The Radon cumulative distribution transform and its application to image classification

PubMed Central

Kolouri, Soheil; Park, Se Rim; Rohde, Gustavo K.

2016-01-01

Invertible image representation methods (transforms) are routinely employed as low-level image processing operations based on which feature extraction and recognition algorithms are developed. Most transforms in current use (e.g. Fourier, Wavelet, etc.) are linear transforms, and, by themselves, are unable to substantially simplify the representation of image classes for classification. Here we describe a nonlinear, invertible, low-level image processing transform based on combining the well known Radon transform for image data, and the 1D Cumulative Distribution Transform proposed earlier. We describe a few of the properties of this new transform, and with both theoretical and experimental results show that it can often render certain problems linearly separable in transform space. PMID:26685245

Reporting on Radon: The Role of Local Newspapers.

ERIC Educational Resources Information Center

Post, James F.; And Others

Noting that past local media coverage of environmental topics, including those dealing with radiation topics, has often been superficial, a study assessed press coverage of the radon problem in the Lehigh Valley region of Pennsylvania during the first nine months of 1985. The study explored whether local media coverage of radon--a colorless,…

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

PubMed

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

2016-11-15

Indoor radon concentration was studied in the 14 settlements located near the Techa River, which was contaminated by radioactive wastes in 1950-s. Results of the radon survey were used for analysis of the relationship between the indoor radon and main geologic factors (Pre-Jurassic formations, Quaternary sediments and faults), local geogenic radon potential and anthropogenic factors. Main influencing factors explain 58% of the standard deviation of indoor radon concentration. Association of the air exchange influence over radon concentration with underlying geological media was related to different contributions of geogenic advective and diffusive radon entries. The properties of geological formation to transfer radon gas in interaction with the house can be considered within the radon geogenic potential concept. The study of the radon exposure of the Techa River population can be used to estimate the contribution of natural radon to the overall radiation exposure of the local population during the period of radioactive waste discharges. Copyright © 2016 Elsevier B.V. All rights reserved.

Frequency Dynamics of the First Heart Sound

NASA Astrophysics Data System (ADS)

Wood, John Charles

Cardiac auscultation is a fundamental clinical tool but first heart sound origins and significance remain controversial. Previous clinical studies have implicated resonant vibrations of both the myocardium and the valves. Accordingly, the goals of this thesis were threefold, (1) to characterize the frequency dynamics of the first heart sound, (2) to determine the relative contribution of the myocardium and the valves in determining first heart sound frequency, and (3) to develop new tools for non-stationary signal analysis. A resonant origin for first heart sound generation was tested through two studies in an open-chest canine preparation. Heart sounds were recorded using ultralight acceleration transducers cemented directly to the epicardium. The first heart sound was observed to be non-stationary and multicomponent. The most dominant feature was a powerful, rapidly-rising frequency component that preceded mitral valve closure. Two broadband components were observed; the first coincided with mitral valve closure while the second significantly preceded aortic valve opening. The spatial frequency of left ventricular vibrations was both high and non-stationary which indicated that the left ventricle was not vibrating passively in response to intracardiac pressure fluctuations but suggested instead that the first heart sound is a propagating transient. In the second study, regional myocardial ischemia was induced by left coronary circumflex arterial occlusion. Acceleration transducers were placed on the ischemic and non-ischemic myocardium to determine whether ischemia produced local or global changes in first heart sound amplitude and frequency. The two zones exhibited disparate amplitude and frequency behavior indicating that the first heart sound is not a resonant phenomenon. To objectively quantify the presence and orientation of signal components, Radon transformation of the time -frequency plane was performed and found to have considerable potential for pattern classification. Radon transformation of the Wigner spectrum (Radon-Wigner transform) was derived to be equivalent to dechirping in the time and frequency domains. Based upon this representation, an analogy between time-frequency estimation and computed tomography was drawn. Cohen's class of time-frequency representations was subsequently shown to result from simple changes in reconstruction filtering parameters. Time-varying filtering, adaptive time-frequency transformation and linear signal synthesis were also performed from the Radon-Wigner representation.

Fast quantum nD Fourier and radon transforms

NASA Astrophysics Data System (ADS)

Labunets, Valeri G.; Labunets-Rundblad, Ekaterina V.; Astola, Jaakko T.

2001-07-01

Fast Classical and quantum algorithms are introduced for a wide class of non-separable nD discrete unitary K- transforms(DKT)KNn. They require a number of 1D DKT Kn smaller than in the Cooley-Tukey radix-p FFT-type approach. The method utilizes a decomposition of the nDK- transform into a product of original nD discrete Radon Transform and of a family parallel/independ 1DK-transforms. If the nDK-transform has a separable kernel, that again in this case our approach leads to decrease of multiplicative complexity by factor of n compared to the tow/column separable Cooley-Tukey p-radix approach.

Microaneurysms detection with the radon cliff operator in retinal fundus images

NASA Astrophysics Data System (ADS)

Giancardo, Luca; Mériaudeau, Fabrice; Karnowski, Thomas P.; Tobin, Kenneth W.; Li, Yaqin; Chaum, Edward

2010-03-01

Diabetic Retinopathy (DR) is one of the leading causes of blindness in the industrialized world. Early detection is the key in providing effective treatment. However, the current number of trained eye care specialists is inadequate to screen the increasing number of diabetic patients. In recent years, automated and semi-automated systems to detect DR with color fundus images have been developed with encouraging, but not fully satisfactory results. In this study we present the initial results of a new technique for the detection and localization of microaneurysms, an early sign of DR. The algorithm is based on three steps: candidates selection, the actual microaneurysms detection and a final probability evaluation. We introduce the new Radon Cliff operator which is our main contribution to the field. Making use of the Radon transform, the operator is able to detect single noisy Gaussian-like circular structures regardless of their size or strength. The advantages over existing microaneurysms detectors are manifold: the size of the lesions can be unknown, it automatically distinguishes lesions from the vasculature and it provides a fair approach to microaneurysm localization even without post-processing the candidates with machine learning techniques, facilitating the training phase. The algorithm is evaluated on a publicly available dataset from the Retinopathy Online Challenge.

Logo recognition using alpha-rooted phase correlation in the radon transform domain

NASA Astrophysics Data System (ADS)

DelMarco, Stephen

2009-08-01

Alpha-rooted phase correlation (ARPC) is a recently-developed variant of classical phase correlation that includes a Fourier domain image enhancement operation. ARPC combines classical phase correlation with alpha-rooting to provide tunable image enhancement. The alpha-rooting parameters may be adjusted to provide a tradeoff between height and width of the ARPC main lobe. A high narrow main lobe peak provides high matching accuracy for aligned images, but reduced matching performance for misaligned logos. A lower, wider peak trades matching accuracy on aligned logos, for improved matching performance on misaligned imagery. Previously, we developed ARPC and used it in the spatial domain for logo recognition as part of an overall automated document analysis problem. However, spatial domain ARPC performance can be sensitive to logo misalignments, including rotational misalignment. In this paper we use ARPC as a match metric in the radon transform domain for logo recognition. In the radon transform domain, rotational misalignments correspond to translations in the radon transform angle parameter. These translations are captured by ARPC, thereby producing rotation-invariant logo matching. In the paper, we first present an overview of ARPC, and then describe the logo matching algorithm. We present numerical performance results demonstrating matching tolerance to rotational misalignments. We demonstrate robustness of the radon transform domain rotation estimation to noise. We present logo verification and recognition performance results using the proposed approach on a public domain logo database. We compare performance results to performance obtained using spatial domain ARPC, and state-of-the-art SURF features, for logos in salt-and-pepper noise.

Relations among soil radon, environmental parameters, volcanic and seismic events at Mt. Etna (Italy)

NASA Astrophysics Data System (ADS)

Giammanco, S.; Ferrera, E.; Cannata, A.; Montalto, P.; Neri, M.

2013-12-01

From November 2009 to April 2011 soil radon activity was continuously monitored using a Barasol probe located on the upper NE flank of Mt. Etna volcano (Italy), close both to the Piano Provenzana fault and to the NE-Rift. Seismic, volcanological and radon data were analysed together with data on environmental parameters, such as air and soil temperature, barometric pressure, snow and rain fall. In order to find possible correlations among the above parameters, and hence to reveal possible anomalous trends in the radon time-series, we used different statistical methods: i) multivariate linear regression; ii) cross-correlation; iii) coherence analysis through wavelet transform. Multivariate regression indicated a modest influence on soil radon from environmental parameters (R2 = 0.31). When using 100-day time windows, the R2 values showed wide variations in time, reaching their maxima (~0.63-0.66) during summer. Cross-correlation analysis over 100-day moving averages showed that, similar to multivariate linear regression analysis, the summer period was characterised by the best correlation between radon data and environmental parameters. Lastly, the wavelet coherence analysis allowed a multi-resolution coherence analysis of the time series acquired. This approach allowed to study the relations among different signals either in the time or in the frequency domain. It confirmed the results of the previous methods, but also allowed to recognize correlations between radon and environmental parameters at different observation scales (e.g., radon activity changed during strong precipitations, but also during anomalous variations of soil temperature uncorrelated with seasonal fluctuations). Using the above analysis, two periods were recognized when radon variations were significantly correlated with marked soil temperature changes and also with local seismic or volcanic activity. This allowed to produce two different physical models of soil gas transport that explain the observed anomalies. Our work suggests that in order to make an accurate analysis of the relations among different signals it is necessary to use different techniques that give complementary analytical information. In particular, the wavelet analysis showed to be the most effective in discriminating radon changes due to environmental influences from those correlated with impending seismic or volcanic events.

Improved blood velocity measurements with a hybrid image filtering and iterative Radon transform algorithm

PubMed Central

Chhatbar, Pratik Y.; Kara, Prakash

2013-01-01

Neural activity leads to hemodynamic changes which can be detected by functional magnetic resonance imaging (fMRI). The determination of blood flow changes in individual vessels is an important aspect of understanding these hemodynamic signals. Blood flow can be calculated from the measurements of vessel diameter and blood velocity. When using line-scan imaging, the movement of blood in the vessel leads to streaks in space-time images, where streak angle is a function of the blood velocity. A variety of methods have been proposed to determine blood velocity from such space-time image sequences. Of these, the Radon transform is relatively easy to implement and has fast data processing. However, the precision of the velocity measurements is dependent on the number of Radon transforms performed, which creates a trade-off between the processing speed and measurement precision. In addition, factors like image contrast, imaging depth, image acquisition speed, and movement artifacts especially in large mammals, can potentially lead to data acquisition that results in erroneous velocity measurements. Here we show that pre-processing the data with a Sobel filter and iterative application of Radon transforms address these issues and provide more accurate blood velocity measurements. Improved signal quality of the image as a result of Sobel filtering increases the accuracy and the iterative Radon transform offers both increased precision and an order of magnitude faster implementation of velocity measurements. This algorithm does not use a priori knowledge of angle information and therefore is sensitive to sudden changes in blood flow. It can be applied on any set of space-time images with red blood cell (RBC) streaks, commonly acquired through line-scan imaging or reconstructed from full-frame, time-lapse images of the vasculature. PMID:23807877

Imaging ultrasonic dispersive guided wave energy in long bones using linear radon transform.

PubMed

Tran, Tho N H T; Nguyen, Kim-Cuong T; Sacchi, Mauricio D; Le, Lawrence H

2014-11-01

Multichannel analysis of dispersive ultrasonic energy requires a reliable mapping of the data from the time-distance (t-x) domain to the frequency-wavenumber (f-k) or frequency-phase velocity (f-c) domain. The mapping is usually performed with the classic 2-D Fourier transform (FT) with a subsequent substitution and interpolation via c = 2πf/k. The extracted dispersion trajectories of the guided modes lack the resolution in the transformed plane to discriminate wave modes. The resolving power associated with the FT is closely linked to the aperture of the recorded data. Here, we present a linear Radon transform (RT) to image the dispersive energies of the recorded ultrasound wave fields. The RT is posed as an inverse problem, which allows implementation of the regularization strategy to enhance the focusing power. We choose a Cauchy regularization for the high-resolution RT. Three forms of Radon transform: adjoint, damped least-squares, and high-resolution are described, and are compared with respect to robustness using simulated and cervine bone data. The RT also depends on the data aperture, but not as severely as does the FT. With the RT, the resolution of the dispersion panel could be improved up to around 300% over that of the FT. Among the Radon solutions, the high-resolution RT delineated the guided wave energy with much better imaging resolution (at least 110%) than the other two forms. The Radon operator can also accommodate unevenly spaced records. The results of the study suggest that the high-resolution RT is a valuable imaging tool to extract dispersive guided wave energies under limited aperture. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Texture analysis of clinical radiographs using radon transform on a local scale for differentiation between post-menopausal women with and without hip fracture

NASA Astrophysics Data System (ADS)

Boehm, Holger F.; Körner, Markus; Baumert, Bernhard; Linsenmaier, Ulrich; Reiser, Maximilian

2011-03-01

Osteoporosis is a chronic condition characterized by demineralization and destruction of bone tissue. Fractures associated with the disease are becoming an increasingly relevant issue for public health institutions. Prediction of fracture risk is a major focus research and, over the years, has been approched by various methods. Still, bone mineral density (BMD) obtained by dual-energy X-ray absorptiometry (DXA) remains the clinical gold-standard for diagnosis and follow-up of osteoporosis. However, DXA is restricted to specialized diagnostic centers and there exists considerable overlap in BMD results between populations of individuals with and without fractures. Clinically far more available than DXA is conventional x-ray imaging depicting trabecular bone structure in great detail. In this paper, we demonstrate that bone structure depicted by clinical radiographs can be analysed quantitatively by parameters obtained from the Radon Transform (RT). RT is a global analysis-tool for detection of predefined, parameterized patterns, e.g. straight lines or struts, representing suitable approximations of trabecular bone texture. The proposed algorithm differentiates between patients with and without fractures of the hip by application of various texture-metrics based on the Radon-Transform to standard x-ray images of the proximal femur. We consider three different regions-of-interest in the proximal femur (femoral head, neck, and inter-trochanteric area), and conduct an analysis with respect to correct classification of the fracture status. Performance of the novel approach is compared to DXA. We draw the conclusion that performance of RT is comparable to DXA and may become a useful supplement to densitometry for the prediction of fracture risk.

Detection and Classification of Objects in Synthetic Aperture Radar Imagery

DTIC Science & Technology

2006-02-01

a higher False Alarm Rate (FAR). Currently, a standard edge detector is the Canny algorithm, which is available with the mathematics package MATLAB ...the algorithm used to calculate the Radon transform. The MATLAB implementation uses the built in Radon transform procedure, which is extremely... MATLAB code for a faster forward-backwards selection process has also been provided. In both cases, the feature selection was accomplished by using

Uncertainties in radon related to house-specific factors and proximity to geological boundaries in England.

PubMed

Hunter, Nezahat; Muirhead, Colin R; Miles, Jon C H; Appleton, J Donald

2009-08-01

Data collected as a part of a survey on radon concentrations from about 40 000 dwellings in England for six contrasting geological units were analysed to evaluate the impact of house-specific factors (building characteristics and construction dates) and of proximity to geological boundaries. After adjusting for temperature and outdoor radon, geological unit, house type, double glazing and date of building were found to have a statistically significant influence on indoor radon concentrations and explained about 29 % of the total variation between dwellings in logarithmically transformed radon values. In addition, there were statistically significant differences in radon concentrations according to proximity to geological boundaries categories for most of the geological units, but no consistent pattern could be detected.

Radon potential, geologic formations, and lung cancer risk

PubMed Central

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

2015-01-01

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

40 CFR 35.700 - Purpose.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants for Tribes Indoor Radon Grants (section 306) § 35.700 Purpose. (a... programs that assess and mitigate radon and that aim at reducing radon health risks. Indoor Radon Grant...

Characterising fifteen years of continuous atmospheric radon activity observations at Cape Point (South Africa)

NASA Astrophysics Data System (ADS)

Botha, R.; Labuschagne, C.; Williams, A. G.; Bosman, G.; Brunke, E.-G.; Rossouw, A.; Lindsay, R.

2018-03-01

This paper describes and discusses fifteen years (1999-2013) of continuous hourly atmospheric radon (222Rn) monitoring at the coastal low-altitude Southern Hemisphere Cape Point Station in South Africa. A strong seasonal cycle is evident in the observed radon concentrations, with maxima during the winter months, when air masses arriving at the Cape Point station from over the African continental surface are more frequently observed, and minima during the summer months, when an oceanic fetch is predominant. An atmospheric mean radon activity concentration of 676 ± 2 mBq/m3 is found over the 15-year record, having a strongly skewed distribution that exhibits a large number of events falling into a compact range of low values (corresponding to oceanic air masses), and a smaller number of events with high radon values spread over a wide range (corresponding to continental air masses). The mean radon concentration from continental air masses (1 004 ± 6 mBq/m3) is about two times higher compared to oceanic air masses (479 ± 3 mBq/m3). The number of atmospheric radon events observed is strongly dependent on the wind direction. A power spectral Fast Fourier Transform analysis of the 15-year radon time series reveals prominent peaks at semi-diurnal, diurnal and annual timescales. Two inter-annual radon periodicities have been established, the diurnal 0.98 ± 0.04 day-1 and half-diurnal 2.07 ± 0.15 day-1. The annual peak reflects major seasonal changes in the patterns of offshore versus onshore flow associated with regional/hemispheric circulation patterns, whereas the diurnal and semi-diurnal peaks together reflect the influence of local nocturnal radon build-up over land, and the interplay between mesoscale sea/land breezes. The winter-time diurnal radon concentration had a significant decrease of about 200 mBq/m3 (17%) while the summer-time diurnal radon concentration revealed nearly no changes. A slow decline in the higher radon percentiles (75th and 95th) for the winter and spring seasons is found over the 15-year data set, with most of the change occurring in the first 9 years (1999-2007). This observed inter-annual decline appears to be associated with changes in the frequency of air masses having originated from over the African continental surfaces, and no significant trend is found in the lower radon percentiles associated with oceanic air masses. The general decrease of atmospheric radon-associated with continental air-masses at Cape Point could be attributed to changing meteorological conditions, possibly driven by climate change.

40 CFR 35.290 - Purpose.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants State Indoor Radon Grants (section 306) § 35.290 Purpose. (a) Purpose... mitigate radon and that aim at reducing radon health risks. State Indoor Radon Grant funds may be used for...

Baseline-Subtraction-Free (BSF) Damage-Scattered Wave Extraction for Stiffened Isotropic Plates

NASA Technical Reports Server (NTRS)

He, Jiaze; Leser, Patrick E.; Leser, William P.

2017-01-01

Lamb waves enable long distance inspection of structures for health monitoring purposes. However, this capability is diminished when applied to complex structures where damage-scattered waves are often buried by scattering from various structural components or boundaries in the time-space domain. Here, a baseline-subtraction-free (BSF) inspection concept based on the Radon transform (RT) is proposed to identify and separate these scattered waves from those scattered by damage. The received time-space domain signals can be converted into the Radon domain, in which the scattered signals from structural components are suppressed into relatively small regions such that damage-scattered signals can be identified and extracted. In this study, a piezoelectric wafer and a linear scan via laser Doppler vibrometer (LDV) were used to excite and acquire the Lamb-wave signals in an aluminum plate with multiple stiffeners. Linear and inverse linear Radon transform algorithms were applied to the direct measurements. The results demonstrate the effectiveness of the Radon transform as a reliable extraction tool for damage-scattered waves in a stiffened aluminum plate and also suggest the possibility of generalizing this technique for application to a wide variety of complex, large-area structures.

Soil and building material as main sources of indoor radon in Băiţa-Ştei radon prone area (Romania).

PubMed

Cosma, Constantin; Cucoş-Dinu, Alexandra; Papp, Botond; Begy, Robert; Sainz, Carlos

2013-02-01

Radon contributes to over than 50% of the natural radiation dose received by people. In radon risk areas this contribution can be as high as 90-95%, leading to an exposure to natural radiation 5-10 times higher than normal. This work presents results from radon measurements (indoor, soil and exhalation from building materials) in Băiţa-Ştei, a former uranium exploitation area in NW Romania. In this region, indoor radon concentrations found were as high as 5000 Bq m(-3) and soil radon levels ranged from 20 to 500 kBq m(-3). An important contribution from building materials to indoor radon was also observed. Our results indicate two independent sources of indoor radon in the surveyed houses of this region. One source is coming from the soil and regular building materials, and the second source being uranium waste and local radium reached material used in building construction. The soil as source of indoor radon shows high radon potential in 80% of the investigated area. Some local building materials reveal high radon exhalation rate (up to 80 mBq kg(-1) h(-1) from a sandy-gravel material, ten times higher than normal material). These measurements were used for the radon risk classification of this area by combining the radon potential of the soil with the additional component from building materials. Our results indicate that Băiţa-Ştei area can be categorized as a radon prone area. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Sky and Elemental Planetary Mapping Via Gamma Ray Emissions

NASA Technical Reports Server (NTRS)

Roland, John M.

2011-01-01

Low-energy gamma ray emissions ((is) approximately 30keV to (is) approximately 30MeV) are significant to astrophysics because many interesting objects emit their primary energy in this regime. As such, there has been increasing demand for a complete map of the gamma ray sky, but many experiments to do so have encountered obstacles. Using an innovative method of applying the Radon Transform to data from BATSE (the Burst And Transient Source Experiment) on NASA's CGRO (Compton Gamma-Ray Observatory) mission, we have circumvented many of these issues and successfully localized many known sources to 0.5 - 1 deg accuracy. Our method, which is based on a simple 2-dimensional planar back-projection approximation of the inverse Radon transform (familiar from medical CAT-scan technology), can thus be used to image the entire sky and locate new gamma ray sources, specifically in energy bands between 200keV and 2MeV which have not been well surveyed to date. Samples of these results will be presented. This same technique can also be applied to elemental planetary surface mapping via gamma ray spectroscopy. Due to our method's simplicity and power, it could potentially improve a current map's resolution by a significant factor.

Mathematics of Computed Tomography

NASA Astrophysics Data System (ADS)

Hawkins, William Grant

A review of the applications of the Radon transform is presented, with emphasis on emission computed tomography and transmission computed tomography. The theory of the 2D and 3D Radon transforms, and the effects of attenuation for emission computed tomography are presented. The algebraic iterative methods, their importance and limitations are reviewed. Analytic solutions of the 2D problem the convolution and frequency filtering methods based on linear shift invariant theory, and the solution of the circular harmonic decomposition by integral transform theory--are reviewed. The relation between the invisible kernels, the inverse circular harmonic transform, and the consistency conditions are demonstrated. The discussion and review are extended to the 3D problem-convolution, frequency filtering, spherical harmonic transform solutions, and consistency conditions. The Cormack algorithm based on reconstruction with Zernike polynomials is reviewed. An analogous algorithm and set of reconstruction polynomials is developed for the spherical harmonic transform. The relations between the consistency conditions, boundary conditions and orthogonal basis functions for the 2D projection harmonics are delineated and extended to the 3D case. The equivalence of the inverse circular harmonic transform, the inverse Radon transform, and the inverse Cormack transform is presented. The use of the number of nodes of a projection harmonic as a filter is discussed. Numerical methods for the efficient implementation of angular harmonic algorithms based on orthogonal functions and stable recursion are presented. The derivation of a lower bound for the signal-to-noise ratio of the Cormack algorithm is derived.

Local Efforts to Reduce Radon Risks - Highlights and Lessons Learned

EPA Pesticide Factsheets

In these stories, you will read about people who educated their families, neighbors, colleagues,and communities, and challenged local builders, governments, code enforcement officials, and others to protect the public from indoor radon.

Some inversion formulas for the cone transform

NASA Astrophysics Data System (ADS)

Terzioglu, Fatma

2015-11-01

Several novel imaging applications have lead recently to a variety of Radon type transforms, where integration is made over a family of conical surfaces. We call them cone transforms (in 2D they are also called V-line or broken ray transforms). Most prominently, they are present in the so called Compton camera imaging that arises in medical diagnostics, astronomy, and lately in homeland security applications. Several specific incarnations of the cone transform have been considered separately. In this paper, we address the most general (and overdetermined) cone transform, obtain integral relations between cone and Radon transforms in {{{R}}}n, and a variety of inversion formulas. In many applications (e.g., in homeland security), the signal to noise ratio is very low. So, if overdetermined data is collected (as in the case of Compton imaging), attempts to reduce the dimensionality might lead to essential elimination of the signal. Thus, our main concentration is on obtaining formulas involving overdetermined data.

Geographically weighted regression and geostatistical techniques to construct the geogenic radon potential map of the Lazio region: A methodological proposal for the European Atlas of Natural Radiation.

PubMed

Ciotoli, G; Voltaggio, M; Tuccimei, P; Soligo, M; Pasculli, A; Beaubien, S E; Bigi, S

2017-01-01

In many countries, assessment programmes are carried out to identify areas where people may be exposed to high radon levels. These programmes often involve detailed mapping, followed by spatial interpolation and extrapolation of the results based on the correlation of indoor radon values with other parameters (e.g., lithology, permeability and airborne total gamma radiation) to optimise the radon hazard maps at the municipal and/or regional scale. In the present work, Geographical Weighted Regression and geostatistics are used to estimate the Geogenic Radon Potential (GRP) of the Lazio Region, assuming that the radon risk only depends on the geological and environmental characteristics of the study area. A wide geodatabase has been organised including about 8000 samples of soil-gas radon, as well as other proxy variables, such as radium and uranium content of homogeneous geological units, rock permeability, and faults and topography often associated with radon production/migration in the shallow environment. All these data have been processed in a Geographic Information System (GIS) using geospatial analysis and geostatistics to produce base thematic maps in a 1000 m × 1000 m grid format. Global Ordinary Least Squared (OLS) regression and local Geographical Weighted Regression (GWR) have been applied and compared assuming that the relationships between radon activities and the environmental variables are not spatially stationary, but vary locally according to the GRP. The spatial regression model has been elaborated considering soil-gas radon concentrations as the response variable and developing proxy variables as predictors through the use of a training dataset. Then a validation procedure was used to predict soil-gas radon values using a test dataset. Finally, the predicted values were interpolated using the kriging algorithm to obtain the GRP map of the Lazio region. The map shows some high GRP areas corresponding to the volcanic terrains (central-northern sector of Lazio region) and to faulted and fractured carbonate rocks (central-southern and eastern sectors of the Lazio region). This typical local variability of autocorrelated phenomena can only be taken into account by using local methods for spatial data analysis. The constructed GRP map can be a useful tool to implement radon policies at both the national and local levels, providing critical data for land use and planning purposes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Radon-contaminated drinking water from private wells: an environmental health assessment examining a rural Colorado mountain community's exposure.

PubMed

Cappello, Michael Anthony; Ferraro, Aimee; Mendelsohn, Aaron B; Prehn, Angela Witt

2013-11-01

In the study discussed in this article, 27 private drinking water wells located in a rural Colorado mountain community were sampled for radon contamination and compared against (a) the U.S. Environmental Protection Agency's (U.S. EPA's) proposed maximum contaminant level (MCL), (b) the U.S. EPA proposed alternate maximum contaminate level (AMCL), and (c) the average radon level measured in the local municipal drinking water system. The data from the authors' study found that 100% of the wells within the study population had radon levels in excess of the U.S. EPA MCL, 37% were in excess of the U.S. EPA AMCL, and 100% of wells had radon levels greater than that found in the local municipal drinking water system. Radon contamination in one well was found to be 715 times greater than the U.S. EPA MCL, 54 times greater than the U.S. EPA AMLC, and 36,983 times greater than that found in the local municipal drinking water system. According to the research data and the reviewed literature, the results indicate that this population has a unique and elevated contamination profile and suggest that radon-contaminated drinking water from private wells can present a significant public health concern.

Fourier-Domain Shift Matching: A Robust Time-of-Flight Approach for Shear Wave Speed Estimation.

PubMed

Rosen, David; Jiang, Jingfeng

2018-05-01

Our primary objective of this work was to design and test a new time-of-flight (TOF) method that allows measurements of shear wave speed (SWS) following impulsive excitation in soft tissues. Particularly, under the assumption of the local plane shear wave, this work named the Fourier-domain shift matching (FDSM) method, estimates SWS by aligning a series of shear waveforms either temporally or spatially using a solution space deduced by characteristic curves of the well-known 1-D wave equation. The proposed SWS estimation method was tested using computer-simulated data, and tissue-mimicking phantom and ex vivo tissue experiments. Its performance was then compared with three other known TOF methods: lateral time-to-peak (TTP) method with robust random sampling consensus (RANSAC) fitting method, Radon sum transformation method, and a modified cross correlation method. Hereafter, these three TOF methods are referred to as the TTP-RANSAC, Radon sum, and X-corr methods, respectively. In addition to an adapted form of the 2-D Fourier transform (2-D FT)-based method in which the (group) SWS was approximated by averaging phase SWS values was considered for comparison. Based on data evaluated, we found that the overall performance of the above-mentioned temporal implementation of the proposed FDSM method was most similar to the established Radon sum method (correlation = 0.99, scale factor = 1.03, and mean difference = 0.07 m/s), and the 2-D FT (correlation = 0.98, scale factor = 1.00, and mean difference = 0.10 m/s) at high signal quality. However, results obtained from the 2-D FT method diverged (correlation = 0.201) from these of the proposed temporal implementation in the presence of diminished signal quality, whereas the agreement between the Radon sum approach and the proposed temporal implementation largely remained the same (correlation = 0.98).

γ-H2AX/53BP1/pKAP-1 foci and their linear tracks induced by in vitro exposure to radon and its progeny in human peripheral blood lymphocytes

PubMed Central

Ding, Defang; Zhang, Yaping; Wang, Jing; Wang, Xufei; Fan, Dunhuang; He, Linfeng; Zhang, Xuxia; Gao, Yun; Li, Qiang; Chen, Honghong

2016-01-01

The biodosimetric information is critical for evaluating the human health hazards caused by radon and its progeny. Here, we demonstrated that the formation of phosphorylated histone variant H2AX (γ-H2AX), p53-binding protein 1 (53BP1) and phosphorylated KRAB-associated protein 1 (pKAP-1) foci and their linear tracks in human peripheral blood lymphocytes (HPBLs) in vitro exposed to radon and its progeny were dependent on the cumulative absorbed dose of radon exposure but was unrelated to the concentration of radon. Among them, γ-H2AX foci and its linear tracks were the most sensitive indicators with the lowest estimable cumulative absorbed dose of 1.74 mGy from their linear dose-response curves and sustained for 12 h after termination of radon exposure. In addition, three types of foci showed an overdispersed non-Poisson distribution in HPBLs. The ratios of pKAP-1/γ-H2AX foci co-localization, 53BP1/γ-H2AX foci co-localization and 53BP1/pKAP-1 foci co-localization were significantly increased in HPBLs exposed to radon while they were unrelated to the cumulative dose of radon exposure, suggesting that γ-H2AX, pKAP-1 and 53BP1 play an important role in the repair of heterochromatic double-strand breaks. Altogether, our findings provide an experimental basis for estimating the biological dose of internal α-particle irradiation from radon and its progeny exposure in humans. PMID:27922110

Research on autonomous identification of airport targets based on Gabor filtering and Radon transform

NASA Astrophysics Data System (ADS)

Yi, Juan; Du, Qingyu; Zhang, Hong jiang; Zhang, Yao lei

2017-11-01

Target recognition is a leading key technology in intelligent image processing and application development at present, with the enhancement of computer processing ability, autonomous target recognition algorithm, gradually improve intelligence, and showed good adaptability. Taking the airport target as the research object, analysis the airport layout characteristics, construction of knowledge model, Gabor filter and Radon transform based on the target recognition algorithm of independent design, image processing and feature extraction of the airport, the algorithm was verified, and achieved better recognition results.

Geometric shapes inversion method of space targets by ISAR image segmentation

NASA Astrophysics Data System (ADS)

Huo, Chao-ying; Xing, Xiao-yu; Yin, Hong-cheng; Li, Chen-guang; Zeng, Xiang-yun; Xu, Gao-gui

2017-11-01

The geometric shape of target is an effective characteristic in the process of space targets recognition. This paper proposed a method of shape inversion of space target based on components segmentation from ISAR image. The Radon transformation, Hough transformation, K-means clustering, triangulation will be introduced into ISAR image processing. Firstly, we use Radon transformation and edge detection to extract space target's main body spindle and solar panel spindle from ISAR image. Then the targets' main body, solar panel, rectangular and circular antenna are segmented from ISAR image based on image detection theory. Finally, the sizes of every structural component are computed. The effectiveness of this method is verified using typical targets' simulation data.

40 CFR 35.298 - Award limitations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... STATE AND LOCAL ASSISTANCE Environmental Program Grants State Indoor Radon Grants (section 306) § 35.298 Award limitations. (a) The Regional Administrator shall not include State Indoor Radon funds in a... has the primary responsibility for radon programs as designated by the Governor of the affected State...

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

PubMed

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

2016-07-01

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

Study of Local Radon Occurrence as an Interdisciplinary Undergraduate Research Project.

ERIC Educational Resources Information Center

Purdom, William Berlin; And Others

1990-01-01

Described is an undergraduate interdisciplinary project encompassing physics, computer science, and geology and involving a number of students from several academic departments. The project used the topic of the occurrence of in-home radon. Student projects, radon sampling, and results are discussed. (CW)

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

PubMed

Shendell, Derek G; Carr, Michael

2013-10-01

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

40 CFR 35.703 - Eligible recipients.

Code of Federal Regulations, 2010 CFR

2010-07-01

... STATE AND LOCAL ASSISTANCE Environmental Program Grants for Tribes Indoor Radon Grants (section 306... Consortium as eligible to apply for an Indoor Radon Grant if the Tribe or each member of the Intertribal... that information unique to the radon grant program required by paragraphs (a)(3) and (4) of this...

40 CFR 35.702 - Basis for allotment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... STATE AND LOCAL ASSISTANCE Environmental Program Grants for Tribes Indoor Radon Grants (section 306) § 35.702 Basis for allotment. (a) The Regional Administrator will allot Indoor Radon Grant funds based... Control Act. (b) No Tribe or Intertribal Consortium may receive an Indoor Radon Grant in excess of 10...

40 CFR 35.292 - Basis for allotment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... STATE AND LOCAL ASSISTANCE Environmental Program Grants State Indoor Radon Grants (section 306) § 35.292 Basis for allotment. (a) The Regional Administrator will allot State Indoor Radon Grant funds based on... Control Act. (b) No State may receive a State Indoor Radon Grant in excess of 10 percent of the total...

40 CFR 35.292 - Basis for allotment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... STATE AND LOCAL ASSISTANCE Environmental Program Grants State Indoor Radon Grants (section 306) § 35.292 Basis for allotment. (a) The Regional Administrator will allot State Indoor Radon Grant funds based on... Control Act. (b) No State may receive a State Indoor Radon Grant in excess of 10 percent of the total...

40 CFR 35.702 - Basis for allotment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... STATE AND LOCAL ASSISTANCE Environmental Program Grants for Tribes Indoor Radon Grants (section 306) § 35.702 Basis for allotment. (a) The Regional Administrator will allot Indoor Radon Grant funds based... Control Act. (b) No Tribe or Intertribal Consortium may receive an Indoor Radon Grant in excess of 10...

40 CFR 35.703 - Eligible recipients.

Code of Federal Regulations, 2011 CFR

2011-07-01

... STATE AND LOCAL ASSISTANCE Environmental Program Grants for Tribes Indoor Radon Grants (section 306... Consortium as eligible to apply for an Indoor Radon Grant if the Tribe or each member of the Intertribal... that information unique to the radon grant program required by paragraphs (a)(3) and (4) of this...

A new local GPS water vapor tomography imaging technique using spectral functions w.r.t space and time: initial tests and results for the Tahiti Island case (French Polynesia)

NASA Astrophysics Data System (ADS)

Sichoix, L.; Barriot, J.; Fadil, A.; Ortega, P.

2009-12-01

In this study, we present the initial tests and validation results performed on a newly-developed GPS water vapor tomography inversion code based on a spectral approach tailored to coarse networks of GPS stations. Our work is mainly motivated by the lack of dense GPS coverage in Tahiti Island. Firstly, we use the GAMIT software to estimate the tropospheric slant wet delays (SWD) from a single GPS ground-based receiver to each visible satellite. SWD values are our model input. Secondly, the refractivity along ray paths is written as 3D Zernike radial and spherical harmonic series as well as sinusoidal time series and then inserted into the Radon transform linking slant delays and refractivity. This approach is in contrast with usual previous approaches where the atmosphere is divided into voxels (3D pixels). These approaches may exhibit instabilities as a voxel is crossed by more than one ray. Thirdly, we overcome the ill-posedness of the Radon transform by adding a priori constraints in the form of a full covariance matrix of the atmospheric refractivity taking into account the transport and mixing processes in the atmosphere.

Deblending using an improved apex-shifted hyperbolic radon transform based on the Stolt migration operator

NASA Astrophysics Data System (ADS)

Gong, Xiangbo; Feng, Fei; Jiao, Xuming; Wang, Shengchao

2017-10-01

Simultaneous seismic source separation, also known as deblending, is an essential process for blended acquisition. With the assumption that the blending noise is coherent in the common shot domain but is incoherent in other domains, traditional deblending methods are commonly performed in the common receiver, common midpoint or common offset domain. In this paper, we propose an improved apex-shifted hyperbolic radon transform (ASHRT) to deblend directly in the common shot domain. A time-axis stretch strategy named Stolt-stretch is introduced to overcome the limitation of the constant velocity assumption of Stolt-based operators. To improve the sparsity in the transform domain, a total variation (TV) norm inversion is implemented to enhance the energy convergence in the radon panel. Because of highly efficient Stolt migration and the demigration operator in the frequency-wavenumber domain, as well as the flexible geometry condition of the source-receiver, this approach is quite suitable for quality control (QC) during streamer acquisition. The synthetic and field examples demonstrate that our proposition is robust and efficient.

Geohydrologic, geochemical, and geologic controls on the occurrence of radon in ground water near Conifer, Colorado, USA

USGS Publications Warehouse

Lawrence, E.; Poeter, E.; Wanty, R.

1991-01-01

Integrated studies of geohydrology, geochemistry, and geology of crystalline rocks in the vicinity of Conifer, Colorado, reveal that radon concentrations do not correlate with variations in concentrations of other dissolved species. Concentrations of major ions show systematic variations along selected groundwater flowpaths, whereas radon concentrations are dependent on local geochemical and geologic phenomena (such as localized uranium concentration in the rock or the presence of faults or folds). When radon enters the flow system, concentrations do not increase along flowpaths because its decay rate is fast relative to groundwater flow rates. Radon-222 is not in secular equilibrium with 238U and 226Ra in the water. Therefore, most of the 238U and 226Ra necessary to support the waterborne 222Rn must be present locally in the rock. High concentrations of dissolved radon are not found in zones of high transmissivity, and transmissivity is not correlated with rock type in the study area. A higher transmissivity can be indicative of higher water-volume to rock-surface-area ratios, which could effectively dilute 222Rn entering the water and/or may indicate that emanated radon is carried away more rapidly. Water samples collected from individual wells over periods of several months showed significant fluctuations in the dissolved 222Rn content. This fluctuation may be controlled by changes in the contributions of water-producing zones within the well resulting from seasonal fluctuations of the water table and/or pumping stresses. ?? 1991.

Influence of meteorological parameters on the soil radon (Rn222) emanation in Kutch, Gujarat, India.

PubMed

Sahoo, Sushanta Ku; Katlamudi, Madhusudhanarao; Shaji, Jerin P; Murali Krishna, K S; Udaya Lakshmi, G

2018-02-02

The soil radon (Rn 222 ) and thoron (Rn 220 ) concentrations recorded at Badargadh and Desalpar observatories in the Kutch region of Gujarat, India, have been analyzed to study the sources of the radon emissions, earthquake precursors, and the influence of meteorological parameters on radon emission. Radon and meteorological parameters were recorded using Radon Monitor RMT 1688-2 at these two stations. We used the radon data during February 21, 2011 to June 8, 2011, for Badargadh and March 2, 2011 to May 19, 2011, for the Desalpar station with a sampling interval of 10 min. It is observed that the radon concentrations at Desalpar varies between 781 and 4320 Bq m -3 with an average value of 2499 Bq m -3 , whereas thoron varies between 191 and 2017 Bq m -3 with an average value of 1433.69 Bq m -3 . The radon concentration at Badargadh varies between 264 and 2221 Bq m -3 with an average value of 1135.4 Bq m -3 , whereas thoron varies between 97 and 556 Bq m -3 . To understand how the meteorological parameters influence radon emanation, the radon and other meteorological parameters were correlated with linear regression analysis. Here, it was observed that radon and temperature are negatively correlated whereas radon and other two parameters, i.e., humidity and pressure are positively correlated. The cross correlogram also ascertains similar relationships between radon and other parameters. Further, the ratio between radon and thoron has been analyzed to determine the deep or shallow source of the radon emanation in the study area. These results revealed that the ratio radon/thoron enhanced during this period which indicates the deeper source contribution is prominent. Incidentally, all the local earthquakes occurred with a focal depth of 18-25 km at the lower crust in this region. We observed the rise in the concentrations of radon and the ratio radon/thoron at Badargadh station before the occurrence of the local earthquakes on 29th March 2011 (M 3.7) and 17th May 2011 (M 4.2). We clearly observed the radon level crossing the mean + 2*sigma level before the occurrence of these events. We conclude that these enhanced radon emissions are linked with alteration of the crustal stress/strain in this region as this observing station is near the epicenters of the earthquakes. We did not observe considerable variations in radon at the Desalpar station which is far from the earthquake location.

An overview of Ireland's National Radon Policy.

PubMed

Long, S; Fenton, D

2011-05-01

In Ireland radon is a significant public health issue and is linked to 150-200 lung cancer deaths each year. Irish National Radon Policy aims to reduce individual risk by identifying and remediating buildings with high radon concentrations and also to reduce collective dose through radon prevention as required by revised building regulations. Achievements to date are significant and include the completion of the National Radon Survey, the testing of every school in Ireland, the on-going testing of social housing, collaboration between the public health and radiation protection authorities and the inclusion of radon in inspections of workplaces. However, this work now needs to be drawn together centrally to comprehensively address the radon problem. The RPII and the relevant central governing department, the Department of Environment, Heritage and Local Government are currently working to constitute a group of key experts from relevant public authorities to drive the development of a National Radon Control Strategy.

Performance analysis of a finite radon transform in OFDM system under different channel models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dawood, Sameer A.; Anuar, M. S.; Fayadh, Rashid A.

In this paper, a class of discrete Radon transforms namely Finite Radon Transform (FRAT) was proposed as a modulation technique in the realization of Orthogonal Frequency Division Multiplexing (OFDM). The proposed FRAT operates as a data mapper in the OFDM transceiver instead of the conventional phase shift mapping and quadrature amplitude mapping that are usually used with the standard OFDM based on Fast Fourier Transform (FFT), by the way that ensure increasing the orthogonality of the system. The Fourier domain approach was found here to be the more suitable way for obtaining the forward and inverse FRAT. This structure resultedmore » in a more suitable realization of conventional FFT- OFDM. It was shown that this application increases the orthogonality significantly in this case due to the use of Inverse Fast Fourier Transform (IFFT) twice, namely, in the data mapping and in the sub-carrier modulation also due to the use of an efficient algorithm in determining the FRAT coefficients called the optimal ordering method. The proposed approach was tested and compared with conventional OFDM, for additive white Gaussian noise (AWGN) channel, flat fading channel, and multi-path frequency selective fading channel. The obtained results showed that the proposed system has improved the bit error rate (BER) performance by reducing inter-symbol interference (ISI) and inter-carrier interference (ICI), comparing with conventional OFDM system.« less

Performance analysis of a finite radon transform in OFDM system under different channel models

NASA Astrophysics Data System (ADS)

Dawood, Sameer A.; Malek, F.; Anuar, M. S.; Fayadh, Rashid A.; Abdullah, Farrah Salwani

2015-05-01

In this paper, a class of discrete Radon transforms namely Finite Radon Transform (FRAT) was proposed as a modulation technique in the realization of Orthogonal Frequency Division Multiplexing (OFDM). The proposed FRAT operates as a data mapper in the OFDM transceiver instead of the conventional phase shift mapping and quadrature amplitude mapping that are usually used with the standard OFDM based on Fast Fourier Transform (FFT), by the way that ensure increasing the orthogonality of the system. The Fourier domain approach was found here to be the more suitable way for obtaining the forward and inverse FRAT. This structure resulted in a more suitable realization of conventional FFT- OFDM. It was shown that this application increases the orthogonality significantly in this case due to the use of Inverse Fast Fourier Transform (IFFT) twice, namely, in the data mapping and in the sub-carrier modulation also due to the use of an efficient algorithm in determining the FRAT coefficients called the optimal ordering method. The proposed approach was tested and compared with conventional OFDM, for additive white Gaussian noise (AWGN) channel, flat fading channel, and multi-path frequency selective fading channel. The obtained results showed that the proposed system has improved the bit error rate (BER) performance by reducing inter-symbol interference (ISI) and inter-carrier interference (ICI), comparing with conventional OFDM system.

Prediction of 222Rn in Danish dwellings using geology and house construction information from central databases.

PubMed

Andersen, Claus E; Raaschou-Nielsen, Ole; Andersen, Helle Primdal; Lind, Morten; Gravesen, Peter; Thomsen, Birthe L; Ulbak, Kaare

2007-01-01

A linear regression model has been developed for the prediction of indoor (222)Rn in Danish houses. The model provides proxy radon concentrations for about 21,000 houses in a Danish case-control study on the possible association between residential radon and childhood cancer (primarily leukaemia). The model was calibrated against radon measurements in 3116 houses. An independent dataset with 788 house measurements was used for model performance assessment. The model includes nine explanatory variables, of which the most important ones are house type and geology. All explanatory variables are available from central databases. The model was fitted to log-transformed radon concentrations and it has an R(2) of 40%. The uncertainty associated with individual predictions of (untransformed) radon concentrations is about a factor of 2.0 (one standard deviation). The comparison with the independent test data shows that the model makes sound predictions and that errors of radon predictions are only weakly correlated with the estimates themselves (R(2) = 10%).

On a problem of reconstruction of a discontinuous function by its Radon transform

DOE Office of Scientific and Technical Information (OSTI.GOV)

Derevtsov, Evgeny Yu.; Maltseva, Svetlana V.; Svetov, Ivan E.

