitamin D metabolism, nephropathy, hypertension and reproductive abnormalities. Asbestos, which is used in a vast number of products, is primarily associated with parenchymal asbestosis, pleural fibrosis, mesothelioma and lung cancer. The family physician can play a pivotal role in providing information about hazardous exposure, sources of exposure, epidemiology and disease prevention.29 references.

  3. Radon free storage container and method

    DOEpatents

    Langner, Jr., G. Harold; Rangel, Mark J.

    1991-01-01

    A radon free containment environment for either short or long term storage of radon gas detectors can be provided as active, passive, or combined active and passive embodiments. A passive embodiment includes a resealable vessel containing a basket capable of holding and storing detectors and an activated charcoal adsorbing liner between the basket and the containment vessel wall. An active embodiment includes the resealable vessel of the passive embodiment, and also includes an external activated charcoal filter that circulates the gas inside the vessel through the activated charcoal filter. An embodiment combining the active and passive embodiments is also provided.

  4. Study of Relation between Indoor Radon in Multi-storey Building and Outdoor Factors

    SciTech Connect

    Muellerova, Monika; Holy, Karol

    2010-01-05

    A continuous radon monitoring in indoor and outdoor air was carried out for the period of one year. The relation between indoor radon and indoor-outdoor temperature difference, as well as between indoor radon and outdoor radon was investigated. The best correlation was obtained between indoor and outdoor radon concentrations.

  5. Radon-gas extraction and counting system for analyzing radon and radium in groundwater in seismically active areas

    SciTech Connect

    Knauss, K.

    1980-12-08

    A high concentration of radon in groundwater has attracted recent attention as a precursor of seismic activity. We have constructed a system that extracts and counts radon gas from solid, liquid, and gas samples. The radon is extracted in a closed system onto activated charcoal. The desorbed radon is then measured in a phosphored acrylic cell by scintillation counting of gross alpha radiation. The efficiency of the total system (extraction plus counting) is 90 +- 3% or better. Compact design and sturdy construction make the system completely portable and well suited to field operations in remote loations. Results are given for radon and radium in groundwaters in the Livermore area.

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

    SciTech Connect

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

    1984-04-01

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

  7. Recent developments in radon metrology: new aspects in the calibration of radon, thoron and progeny devices.

    PubMed

    Röttger, A; Honig, A

    2011-05-01

    Due to the importance of reliable measurements of radon activity concentration, one of the past developments in metrology was applied to the field of radon, thus meeting two basic needs: (1) the harmonisation of metrology within the scope of the mutual recognition arrangement, an arrangement drawn up by the International Committee of Weights and Measures for the mutual recognition of national standards and of calibrations issued by national metrology institutes and (2) the increased demands of the European Atomic Energy Community (EURATOM) directive, transferred into national radiation protection regulations with regard to natural radioactivity and its quality-assured measurements. This paper gives an overview of typical technical procedures in the radon-measuring technique group of PTB, covering all aspects of reference atmospheres (primary standards) for radon, thoron and their respective progenies.

  8. New study on the correlation between carbon dioxide concentration in the environment and radon monitor devices.

    PubMed

    Shahrokhi, A; Burghele, B D; Fábián, F; Kovács, T

    2015-12-01

    The influence of high geogenic carbon dioxide concentrations on monitoring devices might present a significant challenge to the measurement of radon concentrations in environments with a high level of carbon dioxide concentration such as volcano sites, mofettes, caves, etc. In this study, the influence of carbon dioxide concentration on several different types of radon monitor devices - including Alpha Spectrometry (Sarad RTM 2200, EQF 3220, RAD7), Ionizing Chamber (AlphaGUARD PQ2000 PRO) and Active Cell (Active scintillation cell, Pylon 300A) - was examined to represent new aspects of radon measuring in environments with carbon dioxide. In light of the results, all measuring devices were exposed to variable conditions affected by carbon dioxide concentration, except for the AlphaGUARD, which was kept in a steady state throughout the experiment. It was observed that alpha spectroscopy devices were affected by carbon dioxide, since measured radon concentrations decreased in the presence of 70% and 90% carbon dioxide concentrations by 26.5 ± 2% and 14.5 ± 2.5% for EQF 3220, and 32 ± 2% and 35.5 ± 2% for RTM 2200. However, the ionizing chamber instrument was unaffected by changes in carbon dioxide concentration. It was determined that the RAD7 performed relatively inefficiently in the presence of carbon dioxide concentrations higher than 67% by an overall efficiency factor of approximately 0.52, confirming that it is not an admissible radon monitor instrument in environments with high carbon dioxide concentrations.

  9. AN ALTERNATIVE CALIBRATION OF CR-39 DETECTORS FOR RADON DETECTION BEYOND THE SATURATION LIMIT.

    PubMed

    Franci, Daniele; Aureli, Tommaso; Cardellini, Francesco

    2016-12-01

    Time-integrated measurements of indoor radon levels are commonly carried out using solid-state nuclear track detectors (SSNTDs), due to the numerous advantages offered by this radiation detection technique. However, the use of SSNTD also presents some problems that may affect the accuracy of the results. The effect of overlapping tracks often results in the underestimation of the detected track density, which leads to the reduction of the counting efficiency for increasing radon exposure. This article aims to address the effect of overlapping tracks by proposing an alternative calibration technique based on the measurement of the fraction of the detector surface covered by alpha tracks. The method has been tested against a set of Monte Carlo data and then applied to a set of experimental data collected at the radon chamber of the Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti, at the ENEA centre in Casaccia, using CR-39 detectors. It has been proved that the method allows to extend the detectable range of radon exposure far beyond the intrinsic limit imposed by the standard calibration based on the track density.

  10. The effect of moisture content on radon diffusion through soil: assessment in laboratory and field experiments.

    PubMed

    Papachristodoulou, C; Ioannides, K; Spathis, S

    2007-03-01

    The diffusion of radon through soil is strongly affected by the degree of water saturation of the soil pores. In the present work, a laboratory technique for studying radon diffusion has been developed and applied to determine diffusion coefficients in a sandy loam, containing various amounts of water, from null to saturation. The results indicate that, once the soil pore volume becomes saturated to values above approximately 20%, the diffusion of radon is markedly hampered; the bulk diffusion coefficient drops from 1.2 x 10(-6) to 2 x 10(-9) m2 s(-1) as soil saturation increases from 20 to 90%. The effect of soil moisture was further evaluated in field experiments conducted on soil of the same matrix. Comparison between results obtained by the two methods showed that laboratory studies may provide a good indication of radon diffusion coefficients to be expected in situ. However, values determined in the field were systematically lower than those assessed in the laboratory, illustrating the key role of structural differences between undisturbed and repacked soil.

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

    NASA Astrophysics Data System (ADS)

    Zafrir, Hovav; Ben Horin, Yochai; Malik, Uri; Chemo, Chaim; Zalevsky, Zeev

    2016-09-01

    A novel technique utilizing simultaneous radon monitoring by gamma and alpha detectors to differentiate between the radon climatic driving forces and others has been improved and used for deep subsurface investigation. Detailed long-term monitoring served as a proxy for studying radon movement within the shallow and deep subsurface, as well as for analyzing the effect of various parameters of the radon transport pattern. The main achievements of the investigation are (a) determination, for the first time, of the radon movement velocity within rock layers at depths of several tens of meters, namely, 25 m/h on average; (b) distinguishing between the diurnal periodical effect of the ambient temperature and the semidiurnal effect of the ambient pressure on the radon temporal spectrum; and (c) identification of a radon random preseismic anomaly preceding the Nuweiba, M 5.5 earthquake of 27 June 2015 that occurred within Dead Sea Fault Zone.

  12. Orion Entry Monitor

    NASA Technical Reports Server (NTRS)

    Smith, Kelly M.

    2016-01-01

    NASA is scheduled to launch the Orion spacecraft atop the Space Launch System on Exploration Mission 1 in late 2018. When Orion returns from its lunar sortie, it will encounter Earth's atmosphere with speeds in excess of 11 kilometers per second, and Orion will attempt its first precision-guided skip entry. A suite of flight software algorithms collectively called the Entry Monitor has been developed in order to enhance crew situational awareness and enable high levels of onboard autonomy. The Entry Monitor determines the vehicle capability footprint in real-time, provides manual piloting cues, evaluates landing target feasibility, predicts the ballistic instantaneous impact point, and provides intelligent recommendations for alternative landing sites if the primary landing site is not achievable. The primary engineering challenges of the Entry Monitor is in the algorithmic implementation in making a highly reliable, efficient set of algorithms suitable for onboard applications.

  13. 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.

  14. Low-cost Radon Reduction Pilot Study

    SciTech Connect

    Rose, William B.; Francisco, Paul W.; Merrin, Zachary

    2015-09-01

    The U.S. Department of Energy's Building America research team Partnership for Advanced Residential Retrofits conducted a primary scoping study on the impact of air sealing between the foundation and the living space on radon transport reduction across the foundation and living space floor assembly. Fifteen homes in the Champaign, Illinois, area participated in the study. These homes were instrumented for hourly continuous radon measurements and simultaneous temperature and humidity measurements. Blower door and zone pressure diagnostics were conducted at each house. The treatments consisted of using air-sealing foams at the underside of the floor that separated the living space from the foundation and providing duct sealing on the ductwork that is situated in the foundation area. The hypothesis was that air sealing the floor system that separated the foundation from the living space should better isolate the living space from the foundation; this isolation should lead to less radon entering the living space from the foundation. If the hypothesis had been proven, retrofit energy-efficiency programs may have chosen to adopt these isolation methods for enhanced radon protection to the living space.

  15. RADON REDUCTION IN A CRAWL SPACE HOUSE

    EPA Science Inventory

    Radon, a naturally occurring radioactive gas, is drawn from the soil into a house when low air pressure exists in the house. This is a commonplace environmental hazard in the United States, Canada, and northern Europe. The U.S. Environmental Protection Agency (EPA) is developing ...

