Method for the determination of the radon entry rate inside buildings; Methodik zur Bestimmung der Radonquellstaerke in Gebaeuden

Energy Technology Data Exchange (ETDEWEB)

Neugebauer, T.; Hingmann, H.; Buermeyer, J.; Grimm, V.; Spruck, K.; Breckow, J. [Technische Hochschule Mittelhessen (THM), Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz (IMPS)

2016-07-01

The radon entry rate describes the radon characteristics of a building, which are defined by its constructional condition (tightness of building envelope) and the geological realities (radon soil gas concentration). All possible radon sources of a building are considered. The determination of the radon entry rate is based on the measurement of the radon concentration inside a building and the determination of the air change rate. The air change rate can be calculated via several approaches, VDI 4300-7 provides the most common methods. The main approaches are based on the use of a tracer gas, which concentration is measured over the time. In a first attempt, a one-time and punctual injection of a tracer gas was used. A disadvantage was that the air change rate could be determined only for short periods. In the follow-up, the constant injection of a tracer gas at multiple spots was executed. With this method, it is possible to calculate the air change rate over several weeks on a continuous base; the data can be used to determine the radon entry rate. Based on those series of measurements a first analysis of possible dependencies of the radon entry rate was performed.

Soil gas and radon entry into a simple test structure: Comparison of experimental and modelling results

DEFF Research Database (Denmark)

Andersen, C.E.; Søgaard-Hansen, J.; Majborn, B.

1994-01-01

A radon test structure has been established at a field site at Riso National Laboratory. Measurements have been made of soil gas entry rates, pressure couplings and radon depletion. The experimental results have been compared with results obtained from measured soil parameters and a two......-dimensional steady-state numerical model of Darcy flow and combined diffusive and advective transport of radon. For most probe locations, the calculated values of the pressure couplings and the radon depletion agree well with the measured values, thus verifying important elements of the Darcy flow approximation......, and the ability of the model to treat combined diffusive and advective transport of radon. However, the model gives an underestimation of the soil gas entry rate. Even if it is assumed that the soil has a permeability equal to the highest of the measured values, the model underestimates the soil gas entry rate...

Toward resolving model-measurement discrepancies of radon entry into houses

International Nuclear Information System (INIS)

Garbesi, K.; Lawrence Berkeley Lab., CA

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

Application of a radon model to explain indoor radon levels in a Swedish house

International Nuclear Information System (INIS)

Font, LL.; Baixeras, C.; Joensson, G.; Enge, W.; Ghose, R.

1999-01-01

Radon entry from soil into indoor air and its accumulation indoors depends on several parameters, the values of which normally depend on the specific characteristics of the site. The effect of a specific parameter is often difficult to explain from the result of indoor radon measurements only. The adaptation of the RAGENA (RAdon Generation, ENtry and Accumulation indoors) model to a Swedish house to characterise indoor radon levels and the relative importance of the different radon sources and entry mechanisms is presented. The building is a single-zone house with a naturally-ventilated crawl space in one part and a concrete floor in another part, leading to different radon levels in the two parts of the building. The soil under the house is moraine, which is relatively permeable to radon gas. The house is naturally-ventilated. The mean indoor radon concentration values measured with nuclear track detectors in the crawl-space and concrete parts of the house are respectively 75±30 and 200±80 Bq m -3 . Results of the model adaptation to the house indicate that soil constitutes the most relevant radon source in both parts of the house. The radon concentration values predicted by the model indoors fall into the same range as the experimental results

Radon as a tracer for soil-gas entry into a house located next to a contaminated dry-cleaning property; Radon som sporgas for jordluftindtraengning til hus ved forurenet renserigrund

Energy Technology Data Exchange (ETDEWEB)

Andersen, C.E

2001-07-01

This study applies the naturally occurring radioactive gas radon-222 as a tracer for soil-gas entry into a house located next to a dry-cleaners shop. This is possible because the concentration of radon in the soil below the house is about 1000 times higher than the concentration in outdoor air. The study is based on continuous indoor measurement of radon, differential pressures, barometric pressure and temperatures and grab samples of radon below the slab and in the soil in the vicinity of the house. During the investigation, vacuum extraction were used to remove chlorinated solvents (perchloroethylene, PCE) from the unsaturated zone. The study shows that the vacuum extraction influences the radon concentration in and below the house. When the vacuum pump is on, the indoor radon concentration is only 10 Bq/m{sup 3} corresponding to the contribution from radon in outdoor air and exhalation from building materials. When the vacuum pump is set off, the average indoor radon concentration increases to 30 Bq/m{sup 3}. It is believed that the increase is caused by radon entry from the soil. Regression analysis demonstrates that changes in the indoor radon concentration can be explained by changes in indoor-outdoor pressure differences and changes in the atmospheric pressure. This suggests that advection is the primary mode of entry. Under some highly simplifying assumptions the soil-gas entry is found to be around 1 m{sup 3}/h. This, however, is most likely an overestimate. Based on the measured radon concentration in the exhaust air from the vacuum system and a typical radon emanation rate for Danish soil, it is estimated that the soil vapor extraction system ventilates about 10000 m{sup 3} of soil. The investigation is supported by numerical model calculations with the finite-volume model Rnmod3d. (au)

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

International Nuclear Information System (INIS)

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

Radon in schools. Report for May 1988-September 1989

International Nuclear Information System (INIS)

Leovic, K.W.

1989-01-01

The paper discusses radon entry into schools, radon mitigation approaches for schools, and school characteristics (e.g., HVAC system design and operation) that influence radon entry and mitigation system design. It also discusses mitigation systems installed by the U.S. EPA in four schools. The primary source of radon entry into a school with significantly elevated radon levels is normally soil gas that is drawn in by pressure differentials between the soil surrounding the substructure and the building interior. If the building interior is at a lower pressure than the soil surrounding the substructure and radon is present in the soil, the radon can be pulled in through cracks and other openings that are in contact with the soil. The amount of radon in a given classroom depends on the level of radon in the underlying material, the ease with which the radon moves as a component of the soil gas through the soil, the magnitude and direction of the pressure differentials, the number and size of the radon entry routes, and dilution and mixing of the room air. HVAC systems in schools vary considerably and tend to have greater impact on pressure differentials--and consequently radon levels--than do heating and air-conditioning (HAC) systems in houses

Radon as a tracer for soil-gas entry into a house located next to a contaminated dry-cleaning property

International Nuclear Information System (INIS)

Andersen, C.E.

2001-07-01

This study applies the naturally occurring radioactive gas radon-222 as a tracer for soil-gas entry into a house located next to a dry-cleaners shop. This is possible because the concentration of radon in the soil below the house is about 1000 times higher than the concentration in outdoor air. The study is based on continuous indoor measurement of radon, differential pressures, barometric pressure and temperatures and grab samples of radon below the slab and in the soil in the vicinity of the house. During the investigation, vacuum extraction were used to remove chlorinated solvents (perchloroethylene, PCE) from the unsaturated zone. The study shows that the vacuum extraction influences the radon concentration in and below the house. When the vacuum pump is on, the indoor radon concentration is only 10 Bq/m 3 corresponding to the contribution from radon in outdoor air and exhalation from building materials. When the vacuum pump is set off, the average indoor radon concentration increases to 30 Bq/m 3 . It is believed that the increase is caused by radon entry from the soil. Regression analysis demonstrates that changes in the indoor radon concentration can be explained by changes in indoor-outdoor pressure differences and changes in the atmospheric pressure. This suggests that advection is the primary mode of entry. Under some highly simplifying assumptions the soil-gas entry is found to be around 1 m 3 /h. This, however, is most likely an overestimate. Based on the measured radon concentration in the exhaust air from the vacuum system and a typical radon emanation rate for Danish soil, it is estimated that the soil vapor extraction system ventilates about 10000 m 3 of soil. The investigation is supported by numerical model calculations with the finite-volume model Rnmod3d. (au)

Control of indoor radon and radon progeny concentrations

International Nuclear Information System (INIS)

Sextro, R.G.

1985-05-01

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

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

DEFF Research Database (Denmark)

Andersen, C.E.

2001-01-01

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

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

International Nuclear Information System (INIS)

Zhukovsky, M.V.; Vasilyev, A.V.

2014-01-01

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 ( -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 226 Ra in building materials should not exceed the value of 100 Bq kg -1 . (authors)

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

International Nuclear Information System (INIS)

Riley, W.J.

1996-05-01

Indoor air exposures to gaseous contaminants originating in soil can cause large human health risks. To predict and control these exposures, the mechanisms that affect vapor transport in near-surface soils need to be understood. In particular, radon exposure is a concern since average indoor radon concentrations lead to much higher risks than are generally accepted for exposure to other environmental contaminants. This dissertation examines an important component of the indoor radon problem: the impacts of wind on soil-gas and radon transport and entry into buildings. The research includes experimental and modeling studies of wind's interactions with a building's superstructure and the resulting soil-gas and radon flows in the surrounding soil. In addition to exploring the effects of steady winds, a novel modeling technique is developed to examine the impacts of fluctuating winds on soil-gas and radon transport

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

Energy Technology Data Exchange (ETDEWEB)

Riley, William Jowett [Univ. of California, Berkeley, CA (United States)

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.

Determination of the factors that control migration and entry of radon into basements

International Nuclear Information System (INIS)

Borak, T.B.; Gadd, M.S.; Ward, D.C.; Barry, M.S.

1992-01-01

'Full Text:' Elevated concentrations of radon gas indoors are the result or a complicated combination of factors. This report describes results from a facility designed to test and verify theories of radon migration into underground structures. The buildings resemble miniature basements using conventional construction methods, hut eliminate other confounding factors introduced by the activities of occupants. Sensors accumulate data on soil properties such as temperature, moisture, pressure differentials, and permeability, as well as outdoor meteorological conditions and indoor environment. Results indicate that indoor radon concentrations do not correlate with changes in the adjacent soil gas concentration or the rate that radon enters the structure. When no attempt is made to control the indoor environment, periods of highest indoor concentration occur when the rate of entry is low. Methods to identify the driving mechanisms and implication for mitigation and control will he described. (author)

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

International Nuclear Information System (INIS)

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

1992-01-01

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

Analytical and numerical models for estimating the effect of exhaust ventilation on radon entry in houses with basements or crawl spaces

International Nuclear Information System (INIS)

Mowris, R.J.

1986-08-01

Mechanical exhaust ventilation systems are being installed in newer, energy-efficient houses and their operation can increase the indoor-outdoor pressure differences that drive soil gas and thus radon entry. This thesis presents simplified models for estimating the pressure driven flow of radon into houses with basements or crawl spaces, due to underpressures induced by indoor-outdoor temperature differences, wind, or exhaust ventilation. A two-dimensional finite difference model is presented and used to calculate the pressure field and soil gas flow rate into a basement situated in soil of uniform permeability. A simplified analytical model is compared to the finite difference model with generally very good agreement. Another simplified model is presented for houses with a crawl space. Literature on radon research is also reviewed to show why pressure driven flow of soil gas is considered to be the major source of radon entry in houses with higher-than-average indoor radon concentrations. Comparisons of measured vs. calculated indoor radon concentrations for a house with a basement showed the simplified basement model underpredicting on average by 25%. For a house with a crawl space the simplified crawl space model overpredicted by 23% when the crawl space vents are open and 48% when the crawl space vents are sealed

State-Space Dynamic Model for Estimation of Radon Entry Rate, based on Kalman Filtering

Czech Academy of Sciences Publication Activity Database

Brabec, Marek; Jílek, K.

2007-01-01

Roč. 98, - (2007), s. 285-297 ISSN 0265-931X Grant - others:GA SÚJB JC_11/2006 Institutional research plan: CEZ:AV0Z10300504 Keywords : air ventilation rate * radon entry rate * state-space modeling * extended Kalman filter * maximum likelihood estimation * prediction error decomposition Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.963, year: 2007

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

Science.gov (United States)

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

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

International Nuclear Information System (INIS)

Reimer, G.M.

1995-01-01

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 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

Automatically processed alpha-track radon monitor

International Nuclear Information System (INIS)

Langner, G.H. Jr.

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

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

International Nuclear Information System (INIS)

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

1991-01-01

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

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

Science.gov (United States)

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

Log-normality of indoor radon data in the Walloon region of Belgium

International Nuclear Information System (INIS)

Cinelli, Giorgia; Tondeur, François

2015-01-01

The deviations of the distribution of Belgian indoor radon data from the log-normal trend are examined. Simulated data are generated to provide a theoretical frame for understanding these deviations. It is shown that the 3-component structure of indoor radon (radon from subsoil, outdoor air and building materials) generates deviations in the low- and high-concentration tails, but this low-C trend can be almost completely compensated by the effect of measurement uncertainties and by possible small errors in background subtraction. The predicted low-C and high-C deviations are well observed in the Belgian data, when considering the global distribution of all data. The agreement with the log-normal model is improved when considering data organised in homogeneous geological groups. As the deviation from log-normality is often due to the low-C tail for which there is no interest, it is proposed to use the log-normal fit limited to the high-C half of the distribution. With this prescription, the vast majority of the geological groups of data are compatible with the log-normal model, the remaining deviations being mostly due to a few outliers, and rarely to a “fat tail”. With very few exceptions, the log-normal modelling of the high-concentration part of indoor radon data is expected to give reasonable results, provided that the data are organised in homogeneous geological groups. - Highlights: • Deviations of the distribution of Belgian indoor Rn data from the log-normal trend. • 3-component structure of indoor Rn: subsoil, outdoor air and building materials. • Simulated data generated to provide a theoretical frame for understanding deviations. • Data organised in homogeneous geological groups; better agreement with the log-normal

Radon diagnostics and tracer gas measurements

International Nuclear Information System (INIS)

Jilek, K.; Brabec, M.

2004-01-01

An outline is presented of the tracer gas technique, which is used for continuous measurements of air ventilation rate (generally time-varying) and for simultaneous estimation of air ventilation rate and radon entry rate, and some of its limitations are discussed. The performance of this technique in the calculation of the air ventilation rate is demonstrated on real data from routine measurements. The potential for air ventilation rate estimation based on radon measurements only is discussed. A practical application is described of the tracer gas technique to a simultaneous estimation of the air ventilation rate and radon entry rate in a real house where the effectiveness of radon remedy was tested. The following main advantages of the CO tracer gas techniques are stressed: (i) The averaging method continuous determination of the ventilation rate with good accuracy (≤ 20 %). (ii) The newly presented and verified method based on simultaneous measurements of radon concentration and CO gas concentration enables separate continuous measurements of the radon entry rate and ventilation rate. The results of comparative measurements performed with the aim to estimate the inaccuracy in determination of radon entry rate showed acceptable and good agreement up to approximately 10 %. The results of comparative measurements performed with the aim to estimate the mutual commensuration of the method to the determination of the ventilation rate confirmed the expected unreliability the two parametric non-linear regression method, which is the most frequently used method in radon diagnostic in the Czech Republic

Rehabilitation Measures against radon gas entry

International Nuclear Information System (INIS)

Frutos Vazquez, Borja; Olaya Adan, Manuel; Esteban Saiz, Jose Luis

2011-01-01

Radon gas is a pathological agent for inhabitants of buildings where it is present. Due to its origin in uranium decay chain, it bears radioactive effects that inside human body lead to higher risks of developing lung cancer. It comes from soils containing granite masses or other substrates containing uranium. It enters through common material used in constructions, such as concrete ground slabs, basement walls, etc. In order to avoid such gas immission into inhabited rooms, several measurements cab be considered for existing buildings. This study intends to show the results obtained for radon reductions by means of different constructive solutions, already designed and executed so as to stop radon gas immission into a prototype building constructed for this specific purpose

Compact detector for radon and radon daughter products

International Nuclear Information System (INIS)

Alter, H.W.; Oswald, R.A.

1986-01-01

This invention provides an improved compact track registration detector for radon gas. The detector comprises a housing having an open mouth, a bottom, and side walls; track registration means, supported inside the housing, which forms damage tracks along paths traversed by alpha particles; a microporous filter positioned across the mouth of the housing to prevent entry of radon daughters and particulate matter; and a cap that may be placed on the mouth of the housing to retain the filter. The housing has internal wall surfaces dimensioned to optimize the registration of alpha particles from radon and radon daughters present in the housing

Identification of advective entry of soil-gas radon into a crawl space covered with sheets of polyethylene foil

International Nuclear Information System (INIS)

Andersen, C.; Koopmanns, M.; Meijer, R.J. de

1996-04-01

To assess the effectiveness of mitigative measures against radon ( 222 Rn) entry into houses, experiments were conducted in a crawl-space house where the dirt floor of the crawl space was covered with sheets of 0.23 mm polyethylene foil fixed to the walls. The radon concentration was measured below the foil and in the crawl space together with environmental variables such as indoor-outdoor pressure differences. The experimental data was analyzed using various types of models including a simplistic mass-balance model, a regression model, and a two-dimensional numerical model based on Darcy flow or soil gas and combined diffusive and advective transport of radon. The main outcome of the work was that: (i) The soil-gas entry rate per pascal depressurization was at the order of 1 m 3 h -1 , (ii) the stack-related part of the depressurization of the crawl space (approx. 0.1 Pa deg. C -1 ) was controlled by the temperature difference between the living room of the house and the outdoors (not by the difference between the crawl space and the outdoors), (iii) that part of the wind-related depressurization that was measured by the pressure transducers seemed to force radon into the crawl space in the same proportion as the stack-related part of the depressurization, (iv) the ratio of advective and diffusive entry was approx. 0.7, when the crawl space was depressurized 1.5 Pa, (v) the effective diffusivity of the foil was found to be three orders of magnitude larger than that measured in the laboratory (the enhanced diffusivity was most likely caused by leaks in the foil and by mixing fans located in the crawl space), and (vi) there was no measurable mitigative impact of having the sheets of foil on the crawl-space floor even if the crawl space was artificially pressurized or depressurized. (au) 28 tabs., 36 ills., 61 refs

Identification of advective entry of soil-gas radon into a crawl space covered with sheets of polyethylene foil

Energy Technology Data Exchange (ETDEWEB)

Andersen, C. [Risoe National Lab., Dept. of Nucl. Safety Res. and Nucl. Facilities, Roskilde (Denmark); Koopmanns, M.; Meijer, R.J. de [Kernfysische Versneller Inst., Environmental Radioactivity Res., Groningen (Netherlands)

1996-04-01

To assess the effectiveness of mitigative measures against radon ({sup 222}Rn) entry into houses, experiments were conducted in a crawl-space house where the dirt floor of the crawl space was covered with sheets of 0.23 mm polyethylene foil fixed to the walls. The radon concentration was measured below the foil and in the crawl space together with environmental variables such as indoor-outdoor pressure differences. The experimental data was analyzed using various types of models including a simplistic mass-balance model, a regression model, and a two-dimensional numerical model based on Darcy flow or soil gas and combined diffusive and advective transport of radon. The main outcome of the work was that: (i) The soil-gas entry rate per pascal depressurization was at the order of 1 m{sup 3} h{sup -1}, (ii) the stack-related part of the depressurization of the crawl space (approx. 0.1 Pa deg. C{sup -1}) was controlled by the temperature difference between the living room of the house and the outdoors (not by the difference between the crawl space and the outdoors), (iii) that part of the wind-related depressurization that was measured by the pressure transducers seemed to force radon into the crawl space in the same proportion as the stack-related part of the depressurization, (iv) the ratio of advective and diffusive entry was approx. 0.7, when the crawl space was depressurized 1.5 Pa, (v) the effective diffusivity of the foil was found to be three orders of magnitude larger than that measured in the laboratory (the enhanced diffusivity was most likely caused by leaks in the foil and by mixing fans located in the crawl space), and (vi) there was no measurable mitigative impact of having the sheets of foil on the crawl-space floor even if the crawl space was artificially pressurized or depressurized. (au) 28 tabs., 36 ills., 61 refs.

Radon reduction in wood foundation system

International Nuclear Information System (INIS)

Clark, R.J.

1990-01-01

Radon, an issue of growing concern to the building industry. Silently, invisibly, it invades existing structures as it will future foundation structures. This paper addresses the nature and causes of radon, and cost-effective prevention and retrofit techniques used for wood foundation systems. Radon also can enter homes with foundations that use the under-floor as an air distribution system. These building practices will be shown; even materials used in construction may release radon, for example, this may be a problem in a house that has a solar heating system in which its heat is stored in large beds of stone. Stone is most often used in wood foundation construction. The common radon entry points will be looked at, and the latest prevention techniques will be illustrated, such as natural and forced ventilation, sealing major radon sources and entry routes, and sub-slab and sump crock ventilations

Control of radon and its progeny concentration in indoor atmosphere

International Nuclear Information System (INIS)

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

1986-01-01

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

Radon-technical design methods based on radon classification of the soil

International Nuclear Information System (INIS)

Kettunen, A.V.

1993-01-01

Radon-technical classification of the foundation soil divides the foundation soil into four classes: negligible, normal, high and very high. Separate radon-technical designing methods and radon-technical solutions have been developed for each class. On regions of negligible class, no specific radon-technical designing methods are needed. On regions of normal radon class, there is no need for actual radon-technical designing based on calculations, whereas existing radon-technical solutions can be used. On regions of high and very high radon class, a separate radon-technical designing should be performed in each case, where radon-technical solutions are designed so that expected value for indoor radon content is lower than the maximum allowable radon content. (orig.). (3 refs., 2 figs., 2 tabs.)

Control methods of radon and its progeny concentration in indoor atmosphere

International Nuclear Information System (INIS)

Ramachandran, T.V.; Subba Ramu, M.C.

1990-01-01

Exposure to radon-222 and its progeny in indoor atmosphere can result in significant inhalation risk to the population particularly to those living in houses with much higher levels of Rn. There are three methods generally used for the control of Rn and its progeny concentration in the indoor environment: (1) restricting the radon entry, (2) reduction of indoor radon concentration by ventilation or by aircleaning and (3) removal of airborne radon progeny by aerosol reduction. Prominent process of radon entry in most of the residence appears to be the pressure driven flow of soil gas through cracks or through other openings in the basements slab or subfloor. Sealing off these openings or ventilation of the slab or subfloor spaces are the methods of reducing the radon entry rate. Indoor radon progeny levels can also be reduced by decreasing the aerosol load in the dwellings. The results of a few experiments carried out to study the reduction in the working level concentration of radon, by decreasing the aerosol load are discussed in this paper. (author). 9 tabs., 8 figs., 37 refs

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

International Nuclear Information System (INIS)

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

1990-01-01

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

ERRICCA radon model intercomparison exercise

DEFF Research Database (Denmark)

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

1999-01-01

-state diffusive radon profiles in dry and wet soils, (2) steady-state entry of soil gas and radon into a house, (3) time-dependent radon exhalation from abuilding-material sample. These cases cover features such as: soil heterogeneity, anisotropy, 3D-effects, time dependency, combined advective and diffusive......, still remain. All in all, it seems that the exercise has served its purpose and stimulated improvements relating to the quality of numerical modelling of radon transport. To maintain a high quality of modelling, it is recommendedthat additional exercises are carried out....

Contribution of radon and radon daughters to respiratory cancer

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

Soroka, Y.; Molchanov, A.

1998-01-01

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

Normal and seasonally amplified indoor radon levels

International Nuclear Information System (INIS)

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

Radon in energy-efficient earth-sheltered structures

International Nuclear Information System (INIS)

Nero, A.V.

1983-05-01

Exposure o the radioactive-decay products of radon 222 that are present in indoor air constitutes the most-significant radiation dose received by the general population in most countries. Indoor concentrations vary from one building to another, ranging from insignificant to very high levels that cause radiation doses higher than those experienced by uranium miners. This wide range of concentrations is attributable to variability in the rate at which radon enters buildings, and differences in the ventilation rate. Earth-sheltered dwellings, because they are more completely surrounded by earth material than other structures, have an as yet unquantified potential for having radon entry rates that are higher than typical for other houses in the region. Moreover, measures that save energy by reducing ventilation rates (for example by reducing infiltration) can also raise indoor radon concentrations. For these reasons a significant effort is needed to determine the potential for ventilation-reducing measures and earth sheltering to increase radon concentrations, especially in regions where they are already high. Where necessary, proper attention to specific design features that affect radon entry rates or residence time indoors should be adequate to avoid undue risk to the public

Dependence of radon level on ventilation systems in residences

International Nuclear Information System (INIS)

Kokotti, H.

1995-01-01

The concentration of indoor radon and radon entry from soil into a house are expected to increase with increasing radon concentration in soil pores, and indoor radon concentration is expected to decrease with increasing ventilation rate. Depressurization, which can be caused by the stack effect, by wind and by unbalanced ventilation, creates different pressure conditions in a house and in the soil beneath it. To reveal the possible differences in radon removal and entry resulting from different ventilation systems, radon concentrations were determined in three similar slab-on-grade buildings provided with mechanical supply and exhaust ventilation, mechanical exhaust or natural ventilation. To limitate the effect of differences in soil parameters, the houses were constructed on the same gravel esker in Kuopio. Thus, the variation in radon entry as a result of different depressurisation of the houses (caused by unbalanced mechanical ventilation systems) could also be observed. In addition, the effect of pressurisation on living rooms could be determined in five slab-on-grade houses constructed on the same esker in Hollola. Mechanical supply and exhaust ventilation system controlled by measured indoor-outdoor pressure difference, was installed in the six houses. The seasonal variation with and without controlled pressure conditions were followed in a slab-on-grade house constructed on a gravel esker in Rekola. Long-term radon concentrations were observed to correlate negatively with air exchange rates. However, the removal effect of ventilation was found to be disturbed by negative pressure due to the stack effect and/or to unbalanced mechanical ventilation. (91 refs., 17 figs., 10 tabs.)

Point-of-entry removal of radon from drinking water

International Nuclear Information System (INIS)

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

1987-01-01

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

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

Science.gov (United States)

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

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

Directory of Open Access Journals (Sweden)

R. G. M. Crockett

2011-07-01

Full Text Available During the second half of 2002, from late June to mid December, the University of Northampton Radon Research Group operated two continuous hourly-sampling radon detectors 2.25 km apart in the English East Midlands. This period included the Dudley earthquake (M_L = 5, 22 September 2002 and also a smaller earthquake in the English Channel (M_L = 3, 26 August 2002. Rolling/sliding windowed cross-correlation of the paired radon time-series revealed periods of simultaneous similar radon anomalies which occurred at the time of these earthquakes but at no other times during the overall radon monitoring period. Standardising the radon data in terms of probability of magnitude, analogous to the Standardised Precipitation Indices (SPIs used in drought modelling, which effectively equalises different non-linear responses, reveals that the dissimilar relative magnitudes of the anomalies are in fact closely equiprobabilistic. Such methods could help in identifying anomalous signals in radon – and other – time-series and in evaluating their statistical significance in terms of earthquake precursory behaviour.

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

International Nuclear Information System (INIS)

Collignan, Bernard; Powaga, Emilie

2014-01-01

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. - Highlights: • Test of a daily procedure to characterize radon potential in dwellings. • Numerical assessment of the annual radon concentration. • Procedure applied on thirteen dwellings, characterization generally satisfactory. • Procedure useful to manage radon risk in dwellings, for real

New-construction techniques and HVAC overpressurization for radon reduction in schools

International Nuclear Information System (INIS)

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

1988-01-01

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. Radon-resistant features have been incorporated into construction of the school and include the placing of at least 100 mm of clean coarse aggregate under the slab and a plastic film barrier between the aggregate and the slab, the sealing of all expansion joints, the sealing or plugging of all utility penetrations where possible, and the painting of interior block walls. In addition, the school's heating, ventilating, and air-conditioning (HVAC) system has been designed to operate continuously 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

Assessing the effectiveness of slab flooring as a barrier to soil gas and radon infiltration

International Nuclear Information System (INIS)

Williamson, A.D.; Fowler, C.S.; McDonough, S.E.

1995-01-01

Experimental studies on the entry of soil gas and radon into slab-on-grade buildings have been carried out in instrumented, single-zone test structures. This work, as part of the Florida Radon Research Program, focused on the effectiveness of slab flooring variants as barriers to soil gas/radon entry. A second objective was the study of the role of subslab fill soil as both a potential source of and barrier to radon entry. Studies were made in well-sealed (∼ 600 mm 2 ELA) unoccupied test buildings placed on well-characterized, radium-bearing sandy fill soil. The buildings were instrumented with data acquisition systems to continuously monitor indoor radon concentrations, differential pressures at several subsurface locations, weather conditions, and soil moisture. The response of the structures to mechanical depressurization as well as natural driving forces was measured. Limited measurements were made regarding direct diffusive transport of radon through apparently intact concrete slabs, as well as transport through cracks in the floor structure

Characterizing the source of radon indoors

International Nuclear Information System (INIS)

Nero, A.V.; Nazaroff, W.W.

1983-09-01

Average indoor radon concentrations range over more than two orders of magnitude, largely because of variability in the rate at which radon enters from building materials, soil, and water supplies. Determining the indoor source magnitude requires knowledge of the generation of radon in source materials, its movement within materials by diffusion and convection, and the means of its entry into buildings. This paper reviews the state of understanding of indoor radon sources and transport. Our understanding of generation rates in and movement through building materials is relatively complete and indicates that, except for materials with unusually high radionuclide contents, these sources can account for observed indoor radon concentrations only at the low end of the range observed. Our understanding of how radon enters buildings from surrounding soil is poorer, however recent experimental and theoretical studies suggest that soil may be the predominant source in many cases where the indoor radon concentration is high. 73 references, 3 figures, 1 table

Radon transport in fractured soil. Laboratory experiments and modelling

International Nuclear Information System (INIS)

Hoff, A.

1997-10-01

Radon (Rn-222) transport in fractured soil has been investigated by laboratory experiments and by modelling. Radon transport experiments have been performed with two sand columns (homogeneous and inhomogeneous) and one undisturbed clayey till column containing a net of preferential flow paths (root holes). A numerical model (the finite-element model FRACTRAN) and an analytic model (a pinhole model) have been applied in simulations if soil gas and radon transport in fractured soil. Experiments and model calculations are included in a discussion of radon entry rates into houses placed on fractured soil. The main conclusion is, that fractures does not in general alter transport of internally generated radon out of soil, when the pressure and flow conditions in the soil is comparable to the conditions prevailing under a house. This indicates the important result, that fractures in soil have no impact on radon entry into a house beyond that of an increased gas permeability, but a more thorough investigation of this subject is needed. Only in the case where the soil is exposed to large pressure gradients, relative to gradients induced by a house, may it be possible to observe effects of radon exchange between fractures and matrix. (au) 52 tabs., 60 ill., 5 refs

Radon transport in fractured soil. Laboratory experiments and modelling

Energy Technology Data Exchange (ETDEWEB)

Hoff, A

1997-10-01

Radon (Rn-222) transport in fractured soil has been investigated by laboratory experiments and by modelling. Radon transport experiments have been performed with two sand columns (homogeneous and inhomogeneous) and one undisturbed clayey till column containing a net of preferential flow paths (root holes). A numerical model (the finite-element model FRACTRAN) and an analytic model (a pinhole model) have been applied in simulations if soil gas and radon transport in fractured soil. Experiments and model calculations are included in a discussion of radon entry rates into houses placed on fractured soil. The main conclusion is, that fractures does not in general alter transport of internally generated radon out of soil, when the pressure and flow conditions in the soil is comparable to the conditions prevailing under a house. This indicates the important result, that fractures in soil have no impact on radon entry into a house beyond that of an increased gas permeability, but a more thorough investigation of this subject is needed. Only in the case where the soil is exposed to large pressure gradients, relative to gradients induced by a house, may it be possible to observe effects of radon exchange between fractures and matrix. (au) 52 tabs., 60 ill., 5 refs.

Ventilation influence upon indoor air radon level

International Nuclear Information System (INIS)

Tian Deyuan

1995-01-01

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

The control of radon levels in houses

International Nuclear Information System (INIS)

Al-Jarallah, M. B. I.

2007-01-01

The article speaks about radon entry ways to houses, the technologies of controlling the level of radon in indoors and four possible ways to solve the problem of high concentration of radon gas in housing and protection from being gathered to a certain extent that is harmful to health. These methods are: removal of the radon source, modifying the radon source, ventilation and air filtration. The article also addresses the impact of reducing the consumption of heating energy in homes and buildings using thermal insulators in floors, walls, ceilings and doors and making double glazed windows that confine the air. It has been proven that there is a steady relationship between energy conservation measures in housing and the increase of radon concentration by two to three times. In a lot of buildings, where conservation measures have been taken, materials to conserve heat are used, which themselves launch radon and this may lead to increased levels of the gas in the housing.

Indoor radon measurements and radon prognosis for eastern Uusimaa. Askola, Lapinjaervi, Liljendal, Loviisa, Myrskylae, Maentsaelae, Maentsaelae, Pernaja, Pornainen, Porvoo, Porvoon mlk, Pukkila, Ruotsinpyhtaeae and Sipoo

International Nuclear Information System (INIS)

Voutilainen, A.; Maekelaeinen, I.

1995-02-01

The purpose of the regional radon prognosis is to classify areas with different levels of radon risk. The radon prognosis gives the percentages of future homes expected to have indoor radon concentrations exceeding the levels of 200 and 400 Bq/m 3 . It is assumed that no protection against the entry of radon is used in construction. In the study about 2400 indoor radon measurements made in single family houses, semi-detached houses and row houses were used. Data on the location, geology and construction of buildings were determined form maps and questionnaires. An empirical statistical model, the adjusted indoor radon measurement and geological data were used to assess the radon risk form soil and bedrock in different areas. (15 refs., 19 figs., 9 tabs.)

Radon dosimetry: a review of radon and radon daughter exposure conditions in dwellings and other structures

International Nuclear Information System (INIS)

Ryan, M.T.; Goldsmith, W.A.; Poston, J.W.; Haywood, F.F.; Witherspoon, J.P.