A problem of reconstruction of a discontinuous function by its Radon transform is considered. One of the approaches to the numerical solution for the problem consists in the next sequential steps: a visualization of a set of breaking points; an identification of this set; a determination of jump values; an elimination of discontinuities. We consider three of listed problems except the problem of jump values. The problems are investigated by mathematical modeling using numerical experiments. The results of simulation are satisfactory and allow to hope for the further development of the approach.

Radon measurement and mitigation activity in Finland.

PubMed

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

2014-07-01

Radon prevention, measurement and mitigation activities have been increasing in Finland during the 2000s. Nowadays, many municipal authorities, especially those located in high-radon areas, require radon prevention measures. This has activated radon measurements. Owners of new houses having radon piping installed under the floor slab are the most active group to measure and reduce the found high-radon values. Their radon awareness is apparently better than on the average, and the existing piping makes it easier and cheaper to reduce the radon levels. Local campaigns involving invitation flyers mailed to the residents have been a cost-effective means to activate measurements of older houses. So far 116,611 dwellings in low-rise residential buildings have been measured. At least 15% of the 16,860 dwellings found to exceed the reference level of 400 Bq m(-3) had their indoor radon level reduced below that. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Rehabilitative treatment of patients with ureterolithiasis using pulsed vacuum depression, pulsed low-frequency electric current, and radon therapy].

PubMed

Li, A A; Karpukhin, I V; Korchazhkina, N B; Gusarov, I I; Kotenko, K V; Slepushkina, T G; Dubovskiĭ, A V

2009-01-01

The authors report results of the treatment of 60 patients with ureterolithiasis using a combination of pulsed vacuum depression (local vibrotherapy), low-frequency pulsed (alternating sinusoidal) current, radon water and radon baths. Clinical efficiency of combined therapy is estimated at 93.3%.

The oncogenic transforming potential of the passage of single α particles through mammalian cell nuclei

PubMed Central

Miller, Richard C.; Randers-Pehrson, Gerhard; Geard, Charles R.; Hall, Eric J.; Brenner, David J.

1999-01-01

Domestic, low-level exposure to radon gas is considered a major environmental lung-cancer hazard involving DNA damage to bronchial cells by α particles from radon progeny. At domestic exposure levels, the relevant bronchial cells are very rarely traversed by more than one α particle, whereas at higher radon levels—at which epidemiological studies in uranium miners allow lung-cancer risks to be quantified with reasonable precision—these bronchial cells are frequently exposed to multiple α-particle traversals. Measuring the oncogenic transforming effects of exactly one α particle without the confounding effects of multiple traversals has hitherto been unfeasible, resulting in uncertainty in extrapolations of risk from high to domestic radon levels. A technique to assess the effects of single α particles uses a charged-particle microbeam, which irradiates individual cells or cell nuclei with predefined exact numbers of particles. Although previously too slow to assess the relevant small oncogenic risks, recent improvements in throughput now permit microbeam irradiation of large cell numbers, allowing the first oncogenic risk measurements for the traversal of exactly one α particle through a cell nucleus. Given positive controls to ensure that the dosimetry and biological controls were comparable, the measured oncogenicity from exactly one α particle was significantly lower than for a Poisson-distributed mean of one α particle, implying that cells traversed by multiple α particles contribute most of the risk. If this result applies generally, extrapolation from high-level radon risks (involving cellular traversal by multiple α particles) may overestimate low-level (involving only single α particles) radon risks. PMID:9874764

Automated road network extraction from high spatial resolution multi-spectral imagery

NASA Astrophysics Data System (ADS)

Zhang, Qiaoping

For the last three decades, the Geomatics Engineering and Computer Science communities have considered automated road network extraction from remotely-sensed imagery to be a challenging and important research topic. The main objective of this research is to investigate the theory and methodology of automated feature extraction for image-based road database creation, refinement or updating, and to develop a series of algorithms for road network extraction from high resolution multi-spectral imagery. The proposed framework for road network extraction from multi-spectral imagery begins with an image segmentation using the k-means algorithm. This step mainly concerns the exploitation of the spectral information for feature extraction. The road cluster is automatically identified using a fuzzy classifier based on a set of predefined road surface membership functions. These membership functions are established based on the general spectral signature of road pavement materials and the corresponding normalized digital numbers on each multi-spectral band. Shape descriptors of the Angular Texture Signature are defined and used to reduce the misclassifications between roads and other spectrally similar objects (e.g., crop fields, parking lots, and buildings). An iterative and localized Radon transform is developed for the extraction of road centerlines from the classified images. The purpose of the transform is to accurately and completely detect the road centerlines. It is able to find short, long, and even curvilinear lines. The input image is partitioned into a set of subset images called road component images. An iterative Radon transform is locally applied to each road component image. At each iteration, road centerline segments are detected based on an accurate estimation of the line parameters and line widths. Three localization approaches are implemented and compared using qualitative and quantitative methods. Finally, the road centerline segments are grouped into a road network. The extracted road network is evaluated against a reference dataset using a line segment matching algorithm. The entire process is unsupervised and fully automated. Based on extensive experimentation on a variety of remotely-sensed multi-spectral images, the proposed methodology achieves a moderate success in automating road network extraction from high spatial resolution multi-spectral imagery.

A line-source method for aligning on-board and other pinhole SPECT systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Susu; Bowsher, James; Yin, Fang-Fang

2013-12-15

Purpose: In order to achieve functional and molecular imaging as patients are in position for radiation therapy, a robotic multipinhole SPECT system is being developed. Alignment of the SPECT system—to the linear accelerator (LINAC) coordinate frame and to the coordinate frames of other on-board imaging systems such as cone-beam CT (CBCT)—is essential for target localization and image reconstruction. An alignment method that utilizes line sources and one pinhole projection is proposed and investigated to achieve this goal. Potentially, this method could also be applied to the calibration of the other pinhole SPECT systems.Methods: An alignment model consisting of multiple alignmentmore » parameters was developed which maps line sources in three-dimensional (3D) space to their two-dimensional (2D) projections on the SPECT detector. In a computer-simulation study, 3D coordinates of line-sources were defined in a reference room coordinate frame, such as the LINAC coordinate frame. Corresponding 2D line-source projections were generated by computer simulation that included SPECT blurring and noise effects. The Radon transform was utilized to detect angles (α) and offsets (ρ) of the line-source projections. Alignment parameters were then estimated by a nonlinear least squares method, based on the α and ρ values and the alignment model. Alignment performance was evaluated as a function of number of line sources, Radon transform accuracy, finite line-source width, intrinsic camera resolution, Poisson noise, and acquisition geometry. Experimental evaluations were performed using a physical line-source phantom and a pinhole-collimated gamma camera attached to a robot.Results: In computer-simulation studies, when there was no error in determining angles (α) and offsets (ρ) of the measured projections, six alignment parameters (three translational and three rotational) were estimated perfectly using three line sources. When angles (α) and offsets (ρ) were provided by the Radon transform, estimation accuracy was reduced. The estimation error was associated with rounding errors of Radon transform, finite line-source width, Poisson noise, number of line sources, intrinsic camera resolution, and detector acquisition geometry. Statistically, the estimation accuracy was significantly improved by using four line sources rather than three and by thinner line-source projections (obtained by better intrinsic detector resolution). With five line sources, median errors were 0.2 mm for the detector translations, 0.7 mm for the detector radius of rotation, and less than 0.5° for detector rotation, tilt, and twist. In experimental evaluations, average errors relative to a different, independent registration technique were about 1.8 mm for detector translations, 1.1 mm for the detector radius of rotation (ROR), 0.5° and 0.4° for detector rotation and tilt, respectively, and 1.2° for detector twist.Conclusions: Alignment parameters can be estimated using one pinhole projection of line sources. Alignment errors are largely associated with limited accuracy of the Radon transform in determining angles (α) and offsets (ρ) of the line-source projections. This alignment method may be important for multipinhole SPECT, where relative pinhole alignment may vary during rotation. For pinhole and multipinhole SPECT imaging on-board radiation therapy machines, the method could provide alignment of SPECT coordinates with those of CBCT and the LINAC.« less

A line-source method for aligning on-board and other pinhole SPECT systems

PubMed Central

Yan, Susu; Bowsher, James; Yin, Fang-Fang

2013-01-01

Purpose: In order to achieve functional and molecular imaging as patients are in position for radiation therapy, a robotic multipinhole SPECT system is being developed. Alignment of the SPECT system—to the linear accelerator (LINAC) coordinate frame and to the coordinate frames of other on-board imaging systems such as cone-beam CT (CBCT)—is essential for target localization and image reconstruction. An alignment method that utilizes line sources and one pinhole projection is proposed and investigated to achieve this goal. Potentially, this method could also be applied to the calibration of the other pinhole SPECT systems. Methods: An alignment model consisting of multiple alignment parameters was developed which maps line sources in three-dimensional (3D) space to their two-dimensional (2D) projections on the SPECT detector. In a computer-simulation study, 3D coordinates of line-sources were defined in a reference room coordinate frame, such as the LINAC coordinate frame. Corresponding 2D line-source projections were generated by computer simulation that included SPECT blurring and noise effects. The Radon transform was utilized to detect angles (α) and offsets (ρ) of the line-source projections. Alignment parameters were then estimated by a nonlinear least squares method, based on the α and ρ values and the alignment model. Alignment performance was evaluated as a function of number of line sources, Radon transform accuracy, finite line-source width, intrinsic camera resolution, Poisson noise, and acquisition geometry. Experimental evaluations were performed using a physical line-source phantom and a pinhole-collimated gamma camera attached to a robot. Results: In computer-simulation studies, when there was no error in determining angles (α) and offsets (ρ) of the measured projections, six alignment parameters (three translational and three rotational) were estimated perfectly using three line sources. When angles (α) and offsets (ρ) were provided by the Radon transform, estimation accuracy was reduced. The estimation error was associated with rounding errors of Radon transform, finite line-source width, Poisson noise, number of line sources, intrinsic camera resolution, and detector acquisition geometry. Statistically, the estimation accuracy was significantly improved by using four line sources rather than three and by thinner line-source projections (obtained by better intrinsic detector resolution). With five line sources, median errors were 0.2 mm for the detector translations, 0.7 mm for the detector radius of rotation, and less than 0.5° for detector rotation, tilt, and twist. In experimental evaluations, average errors relative to a different, independent registration technique were about 1.8 mm for detector translations, 1.1 mm for the detector radius of rotation (ROR), 0.5° and 0.4° for detector rotation and tilt, respectively, and 1.2° for detector twist. Conclusions: Alignment parameters can be estimated using one pinhole projection of line sources. Alignment errors are largely associated with limited accuracy of the Radon transform in determining angles (α) and offsets (ρ) of the line-source projections. This alignment method may be important for multipinhole SPECT, where relative pinhole alignment may vary during rotation. For pinhole and multipinhole SPECT imaging on-board radiation therapy machines, the method could provide alignment of SPECT coordinates with those of CBCT and the LINAC. PMID:24320537

A line-source method for aligning on-board and other pinhole SPECT systems.

PubMed

Yan, Susu; Bowsher, James; Yin, Fang-Fang

2013-12-01

In order to achieve functional and molecular imaging as patients are in position for radiation therapy, a robotic multipinhole SPECT system is being developed. Alignment of the SPECT system-to the linear accelerator (LINAC) coordinate frame and to the coordinate frames of other on-board imaging systems such as cone-beam CT (CBCT)-is essential for target localization and image reconstruction. An alignment method that utilizes line sources and one pinhole projection is proposed and investigated to achieve this goal. Potentially, this method could also be applied to the calibration of the other pinhole SPECT systems. An alignment model consisting of multiple alignment parameters was developed which maps line sources in three-dimensional (3D) space to their two-dimensional (2D) projections on the SPECT detector. In a computer-simulation study, 3D coordinates of line-sources were defined in a reference room coordinate frame, such as the LINAC coordinate frame. Corresponding 2D line-source projections were generated by computer simulation that included SPECT blurring and noise effects. The Radon transform was utilized to detect angles (α) and offsets (ρ) of the line-source projections. Alignment parameters were then estimated by a nonlinear least squares method, based on the α and ρ values and the alignment model. Alignment performance was evaluated as a function of number of line sources, Radon transform accuracy, finite line-source width, intrinsic camera resolution, Poisson noise, and acquisition geometry. Experimental evaluations were performed using a physical line-source phantom and a pinhole-collimated gamma camera attached to a robot. In computer-simulation studies, when there was no error in determining angles (α) and offsets (ρ) of the measured projections, six alignment parameters (three translational and three rotational) were estimated perfectly using three line sources. When angles (α) and offsets (ρ) were provided by the Radon transform, estimation accuracy was reduced. The estimation error was associated with rounding errors of Radon transform, finite line-source width, Poisson noise, number of line sources, intrinsic camera resolution, and detector acquisition geometry. Statistically, the estimation accuracy was significantly improved by using four line sources rather than three and by thinner line-source projections (obtained by better intrinsic detector resolution). With five line sources, median errors were 0.2 mm for the detector translations, 0.7 mm for the detector radius of rotation, and less than 0.5° for detector rotation, tilt, and twist. In experimental evaluations, average errors relative to a different, independent registration technique were about 1.8 mm for detector translations, 1.1 mm for the detector radius of rotation (ROR), 0.5° and 0.4° for detector rotation and tilt, respectively, and 1.2° for detector twist. Alignment parameters can be estimated using one pinhole projection of line sources. Alignment errors are largely associated with limited accuracy of the Radon transform in determining angles (α) and offsets (ρ) of the line-source projections. This alignment method may be important for multipinhole SPECT, where relative pinhole alignment may vary during rotation. For pinhole and multipinhole SPECT imaging on-board radiation therapy machines, the method could provide alignment of SPECT coordinates with those of CBCT and the LINAC.

40 CFR 35.705 - Maximum federal share.

Code of Federal Regulations, 2011 CFR

2011-07-01

... STATE AND LOCAL ASSISTANCE Environmental Program Grants for Tribes Indoor Radon Grants (section 306... up to 75 percent of the approved costs for the development and implementation of radon program...

3D-modelling of radon-induced cellular radiobiological effects in bronchial airway bifurcations: direct versus bystander effects.

PubMed

Szőke, István; Farkas, Arpád; Balásházy, Imre; Hofmann, Werner; Madas, Balázs G; Szőke, Réka

2012-06-01

The primary objective of this paper was to investigate the distribution of radiation doses and the related biological responses in cells of a central airway bifurcation of the human lung of a hypothetical worker of the New Mexico uranium mines during approximately 12 hours of exposure to short-lived radon progenies. State-of-the-art computational modelling techniques were applied to simulate the relevant biophysical and biological processes in a central human airway bifurcation. The non-uniform deposition pattern of inhaled radon daughters caused a non-uniform distribution of energy deposition among cells, and of related cell inactivation and cell transformation probabilities. When damage propagation via bystander signalling was assessed, it produced more cell killing and cell transformation events than did direct effects. If bystander signalling was considered, variations of the average probabilities of cell killing and cell transformation were supra-linear over time. Our results are very sensitive to the radiobiological parameters, derived from in vitro experiments (e.g., range of bystander signalling), applied in this work and suggest that these parameters may not be directly applicable to realistic three-dimensional (3D) epithelium models.

Lung cancer risk due to residential radon exposures: estimation and prevention.

PubMed

Truta, L A; Hofmann, W; Cosma, C

2014-07-01

Epidemiological studies proved that cumulative exposure to radon is the second leading cause of lung cancer, the world's most common cancer. The objectives of the present study are (i) to analyse lung cancer risk for chronic, low radon exposures based on the transformation frequency-tissue response (TF-TR) model formulated in terms of alpha particle hits in cell nuclei; (ii) to assess the percentage of attributable lung cancers in six areas of Transylvania where the radon concentration was measured and (iii) to point out the most efficient remediation measures tested on a pilot house in Stei, Romania. Simulations performed with the TF-TR model exhibit a linear dose-effect relationship for chronic, residential radon exposures. The fraction of lung cancer cases attributed to radon ranged from 9 to 28% for the investigated areas. Model predictions may represent a useful tool to complement epidemiological studies on lung cancer risk and to establish reasonable radiation protection regulations for human safety. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A New Approach to the Numerical Evaluation of the Inverse Radon Transform with Discrete, Noisy Data.

DTIC Science & Technology

1980-07-01

spline form. The resulting analytic expression for the inner integral in the inverse transform is then readily evaluated, and the outer (periodic...integral is replaced by a sum. The work involved to obtain the inverse transform appears to be within the capability of existing computing equipment for

High time-resolved radon progeny measurements in the Arctic region (Svalbard islands, Norway): results and potentialities

NASA Astrophysics Data System (ADS)

Salzano, Roberto; Pasini, Antonello; Ianniello, Antonietta; Mazzola, Mauro; Traversi, Rita; Udisti, Roberto

2018-05-01

The estimation of radon progeny in the Arctic region represents a scientific challenge due to the required low limit of detection in consideration of the limited radon emanation associated with permafrost dynamics. This preliminary study highlighted, for the first time above 70° N, the possibility to monitor radon progeny in the Arctic region with a higher time resolution. The composition of the radon progeny offered the opportunity to identify air masses dominated by long-range transport, in presence or absence of near-constant radon progeny instead of long- and short-lived progenies. Furthermore, the different ratio between radon and thoron progenies evidenced the contributions of local emissions and atmospheric stability. Two different emanation periods were defined in accordance with the permafrost dynamics at the ground and several accumulation windows were recognized coherently to the meteo-climatic conditions occurring at the study site.

Radon soil gas measurements in a geological versatile region as basis to improve the prediction of areas with a high radon potential.

PubMed

Kabrt, Franz; Seidel, Claudia; Baumgartner, Andreas; Friedmann, Harry; Rechberger, Fabian; Schuff, Michael; Maringer, Franz Josef

2014-07-01

With the aim to predict the radon potential by geological data, radon soil gas measurements were made in a selected region in Styria, Austria. This region is characterised by mean indoor radon potentials of 130-280 Bq m(-3) and a high geological diversity. The distribution of the individual measuring sites was selected on the basis of geological aspects and the distribution of area settlements. In this work, the radon soil gas activity concentration and the soil permeability were measured at 100 sites, each with three single measurements. Furthermore, the local dose rate was determined and soil samples were taken at each site to determine the activity concentration of natural radionuclides. During two investigation periods, long-term soil gas radon measurements were made to study the time dependency of the radon activity concentration. All the results will be compared and investigated for correlation among each other to improve the prediction of areas with high radon potential. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radon-induced reduced apoptosis in human bronchial epithelial cells with knock-down of mitochondria DNA

PubMed Central

Li, Bing-Yan; Sun, Jing; Wei, Hong; Cheng, Yu-Zhi; Xue, Lian; Cheng, Zhi-Hai; Wan, Jian-Mei; Wang, Ai-Qing; Hei, Tom K.; Tong, Jian

2012-01-01

Radon and radon progeny inhalation exposure are recognized to induce lung cancer. To explore the role of mitochondria in radon-induced carcinogenesis in humans, an in vitro partially depleted mitochondrial DNA (mtDNA) cell line (ρ−) was generated by treatment of human bronchial epithelial (HBE) cells (ρ+) with ethidium bromide (EB). The characterization of ρ− cells indicated the presence of dysfunctional mitochondria and might thus serve a reliable model to investigate the role of mitochondria. In a gas inhalation chamber, ρ− and ρ+ cells were exposed to radon gas produced by a radium source. Results showed that apoptosis was significantly increased both in ρ− and ρ+ cells irradiated by radon. Moreover, apoptosis in ρ− cells showed a lower level than in ρ+ cells. Radon was further found to depress mitochondrial membrane potential (MMP) of HBE cells with knock-down mtDNA. Production of reactive oxygen species (ROS) was markedly elevated both in ρ− and ρ+ cells exposed to radon. The distribution of phases of cell cycle was different in ρ− compared to ρ+ cells. Radon-irradiation induced a rise in G2/M and decrease in S phase in ρ+ cells. In ρ− cells, G1, G2/M and S populations remained similar to cells exposed to radon. In conclusion, radon-induced changes in ROS generation, MMP and cell cycle are all attributed to reduction of apoptosis which may trigger and promote cell transformation leading to carcinogenesis. Our study indicates that the use of the ρ− knock-down mtDNA HBE cells may serve as a reliable model to study the role played by mitochondria in carcinogenic diseases. PMID:22891884

Microaneurysm detection with radon transform-based classification on retina images.

PubMed

Giancardo, L; Meriaudeau, F; Karnowski, T P; Li, Y; Tobin, K W; Chaum, E

2011-01-01

The creation of an automatic diabetic retinopathy screening system using retina cameras is currently receiving considerable interest in the medical imaging community. The detection of microaneurysms is a key element in this effort. In this work, we propose a new microaneurysms segmentation technique based on a novel application of the radon transform, which is able to identify these lesions without any previous knowledge of the retina morphological features and with minimal image preprocessing. The algorithm has been evaluated on the Retinopathy Online Challenge public dataset, and its performance compares with the best current techniques. The performance is particularly good at low false positive ratios, which makes it an ideal candidate for diabetic retinopathy screening systems.

MuSCoWERT: multi-scale consistence of weighted edge Radon transform for horizon detection in maritime images.

PubMed

Prasad, Dilip K; Rajan, Deepu; Rachmawati, Lily; Rajabally, Eshan; Quek, Chai

2016-12-01

This paper addresses the problem of horizon detection, a fundamental process in numerous object detection algorithms, in a maritime environment. The maritime environment is characterized by the absence of fixed features, the presence of numerous linear features in dynamically changing objects and background and constantly varying illumination, rendering the typically simple problem of detecting the horizon a challenging one. We present a novel method called multi-scale consistence of weighted edge Radon transform, abbreviated as MuSCoWERT. It detects the long linear features consistent over multiple scales using multi-scale median filtering of the image followed by Radon transform on a weighted edge map and computing the histogram of the detected linear features. We show that MuSCoWERT has excellent performance, better than seven other contemporary methods, for 84 challenging maritime videos, containing over 33,000 frames, and captured using visible range and near-infrared range sensors mounted onboard, onshore, or on floating buoys. It has a median error of about 2 pixels (less than 0.2%) from the center of the actual horizon and a median angular error of less than 0.4 deg. We are also sharing a new challenging horizon detection dataset of 65 videos of visible, infrared cameras for onshore and onboard ship camera placement.

Isotropic-resolution linear-array-based photoacoustic computed tomography through inverse Radon transform

NASA Astrophysics Data System (ADS)

Li, Guo; Xia, Jun; Li, Lei; Wang, Lidai; Wang, Lihong V.

2015-03-01

Linear transducer arrays are readily available for ultrasonic detection in photoacoustic computed tomography. They offer low cost, hand-held convenience, and conventional ultrasonic imaging. However, the elevational resolution of linear transducer arrays, which is usually determined by the weak focus of the cylindrical acoustic lens, is about one order of magnitude worse than the in-plane axial and lateral spatial resolutions. Therefore, conventional linear scanning along the elevational direction cannot provide high-quality three-dimensional photoacoustic images due to the anisotropic spatial resolutions. Here we propose an innovative method to achieve isotropic resolutions for three-dimensional photoacoustic images through combined linear and rotational scanning. In each scan step, we first elevationally scan the linear transducer array, and then rotate the linear transducer array along its center in small steps, and scan again until 180 degrees have been covered. To reconstruct isotropic three-dimensional images from the multiple-directional scanning dataset, we use the standard inverse Radon transform originating from X-ray CT. We acquired a three-dimensional microsphere phantom image through the inverse Radon transform method and compared it with a single-elevational-scan three-dimensional image. The comparison shows that our method improves the elevational resolution by up to one order of magnitude, approaching the in-plane lateral-direction resolution. In vivo rat images were also acquired.

Tomography and the Herglotz-Wiechert inverse formulation

NASA Astrophysics Data System (ADS)

Nowack, Robert L.

1990-04-01

In this paper, linearized tomography and the Herglotz-Wiechert inverse formulation are compared. Tomographic inversions for 2-D or 3-D velocity structure use line integrals along rays and can be written in terms of Radon transforms. For radially concentric structures, Radon transforms are shown to reduce to Abel transforms. Therefore, for straight ray paths, the Abel transform of travel-time is a tomographic algorithm specialized to a one-dimensional radially concentric medium. The Herglotz-Wiechert formulation uses seismic travel-time data to invert for one-dimensional earth structure and is derived using exact ray trajectories by applying an Abel transform. This is of historical interest since it would imply that a specialized tomographic-like algorithm has been used in seismology since the early part of the century (see Herglotz, 1907; Wiechert, 1910). Numerical examples are performed comparing the Herglotz-Wiechert algorithm and linearized tomography along straight rays. Since the Herglotz-Wiechert algorithm is applicable under specific conditions, (the absence of low velocity zones) to non-straight ray paths, the association with tomography may prove to be useful in assessing the uniqueness of tomographic results generalized to curved ray geometries.

A Motion Detection Algorithm Using Local Phase Information

PubMed Central

Lazar, Aurel A.; Ukani, Nikul H.; Zhou, Yiyin

2016-01-01

Previous research demonstrated that global phase alone can be used to faithfully represent visual scenes. Here we provide a reconstruction algorithm by using only local phase information. We also demonstrate that local phase alone can be effectively used to detect local motion. The local phase-based motion detector is akin to models employed to detect motion in biological vision, for example, the Reichardt detector. The local phase-based motion detection algorithm introduced here consists of two building blocks. The first building block measures/evaluates the temporal change of the local phase. The temporal derivative of the local phase is shown to exhibit the structure of a second order Volterra kernel with two normalized inputs. We provide an efficient, FFT-based algorithm for implementing the change of the local phase. The second processing building block implements the detector; it compares the maximum of the Radon transform of the local phase derivative with a chosen threshold. We demonstrate examples of applying the local phase-based motion detection algorithm on several video sequences. We also show how the locally detected motion can be used for segmenting moving objects in video scenes and compare our local phase-based algorithm to segmentation achieved with a widely used optic flow algorithm. PMID:26880882

Iodine 125 source in interstitial tumor therapy. Clinical and biological considerations.

PubMed

Kim, J H; Hilaris, B

1975-01-01

Our clinical experience with interstitial tumor therapy is presented in 2 groups of patients: 98 patients with metastatic carcinoma in neck lymph nodes implanted with iodine 125, iridium 192 or radon 222 encapsulated sources, and 105 patients with primary unresectable lung tumors, which were implanted either with radon 222 or iodine 125 seeds. The local tumor control rates with iodine 125, radon 222 and iridium 192 were 78 per cent (38/49), 65 per cent (15/23) and 58 per cent (7/12), while the local complication rates were 17 per cent, 35 per cent and 43 per cent, respectively. An analysis of the tumor control rate as a function of the implanted tumor dose shows that the iodine 125 implants with a delivery of the minimal effective tumor dose of 16,000 rads have a higher therapeutic effect than either radon 222 or iridium 192. The results of the patients with unresectable lung tumors similarly show that the implants with iodine 125 sources are superior to those with radon 222. The advantages could stem from the better spatial dose distribution, and from radiobiologic considerations associated with low dose rates, continous irradiation, and possibly gains in RBE. There present clinical data clearly demonstrate that iodine 125 seeds have a higher therapeutic ratio than radon 222 seeds. There are, in addition, distinct physical advantages making iodine 125 an attractive substitute for radon 222 for the interstitial implantation of malignant tumors.

Room model based Monte Carlo simulation study of the relationship between the airborne dose rate and the surface-deposited radon progeny.

PubMed

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

2010-01-01

The quantitative relationships between radon gas concentration, the surface-deposited activities of various radon progeny, the airborne radon progeny dose rate, and various residential environmental factors were investigated through a Monte Carlo simulation study based on the extended Jacobi room model. Airborne dose rates were calculated from the unattached and attached potential alpha-energy concentrations (PAECs) using two dosimetric models. Surface-deposited (218)Po and (214)Po were significantly correlated with radon concentration, PAECs, and airborne dose rate (p-values <0.0001) in both non-smoking and smoking environments. However, in non-smoking environments, the deposited radon progeny were not highly correlated to the attached PAEC. In multiple linear regression analysis, natural logarithm transformation was performed for airborne dose rate as a dependent variable, as well as for radon and deposited (218)Po and (214)Po as predictors. In non-smoking environments, after adjusting for the effect of radon, deposited (214)Po was a significant positive predictor for one dose model (RR 1.46, 95% CI 1.27-1.67), while deposited (218)Po was a negative predictor for the other dose model (RR 0.90, 95% CI 0.83-0.98). In smoking environments, after adjusting for radon and room size, deposited (218)Po was a significant positive predictor for one dose model (RR 1.10, 95% CI 1.02-1.19), while a significant negative predictor for the other model (RR 0.90, 95% CI 0.85-0.95). After adjusting for radon and deposited (218)Po, significant increases of 1.14 (95% CI 1.03-1.27) and 1.13 (95% CI 1.05-1.22) in the mean dose rates were found for large room sizes relative to small room sizes in the different dose models.

Low pressure radon diffusion - A laboratory study and its implications for lunar venting

NASA Technical Reports Server (NTRS)

Friesen, L. J.; Adams, J. A. S.

1976-01-01

Results of a study of radon migration through columns of fine particulate materials, at total pressures of 0.02-0.2 torr, are reported. Materials studied were: NBS Glass Spheres (SRM 1003), Emerson & Cuming Eccospheres (IG-101), activated coconut charcoal, Lipaci obsidian, and W-1 Standard Diabase. Rates of diffusion were used to derive heats of adsorption for radon on the materials tested. The most reliable values found clustered around 8-9 kcal/mole. These high heats of adsorption, if typical for most materials, combined with low percentages of radon emanation by lunar soils found by other researchers, imply that random walk diffusion will not be an important mechanism for redistributing the radon and the radon daughters produced in the lunar regolith. In particular, since random walk migration is not a sufficient mechanism to account for localized high concentrations of radon-222 and its daughter polonium-210 observed by the Apollo 15 and 16 command modules, an alternative mechanism is proposed, in which radon would be swept to the surface by other gases during intermittent venting events.

3-D discrete analytical ridgelet transform.

PubMed

Helbert, David; Carré, Philippe; Andres, Eric

2006-12-01

In this paper, we propose an implementation of the 3-D Ridgelet transform: the 3-D discrete analytical Ridgelet transform (3-D DART). This transform uses the Fourier strategy for the computation of the associated 3-D discrete Radon transform. The innovative step is the definition of a discrete 3-D transform with the discrete analytical geometry theory by the construction of 3-D discrete analytical lines in the Fourier domain. We propose two types of 3-D discrete lines: 3-D discrete radial lines going through the origin defined from their orthogonal projections and 3-D planes covered with 2-D discrete line segments. These discrete analytical lines have a parameter called arithmetical thickness, allowing us to define a 3-D DART adapted to a specific application. Indeed, the 3-D DART representation is not orthogonal, It is associated with a flexible redundancy factor. The 3-D DART has a very simple forward/inverse algorithm that provides an exact reconstruction without any iterative method. In order to illustrate the potentiality of this new discrete transform, we apply the 3-D DART and its extension to the Local-DART (with smooth windowing) to the denoising of 3-D image and color video. These experimental results show that the simple thresholding of the 3-D DART coefficients is efficient.

40 CFR 35.708 - Award limitations.

Code of Federal Regulations, 2010 CFR

2010-07-01

....708 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants for Tribes Indoor Radon Grants (section 306...)(iv)) and demonstration of radon mitigation, methods, and technologies (see § 35.820(b)(1)(ix)) shall...

Spanish experience on the design of radon surveys based on the use of geogenic information.

PubMed

Sainz Fernández, C; Quindós Poncela, L S; Fernández Villar, A; Fuente Merino, I; Gutierrez-Villanueva, J L; Celaya González, S; Quindós López, L; Quindós López, J; Fernández, E; Remondo Tejerina, J; Martín Matarranz, J L; García Talavera, M

2017-01-01

One of the requirements of the recently approved EU-BSS (European Basic Safety Standards Directive, EURATOM, 2013) is the design and implementation of national radon action plans in the member states (Annex XVIII). Such plans require radon surveys. The analysis of indoor radon data is supported by the existing knowledge about geogenic radiation. With this aim, we used the terrestrial gamma dose rate data from the MARNA project. In addition, we considered other criterion regarding the surface of Spain, population, permeability of rocks, uranium and radium contain in soils because currently no data are available related to soil radon gas concentration and permeability in Spain. Given that, a Spanish radon map was produced which will be part of the European Indoor Radon Map and a component of the European Atlas of Natural Radiation. The map indicates geographical areas with high probability of finding high indoor radon concentrations. This information will support legislation regarding prevention of radon entry both in dwellings and workplaces. In addition, the map will serve as a tool for the development of strategies at all levels: individual dwellings, local, regional and national administration. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effectiveness of radon preventive and remedial measures in Irish homes.

PubMed

Long, S; Fenton, D; Cremin, M; Morgan, A

2013-03-01

It is estimated that approximately 100 000 Irish homes have radon concentrations above the reference level of 200 Bq m(-3). To minimise the number of new homes with this problem, building regulations require that all new homes built since July 1998 in high radon areas are installed with radon barriers during construction. Measurements on local authority homes in a number of high radon areas have allowed the impact of these new regulations to be assessed. In County Cork a reduction of up to 70% in the mean radon concentration was observed in homes built since 1998 relative to those built before this date. A reduction in both the number of homes exceeding the reference level and the maximum concentration measured in homes was also measured. Homes exceeding the reference level were remediated with the use of an active sump. The results of this remedial work are also presented and show that the mean reduction in radon concentration achieved was 92%.

Discrete Radon transform has an exact, fast inverse and generalizes to operations other than sums along lines

PubMed Central

Press, William H.

2006-01-01

Götz, Druckmüller, and, independently, Brady have defined a discrete Radon transform (DRT) that sums an image's pixel values along a set of aptly chosen discrete lines, complete in slope and intercept. The transform is fast, O(N2log N) for an N × N image; it uses only addition, not multiplication or interpolation, and it admits a fast, exact algorithm for the adjoint operation, namely backprojection. This paper shows that the transform additionally has a fast, exact (although iterative) inverse. The inverse reproduces to machine accuracy the pixel-by-pixel values of the original image from its DRT, without artifacts or a finite point-spread function. Fourier or fast Fourier transform methods are not used. The inverse can also be calculated from sampled sinograms and is well conditioned in the presence of noise. Also introduced are generalizations of the DRT that combine pixel values along lines by operations other than addition. For example, there is a fast transform that calculates median values along all discrete lines and is able to detect linear features at low signal-to-noise ratios in the presence of pointlike clutter features of arbitrarily large amplitude. PMID:17159155

Discrete Radon transform has an exact, fast inverse and generalizes to operations other than sums along lines.

PubMed

Press, William H

2006-12-19

Götz, Druckmüller, and, independently, Brady have defined a discrete Radon transform (DRT) that sums an image's pixel values along a set of aptly chosen discrete lines, complete in slope and intercept. The transform is fast, O(N2log N) for an N x N image; it uses only addition, not multiplication or interpolation, and it admits a fast, exact algorithm for the adjoint operation, namely backprojection. This paper shows that the transform additionally has a fast, exact (although iterative) inverse. The inverse reproduces to machine accuracy the pixel-by-pixel values of the original image from its DRT, without artifacts or a finite point-spread function. Fourier or fast Fourier transform methods are not used. The inverse can also be calculated from sampled sinograms and is well conditioned in the presence of noise. Also introduced are generalizations of the DRT that combine pixel values along lines by operations other than addition. For example, there is a fast transform that calculates median values along all discrete lines and is able to detect linear features at low signal-to-noise ratios in the presence of pointlike clutter features of arbitrarily large amplitude.

Future initiatives to reduce lung cancer incidence in the United Kingdom: smoking cessation, radon remediation and the impact of social change.

PubMed

Denman, Antony R; Rogers, Stephen; Timson, Karen; Phillips, Paul S; Crockett, Robin Gm; Groves-Kirkby, Christopher J

2015-03-01

Smoking and radon cause lung cancer, with smoking being the more significant risk factor. Although programmes to identify UK houses with raised radon levels and to encourage remedial action started in 1990, uptake has been limited and those most at risk, smokers and young families, are not being reached. The risks from smoking and radon are multiplicative. Public health campaigns have reduced smoking prevalence significantly. Since most radon-induced lung cancers occur in smokers, reducing the number of smokers will reduce the number of radon-induced lung cancers. This article considers the impact of reducing smoking prevalence on the effectiveness of radon remediation programmes, combining this with demographic trends and regional variations to assess implications for future public health. Results on cost-effectiveness of smoking cessation and radon remediation programmes were combined with government figures for smoking prevalence to estimate the number of cancers averted and the cost-effectiveness of such programmes, taking into account demographic changes, including increasing life expectancy. Regional variations in smoking prevalence and smoking cessation programmes were reviewed, comparing these to the geographic variation of radon. The continuing impact of smoking cessation programmes in reducing smoking prevalence will reduce the number of radon-induced lung cancers, but with a lag. Smoking cessation programmes are more cost-effective than radon remediation programmes, presenting an additional opportunity to reduce radon risk to smokers. Regional data show no correlation between smoking prevalence and radon levels. Reduced smoking prevalence reduces the effectiveness of radon remediation programmes. This, coupled with limited uptake of radon remediation, suggests that radon remediation programmes should be targeted, and that an integrated public health policy for smoking and radon is appropriate. Lack of correlation between smoking prevalence and radon suggests that local assessment of relative priorities for public health strategies, such as the 'Total Place' initiative, is appropriate. © Royal Society for Public Health 2014.

Hyperfunction solutions of the zero rest mass equations and representations of LIE groups

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunne, E.G.

1984-01-01

Recently, hyperfunctions have arisen in an essential way in separate results in mathematical physics and in representation theory. In the setting of the twistor program, Wells, with others, has extended the Penrose transform to hyperfunction solutions of the zero rest mass equations, showing that the fundamental isomorphisms hold for this larger space. Meanwhile, Schmid has shown the existence of a canonical globalization of a Harish-Chandra module, V, to a representation of the group. This maximal globalization may be realized as the completion of V in a locally convex vector space in the hyperfunction topology. This thesis shows that the formermore » is a particular case of the latter where the globalization can be done by hand. This explicit globalization is then carried out for a more general case of the Radon transform on homogeneous spaces.« less

Radon Testing: Community Engagement By a Rural Family Medicine Office.

PubMed

Levy, Barcey T; Wolff, Cynthia K; Niles, Paul; Morehead, Heather; Xu, Yinghui; Daly, Jeanette M

2015-01-01

Iowa has the highest average radon concentrations in the nation, with an estimated 400 radon-induced lung cancer deaths each year. Radon is the second leading cause of lung cancer death overall. The objectives of this study were (1) to educate the population attending a family medicine office about the dangers of radon, (2) to encourage homeowners to test for radon, (3) to work with the community to identify resources for mitigation, and (4) to assess the utility of working with a local family medicine office as a model that could be adopted for other communities with high home radon concentrations. Participants obtained a US Environmental Protection Agency-certified activated charcoal short-term radon kit through their primary care office or by attending a seminar held by their medical office. Participants completed a short investigator-developed questionnaire about their home, heating, and demographics. Of 746 radon kits handed out, 378 valid results (51%) were received, of which 351 questionnaires could be matched to the kit results. The mean radon result was 10.0 pCi/L (standard deviation, 8.5 pCi/L). A radon result of 4 pCi/L or higher, the Environmental Protection Agency action level for mitigation, was found in 81% of homes (n = 285). Four of 5 homes tested had elevated radon levels. This family medicine office/university collaborative educational model could be useful for educating patients about other environmental dangers. © Copyright 2015 by the American Board of Family Medicine.

Direct integration of the inverse Radon equation for X-ray computed tomography.

PubMed

Libin, E E; Chakhlov, S V; Trinca, D

2016-11-22

A new mathematical appoach using the inverse Radon equation for restoration of images in problems of linear two-dimensional x-ray tomography is formulated. In this approach, Fourier transformation is not used, and it gives the chance to create the practical computing algorithms having more reliable mathematical substantiation. Results of software implementation show that for especially for low number of projections, the described approach performs better than standard X-ray tomographic reconstruction algorithms.

40 CFR 35.298 - Award limitations.

Code of Federal Regulations, 2010 CFR

2010-07-01

....298 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants State Indoor Radon Grants (section 306) § 35.298... measurement equipment or devices (see § 35.290(b)(1)(iv)) and demonstration of radon mitigation, methods, and...

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

PubMed Central

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

2016-01-01

Because 222Rn is a progeny of 238U, the relative abundance of uranium may be used to predict the areas that have the potential for high indoor radon concentration and therefore determine the best areas to conduct future surveys. Geographic Information System (GIS) mapping software was used to construct maps of South Dakota that included levels of uranium concentrations in soil and stream water and uranium deposits. Maps of existing populations and the types of land were also generated. Existing data about average indoor radon levels by county taken from a databank were included for consideration. Although the soil and stream data and existing recorded average indoor radon levels were sparse, it was determined that the most likely locations of elevated indoor radon would be in the northwest and southwest corners of the state. Indoor radon levels were only available for 9 out of 66 counties in South Dakota. This sparcity of data precluded a study of correlation of radon to geological features, but further motivates the need for more testing in the state. Only actual measurements should be used to determine levels of indoor radon because of the strong roles home construction and localized geology play in radon concentration. However, the data visualization method demonstrated here is potentially useful for directing resources relating to radon screening campaigns. PMID:26472478

In-soil radon anomalies as precursors of earthquakes: a case study in the SE slope of Mt. Etna in a period of quite stable weather conditions.

PubMed

Vizzini, Fabio; Brai, Maria

2012-11-01

In-soil radon concentrations as well as climatic parameters (temperature, atmospheric pressure and relative humidity) were collected in St. Venerina (Eastern Sicily - Italy) from March 19th to May 22nd 2009, close to an active fault system called Timpe Fault System (TFS), which is strictly linked to the geodynamics of Mt. Etna. During the monitoring period no drastic climatic variations were observed and, on the other hand, important seismic events were recorded close to the monitoring site. A seismic swarm composed of 5 earthquakes was observed in the Milo area on March 25th (M(max) = 2.7) at just 5.1 km from the site, and on May 13th an earthquake of 3.6 magnitude was recorded in the territory of St. Venerina, at just 3.2 km from the site; the earthquake was felt by the population and reported by all local and regional media. The in-soil radon concentrations have shown anomalous increases possibly linked to the earthquakes recorded, but certainly not attributable to local meteorology. To verify this assumption the average radon concentration and the standard deviation (σ) have been calculated and the regions of ±1.5σ and ±2σ deviation from the average concentration have been investigated. Moreover, to further minimise the contribution of the meteorological parameters on the in-soil radon fluctuations, a multiple regressions method has been used. To distinguish those earthquakes which could generate in-soil radon anomalies as precursors, the Dobrovolsky radius has been applied. The results obtained suggests that a clear correlation between earthquakes and in-soil radon increases exist, and that the detection of the in-soil radon anomalies becomes surely simpler in particular favourable conditions: weather stability, earthquakes within the Dobrovolsky radius and close to the monitoring area. Moreover, the absence of large variations of the climatic parameters, which could generate incoherent noise components to the radon signal, has made the radon fluctuations more evident and so more legible. Copyright © 2012 Elsevier Ltd. All rights reserved.

White sand potentially suppresses radon emission from uranium tailings

NASA Astrophysics Data System (ADS)

Abdel Ghany, H. A.; El Aassy, Ibrahim E.; Ibrahim, Eman M.; Gamil, S. H.

2018-03-01

Uranium tailings represent a huge radioactive waste contaminant, where radon emanation is considered a major health hazard. Many trials have been conducted to minimize radon exhalation rate by using different covering materials. In the present work, three covering materials, commonly available in the local environment, (kaolin, white sand and bentonite) have been used with different thickness 10, 15, and 20 mm). 238U, 232Th, 40K and the radon exhalation rate were measured by using gamma spectrometry with a Hyper Pure Germanium (HPGe) detector and solid state nuclear track detectors (CR-39). Radon exhalation rate, calculated before and after covering, ranged from 2.80 ± 0.14 to 4.20 ± 0.21 Bq m-2 h-1, and from 0.30 ± 0.01 to 4.00 ± 0.20 Bq m-2 h-1, respectively. Also, the attenuation coefficients of different covering materials and radon emanation were calculated. The obtained results demonstrate that covering of uranium tailings by kaolin, white sand and bentonite has potentially minimized both the radon exhalation rate and the corresponding internal doses.

Radon exhalation rate and natural radionuclide content in building materials of high background areas of Ramsar, Iran.

PubMed

Bavarnegin, E; Fathabadi, N; Vahabi Moghaddam, M; Vasheghani Farahani, M; Moradi, M; Babakhni, A

2013-03-01

Radon exhalation rates from building materials used in high background radiation areas (HBRA) of Ramsar were measured using an active radon gas analyzer with an emanation container. Radon exhalation rates from these samples varied from below the lower detection limit up to 384 Bq.m(-2) h(-1). The (226)Ra, (232)Th and (40)K contents were also measured using a high resolution HPGe gamma- ray spectrometer system. The activity concentration of (226)Ra, (232)Th and (40)K content varied from below the minimum detection limit up to 86,400 Bq kg(-1), 187 Bq kg(-1) and 1350 Bq kg(-1), respectively. The linear correlation coefficient between radon exhalation rate and radium concentration was 0.90. The result of this survey shows that radon exhalation rate and radium content in some local stones used as basements are extremely high and these samples are main sources of indoor radon emanation as well as external gamma radiation from uranium series. Copyright © 2012 Elsevier Ltd. All rights reserved.

CT reconstruction from portal images acquired during volumetric-modulated arc therapy

NASA Astrophysics Data System (ADS)

Poludniowski, G.; Thomas, M. D. R.; Evans, P. M.; Webb, S.

2010-10-01

Volumetric-modulated arc therapy (VMAT), a form of intensity-modulated arc therapy (IMAT), has become a topic of research and clinical activity in recent years. As a form of arc therapy, portal images acquired during the treatment fraction form a (partial) Radon transform of the patient. We show that these portal images, when used in a modified global cone-beam filtered backprojection (FBP) algorithm, allow a surprisingly recognizable CT-volume to be reconstructed. The possibility of distinguishing anatomy in such VMAT-CT reconstructions suggests that this could prove to be a valuable treatment position-verification tool. Further, some potential for local-tomography techniques to improve image quality is shown.

Linear Transforms for Fourier Data on the Sphere: Application to High Angular Resolution Diffusion MRI of the Brain

PubMed Central

Haldar, Justin P.; Leahy, Richard M.