  16. Seasonal indoor radon concentration in Eskisehir, Turkey.

    PubMed

    Sogukpinar, H; Algin, E; Asici, C; Altinsoz, M; Cetinkaya, H

    2014-12-01

    Indoor radon concentrations are subject to seasonal variation, which directly depends on weather conditions. The seasonal indoor radon concentrations were measured and the annual effective dose was estimated for the city centre of Eskisehir, Turkey. In order to reflect annual averages measurements were performed over all seasons (winter, spring, summer and autumn) including also the entire year. Measurements were carried out using Kodak-Pathe LR 115 Type II passive alpha track detectors in 220 different houses. A total of 534 measurements including measurements of different seasons were taken between 2010 and 2011. The radon concentrations for winter ranged from 34 to 531 Bq m(-3), for spring ranged from 22 to 424 Bq m(-3), for summer ranged from 25 to 320 Bq m(-3), and for autumn ranged from 19 to 412 Bq m(-3). Yearly measurements ranged from 19 to 338 Bq m(-3). In this study the average annual effective total dose from radon and its decay products was calculated to be 3.398 mSv y(-1).

  17. A predictive geologic model of radon occurrence

    SciTech Connect

    Gregg, L.T. )

    1990-01-01

    Earlier work by LeGrand on predictive geologic models for radon focused on hydrogeologic aspects of radon transport from a given uranium/radium source in a fractured crystalline rock aquifer, and included submodels for bedrock lithology (uranium concentration), topographic slope, and water-table behavior and characteristics. LeGrand's basic geologic model has been modified and extended into a submodel for crystalline rocks (Blue Ridge and Piedmont Provinces) and a submodel for sedimentary rocks (Valley and Ridge and Coastal Plain Provinces). Each submodel assigns a ranking of 1 to 15 to the bedrock type, based on (a) known or supposed uranium/thorium content, (b) petrography/lithology, and (c) structural features such as faults, shear or breccia zones, diabase dikes, and jointing/fracturing. The bedrock ranking is coupled with a generalized soil/saprolite model which ranks soil/saprolite type and thickness from 1 to 10. A given site is thus assessed a ranking of 1 to 150 as a guide to its potential for high radon occurrence in the upper meter or so of soil. Field trials of the model are underway, comparing model predictions with measured soil-gas concentrations of radon.

  18. TECHNOLOGIES FOR RADON AND RADIONUCLIDE REMOVAL

    EPA Science Inventory

    This paper provides a summary of the technologies that are currently being used to remove radionuclides from drinking water. The radionuclides that are featured are the radionuclides currently regulated by EPA; radium, radon and uranium. Tehnologies effective for removal of eac...

  19. RADON GENERATION AND TRANSPORT IN AGED CONCRETE

    EPA Science Inventory

    The report gives results of a characterization of radon generation and transport in Florida concretes sampled from 12- to 45-year-old residential slabs. It also compares measurements from old concrete samples to previous measurements on newly poured Florida residential concretes....

  20. STANDARD MEASUREMENT PROTOCOLS - FLORIDA RADON RESEARCH PROGRAM

    EPA Science Inventory

    The manual, in support of the Florida Radon Research Program, contains standard protocols for key measurements where data quality is vital to the program. t contains two sections. he first section, soil measurements, contains field sampling protocols for soil gas permeability and...

  1. State Indoor Radon Grant (SIRG) Program

    EPA Pesticide Factsheets

    Each year EPA distributes grant funds to the States and Tribes to support their radon risk reduction programs. The State and Tribal programs are critical to the Agency's national risk reduction effort and its achievements. These SIRG funds are put to a wid

  2. Preliminary radon measurements at Villarrica volcano, Chile

    NASA Astrophysics Data System (ADS)

    Cigolini, C.; Laiolo, M.; Coppola, D.; Ulivieri, G.

    2013-10-01

    We report data from a radon survey conducted at Villarrica volcano. Measurements have been obtained at selected sites by E-PERM® electrets and two automatic stations utilizing DOSEman detectors (SARAD Gmbh). Mean values for Villarrica are 1600 (±1150) Bq/m3 are similar to values recorded at Cerro Negro and Arenal in Central America. Moderately higher emissions, at measurement sites, were recorded on the NNW sector of the volcano and the summit, ranging from 1800 to 2400 Bq/m3. These measurements indicate that this area could potentially be a zone of flank weakness. In addition, the highest radon activities, up to 4600 Bq/m3, were measured at a station located near the intersection of the Liquiñe-Ofqui Fault Zone with the Gastre Fault Zone. To date, the Villarrica radon measurements reported here are, together with those collected at Galeras (Colombia), the sole radon data reported from South American volcanoes. This research may contribute to improving future geochemical monitoring and volcano surveillance.

  3. Protect Your Home and Family from Radon

    EPA Pesticide Factsheets

    DALLAS - (Jan. 11, 2016) Radon-the silent killer-is responsible for about 21,000 lung cancer deaths every year. The U.S. Environmental Protection Agency encourages Americans around the country to test their homes for this naturally occurring radioac

  4. Development of a model for radon concentration in indoor air.

    PubMed

    Jelle, Bjørn Petter

    2012-02-01

    A model is developed for calculation of the radon concentration in indoor air. The model takes into account various important parameters, e.g. radon concentration in ground, radon diffusion resistance of radon barrier, air permeance of ground, air pressure difference between outdoor ground and indoor at ground level, ventilation of the building ground and number of air changes per hour due to ventilation. Characteristic case studies are depicted in selected 2D and 3D graphical plots for easy visualization and interpretation. The radon transport into buildings might be dominated by diffusion, pressure driven flow or a mixture of both depending on the actual values of the various parameters. The results of our work indicate that with realistic or typical values of the parameters, most of the transport of radon from the building ground to the indoor air is due to air leakage driven by pressure differences through the construction. By incorporation of various and realistic values in the radon model, valuable information about the miscellaneous parameters influencing the indoor radon level is gained. Hence, the presented radon model may be utilized as a simple yet versatile and powerful tool for examining which preventive or remedial measures should be carried out to achieve an indoor radon level below the reference level as set by the authorities.

  5. Optimizing laboratory-based radon flux measurements for sediments.

    PubMed

    Chanyotha, Supitcha; Kranrod, Chutima; Kritsananuwat, Rawiwan; Lane-Smith, Derek; Burnett, William C

    2016-07-01

    Radon flux via diffusion from sediments and other materials may be determined in the laboratory by circulating air through the sample and a radon detector in a closed loop. However, this approach is complicated by the necessity of having to determine the total air volume in the system and accounting for any small air leaks that can arise if using extended measurement periods. We designed a simple open-loop configuration that includes a measured mass of wet sediment and water inside a gas-tight reaction flask connected to a drying system and a radon-in-air analyzer. Ambient air flows through two charcoal columns before entering the reaction vessel to eliminate incoming radon. After traveling through the reaction flask, the air passes the drier and the radon analyzer and is then vented. After some time, the radon activity will reach a steady state depending upon the airflow rate. With this approach, the radon flux via diffusion is simply the product of the steady-state radon activity (Bq/m(3)) multiplied by the airflow rate (mL/min). We demonstrated that this setup could produce good results for materials that produce relatively high radon fluxes. We also show that a modified closed system approach, including radon removal of the incoming air by charcoal filtration in a bypass, can produce very good results including samples with very low emission rates.

  6. Assessing exposure to granite countertops--Part 2: Radon.

    PubMed

    Allen, Joseph G; Minegishi, Taeko; Myatt, Theodore A; Stewart, James H; McCarthy, John F; Macintosh, David L

    2010-05-01

    Radon gas ((222)Rn) is a natural constituent of the environment and a risk factor for lung cancer that we are exposed to as a result of radioactive decay of radium ((226)Ra) in stone and soil. Granite countertops, in particular, have received recent media attention regarding their potential to emit radon. Radon flux was measured on 39 full slabs of granite from 27 different varieties to evaluate the potential for exposure and examine determinants of radon flux. Flux was measured at up to six pre-selected locations on each slab and also at areas identified as potentially enriched after a full-slab scan using a Geiger-Muller detector. Predicted indoor radon concentrations were estimated from the measured radon flux using the CONTAM indoor air quality model. Whole-slab average emissions ranged from less than limit of detection to 79.4 Bq/m(2)/h (median 3.9 Bq/m(2)/h), similar to the range reported in the literature for convenience samples of small granite pieces. Modeled indoor radon concentrations were less than the average outdoor radon concentration (14.8 Bq/m(3); 0.4 pCi/l) and average indoor radon concentrations (48 Bq/m(3); 1.3 pCi/l) found in the United States. Significant within-slab variability was observed for stones on the higher end of whole slab radon emissions, underscoring the limitations of drawing conclusions from discrete samples.

  7. The assessment of radon/thoron ratio in Ukraine dwellings

    SciTech Connect

    Geets, V.I.; Varbanets, A.N.; Sorokobatkina, V.D.

    1995-12-31

    The main task of their work was the determination of radon/thoron ratio in air of dwellings for assessing thoron contribution to total individual dose of exposure to radon and thoron. The measurements of equivalent balance concentration (EBC) have been conducted by using radonometer (model 3S, Silena, Italy) for estimating a volume activity of short-lived radionuclides associated with radon/thoron semi-decay. The results obtained show that in the regions contaminated due to the Chernobyl accident depending on regional and residential peculiarities the average EBC value for radon in air of dwellings in 1992--1993 was ranged from 1.0 to 27.5 Bg/m{sup 3}, the EBC value for thoron (radon-220) -- from 0.15 to 8.6 Bq/m{sup 3}; radon/thoron ratio was equal to 1.1--17.4; and total average dose of exposure to radon -- from 0.31 to 2.69 mkZv/year. Their calculations show that a great correlation (correlation factor was recorded to be more that 0.52) between the EBC values for radon and thoron was registered in air of dwellings. In some cases thoron contribution (78.0%) to total individual exposure dose is greater that radon-contribution. Thus, when assessing exposure it is urgent to take into account not only the EBC value for radon but the EBC value for thoron, too.