1983-07-01

Within the past few years several situations have been brought to light which indicate an increased radiation exposure of certain segments of the general population caused by human activities. The most widely publicized activities are those associated with the mining and milling of uranium in the western United States, the phosphate industry in Florida, and those potential problems represented by former Manhattan Engineer District sites. One of the primary problems involves exposure to radon and radon daughters which are released from large waste piles or, in some cases, evolve from backfill and construction materials used in homes, schools, and other buildings. This report presents a review of the available data on radon and radon daughter concentrations in dwellings and other structures. The primary objectives were to compile and tabulate pertinent radon exposure data and to prepare a statistical summary of the data which will be useful in the prediction of normal levels of radon and radon daughter concentrations in these structures. In addition, other parameters associated with radon exposure conditions are presented and discussed

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

Science.gov (United States)

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...

Indoor radon measurements and radon prognosis for the province of Kymi, southeastern Finland

International Nuclear Information System (INIS)

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

1996-12-01

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

Radon in water aeration system operational performance

International Nuclear Information System (INIS)

Lamarre, B.L.

1990-01-01

North East Environmental Products, Inc. is a manufacturer of residential scale aeration systems for removal of radon and volatile organic chemicals from private water supplies. This paper is a review of the operational history of residential scale point of entry (POE) radon aeration systems. Emphasis is placed on the difficulties and solutions encountered in actual installations caused by both mechanical difficulties and water quality parameters. A summary of radon reduction efficiency is presented for wells with radon concentrations from 21,000 to 2,600,000 pCi/L. A discussion of customer concerns and attitudes is presented along with other areas for further technical improvement. Training techniques for dealers and installers are also discussed. An update of the current status of the radon in water industry includes current sales volumes as compared to the potential market and an update on the radon in water MCL standard setting process from an industry perspective

Measurement and apportionment of radon source terms for modeling indoor environments

International Nuclear Information System (INIS)

Harley, N.H.

1990-01-01

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

Comparison of predicted and measured variations of indoor radon concentration

International Nuclear Information System (INIS)

Arvela, H.; Voutilainen, A.; Maekelaeinen, I.; Castren, O.; Winqvist, K.

1988-01-01

Prediction of the variations of indoor radon concentration were calculated using a model relating indoor radon concentration to radon entry rate, air infiltration and meteorological factors. These calculated variations have been compared with seasonal variations of 33 houses during 1-4 years, with winter-summer concentration ratios of 300 houses and the measured diurnal variation. In houses with a slab in ground contact the measured seasonal variations are quite often in agreement with variations predicted for nearly pure pressure difference driven flow. The contribution of a diffusion source is significant in houses with large porous concrete walls against the ground. Air flow due to seasonally variable thermal convection within eskers strongly affects the seasonal variations within houses located thereon. Measured and predicted winter-summer concentration ratios demonstrate that, on average, the ratio is a function of radon concentration. The ratio increases with increasing winter concentration. According to the model the diurnal maximum caused by a pressure difference driven flow occurs in the morning, a finding which is in agreement with the measurements. The model presented can be used for differentiating between factors affecting radon entry into houses. (author)

Radon in buildings

International Nuclear Information System (INIS)

Ryan, N.M.; Finn, M.

1995-01-01

This guide is intended to inform designers, contractors, householders and other building owners about radon in buildings and to provide guidance where it has been decided to take action to reduce radon levels. It gives some pointers to good practice insofar as it relates to non complex buildings of normal design and construction. Reference is made to the usual ways of reducing l;levels of radon and guidance is given on sources of further information. I

Radon mitigation in schools

International Nuclear Information System (INIS)

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

1990-01-01

Since 1987, more than 40 schools in Maryland, Virginia, Tennessee and North Carolina were visited by the U.S. Environmental Protection Agency (EPA). School characteristics that potentially influence radon entry and impact mitigation system design and performance were identified. Mitigation systems that had proven successful in house mitigation were then installed in several of these schools. Many of the systems were installed by school personnel with some assistance from EPA and an experienced radon diagnostician. This article presents the diagnostic measurements made in the schools and it discusses in detail the specific mitigation systems that were installed in four Maryland schools by the EPA

Radon studies in Indian dwellings

International Nuclear Information System (INIS)

Khan, A.J.

2000-01-01

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

Effects of vegetation of radon transport processes in soil: The origins and pathways of {sup 222}Rn entering into basement structures. Final report, March 15, 1987--May 15, 1993

Energy Technology Data Exchange (ETDEWEB)

Borak, T.B.

1992-08-01

The entry rate of {sup 22}Rn into a basement structure was measured continuously. These measurements demonstrated that radon entry did not vanish even when the structure was slightly pressurized. This persistent entry has been determined to be dominated by diffusion through the floor and walls and a combination of diffusion and convection through the floor-wall joint. The highest indoor radon concentrations occurred during calm periods when the pressure differentials between the inside and outside of the structure were small. The objectives of this work were to identify the origins of the radon and investigate the entry pathways. The radon could originate either in the concrete or in the soil surrounding the structure. Entry pathways into the basement were through the concrete floor and walls as well as through the floor-wall joint. The contributions of the origins and entry pathways were determined by continuously measuring the radon entry rate into the basement, using a trace gas system, and the flux density through portions of the floor and walls. Radon entry through the floor-wall joint could be controlled using a baseboard barrier system. Results indicated that, during calm conditions with wind speeds less than 1 m s{sup {minus}1}, 25 % of the radon enters through the floor-wall joint and 75 % enters through the concrete. About 30 % of the radon originated in the concrete floor and walls. A method for in-situ determination of the diffusion length and emanation fraction of radon in concrete was developed. For the concrete used in the structure, the average diffusion length and emanation fraction were 27{plus_minus}4 cm and 0.19{plus_minus}0.02 respectively.

A review of radon mitigation in large buildings in the US

International Nuclear Information System (INIS)

Craig, A.B.

1994-01-01

The Environmental Protection Agency of the US carried out its initial research on radon mitigation in houses, both existing and new. A review of this work is presented in another paper at this workshop. Four years ago, this work was expanded to include the study of radon in schools, both new and existing, and now includes studies in other large buildings, as well. Factors affecting ease of mitigation of existing schools using active soil depressurisation (ASD) have been identified and quantified. Examination of the building and architectural plans makes it possible to predict the ease of mitigation of a specific building. Many schools can be easily and inexpensively mitigated using ASD. However, examination of a fairly large number of schools has shown that a significant percentage of existing schools will be hard to mitigate with ASD. In some cases, the heating, ventilating, and air conditioning (HVAC) system can be used to pressurise the building and retard radon entry. However, in some cases no central HVAC system exists and the school is difficult and/or expensive to mitigate by any technique. Prevention of radon entry is relatively easy and inexpensive to accomplish during construction of schools and other large buildings. It is also possible to control radon to near ambient levels in new construction, a goal which is much more difficult to approach in existing large buildings. The preferred method of radon prevention in the construction of large buildings is to design the HVAC system for building pressurisation, install a simple ASD system, and seal all entry routes between the sub-slab and the building interior. (author)

ERRICCA radon model intercomparison exercise

International Nuclear Information System (INIS)

Andersen, C.E.; Albarracin, D.; Csige, I.; Graaf, E.R. van der; Jiranek, M.; Rehs, B.; Svoboda, Z.; Toro, L.

1999-04-01

Numerical models based on finite-difference or finite-element methods are used by various research groups in studies of radon-222 transport through soil and building materials. Applications range from design of radon remediation systems to more fundamental studies of radon transport. To ascertain that results obtained with these models are of good quality, it is necessary that such models are tested. This document reports on a benchmark test organized by the EU project ERRICCA: European Research into Radon in Construction Concerted Action. The test comprises the following cases: 1) Steady-state diffusive radon profiles in dry and wet soils, 2) steady-state entry of soil gas and radon into a house, 3) time-dependent radon exhalation from a building-material sample. These cases cover features such as: soil heterogeneity, anisotropy, 3D-effects, time dependency, combined advective and diffusive transport of radon, flux calculations, and partitioning of radon between air and water in soil pores. Seven groups participated in the intercomparison. All groups submitted results without knowing the results of others. For these results, relatively large group-to-group discrepancies were observed. Because of this, all groups scrutinized their computations (once more) and engaged in follow-up discussions with others. During this debugging process, problems were indeed identified (and eliminated). The accordingly revised results were in better agreement than those reported initially. Some discrepancies, however, still remain. All in all, it seems that the exercise has served its purpose and stimulated improvements relating to the quality of numerical modelling of radon transport. To maintain a high quality of modelling, it is recommended that additional exercises are carried out. (au)

Effects of natural and forced basement ventilation on radon levels in single-family dwellings. Final report, May 90-Aug 91

International Nuclear Information System (INIS)

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

1992-06-01

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 University research houses over several seasons and under different building operating conditions show the functional dependence of radon entry rate on basement depressurization. The work clarifies the role of natural ventilation in reducing indoor radon concentrations. The work shows conclusively that natural ventilation can decrease radon levels two ways: (1) by simple dilution, and (2) by providing a pressure break (defined as any opening in the building shell that reduces the outdoor/indoor differential pressure). This reduces building depressurization and thus the amount of radon-contaminated soil gas that is drawn into the building

Measurement and apportionment of radon source terms for modeling indoor environments

International Nuclear Information System (INIS)

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

Emission of radon from soil

International Nuclear Information System (INIS)

Ahlberg, P.; Lindmark, A.; Rosen, B.

1980-03-01

The report deals with the measurement of radon daughters in the soil Radon migrates readily through the limestone which is superpositioned the alum shale. The level of gamma radiation is normal. Measurements have been made by the track etch technique and with Kodak film. The contents of radon daughters are shown to be due to the measuring depth. (G.B.)

Reasons for increasing radon concentrations in radon remediated houses

International Nuclear Information System (INIS)

Clavensjoe, B.

1997-01-01

The study comprises 31 single-dwelling houses where remedial actions were carried out in the 1980s. In all of them the radon concentrations have increased more than 30% according to recent control measurements. Radon sources are building material as well as the soil. The remedial actions dealt with ventilation systems, leakage through the basement floor, air cushions, sub-slab suction or radon wells according to the original problems. Causes for the increase varied: In many houses with soil radon problems, the installation of a normal mechanical ventilation system is not a good remedial action. In some houses on a ground with high permeability and high radon content in the soil air, the radon concentration may increase by the lowering of the indoor air pressure. In other houses the increase was a measurement effect, where sites/rooms were confused. Living related causes were identified in a number of cases, where fan speeds were reduced for energy conservation/noise reduction purposes or different use of windows airing had occurred. Extension of the dwelling space without changing the ventilation system caused the increase in one house. 23 refs

Sampling strategies for indoor radon investigations

International Nuclear Information System (INIS)

Prichard, H.M.

1983-01-01

Recent investigations prompted by concern about the environmental effects of residential energy conservation have produced many accounts of indoor radon concentrations far above background levels. In many instances time-normalized annual exposures exceeded the 4 WLM per year standard currently used for uranium mining. Further investigations of indoor radon exposures are necessary to judge the extent of the problem and to estimate the practicality of health effects studies. A number of trends can be discerned as more indoor surveys are reported. It is becoming increasingly clear that local geological factors play a major, if not dominant role in determining the distribution of indoor radon concentrations in a given area. Within a giving locale, indoor radon concentrations tend to be log-normally distributed, and sample means differ markedly from one region to another. The appreciation of geological factors and the general log-normality of radon distributions will improve the accuracy of population dose estimates and facilitate the design of preliminary health effects studies. The relative merits of grab samples, short and long term integrated samples, and more complicated dose assessment strategies are discussed in the context of several types of epidemiological investigations. A new passive radon sampler with a 24 hour integration time is described and evaluated as a tool for pilot investigations

Radon and radon daughters in South African underground mines

International Nuclear Information System (INIS)

Rolle, R.

1980-01-01

Radon and the radon daughters are the radionuclides which primarily determine the level of the radiation hazard in underground uranium mines and to a smaller extent in non-uranium mines. Radon is a gas, and its daughters adsorb on aerosol particles which are of respirable size. The hazard thus arises from the alpha decay of radon and its daughters in contact with lung tissue. Radon is itself part of the uranium decay chain. The major radionuclide, 238 U, decays successively through thirteen shorter-lived radionuclides to 206 Pb. Radon is the only gaseous decay product at room temperature; the other twelve are solids. The main hazard presented by the uranium decay chain is normally determined by the radon concentration because gaseous transport can bring alpha emitters close to sensitive tissue. There is no such transport route for the other alpha emitters, and the level of beta and gamma radiation caused by the uranium decay chain generally presents a far lower external radiation hazard. Radon itself is the heaviest of the noble gases, which are He, Ne, Ar, Kr, Xe and Rn. Its chemical reactions are of no concern in regard to its potential hazard in mines as it may be considered inert. It does, however, have a solubility ten times higher than oxygen in water, and this can play a significant part in assisting the movement of the gas from the rock into airways. Radon continuously emanates into mine workings from uranium ores and from the uranium present at low concentrations in practically any rock. It has been found that the control of the exposure level is most effectively achieved by sound ventilation practices. In South African mines the standard of ventilation is generally high and exposure to radon and radon daughters is at acceptably low levels

Indoor radon level in schools of Shillong, Meghalaya

International Nuclear Information System (INIS)

Saxena, A.; Sharma, Y.; Maibam, D.; Walia, D.; Diengdoh, E.

2010-01-01

Radon ( 222 Rn) in the atmosphere is the most important contributor to human exposure from natural sources. Radon is a noble inert gas; and it decays to radionuclides that are chemically active and relatively short lived. Inhalation of the short lived radon progeny imparts a radiation dose to the lung, to which an increased risk of lung cancer is attributed due to the alpha particle irradiation of the secretory and basal cells of the respiratory tract. The indoor radon concentration is dependent on the texture, porosity, permeability, water content of the soil underlying the structure and the radon behaviour in soils on aspects of geology and climate. The direct cause of high radon entry rates into structures exhibiting high indoor radon concentrations are fractures in bedrock formations, cracks in the soil, and similar inhomogeneities in the materials of the foundation of the structures. Other factors influencing indoor radon concentration includes exhalations from the walls and ceilings, building design and material, cracks and openings in the foundation of the buildings. The geological factors in the study area promote radon accumulation especially in buildings and dwellings. The world average annual effective dose in the indoor environments is 1.01 mSv.y -1 . The importance of radon level measurements in school buildings is of interest as children are more sensitive to radon exposure than adults. Hence, radon measurements in 10 schools have been undertaken in the present study

Certain problems about radon. Pt.1

International Nuclear Information System (INIS)

Wu Huishan

2005-01-01

Discussion has been made on certain pointed out problems which presently influence the work and development of radon survey, and certain specific problems have been put forward which should be paid much attention and taken measures. Among the problems, some come from cognition, i.e. two kinds of balance and examination about radon, chief culprit of radon's daughter, multiply control and migration, the significance of radon in the water and soil, important standards for designing and evaluating the sites of construction projects, thoughts on the mechanism of the harm of radon and its daughters, diseases causing of both high and low radon, difficulty of emanation of indoor radon, normal low radon from natural marble; and others must be resolved specifically, i.e. establishment of national radon standards as quickly as possible, improvement of on-the-spot examination technique, national-wide radon survey with multiple disciplines and technology, the research on the mechanism of radon's harm and the establishment national radon study center. (authors)

31 CFR 538.504 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... Entries in certain accounts for normal service charges authorized. (a) U.S. financial institutions are... reimbursement for normal service charges owed to such U.S. financial institution by the owner of such blocked account. (b) As used in this section, the term normal service charge shall include charges in payment or...

31 CFR 595.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... Entries in certain accounts for normal service charges authorized. (a) U.S. financial institutions are... reimbursement for normal service charges owed to such U.S. financial institution by the owner of such blocked account. (b) As used in this section, the term normal service charge shall include charges in payment or...

31 CFR 536.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... § 536.505 Entries in certain accounts for normal service charges authorized. (a) U.S. financial... or reimbursement for normal service charges owed to such U.S. financial institution by the owner of such blocked account. (b) As used in this section, the term normal service charge shall include charges...

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

International Nuclear Information System (INIS)

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

1998-01-01

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

31 CFR 597.504 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... Licensing Policy § 597.504 Entries in certain accounts for normal service charges authorized. (a) U.S... institution in payment or reimbursement for normal service charges owed to such U.S. financial institution by the owner of such blocked account. (b) As used in this section, the term normal service charge shall...

31 CFR 598.506 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... Policy § 598.506 Entries in certain accounts for normal service charges authorized. (a) U.S. financial... reimbursement for normal service charges owed to such U.S. financial institution by the owner of such blocked account. (b) As used in this section, the term normal service charges includes but is not limited to...

Effectiveness of ventilation improvements as a protective measure against radon

International Nuclear Information System (INIS)

Hoving, P.; Arvela, H.

1993-01-01

Radon reduction rates for ventilation improvement measures vary considerably. In 70% of the cases studied, further mitigation is needed to reach a level of 400 Bq/m 3 . Ventilation measures in crawl spaces and basements have resulted in reduction rates of up to 90%, though more typically 30-70%. Installing new mechanical systems in dwellings has resulted in 20-80% reduction rates. If fan use or fan efficiency is increased, radon levels can be reduced as much as when new systems are installed. Increasing fresh-air supply through vents or window gaps reduces radon concentrations 10-40%. Low ventilation rates, measured after mitigation using the passive per fluorocarbon tracer gas method, seem to be accompanied by also low radon reduction rates. Multiple zone tracer gas measurements were conducted in order to reveal radon entry from the soil and radon transport between zones. (orig.). (3 refs., 3 figs., 2 tabs.)

Basement radon entry and stack driven moisture infiltration reduced by active soil depressurization

Science.gov (United States)

C.R. Boardman; Samuel V. Glass

2015-01-01

This case study presents measurements of radon and moisture infiltration from soil gases into the basement of an unoccupied research house in Madison, Wisconsin, over two full years. The basement floor and exterior walls were constructed with preservative-treated lumber and plywood. In addition to continuous radon monitoring, measurements included building air...

Improved thomas formula for radon measurement

International Nuclear Information System (INIS)

Ji Changsong

1991-06-01

The FT 648 type portable absolute radon meter has been developed and the designing principle of this instrument is introduced. The absolute radon meter differs from relative radon meter. By using structure parameters, operating parameters and readout of this instrument, the radon content of measured gas is obtained directly without calibration in advance. Normally, the calibration is done by a standard radioactive gaseous source of which the radon concentration is known. The systematic error is removed by adding filter-efficiency Σ, α self-absorption correction β, energy spectrum correction S, geometric factor Ω of probe and gravity dropping correction factor G to the Thomas formula for radon measurement of two-filter method. The atmosphere radon content, which is given in hour-average, in Beijing area was measured by FT 648 type absolute radon meter. The measurement lasted continuously for several days and nights and a 'saddle shape' of radon content-time curve was observed. The day's average radon content was 8.5 Bq·m -3

Radon classification of building ground

International Nuclear Information System (INIS)

Slunga, E.

1988-01-01

The Laboratories of Building Technology and Soil Mechanics and Foundation Engineering at the Helsinki University of Technology in cooperation with The Ministry of the Environment have proposed a radon classification for building ground. The proposed classification is based on the radon concentration in soil pores and on the permeability of the foundation soil. The classification includes four radon classes: negligible, normal, high and very high. Depending on the radon class the radon-technical solution for structures is chosen. It is proposed that the classification be done in general terms in connection with the site investigations for the planning of land use and in more detail in connection with the site investigations for an individual house. (author)

Radon in Norwegian dwellings

International Nuclear Information System (INIS)

Strand, T.; Green, B.M.R.; Lomas, P.R.

1992-01-01

The results of a large-scale survey of radon concentrations in Norwegian dwellings are reported. Measurements of radon have been made in a total of 7500 dwellings. The dwellings were randomly selected and the number in each municipality is proportional to its population. The measurements were performed using etched track detectors from the National Radiological Protection Board in the UK. One detector was placed in the main bedroom in each dwelling for 6 months. The annual average of radon concentration in Norwegian bedrooms is calculated to be 51 Bq.m -3 . The frequency distribution is approximately log-normal with a geometric mean of 26 Bq.m -3 and about 4% of the bedrooms have concentrations above 200 Bq.m -3 . The radon concentrations are found to be about 40% higher for bedrooms in single-family houses than in blocks of flats and other multifamily houses. In a large proportion of single-family houses the living room and the kitchen are located on the ground floor and the bedrooms on the first floor. An additional factor is that the winters of 1987-1988 and 1988-1989 were much warmer than normal. Taking these factors into account, the average radon concentration in Norwegian dwellings is estimated to be between 55 and 65 Bq.m -3 . (author)

Radon levels in Croatian spas

International Nuclear Information System (INIS)

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

2005-01-01

Average radon concentrations in the air and geothermal water of spa pools in Croatia were 40.3 Bq/m 3 and 4.5 kBq/m 3 , respectively. Substantial difference between radon concentrations in pool and spring water is explained by the mixing normal and geothermal water in the pool and with radon decay. The estimated annual effective dose received by the personnel in the spa of Stubicke toplice, Croatia was 0.7 mSv. At the same location, the calculated transfer factor of radon for the air and thermal water in the pool was 4.9x10 -3 .(author)

Measurement of activity-weighted size distributions of radon decay products in a normally occupied home

International Nuclear Information System (INIS)

Hopke, P.K.; Wasiolek, P.; Montassier, N.; Cavallo, A.; Gadsby, K.; Socolow, R.

1992-01-01

In order to assess the exposure of individuals to the presence of indoor radioactivity arising from the decay of radon, an automated, semicontinuous graded screen array system was developed to permit the measurement of the activity-weighted size distributions of the radon progeny in homes. The system has been modified so that the electronics and sampling heads can be separated from the pump by approximately 15 m. The system was placed in the living room of a one-storey house with basement in Princeton, NJ and operated for 2 weeks while the house was occupied by the home owners in their normal manner. One of the house occupants was a cigarette smoker. Radon and potential alpha energy concentration (PAEC) measurements were also made, but condensation nuclei counts were not performed. PAEC values ranged from 23.4 to 461.6 mWL. In the measured activity size distributions, the amount of activity in the 0.5-1.5 nm size range can be considered to be the unattached fraction. The mean value for the 218 Po unattached fraction is 0.217 with a range of 0.054-0.549. The median value for the unattached fraction of PAEC is 0.077 with a range of 0.022-0.178. (author)

The finnish guide to radon-resistant homes

International Nuclear Information System (INIS)

Arvela, H.

2006-01-01

Full text of publication follows: New regulations of the National Finnish Building Code require consideration of radon risks and as a main rule radon technical design in the building permission documents. Slab-on-grade is the prevalent substructure in Finnish low-rise residential buildings. Building statistics show that the prevalent practices in foundation construction promote the flow of radon-bearing soil air into living spaces. Without prevention the normal practices would result in high indoor radon concentrations in Finland. In wide areas more than 50% of houses exceed the reference level of 200 Bq/m 3 given for new buildings. The new guide published in 2003 requires installation of protective sheet in the slab-on-ground foundation and a preparatory radon piping. A protective sheet of durable reinforced bitumen felt with a width of 50 - 100 cm should be installed in the slab-foundation wall joint. Careful sealing of lead-troughs plays also an important role. In the case the sealing work does not result in low indoor radon concentration, the radon piping should be activated through radon-fan installation. Careful implementation of the sealing work reduces indoor radon concentration to a level of less than 50 Bq/m 3 , also in areas where the normal building practices result in indoor radon concentrations exceeding the reference level of 200 Bq/m 3 in more than 50% of new houses. Recent experiences from the implementation of the guide will be considered. (author)

Radon Mapping of the Osijek Town

International Nuclear Information System (INIS)

Radolic, V.; Faj, Z.; Smit, G.; Culo, D.; Planinic, J.

1998-01-01

After ten years investigation of radon seasonal variations at three very different locations, as well as radon concentration measurements in kindergartens and schools, systematical indoor radon measurements were undertaken in dwellings of Osijek. Indoor radon was measured by means of the LR-115 nuclear track detector at 48 town locations that gave the arithmetic mean of 71.6 Bq m -3 , standard deviation of 44.0 Bq m -3 and geometric mean of 60.1 Bq m -3 , for the radon concentration range from 23 to 186 Bq m -3 . The empirical frequency distribution of radon concentrations, with the class width of 20 Bq m -3 , was in accordance with the theoretical log-normal distribution which was shown with χ 2 - test. The radon map pointed out a region of higher radon concentrations (central part of the town) that was ascribed to the geological soil structure. Thus supposition was confirmed by radon measurement in the soil gas using radon emanators with the LR-115 film that showed the positive correlation between radon concentrations in the soil and indoors. Radon measurements in Osijeks primary schools pointed out a school that had the highest radon concentration (300 Bq m -3 ) considering all the former indoor radon measurements. The radon distribution in the school building was investigated afterwards radon mitigation procedures were undertaken. (author)

31 CFR 543.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... reimbursement for normal service charges owed it by the owner of that blocked account. (b) As used in this....505 Entries in certain accounts for normal service charges authorized. (a) A U.S. financial... charges to correct bookkeeping errors; and, but not by way of limitation, minimum balance charges, notary...

31 CFR 594.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... reimbursement for normal service charges owed it by the owner of that blocked account. (b) As used in this....505 Entries in certain accounts for normal service charges authorized. (a) A U.S. financial... to correct bookkeeping errors; and, but not by way of limitation, minimum balance charges, notary and...

31 CFR 586.508 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... institution by the owner of such blocked account. (b) As used in this section, the term normal service charge..., and Statements of Licensing Policy § 586.508 Entries in certain accounts for normal service charges... by way of limitation, minimum balance charges, notary and protest fees, and charges for reference...

31 CFR 540.504 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... Statements of Licensing Policy § 540.504 Entries in certain accounts for normal service charges authorized. (a) A U.S. financial institution is authorized to debit any blocked account held by that financial institution in payment or reimbursement for normal service charges owed to it by the owner of the blocked...

The role of the ventilation industry in addressing indoor radon

International Nuclear Information System (INIS)

Wellford, B.W.

1988-01-01

It is generally acknowledged that radon mitigation can only be accomplished on a national scale through a cooperative effort of government, industry and an informed public. The Environmental Protection Agency has developed, demonstrated and published acceptable procedures for testing and preventing the entry or radon into occupancies, as well as procedures for removal when it is not possible or economically viable to prevent radon from entering these occupancies. Various states have instituted programs for industry implementation of EPA procedures and public education programs are now underway. Industry effort will be required to mitigate existing housing stock, to insure new radon resistant housing and, equally important, to provide for radon monitoring and servicing of mitigation measures for centuries to come. What the nature of that industry can and should be and how government agencies can encourage the development of such industry is the subject of this paper

31 CFR 544.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... payment or reimbursement for normal service charges owed it by the owner of that blocked account. (b) As... Licensing Policy § 544.505 Entries in certain accounts for normal service charges authorized. (a) A U.S... adjustment charges to correct bookkeeping errors; and, but not by way of limitation, minimum balance charges...

31 CFR 593.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... payment or reimbursement for normal service charges owed it by the owner of that blocked account. (b) As... Licensing Policy § 593.505 Entries in certain accounts for normal service charges authorized. (a) A U.S... adjustment charges to correct bookkeeping errors; and, but not by way of limitation, minimum balance charges...

31 CFR 547.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... reimbursement for normal service charges owed it by the owner of that blocked account. (b) As used in this... Policy § 547.505 Entries in certain accounts for normal service charges authorized. (a) A U.S. financial... charges to correct bookkeeping errors; and, but not by way of limitation, minimum balance charges, notary...

31 CFR 537.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... normal service charges owed it by the owner of that blocked account. (b) As used in this section, the... Entries in certain accounts for normal service charges authorized. (a) A U.S. financial institution is... bookkeeping errors; and, but not by way of limitation, minimum balance charges, notary and protest fees, and...

31 CFR 541.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... normal service charges owed it by the owner of that blocked account. (b) As used in this section, the... Entries in certain accounts for normal service charges authorized. (a) A U.S. financial institution is... bookkeeping errors; and, but not by way of limitation, minimum balance charges, notary and protest fees, and...

31 CFR 548.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... normal service charges owed it by the owner of that blocked account. (b) As used in this section, the... Entries in certain accounts for normal service charges authorized. (a) A U.S. financial institution is... bookkeeping errors; and, but not by way of limitation, minimum balance charges, notary and protest fees, and...

31 CFR 588.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... reimbursement for normal service charges owed it by the owner of that blocked account. (b) As used in this... § 588.505 Entries in certain accounts for normal service charges authorized. (a) A U.S. financial... to correct bookkeeping errors; and, but not by way of limitation, minimum balance charges, notary and...

31 CFR 546.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... normal service charges owed it by the owner of that blocked account. (b) As used in this section, the... Entries in certain accounts for normal service charges authorized. (a) A U.S. financial institution is... bookkeeping errors; and, but not by way of limitation, minimum balance charges, notary and protest fees, and...

31 CFR 542.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... normal service charges owed it by the owner of that blocked account. (b) As used in this section, the... Entries in certain accounts for normal service charges authorized. (a) A U.S. financial institution is... bookkeeping errors; and, but not by way of limitation, minimum balance charges, notary and protest fees, and...

31 CFR 545.504 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... reimbursement for normal service charges owed it by the owner of that blocked account. (b) As used in this... § 545.504 Entries in certain accounts for normal service charges authorized. (a) A U.S. financial... to correct bookkeeping errors; and, but not by way of limitation, minimum balance charges, notary and...

31 CFR 551.505 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... normal service charges owed it by the owner of that blocked account. (b) As used in this section, the... Entries in certain accounts for normal service charges authorized. (a) A U.S. financial institution is... bookkeeping errors; and, but not by way of limitation, minimum balance charges, notary and protest fees, and...

Reduction of radon concentration in a basement workplace: study of the problem and characterization of the main parameters affecting the radon concentration

International Nuclear Information System (INIS)

Chiaberto, E.M.; Magnoni, M.; Righino, F.; Costa Laia, R.

2002-01-01

In this work is described the method used for the mitigation of high radon concentrations found in a basement workplace, the ARPA laboratory used for the metrology of EMF. In this lab was in fact measured a radon concentration up to 1900 Bq/m 3 , a value largely exceeding the Italian limit for workplaces (500 Bq/m 3 ). The basement workplace affected by radon is a room of around 500 m 3 with no windows and only one door, during work usually close, and therefore with a very low ventilation rate. In this workplace, usually two persons spent about 6 hour per day. Therefore their exposure to the radon and its decay products can attain a considerable value. For this people, accordingly to the accepted dosimetric models, an effective dose of several mSv per year could be estimated (ICRP Publication n. 65, 1993). It is thus important to reduce the radon concentration to acceptable levels, i.e. at least lower than 500 Bq/m 3 . This paper deals not only with the simple method used for the remedial action, but also to the investigation of the relevant parameters affecting the radon concentration. In particular, the monitoring of the radon concentration before and after the remedial action, allowed the calculation of the radon entry rates (Bq/s) and the ventilation rates (s-1) in the different experimental condition

Pre- and post construction radon measurements in a new housing development

International Nuclear Information System (INIS)

Rydock, J.P.; Naess-Rolstad, A.; Brunsell, J.T.

2001-01-01

Results from pre- and post construction radon measurements in a new housing development are presented. The houses were built in an area that had not been previously associated with elevated indoor radon concentrations. Exhalation measurements of gravel and stone from the site and soil gas measurements under several houses did not indicate an elevated radon potential. However, 4 of 21 finished houses (or 19%) exhibited annual average indoor radon concentrations over 200 Bq.m -3 (5.4 pCi/l). The highest concentrations were observed in the first house built in 1 of the 6 houses built differently than the original designs, with the elements of a sub floor ventilation system included for possible radon control if necessary. These results suggest that site investigations can be of limited value in determining where not to include radon protection measures in new housing. Also, that care must be taken to adequately inform everyone involved in the building process of the importance of maintaining a tight seal against the ground to prevent possible radon gas entry into a house. (author)

Occupational and environmental exposures to radon: A perspective for mitigators

International Nuclear Information System (INIS)

Sanchez, D.C.; Messing, M.; Saum, D.

1989-01-01

This paper compares normal environmental and occupational exposures to radon and radon decay products for the occupational group, including radon mitigators and diagnosticians. Occupational exposures to radon and radon decay products and the associated high incidence of radiation-induced lung cancer form the basis for current concern for limiting exposures to radon. While it is now known that radon is a ubiquitous environmental pollutant and estimates exist as to what this means in terms of cancer risk to the general population, similar estimates are not available for radon mitigators and diagnosticians

Toward resolving model-measurement discrepancies of radon entry into houses

International Nuclear Information System (INIS)

Garbesi, K.

1993-01-01

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 (Chapter II) 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 measurement 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. In Chapter III, I describe the development of a dual-probe dynamic pressure technique to measure soil permeability to air (and anisotropy of permeability) at various length scales. Preliminary field tests of the apparatus indicated that soil permeability was indeed scale dependent

Long term and equilibrium factor indoor radon measurements

International Nuclear Information System (INIS)

Martinez, T.; Lartigue, J.; Navarrete, M.; Cabrera, L.; Ramirez, A.; Elizarraras, V.