2013-01-01

This paper presents a novel family of linear transforms that can be applied to data collected from the surface of a 2-sphere in three-dimensional Fourier space. This family of transforms generalizes the previously-proposed Funk-Radon Transform (FRT), which was originally developed for estimating the orientations of white matter fibers in the central nervous system from diffusion magnetic resonance imaging data. The new family of transforms is characterized theoretically, and efficient numerical implementations of the transforms are presented for the case when the measured data is represented in a basis of spherical harmonics. After these general discussions, attention is focused on a particular new transform from this family that we name the Funk-Radon and Cosine Transform (FRACT). Based on theoretical arguments, it is expected that FRACT-based analysis should yield significantly better orientation information (e.g., improved accuracy and higher angular resolution) than FRT-based analysis, while maintaining the strong characterizability and computational efficiency of the FRT. Simulations are used to confirm these theoretical characteristics, and the practical significance of the proposed approach is illustrated with real diffusion weighted MRI brain data. These experiments demonstrate that, in addition to having strong theoretical characteristics, the proposed approach can outperform existing state-of-the-art orientation estimation methods with respect to measures such as angular resolution and robustness to noise and modeling errors. PMID:23353603

Discrimination of malignant lymphomas and leukemia using Radon transform based-higher order spectra

NASA Astrophysics Data System (ADS)

Luo, Yi; Celenk, Mehmet; Bejai, Prashanth

2006-03-01

A new algorithm that can be used to automatically recognize and classify malignant lymphomas and leukemia is proposed in this paper. The algorithm utilizes the morphological watersheds to obtain boundaries of cells from cell images and isolate them from the surrounding background. The areas of cells are extracted from cell images after background subtraction. The Radon transform and higher-order spectra (HOS) analysis are utilized as an image processing tool to generate class feature vectors of different type cells and to extract testing cells' feature vectors. The testing cells' feature vectors are then compared with the known class feature vectors for a possible match by computing the Euclidean distances. The cell in question is classified as belonging to one of the existing cell classes in the least Euclidean distance sense.

3D Compton scattering imaging and contour reconstruction for a class of Radon transforms

NASA Astrophysics Data System (ADS)

Rigaud, Gaël; Hahn, Bernadette N.

2018-07-01

Compton scattering imaging is a nascent concept arising from the current development of high-sensitive energy detectors and is devoted to exploit the scattering radiation to image the electron density of the studied medium. Such detectors are able to collect incoming photons in terms of energy. This paper introduces potential 3D modalities in Compton scattering imaging (CSI). The associated measured data are modeled using a class of generalized Radon transforms. The study of this class of operators leads to build a filtered back-projection kind algorithm preserving the contours of the sought-for function and offering a fast approach to partially solve the associated inverse problems. Simulation results including Poisson noise demonstrate the potential of this new imaging concept as well as the proposed image reconstruction approach.

Electromagnetic holographic sensitivity field of two-phase flow in horizontal wells

NASA Astrophysics Data System (ADS)

Zhang, Kuo; Wu, Xi-Ling; Yan, Jing-Fu; Cai, Jia-Tie

2017-03-01

Electromagnetic holographic data are characterized by two modes, suggesting that image reconstruction requires a dual-mode sensitivity field as well. We analyze an electromagnetic holographic field based on tomography theory and Radon inverse transform to derive the expression of the electromagnetic holographic sensitivity field (EMHSF). Then, we apply the EMHSF calculated by using finite-element methods to flow simulations and holographic imaging. The results suggest that the EMHSF based on the partial derivative of radius of the complex electric potential φ is closely linked to the Radon inverse transform and encompasses the sensitivities of the amplitude and phase data. The flow images obtained with inversion using EMHSF better agree with the actual flow patterns. The EMHSF overcomes the limitations of traditional single-mode sensitivity fields.

Predictors of Indoor Radon Concentrations in Pennsylvania, 1989-2013.

PubMed

Casey, Joan A; Ogburn, Elizabeth L; Rasmussen, Sara G; Irving, Jennifer K; Pollak, Jonathan; Locke, Paul A; Schwartz, Brian S

2015-11-01

Radon is the second-leading cause of lung cancer worldwide. Most indoor exposure occurs by diffusion of soil gas. Radon is also found in well water, natural gas, and ambient air. Pennsylvania has high indoor radon concentrations; buildings are often tested during real estate transactions, with results reported to the Department of Environmental Protection (PADEP). We evaluated predictors of indoor radon concentrations. Using first-floor and basement indoor radon results reported to the PADEP between 1987 and 2013, we evaluated associations of radon concentrations (natural log transformed) with geology, water source, building characteristics, season, weather, community socioeconomic status, community type, and unconventional natural gas development measures based on drilled and producing wells. Primary analysis included 866,735 first measurements by building, with the large majority from homes. The geologic rock layer on which the building sat was strongly associated with radon concentration (e.g., Axemann Formation, median = 365 Bq/m3, IQR = 167-679 vs. Stockton Formation, median = 93 Bq/m3, IQR = 52-178). In adjusted analysis, buildings using well water had 21% higher concentrations (β = 0.191, 95% CI: 0.184, 0.198). Buildings in cities (vs. townships) had lower concentrations (β = -0.323, 95% CI: -0.333, -0.314). When we included multiple tests per building, concentrations declined with repeated measurements over time. Between 2005 and 2013, 7,469 unconventional wells were drilled in Pennsylvania. Basement radon concentrations fluctuated between 1987 and 2003, but began an upward trend from 2004 to 2012 in all county categories (p < 0.001), with higher levels in counties having ≥ 100 drilled wells versus counties with none, and with highest levels in the Reading Prong. Geologic unit, well water, community, weather, and unconventional natural gas development were associated with indoor radon concentrations. Future studies should include direct environmental measurement of radon, as well as building features unavailable for this analysis. Casey JA, Ogburn EL, Rasmussen SG, Irving JK, Pollak J, Locke PA, Schwartz BS. 2015. Predictors of indoor radon concentrations in Pennsylvania, 1989-2013. Environ Health Perspect 123:1130-1137; http://dx.doi.org/10.1289/ehp.1409014.

Predictors of Indoor Radon Concentrations in Pennsylvania, 1989–2013

PubMed Central

Casey, Joan A.; Ogburn, Elizabeth L.; Rasmussen, Sara G.; Irving, Jennifer K.; Pollak, Jonathan; Locke, Paul A.

2015-01-01

Background Radon is the second-leading cause of lung cancer worldwide. Most indoor exposure occurs by diffusion of soil gas. Radon is also found in well water, natural gas, and ambient air. Pennsylvania has high indoor radon concentrations; buildings are often tested during real estate transactions, with results reported to the Department of Environmental Protection (PADEP). Objectives We evaluated predictors of indoor radon concentrations. Methods Using first-floor and basement indoor radon results reported to the PADEP between 1987 and 2013, we evaluated associations of radon concentrations (natural log transformed) with geology, water source, building characteristics, season, weather, community socioeconomic status, community type, and unconventional natural gas development measures based on drilled and producing wells. Results Primary analysis included 866,735 first measurements by building, with the large majority from homes. The geologic rock layer on which the building sat was strongly associated with radon concentration (e.g., Axemann Formation, median = 365 Bq/m3, IQR = 167–679 vs. Stockton Formation, median = 93 Bq/m3, IQR = 52–178). In adjusted analysis, buildings using well water had 21% higher concentrations (β = 0.191, 95% CI: 0.184, 0.198). Buildings in cities (vs. townships) had lower concentrations (β = –0.323, 95% CI: –0.333, –0.314). When we included multiple tests per building, concentrations declined with repeated measurements over time. Between 2005 and 2013, 7,469 unconventional wells were drilled in Pennsylvania. Basement radon concentrations fluctuated between 1987 and 2003, but began an upward trend from 2004 to 2012 in all county categories (p < 0.001), with higher levels in counties having ≥ 100 drilled wells versus counties with none, and with highest levels in the Reading Prong. Conclusions Geologic unit, well water, community, weather, and unconventional natural gas development were associated with indoor radon concentrations. Future studies should include direct environmental measurement of radon, as well as building features unavailable for this analysis. Citation Casey JA, Ogburn EL, Rasmussen SG, Irving JK, Pollak J, Locke PA, Schwartz BS. 2015. Predictors of indoor radon concentrations in Pennsylvania, 1989–2013. Environ Health Perspect 123:1130–1137; http://dx.doi.org/10.1289/ehp.1409014 PMID:25856050

The newest international trend about regulation of indoor radon.

PubMed

Bochicchio, Francesco

2011-07-01

On the basis of recent epidemiological findings, many international and national organisations have revised their recommendations and regulations on radon exposure in dwellings and workplaces, or are in the process to do it. In particular, new recommendations and regulations were recently published (or are going to be) by World Health Organization, Nordic Countries, International Commission on Radiological Protection, International, Atomic Energy Agency (and the other international organisations sponsoring the International Basic Safety Standards), European Commission. Although with some differences, these new documents recommend lower radon concentrations in indoor air, especially in dwellings, compared with previous ones. Moreover, preventive measures in all new buildings are more and more considered as one of the most cost-effective way to reduce the radon-related lung cancers, compared with previous approach restricting preventive measures in radon-prone areas only. A comprehensive national action plan, involving several national and local authorities, is generally considered a necessary tool to deal with the many complex actions needed to reduce the risk from radon exposure in an effective way.

Finite-mode analysis by means of intensity information in fractional optical systems.

PubMed

Alieva, Tatiana; Bastiaans, Martin J

2002-03-01

It is shown how a coherent optical signal that contains only a finite number of Hermite-Gauss modes can be reconstructed from the knowledge of its Radon-Wigner transform-associated with the intensity distribution in a fractional-Fourier-transform optical system-at only two transversal points. The proposed method can be generalized to any fractional system whose generator transform has a complete orthogonal set of eigenfunctions.

Determination of vessel cross-sectional area by thresholding in Radon space

PubMed Central

Gao, Yu-Rong; Drew, Patrick J

2014-01-01

The cross-sectional area of a blood vessel determines its resistance, and thus is a regulator of local blood flow. However, the cross-sections of penetrating vessels in the cortex can be non-circular, and dilation and constriction can change the shape of the vessels. We show that observed vessel shape changes can introduce large errors in flux calculations when using a single diameter measurement. Because of these shape changes, typical diameter measurement approaches, such as the full-width at half-maximum (FWHM) that depend on a single diameter axis will generate erroneous results, especially when calculating flux. Here, we present an automated method—thresholding in Radon space (TiRS)—for determining the cross-sectional area of a convex object, such as a penetrating vessel observed with two-photon laser scanning microscopy (2PLSM). The thresholded image is transformed back to image space and contiguous pixels are segmented. The TiRS method is analogous to taking the FWHM across multiple axes and is more robust to noise and shape changes than FWHM and thresholding methods. We demonstrate the superior precision of the TiRS method with in vivo 2PLSM measurements of vessel diameter. PMID:24736890

Rayleigh-wave dispersive energy imaging using a high-resolution linear radon transform

USGS Publications Warehouse

Luo, Y.; Xia, J.; Miller, R.D.; Xu, Y.; Liu, J.; Liu, Q.

2008-01-01

Multichannel Analysis of Surface Waves (MASW) analysis is an efficient tool to obtain the vertical shear-wave profile. One of the key steps in the MASW method is to generate an image of dispersive energy in the frequency-velocity domain, so dispersion curves can be determined by picking peaks of dispersion energy. In this paper, we propose to image Rayleigh-wave dispersive energy by high-resolution linear Radon transform (LRT). The shot gather is first transformed along the time direction to the frequency domain and then the Rayleigh-wave dispersive energy can be imaged by high-resolution LRT using a weighted preconditioned conjugate gradient algorithm. Synthetic data with a set of linear events are presented to show the process of generating dispersive energy. Results of synthetic and real-world examples demonstrate that, compared with the slant stacking algorithm, high-resolution LRT can improve the resolution of images of dispersion energy by more than 50%. ?? Birkhaueser 2008.

Application of the Radon-FCL approach to seismic random noise suppression and signal preservation

NASA Astrophysics Data System (ADS)

Meng, Fanlei; Li, Yue; Liu, Yanping; Tian, Yanan; Wu, Ning

2016-08-01

The fractal conservation law (FCL) is a linear partial differential equation that is modified by an anti-diffusive term of lower order. The analysis indicated that this algorithm could eliminate high frequencies and preserve or amplify low/medium-frequencies. Thus, this method is quite suitable for the simultaneous noise suppression and enhancement or preservation of seismic signals. However, the conventional FCL filters seismic data only along the time direction, thereby ignoring the spatial coherence between neighbouring traces, which leads to the loss of directional information. Therefore, we consider the development of the conventional FCL into the time-space domain and propose a Radon-FCL approach. We applied a Radon transform to implement the FCL method in this article; performing FCL filtering in the Radon domain achieves a higher level of noise attenuation. Using this method, seismic reflection events can be recovered with the sacrifice of fewer frequency components while effectively attenuating more random noise than conventional FCL filtering. Experiments using both synthetic and common shot point data demonstrate the advantages of the Radon-FCL approach versus the conventional FCL method with regard to both random noise attenuation and seismic signal preservation.

Indoor radon concentration in Korea residential environments.

PubMed

Park, Tae Hyun; Kang, Dae Ryong; Park, Si Hyun; Yoon, Dan Ki; Lee, Cheol Min

2018-05-01

The purpose of this study is to provide basic data for the evaluation and management of health effects with respect to exposure to radon within residential environments in South Korea. It is part of a case-control study to develop a management plan based on indoor radon exposure levels and assess their impact on health. To investigate the long-term cumulative concentration levels of radon, 599 patients who have respiratory diseases were recruited in South Korea, and alpha track detectors were installed in their residences for a period of 3 months from mid-2015 to late 2016. A survey was then conducted to determine the factors affecting the radon concentration. The radon concentration levels were analyzed in conjunction with the survey results. The results show that the arithmetic mean of the radon concentrations in domestic residences was in the range of 70.8 ± 65.2 Bq/m 3 . An analysis of covariance (ANCOVA) was performed to identify the environmental factors affecting the radon concentration and contributing to variations in the residential radon concentration based on the height of the residence. The results show that the contribution of the local environmental factor to the variation in radon concentration (p < 0.05) was greater than that of other environmental factors. Although no statistically significant difference was found with regard to the construction year of the building before the control (p > 0.05), the same was found with regard to the construction year after the control (p < 0.05).

A motion artefact study and locally deforming objects in computerized tomography

NASA Astrophysics Data System (ADS)

Hahn, Bernadette N.

2017-11-01

Movements of the object during the data collection in computerized tomography can introduce motion artefacts in the reconstructed image. They can be reduced by employing information about the dynamic behaviour within the reconstruction step. However, inaccuracies concerning the movement are inevitable in practice. In this article, we give an explicit characterization of what is visible in an image obtained by a reconstruction algorithm with incorrect motion information. Then, we use this result to study in detail the situation of locally deforming objects, i.e. individual parts of the object have a different dynamic behaviour. In this context, we prove that additional artefacts arise due to the global nature of the Radon transform, even if the motion is exactly known. Based on our analysis, we propose a numerical scheme to reduce these artefacts in the reconstructed image. All our results are illustrated by numerical examples.

Very Low Frequency Seismo-Acoustic Noise Below the Sea Floor (0.2-10 Hz).

DTIC Science & Technology

1994-02-01

applications see Stoffa et al., 1981 and Kappus et al., 1990). Fricke (1991, 1993) outlines a method for calculating the Radon transform on "ser...of Ocean Eng., OE-6, 50-58, 1981. Kappus , M. E. , A. J. Harding, and J. A. Orcutt, A comparison of tau-p transforms methods, Geophysics, 55, 1202

Spatio-temporal variations of soil radon patterns around the Sea of Marmara

NASA Astrophysics Data System (ADS)

Passarelli, Luigi; Seyis, Cemil; Woith, Heiko

2016-04-01

Typically, the noble gas radon displays cyclic daily (S1), semidiurnal (S2) as well as seasonal variations in geological environments like soil air, groundwater, rock, caves, and tunnels. But there are also cases where theses cycles are absent. We present examples from a radon monitoring network of 21 sites around the Sea of Marmara. The works were carried out in the frame of MARsite, a project related to the EU supersite initiative (MARsite has received funding from the European Union's Seventh Programme for research, technological development and demonstration under grant agreement No 308417). Alpha-meters from the Canadian company alpha-nuclear are used to measure the radon concentration in counts per 15 minutes at a depth of 80 cm. The long-term average radon concentrations at 21 sites vary between 35 and 1,000 counts per 15 minutes. Typical seasonal variations are absent at more than 6 sites. Sites with seasonal variations have radon minima usually during winter (December to April), radon maxima during summer months (June to October). We carefully investigated radon time series for all the monitoring stations. We find that at some sites the empirical distribution of radon counts is clearly bimodal and in other bimodality is absent. In those stations we analysed the time series in different time intervals in order to highlight seasonal periodicity in the radon emission. The empirical distributions obtained by time-windowing of the radon signals results to be statistically different one another after applying a Kolmogorov-Smirnov test at significance level of 0.1. Usually the maxima in radon emission occur in summer time but, interestingly enough, two sites are characterized by radon maxima in winter periods. We further investigate the radon signals seeking for smaller scale periodicity. We calculated Fourier spectra of all 21 sites. Daily cycles are absent at 6 sites which is an unusual phenomenon. Daily cycles may disappear, if the local system is heavily disturbed, e.g. by fluid extraction from geothermal systems or during earthquakes.

United role of radon decay products and nano-aerosols in radon dosimetry

NASA Astrophysics Data System (ADS)

Smerajec, M.; Vaupotič, J.

2012-04-01

The major part of human exposure to natural radiation originates from inhalation of radon (Rn) and radon short-lived decay products (RnDP: 218Po, 214Pb, 214Bi and 214Po). RnDP are formed as a result of α-transformation of radon. In the beginning they are positive ions which neutralize and form clusters with air molecules, and later partly attach to background aerosol particles in indoor air. Eventually, they appear as radioactive nano-aerosols with a bimodal size distribution in ranges of 1-10 nm (unattached RnDP) and of 200-800 nm (attached RnDP). When inhaled, they are deposited in the respiratory tract. Deposition is more efficient for smaller particles. Therefore, the fraction (fun) of the unattached RnDP, which appears to be influenced by the number concentration and size distribution of general (background) aerosols in the ambient air, has a crucial role in radon dosimetry. Radon, radon decay products and general aerosols have been monitored simultaneously in the kitchen of a typical rural house under real living conditions, also comprising four human activities generating particular matter: cooking and baking, as two typical activities in kitchen, and cigarette smoking and candle burning. In periods without any human activity, the total number concentration of general aerosol ranged from 1000 to 3000 cm-3,with the geometric mean of particle diameter in the range of 60-68 nm and with 0.1-1 % of particles smaller than 10 nm. Preparation of coffee changed the concentration to 193,000 cm-3, the geometric mean of diameter to 20 nm and fraction of particles smaller than 10 nm to 11 %. The respective changes were for baking cake: 503,000 cm-3, 17 nm and 19 %, for smoking:423,000 cm-3, 83 nm and 0.4 %, and forcandle burning: 945,000 cm-3, 8 nm and 85 %. While, as expected, a reduction of fun was observed during cooking, baking and smoking, when larger particles were emitted, fun did not increase during candle burning with mostly particles smaller than 10 nm produced. Because the processes of RnDP creation by radioactive transformation, their neutralization, clustering and association with aerosol particles need time, the response of fun on the changes in general aerosol is delayed in time and therefore fun response on the fast changes, such as those caused by short human activities, may be obscured and even not observed.

Anomalous radon emission as precursor of medium to strong earthquakes

NASA Astrophysics Data System (ADS)

Zoran, Maria

2016-03-01

Anomalous radon (Rn222) emissions enhanced by forthcoming earthquakes is considered to be a precursory phenomenon related to an increased geotectonic activity in seismic areas. Rock microfracturing in the Earth's crust preceding a seismic rupture may cause local surface deformation fields, rock dislocations, charged particle generation and motion, electrical conductivity changes, radon and other gases emission, fluid diffusion, electrokinetic, piezomagnetic and piezoelectric effects as well as climate fluctuations. Space-time anomalies of radon gas emitted in underground water, soil and near the ground air weeks to days in the epicentral areas can be associated with the strain stress changes that occurred before the occurrence of medium and strong earthquakes. This paper aims to investigate temporal variations of radon concentration levels in air near or in the ground by the use of solid state nuclear track detectors (SSNTD) CR-39 and LR-115 in relation with some important seismic events recorded in Vrancea region, Romania.

Radon in harvested rainwater at the household level, Palestine.

PubMed

Al-Khatib, Issam A; Al Zabadi, Hamzeh; Saffarini, Ghassan

2017-04-01

The main objective of this study was to assess Radon concentration in the harvested rainwater (HRW) at the household level in Yatta area, Palestine. HRW is mainly used for drinking as it is the major source of water for domestic uses due to water scarcity. Ninety HRW samples from the household cisterns were collected from six localities (a town and five villages) and Radon concentrations were measured. The samples were randomly collected from different households to represent the Yatta area. Fifteen samples were collected from each locality at the same day. RAD7 device was used for analysis and each sample was measured in duplicate. Radon concentrations ranged from 0.037 to 0.26 Bq/L with a mean ± standard deviation of 0.14 ± 0.06 Bq/L. The estimated annual effective radiation doses for babies, children and adults were all far below the maximum limit of 5 mSvy -1 set by the National Council on Radiation Protection and Measurements. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterising terrestrial influences on Antarctic air masses using Radon-222 measurements at King George Island

NASA Astrophysics Data System (ADS)

Chambers, S. D.; Hong, S.-B.; Williams, A. G.; Crawford, J.; Griffiths, A. D.; Park, S.-J.

2014-09-01

We report on one year of high-precision direct hourly radon observations at King Sejong Station (King George Island) beginning in February 2013. Findings are compared with historic and ongoing radon measurements from other Antarctic sites. Monthly median concentrations reduced from 72 mBq m-3 in late-summer to 44 mBq m-3 in late winter and early spring. Monthly 10th percentiles, ranging from 29 to 49 mBq m-3, were typical of oceanic baseline values. Diurnal cycles were rarely evident and local influences were minor, consistent with regional radon flux estimates one tenth of the global average for ice-free land. The predominant fetch region for terrestrially influenced air masses was South America (47-53° S), with minor influences also attributed to aged Australian air masses and local sources. Plume dilution factors of 2.8-4.0 were estimated for the most terrestrially influenced (South American) air masses, and a seasonal cycle in terrestrial influence on tropospheric air descending at the pole was identified and characterised.

Characterising terrestrial influences on Antarctic air masses using radon-222 measurements at King George Island

NASA Astrophysics Data System (ADS)

Chambers, S. D.; Hong, S.-B.; Williams, A. G.; Crawford, J.; Griffiths, A. D.; Park, S.-J.

2014-05-01

We report on one year of high precision direct hourly radon observations at King Sejong Station (King George Island) beginning in February 2013. Findings are compared with historic and ongoing radon measurements from other Antarctic sites. Monthly median concentrations reduced from 72 mBq m-3 in late summer to 44 mBq m-3 in late-winter and early-spring. Monthly 10th percentiles, ranging from 29 to 49 mBq m-3, were typical of oceanic baseline values. Diurnal cycles were rarely evident and local influences were minor, consistent with regional radon flux estimates one tenth of the global average for ice-free land. The predominant fetch region for terrestrially influenced air masses was South America (47-53° S), with minor influences also attributed to aged Australian air masses and local sources. Plume dilution factors of 2.8-4.0 were estimated for the most terrestrially influenced (South American) air masses, and a seasonal cycle in terrestrial influence on tropospheric air descending at the pole was identified and characterised.

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

PubMed

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

2017-01-01

Radon exposure is considered to cause several hundred fatalities from lung-cancer each year in Norway. A national map identifying areas which are likely to be exposed to elevated radon concentrations would be a useful tool for decision-making authorities, and would be particularly important in areas where only few indoor radon measurements exist. An earlier Norwegian study (Smethurst et al. 2008) produced radon hazard maps by examining the relationship between airborne gamma-ray spectrometry, bedrock and drift geology, and indoor radon. The study was limited to the Oslo region where substantial indoor radon and airborne equivalent uranium datasets were available, and did not attempt to test the statistical significance of relationships, or to quantify the confidence of its predictions. While it can be anticipated that airborne measurements may have useful predictive power for indoor radon, airborne measurement coverage in Norway is at present sparse; to provide national coverage of radon hazard estimates, a good understanding of the relationship between geology and indoor radon is therefore important. In this work we use a new enlarged (n = 34,563) form of the indoor radon dataset with national coverage, and we use it to examine the relationship between geology and indoor radon concentrations. We use this relationship to characterise geological classes by their radon potential, and we produce a national radon hazard map which includes confidence limits on the likelihood of areas having elevated radon concentrations, and which covers the whole of mainland Norway, even areas where little or no indoor radon data are available. We find that bedrock and drift geology classes can account for around 40% of the total observed variation in radon potential. We test geology-based predictions of RP (radon potential) against locally-derived estimates of RP, and produce classification matrices with kappa values in the range 0.37-0.56. Our classifier has high predictive value but suffers from low sensitivities for radon affected areas. We investigate an alternative classification method based on a Naïve Bayes classifier which results in similar overall performance. The work forms part of an ongoing study which will eventually incorporate airborne equivalent uranium data, as and when new airborne data become available. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rapid determination of particle velocity from space-time images using the Radon transform

PubMed Central

Drew, Patrick J.; Blinder, Pablo; Cauwenberghs, Gert; Shih, Andy Y.; Kleinfeld, David

2016-01-01

Laser-scanning methods are a means to observe streaming particles, such as the flow of red blood cells in a blood vessel. Typically, particle velocity is extracted from images formed from cyclically repeated line-scan data that is obtained along the center-line of the vessel; motion leads to streaks whose angle is a function of the velocity. Past methods made use of shearing or rotation of the images and a Singular Value Decomposition (SVD) to automatically estimate the average velocity in a temporal window of data. Here we present an alternative method that makes use of the Radon transform to calculate the velocity of streaming particles. We show that this method is over an order of magnitude faster than the SVD-based algorithm and is more robust to noise. PMID:19459038

Numerical Aspects of Cone Beam Contour Reconstruction

NASA Astrophysics Data System (ADS)

Louis, Alfred K.

2017-12-01

We describe a method for directly calculating the contours of a function from cone beam data. The algorithm is based on a new inversion formula for the gradient of a function presented in Louis (Inverse Probl 32(11):115005, 2016. http://stacks.iop.org/0266-5611/32/i=11/a=115005). The Radon transform of the gradient is found by using a Grangeat type of formula, reducing the inversion problem to the inversion of the Radon transform. In that way the influence of the scanning curve, vital for all exact inversion formulas for complete data, is avoided Numerical results are presented for the circular scanning geometry which neither fulfills the Tuy-Kirillov condition nor the much weaker condition given by the author in Louis (Inverse Probl 32(11):115005, 2016. http://stacks.iop.org/0266-5611/32/i=11/a=115005).

Linear transforms for Fourier data on the sphere: application to high angular resolution diffusion MRI of the brain.

PubMed

Haldar, Justin P; Leahy, Richard M

2013-05-01

This paper presents a novel family of linear transforms that can be applied to data collected from the surface of a 2-sphere in three-dimensional Fourier space. This family of transforms generalizes the previously-proposed Funk-Radon Transform (FRT), which was originally developed for estimating the orientations of white matter fibers in the central nervous system from diffusion magnetic resonance imaging data. The new family of transforms is characterized theoretically, and efficient numerical implementations of the transforms are presented for the case when the measured data is represented in a basis of spherical harmonics. After these general discussions, attention is focused on a particular new transform from this family that we name the Funk-Radon and Cosine Transform (FRACT). Based on theoretical arguments, it is expected that FRACT-based analysis should yield significantly better orientation information (e.g., improved accuracy and higher angular resolution) than FRT-based analysis, while maintaining the strong characterizability and computational efficiency of the FRT. Simulations are used to confirm these theoretical characteristics, and the practical significance of the proposed approach is illustrated with real diffusion weighted MRI brain data. These experiments demonstrate that, in addition to having strong theoretical characteristics, the proposed approach can outperform existing state-of-the-art orientation estimation methods with respect to measures such as angular resolution and robustness to noise and modeling errors. Copyright © 2013 Elsevier Inc. All rights reserved.

Wavelet analysis for the study of the relations among soil radon anomalies, volcanic and seismic events: the case of Mt. Etna (Italy)

NASA Astrophysics Data System (ADS)

Ferrera, Elisabetta; Giammanco, Salvatore; Cannata, Andrea; Montalto, Placido

2013-04-01

From November 2009 to April 2011 soil radon activity was continuously monitored using a Barasol® probe located on the upper NE flank of Mt. Etna volcano, close either to the Piano Provenzana fault or to the NE-Rift. Seismic and volcanological data have been analyzed together with radon data. We also analyzed air and soil temperature, barometric pressure, snow and rain fall data. In order to find possible correlations among the above parameters, and hence to reveal possible anomalies in the radon time-series, we used different statistical methods: i) multivariate linear regression; ii) cross-correlation; iii) coherence analysis through wavelet transform. Multivariate regression indicated a modest influence on soil radon from environmental parameters (R2 = 0.31). When using 100-days time windows, the R2 values showed wide variations in time, reaching their maxima (~0.63-0.66) during summer. Cross-correlation analysis over 100-days moving averages showed that, similar to multivariate linear regression analysis, the summer period is characterised by the best correlation between radon data and environmental parameters. Lastly, the wavelet coherence analysis allowed a multi-resolution coherence analysis of the time series acquired. This approach allows to study the relations among different signals either in time or frequency domain. It confirmed the results of the previous methods, but also allowed to recognize correlations between radon and environmental parameters at different observation scales (e.g., radon activity changed during strong precipitations, but also during anomalous variations of soil temperature uncorrelated with seasonal fluctuations). Our work suggests that in order to make an accurate analysis of the relations among distinct signals it is necessary to use different techniques that give complementary analytical information. In particular, the wavelet analysis showed to be very effective in discriminating radon changes due to environmental influences from those correlated with impending seismic or volcanic events.

Forensic hash for multimedia information

NASA Astrophysics Data System (ADS)

Lu, Wenjun; Varna, Avinash L.; Wu, Min

2010-01-01

Digital multimedia such as images and videos are prevalent on today's internet and cause significant social impact, which can be evidenced by the proliferation of social networking sites with user generated contents. Due to the ease of generating and modifying images and videos, it is critical to establish trustworthiness for online multimedia information. In this paper, we propose novel approaches to perform multimedia forensics using compact side information to reconstruct the processing history of a document. We refer to this as FASHION, standing for Forensic hASH for informatION assurance. Based on the Radon transform and scale space theory, the proposed forensic hash is compact and can effectively estimate the parameters of geometric transforms and detect local tampering that an image may have undergone. Forensic hash is designed to answer a broader range of questions regarding the processing history of multimedia data than the simple binary decision from traditional robust image hashing, and also offers more efficient and accurate forensic analysis than multimedia forensic techniques that do not use any side information.

Four passive sampling elements (quatrefoil)--I. Monitoring radon and its progeny by surface-contamination monitors.

PubMed

Tommasino, L; Tokonami, S

2011-05-01

Four passive sampling elements (quatrefoil) have been recently developed, which transform airborne radionuclides into surface-bound radionuclides. These samplers, once exposed, result in thin radiation sources that can be detected by any real-time or passive detector. In particular, by using a large collecting-area sampler with a low surface density (g cm(-2)), it is possible to measure radon and its decay products by beta surface-contamination monitors, which are rarely used for these applications. The results obtained to date prove that it is finally possible to carry out the measurements of radon (and its decay products) indoors, in soil and in water simply by a Pancake Geiger-Muller counter. Emphasis will be given to those measurements, which are difficult, if not impossible, to carry out with existing technologies.

Indoor radon mapping and its relation to geology in Hungary

NASA Astrophysics Data System (ADS)

Minda, Mihály; Tóth, György; Horváth, István; Barnet, Ivan; Hámori, Krisztián; Tóth, Eszter

2009-04-01

Indoor radon mapping may show stronger dependence on geological formations if the measured homes are one-storied houses with no basement. In Hungary, 17,244 homes were investigated on the yearly average of indoor radon concentrations; among these homes, there were 6,154, one-storied, no-basement houses. In Hungary, 21 geological units were created relevant for indoor radon index characterized by lithology, the position of the ground water table, and the gas permeability. Maps were drawn of different topography (counties, grid, geological units) and different values (maximum, mean, indoor radon indexes). A kind of standardization of houses was that only the one-storied, no-basement ones were chosen, but from geological point of view some more information was gained when the wall materials (bricks or adobe) were also taken into account. (“Adobe” is made of clay and straw in Hungary, and not burned as brick, just dried on sunshine). Enhanced indoor radon values can be observed on the bedrock of Cenozoic volcanic rocks and their eroded materials deposited on the local alluvial valleys. Another group with relatively increased indoor radon values can be connected to granite bodies. The grid method is useful for covering large state or even continental areas. For practical public use and detailed radon risk mapping geological or administrative unit-systems could yield more reasonable and useful results.

Limited angle CT reconstruction by simultaneous spatial and Radon domain regularization based on TV and data-driven tight frame

NASA Astrophysics Data System (ADS)

Zhang, Wenkun; Zhang, Hanming; Wang, Linyuan; Cai, Ailong; Li, Lei; Yan, Bin

2018-02-01

Limited angle computed tomography (CT) reconstruction is widely performed in medical diagnosis and industrial testing because of the size of objects, engine/armor inspection requirements, and limited scan flexibility. Limited angle reconstruction necessitates usage of optimization-based methods that utilize additional sparse priors. However, most of conventional methods solely exploit sparsity priors of spatial domains. When CT projection suffers from serious data deficiency or various noises, obtaining reconstruction images that meet the requirement of quality becomes difficult and challenging. To solve this problem, this paper developed an adaptive reconstruction method for limited angle CT problem. The proposed method simultaneously uses spatial and Radon domain regularization model based on total variation (TV) and data-driven tight frame. Data-driven tight frame being derived from wavelet transformation aims at exploiting sparsity priors of sinogram in Radon domain. Unlike existing works that utilize pre-constructed sparse transformation, the framelets of the data-driven regularization model can be adaptively learned from the latest projection data in the process of iterative reconstruction to provide optimal sparse approximations for given sinogram. At the same time, an effective alternating direction method is designed to solve the simultaneous spatial and Radon domain regularization model. The experiments for both simulation and real data demonstrate that the proposed algorithm shows better performance in artifacts depression and details preservation than the algorithms solely using regularization model of spatial domain. Quantitative evaluations for the results also indicate that the proposed algorithm applying learning strategy performs better than the dual domains algorithms without learning regularization model

Radon emanation from the moon - Spatial and temporal variability.

NASA Technical Reports Server (NTRS)

Gorenstein, P.; Golub, L.; Bjorkholm, P.

1973-01-01

Observations of Rn-222 and Po-210 on the lunar surface with the orbiting Apollo alpha particle spectrometer reveal a number of features in their spatial distribution and indicate the existence of time variations in lunar radon emission. Localized Rn-222 or Po-210 around the craters Aristarchus and Grimaldi and the edges of virtually all maria indicates time varying radon emission and suggests a correlation between alpha 'hot spots' and sites of transient optical events observed from the earth. In a gross sense, the slower variations of Rn-222 seem to correlate with the distribution of gamma activity.

Geochemical Cycle of Radon and its Bioremediation Opportunity from Water Environment: A Review.

PubMed

Pradhan, Debabrata; Sukla, Lala Behari; Devi, Niharbala; Acharya, Sridhara

2018-05-01

The waterborne or airborne radon causes carcinogenesis in the human bodies due to the continuous decay of α- and β- particles. The health risks related to radioactive radon instigate to develop an advanced technology for its removal from the environment. There are two standard tech-niques, such as aeration and activated carbon filtration, available for its removal. However, both of them face different technological drawbacks resulting in the processes either inefficient or inappropriate for the purpose. There are several technologies utilizing either algae or microorganisms that could be useful in the bioremediation of radon. Some of the algae and microorganisms are examined and found to be tolerated and decontaminated various ionization radiations like α-, β-, and γ- radiations. In a US patent, the microalgae Coccomyxa actinabiotis isolated from a nuclear facility showed the properties of biore-mediation towards radionuclides. They overcome the physiological stress in the extreme environment for their growth due to the evolution under the prolonged influence of high energy radiation. Further, they are stimulated by the process of cloning, genetic transformations and adaptations for the purpose of enhancing the tolerance and decontamination power. Therefore, biotechnological researches have lots of prospects to remove radon from the water environment using algae and microorganisms. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Inhalation dose assessment of indoor radon progeny using biokinetic and dosimetric modeling and its application to Jordanian population.

PubMed

Al-Jundi, J; Li, W B; Abusini, M; Tschiersch, J; Hoeschen, C; Oeh, U

2011-06-01

High indoor radon concentrations in Jordan result in internal exposures of the residents due to the inhalation of radon and its short-lived progeny. It is therefore important to quantify the annual effective dose and further the radiation risk to the radon exposure. This study describes the methodology and the biokinetic and dosimetric models used for calculation of the inhalation doses exposed to radon progeny. The regional depositions of aerosol particles in the human respiratory tract were firstly calculated. For the attached progeny, the activity median aerodynamic diameters of 50 nm, 230 nm and 2500 nm were chosen to represent the nucleation, accumulation and coarse modes of the aerosol particles, respectively. For the unattached progeny, the activity median thermodynamic diameter of 1 nm was chosen to represent the free progeny nuclide in the room air. The biokinetic models developed by the International Commission on Radiological Protection (ICRP) were used to calculate the nuclear transformations of radon progeny in the human body, and then the dosimetric model was applied to estimate the organ equivalent doses and the effective doses with the specific effective energies derived from the mathematical anthropomorphic phantoms. The dose conversion coefficient estimated in this study was 15 mSv WLM(-1) which was in the range of the values of 6-20 mSv WLM(-1) reported by other investigators. Implementing the average indoor radon concentration in Jordan, the annual effective doses were calculated to be 4.1 mSv y(-1) and 0.08 mSv y(-1) due to the inhalation of radon progeny and radon gas, respectively. The total annual effective dose estimated for Jordanian population was 4.2 mSv y(-1). This high annual effective dose calculated by the dosimetric approach using ICRP biokinetic and dosimetric models resulted in an increase of a factor of two in comparison to the value by epidemiological study. This phenomenon was presented by the ICRP in its new published statement on radon. Copyright © 2011 Elsevier Ltd. All rights reserved.

Possible association between mutant frequency in peripheral lymphocytes and domestic radon concentrations.

PubMed

Bridges, B A; Cole, J; Arlett, C F; Green, M H; Waugh, A P; Beare, D; Henshaw, D L; Last, R D

1991-05-18

To investigate whether previously found geographical correlations between leukaemia incidence and exposure to radon are reflected in a detectable mutagenic effect on individuals, the frequency of mutations in the hypoxanthine guanine phosphoribosyl transferase gene (hprt) in peripheral blood T lymphocytes was measured in subjects with known domestic radon concentrations. These concentrations were measured in December, 1989, in houses in Street, Somerset, UK, by passive alpha-track radon detectors. 20 non-smoking subjects aged 36-55 years were selected from the patient list at the local health centre on the basis of the radon concentrations in their homes--the range selected varied by a factor of ten. Blood samples for preparation of T lymphocytes were taken in July, 1990. There was a significant association between the log mutant frequency and radon concentration (t = 3.47, p less than 0.01). A second analysis of a further set of radon measurements (October, 1990, to January, 1991), in both living rooms and bedrooms, and repeated mutant frequency determinations also showed a significant relation, which remained significant even after exclusion of the highest frequency and adjustment for subject's age and cloning efficiency. These data must be regarded as preliminary and further more extensive studies should be done to determine whether the observed association is causal.

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

PubMed Central

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

2009-01-01

The quantitative relationships between radon gas concentration, the surface-deposited activities of various radon progeny, the airborne radon progeny dose rate, and various residential environmental factors were investigated through actual field measurements in 38 selected Iowa houses occupied by either smokers or nonsmokers. Airborne dose rate was calculated from unattached and attached potential alpha energy concentrations (PAECs) using two dosimetric models with different activity-size weighting factors. These models are labeled Pdose and Jdose, respectively. Surface-deposited 218Po and 214Po were found significantly correlated to radon, unattached PAEC, and both airborne dose rates (p < 0.0001) in nonsmoking environments. However, deposited 218Po was not significantly correlated to the above parameters in smoking environments. In multiple linear regression analysis, natural logarithm transformation was performed for airborne dose rate as the dependent variable, as well as for radon and deposited 218Po and 214Po as predictors. An interaction effect was found between deposited 214Po and an obstacle in front of the Retrospective Reconstruction Detector (RRD) in predicting dose rate (p = 0.049 and 0.058 for Pdose and Jdose, respectively) for nonsmoking environments. After adjusting for radon and deposited radon progeny effects, the presence of either cooking, usage of a fireplace, or usage of a ceiling fan significantly, or marginal significantly, reduced the Pdose to 0.65 (90% CI 0.42–0.996), 0.54 (90% CI 0.28–1.02) and 0.66 (90% CI 0.45–0.96), respectively. For Jdose, only the usage of a ceiling fan significantly reduced the dose rate to 0.57 (90% CI 0.39–0.85). In smoking environments, deposited 218Po was a significant negative predictor for Pdose (RR 0.68, 90% CI 0.55–0.84) after adjusting for long-term 222Rn and environmental factors. A significant decrease of 0.72 (90% CI 0.64–0.83) in the mean Pdose was noted, after adjusting for the radon and radon progeny effects and other environmental factors, for every 10 increasing cigarettes smoked in the room. A significant increase of 1.71 in the mean Pdose was found for large room size relative to small room size (90% CI 1.08–2.79) after adjusting for the radon and radon progeny effects as well as other environmental factors. Fireplace usage was found to significantly increase the mean Pdose to 1.71 (90% CI 1.20–2.45) after adjusting for other factors. PMID:19590273

Vehicle detection and orientation estimation using the radon transform

NASA Astrophysics Data System (ADS)

Pelapur, Rengarajan; Bunyak, Filiz; Palaniappan, Kannappan; Seetharaman, Gunasekaran

2013-05-01

Determining the location and orientation of vehicles in satellite and airborne imagery is a challenging task given the density of cars and other vehicles and complexity of the environment in urban scenes almost anywhere in the world. We have developed a robust and accurate method for detecting vehicles using a template-based directional chamfer matching, combined with vehicle orientation estimation based on a refined segmentation, followed by a Radon transform based profile variance peak analysis approach. The same algorithm was applied to both high resolution satellite imagery and wide area aerial imagery and initial results show robustness to illumination changes and geometric appearance distortions. Nearly 80% of the orientation angle estimates for 1585 vehicles across both satellite and aerial imagery were accurate to within 15? of the ground truth. In the case of satellite imagery alone, nearly 90% of the objects have an estimated error within +/-1.0° of the ground truth.

Offline Signature Verification Using the Discrete Radon Transform and a Hidden Markov Model

NASA Astrophysics Data System (ADS)

Coetzer, J.; Herbst, B. M.; du Preez, J. A.

2004-12-01

We developed a system that automatically authenticates offline handwritten signatures using the discrete Radon transform (DRT) and a hidden Markov model (HMM). Given the robustness of our algorithm and the fact that only global features are considered, satisfactory results are obtained. Using a database of 924 signatures from 22 writers, our system achieves an equal error rate (EER) of 18% when only high-quality forgeries (skilled forgeries) are considered and an EER of 4.5% in the case of only casual forgeries. These signatures were originally captured offline. Using another database of 4800 signatures from 51 writers, our system achieves an EER of 12.2% when only skilled forgeries are considered. These signatures were originally captured online and then digitally converted into static signature images. These results compare well with the results of other algorithms that consider only global features.

Anomalous radon emission as precursor of medium to strong earthquakes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zoran, Maria

Anomalous radon (Rn{sup 222}) emissions enhanced by forthcoming earthquakes is considered to be a precursory phenomenon related to an increased geotectonic activity in seismic areas. Rock microfracturing in the Earth’s crust preceding a seismic rupture may cause local surface deformation fields, rock dislocations, charged particle generation and motion, electrical conductivity changes, radon and other gases emission, fluid diffusion, electrokinetic, piezomagnetic and piezoelectric effects as well as climate fluctuations. Space-time anomalies of radon gas emitted in underground water, soil and near the ground air weeks to days in the epicentral areas can be associated with the strain stress changes that occurredmore » before the occurrence of medium and strong earthquakes. This paper aims to investigate temporal variations of radon concentration levels in air near or in the ground by the use of solid state nuclear track detectors (SSNTD) CR-39 and LR-115 in relation with some important seismic events recorded in Vrancea region, Romania.« less

RADON CONCENTRATION TIME SERIES MODELING AND APPLICATION DISCUSSION.

PubMed

Stránský, V; Thinová, L

2017-11-01

In the year 2010 a continual radon measurement was established at Mladeč Caves in the Czech Republic using a continual radon monitor RADIM3A. In order to model radon time series in the years 2010-15, the Box-Jenkins Methodology, often used in econometrics, was applied. Because of the behavior of radon concentrations (RCs), a seasonal integrated, autoregressive moving averages model with exogenous variables (SARIMAX) has been chosen to model the measured time series. This model uses the time series seasonality, previously acquired values and delayed atmospheric parameters, to forecast RC. The developed model for RC time series is called regARIMA(5,1,3). Model residuals could be retrospectively compared with seismic evidence of local or global earthquakes, which occurred during the RCs measurement. This technique enables us to asses if continuously measured RC could serve an earthquake precursor. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Mapping the geogenic radon potential: methodology and spatial analysis for central Hungary.

PubMed

Szabó, Katalin Zsuzsanna; Jordan, Gyozo; Horváth, Ákos; Szabó, Csaba

2014-03-01

A detailed geogenic radon potential (GRP) mapping based on field soil gas radon and soil gas permeability measurements was carried out in this study. A conventional continuous variable approach was used in this study for GRP determination and to test its applicability to the selected area of Hungary. Spatial pattern of soil gas radon concentration, soil permeability and GRP and the relationship between geological formations and these parameters were studied by performing detailed spatial analysis. Exploratory data analysis revealed that higher soil gas radon activity concentration and GRP characterizes the mountains and hills than the plains. The highest values were found in the proluvial-deluvial sediments, rock debris on the downhill slopes eroded from hills. Among the Quaternary sediments, which characterize the study area, the fluvial sediment has the highest values, which are also located in the hilly areas. The lowest values were found in the plain areas covered by drift sand, fluvioeolic sand, fluvial sand and loess. As a conclusion, radon is related to the sediment cycle in the study area. A geogenic radon risk map was created, which assists human health risk assessment and risk reduction since it indicates the potential of the source of indoor radon. The map shows that low and medium geogenic radon potential characterizes the study area in central Hungary. High risk occurs only locally. The results reveal that Quaternary sediments are inhomogeneous from a radon point of view, fluvial sediment has medium GRP, whereas the other rock formations such as drift sand, fluioeolic sand, fluvial sand and loess, found in the study area, have low GRP. Copyright © 2013 Elsevier Ltd. All rights reserved.