  8. Adsorption of radon and water vapor on commercial activated carbons

    SciTech Connect

    Hassan, N.M.; Ghosh, T.K.; Hines, A.L.; Loyalka, S.K.

    1995-02-01

    Equilibrium adsorption isotherms are reported for radon and water vapor on two commercial activated carbons: coconut shell Type PCB and hardwood Type BD. The isotherms of the water vapor were measured gravimetrically at 298 K. The isotherms of radon from dry nitrogen were obtained at 293, 298, and 308 K while the data for the mixture of radon and water vapor were measured at 298 K. The concentrations of radon in the gas and solid phases were measured simultaneously, once the adsorption equilibrium and the radioactive equilibrium between the radon and its daughter products were established. The shape of the isotherms was of Type III for the radon and Type V for the water vapor, according to Brunauer`s classification. The adsorption mechanism was similar for both the radon and the water vapor, being physical adsorption on the macropore surface area in the low pressure region and micropore filling near saturation pressure. The uptake capacity of radon decreased both with increasing temperature and relative humidity. The heat of adsorption data indicated that the PCB- and the BD-activated carbons provided a heterogeneous surface for radon adsorption. The equilibrium data for radon were correlated with a modified Freundlich equation.

  9. 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.

  10. Fractal Theory and Field Cover Experiments: Implications for the Fractal Characteristics and Radon Diffusion Behavior of Soils and Rocks.

    PubMed

    Tan, Wanyu; Li, Yongmei; Tan, Kaixuan; Duan, Xianzhe; Liu, Dong; Liu, Zehua

    2016-12-01

    Radon diffusion and transport through different media is a complex process affected by many factors. In this study, the fractal theories and field covering experiments were used to study the fractal characteristics of particle size distribution (PSD) of six kinds of geotechnical materials (e.g., waste rock, sand, laterite, kaolin, mixture of sand and laterite, and mixture of waste rock and laterite) and their effects on radon diffusion. In addition, the radon diffusion coefficient and diffusion length were calculated. Moreover, new formulas for estimating diffusion coefficient and diffusion length functional of fractal dimension d of PSD were proposed. These results demonstrate the following points: (1) the fractal dimension d of the PSD can be used to characterize the property of soils and rocks in the studies of radon diffusion behavior; (2) the diffusion coefficient and diffusion length decrease with increasing fractal dimension of PSD; and (3) the effectiveness of final covers in reducing radon exhalation of uranium tailings impoundments can be evaluated on the basis of the fractal dimension of PSD of materials.

  11. Mapping geogenic radon potential by regression kriging.

    PubMed

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

    2016-02-15

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

  12. Radon in atmospheric studies: a review

    SciTech Connect

    Wilkening, M.

    1981-01-01

    The distribution of the isotopes of radon in space and time, their physical characteristics, and their behavior in the dynamics of the atmosphere have presented challenges for many decades. /sup 220/Rn, /sup 222/Rn and their daughters furnish a unique set of tracers for the study of transport and mixing processes in the atmosphere. Appropriate applications of turbulent diffusion theory yield general agreement with measured profiles. Diurnal and seasonal variations follow patterns set by consideration of atmospheric stability. /sup 222/Rn has been used successfully in recent studies of nocturnal drainage winds and cumulus convection. Good results have been obtained using /sup 222/Rn and its long-lived /sup 210/Pb daughter as tracers in the study of continent-to-ocean and ocean-to-continent air mass trajectories, /sup 220/Rn (thoron) because of its short half-life of only 55 seconds has been used to measure turbulent diffusion within the first few meters of the earth's surface and to study the influence of meteorological variables on the rate of exhalation from the ground. Radon daughters attach readily to atmospheric particulate matter which makes it possible to study these aerosols with respect to size spectra, attachment characteristics, removal by gravitation and precipitation, and residence times in the troposphere. The importance of ionization by radon and its daughters in the lower atmosphere and its effect on atmospheric electrical parameters is well known. Knowledge of the mobility and other characteristics of radon daughter ions has led to applications in the study of atmospheric electrical environments under fair weather and thunderstorm conditions and in the formation of condensation nuclei. The availability of increasingly sophisticated analytical tools and atmospheric measurement systems can be expected to add much to our understanding of radon and its daughters as trace components of the atmospheric environment in the years ahead.

  13. Active faults on the eastern flank of Etna volcano (Italy) monitored through soil radon measurements

    NASA Astrophysics Data System (ADS)

    Neri, M.; Giammanco, S.; Ferrera, E.; Patanè, G.; Zanon, V.

    2012-04-01

    This study concerns measurements of radon and thoron emissions from soil carried out in 2004 on the unstable eastern flank of Mt. Etna, in a zone characterized by the presence of numerous seismogenic and aseismic faults. The statistical treatment of the geochemical data allowed recognizing anomaly thresholds for both parameters and producing distribution maps that highlighted a significant spatial correlation between soil gas anomalies and tectonic lineaments. In particular, the highest anomalies were found at the intersection between WNW-ESE and NW-SE -running faults. The seismic activity occurring in and around the study area during 2004 was analyzed, producing maps of hypocentral depth and released seismic energy. These maps revealed a progressive deepening of hypocenters from NW to SE, with the exception of a narrow zone in the central part of the area, with a roughly WNW-ESE direction. Also, the highest values of seismic energy were released during events in the southern and northwestern sectors of the area. Both radon and thoron anomalies were located in areas affected by relatively deep (5-10 km depth) seismic activity, while less evident correlation was found between soil gas anomalies and the released seismic energy. This study confirms that mapping the distribution of radon and thoron in soil gas can reveal hidden faults buried by recent soil cover or faults that are not clearly visible at the surface. The correlation between soil gas data and earthquake depth and intensity can give some hints on the source of gas and/or on fault dynamics. Lastly, an important spin-off of this study is the recognition of some areas where radon activity was so high (>50000 Bq/m3) that it may represent a potential hazard to the local population. In fact, radon is the leading cause of lung cancer after cigarette smoke for long exposures and, due to its molecular weight, it accumulates in underground rooms or in low ground, particularly where air circulation is low or absent

  14. Temporal signatures of advective versus diffusive radon transport at a geothermal zone in Central Nepal.

    PubMed

    Richon, Patrick; Perrier, Frédéric; Koirala, Bharat Prasad; Girault, Frédéric; Bhattarai, Mukunda; Sapkota, Soma Nath

    2011-02-01

    Temporal variation of radon-222 concentration was studied at the Syabru-Bensi hot springs, located on the Main Central Thrust zone in Central Nepal. This site is characterized by several carbon dioxide discharges having maximum fluxes larger than 10 kg m(-2) d(-1). Radon concentration was monitored with autonomous Barasol™ probes between January 2008 and November 2009 in two small natural cavities with high CO(2) concentration and at six locations in the soil: four points having a high flux, and two background reference points. At the reference points, dominated by radon diffusion, radon concentration was stable from January to May, with mean values of 22 ± 6.9 and 37 ± 5.5 kBq m(-3), but was affected by a large increase, of about a factor of 2 and 1.6, respectively, during the monsoon season from June to September. At the points dominated by CO(2) advection, by contrast, radon concentration showed higher mean values 39.0 ± 2.6 to 78 ± 1.4 kBq m(-3), remarkably stable throughout the year with small long-term variation, including a possible modulation of period around 6 months. A significant difference between the diffusion dominated reference points and the advection-dominated points also emerged when studying the diurnal S(1) and semi-diurnal S(2) periodic components. At the advection-dominated points, radon concentration did not exhibit S(1) or S(2) components. At the reference points, however, the S(2) component, associated with barometric tide, could be identified during the dry season, but only when the probe was installed at shallow depth. The S(1) component, associated with thermal and possibly barometric diurnal forcing, was systematically observed, especially during monsoon season. The remarkable short-term and long-term temporal stability of the radon concentration at the advection-dominated points, which suggests a strong pressure source at depth, may be an important asset to detect possible temporal variations associated with the

  15. Experimental study of radon production and transport in an analogue for the Martian regolith

    NASA Astrophysics Data System (ADS)

    Meslin, P. Y.; Sabroux, J. C.; Bassot, S.; Chassefière, E.

    2011-05-01

    The suggestion that radon could be used as a radioactive tracer of regolith-atmosphere exchanges and as a proxy for subsurface water on Mars, as well as its indirect detection in the Martian atmosphere by the rover Opportunity, have raised the need for a better characterization of its production process and transport efficiency in the Martian soil. More specifically, a proper estimation of radon exhalation rate on Mars requires its emanation factor and diffusion length to be determined. The dependence of the emanation factor as a function of pore water content (at 267 and 293 K) and the dependence of the adsorption coefficient on temperature, specific surface area and nature of the carrier gas (He, He + CO 2) have been measured on a Martian soil analogue (Hawaiian palagonitized volcanic ash, JSC Mars-1), whose radiometric analysis has been performed. An estimation of radon diffusion lengths on Mars is provided and is used to derive a global average emanation factor (2-6.5%) that accounts for the exhalation rate inferred from the 210Po surface concentration detected on Martian dust and from the 214Bi signal measured by the Mars Odyssey Gamma Ray Spectrometer. It is found to be much larger than emanation factors characterizing lunar samples, but lower than the emanation factor of the palagonite samples obtained under dry conditions. This result probably reflects different degrees of aqueous alteration and could indicate that the emanation factor is also affected by the current presence of pore water in the Martian soil. The rationale of the "radon method" as a technique to probe subsurface water on Mars, and its sensitivity to soil parameters are discussed. These experimental data are useful to perform more detailed studies of radon transport in the Martian atmosphere using Global Climate Models and to interpret neutron and gamma data from Mars Odyssey Gamma Ray Spectrometer.

  16. Changing Times: Trials and Tribulations of the Move to Master's Entry-Level Education in Canada.

    ERIC Educational Resources Information Center

    Lall, Alison; Klein, Jennifer; Brown, G. Ted

    2003-01-01

    Describes the historical evolution of Canadian occupational therapy education, outlines issues within occupational therapy that affect increased entry-level training requirements, and discusses benefits and challenges to master's entry-level training. (Contains 61 references.) (Author/JOW)

  17. 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.