1998-01-01

This paper presents the annual radon gas concentrations obtained during the 1994-1995 monitoring campaign using passive electret system (type E-PERM). Radon levels were measured in 154 single family dwellings, in normal occupancy conditions (open house condition) in the metropolitan zone of Mexico City. At the same time radon monitoring was performed outdoors. The results show the general log-normal distribution of integrated indoor radon concentration with an annual indoor mean of 3.8 pCi x l -1 . The seasonal variations show the minimum mean values in the summer season which are 39% lower than that in autumn. Equilibrium factors (F) were measured in 12 typical houses both in autumn and winter using a continuous working level monitor for short-lived radon decay products and H-chamber loaded with a short term electret (HST, E-PERM) for radon gas. The obtained total mean equilibrium factors are: F=0.41±0.17 and F=0.29±0.04 for indoor and outdoor, respectively. A quality program was also improved. (author)

Use of natural basement ventilation to control radon in single family dwellings

International Nuclear Information System (INIS)

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

1992-01-01

Natural basement ventilation has always been recommended as a means of reducing radon levels in houses. However, its efficacy has never been documented. In these experiments, natural ventilation has for the first time been studied systematically in two research houses during both the summer cooling season and the winter heating season. Ventilation rates, environmental and house operating parameters, as well as radon levels, have been monitored. It can be definitely concluded from radon entry rate calculations that natural ventilation can reduce radon levels in two ways. The first is by simple dilution. The second is by reducing basement depressurization and thus the amount of radon-contaminated soil gas drawn into the structure. Therefore, basement ventilation can be an effective mitigation strategy under some circumstances. It might be especially useful in houses with low radon concentrations (of the order of 370 Bq m -1 ) or those with low levels and which cannot be mitigated cost-effectively with conventional technology. (Author)

31 CFR 585.520 - Entries in certain accounts for normal service charges authorized.

Science.gov (United States)

2010-07-01

... account; and (2) Make book entries against any foreign currency account maintained by it with a financial... charges in connection therewith. (b) As used in this section, the term normal service charge shall include...

Modelling and experimental study of the behavior of radon and radon decay products in an enclosure. Application to houses

International Nuclear Information System (INIS)

Gouronnec, A.M.

1995-01-01

Since the eighties, more and more studies were performed about radon and its decay products in houses with one of the aim being the estimation of the dose received by their inhabitants. Then, the principal objective of this work is to describe the behaviour of radon and its decay products within a dwelling. In the first part to the report, a few definitions are given and data from literature give an idea of indoor radon and radon decay products activities and/or size distribution. Aspects of dosimetry are presented too. In the second part of the work, a mathematical model, called 'PRADDO' of Physic of Radon and radon Decay products in Domestic environment is developed on the basis of the classical model written by Jacobi in 1972. On the one hand, it has to predict radon decay products activities in systems consisting in one or more enclosure(s), from radon activity and from ambient aerosol concentration and size distribution. On the other hand, one part of the model is assigned to study the influence of the entry model parameters variation on the calculated quantities. Then, in the third part of the work, two experimental studies are realised in order to compare measurements to modelization. The first experimentation is a laboratory work, made on the test bench ICARE from IPSN, and the second one consists in describing the basement of an occupied house from Brittany. In the two cases, the comparison between experiments and modelling shows a good agreement if particles are present in the air, but any conclusion is made when is no aerosol in the enclosure. (author). 158 refs., 81 figs., 42 tabs

Unusually amplified summer or winter indoor levels of radon

International Nuclear Information System (INIS)

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

1993-01-01

The ratios of winter/summer indoor radon levels for houses in different regions of the southern Appalachians are characterized by individual log-normal distributions with geometric means both above and below unity. In some counties and cities, subpopulations of houses have unusually exaggerated winter/summer ratios of indoor radon, as well as high indoor radon levels, during periods of either warm or cool weather. It is proposed that in many instances, houses are communicating with larger than normal underground reservoirs of radon-bearing air in hilly karst terrains; differences between the outdoor and underground air temperatures are believed to provide density gradients producing aerostatic pressure differences for seasonally directed underground transport and subsequently elevated indoor radon. These seasonal movements of air are analogous to the well-known underground chimney effects, which produce interzonal flows of air inside caves

Radon removal using point-of-entry water-treatment techniques. Final report, October 1988-June 1990

International Nuclear Information System (INIS)

Kinner, N.E.; Malley, J.P.; Clement, J.A.

1990-10-01

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 + or - 6,717 pCi/L). The pattern of loading to the units was designed to simulate daily demand in a household. Each of the systems was evaluated with respect to three primary factors: radon removal efficiency, potential problems, and economics. The radon removal efficiencies of the POE GAC units gradually deteriorated over time from 99.7% to 79% for the GAC without pretreatment and 99.7% to 85% for the units preceded by ion exchange. The bubble plate and diffused bubble POE units were very efficient (99%) at removing radon from the water. The resilience is primarly due to the high air to water ratios supplied by the aeration blowers. One major problem associated with the aeration techniques is iron oxidation/precipitation

Radon in houses and soil of Croatia

Energy Technology Data Exchange (ETDEWEB)

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

2006-07-01

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

Radon transport modelling: User's guide to RnMod3d

DEFF Research Database (Denmark)

Andersen, Claus Erik

2000-01-01

RnMod3d is a numerical computer model of soil-gas and radon transport in porous media. It can be used, for example, to study radon entry from soil into houses in response to indoor-outdoor pressure differences or changes in atmospheric pressure. It canalso be used for flux calculations of radon...... decay, diffusion and advection of radon can be solved. Moisture is included in the model, and partitioning ofradon between air, water and soil grains (adsorption) is taken into account. Most parameters can change in time and space, and transport parameters (diffusivity and permeability) may...... be anisotropic. This guide includes benchmark tests based on simpleproblems with known solutions. RnMod3d has also been part of an international model intercomparison exercise based on more complicated problems without known solutions. All tests show that RnMod3d gives results of good quality....

Methods of radon remediation in Finnish dwellings; Asuntojen radonkorjauksen menetelmaet

Energy Technology Data Exchange (ETDEWEB)

Arvela, H.

1995-12-01

A study was made of remedial measures taken in dwellings with high indoor radon concentrations and the results obtained. The data regarding the remedial measures taken in 400 dwellings was obtained from a questionnaire study. The mean annual average indoor radon concentration before the remedies was 1.500 Bq/m{sup 3}, the concentration exceeding in nearly every house the action level of 400 Bq/m{sup 3}. After the measures were taken the mean indoor radon concentration was 500 Bq/m{sup 3}. The resulting indoor radon concentration was less than 400 Bq/m{sup 3} in 60 percent of the dwellings. The best results were achieved using sub-slab-suction and radon well. These methods effectively decrease both the flow of radon bearing air from soil into dwellings and the radon concentration of leakage air. Typical reduction rates in radon concentration were 70-95 percent. The action level was achieved in more than 70 percent of the houses. Sealing the entry routes and improvement of the ventilation resulted typically in reduction rates of 10-50 percent. The goal of the report is to give useful information for the house owners, the do-it-yourself-mitigators, the mitigation firms and the local authorities. The report includes practical guidance, price information and examples of remedial measures. (13 refs., 10 figs., 2 tabs.).

The impacts of balanced and exhaust mechanical ventilation on indoor radon

International Nuclear Information System (INIS)

Fisk, W.J.; Mowris, R.J.

1987-02-01

Models for estimating radon entry rates, indoor radon concentrations, and ventilation rates in houses with a basement or a vented crawl-space and ventilated by natural infiltration, mechanical exhaust ventilation, or balanced mechanical ventilation are described. Simulations are performed for a range of soil and housing characteristics using hourly weather data for the heating season in Spokane, WA. For a house with a basement, we show that any ventilation technique should be acceptable when the soil permeability is less than approximately 10 -12 m 2 . However, exhaust ventilation leads to substantially higher indoor radon concentrations than infiltration or balanced ventilation with the same average air exchange rate when the soil permeability is 10 -10 m 2 or greater. For houses with a crawl-space, indoor radon concentrations are lowest with balanced ventilation, intermediate with exhaust ventilation, and highest with infiltration

Radon in the spas of Croatia

International Nuclear Information System (INIS)

Radolic, V.; Vukovic, B.; Smit, G.; Stanic, D.; Planinic, J.

2005-01-01

Radon concentrations in air and geothermal water of the spa pools in Croatia were measured and the average values of 40.3 and 4.5 kBq/m 3 were obtained, respectively. Great difference between radon concentrations in pool and spring water was considered as a result of mixing normal and geothermal water in the pool as well as the radon decay. Estimation of an effective dose, received by the personnel in the Bizovac spa, gave the value of 0.27 mSv/y. At the location Stubica, the transfer factor of the radon for air and thermal water in the pool was calculated, and the value of 4.9 ± 0.7 x 10 -3 was obtained

Radon in the spas of Croatia

Energy Technology Data Exchange (ETDEWEB)

Radolic, V. [Department of Physics, University of Osijek, P.O. Box 144, 31000 Osijek (Croatia); Vukovic, B. [Department of Physics, University of Osijek, P.O. Box 144, 31000 Osijek (Croatia); Smit, G. [Department of Chemistry, University of Osijek, P.O. Box 144, 31000 Osijek (Croatia); Stanic, D. [Department of Physics, University of Osijek, P.O. Box 144, 31000 Osijek (Croatia); Planinic, J. [Department of Physics, University of Osijek, P.O. Box 144, 31000 Osijek (Croatia)]. E-mail: planinic@pedos.hr

2005-07-01

Radon concentrations in air and geothermal water of the spa pools in Croatia were measured and the average values of 40.3 and 4.5 kBq/m{sup 3} were obtained, respectively. Great difference between radon concentrations in pool and spring water was considered as a result of mixing normal and geothermal water in the pool as well as the radon decay. Estimation of an effective dose, received by the personnel in the Bizovac spa, gave the value of 0.27 mSv/y. At the location Stubica, the transfer factor of the radon for air and thermal water in the pool was calculated, and the value of 4.9 {+-} 0.7 x 10{sup -3} was obtained.

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

International Nuclear Information System (INIS)

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

1978-01-01

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

Characterization of radon penetration of different structural domains of concrete. Final project report

International Nuclear Information System (INIS)

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

1996-05-01

This report documents the research activities by Rogers and Associates Engineering Corporation on grant DE-FG03-93ER61600 during the funded project period from August 1993 to April 1996. The objective of this research was to characterize the mechanisms and rates of radon gas penetration of the different structural domains of the concrete components of residential floor slabs, walls, and associated joints and penetrations. The research was also to characterize the physical properties of the concretes in these domains to relate their radon resistance to their physical properties. These objectives support the broader goal of characterizing which, if any, concrete domains and associated properties constitute robust barriers to radon and which permit radon entry, either inherently or in ways that could be remediated or avoided

Radiation hazard due to radon in indoor air

International Nuclear Information System (INIS)

Keller, G.

1987-01-01

Inhalation of the noble gas radon and its short-lived daughter products present in normal room air causes a considerable increase of the mean natural radiation exposure of the population. As there is an uncontested relationship between lung dose and cancer risk, measures should be taken to guarantee that the radon concentrations in room air do at least not reach maxima. The most simple measure is frequent, brief, good ventilation. Very high radon concentrations are measured in houses where radon pentrates direct from the soil into buildings. For this case, radon-tight insulation of the building from the soil is recommended. A forced ventilation system with heat recovery, installed by experts, has shown to be very successful in radon reduction in 'problematic' houses. (orig.) [de

Radon anomalies prior to earthquakes (2). Atmospheric radon anomaly observed before the Hyogoken-Nanbu earthquake

International Nuclear Information System (INIS)

Ishikawa, Tetsuo; Tokonami, Shinji; Yasuoka, Yumi; Shinogi, Masaki; Nagahama, Hiroyuki; Omori, Yasutaka; Kawada, Yusuke

2008-01-01

Before the 1995 Hyogoken-Nanbu earthquake, various geochemical precursors were observed in the aftershock area: chloride ion concentration, groundwater discharge rate, groundwater radon concentration and so on. Kobe Pharmaceutical University (KPU) is located about 25 km northeast from the epicenter and within the aftershock area. Atmospheric radon concentration had been continuously measured from 1984 at KPU, using a flow-type ionization chamber. The radon concentration data were analyzed using the smoothed residual values which represent the daily minimum of radon concentration with the exclusion of normalized seasonal variation. The radon concentration (smoothed residual values) demonstrated an upward trend about two months before the Hyogoken-Nanbu earthquake. The trend can be well fitted to a log-periodic model related to earthquake fault dynamics. As a result of model fitting, a critical point was calculated to be between 13 and 27 January 1995, which was in good agreement with the occurrence date of earthquake (17 January 1995). The mechanism of radon anomaly before earthquakes is not fully understood. However, it might be possible to detect atmospheric radon anomaly as a precursor before a large earthquake, if (1) the measurement is conducted near the earthquake fault, (2) the monitoring station is located on granite (radon-rich) areas, and (3) the measurement is conducted for more than several years before the earthquake to obtain background data. (author)

Radon and remedial action in Spokane River Valley residences: an interim report

International Nuclear Information System (INIS)

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

1986-03-01

Fifty-six percent of 46 residences monitored in the Spokane River Valley in eastern Washington/northern Idaho have indoor radon concentrations above the National Council for Radiation Protection (NCRP) guidelines of 8 pCi/1. Indoor levels were over 20 pCi/1 in eight homes, and ranged up to 132 pCi/1 in one house. Radon concentrations declined by factors of 4 to 38 during summer months. Measurements of soil emanation rates, domestic water supply concentrations, and building material flux rates indicate that diffusion of radon does not significantly contribute to the high concentrations observed. Rather, radon entry is dominated by pressure-driven bulk soil gas transport, aggravated by the local subsurface soil composition and structure. A variety of radon control strategies are being evaluated in 14 of these homes. Sub-surface ventilation by depressurization and overpressurization, basement overpressurization, and crawlspace ventilation are capable of successfully reducing radon levels below 5 pCi/1 in these homes. House ventilation is appropriate in buildings with low-moderate concentrations, while sealing of cracks has been relatively ineffective

Radon measurement in the spa of Bizovac

International Nuclear Information System (INIS)

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

1996-01-01

The spa of Bizovac is located 20 km on the west of Osijek in east Croatia. Radon concentrations in the air and water of the Bizovac spa were measured by the Radhome silicon detector and the average values were obtained as 70 Bq/m 3 in the indoor pool, 40 Bq/m 3 in the hotel room and 135 Bq/m 3 in the closed therapeutic bathroom. A special experiment was performed in a closed therapeutic bathroom by three bathtubes filled up with geothermal water as well as normal (potable) one from water-supply. Using measured radon concentrations in air by Radhome detector under the mentioned conditions in the closed bathroom, radon concentrations were assessed for the geothermal water as 25.3 Bq/m 3 and 2.7 Bq/m 3 for potable water. Radon in potable water, measured by the sampling glass ampoule and scintillation cell, had the concentration of 3.5 Bq/m 3 . The radon transfer factor from water to air in the indoor pool and therapeutic bathroom was 10 and 40 times higher than for normal dwelling factor (10 -4 ), respectively. The effective dose equivalent of inhaled radon for permanent personnel under the worst conditions in the spa (closed therapeutic bathroom) was 5.4 mSv/y, but visitors spending two weeks in the Bizovac spa could receive the dose of 77 μSv. (author)

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

International Nuclear Information System (INIS)

Akbari, Keramatollah; Mahmoudi, Jafar; Ghanbari, Mahdi

2013-01-01

Radon is released from soil and building materials and can accumulate in residential buildings. Breathing radon and radon progeny for extended periods hazardous to health and can lead to lung cancer. Indoor air conditions and ventilation systems strongly influence indoor radon concentrations. This paper focuses on effects of air change rate, indoor temperature and relative humidity on indoor radon concentrations in a one family detached house in Stockholm, Sweden. In this study a heat recovery ventilation system unit was used to control the ventilation rate and a continuous radon monitor (CRM) was used to measure radon levels. FLUENT, a computational fluid dynamics (CFD) software package was used to simulate radon entry into the building and air change rate, indoor temperature and relative humidity effects using a numerical approach. The results from analytical solution, measurements and numerical simulations showed that air change rate, indoor temperature and moisture had significant effects on indoor radon concentration. Increasing air change rate reduces radon level and for a specific air change rate (in this work Ach = 0.5) there was a range of temperature and relative humidity that minimized radon levels. In this case study minimum radon levels were obtained at temperatures between 20 and 22 °C and a relative humidity of 50–60%. - Highlights: ► We use CFD to simulate indoor radon concentration and distribution. ► The effects of ventilation rate, temperature and moisture are investigated. ► Model validation is performed through analytical solution and measurement results. ► Results show that ventilation rate is inversely proportional to radon level. ► There is a range of temperature and relative humidity that minimize radon level.

Indoor Radon Concentration Related to Different Radon Areas and Indoor Radon Prediction

Science.gov (United States)

Juhásová Šenitková, Ingrid; Šál, Jiří

2017-12-01

Indoor radon has been observed in the buildings at areas with different radon risk potential. Preventive measures are based on control of main potential radon sources (soil gas, building material and supplied water) to avoid building of new houses above recommended indoor radon level 200 Bq/m3. Radon risk (index) estimation of individual building site bedrock in case of new house siting and building protection according technical building code are obligatory. Remedial actions in buildings built at high radon risk areas were carried out principally by unforced ventilation and anti-radon insulation. Significant differences were found in the level of radon concentration between rooms where radon reduction techniques were designed and those where it was not designed. The mathematical model based on radon exhalation from soil has been developed to describe the physical processes determining indoor radon concentration. The model is focused on combined radon diffusion through the slab and advection through the gap from sub-slab soil. In this model, radon emanated from building materials is considered not having a significant contribution to indoor radon concentration. Dimensional analysis and Gauss-Newton nonlinear least squares parametric regression were used to simplify the problem, identify essential input variables and find parameter values. The presented verification case study is introduced for real buildings with respect to various underground construction types. Presented paper gives picture of possible mathematical approach to indoor radon concentration prediction.

The passive radon-thoron discriminative dosimeter for practical use

International Nuclear Information System (INIS)

Doi, Masahiro; Kobayashi, Sadayoshi

1994-01-01

A passive radon-thoron discriminative dosimeter for practical use has been developed. The body of the practical R-T dosimeter is made of two hemispheric diffusion chambers of carbonized plastic whose diameters are 110 mm and 70 mm, respectively. These diameters are determined to improve the detection efficiency of radon as well as thoron and also the discrimination ratio of radon to thoron. Inner surface of the detector housing is smooth and free from electrified charge to assure the uniform deposition of radon and thoron progeny, because the detector housing is molded out of carbonized plastic as an anti-static material. In addition, structure of an air inlet has improved to contact more tightly with a glass fiber filter to prevent dust from entering the detector housing. The air inlet of the detector housing is also covered with a half-cutted hemispherical windbreak to protect the glass fiber filter from weathering and to stabilize the influence of convectional air flow on the radon and thoron entry rate into two hemispherical diffusion chambers of the dosimeter. The results of calibration exercises showed that the lower detection limit of radon and thoron concentrations were estimated to be 5.1 Bqm -3 and 7.9 Bqm -3 respectively in 2 months exposure. And an interim measurement in the concrete cellar proved that the practical R-T dosimeter has enough specifications to be used in the large-scale radon-thoron discriminative survey. (author)

Summary of EPA's radon-reduction research in schools during 1989-90

International Nuclear Information System (INIS)

Leovic, K.W.

1990-10-01

The report details radon mitigation research in schools conducted by EPA during 1989 and part of 1990. The major objective was to evaluate the potential of active subslab depressurization (ASD) in various geologic and climatic regions. The different geographic regions also presented a variety of construction types and heating, ventilating, and air-conditioning (HVAC) system designs that are encountered in radon mitigation of school buildings. A secondary objective was to initiate research in difficult-to-mitigate schools. The research led to the following major conclusions on radon diagnostics and mitigation in schools: (1) Schools have many physical characteristics that typically make their mitigation more complex than house mitigation, including building size and substructure, subslab barriers, HVAC systems, and locations of utility lines. (2) Important school diagnostic procedures and measurements include review of radon measurements and building plans, investigation of the building to assess potential radon entry routes and confirm information in the building plans, analysis of the HVAC system and its influence on pressure differentials and radon levels, and subslab pressure field extension measurements to determine the potential applicability of ASD. (3) ASD can be applied successfully in schools where subslab communication barriers are limited

Effectiveness of radon control techniques in fifteen homes

International Nuclear Information System (INIS)

Turk, B.H.; Prill, R.J.; Fisk, W.J.; Grimsrud, D.T.; Sextro, R.G.

1991-01-01

Radon control systems were installed and evaluated in fourteen homes in the Spokane River Valley/Rathdrum Prairie and in one home in Vancouver, Washington. Because of local soil conditions, subsurface ventilation (SSV) by pressurization was always more effective in these houses than SSV by depressurization in reducing indoor radon levels to below guidelines. Basement overpressurization was successfully applied in five houses with airtight basements where practical-sized fans could develop an overpressure of 1 to 3 Pascals. Crawlspace ventilation was more effective than crawlspace isolation in reducing radon entry from the crawlspace, but had to be used in conjunction with other mitigation techniques, from the crawlspace, but had to be used in conjunction with other mitigation techniques, since the houses also had basements. Indoor radon concentrations in two houses with air-to-air heat exchangers (AAHX) were reduced to levels inversely dependent on the new total ventilation rates and were lowered even further in one house where the air distribution system was modified. Sealing penetrations in the below-grade surfaces of substructures was relatively ineffective in controlling radon. Operation of the radon control systems (except for the AAHX's) made no measurable change in ventilation rates or indoor concentrations of other measured pollutants. Installation costs ranged from approximately $4/m 2 for sealing to $28/m 2 for the AAHXs. Annual operating costs for the active systems were estimated to be approximately $60 to $170

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

International Nuclear Information System (INIS)

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

2015-01-01

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. (authors)

Reduction of radon from household water supplies

International Nuclear Information System (INIS)

Shapiro, P.S.; Sorg, T.J.

1988-01-01

Groundwater can be a major source of indoor radon in homes that use individual wells or are served by very small community water supply systems. In the United States, several wells have been found to contain more than 37,000,000 Bq.m -3 of radon dissolved in the water. This radon can be released in the indoor air in the course of using water for normal household activities. A measurement of the radon in the drinking water can be made when an indoor radon problem is suspected. While ventilation may reduce indoor radon levels that result from household water usage, the most common control technique presently applied is removing the radon from the water using a granular activated carbon (GAC) treatment system. Aeration methods are also effective and have been proven to be economical for small community water supplies. Some of the issues faced in using GAC are sizing and maintaining the unit and shielding and disposing of the GAC to prevent exposure from gamma radiation. (author)

Radon mitigation experience in difficult-to-mitigate schools

International Nuclear Information System (INIS)

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

1990-01-01

Initial radon mitigation experience in schools has shown sub-slab depressurization (SSD) to be generally effective in reducing elevated levels of radon in schools that have a continuous layer of clean, coarse aggregate underneath the slab. However, mitigation experience is limited in schools without sub-slab aggregate and in schools with characteristics such as return-air ductwork underneath the slab or unducted return-air plenums in the drop ceiling that are open to the sub-slab area (via open tops of block walls). Mitigation of schools with utility tunnels and of schools constructed over crawl spaces is also limited. Three Maryland schools exhibiting some of the above characteristics are being researched to help understand the mechanisms that control radon entry and mitigation in schools where standard SSD systems are not effective. This paper discusses specific characteristics of potentially difficult-to-mitigate schools and, where applicable, details examples from the three Maryland schools

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Radon in Norwegian dwellings

International Nuclear Information System (INIS)

Strand, T.; Green, B.M.R; Lomas, P.R.; Mangnus, K.; Stranden, E.

1991-01-01

Measurements of radon in indoor air have been made in a total of about 7500 randomly selected dwellings in Norway from all parts of the country. The number of selected dwellings in each municipality is about proportional to its population, except for the two largest municipalities, Oslo and Bergen, where somewhat smaller samples were taken due to the higher population density. The measurements were performed by nuclear track detectors from the National Radiological Protection Boards in United Kingdom, and the integration time for the measurements was 6 months. The detectors were spread evenly over all seasons of the year to eliminate influence from seasonal variation in the radon level. One single measurement was performed in each dwelling: in the main bedroom. The results shows that the distribution of radon concentrations in Norwegian bedrooms is log-normal. The aritmetic mean of the measurements, including all categories of dwellings, is calculated to be 51 Bq/m 3 and the corresponding geometric mean to be 26 Bq/m 3 . In a large proportion of single-family houses the living room and the kitchen are located on the ground floor while the bedrooms are located one floor higher. The results of the study shows that the radon level is somewhat higher at the ground floor than on the first floor, and higher in the basement than on the first floor. Taking this into account, and assuming that measurements in bedrooms on the first floor is a representative average for living room and kitchen, the average radon concentration for Norwegian dwellings is estimated to be between 55-65 Bq/m 3 . In this estimate, possible influences of the fact that the winters 87/88 and 88/89 were much warmer than normal and may therefor have lowered the results, has been taken into account. 15 refs., 9 figs., 15 tabs

Study of radon diffusion from RHA-modified ordinary Portland cement using SSNTD technique

International Nuclear Information System (INIS)

Narula, A.K.; Goyal, S.K.; Chauhan, R.P.; Chakarvarti, S.K.

2013-01-01

The diffusion coefficient of radon is a very important factor in estimating the rate of indoor radon inflow. The aim of this work is to develop and assess the potential of radon resistant construction materials in residential buildings. Of late, rice husk ash (RHA) has been used as a component in cement. The X-ray diffraction of RHA indicates that the RHA contains mainly amorphous materials while the X-ray fluorescence analysis shows that the major percentage of it is composed of silica. The amorphous silica present in the RHA is responsible for the pozzolonic activity of the ash. The results of the present study indicate that the RHA when mixed with cement initially reduces radon diffusion coefficient, followed by enhancement when the percentage of RHA is increased above 30% by weight. - Highlights: ► Radon diffusion coefficient has been measured in Portland cement with different percentage of rice husk ash (RHA). ► The mixing of RHA to cement changes the radon diffusion coefficient. ► The mixture of cement and RHA can be used to make building materials more resistant to radon entry through diffusion

Radon in the Houses of Virovitica and Podravina County

International Nuclear Information System (INIS)

Varga Pajtler, M.; Miklavcic, I.; Poje, M.; Radolic, V.; Vukovic, B.; Ivkovic, I.; Jurisic, D.

2011-01-01

222Ra is the gaseous radioactive product of the decay of radium isotope 226Ra which is present in soil. Radon atoms that are released from the ground are transported by diffusion and then released in the atmosphere. Radon entries into buildings by advection that is driven by the pressure difference between the building and the ground around the foundation. The aim of this study was to measure radon concentrations in the houses of Virovitica and Podravina county. The measurements were performed by means of two passive track detectors LR-115 (Kodak-Pathe, France), one of which (the open detector) detected total number of alpha-particles of radon and its short-lived progeny, while the other (diffusion detector) registerd tracks only of alpha particles emitted by radon. After being exposed to radiation, the LR-115 detectors were etched in 10 % NaOH aqueous solution at 60 degrees of C for 120 minutes and the detector tracks were counted. Radon concentrations in air were determined according to equation (1), where D 0 was the number of tracks per one day of exposure of the open detector and k is the sensitivity coefficient od the person that counted the tracks. For the track densities D and D 0 of the open and diffusion detectors, respectively, the equilibrium factor was calculated according to equation (2), with the parameters a = 0,50, and b = -0,53. Obtained value for the equilibrium factor was 0,85. Measurements gave radon concentrations in the range of 5.7 - 187.7 Bq m -3 . Average annual effective radon dose for population of Virovitica and Podravina county is 1,5 mSv. (author)

Investigation of radon entry and effectiveness of mitigation measures in seven houses in New Jersey: Midproject report

Energy Technology Data Exchange (ETDEWEB)

Matthews, T.G.; Dudney, C.S.; Monar, K.P.; Landguth, D.C.; Wilson, D.L.; Hawthorne, A.R.; Hubbard, L.M.; Gadsby, K.J.; Bohac, D.L.; Decker, C.A.

1987-12-01

A detailed radon mitigation study is in progress in 14 homes in the New Jersey Piedmont area. The principal goals are the refinement of diagnostic measurements for selection and implementation of mitigation systems, and the reduction of radon concentrations to acceptable levels inside the study houses. Monitoring stations were installed in each home in October, 1986. Instrumented measurements included: basement and upstairs radon; differential pressures across the basement/subslag, basement/upstairs and basement/outdoor interfaces; temperatures at basement, upstairs and outdoor locations; and central air handler usage. A weather station was located at one house, monitoring wind speed and direction; barometric pressure; precipitation; soil temperature; and outdoor temperature and relative humidity. A time-averaged value of all of the above parameters was recorded every 30 min. Several additional parameters were monitored on an intermittent basis in all or selected homes. These include multizone air infiltration rates which have been measured in all homes using passive perfluorocarbon tracers (PFT) and in two homes using a constant concentration tracer gas system (CCTG). Total radon progeny, soil gas radon concentration and permeability characteristics, and gamma radiation levels were also monitored periodically in all study homes. 10 refs., 53 figs.

Investigation of radon entry and effectiveness of mitigation measures in seven houses in New Jersey: Midproject report

International Nuclear Information System (INIS)

Matthews, T.G.; Dudney, C.S.; Monar, K.P.

1987-12-01

A detailed radon mitigation study is in progress in 14 homes in the New Jersey Piedmont area. The principal goals are the refinement of diagnostic measurements for selection and implementation of mitigation systems, and the reduction of radon concentrations to acceptable levels inside the study houses. Monitoring stations were installed in each home in October, 1986. Instrumented measurements included: basement and upstairs radon; differential pressures across the basement/subslag, basement/upstairs and basement/outdoor interfaces; temperatures at basement, upstairs and outdoor locations; and central air handler usage. A weather station was located at one house, monitoring wind speed and direction; barometric pressure; precipitation; soil temperature; and outdoor temperature and relative humidity. A time-averaged value of all of the above parameters was recorded every 30 min. Several additional parameters were monitored on an intermittent basis in all or selected homes. These include multizone air infiltration rates which have been measured in all homes using passive perfluorocarbon tracers (PFT) and in two homes using a constant concentration tracer gas system (CCTG). Total radon progeny, soil gas radon concentration and permeability characteristics, and gamma radiation levels were also monitored periodically in all study homes. 10 refs., 53 figs

Influence of ventilation strategies on indoor radon concentrations based on a semiempirical model for Florida-style houses

International Nuclear Information System (INIS)

Hintenlang, D.E.; Al-Ahmady, K.K.

1994-01-01

Measurements in a full-scale experimental facility are used to benchmark a semiempirical model for predicting indoor radon concentrations for Florida-style houses built using slab-on-grade construction. The model is developed to provide time-averaged indoor radon concentrations from quantitative relationships between the time-dependent radon entry and elimination mechanisms that have been demonstrated to be important for this style of residential construction. The model successfully predicts indoor radon concentrations in the research structure for several pressure and ventilation conditions. Parametric studies using the model illustrate how different ventilation strategies affect indoor radon concentrations. It is demonstrated that increasing house ventilation rates by increasing the effective leakage area of the house shell does not reduce indoor radon concentrations as effectively as increasing house ventilation rates by controlled duct ventilation associated with the heating, ventilating, and air conditioning system. The latter strategy provides the potential to minimize indoor radon concentrations while providing positive control over the quality of infiltration air. 9 refs., 5 figs

Attainment of gross motor milestones by preterm children with normal development upon school entry

NARCIS (Netherlands)

van Dokkum, Nienke H; de Kroon, Marlou L A; Bos, Arend F; Reijneveld, Sijmen A; Kerstjens, Jorien M

BACKGROUND: Little is known on the motor development of moderately preterm born (MPT) children, in comparison with early preterm born (EPT) children and fullterm born (FT), for children with normal motor outcomes at school entry. AIMS: To compare attainment rates of gross motor milestones reached

An improved model for the reconstruction of past radon exposure.

Science.gov (United States)

Cauwels, P; Poffijn, A

2000-05-01

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

Radon -- an environmental hazard

International Nuclear Information System (INIS)

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

2005-01-01

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

Monitoring of the radon exposure in workplaces: Regulatory approaches

International Nuclear Information System (INIS)

Ettenhuber, E.

2002-01-01

Germany has a reference level of 2 10 6 Bqh/m 3 for radon in workplaces, corresponding to an annual dose of 6 mSv and a limit of 6 10 6 Bqh/m 3 , corresponding to 10 mSv/y. If the reference level is exceeded remedial action has to be taken and a new radon measurement should be carried out. If it is not possible to reduce the radon concentration below the reference level the competent authority has to be notified and monitoring of the radon concentrations performed. Germany has performed a study to investigate the exposure by natural radionuclides in workplaces in a large number of industrial activities, with a dose assessment of the workers under normal circumstances. They made a categorization of NORM activities in dose ranges of 20 mSv/y. Most of the NORM activities fall in the category <1 mSv/y when normal occupational hygiene measures are taken

Modelling and experimental study of the behavior of radon and radon decay products in an enclosure. Application to houses; Modelisation et etude experimentale du comportement du radon et de ses descendants dans une enceinte confinee. Application a une habitation

Energy Technology Data Exchange (ETDEWEB)

Gouronnec, A M

1995-02-03

Since the eighties, more and more studies were performed about radon and its decay products in houses with one of the aim being the estimation of the dose received by their inhabitants. Then, the principal objective of this work is to describe the behaviour of radon and its decay products within a dwelling. In the first part to the report, a few definitions are given and data from literature give an idea of indoor radon and radon decay products activities and/or size distribution. Aspects of dosimetry are presented too. In the second part of the work, a mathematical model, called `PRADDO` of Physic of Radon and radon Decay products in Domestic environment is developed on the basis of the classical model written by Jacobi in 1972. On the one hand, it has to predict radon decay products activities in systems consisting in one or more enclosure(s), from radon activity and from ambient aerosol concentration and size distribution. On the other hand, one part of the model is assigned to study the influence of the entry model parameters variation on the calculated quantities. Then, in the third part of the work, two experimental studies are realised in order to compare measurements to modelization. The first experimentation is a laboratory work, made on the test bench ICARE from IPSN, and the second one consists in describing the basement of an occupied house from Brittany. In the two cases, the comparison between experiments and modelling shows a good agreement if particles are present in the air, but any conclusion is made when is no aerosol in the enclosure. (author). 158 refs., 81 figs., 42 tabs.

An assessment of indoor radon exposure in Ireland

International Nuclear Information System (INIS)

McLaughlin, J.P.