A critical analysis of climatic influences on indoor radon concentrations: Implications for seasonal correction.

PubMed

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

2015-10-01

Although statistically-derived national Seasonal Correction Factors (SCFs) are conventionally used to convert sub-year radon concentration measurements to an annual mean, it has recently been suggested that external temperature could be used to derive local SCFs for short-term domestic measurements. To validate this approach, hitherto unanalysed radon and temperature data from an environmentally-stable location were analysed. Radon concentration and internal temperature were measured over periods totalling 1025 days during an overall period of 1762 days, the greatest continuous sampling period being 334 days, with corresponding meteorological data collected at a weather station 10 km distant. Mean daily, monthly and annual radon concentrations and internal temperatures were calculated. SCFs derived using monthly mean radon concentration, external temperature and internal-external temperature-difference were cross-correlated with each other and with published UK domestic SCF sets. Relatively good correlation exists between SCFs derived from radon concentration and internal-external temperature difference but correlation with external temperature, was markedly poorer. SCFs derived from external temperature correlate very well with published SCF tabulations, confirming that the complexity of deriving SCFs from temperature data may be outweighed by the convenience of using either of the existing domestic SCF tabulations. Mean monthly radon data fitted to a 12-month sinusoid showed reasonable correlation with many of the annual climatic parameter profiles, exceptions being atmospheric pressure, rainfall and internal temperature. Introducing an additional 6-month sinusoid enhanced correlation with these three parameters, the other correlations remaining essentially unchanged. Radon latency of the order of months in moisture-related parameters suggests that the principal driver for radon is total atmospheric moisture content rather than relative humidity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lung and stomach cancer associations with groundwater radon in North Carolina, USA

PubMed Central

Messier, Kyle P; Serre, Marc L

2017-01-01

Abstract Background: The risk of indoor air radon for lung cancer is well studied, but the risks of groundwater radon for both lung and stomach cancer are much less studied, and with mixed results. Methods: Geomasked and geocoded stomach and lung cancer cases in North Carolina from 1999 to 2009 were obtained from the North Carolina Central Cancer Registry. Models for the association with groundwater radon and multiple confounders were implemented at two scales: (i) an ecological model estimating cancer incidence rates at the census tract level; and (ii) a case-only logistic model estimating the odds that individual cancer cases are members of local cancer clusters. Results: For the lung cancer incidence rate model, groundwater radon is associated with an incidence rate ratio of 1.03 [95% confidence interval (CI) = 1.01, 1.06] for every 100 Bq/l increase in census tract averaged concentration. For the cluster membership models, groundwater radon exposure results in an odds ratio for lung cancer of 1.13 (95% CI = 1.04, 1.23) and for stomach cancer of 1.24 (95% CI = 1.03, 1.49), which means groundwater radon, after controlling for multiple confounders and spatial auto-correlation, increases the odds that lung and stomach cancer cases are members of their respective cancer clusters. Conclusion: Our study provides epidemiological evidence of a positive association between groundwater radon exposure and lung cancer incidence rates. The cluster membership model results find groundwater radon increases the odds that both lung and stomach cancer cases occur within their respective cancer clusters. The results corroborate previous biokinetic and mortality studies that groundwater radon is associated with increased risk for lung and stomach cancer. PMID:27639278

Lung and stomach cancer associations with groundwater radon in North Carolina, USA.

PubMed

Messier, Kyle P; Serre, Marc L

2017-04-01

The risk of indoor air radon for lung cancer is well studied, but the risks of groundwater radon for both lung and stomach cancer are much less studied, and with mixed results. Geomasked and geocoded stomach and lung cancer cases in North Carolina from 1999 to 2009 were obtained from the North Carolina Central Cancer Registry. Models for the association with groundwater radon and multiple confounders were implemented at two scales: (i) an ecological model estimating cancer incidence rates at the census tract level; and (ii) a case-only logistic model estimating the odds that individual cancer cases are members of local cancer clusters. For the lung cancer incidence rate model, groundwater radon is associated with an incidence rate ratio of 1.03 [95% confidence interval (CI) = 1.01, 1.06] for every 100 Bq/l increase in census tract averaged concentration. For the cluster membership models, groundwater radon exposure results in an odds ratio for lung cancer of 1.13 (95% CI = 1.04, 1.23) and for stomach cancer of 1.24 (95% CI = 1.03, 1.49), which means groundwater radon, after controlling for multiple confounders and spatial auto-correlation, increases the odds that lung and stomach cancer cases are members of their respective cancer clusters. Our study provides epidemiological evidence of a positive association between groundwater radon exposure and lung cancer incidence rates. The cluster membership model results find groundwater radon increases the odds that both lung and stomach cancer cases occur within their respective cancer clusters. The results corroborate previous biokinetic and mortality studies that groundwater radon is associated with increased risk for lung and stomach cancer. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association

Lung cancer risk from radon in Ontario, Canada: how many lung cancers can we prevent?

PubMed

Peterson, Emily; Aker, Amira; Kim, JinHee; Li, Ye; Brand, Kevin; Copes, Ray

2013-11-01

To calculate the burden of lung cancer illness due to radon for all thirty-six health units in Ontario and determine the number of radon-attributable lung cancer deaths that could be prevented. We calculated the population attributable risk percent, excess life-time risk ratio, life-years lost, the number of lung cancer deaths due to radon, and the number of deaths that could be prevented if all homes above various cut-points were effectively reduced to background levels. It is estimated that 13.6 % (95 % CI 11.0, 16.7) of lung cancer deaths in Ontario are attributable to radon, corresponding to 847 (95 % CI 686, 1,039) lung cancer deaths each year, approximately 84 % of these in ever-smokers. If all homes above 200 Bq/m(3), the current Canadian guideline, were remediated to background levels, it is estimated that 91 lung cancer deaths could be prevented each year, 233 if remediation was performed at 100 Bq/m(3). There was important variation across health units. Radon is an important contributor to lung cancer deaths in Ontario. A large portion of radon-attributable lung cancer deaths are from exposures below the current Canadian guideline, suggesting interventions that install effective radon-preventive measures into buildings at build may be a good alternative population prevention strategy to testing and remediation. For some health units, testing and remediation may also prevent a portion of radon-related lung cancer deaths. Regional attributable risk estimates can help with local public health resource allocation and decision making.

Methods for investigating the local spatial anisotropy and the preferred orientation of cones in adaptive optics retinal images

PubMed Central

Cooper, Robert F.; Lombardo, Marco; Carroll, Joseph; Sloan, Kenneth R.; Lombardo, Giuseppe

2016-01-01

The ability to non-invasively image the cone photoreceptor mosaic holds significant potential as a diagnostic for retinal disease. Central to the realization of this potential is the development of sensitive metrics for characterizing the organization of the mosaic. Here we evaluated previously-described (Pum et al., 1990) and newly-developed (Fourier- and Radon-based) methods of measuring cone orientation in both simulated and real images of the parafoveal cone mosaic. The proposed algorithms correlated well across both simulated and real mosaics, suggesting that each algorithm would provide an accurate description of individual photoreceptor orientation. Despite the high agreement between algorithms, each performed differently in response to image intensity variation and cone coordinate jitter. The integration property of the Fourier transform allowed the Fourier-based method to be resistant to cone coordinate jitter and perform the most robustly of all three algorithms. Conversely, when there is good image quality but unreliable cone identification, the Radon algorithm performed best. Finally, in cases where both the image and cone coordinate reliability was excellent, the method of Pum et al. (1990) performed best. These descriptors are complementary to conventional descriptive metrics of the cone mosaic, such as cell density and spacing, and have the potential to aid in the detection of photoreceptor pathology. PMID:27484961

Theoretical modeling of indoor radon concentration and its validation through measurements in South-East Haryana, India.

PubMed

Singh, Prabhjot; Sahoo, B K; Bajwa, B S

2016-04-15

A three dimensional semi-empirical model deduced from the existing 1-D model has been used to predict indoor radon concentration with theoretical calculations. Since the major contributor of radon concentration in indoors originates from building materials used in construction of walls and floor which are mostly derived from soil. In this study different building materials have been analyzed for radon exhalation, diffusion length along with physical dimensions of observation area to calculate indoor radon concentration. Also calculated values have been validated by comparing with experimental measurements. The study has been carried out in the mud, brick and cement houses constructed from materials available locally in South-East region of Haryana. This region is also known for its protruding land structure consisting volcanic, felsite and granitic rocks in plane. Further, exhalation (Jw) ratio from wall and floor comparison has been plotted for each selected village dwelling to identify the high radon emanating source (building material) from the study region. All those measured factors might be useful in building construction code development and selection of material to be used in construction. Copyright © 2016 Elsevier Ltd. All rights reserved.

Correlating precursory declines in groundwater radon with earthquake magnitude.

PubMed

Kuo, T

2014-01-01

Both studies at the Antung hot spring in eastern Taiwan and at the Paihe spring in southern Taiwan confirm that groundwater radon can be a consistent tracer for strain changes in the crust preceding an earthquake when observed in a low-porosity fractured aquifer surrounded by a ductile formation. Recurrent anomalous declines in groundwater radon were observed at the Antung D1 monitoring well in eastern Taiwan prior to the five earthquakes of magnitude (Mw ): 6.8, 6.1, 5.9, 5.4, and 5.0 that occurred on December 10, 2003; April 1, 2006; April 15, 2006; February 17, 2008; and July 12, 2011, respectively. For earthquakes occurring on the longitudinal valley fault in eastern Taiwan, the observed radon minima decrease as the earthquake magnitude increases. The above correlation has been proven to be useful for early warning local large earthquakes. In southern Taiwan, radon anomalous declines prior to the 2010 Mw 6.3 Jiasian, 2012 Mw 5.9 Wutai, and 2012 ML 5.4 Kaohsiung earthquakes were also recorded at the Paihe spring. For earthquakes occurring on different faults in southern Taiwan, the correlation between the observed radon minima and the earthquake magnitude is not yet possible. © 2013, National Ground Water Association.

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

NASA Astrophysics Data System (ADS)

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

2009-04-01

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

Homogenity of geological units with respect to the radon risk in the Walloon region of Belgium.

PubMed

Tondeur, François; Cinelli, Giorgia; Dehandschutter, Boris

2014-10-01

In the process of mapping indoor radon risk, an important step is to define geological units well-correlated with indoor radon. The present paper examines this question for the Walloon region of Belgium, using a database of more than 18,000 indoor radon measurements. With a few exceptions like the Carboniferous (to be divided into Tournaisian, Visean and Namurian-Westphalian) and the Tertiary (in which all Series may be treated together), the Series/Epoch stratigraphic level is found to be the most appropriate geological unit to classify the radon risk. A further division according to the geological massif or region is necessary to define units with a reasonable uniformity of the radon risk. In particular, Paleozoic series from Cambrian to Devonian show strong differences between different massifs. Local hot-spots are also observed in the Brabant massif. Finally, 35 geological units are defined according to their radon risk, 6 of which still present a clear weak homogeneity. In the case of 4 of these units (Jurassic, Middle Devonian of Condroz and of Fagne-Famenne, Ordovician of the Stavelot massif) homogeneity is moderate, but the data are strongly inhomogeneous for Visean in Condroz and in the Brabant massif. The 35 geological units are used in an ANOVA analysis, to evaluate the part of indoor radon variability which can be attributed to geology. The result (15.4-17.7%) agrees with the values observed in the UK. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Assessment of Community Awareness and Practices Concerning Indoor Air Pollutants - Madison County, Alabama, June 2017.

PubMed

Siza, Charlene; Morrison, Melissa; Harris, Scott; Hatch, Timothy; Tyler, Michael

2018-04-20

The Alabama Department of Public Health (ADPH) conducts an annual community assessment to evaluate household preparedness and local public health concerns. In June 2017, ADPH conducted a Community Assessment for Public Health Emergency Response (CASPER), focusing on indoor air pollutants in seven neighborhoods in Madison County, Alabama, where a large percentage of homes were built before 1980. Local health partners had concerns about indoor air quality and environmental risks such as radon; however, limited information was available regarding community awareness, prevention, and mitigation measures related to potential exposures. Weighted response frequencies were calculated from assessment responses. Among 192 household interview respondents, 78.4% were aware of potential indoor lead exposures, but only 12.6% of respondents living in houses built before 1978 reported that the house had been tested for lead. Similarly, respondents in 70.2% of households had heard of radon; however, only 7.3% of houses had been tested for radon. Smoking was reported by residents of 45.7% of households; among those, 48.4% reported that smoking occurred inside the house. Identified gaps in exposure prevention and mitigation, including low lead and radon testing rates and a high prevalence of indoor smoking, were shared with the local health department, and recommendations for timely interventions and policy guidance (e.g., targeted education campaigns and smoking cessation programs) were presented. Results of this CASPER demonstrated its usefulness and efficiency in gathering community-level data to help guide public health policies and timely interventions.

Parallel Monte Carlo Search for Hough Transform

NASA Astrophysics Data System (ADS)

Lopes, Raul H. C.; Franqueira, Virginia N. L.; Reid, Ivan D.; Hobson, Peter R.

2017-10-01

We investigate the problem of line detection in digital image processing and in special how state of the art algorithms behave in the presence of noise and whether CPU efficiency can be improved by the combination of a Monte Carlo Tree Search, hierarchical space decomposition, and parallel computing. The starting point of the investigation is the method introduced in 1962 by Paul Hough for detecting lines in binary images. Extended in the 1970s to the detection of space forms, what came to be known as Hough Transform (HT) has been proposed, for example, in the context of track fitting in the LHC ATLAS and CMS projects. The Hough Transform transfers the problem of line detection, for example, into one of optimization of the peak in a vote counting process for cells which contain the possible points of candidate lines. The detection algorithm can be computationally expensive both in the demands made upon the processor and on memory. Additionally, it can have a reduced effectiveness in detection in the presence of noise. Our first contribution consists in an evaluation of the use of a variation of the Radon Transform as a form of improving theeffectiveness of line detection in the presence of noise. Then, parallel algorithms for variations of the Hough Transform and the Radon Transform for line detection are introduced. An algorithm for Parallel Monte Carlo Search applied to line detection is also introduced. Their algorithmic complexities are discussed. Finally, implementations on multi-GPU and multicore architectures are discussed.

[Experimental study on the influence of natural and artificial ventilation on indoor radon concentration].

PubMed

Remetti, R; Gigante, G E

2010-01-01

The study presents the results of a campaign of measurements on the daily radon concentration using a Genitron Alpha Guard spectrometer. All the measurements have been intended to highlight the radon concentration variability during the 24 hours of the day and trying to find correlations with other ambient parameters such as temperature and pressure or local conditions such as the presence or not of a forced ventilation system. The main part of the measurements have been carried in the area of the Nuclear Measurement Laboratory of the Department of Basic and Applied Sciences for Engineering of "Sapienza" University of Rome. Results show a rapid rise of radon concentration in the night, when the artificial ventilation system was off and with door and windows closed. In the morning, after the opening of door and windows, the concentration falls down abruptly. With artificial ventilation system in function concentration never reaches significant values.

Identification of candidate houses for the north florida portion of the Florida radon mitigation project. Final report, October 1987-May 1988

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roessler, G.S.; Hintenlang, D.E.; Roessler, C.E.

1990-09-01

The report gives results of a study to locate candidate houses for a proposed radon mitigation research and demonstration project in North Florida. The effort involved: identification of target geographical areas, radon monitoring in identified clusters, and house characterization. Selection of target areas with a potential for elevated indoor radon started with a review of a statewide radiation study completed in 1987 and examination of the local geographic pattern observed in a 1986-87 pilot study of the Gainesville area. This effort indicated that North Florida target areas could be selected on the basis of the near-surface occurrence of the Hawthornmore » geological formation. Volunteer houses for radon monitoring in Alachua and Marion counties were obtained by announcing the study in newspaper articles. Screening measurements were made in about 400 target area houses according to EPA protocols using a vendor-supplied charcoal collector method. Results were similar in the two counties, and distributions were similar in both slab and crawl-space houses.« less

Influence of architectural style on indoor radon concentration in a radon prone area: A case study.

PubMed

Baeza, A; García-Paniagua, J; Guillén, J; Montalbán, B

2018-01-01

Indoor radon is a major health concern as it is a known carcinogenic. Nowadays there is a trend towards a greater energy conservation in buildings, which is reflected in an increasing number of regulations. But, can this trend increase the indoor radon concentration? In this paper, we selected a radon prone area in Spain and focused on single-family dwellings constructed in a variety of architectural styles. These styles ranged from 1729 up to 2014, with varying construction techniques (from local resources to almost universally standard building materials) and regulations in force (from none to the Spanish regulation in force). The 226 Ra concentrations in soil and surface radon exhalation rates were rather similar in this area, mean values ranging 70-126Bq/kg and 49-100mBq/m 2 ·s, respectively. Indoor radon concentration was generally greater than the contribution from soil exhalation (surface exhalation rates), especially in New dwellings (1980-2014). Its concentration in dwellings built in the Traditional style (1729-1940) was significantly lower than in the new houses. This can be consequence of the air tightness of the dwellings as a consequence of the different regulations in force. In the period covered by the Traditional style, there was no regulation in force, and dwelling had loose air tight. Whereas in recent times, there are mandatory regulations assuring a better air tightness of the buildings. Refurbishment of Traditional dwellings also seems to increase the indoor radon concentration, as they must also comply with the regulations in force. Copyright © 2017 Elsevier B.V. All rights reserved.

Dissolved radon and uranium in groundwater in a potential coal seam gas development region (Richmond River Catchment, Australia).

PubMed

Atkins, Marnie L; Santos, Isaac R; Perkins, Anita; Maher, Damien T

2016-04-01

The extraction of unconventional gas resources such as shale and coal seam gas (CSG) is rapidly expanding globally and often prevents the opportunity for comprehensive baseline groundwater investigations prior to drilling. Unconventional gas extraction often targets geological layers with high naturally occurring radioactive materials (NORM) and extraction practices may possibly mobilise radionuclides into regional and local drinking water resources. Here, we establish baseline groundwater radon and uranium levels in shallow aquifers overlying a potential CSG target formation in the Richmond River Catchment, Australia. A total of 91 groundwater samples from six different geological units showed highly variable radon activities (0.14-20.33 Bq/L) and uranium levels (0.001-2.77 μg/L) which were well below the Australian Drinking Water Guideline values (radon; 100 Bq/L and uranium; 17 μg/L). Therefore, from a radon and uranium perspective, the regional groundwater does not pose health risks to consumers. Uranium could not explain the distribution of radon in groundwater. Relatively high radon activities (7.88 ± 0.83 Bq/L) in the fractured Lismore Basalt aquifer coincided with very low uranium concentrations (0.04 ± 0.02 μg/L). In the Quaternary Sediments aquifers, a positive correlation between U and HCO3(-) (r(2) = 0.49, p < 0.01) implied the uranium was present as uranyl-carbonate complexes. Since NORM are often enriched in target geological formations containing unconventional gas, establishing radon and uranium concentrations in overlying aquifers comprises an important component of baseline groundwater investigations. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Knowledge about radon and its associated risk perception in France].

PubMed

Beck, F; Richard, J B; Deutsch, A; Benmarhnia, T; Pirard, P; Roudier, C; Peretti-Watel, P

2013-12-01

Radon exposure is a major environmental risk in health. It remains badly known by the general population. It is the second cause of lung cancer, after tobacco smoking. The aim of this cross-sectional general population survey was to describe radon exposure risk knowledge and the socioeconomic factors related to this knowledge. The Cancer Barometer survey 2010 questioned the French population about its knowledge of radon as such and as health risk factor. This survey was a two-stage random sampling with computer-assisted telephone interview that was performed from April 3, 2010 to August 7, 2010 on a sample of 3,359 people aged 15 to 75 years old. Among people aged 15 to 75 years old, only one in five knows that radon is a natural gas coming from the ground. This knowledge is more frequent among people living in an area that is directly concerned by radon, among men and increases with age, with the level of education and the level of income. Radon risk remains still widely underestimated by the general public, including in areas concerned by this risk. When people were confronted with radon exposure, few intended to remedy by improving their home. The success of prevention initiatives implies the support and the collaboration of various national and local actors. To improve their impact for the prevention of lung cancers, it could be more effective to couple these actions with prevention messages on tobacco. Copyright © 2013 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

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

PubMed

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

2017-01-01

It is estimated that exposure to radon in Norwegian dwellings is responsible for as many as 300 deaths a year due to lung cancer. To address this, the authorities in Norway have developed a national action plan that has the aim of reducing exposure to radon in Norway (Norwegian Ministries, 2010). The plan includes further investigation of the relationship between radon hazard and geological conditions, and development of map-based tools for assessing the large spatial variation in radon hazard levels across Norway. The main focus of the present contribution is to describe how we generate map predictions of radon potential (RP), a measure of radon hazard, from available airborne gamma ray spectrometry (AGRS) surveys in Norway, and what impact these map predictions can be expected to have on radon protection work including land-use planning and targeted surveying. We have compiled 11 contiguous AGRS surveys centred on the most populated part of Norway around Oslo to produce an equivalent uranium map measuring 180 km × 102 km that represents the relative concentrations of radon in the near surface of the ground with a spatial resolution in the 100 s of metres. We find that this map of radon in the ground offers a far more detailed and reliable picture of the distribution of radon in the sub-surface than can be deduced from the available digital geology maps. We tested the performances of digital geology and AGRS data as predictors of RP. We find that digital geology explains approximately 40% of the observed variance in ln RP nationally, while the AGRS data in the Oslo area split into 14 bands explains approximately 70% of the variance in the same parameter. We also notice that there are too few indoor data to characterise all geological settings in Norway which leaves areas in the geology-based RP map in the Oslo area, and elsewhere, unclassified. The AGRS RP map is derived from fewer classes, all characterised by more than 30 indoor measurements, and the corresponding RP map of the Oslo area has no unclassified parts. We used statistics of proportions to add 95% confidence limits to estimates of RP on our predictive maps, offering public health strategists an objective measure of uncertainty in the model. The geological and AGRS RP maps were further compared in terms of their performances in correctly classifying local areas known to be radon affected and less affected. Both maps were accurate in their predictions; however the AGRS map out-performed the geology map in its ability to offer confident predictions of RP for all of the local areas tested. We compared the AGRS RP map with the 2015 distribution of population in the Oslo area to determine the likely impact of radon contamination on the population. 11.4% of the population currently reside in the area classified as radon affected. 34% of ground floor living spaces in this affected area are expected to exceed the maximum limit of 200 Bq/m 3 , while 8.4% of similar spaces outside the affected area exceed this same limit, indicating that the map is very efficient at separating areas with quite different radon contamination profiles. The usefulness of the AGRS RP map in guiding new indoor radon surveys in the Oslo area was also examined. It is shown that indoor measuring programmes targeted on elevated RP areas could be as much as 6 times more efficient at identifying ground floor living spaces above the radon action level compared with surveys based on a random sampling strategy. Also, targeted measuring using the AGRS RP map as a guide makes it practical to search for the worst affected homes in the Oslo area: 10% of the incidences of very high radon contamination in ground floor living spaces (≥800 Bq/m 3 ) are concentrated in just 1.2% of the populated part of the area. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

A novel joint timing/frequency synchronization scheme based on Radon-Wigner transform of LFM signals in CO-OFDM systems

NASA Astrophysics Data System (ADS)

Liu, Jianfei; Wei, Ying; Zeng, Xiangye; Lu, Jia; Zhang, Shuangxi; Wang, Mengjun

2018-03-01

A joint timing and frequency synchronization method has been proposed for coherent optical orthogonal frequency-division multiplexing (CO-OFDM) system in this paper. The timing offset (TO), integer frequency offset (FO) and the fractional FO can be realized by only one training symbol, which consists of two linear frequency modulation (LFM) signals with opposite chirp rates. By detecting the peak of LFM signals after Radon-Wigner transform (RWT), the TO and the integer FO can be estimated at the same time, moreover, the fractional FO can be acquired correspondingly through the self-correlation characteristic of the same training symbol. Simulation results show that the proposed method can give a more accurate TO estimation than the existing methods, especially at poor OSNR conditions; for the FO estimation, both the fractional and the integer FO can be estimated through the proposed training symbol with no extra overhead, a more accurate estimation and a large FO estimation range of [ - 5 GHz, 5GHz] can be acquired.

Task Order 2 enhanced preliminary assessment, Fort Douglas, Salt Lake City, Utah. Final report, October-December 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mirchandani, M.G.; Johnson, G.M.; Bove, L.J.

1989-12-01

An enhanced preliminary assessment (PA) of air pollution was conducted at Fort Douglas (FD) under the Base Closure Program. FD is an active military installation located in Salt Lake City, Utah. The Fort consists of the U.S. Army and Navy Reserve Centers, family housing units, a military museum, a chapel, clubs, swimming pool, a cemetery and various other support buildings. 50.8 acres of the 119 acres owned by FD are proposed to be excessed. Based on information obtained during the onsite visit and from available drawings and reports, three environmentally significant operations (ESOs) have been identified. These include asbestos, radonmore » and transformers. No immediate action has been recommended for any of the ESOs. Site investigations have been recommended for asbestos and the transformers. A radon sampling program is currently underway at FD. This radon sampling program is being conducted by Fort Carson; the results should be evaluated as they become available, and the appropriate actions taken.« less

Beam hardening correction for interior tomography based on exponential formed model and radon inversion transform

NASA Astrophysics Data System (ADS)

Chen, Siyu; Zhang, Hanming; Li, Lei; Xi, Xiaoqi; Han, Yu; Yan, Bin

2016-10-01

X-ray computed tomography (CT) has been extensively applied in industrial non-destructive testing (NDT). However, in practical applications, the X-ray beam polychromaticity often results in beam hardening problems for image reconstruction. The beam hardening artifacts, which manifested as cupping, streaks and flares, not only debase the image quality, but also disturb the subsequent analyses. Unfortunately, conventional CT scanning requires that the scanned object is completely covered by the field of view (FOV), the state-of-art beam hardening correction methods only consider the ideal scanning configuration, and often suffer problems for interior tomography due to the projection truncation. Aiming at this problem, this paper proposed a beam hardening correction method based on radon inversion transform for interior tomography. Experimental results show that, compared to the conventional correction algorithms, the proposed approach has achieved excellent performance in both beam hardening artifacts reduction and truncation artifacts suppression. Therefore, the presented method has vitally theoretic and practicable meaning in artifacts correction of industrial CT.

A trace map comparison algorithm for the discrete fracture network models of rock masses

NASA Astrophysics Data System (ADS)

Han, Shuai; Wang, Gang; Li, Mingchao

2018-06-01

Discrete fracture networks (DFN) are widely used to build refined geological models. However, validating whether a refined model can match to reality is a crucial problem, concerning whether the model can be used for analysis. The current validation methods include numerical validation and graphical validation. However, the graphical validation, aiming at estimating the similarity between a simulated trace map and the real trace map by visual observation, is subjective. In this paper, an algorithm for the graphical validation of DFN is set up. Four main indicators, including total gray, gray grade curve, characteristic direction and gray density distribution curve, are presented to assess the similarity between two trace maps. A modified Radon transform and loop cosine similarity are presented based on Radon transform and cosine similarity respectively. Besides, how to use Bézier curve to reduce the edge effect is described. Finally, a case study shows that the new algorithm can effectively distinguish which simulated trace map is more similar to the real trace map.

Barometric pressure forcing on radon-222 and temperature in fumarolic gases: a tool to describe flow-rate dynamics

NASA Astrophysics Data System (ADS)

Richon, P.; Salaun, A.; Boudon, G.; Villemant, B.; Crispi, O.; Sabroux, J.

2010-12-01

We propose two conceptual models for the dynamics of fumarolic gases, during their ascent through the volcano plumbing, based on radon-222 and temperature data collected on fumaroles of La Soufrière volcano (Guadeloupe,FWI) together with local barometric pressure, and on a new interpretation of older data collected on Merapi volcano (1), Indonesia. All these in-situ measurements prove that the diurnal (24h, S1 barometric wave) and semidiurnal (12h, S2 barometric wave) variations in radon concentration are clearly observable, and positively or negatively correlated with barometric pressure variation. Two models are used to interpret this correlation. The first model, called “Accumulation mode”, is characterized by an initial and negligible deep radon-222 source and by a major contribution of radon-222 from conduit walls and connected fractures (emanation and exhalation mechanisms) during the gas ascent through the fumarolic system. This model is substantiated by a positive correlation between radon and pressure in the Merapi fumaroles. The second model, or “Decay mode”, is exemplified by a negative correlation between radon and pressure as measured in fumaroles at La Soufrière volcano. It is characterized by radioactive decay of a strong initial radon-222 source generated by a deeper reservoir (hydrothermal system or magmatic chamber) whereas contribution by conduit walls and connected fractures to the total radon-222 activity in the fumarole is comparatively minor during the transit time of the gas. In these two modes, it is possible to infer that, for transit times longer than ca. 21 days, the barometric pressure does not modulate the radon signal. Thus, the simultaneous monitoring of radon-222, temperature and barometric pressure provides a precise fumarole flowmeter. In addition, it is a tool to decipher shallow versus deep feeding of volcanic fumaroles that should prove useful for volcano monitoring. (1)Zimmer, M. & Erzinger, J. Continuous H2O, CO2, 222Rn and temperature measurements on Merapi Volcano, Indonesia. J. Volcanol. Geoth. Res. 125, 25-38 (2003).

Radon-domain interferometric interpolation for reconstruction of the near-offset gap in marine seismic data

NASA Astrophysics Data System (ADS)

Xu, Zhuo; Sopher, Daniel; Juhlin, Christopher; Han, Liguo; Gong, Xiangbo

2018-04-01

In towed marine seismic data acquisition, a gap between the source and the nearest recording channel is typical. Therefore, extrapolation of the missing near-offset traces is often required to avoid unwanted effects in subsequent data processing steps. However, most existing interpolation methods perform poorly when extrapolating traces. Interferometric interpolation methods are one particular method that have been developed for filling in trace gaps in shot gathers. Interferometry-type interpolation methods differ from conventional interpolation methods as they utilize information from several adjacent shot records to fill in the missing traces. In this study, we aim to improve upon the results generated by conventional time-space domain interferometric interpolation by performing interferometric interpolation in the Radon domain, in order to overcome the effects of irregular data sampling and limited source-receiver aperture. We apply both time-space and Radon-domain interferometric interpolation methods to the Sigsbee2B synthetic dataset and a real towed marine dataset from the Baltic Sea with the primary aim to improve the image of the seabed through extrapolation into the near-offset gap. Radon-domain interferometric interpolation performs better at interpolating the missing near-offset traces than conventional interferometric interpolation when applied to data with irregular geometry and limited source-receiver aperture. We also compare the interferometric interpolated results with those obtained using solely Radon transform (RT) based interpolation and show that interferometry-type interpolation performs better than solely RT-based interpolation when extrapolating the missing near-offset traces. After data processing, we show that the image of the seabed is improved by performing interferometry-type interpolation, especially when Radon-domain interferometric interpolation is applied.

Radon as a natural tracer for underwater cave exploration and hypogenic cave formation

NASA Astrophysics Data System (ADS)

Csondor, Katalin; Erőss, Anita; Horváth, Ákos; Szieberth, Dénes

2017-04-01

Using 222Rn as a natural tracer is a novel approach in underwater cave exploration and in the research of active hypogenic caves. The research area, the Molnár János cave is one of the largest caves of an unique hypogenic karst system, the Buda Thermal Karst (Budapest, Hungary). The cave system is mainly characterized by water-filled passages. The cave is located at one of the main discharge areas of the Buda Thermal Karst and the major outflow point of the waters of the cave system is the Boltív spring, which feeds the artificial Malom Lake. Previous complex hydrogeological studies and radon measurements in the cave system and in the spring established the highest radon concentration (71 Bq/L, where the average is 44 Bq/L) in the springwater. The origin of radon was identified in the form of iron-hydroxide containing biofilms, which form by mixing of waters and efficiently adsorb radium from the thermal water component and cause local radon anomalies. Since mixing of waters is responsible for the formation of the cave as well, these iron-hydroxide containing biofilms and consequently high radon concentrations mark the active cave forming zones. The aim of the study was to use the radon as a natural tracer to locate active mixing and cave forming zones. Based on previous radon measurements it is supposed that the active mixing and cave forming zone has to be close to the spring, since the highest radon concentration was measured there. Therefore, the radon activity concentration mapping was carried out with the help of divers and involving that part of the cave which closest to the spring. Based on our measurements the highest radon concentration (84 Bq/L) ever was achieved in the springwater. Based on the radon concentration distribution direct connection and active karst conduit was established between the spring and the deepest room of the researched part of the cave, which was verified by artificial tracer as well. However, the distribution of radon in the cave passages shows lower concentrations (18-46 Bq/L) compared to the spring, therefore an addition deep inflow from a hitherto unknown cave passages is assumed, from which waters with high radon content arrive to the spring. These passages are supposed to be in the active cave formation (mixing) zone. The Buda Thermal Karst research was funded by the Hungarian Scientific Research Fund under the grant agreement no. NK 101356.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

1984-04-01

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

Identification of Piecewise Linear Uniform Motion Blur

NASA Astrophysics Data System (ADS)

Patanukhom, Karn; Nishihara, Akinori

A motion blur identification scheme is proposed for nonlinear uniform motion blurs approximated by piecewise linear models which consist of more than one linear motion component. The proposed scheme includes three modules that are a motion direction estimator, a motion length estimator and a motion combination selector. In order to identify the motion directions, the proposed scheme is based on a trial restoration by using directional forward ramp motion blurs along different directions and an analysis of directional information via frequency domain by using a Radon transform. Autocorrelation functions of image derivatives along several directions are employed for estimation of the motion lengths. A proper motion combination is identified by analyzing local autocorrelation functions of non-flat component of trial restored results. Experimental examples of simulated and real world blurred images are given to demonstrate a promising performance of the proposed scheme.

Using {sup 222}Rn as a tracer of geophysical processes in underground environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lacerda, T.; Anjos, R. M.; Valladares, D. L.

2014-11-11

Radon levels in two old mines in San Luis, Argentina, are reported and analyzed. These mines are today used for touristic visitation. Our goal was to assess the potential use of such radioactive noble gas as tracer of geological processes in underground environments. CR-39 nuclear track detectors were used during the winter and summer seasons. The findings show that the significant radon concentrations reported in this environment are subject to large seasonal modulations, due to the strong dependence of natural ventilation on the variations of outside temperature. The results also indicate that radon pattern distribution appear as a good methodmore » to localize unknown ducts, fissures or secondary tunnels in subterranean environments.« less

Specific features of electric field in the atmosphere and Radon emanations in Tunkin Basin of Baikal rift zone

NASA Astrophysics Data System (ADS)

Soloviev, S.; Loktev, D.

2013-05-01

Development of methods for diagnosing local crust encourages finding new ways for preventing hazardous geologic phenomena. Using measurements of several geophysical fields in addition to seismic methods enables to improve the existing methods and increase their reliability. In summer of 2009 and 2010, complex geophysical acquisition company was organized in the Tunkin Basin of the Baikal rift zone in South-Eastern Siberia, that runs 200 km to East-West from the southern tip of Baikal. Stationary observations were carried out in the central part of the Tunkin Basin, at the Geophysical observatory "I" of Institute of Solar-Terrestrial Physics of Siberian Branch of RAS and "II" near the Arshan settlement. Along with observations of microseismic noise and electric field variations in soil, there were performed measurements of electric field strength (Ez) in lowest atmosphere and volumetric activity of natural Radon in subsoil. Meteorological parameters were monitored with the use of DavisVantagePro meteorological stations. The analysis of observations showed that characteristic features of electric field in near-surface atmosphere are majorly defined by complex orography of the place and, consequently, by quickly changing meteorological conditions: thunderstorm activity and other mesometeorological events (with characteristic scale of tens of km and few hours long) in nearby rocks. The results of Ez(t) measurements performed under "good" weather conditions showed that the character of field variations depended on the local time with their maximum in daylight hours and minimum in the night. The analysis of Radon volumetric activity evidenced that its variations are influenced by atmospheric pressure and tides, and such influence is different at points "I" and "II". In particular, the tidal and atmospheric influence on Radon variations is more pronounced at "II" if compared to "I", which can be explained by locations of the registration points. Registration Point "II" is located close to tectonic faults, while "I" is in the center of the basin with its quite thick layer of sediments. Axial section observations of spatial inhomogeneities of electric field and Radon emanation were set along and across the Tunkin Basin. Observation points were set 3 to 10 km apart depending on the local relief. Each point was registering for 60 min under the conditions of "good" weather. There were analysed changes in mean strength of electric field and Radon volumetric activity as a function of distance along the axial section. It was found out that volumetric activity and electric field strength change in phase opposition - radon volumetric activity increase results in more intense ionization in near-surface atmosphere and consequently to decrease in the electric field strength. The concentration of Radon in subsoil atmosphere increases, and electric field strength decreases when approaching to rift zones rimming the Tunkin Basin from North and South. The results of axial section observations can be successfully used when mapping geological inhomogeneities in the Earth's crust. The research was done with financial support of RFBR, project# 12-05-00578

Improved predictive mapping of indoor radon concentrations using ensemble regression trees based on automatic clustering of geological units.

PubMed

Kropat, Georg; Bochud, Francois; Jaboyedoff, Michel; Laedermann, Jean-Pascal; Murith, Christophe; Palacios Gruson, Martha; Baechler, Sébastien

2015-09-01

According to estimations around 230 people die as a result of radon exposure in Switzerland. This public health concern makes reliable indoor radon prediction and mapping methods necessary in order to improve risk communication to the public. The aim of this study was to develop an automated method to classify lithological units according to their radon characteristics and to develop mapping and predictive tools in order to improve local radon prediction. About 240 000 indoor radon concentration (IRC) measurements in about 150 000 buildings were available for our analysis. The automated classification of lithological units was based on k-medoids clustering via pair-wise Kolmogorov distances between IRC distributions of lithological units. For IRC mapping and prediction we used random forests and Bayesian additive regression trees (BART). The automated classification groups lithological units well in terms of their IRC characteristics. Especially the IRC differences in metamorphic rocks like gneiss are well revealed by this method. The maps produced by random forests soundly represent the regional difference of IRCs in Switzerland and improve the spatial detail compared to existing approaches. We could explain 33% of the variations in IRC data with random forests. Additionally, the influence of a variable evaluated by random forests shows that building characteristics are less important predictors for IRCs than spatial/geological influences. BART could explain 29% of IRC variability and produced maps that indicate the prediction uncertainty. Ensemble regression trees are a powerful tool to model and understand the multidimensional influences on IRCs. Automatic clustering of lithological units complements this method by facilitating the interpretation of radon properties of rock types. This study provides an important element for radon risk communication. Future approaches should consider taking into account further variables like soil gas radon measurements as well as more detailed geological information. Copyright © 2015 Elsevier Ltd. All rights reserved.

Radon and its daughter products behaviour in the air of an underground tourist route in the former arsenic and gold mine in Złoty Stok (Sudety Mountains, SW Poland).

PubMed

Przylibski, T A

2001-01-01

This paper describes the occurrence of radon and its daughter products in the accessible workings, partially open to the public, in the former arsenic and gold mine in Zloty Stok. The geology of the area and the characteristics of the workings provide the background for explanation of the genesis of radon and its daughter products and of the spatial and temporal variations in their concentrations. The results demonstrate that well-ventilated areas along the tourist route have the lowest values of all the measured parameters and that temporal variations of these parameters are irregular. The highest concentration values for radon (up to 18.50kBq/m3) and its daughter products (up to 14.49kBq/m3) have been recorded in the workings with obstructed natural ventilation. These are the areas where seasonal oscillations in the concentrations of these isotopes have been registered, with the maxima in summer and the minima in winter. These sections of the workings are inaccessible to the casual visitor. Radon is supplied to the workings from the side walls and its concentration is influenced, most of all, by ventilation and the degree of rock fissuring. The reason is the uniform and not very high content of 226Ra in the rocks where the galleries were excavated. Only locally, in the workings of the Gertruda adit lying outside the tourist route, do open fault zones have significant influence on enhanced concentrations of radon and its daughter products. These fault zones constitute effective routes of radon migration to the workings. In spite of this, it must be stated that neither guides nor tourists are exposed to excessive concentrations of radon or its daughter products in the tourist route area. However, the extension of the route to other workings will require the introduction of forced ventilation in order to lower theconcentration of radon and its daughter products. reserved.

Investigating Local and Remote Terrestrial Influence on Air Masses at Contrasting Antarctic Sites Using Radon-222 and Back Trajectories

NASA Astrophysics Data System (ADS)

Chambers, S. D.; Choi, T.; Park, S.-J.; Williams, A. G.; Hong, S.-B.; Tositti, L.; Griffiths, A. D.; Crawford, J.; Pereira, E.

2017-12-01

We report on the first summer of high-sensitivity radon measurements from a two-filter detector at Jang Bogo Station (Terra Nova Bay) and contrast them with simultaneous observations at King Sejong Station (King George Island). King Sejong radon concentrations were characteristic of a marine baseline station (0.02-0.3 Bq m-3), whereas Jang Bogo values were highly variable (0.06-5.2 Bq m-3), mainly due to emissions from exposed coastal ground (estimated mean flux 0.09-0.11 atoms cm-2 s-1) and shallow atmospheric mixing depths. For wind speeds of ≤3.5 m s-1 the influence of local radon emissions became increasingly more prominent at both sites. A cluster analysis of back trajectories from King Sejong (62°S) revealed a fairly even distribution between air masses that had passed recently over South America, the Southern Ocean, and Antarctica, whereas at Jang Bogo (75°S) 80% of events had recently passed over the Ross Ice Shelf and West Antarctica, 12% were synoptically forced over Cape Adare, and 8% were associated with subsidence over the Antarctic interior and katabatic flow to the station. When cross-checked against radon concentrations, only half of the back trajectories ending at Jang Bogo that had indicated distant contact with nonpolar southern hemisphere continents within the past 10 days showed actual signs of terrestrial influence. A simple-to-implement technique based on high-pass filtered absolute humidity is developed to distinguish between predominantly katabatic, oceanic, and near-coastal air masses for characterization of trace gas and aerosol measurements at coastal East Antarctic sites.

Radon measurements in an area of tectonic zone: A case study in Central Slovakia.

PubMed

Mojzeš, Andrej; Marko, František; Porubčanová, Barbara; Bartošová, Andrea

2017-01-01

General overviews of the spatial distribution of radon and other natural radionuclides in the geological basement as commonly presented on regional or country maps tend to offer a low density of information, insufficient for gaining relevant knowledge of the environmental impact, especially in the areas of tectonic zones often assumed to be radon prone and therefore dangerous for the human population. An additional survey, employing radon measurements in soil and indoor air, was carried out seeking to provide a more detailed characterization of the expressive fault zone of the Malá Magura in the Horná Nitra region of Central Slovakia. Eventually, the results of soil 222 Rn volume activity measurements along two short profiles crossing the assumed fault line did not reveal any indication of active nature of local tectonics, but merely pointed to an existence of a zone of contact between different types of rocks. The results of indoor radon measurements in dwellings of two villages lying on the studied fault showed values that were lower than those commonly observed on the Slovak territory, ruling out any negative health impact on population. Nevertheless, in order to add new findings to an already well established study of geological structure of the region, the indoor radon data collected through a previous survey require a further analysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rapid Feature Extraction via the Radon Transform.

DTIC Science & Technology

1988-02-01

preprint NSF- ITP -86- 138, submitted to Biological Cybernetics.(1986) [14] G.R. Gindi, A.F. Gmitro. and K. Parthasarathy, "\\Vinner-Take- All Net- works and...34Associative Holographic Memories," IBM J. Res. Development 13, 156 (1969). [46] A. F. Gmitro, and G. R. Gindi, "Computed Tomography Videography: An

Physical setting and natural sources of exposure to carcinogenic trace elements and radionuclides in Lahontan Valley, Nevada

USGS Publications Warehouse

Seiler, Ralph L.

2012-01-01

In Lahontan Valley, Nevada, arsenic, cobalt, tungsten, uranium, radon, and polonium-210 are carcinogens that occur naturally in sediments and groundwater. Arsenic and cobalt are principally derived from erosion of volcanic rocks in the local mountains and tungsten and uranium are derived from erosion of granitic rocks in headwater reaches of the Carson River. Radon and 210Po originate from radioactive decay of uranium in the sediments. Arsenic, aluminum, cobalt, iron, and manganese concentrations in household dust suggest it is derived from the local soils. Excess zinc and chromium in the dust are probably derived from the vacuum cleaner used to collect the dust, or household sources such as the furnace. Some samples have more than 5 times more cobalt in the dust than in the local soil, but whether the source of the excess cobalt is anthropogenic or natural cannot be determined with the available data. Cobalt concentrations are low in groundwater, but arsenic, uranium, radon, and 210Po concentrations often exceed human-health standards, and sometime greatly exceed them. Exposure to radon and its decay products in drinking water can vary significantly depending on when during the day that the water is consumed. Although the data suggests there have been no long term changes in groundwater chemistry that corresponds to the Lahontan Valley leukemia cluster, the occurrence of the very unusual leukemia cluster in an area with numerous 210Po and arsenic contaminated wells is striking, particularly in conjunction with the exceptionally high levels of urinary tungsten in Lahontan Valley residents. Additional research is needed on potential exposure pathways involving food or inhalation, and on synergistic effects of mixtures of these natural contaminants on susceptibility to development of leukemia.

Physical setting and natural sources of exposure to carcinogenic trace elements and radionuclides in Lahontan Valley, Nevada.