  18. 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.

  19. A double chamber system for producing constant radon concentration.

    PubMed

    Haider, B; Peter, J

    1995-01-01

    An experimental arrangement of a radon chamber with an intrinsic constancy of the relative radon concentration is described. The system consists of a reference chamber and an auxiliary storage chamber. The only active device is a timer-controlled pump or valve which feeds radon gas from the storage into the reference chamber. The switching pattern of the timer is extracted from model calculations and theoretically performs an exact compensation of the radon loss by radioactive decay. If the calculations are done in real time and online, every known external event influencing the radon concentration can be compensated. This paper presents a simple timer circuit and a computer code which generates the timer program. The influence of the air flow stability and the leakage of the chambers are discussed. It is planned to apply this theoretical approach to provide a constant radon gas concentration for an actual chamber.

  20. 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.

  1. Indoor radon problem in energy efficient multi-storey buildings.

    PubMed

    Yarmoshenko, I V; Vasilyev, A V; Onishchenko, A D; Kiselev, S M; Zhukovsky, M V

    2014-07-01

    Modern energy-efficient architectural solutions and building construction technologies such as monolithic concrete structures in combination with effective insulation reduce air permeability of building envelope. As a result, air exchange rate is significantly reduced and conditions for increased radon accumulation in indoor air are created. Based on radon survey in Ekaterinburg, Russia, remarkable increase in indoor radon concentration level in energy-efficient multi-storey buildings was found in comparison with similar buildings constructed before the-energy-saving era. To investigate the problem of indoor radon in energy-efficient multi-storey buildings, the measurements of radon concentration have been performed in seven modern buildings using radon monitoring method. Values of air exchange rate and other parameters of indoor climate in energy-efficient buildings have been estimated.

  2. Radon Concentration in the Drinking Water of Aliabad Katoul, Iran

    PubMed Central

    Adinehvand, Karim; Sahebnasagh, Amin; Hashemi-Tilehnoee, Mehdi

    2016-01-01

    Background According to the world health organization, radon is a leading cause of cancer in various internal organs and should be regarded with concern. Objectives The aim of this study is to evaluate the concentration of soluble radon in the drinking water of the city of Aliabad Katoul, Iran. Materials and Methods The radon concentration was measured by using a radon meter, SARADTM model RTM 1688-2, according to accepted standards of evaluation. Results The mean radon concentration in the drinking water of Aliabad Katoul is 2.90 ± 0.57 Bq/L. Conclusions The radon concentration in Aliabad Katoul is below the limit for hazardous levels, but some precautions will make conditions even safer for the local populace. PMID:27651948

  3. Mathematical model for radon diffusion in earthen materials

    SciTech Connect

    Nielson, K.K.; Rogers, V.C.

    1982-10-01

    Radon migration in porous, earthen materials is characterized by diffusion in both the air and water components of the system as well as by the interaction of the radon between the air and water. The size distribution and configuration of the pore spaces and their moisture distributions are key parameters in determining the radon diffusion coefficient for the bulk material. A mathematical model is developed and presented for calculating radon diffusion coefficients solely from the moisture content and pore size distribution of a soil, reducing the need for resorting to radon diffusion measurements. The resulting diffusion coefficients increase with the median pore diameter of the soil and decrease with increasing widths of the pore size distribution. The calculated diffusion coefficients are suitable for use in simple homogeneous-medium diffusion expressions for predicting radon transport and compare well with measured diffusion coefficients and with empirical diffusion coefficient correlations.

  4. Geologic and climatic controls on the radon emanation coefficient

    USGS Publications Warehouse

    Schumann, R.R.; Gundersen, L.C.S.; ,

    1997-01-01

    Geologic, pedologic, and climatic factors, including radium content, grain size, siting of radon parents within soil grains or on grain coatings, and soil moisture conditions, determine a soil's emanating power and radon transport characteristics. Data from field studies indicate that soils derived from similar parent rocks in different regions have significantly different emanation coefficients due to the effects of climate on these soil characteristics. An important tool for measuring radon source strength (i.e., radium content) is ground-based and aerial gamma radioactivity measurements. Regional correlations between soil radium content, determined by gamma spectrometry, and soil-gas or indoor radon concentrations can be traced to the influence of climatic and geologic factors on intrinsic permeability and radon emanation coefficients. Data on soil radium content, permeability, and moisture content, when combined with data on emanation coefficients, can form a framework for development of quantitative predictive models for radon generation in rocks and soils.

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

    PubMed Central

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

    2014-01-01

    The primary objective of this study was to investigate the temporal variability between basement winter short-term (7 to 10 days) and basement annual radon measurements. Other objectives were to test the short-term measurement’s diagnostic performance at two reference levels and to evaluate its ability to predict annual average basement radon concentrations. Electret ion chamber (short-term) and alpha track (annual) radon measurements were obtained by trained personnel in Iowa residences. Overall, the geometric mean of the short-term radon concentrations (199 Bq m−3) was slightly greater than the geometric mean of the annual radon concentrations (181 Bq m−3). Short-term tests incorrectly predicted that the basement annual radon concentrations would be below 148 Bq m−3 12% of the time and 2% of the time at 74 Bq m−3. The short-term and annual radon concentrations were strongly correlated (r=0.87, p<0.0001). The foundation wall material of the basement was the only significant factor to have an impact on the absolute difference between the short-term and annual measurements. The findings from this study provide evidence of a substantially lower likelihood of obtaining a false negative result from a single short-term test in a region with high indoor radon potential when the reference level is lowered to 74 Bq m−3. PMID:24670901

  6. A comparison of winter short-term and annual average radon measurements in basements of a radon-prone region and evaluation of further radon testing indicators.

    PubMed

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

    2014-05-01

    The primary objective of this study was to investigate the temporal variability between basement winter short-term (7 to 10 d) and basement annual radon measurements. Other objectives were to test the short-term measurement's diagnostic performance at two reference levels and to evaluate its ability to predict annual average basement radon concentrations. Electret ion chamber (short-term) and alpha track (annual) radon measurements were obtained by trained personnel in Iowa residences. Overall, the geometric mean of the short-term radon concentrations (199 Bq m) was slightly greater than the geometric mean of the annual radon concentrations (181 Bq m). Short-term tests correctly predicted annual radon concentrations to be above the 148 Bq m action level 88% of the time and above a 74 Bq m level 98% of the time. The short-term and annual radon concentrations were strongly correlated (r = 0.87, p < 0.0001). The foundation wall material of the basement was the only significant factor to have an impact on the absolute difference between the short-term and annual measurements. The findings from this study provide evidence of a substantially lower likelihood of obtaining a false negative result from a single short-term test in a region with high indoor radon potential when the reference level is lowered to 74 Bq m.

  7. Shuttle entry guidance

    NASA Technical Reports Server (NTRS)

    Harpold, J. C.; Graves, C. A., Jr.

    1978-01-01

    This paper describes the design of the entry guidance for the Space Shuttle Orbiter. This guidance provides the steering commands for trajectory control from initial penetration of the earth's atmosphere until the terminal area guidance is activated at an earth-relative speed of 2500 fps. At this point, the Orbiter is at a distance of about 50 nmi from the runway threshold, and at an altitude of about 80,000 ft. The entry guidance design is based on an analytic solution of the equations of motion defining the drag acceleration profile that meets the terminal criteria of the entry flight while maintaining the flight within systems and operational constraints. Guidance commands, which are based on a control law that ensures damping of oscillatory type trajectory motion, are computed to steer the Orbiter to this drag acceleration profile.

  8. Orbiter entry aerothermodynamics

    NASA Technical Reports Server (NTRS)

    Ried, R. C.

    1985-01-01

    The challenge in the definition of the entry aerothermodynamic environment arising from the challenge of a reliable and reusable Orbiter is reviewed in light of the existing technology. Select problems pertinent to the orbiter development are discussed with reference to comprehensive treatments. These problems include boundary layer transition, leeward-side heating, shock/shock interaction scaling, tile gap heating, and nonequilibrium effects such as surface catalysis. Sample measurements obtained from test flights of the Orbiter are presented with comparison to preflight expectations. Numerical and wind tunnel simulations gave efficient information for defining the entry environment and an adequate level of preflight confidence. The high quality flight data provide an opportunity to refine the operational capability of the orbiter and serve as a benchmark both for the development of aerothermodynamic technology and for use in meeting future entry heating challenges.

  9. Mortality of a cohort of French uranium miners exposed to relatively low radon concentrations.

    PubMed Central

    Tirmarche, M.; Raphalen, A.; Allin, F.; Chameaud, J.; Bredon, P.

    1993-01-01

    A cohort mortality study has been performed on French uranium miners having experienced more than 2 years of underground mining, with first radon exposure between 1946 and 1972. Vital status has been ascertained from the date of entry to the 31 December 1985 for 99% of the members of this cohort; causes of death are identified for 95.5% of the decedents. The different causes of death are compared to the age specific national death rates by indirect standardisation and expressed by standardised mortality ratios (SMR). A statistically significant excess has been observed for lung and laryngeal cancer deaths. The Poisson trend test shows a statistically significant trend for the risk of lung cancer death as a function of cumulative radon exposure, assuming a lag time of 5 years; for laryngeal cancer no significant trend has been observed. Poisson regression modelling has been applied to the following exposure groups: < 10 WLM (Working Level Month); 10-49 WLM; 50-149 WLM; 150-299 WLM; > or = 300 WLM; it indicates an increase in the SMR for lung cancer of 0.6% per WLM (standard error: 0.4%) with an estimated intercept at 0 WLM of 1.68 (standard error: 0.4). The distinction of two working periods, differing by their annual radon concentration (before/since 1956) does not modify this exposure-response relationship. This coefficient of risk per unit of exposure is lower than in most of the other uranium miners' studies but it lies in the range of the evaluation of the ICRP 50 committee and the 'BEIR IV' report of the U.S. National Academy of Science. It is observed in a cohort having experienced low cumulative exposure to radon (mean: 70 WLM) spread over a mean duration of 14.5 years. Even though occupational exposure in mines differs in several particulars from domestic exposure, this study presents characteristics of low annual exposure comparable to radon gas concentrations in houses of 500-1000 Bq.m-3, and will contribute to the evaluation of cancer risk for the public

  10. Generation and mobility of radon in soils. Final report

    SciTech Connect

    Rose, A.W.