1987-01-01

The results of measurements of indoor radon in over 700 dwellings chosen at ''random'' throughout the Republic of Ireland are presented. The median value of radon in these dwellings was found to be 37 Bq/m 3 (1 pCi/1). The distribution of indoor radon concentration appears to be approximately log-normal with about 2% of the dwellings surveyed having concentrations greater than 400 Bq/m 3 . High radon values were generally found to be more common in western and southern regions of the country than in the more densely populated eastern seabord. Using dose conversion factors in keeping with recent developments in lung dosimetry the median effective dose equivalent to occupants arising from the inhalation of radon daughters in the dwellings surveyed is estimated to be about 1.8 mSv per year. On the same basis for dwellings with indoor radon above 400 Bq/m 3 the continuous effective dose equivalent is estimated to be in excess of 20 mSv per year

Radon

Energy Technology Data Exchange (ETDEWEB)

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

1978-09-01

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

A search profile for dwellings with elevated radon levels

DEFF Research Database (Denmark)

Damkjær, A.; Andersen, C.E.; Majborn, B.

1996-01-01

A search profile for dwellings with elevated radon levels has been employed to investigate possibly radon-prone areas in Denmark and to find houses suitable for radon mitigation studies. The profile is defined as dwellings which are single-family houses with slab-on-grade foundation or partly...... basement/slab-on-grade foundation built on either fractured granitic basement rocks, or fractured limestone. Clayey till areas were also included in the profile in order to confirm earlier findings. Three areas representing these surface geologies were selected for indoor radon measurements with CR-39...... track detectors, and a total of 200 houses matching the profile underwent radon measurements during the winter 1994-95. The distribution of the measured radon concentrations were found in most cases to comply with log-normal distributions. Measurements in the living rooms of houses in each of the three...

Monitoring of the Syrian rift valley using radon technique

International Nuclear Information System (INIS)

Al-Hilal, M.; Al-Ali, A.; Jubeli, Y.

1997-02-01

Groundwater radon data were recorded once every two months from six monitoring sites of the Syrian rift valley during the year 1996. Radon samples were measured from deep artesian wells and from continuously-flowing springs that are distributed along this most active seismic zone in Syria. The available data were integrated with previously measured groundwater radon data from the same stations in order to estimate the range of normal radon fluctuations in the region. The estimation of such range may enable the separation between usual groundwater radon variations from other outliers which may indicate possible tectonic activities or earthquake hazards in the study area. Periodical radon measurements based on two months intervals and long distance between sampling stations does not enable us to trust with high level of confidence the connection between radon values and any possible earth dynamics. Therefore, shorter measuring time with closer monitoring sites are highly recommended to achieve the optimum advantage of such application. (Author). 8 Figs., 2 Tabs., 10 Refs

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

Science.gov (United States)

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. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Parametric modelling of temporal variations in radon concentrations in homes

International Nuclear Information System (INIS)

Revzan, K.L.; Turk, B.H.; Harrison, J.; Nero, A.V.; Sextro, R.G.

1988-01-01

The 222 Rn concentrations in the living area, the basement, and the undelying soil of a New Jersey home have been measured at half-hour intervals over the course of a year, as have indoor and outdoor temperatures, wind speed and direction, and indoor-outdoor and basement-subslab pressures; in addition, periods of furnace opration have been logged. We generalize and extend an existing radon entry model in order to demonstrate the dependence of the radon concentration on the environmental variales and the extent of furnace use. The model contains parameters which are dependent on geological and structural factors which have not been measured or otherwise determined; statistical methods are used to find the best values of the parameters. The non-linear regression of the model predictions (over time) on the measured living area radon concentrations yields an R/aup 2/ of 0.88. 9 refs., 2 figs

Measuring radon source magnitude in residential buildings

International Nuclear Information System (INIS)

Nazaroff, W.W.; Boegel, M.L.; Nero, A.V.

1981-08-01

A description is given of procedures used in residences for rapid grab-sample and time-dependent measurements of the air-exchange rate and radon concentration. The radon source magnitude is calculated from the results of simultaneous measurements of these parameters. Grab-sample measurements in three survey groups comprising 101 US houses showed the radon source magnitude to vary approximately log-normally with a geometric mean of 0.37 and a range of 0.01 to 6.0 pCi 1 -1 h -1 . Successive measurements in six houses in the northeastern United States showed considerable variability in source magnitude within a given house. In two of these houses the source magnitude showed a strong correlation with the air-exchange rate, suggesting that soil gas influx can be an important transport process for indoor radon

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

Science.gov (United States)

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.

Characterizing the occurrence, sources, and variability of radon in pacific northwest homes

International Nuclear Information System (INIS)

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

1990-01-01

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 ( 222 Rn) 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 m 2 ) surrounding the house substructures. Estimated soil gas entry rates ranged from 0.4 to 39 m 3 h -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 operations, 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

Radon-thoron discrimination using a polythene foil: an application in uranium exploration

International Nuclear Information System (INIS)

Ramola, R.C.; Singh, M.; Sandhu, A.S.; Singh, S.; Virk, H.S.

1989-01-01

Integrated measurements of radon concentrations in subsurface soil are being used extensively for uranium exploration and earthquake prediction. For uranium exploration only the radon signals are needed; however, a part of the α-activity may derive from thoron. To exclude thoron, a polythene foil has been used as an anti-thoron membrane to delay the entry of thoron into the detector system so that only the longer lived isotope 222 Rn survives to be measured. A long term integrated measurement has been carried out using LR-115 and CR-39 plastic track detectors. The observed track density has been determined as a function of foil thickness. It is found that a polythene foil of appropriate thickness could be successfully employed for the separation of radon and thoron in soil. (author)

Basic study on positive effects of radon inhalation on pet's health

International Nuclear Information System (INIS)

Kataoka, Takahiro; Sakoda, Akihiro; Kawabe, Atsushi; Hanamoto, Katsumi; Yamaoka, Kiyonori; Tokunaga, Rikizo

2012-01-01

Radon inhalation using our radon exposure device activated anti-oxidative function in some organs of mouse. To assess the possibility of its application to veterinary care, healthy dogs and cats with chronic renal failure were inhaled radon at a concentration of 5500 Bq/m 3 for 30 minutes every 2 days for 30 days. In result, radon inhalation within a relatively long time period significantly decreased the triglyceride level of dogs. On the other hand, some cats increased the volume of drinking water by radon inhalation and the creatinine level in blood of these cats was decreased to normal level. These findings suggest that radon inhalation may have curative properties against chronic renal failure. (author)

High indoor radon concentrations in some Swedish waterworks

International Nuclear Information System (INIS)

Aakerblom, G.; Hagberg, N.; Mjoenes, L.; Heiberg, A.

2002-01-01

High indoor radon concentrations in buildings used for water treatment are not uncommon. When raw water is processed in an open system radon escapes from the water to the indoor air of the premises. It is not unusual that the staff of the waterworks have their offices in the building where the water is processed. If large volumes of water are processed and the evaporated radon can reach the workplaces the indoor radon concentration can be very high even if the radon concentration of the raw water is moderate. Groundwaters from aquifers in bedrock and soil and surface water that has been infiltrated through deposits of sand or gravel have the potential to cause high indoor radon levels. In surface water emanating directly from a lake or a river the radon concentrations are normally too low to cause problems. Three waterworks in central Sweden have been studied, Ludvika, Fredriksberg and Kolbaeck. The radon concentrations in the raw water of these waterworks are from 85 Bq/l to 300 Bq/l. Average indoor radon concentrations exceeding 17,000 Bq/m 3 have been measured in Ludvika with peaks of almost 37,000 Bq/m 3 . In Kolbaeck radon concentrations up to 56,000 Bq/m 3 have been measured. It is quite possible that employees of waterworks can receive doses exceeding 20 mSv per year (calculated according to ICRP:s dose conversion convention). Measurements of radon and gamma radiation from the waterworks are reported and methods to lower the indoor radon concentrations are discussed. (author)

Radon transport modelling: User's guide to RnMod3d

International Nuclear Information System (INIS)

Andersen, C.E.

2000-08-01

RnMod3d is a numerical computer model of soil-gas and radon transport in porous media. It can be used, for example, to study radon entry from soil into houses in response to indoor-outdoor pressure differences or changes in atmospheric pressure. It can also be used for flux calculations of radon from the soil surface or to model radon exhalation from building materials such as concrete. The finite-volume model is a technical research tool, and it cannot be used meaningfully without good understanding of the involved physical equations. Some understanding of numerical mathematics and the programming language Pascal is also required. Originally, the code was developed for internal use at Risoe only. With this guide, however, it should be possible for others to use the model. Three-dimensional steady-state or transient problems with Darcy flow of soil gas and combined generation, radioactive decay, diffusion and advection of radon can be solved. Moisture is included in the model, and partitioning of radon between air, water and soil grains (adsorption) is taken into account. Most parameters can change in time and space, and transport parameters (diffusivity and permeability) may be anisotropic. This guide includes benchmark tests based on simple problems with known solutions. RnMod3d has also been part of an international model intercomparison exercise based on more complicated problems without known solutions. All tests show that RnMod3d gives results of good quality. (au)

An investigation of factors influencing indoor radon concentrations

International Nuclear Information System (INIS)

Majborn, B.; Soerensen, A.; Nielsen, S.P.; Boetter-Jensen, L.

1988-05-01

Variations in indoor radon concentrations and some influencing factors have been studied during a two-year period (1986-1987) in 16 almost identical single-family houses.The annual average radon concentration in the houses varied from about 50 to about 400 Bq/m 3 . Variations in soil characteristics and radon concentration in soil gas could not be directly related to the variations of the average indoor radon concentrations. Most of the houses showed a ''normal'' seasonal variation of the radon concentration with a maximum in the winter and minimum in the summer. A deviating seasonal variation was found in three of the houses. Hourly data obtained in one unoccupied house during a period of 2-1/2 months showed no or only weak correlations between the indoor radon concentration and meteorological factors. However, for most of the houses, the seasonal variation of the indoor radon concentration was well correlated with the average indoor-outdoor temperature difference on a 2-month basis. It was demonstrated that the radon concentration can be strongly reduced in the Risoe houses if a district-heating duct, which is connected to all the houses, is ventilated, so that a slightly lowered pressure is maintained in the duct. 5 taps., 24 ill. (author)

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

International Nuclear Information System (INIS)

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

2000-01-01

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

Radon, a real threat to our health

International Nuclear Information System (INIS)

Mauna, T.; Mauna, A.; Ghita, R.

2005-01-01

Radon is invisible, odorless and tasteless a radioactive gas that comes from the radioactive decay of naturally occurring uranium and thorium in soil and rock, can concentrate in domestic homes, overground workplaces, and caves. Radon has been identified as the second leading cause of lung cancers in the U.S., about 20.000 per year, and is present in millions of homes. The Environmental Protection Agency (EPA) of USA designated January 2005 as National Radon Action Month (NRAM) and held the second week of October every year as National Radon Action Week (NRAW). The focus of NRAM and NRW is to promote awareness about, testing for and mitigation of indoor radon gas with various events and outreach campaigns. The EPA considering radon exposure as capital problem for the population health decided to have a special dedicated free phone number the similar for every county state of USA taking into account the increase easy call by interested people. Many universities and research centers, including NGO from different countries world wide, following the recommendation of 'United Nations Scientific Committee on the Effects of Atomic Radiation' (USNCEAR) and 'International Commission on Radiological Protection ' (ICRP) until 1977, developed their own radon researches in order to clarify the properties, area distribution and concentration, geological production and other needed aspects. This paper compare the radon risk versus radioactive waste gaseous Nuclear Power Plant release in normal or abnormal operation and underlines the needs for Romanian's radiation research laboratories to undertake radon protection programs similar to to those underway in other countries. (authors)

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

Science.gov (United States)

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

1988-01-01

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

Radon

Science.gov (United States)

... radon-resistant features. These features include gravel and plastic sheeting below the foundation, along with proper sealing ... lower the radon level. Detailed information about radon reduction in your home or building can be found ...

The radon

International Nuclear Information System (INIS)

1998-01-01

This booklet is intended to answer briefly the most important questions about the nature and sources of radon, its pathways from environment to organism, as well as the ways to minimize its concentration in the habitat's atmosphere. The radon is a naturally appearing radioactive gas, produced through the decay of uranium and radium present in the terrestrial crust. It can be found everywhere on the planet's surface and it is emitted particularly from the granite and volcanic underground rocks as well as from certain construction materials. It is one of the agents producing pulmonary cancer, although not so dangerous as the tobacco is. The following items are elaborated in this booklet: - the place of radon in the average exposure to ionizing radiations of the French population; - the risk; - the radon in the environment (the meteorological conditions, the nature of the rocks); - radon in dwellings (radon measurements in the French dwellings, the entrance pathways of radon, the dependence of radon concentration on the profession and way of life of the inhabitants); - radon measurements; - how to reduce the radon concentration in dwellings

Sorption of radon-222 to natural sediments

International Nuclear Information System (INIS)

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

1992-01-01

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

Effect of radon transport in groundwater upon gamma-ray borehole logs

International Nuclear Information System (INIS)

Nelson, P.H.; Rachiele, R.; Smith, A.

1980-09-01

Granitic rock at an experimental waste storage site at Stripa, Sweden, is unusually high in natural radioelements (40 ppM uranium) with higher concentrations occurring locally in thin chloritic zones and fractures. Groundwater seeping through fractures into open boreholes is consequently highly anomalous in its radon content, with activity as high as one microcurie per liter. When total count gamma-ray logs are run in boreholes where groundwater inflow is appreciable, the result is quite unusual: the radon daughter activity in the water adds considerably to the contribution from the rock, and in fact often dominates the log response. The total gamma activity increases where radon-charged groundwater enters a borehole, and remains at a high level as the water flows along the hole in response to the hydraulic gradient. As a consequence, the gamma log serves as a flow profile, locating zones of water entry (or loss) by an increase (or decrease) in the total gamma activity. A simple model has been developed for flow through a thin crack emanating radon at a rate E showing that the radon concentration of water entering a hole is E/Λh, where Λ is the radon decay rate and h the crack aperture, assuming that the flow rate and crack source area are such that an element of water resides within the source area for several radon half-lives or more. Concentration measurements can provide a measurement of the inflow rate. Data from the 127-mm holes in the time-scale drift behave in this fashion

Radon dynamics in underwater thermal radon therapy

International Nuclear Information System (INIS)

Lettner, H.; Hofmann, W.; Winkler, R.; Rolle, R.; Foisner, W.

1998-01-01

At a facility for underwater thermal radon therapy in Bad Hofgastein, experiments were carried out with the aim of establishing radon in the air exhaled by the treated patients and of radon decay products on the skin of the patients. The time course of radon concentration in the exhaled air shows a maximum a few minutes after entering the bath, then the Rn concentration remains constant over the remaining time spent in the bath. Taking into account several simplifying assumptions, the average dose to the epidermis from radon daughters is about 50 μGy. (A.K.)

Radon in Schools

Science.gov (United States)

... Search Search Radon Contact Us Share Radon in Schools Related Information Managing Radon in Schools Radon Measurement ... Radon Could Be a Serious Threat to Your School Chances are you've already heard of radon - ...

Radon in houses due to radon in potable water

International Nuclear Information System (INIS)

Hess, C.T.; Korsah, J.K.; Einloth, C.J.

1987-01-01

Radon concentration in the air of 10 houses has been measured as a function of water use and meterological parameters such as barometric pressure, wind velocity and direction, indoor and outdoor temperature, and rainfall. Results of calibrations and data collected in winter, spring, fall, and summer are given for selected houses. Average values of radon concentration in air are from 0.80 to 77 rhoCi/1. Water use average ranges from 70 to 240 gal/day. Average potential alpha energy concentrations in these houses range from 0.02 to 1.6 working levels. The radon level due to water use ranges from 0 to 36% of the house radon from soil and water combined. The radon level change due to use of a filter on the water supply shows a 60% reduction in radon in the house. Conclusions are that water radon can be a major fraction of the radon in houses. The ratio of airborne radon concentration due to water use to the radon concentration in water is 4.5 x 10/sup -5/ - 13 x 10/sup -5/

Hazardous waste disposal in relationship to radon gas emanation in atmosphere

International Nuclear Information System (INIS)

Fang, H.Y.

1990-01-01

Radioactive/toxic radon gas (Rn) produced naturally in the ground by the normal decay of uranium (U) and radium (Ra) is widely distributed in trace amounts in the earth's crust. It is a colorless, odorless and tasteless element and is one of the six generally known noble gases which are inert gases lacking the usual or anticipated chemical or biological action. Most radon gas is concentrated in the oxidation belt which is at a relatively shallow depth from the ground surface. Under normal conditions, the amount of radon gas seeping into the atmosphere or entering into residential buildings is very little and will not be harmful to human health. In recent years, due to population growth, a progressive living standard and industrial progress, many natural farm lands, forests and wetlands have been destroyed by conversion into residential and industrial compounds; consequently, such construction activities and industrial waste disposal changes the dynamic equilibrium of the ecosystem which can trigger and accelerate radon gas emanation and mobilization. This change is the major reason for the problem of indoor radon concentration which has significantly increased in recent years. Recent findings indicate that radon is not a totally inert element as previously thought. It can be influenced by local environments such as temperature, pH value, ion exchange, redox reaction, etc. to some degree. Also radon gas interacts with soil, water, air and others; unfortunately, the interface mechanisms between radon and the environment are not yet clearly understood and little information on these aspects is available. In this paper only the hazardous waste disposal causes for radon emanation are discussed. To deal with such complex phenomena, a new approach is presented that assumes radon gas interaction with the environment through dust in the air and suspensions in the water and soil-water system

Radon in the workplace

International Nuclear Information System (INIS)

Scivyer, C.R.; Gregory, T.J.

1995-01-01

This Guide has been prepared for the Health and Safety Executive (HSE) by the Building Research Establishment (BRE). Following the guidance is not compulsory and you are free to take other action. However if you do follow the guidance you will normally be doing enough to comply with the law. Health and Safety Inspectors seek to secure compliance with the law and may refer to this guidance as illustrating good practice. In the past, concern about exposure of employees to radon has largely centred on the mining environment. In recent times, with increased knowledge and mapping of radon levels in homes, attention has increasingly turned to radon exposure in buildings used for work purposes. Now there is a considerable fund of information to show that employees in some buildings can receive very significant radiation doses from radon. Surveys show that levels of radon tend to be higher in buildings with small rooms, such as offices rather than larger factory and warehouse constructions. The particular problem is that the nature of the work process gives no clue as to the radon hazard that may exist, and the employer may be unaware of its presence and how to deal with it. This Guide is aimed principally at employers and those who control buildings used for work purposes, or their representatives. It offers guidance on practical measures for reducing radon levels in workplaces. The guidance should also be of interest and assistance to those, such as surveyors and builders, concerned with specifying and carrying out the necessary remedial measures. Advice is provided for the majority of building types and construction situations likely to be encountered in larger non-domestic buildings. For buildings where construction is similar to that found in dwellings the guidance published by BRE on remedial measures for dwellings should be used. BRE prepared this Guide with assistance from the National Radiological Protection Board (NRPB) and Cornwall County Council under contract

Blower door method in radon diagnostics

International Nuclear Information System (INIS)

Fronka, A.; Moucka, L.

2004-01-01

The idea of the radon transfer factor is commonly presented as the ratio of the building indoor radon concentration to the subsoil radon concentration. Ventilation and the pressure field over the whole building envelope, which varies in a time over a very wide range even in the same building, poses a major problem. Therefore a new approach based on the controlled conditions determining the soil air infiltration was developed. Radon in soil gas infiltrates into the building indoor environment particularly through cracks and other leakages in the structure providing the building contact with its subsoil. The infiltration is driven by the air pressure difference on the two sides of the structure. The pressure difference is caused by the stack effect and its value ranges from 1-2 Pa in family houses to some tens of Pa in higher buildings. Unfortunately, the pressure difference is very unstable under normal conditions, being affected by a host of parameters such as the height of the building, distribution and geometry of leakages, outdoor-indoor temperature difference, etc. Wind direction and velocity of the wind plays a major role. In our research the blower door method was applied in combination with a monitoring of the indoor radon concentration. The indoor-outdoor pressure difference and the pressure difference at the two sides of the screen shutter of the blower door fan are also measured. The blower door ensures a constant, evaluable air exchange rate. The fan power is regulated to provide a stable pressure difference within the range of roughly 5-100 Pa. This approach provides very well defined conditions allowing us to apply a constant ventilation-constant radon supply model. In such circumstances the dynamical changes of radon concentrations are very fast, and therefore a unique continual radon monitor was applied. The radon supply rate is evaluated from the radon steady state of the time course of radon concentration. The dependence of the radon supply rate on

Radon mitigation in schools utilising heating, ventilating and air conditioning systems

International Nuclear Information System (INIS)

Fisher, G.; Ligman, B.; Brennan, T.; Shaughnessy, R.; Turk, B.H.; Snead, B.

1994-01-01

As part of a continuing radon in schools technology development effort, EPA's School Evaluation Team has performed radon mitigation in schools by the method of ventilation/pressurisation control technology. Ventilation rates were increased, at a minimum, to meet the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) standard, Ventilation for Acceptable Indoor Air Quality (ASHRAE 62-1989). This paper presents the results and the preliminary evaluations which led to the team's decision to implement this technology. Factors considered include energy penalties, comfort, indoor air quality (IAQ), building shell tightness, and equipment costs. Cost benefit of heat recovery ventilation was also considered. Earlier results of the SEP team's efforts have indicated a severe ventilation problem within the schools of the United States. Two case studies are presented where HVAC technology was implemented for controlling radon concentrations. One involved the installation of a heat recovery ventilator to depressurise a crawl space and provide ventilation to the classrooms which previously had no mechanical ventilation. The other involved the restoration of a variable air volume system in a two-storey building. The HVAC system's controls were restored and modified to provide a constant building pressure differential to control the entry of radon. Pre-mitigation and post-mitigation indoor air pollutant measurements were taken, including radon, carbon dioxide (CO 2 ), particulates, and bio-aerosols. Long-term monitoring of radon, CO 2 , building pressure differentials, and indoor/outdoor temperature and relative humidity is presented. (author)

Dosimetry of inhaled radon and thoron progeny

International Nuclear Information System (INIS)

James, A.C.

1994-06-01

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

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Radon concentration and natural radioactivity evaluation in the Vysehrad casemates

International Nuclear Information System (INIS)

Berka, Z.; Thinova, L.; Stepan, M.

2004-01-01

The Vysehrad casemates formed a part of Prague's defense system in the middle ages. The casemates consist of a large system of underground corridors (which are in direct contact with subsoils) that run around the whole Vysehrad hill. The corridors are covered by an artificially made-up ground. Although there are many vents and embrasures in the casemates, investigation of radon accumulation in the casemates is of interest. A comprehensive radon and natural radioactivity survey has been carried out on the Vysehrad hill as part of special scientific programme for secondary school students. No extreme radon concentration or extremely high natural radioactivity has been observed. The highest radon concentration were measured in the blind parts of corridors that are normally unused. The radon concentrations found can be described as health-safe

Radon and health

International Nuclear Information System (INIS)

Chobanova, Nina

2016-01-01

Radon is radioactive noble gas that can be found in soil, water, outdoor and indoor air. Since environmental radon on average accounts for about half of all human exposure to radiation from natural sources, increasing attention has been paid to exposure to radon and its associated health risks. Many countries have introduced regulations to protect their population from radon in dwellings and workplaces. In this article are discussed main characteristics of radon, including sources of exposure, variation in radon exposure, how managing risks from radon exposure, how to measure the concentration of radon. There are results of measurements conducted under the 'National radon programme' in Bulgaria also. Key words: radon, sources of exposure, risk, cancer, measure to decrease the concentration [bg

Rating radon through the looking glass

International Nuclear Information System (INIS)

Anon.

1993-01-01

Radon emerged as a health threat in the last five years as studies showed that exposure to high levels in the home can cause lung cancer. But many families move so often that its difficult to determine their exposure over a lifetime. Now, Battelle Memorial Institute scientists at the Energy Dept.'s Pacific Northwest Lab in Richland, Wash., have devised a clever way to do so. They tape a 2-inch-square piece of clear plastic polymer to the glass on an old mirror or framed picture. Such items as wedding photos are easily datable and normally carried from home to home. As radon decays over the years, it emits alpha particles, which embed themselves in glass. The particles leave tracks in the polymer. By analyzing these tracks, scientists can estimate a person's average annual exposure to indoor radon over 20 years or more. Starting in May, the technique will be used in a three-year National Cancer Institute study that examines radon, smoking, and diet as co-factors in the risk of lung cancer

Review of selected state-of-the-art applications of diagnostic measurements for radon-mitigation planning. Report for April 1986-June 1987

International Nuclear Information System (INIS)

Hubbard, L.M.; Harrje, D.T.; Gadsby, K.J.; Sanchez, D.C.; Turk, B.H.

1987-09-01

Since late-1984, EPA's AEERL has supported a program to develop and demonstrate radon-mitigation techniques for single-family detached dwellings. As part of the program, projects have been started, directed at developing and demonstrating the use of diagnostic measurements in all phases of the radon-mitigation process. Diagnostic measurements are used to assess: (1) the radon sources strengths, variability, and locations; and, (2) radon transport to the house and its entry and distribution in the house as influenced by environmental, house characteristics, and occupancy factors. The diagnostic measurements reported include: (1) soil-gas grab sampling; (2) communication (air flow or pressure-field extension) tests; (3) whole house infiltration; (4) differential pressure, (5) gamma radiation; and, (6) radon flux. The paper concludes that the above selected diagnostic measurements were especially useful in characterizing houses with indoor radon problems attributable to soil-gas-borne radon that may be amenable to mitigation through the use of subslab ventilation

Radon in the water from drilled wells. Results from an investigation in Oerebro; Radon i vatten fraan bergborrade brunnar. Resultat fraan en undersoekning i oerebro kommun

Energy Technology Data Exchange (ETDEWEB)

Liden, E.; Andersson, Lennart [Regionsjukhuset, Oerebro (Sweden). Yrkes- och miljoemedicinska kliniken; Linden, A. [Svensk Geofysik AB, Falun (Sweden); Aakerblom, G. [Statens Straalskyddsinstitut, Stockholm (Sweden); Aakesson, T. [Miljoe- och haelsoskyddsfoervaltningen, Oerebro (Sweden)

1995-09-01

In 1991 a drilled well containing water with a radon count of about 20,000 Bq/l was found in the city of Oerebro in southern Sweden. A study was started to develop measures to decrease the radon content of water, investigate public health risks and determine the prevalence of high-radon waters in Sweden. 1991-94 various techniques were tested to reduce the concentration of radon in water. The efficiency of aerating high-radon drinking water was studied under field conditions using two modified aerators in a well, in a pressure tank, and in a column of pellets. The efficiency varied from 20 to 99%. A survey of radon in water from 269 drilled wells was conducted in the Municipality of Oerebro. In water from 78 wells, the mean concentration of radon was 1336 Bq/l. The emanation of radon during normal household activities was studied in a home supplied with water from a drilled well whose radon count was approx 20,000 Bq/l. A geological investigation revealed the presence of thin Uranium-loaded fissures in the bedrock (granite) surrounding the well. 130 refs, 16 figs, 14 tabs.

Predicting radon/radon daughter concentrations in underground mines

International Nuclear Information System (INIS)

Leach, V.A.

1984-01-01

A detailed description of a computer programme is outlined for the calculation of radon/radon daughter concentrations in air. This computer model is used to predict the radon/radon daughter concentrations in Working Level (WL) at the workplace and at the various junctions at either end of the branches in a typical ventilation network proposed for the Jabiluka mine in the Northern Territory

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

International Nuclear Information System (INIS)

Nero, A.V. Jr.

1985-04-01

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

Measurement of indoor and outdoor radon concentrations during Superstorm Sandy.

Science.gov (United States)

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.

Significance of independent radon entry rate and air exchange rate assessment for the purpose of radon mitigation effectiveness proper evaluation: case studies

Czech Academy of Sciences Publication Activity Database

Froňka, A.; Jílek, K.; Moučka, L.; Brabec, Marek

2011-01-01

Roč. 145, 2-3 (2011), s. 133-137 ISSN 0144-8420 Institutional research plan: CEZ:AV0Z10300504 Keywords : indoor radon * kalman filter * state-space modeling Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.822, year: 2011

Radon occurrence in soil-gas and groundwater around an active landslide

Energy Technology Data Exchange (ETDEWEB)

Ramola, R.C. [Department of Physics, H.N.B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal -249 199 (India)], E-mail: rcramola@gmail.com; Choubey, V.M. [Wadia Institute of Himalayan Geology, Dehradun 248 001 (India); Negi, M.S.; Prasad, Yogesh; Prasad, Ganesh [Department of Physics, H.N.B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal -249 199 (India)

2008-01-15

This paper presents the results of investigation of radon levels in the soil-gas and groundwater of Uttarkashi, India within the distance of 5 km in vertical and horizontal directions from the landslide of Varunawat hill. Radon release from the soil and groundwater was found higher than the normal values. Radon concentration in groundwater over and around the landslide was found to vary from 0.51 to 86kBqm{sup -3}. The soil-gas radon concentration was found to vary from 219 to 3kBqm{sup -3} along the slope of landslide. Radon exhalation rate in collected soil samples was found to vary from 2.28x10{sup -5} to 9.01x10{sup -5}Bqkg{sup -1}h{sup -1}. Radon values were not found correlated with major and trace element contents in the upper soil of the area, which indicate that the migration of radon from deeper part of the earth along with landslide contribute to the surface radon concentration. Recorded values show a close association with local geology and Varunawat eruptions.

Radon occurrence in soil-gas and groundwater around an active landslide

International Nuclear Information System (INIS)

Ramola, R.C.; Choubey, V.M.; Negi, M.S.; Prasad, Yogesh; Prasad, Ganesh

2008-01-01

This paper presents the results of investigation of radon levels in the soil-gas and groundwater of Uttarkashi, India within the distance of 5 km in vertical and horizontal directions from the landslide of Varunawat hill. Radon release from the soil and groundwater was found higher than the normal values. Radon concentration in groundwater over and around the landslide was found to vary from 0.51 to 86kBqm -3 . The soil-gas radon concentration was found to vary from 219 to 3kBqm -3 along the slope of landslide. Radon exhalation rate in collected soil samples was found to vary from 2.28x10 -5 to 9.01x10 -5 Bqkg -1 h -1 . Radon values were not found correlated with major and trace element contents in the upper soil of the area, which indicate that the migration of radon from deeper part of the earth along with landslide contribute to the surface radon concentration. Recorded values show a close association with local geology and Varunawat eruptions

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

Science.gov (United States)

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

2013-12-01

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

Cleaners in reducing the hazards of indoor radon decay products

International Nuclear Information System (INIS)

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

1992-01-01

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

Overview of current radon and radon daughter research at LBL

International Nuclear Information System (INIS)

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

Treatment technology for removing radon from small community water supplies

International Nuclear Information System (INIS)

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

1990-01-01

This paper reports on the selection of an appropriate treatment system to remove radon from drinking water which depends primarily upon percent removal; capital and operating and maintenance costs; safety; raw water quality with respect to parameters such as Fe, Mn, bacteria, and organics. The radon removal efficiency of the diffused bubble and packed tower aeration exceeded 99% at A:W ratios of 15:1 and 5:1, respectively; the GAC system averaged 81 ± 7.7%. Though our field evaluations indicated that GAC systems may not be as efficient as aeration systems, the system tested was operated above design requirements for most of the study period. Other researchers have found removals of greater than 99% with GAC point-of-entry applications. Therefore, each of these processes has the potential to consistently remove 99% of the radon applied. However, even this percent removal may not be sufficient to meet an MCL in the range of 200 to 1000 pCi/L if the raw water contained more than 20,000 to 100,000 pCi/L, respectively

Seismic and radon monitoring of Algocen site at Elliot Lake

International Nuclear Information System (INIS)

1981-03-01

Remedial works to reduce radon/radon daughters to acceptable levels in houses in Elliot Lake have been going on for the last three years under the Atomic Energy Control Board (AECB) remedial action program. In December 1978, a routine inspection of treated houses showed extensions to cracks already filled, and the opening up of filled cracks. The homeowners attributed this to the blasting operations for building construction which were going on in town at that time. This prompted the need to monitor any subsequent major scale blasting in the town and to record the damages in nearby houses. This report presents the results of monitoring one such major blasting operation which was carried out between March 1979 and June 1979 for the building of the Algocen Shopping Mall east of Hutchison Avenue. The AECB were concerned about the possible damage to the houses along Hutchison Avenue which had already received remedial treatment to prevent the entry of radon gas, and authorized DSMA/Acres to record the level of vibrations and damages in these houses during the blasting period. (author)

Radon analyser

International Nuclear Information System (INIS)

1981-01-01

The process claimed includes the steps of transferring radon gas produced by a sample to a charcoal trap, cooled to a temperature whereby the radon is absorbed by the charcoal, heating the charcoal trap to a sufficient temperature to release the radon, and transferring the radon to a counting device where the gas particles are counted

Radon transport modelling: User's guide to RnMod3d

Energy Technology Data Exchange (ETDEWEB)

Andersen, C.E

2000-08-01

RnMod3d is a numerical computer model of soil-gas and radon transport in porous media. It can be used, for example, to study radon entry from soil into houses in response to indoor-outdoor pressure differences or changes in atmospheric pressure. It can also be used for flux calculations of radon from the soil surface or to model radon exhalation from building materials such as concrete. The finite-volume model is a technical research tool, and it cannot be used meaningfully without good understanding of the involved physical equations. Some understanding of numerical mathematics and the programming language Pascal is also required. Originally, the code was developed for internal use at Risoe only. With this guide, however, it should be possible for others to use the model. Three-dimensional steady-state or transient problems with Darcy flow of soil gas and combined generation, radioactive decay, diffusion and advection of radon can be solved. Moisture is included in the model, and partitioning of radon between air, water and soil grains (adsorption) is taken into account. Most parameters can change in time and space, and transport parameters (diffusivity and permeability) may be anisotropic. This guide includes benchmark tests based on simple problems with known solutions. RnMod3d has also been part of an international model intercomparison exercise based on more complicated problems without known solutions. All tests show that RnMod3d gives results of good quality. (au)

Modification of radon levels in homes

International Nuclear Information System (INIS)

Breysse, P.A.