PubMed

Seiler, Ralph

2012-04-05

In Lahontan Valley, Nevada, arsenic, cobalt, tungsten, uranium, radon, and polonium-210 are carcinogens that occur naturally in sediments and groundwater. Arsenic and cobalt are principally derived from erosion of volcanic rocks in the local mountains and tungsten and uranium are derived from erosion of granitic rocks in headwater reaches of the Carson River. Radon and 210Po originate from radioactive decay of uranium in the sediments. Arsenic, aluminum, cobalt, iron, and manganese concentrations in household dust suggest it is derived from the local soils. Excess zinc and chromium in the dust are probably derived from the vacuum cleaner used to collect the dust, or household sources such as the furnace. Some samples have more than 5 times more cobalt in the dust than in the local soil, but whether the source of the excess cobalt is anthropogenic or natural cannot be determined with the available data. Cobalt concentrations are low in groundwater, but arsenic, uranium, radon, and 210Po concentrations often exceed human-health standards, and sometime greatly exceed them. Exposure to radon and its decay products in drinking water can vary significantly depending on when during the day that the water is consumed. Although the data suggests there have been no long term changes in groundwater chemistry that corresponds to the Lahontan Valley leukemia cluster, the occurrence of the very unusual leukemia cluster in an area with numerous 210Po and arsenic contaminated wells is striking, particularly in conjunction with the exceptionally high levels of urinary tungsten in Lahontan Valley residents. Additional research is needed on potential exposure pathways involving food or inhalation, and on synergistic effects of mixtures of these natural contaminants on susceptibility to development of leukemia. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Implementing remediation measures against radon for houses located in Baita-Stei uraniferous region

NASA Astrophysics Data System (ADS)

Cosma, Constantin; Cucos (Dinu), Alexandra; Papp, Botond; Iurian, Andra-Rada; Moldovan, Mircea; Burghele, Bety; Dumitru (Rusu), Oana; Begy, Robert; Dicu, Tiberius; Fulea, Dan; Cindea, Ciprian; Nita, Dan; Suciu, Liviu; Banciu, Gheorghe; Sainz, Carlos

2014-05-01

Radon is the second cause after smoking, inducing lung cancer. Twenty one houses from the area of Băiţa-Ştei Old Uranium Mine (Romania) have been selected for remediation against radon, in the frame of the IRART project (2010-2013). The selection was performed from a batch of 303 houses (representing 58% of the total houses from Băita, Campani, Fînate and Nucet localities), following two campaigns of indoor radon measurements. Analysis of the preliminary data identified the targeted houses having initial indoor radon values between 800 - 2500 Bq m-3. The remediation techniques have been particularly selected for each house after detailed diagnostic measurements of indoor and outdoor radon, including subsoil, water supply and building materials, to identify the major radon source in each location. The different mitigation methods (e.g. pressurization, depressurization, aeolian extraction, antiradon membranes, isolation) were firstly tested for a representative pilot-house. The efficiency of the remediation strategy was estimated in each case based on the coefficient of remediation (R) through both continuous and integrated measurements: R=(Ci-Cf)/Cix100 where Ci and Cf are the radon concentrations before and after the remediation. The final results of the project showed that the applied mitigation techniques were appropriate for our purpose, leading to values of the coefficient of remediation/house in a range of 65.2-95.1%, with a medium value of 80.9%. Our results are comparable with the ones obtained in the RADPAR European Project (2009-2012), which involved 14 countries. The medium radon concentration (992 Bq m-3) of the 21 targeted houses was reduced to a value of 160 Bq m-3. Based on the TF-TR model for the estimation of radon exposure risk, the project implementation will reduce to half the lung cancer cases for the habitants of theses houses. Acknowledgements: The survey was supported by the Sectorial Operational Programme "Increase of Economic Competitiveness" co-financed by the European Regional Development Fund under the project IRART 586-12487, Contract No. 160/15.06.2010.

Seasonal Variability in European Radon Measurements

NASA Astrophysics Data System (ADS)

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

2009-04-01

In temperate climates, domestic radon concentration levels are generally seasonally dependent, the level in the home reflecting the convolution of two time-dependent functions. These are the source soil-gas radon concentration itself, and the principal force driving radon into the building from the soil, namely the pressure-difference between interior and exterior environment. While the meteorological influence can be regarded as relatively uniform on a European scale, its variability being defined largely by the influence of North-Atlantic weather systems, soil-gas radon is generally more variable as it is essentially geologically dependent. Seasonal variability of domestic radon concentration can therefore be expected to exhibit geographical variability, as is indeed the case. To compensate for the variability of domestic radon levels when assessing the long term radon health risks, the results of individual short-term measurements are generally converted to equivalent mean annual levels by application of a Seasonal Correction Factor (SCF). This is a multiplying factor, typically derived from measurements of a large number of homes, applied to the measured short-term radon concentration to provide a meaningful annual mean concentration for dose-estimation purposes. Following concern as to the universal applicability of a single SCF set, detailed studies in both the UK and France have reported location-specific SCF sets for different regions of each country. Further results indicate that SCFs applicable to the UK differ significantly from those applicable elsewhere in Europe and North America in both amplitude and phase, supporting the thesis that seasonal variability in indoor radon concentration cannot realistically be compensated for by a single national or international SCF scheme. Published data characterising the seasonal variability of European national domestic radon concentrations, has been collated and analysed, with the objective of identifying correlations between published datasets and local geographic/geological conditions. Available data included regional SCF figures from the United Kingdom and from France, together with nationally-consolidated results from a number of other European countries. Analysis of this data shows significant variability between different countries and from region to region within those countries where regional data is available. Overall, radon-rich sedimentary geologies, particularly high porosity limestones etc., exhibit high seasonal variation, while radon-rich igneous geologies demonstrate relatively constant, albeit somewhat higher, radon concentration levels. Examples of the former can be found in the Pennines and South Downs in England, Languedoc and Brittany in France. Greatest variability is found in Switzerland, still subject to the ongoing Alpine orogeny, where the inhabited part of the country is largely overlain with recently-deposited light, porous sediments. Low-variability high-radon regions include the granite-rich Cornwall/Devon peninsular in England, and Auvergne and the Ardennes in France, all components of the Devonian-Carboniferous Hercynian belt, which extends from the Iberian peninsular through South-West Ireland and South-West England to France and Germany.

A Novel Optical/digital Processing System for Pattern Recognition

NASA Technical Reports Server (NTRS)

Boone, Bradley G.; Shukla, Oodaye B.

1993-01-01

This paper describes two processing algorithms that can be implemented optically: the Radon transform and angular correlation. These two algorithms can be combined in one optical processor to extract all the basic geometric and amplitude features from objects embedded in video imagery. We show that the internal amplitude structure of objects is recovered by the Radon transform, which is a well-known result, but, in addition, we show simulation results that calculate angular correlation, a simple but unique algorithm that extracts object boundaries from suitably threshold images from which length, width, area, aspect ratio, and orientation can be derived. In addition to circumventing scale and rotation distortions, these simulations indicate that the features derived from the angular correlation algorithm are relatively insensitive to tracking shifts and image noise. Some optical architecture concepts, including one based on micro-optical lenslet arrays, have been developed to implement these algorithms. Simulation test and evaluation using simple synthetic object data will be described, including results of a study that uses object boundaries (derivable from angular correlation) to classify simple objects using a neural network.

Application of high-resolution linear Radon transform for Rayleigh-wave dispersive energy imaging and mode separating

USGS Publications Warehouse

Luo, Y.; Xia, J.; Miller, R.D.; Liu, J.; Xu, Y.; Liu, Q.

2008-01-01

Multichannel Analysis of Surface Waves (MASW) analysis is an efficient tool to obtain the vertical shear-wave profile. One of the key steps in the MASW method is to generate an image of dispersive energy in the frequency-velocity domain, so dispersion curves can be determined by picking peaks of dispersion energy. In this paper, we image Rayleigh-wave dispersive energy and separate multimodes from a multichannel record by high-resolution linear Radon transform (LRT). We first introduce Rayleigh-wave dispersive energy imaging by high-resolution LRT. We then show the process of Rayleigh-wave mode separation. Results of synthetic and real-world examples demonstrate that (1) compared with slant stacking algorithm, high-resolution LRT can improve the resolution of images of dispersion energy by more than 50% (2) high-resolution LRT can successfully separate multimode dispersive energy of Rayleigh waves with high resolution; and (3) multimode separation and reconstruction expand frequency ranges of higher mode dispersive energy, which not only increases the investigation depth but also provides a means to accurately determine cut-off frequencies.

Observation of lunar radon emanation with the Apollo 15 alpha particle spectrometer.

NASA Technical Reports Server (NTRS)

Gorenstein, P.; Bjorkholm, P.

1972-01-01

The alpha particle spectrometer, a component of the orbital Sim Bay group of 'geochemistry' experiments on Apollo 15, was designed to detect alpha particles emitted during the decay of isotopes of radon gas and her daughter products. The purpose was to measure the gross activity of radon on the lunar surface and to find possible regions of increased local activity. Results are presented from a partial analysis of Apollo 15 data. For the moon as a whole, Rn220 was not observed and the upper limit on its decay rate above the lunar surface is 0.00038 disintegrations/sq cm-sec. Rn222 was marginally observed. Possible variations of radon activity on the lunar surface are being investigated. Po210 (a daughter product of Rn222) has been detected in a broad region from west of Mare Crisium to the Van de Graaff-Orlov region. The observed count rate is (4.6 plus or minus 1.4) x 0.001 disintegrations/sq cm-sec. The observed level of Po210 activity is in excess of the amount that would be in equilibrium with Rn222 by about an order of magnitude. This implies that larger levels of radon emanation have occurred on the moon within a time scale of 10 to 100 years.

Radon in a self-selected sample of Israeli homes, schools, and workplaces.

PubMed

Westin, J B; Cramer, Z; Richter, E D; Shani, J; Ne'eman, E; Elyakim, O; Tal, Y

Some 1,100 residences and places of work and 400 schoolrooms in Israel were tested for ambient air radon activity concentration in response to requests by the owners, tenants, or local authorities. A polyethylene vial containing activated charcoal was exposed to room air in each of these structures for 7 days, sealed, and transported to the laboratory. Adsorbed radon was extracted with a toluene-based cocktail which was then subjected to liquid scintillation counting. Mean radon activity concentrations were found to vary from city to city by more than an order of magnitude, indicating strong regional differences. The countrywide geometric mean was found to be 38 Bq/m3; the median, 37. The range for these means was 6-77 Bq/m3; for the medians, 11-100 Bq/m3. The highest reading was 9,100 Bq/m3. Our results are basically in line with those from the United States and much of Europe, but apparently higher than those found in the United Kingdom and Japan. It may be fairly said that mass testing for radon (222Rn) inside buildings in the United States began in the wake of the finding of a radon activity concentration in excess of 100,000 Bq/m3 in the home of the Watras family in Boyertown, PA in December 1984. To date, literally millions of American buildings have been tested, and mandatory testing of schoolrooms has begun in some states. In Israel, by contrast, where such a dramatically high measurement has not (yet) occurred, only 5 structures had been checked for radon by 1989.(ABSTRACT TRUNCATED AT 250 WORDS)

Atmospheric stability effects on potential radiological releases at a nuclear research facility in Romania: Characterising the atmospheric mixing state.

PubMed

Chambers, Scott D; Galeriu, Dan; Williams, Alastair G; Melintescu, Anca; Griffiths, Alan D; Crawford, Jagoda; Dyer, Leisa; Duma, Marin; Zorila, Bogdan

2016-04-01

A radon-based nocturnal stability classification scheme is developed for a flat inland site near Bucharest, Romania, characterised by significant local surface roughness heterogeneity, and compared with traditional meteorologically-based techniques. Eight months of hourly meteorological and atmospheric radon observations from a 60 m tower at the IFIN-HH nuclear research facility are analysed. Heterogeneous surface roughness conditions in the 1 km radius exclusion zone around the site hinder accurate characterisation of nocturnal atmospheric mixing conditions using conventional meteorological techniques, so a radon-based scheme is trialled. When the nocturnal boundary layer is very stable, the Pasquill-Gifford "radiation" scheme overestimates the atmosphere's capacity to dilute pollutants with near-surface sources (such as tritiated water vapour) by 20% compared to the radon-based scheme. Under these conditions, near-surface wind speeds drop well below 1 m s(-1) and nocturnal mixing depths vary from ∼ 25 m to less than 10 m above ground level (a.g.l.). Combining nocturnal radon with daytime ceilometer data, we were able to reconstruct the full diurnal cycle of mixing depths. Average daytime mixing depths at this flat inland site range from 1200 to 1800 m a.g.l. in summer, and 500-900 m a.g.l. in winter. Using tower observations to constrain the nocturnal radon-derived effective mixing depth, we were able to estimate the seasonal range in the Bucharest regional radon flux as: 12 mBq m(-2) s(-1) in winter to 14 mBq m(-2) s(-1) in summer. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Exploring the Origin of Kinematically Irregular Galaxies with MaNGA

NASA Astrophysics Data System (ADS)

Stark, David Vincent; Bundy, Kevin; Westfall, Kyle; Bershady, Matthew; Cheung, Edmond; Soler, Juan; Brinchmann, Jarle; Abraham, Roberto; Bizyaev, Dmitry; Masters, Karen; Weijmans, Anne-Marie; Chen, Yanmei; Jin, Yifei; Drory, Niv; Lopes, Alexandre Roman; Law, David

2018-01-01

Deviations from normal rotation in galaxies may have a number of potential drivers, including tidal interactions, gas inflows/outflows, spiral structure, bar/oval distortions, or other internally generated instabilities. Thanks to new massive IFU surveys like MaNGA, we can now characterize the gas and stellar kinematics of thousands of galaxies in the local universe, enabling statistical analyses on the frequency of disturbed kinematics, their origin, and their impact on their host galaxies. We present a census of kinematics in MaNGA using a modified version of the Radon transform to map radial variations in kinematic position angles (PA). We discuss the frequency of kinematically irregular disks, and describe commonly observed patterns in radial PA profiles. In order to constrain the drivers of these kinematic signatures, we analyze how they correlate with galaxy mass, environment, star formation history, and gas-phase metallicity.

Radon measurements in the lower tropical stratosphere - Evidence for rapid vertical transport and dehydration of tropospheric air

NASA Technical Reports Server (NTRS)

Kritz, Mark A.; Rosner, Stefan W.; Kelly, Kenneth K.; Loewenstein, Max; Chan, K. R.

1993-01-01

During the tropical experiment of NASA's Stratosphere-Troposphere Exchange Program (STEP), in situ radon and other trace constituent measurements were made aboard a NASA ER-2 high-altitude research aircraft to investigate the mechanisms of irreversible transfers from the troposphere into the tropical stratosphere. Observations made in and downwind of the cirrus shields of three large tropical cyclones and downwind of the cirrus anvil of a large cumulonimbus cloud cluster showed several clear instances of elevated radon activity occurring simultaneously with low total water mixing ratios. These observations are unambiguous evidence of an effective dehydration process, capable of reducing total water vapor mixing ratios to less than 2.5 ppmv, occurring in conjunction with troposphere-to-stratosphere transport and indicate that rapid localized convection, rather than slow regional mean motions, was responsible for the observed transports and associated with the accompanying dehydration. Radon activities measured in regions of active or recent troposphere-to-stratosphere transport were consistent with the 17 pCi/scm mean value needed to support the observed abundance of stratospheric 210 Pb.

Characterization of radon levels in soil and groundwater in the North Maladeta Fault area (Central Pyrenees) and their effects on indoor radon concentration in a thermal spa.

PubMed

Moreno, V; Bach, J; Zarroca, M; Font, Ll; Roqué, C; Linares, R

2018-09-01

Radon levels in the soil and groundwater in the North Maladeta Fault area (located in the Aran Valley sector, Central Pyrenees) are analysed from both geological and radiation protection perspectives. This area is characterized by the presence of two important normal faults: the North Maladeta fault (NMF) and the Tredós Fault (TF). Two primary aspects make this study interesting: (i) the NMF shows geomorphic evidence of neotectonic activity and (ii) the presence of a thermal spa, Banhs de Tredós, which exploits one of the several natural springs of the area and needs to be evaluated for radiation dosing from radon according to the European regulation on basic safety standards for protection against ionizing radiation. The average soil radon and thoron concentrations along a profile perpendicular to the two normal faults - 22 ± 3 kBq·m -3 and 34 ± 3 kBq·m -3 , respectively - are not high and can be compared to the radionuclide content of the granitic rocks of the area, 25 ± 4 Bq·kg -1 for 226 Ra and 38 ± 2 Bq·kg -1 for 224 Ra. However, the hypothesis that the normal faults are still active is supported by the presence of anomalies in both the soil radon and thoron levels that are unlikely to be of local origin together with the presence of similar anomalies in CO 2 fluxes and the fact that the highest groundwater radon values are located close to the normal faults. Additionally, groundwater 222 Rn data have complemented the hydrochemistry data, enabling researchers to better distinguish between water pathways in the granitic and non-granitic aquifers. Indoor radon levels in the spa vary within a wide range, [7-1664] Bq·m -3 because the groundwater used in the treatment rooms is the primary source of radon in the air. Tap water radon levels inside the spa present an average value of 50 ± 8 kBq·m -3 , which does not exceed the level stipulated by the Spanish Nuclear Safety Council (CSN) of 100 kBq·m -3 for water used for human consumption. This finding implies that even relatively low radon concentration values in water can constitute a relevant indoor radon source when the transfer from water to indoor air is efficient. The estimated effective dose range of values for a spa worker due to radon inhalation is [1-9] mSv·y -1 . The use of annual averaged radon concentration values may significantly underestimate the dose in these situations; therefore, a detailed dynamic study must be performed by considering the time that the workers spend in the spa. Copyright © 2018 Elsevier Ltd. All rights reserved.

Radon Pollution Control Act of 1987. Hearing before the Subcommittee on Transportation, Tourism, and Hazardous Materials of the Committee on Energy and Commerce, House of Representatives, One Hundredth Congress, First Session, April 23, 1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Ten witnesses from the Environmental Protection Agency (EPA), state and local environmental agencies, teachers, health providers, and others testified on the risks and possible control measures of radon gas emissions in homes. Home tests are finding as many as 40% to have unacceptable levels, but EPA and other government agencies have waited for the media to alert the population. The witnesses were asked to suggest ways in which EPA can initiate assistance in this area in order to protect public health. EPA spokesmen reviewed their programs, including the Radon Action Program, which began operating in 1985. Material submitted for themore » record by EPA follows the testimony.« less

Evaluation of local versus remote areas of CH4 sources at IC3 stations using a combined analysis of 222Rn tracer and Atmospheric Particles Transport Model (APTM) results. Application at the Gredos and Iruelas station (GIC3), Spain.

NASA Astrophysics Data System (ADS)

Grossi, Claudia; Morguí, Josep Anton; Curcoll, Roger; Àgueda, Alba; Arnold, Delia; Batet, Oscar; Cañas, Lidia; Nofuentes, Manel; Occhipinti, Paola; Vogel, Felix; Vargas, Arturo; Rodó, Xavier

2014-05-01

The Gredos and Iruelas station (GIC3) is part of the IC3 (Institut Català de Ciències del Clima) atmospheric monitoring network. This station is located in the Gredos Natural Park (40.22º N; -5.14º E) in the Spanish central plateau. The IC3 network consists of 8 stations distributed across Spain. It has been developed with the aim of studying climatic processes and the responses of impacted systems at different temporal and spatial scales. Since 2012, CO2, CH4, 222Rn (a natural radioactive gas) and meteorological variables are continuously measured at GIC3 at 20 m a.g.l. (1100 m a.s.l.). Furthermore, 4-days backward simulations are run daily for each IC3 station using the FLEXPART model. Simulations use ECMWF meteorological data as input and a horizontal spatial resolution of 0.2 degrees. The Laboratory of the Atmosphere and the Oceans (LAO) of the IC3 has elaborated a new approach to evaluate the local or remote greenhouse gases emissions using the radon gas as tracer and the atmospheric particles transport model FLEXPART under nocturnal and winter conditions. The ratios between the normalized and rescaled measured concentrations of CH4 and 222Rn during nocturnal hours (21h, 00h, 03h and 06h) and in the winter season, in order to reduce local radon flux and methane source due to seasonal livestock migration and to get stable atmospheric conditions, have been analyzed in relation to the influence of the local area (set to an initial dimension of 20x20 km2). The influence area (IA) has been defined as the percentage of the ratio between the residence time of the fictitious particles released in FLEXPART simulations over the area of interest (TLocal Area) and the residence time of these fictitious particles over the total area included in the simulation (TTotal Area ), i.e. IA = (TLocal Area/TTotal Area * 100). First results considering an area of interest of 20x20 km2 show a linear increase of the radon concentration with IA until reaching a maximum when IA is about 50%. This can be explained taking into consideration that GIC3 station area has high radon exhalation rates according to the literature and the radon uptake from air masses can reach a plateau. On the other hand, CH4 concentrations do not seem to be significantly influenced by IA. The log-log plot between the ratio of normalized and rescaled gases concentrations (CH4/222Rn) and the percentage of the influence of the local area shows a negative linear relation under nocturnal and winter conditions which could depend on the increase of the radon not compensated by the methane increase. Indeed, when the influence of the local area of Gredos and Iruelas station is under the 20% the major methane contribution seems to come from outside the 20x20 km2 IA. Results considering a larger area of interest (up to 80x80 km2) may indicate possible methane sources detected at the GIC3 station.

Persistent Target Tracking Using Likelihood Fusion in Wide-Area and Full Motion Video Sequences

DTIC Science & Technology

2012-07-01

624–637, 2010. [33] R. Pelapur, K. Palaniappan, F. Bunyak, and G. Seetharaman, “Vehicle orientation estimation using radon transform-based voting in...pp. 873–880. [37] F. Bunyak, K. Palaniappan, S. K. Nath, and G. Seetharaman, “Flux tensor constrained geodesic active contours with sensor fusion for

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

NASA Astrophysics Data System (ADS)

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

2017-04-01

The Azores archipelago, located in the middle of the North Atlantic Ocean, is composed of nine volcanic islands that formed at the triple junction of the North American, Eurasian and African (Nubian) tectonic plates. These volcanic islands were the sites of several eruptions and destructive earthquakes since human settlement in the 15th century. S. Miguel Island, the largest and most densely populated island of the Azores, hosts three active strato-volcanoes with calderas. Furnas Volcano is one of these. Its eruptive activity has been essentially explosive, involving magmas with trachytic (s.l.) composition. In the last 5000 years at least 10 explosive eruptions occurred inside the caldera of Furnas. The last one occurred in 1630 and was subplinian in character. Since then an intense hydrothermal activity has persisted, involving four main fumarolic fields, thermal springs, CO2-rich springs, several soil diffuse degassing areas (CO2 and 222Rn), as well as occasional hydrothermal explosions. In the past decade we have developed a radon survey of Furnas hydrothermal manifestations. Here we report on the radon survey of twelve water springs, located inside the caldera, and representative of the different water types encountered at the volcano (orthothermal, thermal and CO2-rich springs). Bimonthly sampling and determination of radon activity and water temperature was performed in the selected springs between years 2007 and 2011. At each sampling point two water samples were collected for radon dosing in laboratory with the RAD7 equipment. A decay correction was applied to each sample. The average radon activities were found to vary between 1.15 Bq/L and 29.77 Bq/L, while water temperatures ranged between 16.5 °C and 76.2 °C. As a whole radon activities inversely correlate with water temperature, with orthothermal springs showing higher radon activity than thermal springs. Temporal variations in both parameters appear to be mainly determined by seasonal variations of environmental conditions as soil temperature, rainfall and soil water content, rather than by volcanic activity, with the exception of one spring where radon activity seems to change more closely relate to the seismic activity of Furnas Volcano. Because some of the surveyed waters are often drunk by the local population and tourists, our results are also useful in a public health perspective. We conclude that the measured radon activities do not pose any health problem, as they remain under the safety threshold (100 Bq/L) defined by the World Health Organization. The research performed allowed to define the radon background for each one of the groundwater discharges sampled and to identify the environmental parameters that can influence the radon concentration in the groundwater of Furnas Volcano, allowing more easily to identify a future reactivation of this volcanic system.

Radon transport model into a porous ground layer of finite capacity

NASA Astrophysics Data System (ADS)

Parovik, Roman

2017-10-01

The model of radon transfer is considered in a porous ground layer of finite power. With the help of the Laplace integral transformation, a numerical solution of this model is obtained which is based on the construction of a generalized quadrature formula of the highest degree of accuracy for the transition to the original - the function of solving this problem. The calculated curves are constructed and investigated depending on the diffusion and advection coefficients.The work was a mathematical model that describes the effect of the sliding attachment (stick-slip), taking into account hereditarity. This model can be regarded as a mechanical model of earthquake preparation. For such a model was proposed explicit finite- difference scheme, on which were built the waveform and phase trajectories hereditarity effect of stick-slip.

Analytical properties of time-of-flight PET data.

PubMed

Cho, Sanghee; Ahn, Sangtae; Li, Quanzheng; Leahy, Richard M

2008-06-07

We investigate the analytical properties of time-of-flight (TOF) positron emission tomography (PET) sinograms, where the data are modeled as line integrals weighted by a spatially invariant TOF kernel. First, we investigate the Fourier transform properties of 2D TOF data and extend the 'bow-tie' property of the 2D Radon transform to the time-of-flight case. Second, we describe a new exact Fourier rebinning method, TOF-FOREX, based on the Fourier transform in the time-of-flight variable. We then combine TOF-FOREX rebinning with a direct extension of the projection slice theorem to TOF data, to perform fast 3D TOF PET image reconstruction. Finally, we illustrate these properties using simulated data.

Analytical properties of time-of-flight PET data

NASA Astrophysics Data System (ADS)

Cho, Sanghee; Ahn, Sangtae; Li, Quanzheng; Leahy, Richard M.

2008-06-01

We investigate the analytical properties of time-of-flight (TOF) positron emission tomography (PET) sinograms, where the data are modeled as line integrals weighted by a spatially invariant TOF kernel. First, we investigate the Fourier transform properties of 2D TOF data and extend the 'bow-tie' property of the 2D Radon transform to the time-of-flight case. Second, we describe a new exact Fourier rebinning method, TOF-FOREX, based on the Fourier transform in the time-of-flight variable. We then combine TOF-FOREX rebinning with a direct extension of the projection slice theorem to TOF data, to perform fast 3D TOF PET image reconstruction. Finally, we illustrate these properties using simulated data.

THORON-SCOUT - first diffusion based active Radon and Thoron monitor

NASA Astrophysics Data System (ADS)

Wagner, W.; Streil, T.; Oeser, V.; Horak, G.; Duzynski, M.

2016-10-01

THORON-SCOUT is a stand-alone diffusion based active Radon and Thoron monitor for long term indoor measurements to evaluate the human health risk due to activity concentration in the breathing air. Alpha-particle spectroscopy of Po isotopes, being the progeny of the decay of the radioactive noble gas Radon, is applied to separately monitor activity contributions of 222Rn and 220Rn (Thoron) as well. In this work we show that the portion of Thoron (Tn) may locally be remarkable and even dominating and cannot be neglected as often has been assumed up to now. Along with tobacco consumption, Rn radioactivity turned out to be a dangerous cause of lung cancer, especially in older badly vented buildings situated in regions of radioactive geological formations. THORON-SCOUT allows a precise examination of the indoor atmosphere with respect to Rn and Inactivity concentration and, therefore, a realistic evaluation of corresponding health risk.

Detecting mammographically occult cancer in women with dense breasts using Radon Cumulative Distribution Transform: a preliminary analysis

NASA Astrophysics Data System (ADS)

Lee, Juhun; Nishikawa, Robert M.; Rohde, Gustavo K.

2018-02-01

We propose using novel imaging biomarkers for detecting mammographically-occult (MO) cancer in women with dense breast tissue. MO cancer indicates visually occluded, or very subtle, cancer that radiologists fail to recognize as a sign of cancer. We used the Radon Cumulative Distribution Transform (RCDT) as a novel image transformation to project the difference between left and right mammograms into a space, increasing the detectability of occult cancer. We used a dataset of 617 screening full-field digital mammograms (FFDMs) of 238 women with dense breast tissue. Among 238 women, 173 were normal with 2 - 4 consecutive screening mammograms, 552 normal mammograms in total, and the remaining 65 women had an MO cancer with a negative screening mammogram. We used Principal Component Analysis (PCA) to find representative patterns in normal mammograms in the RCDT space. We projected all mammograms to the space constructed by the first 30 eigenvectors of the RCDT of normal cases. Under 10-fold crossvalidation, we conducted quantitative feature analysis to classify normal mammograms and mammograms with MO cancer. We used receiver operating characteristic (ROC) analysis to evaluate the classifier's output using the area under the ROC curve (AUC) as the figure of merit. Four eigenvectors were selected via a feature selection method. The mean and standard deviation of the AUC of the trained classifier on the test set were 0.74 and 0.08, respectively. In conclusion, we utilized imaging biomarkers to highlight differences between left and right mammograms to detect MO cancer using novel imaging transformation.

Radon-222 in groundwater and effective dose due to ingestion and inhalation in the city of Ibadan, Nigeria.

PubMed

Ademola, Janet Ayobami; Oyeleke, Oyebode Akanni

2017-03-20

Radon concentration in groundwater collected from the eleven Local Government Areas (LGAs) of Ibadan, Nigeria, was analyzed. Annual effective doses due to ingestion and inhalation of radon from the consumption of the water were determined. The arithmetic means (AMs) of radon concentration for the 11 LGAs varied from 2.18 to 76.75 Bq l -1 with a standard deviation of 1.57 and 70.64 Bq l -1 , respectively. The geometric means (GMs) varied from 1.67 to 49.47 Bq l -1 with geometric standard deviation of 2.22 and 3.04, respectively. About 58% of the 84 water samples examined had a higher concentration of radon than the 11.1 Bq l -1 recommended by United States Environmental Protection Agency (USEPA); the AMs of six LGAs and GMs of three LGAs were higher than the recommended value. However the AMs and GMs of all the LGAs with about 93% of the water sampled were lower than the 100 Bq l -1 recommended by the World Health Organization and EURATOM drinking water directive. The concentration of radon varied with the geological formation of the area. The AMs of the annual effective dose due to ingestion of radon in water ranged from 0.036 to 1.261 mSv y -1 , 0.071 to 2.521 mSv y -1 and 0.042 to 1.471 mSv y -1 for adult, child and infant, respectively and the GMs in the range of 0.026 to 0.813, 0.055 to 1.625 and 0.032 to 0.948 mSv y -1 , respectively. The AMs of 10 LGAs and GMs of 7 LGAs were higher than the recommended reference dose level of 0.1 mSv y -1 from the consumption of water for the duration of one year for all the three categories of people. The AMs and GMs of the annual effective dose due to inhalation of radon in drinking water ranged from 0.533 to 18.82 μSv y -1 and 0.411 to 12.13 μSv y -1 , respectively, contributing less to the overall dose.

Preliminary results on variations of radon concentration associated with rock deformation in a uranium mine

NASA Astrophysics Data System (ADS)

Verdoya, Massimo; Bochiolo, Massimo; Chiozzi, Paolo; Pasquale, Vincenzo; Armadillo, Egidio; Rizzello, Daniele; Chiaberto, Enrico

2013-04-01

Time-series of radon concentration and environmental parameters were recently recorded in a uranium mine gallery, located in the Maritime Alps (NW Italy). The mine was bored in metarhyolites and porphyric schists mainly composed by quartz, feldspar, sericite and fluorite. U-bearing minerals are generally concentrated in veins heterogeneously spaced and made of crystals of metaautunite and metatorbernite. Radon air concentration monitoring was performed with an ionization chamber which was placed at the bottom of the gallery. Hourly mean values of temperature, pressure, and relative humidity were also measured. External data of atmospheric temperature, pressure and rainfall were also available from a meteorological station located nearby, at a similar altitude of the mine. The analysis of the time series recorded showed variation of radon concentration, of large amplitude, exhibiting daily and half-daily periods, which do not seem correlated with meteorological records. Searching for the origin of radon concentration changes and monitoring their amplitude as a function of time can provide important clues on the complex emanation process. During this process, radon reaches the air- and water-filled interstices by recoil and diffusion, where its migration is directed towards lower concentration regions, following the local gradient. The radon emanation from the rock matrix could also be controlled by stress changes acting on the rate of migration of radon into fissures, and fractures. This may yield emanation boosts due to rock extension and the consequent crack broadening, and emanation decrease when joints between cracks close. Thus, besides interaction and mass transfer with the external atmospheric environment, one possible explanation for the periodic changes in radon concentrations in the investigated mine, could be the variation of rock deformation related to lunar-solar tides. The large variation of concentration could be also due to the fact that the mine is located next to the Ligurian Sea coast. When the sea tides change the water level at the shore, this might produce additional pressure which increases the deformations (sea loading). This paper presents the preliminary results of an experiment, which is in progress in the uranium mine. During the experiment, several geophysical parameters are monitored together with radon concentration. After appropriate insulation in order to prevent radon escape through normal atmospheric circulation, the gallery was equipped with three radon detectors, four passive dosimeters, an array of unpolarisable electrodes for measurements of self-potential variations and a microgravimeter for monitoring of the tidal effect. We expect that changes in the mechanical state can be accompanied by changes in the electric potential. Since the latter variation can be related also to changes in the natural magnetic field, measurements with a three components fluxgate magnetometer are also being carried out. The recorded signals will be analysed according to standard procedures, such as spectral analysis and cross-correlation, aimed at discriminating the periodic components and the governing physical processes.

Research on Radar Micro-Doppler Feature Parameter Estimation of Propeller Aircraft

NASA Astrophysics Data System (ADS)

He, Zhihua; Tao, Feixiang; Duan, Jia; Luo, Jingsheng

2018-01-01

The micro-motion modulation effect of the rotated propellers to radar echo can be a steady feature for aircraft target recognition. Thus, micro-Doppler feature parameter estimation is a key to accurate target recognition. In this paper, the radar echo of rotated propellers is modelled and simulated. Based on which, the distribution characteristics of the micro-motion modulation energy in time, frequency and time-frequency domain are analyzed. The micro-motion modulation energy produced by the scattering points of rotating propellers is accumulated using the Inverse-Radon (I-Radon) transform, which can be used to accomplish the estimation of micro-modulation parameter. Finally, it is proved that the proposed parameter estimation method is effective with measured data. The micro-motion parameters of aircraft can be used as the features of radar target recognition.

Analytical Properties of Time-of-Flight PET Data

PubMed Central

Cho, Sanghee; Ahn, Sangtae; Li, Quanzheng; Leahy, Richard M.

2015-01-01

We investigate the analytical properties of time-of-flight (TOF) positron emission tomography (PET) sinograms, where the data are modeled as line integrals weighted by a spatially invariant TOF kernel. First, we investigate the Fourier transform properties of 2D TOF data and extend the “bow-tie” property of the 2D Radon transform to the time of flight case. Second, we describe a new exact Fourier rebinning method, TOF-FOREX, based on the Fourier transform in the time-of-flight variable. We then combine TOF-FOREX rebinning with a direct extension of the projection slice theorem to TOF data, to perform fast 3D TOF PET image reconstruction. Finally, we illustrate these properties using simulated data. PMID:18460746

Comparative survey of outdoor, residential and workplace radon concentrations

PubMed Central

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

2015-01-01

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

Radon Resources for Home Buyers and Sellers

MedlinePlus

... and Research Centers Radon Contact Us Share Radon Resources for Home Buyers and Sellers Radon Protection: Buying ... Radon-Resistant New Construction Radon and Real Estate Resources Home Buyer's/Seller's Guide to Radon Consumer's Guide ...

A survey of ²²²Rn in drinking water in Mexico City.

PubMed

Vázquez-López, C; Zendejas-Leal, B E; Golzarri, J I; Espinosa, G

2011-05-01

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

Radon control activities for lung cancer prevention in national comprehensive cancer control program plans, 2005-2011.

PubMed

Neri, Antonio; Stewart, Sherri L; Angell, William

2013-08-08

Radon is the second leading cause of lung cancer among smokers and the leading cause among nonsmokers. The US Environmental Protection Agency recommends that every home be tested for radon. Comprehensive Cancer Control (CCC) programs develop cancer coalitions that coordinate funding and resources to focus on cancer activities that are recorded in cancer plans. Radon tests, remediation, and radon mitigation techniques are relatively inexpensive, but it is unclear whether coalitions recognize radon as an important carcinogen. We reviewed 65 cancer plans created from 2005 through 2011 for the terms "radon," "radiation," or "lung." Plan activities were categorized as radon awareness, home testing, remediation, supporting radon policy activities, or policy evaluation. We also reviewed each CCC program's most recent progress report. Cancer plan content was reviewed to assess alignment with existing radon-specific policies in each state. Twenty-seven of the plans reviewed (42%) had radon-specific terminology. Improving awareness of radon was included in all 27 plans; also included were home testing (n=21), remediation (n=11), support radon policy activities (n=13), and policy evaluation (n=1). Three plans noted current engagement in radon activities. Thirty states had radon-specific laws; most (n=21) were related to radon professional licensure. Eleven states had cancer plan activities that aligned with existing state radon laws. Although several states have radon-specific policies, approximately half of cancer coalitions may not be aware of radon as a public health issue. CCC-developed cancer coalitions and plans should prioritize tobacco control to address lung cancer but should consider addressing radon through partnership with existing radon control programs.

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

MedlinePlus

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

Development of a System to Perform, Record, and Analyze Measurements of Radon Concentrations on a Large Scale.

DTIC Science & Technology

1990-10-01

Radiation Protection and Measurements. Measurement of Radon and Radon Daughters in Air, NCRP Report No. 97. 1988. 2. Cohen, Bernard L., et al. "Theory and...Measurements. Measurement of Radon and Radon Daughters in Air, NCRP Report No. 97. 1988. 4. Stein, Lawrence. "Chemical Properties of Radon," Radon and Its...Measurement of Radon and Radon Daughters in Air, NCRP Report No. 97. 1988. 6. Frame, R. "Radon and Its Daughters." ORNL Briefing, June 16, 1989. 7

Position Estimation and Local Mapping Using Omnidirectional Images and Global Appearance Descriptors

PubMed Central

Berenguer, Yerai; Payá, Luis; Ballesta, Mónica; Reinoso, Oscar

2015-01-01

This work presents some methods to create local maps and to estimate the position of a mobile robot, using the global appearance of omnidirectional images. We use a robot that carries an omnidirectional vision system on it. Every omnidirectional image acquired by the robot is described only with one global appearance descriptor, based on the Radon transform. In the work presented in this paper, two different possibilities have been considered. In the first one, we assume the existence of a map previously built composed of omnidirectional images that have been captured from previously-known positions. The purpose in this case consists of estimating the nearest position of the map to the current position of the robot, making use of the visual information acquired by the robot from its current (unknown) position. In the second one, we assume that we have a model of the environment composed of omnidirectional images, but with no information about the location of where the images were acquired. The purpose in this case consists of building a local map and estimating the position of the robot within this map. Both methods are tested with different databases (including virtual and real images) taking into consideration the changes of the position of different objects in the environment, different lighting conditions and occlusions. The results show the effectiveness and the robustness of both methods. PMID:26501289

The role of natural ventilation in the exposure to radon in the Postojna Cave

NASA Astrophysics Data System (ADS)

Gregorič, A.; Smerajec, M.; Vaupotič, J.

2012-04-01

Postojna Cave is the biggest of 21 show caves in Slovenia and one of present day's most visited show caves in the world. Long and branched out cave system, large entrances at different levels, inflow of the Pivka river, and large variation of the outdoor air temperature and precipitation, make the Postojna Cave also a very complex climatic system in which each part shows different conditions. The cave is only naturally ventilated and it is therefore characterised by high radon concentration, which depends on the ventilation regime in different seasons, resulting in typical annual cycles of radon levels in the cave air. Postojna Cave is a typical horizontal cave, where the difference between outside and cave air temperature represents the main driving force for air circulation. In winter, when the cave temperature is higher than outside, cave air is released from the cave into the outdoor atmosphere due to the air draught caused by the 'chimney effect', thus allowing fresh and cold outdoor air to enter the cave through low lying openings. This effect is not operative in summer, when the outside temperature is higher than in the cave, and air draught is minimal or reversed. In addition, air circulation can be locally altered due to other processes, like changing level of Pivka river during the rainy season and local geomorphologic characteristics of cave passages. High radon concentration in the Postojna Cave is the reason for thorough studies of the methodology for dose estimates of the personnel working in the cave. Due to high relative humidity and low air circulation, the cave air is characterised by very low particle concentration, which play an important role in radon dosimetry. Therefore parallel monitoring of radioactive aerosols of radon decay products (RnDP) and general (non-radioactive) aerosols in the particle size range of 10-1100 nm was performed in the air of Postojna Cave at the lowest point of tourist path in summer, winter and both transitional periods (spring and autumn), focusing on the unattached fraction of RnDP (fun), a key parameter in radon dosimetry. Dose conversion factors (DCF) were calculated (using Porstendörfer approach) from measured fun for the four periods and compared with recommended DCF, based on the results of epidemiological studies. Results of calculated DCF are in the range from 8-18 mSV WLM-1, much higher that recommended values, and differ significantly for summer and winter period. The lowest value of DCF was calculated for winter period, when the enhanced inflow of cold outside air introduces outdoor aerosols into the cave and consequently lowers fun. On the other hand, calculated DCF during summer period was significantly higher, caused by high fun, which is the consequence of very low particle concentration in cave air during summer ventilation regime. Taking into account also significantly higher radon concentration during summer, when about 70 % of visits is recorded, it is evident, that personnel receives the highest annual dose during summer months.

Radon Control Activities for Lung Cancer Prevention in National Comprehensive Cancer Control Program Plans, 2005–2011

PubMed Central

Stewart, Sherri L.; Angell, William

2013-01-01

Introduction Radon is the second leading cause of lung cancer among smokers and the leading cause among nonsmokers. The US Environmental Protection Agency recommends that every home be tested for radon. Comprehensive Cancer Control (CCC) programs develop cancer coalitions that coordinate funding and resources to focus on cancer activities that are recorded in cancer plans. Radon tests, remediation, and radon mitigation techniques are relatively inexpensive, but it is unclear whether coalitions recognize radon as an important carcinogen. Methods We reviewed 65 cancer plans created from 2005 through 2011 for the terms “radon,” “radiation,” or “lung.” Plan activities were categorized as radon awareness, home testing, remediation, supporting radon policy activities, or policy evaluation. We also reviewed each CCC program’s most recent progress report. Cancer plan content was reviewed to assess alignment with existing radon-specific policies in each state. Results Twenty-seven of the plans reviewed (42%) had radon-specific terminology. Improving awareness of radon was included in all 27 plans; also included were home testing (n = 21), remediation (n = 11), support radon policy activities (n = 13), and policy evaluation (n = 1). Three plans noted current engagement in radon activities. Thirty states had radon-specific laws; most (n = 21) were related to radon professional licensure. Eleven states had cancer plan activities that aligned with existing state radon laws. Conclusion Although several states have radon-specific policies, approximately half of cancer coalitions may not be aware of radon as a public health issue. CCC-developed cancer coalitions and plans should prioritize tobacco control to address lung cancer but should consider addressing radon through partnership with existing radon control programs. PMID:23928457

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

NASA Astrophysics Data System (ADS)

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.

Comparative survey of outdoor, residential and workplace radon concentrations.

PubMed

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

2015-02-01

This study investigated radon concentrations in above-ground (i.e. first floor) workplace in Missouri and compared them with above-ground radon concentrations in nearby homes and outdoor locations. This study also examined the potential utility of using home and outdoor radon concentrations to predict the radon concentration at a nearby workplace (e.g. county agencies and schools). Even though workplace radon concentrations were not statistically different from home radon concentrations, the radon concentration at a particular home, or outdoor location, was a poor predictor of the radon concentration at a nearby workplace. Overall, 9.6 and 9.9 % of homes and workplace, respectively, exhibited radon concentrations of ≥148 Bq m(-3). Because of the percentage of workplace with elevated radon concentrations, the results suggest that additional surveys of workplace radon concentrations are needed, especially in areas of high radon potential, to assess the contribution of workplace radon exposure to an individual's overall radon exposure. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Residential radon in Galicia: a cross-sectional study in a radon-prone area.

PubMed

Lorenzo-González, María; Ruano-Ravina, Alberto; Peón, Joaquín; Piñeiro, María; Barros-Dios, Juan Miguel

2017-09-01

Residential radon exposure is a major public health problem. It is the second greatest cause of lung cancer, after smoking, and the greatest in never-smokers. This study shows the indoor radon exposure distribution in Galicia and estimates the percentage of dwellings exceeding reference levels. It is based on 3245 residential radon measurements obtained from the Galician Radon Map project and from controls of two previous case-control studies on residential radon and lung cancer. Results show a high median residential radon concentration in Galicia (99 Bq m -3 ), with 49.3% of dwellings having a radon concentration above 100 Bq m -3 and 11.1% having a concentration above 300 Bq m -3 . Ourense and Pontevedra, located in South Galicia, are the provinces with the highest median indoor radon concentrations (137 Bq m -3 and 123.5 Bq m -3 , respectively). Results also show lower radon levels in progressively higher building storeys. These high residential radon concentrations confirm Galicia as a radon-prone area. A policy on radon should be developed and implemented in Galicia to minimize the residential radon exposure of the population.

30 CFR 57.5046 - Protection against radon gas.

Code of Federal Regulations, 2010 CFR

2010-07-01

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

A blind transform based approach for the detection of isolated astrophysical pulses

NASA Astrophysics Data System (ADS)

Alkhweldi, Marwan; Schmid, Natalia A.; Prestage, Richard M.

2017-06-01

This paper presents a blind algorithm for the automatic detection of isolated astrophysical pulses. The detection algorithm is applied to spectrograms (also known as "filter bank data" or "the (t,f) plane"). The detection algorithm comprises a sequence of three steps: (1) a Radon transform is applied to the spectrogram, (2) a Fourier transform is applied to each projection parametrized by an angle, and the total power in each projection is calculated, and (3) the total power of all projections above 90° is compared to the total power of all projections below 90° and a decision in favor of an astrophysical pulse present or absent is made. Once a pulse is detected, its Dispersion Measure (DM) is estimated by fitting an analytically developed expression for a transformed spectrogram containing a pulse, with varying value of DM, to the actual data. The performance of the proposed algorithm is numerically analyzed.

Towards weakly constrained double field theory

NASA Astrophysics Data System (ADS)

Lee, Kanghoon

2016-08-01

We show that it is possible to construct a well-defined effective field theory incorporating string winding modes without using strong constraint in double field theory. We show that X-ray (Radon) transform on a torus is well-suited for describing weakly constrained double fields, and any weakly constrained fields are represented as a sum of strongly constrained fields. Using inverse X-ray transform we define a novel binary operation which is compatible with the level matching constraint. Based on this formalism, we construct a consistent gauge transform and gauge invariant action without using strong constraint. We then discuss the relation of our result to the closed string field theory. Our construction suggests that there exists an effective field theory description for massless sector of closed string field theory on a torus in an associative truncation.