    1997-06-30

    This report emphasizes research since 1993, but includes some description of previous work which has been discussed in prior reports and publications. The research has the objectives of answering the following questions: (1) How are Rn emanation coefficients related to the form of Ra and other U-series decay products? (2) How do Ra and Rn in soil depend on the form and behavior of their ancestors {sup 234}U and {sup 230}Th? (3) Under what conditions can thermally driven convection in soil have significant effects on radon transport in soil? (4) Under what conditions do soil moisture and soil air convection affect Rn in homes, and how are these variables relevant in mitigation?

  11. Radon Assessment of Occupational Facilities, Homestead ARB, FL

    DTIC Science & Technology

    2013-11-21

    Consultative Letter 3. DATES COVERED (From – To) May 2013 – August 2013 4. TITLE AND SUBTITLE Radon Assessment of Occupational Facilities...unlimited. Case Number: 88ABW-2013-4919, 21 Nov 2013 13. SUPPLEMENTARY NOTES 14. ABSTRACT An assessment of indoor radon concentrations was...established in AFI 48-148 for long-term monitoring. Historical results indicate a radon risk characterization category of “medium,” requiring all

  12. Measuring and understanding radon adsorption in microporous materials

    SciTech Connect

    Noel, Raymond; Busto, José

    2015-08-17

    The background from the radon decay chain is the strongest constraint for many experiments working at low energy and very low counting rate. A facility for studying the optimum radon capture by very selective porous materials was developed at CPPM in the context of the SuperNEM O project. In collaboration with Institut Jean Lamour, studies were carried out for better understanding radon adsorption in carbon adsorbents.

  13. Mobile physician order entry.

    PubMed

    Ying, Alan

    2003-01-01

    Because both computerized physician order entry (CPOE) systems and mobile technologies such as handheld devices have the potential to greatly impact the industry's future, IT vendors, hospitals, and clinicians are simply merging them into a logical convergence--"CPOE on a handheld"--with an expectation of full functionality on all platforms: computer workstations, rolling laptops, tablet PCs, and handheld devices. For these trends to succeed together, however, this expectation must be revised to establish a distinct category--mobile physician order entry (MPOE)--that is different from CPOE in form, function, and implementation.

  14. Testing radon mitigation techniques in a pilot house from Băiţa-Ştei radon prone area (Romania).

    PubMed

    Cosma, Constantin; Papp, Botond; Cucoş Dinu, Alexandra; Sainz, Carlos

    2015-02-01

    This work presents the implementation and testing of several radon mitigation techniques in a pilot house in the radon prone area of Băiţa-Ştei in NW part of Romania. Radon diagnostic investigations in the pilot house showed that the main source of radon was the building sub-soil and the soil near the house. The applied techniques were based on the depressurization and pressurization of the building sub-soil, on the combination of the soil depressurization system by an electric and an eolian fans. Also, there was made an application of a radon barrier membrane and a testing by the combination of the radon membrane by the soil depressurization system. Finally, the better obtained remedial efficiency was about 85%.

  15. Health effects from radon-222 in drinking water in Algiers.

    PubMed

    Amrani, D; Cherouati, D E

    1999-09-01

    As part of a national programme, 222Rn in public water supply systems, private wells and in natural mineral waters has been measured in some locations of Algiers City. Radon concentration was determined by means of a passive method based on the use of electret ion chambers (EIC). The determination of radon concentration in the water samples consisted of sealing a known volume of water in a jar and measuring the airborne radon using an E-PERM (electret-passive environmental radon monitor) device. The radon concentrations in natural mineral waters were found to be the highest of all other water samples. It is found that the mean radon concentration of water samples was lower than the value of 11000 Bq m(-3) (11 Bq l(-1)) reported by the US Environmental Protection Agency. These investigations enabled a first estimate of the corresponding annual effective dose to the stomach and the lungs. It was observed that the annual effective dose resulting from direct consumption of water is far greater than that due to inhalation of radon emanating from tap water. Moreover, it is also shown that the annual effective dose due to inhalation of radon emanating from tap water and flushing water is negligible compared to the total annual dose for indoor radon in Algiers.

  16. Radon diffusion through multilayer earthen covers: Models and simulations

    NASA Astrophysics Data System (ADS)

    Mayer, D. W.; Oster, C. A.; Nelson, R. W.; Gee, G. W.

    1981-09-01

    A capability to model and analyze the fundamental interactions that influence the diffusion of radon gas through uranium mill tailings and cover systems were investigated. The theoretical basis for modeling radon diffusion and an understanding of the fundamental interactions that influence radon diffusion were developed. The theory was incorporated into three computer models that are used to analyze several tailings and cover configurations. The theoretical basis for modeling radon diffusion and the computer models used to analyze uranium mill tailings and multilayered cover systems are discussed.

  17. Radon exhalation from building materials used in Libya

    NASA Astrophysics Data System (ADS)

    Saad, A. F.; Al-Awami, Hend H.; Hussein, N. A.

    2014-08-01

    Radon exhalation rates have been determined for various different samples of domestic and imported building materials available in the Libyan market for home construction and interior decoration. Radon exhalation rates were measured by the sealed-can technique based on CR-39 nuclear track detectors (NTDs). The results show that radon exhalation rates from some imported building materials used as foundations and for decoration are extremely high, and these samples are the main sources of indoor radon emanation. Radium contents and annual effective doses have also been estimated.

  18. Radon exhalation from building materials for decorative use.

    PubMed

    Chen, Jing; Rahman, Naureen M; Abu Atiya, Ibrahim

    2010-04-01

    Long-term exposure to radon increases the risk of developing lung cancer. There is considerable public concern about radon exhalation from building materials and the contribution to indoor radon levels. To address this concern, radon exhalation rates were determined for 53 different samples of drywall, tile and granite available on the Canadian market for interior home decoration. The radon exhalation rates ranged from non-detectable to 312 Bq m(-2) d(-1). Slate tiles and granite slabs had relatively higher radon exhalation rates than other decorative materials, such as ceramic or porcelain tiles. The average radon exhalation rates were 30 Bq m(-2) d(-1) for slate tiles and 42 Bq m(-2) d(-1) for granite slabs of various types and origins. Analysis showed that even if an entire floor was covered with a material having a radon exhalation rate of 300 Bq m(-2) d(-1), it would contribute only 18 Bq m(-3) to a tightly sealed house with an air exchange rate of 0.3 per hour. Generally speaking, building materials used in home decoration make no significant contribution to indoor radon for a house with adequate air exchange.

  19. A theoretical investigation of the distribution of indoor radon concentrations

    NASA Astrophysics Data System (ADS)

    Rabi, R.; Oufni, L.

    2016-11-01

    Inhalation of radon (222Rn) and its decay products are a major source of natural radiation exposure. It is known from recent surveys in many countries that radon and its progeny contribute significantly to total inhalation dose and it is fairly established that radon when inhaled in large quantity causes lung disorder. In recent times, numerical modelling has become the cost effective replacement of experimental methods for the prediction and visualization of indoor pollutant distribution. The aim of this study is to implement the Finite Volume Method (FVM) for studying the radon distribution indoor. The findings show that the radon concentration which is distributed in a non-homogeneous way in the room is due to the difference in the radon concentration of different sources (wall, floor and ceiling). Moreover, the radon concentration is much larger near walls, and decreases in the middle of the room because of the effect of air velocity. We notice that the simulation results of radon concentration are in agreement with the results of other experimental studies. The annual effective dose of radon in the model room has been also investigated.

  20. Efficiency Analysis and Comparison of Different Radon Progeny Measurement Methods

    PubMed Central

    Zhang, Lei

    2013-01-01

    Radon exposure to the public contributes more than half of all the radiation doses caused by natural radiation; accurate measurement of radon progeny is quite essential for the dose evaluation of radon exposure in environment. For the purpose of establishing a radon progeny standard and controlling measurement quality of commercial devices, it is quite important to analyze the efficiency of different measurement methods and determine which would be the most appropriate for radon progeny measurements. Through theoretical analysis and experimental measurement, some commonly used measurement methods were compared in this study and the development trends of those methods were reviewed. Results show that for radon progeny measurement, the spectroscopic analysis method is better than the gross count method, while least-square calculation methods is better than traditional three-count or five-count method. Multiperiod counting of α plus β spectrum as well as using weighted least-square calculation method might be the best choice for accurate measurement on radon progeny in standard radon chamber when calibrating commercial radon progeny monitors. PMID:24385873

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

    SciTech Connect

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

    1983-01-01

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

  2. Orthopoxvirus species and strain differences in cell entry

    SciTech Connect

    Bengali, Zain; Satheshkumar, P.S.; Moss, Bernard

    2012-11-25

    Vaccinia virus (VACV) enters cells by a low pH endosomal route or by direct fusion with the plasma membrane. We previously found differences in entry properties of several VACV strains: entry of WR was enhanced by low pH, reduced by bafilomycin A1 and relatively unaffected by heparin, whereas entry of IHD-J, Copenhagen and Elstree were oppositely affected. Since binding and entry modes may have been selected by specific conditions of in vitro propagation, we now examined the properties of three distinct, recently isolated cowpox viruses and a monkeypox virus as well as additional VACV and cowpox virus strains. The recent isolates were more similar to WR than to other VACV strains, underscoring the biological importance of endosomal entry by orthopoxviruses. Sequence comparisons, gene deletions and gene swapping experiments indicated that viral determinants, other than or in addition to the A26 and A25 'fusion-suppressor' proteins, impact entry properties.