1987-01-01

Radon infiltration from the ground into a house is primarily due to pressure differences between the interior of the home and the soil. If the atmospheric pressure inside the home is lower than the pressure in the soil, flow into the house will be accelerated since air flows from high pressure to lower pressure. Pressure differences can arise due to wind action. Temperature differences between indoors and outdoors also affect the relative indoor and outdoor pressure. These temperature and pressure variations can produce a stack effect which sucks air in from the bottom of the structure where the interior pressure is lowered and out toward the top. The internal pressure in houses is usually less than the gas pressure in the soil. Internal pressure in houses, however, can be further lowered as the result of the operation of kitchen, bathroom and attic exhaust fans as well as by the use of fireplaces, furnaces and wood stoves, and clothes dryers. This further reduction in internal pressure will likely increase the entry of radon into the house

Investigations of radon and radon daughters in surficial aquifers of florida

International Nuclear Information System (INIS)

1991-05-01

The principal purpose of the investigation was to test the hypothesis that radon soil flux, considered the principal source of indoor radon contamination, has an underlying relationship to the radon content of associated shallow groundwaters. The working hypothesis was that radon build-up in both soil and shallow groundwater is basically a consequence of the same factor, radon emanation from soil grains and the solid surfaces of the aquifers. Groundwater may be advantageous as an indicator of radon potential. Another object of the project was to investigate temporal and spatial trends of radon daughter products in shallow aquifers. After analyzing all of the radon soil, flux, and groundwater measurements made over the two-year study period, it is clear that while there is no direct relationship between either radon soil concentration or flux and groundwater radon. Measurements in wells where polonium is present at very high concentrations have shown that 210Po is largely unsupported by its radioactive predecessor, and that polonium is considerably more variable, in both space and time than other parameters measured in the same wells, including radon

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Radon as a risk factor in mines and dwellings

Energy Technology Data Exchange (ETDEWEB)

Axelson, O [Yrkesmedicinska kliniken, Regionsjukhuset, Linkoeping (Sweden)

1985-03-01

In mines, exposure to radon and radon daughters is the most important factor for the initiation of lung cancer. Tobacco smoke probably acts as a lung cancer promotor, but the relationship between minework, smoking and lung cancer is complicated. It is suggested that smokers may have a relative protection from a mucous sheet covering their basal cells. There is a connection between radon exposure in dwellings and lung cancer. Radon in buildings comes from the building material or the ground. The risk for developing lung cancer seems to be enhanced considerably by smoking. Tobacco contains some radioactivity itself (Lead 210 and Polonium 210), but tobacco smoke also adsorb electrically charged radon daughters and keeps them floating in the breathing air. Measurements show a doubling of radon daughter concentration in a room of normal size if 3-4 cigarettes are burnt out in it. A raised risk for lung cancer has been observed in connection with passive smoking. The relative risk for lung cancer is 2-3 for passive smokers and 5-6 for active smoking women. Children of smoking mothers who start smoking themselves develop lung cancer more easily than other groups. There seems to be a connection between early exposure to radon daughters, passive smoking and lung cancer.

Background concentrations of radon and radon daughters in Canadian homes

International Nuclear Information System (INIS)

McGregor, R.G.; Vasudev, P.; Letourneau, E.G.; McCullough, R.S.; Prantl, F.A.; Taniguchi, H.

1980-01-01

Measurements of radon and radon daughters were carried out in 14 Canadian cities on a total of 9999 homes selected in a statistically random manner. The geometric means of the different cities varied from 0.14 to 0.88 pCi/l. for radon and 0.0009 to 0.0036 Working Levels for radon daughters. The radon originates from natural radioactivity in the soil surrounding the homes. (author)

Bronchial dosimeter for radon progeny

Energy Technology Data Exchange (ETDEWEB)

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

2000-05-01

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

Radon in public buildings; Radon in oeffentlichen Gebaeuden

Energy Technology Data Exchange (ETDEWEB)

Schulz, H.; Flesch, K. [IAF - Radiooekologie GmbH, Dresden (Germany); Hermann, E. [B.P.S. Engineering GmbH, Zwickau (Germany); Loebner, W. [Wismut GmbH, Chemnitz (Germany); Leissring, B. [Bergtechnisches Ingenieurbuero GEOPRAX, Chemnitz (Germany)

2009-07-01

From the Free State of Saxony, a study was commissioned to survey how reliable measurements to characterize the radon situation in public buildings at a reasonable financial and human effort can be carried out to reduce radiation exposure in public buildings. The study approach was for 6 objects. To characterize the radon situation the time evolution measurement of radon concentrations of more than 1 to 2 weeks turned out to be sufficient. A novel data analysis enables the identification of a ''typical daily alteration of the radon concentration'' depending on the ventilation conditions and the daily use of the offices or class rooms. The identification of typical diurnal radon variations for the working time and weekends or holidays is of fundamental importance for assessing the exposure situation in public buildings. It was shown that the radon concentration during working time are in general much lower than in the times when the buildings (offices) are unused. It turned out that the long-term radon measurements with nuclear track detectors within distinct time regimes (day / night, working hours / leisure time) by utilizing switch modules are very efficient to estimate the actual exposure. (orig.)

Radon in Austria

International Nuclear Information System (INIS)

Friedmann, H.

2000-01-01

Several projects in Austria deal with the problem of enhanced radon exposure to the public. The Austrian Radon Project is the largest project within this task, with the aim of investigating the radon concentrations in Austrian homes. Another project concerns mitigation methods. According to the EU directive EURATOM 96/29 it is also necessary to check working places for possibly enhanced radon concentrations. These projects are and will be funded by the government. The federal government of Upper Austria sponsored a project to test the indoor air quality in kindergartens including radon measurements. Within an EU research project, the radon concentrations in Austrian springs and groundwater were systematically listed and analyzed. Additional investigations will focus on methods to improve the radon potential maps from the Austrian Radon Project by including geological and other information. (author)

Radon exhalation rates from slate stone samples in Aravali Range in Haryana

International Nuclear Information System (INIS)

Upadhyay, S.B.; Kant, K.; Chakarvarti, S.K.

2012-01-01

The slate stone tiles are very popular in covering the walls of the rooms. Radon is released into ambient air from slate stones due to ubiquitous uranium and radium in them, thus increasing the airborne radon concentration. The radioactivity in slates stones is related to radioactivity in the rocks from which the slate stone tiles are formed. In the present investigation, the radon emanated from slate stone samples collected from different slate mines in Aravali range of hills in the Haryana state of Northern India has been estimated. For the measurement of radon concentration emanated from these samples, alpha-sensitive LR-115 type II plastic track detectors have been used. The alpha particles emitted from the radon form tracks in these detectors. After chemical etching the track density of registered tracks is used to calculate radon concentration and exhalation rates of radon using required formulae. The measurements indicate normal to some higher levels of radon concentration emanated from the slat stone samples collected from Aravali range of hills in north India. The results will be discussed in full paper. (author)

Measurements of indoor radon and radon progeny in Mexico City

International Nuclear Information System (INIS)

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

1996-01-01

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

Result of the intercomparison exercise on radon measuring instruments and radon detectors 'bev- radon ring 2005'

International Nuclear Information System (INIS)

Baumgartner, A.; Maringer, F.J.; Michai, P.; Kreuziger, M.

2006-01-01

In spring 2005 the Federal Office of Metrology and Surveying (B.E.V.) invited all in Austria working radon measuring institutes to an intercomparison exercise at the radon calibration laboratory in the Arsenal. The aim of this intercomparison was on the one hand an objective inquiry and documentation of the current metrological potential on the section of radon measurement in Austria - both quantitative and qualitative- and on the other hand an initiative for the participating laboratories to optimize and improve their applied calibration-, measurement and analyse technique. Ten contacted Austrian radon laboratories were prepared to participate on the radon intercomparison exercise. The intercomparison exercise was carried out from 14. till 29. June at the radon calibration laboratory in the Arsenal of the B.E.V.. As radon emanation source a five stepped arranged, at the Arsenal built radon source was used. The source ( A.D.O.T.T.O. 1 is filled with a certified Ra- 226-standard solution of the Czech Metrological Institute (C.M.I.), Prag. A simple statistic based model was used for the evaluation and assessment of the results from the participants, which consider the statistic nature of the radioactive decay combined uncertainty. Altogether 183 measuring instruments participated the intercomparison exercise. Two reference measuring instruments, 22 active and 159 passive measuring instruments. The active measuring instruments formed 6 types of instruments and as passive radon detectors were 7 different types used from the participants. The positioning of the radon measuring instruments and detectors in the radon calibration laboratory was executed in regard to statistic points of view. From the active measuring instruments 17 could qualify and from the passive methods six from eight participants were in compliance to the given criteria. Radon measurements, which could have financial and economics relating implications (e.g. architectural redevelopment or

Radon in soil gas in the metropolitan region of Belo Horizonte, Brazil

International Nuclear Information System (INIS)

Teixeira, Giane Gariglio; Rocha, Zildete

2007-01-01

Radon, the natural radioactive gas is produced by the radioactive decay of uranium and thorium which are ubiquitous, specially in rock and soil. By diffusion and convection. Radon migrate from the rocks and to the groundwater and to the soil and from them the radon migrate through fissures, pipes and hales to the surface. Measurements were carried out in the Metropolitan Region of Belo Horizonte, whose greatest part of the in habitants occupies the great pre cambrian unit of the Iron Quadrangle of Minas Gerais denominated 'Granitic Gneissic Complex', composed of Archean rocks of age between 3,2 Ga and 2,6 Ga. The part in which occurs in the municipal area of Belo Horizonte was denominated as Complexo Belo Horizonte, whose most characteristics rocks named Gneiss Belo Horizonte. The soil gas radon concentrations were determined by using a samples and a continuos flow through ionization chamber detector AlphaGUARD PQ2000PRO - Genitron Instruments GmbH in a Instrumental Neutron Activation Analysis). Most results of radon concentration soil gas were in the range 10 kBq/m 3 to 50 kBq/m 3 . This values, according to the established Swedish Criteria are normal risk values. For soils classified as normal risk require 'radon protective construction', but the necessity of mitigation actions will depend on other factors, for example the soil permeability and rock type. (author)

Radon exposure of passengers in the Prague metro

International Nuclear Information System (INIS)

Sabol, J.

1996-01-01

This paper summarises the results of radon concentration monitoring in the carriages and at some stations of the Prague Metro network. The measurements revealed that radon levels in the Metro are relatively low in comparison to those normally encountered in dwellings in the Prague region. On average, the radon concentrations in the air inside the carriages have been found to be about 11 - 12 Bq m -3 while the levels at most stations reached values between 10 and 15 Bq m -3 . The Metro is intensively ventilated by means of powerful blowers and fans; the piston effect of the moving trains also contributes to air exchange. The ventilation rate is typically 3-4 h -1 . The highest rate is in line C, where the air in all underground areas is completely exchanged 6 times within each hour. These results demonstrate that Metro passengers receive about the same effective dose as passengers using surface transport. The doses from radon in the metro are only slightly higher than radon-related doses in the open air, while exposure due to external photon radiation seems to be a few percent lower than dose rates common in typical Czech houses. (author)

Radon in Kindergartens and Schools of Tomsk Region

International Nuclear Information System (INIS)

Iakovleva, V.S.

2001-01-01

Full text: As children spend a significant part of their time in schools and in kindergartens (about 1800 hours in a year), it is not only necessary to provide their comfortable stay but also normal radiation-hygienic conditions. One of the sources of radiation exposure is radon and short-lived radon daughters. In the city of Tomsk and Tomsk region monitoring radon levels in the rooms of 30 kindergartens and 36 schools was carried out. Measurements of the radon concentration in the air were realised using solid state nuclear track detectors. The duration of one measurement was 1-3 months. Another effort was directed on the collection of statistical data, necessary for an accurate estimation of the received dose. The data include the average annual time a child spends in the kindergarten (in view of holidays and time of preventive maintenance) and outdoors, constructional features of building, conditions of ventilation, etc. The statistical analyses of radon data show that arithmetic mean, geometric mean and standard deviation are 60, 51 and 33 Bq/m 3 , respectively, for kindergartens and are 50, 38 and 56 Bq/m 3 , respectively, for schools. The results are presented and discussed in this paper. (author)

Size distribution of radon daughter particles in uranium mine atmospheres

International Nuclear Information System (INIS)

George, A.C.; Hinchliffe, L.; Sladowski, R.

1975-01-01

The size distribution of radon daughters was measured in several uranium mines using four compact diffusion batteries and a round jet cascade impactor. Simultaneously, measurements were made of uncombined fractions of radon daughters, radon concentration, working level, and particle concentration. The size distributions found for radon daughters were log normal. The activity median diameters ranged from 0.09 μm to 0.3 μm with a mean value of 0.17 μm. Geometric standard deviations were in the range from 1.3 to 4 with a mean value of 2.7. Uncombined fractions expressed in accordance with the ICRP definition ranged from 0.004 to 0.16 with a mean value of 0.04. The radon daughter sizes in these mines are greater than the sizes assumed by various authors in calculating respiratory tract dose. The disparity may reflect the widening use of diesel-powered equipment in large uranium mines. (U.S.)

Indoor radon

International Nuclear Information System (INIS)

1997-12-01

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

Radon reduction and radon-resistant construction demonstrations in New York state. Final report

International Nuclear Information System (INIS)

1991-02-01

A survey of radon levels in New York State homes indicates that approximately 4.4 percent of the homes have long-term living area radon concentrations above the U.S. EPA guideline of four pCi/l. The project addressed the effectiveness of techniques to reduce the radon level in existing homes and to prevent the occurrence of high radon concentrations in new homes. The goal of the project was to demonstrate the effectiveness of radon reduction techniques in homes containing indoor radon concentrations of more than the current EPA guidelines of four pCi/l. At the same time, radon-resistant construction techniques were demonstrated in homes under construction to provide guidelines for houses being built in areas with a danger of high radon levels. The project demonstrated new radon mitigation techniques in homes containing indoor radon concentrations exceeding four pCi/l; assessed the value of previously installed radon reduction procedures, and demonstrated new radon-resistant construction methods

Mechanisms of radon injury

International Nuclear Information System (INIS)

Cross, F.T.

1988-01-01

In this new project, they conduct molecular, cellular and whole-animal research relevant to understanding the inhalation toxicology of radon and radon-daughter exposures. The work specifically addresses the exposure-rate effect in radon-daughter carcinogenesis; the induction-promotion relationships associated with exposure to radon and cigarette-smoke mixtures; the role of oncogenes in radon-induced cancers; the effects of radon on DNA as well as on DNA repair processes; and the involvement of growth factors and their receptors in radon-induced carcinogenesis. Preliminary experiments showed that oncogenes are activated in radon-induced lung tumors. They have therefore begun further exposures pertinent to the oncogene and growth-factor studies. An in vitro radon cellular-exposure system was designed, and cell exposures were initiated. Initiation-promotion-initiation studies with radon and cigarette-smoke mixtures have also begun; and they are compiling a radon health-effects bibliography

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

International Nuclear Information System (INIS)

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

Radon: Chemical and physical processes associated with its distribution

International Nuclear Information System (INIS)

Castleman, A.W. Jr.

1992-01-01

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

Construction of radon/radon daughter calibraton chamber

International Nuclear Information System (INIS)

Fry, J.; Gan, T.H.; Leach, V.A.; Saddlier, J.; Solomon, S.B.; Tam, K.K.; Travis, E.; Wykes, P.

1983-01-01

The radon/radon daughter test chamber is a copper lined room 1.65x1.75x2.75m with an effective volume of 8000 litres. The air residence time is controlled by circulating the air in the chamber through absolute filters which remove 99.9% of particulates. Radon is drawn into the chamber from a 17 μCi 226 RaCl source using the pressure differential across the blowers (<3 psi)

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

International Nuclear Information System (INIS)

Meng Yecheng; Huang Zhanyun; She Chengye

1992-01-01

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

The use of soil gas as radon source in radon chambers

International Nuclear Information System (INIS)

Al-Azmi, Darwish

2009-01-01

A procedure is described in which soil gas is utilized as an alternative to the 226 Ra source for the supply of the radon gas required to fill a radon chamber where radon-measuring devices are calibrated. The procedure offers opportunities to vary the radon concentration within the chamber around an average value of about 500 Bq/m 3 , which is considered to be sufficient for calibrating indoor radon detectors. The procedure is simple and the radon source does not require radiation protection certification (for import and/or use), unlike the commercially produced standard radioactive ( 226 Ra) sources.

Radon in Antarctica

International Nuclear Information System (INIS)

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

2005-01-01

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

Modeling of lung cancer risk due to radon exhalation of granite stone in dwelling houses

Directory of Open Access Journals (Sweden)

Akbar Abbasi

2017-01-01

Conclusions: The estimated numbers of lung cancer deaths attributable to indoor radon due to granite stones in 2013 were 145 (3.33% and 103 (2.37% for poor and normal ventilation systems, respectively. According to our estimations, the values of 3.33% and 2.37% of lung cancer deaths in 2013 are attributed to radon exhalation of granite stones with poor and normal ventilation systems, respectively.

Radon and lung cancer in Bangalore Metropolitan, India

International Nuclear Information System (INIS)

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

2012-01-01

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

Radon-Instrumentation; Radon-Instrumentacion

Energy Technology Data Exchange (ETDEWEB)

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

2003-07-01

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

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

International Nuclear Information System (INIS)

Slater, M.; Gooding, M.

2006-01-01

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

A method for purifying air containing radioactive substances resulting from the disintegration of radon

International Nuclear Information System (INIS)

Stringer, C.W.

1974-01-01

The invention relates to the extraction of radioactive isotopes from air. It refers to a method for withdrawing the radioactive substances resulting from the disintegration of radon from air, said method of the type comprising filtrating the air contaminated by the radon daughter products in a filter wetted with water in order to trap said substances in water. It is characterized in that it comprises the steps of causing the water contaminated by the radon daughter products to flow through a filtrating substance containing a non hydrosoluble granular substrate, the outer surface of which has been dried then wetted by a normally-liquid hydrocarbon, and of returning then wetted by a normally-liquid hydrocarbon, and of returning the thus filtrated water so that it wets again the air filter and entraps further radon daughter products. This can be applied to the purification of the air in uranium mines [fr

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

International Nuclear Information System (INIS)

Santos, Marcelo T.; Silva, Nivaldo C.; Guerrero, Eder T.Z.; Navarro, Fabiano C.; Oliveira, Rodrigo J.

2015-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-07-01

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

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

International Nuclear Information System (INIS)

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

1994-01-01

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

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

International Nuclear Information System (INIS)

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

Radon parameters in outdoor air

International Nuclear Information System (INIS)

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

2002-01-01

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

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

International Nuclear Information System (INIS)

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

2011-10-01

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

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

International Nuclear Information System (INIS)

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

1986-01-01

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

Diurnal variations of indoor radon progeny for Bangalore metropolitan, India

International Nuclear Information System (INIS)

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

2010-01-01

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

Radon programme: presence and future

International Nuclear Information System (INIS)

Hulka, J.

2009-01-01

In this presentation an overview of radon programme experiences is presented. The paper summarises national radon policy, national programmes, legislation, the role of preventive measures and interventions with respect to existing and future exposure and knowledge of radon risk, problems of remediation strategies, practical protection in dwellings, radon measurements strategies, progress in radon measurement of an individual house (radon diagnosis), radon mapping process and sense of delineation of radon prone areas, natural radioactivity of building materials and radioactivity in public water and their role in the radon programme, public awareness on radon issue and publicity campaign. Some research activities are proposed aiming at effective solutions of radon issues in future

Radon

International Nuclear Information System (INIS)

1990-01-01

This leaflet in the At-a-Glance Series, describes what radon is, where it is found, why it presents a risk to health, the official advice, and the remedies that are available to reduce radon levels. (author)

Testing of indoor radon reduction techniques in eastern Pennsylvania: An update

International Nuclear Information System (INIS)

Henschel, D.B.; Scott, A.G.

1987-01-01

EPA has installed radon reduction measures in 38 houses in the Reading Prong region of eastern Pennsylvania. All were basement houses with hollow block or poured concrete foundation walls. The reduction approaches tested in most houses involved active soil ventilation, including: suction on the footing drain tile system; suction underneath the concrete slabs, using pipes inserted through the slabs from inside the house; and ventilation of the void network inside hollow block foundation walls. Heat recovery ventilators (HRVs) were tested in three houses. The current results confirm that, for the houses tested here, drain tile suction appears consistently able to provide high radon reductions when a complete loop of drain tile exists, often reducing high-radon houses to 4 pCi/l (148 B1/m 3 ) and less. Sub-slab suction (with pipes through the slab) can also provide high reductions if a sufficient number of suction pipes are located properly. Placement of one or more sub-slab suction pipes near each perimeter wall appears in this testing to aid in treating the major soil gas entry routes, although fewer pipes can sometimes give high reductions if conditions are favorable. For effective radon reduction using any active soil ventilation technique, it is important that major wall and slab openings be closed, and that a fan be employed that is capable of developing adequate static pressure

Radon emanation from soils

International Nuclear Information System (INIS)

Markkanen, M.; Arvela, H.

1992-01-01

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

Radon in Houses of Vukovar-Srijem County

International Nuclear Information System (INIS)

Radolic, V.; Novakovic, L.; Jerkovic, G.; Vukovic, B.

2008-01-01

During years 2003 and 2004, a long-term indoor radon measurements in some, randomly selected, homes in Croatia were performed by LR-115 track etch detectors. The number of exposed detectors in each of 20 Croatian counties was set according to population criteria (one detector per 4000 inhabitants) and around 40 measurements were performed in Vukovar-Srijem County. Additional measurements are followed in years 2006-07 and these results rapidly improve the knowledge of spatial distribution of indoor radon concentration in this County. Radon was measured by method with two LR-115 type II nuclear track detectors which enable the estimation of equilibrium factor as well as the assessment of the annual effective dose. The obtained values were in range of 18 to 548 Bq m -3 , with the arithmetic and geometric means of 95 Bq m -3 and 74 Bq m -3 , respectively. The municipality with lowest average radon level of 51 Bq m -3 is city of Vukovar while Andrijasevci has the highest average radon concentration of 269 Bq m -3 . The average estimated equilibrium factor in Vukovar-Srijem County is 0.512; the relative error of the estimation is 14.8 percent. The statistical χ 2 -test, applied on the empirical and theoretical frequencies, show that the empirical frequency distribution for the radon in houses of Vukovar-Srijem County belonged to the log-normal distribution (calculated parameter, χ 2 = 7.39, was lower than the theoretical one, χ 2 0.05 = 9.49, for 4 degrees of freedom and significance level of 0.05). The percentage of houses with radon concentrations above 200 or 400 Bq/m 3 was 8.7 percent and 1.4 percent, respectively. The assessment of the annual effective dose from the indoor radon and its short-lived progenies for the inhabitants of Vukovar-Srijem County (for the average equilibrium factor of 0.512 and occupancy factor of 0.6) gave the average effective dose of 2.4 mSv/y.(author)

Result of the intercomparison exercise on radon measuring instruments and radon detectors 'bev- radon ring 2005'

Energy Technology Data Exchange (ETDEWEB)

Baumgartner, A. [Vienna Univ. of Technology, Atominstitut, Wien (Austria); Maringer, F.J.; Michai, P.; Kreuziger, M. [BEV-Federal Office of Metrology and Surveying, Wien (Austria)

2006-07-01

In spring 2005 the Federal Office of Metrology and Surveying (B.E.V.) invited all in Austria working radon measuring institutes to an intercomparison exercise at the radon calibration laboratory in the Arsenal. The aim of this intercomparison was on the one hand an objective inquiry and documentation of the current metrological potential on the section of radon measurement in Austria - both quantitative and qualitative- and on the other hand an initiative for the participating laboratories to optimize and improve their applied calibration-, measurement and analyse technique. Ten contacted Austrian radon laboratories were prepared to participate on the radon intercomparison exercise. The intercomparison exercise was carried out from 14. till 29. June at the radon calibration laboratory in the Arsenal of the B.E.V.. As radon emanation source a five stepped arranged, at the Arsenal built radon source was used. The source ( A.D.O.T.T.O. 1 is filled with a certified Ra- 226-standard solution of the Czech Metrological Institute (C.M.I.), Prag. A simple statistic based model was used for the evaluation and assessment of the results from the participants, which consider the statistic nature of the radioactive decay combined uncertainty. Altogether 183 measuring instruments participated the intercomparison exercise. Two reference measuring instruments, 22 active and 159 passive measuring instruments. The active measuring instruments formed 6 types of instruments and as passive radon detectors were 7 different types used from the participants. The positioning of the radon measuring instruments and detectors in the radon calibration laboratory was executed in regard to statistic points of view. From the active measuring instruments 17 could qualify and from the passive methods six from eight participants were in compliance to the given criteria. Radon measurements, which could have financial and economics relating implications (e.g. architectural redevelopment or

Radon in geological medium

Energy Technology Data Exchange (ETDEWEB)

Hricko, J [GEOCOMPLEX, a.s., Bratislava (Slovakia)

1996-12-31

The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a{sub v} has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km{sup 2}. The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a{sub v} > 50 kBq/m{sup 3}). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs.

Radon in geological medium

International Nuclear Information System (INIS)

Hricko, J.

1995-01-01

The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a v has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km 2 . The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a v > 50 kBq/m 3 ). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs

Interaction of radon Exposure and cigarette smoking on cells

International Nuclear Information System (INIS)

Zhu, Maoxiang; Wei, Han; Yang, Zhihua; Pan, Xiujie; Cao, Zhenshan

2008-01-01

Full text: Environmental radon and its progenies is important lung carcinogen both in occupational underground miners and in the general population. Exposure to radon often occurs combined with smoking, another most important lung carcinogen. The join biological effects of alpha- particle radiation and cigarette smoke condense (CSC) were investigated here in order to provide experimental base for medical protection from lung cancer inducing by joint exposure of radon and smoking. Immortalized human bronchial epithelial cells (BEP2D) were divided into 5 groups, namely normal control group (NC), alpha particles irradiation group (0.25 Gy,α), CSC administration group (1μg/ml, CSC), CSC administration (1μg/ml) before (CSC + α) and after (α + CSC) alpha particles irradiation (0.25 Gy) group. On the 35 th passage after treated by alpha particles irradiation and CSC singly or jointly, only α + CSC cells showed malignant transformation characteristics, representing anchor growing independently, losing contact inhibition, and cell cycle disordering, whereas, there were no distinct difference between cells of other groups and normal cells. Moreover, comparison to the groups treated alone with alpha particles radiation or CSC administration, in the groups of joint exposure to alpha particles radiation and CSC treatment, cell survival fractions markedly decreased, intracellular ROS levels, frequencies of comet cell generation significantly increase, and could found that cell survival fractions of group CSC administration after α particle radiation was significantly higher than that of group CSC administration before alpha particles irradiation, suggesting that interaction of radon and smoking associated with their exposure sequence. In summary, interaction of radon and smoking was synergistic effect, and which was impacted by the order of exposure. (author)

Radiation exposure due to radon and radon daughters

International Nuclear Information System (INIS)

Ullmann, W.

1976-01-01

Underground miners working over long periods of time in mines with a high content of radon and radon daughters belong to that group of occupationally exposed persons who are subject to the greatest somatic risk, with values especially high if the permissible dose limits are exceeded. Follwing an overview of the permissible limits currently in use for radon and radon daughters as well as the results of examinations performed in nationally-owned underground mining of the G.D.R., considerations are presented on the measuring quantities requisite for statistical, control and safety measurements in this field. Finally, conclusions are drawn concerning the measuring procedures and instruments to be employed for practical work. (author)

Tritium and radon risks for humans

International Nuclear Information System (INIS)

Mauna, Traian; Mauna, Andriesica

2008-01-01

Full text: The gaseous and liquid releases into environment from the two CANDU type units of Cernavoda NPP now in operation has more tritium contents than other kind of western power reactors. CANDU type reactor uses heavy water as moderator and primary circuit heat transfer agent. In normal operation deuterium go to tritium by neutron capture, the molecule of tritiated heavy water can escape from nuclear systems in very small amounts and so it is released into environment. After release the tritium follows the way of water into environment. One year ago the antinuclear NGO led a hard attack against Units 3 and 4 during the procedure of public acceptance request. This attack tried to demonstrate the great risk for humans of the tritium released by Cernavoda NPP. Obviously this risk is very low as demonstrated by many years reactor operation. SNN as owner of Cernavoda NPP ensures by all kind of information channels about the radioactive potential risk for humans. By the other hand, ironically, the antinuclear NGO makes nothing to inform the people about radon risk magnitude in some areas. This is a well-known fact but the radon concentration in dwellings can be decreased by some improved building procedures. The radon is the first natural cause of lung cancer. The environmental NGO and Romanian authorities do not have an information service about radon hazard data neither in dwellings or in uranium mining areas. The paper compares the properties and risks for tritium and radon. (authors)

BGS Radon Protective Measures GIS

International Nuclear Information System (INIS)

Appleton, D.; Adlam, K.

2000-01-01

The British Geological Survey Radon Protective Measures Geographical Information System is described. The following issues are highlighted: Identification of development sites where radon protection is required in new dwellings; Mapping radon potential on the basis of house radon and geology; Radon Protective Measures GIS; Radon site reports; and Follow-up radon protective measures sire reports

Strategy for the reduction of radon exposure in Norway

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-05-15

Elevated indoor radon concentrations are a more extensive problem in Norway than in many other countries. It has been estimated that indoor radon causes approximately 300 deaths from lung cancer each year in Norway. On average, avoiding lung cancer increases life expectancy by 14 to 18 years. Radon is a radioactive noble gas formed continually is a decay product from uranium. Uranium is a natural constituent existing in varying concentrations in bedrock, minerals and soils. For this reason, both the soil air and groundwater contain radon. Radon in buildings normally originates from the soil air in the underlying ground. Indoor air pressure is often low, so that radon-containing air from the surrounding ground gets sucked in through cracks in the building foundations. Elevated indoor radon concentrations can be due to household water drawn from groundwater wells, and radon gas can also be emitted from building materials such as certain types of stone or concrete containing high levels of natural radioactivity. Norway, Sweden and Finland are among the the countries in the world with the highest average indoor radon concentrations. Geological conditions and the cool climate pose a big challenge, but the radon problem can be solved in a cost-effective way. Radon is the most common cause of lung cancer after active smoking. At a radon concentration of 100 Bq/m3, which is not far from the estimated average for Norwegian housing, the risks of dying of radon-induced lung cancer before the age of 75 are 0.1 % for non-smokers and 2 % for smokers, respectively. Many buildings in Norway have radon levels that exceed this. The most important health impact of radon exposure is the increased risk of lung cancer. This increase in risk is assumed to be linear in relation to radon concentration (i.e., the risk is 10 times higher at 1000 Bq/m3 compared to 100 Bq/m3). The risk also increases linearly with exposure time, i.e. there is a tenfold greater risk of contracting lung cancer

Strategy for the reduction of radon exposure in Norway

International Nuclear Information System (INIS)

2010-05-01

Elevated indoor radon concentrations are a more extensive problem in Norway than in many other countries. It has been estimated that indoor radon causes approximately 300 deaths from lung cancer each year in Norway. On average, avoiding lung cancer increases life expectancy by 14 to 18 years. Radon is a radioactive noble gas formed continually is a decay product from uranium. Uranium is a natural constituent existing in varying concentrations in bedrock, minerals and soils. For this reason, both the soil air and groundwater contain radon. Radon in buildings normally originates from the soil air in the underlying ground. Indoor air pressure is often low, so that radon-containing air from the surrounding ground gets sucked in through cracks in the building foundations. Elevated indoor radon concentrations can be due to household water drawn from groundwater wells, and radon gas can also be emitted from building materials such as certain types of stone or concrete containing high levels of natural radioactivity. Norway, Sweden and Finland are among the the countries in the world with the highest average indoor radon concentrations. Geological conditions and the cool climate pose a big challenge, but the radon problem can be solved in a cost-effective way. Radon is the most common cause of lung cancer after active smoking. At a radon concentration of 100 Bq/m3, which is not far from the estimated average for Norwegian housing, the risks of dying of radon-induced lung cancer before the age of 75 are 0.1 % for non-smokers and 2 % for smokers, respectively. Many buildings in Norway have radon levels that exceed this. The most important health impact of radon exposure is the increased risk of lung cancer. This increase in risk is assumed to be linear in relation to radon concentration (i.e., the risk is 10 times higher at 1000 Bq/m3 compared to 100 Bq/m3). The risk also increases linearly with exposure time, i.e. there is a tenfold greater risk of contracting lung cancer

Radon Measurements in Vojvodina

International Nuclear Information System (INIS)

Bikit, I.; Bikit, K.; Forkapic, S.; Mrda, D.; Nikolov, J.; Todorovic, N.; Veskovic, M.