Atmosphere purification of radon and radon daughter elements

DOEpatents

Stein, L.

1974-01-01

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

Comparison of urinary excretion of radon from the human body before and after radon bath therapy.

PubMed

Kávási, Norbert; Kovács, Tibor; Somlai, János; Jobbágy, Viktor; Nagy, Katalin; Deák, Eszter; Berhés, István; Bender, Tamás; Ishikawa, Tetsuo; Tokonami, Shinji

2011-07-01

Theoretically, the human body absorbs radon through the lungs and the skin and excretes it through the lungs and the excretory organs during radon bath therapy. To check this theory, the radon concentrations in urine samples were compared before and after radon bath therapy. During the therapy, the geometric mean (GM) and the geometric standard deviation of the radon concentration in air and in the bath water were 979 Bq m(-3), 1.58 and 73.6 Bq dm(-3), 1.1, respectively. Since radon was detected in each urine sample (GM around 3.0 Bq dm(-3)), urinary excretion of radon was confirmed. The results of this study can neither reject nor confirm the hypothesis of radon absorption through the skin. A 15 times higher increment of inhaled radon level did not cause significant changes in radon of urine samples.

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

PubMed

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

2017-01-01

The indoor radon concentration was measured in most houses in a couple of municipalities in Austria. At the same time the activity concentration of radium in soil, the soil gas radon concentration, the permeability of the ground and the ambient dose equivalent rate were also measured and the geological situations (geological units) were recorded too. From the indoor radon concentration and different house and living parameters a radon potential (Austrian radon potential) was derived which should represent the radon concentration in a standard room. Another radon potential (Neznal radon potential) was calculated from the soil gas radon concentration and the permeability. The aim of the investigation was to correlate all the different variables and to test if the use of surrogate data (e.g. geological information, ambient dose equivalent rate, etc.) can be used to judge the radon risk for an area without performing numerous indoor measurements. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Patients' exposure to electromagnetic fields and radon in radon spas].

PubMed

Politański, Piotr; Olszewski, Jerzy; Mamrot, Paweł; Mariańska, Mlagda; Zmyślony, Marek

2014-01-01

Many patients of physiotherapeutic facilities using therapeutic radon are also referred to other treatments involving the use of electromagnetic field (EMF). However, in the light of the theory of EMF influence on free radicals, it is still an open question whether, application of EMF shortly after the radon treatment may alter the biological effects of radon or EMF. The aim of the study was to determine how large is the group of patients exposed to radon and EMF in Poland, and how high is the exposure of these patients to analyzed factors. The results of the study are to be used in the future assessment of the combined effects of radon and EMF in radon spas. Based on the statistical data and interviews held in the major Polish radon spas, the analysis of treatment structure was performed and exposure to radon and EMF was assessed by measuring radon concentrations and characteristic values of exposure to EMF. More than 8000 people per year are subjected to combined exposure to radon and EMF. Significant differences were found between measured radon concentrations (they ranged from approximately 61 kBq/m3 for inhalations with inhaler to only 290 Bq/m3 for graduation towers, p = 0.049) and EMF intensities corresponded to those observed in hazardous and dangerous zones for occupational exposure. The results of the study showed significant differences between radon concentrations during various radon treatments. There is a need to develop clear and universal procedures for the application of radon or radon combined with EMF in radon spas. The effects of patients' exposure to radon, especially combined with EMF need to be further studied.

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

PubMed

Foster, Stephanie; Everett Jones, Sherry

2016-12-13

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

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

PubMed Central

Foster, Stephanie; Everett Jones, Sherry

2016-01-01

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

Flow of ground water through fractured carbonate rocks in the Prairie du Chien-Jordan Aquifer, southeastern Minnesota

USGS Publications Warehouse

Ruhl, J.F.

1989-01-01

Contamination of groundwater from point and nonpoint sources (such as landfills, feedlots, agricultural chemicals applied to fields, and septic systems) is a recognized problem in the karst area of southeastern Minnesota. The US Geological Survey, in cooperation with the Minnesota Department of Natural Resources and the Legislative Commission on Minnesota Resources, Began a study in October 1987 to improve the understanding of local groundwater flow through karst terrain in southeastern Minnesota. The objectives of the study are to: (1) describe the orientations of systematic rock fractures and solution channels of the Prairie du Chien Group of Ordovician-age carbonate rocks in southeastern Minnesota, and, if possible, to define the principal and minor axes of these orientations; and (2) evaluate the effect of fractures and solution channels in the Prairie du Chien Group on the local flow of groundwater. Groundwater in the Upper Carbonate aquifer regionally flows toward the periphery of the aquifer and locally flows into streams and bedrock valleys. The hydraulic gradient in this aquifer generally is greatest near areas of groundwater seepage to streams. Regional groundwater flow in the Prairie du Chien-Jordan aquifer generally is to the south and east in much of Fillmore and Houston Counties and in the southern parts of Olmsted and Winona Counties. Groundwater seepage to selected streams was evaluated by current-meter measurements of downstream gains or losses of streamflow and by an experimental approach based on radon activity in streams. The activity of radon in groundwater ranges from two to four orders of magnitude greater than the activity in surface water; therefore, groundwater seepage to streams generally increases the in-stream radon activity.

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

PubMed

Chen, Jing; Ford, Ken L

2017-01-01

Exposure to indoor radon is identified as the main source of natural radiation exposure to the population. Since radon in homes originates mainly from soil gas radon, it is of public interest to study the correlation between radon in soil and radon indoors in different geographic locations. From 2007 to 2010, a total of 1070 sites were surveyed for soil gas radon and soil permeability. Among the sites surveyed, 430 sites were in 14 cities where indoor radon information is available from residential radon and thoron surveys conducted in recent years. It is observed that indoor radon potential (percentage of homes above 200 Bq m -3 ; range from 1.5% to 42%) correlates reasonably well with soil radon potential (SRP: an index proportional to soil gas radon concentration and soil permeability; average SRP ranged from 8 to 26). In five cities where in-situ soil permeability was measured at more than 20 sites, a strong correlation (R 2  = 0.68 for linear regression and R 2  = 0.81 for non-linear regression) was observed between indoor radon potential and soil radon potential. This summary report shows that soil gas radon measurement is a practical and useful predictor of indoor radon potential in a geographic area, and may be useful for making decisions around prioritizing activities to manage population exposure and future land-use planning. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

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

PubMed Central

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

1998-01-01

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

Radon assay and purification techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simgen, Hardy

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

Radon assay and purification techniques

NASA Astrophysics Data System (ADS)

Simgen, Hardy

2013-08-01

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

Multi-scale variability and long-range memory in indoor Radon concentrations from Coimbra, Portugal

NASA Astrophysics Data System (ADS)

Donner, Reik V.; Potirakis, Stelios; Barbosa, Susana

2014-05-01

The presence or absence of long-range correlations in the variations of indoor Radon concentrations has recently attracted considerable interest. As a radioactive gas naturally emitted from the ground in certain geological settings, understanding environmental factors controlling Radon concentrations and their dynamics is important for estimating its effect on human health and the efficiency of possible measures for reducing the corresponding exposition. In this work, we re-analyze two high-resolution records of indoor Radon concentrations from Coimbra, Portugal, each of which spans several months of continuous measurements. In order to evaluate the presence of long-range correlations and fractal scaling, we utilize a multiplicity of complementary methods, including power spectral analysis, ARFIMA modeling, classical and multi-fractal detrended fluctuation analysis, and two different estimators of the signals' fractal dimensions. Power spectra and fluctuation functions reveal some complex behavior with qualitatively different properties on different time-scales: white noise in the high-frequency part, indications of some long-range correlated process dominating time scales of several hours to days, and pronounced low-frequency variability associated with tidal and/or meteorological forcing. In order to further decompose these different scales of variability, we apply two different approaches. On the one hand, applying multi-resolution analysis based on the discrete wavelet transform allows separately studying contributions on different time scales and characterize their specific correlation and scaling properties. On the other hand, singular system analysis (SSA) provides a reconstruction of the essential modes of variability. Specifically, by considering only the first leading SSA modes, we achieve an efficient de-noising of our environmental signals, highlighting the low-frequency variations together with some distinct scaling on sub-daily time-scales resembling the properties of a long-range correlated process.

What Teachers Should Know about Radon.

ERIC Educational Resources Information Center

Bettis, Clifford; Throckmorton, Carl

1991-01-01

Attempts to clear up misunderstandings about radon and outlines information teachers can convey to their students. Includes a brief history of radon, health threats posed by radon, methods to measure radon quantities, homeowner risks and preventative actions, and a glossary of radon terms. (MDH)

Wigner-Hough/Radon Transform for GPS Post-Correlation Integration (Preprint)

DTIC Science & Technology

2007-09-01

Wigner - Ville distribution ( WVD ) is a well known method to estimate instantaneous frequency, which appears as a...Barbarossa, 1996]. In this method, the Wigner - Ville distribution ( WVD ) is used to represent the signal energy in the time-frequency plane while the...its Wigner - Ville 4 distribution or WVD is computed as: ∫ +∞ ∞− −−+= τττ τπ detxtxftW fj 2* ) 2 () 2 (),( (4) where * stands for complex

Tomographic imaging of transparent biological samples using the pyramid phase microscope

PubMed Central

Iglesias, Ignacio

2016-01-01

We show how a pyramid phase microscope can be used to obtain tomographic information of the spatial variation of refractive index in biological samples using the Radon transform. A method that uses the information provided by the phase microscope for axial and lateral repositioning of the sample when it rotates is also described. Its application to the reconstruction of mouse embryos in the blastocyst stage is demonstrated. PMID:27570696

The Concept of Equivalent Radon Concentration for Practical Consideration of Indoor Exposure to Thoron

PubMed Central

Chen, Jing; Moir, Deborah

2012-01-01

To consider the total exposure to indoor radon and thoron, a concept of equivalent radon concentration for thoron is introduced, defined as the radon concentration that delivers the same annual effective dose as that resulting from the thoron concentration. The total indoor exposure to radon and thoron is then the sum of the radon concentration and the equivalent radon concentration for thoron. The total exposure should be compared to the radon guideline value, and if it exceeds the guideline value, appropriate remedial action is required. With this concept, a separate guideline for indoor thoron exposure is not necessary. For homes already tested for radon with radon detectors, Health Canada’s recommendation of a 3-month radon test performed during the fall/winter heating season not only ensures a conservative estimate of the annual average radon concentration but also covers well any potentially missing contribution from thoron exposure. In addition, because the thoron concentration is much lower than the radon concentration in most homes in Canada, there is no real need to re-test homes for thoron. PMID:22470292

RADON REDUCTION AND RADON-RESISTANT CONSTRUCTION DEMONSTRATIONS IN NEW YORK - VOLUME 1: TECHNICAL REPORT

EPA Science Inventory

The report gives results of radon reduction and radon-resistant construction demonstrations in New York. The existing house evaluation demonstrated radon mitigation techniques where indoor radon concentrations exceeded 4 pCi/L. Results demonstrated that sealing all accessible fou...

The Austrian radon activities on the way to the national radon action plan.

PubMed

Gruber, V; Ringer, W; Wurm, G; Haider, W

2014-07-01

Based on the new Euratom Basic Safety Standards (BSS), all EU member states will be obliged to design a strategy to address long-term risks from radon exposure, which is laid down in the 'national radon action plan'. In Austria, the National Radon Centre is responsible for the development of the action plan. This paper presents the current and planned radon protection activities on the way to establish the radon action plan--like the national radon database, the definition of radon risk areas by improving the existing radon map, as well as strategies and activities to increase the radon awareness of the public and decision-makers and to involve the building sector. The impact of and the need for actions caused by the BSS requirements on the Austrian radon legislation, strategy and programme are discussed. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[The modern applications of radon therapy for the medical rehabilitation of the patients].

PubMed

Razumov, A N; Puriga, A O; Yurova, O V

2015-01-01

Radon therapy is one of the methods of physiobalneotherapy the mechanism of action of which is believed to consist of the influence of the small radiation doses of radon and its daughter products on the nervous, vascular, and immune apparatuses of the skin and mucosal membranes that eventually enhances the protective and adaptive potential of the body and thereby its ability to resist pathological impacts. At present, the high effectiveness of radon therapy is universally recognized and this method is widely applied for the combined treatment of various diseases in different fields of medicine. These include (1) diseases of the musculoskeletal system and locomotor disorders in the patients presenting with recurrent rheumatic fever, reactive arthritis, ankylosing spondylitis, post-traumatic osteoarthrosis and knee joint synovitis, the sympathico-tonic course of vegetative dystonia associated with connective tissue dysplasia, etc.; (2) neurological disorders in the patients presenting with cervical dorsopathy, neurological manifedstations of degenerative lesions of the cervical and lumbar spine, etc.; (3) cardiological disorders in the patients presenting with hypertensive disease, coronary heart disease, atherosclerosis of different localization, etc.; (4) gastrointestinal disorders in the patients presenting with gastric and duodenal ulcers, irritated bowel syndrome, etc.; (5) gynecological problems in the patients presenting with primary and secondary dysmenorrhea, genital endometriosis, uterine myoma, dysregulated reproductive function, polycystic ovary - syndrome, polycystic ovary syndrome and ovulatory disorders of proinflammatory origin, etc.

Radon

MedlinePlus

... My Home? Radon Guide for Tenants Builders and Contractors Radon-Resistant Construction Basics and Techniques EPA's Directory of Builders Resources for Builders and Contractors Radon Action Plans The National Radon Action Plan ( ...

Neural network-based multiple robot simultaneous localization and mapping.

PubMed

Saeedi, Sajad; Paull, Liam; Trentini, Michael; Li, Howard

2011-12-01

In this paper, a decentralized platform for simultaneous localization and mapping (SLAM) with multiple robots is developed. Each robot performs single robot view-based SLAM using an extended Kalman filter to fuse data from two encoders and a laser ranger. To extend this approach to multiple robot SLAM, a novel occupancy grid map fusion algorithm is proposed. Map fusion is achieved through a multistep process that includes image preprocessing, map learning (clustering) using neural networks, relative orientation extraction using norm histogram cross correlation and a Radon transform, relative translation extraction using matching norm vectors, and then verification of the results. The proposed map learning method is a process based on the self-organizing map. In the learning phase, the obstacles of the map are learned by clustering the occupied cells of the map into clusters. The learning is an unsupervised process which can be done on the fly without any need to have output training patterns. The clusters represent the spatial form of the map and make further analyses of the map easier and faster. Also, clusters can be interpreted as features extracted from the occupancy grid map so the map fusion problem becomes a task of matching features. Results of the experiments from tests performed on a real environment with multiple robots prove the effectiveness of the proposed solution.

First radon measurements and occupational exposure assessments in underground geodynamic laboratory the Polish Academy of Sciences Space Research Centre in Książ Castle (SW Poland).

PubMed

Fijałkowska-Lichwa, Lidia; Przylibski, Tadeusz A

2016-12-01

The article presents the results of the first radon activity concentration measurements conducted continuously between 17 th May 2014 and 16 th May 2015 in the underground geodynamic laboratory of the Polish Academy of Sciences Space Research Centre in Książ. The data were registered with the use of three Polish semiconductor SRDN-3 detectors located the closest (SRDN-3 No. 6) to and the furthest (SRDN-3 No. 3) from the facility entrance, and in the fault zone (SRDN-3 No. 4). The study was conducted to characterize the radon behaviour and check it possibility to use with reference to long- and short-term variations of radon activity concentration observed in sedimentary rocks strongly fractured and intersected by systems of multiple faults, for integrated comparative assessments of changes in local orogen kinetics. The values of radon activity concentration in the underground geodynamic laboratory of the Polish Academy of Sciences (PAN) Space Research Centre in Książ undergo changes of a distinctly seasonal character. The highest values of radon activity concentration are recorded from late spring (May/June) to early autumn (October), and the lowest - from November to April. Radon activity concentrations varied depending on the location of measurement points. Between late spring and autumn they ranged from 800 Bq·m -3 to 1200 Bq·m -3 , and even 3200 Bq·m -3 in the fault zone. Between November and April, values of radon activity concentration are lower, ranging from 500 Bq·m -3 to 1000 Bq·m -3 and 2700 Bq·m -3 in the fault zone. The values of radon activity concentration recorded in the studied facility did not undergo short-term changes in either the whole annual measuring cycle or any of its months. Effective doses received by people staying in the underground laboratory range from 0.001 mSv/h to 0.012 mSv/h. The mean annual effective dose, depending on the measurement site, equals 1 or is slightly higher than 10 mSv/year, while the maximum dose exceeds 20 mSv/year. The estimated annual effective doses are comparable to the standard value of 20 mSv/year defined by Polish law for people employed in the conditions of radiation exposure. They are also in the range of annual effective dose value (8 mSv/year) recommended in workplaces by International Commission on Radiation Protection. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

PubMed

Guo, Lu; Zhang, Lei; Guo, Qiuju

2016-06-01

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

Novel method of measurement of radon exhalation from building materials.

PubMed

Awhida, A; Ujić, P; Vukanac, I; Đurašević, M; Kandić, A; Čeliković, I; Lončar, B; Kolarž, P

2016-11-01

In the era of the energy saving policy (i.e. more air tight doors and windows), the radon exhaled from building materials tends to increase its concentration in indoor air, which increases the importance of the measurement of radon exhalation from building materials. This manuscript presents a novel method of the radon exhalation measurement using only a HPGe detector or any other gamma spectrometer. Comparing it with the already used methods of radon exhalation measurements, this method provides the measurement of the emanation coefficient, the radon diffusion length and the radon exhalation rate, all within the same measurement, which additionally defines material's radon protective properties. Furthermore it does not necessitate additional equipment for radon or radon exhalation measurement, which simplifies measurement technique, and thus potentially facilitates introduction of legal obligation for radon exhalation determination in building materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Exposure to atmospheric radon.

PubMed Central

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

1999-01-01

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

Radon induced hyperplasia: effective adaptation reducing the local doses in the bronchial epithelium.

PubMed

Madas, Balázs G

2016-09-01

There is experimental and histological evidence that chronic irritation and cell death may cause hyperplasia in the exposed tissue. As the heterogeneous deposition of inhaled radon progeny results in high local doses at the peak of the bronchial bifurcations, it was proposed earlier that hyperplasia occurs in these deposition hot spots upon chronic radon exposure. The objective of the present study is to quantify how the induction of basal cell hyperplasia modulates the microdosimetric consequences of a given radon exposure. For this purpose, computational epithelium models were constructed with spherical cell nuclei of six different cell types based on histological data. Basal cell hyperplasia was modelled by epithelium models with additional basal cells and increased epithelium thickness. Microdosimetry for alpha-particles was performed by an own-developed Monte-Carlo code. Results show that the average tissue dose, and the average hit number and dose of basal cells decrease by the increase of the measure of hyperplasia. Hit and dose distribution reveal that the induction of hyperplasia may result in a basal cell pool which is shielded from alpha-radiation. It highlights that the exposure history affects the microdosimetric consequences of a present exposure, while the biological and health effects may also depend on previous exposures. The induction of hyperplasia can be considered as a radioadaptive response at the tissue level. Such an adaptation of the tissue challenges the validity of the application of the dose and dose rate effectiveness factor from a mechanistic point of view. As the location of radiosensitive target cells may change due to previous exposures, dosimetry models considering the tissue geometry characteristic of normal conditions may be inappropriate for dose estimation in case of protracted exposures. As internal exposures are frequently chronic, such changes in tissue geometry may be highly relevant for other incorporated radionuclides.

Canadian population risk of radon induced lung cancer: a re-assessment based on the recent cross-Canada radon survey

PubMed Central

Chen, J.; Moir, D.; Whyte, J.

2012-01-01

Exposure to indoor radon has been determined to be the second leading cause of lung cancer after tobacco smoking. Canadian population risk of radon induced lung cancer was assessed in 2005 with the radon distribution characteristics determined from a radon survey carried out in the late 1970s in 19 cities. In that survey, a grab sampling method was used to measure radon levels. The observed radon concentration in 14 000 Canadian homes surveyed followed a log–normal distribution with a geometric mean (GM) of 11.2 Bq m–3 and a geometric standard deviation (GSD) of 3.9. Based on the information from that survey, it was estimated that ∼10 % of lung cancers in Canada resulted from indoor radon exposure. To gain a better understanding of radon concentrations in homes across the country, a national residential radon survey was launched in April 2009. In the recent survey, long-term (3 month or longer) indoor radon measurements were made in roughly 14 000 homes in 121 health regions across Canada. The observed radon concentrations follow, as expected, a log–normal distribution with a GM of 41.9 Bq m–3 and a GSD of 2.8. Based on the more accurate radon distribution characteristics obtained from the recent cross-Canada radon survey, a re-assessment of Canadian population risk for radon induced lung cancer was undertaken. The theoretical estimates show that 16 % of lung cancer deaths among Canadians are attributable to indoor radon exposure. These results strongly suggest the ongoing need for the Canadian National Radon Program. In particular, there is a need for a focus on education and awareness by all levels of government, and in partnership with key stakeholders, to encourage Canadians to take action to reduce the risk from indoor radon exposure. PMID:22874897

RADON REDUCTION AND RADON RESISTANT CONSTRUCTION DEMONSTRATIONS IN NEW YORK

EPA Science Inventory

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

Modeling of indoor radon concentration from radon exhalation rates of building materials and validation through measurements.

PubMed

Kumar, Amit; Chauhan, R P; Joshi, Manish; Sahoo, B K

2014-01-01

Building materials are the second major source of indoor radon after soil. The contribution of building materials towards indoor radon depends upon the radium content and exhalation rates and can be used as a primary index for radon levels in the dwellings. The radon flux data from the building materials was used for calculation of the indoor radon concentrations and doses by many researchers using one and two dimensional model suggested by various researchers. In addition to radium content, the radon wall flux from a surface strongly depends upon the radon diffusion length (L) and thickness of the wall (2d). In the present work the indoor radon concentrations from the measured radon exhalation rate of building materials calculated using different models available in literature and validation of models was made through measurement. The variation in the predicted radon flux from different models was compared with d/L value for wall and roofs of different dwellings. The results showed that the radon concentrations predicted by models agree with experimental value. The applicability of different model with d/L ratio was discussed. The work aims to select a more appropriate and general model among available models in literature for the prediction of indoor radon. Copyright © 2013 Elsevier Ltd. All rights reserved.

Radon flux at King George Island, Antarctic Peninsula.

PubMed

Evangelista, H; Pereira, E B

2002-01-01

Fluxes of 222Rn from the ice-free terrain to the atmosphere were measured directly, for the first time, at the Brazilian Antarctic Station Ferraz during the summer field campaign of 1998/99. Average value for the flux was 7.7 +/- 4.8 x 10(-2) atoms cm(-2) s(-1) and it ranged between 0.21 x 10(-2) atoms cm(-2) s(-1) and 28 x l0(-2) atoms cm(-2) s(-1). The average flux of 220Rn was estimated to be 23 atoms cm(-2) s(-1), using a combination of two techniques: nuclear track detection and alpha spectrometry of radon daughters. It was found that the production of radon by uranium (41.54 + /-7.17 Bq kg(-1)) and thorium (57.97 +/- 12.14 Bq kg(-1)) equivalent soil contents, and a diffusion coefficient derived from experimental data for the local terrain could account for this average flux. Nevertheless, the large surges of 222Rn in the atmosphere frequently observed for that area could not be explained by this flux only.

Comparison study and thoron interference test of different radon monitors.

PubMed

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

2013-03-01

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

Remote online monitoring of radon wells used for therapy in bathtubs

NASA Astrophysics Data System (ADS)

von Philipsborn, Henning

2017-04-01

Sibyllenbad, in the community of Neualbenreuth, 140 km NNE of Regensburg, is well known for two radon wells and one containing carbon dioxide. The water is used pure or mixed for therapy in 200 L bathtubs for a number of indications. Since its beginning, 26 years ago, the author is active in measuring radon and radon decay products and their factor of equilibrium in air and in water for radiation protection of the personnel and for radon water quality assurance for the patients. For the special local operating conditions - high time resolution of measurements is asked - novel measuring methods and instruments were developed. These proved to be useful for several other applications, not foreseen at the beginning. Recently, a probe was installed for online monitoring of water entering the main water storage tank of 42 m3, at the Kurhaus, two km from the radon wells. The probe consists of a 51 mm x 76 mm NaI (Tl) scintillator with photomultiplier, immersed in continuously flowing water in an 8 L pot. The MCA registers the pulses between 200 and 650 keV of the Rn decay products Pb-214 and Bi-214. Specially developed software calculates the gross [cps] from the total counts for variable counting times. The background, determined separately, is subtracted and the net is multiplied with a calibration factor [Bq/L per net cps], determined separately. The activity concentration [Bq/L] of the radon decay products in water is plotted vs. real time (plot P). With Teamviewer, remote online monitoring is possible from the Radiometric Seminar. At the Rn wells, the flow rate [L/s] of the discontinuously working pumps and the lowering of the water level in [m] is measured online. The two quantities are directly correlated, and with a time lag to the demand of radon water from the Kurhaus. Several series of discrete measurements of water, both at the well and at the storage tank, fresh and after 1, 2 and 3 h after storage in full, closed bottles, reveal factors of equilibrium k between Rn and the decay products as low as 0.5. This explains strong, but systematic fluctuations in the continuous plot P following demand of water for the patients. The true Rn-222 concentration fluctuates much less and is not lowered at the well after heavy rain falls. The variation of k requires a lengthy discussion and reveals valuable information.

Radon monitoring and hazard prediction in Ireland

NASA Astrophysics Data System (ADS)

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

2016-04-01

Radon is a naturally occurring radioactive gas which forms as a decay product from uranium. It is the largest source of natural ionizing radiation affecting the global population. When radon is inhaled, its short-lived decay products can interact with lung tissue leading to DNA damage and development of lung cancer. Ireland has among the highest levels of radon in Europe and eighth highest of an OECD survey of 29 countries. Every year some two hundred and fifty cases of lung cancer in Ireland are linked to radon exposure. This new research project will build upon previous efforts of radon monitoring in Ireland to construct a high-resolution radon hazard map. This will be achieved using recently available high-resolution airborne gamma-ray spectrometry (radiometric) and soil geochemistry data (http://www.tellus.ie/), indoor radon concentrations (http://www.epa.ie/radiation), and new direct measurement of soil radon. In this regard, legacy indoor radon concentrations will be correlated with soil U and Th concentrations and other geogenic data. This is a new approach since the vast majority of countries with a national radon monitoring programme rely on indoor radon measurements, or have a spatially limited dataset of soil radon measurements. Careful attention will be given to areas where an indicative high radon hazard based on geogenic factors does not match high indoor radon concentrations. Where such areas exist, it may imply that some parameter(s) in the predictive model does not match that of the environment. These areas will be subjected to measurement of radon soil gas using a combination of time averaged (passive) and time dependant (active) measurements in order to better understand factors affecting production, transport and accumulation of radon in the natural environment. Such mapping of radon-prone areas will ultimately help to inform when prevention and remediation measures are necessary, reducing the radon exposure of the population. Therefore, given that an estimated 250,000 people in Ireland are exposed to high radon levels, the findings of this research stand to make a considerable positive impact in enhancing the quality of life and long-term health for a significant proportion of inhabitants.

Radon in ground water: A study of the measurement and release of waterborne radon and modeling of radon variation in bedrock wells

NASA Astrophysics Data System (ADS)

Guiseppe, Vincente E.

Naturally occurring radon gas (222Rn) exists in ground water and drinking water supplies. Research involving radon in ground water requires the ability to accurately measure radon in water. In the absence of a national program, an intercomparison study of laboratories was sanctioned by the State of Maine. The University of Maine research laboratory supplied each laboratory with water samples of various radon concentrations, served as the reference laboratory, and analyzed the results presented here. The external review of the University of Maine laboratory and agreement with some of the participating laboratories verifies its accuracy in measuring radon in water. A study of nine elementary schools in Maine examined the release of waterborne radon during water use. The release of radon into the kitchen air was measured to be greater than the EPA action level of 0.150 Bq L -1 (4 pCi L-1) in all schools but negligible concentrations of radon were found in adjacent classrooms. In two schools over a three-fold spatial radon variation was measured suggesting that multiple detectors are needed to accurately measure waterborne radon in air. During water use, the radon in water concentration was measured periodically and many of the schools showed an increase in the radon concentration by 200 BqL-1 or more. To explore this effect, nine bedrock wells were studied in detail. Measurements of the ambient and purged radon profiles in the wells showed variations of radon concentration of samples within the well. The rock chips removed during well-drilling were analyzed for radionuclides in the 238U decay series. The 226Ra concentrations in the rock chips do not explain the measured vertical variation of dissolved radon. The vertical flow and fracture locations were previously determined by borehole logging to determine location of ground water inflow. A mathematical model of the ground-water flow into and through the well with radon as a tracer was tested. The model was successfully fit to data obtained from the wells that had a variation in radon concentration.

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

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-21

.... Discussion Uranium recovery facility licensees, including in-situ recovery facilities and conventional... Recovery Facility Surveys of Radon and Radon Progeny in Air and Demonstrations of Compliance AGENCY... Staff Guidance, ``Evaluations of Uranium Recovery Facility Surveys of Radon and Radon Progeny in Air and...

Effects of air exchange property of passive-type radon-thoron discriminative detectors on performance of radon and thoron measurements.

PubMed

Omori, Y; Janik, M; Sorimachi, A; Ishikawa, T; Tokonami, S

2012-11-01

Pairs of diffusion chambers with different air exchange rates are used in a large-scale survey to determine radon and thoron, separately. When they are enclosed in radon-proof bags for keeping after the exposure, since radon does not escape out immediately from the low-diffusion chamber, it leads to further exposure in the bags and disturbs the estimation of radon and thoron concentrations. In this study, the effects of the different air exchange properties of the radon-thoron discriminative detectors with CR-39 chips on the estimations of radon and thoron concentrations were investigated. The commercially available and frequently used detectors, Raduet, are examined in this study. The result shows that radon escapes out in 10 h. When degassing is not enough after the exposure in a calibration experiment or high-background radiation area, the residual radon causes the overestimation of the radon concentration and increase in the uncertainty in the thoron concentration, i.e. a low-performance quality of radon and thoron measurements.

Soil radium, soil gas radon and indoor radon empirical relationships to assist in post-closure impact assessment related to near-surface radioactive waste disposal.

PubMed

Appleton, J D; Cave, M R; Miles, J C H; Sumerling, T J

2011-03-01

Least squares (LS), Theil's (TS) and weighted total least squares (WTLS) regression analysis methods are used to develop empirical relationships between radium in the ground, radon in soil and radon in dwellings to assist in the post-closure assessment of indoor radon related to near-surface radioactive waste disposal at the Low Level Waste Repository in England. The data sets used are (i) estimated ²²⁶Ra in the < 2 mm fraction of topsoils (eRa226) derived from equivalent uranium (eU) from airborne gamma spectrometry data, (ii) eRa226 derived from measurements of uranium in soil geochemical samples, (iii) soil gas radon and (iv) indoor radon data. For models comparing indoor radon and (i) eRa226 derived from airborne eU data and (ii) soil gas radon data, some of the geological groupings have significant slopes. For these groupings there is reasonable agreement in slope and intercept between the three regression analysis methods (LS, TS and WTLS). Relationships between radon in dwellings and radium in the ground or radon in soil differ depending on the characteristics of the underlying geological units, with more permeable units having steeper slopes and higher indoor radon concentrations for a given radium or soil gas radon concentration in the ground. The regression models comparing indoor radon with soil gas radon have intercepts close to 5 Bq m⁻³ whilst the intercepts for those comparing indoor radon with eRa226 from airborne eU vary from about 20 Bq m⁻³ for a moderately permeable geological unit to about 40 Bq m⁻³ for highly permeable limestone, implying unrealistically high contributions to indoor radon from sources other than the ground. An intercept value of 5 Bq m⁻³ is assumed as an appropriate mean value for the UK for sources of indoor radon other than radon from the ground, based on examination of UK data. Comparison with published data used to derive an average indoor radon: soil ²²⁶Ra ratio shows that whereas the published data are generally clustered with no obvious correlation, the data from this study have substantially different relationships depending largely on the permeability of the underlying geology. Models for the relatively impermeable geological units plot parallel to the average indoor radon: soil ²²⁶Ra model but with lower indoor radon: soil ²²⁶Ra ratios, whilst the models for the permeable geological units plot parallel to the average indoor radon: soil ²²⁶Ra model but with higher than average indoor radon: soil ²²⁶Ra ratios. Copyright © 2010 Natural Environment Research Council. Published by Elsevier Ltd.. All rights reserved.

STUDY OF RADON FLUX FROM SOIL IN BUDHAKEDAR REGION USING SRM.

PubMed

Bourai, A A; Aswal, Sunita; Kandari, Tushar; Kumar, Shiv; Joshi, Veena; Sahoo, B K; Ramola, R C

2016-10-01

In the present study, the radon flux rate of the soil is measured using portable radon monitor (scintillation radon monitor) in the Budhakedar region of District Tehri, India. The study area falls along a fault zone named Main Central Thrust, which is relatively rich in radium-bearing minerals. Radon flux rate from the soil is one of the most important factors for the evaluation of environmental radon levels. The earlier studies in the Budhakedar region shows a high level of radon (>4000 Bq m -3 ). Hence, it is important to measure the radon flux rate. The aim of the present study is to calculate the average estimate of the surface radon flux rate as well as the effective mass exhalation rate. A positive correlation of 0.54 was found between radon flux rate and radon mass exhalation rate. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

EML indoor radon workshop, 1982

DOE Office of Scientific and Technical Information (OSTI.GOV)

George, A.C.; Lowder, W.; Fisenne, I.

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 techniquesmore » 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.« less

Radon Testing for Safe Schools Act. Report (To Accompany S. 1697) from the Committee on Environment and Public Works, United States Senate, One Hundred First Congress, Second Session.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. Senate Committee on Environment and Public Works.

This report was written to accompany the Radon Testing for Safe Schools Act (S.1697), a bill that provides for radon testing of schools located in high risk radon areas and provides limited financial assistance to schools for mitigation of high levels of radon. A description of radon, its harmful effects, and the radon levels detected in schools…

Atmosphere purification of radon and radon daughter elements

DOEpatents

Stein, L.

1973-12-11

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

Radon remediation and prevention status in 23 European countries.

PubMed

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

2013-12-01

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

Estimation of waste water treatment plant methane emissions: methodology and results from a short campaign

NASA Astrophysics Data System (ADS)

Yver-Kwok, C. E.; Müller, D.; Caldow, C.; Lebegue, B.; Mønster, J. G.; Rella, C. W.; Scheutz, C.; Schmidt, M.; Ramonet, M.; Warneke, T.; Broquet, G.; Ciais, P.

2013-10-01

This paper describes different methods to estimate methane emissions at different scales. These methods are applied to a waste water treatment plant (WWTP) located in Valence, France. We show that Fourier Transform Infrared (FTIR) measurements as well as Cavity Ring Down Spectroscopy (CRDS) can be used to measure emissions from the process to the regional scale. To estimate the total emissions, we investigate a tracer release method (using C2H2) and the Radon tracer method (using 222Rn). For process-scale emissions, both tracer release and chamber techniques were used. We show that the tracer release method is suitable to quantify facility- and some process-scale emissions, while the Radon tracer method encompasses not only the treatment station but also a large area around. Thus the Radon tracer method is more representative of the regional emissions around the city. Uncertainties for each method are described. Applying the methods to CH4 emissions, we find that the main source of emissions of the plant was not identified with certainty during this short campaign, although the primary source of emissions is likely to be from solid sludge. Overall, the waste water treatment plant represents a small part (3%) of the methane emissions of the city of Valence and its surroundings,which is in agreement with the national inventories.

Registration in a radon system of signals related to the Tohoku Earthquake

NASA Astrophysics Data System (ADS)

Steinitz, Gideon; Piatibratova, Oksana; Kotlarsky, Peter

2013-04-01

The behavior of radon (Rn-222) within confined volumes of air is examined experimentally at the GSI (Jerusalem) since several years. In these experiments a relatively high level of radon is maintained by diffusion from a source via a tube and radiation from it is measured using nuclear detectors. In difference with the expected, nuclear radiation from the radon (progeny) shows: a) temporal variations (signals) spanning annual to daily scale; b) directionality of the nuclear radiation reflected as inverse signal patterns in the east-west versus north-south directions. The experimental setup at the GSI lab consists of a leak tight stainless steel (SS) canister (3.53 l) fed with radon by diffusing via SS tube (0.8 m) from a commercial source (RaCl2; 103 kBq). Four identical gamma detectors (2×2") were placed around its central horizontal plane of the canister, at the primary geographic directions, and a further detector (36×76 mm) was placed along the vertical axis of the canister. Count rates (1-minute intervals) were acquired by a datalogger. The system was used in this configuration in a series of experiments conducted from May 2009 to June 2012. An experiment was operating from 30.1.2011 to 22.3.11. The host gas in this experiment was argon at a pressure of ~1 atmosphere. Distinctive short term periodic (STP) signals with periods of 2-3 hours (frequencies in the range of 9-12 CPD) occur in a time interval of three days in association with the Tohoku earthquake (TE; 11.3.2011) and possibly also with its pre-shock. The STP signals occur from around 6 hours prior to the TE and are maintained to around 48 hours after the TE. These signals are observed at all five sensors and are superimposed on the DR signals with relative amplitudes of around 20%. They exhibit differing forms and phase at the different sensors, located at different directions around the canister. The pattern is similar but not identical to the spatial manifestation of form and phase of the DR signal in such experiments, indicating a communality of the driving mechanism. Similar short term signals have not been encountered in other experiments using this configuration, nor at any of the other configurations. Both DR and STP signals are due neither to mechanical nor to local environmental influences on the experimental system. The DR signals have recently been interpreted to be due to a remote influence on the radon system, possible by a component in solar irradiance. Concerning the TE the implications are: 1. The overall progression of the TE (Mw=9) event is also associated with a non-mechanical geodynamic process which is reflected by nuclear radiation features of radon in air. This process is modifying (superimposed) the driver of the primary DR signal of the radon system. 2. The influencing process is operating at a global scale, but at this stage it remains open whether the effect is transferred to the experimental setup via the solid earth and/or the atmosphere. 3. Detection of such phenomena is possible in radon systems of specific configuration the parameters of which are so far undetermined. 4. The possibility is raised that a pre-cursor of the TE has been detected. Concerning the radon system the implications are: 1. Results obtained by the GSI group indicate that nuclear radiation from radon (and progeny) inside a confined volume of air varies spatially and temporally at time scales from annually to daily. The geophysical drivers of these signals are unclear at this stage. The new experimental results demonstrate that the same radon system is responding to further geophysical drivers operating at a time scale of 2-3 hours. 2. The results further demonstrate the potential of investigations utilizing enhanced radon levels within confined volumes for detection of a new type of time varying geophysical phenomena. References: Steinitz, G., Piatibratova, O., Kotlarsky, P., 2011. Possible effect of solar tides on radon signals. Journal of Environmental Radioactivity, 102, 749-765. doi: 10.1016/j.jenvrad.2011.04.002. Sturrock, P.A., Steinitz, G., Fischbach, E., Javorsek, D. and Jenkins, J.H., 2012. Analysis of Gamma Radiation from a Radon Source: Indications of a Solar Influence. Journal of Astroparticle Physics, 35/1, 18-25.

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

PubMed

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

2004-01-01

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

Emanation of radon from household granite.

PubMed

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

2009-04-01

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

Recovery of singularities from a backscattering Born approximation for a biharmonic operator in 3D

NASA Astrophysics Data System (ADS)

Tyni, Teemu

2018-04-01

We consider a backscattering Born approximation for a perturbed biharmonic operator in three space dimensions. Previous results on this approach for biharmonic operator use the fact that the coefficients are real-valued to obtain the reconstruction of singularities in the coefficients. In this text we drop the assumption about real-valued coefficients and also establish the recovery of singularities for complex coefficients. The proof uses mapping properties of the Radon transform.

Accurate estimation of motion blur parameters in noisy remote sensing image

NASA Astrophysics Data System (ADS)

Shi, Xueyan; Wang, Lin; Shao, Xiaopeng; Wang, Huilin; Tao, Zhong

2015-05-01

The relative motion between remote sensing satellite sensor and objects is one of the most common reasons for remote sensing image degradation. It seriously weakens image data interpretation and information extraction. In practice, point spread function (PSF) should be estimated firstly for image restoration. Identifying motion blur direction and length accurately is very crucial for PSF and restoring image with precision. In general, the regular light-and-dark stripes in the spectrum can be employed to obtain the parameters by using Radon transform. However, serious noise existing in actual remote sensing images often causes the stripes unobvious. The parameters would be difficult to calculate and the error of the result relatively big. In this paper, an improved motion blur parameter identification method to noisy remote sensing image is proposed to solve this problem. The spectrum characteristic of noisy remote sensing image is analyzed firstly. An interactive image segmentation method based on graph theory called GrabCut is adopted to effectively extract the edge of the light center in the spectrum. Motion blur direction is estimated by applying Radon transform on the segmentation result. In order to reduce random error, a method based on whole column statistics is used during calculating blur length. Finally, Lucy-Richardson algorithm is applied to restore the remote sensing images of the moon after estimating blur parameters. The experimental results verify the effectiveness and robustness of our algorithm.

Analysis of Radon and Radon Progeny in Residences: Factors that Affect Their Amounts and Methods of Reduction

DTIC Science & Technology

1985-03-01

figures 6 - 14 a plot of the radon daughters concentration versua the Electronic Air Cleener operation time is shown. The variations in the daughter...34Uncertainties in the Measurement of Airborne Radon Daughters ," Health Physics, 39, 943-955 (1980). 4. Cliff, K.D. and others. "Radon Daughter Exposures in...Radon and Radon Daughters in Canadian Homes," Health Physics, 39: 285-289 (1980). 25. Nero, A.V. "Indoor Radiation Exposures from Rn-222 and its

Contribution of radon and radon daughters to respiratory cancer.

PubMed Central

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

1986-01-01

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

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

PubMed Central

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

2016-01-01

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

Residents in a High Radon Potential Geographic Area: Their Risk Perception and Attitude toward Testing and Mitigation.

ERIC Educational Resources Information Center

Ferng, Shiaw-Fen; Lawson, Jay K.

1996-01-01

Results of a study in Boone County, Indiana--a high radon potential geographic area--show that residents' knowledge about radon is at a relatively superficial level. A significant correlation between radon knowledge and home radon tests is observed. Respondents chose the newspaper as the favorite medium through which to launch radon health…

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

NASA Astrophysics Data System (ADS)

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

2013-03-01

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

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

PubMed

Froňka, A; Jílek, K; Moučka, L; Brabec, M

2011-05-01

Two new single-family houses identified as insufficient with regard to existing radon barrier efficiency, have been selected for further examination. A complex set of radon diagnosis procedures has been applied in order to localise and quantify radon entry pathways into the indoor environment. Independent assessment of radon entry rate and air exchange rate has been carried out using the continuous indoor radon measurement and a specific tracer gas application. Simultaneous assessment of these key determining factors has turned out to be absolutely crucial in the context of major cause identification of elevated indoor radon concentration.

Experimental assessment of indoor radon and soil gas variability: the RADON project

NASA Astrophysics Data System (ADS)

Barbosa, S. M.; Pereira, A. J. S. C.; Neves, L. J. P. F.; Steinitz, G.; Zafrir, H.; Donner, R.; Woith, H.

2012-04-01

Radon is a radioactive noble gas naturally present in the environment, particularly in soils derived from rocks with high uranium content. Radon is formed by alpha decay from radium within solid mineral grains, but can migrate via diffusion and/or advection into the air space of soils, as well as into groundwater and the atmosphere. The exhalation of radon from the pore space of porous materials into the atmosphere of indoor environments is well known to cause adverse health effects due to the inhalation of radon's short-lived decay products. The danger to human health is particularly acute in the case of poorly ventilated dwellings located in geographical areas of high radon potential. The RADON project, funded by the Portuguese Science Foundation (FCT), aims to evaluate the temporal variability of radon in the soil and atmosphere and to examine the influence of meteorological effects in radon concentration. For that purpose an experimental monitoring station is being installed in an undisturbed dwelling located in a region of high radon potential near the old uranium mine of Urgeiriça (central Portugal). The rationale of the project, the set-up of the experimental radon monitoring station, and preliminary monitoring results will be presented.

Radon in the Exhaled Air of Patients in Radon Therapy.

PubMed

Lettner, Herbert; Hubmer, Alexander; Hofmann, Werner; Landrichinger, Julia; Gaisberger, Martin; Winkler-Heil, Renate

2017-11-01

In the Gastein valley, numerous facilities use radon for the treatment of various diseases either by exposure to radon in air or in radon rich thermal water. In this study, six test persons were exposed to radon thermal water in a bathtub and the time-dependent radon activity concentration in the exhaled air was recorded. At temperatures between 38°C and 40°C, the radon activity concentration in the water was about 900 kBq/m3 in a total volume of 600 l, where the patients were exposed for 20 min, while continuously sampling the exhaled air during the bathing and 20 min thereafter. After entering the bath, the exhaled radon activity concentration rapidly increased, reaching some kind of saturation after 20 min exposure. The radon activity concentration in the exhaled air was about 8000 Bq/m3 at the maximum, with higher concentrations for male test persons. The total radon transfer from water to the exhaled air was between 480 and 1000 Bq, which is equivalent to 0.08% and 0.2% of the radon in the water. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

PubMed Central

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

2015-01-01

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

Estimation of residential radon exposure and definition of Radon Priority Areas based on expected lung cancer incidence.