  3. Atmospheric Entry Studies for Uranus

    NASA Technical Reports Server (NTRS)

    Agrawal, Parul; Allen, Gary A.; Hwang, Helen; Prabhu, Dinesh; Aliaga, Jose; Marley, Mark; McGuire, Kathy; Huynh, Loc; Garcia, Joseph; Moses, Robert; Winski, Rick; Skylanskiy, Evgeniy

    2013-01-01

    The Objectives of this work are: 1) Establish a range of probe atmospheric entry environments based on the Uranus Flagship mission outlined in the Planetary Science Decadal Survey for two launch windows: Year 2021 and 2034. 2) Define Uranus entry trade space by performing parametric studies, by varying vehicle mass and size and entry Flight Path Angle (FPA). 3) Investigate various trajectory options, including direct ballistic entry and aero-capture entry. 4) Identify entry technologies that could be leveraged to enable a viable mission to Uranus that meets science objectives.

  4. 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

  5. Think Exit at Entry

    ERIC Educational Resources Information Center

    O'Rourke, Tom; Satterfield, Coy E.

    2005-01-01

    This paper describes the "Think Exit at Entry" program that has become the guiding principle for the Georgia Department of Juvenile Justice (DJJ). The Georgia DJJ believes that the transition process begins the day the youth enters the system and continues well after release from the institution. Literature points the need for transition…

  6. 9. FIRST FLOOR, ENTRY HALL, LOOKING SOUTHWEST TOWARDS FRONT ENTRY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. FIRST FLOOR, ENTRY HALL, LOOKING SOUTHWEST TOWARDS FRONT ENTRY WITH OPEN DOORWAY TO WINDER STAIRWAY ON RIGHT - Open Gate Farm, House, Ridge Road, 1 mile East of Elephant Road, Perkasie, Bucks County, PA

  7. Calibration system for radon EEC measurements.

    PubMed

    Mostafa, Y A M; Vasyanovich, M; Zhukovsky, M; Zaitceva, N

    2015-06-01

    The measurement of radon equivalent equilibrium concentration (EECRn) is very simple and quick technique for the estimation of radon progeny level in dwellings or working places. The most typical methods of EECRn measurements are alpha radiometry or alpha spectrometry. In such technique, the influence of alpha particle absorption in filters and filter effectiveness should be taken into account. In the authors' work, it is demonstrated that more precise and less complicated calibration of EECRn-measuring equipment can be conducted by the use of the gamma spectrometer as a reference measuring device. It was demonstrated that for this calibration technique systematic error does not exceed 3 %. The random error of (214)Bi activity measurements is in the range 3-6 %. In general, both these errors can be decreased. The measurements of EECRn by gamma spectrometry and improved alpha radiometry are in good agreement, but the systematic shift between average values can be observed.

  8. Radon applications in geosciences - Progress & perspectives

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

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

  9. RADON reconstruction in longitudinal phase space

    SciTech Connect

    Mane, V.; Peggs, S.; Wei, J.

    1997-07-01

    Longitudinal particle motion in circular accelerators is typically monitoring by one dimensional (1-D) profiles. Adiabatic particle motion in two dimensional (2-D) phase space can be reconstructed with tomographic techniques, using 1-D profiles. A computer program RADON has been developed in C++ to process digitized mountain range data and perform the phase space reconstruction for the AGS, and later for Relativistic Heavy Ion Collider (RHIC).

  10. Radon earthquake precursor studied in Iceland

    SciTech Connect

    Hauksson, E.; Goddard, J.G.

    1981-08-10

    Discrete samples of geothermal water have been collected from a network of nine stations for analysis of randon (/sup 222/Rn) content. The sampling network consisted of wells that range in wellhead temperature from 48 /sup 0/C to 100 /sup 0/C, and the depths range from 38 m to 1338 m. The sampling frequency at most stations was about once per week and twice per week at the station Fludir. The wells are either artesian or pumped more or less continously. The network covered two regions of transform faulting in Iceland with seven stations in the Southern Iceland Seismic Zone (SISZ) and two stations in northern Iceland in the Tjornes Fracture Zone (TFZ). During 1978 and 1979 several anomalous changes in radon content were observed to precede some of the local earthquakes. Criteria based on tectonic regimes, a magnitude-distance relationship and time clustering were applied to select a set of 23 earthquakes that could be expected to be preceded by a randon anomaly. The magnitude of these earthquakes ranged between 1.0 and 4.3. Each of the 23 earthquakes was within the distance range of one or more stations such that altogether 57 potential observations of possible anomalies were available. The method of analysis applied to the radon and earthquake data consisted of identifying radon anomalies in retrospect, and resulted in nine precursory anomalies, 48 cases of failure to observe an anomaly, and seven false alarms. The probability of observing radon anomalies before earthquakes with magnitudes between 2.0 and 4.3 (the largest event observed) was found to be approximately 65% based on a weekly sampling rate. In the SISZ, five out of eight earthquakes (M>2) were preceded by an anomaly. In two cases, anomalies were observed at two different stations prior to the same earthquake. The anomalies appeared to occur father away for larger earthquake magnitude.

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

    PubMed

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

    2017-01-01

    corresponding RP map of the Oslo area has no unclassified parts. We used statistics of proportions to add 95% confidence limits to estimates of RP on our predictive maps, offering public health strategists an objective measure of uncertainty in the model. The geological and AGRS RP maps were further compared in terms of their performances in correctly classifying local areas known to be radon affected and less affected. Both maps were accurate in their predictions; however the AGRS map out-performed the geology map in its ability to offer confident predictions of RP for all of the local areas tested. We compared the AGRS RP map with the 2015 distribution of population in the Oslo area to determine the likely impact of radon contamination on the population. 11.4% of the population currently reside in the area classified as radon affected. 34% of ground floor living spaces in this affected area are expected to exceed the maximum limit of 200 Bq/m(3), while 8.4% of similar spaces outside the affected area exceed this same limit, indicating that the map is very efficient at separating areas with quite different radon contamination profiles. The usefulness of the AGRS RP map in guiding new indoor radon surveys in the Oslo area was also examined. It is shown that indoor measuring programmes targeted on elevated RP areas could be as much as 6 times more efficient at identifying ground floor living spaces above the radon action level compared with surveys based on a random sampling strategy. Also, targeted measuring using the AGRS RP map as a guide makes it practical to search for the worst affected homes in the Oslo area: 10% of the incidences of very high radon contamination in ground floor living spaces (≥800 Bq/m(3)) are concentrated in just 1.2% of the populated part of the area.

  12. 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.

  13. Navy Radon Assessment and Mitigation Program

    SciTech Connect

    Not Available

    1991-10-01

    This reporting period marks the end of Phase 1 Screening and the beginning of Phase 2 Assessment. During Phase 1, radon detectors were shipped to all Department of Navy (DON) sites with family housing areas, child-care centers, schools, hospitals, bachelor quarters, and brigs. 14,350 radon detectors have been returned and analyzed, and 3.4% of the housing and nonhousing results obtained were above the Environmental Protection Agency's action level of 4 pCi/L. Suspect screening results were confirmed. Phase 2 Assessment consists of two categories, Assessment and Phase 2 Screening. All activities with radon in excess of 4 pCi/L are included in Assessment. Phase 2 Screening consists of screening Navy-Owned Reserve Centers, Rescreening (sites with inconclusive data), and screening of Nonhousing Unit Identity Codes ((UICs) activities without Phase 1 test structures). All housing assessment was scheduled to be conducted during 1991 and 1992. Phase 2 housing and nonhousing have been established. In addition, a quality assurance program and technical guidebook have been developed to achieve accurate data during Phase 2. As of July 1, 1991, assessment of housing was 40% complete, nonhousing 4%, reserve centers 100%, and nonhousing UICs were 9% complete.

  14. Occurrence of radon in Riyadh groundwater supplies.

    PubMed

    Alabdula'aly, A I

    1996-01-01

    A study of 222Rn levels in the ground water supplies of the capital city of Saudi Arabia (Riyadh) was carried out. Such sources contribute up to 34% of the total city water demand. Samples were collected from 90 wells (75 deep and 15 shallow) out of 161 that supply water to six water treatment plants and from three locations within each plant. All samples have low radon levels with an average concentration of 2.99 +/- 0.29 and 3.44 +/- 0.35 Bq L-1 (61.8 +/- 7.8 and 92.9 +/- 9.5 pCi L-1) for the deep and shallow well waters, respectively. Due to water cooling, radon level reduction in the treatment plants was found to be in the range of 74-96%. The plants' product waters were found to have very low levels of radon with an overall average value of 0.49 +/- 0.14 Bq L-1 (13.2 +/- 3.8 pCi L-1).

  15. Indoor radon prediction from soil gas measurements.

    PubMed

    Varley, N R; Flowers, A G

    1998-06-01

    This study of radon levels in southwest England investigates the correlation between indoor and soil gas radon concentrations and considers the influence of geology, meteorological variables, spatial and depth variations. This paper examines the value of soil gas measurements as an indicator of potential indoor radon concentrations and highlights a number of factors that need to be considered. Only a very weak correlation was obtained between the overall 222Rn concentration in soil gas and inside the home. However, for high soil gas concentrations a stronger correlation with the indoor level was observed. Typically, the soil gas concentration was between a factor of 10 and 1,000 times greater than that indoors. Levels as low as 10 kBq m(-3) in the soil could produce an indoor concentration above the UK action level of 200 Bq m(-3). The moisture content and the inhomogeneity of soil permeability were identified as chiefly responsible for any perturbation of a soil gas concentration associated with a particular geology. Alone, measured soil gas concentrations have only a limited use in the prediction of indoor 222Rn concentrations.

  16. Radon release and dispersion from an open pit uranium mine

    SciTech Connect

    Kisieleski, W.E.