2013-01-01

Recent analyses of epidemiological studies of lung cancer risk from residential exposures demonstrate a statistically significant increase per unit of exposure below average annual concentrations of about 200 Bq/m 3 . Indoor radon measurements performed in Novi Sad in about 400 houses and flats are presented and discussed in this paper. By measuring gamma-activity of radon daughters, radon activity concentration was determined to be 50 Bq/m 3 . In Vojvodina region indoor radon levels were measured by alpha track detectors CR-39 on about 3000 locations during the winter seasons in the period of three years (2003-2005). The main aim of the present study was to explore the critical group of population for radon exposure and to estimate maximal annual doses. Existing radon maps which identify regions with elevated radon levels will improve data collection and analysis for the future radon campaigns. Collaboration on the JRC program of European indoor radon map and implementation of grid system are also discussed.(author)

Radon and cancer

International Nuclear Information System (INIS)

2011-01-01

This publication proposes an overview on what is known about the carcinogenic effect of radon. It recalls the origin of radon, its presence in the environment, and its radioactivity. It comments data on the relationship between exposure to radon and lung cancer, and with other forms of cancer. It discusses the role of the exposure level, and the cases of professional and domestic exposure with respect to these risks. It indicates the hazardous areas in France which are well identified, outlines that smokers are more likely victims of risks related to radon, that this risk is still underrated and underestimated (notably by the public). It gives an overview of existing regulations regarding exposure to radon, of public health policies and national plans concerning radon, and recalls some WHO recommendations

Radon awareness in Ireland: a assessment of the effectiveness of radon road shows

International Nuclear Information System (INIS)

Synnott, H.

2006-01-01

Full text: In late 2004 the Radiological Protection Institute of Ireland (R.P.I.I.) initiated a series of radon road shows in areas designated as High Radon Areas 1 in the R.P.I.I. s national radon survey of homes. The main objective of these road shows was to provide information to a local audience on the risks of exposure to radon. These road shows target both employers and householders. Each road show has the same general format. A presentation and/or meeting with a major employer representative group within the area. The purpose is to make employers aware of the risks associated with exposure to radon in the workplace and to highlight their obligations under current Irish health and safety legislation regarding radon in the workplace. An information stand on radon manned by R.P.I.I. staff members in a local shopping centre or other similar area. This provides those concerned about radon with accessible information on radon exposure risks, how to measure radon and the steps a home owner could take to reduce radon concentrations where necessary. Where possible R.P.I.I. staff members visit one or more schools in the general area. A short presentation on radon was given to students and students were given an opportunity to asks questions Maximizing media exposure to publicize our visits is vital to the success of these visits. Each visit is preceded by a Press Release whose main aim is to brief local and national media on the radon issue so as to achieve maximum publicity mainly through radio and television coverage. In general the media are very interested in the whole radon area and R.P.I.I. staff members have given 57 radio and 10 television interviews to date since the commencement of this initiative. The four road shows carried out to date have been successful in encouraging householders to carry out radon measurements. Since the start of the road shows to the present, the R.P.I.I. has seen a 44% increase in the number of householders requesting radon

Project Radon

International Nuclear Information System (INIS)

Ekholm, S.

1988-01-01

The project started in March 1987. The objective is to perform radon monitoring in 2000 dwellings occupied by people employed by State Power Board and to continue to contribute to the development of radon filters. The project participates in developing methods for radon measurement and decontamination and in adapting the methods to large scale application. About 400 so called radon trace measurements (coarse measurement) and about 10 action measurements (decontamination measurement) have been made so far. Experience shows that methods are fully applicable and that the decontamination measures recommended give perfectly satisfactory results. It is also established that most of the houses with high radon levels have poor ventilation Many of them suffer from moisture and mould problems. The work planned for 1988 and 1989 will in addition to measurements be directed towards improvement of the measuring methods. An activity catalogue will be prepared in cooperation with ventilation enterprises. (O.S.)

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

International Nuclear Information System (INIS)

Al-Azmi, D.; Karunakara, N.

2008-01-01

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

Radon reduction in waterworks

International Nuclear Information System (INIS)

Raff, O.; Haberer, K.; Wilken, R.D.; Funk, H.; Stueber, J.; Wanitschek, J.; Akkermann-Kubillus, A.; Stauder, S.

2000-01-01

The removal of radon from water using water aeration is one of the most effective methods for reducing radon in waterworks. Therefore, this report describes investigations on packed tower columns and shallow aeration devices and a method for mathematical modelling of gas exchange processes for dimensioning packed tower columns for radon removal. Moreover, possibilities for removing radon using active carbon filtration under waterworks typical conditions and for reducing indoor radon levels in waterworks are discussed. Finally, conclusions on the necessity of radon removal in German waterworks are drawn. (orig.) [de

Radon house doctor

International Nuclear Information System (INIS)

Nitschke, I.A.; Brennan, T.; Wadach, J.B.; O'Neil, R.

1986-01-01

The term house doctor may be generalized to include persons skilled in the use of instruments and procedures necessary to identify, diagnose, and correct indoor air quality problems as well as energy, infiltration, and structural problems in houses. A radon house doctor would then be a specialist in radon house problems. Valuable experience in the skills necessary to be developed by radon house doctors has recently been gained in an extensive radon monitoring and mitigation program in upstate New York sponsored by Niagara Mohawk Power Corporation and the New York State Energy Research and Development Authority. These skills, to be described in detail in this paper, include: (i) the use of appropriate instruments, (ii) the evaluation of the symptoms of a radon-sick house, (iii) the diagnostic procedures required to characterize radon sources in houses, (iv) the prescription procedures needed to specify treatment of the problem, (v) the supervision of the implementation of the treatment program, (vi) the check-up procedures required to insure the house cured of radon problems. 31 references, 3 tables

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

International Nuclear Information System (INIS)

Richon, Patrick

2011-01-01

Gases, especially radon, have often been cited as indicators of large-scale geodynamic processes, or as precursors of earthquakes and volcanic eruptions. Measurable in the air, water and rocks, natural radon concentrations are generally extremely low, because 1 Bq m -3 corresponds to a mixing ratio of 1,77 * 10 -20 in air at normal temperature and pressure (NPT). Expressed in a usual unit in chemistry of air pollution, an usual activity concentration of 37 Bq m -3 is only a billion th of ppb by volume (ppbv) in the atmosphere. Yet such, concentrations of radon are very easy to measure, because the decay α is an energetic phenomenon: It makes it theoretically possible to detect a single atom of radon, which is an inaccessible performance by chemical analysis. This feature, combined with a half-life of 3.82 days, makes radon so interesting for tracing natural phenomena. But the major drawback is that radon becomes very sensitive to subsurface meteorological and hydrogeological processes especially if the measurement methodology is not perfectly controlled. These aspects are not addressed in the past and in recent literatures and are rarely taken into account when analyzing and interpreting radon signal. We review these issues by addressing problems related to instrumentation, to measurement methods, and to data processing. We show how to extract signatures of geodynamical processes dissimulated in radon data for very different sites with strong dynamic like volcanic sites (La Soufriere of Guadeloupe, FWI, Merapi, Indonesia), tectonic sites (Syabru-Bensi in Nepal and the Kunlun fault in Tibet) and underground laboratories (Roselend and Argentiere). For this, we had to develop signals processing tools that allow us to extract the effect of barometric and gravimetric tide waves from the radon signal. This is a very sensitive for a detailed survey of the transport processes of radon that are closely linked to geodynamic processes involved in different sites. The

Indoor radon and environmental gamma radiation in Hong Kong

International Nuclear Information System (INIS)

Yu, K.N.; Young, E.C.M.; Stokes, M.J.; Luo, D.L.; Zhang, C.X.

1992-01-01

Activated charcoal canisters have been used to measured the indoor radon concentrations of 160 sites in different buildings in Hong Kong during the period from July to October 1990. The average value is 40.0 Bq.m -3 . Furthermore, CR-39 nuclear track detectors and two kinds of LiF TLDs have been used to measure the average indoor radon concentrations and the absorbed gamma dose rates in air of 71 sites over the period from January to April 1991. The results all show log-normal distribution. The indoor radon concentrations are respectively 72.2 Bq.m -3 and 155.4 Bq.m -3 for dwellings and offices, while the absorbed gamma dose rates in air are respectively 213.0 nGy.h -1 and 198.3 nGy.h -1 . (author)

EPA program to demonstrate mitigation measures for indoor radon: initial results

International Nuclear Information System (INIS)

Henschel, D.B.; Scott, A.G.

1986-01-01

EPA has installed radon mitigation techniques in 18 concrete block basement homes in the Reading Prong region of eastern Pennsylvania. Three alternative active soil ventilation approaches were tested: suction on the void network within the concrete block basement walls; suction on the footing drain tile system; and suction on the aggregate underneath the concrete slab. The initial 18 mitigation installations were designed to demonstrate techniques which would have low to moderate installation and operating costs. Where effective closure of major openings in the block walls is possible, suction on the wall voids has proved to be extremely effective, able to reduce homes having very high radon Working Levels (up to 7 WL) to 0.02 WL and less. However, where inaccessible major openings are concealed within the wall, it is more difficult and/or more expensive to develop adequate suction on the void network, and performance is reduced. Testing is continuing to demonstrate the steps required to achieve high performance with wall suction in homes with such difficult-to close walls. Drain tile suction can be very effective where the drain tiles completely surround the home; drain tile suction is the least expensive and most aesthetic of the active soil ventilation approaches, but appears susceptible to spikes in radon levels when the basement is depressurized. Sub-slab suction as tested in this study - with one or two individual suction points in the slab - does not appear adequate to ensure sustained high levels of reduction on block wall basement homes; it appears to effectively treat slab-related soil gas entry routes so long as a uniform layer of aggregate is present, but it does not appear to effectively treat the wall-related entry routes. Closure of major openings might have improved sub-slab suction performance. 5 figures, 3 tables

External gamma exposure to radon progeny in indoor air

International Nuclear Information System (INIS)

Fujimoto, Kenzo

1985-01-01

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

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

International Nuclear Information System (INIS)

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

2014-10-01

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

Radon in workplaces

International Nuclear Information System (INIS)

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

2000-01-01

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

Public perceptions of radon risk

International Nuclear Information System (INIS)

Mainous, A.G. III; Hagen, M.D.

1993-01-01

Since 1984, a significant amount of media attention has focused on health threats from radon gas exposure. Using a probability telephone survey of adults (n = 685), we studied public perceptions of risk from radon exposure versus other environmental health risks. The results indicated that 92% of those individuals who had heard of radon believe radon to be a health risk, although only 4% believe they are currently exposed to high levels of radon gas. Perception of risk from radon was positively related to other perceptions of environmental risks. Younger and less educated individuals were more likely to perceive radon as a health risk. Women were three-and-one-half times as likely as men to perceive risk from radon. However, there was no significant relationship between perceived risk from radon and cigarette smoking. Media attention has apparently led to public awareness of radon hazards, but further attention is needed to improve smokers' awareness of their special risks from radon

Radon Research Program, FY 1991

International Nuclear Information System (INIS)

1992-03-01

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

Some measurements of radon and its daughters in houses

International Nuclear Information System (INIS)

Rundo, J.; Markun, F.; May, H.A.; Plondke, N.J.; Keefe, D.J.

1979-01-01

The bare soil in the unpaved crawl space of a house is the source of unusually high levels (greater than or equal to 185 Bq m -3 ) of radon in the air of some houses (46% of those investigated), although the radium content of the soil is normal (approx. 40 Bq kg -1 ). High concentrations can also be found in the air in the basement sump. Measurements made with an Environmental Working Level Monitor in two houses showed that the average annual concentration of radon daughters may be in the region of 0.01 WL

Swiss radon programme 'RAPROS'

International Nuclear Information System (INIS)

Zeller, W.

1992-03-01

The results of the five-year radon research program RAPROS presented in this report, allow for scientifically valid statements on the origin of elevated levels of indoor radon in Switzerland. These results form a basis for recommendations and for actions to be taken. Indoor radon concentrations have been measured in more than 4000 living-rooms and 2000 basements; a sampling density of about 0.2% of the Swiss housing stock. According to these measurements radon leads to an estimated average annual effective dose of 2 milli-Sievert, although in some regions the annual dose may be much higher. Extrapolation of the existing data shows that in about 10'000 Swiss houses radon may exceed 1000 Bq/m 3 . For these houses remedial actions are recommended. There seems to be no radon problem in the large cities in the Swiss Plateau. High indoor radon concentrations in Switzerland are due to the soil beneath the buildings. Data from the study indicated that the most important soil characteristic influencing indoor radon concentrations was its gas permeability. Because natural ventilation in a heated house creates a slight underpressure in the lower levels with respect to surrounding soils, radon is driven from the soil into the building. Weatherization of the houses to reduce energy consumption had in most cases no effect on the indoor radon concentrations. Radon from tap water or from building materials does not contribute significantly to indoor radon levels in Switzerland. The high levels in the Jura Mountains are thought to be associated with karstic limestone bedrock. Several houses within Switzerland have now been modified to reduce radon levels. The most successful mitigation technique combined forced-air ventilation with tightening of the basement to decrease or prevent air infiltration from the soil. (author) figs., tabs., refs

Environmental radon

International Nuclear Information System (INIS)

Majumdar, S.K.; Schmalz, R.F.; Miller, E.W.

1990-01-01

This book covers many aspects of environmental radon, including: historical perspectives; occurrence and properties; detection, measurement, and mitigation, radon and health; and political, economic, and legislative impacts

Radon thematic days - Conference proceedings

International Nuclear Information System (INIS)

2011-03-01

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

Size distribution of radon daughter particles in uranium mine atmospheres

International Nuclear Information System (INIS)

George, A.C.; Hinchliffe, L.; Sladowski, R.

1977-07-01

An investigation of the particle size distribution and other properties of radon daughters in uranium mines was reported earlier but only summaries of the data were presented. This report consists mainly of tables of detailed measurements that were omitted in the original article. The tabulated data include the size distributions, uncombined fractions and ratios of radon daughters as well as the working levels, radon concentrations, condensation nuclei concentrations, temperature, and relative humidity. The measurements were made in 27 locations in four large underground mines in New Mexico during typical mining operations. The size distributions of the radon daughters were log normal. The activity median diameters ranged from 0.09 μm to 0.3 μm with a mean of 0.17 μm. Geometric standard deviations were from 1.3 to 4 with a mean of 2.7. Uncombined fractions expressed in accordance with the ICRP definition ranged from 0.004 to 0.16 with a mean of 0.04

Radon in Estonian dwellings - Results from a National Radon Survey

Energy Technology Data Exchange (ETDEWEB)

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

2003-10-01

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

Radon in Estonian dwellings - Results from a National Radon Survey

International Nuclear Information System (INIS)

Pahapill, Lia; Rulkov, Anne; Rajamaee, Raivo; Aakerblom, Gustav

2003-10-01

A countrywide survey of radon concentrations in Estonian dwellings was carried out during the period 1998-2001. The survey formed a part of the cooperation program on radiation protection between the Estonian Radiation Protection (Kiirguskeskus) Centre and the Swedish Radiation Protection Authority (SSI). The survey included measurements in a number of dwellings representative for Estonia in detached houses and multifamily buildings (only dwellings on the bottom floor were included in the survey). Altogether, radon concentrations were measured in 515 dwellings, a number large enough to be statistically significant. All measurements were made with alphatrack film detectors of the same type that SSI uses in Sweden. The measurements were made during a 2-3 month period during the winter half-year. Two detectors were used in each dwelling. In Estonia there are 0.17 million dwellings in detached houses and 0.45 million in multi apartment buildings. Of the 1.26 million inhabitants in Estonia. 0.36 million live in detached houses and 0.90 million in multi apartment buildings. Most of the latter were built during the Soviet occupation. Of the dwellings in multifamily buildings 30 % are assumed to be situated on the first floor. The mean radon concentration in dwellings in detached hoses, according to the survey results, is 103 Bq/m 3 , in dwellings on the bottom floor in multi apartment buildings it is 78 Bq/m 3 . In 1% of the dwellings the radon concentration exceeded 400 Bq/m 3 . The highest radon concentration found in the study was 1040 Bq/m 3 . Based on the assumption that the average radon concentration in the dwellings in multi-apartment buildings that are not situated on the bottom floor is 30 Bq/m 3 , and that these dwellings constitute 70% of all dwellings in multi apartment buildings, the mean radon concentration in dwellings in multi apartment buildings is calculated to be 44 Bq/m 3 . The mean value for all Estonia dwellings is calculated to be 60 Bq/m 3 . Using

Radon-film-badges by solid radiators to complement track detector-based radon monitors

International Nuclear Information System (INIS)

Tommasino, L.; Tommasino, M.C.; Viola, P.

2009-01-01

Existing passive radon monitors, based on track detectors, present many shortcomings, such as a limited response sensitivity for one-week-indoor measurements and a limited response linearity for the assessment of large radon exposures indoors, in thermal spa, in caves, and in soil. Moreover, for in-soil measurements these monitors are too bulky and are often conducive to wrong results. For what concerns the radon-in-water measurements, they are just not suitable. A new generation of passive radon monitors is introduced in this paper, which are very similar to the compact badges used in neutron- and gamma-dosimetry and will be referred to as radon-film-badges. These film-badges are formed by thin-film radiators with suitable radon-sorption characteristics, facing track detectors. The key strategy adopted for these radiators is to exploit an equilibrium type of radon sorption in solids. Even though this new generation of passive monitors is at its infancy, it appears already clear that said monitors make it finally possible to overcome most of the shortcomings of existing passive radon monitors. These devices are uniquely simple and can be easily acquired by any existing radon service to complement their presently used passive radon monitors with little or no effort.

Radon in buildings

International Nuclear Information System (INIS)

Connell, J.J.

1991-01-01

This guide is intended to inform designers, householders and other building owners about the radon problem and to help in deciding if there is need to take any action to reduce radon levels in their homes or other buildings.It explains what radon is, how it enters buildings and what effect it may have on health. Reference is made to some of the usual ways of reducing the level of radon and guidance is given on some sources of assistance

Radon and its hazards

International Nuclear Information System (INIS)

Chang Guilan

2002-01-01

The author describes basic physical and chemical properties of radon and the emanation, introduces methods of radon measurement, expounds the hazards of non-mine radon accumulation to the health of human being and the protection, as well as the history how the human being recognizes the hazards of radon through the specific data and examples, and finally proposes protecting measures to avoid the hazards of radon to the health of human being, and to do ecologic evaluation of environments

Entry-Control Systems Handbook

International Nuclear Information System (INIS)

1978-09-01

The function of an entry-control system in a total Physical Protection System is to allow the movement of authorized personnel and material through normal access routes, yet detect and delay unauthorized movement of personnel and material from uncontrolled areas. The ten chapters of this handbook cover: introduction, credentials, personnel identity verification systems, special nuclear materials monitors, metal detectors, explosives sensors, package search systems, criteria for selection of entry-control equipment, machine-aided manual entry-control systems, and automated entry-control systems. A system example and its cost are included as an appendix

Radon reduction

International Nuclear Information System (INIS)

Hamilton, M.A.

1990-01-01

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

Human perception of radon risk and radon mitigation: Some remarks

International Nuclear Information System (INIS)

Neznal, M.; Neznal, M.

2008-01-01

The Radon program in the Czech Republic has a relatively long and rich history. Procedures, which enable to evaluate the risk of radon penetration from the ground, to protect new buildings, to find existing buildings with elevated indoor radon levels and to realise remedial measures in such buildings, have been developed, published and tested. In some cases, the whole system may fail due to psychological or sociological reasons. Three types of problems (conflicts) will be presented: human behaviour affecting measurement results, conflict between individual and 'all-society' points of view, interpretation of radon risk itself. (authors)

Radon/radon-daughter measurement methods and instrumentation

International Nuclear Information System (INIS)

Rock, R.L.

1977-01-01

Radon-daughter measurement equipment and techniques have been continuously improved over the last 25 years. Improvements have been in the areas of accuracy, time and convenience. We now have miniaturized scalers and detectors available for measuring the alpha particle count rates from aerosol samples collected on filter papers. We also have small lightweight efficient pumps for conveniently collecting samples and we have various counting methods which allow us to choose between making very precise measurements or nominal measurements. Radon-daughter measurement methods used in uranium mines and mills are discussed including a personal radon-daughter-exposure integrating device which can be worn by miners

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

International Nuclear Information System (INIS)

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

2005-01-01

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

EML indoor radon workshop, 1982

International Nuclear Information System (INIS)

George, A.C.; Lowder, W.; Fisenne, I.; Knutson, E.O.; Hinchliffe, L.

1983-07-01

A workshop on indoor radon, held at the Environmental Measurements Laboratory (EML) on November 30 and December 1, 1982, covered recent developments in radon daughter research and development. Thirty papers were presented dealing with standardization and quality assurance measurement methods, surveys, measurements strategy, physical mechanisms of radon and radon daughter transport and development of guidance standards for indoor exposures. The workshop concluded with a planning session that identified the following needs: (1) national and international intercomparisons of techniques for measuring radon and radon daughter concentrations, working level and radon exhalation flux density; (2) development and refinement of practical measurement techniques for thoron and its daughter products; (3) quantitative definition of the sources of indoor radon and the mechanisms of transport into structures; (4) better knowledge of the physical properties of radon daughters; (5) more complete and accurate data on the population exposure to radon, which can only be met by broadly based surveys; and (6) more international cooperation and information exchange among countries with major research programs

Radon therapy; Radon in der Therapie

Energy Technology Data Exchange (ETDEWEB)

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

2017-04-01

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

Radon atlas of Finland

International Nuclear Information System (INIS)

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

1997-11-01

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

Scopingreport radon

International Nuclear Information System (INIS)

Blaauboer, R.O.; Vaas, L.H.; Hesse, J.M.; Slooff, W.

1989-09-01

This report contains general information on radon concerning the existing standards, sources and emissions, the exposure levels and effect levels. lt serves as a basis for the discussion during the exploratory melting to be held in November/December 1989, aimed at determining the contents of the Integrated Criteria Document Radon. Attention is focussd on Rn-222 (radon) and Rn-220 (thoron), presently of public interest because of radon gas pollution in private homes. In the Netherlands air quality standards nor product standards for the exhalation rate of building materials have been recommended. The major source of radon in the Netherlands is the soil gas (> 97%), minor sources are phosphate residues and building materials (> 2% in total). Hence, the major concern is the transfer through the inhalation of air, the lung being the most critical organ at risk to develop cancer. Compared to risks for humans, the risks of radon and its daughters for aquatic and terrestric organisms, as well as for agricultural crops and livestock, are assumed to be limited. In the Netherlands the average dose for man due to radon and thoron progeny is appr. 1.2 mSv per year, the estimated dose range being 0.1-3.5 mSv per year. This dose contributes for about 50% to rhe total exposure due to all sources of ionizing radiation. Of this dose respectively 80% is caused by radon and about 90% is received indoor. The estimated dose for the general population corresponds to a risk for inducing fatal cancers of about 15 x 10-6 per year, ranging from 1.2 x 10-6 to 44 x 10-6 which exceeds the risk limit of 1 x 10-6 per year -as defined in the standardization policy in the Netherlands for a single source of ionizing radiation-with a factor 15 (1- 44). Reduction of exposure is only possible in the indoor environment. Several techniques have been described to reduce the indoor dose, resulting from exhalation of the soil and building materials. )aut- hor). 37 refs.; 3 figs.; 8 tabs

A discussion of radon and the mitigation strategy at the Henderson Mine

International Nuclear Information System (INIS)

Loring, D.M.; Meisburger, E.P. IV

2010-01-01

The geology at the Henderson molybdenum mine near Denver, Colorado makes radon a ventilation challenge. Unforeseen events can occur due to the dynamic nature of caving mining. As such, the Climax Molybdenum Company has adopted proper ventilation, monitoring and control strategies at the mine to mitigate concerns regarding radon. Due to the granitic ore and presence of trace uranium mineralization, radon daughters are generated and make their way through the caved orebody to drawpoints on the production level. This paper described historical geological events which involved reaction by the ventilation group to mitigate higher-than-normal radon concentrations, with particular reference to the causes, responses and planning to avoid similar issues in the future. The radon control strategy involves 3 items, notably negative pressure on the cave through regulators or fans connecting the broken ore of the cave to an isolated main exhaust drift; isolation of the cave through bulkheading of all intake air sources to the caved ore; and positive pressurization of the undercut level through forcing fans in the drill drifts so that pressure can be maintained in the cave, thus preventing radon daughters from leaking into the work area. 7 refs., 1 tab., 9 figs.

Robust Image Hashing Using Radon Transform and Invariant Features

Directory of Open Access Journals (Sweden)

Y.L. Liu

2016-09-01

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

Radon og boligen

DEFF Research Database (Denmark)

Rasmussen, Torben Valdbjørn

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

Assessment of current techniques for reduction of indoor radon concentration in existing and new houses in European countries

International Nuclear Information System (INIS)

Holmgren, O.; Arvela, H.

2012-03-01

Radon control technologies aim at the reduction of indoor radon concentrations in existing buildings and in new construction through remedial and preventive measures. In recent years, rising ecological awareness and rising energy costs have stimulated the development of low energy and passive houses to save energy. This report contains the analysis and assessment of current techniques and technologies used to achieve the reduction of indoor radon concentrations in existing and new houses with regard to the reduction efficiency and potential impact on energy consumption (qualitative analysis). A questionnaire was prepared and sent to all RADPAR partners in 14 different countries in order to gather national information about the current remediation and prevention techniques. Responses with variable amounts of information were obtained. Based on the questionnaire responses, the status of radon remediation and prevention in each country was assessed, in addition to the reduction efficiency and potential impact on energy consumption of the current remediation and prevention techniques. The number of dwellings with an elevated indoor radon concentration typically ranges from tens of thousands to a million. The percentage of these houses already remediated varies from zero to 15%. Preventive measures in new construction have been taken from a small number of houses to over half a million houses. The research data on the current situation, the number of houses with preventive measures and the efficiency of these measures is currently still quite inadequate. Assessment of the techniques and also the surveys aiming at exploring the impact of remedial and preventive measures is greatly needed in order to promote the work at the national level. The most efficient remediation method is the active sub-slab depressurization (SSD) and the radon well, for which the reduction in the radon concentration is typically 70 - 95%. Other methods, such as sealing entry routes and improving

Radon campaigns. Status report 2008

International Nuclear Information System (INIS)

Arvela, H.; Valmari, T.; Reisbacka, H.; Niemelae, H.; Oinas, T.; Maekelaeinen, I.; Laitinen-Sorvari, R.

2008-12-01

Radon campaigns aim at activating citizens to make indoor radon measurements and remediation as well as increasing the common awareness of indoor radon questions. Indoor radon increases the risk of lung cancer. Through radon campaigns Radiation and Nuclear Safety Authority (STUK) also promotes the attainment of those goals that the Ministry of Social Affairs and Health has set for municipal authorities in Finland for prevention of the harmful effects of radon. The Ministry of Social Affairs and Health supports this campaign. Radon campaigns were started in autumn 2003. By autumn 2008 the campaigns have been organised already in 64 regions altogether in 160 municipalities. In some municipalities they have already arranged two campaigns. Altogether 14 100 houses have been measured and in 2 100 of these the action limit of radon remediation 400 Bq / m 3 has been exceeded. When participating in radon campaigns the house owners receive a special offer on radon detectors with a reduced price. In 2008 a new practice was introduced where the campaign advertisements were distributed by mail to low-rise residential houses in a certain region. The advertisement includes an order / deposit slip with postage paid that the house owner can send directly to STUK to easily make an order for radon measurement. In the previous radon campaigns in 2003 - 2007 the municipal authorities collected the orders from house owners and distributed later the radon detectors. The radon concentrations measured in the campaign regions have exceeded the action limit of 400 Bq / m 3 in 0 - 39% of houses, depending on the region. The total of 15% of all measurements made exceeded this limit. The remediation activities have been followed by sending a special questionnaire on remedies performed to the house owners. In 2006 - 2007 a questionnaire was sent to those households where the radon concentration of 400 Bq / m 3 was exceeded during the two first campaign seasons. Among the households that replied

Radon and its daughters in vivo

Energy Technology Data Exchange (ETDEWEB)

Rundo, J

1984-05-01

Prolonged exposure to radon should build up a reservoir of radon in body fat and fluids. Movement of the subject to an environment with a lower radon concentration from an environment with a higher level of radon would result in an exhalation of radon, and the initial exhalation rate of radon should depend on the radon concentration inhaled. This paper describes the behavior of radon and its daughters in vivo and a relationship between the radon exhalation rate and the time after a meal. A major but short-lived postprandial increase in the exhalation rate of radon was observed. We report a similar effect in the exhalation rate of radon by persons containing no radium. It should be noted that the possibility exists that a large amount of radon daughters in the chest may interfere in the investigation of possible internal contamination with plutonium or other actinides by external counting. (author).

Radon in balneology - measurement of radon retention by patients and radiation protection for personell

International Nuclear Information System (INIS)

Just, G.; Falkenbach, A.; Grunewald, W.A.; Philipsborn, H. von

2001-01-01

In radon balneology patients are exposed to radon either from water or air through the skin or through inhalation. Drinking radon water was not included in the study. Previously, the radon transfer has been determined for an estimate of the medically active amount of radon retained in the patient. A simpler approach of measuring radon in expiration under and after exposure has now been standardised and applied to probands under different conditions of exposure. In addition, radon decay products were measured in sweat, saliva and in the skin. Experimental parameters were evaluated for a comparison of different concentrations observed under different conditions. Results are likely to improve both therapy for patients and radiation protection for members of the personnel. (orig.) [de

The effect and the amendment of thermoregulation to the stability of radon concentration in radon chamber

International Nuclear Information System (INIS)

Zhang Xiongjie; Wang Renbo; Qu Jinhui; Tang Bin; Zhu Zhifu; Man Zaigang

2010-01-01

When the temperature in the airtight radon chamber was adjusted, it would induce the frequent changes of the air pressure in chamber, then the radon concentration in the radon chamber would continuously reduce, which could seriously destroy the stability of the radon concentration in radon chamber. In this paper, on the study of the effect reasons to the stability of radon concentration in airtight radon chamber due to the thermoregulation, a new amendment scheme was put forward, and the solutions of the relevant parameters were discussed. The amendment scheme had been successfully applied to HD-6 radon chamber, and achieved good results. (authors)

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

NARCIS (Netherlands)

DEMEIJER, RJ; STOOP, P; PUT, LW

1992-01-01

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

Radon and radon daughter monitoring (including thoron daughter monitoring)

International Nuclear Information System (INIS)

Leach, V.A.; Grealy, G.; Gan, W.

1982-01-01

Radon/radon daughter and thoron daughter measurement techniques are outlined. The necessary precautions and critical assessments of each method are also presented with a view to providing a better understanding of the various measurement methods

Uranium prospecting through radon detection; La prospection de l'uranium par le radon

Energy Technology Data Exchange (ETDEWEB)

Pradel, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1956-07-01

Prospecting rests on the determination of the concentration of ground air in radon. Radon diffusing from deep uranium bearing layers is detected in upper ground layers. (author) [French] La prospection est basee sur l'etude de la concentration en radon dans l'air du sol. Dans les terrains superficiels, on decele le radon qui diffuse a partir des couches profondes uraniferes. (auteur)

Radon and its daughters in vivo

Energy Technology Data Exchange (ETDEWEB)

Rundo, J

1984-05-01

Prolonged exposure to radon should build up a reservoir of radon in body fat and fluids. If the subject moved to an environment with a lower radon concentration from an environment with a higher level of radon, the result would be an exhalation of radon, and the initial exhalation rate of radon should depend of the radon concentration inhaled. This paper describes the behavior of radon and its daughters in vivo and a relationship between the radon exhalation rate and the time after a meal. A major but short-lived postprandial increase in the exhalation rate of radon was observed. The author reports a similar effect in the exhalation rate of radon by persons containing no radium. It should be noted that the possibility exists that a large amount of radon daughters in the chest may interfere in the investigation of possible internal contamination with plutonium or other actinides by external counting. 8 figures.

Measurement of exhalation rate of radon and radon concentration in air using open vial method

International Nuclear Information System (INIS)

Horiuchi, Kimiko; Ishii, Tadashi.

1991-01-01

It was recognized that more than half of total exposure dose on human subject is caused by radon and its decay products which originate from naturally occurring radioactive substances (1988 UNSCEAR). Since then the exhalation of radon from the ground surface has received increasing attention. The authors have developed a new method for the determination of radon in natural water using toluene extraction of radon and applying a liquid scintillation counter of an integral counting technique which is able to get the absolute counting of radon. During these studies, the authors found out that when a counting vial containing of Liquid scintillator (LS)-toluene solution, without a lid, is exposed to the atmosphere for a while, dissolution of radon clearly occurs due to high solubility of radon into toluene layer. To extend this finding for the determination of radon in the atmosphere, the authors devised a new method to actively collect the atmosphere containing radon in a glass bottle by discharging a definite amount of water in it, which is named as open-vial dynamic method. The radon concentration can be easily calculated after the necessary corrections such as the partition coefficient and others. Applying proposed method to measure the radon exhalation rate from the ground surface and radon concentration in air of the dwelling environment, radioactive mineral spring zone and various geological formation such as granitic or sedimentary rocks. (author)

Risks from radon

International Nuclear Information System (INIS)

Doll, Richard

1992-01-01

The best estimate of risk to which everyone is exposed from natural radon in buildings is now obtained by extrapolation from observations on men exposed to radon in mines. The relationship between dose and effect derived by the US National Research Council implies that about 6% of the current life-time risk of developing the disease in the UK is attributable to radon, but for residents of some houses it will be much greater. This estimate is dependent on many assumptions, some of which are certainly wrong, and reliable estimates can be obtained only by direct observations on people living in different houses. It is possible that radon may also cause some risk of other cancers, notably leukaemia, but such risks, if real, are certainly small. Studies in progress should provide reliable estimates of all radon induced risks within a few years. (author)

Radon: Detection and treatment

International Nuclear Information System (INIS)

Loken, S.; Loken, T.

1989-01-01

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

Estimation of risk from environmental exposure to radon in Tehri Garhwal

International Nuclear Information System (INIS)

Ramola, R.C.; Rawat, R.B.S.; Kandari, M.S.