PubMed

Elío, J; Crowley, Q; Scanlon, R; Hodgson, J; Zgaga, L

2018-05-01

Radon is a naturally occurring gas, classified as a Class 1 human carcinogen, being the second most significant cause of lung cancer after tobacco smoking. A robust spatial definition of radon distribution in the built environment is therefore essential for understanding the relationship between radon exposure and its adverse health effects on the general population. Using Ireland as a case study, we present a methodology to estimate an average indoor radon concentration and calculate the expected radon-related lung cancer incidence. We use this approach to define Radon Priority Areas at the administrative level of Electoral Divisions (EDs). Geostatistical methods were applied to a data set of almost 32,000 indoor radon measurements, sampled in Ireland between 1992 and 2013. Average indoor radon concentrations by ED range from 21 to 338 Bq m -3 , corresponding to an effective dose ranging from 0.8 to 13.3 mSv y -1 respectively. Radon-related lung cancer incidence by ED was calculated using a dose-effect model giving between 15 and 239 cases per million people per year, depending on the ED. Based on these calculations, together with the population density, we estimate that of the approximately 2,300 lung cancer cases currently diagnosed in Ireland annually, about 280 may be directly linked to radon exposure. This figure does not account for the synergistic effect of radon exposure with other factors (e.g. tobacco smoking), so likely represents a minimum estimate. Our approach spatially defines areas with the expected highest incidence of radon-related lung cancer, even though indoor radon concentrations for these areas may be moderate or low. We therefore recommend that both indoor radon concentration and population density by small area are considered when establishing national radon action plans. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

PubMed Central

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

2014-01-01

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

Lung cancer deaths from indoor radon and the cost effectiveness and potential of policies to reduce them

PubMed Central

Read, Simon; McGale, Paul; Darby, Sarah

2009-01-01

Objective To determine the number of deaths from lung cancer related to radon in the home and to explore the cost effectiveness of alternative policies to control indoor radon and their potential to reduce lung cancer mortality. Design Cost effectiveness analysis. Setting United Kingdom. Data sources Epidemiological data on risks from indoor radon and from smoking, vital statistics on deaths from lung cancer, survey information on effectiveness and costs of radon prevention and remediation. Main outcome measures Estimated number of deaths from lung cancer related to indoor radon, lifetime risks of death from lung cancer before and after various potential interventions to control radon, the cost per quality adjusted life year (QALY) gained from different policies for control of radon, and the potential of those policies to reduce lung cancer mortality. Results The mean radon concentration in UK homes is 21 becquerels per cubic metre (Bq/m3). Each year around 1100 deaths from lung cancer (3.3% of all deaths from lung cancer) are related to radon in the home. Over 85% of these arise from radon concentrations below 100 Bq/m3 and most are caused jointly by radon and active smoking. Current policy requiring basic measures to prevent radon in new homes in selected areas is highly cost effective, and such measures would remain cost effective if extended to the entire UK, with a cost per QALY gained of £11 400 ( €12 200; $16 913). Current policy identifying and remediating existing homes with high radon levels is, however, neither cost effective (cost per QALY gained £36 800) nor effective in reducing lung cancer mortality. Conclusions Policies requiring basic preventive measures against radon in all new homes throughout the UK would be cost effective and could complement existing policies to reduce smoking. Policies involving remedial work on existing homes with high radon levels cannot prevent most radon related deaths, as these are caused by moderate exposure in many homes. These conclusions are likely to apply to most developed countries, many with higher mean radon concentrations than the UK. PMID:19129153

Lung cancer deaths from indoor radon and the cost effectiveness and potential of policies to reduce them.

PubMed

Gray, Alastair; Read, Simon; McGale, Paul; Darby, Sarah

2009-01-06

To determine the number of deaths from lung cancer related to radon in the home and to explore the cost effectiveness of alternative policies to control indoor radon and their potential to reduce lung cancer mortality. Cost effectiveness analysis. United Kingdom. Epidemiological data on risks from indoor radon and from smoking, vital statistics on deaths from lung cancer, survey information on effectiveness and costs of radon prevention and remediation. Estimated number of deaths from lung cancer related to indoor radon, lifetime risks of death from lung cancer before and after various potential interventions to control radon, the cost per quality adjusted life year (QALY) gained from different policies for control of radon, and the potential of those policies to reduce lung cancer mortality. The mean radon concentration in UK homes is 21 becquerels per cubic metre (Bq/m(3)). Each year around 1100 deaths from lung cancer (3.3% of all deaths from lung cancer) are related to radon in the home. Over 85% of these arise from radon concentrations below 100 Bq/m(3) and most are caused jointly by radon and active smoking. Current policy requiring basic measures to prevent radon in new homes in selected areas is highly cost effective, and such measures would remain cost effective if extended to the entire UK, with a cost per QALY gained of pound11,400 ( euro12 200; $16,913). Current policy identifying and remediating existing homes with high radon levels is, however, neither cost effective (cost per QALY gained pound36,800) nor effective in reducing lung cancer mortality. Policies requiring basic preventive measures against radon in all new homes throughout the UK would be cost effective and could complement existing policies to reduce smoking. Policies involving remedial work on existing homes with high radon levels cannot prevent most radon related deaths, as these are caused by moderate exposure in many homes. These conclusions are likely to apply to most developed countries, many with higher mean radon concentrations than the UK.

Approximate non-linear multiparameter inversion for multicomponent single and double P-wave scattering in isotropic elastic media

NASA Astrophysics Data System (ADS)

Ouyang, Wei; Mao, Weijian

2018-03-01

An asymptotic quadratic true-amplitude inversion method for isotropic elastic P waves is proposed to invert medium parameters. The multicomponent P-wave scattered wavefield is computed based on a forward relationship using second-order Born approximation and corresponding high-frequency ray theoretical methods. Within the local double scattering mechanism, the P-wave transmission factors are elaborately calculated, which results in the radiation pattern for P-waves scattering being a quadratic combination of the density and Lamé's moduli perturbation parameters. We further express the elastic P-wave scattered wavefield in a form of generalized Radon transform (GRT). After introducing classical backprojection operators, we obtain an approximate solution of the inverse problem by solving a quadratic non-linear system. Numerical tests with synthetic data computed by finite-differences scheme demonstrate that our quadratic inversion can accurately invert perturbation parameters for strong perturbations, compared with the P-wave single-scattering linear inversion method. Although our inversion strategy here is only syncretized with P-wave scattering, it can be extended to invert multicomponent elastic data containing both P-wave and S-wave information.

Approximate nonlinear multiparameter inversion for multicomponent single and double P-wave scattering in isotropic elastic media

NASA Astrophysics Data System (ADS)

Ouyang, Wei; Mao, Weijian

2018-07-01

An asymptotic quadratic true-amplitude inversion method for isotropic elastic P waves is proposed to invert medium parameters. The multicomponent P-wave scattered wavefield is computed based on a forward relationship using second-order Born approximation and corresponding high-frequency ray theoretical methods. Within the local double scattering mechanism, the P-wave transmission factors are elaborately calculated, which results in the radiation pattern for P-wave scattering being a quadratic combination of the density and Lamé's moduli perturbation parameters. We further express the elastic P-wave scattered wavefield in a form of generalized Radon transform. After introducing classical backprojection operators, we obtain an approximate solution of the inverse problem by solving a quadratic nonlinear system. Numerical tests with synthetic data computed by finite-differences scheme demonstrate that our quadratic inversion can accurately invert perturbation parameters for strong perturbations, compared with the P-wave single-scattering linear inversion method. Although our inversion strategy here is only syncretized with P-wave scattering, it can be extended to invert multicomponent elastic data containing both P- and S-wave information.

Operator product expansion for conformal defects

NASA Astrophysics Data System (ADS)

Fukuda, Masayuki; Kobayashi, Nozomu; Nishioka, Tatsuma

2018-01-01

We study the operator product expansion (OPE) for scalar conformal defects of any codimension in CFT. The OPE for defects is decomposed into "defect OPE blocks", the irreducible representations of the conformal group, each of which packages the contribution from a primary operator and its descendants. We use the shadow formalism to deduce an integral representation of the defect OPE blocks. They are shown to obey a set of constraint equations that can be regarded as equations of motion for a scalar field propagating on the moduli space of the defects. By employing the Radon transform between the AdS space and the moduli space, we obtain a formula of constructing an AdS scalar field from the defect OPE block for a conformal defect of any codimension in a scalar representation of the conformal group, which turns out to be the Euclidean version of the HKLL formula. We also introduce a duality between conformal defects of different codimensions and prove the equivalence between the defect OPE block for codimension-two defects and the OPE block for a pair of local operators.

SITE-SPECIFIC MEASUREMENTS OF RESIDENTIAL RADON PROTECTION CATEGORY

EPA Science Inventory

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

Find a Radon Test Kit or Measurement and Mitigation Professional

EPA Pesticide Factsheets

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

Ultrasound mammography

NASA Astrophysics Data System (ADS)

Mensah, Serge; Franceschini, Emilie; Pauzin, Marie-Christine

2007-02-01

We introduce a near-field formulation of the acoustic field scattered by a soft tissue organ. This derivation is based on the Huygens-Fresnel principle that describes the scattered field as the result of the interferential scheme of all the secondary spherical waves. This leads us to define a new Fourier transform which yields a spectrum whose harmonic components have an elliptical spatial support. Based on these projections, we define an Elliptical Radon transform that enables us to reconstruct either the impedance or the celerity maps of an acoustical model characterized in terms of impedance and celerity fluctuations. The formulation is very similar to that developed in the far-field domain where the Radon transform pair is derived from an harmonic plane wave decomposition. This formulation allows us to introduce the Ductal Tomography, following the example of the Ductal Echography, that provides a systematic inspection of each mammary lobe, in order to reveal breast lesions at an early stage. In order to review the performances obtained with current echographs in view of specific experiment (numerical simulations), we develop a computer phantom that gains in realism. This 2-D anatomical phantom is an axial cut of the ductolobular structure corresponding to a daisy-like internal arrangement with petals (lobes) radiating around the nipple, for healthy and pathological situations. The different constitutive tissues and ducts are characterized in terms of density and celerity parameters whose spatial distributions are defined with specific random density laws. The use of a velocity-pressure formulation permits us to model time domain acoustic wave propagation. Broadband US pulses are transmitted and measured in diffraction around the breast with a ring antenna, the images are reconstructed using the elliptical back-projection-based procedure mentioned above.

High sensitivity detectors for measurement of diffusion, emanation and low activity of radon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mamedov, Fadahat; Štekl, Ivan; Smolek, Karel

Today's underground experiments require ultra-low background conditions. One of the most important source of background is radon. It is necessary to suppress it and consequently to detect very low radon concentration. In the frame of SuperNEMO collaboration experimental setups for measurement of low radon activity, radon diffusion through shielding foils and radon emanation from construction materials have been constructed in IEAP CTU in Prague and the obtained results are presented. The application of Timepix device in radon detection is briefly discussed.

A continuous plutonium aerosol monitor for use in high radon environments.

PubMed

Li, HuiBin; Jia, MingYan; Li, GuoShen; Wang, YinDong

2012-01-01

Radon concentration is very high in underground basements and other facilities. Radon concentration in a nuclear facility locates in the granite tunnel can be as high as 10(4) Bq m(-3) in summer. Monitoring plutonium aerosol in this circumstance is seriously interfered by radon daughters. In order to solve this problem, a new continuous aerosol monitor that can monitor very low plutonium aerosol concentration in high radon background was developed. Several techniques were used to reduce interference of radon daughters, and the minimum detectable concentrations in various radon concentrations were measured.

Radon mitigation in domestic properties and its health implications--a comparison between during-construction and post-construction radon reduction.

PubMed

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

2006-05-01

Although United Kingdom (UK) Building Regulations applicable to houses constructed since 1992 in Radon Affected Areas address the health issues arising from the presence of radon in domestic properties and specify the installation of radon-mitigation measures during construction, no legislative requirement currently exists for monitoring the effectiveness of such remediation once construction is completed and the houses are occupied. To assess the relative effectiveness of During-Construction radon reduction and Post-Construction remediation, radon concentration data from houses constructed before and after 1992 in Northamptonshire, UK, a designated Radon Affected Area, was analysed. Post-Construction remediation of 73 pre-1992 houses using conventional fan-assisted sump technology proved to be extremely effective, with radon concentrations reduced to the Action Level, or below, in all cases. Of 64 houses constructed since 1992 in a well-defined geographical area, and known to have had radon-barrier membranes installed during construction, 11% exhibited radon concentrations in excess of the Action Level. This compares with the estimated average for all houses in the same area of 17%, suggesting that, in some 60% of the houses surveyed, installation of a membrane has not resulted in reduction of mean annual radon concentrations to below the Action Level. Detailed comparison of the two data sets reveals marked differences in the degree of mitigation achieved by remediation. There is therefore an ongoing need for research to resolve definitively the issue of radon mitigation and to define truly effective anti-radon measures, readily installed in domestic properties at the time of construction. It is therefore recommended that mandatory testing be introduced for all new houses in Radon Affected Areas.

Quantitative health impact of indoor radon in France.

PubMed

Ajrouche, Roula; Roudier, Candice; Cléro, Enora; Ielsch, Géraldine; Gay, Didier; Guillevic, Jérôme; Marant Micallef, Claire; Vacquier, Blandine; Le Tertre, Alain; Laurier, Dominique

2018-05-08

Radon is the second leading cause of lung cancer after smoking. Since the previous quantitative risk assessment of indoor radon conducted in France, input data have changed such as, estimates of indoor radon concentrations, lung cancer rates and the prevalence of tobacco consumption. The aim of this work was to update the risk assessment of lung cancer mortality attributable to indoor radon in France using recent risk models and data, improving the consideration of smoking, and providing results at a fine geographical scale. The data used were population data (2012), vital statistics on death from lung cancer (2008-2012), domestic radon exposure from a recent database that combines measurement results of indoor radon concentration and the geogenic radon potential map for France (2015), and smoking prevalence (2010). The risk model used was derived from a European epidemiological study, considering that lung cancer risk increased by 16% per 100 becquerels per cubic meter (Bq/m 3 ) indoor radon concentration. The estimated number of lung cancer deaths attributable to indoor radon exposure is about 3000 (1000; 5000), which corresponds to about 10% of all lung cancer deaths each year in France. About 33% of lung cancer deaths attributable to radon are due to exposure levels above 100 Bq/m 3 . Considering the combined effect of tobacco and radon, the study shows that 75% of estimated radon-attributable lung cancer deaths occur among current smokers, 20% among ex-smokers and 5% among never-smokers. It is concluded that the results of this study, which are based on precise estimates of indoor radon concentrations at finest geographical scale, can serve as a basis for defining French policy against radon risk.

Automatically processed alpha-track radon monitor

DOEpatents

Langner, Jr., G. Harold

1993-01-01

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

Automatically processed alpha-track radon monitor

DOEpatents

Langner, G.H. Jr.

1993-01-12

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

Development of a real-time radon monitoring system for simultaneous measurements in multiple sites

NASA Astrophysics Data System (ADS)

Yamamoto, S.; Yamasoto, K.; Iida, T.

1999-12-01

A real-time radon monitoring system that can simultaneously measure radon concentrations in multiple sites was developed and tested. The system consists of maximum of four radon detectors, optical fiber cables and a data acquisition personal computer. The radon detector uses a plastic scintillation counter that collects radon daughters in the chamber electrostatically. The applied voltage on the photocathode for the photomultiplier tube (PMT) acts as an electrode for radon daughters. The thickness of the plastic scintillator was thin, 50 /spl mu/m, so as to minimize the background counts due to the environmental gamma rays or beta particles. The energy discriminated signals from the radon detectors are fed to the data acquisition personal computer via optical fiber cables. The system made it possible to measure the radon concentrations in multiple sites simultaneously.

Radon Detection and Counting

NASA Astrophysics Data System (ADS)

Peterson, David

2004-11-01

One of the daughter products of the naturally occuring U 238 decay chain is the colorless, odorless, inert gas radon. The daughter products of the radon, from Po 218 through Po 214, can remain in the lungs after breathing radon that has diffused into the atmosphere. Radon testing of homes before sale or purchase is necessary in many parts of the U.S. Testing can be accomplished by the simple procedure of exposing a canister of activated charcoal to the ambient air. Radon atoms in the air are adsorbed onto the surface of the charcoal, which is then sealed in the canister. Gamma rays of the daughter products of the radon, in particular Pb 214 and Bi 214, can then be detected in low background counting system. Radon remediation procedures are encouraged for radon activities in the air greater than 4 pCi/L.

International intercomparison of measuring instruments for radon/thoron gas and radon short-lived daughter products in the NRPI Prague.

PubMed

Jílek, K; Hýža, M; Kotík, L; Thomas, J; Tomášek, L

2014-07-01

During the 7th European Conference on Protection Against Radon at Home and at Work held in the autumn of 2013 in Prague, the second intercomparison of measuring instruments for radon and its short-lived decay products and the first intercomparison of radon/thoron gas discriminative passive detectors in mix field of radon/thoron were organised by and held at the Natural Radiation Division of the National Radiation Protection Institute (NRPI) in Prague. In total, 14 laboratories from 11 different countries took part in the 2013 NRPI intercomparison. They submitted both continuous monitors for the measurement of radon gas and equivalent equilibrium radon concentration in a big NRPI chamber (48 m3) and sets of passive detectors including radon/thoron discriminative for the measurement of radon gas in the big chamber and thoron gas in a small thoron chamber (150 dm3). © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radon Sampling, Building 54, Nellis AFB, NV

DTIC Science & Technology

2012-07-13

BEF) performed radon testing in response to a concern of elevated radon levels in Building 54. The building was previously remediated to reduce the... TESTING METHODOLOGY: a. Test Scenario: Building 54 was chosen to test for radon gas levels. Radon detectors were placed in the test ...Consultative Letter 3. DATES COVERED (From – To) 22-24 March 2012 4. TITLE AND SUBTITLE Radon Sampling, Building 54, Nellis AFB, NV 5a. CONTRACT

Temporal variations of radon in soil related to earthquakes.

PubMed

Planinić, J; Radolić, V; Lazanin, Z

2001-08-01

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

The radon indicator

NASA Astrophysics Data System (ADS)

Samuelsson, L.

2005-11-01

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

Intercomparison of active, passive and continuous instruments for radon and radon progeny measurements in the EML chamber and test facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

1995-12-01

The results from the May 1995 Intercomparison of Active, Passive and Continuous Instruments for Radon and Radon Progeny Measurement conducted in the EML radon exposure and test facility are presented. Represented were 13 participants that measure radon with open faced and diffusion barrier activated carbon collectors, 10 with nuclear alpha track detectors, 9 with short-term and long-term electret/ionization chambers, and 13 with active and passive commercial electronic continuous monitors. For radon progeny, there were four participants that came in person to take part in the grab sampling methodology for measuring individual radon progeny and the potential alpha energy concentration (PAEC).more » There were 11 participants with continuous and integrating commercial electronic instruments that are used for measuring the PAEC. The results indicate that all the tested instruments that measure radon fulfill their intended purpose. All instruments and methods used for grab sampling for radon progeny did very well. However, most of the continuous and integrating electronic instruments used for measuring the PAEC or working level appear to underestimate the potential risk from radon progeny when the concentration of particles onto which the radon progeny are attached is <5,000 cm{sup -3}.« less

An updated review of case-control studies of lung cancer and indoor radon-Is indoor radon the risk factor for lung cancer?

PubMed

Sheen, Seungsoo; Lee, Keu Sung; Chung, Wou Young; Nam, Saeil; Kang, Dae Ryong

2016-01-01

Lung cancer is a leading cause of cancer-related death in the world. Smoking is definitely the most important risk factor for lung cancer. Radon ((222)Rn) is a natural gas produced from radium ((226)Ra) in the decay series of uranium ((238)U). Radon exposure is the second most common cause of lung cancer and the first risk factor for lung cancer in never-smokers. Case-control studies have provided epidemiological evidence of the causative relationship between indoor radon exposure and lung cancer. Twenty-four case-control study papers were found by our search strategy from the PubMed database. Among them, seven studies showed that indoor radon has a statistically significant association with lung cancer. The studies performed in radon-prone areas showed a more positive association between radon and lung cancer. Reviewed papers had inconsistent results on the dose-response relationship between indoor radon and lung cancer risk. Further refined case-control studies will be required to evaluate the relationship between radon and lung cancer. Sufficient study sample size, proper interview methods, valid and precise indoor radon measurement, wide range of indoor radon, and appropriate control of confounders such as smoking status should be considered in further case-control studies.

An investigation into the knowledge and attitudes towards radon testing among residents in a high radon area.

PubMed

Clifford, Susan; Hevey, David; Menezes, Gerard

2012-12-01

The aim of this study was to investigate the knowledge and attitudes of residents in the Castleisland area to radon. Castleisland in Co. Kerry was described as a high radon area following the discovery of a house in the area with radon levels 245 times that of the national reference level. Residents in this area were then asked to measure their homes for radon in the Castleisland radon survey. The uptake of this measurement was 17%. In order to investigate this response rate further, a questionnaire was designed and distributed to residents in the Castleisland area. This questionnaire measured the testing history of the participants, the reasons for testing/not testing, the factors important to them when considering having their home tested, radon knowledge and finally intentions to measure their home for radon. It was found that the main reason people do not test their home for radon is that they believe their home does not have a problem. Optimistic bias was thought to play a role here. The subjective norm component of the theory of planned behaviour was found to have a significant independent contribution in the variation in intentions to measure one's home for radon and this in turn could be targeted to increase uptake of radon measurement in the future.

An Integrated Monitoring System of Pre-earthquake Processes in Peloponnese, Greece

NASA Astrophysics Data System (ADS)

Karastathis, V. K.; Tsinganos, K.; Kafatos, M.; Eleftheriou, G.; Ouzounov, D.; Mouzakiotis, E.; Papadopoulos, G. A.; Voulgaris, N.; Bocchini, G. M.; Liakopoulos, S.; Aspiotis, T.; Gika, F.; Tselentis, A.; Moshou, A.; Psiloglou, B.

2017-12-01

One of the controversial issues in the contemporary seismology is the ability of radon accumulation monitoring to provide reliable earthquake forecasting. Although there are many examples in the literature showing radon increase before earthquakes, skepticism arises from instability of the measurements, false alarms, difficulties in interpretation caused by the weather influence (eg. rainfall) and difficulties on the consideration an irrefutable theoretical background of the phenomenon.We have developed and extensively tested a multi parameter network aimed for studying of the pre-earthquake processes and operating as a part of integrated monitoring system in the high seismicity area of the Western Hellenic Arc (SW Peloponnese, Greece). The prototype consists of four components: A real-time monitoring system of Radon accumulation. It consists of three gamma radiation detectors [NaI(Tl) scintillators] A nine-station seismic array to monitor the microseismicity in the offshore area of the Hellenic arc. The processing of the data is based on F-K and beam-forming techniques. Real-time weather monitoring systems for air temperature, relative humidity, precipitation and pressure. Thermal radiation emission from AVHRR/NOAA-18 polar orbit satellite observation. The project revolved around the idea of jointly studying the emission of Radon that has been proven in many cases as a reliable indicator of the possible time of an event, with the accurate location of the foreshock activity detected by the seismic array that can be a more reliable indicator of the possible position of an event. In parallel a satellite thermal anomaly detection technique has been used for monitoring of larger magnitude events (possible indicator for strong events M ≥5.0.). The first year of operations revealed a number of pre-seismic radon variation anomalies before several local earthquakes (M>3.6). The Radon increases systematically before the larger events.Details about the overall performance in registration of pre-seismic signals in Peloponnese region, along with two distant but very strong earthquakes in Jun 12, 2017 M6.3 and Jul 20, 2017 M6.6 in Greece will be discussed.

Environmental radon exposure and childhood leukemia.

PubMed

Tong, Jian; Qin, Liqiang; Cao, Yi; Li, Jianxiang; Zhang, Jie; Nie, Jihua; An, Yan

2012-01-01

Despite the fact that animal and human epidemiological studies confirmed a link between radon exposure in homes and increased risk of lung cancer in general population, other types of cancers induced by radon, such as leukemia, have not been consistently demonstrated. The aim of this review was to summarize data published thus far from ecological and case-control studies in exposed populations, taking into account radon dose estimation and evidence of radon-induced genotoxicity, in an effort to clarify the correlation between home radon exposure and incidence of childhood leukemia. Among 12 ecological studies, 11 reported a positive association between radon levels and elevated frequency of childhood leukemia, with 8 being significant. In conjunction with ecological studies, several case-control studies on indoor radon exposure and childhood leukemia were examined, and most investigations indicated a weak association with only a few showing significance. A major source of uncertainty in radon risk assessment is radon dose estimate. Methods for radon exposure measurement in homes of children are one of the factors that affect the risk estimates in a case-control study. The effects of radon-induced genetic damage were studied both in vitro and in vivo using genetic endpoints including chromosomal aberration (CA), micronuclei (MN) formation, gene mutation, and deletions and insertions. By applying a meta-analysis, an increased risk of childhood leukemia induced by indoor radon exposure was noted for overall leukemia and for acute lymphoblastic leukemia (ALL). Data thus indicated an association between environmental radon exposure and elevated leukemia incidence, but more evidence is required in both human investigations and animal mechanistic research before this assumption may be confirmed with certainty.

Radon concentration of waters in Greece and Cyprus

NASA Astrophysics Data System (ADS)

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

2009-04-01

Radon (222Rn) is a radioactive gas generated by the decay of the naturally occurring 238U series. It is considered very important from radiological point of view, since it is the most significant natural source of human radiation exposure (approximately 50% from all natural sources). Radon is present in soil, rocks, building materials and waters. Through diffusion and convection, radon migrates and emanates to the atmosphere. Outdoors, radon concentrates at low levels (in the order of 10 Bq/m3). However indoors, radon accumulates significantly. It is trivial to observe indoor environments with high radon levels (in the order of 400 Bq/m3 or higher). Radon accumulation indoors, depends on the composition of the underlying soil and rock formation, on building materials, meteorological parameters, ventilation, heating and water use. Although soil and building materials are the most significant radon sources, there have been reported elevated radon concentrations in building structures due to entering water. It is the radon concentrations in the entering water, the volume and the way of water usage, separated or in combination, that result in large amounts of radon in indoor air. Moreover, radon is a factor of stomach radiation burden due to water consumption. This burden is estimated by measurements of radon concentrations in waters. Due to the health impact of radon exposure, the reporting team continuously measures radon. This work focused on the radon concentrations exposure due to water consumption and use in Greece and Cyprus. Various locations in Greece and Cyprus were accessed taking into consideration existing natural radioactivity data (mainly radon in water), however under the restriction of the capability of movement. Radon in water was measured by Alpha Guard (Genitron Ltd) via a special unit (Aqua Kit). This unit consists of a vessel used for forced degassing of radon diluted in water samples, a security vessel used for water drop deposition. Vessels and Alpha Guard are connected via plastic radon proof tubes. Forced degassing of radon gas is performed by circulating the air in the set up with the use of a pump. Water sampling (to avoid radon escape) was driven by a strict protocol. Water taps were opened for 10 minutes before drawing the sample. Glass storage vessels of 200 to 1000 ml, with adjustment glass stoppers with standard NS 29/32 grounding, as well as sealing rings and granted security clamps for taper grounding, were completely filled slowly and immediately closed (to avoid the formation of air bubbles). Similar procedure (except tap opening) was followed for underground and surface waters. Laboratory measurements were performed at least one hour after drawing the sample in order to assure the full decay of any thoron content and to the minimum achievable time interval, so as the radon content to be the highest possible to allow higher precision. For the measurement the glass stopper was removed and immediately exchanged with the degassing cap. Afterwards water quantity was reduced to about half and measured. From the measurements, the mean annual equivalent dose rate (aEDr) delivered to stomach due to ingestion and the contribution to aEDr due to inhalation of radon in drinking water were calculated as using the EURATOM 2001 dose conversion factor (0.00144 mSv/Bq). Radon concentrations in drinking waters ranged between (1.1+/-0.5) Bq/L and (15+/4) Bq/L. Only three samples collected from the radon prone area of Arnea Chalkidikis presented high radon concentrations (120+/20 Bq/L, 320+/-40 Bq/L, 410+/-50 Bq/L). Radon concentrations in underground waters ranged between (1.2+/-0.7) Bq/L and (14.7+/-1.1) Bq/L. The corresponding concentration range in surface waters was (2.7+/-0.8) Bq/L and (24+/-6) Bq/L. The radon concentrations in thermal waters (some of which are used for drinking) were quite higher (in the range of (220+/-20) to (340+/-40) Bq/L). In both countries, no correlation of radon in underground waters with depth was observed. In Cyprus, the highest water radon concentrations were found in Protaras region. The average value of radon in water resulted to an average contribution of 0.3% in respect to the average indoor radon concentration and mean annual effective dose. The corresponding values for Greece resulted to a 0.1% contribution. This contribution is considered quite low both for Cyprus and Greece (0.1%) and hence this part of effective dose may be considered of slighter significance compared to inhalation of total radon. Yet this contribution is comparable to the effective dose values delivered through medical uses of radiation. On the other hand, significant doses are delivered to stomach of the Cypriot and Greek population due to ingested radon following water consumption. The corresponding average annual dose rates were found equal to 0.085 mSv/y (S.D of 0.080 mSv/y) for Cyprus and 0.081 mSv/y (S.D of 0.081 mSv/y) for Greece.

40 CFR 61.203 - Radon monitoring and compliance procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

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

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

EPA Science Inventory

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

40 CFR 61.203 - Radon monitoring and compliance procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

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

Field evaluations of digital radon detectors.

PubMed

Chen, Jing; Falcomer, Renato; Walker, Bill

2007-11-01

Recently, digital radon detectors were made available on the market for homeowners at a cost comparable to that charged by some service providers for a single radon test. Digital radon detectors provide an easy and less expensive way for homeowners to monitor radon levels in their homes. In order to answer a frequently asked question regarding the performance of such low-cost electronic radon detectors, field evaluations were conducted. Evaluation results are reported here.

The Effects of Radon Exposure on Physical and Psychological Health

DTIC Science & Technology

1991-08-15

by inhaled radon-222 at various equilibriums with radon daughters . In E. Karbe & J. F. Parke (Eds.) Experimental lung cancer. Carcinogenesis and...Relationship between the ’̂’°Pb content of teeth and exposure to radon and radon daughters . Health Physics. 47. 253-262. 49 Cohen, B. L. & Gromicko, N...ore dust, radon daughters , and diesel oil exhaust fumes in hamsters and dogs (Report No. DNL—2744). Richland, WA: Batelle Pacific Northwest

Radon Assessment of Occupational Facilities, Homestead ARB, FL

DTIC Science & Technology

2013-11-21

electrets is directly measured and used to calculate radon levels. The radon detectors were placed in the test locations for greater than 90 days in...of USAFSAM’s radon analysis. A proficiency test was last performed and passed on 18 July 2012. (2) Blanks: Six field blanks were used during the...voltage. 5. CONCLUSIONS AND RECOMMENDATIONS: a. All 46 facilities tested had radon concentrations below the action limit of 4 pCi/L; no radon

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

PubMed

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 <20 %, when the radon concentration in the mineral water was >20 Bq l(-1).

Radon Exposure: Using the Spectrum of Prevention Framework to Increase Healthcare Provider Awareness.

PubMed

Worrell, Jane; Gibson, Phillip; Allen, Deborah

2016-12-01

The radioactive properties of radon have been known for decades, but the risks of exposure have been understated in most professional healthcare curriculums. Healthcare providers in areas with low levels of radon exposure may not consider radon to be a main source of concern in the development of lung and other cancers. Just as nurses counsel patients to avoid tobacco exposure, they should advocate that patients have their homes tested for radon. This article aims to increase radon awareness and address opportunities for providers to work toward various objectives to reduce radon exposure.
.

Radon, smoking, and lung cancer: the need to refocus radon control policy.

PubMed

Lantz, Paula M; Mendez, David; Philbert, Martin A

2013-03-01

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

Radon inhalation protects against transient global cerebral ischemic injury in gerbils.

PubMed

Kataoka, Takahiro; Etani, Reo; Takata, Yuji; Nishiyama, Yuichi; Kawabe, Atsushi; Kumashiro, Masayuki; Taguchi, Takehito; Yamaoka, Kiyonori

2014-10-01

Although brain disorders are not the main indication for radon therapy, our previous study suggested that radon inhalation therapy might mitigate brain disorders. In this study, we assessed whether radon inhalation protects against transient global cerebral ischemic injury in gerbils. Gerbils were treated with inhaled radon at a concentration of 2,000 Bq/m(3) for 24 h. After radon inhalation, transient global cerebral ischemia was induced by bilateral occlusion of the common carotid artery. Results showed that transient global cerebral ischemia induced neuronal damage in hippocampal CA1, and the number of damaged neurons was significantly increased compared with control. However, radon treatment inhibited ischemic damage. Superoxide dismutase (SOD) activity in the radon-treated gerbil brain was significantly higher than that in sham-operated gerbils. These findings suggested that radon inhalation activates antioxidative function, especially SOD, thereby inhibiting transient global cerebral ischemic injury in gerbils.

Protective effects of radon inhalation on carrageenan-induced inflammatory paw edema in mice.

PubMed

Kataoka, Takahiro; Teraoka, Junichi; Sakoda, Akihiro; Nishiyama, Yuichi; Yamato, Keiko; Monden, Mayuko; Ishimori, Yuu; Nomura, Takaharu; Taguchi, Takehito; Yamaoka, Kiyonori

2012-04-01

We assessed whether radon inhalation inhibited carrageenan-induced inflammation in mice. Carrageenan (1% v/v) was injected subcutaneously into paws of mice that had or had not inhaled approximately 2,000 Bq/m(3) of radon for 24 h. Radon inhalation significantly increased superoxide dismutase (SOD) and catalase activities and significantly decreased lipid peroxide levels in mouse paws, indicating that radon inhalation activates antioxidative functions. Carrageenan administration induced paw edema and significantly increased tumor necrosis factor-alpha (TNF-α) and nitric oxide in serum. However, radon inhalation significantly reduced carrageenan-induced paw edema. Serum TNF-α levels were lower in the radon-treated mice than in sham-treated mice. In addition, SOD and catalase activities in paws were significantly higher in the radon-treated mice than in the sham-treated mice. These findings indicated that radon inhalation had anti-inflammatory effects and inhibited carrageenan-induced inflammatory paw edema.

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

USGS Publications Warehouse

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

1988-01-01

This report summarizes the radon potential of Montgomery County in the context of its geology. Radon is a naturally occurring gas produced by the radioactive decay of uranium. Radon produced by uraniferous rocks and soils may enter a house through porous building materials and through openings in walls and floors. Radon gases has a tendency to move from the higher pressure commonly existing in the soil to the lower pressure commonly existing in the house. The U.S. Environmental Protection Agency (U.S. EPA, 1986a) estimates that elevated levels of indoor radon may be associated with 5,000 to 20,000 of the 130,000 lung cancer deaths per year. They also estimate that 8 to 12 percent of the homes in the United States will have annual average indoor radon levels exceeding 4 picoCuries per liter of air (pCi/L). Above this level, the U.S. EPA recommends homeowners take remedial action. May factors control the amount of radon which may enter a home from the geologic environment. Soil drainage, permeability, and moisture content effect the amount of radon that can be released from rocks and soils (known as the emmanation) and may limit or increase how far it can migrate. Well drained, highly permeable soils facilitate the movement of radon. Soils with water content in the 8 to 15 percent range enhance the emmanation of radon (Lindmark, 1985). Daily and seasonal variations in soil and indoor radon can be caused by meteorologic factors such as barometric pressure, temperature, and wind (Clements and Wilkening, 1974; Schery and other, 1984). Construction practices also inhibit or promote entry of radon into the home (U.S. EPA, 1986b). In general, however, geology controls the source and distribution of radon (Akerblom and Wilson, 1982; Gundersen and others, 1987, 1988; Sextro and others, 1987; U.S. EPA, 1983; Peake, 1988; Peake and Hess, 1988). The following sections describe: 1) the methods used to measure radon and equivalent uranium (eU) in soil; 2) the radon potential ratings that were developed for this study; and 3) the characteristics of the rocks and soils in Montgomery County that give them their radon potential.

Effect of biogas generation on radon emissions from landfills receiving radium-bearing waste from shale gas development.

PubMed

Walter, Gary R; Benke, Roland R; Pickett, David A

2012-09-01

Dramatic increases in the development of oil and natural gas from shale formations will result in large quantities of drill cuttings, flowback water, and produced water. These organic-rich shale gas formations often contain elevated concentrations of naturally occurring radioactive materials (NORM), such as uranium, thorium, and radium. Production of oil and gas from these formations will also lead to the development of technologically enhanced NORM (TENORM) in production equipment. Disposal of these potentially radium-bearing materials in municipal solid waste (MSW) landfills could release radon to the atmosphere. Risk analyses of disposal of radium-bearing TENORM in MSW landfills sponsored by the Department of Energy did not consider the effect of landfill gas (LFG) generation or LFG control systems on radon emissions. Simulation of radon emissions from landfills with LFG generation indicates that LFG generation can significantly increase radon emissions relative to emissions without LFG generation, where the radon emissions are largely controlled by vapor-phase diffusion. Although the operation of LFG control systems at landfills with radon source materials can result in point-source atmospheric radon plumes, the LFG control systems tend to reduce overall radon emissions by reducing advective gas flow through the landfill surface, and increasing the radon residence time in the subsurface, thus allowing more time for radon to decay. In some of the disposal scenarios considered, the radon flux from the landfill and off-site atmospheric activities exceed levels that would be allowed for radon emissions from uranium mill tailings. Increased development of hydrocarbons from organic-rich shale formations has raised public concern that wastes from these activities containing naturally occurring radioactive materials, particularly radium, may be disposed in municipal solid waste landfills and endanger public health by releasing radon to the atmosphere. This paper analyses the processes by which radon may be emitted from a landfill to the atmosphere. The analyses indicate that landfill gas generation can significantly increase radon emissions, but that the actual level of radon emissions depend on the place of the waste, construction of the landfill cover, and nature of the landfill gas control system.

Nanomaterial containing wall paints can increase radon concentration in houses located in radon prone areas.

PubMed

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

2013-09-01

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

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

PubMed Central

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

2013-01-01

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

Environmental Sensor Technologies and Procedures for Detecting and Identifying Indoor Air Pollution

DTIC Science & Technology

1992-03-01

problem of radon or biological contaminants. Radon daughters --the radioactive decay products of radon gas-are most dangerous when they attach to a...entry points. Radon itself decays into radon daughters which are dangerous when they bond with dust particles that allow them to embed in the lining...because it contains respirable particles to which radon daughters can attach and embed in the lungs. The most direct way to check the ETS level is to

Environmental Sensor Technologies and Procedures for Detecting and Identifying Indoor Air Pollution

DTIC Science & Technology

1992-03-01

level of RSP in the air. RSP aggravates dust-related allergies. It also aggravates the problem of radon or biological contaminants. Radon daughters -the...the earth and is pulled into buildings through cracks in the foundation and other entry points. Radon itself decays into radon daughters which are...heart disease. ETS aggravates the danger of exposure to radon by a factor of 5 because it contains respirable particles to which radon daughters can

Activation of Antioxidative Functions by Radon Inhalation Enhances the Mitigation Effects of Pregabalin on Chronic Constriction Injury-Induced Neuropathic Pain in Mice

PubMed Central

Horie, Shunsuke; Etani, Reo; Kanzaki, Norie; Sasaoka, Kaori; Kobashi, Yusuke; Hanamoto, Katsumi; Yamaoka, Kiyonori

2016-01-01

Radon inhalation brings pain relief for chronic constriction injury- (CCI-) induced neuropathic pain in mice due to the activation of antioxidative functions, which is different from the mechanism of the pregabalin effect. In this study, we assessed whether a combination of radon inhalation and pregabalin administration is more effective against neuropathic pain than radon or pregabalin only. Mice were treated with inhaled radon at a concentration of 1,000 Bq/m3 for 24 hours and pregabalin administration after CCI surgery. In mice treated with pregabalin at a dose of 3 mg/kg weight, the 50% paw withdrawal threshold of mice treated with pregabalin or radon and pregabalin was significantly increased, suggesting pain relief. The therapeutic effects of radon inhalation or the combined effects of radon and pregabalin (3 mg/kg weight) were almost equivalent to treatment with pregabalin at a dose of 1.4 mg/kg weight or 4.1 mg/kg weight, respectively. Radon inhalation and the combination of radon and pregabalin increased antioxidant associated substances in the paw. The antioxidant substances increased much more in radon inhalation than in pregabalin administration. These findings suggested that the activation of antioxidative functions by radon inhalation enhances the pain relief of pregabalin and that this combined effect is probably an additive effect. PMID:26798431

Quantile regression and Bayesian cluster detection to identify radon prone areas.

PubMed

Sarra, Annalina; Fontanella, Lara; Valentini, Pasquale; Palermi, Sergio

2016-11-01

Albeit the dominant source of radon in indoor environments is the geology of the territory, many studies have demonstrated that indoor radon concentrations also depend on dwelling-specific characteristics. Following a stepwise analysis, in this study we propose a combined approach to delineate radon prone areas. We first investigate the impact of various building covariates on indoor radon concentrations. To achieve a more complete picture of this association, we exploit the flexible formulation of a Bayesian spatial quantile regression, which is also equipped with parameters that controls the spatial dependence across data. The quantitative knowledge of the influence of each significant building-specific factor on the measured radon levels is employed to predict the radon concentrations that would have been found if the sampled buildings had possessed standard characteristics. Those normalised radon measures should reflect the geogenic radon potential of the underlying ground, which is a quantity directly related to the geological environment. The second stage of the analysis is aimed at identifying radon prone areas, and to this end, we adopt a Bayesian model for spatial cluster detection using as reference unit the building with standard characteristics. The case study is based on a data set of more than 2000 indoor radon measures, available for the Abruzzo region (Central Italy) and collected by the Agency of Environmental Protection of Abruzzo, during several indoor radon monitoring surveys. Copyright © 2016 Elsevier Ltd. All rights reserved.

Activation of Antioxidative Functions by Radon Inhalation Enhances the Mitigation Effects of Pregabalin on Chronic Constriction Injury-Induced Neuropathic Pain in Mice.

PubMed

Kataoka, Takahiro; Horie, Shunsuke; Etani, Reo; Kanzaki, Norie; Sasaoka, Kaori; Kobashi, Yusuke; Hanamoto, Katsumi; Yamaoka, Kiyonori

2016-01-01

Radon inhalation brings pain relief for chronic constriction injury- (CCI-) induced neuropathic pain in mice due to the activation of antioxidative functions, which is different from the mechanism of the pregabalin effect. In this study, we assessed whether a combination of radon inhalation and pregabalin administration is more effective against neuropathic pain than radon or pregabalin only. Mice were treated with inhaled radon at a concentration of 1,000 Bq/m(3) for 24 hours and pregabalin administration after CCI surgery. In mice treated with pregabalin at a dose of 3 mg/kg weight, the 50% paw withdrawal threshold of mice treated with pregabalin or radon and pregabalin was significantly increased, suggesting pain relief. The therapeutic effects of radon inhalation or the combined effects of radon and pregabalin (3 mg/kg weight) were almost equivalent to treatment with pregabalin at a dose of 1.4 mg/kg weight or 4.1 mg/kg weight, respectively. Radon inhalation and the combination of radon and pregabalin increased antioxidant associated substances in the paw. The antioxidant substances increased much more in radon inhalation than in pregabalin administration. These findings suggested that the activation of antioxidative functions by radon inhalation enhances the pain relief of pregabalin and that this combined effect is probably an additive effect.

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

USGS Publications Warehouse

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

1999-01-01

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

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

ERIC Educational Resources Information Center

Gundersen, Linda C. S.

1992-01-01

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

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

EPA Science Inventory

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

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

EPA Science Inventory

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

Canadian Lung Cancer Relative Risk from Radon Exposure for Short Periods in Childhood Compared to a Lifetime

PubMed Central

Chen, Jing

2013-01-01

Long-term exposure to elevated indoor radon concentrations has been determined to be the second leading cause of lung cancer in adults after tobacco smoking. With the establishment of a National Radon Program in Canada in 2007 thousands of homes across the country have been tested for radon. Although the vast majority of people are exposed to low or moderate radon concentrations; from time to time; there are homes found with very high concentrations of radon. Among those living in homes with very high radon concentrations, it is typically parents of young children that demonstrate a great deal of concern. They want to know the equivalent risk in terms of the lifetime relative risk of developing lung cancer when a child has lived in a home with high radon for a few years. An answer to this question of risk equivalency is proposed in this paper. The results demonstrate clearly that the higher the radon concentration; the sooner remedial measures should be undertaken; as recommended by Health Canada in the Canadian radon guideline. PMID:23698696

A global numerical study of radon-222 and lead-210 in the atmosphere using the AES and York University CDT General Circulation Model (AYCG)

NASA Technical Reports Server (NTRS)

Beagley, Stephen R.; Degrandpre, Jean; Mcconnell, John C.; Laprise, Rene; Mcfarlane, Norman

1994-01-01

The Canadian Climate Center (CCC) GCM has been modified to allow its use for studies in atmospheric chemistry. The initial experiments reported here have been run to test and allow sensitivity studies of the new transport module. The impact of different types of parameterization for the convective mixing have been studied based on the large scale evolution of Rn-222 and Pb-210. Preliminary results have shown that the use of a scheme, which mixes unstable columns over a very short time scale, produces a global distribution of lead that agrees in some aspects with observations. The local impact of different mixing schemes on a short lived tracer like the radon is very important.

Radon: The Invisible Invader.

ERIC Educational Resources Information Center

School Leader, 1987

1987-01-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Ajay, E-mail: ajay782@rediffmail.com; Sharma, Sumit, E-mail: sumitshrm210@gmail.com

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

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

PubMed Central

Mendez, David; Philbert, Martin A.

2013-01-01

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

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

NASA Astrophysics Data System (ADS)

Kumar, Ajay; Sharma, Sumit

2015-08-01

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

A combined analysis of North American case-control studies of residential radon and lung cancer.