    1980-06-01

    Radon-222 flux from representative sections of the United Nuclear St. Anthony open-pit mine complex was measured. The collected radon was adsorbed on activated charcoal and the radon activity was measured by gamma spectroscopy. System design, calibration, and the procedure to determine radon flux density (pCi/m/sup 2/.s) are described. A continuous series of radon flux densities were measured over a 5-month period at a control point in the mine. The average flux density at the control point was 1.9 pCi/m/sup 2/.s. A close correlation between radon flux density variations and changes in barometric pressure was observed by a comparison of meteorological data and average daily radon flux density measured at the control point. The release rate from each section of the mine was calculated from the average radon flux density and the area of the section, as determined from enlarged aerial photographs. The average radon flux density for eight locations over the ore-bearing section was 7.3 pCi/m/sup 2/.s. The average flux density for four locations over undisturbed topsoil was 0.17 pCi/m/sup 2/.s. The average Ra-226 content of ten samples taken from the ore-bearing region was 102 pCi/g ore. The ratio of radon flux density to radium content (specific flux) was 0.072. The release rate from the entire St. Anthony open pit was determined to be 3.5 x 10/sup 5/ pCi/s. This rate is comparable to the natural release of radon from one square mile of undisturbed topsoil. 16 refs., 31 figs., 11 tabs.

  17. Hierarchical modeling of indoor radon concentration: how much do geology and building factors matter?

    PubMed

    Borgoni, Riccardo; De Francesco, Davide; De Bartolo, Daniela; Tzavidis, Nikos

    2014-12-01

    Radon is a natural gas known to be the main contributor to natural background radiation exposure and only second to smoking as major leading cause of lung cancer. The main concern is in indoor environments where the gas tends to accumulate and can reach high concentrations. The primary contributor of this gas into the building is from the soil although architectonic characteristics, such as building materials, can largely affect concentration values. Understanding the factors affecting the concentration in dwellings and workplaces is important both in prevention, when the construction of a new building is being planned, and in mitigation when the amount of Radon detected inside a building is too high. In this paper we investigate how several factors, such as geologic typologies of the soil and a range of building characteristics, impact on indoor concentration focusing, in particular, on how concentration changes as a function of the floor level. Adopting a mixed effects model to account for the hierarchical nature of the data, we also quantify the extent to which such measurable factors manage to explain the variability of indoor radon concentration.

  18. ASSESSMENT OF THE EFFECTS OF WEATHERIZATION ON RESIDENTIAL RADON LEVELS

    EPA Science Inventory

    The report gives results of an assessment of the effects of weatherization on residential radon levels. For this assessment, time-integrated radon measurements were taken for 30- to 45-day periods both before and after weatherization in 32 Retro-Tech homes, 28 advanced homes, and...

  19. Radon exhalation rate of some building materials used in Egypt.

    PubMed

    Maged, A F; Ashraf, F A

    2005-09-01

    Indoor radon has been recognized as one of the health hazards for mankind. Common building materials used for construction of houses, which are considered as one of the major sources of this gas in indoor environment, have been studied for exhalation rate of radon. Non-nuclear industries, such as coal fired power plants or fertilizer production facilities, generate large amounts of waste gypsum as by-products. Compared to other building materials waste gypsum from fertilizer production facilities (phosphogypsum) shows increased rates of radon exhalation. In the present, investigation solid state alpha track detectors, CR-39 plastic detectors, were used to measure the indoor radon concentration and the radon exhalation rates from some building materials used in Egypt. The indoor radon concentration and the radon exhalation rate ranges were found to be 24-55 Bq m(-3 )and 11-223 mBq m(-2) h(-1), respectively. The effective dose equivalent range for the indoor was found 0.6-1.4 mSv y(-1). The equilibrium factor between radon and its daughters increased with the increase of relative humidity.

  20. Radon exhalation from granites used in Saudi Arabia.

    PubMed

    al-Jarallah, M

    2001-01-01

    Measurements of radon exhalation for a total of 50 selected samples of construction materials used in Saudi Arabia were taken using a radon gas analyzer. These materials included sand, aggregate, cement, gypsum, hydrated lime, ceramics and granite. It was found that the granite samples were the main source of radon emanations. A total of 32 local and imported granite samples were tested. It was found that the radon exhalation rates per unit area from these granite samples varied from not detectable to 10.6 Bq m-2 h-1 with an average of 1.3 Bq m-2 h-1. The linear correlation coefficient between emanated radon and radium content was 0.92. The normalized radon exhalation rates from 2.0 cm thick granite samples varied from not detectable to 0.068 (Bq m-2 h-1)/(Bq kg-1) with an average of 0.030 (Bq m-2 h-1)/(Bq kg-1). The average radon emanation of the granite samples was found to be 21% of the total radium concentration. Therefore, granite can be a source of indoor radon as well as external gamma-radiation from the uranium decay series.

  1. Ultra-low level radon assays in gases

    SciTech Connect

    Liu, Xin Ran

    2015-08-17

    The SuperNEMO experiment aims to search for the neutrinoless double beta decay (0νβ β) to T{sub 1{sub /{sub 2}}}(0ν) > 10{sup 26} years, this corresponds to an effective neutrino mass of 50-100 meV. The extremely rare event rate means the minimisation of background is of critical concern. The stringent strategy instigated to ensure detector radiopurity is outlined here for all construction materials. In particular the large R&D programme undertaken to reach the challengingly low level of radon, < 0.15 mBq/m{sup 3}, required inside the SuperNEMO gaseous tracker will be detailed. This includes an experiment designed to measure radon diffusion through various materials. A “Radon Concentration Line” (RnCL) was developed to be used in conjunction with a state-of-the-art radon detector in order to achieve world leading sensitivity to {sup 222}Rn content in large gas volumes at the level of a few µBq/m{sup 3}. A radon purification system was developed and installed which has demonstrated radon suppression by several orders of magnitude depending on the carrier gas. This apparatus has now been commissioned and measurements of cylindered gas have been made to confirm radon suppression by a factor 20 when using nitrogen as the carrier gas. The results from measurements of radon content in various gases, used inside SuperNEMO, using the RnCL will be presented.

  2. Environmental Challenges: Radon and Carbon Dioxide in School Buildings.

    ERIC Educational Resources Information Center

    Krueger, James

    1991-01-01

    Many school buildings with high radon levels also exhibit high carbon dioxide levels that starve the minds of students for oxygen. Administrators must realize that the world's best educator cannot teach minds made dysfunctional by their environment. This article describes Environmental Protection Agency testing results and offers radon monitoring…

  3. Reporting on Radon: The Role of Local Newspapers.

    ERIC Educational Resources Information Center

    Post, James F.; And Others

    Noting that past local media coverage of environmental topics, including those dealing with radiation topics, has often been superficial, a study assessed press coverage of the radon problem in the Lehigh Valley region of Pennsylvania during the first nine months of 1985. The study explored whether local media coverage of radon--a colorless,…

  4. Radon gas, useful for medical purposes, safely fixed in quartz

    NASA Technical Reports Server (NTRS)

    Fields, P. R.; Stein, L.; Zirin, M. H.

    1966-01-01

    Radon gas is enclosed in quartz or glass ampules by subjecting the gas sealed at a low pressure in the ampules to an ionization process. This process is useful for preparing fixed radon sources for radiological treatment of malignancies, without the danger of releasing radioactive gases.

  5. Radon Assessment of Occupational Facilities, Grissom ARB, IN

    DTIC Science & Technology

    2012-11-28

    public release; distribution is unlimited. Case Number: 88ABW-2012-6204, 28 Nov 2012 13. SUPPLEMENTARY NOTES 14. ABSTRACT A radon assessment...of 42 buildings on Grissom ARB was performed to meet the monitoring requirements outlined in Air Force Instruction 48-148. Radon monitors were in

  6. Assessment of the multimedia mitigation of radon in New York.

    PubMed

    Kitto, Michael E

    2007-05-01

    Although not yet implemented, the 1996 amendments to the Safe Drinking Water Act instructed the states (or local water suppliers) to address radon concentrations in community water systems (CWS). As an alternative to reducing waterborne radon concentrations in the CWS to the maximum contaminant level (MCL) of 11 Bq L(-1), states (or individual CWS) would be permitted to develop a multimedia mitigation (MMM) program, which allowed a greater concentration (148 Bq L(-1)) of waterborne radon in the CWS, if it could be shown that an equivalent health risk reduction could be achieved by reducing indoor radon concentrations. For a MMM program to be acceptable, the U.S. Environmental Protection Agency required the health-risk reduction attained through mitigations and radon-resistant new construction (RRNC) to offset the increased health risk due to radon in community water systems above the MCL of 11 Bq L(-1). A quantitative assessment indicates that the reduction in health risk currently achieved in New York State through radon mitigations and RRNC exceeded the increase in risk associated with an alternative MCL of 148 Bq L(-1). The implementation of a MMM program in New York would result in an overall reduction in the health risk associated with exposure to radon.

  7. FOLLOW-UP RADON MEASUREMENTS IN 14 MITIGATED SCHOOLS

    EPA Science Inventory

    The report gives results of a determination of the long-term performance of radon mitigation systems installed in U. S. EPA research schools: radon measurements were conducted in 14 schools that had been mitigated between 1988 and 1991. The measurements were made between Februar...

  8. PREFERENTIAL RADON TRANSPORT THROUGH HIGHLY PERMEABLE CHANNELS IN SOILS

    EPA Science Inventory

    The paper discusses preferential radon transport through highly permeable channels in soils. Indoor radon levels (that can pose a serious health risk) can be dramatically increased by air that is drawn into buildings through pipe penetrations that connect to permeable channels in...

  9. SUPPLEMENT TO: STANDARD MEASUREMENT PROTOCOLS - FLORIDA RADON RESEARCH PROGRAM

    EPA Science Inventory

    The report supplements earlier published standard protocols for key measurements where data quality is vital to the Florida Radon Research Program. The report adds measurements of small canister radon flux and soil water potential to the section on soil measurements. It adds indo...