1995-01-01

Some preliminary results from a radon survey carried out in mud houses in Tehri Garhwal are reported. The radon values recorded were found to be higher than the recommended value under normal ventilation conditions. The estimated total life time risk and attributed loss of life expectancy are found to be 0.58 per Bq/m 3 and 15 years, respectively. The abnormal values recorded in mud houses in Tehri Garhwal are of sufficient importance for initiating further investigations in this area. (author)

Managing Radon in Schools

Science.gov (United States)

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

Radon in workplaces

International Nuclear Information System (INIS)

Gooding, Tracy

1995-01-01

The naturally occurring radioactive gas radon has been found at excessive levels in many workplaces other than mines throughout the country. Prolonged exposure to radon and its decay products increases the risk of developing lung cancer, and controls to protect employees from excessive exposure are included in the Ionising Radiations Regulations 1985. The control of occupational exposure to radon is discussed here. (author)

In-situ performance evaluation of radon measurement techniques in Uranium mine exhausts of Jaduguda

International Nuclear Information System (INIS)

Patnaik, R.L.; Jha, V.N.; Singh, M.K.; Meena, J.S.; Rajesh Kumar; Srivastava, V.S.; Sethy, N.K.; Ravi, P.M.; Tripathi, R.M.

2014-01-01

Several techniques are used for the measurement of the activity concentration of radon in the work place and the environment. Devices like Scintillation cell, Alpha guard and Low Level Radon Detection System (LLRDS) are widely used for the estimation of radon. Some of the devices like scintillation cell is normally used in high activity concentration, whereas, device like LLRDS is used in low activity concentration range. All these above devices are used in ambient mode in which air sample is either collected in a cell or in a chamber and the alpha counts are recorded after a definite delay. In some device, air is allowed to be diffused through a filter and alpha activity is estimated using proper detection system. Passive radon dosimeters can effectively be used both in low and high activity concentration range. The cumulative radon exposure can be assessed using passive radon dosimeters. For in situ performance evaluation an area is required where both high and low level activity concentration of radon is anticipated. Uranium mines exhaust area is presumed to be an area where both these conditions can be found by mere variation in the placement of the device. Inter comparison exercise can also be done effectively at this location using various devices of radon estimation

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

Science.gov (United States)

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

2016-10-01

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

Radon and radon daughter measurements at and near the former Middlesex Sampling Plant, Middlesex, New Jersey

International Nuclear Information System (INIS)

Haywood, F.F.; Perdue, P.T.; Christian, D.J.; Leggett, R.W.; Dickson, H.W.; Myrick, T.E.

1980-03-01

The results of the radon and radon daughter measurements made to date (1978) at the Middlesex Sampling Plant in Middlesex, New Jersey, are presented in this report. These measurements were one portion of a more comprehensive radiological survey conducted at this site and the surrounding area from 1976 to 1978. The surveyed property served as a uranium ore sampling plant during the 1940's and early 1950's and as a result contains elevated levels of surface an subsurface contamination. On-site indoor radon daughter and radon concentrations exceeded both the US Surgeon General Guidelines and the Nuclear Regulatory Commission's maximum permissible concentration limits for radon (10 CFR Part 20) in all structures surveyed. Off-site structures showed concentrations of radon and radon daughters at or only slightly above background levels, except for one site where the radon levels were found to be above the 10 CFR Part 20 guidelines. Outdoor radon ad radon daughter concentrations, measured both on and off the site, were well below the guidelines, and the data give no indication of significant radon transport from the site

Geographical associations between radon and cancer: is domestic radon level a marker of socioeconomic status?

International Nuclear Information System (INIS)

Wolff, S.P.; Stern, G.

1991-01-01

Previous studies showing a geographical association between radon and various cancers, particularly the leukaemias and lymphomas, appear to be confounded by the role of radon levels as a surrogate for socioeconomic status. Higher socioeconomic status (at least at the UK county level) is correlated with higher levels of domestic radon. Controlling for the relationship between socioeconomic status and radon removes the correlation between radon exposure and lymphoproliferative disease. Reported associations between radon and lymphoproliferative disease (and possibly other cancers) may be secondary to socioeconomic variables. (author)

Inverse method for determining radon diffusion coefficient and free radon production rate of fragmented uranium ore

International Nuclear Information System (INIS)

Ye, Yong-jun; Wang, Li-heng; Ding, De-xin; Zhao, Ya-li; Fan, Nan-bin

2014-01-01

The radon diffusion coefficient and the free radon production rate are important parameters for describing radon migration in the fragmented uranium ore. In order to determine the two parameters, the pure diffusion migration equation for radon was firstly established and its analytic solution with the two parameters to be determined was derived. Then, a self manufactured experimental column was used to simulate the pure diffusion of the radon, the improved scintillation cell method was used to measure the pore radon concentrations at different depths of the column loaded with the fragmented uranium ore, and the nonlinear least square algorithm was used to inversely determine the radon diffusion coefficient and the free radon production rate. Finally, the solution with the two inversely determined parameters was used to predict the pore radon concentrations at some depths of the column, and the predicted results were compared with the measured results. The results show that the predicted results are in good agreement with the measured results and the numerical inverse method is applicable to the determination of the radon diffusion coefficient and the free radon production rate for the fragmented uranium ore. - Highlights: • Inverse method for determining two transport parameters of radon is proposed. • A self-made experimental apparatus is used to simulate radon diffusion process. • Sampling volume and position for measuring radon concentration are optimized. • The inverse results of an experimental sample are verified

Radon exhalation rates corrected for leakage and back diffusion – Evaluation of radon chambers and radon sources with application to ceramic tile

Directory of Open Access Journals (Sweden)

M. Abo-Elmagd

2014-10-01

Full Text Available The natural radon decay, leakage and back diffusion are the main removal processes of radon from its container. Ignoring these processes leads to underestimate the measured value of radon related parameters like exhalation rate and radium content. This work is aimed to evaluate two different radon chambers through determining their leakage rate λv and evaluation of radon source by determine its back diffusion rate λb inside the evaluated radon chambers as well as a small sealed cup. Two different methods are adapted for measuring both the leakage rate and the back diffusion rate. The leakage rate can be determined from the initial slope of the radon decay curve or from the exponential fitting of the whole decay curve. This can be achieved if a continuous monitoring of radon concentration inside the chamber is available. Also, the back diffusion rate is measured by sealing the radon source in the chamber and used the initial slope of the buildup curve to determine λb and therefore the exhalation rate of the source. This method was compared with simple equation for λb based on the ratio of the source to the chamber volume. The obtained results are applied to ceramic tile as an important radon source in homes. The measurement is targeted the ceramic glaze before and after firing as well as the obtained tile after adhere the glaze on the tile main body. Also, six different tile brands from Egyptian market are subjected to the study for comparison.

Measurement of the Radon equilibrium factor in Ottawa dwellings

International Nuclear Information System (INIS)

Rahman, Naureen M.; Tracy, Bliss L.; Chen, Jing; Moir, Deborah

2008-01-01

The degree of radioactive equilibrium between radon and its short-lived radioactive decay products can be expressed as the equilibrium factor 'F'. It is often assumed to be 0.40 for assessing risk. While this is usually a reasonable assumption, there are cases where the equilibrium factor can differ from 0.40 significantly due to various housing and environmental factors. Because the effective dose depends strongly on the F value, it is important for risk assessment to know the normal range of the F factor for settings specific to Canada. For this purpose, measurements were undertaken at several Ottawa homes with a wide range of radon concentrations. The experimental homes were detached houses with a composite structure of brick, concrete blocks and wood. The hourly variation of radon concentration and its decay products concentration were observed employing a portable ionisation chamber (permitting the continuous radon monitoring as well as the determination of selected parameters -- air temperature, pressure and humidity), Lucas type passive scintillation cell and a working level monitor. The calculated F value lay between 0.20 - 0.52. In addition, the diurnal variation of the F value was observed and the indoor environment was monitored. (author)

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

International Nuclear Information System (INIS)

Kelleher, K.; McLaughlin, J.P.; Fenton, D.; Colgan, P.A.

2006-01-01

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

Radon in workplaces

International Nuclear Information System (INIS)

Markkanen, M.; Annanmaeki, M.; Oksanen, E.

2000-01-01

The EU Member States have to implement the new Basic Safety Standards Directive (BSS) by May 2000. The Title VII of the Directive applies in particular to radon in workplaces. The Member States are required to identify workplaces which may be of concern, to set up appropriate means for monitoring radon exposures in the identified workplaces and, as necessary, to apply all or part of the system of radiological protection for practices or interventions. The BSS provisions on natural radiation are based on the ICRP 1990 recommendations. These recommendations were considered in the Finnish radiation legislation already in 1992, which resulted in establishing controls on radon in all types of workplaces. In this paper issues are discussed on the practical implementation of the BSS concerning occupational exposures to radon basing on the Finnish experiences in monitoring radon in workplaces during the past seven years. (orig.) [de

Radon Research Program, FY 1992

International Nuclear Information System (INIS)

1993-04-01

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

Modeling of indoor radon

International Nuclear Information System (INIS)

Paschoa, A.S.

1990-01-01

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

Scopingsreport Radon

NARCIS (Netherlands)

Blaauboer RO; Vaas LH; Hesse JM; Slooff W

1989-01-01

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

Radon in dwellings

International Nuclear Information System (INIS)

Erikson, B.E.; Boman, C.A.; Nyblom, L.; Swedjemark, G.A.

1980-06-01

The report presents the function of the ventilation by natural draught in three-storey houses. In some cases also the measurement of gamma radiation, radon and radon daughters was made. The investigation took place in Uppsala. The houses were built of light weight concrete made of alum-shale. The measurements showed that the contents of radon daughters were far below the provisional limits. (G.B.)

Review of existing instrumentation and evaluation of possibilities for research and development of instrumentation to determine future levels of radon at a proposed building site

International Nuclear Information System (INIS)

1983-01-01

The rate at which radon enters houses from the soil depends on the pressure differential between the house and the soil, the resistance of the soil to gas movement, and the radon release rate of the soil near the house. The pressure differential between house and soil is caused by wind forces and temperature differences, which depend on the size of the building and the season, and are therefore almost independent of the site location. The soil resistance (permeability) and radon release rate are site specific, and a computer study of radon movement through the soil suggested that these parameters could be combined to give a Radon Index Number (RIN) for a site that would be proportional to the radon entry rate into a typical house. Regional RIN estimates would be produced using existing airborne gamma survey maps to estimate average soil radon release rate, plus agricultural soil classification maps to estimate permeability. Area RIN estimates would be produced using portable gamma spectroscopy equipment to estimate soil radon release rates over an area, plus simple soil grain size analysis techniques to estimate permeability. Site RIN estimates would be produced using laboratory techniques to measure both the radon release rate and the permeability of several undisturbed soil core samples taken at depths over the site. These would provide the most accurate value of RIN possible for a given site

Meteorological factors influencing on the radon concentrations in indoor and outdoor airs

International Nuclear Information System (INIS)

Kojima, Hiroshi

1989-01-01

Factors influencing radon concentrations in indoor and outdoor airs are discussed. A balance between source and loss is required in determining the radon concentration. Source refers to as the outdoor and indoor exhalation rate from the ground and the building materials. Loss is caused by turbulent diffusion outdoors and ventilation indoors. A significant factor influencing the exhalation rate of indoor and outdoor radon may be the change in atmospheric pressure. A drop of pressure feeds the high concentration air under the ground or building materials into the open air, and contributes to the increased exhalation rate. The exhalation rate of radon closely depends on the moisture content of the ground or building materials. Up to a certain level of moisture, the radon exhalation increases with increasing moisture content because the emanation power increases by a recoil effect of a fluid present in the internal pores of the materials. Beyond a certain level of moisture, the exhalation decreases rapidly because the pores are filled with water. Radon exhalated from the ground is spread out by turbulent diffusion. The turbulent diffusion may be related to wind velocity and the lapse rate of temperature. There is a remakable difference between indoor and outdoor radon concentrations. The ventilation rate of the house exerted a great effect upon the indoor radon concentration. The ventilation rate is influenced by meteorological factors together with human activities. Of such factors, wind velocity and temperature gradient between indoor and outdoor airs may be the most significant. The correlation coefficients between RaA or radon and some meteorological factors were calculated on the data from the long term measurements on radon and its decay products in and out of a house under normal living conditions. The changes in atmospheric pressure and wind velocity are found to be a significant factor in the variation of concentration of these nuclides. (N.K.)

Comparing summer and winter indoor radon and radon daughters activity in Campinas, Brazil

International Nuclear Information System (INIS)

Guedes, O.S.; Hadler, N.J.C.; Iunes, P.J.; Neman, R.S.; Souza, W.F.; Tello, S.C.A.; Paulo, S.R.

2002-01-01

We developed a technique - based on alpha particle track detection using CR-39 - where the activity originated from indoor radon can be potentially separated into three fraction: (i) radon in the air, (ii) radon daughters (RD), 218 Po and 214 Po, in the air and (iii) RD plated-out on the detector surface during exposure. In this work only a partial separation was carried out, then our results are limited to radon plus RD in the air and RD attached to detector surface. These activities can be separated if size and gray level of the round tracks are measured using an automatic optical microscopy system.Our group carried out an indoor radon and radon daughters (RD) survey in Campinas made up by a summer (November, 96 to May, 97) and a winter (May, 97 to November, 97) exposure, where the detectors were placed in the same rooms of the same dwellings (approximately 100) in both cases. Comparing winter and summer alpha activity for the detectors analyzed up to now, approximately 45 dwellings, we observed that: i) it seems that the source of radon is the material (brick and concrete mainly) making up walls, floor and ceiling of the dwellings, ii) there is no clear relationship between intensity of aeration and the activities measured in this work, and iii) the average ratio between winter and summer activity in the air (radon plus RD) is approximately equal to similar ratios observed in other countries, but for radon only. (author)

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

Energy Technology Data Exchange (ETDEWEB)

Fazal-ur-Rehman E-mail: fazalr@kfupm.edu.sa; Al-Jarallah, M.I.; Musazay, M.S.; Abu-Jarad, F

2003-12-01

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

LIFETIME LUNG CANCER RISKS ASSOCIATED WITH INDOOR RADON EXPOSURE BASED ON VARIOUS RADON RISK MODELS FOR CANADIAN POPULATION.

Science.gov (United States)

Chen, Jing

2017-04-01

This study calculates and compares the lifetime lung cancer risks associated with indoor radon exposure based on well-known risk models in the literature; two risk models are from joint studies among miners and the other three models were developed from pooling studies on residential radon exposure from China, Europe and North America respectively. The aim of this article is to make clear that the various models are mathematical descriptions of epidemiologically observed real risks in different environmental settings. The risk from exposure to indoor radon is real and it is normal that variations could exist among different risk models even when they were applied to the same dataset. The results show that lifetime risk estimates vary significantly between the various risk models considered here: the model based on the European residential data provides the lowest risk estimates, while models based on the European miners and Chinese residential pooling with complete dosimetry give the highest values. The lifetime risk estimates based on the EPA/BEIR-VI model lie within this range and agree reasonably well with the averages of risk estimates from the five risk models considered in this study. © Crown copyright 2016.

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

International Nuclear Information System (INIS)

Guedes, S.; Hadler, J.C.N.; Iunes, P.J.; Navia, L.M.S.; Neman, R.S.; Paulo, S.R.; Rodrigues, V.C.; Souza, W.F.; Tello, C.A.S.; Zuniga, A.

1999-01-01

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

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

CERN Document Server

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

1999-01-01

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

Radon as a hydrological indicator

Energy Technology Data Exchange (ETDEWEB)

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

1997-02-01

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

Control of radon in Finnish workplaces

International Nuclear Information System (INIS)

Markkanen, M.

2002-01-01

Natural radiation in Finland is regulated in the Finnish Radiation Act from 1992. Occupational exposure to natural radiation is regulated by an amendment of the Radiation Decree in 1998. The most important issues in Finland are radon in workplaces, radioactivity in drinking water and in building materials, and mining and industrial processes. Radon levels in mines have been measured regularly since 1972. Finland has an action level for radon in workplaces of 400 Bq/m 3 . Radon prone areas have been identified primarily from measurements of radon in dwellings. Radon measurements are compulsory in workplaces in radon prone areas unless it can be shown by other means that radon levels are low. A programme focusing on radon in workplaces was initiated in 1992. To date, radon measurements have been carried out in 10,000 workplaces and remedial actions have been taken in 200 of these. The average reduction in radon concentration in remediated buildings is about 1,500 Bq/m 3 . Identification of NORM industries is based on the radionuclide content of the materials used (>1.4 Bq/g U and >0.4 Bq/g Th). The occupational exposure should not exceed 1 mSv/y (excluding radon)

Distribution of indoor radon concentrations and elements of a strategy for control

International Nuclear Information System (INIS)

Nero, A.V. Jr.

1986-05-01

Indoor radon concentrations vary widely in the US housing stock, with normal concentrations estimated to cause a significant risk of lung cancer by comparison with environmental exposures normally considered, and high concentrations causing risks that exceed even those from cigarette smoking. The probability distribution, i.e., the number of houses at various concentrations, can be estimated from an analysis of the US indoor radon data accumulated to date. Such an analysis suggests that in about a million houses, occupants are receiving exposures greater than those experienced by uranium miners. The form of the frequency distribution, including not only the average concentration, but also the number of houses with high levels, has substantial influence on strategies for control of indoor radon. Such strategies require three major elements: formulation of control objectives in terms of guidelines for remedial action and for new houses; selection of means for identifying homes with high concentrations; and a framework for deciding what types of control measures are appropriate to particular circumstances and how rapidly they should be employed

Lessons from radon

International Nuclear Information System (INIS)

Nichols, M.

1993-01-01

At EPA there is a public outreach program that the Office of Air and Radiation (OAR) has developed for radon. To meet the difficult challenge radon presented, OAR's Radon Division developed working relationships with national nonprofit groups who share a mission. These groups have well-established communication networks with their memberships for advancing their goals. Such diverse groups as the American Lung Association, the Advertising Council, the National Association of Counties (NACo), the Consumer Federation of America, the National Association of Homebuilders, and the National Safety Council have joined with EPA to reduce radon health risks. Through this alliance, EPA has been able to take advantage of communication channels that it could never replicate on tis own. Every group working with EPA disseminates the radon message through its own established channels to reach its constituency. These partners wield authority in their fields and are ideal for addressing the concerns of their audiences

Radon mitigation in schools

International Nuclear Information System (INIS)

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

1990-01-01

This article reports on radon mitigation in school buildings. Subslab depressurization (SSD) has been the most successful and widely used radon reduction method in houses. Thus far, it has also substantially reduced radon levels in a number of schools. Schools often have interior footings or thickened slabs that may create barriers for subslab air flow if a SSD system is the mitigation option. Review of foundation plans and subslab air flow testing will help to determine the presence and effect of such barriers. HVAC systems in schools vary considerable and tend to have a greater influence on pressure differentials (and consequently radon levels) than do heating and air-conditioning systems encountered in the radon mitigation of houses. As part of any radon mitigation method, ASHRAE Standard 62-1989 should be consulted to determine if the installed HVAC system is designed and operated to achieve minimum ventilation standards for indoor air quality

Health effects of radon

International Nuclear Information System (INIS)

Easterly, C.

1994-01-01

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

Radon risk in the house; Il rischio radon nelle abitazioni

Energy Technology Data Exchange (ETDEWEB)

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

2001-04-01

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

Radon in Syrian houses

International Nuclear Information System (INIS)

Othman, I.; Hushari, M.; Raja, G.; Alsawaf, A.

1996-01-01

A nationwide investigation of radon levels in Syrian houses was carried out during the period 1991-1993. Passive radon diffusion dosemeters using polycarbonate detectors were distributed in houses all over Syria. Detectors were subjected to electrochemical etching to reveal latent tracks of alpha particles. The mean radon concentration in Syrian houses was found to be 45 Bq m -3 with some values several times higher. This investigation indicated that there were a few houses in Syria that require remedial action. Most houses that have high levels of radon were found in the southern area, especially in the Damascus governorate. The study also indicated that radon concentrations were higher in old houses built from mud with no tiling. (author)

The therapeutic use of radon; Radon als Heilmittel

Energy Technology Data Exchange (ETDEWEB)

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

1995-09-01

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

Radon and its measurement

International Nuclear Information System (INIS)

Penzo, Silvia

2006-03-01

The work reviews the topics concerning the problem of the indoor radon and its measurement. The initial stage deals with the general features of radon, from the historical remarks about its discovery to the formation mechanisms in the soil, then passing to describe the transport processes that lead the radon to enter into the buildings. The mean radon concentration distribution among the Italian regions is reported and compared with the situation in the other countries of the world. A particular importance is given to present the national law concerning the radioprotection from the natural sources of ionizing radiations; a paragraph is completely devoted to this argument and to discuss the differences between the Italian approach and the regulations applied in the Test of Europe for both workplaces and dwellings. Chapter 3 describes the different detectors and methods to measure the radon and its short mean live decay products concentrations, together with the operative procedures and guides provided by the Italian law and by the international bodies. As an example of typical radon passive measurement device. the new ENEA detector developed at the Institute of Radioprotection is presented and discussed. Appendix 1 is entirely devoted to discuss the main remedial actions for decreasing the radon indoor concentration both for old and new buildings; appendix 2 reports the main quantities related to radon and radioprotection [it

Study on the measurement method of diffusion coefficient for radon in the soil. 2

International Nuclear Information System (INIS)

Iida, Takao

2000-03-01

To investigate radon behavior in the soil at Ningyo Pass, the radon concentrations in the soil and the radon exhalation rate from soil surface were measured by four continuous soil radon monitoring systems, soil gas sampling method, and accumulation method. The radon concentrations in the soil measured with continuous soil radon monitoring systems varied form 5000 Bq·m -3 to 15000 Bq·m -3 at 10 cm to 40 cm depth. On the other hand, the radon concentrations measured by soil gas sampling method was 15000 Bq·m -3 at 15 cm depth. The accumulation method gives the vales of 0. 36∼0.68 Bq·m -2 ·s -1 for radon exhalation rate from soil surface. To simulate the radon transport in soil, the following parameters of the soil are important: radon diffusion coefficients, dry density, wet density, soil particle density, true density, water content and radium concentration. The measured radon diffusion coefficients in the soil were (1.61±0.09)x10 -6 m 2 s -1 , (8.68±0.23)x10 -7 m 2 s -1 ∼ (1.53±0.12)x10 -6 m 2 s -1 and (2.99±0.32)x10 -6 m 2 s -1 ∼ (4.39±0.43)x10 -6 m 2 s -1 for sandy soils of the campus of Nagoya University, Tsuruga peninsula, and Ningyo Pass, respectively. By using these parameters, the radon transport phenomena in the soil of two layers were calculated by analytical and numerical methods. The radon profile calculated by numerical method agrees fairly well with measured values. By covering of 2 m soil, the radon exhalation rate decreases to 1/4 by analytical method, and 3/5 by numerical method. The covering of normal soil is not so effective for reducing the radon exhalation rate. (author)

Evaluation of the performance characteristics of radon and radon-daughter concentration measurement devices under controlled environmental conditions

International Nuclear Information System (INIS)

Pearson, M.D.

1989-04-01

The Technical Measurements Center (TMC) conducted a study to expose 10 radon and 7 radon-daughter concentration measurement devices in the DOE/GJPO Radon/Radon-Daughter Environmental Chamber for a series of 24 controlled-environment tests. The tests evaluated the devices' response to temperature, relative humidity, dew point, condensation-nuclei concentration, radon-daughter/radon equilibrium ratio, and non-uniform radon and radon-daughter concentration. Devices were evaluated for linear response as a function of concentration. In addition to response to environmental parameters, the evaluation included determining the utility of the devices in providing reasonable assurance of compliance with the radon and radon-daughter concentration standards for DOE remedial action programs. This reasonable assurance criterion is based on a coefficient of variation of 25 percent for devices deployed for year-long measurements and a coefficient of variation of 18 percent for devices deployed for intermittent sampling. 39 refs., 65 figs., 33 tabs

Radon in public buildings

International Nuclear Information System (INIS)

Schulz, H.; Flesch, K.; Hermann, E.; Loebner, W.; Leissring, B.

2009-01-01

From the Free State of Saxony, a study was commissioned to survey how reliable measurements to characterize the radon situation in public buildings at a reasonable financial and human effort can be carried out to reduce radiation exposure in public buildings. The study approach was for 6 objects. To characterize the radon situation the time evolution measurement of radon concentrations of more than 1 to 2 weeks turned out to be sufficient. A novel data analysis enables the identification of a ''typical daily alteration of the radon concentration'' depending on the ventilation conditions and the daily use of the offices or class rooms. The identification of typical diurnal radon variations for the working time and weekends or holidays is of fundamental importance for assessing the exposure situation in public buildings. It was shown that the radon concentration during working time are in general much lower than in the times when the buildings (offices) are unused. It turned out that the long-term radon measurements with nuclear track detectors within distinct time regimes (day / night, working hours / leisure time) by utilizing switch modules are very efficient to estimate the actual exposure. (orig.)

Technique and equipment for measuring volume activity of radon in the air of radon laboratories and clinics

International Nuclear Information System (INIS)

Vorob'ev, I.B.; Krivokhatskij, A.S.; Nekrasov, E.V.; Nikolaev, V.A.; Potapov, V.G.; Terent'ev, M.V.

1990-01-01

Usability of a new equipment-technique combination for measuring radon activity in the air of radon laboratories and balneological clinics is studied. The complex includes nitrate-cellulose detector, radon chamber, Aist, Istra type spark counters and technique of spark counting. The method sensitivity is 50 Bqxm 3 , the error is 30%. Usability and advisability of track method in radon laboratories and balneological clinics for simultaneous measurement in several points of integral volumetric radon activities are confirmred. The method permits to carry out rapid and accurate bulk investigations. The results of determining mean volumetric radon activity in the air in different points of radon laboratory and radon clinics are presented

Radon in dwellings the national radon survey Cork and Kerry

International Nuclear Information System (INIS)

McGarry, A.T.; Fennell, S.G.; Mackin, G.M.; Madden, J.S.

1998-07-01

This report presents the results of the third phase of the National Radon Survey carried out by the Radiological Protection Institute of Ireland. The counties included in this phase are Cork and Kerry. The average radon concentrations for the houses measured in these counties were 76 Bq/m 3 and 70 Bq/m 3 . The measurement data were grouped on the basis of the 10 km grid squares of the Irish National Grid System and used to predict the percentage of dwellings in each grid square which exceeds the Reference Level of 200 Bq/m 3 . Grid squares where this percentage is predicted to be 10% or higher are designated High Radon Areas. The health effects of exposure to high radon levels are discussed and recommendations are made regarding both new and existing dwellings. (author)

Seasonal variations of indoor radon concentrations

International Nuclear Information System (INIS)

Majborn, B.

1990-01-01

Seasonal variations of indoor radon concentrations have been studied in a cluster of 10 single-family houses. Eight of the houses are of a similar construction with slab-on-grade foundations. The remaining two houses have different substructures, one of them having a crawl space, and the other having partly a basement and partly a crawl space. A 'normal' seasonal variation of the radon concentration with a maximum in winter and a minimum in summer was observed in most of the houses. In these houses the variation showed a strong correlation with the indoor-outdoor temperature difference on a 2-month basis. However, deviating seasonal variations were observed in some of the houses, notably in the two houses having different substructures. This paper reports that a re-examination of the data obtained in a previous study indicates that winter/summer ratios of indoor radon concentrations in Danish houses depend on the house substructure. The mean winter/summer ratios were about 2.1 for houses with slab-on-grade foundations, 1.5 for houses having a basement, and 1.0 for houses with a crawl space (geometric mean values). However, a study with more houses in each substructure category will be needed to show whether or not the indicated differences are generally valid for Danish houses

Design of a continuous digital-output environmental radon monitor

International Nuclear Information System (INIS)

Wrenn, M.E.; Spitz, H.; Cohen, N.

1975-01-01

A new field instrument for the continuous measurement of radon concentrations has been developed to investigate the magnitude and variability of environmental levels of 222 Rn. Passive diffusion of radon, but not its daughters, occurs through an open pore polyurethane foam into a sensitive volume where a static electric field directs the positively ionized radon daughter products to a central collecting electrode. Pulses in a ZnS(Ag) scintillator, resulting from the alpha emission of 218 Po and 214 Po, are observed with a photomultiplier tube and counted using standard NIM electronics. The detector unit has been fabricated into a small, convenient package for indoor air sampling without the use of air movers or pumps. The unit is unobtrusive and acceptable into a daily routine without disrupting normal family or business activities. The monitor can detect as little as 0.5 pCi/l for a 40-min. count (α = .05). The equilibrium detection efficiency of the instrument is 0.7 cpm/pCi/l. (U.S.)

Radon and Thoron Exhalation Rates from Surface Soil of Bangka - Belitung Islands, Indonesia

Directory of Open Access Journals (Sweden)

Syarbaini Syarbaini

2015-03-01

Full Text Available DOI:10.17014/ijog.2.1.35-42Radon and thoron exhalation rate from soil is one of the most important factors that can influence the radioactivity level in the environment. Radon and thoron gases are produced by the decay of the radioactive elements those are radium and thorium in the soil, where its concentration depends on the soil conditions and the local geological background. In this paper, the results of radon and thoron exhalation rate measurements from surface soil of Bangka Belitung Islands at thirty six measurement sites are presented. Exhalation rates of radon and thoron were measured by using an accumulation chamber equipped with a solid-state alpha particle detector. Furthermore, the correlations between radon and thoron exhalation rates with their parent nuclide (226Ra and 232Th concentrations in collected soil samples from the same locations were also evaluated. The result of the measurement shows that mostly the distribution of radon and thoron is similar to 226Ra and 232Th, eventhough it was not a good correlation between radon and thoron exhalation rate with their parent activity concentrations (226Ra and 232Th due to the environmental factors that can influence the radon and thoron mobilities in the soil. In comparison to a world average, Bangka Belitung Islands have the 222Rn and 220Rn exhalation rates higher than the world average value for the regions with normal background radiation.

Radon programmes and health marketing.

Science.gov (United States)

Fojtikova, Ivana; Rovenska, Katerina

2011-05-01

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

Leukaemia risks and radon

International Nuclear Information System (INIS)

Wolff, S.P.

1991-01-01

A correlation has been established between domestic radon exposure and mutation in peripheral T lymphocytes. Some caution must be exercised, however, in interpreting this result as evidence that levels of domestically encountered radon are sufficient to cause leukaemogenic chromosomal alterations. Radon may simply be acting as a surrogate for some other mutagenic factor. Correlations with Local Authority statistics collected in the United Kingdom 1981 Census appear to show that lower domestic radon levels reflect relatively greater socioeconomic deprivation whereas higher levels reflect greater prosperity. The relative risk of lymphoproliferative disease correlates with the same factors that determine domestic radon levels at the county level. Putative relationships between domestic radon exposure and cancer thus need to be controlled for socioeconomic status and associated factors, at least at the county level. (The correlations may not apply to smaller areas.) Similarly, the causative factors underlying the relationships between higher regional socioeconomic status and leukaemia require closer examination. (author)

Radon in workplaces: First results of an extensive survey and comparison with radon in homes

International Nuclear Information System (INIS)

Bucci, S.; Pratesi, G.; Viti, M. L.; Pantani, M.; Bochicchio, F.; Venoso, G.

2011-01-01

Extensive radon surveys have been carried out in many countries only in dwellings, whereas surveys in workplaces are rather sparse and generally restricted to specific workplaces/activities, e.g. schools, spas and caves. Moreover, radon-prone areas are generally defined on the basis of radon surveys in dwellings, while radon regulations use this concept to introduce specific requirements in workplaces in such areas. This approach does not take into account that work activities and workplace characteristics can significantly affect radon concentration. Therefore, an extensive survey on radon in different workplaces have been carried out in a large region of Italy (Tuscany), in order to evaluate radon distribution in workplaces over the whole territory and to identify activities and workplace characteristics affecting radon concentration. The results of this extensive survey are compared with the results of the survey carried out in dwellings in the same period. The workplaces monitored were randomly selected among the main work activities in the region, including both public and industrial buildings. The survey monitored over 3500 rooms in more than 1200 buildings for two consecutive periods of ∼6 months. Radon concentration was measured by means of passive nuclear track detectors. (authors)

The significance of radon in radioactive pollution of environment. Pt. 2. Radon effect on living organism

International Nuclear Information System (INIS)

Kossakowski, S.; Dziura, A.; Kossakowski, A.

1998-01-01

Authors review the history of radon monitoring. Epidemiological studies of lung cancer and its correlation to radon concentration in mines and buildings are described. The influence of radon on animals living in the buildings built from waste materials is described. Authors review plans concerning creation of radon monitoring system in Poland. The necessity of monitoring influence of radon on animals is described

Monitoring of radon concentration in dwellings

International Nuclear Information System (INIS)

Kurosawa, Ryuhei

1991-01-01

Radon problems in dwellings have recently received much attention. Radon concentration in dwellings, as well as in the general environment, varies with various factors such as meteorological conditions and soil components. Therefore, a long term monitoring of radon concentration is required to obtain an average concentration. This paper reviews a passive type radon monitor that is handy and allows a long term radon monitoring. It provides the structure and principle of the radon monitor, covering the type, filter function, sensitivity of diffusion collecting type (cup type), electrostatic collecting type, adsorption collecting type, and detector of radon monitor. Actual examples of the radon monitor are also given. Radon daughter nuclides will have become major foci of exposure countermeasures. In the future, the development of a passive type monitor for determining potential alpha energy concentration is required. (N.K.)

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

International Nuclear Information System (INIS)

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

1995-02-01

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

Workshop on dosimetry for radon and radon daughters

International Nuclear Information System (INIS)

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

1978-05-01

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

The Pennsylvania radon story

International Nuclear Information System (INIS)

Gerusky, T.M.

1987-01-01

In December 1984, the Pennsylvania Bureau of Radiation Protection found itself confronted with the discovery of a home in eastern Pennsylvania having the highest level of radon daughters ever reported. The Bureau responded with a massive radon monitoring, educational, and remediation effort. As of November, 1986, over 18,000 homes had been screen for radon daughters, of which approximately 59% were found to have levels in excess of the 0.020 Working Level guideline. Pennsylvania's response to the indoor radon problem is detailed in this article

Radon problems

International Nuclear Information System (INIS)

Cohen, B.L.

1985-01-01

This chapter examines the health hazards resulting from the release of naturally occurring radioactive gas derived from the decay of uranium. It is estimated that random inhalation is now causing about 10,000 fatal lung cancers per year in the US. Radon is constantly being generated in rocks and soils (in which uranium is naturally present) and in materials produced from them (e.g., brick, stone, cement, plaster). It is emphasized that radon levels in buildings are typically 5 times higher than outdoors because radon diffusing up from the ground below or out of bricks, stone, cement, or plaster is trapped inside for a relatively long time

Unattached radon daughter atoms and radon daughter equilibrium ratios in uranium mines. Final report

International Nuclear Information System (INIS)

Holaday, D.A.

1972-01-01

Uranium mines in Colorado and New Mexico were surveyed for airborne concentrations of radon (10043922) and radon daughters. A procedure for measuring individual daughters and the fraction of each existing as free atoms was developed and used for field monitoring. Samples were taken in working areas and particle counts were made. The data was analyzed to determine the ratio of radon to radon daughters as well as the ratios among the radon daughters. The author concludes that since the radon to working level ratios have not changed much in 20 years, using the ratio as the basis for estimating relative biological hazard is just as uncertain now as then. The large number of daughters present as free atoms indicate that the lung radiation doses calculated using any of the lung models need reexamination

Measurement of indoor radon Concentrations in Osaka, Nara, Wakayama and Hyogo with passive dosemeters

International Nuclear Information System (INIS)

Mori, Toshiaki; Hori, Yasuharu; Takeda, Atsuhiko; Iwasaki, Tamiko; Uchiyama, Masahumi; Fujimoto, Kenzo; Kankura, Takako; Kobayashi, Sadayosi.

1989-01-01

Indoor radon concentrations of 792 houses in Osaka, Nara, Wakayama and Hyogo were measured by the passive dosemeter which was developed in Karlsruhe Nuclear Research Center in West Germany. Each house was measured at two places for successive two periods of six months to obtain annual average exposure due to radon daughters. The arithmetic mean concentration of all houses was 45.2 Bq/m 3 with a standard deviation of 27.2; the geometric mean, 40.7 Bq/m 3 and the median, 39 Bq/m 3 . The distribution of the radon levels was approximately log-normal with 80% of houses having radon concentrations less than 60 Bq/m 3 . The seasonal variation of the mean radon concentration was evident between the former period including winter value of 45 Bq/m 3 and the latter including summer value of 32 Bq/m 3 . The indoor radon concentrations of wooden houses were found to have the widest distribution with the highest value of 371 Bq/m 3 . The highest value obtained in the ferro-concrete house was 118 Bq/m 3 . Twelve houses having indoor radon concentrations higher than 120 Bq/m 3 were all Japanese traditional wooden houses with walls made of soil. (author)

Radon Research Program, FY-1990

International Nuclear Information System (INIS)

1991-03-01

The Department of Energy (DOE) Office of Health and Environmental Research (OHER) has established a Radon Research Program with the primary objectives of acquiring knowledge necessary to improve estimates of health risks associated with radon exposure and also to improve radon control. Through the Radon Research Program, OHER supports and coordinates the research activities of investigators at facilities all across the nation. From this research, significant advances are being made in our understanding of the health effects of radon. OHER publishes this annual report to provide information to interested researchers and the public about its research activities. This edition of the report summarizes the activities of program researchers during FY90. Chapter 2 of this report describes how risks associated with radon exposure are estimated, what assumptions are made in estimating radon risks for the general public, and how the uncertainties in these assumptions affect the risk estimates. Chapter 3 examines how OHER, through the Radon Research Program, is working to gather information for reducing the uncertainties and improving the risk estimates. Chapter 4 highlights some of the major findings of investigators participating in the Radon Research Program in the past year. And, finally, Chapter 5 discusses the direction in which the program is headed in the future. 20 figs

Radon - The management of the risk related to radon

International Nuclear Information System (INIS)

2010-01-01

This leaflet briefly explains what radon is, where it comes from, and what it becomes. It indicates and briefly comments its concentrations in French departments, describes how radon can affect our health (lung cancer), describes how the risk can be reduced in buildings, and indicates the existing regulatory provisions

Radon programmes and health marketing

International Nuclear Information System (INIS)

Fojtikova, I.; Rovenska, K.

2011-01-01

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. (authors)

Radon in dwellings the national radon survey Galway and Mayo

International Nuclear Information System (INIS)

McGarry, A.T.; Fennell, S.G.; Mackin, G.M.; Madden, J.S.; O'Colmain, M.

1999-07-01

This report presents the results of the final phase of the National Radon Survey carried out by the Radiological Protection Institute of Ireland. The counties included in this phase are Galway and Mayo. The average radon concentrations for the houses measured in these counties were 112 Bq/m 3 and 100 Bq/m 3 , respectively. The measurement data were grouped on the basis of the 10 km grid squares of the Irish National Grid System and used to predict the percentage of dwellings in each grid square which exceeds the Reference Level of 200 Bq/m 3 . Grid squares where this percentage is predicted to be 10% or higher are designated High Radon Areas. The health effects of exposure to high radon levels are discussed and recommendations are made regarding both new and existing dwellings. (author)

The use of mechanical ventilation with heat recovery for controlling radon and radon-daughter concentrations

International Nuclear Information System (INIS)

Nazaroff, W.W.; Boegel, M.L.; Hollowell, C.D.; Roseme, G.D.

1980-01-01

An energy research house in Maryland was found to have radon concentrations far in excess of recommended guidelines. A mechanical ventilation system with heat recovery was installed in this house to test its effectiveness as an energy-efficient control technique for indoor radon. Radon concentration was monitored continuously for two weeks under varying ventilation conditions (0.07 to 0.8 air changes per hour (ach)) and radon daughter concentrations were measured by grab-sample techniques about nine times daily during this period. At ventilation rates of 0.6 ach and higher radon and radon daughter levels dropped below guidelines for indoor concentrations. Comparison with other studies indicates that indoor radon buildup may be a problem in a considerable portion of houses characterized by their low infiltration rates. The use of mechanical ventilation systems with air-to-air heat exchangers may offer a practical, cost-effective, and energy-efficient means of alleviating not only the radon problem specifically but also the general deterioration of indoor air quality in houses designed or retrofitted to achieve low infiltration

Measurement of radon concentration in water using the portable radon survey meter.

Science.gov (United States)

Yokoyama, S; Mori, N; Shimo, M; Fukushi, M; Ohnuma, S

2011-07-01

A measurement method for measuring radon in water using the portable radon survey meter (RnSM) was developed. The container with propeller was used to stir the water samples and release radon from the water into the air in a sample box of the RnSM. In this method, the measurement of error would be water was >20 Bq l(-1).

Radon in the spa of Bizovac

International Nuclear Information System (INIS)

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

1996-01-01

The radon concentration in the air and water of the Bizovac spa was measured by the Radhome silicon detector and the average values were obtained as 70 Bq/m 3 in the indoor pool, 40 Bq/m 3 in the hotel room, 135 Bq/m 3 in the closed therapeutic bathroom, but the geothermal water had a Rn concentration of 25.3 kBq/m 3 and the potable one 2.7 kBq/m 3 . The Rn transfer factor (f) from water to air in the indoor pool and therapeutic bathroom was 10 and 40 times higher than for normal dwellings (f n =10 -4 ), respectively. The effective equivalent dose of inhaled radon for permanent personnel under the worst conditions in the spa was 5.4 mSv/y, but visitors spending two weeks in the spa could receive the dose of 77 μSv. (author). 6 refs., 1 fig

Risk management strategies for the radon paradox in radiation protection

International Nuclear Information System (INIS)

Poffijn, A.; Eggermont, G.X.; Van Deynse, A.

1996-01-01

Indoor radon is recognised as being the most important radiation burden for the general public. In Belgium, as in many other countries, exposure levels giving rise to yearly risks of more than 10 -2 have been found. This latter value is normally considered unacceptable for the public. Moreover, an important fraction of the population lives in houses with radon levels of more than 400 Bq.m -3 , representing a risk level of 10 -3 per year or more. A level of this order is the limit for authorised and regulated activities at work. Prevention and intervention opportunities exist for these situations. The dose reduction opportunities are limited, but higher than the total collective dose in all nuclear activities. The analysis of radiation protection approaches, communication and decision-making for radon, compared to nuclear industrial activities shows incoherence at different levels. As a first attempt to develop a rational and coherent approach, cost-benefit analysis was applied to radon. Four optimisation scenarios were developed: three remediation and one about prevention. Referring to the α values applied by radiation protection authorities in France, Sweden and the Netherlands, the different scenarios are found to be highly justified. (author)

Radon levels in dwelling shielded spaces (DSS) in Israel

International Nuclear Information System (INIS)

Haquin, G.; Margaliot, M.; Riemer, T.; Shamash, S.; Even, O.; Shamai, Y.

2002-01-01

Exposure to radon gas is known as the major contributor to the general public exposure to ionizing radiation. The typical radon concentration in Israeli houses with a direct ground contact is about 50 Bq/m 3 , attributed mainly to soil gas penetration into the house. All newly constructed buildings (since 1991) must include Dwelling Shielded Spaces (DSS) which are rooms made of massive solid concrete, equipped with air-tight steel door and window. The DSS serve as shelters against both explosive and chemical warfare. In normal practice, the DSS serves as a conventional room in the household. Standard size DSS contain a mass of around 35 tons of concrete with typical 2 26R a activity concentration of 30 Bq/kg. This mass of concrete is expected to increase the radon concentration in the DSS room due to exhalation from the building material. Published exhalation rate values from concrete in the US and Europe vary from 0.1 to 8 mBq/m 2 sec. (0.5 - 30 Bq/m 2 h). This work presents short and long-term radon measurements performed in high-rise building DSS's. Measurements of the free exhalation rate and wall exhalation rate as well as ventilation rate in DSS are also presented and the relation between these quantities is analyzed

Radon and radiation biology of the lung

International Nuclear Information System (INIS)

Crameri, R.; Burkart, W.

1989-01-01

The main papers presented at the meeting dealt with the behaviour of radon and the indoor environment, radiation biology of the lung, lung dosis and the possible cancer risk caused by radon in homes, contamination of the room air. A series of special papers treated the radon problem in detail: sources and transport mechanisms of radon, geological aspects of the radon radiation burden in Switzerland, radon in homes, search for radon sources, and the Swiss radon-programme RAPROS. 67 figs., 13 tabs., 75 refs

Multivariate signal processing in measurements of radon and radon daughters in air

International Nuclear Information System (INIS)

Urbanski, P.; Machaj, B.

2000-01-01

Extensive measurements of radon and radon daughters concentration gauge in a radon chamber were carried out. Count rate 'spectra' against time at the output of radiation detectors were measured and registered. The count rate spectra were then processed employing Principal Component Regression (PCR). A root mean square error of the count rate was estimated. It was found that PCR processing removes a great part of count rate random fluctuations originating from the radiation statistics that results in a decrease of count rate random error. The root mean square error of count rate in a radon daughter monitor is about 3 times lower, which is equivalent to the error of the gauge with a 9 times higher air flow rate if no PCR processing is used. In case of the radon concentration gauge the increase of sensitivity is even higher and amounts to 5 times. (author)

Radon measurements in indoor workplaces

International Nuclear Information System (INIS)

Tokonami, S.; Matsumoto, M.; Furukawa, M.; Fujimoto, K.; Fujitaka, K.; Pan, J.; Kurosawa, R.

1996-01-01

Radon measurements in several office buildings located in Tokyo were carried out with two types of device to study the time-dependent radon concentration in indoor workplaces. Both types of device use the electrostatic field for the collection of 218 Po onto the electrode of the detector. One provides an average radon concentration throughout the day. The other, in which a weekly timer is installed in the circuit of the electrode of the device, provides an average radon concentration during working hours (9:00-17:00, Monday-Friday). Although radon concentrations in Japanese dwellings have been found to be generally low, relatively high concentrations were observed in the office buildings. No consistent seasonal variation was recognised in this study. Little difference of average radon concentrations between working hours and the whole day was found throughout the year in two offices. On the other hand, a significant difference was observed in other offices. The operation of an air conditioner might change the radon concentration during working hours. From the results of radon measurements the average effective dose in the workplace was estimated to be 0.23 mSv for 2000 working hours in a year. (Author)

Radon prevention coating in hot and humid environment

International Nuclear Information System (INIS)

Yang Yushan; Dong Faqin; Deng Yuequan; Qu Ruixue

2013-01-01

The radon prevention performance of a new self-made radon prevention coating was researched in the radon contamination provided by the releasing radon modules. With coating thickness of 0.8 mm, the radon mitigation efficiency in 1 # radon module concentration is optimal when the addition of defoaming agent is 0.3% (mass fraction). The radon mitigation efficiency increases with the coating thickness when the defoaming agent of 0.3% is added, but the radon mitigation efficiency tends to be stable as the coating thickness is more than 2.0 mm. The radon mitigation efficiency of radon prevention coating appended precipitated barium sulphate decreases obviously, and the addition of ash calcium, white cement and gesso don't decrease radon mitigation efficiency. The addition of white cement and gesso addition affects the radon prevention stability, while radon mitigation efficiency of radon prevention coating with ash calcium keeps a good performance. Under the hot and humid environment, the radon prevention coating still has good radon mitigation efficiency in 2 # radon module concentration. (authors)

Radon in homes: The Alaskan experience

International Nuclear Information System (INIS)

Seifert, R.D.

1990-01-01

For the past four years, since radon was first found to be a concern in Alaska in 1986, the interest and awareness of radon as a special housing and health concern has continued to grow. This paper will discuss the features of a house in Alaska which would characterize it as at risk for radon, and also those efforts at mitigation which have been most effective in reducing radon under Alaskan conditions. Clearly radon must be able to enter a home in order to be a problem. Riefenstuhl and Kline (personal communication, 1988) have analyzed the conditions for radon transport from soils to home interiors very lucidly through the following scheme: four factors must exist in a house locale for it to be a radon at risk house. Two of the factors are geological in nature: (1) there must be adequate uranium and therefore ample radon to provide a source for transport; (2) there must be enough permeability in the soil to allow rapid soil gas movement to carry radon from its origin to the interior of the home within two half-lives of time (six days) or so. The other two factors are determined by the structure of the house itself and the way in which it is operated: (3) the house must have soil contact and imperfections, holes, cracks, intentional perforations which allow movement of soil gas with radon through the envelope of the basement or crawlspace; (4) there must be a lower pressure inside the house than in the soil so that soil gas flows into the house. All four of these characteristics are required to have radon be a problem. The absence of any single characteristic will eliminate radon (in general). This presents a series of options for mitigation of radon then, since elimination of any of the four characteristics will mitigate radon

A calibration facility for radon fluxmeter

International Nuclear Information System (INIS)

Li Xianjie; Qiu Shoukang; Zhou Jianliang; Liu Chunkui; Pan Jialin; Yang Mingli

1998-01-01

Calibration facilities for radon fluxmeter with three kinds of different emanation medium have been developed. The stability of radon flux is 5%, 9% (RSD) respectively. The uniformity of radon flux is 4.5%, 8.5% (RSD) respectively. These specifications fulfill the calibration requirement for radon fluxmeter. The determination of radon flux of facility takes full account of eliminating the main error source-attenuation effect (including leakage and back diffusion etc.): not only prevent attenuation and make a relevant correction. Therefore the accuracy of determination is assured. The calibration, intercomparison of radon flux meter and the quantitatively evaluation on the measurement method of radon flux are made to be possible by the successful establishment of this facility. (author)

The householders' guide to radon

International Nuclear Information System (INIS)

1988-06-01

This guide is a follow-up to the leaflet Radon in Houses which was issued previously by the Department of the Environment. It is intended for people who live in areas with high levels of radon. It is written particularly for householders whose homes have already been tested and found to have an appreciable level of radon. It explains what radon is, how it gets into houses and what the effects on health may be. It also outlines some of the ways of reducing the level of radon and gives guidance both on how to get the work done and likely costs. (author)

Radon surveys and their implications

International Nuclear Information System (INIS)

Miles, J.C.H.; Cliff, K.D.; Dixon, D.W.; Green, B.M.R.; Strong, J.C.

1989-01-01

In the UK, as in other countries, radon daughter inhalation is the most significant cause of human exposure to ionising radiation either at home or at work whether one considers the mean or the maximum dose. Substantial studies of radon are under way in the UK, and the importance of radon is recognised in several spheres. NRPB investigations of the radon levels in buildings and mines are reported, the distributions of doses presented and risk factors calculated. The bases of radon limitation for workers and members of the public are given and the means of compliance discussed. (author)

Radon exposure and lung cancer

International Nuclear Information System (INIS)

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

2003-01-01

Although studies of radon exposure have established that Rn decay products are a cause of lung cancer among miners, the lung cancer risk to the general population from indoor radon remains unclear and controversial. Our epidemiological investigation of indoor radon influence on lung cancer incidence was carried out for 201 patients from the Osijek town. Ecological method was applied by using the town map with square fields of 1 km 2 and the town was divided into 24 fields. Multiple regression study for the lung cancer rate on field, average indoor radon exposure and smoking showed a positive linear double regression for the mentioned variables. Case-control study showed that patients, diseased of lung cancer, dwelt in homes with significantly higher radon concentrations, by comparison to the average indoor radon level of control sample. (author)

Radon and radon-daughter concentrations in air in the vicinity of the Anaconda Uranium Mill

International Nuclear Information System (INIS)

Momeni, M.H.; Lindstrom, J.B.; Dungey, C.E.; Kisieleski, W.E.

1979-11-01

Radon concentration, working level, and meteorological variables were measured continuously from June 1977 through June 1978 at three stations in the vicinity of the Anaconda Uranium Mill with measurements integrated to hourly intervals. Both radon and daughters show strong variations associated with low wind velocities and stable atmospheric conditions, and diurnal variations associated with thermal inversions. Average radon concentration shows seasonal dependence with highest concentrations observed during fall and winter. Comparison of radon concentrations and working levels between three stations shows strong dependence on wind direction and velocity. Radon concentrations and working-level distributions for each month and each station were analyzed. The average maximum, minimum, and modal concentration and working levels were estimated with observed frequencies. The highest concentration is 11,000 pCi/m 3 on the tailings. Working-level variations parallel radon variations but lag by less than one hour. The highest working levels were observed at night when conditions of higher secular radioactive equilibrium for radon daughters exist. Background radon concentration was measured at two stations, each located about 25 km from the mill, and the average is 408 pCi/m 3 . Average working-level background is 3.6 x 10 -3

Impact of ventilation systems and energy savings in a building on the mechanisms governing the indoor radon activity concentration.

Science.gov (United States)

Collignan, Bernard; Powaga, Emilie

2017-11-23

For a given radon potential in the ground and a given building, the parameters affecting the indoor radon activity concentration (IRnAC) are indoor depressurization of a building and its air change rate. These parameters depend mainly on the building characteristics, such as airtightness, and on the nature and performances of the ventilation system. This study involves a numerical sensitivity assessment of the indoor environmental conditions on the IRnAC in buildings. A numerical ventilation model has been adapted to take into account the effects of variations in the indoor environmental conditions (depressurization and air change rate) on the radon entry rate and on the IRnAC. In the context of the development of a policy to reduce energy consumption in a building, the results obtained showed that IRnAC could be strongly affected by variations in the air permeability of the building associated with the ventilation regime. Copyright © 2017 Elsevier Ltd. All rights reserved.

Consumer's Guide to Radon Reduction

Science.gov (United States)

... Labs and Research Centers Radon Contact Us Share Consumer's Guide to Radon Reduction: How to Fix Your ... See EPA’s About PDF page to learn more. Consumer's Guide to Radon Reduction: How to Fix Your ...

Standardization of radon measurements

International Nuclear Information System (INIS)

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

1988-01-01

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

Radon programme in the Czech Republic

International Nuclear Information System (INIS)

Hulka, J.; Thomas, J.

2003-01-01

The framework of the Radon programme in the Czech republic includes both precautionary measures and interventions. The programme informally started in early eighties has been now incorporated in national legislation (Atomic Act, Radiation Protection Decree, etc.). Aim of precautionary measures is to avert construction of building above natural radiation guidance levels (200 Bq/m 3 for indoor radon concentration and 0.5 Sv/h for gamma dose rate) by protection of new buildings against soil radon ingress, by regulation of natural radioactivity in building materials and supplied water. Aim of interventions is to identify buildings affected by enhanced natural radioactivity and help owners to put into effect reasonable remedial measures. Two sets of intervention levels for indoor natural exposure were established: guidance intervention levels 400 Bq/m 3 (indoor radon), 1.0 Sv/h (indoor gamma dose rate) and limit values 4000 Bq/m 3 and 10 Sv/h. The radon programme is based both on governmental and private activities. The governmental activities include representative and targeted indoor radon survey, subsidy for radon mitigation, mitigation test measurements and public information on radon issue. The private activities include radon measurement (radon index of building site, indoor measurements, radon diagnosis) and remedial measures. More than 100 commercial companies were authorised by Radiation Protection Authority (SUJB) to provide these measurements

Radon survey techniques

International Nuclear Information System (INIS)

Anon.

1976-01-01

The report reviews radon measurement surveys in soils and in water. Special applications, and advantages and limitations of the radon measurement techniques are considered. The working group also gives some directions for further research in this field

Comparison of retrospective and contemporary indoor radon measurements in a high-radon area of Serbia

International Nuclear Information System (INIS)

Zunic, Z.S.; Yarmoshenko, I.V.; Kelleher, K.; Paridaens, J.; Mc Laughlin, J.P.; Celikovic, I.; Ujic, P.; Onischenko, A.D.; Jovanovic, S.; Demajo, A.; Birovljev, A.; Bochicchio, F.

2007-01-01

In Niska Banja, Serbia, which is a high-radon area, a comparison was made between two retrospective radon measuring methods and contemporary radon measurements. The two retrospective methods derive the radon concentrations that occurred in dwellings over longer periods in the past, based on the amount of trapped 210 Po on the surface of glass objects (surface traps, ST) or in the bulk of porous materials (volume traps, VT). Both surface implanted 210 Po in glass objects and contemporary radon in air were measured in 46 rooms, distributed in 32 houses of this radon spa-town, using a dual alpha track detector configuration (CR-39 and LR115) and CR-39 track etched detectors, respectively. In addition to the use of surface trap measurements, in 18 rooms (distributed in 15 houses) VT samples of suitable material were also collected, allowing to compare ST and VT retrospective radon concentration estimates. For each room, contemporary annual radon concentrations (CONT) were measured or estimated using seasonal correction factors. The distribution of the radon concentration in all data sets was found to be close to lognormal (Chi-square test > 0.05). Geometric means (GM) are similar, ranging from 1040 to 1380 Bq m -3 , whereas geometric standard deviations (GSD) for both the retrospective methods are greater than for the CONT method, showing reasonable agreement between VT, ST and CONT measurements. A regression analysis, with respect to the lognormal distribution of each data set, shows that for VT-ST the correlation coefficient r is 0.85, for VT-CONT r is 0.82 and for ST-CONT r is 0.73. Comparison of retrospective and contemporary radon concentrations with regard to supposed long-term indoor radon changes further supports the principal agreement between the retrospective and conventional methods

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

CERN Document Server

Steck, D J

1999-01-01

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

Quality assurance for radon measurements in Germany

International Nuclear Information System (INIS)

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

2005-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Sciocchetti, G.; Cotellessa, G.; Soldano, E.; Pagliari, M. [Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti, ENEA Centro Ricerche Casaccia Roma (Italy)

2006-07-01

The approach of the Italian National Institute of Ionising Radiations (I.N.M.R.I.-ENEA) on radon metrology has been based on a complete and integrated system which can be used to calibrate the main types of {sup 222}Rn in air measuring instruments with international traceability. The Italian radon reference chamber is a research and calibration facility developed at the Casaccia Research Center in Roma. This facility has an inner volume of one m{sup 3}. The wall is a cylindrical stainless steel vessel coupled with an automated climate apparatus operated both at steady and dynamic conditions. The control and data acquisition equipment is based on Radotron system, developed to automate the multitasking management of different sets of radon monitors and climatic sensors. A novel approach for testing passive radon monitors with an alpha track detector exposure standard has been developed. It is based on the direct measurement of radon exposure with a set of passive integrating monitors based on the new ENEA piston radon exposure meter. This paper describes the methodological approach on radon metrology, the status-of-art of experimental apparatus and the standardization procedures. (authors)

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

International Nuclear Information System (INIS)

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

2006-01-01

The approach of the Italian National Institute of Ionising Radiations (I.N.M.R.I.-ENEA) on radon metrology has been based on a complete and integrated system which can be used to calibrate the main types of 222 Rn in air measuring instruments with international traceability. The Italian radon reference chamber is a research and calibration facility developed at the Casaccia Research Center in Roma. This facility has an inner volume of one m 3 . The wall is a cylindrical stainless steel vessel coupled with an automated climate apparatus operated both at steady and dynamic conditions. The control and data acquisition equipment is based on Radotron system, developed to automate the multitasking management of different sets of radon monitors and climatic sensors. A novel approach for testing passive radon monitors with an alpha track detector exposure standard has been developed. It is based on the direct measurement of radon exposure with a set of passive integrating monitors based on the new ENEA piston radon exposure meter. This paper describes the methodological approach on radon metrology, the status-of-art of experimental apparatus and the standardization procedures. (authors)

Radon survey in Metropolitan Toronto schools

International Nuclear Information System (INIS)

Becker, E.; Moridi, R.

1992-01-01

The radon testing survey in Metropolitan Toronto public schools was the most intensive project of its kind ever undertaken in Canadian schools. It also included an extensive public education program on radiation and radon-in-schools. The radon levels at 632 schools were measured using the CAIRS Radon Monitors. Ninety percent of the locations measured were found to have a radon level equal to or less than 2 mWL. Two locations in two different schools were found to have a radon level at or above the Action Level (20 mWL). The remaining results were between the two extremes. Follow-up testing in those schools where more than 10 mWL of radon was found is in progress. (author)

Radon Survey in Hospitals in Slovenia

International Nuclear Information System (INIS)

Vaupotic, J.

2003-01-01

In Slovenia, several radon studies at workplaces have been carried out in last years, supported by the Ministry of Education, Science and Sport, and the Ministry of Health. After radon surveys in kindergartens, schools and homes, within which about 2600 buildings were checked for radon and which provided the level of radon problem in the country, next investigations were focused on the workplaces with potentially higher radon risk. Hence, in the Postojna Cave permanent radon monitoring was introduced in 1995 and comprehensive radon studies were performed: in 5 bigger spas during 1996-1998, in major waterworks and wine cellars in 2001, and in major Slovene hospitals in 2002. This paper reports the results of radon study in 26 major Slovene hospitals, comprising radon concentrations in 201 rooms and dose estimates for 1025 persons working in these rooms. Radon survey in 201 rooms of 26 major hospitals in Slovenia revealed only 7 rooms in which monthly average radon concentration in the indoor air exceeded 400 Bqm -3 . Generally, concentrations in basement were on average for about 30% higher than in ground floor, although exceptionally high values have also been found in the ground floor. For 966 persons (94.2%) of the total of 1025 persons working in the rooms surveyed, the annual effective dose, estimated according to the Basic Safety Standards was below 1 mSv, while for 59 it exceeded 1 mSv. In 7 rooms with more than 400 Bqm -3 in which 16 persons receive between 2.1 and 7.3 mSv per year radon monitoring is continued. (author)

Radon: Residential attitudes toward the risk

International Nuclear Information System (INIS)

Fort, R.; Hinman, G.; Rosenman, R.; Wandschneider, P.

1990-01-01

Veradale, Washington (east of Spokane) is a region of high residential radon concentrations. Three hundred eighty residents of Veradale recently responded to a mail survey designed to elicit (1) their knowledge of and attitudes toward the risks of radon in their homes, (2) the actions they have taken or intend to take to identify and reduce those risks, and (3) policy preferences toward radon. Results reveal that these residents know that they live in an area with high radon levels, that radon causes lung cancer, and that radon will affect their health. However only 11% of respondents have had their homes tested for radon. This especially is puzzling because a large number of respondents claimed that (1) radon was important in home buying decisions, (2) they would test their own homes, (3) they would take action if such tests revealed problems, and (4) their willingness to pay for tests and improvements was well within the current costs of these actions. It remains a mystery why testing is at such a low level. Three other results are of note. First, subsidies for radon tests and home improvements may be having the unintended consequences of unneeded improvements and (potentially) moves without improvements. Second, individuals want radon testing required and results made known during home purchase decisions. Third, at present, weatherization programs that concentrate radon are acceptable to individuals. Of course, the future may hold different results. Administrators of weatherization programs, who are trusted by respondents according to this survey, would do well to institute weatherization programs with reduced radon concentrations in mind

THE REPUBLIC OF BELARUS RADON DANGER MAP

Directory of Open Access Journals (Sweden)

L. A. Chunikhin

2016-01-01

Full Text Available Radon is the major contributor to the background exposure of the population. In the world practice, the radon risk or radon potential mapping are used for the radon dose assessment.The aim of this work was a radon danger mapping of the Republic of Belarus to assess the radiation situation and determine the radon hazard critical areas.Materials and methods: The mapping is based on measured values of radon volume activity in the living rooms of different buildings on the territory of the six regions of the Republic of Belarus. We have performed more than 4000 measurements. Integral track radon radiometers based on the polymer Kodak LR-115 film were used to evaluate radon volume activity. Exposure time ranged from 90 to 120 days. The cartogram was built with using the MAPINFO software package.Results: The low levels of radon concentrations were determined in the Brest and Gomel regions, as well as in the southern districts of Minsk and south-western districts of the Mogilev region. The high levels radon concentrations were determined in some districts of the Vitebsk and Grodno regions, as well as in the north-eastern districts of the Mogilev region. About 2–5 times nonuniformity of radon distribution in settlements of the Republic was observed. The radon hazard critical areas with radon concentrations in the range of 200–400 Bq/m3 were found in some districts of the Vitebsk, Grodno and Mogilev regions.Conclusions: The radon risk map of the Republic of Belarus gives the possibility to estimate the existing radiation risk. Taking into account the low efficiency of countermeasures long after the Chernobyl accident, it is necessary to increase the level of radiation protection through the radon mitigation activities or to change the radon normative documents.

Indoor radon concentration in Poland

International Nuclear Information System (INIS)

Mamont-Ciesla, K.; Jagielak, J.; Rosinski, S.W.; Sosinka, A.; Bysiek, M.; Henschke, J.

1996-01-01

Preliminary survey of Rn concentration indoors by means of track detectors and y-ray dose rate with the use of TLD in almost 500 homes in selected areas of Poland was performed in the late 1980s. It was concluded that radon contributes 1.16 mSv i.e. about 46 per cent of the total natural environment ionizing radiation dose to the Polish population. Comparison of the average radon concentrations in 4 seasons of a year and in 3 groups of buildings: masonry, concrete and wood, revealed that the ground beneath the building structure is likely the dominant source of radon indoors. Since the National Atomic Energy Agency in its regulations of 1988-03-31 set up the permissible limit of the equilibrium equivalent concentration of radon in new buildings (equal 100 Bq/m3), the nation-scale survey project for radon in buildings has been undertaken. These regulations were supposed to take effect in 1995-01-01. The project has 3 objectives: to estimate the radiation exposure due to radon daughters received by Polish population to identify radon-prone areas in Poland to investigate dependence of the indoor radon concentrations on such parameters as: type of construction material, presence (or absence) of cellar under the building, number of floor

Airborne geophysical radon hazard mapping

International Nuclear Information System (INIS)

Walker, P.

1993-01-01

Shales containing uranium pose a radon health hazard even when covered by several meters of overburden. Such an alum shale in southern Norway has been mapped with a joint helicopter borne electromagnetic (HEM) and radiometric survey. Results are compared with ground spectrometer, radon emanometer and radon gas measurements in dwellings, and a model to predict radon gas concentrations from the airborne data is developed. Since the shale is conductive, combining the HEM data with the radiometric channel allows the shale to be mapped with greater reliability than if the radiometric channel were used alone. Radiometrically more active areas which do not pose a radon gas hazard can thus be separated from the shales which do. The ground follow-up work consisted of spectrometer and radon emanometer measurements over a uranium anomaly coinciding with a conductor. The correlation between the airborne uranium channel, the ground uranium channel and emanometry is extremely good, indicating that airborne geophysics can, in this case, be used to predict areas having a high radon potential. Contingency tables comparing both radon exhalation and concentration in dwellings with the airborne uranium data show a strong relationship exists between exhalation and the airborne data and while a relationship between concentration and the airborne data is present, but weaker

Radon content in various types of ground water in south-eastern Sweden. A preliminary report

International Nuclear Information System (INIS)

Knutsson, G.

1977-01-01

The purpose of investigation has been to study the radon content and its seasonal fluctuations in different types of ground water. The investigation was carried out in an area where the hydrogeological conditions are fairly well known. The geology is dominated by granitic bedrock and till. Water samples were collected from drilled wells in different rocks and from dug wells and springs in till and gravel. The seasonal fluctuations were studied in a small area. All radon measurements were made in the laboratory. The main results are following.(1) The highest radon content (max. 40 nCi/l) was observed in water from wells drilled granite. (2) The radon content in ground water from till never exceeds 8 nCi/l; the highest amount is normally found in springs situated in drumlin terrain with basel till and gravel lenses and beds (3-5 nCi/l) the contents in dug wells are 0.5-3.5 nCi/l.(3) Waters from gravel deposits have constantly low radon contents (0.1-3 nCi/l), and surface water has no radon.(4) The seasonal fluctuations in radon content are rather high and show a similar pattern to that of the fluctuations of the ground-water levels in till in the same area. (author)