  10. Radon and nonrespiratory mortality in the American Cancer Society cohort.

    PubMed

    Turner, Michelle C; Krewski, Daniel; Chen, Yue; Pope, C Arden; Gapstur, Susan M; Thun, Michael J

    2012-11-01

    Radon is a known cause of human lung cancer. Previously, the authors observed a significant positive association between mean county-level residential radon concentrations and lung cancer mortality in the Cancer Prevention Study II (CPS-II), a large prospective study of nearly 1.2 million participants recruited in 1982 by the American Cancer Society. There was also a significant positive association with mortality from chronic obstructive pulmonary disease. Because it is unclear whether radon is associated with mortality from other malignant or nonmalignant disease, the authors examined the association between radon and nonrespiratory mortality in the CPS-II. Mean county-level residential radon concentrations (mean = 53.5 (standard deviation: 38.0) Bq/m(3)) were linked to participants by their zip code at enrollment. Cox proportional hazards regression models were used to estimate adjusted hazard ratios and 95% confidence intervals for all-cause (excluding lung cancer and respiratory mortality) and cause-specific mortality associated with radon concentrations. A total of 811,961 participants in 2,754 counties were analyzed, including 265,477 deaths through 2006. There were no clear associations between radon and nonrespiratory mortality in the CPS-II. These findings suggest that residential radon is not associated with any other mortality beyond lung cancer or chronic obstructive pulmonary disease.

  11. Radon and COPD mortality in the American Cancer Society Cohort.

    PubMed

    Turner, Michelle C; Krewski, Daniel; Chen, Yue; Pope, C Arden; Gapstur, Susan M; Thun, Michael J

    2012-05-01

    Although radon gas is a known cause of lung cancer, the association between residential radon and mortality from non-malignant respiratory disease has not been well characterised. The Cancer Prevention Study-II is a large prospective cohort study of nearly 1.2 million Americans recruited in 1982. Mean county-level residential radon concentrations were linked to study participants' residential address based on their ZIP code at enrolment (mean ± SD 53.5 ± 38.0 Bq · m(-3)). Cox proportional hazards regression models were used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for non-malignant respiratory disease mortality associated with radon concentrations. After necessary exclusions, a total of 811,961 participants in 2,754 counties were included in the analysis. Throughout 2006, there were a total of 28,300 non-malignant respiratory disease deaths. Radon was significantly associated with chronic obstructive pulmonary disease (COPD) mortality (HR per 100 Bq · m(-3) 1.13, 95% CI 1.05-1.21). There was a significant positive linear trend in COPD mortality with increasing categories of radon concentrations (p<0.05). Findings suggest residential radon may increase COPD mortality. Further research is needed to confirm this finding and to better understand possible complex inter-relationships between radon, COPD and lung cancer.

  12. RADON REDUCTION TECHNIQUES FOR DETACHED HOUSES, TECHNICAL GUIDANCE (SECOND EDITION)

    EPA Science Inventory

    This document is intended for use by State officials, radon mitigation contractors, building contractors, concerned homeowners, and other persons as an aid in the selection, design, and operation of radon reduction measurements for houses. It is the second edition of EPA's techn...

  13. Survey of radon and thoron in homes of Indian Himalaya.

    PubMed

    Ramola, Rakesh Chand

    2011-07-01

    Measurements of radon, thoron and their progeny were carried out in some houses from Garhwal and Kumaun Himalayas of India using a LR-115 plastic track detector. The measurements were made in various residential houses of the area at a height of 2.5 m above the ground level using a twin chamber radon dosemeter, which can record the values of radon, thoron and their progeny separately. The concentrations of radon and thoron in these homes were found to vary from 11 to 191 and 1 to 156 Bq m(-3), respectively. The equilibrium factor between radon and progeny varies from 0.02 to 0.90, with an average of 0.26 for the region. The resulting dose rate due to radon, thoron and their decay products was found to vary from 0.02 to 0.84 μSv h(-1) with an arithmetic mean of 0.27 μSv h(-1). A detailed analysis of the distribution of radon, thoron and their decay products inside a house is also reported. The observed dose rates due to radon, thoron and progeny were found somewhat higher but well below the international recommendations.

  14. Results of a Test and Win Contest to Raise Radon Awareness in Urban and Rural Settings

    ERIC Educational Resources Information Center

    Hahn, Ellen J.; Rayens, Mary Kay; Kercsmar, Sarah E.; Robertson, Heather; Adkins, Sarah M.

    2014-01-01

    Background: Radon is a leading cause of lung cancer, but few test their homes to determine radon levels. Purpose: The study assessed feasibility and success of a Test and Win Contest to promote radon testing in rural and urban communities. Methods: The prospective, quasi-experimental study tested a novel contest to raise radon awareness. Paid and…

  15. Investigation of Relation Between Outdoor Temperature and Radon Concentration in Buildings

    SciTech Connect

    Muellerova, M.; Holy, K.

    2007-11-26

    The results of measurements of radon concentration variations in two types of buildings in Slovakia are reported. The AlphaGUARD radon monitor was used for continuous monitoring of radon activity concentration in indoor air. The analysis showed that the indoor radon in both buildings had very different responses to outdoor temperature.

  16. DLMS Voice Data Entry.

    DTIC Science & Technology

    1980-06-01

    RUN program features a syntactic structure based upon a group of subroutines to perform a group of functions involved in data entry for the DLMS...Code # 120 AGRICULTURAL 430 10 HOSPITAL GABLE 632 121 STOCKYARD 433 151 OBSERVATORY .640 122 WIND I LL 434 152 OBSERVATORY DOME 641 123 CEMETARY BLGS ...associated with each word or group of words. To illustrate the procedure to be followed with the CREATE program, an example is in order. In this example

  17. The mathematical model of radon-222 accumulation in underground mines

    NASA Astrophysics Data System (ADS)

    Klimshin, A.

    2012-04-01

    Necessity to control underground mine air radon level arises during building and operating mines as well as auto and railway tunnels including those for metros. Calculation of underground mine air radon level can be fulfilled for estimation of potential radon danger of area for underground structure building. In this work the new mathematical model of radon accumulation in underground mines has been suggested. It takes into consideration underground mine dimensions, air exchange factor and soils ability to emanate radon. The following assumptions have been taken for model development. It is assumed that underground mine is a cylinder of length L and of base area S. Due to ventilation atmosphere air of volume activity Catm, is coming in through one cylinder base and is going out of volume activity Cind from underground mine. Diffusion radon flux is coming in through side surfaces of underground mine. The sources of this flux are radium-226 atoms distributed evenly in rock. For simplification of the task it considered possible to disregard radon emanation by loosened rock and underground waters. As a result of solution of the radon diffusion equation the following expression for calculation of radon volume activity in underground space air has been got: 2·r0 ·λv ·Catm-·l·K0(r0/l)-+D-·K1(r0/l)·C0- Cind = 2·(λ+ λv)·r0 ·l·K0 (r0/l)+ D ·K1(r0/l) . The following designations are used in this expression: Kν(r) - the second genus modified Bessel's function, C0 - equilibrium radon volume activity in soil air, l - diffusion radon length in soil, D - radon diffusion factor, r0 - radius of underground tunnel, λv - factor of air exchange. Expression found may be used for calculation of the minimum factor of necessary air exchange for ensuring safe radon levels in underground spaces. With this worked out model expected levels of radon volume activity were calculated for air in the second metro line underground spaces in the city of Yekaterinburg, Russia.

  18. Prospecting for groundwater discharge in the canals of Bangkok via natural radon and thoron

    NASA Astrophysics Data System (ADS)

    Chanyotha, Supitcha; Kranrod, Chutima; Burnett, William C.; Lane-Smith, Derek; Simko, Jesse

    2014-11-01

    We conducted surveys of several canals in Bangkok, Thailand using continuous measurements of naturally occurring 222Rn ("radon") and 220Rn ("thoron"). Shallow groundwater seeping into these canals is an important pathway for contamination of surface waters. Radon, with a half-life (3.82 days) shorter than the suspected flushing time of the canals, is widely distributed throughout the waterway. It can thus be used to estimate discharge via a mass balance approach but cannot specify precisely where the discharge is occurring. Thoron, on the other hand, with its rapid decay (56 s half-life) will only occur very close to points of entry. Thus, if one detects thoron in the environment, there must be a source nearby - a good 'prospecting' tool. We found thoron spikes in Klong Bangkok Noi during a survey in August 2009. We repeated the same survey route in June 2013 and found essentially the same pattern of high thoron peaks (indicating points of discharge) adjacent to several temples along the canal. The connection to temples is thought to be a consequence of these structures being built on relatively higher ground and having sandy substrates.

  19. Realization of radioactive equilibrium in the KRISS radon chamber.

    PubMed

    Lee, Mo Sung; Park, Tae Soon; Lee, Jong Man

    2013-11-01

    The maintenance of radioactive equilibrium between radon and its decay products in a radon chamber is necessary to calibrate radon decay product monitors. In this study, the activity concentrations of radon decay products have been measured, and mosquito-repellent incense has been used to produce aerosol particles in the chamber. Filter papers with 8 μm pore size were used to collect aerosol in the chamber. The activity concentrations of radon decay products have been evaluated by the Modified Tsivoglou Method. The correction factors due to the differences in counting time requirements of the Modified Tsivoglou Method and the time delay between consecutive measurements have been determined. Finally, the radioactive equilibrium has been confirmed by applying the Bateman equation.

  20. Radon and Thoron exhalation rate map in Japan

    SciTech Connect

    Masahiro, Hosoda; Michikuni, Shimo; Kazuyuki, Minami; Kazutaka, Ejiri; Masato, Sugino; Masahide, Furukawa; Masahiro, Fukushi

    2008-08-07

    Measurements of radon and thoron exhalation rates have been done using the radon and thoron exhalation rate measuring instrument adopting the accumulation method. We obtained the 111 data in the 40 sites of the 14 prefectures in Japan. The arithmetic average value of the radon and thoron exhalation rates by all 111 data were obtained to be 8.6 mBq{center_dot}m{sup -2}{center_dot}s{sup -1} and 0.80 Bq{center_dot}m{sup -2}{center_dot}s{sup -1}, respectively, and we have reported the radon and thoron exhalation rates in relation to the geological features. The relation between the exhalation rate and geology was shown that the exhalation rate had an increasing tendency in order of basic rock, neutral rock and acidic rock. We made the nationwide exhalation-rate map using the survey data of exhalation-rate of radon and thoron and the geological distribution map.