PubMed

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

2006-04-01

Cohort studies have consistently shown underground miners exposed to high levels of radon to be at excess risk of lung cancer, and extrapolations based on those results indicate that residential radon may be responsible for nearly 10-15% of all lung cancer deaths per year in the United States. However, case-control studies of residential radon and lung cancer have provided ambiguous evidence of radon lung cancer risks. Regardless, alpha-particle emissions from the short-lived radioactive radon decay products can damage cellular DNA. The possibility that a demonstrated lung carcinogen may be present in large numbers of homes raises a serious public health concern. Thus, a systematic analysis of pooled data from all North American residential radon studies was undertaken to provide a more direct characterization of the public health risk posed by prolonged radon exposure. To evaluate the risk associated with prolonged residential radon exposure, a combined analysis of the primary data from seven large scale case-control studies of residential radon and lung cancer risk was conducted. The combined data set included a total of 4081 cases and 5281 controls, representing the largest aggregation of data on residential radon and lung cancer conducted to date. Residential radon concentrations were determined primarily by a-track detectors placed in the living areas of homes of the study subjects in order to obtain an integrated 1-yr average radon concentration in indoor air. Conditional likelihood regression was used to estimate the excess risk of lung cancer due to residential radon exposure, with adjustment for attained age, sex, study, smoking factors, residential mobility, and completeness of radon measurements. Although the main analyses were based on the combined data set as a whole, we also considered subsets of the data considered to have more accurate radon dosimetry. This included a subset of the data involving 3662 cases and 4966 controls with a-track radon measurements within the exposure time window (ETW) 5-30 yr prior to the index date considered previously by Krewski et al. (2005). Additional restrictions focused on subjects for which a greater proportion of the ETW was covered by measured rather than imputed radon concentrations, and on subjects who occupied at most two residences. The estimated odds ratio (OR) of lung cancer generally increased with radon concentration. The OR trend was consistent with linearity (p = .10), and the excess OR (EOR) was 0.10 per Bq/m3 with 95% confidence limits (-0.01, 0.26). For the subset of the data considered previously by Krewski et al. (2005), the EOR was 0.11 (0.00, 0.28). Further limiting subjects based on our criteria (residential stability and completeness of radon monitoring) expected to improve radon dosimetry led to increased estimates of the EOR. For example, for subjects who had resided in only one or two houses in the 5-30 ETW and who had a-track radon measurements for at least 20 yr of this 25-yr period, the EOR was 0.18 (0.02, 0.43) per 100 Bq/m3. Both estimates are compatible with the EOR of 0.12 (0.02, 0.25) per 100 Bq/m3 predicted by downward extrapolation of the miner data. Collectively, these results provide direct evidence of an association between residential radon and lung cancer risk, a finding predicted by extrapolation of results from occupational studies of radon-exposed underground miners.

MEASUREMENT OF INDOOR RADON-THORON IN AIR AND EXHALATION FROM SOIL IN THE ENVIRONMENT OF WESTERN HARYANA, INDIA.

PubMed

Mann, Nisha; Kumar, Amit; Kumar, Sushil; Chauhan, R P

2016-10-01

Measurement of indoor radon and thoron is important because the inhalation of radon-thoron and their daughters contributes more than 50 % of the total dose from natural sources. One of the important parameters to find out the contribution of soil and building materials towards indoor radon is radon exhalation rates, which can be used for estimation of indoor radon levels. The indoor radon and thoron levels from the air and radon exhalation rates from soil samples collected from two districts (Hisar and Fatehabad) of Western Haryana are measured using pin-hole-based radon-thoron dosimeter and LR-115 solid-state nuclear track detector by canister technique. The results show that the indoor radon and thoron levels from Hisar district varied from 11 to 112 and 11 to 80 Bq m -3 , while for Fatehabad district from 5 to 24 and 59 to 105 Bq m -3 , respectively, in summer season. In winter season, indoor radon and thoron levels from Hisar district varied from 15 to 43 and 32 to 102 Bq m -3 , while for Fatehabad district from 18 to 31 and 11 to 80 Bq m -3 , respectively. The indoor radon levels of 95 % locations lie well below the limit recommended by International Commission of Radiation Protection, 2011. The radon mass exhalation rate varied from 6 to 56 mBq kg -1 h -1 The radon mass exhalation rates from the soil samples were lower than the worldwide average, i.e. 56 mBq kg -1 h -1 There exists a poor correlation between indoor radon and exhalation rates. More investigations of measurement of radionuclide contents from rock and stone of study area can improve the understanding. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Variations of radon concentration in the atmosphere. Gamma dose rate

NASA Astrophysics Data System (ADS)

Tchorz-Trzeciakiewicz, D. E.; Solecki, A. T.

2018-02-01

The purposes of research were following: observation and interpretation of variations of radon concentration in the atmosphere - vertical, seasonal, spatial and analysis of relation between average annual radon concentration and ground natural radiation and gamma dose rate. Moreover we wanted to check the occurrence of radon density currents and the possibility of radon accumulation at the foot of the spoil tip. The surveys were carried out in Okrzeszyn (SW Poland) in the area of the spoil tip formed during uranium mining that took place in 60's of 20th century. The measurements were carried out in 20 measurements points at three heights: 0.2 m, 1 m and 2 m a.g.l. using SSNTD LR-115. The survey lasted one year and detectors were exchanged at the beginning of every season. Uranium eU (ppm), thorium eTh (ppm) and potassium K (%) contents were measured using gamma ray spectrometer Exploranium RS-230, ambient gamma dose rate using radiometer RK-100. The average radon concentration on this area was 52.8 Bq m-3. The highest radon concentrations were noted during autumn and the lowest during winter. We observed vertical variations of radon concentration. Radon concentrations decreased with increase of height above ground level. The decrease of radon with increase of height a.g.l. had logarithmic character. Spatial variations of radon concentrations did not indicate the occurrence of radon density currents and accumulation of radon at the foot of the spoil tip. The analysis of relation between average radon concentrations and ground natural radiation (uranium and thorium content) or gamma dose rate revealed positive relation between those parameters. On the base of results mentioned above we suggested that gamma spectrometry measurements or even cheaper and simpler ambient gamma dose rate measurements can be a useful tool in determining radon prone areas. This should be confirmed by additional research.

Map showing radon potential of rocks and soils in Fairfax County, Virginia

USGS Publications Warehouse

Otton, James K.; Schumann, R. Randall; Owen, Douglass E.; Thurman, Nelson; Duval, Joseph S.

1988-01-01

Since 1984, indoor radon has gained national attention as a significant health hazard in the United States. Radon is a colorless, odorless, radioactive gas derived from uranium by radioactive decay. The U.S. Environmental Protection Agency (EPA) now projects that 5,000 to 20,000 lung-cancer deaths per year may be attributed to the long-term exposure to indoor radon and its radioactive decay products. Indoor radon has been previously recognized as a health hazard associated with uranium-bearing mill tailings or building materials, but it was not until December 1984 that some natural soils and rocks were found to be sources of indoor radon at levels comparable to those in uranium mines. It is now suspected that elevated indoor radon levels are far more widespread than initially though. The EPA considers 4 picoCuries of radon per liter of air (pCi/L) as the level (in a year-round measurement) at which actions ought to be taken to lower the concentration of indoor radon. All soils and rocks contain measurable amounts of uranium, which generate measurable amounts of radon. Certain soils and rocks, however, have a greater potential to cause indoor radon problems than others because (1) they have a higher uranium content and thus can generate higher levels of radon in soil gas (gas that occupies the pores of the soil), and (2) the permeability of the sol or rack is sufficiently high that radon-bearing soil gas can flow freely and move indoors through the foundation of the structure. This study was designed to demonstrate the correlation between the geologic environment and indoor radon levels and to demonstrate a method of assessment that could be used by other informed workers in areas of their interest. A parallel study by Gundersen and others (1988) of the radon potential of rocks and soils in Montgomery County, Md., used somewhat different methods of assessment because the data available for and assessment of Montgomery County differed.

Compact anti-radon facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fajt, L.; Kouba, P.; Mamedov, F.

Suppression of radon background is one of main tasks in ultra-low background experiments. The most promising technique for suppression of radon is its adsorption on charcoal. Within the frame of the NEMO-3 experiment, radon trapping facility (RTF) was installed in Modane underground laboratory in 2004. Based on long-term experience with this facility a new compact transportable anti-radon facility was constructed in cooperation among IEAP CTU, SÚRO and ATEKO company. The device provides 20m{sup 3}/h of purified air (air radon activity at the output ∼10mBq/m{sup 3}). The basic features and preliminary results of anti-radon device testing are presented.

Mapping radon-prone areas using γ-radiation dose rate and geological information.

PubMed

García-Talavera, M; García-Pérez, A; Rey, C; Ramos, L

2013-09-01

Identifying radon-prone areas is key to policies on the control of this environmental carcinogen. In the current paper, we present the methodology followed to delineate radon-prone areas in Spain. It combines information from indoor radon measurements with γ-radiation and geological maps. The advantage of the proposed approach is that it lessens the requirement for a high density of measurements by making use of commonly available information. It can be applied for an initial definition of radon-prone areas in countries committed to introducing a national radon policy or to improving existing radon maps in low population regions.

Radon in Schools

MedlinePlus

... Radon Measurement in Schools Radon Prevention in the Design and Construction of Schools and Other Large Buildings ( ... techniques and quality assurance to address complicated building designs and specialized airflow. Protocols for Measuring Radon and ...

Evaluation of the intake of radon through skin from thermal water

PubMed Central

Sakoda, Akihiro; Ishimori, Yuu; Tschiersch, Jochen

2016-01-01

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

Lung cancer prevalence associated with radon exposure in Norwegian homes.

PubMed

Hassfjell, Christina Søyland; Grimsrud, Tom Kristian; Standring, William J F; Tretli, Steinar

2017-08-22

Radioactive radon gas is generated from uranium and thorium in underlying rocks and seeps into buildings. The gas and its decay products emit carcinogenic radiation and are regarded as the second most important risk factor for lung cancer after active tobacco smoking. The average radon concentration in Norwegian homes is higher than in most other Western countries. From a health and cost perspective, it is important to be able to quantify the risk of lung cancer posed by radon exposure. We estimated the radon-related risk of lung cancer in Norway based on risk estimates from the largest pooled analysis of European case-control studies, combined with the hitherto largest set of data on radon concentration measurements in Norwegian homes. Based on these estimates, we calculate that radon is a contributory factor in 12 % of all cases of lung cancer annually, assuming an average radon concentration of 88 Bq/m3 in Norwegian homes. For 2015, this accounted for 373 cases of lung cancer, with an approximate 95 % confidence interval of 145 – 682. Radon most likely contributes to a considerable number of cases of lung cancer. Since most cases of radon-associated lung cancer involve smokers or former smokers, a reduction of the radon concentration in homes could be a key measure to reduce the risk, especially for persons who are unable to quit smoking. The uncertainty in the estimated number of radon-associated cases can be reduced through a new national radon mapping study with an improved design.

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

PubMed Central

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

2012-01-01

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

Background radiation in the Albuquerque, New Mexico, U.S.A., area

NASA Astrophysics Data System (ADS)

Brookins, Douglas G.

1992-01-01

Background radiation levels in the Albuquerque, New Mexico, area are elevated when compared to much of the United States. Soil K, U, and Th are somewhat elevated compared to average values in this country and generate roughly 60 mrem per year to the average resident. Cosmic ray contribution, due to the mean elevation of 5,200 ft above sea level, is 80 mrem/yr—well over the average for the United States. Thirty percent of the homes in Albuquerque contain indoor radon levels over the EPA action level of 4 pCi/ℓ compared to 10 12 percent of homes for the entire United States. Indoor radon contributes about 100 300 mrem/yr. Food, beverages, and x-ray doses are assumed at an average-equivalent for the United States and locally yield 96 mrem/yr. Total contributions from other minor sources (color TV, coal, weapons fallout, etc.) are under 10 mrem/yr. Thus total background radiation received by Albuquerque residents is about 330 530 mrem/yr, well in excess of the rest of the United States. The spread in mrem values is due to variations in the contribution from indoor radon.

Radon as a causative factor in induction of myeloid leukaemia and other cancers.

PubMed

Henshaw, D L; Eatough, J P; Richardson, R B

1990-04-28

The international incidence of myeloid leukaemia, cancer of the kidney, melanoma, and certain childhood cancers all show significant correlation with radon exposure in the home. For myeloid leukaemia, analysis suggests that in the UK 6-12% of incidence may be attributed to radon. In Cornwall, where radon levels are higher, the range is 23-43%. For the world average radon exposure of 50 Bq.m-3, 13-25% of myeloid leukaemia at all ages may be caused by radon.

Indoor radon survey in Visegrad countries.

PubMed

Műllerová, Monika; Kozak, Krzysztof; Kovács, Tibor; Smetanová, Iveta; Csordás, Anita; Grzadziel, Dominik; Holý, Karol; Mazur, Jadwiga; Moravcsík, Attila; Neznal, Martin; Neznal, Matej

2016-04-01

The indoor radon measurements were carried out in 123 residential buildings and 33 schools in Visegrad countries (Slovakia, Hungary and Poland). In 13.2% of rooms radon concentration exceeded 300Bqm(-3), the reference value recommended in the Council Directive 2013/59/EURATOM. Indoor radon in houses shows the typical radon behavior, with a minimum in the summer and a maximum in the winter season, whereas in 32% of schools the maximum indoor radon was reached in the summer months. Copyright © 2016 Elsevier Ltd. All rights reserved.

Error in measuring radon in soil gas by means of passive detectors

USGS Publications Warehouse

Tanner, A.B.

1991-01-01

Passive detection of radon isotopes depends on diffusion of radon atoms from the sites of their generation to the location of the detecting or collecting device. Because some radon decays en route to a passive detector in soil, the radon concentration measured by the detector must be less than the concentration in those soil pores where it is undiminished by diffusion to the detector cavity. The true radon concentration may be significantly underestimated in moist soils. -Author

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

NASA Astrophysics Data System (ADS)

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

2014-04-01

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

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

PubMed

Hu, Peng-hua; Li, Xian-jie

2012-09-01

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

The effectiveness of mitigation for reducing radon risk in single-family Minnesota homes.

PubMed

Steck, Daniel J

2012-09-01

Increased lung cancer incidence has been linked with long-term exposure to elevated residential radon. Experimental studies have shown that soil ventilation can be effective in reducing radon concentrations in single-family homes. Most radon mitigation systems in the U.S. are installed by private contractors. The long-term effectiveness of these systems is not well known, since few state radon programs regulate or independently confirm post-mitigation radon concentrations. The effectiveness of soil ventilation systems in Minnesota was measured for 140 randomly selected clients of six professional mitigators. Homeowners reported pre-mitigation radon screening concentrations that averaged 380 Bq m (10.3 pCi L). Long term post-mitigation radon measurements on the two lowest floors show that, even years after mitigation, 97% of these homes have concentrations below the 150 Bq m U.S. Environmental Protection Agency action level. The average post-mitigation radon in the houses was 30 Bq m, an average observed reduction of >90%. If that reduction was maintained over the lifetime of the 1.2 million Minnesotans who currently reside in single-family homes with living space radon above the EPA action level, approximately 50,000 lives could be extended for nearly two decades by preventing radon-related lung cancers.

Radon as an Anthropogenic Indoor Air Pollutant

NASA Astrophysics Data System (ADS)

Gillmore, Gavin; Crockett, Robin

2016-04-01

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

Transient radon signals driven by fluid pressure pulse, micro-crack closure, and failure during granite deformation experiments

NASA Astrophysics Data System (ADS)

Girault, Frédéric; Schubnel, Alexandre; Pili, Éric

2017-09-01

In seismically active fault zones, various crustal fluids including gases are released at the surface. Radon-222, a radioactive gas naturally produced in rocks, is used in volcanic and tectonic contexts to illuminate crustal deformation or earthquake mechanisms. At some locations, intriguing radon signals have been recorded before, during, or after tectonic events, but such observations remain controversial, mainly because physical characterization of potential radon anomalies from the upper crust is lacking. Here we conducted several month-long deformation experiments under controlled dry upper crustal conditions with a triaxial cell to continuously monitor radon emission from crustal rocks affected by three main effects: a fluid pressure pulse, micro-crack closure, and differential stress increase to macroscopic failure. We found that these effects are systematically associated with a variety of radon signals that can be explained using a first-order advective model of radon transport. First, connection to a source of deep fluid pressure (a fluid pressure pulse) is associated with a large transient radon emission increase (factor of 3-7) compared with the background level. We reason that peak amplitude is governed by the accumulation time and the radon source term, and that peak duration is controlled by radioactive decay, permeability, and advective losses of radon. Second, increasing isostatic compression is first accompanied by an increase in radon emission followed by a decrease beyond a critical pressure representing the depth below which crack closure hampers radon emission (150-250 MPa, ca. 5.5-9.5 km depth in our experiments). Third, the increase of differential stress, and associated shear and volumetric deformation, systematically triggers significant radon peaks (ca. 25-350% above background level) before macroscopic failure, by connecting isolated cracks, which dramatically enhances permeability. The detection of transient radon signals before rupture indicates that connection of initially isolated cracks in crustal rocks may occur before rupture and potentially lead to radon transients measurable at the surface in tectonically active regions. This study offers thus an experimental and physical basis for understanding predicted or reported radon anomalies.

Transient radon signals driven by fluid pressure pulse, micro-crack closure, and failure during granite deformation experiments

NASA Astrophysics Data System (ADS)

Schubnel, A.; Girault, F.; Pili, E.

2017-12-01

In seismically active fault zones, various crustal fluids including gases are released at the surface. Radon-222, a radioactive gas naturally produced in rocks, is used in volcanic and tectonic contexts to illuminate crustal deformation or earthquake mechanisms. At some locations, intriguing radon signals have been recorded before, during, or after tectonic events, but such observations remain controversial, mainly because physical characterization of potential radon anomalies from the upper crust is lacking. Here we conducted several month-long deformation experiments under controlled dry upper crustal conditions with a triaxial cell to continuously monitor radon emission from crustal rocks affected by three main effects: a fluid pressure pulse, micro-crack closure, and differential stress increase to macroscopic failure. We found that these effects are systematically associated with a variety of radon signals that can be explained using a first-order advective model of radon transport. First, connection to a source of deep fluid pressure (a fluid pressure pulse) is associated with a large transient radon emission increase (factor of 3-7) compared with the background level. We reason that peak amplitude is governed by the accumulation time and the radon source term, and that peak duration is controlled by radioactive decay, permeability, and advective losses of radon. Second, increasing isostatic compression is first accompanied by an increase in radon emission followed by a decrease beyond a critical pressure representing the depth below which crack closure hampers radon emission (150-250 MPa, ca. 5.5-9.5 km depth in our experiments). Third, the increase of differential stress, and associated shear and volumetric deformation, systematically triggers significant radon peaks (ca. 25-350% above background level) before macroscopic failure, by connecting isolated cracks, which dramatically enhances permeability. The detection of transient radon signals before rupture indicates that connection of initially isolated cracks in crustal rocks may occur before rupture and potentially lead to radon transients measurable at the surface in tectonically active regions. This study offers thus an experimental and physical basis for understanding predicted or reported radon anomalies.

Evaluation of radon occurrence in groundwater from 16 geologic units in Pennsylvania, 1986–2015, with application to potential radon exposure from groundwater and indoor air

USGS Publications Warehouse

Gross, Eliza L.

2017-05-11

Results from 1,041 groundwater samples collected during 1986‒2015 from 16 geologic units in Pennsylvania, associated with 25 or more groundwater samples with concentrations of radon-222, were evaluated in an effort to identify variations in radon-222 activities or concentrations and to classify potential radon-222 exposure from groundwater and indoor air. Radon-222 is hereafter referred to as “radon.” Radon concentrations in groundwater greater than or equal to the proposed U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) for public-water supply systems of 300 picocuries per liter (pCi/L) were present in about 87 percent of the water samples, whereas concentrations greater than or equal to the proposed alternative MCL (AMCL) for public water-supply systems of 4,000 pCi/L were present in 14 percent. The highest radon concentrations were measured in groundwater from the schists, gneisses, and quartzites of the Piedmont Physiographic Province.In this study, conducted by the U.S. Geological Survey in cooperation with the Pennsylvania Department of Health and the Pennsylvania Department of Environmental Protection, groundwater samples were aggregated among 16 geologic units in Pennsylvania to identify units with high median radon concentrations in groundwater. Graphical plots and statistical tests were used to determine variations in radon concentrations in groundwater and indoor air. Median radon concentrations in groundwater samples and median radon concentrations in indoor air samples within the 16 geologic units were classified according to proposed and recommended regulatory limits to explore potential radon exposure from groundwater and indoor air. All of the geologic units, except for the Allegheny (Pa) and Glenshaw (Pcg) Formations in the Appalachian Plateaus Physiographic Province, had median radon concentrations greater than the proposed EPA MCL of 300 pCi/L, and the Peters Creek Schist (Xpc), which is in the Piedmont Physiographic Province, had a median radon concentration greater than the EPA proposed AMCL of 4,000 pCi/L. Median concentrations of radon in groundwater and indoor air were determined to differ significantly among the geologic units (Kruskal-Wallis test, significance probability, p<0.001), and Tukey’s test indicated that radon concentrations in groundwater and indoor air in the Peters Creek Schist (Xpc) were significantly higher than those in the other units. Also, the Peters Creek Schist (Xpc) was determined to be the area with highest potential of radon exposure from groundwater and indoor air and one of two units with the highest percentage of population assumed to be using domestic self-supplied water (81 percent), which puts the population at greater potential of exposure to radon from groundwater.Potential radon exposure determined from classification of geologic units by median radon concentrations in groundwater and indoor air according to proposed and recommended regulatory limits is useful for drawing general conclusions about the presence, variation, and potential radon exposure in specific geologic units, but the associated data and maps have limitations. The aggregated indoor air radon data have spatial accuracy limitations owing to imprecision of geocoded test locations. In addition, the associated data describing geologic units and the public water supplier’s service areas have spatial and interpretation accuracy limitations. As a result, data and maps associated with this report are not recommended for use in predicting individual concentrations at specific sites nor for use as a decision-making tool for property owners to decide whether to test for radon concentrations at specific locations. Instead, the data and maps are meant to promote awareness regarding potential radon exposure in Pennsylvania and to point out data gaps that exist throughout the State.

Managing Radon in Schools

EPA Pesticide Factsheets

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

Assessment of the unattached fraction of indoor radon progeny and its contribution to dose: a pilot study in China.

PubMed

Guo, Qiuju; Zhang, Lei; Guo, Lu

2012-12-01

The unattached fraction of radon progeny (f(p)) is one of the most important factors for accurate evaluation of the effective dose from a unit of radon exposure, and it may vary greatly in different environments. For precise evaluation of the indoor radon exposure dose and the influence of unattached radon progeny, a pilot survey of f(p) in different environments was carried out in China with a portable and integrating monitor. The dose conversion factors for radon progeny are calculated with LUDEP(®) code, and the dose contributions from the unattached and the attached radon progenies were simultaneously evaluated based on the results of field measurements. The results show that even though the concentrations of radon progeny vary significantly among different indoor environments, the variations of f(p) seem relatively small (9.3-16.9%). The dose contribution from unattached radon progeny is generally larger (30.2-46.2%) in an indoor environment.

Radon as a Source of External Background at Homestake Mine

NASA Astrophysics Data System (ADS)

Thomas, Keenan; Mei, Dongming; Zhang, Chao; Gray, Fred; Gaitskell, Richard; Fiorucci, Simon

2009-05-01

External sources of radioactivity are important concerns for experiments planned for DUSEL at the Homestake Mine in Lead, South Dakota. Radon emanation and deposition is a major threat to the targeted sensitivity of low background experimentation such as double beta decay detection and dark matter searches. Methods to reduce and mitigate these measured levels will need to be developed to prevent experimental signals from contamination through airborne radon decays as well as the deposition of radon daughters. Radon levels were measured at various depths at the Homestake Mine in December of 2008, January and March of 2009. These measurements will be useful in the development of an underground ventilation system to dilute radon concentrations in the air and subsequent systems to provide radon-free air to clean rooms, as well as preparing researchers for the hazards they pose to their experiments. In addition, the measured radon level will be used to understand the radon emanation from different types of rock.

First Map of Residential Indoor Radon Measurements in Azerbaijan.

PubMed

Hoffmann, M; Aliyev, C S; Feyzullayev, A A; Baghirli, R J; Veliyeva, F F; Pampuri, L; Valsangiacomo, C; Tollefsen, T; Cinelli, G

2017-06-15

This article describes results of the first measurements of indoor radon concentrations in Azerbaijan, including description of the methodology and the mathematical and statistical processing of the results obtained. Measured radon concentrations varied considerably: from almost radon-free houses to around 1100 Bq m-3. However, only ~7% of the total number of measurements exceeded the maximum permissible concentrations. Based on these data, maps of the distribution of volumetric activity and elevated indoor radon concentrations in Azerbaijan were created. These maps reflect a mosaic character of distribution of radon and enhanced values that are confined to seismically active areas at the intersection of an active West Caspian fault with sub-latitudinal faults along the Great and Lesser Caucasus and the Talysh mountains. Spatial correlation of radon and temperature behavior is also described. The data gathered on residential indoor radon have been integrated into the European Indoor Radon Map. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Monitoring trends in civil engineering and their effect on indoor radon.

PubMed

Ringer, W

2014-07-01

In this paper, the importance of monitoring new building concepts is discussed. The effect of energy-efficient construction technologies on indoor radon is presented in more detail. Comparing the radon levels of about 100 low-energy and passive houses in Austria with radon levels in conventional new houses show that, in energy-efficient new houses, the radon level is about one-third lower than in conventional new houses. Nevertheless, certain features or bad practice may cause high radon levels in energy-efficient new houses. Recommendations to avoid adverse effects were set up. Furthermore, the paper deals with the effect of thermal retrofitting on indoor radon. Results from a Swiss study where 163 dwellings were measured before and after thermal retrofit yield an increase of the radon level of 26% in average. Among the various retrofit measures, replacing windows has the greatest impact on the indoor radon level. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

NASA Astrophysics Data System (ADS)

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

2016-09-01

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

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

PubMed

Kotrappa, Payasada; Stieff, Frederick

2009-08-01

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

Residential radon exposure and risk of lung cancer in Missouri.

PubMed Central

Alavanja, M C; Lubin, J H; Mahaffey, J A; Brownson, R C

1999-01-01

OBJECTIVES: This study investigated residential radon exposure and lung cancer risk, using both standard radon dosimetry and a new radon monitoring technology that, evidence suggests, is a better measure of cumulative radon exposure. METHODS: Missouri women (aged 30 to 84 years) newly diagnosed with primary lung cancer during the period January 1, 1993, to January 31, 1994, were invited to participate in this population-based case-control study. Both indoor air radon detectors and CR-39 alpha-particle detectors (surface monitors) were used. RESULTS: When surface monitors were used, a significant trend in lung cancer odds ratios was observed for 20-year time-weighted-average radon concentrations. CONCLUSIONS: When surface monitors were used, but not when standard radon dosimetry was used, a significant lung cancer risk was found for radon concentrations at and above the action level for mitigation of houses currently used in the United States (148 Bqm-3). The risk was below the action level used in Canada (750 Bqm-3) and many European countries (200-400 Bqm-3). PMID:10394313

Numerical and analytical assessment of radon diffusion in various media and potential of charcoal as radon detector

NASA Astrophysics Data System (ADS)

Rybalkin, Andrey

Numerical assessments of radon diffusion together with analytical estimates for short-time and long-time exposure were the first objective of this thesis with the goal to demonstrate how radon propagates in various media. Theoretical predictions were compared to numerical simulations, and obtained values of total radon activities inside each material match quite well with the analytical estimates. These estimates, for activated and nonactivated charcoal, were then used to evaluate the possibility of designing a charcoal system to be used as a radon detector. Another objective was to use nonactivated charcoal samples and measure the level of radon accumulation, and use these data to estimate radon diffusion and adsorption coefficients. The analytical approach was developed to estimate these values. Radon adsorption coefficient in nonactivated charcoal was found to be from 0.2 to 0.4 m3/kg. Radon diffusion coefficient for nonactivated charcoal is in the range of 1.2×10-11 to 5.1×10-10 m2/s in comparison to activated charcoal with adsorption coefficient of 4 m3/kg and diffusion coefficient of 1.43×10-9 m2/s. The third objective was to use GEANT4 numerical code to simulate decay of 238U series and 222Rn in an arbitrary soil sample. Based on that model, the goal was to provide a guideline for merging GEANT4 radioactive decay modeling with the diffusion of radon in a soil sample. It is known that radon can be used as an earthquake predictor by measuring its concentration in groundwater, or if possible, along the faults. Numerical simulations of radon migration by diffusion only were made to estimate how fast and how far radon can move along the fault strands. Among the known cases of successful correlations between radon concentration anomalies and earthquake are the 1966 Tashkent and 1976 Songpan-Pingwu earthquakes. Thus, an idea of radon monitoring along the Wasatch Fault, using system of activated/nonactivated charcoals together with solid state radon detectors is suggested in the thesis. Also, the use of neutron activation analysis for soil samples, collected along and away from Wasatch Fault, and looking for the trace elements can result in correlation with earthquakes, occurred in the past. This approach can be used for earthquake prediction in future.

Radon Testing in Schools.

ERIC Educational Resources Information Center

Wheeler, Robert

1989-01-01

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

Radon programmes and health marketing.

PubMed

Fojtikova, Ivana; Rovenska, Katerina

2011-05-01

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

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

PubMed

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

2015-02-01

This work presents the implementation and testing of several radon mitigation techniques in a pilot house in the radon prone area of Băiţa-Ştei in NW part of Romania. Radon diagnostic investigations in the pilot house showed that the main source of radon was the building sub-soil and the soil near the house. The applied techniques were based on the depressurization and pressurization of the building sub-soil, on the combination of the soil depressurization system by an electric and an eolian fans. Also, there was made an application of a radon barrier membrane and a testing by the combination of the radon membrane by the soil depressurization system. Finally, the better obtained remedial efficiency was about 85%. Copyright © 2014 Elsevier Ltd. All rights reserved.

Protective effects of hot spring water drinking and radon inhalation on ethanol-induced gastric mucosal injury in mice

PubMed Central

Etani, Reo; Kataoka, Takahiro; Kanzaki, Norie; Sakoda, Akihiro; Tanaka, Hiroshi; Ishimori, Yuu; Mitsunobu, Fumihiro; Taguchi, Takehito

2017-01-01

ABSTRACT Radon therapy using radon (222Rn) gas is classified into two types of treatment: inhalation of radon gas and drinking water containing radon. Although short- or long-term intake of spa water is effective in increasing gastric mucosal blood flow, and spa water therapy is useful for treating chronic gastritis and gastric ulcer, the underlying mechanisms for and precise effects of radon protection against mucosal injury are unclear. In the present study, we examined the protective effects of hot spring water drinking and radon inhalation on ethanol-induced gastric mucosal injury in mice. Mice inhaled radon at a concentration of 2000 Bq/m3 for 24 h or were provided with hot spring water for 2 weeks. The activity density of 222Rn ranged from 663 Bq/l (start point of supplying) to 100 Bq/l (end point of supplying). Mice were then orally administered ethanol at three concentrations. The ulcer index (UI), an indicator of mucosal injury, increased in response to the administration of ethanol; however, treatment with either radon inhalation or hot spring water inhibited the elevation in the UI due to ethanol. Although no significant differences in antioxidative enzymes were observed between the radon-treated groups and the non-treated control groups, lipid peroxide levels were significantly lower in the stomachs of mice pre-treated with radon or hot spring water. These results suggest that hot spring water drinking and radon inhalation inhibit ethanol-induced gastric mucosal injury. PMID:28498931

Characteristic Functional of a Probability Measure Absolutely Continuous with Respect to a Gaussian Radon Measure

DTIC Science & Technology

1984-08-01

12. PERSONAL AUTHORISI Hiroshi Sato 13* TYPE OF REPORT TECHNICAL 13b. TIME COVERED PROM TO 14. OATE OF REPORT (Yr. Mo., Day) Aug. 1984...nectuary and identify by bloc* number) Let p and p.. be probability measures on a locally convex Hausdorff real topological linear space E. C.R. Baker [1...THIS PAGE ABSTRACT Let y and y1 be probability measures on a locally convex Hausdorff real topological linear space E. C.R. Baker [1] posed the

Analysis of dissolved gas and fluid chemistry in mountainous region of Goaping river watershed in southern Taiwan

NASA Astrophysics Data System (ADS)

Tang, Kai-Wen; Chen, Cheng-Hong; Liu, Tsung-Kwei

2016-04-01

Annual rainfall in Taiwan is up to 2500 mm, about 2.5 times the average value of the world. However due to high topographic relief of the Central Mountain Range in Taiwan, groundwater storage is critical for water supply. Mountain region of the Goaping river watershed in southern Taiwan is one of the potential areas to develop groundwater recharge model. Therefore the target of this study is to understand sources of groundwater and surface water using dissolved gas and fluid chemistry. Four groundwater and 6 surface water samples were collected from watershed, 5 groundwater and 13 surface water samples were collected from downstream. All samples were analyzed for stable isotopes (hydrogen and oxygen), dissolved gases (including nitrogen, oxygen, argon, methane and carbon dioxide), noble gases (helium and radon) and major ions. Hydrogen and oxygen isotopic ratios of surface water and groundwater samples aligned along meteoric water line. For surface water, dissolved gases are abundant in N2 (>80%) and O2 (>10%); helium isotopic ratio is approximately equal to 1 RA (RA is 3He/4He ratio of air); radon-222 concentration is below the detection limit (<200 Bq/m3); and concentrations of major anions and cations are low (Na+ <20 ppm, Ca2+ < 60 ppm, Cl- <2 ppm). All these features indicate that surface waters are predominately recharged by precipitation. For groundwater, helium isotopic ratios (0.9˜0.23 RA) are lower and radon-222 concentrations (300˜6000 Bq/m3) are much higher than the surface water. Some samples have high amounts of dissolved gases, such as CH4 (>20%) or CO2 (>10%), most likely contributed by biogenic or geogenic sources. On the other hand, few samples that have temperature 5° higher than the average of other samples, show significantly high Na+ (>1000 ppm), Ca2+ (>150 ppm) and Cl- (>80 ppm) concentrations. An interaction between such groundwater and local hot springs is inferred. Watershed and downstream samples differ in dissolved gas species and fluid chemistry for groundwater and surface water. The higher hydrogen and oxygen isotopic ratios for surface water from downstream are most probably caused by evaporation. Low radon-222 concentrations of some groundwater from downstream may represent sources from different aquifers. Therefore, we conclude that surface water from downstream are recharged directly from its watershed, but groundwater are influenced by the local geological environment. Keywords: groundwater, dissolved gas, noble gas, radon in water, 3He/4He

The history, development and the present status of the radon measurement programme in the United States of America.

PubMed

George, A C

2015-11-01

The US radon measurement programme began in the late 1950s by the US Public Health Service in Colorado, New Mexico and Utah during the uranium frenzy. After the 1967 Congressional Hearings on the working conditions in uranium mines, the US Atomic Energy Commission (AEC) was asked to conduct studies in active uranium mines to assess the exposure of the miners on the Colorado Plateau and in New Mexico. From 1967 to 1972, the Health and Safety Laboratory of the US AEC in New York investigated more than 20 uranium mines for radon and radon decay product concentrations and particle size in 4 large uranium mines in New Mexico. In 1970, the US Environmental Protection Agency (EPA) was established and took over some of the AEC radon measurement activities. Between 1975 and 1978, the Environmental Measurements Laboratory of the US Department of Energy conducted the first detailed indoor radon survey in the USA. Later in 1984, the very high concentrations of radon found in Pennsylvania homes set the wheels in motion and gave birth to the US Radon Industry. The US EPA expanded its involvement in radon issues and assumed an active role by establishing the National Radon Proficiency Program to evaluate the effectiveness of radon measurement and mitigation methods. In 1998, due to limited resources EPA privatised the radon programme. This paper presents a personal perspective of past events and current status of the US radon programme. It will present an update on radon health effects, the incidence rate of lung cancer in the USA and the number of radon measurements made from 1988 to 2013 using short-term test methods. More than 23 million measurements were made in the last 25 y and as a result more than 1.24 million homes were mitigated successfully. It is estimated that <2 % of the radon measurements performed in the USA are made using long-term testing devices. The number of homes above the US action level of 148 Bq m(-3) (4 pCi l(-1)) may be ∼8.5 million because ∼50 million homes were added since 1990 to the home inventory. This paper will discuss the current instruments and methods used to measure radon in the USA, and what is the effectiveness of radon resistant new construction, the current status of mitigation standards and the proposed testing protocols in schools and large buildings. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Adaptive detection of missed text areas in OCR outputs: application to the automatic assessment of OCR quality in mass digitization projects

NASA Astrophysics Data System (ADS)

Ben Salah, Ahmed; Ragot, Nicolas; Paquet, Thierry

2013-01-01

The French National Library (BnF*) has launched many mass digitization projects in order to give access to its collection. The indexation of digital documents on Gallica (digital library of the BnF) is done through their textual content obtained thanks to service providers that use Optical Character Recognition softwares (OCR). OCR softwares have become increasingly complex systems composed of several subsystems dedicated to the analysis and the recognition of the elements in a page. However, the reliability of these systems is always an issue at stake. Indeed, in some cases, we can find errors in OCR outputs that occur because of an accumulation of several errors at different levels in the OCR process. One of the frequent errors in OCR outputs is the missed text components. The presence of such errors may lead to severe defects in digital libraries. In this paper, we investigate the detection of missed text components to control the OCR results from the collections of the French National Library. Our verification approach uses local information inside the pages based on Radon transform descriptors and Local Binary Patterns descriptors (LBP) coupled with OCR results to control their consistency. The experimental results show that our method detects 84.15% of the missed textual components, by comparing the OCR ALTO files outputs (produced by the service providers) to the images of the document.

Management of radon: a review of ICRP recommendations.

PubMed

Vaillant, Ludovic; Bataille, Céline

2012-09-01

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

Potential health effects of indoor radon exposure.

PubMed Central

Radford, E P

1985-01-01

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

Radon exhalation from building materials for decorative use.

PubMed

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

2010-04-01

Long-term exposure to radon increases the risk of developing lung cancer. There is considerable public concern about radon exhalation from building materials and the contribution to indoor radon levels. To address this concern, radon exhalation rates were determined for 53 different samples of drywall, tile and granite available on the Canadian market for interior home decoration. The radon exhalation rates ranged from non-detectable to 312 Bq m(-2) d(-1). Slate tiles and granite slabs had relatively higher radon exhalation rates than other decorative materials, such as ceramic or porcelain tiles. The average radon exhalation rates were 30 Bq m(-2) d(-1) for slate tiles and 42 Bq m(-2) d(-1) for granite slabs of various types and origins. Analysis showed that even if an entire floor was covered with a material having a radon exhalation rate of 300 Bq m(-2) d(-1), it would contribute only 18 Bq m(-3) to a tightly sealed house with an air exchange rate of 0.3 per hour. Generally speaking, building materials used in home decoration make no significant contribution to indoor radon for a house with adequate air exchange. Crown Copyright 2010. Published by Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

Lung cancer incidence attributable to residential radon exposure in Alberta in 2012

PubMed Central

Grundy, Anne; Brand, Kevin; Khandwala, Farah; Poirier, Abbey; Tamminen, Sierra; Friedenreich, Christine M.; Brenner, Darren R.

2017-01-01

Background: Radon is carcinogenic, and exposure to radon has been shown to increase the risk of lung cancer. The objective of this study was to quantify the proportion and number of lung cancer cases in Alberta in 2012 that could be attributed to residential radon exposure. Methods: We estimated the population attributable risk of lung cancer for residential radon using radon exposure data from the Cross-Canada Survey of Radon Concentrations in Homes from 2009-2011 and data on all-cause and lung cancer mortality from Statistics Canada from 2008-2012. We used cancer incidence data from the Alberta Cancer Registry for 2012 to estimate the total number of lung cancers attributable to residential radon exposure. Estimates were also stratified by sex and smoking status. Results: The mean geometric residential radon level in Alberta in 2011 was 71.0 Bq/m3 (geometric standard deviation 2.14). Overall, an estimated 16.6% (95% confidence interval 9.4%-29.8%) of lung cancers were attributable to radon exposure, corresponding to 324 excess attributable cancer cases. The estimated population attributable risk of lung cancer due to radon exposure was higher among those who had never smoked (24.8%) than among ever smokers (15.6%). However, since only about 10% of cases of lung cancer occur in nonsmokers, the estimated total number of excess cases was higher for ever smokers (274) than for never smokers (48). Interpretation: With about 17% of lung cancer cases in Alberta in 2012 attributable to residential radon exposure, exposure reduction has the potential to substantially reduce Alberta's lung cancer burden. As such, home radon testing and remediation techniques represent important cancer prevention strategies. PMID:28663187

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

PubMed

Sakoda, Akihiro; Ishimori, Yuu; Tschiersch, Jochen

2016-07-01

The biokinetics of radon in the body has previously been studied with the assumption that its absorption through the skin is negligibly small. This assumption would be acceptable except in specific situations, such as bathing in a radon hot spring where the radon concentration in thermal water is far higher than that in air. The present study focused on such a situation in order to better understand the biokinetics of radon. To mathematically express the entry of radon through the skin into the body, we first modified the latest sophisticated biokinetic model for noble gases. Values of an important parameter for the model-the skin permeability coefficient K (m s(-1))-were derived using data from previous human studies. The analysis of such empirical data, which corresponded to radon concentrations in the air exhaled by subjects during and following bathing in radon-rich thermal water, revealed that the estimated K values had a log-normal distribution. The validity of the K values and the characteristics of the present model are then discussed. Furthermore, the impact of the intake of radon or its progeny via inhalation or skin absorption on radiation dose was also assessed for possible exposure scenarios in a radon hot spring. It was concluded that, depending on the radon concentration in thermal water, there might be situations in which the dose contribution resulting from skin absorption of radon is comparable to that resulting from inhalation of radon and its progeny. This conclusion can also apply to other therapeutic situations (e.g. staying in the pool for a longer period). © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Radon in indoor concentrations and indoor concentrations of metal dust particles in museums and other public buildings.

PubMed

Carneiro, G L; Braz, D; de Jesus, E F; Santos, S M; Cardoso, K; Hecht, A A; Dias da Cunha, Moore K

2013-06-01

The aim of this study was to evaluate the public and occupational exposure to radon and metal-bearing particles in museums and public buildings located in the city of Rio de Janeiro, Brazil. For this study, four buildings were selected: two historic buildings, which currently house an art gallery and an art museum; and two modern buildings, a chapel and a club. Integrated radon concentration measurements were performed using passive radon detectors with solid state nuclear track detector-type Lexan used as nuclear track detector. Air samplers with a cyclone were used to collect the airborne particle samples that were analyzed by the particle-induced X-ray emission technique. The average unattached-radon concentrations in indoor air in the buildings were above 40 Bq/m(3), with the exception of Building D as measured in 2009. The average radon concentrations in indoor air in the four buildings in 2009 were below the recommended reference level by World Health Organization (100 Bq/m(3)); however, in 2011, the average concentrations of radon in Buildings A and C were above this level, though lower than 300 Bq/m(3). The average concentrations of unattached radon were lower than 148 Bq/m(3) (4pCi/L), the USEPA level recommended to take action to reduce the concentrations of radon in indoor air. The unattached-radon average concentrations were also lower than the value recommended by the European Union for new houses. As the unattached-radon concentrations were below the international level recommended to take action to reduce the radon concentration in air, it was concluded that during the period of sampling, there was low risk to human health due to the inhalation of unattached radon in these four buildings.

Indoor Radon: The Deadliest Pollutant.

ERIC Educational Resources Information Center

Kerr, Richard A.

1988-01-01

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

Mapping the geogenic radon potential of the eastern Canary Islands.

NASA Astrophysics Data System (ADS)

Rubiano, Jesús G.; Alonso, Hector; Arnedo, Miguel. A.; Tejera, Alicia; Martel, Pablo; Gil, Juan M.; Rodriguez, Rafael; González, Jonay

2014-05-01

The main contribution of indoor radon comes from soils and thus, the knowledge of the concentration of this gas in soils is important for estimating the risk of finding high radon indoor concentrations. To characterize the behavior of radon in soils, it is common to use the a quantity named Radon Potential which results of a combination of properties of the soil itself and from the underlying rock, such as concentration and distribution of radium, porosity, permeability, the moisture content and meteorological parameters, among others. In this work, the results three year of campaigns of measurement radon gas as well as the permeability in soils of the Eastern Canary Islands (Gran Canaria, Fuerteventura and Lanzarote) are presented. By combining these two parameters and through the use of geostatistic interpolation techniques, the radon potential of soils is estimated and it is used to carry on a classification of the territory into hazard zones according to their potential for radon emanation. To measure the radon soil gas a probe equipped with a "lost" sharp tip is inserted to the desired sampling depth. One of the characteristics of the Canary Islands is the absence of developed soils and so the bedrock is found typically at very shallow depth. This fact has led us to adopt a sampling depth of 50 cm at most. The probe is connected to the continuous radon monitor Durridge RAD7 equipped with a solid-state alpha spectrometer to determine concentration radon using the activity its short-lived progeny. Dried soil air is delivered to the RAD7 radon monitor by pumping. A half hour counting time for all sampling points has been taken. In parallel to the radon measurement campaign, the permeability of soils has also been determined at each point using the permeameter RADON-JOK. The principle of operation of this equipment consists of air withdrawal by means of negative pressure. The gas permeability is then calculated using the known flow of air flowing through the probe using a calibrated nomogram. As results, maps of radon in soils have been developed for the three islands to identify areas where may appear high activity concentrations of radon due to natural sources. Finally to determine the radon potential of soils analyzed we applied a procedure to classify the radon areas in several levels of risk using the measured values of radon activity concentration and soil permeability. Acknowledgments: This work was financed by the Nuclear Safety Council (CSN) through a grant in its R&D program 2009 and by the European Development Fund (ERDF) through a research project program 2007 granted by Canary Agency for Research, Innovation and Information Society (ACIISI) of the Canary Islands.

Radiological Air Sampling. Protocol Development for the Canadian Forces

DTIC Science & Technology

2003-03-01

samplers trap these airborne radon daughters . Because radon is ubiquitous, all air samplers will catch these radioactive radon daughters in the...environment is complicated because all air sampler filters are radioactive because of the radon daughters . ’Actually, D will often depend on the isotope that...simply as "radon". 2 DRDC Ottawa TM 2003-149 -28 - 22 R_ 211p0 214pb 3.8 d 3.0 m 27 m 214Bi 210TI Radon Daughters 20 m ŕ.3 m (Uranium Decay Chain

A comparative study on the characteristics of radioactivities and negative air ions originating from the minerals in some radon hot springs.

PubMed

Sakoda, Akihiro; Hanamoto, Katsumi; Haruki, Naoto; Nagamatsu, Tomohiro; Yamaoka, Kiyonori

2007-01-01

To elucidate the characteristics of some radon hot springs, we simulated a hot spring by soaking the rocks for the radon therapy in water and measured the concentrations of radon and negative air ions in various conditions. In the results, the individual rock structure could contribute to radon leaching because the radon leaching rates were independent of the grain sizes. More negative air ions were generated by the wet rocks than by the dry rocks.

An electrical circuit model for simulation of indoor radon concentration.

PubMed

Musavi Nasab, S M; Negarestani, A

2013-01-01

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

Rayleigh-wave mode separation by high-resolution linear radon transform

USGS Publications Warehouse

Luo, Y.; Xia, J.; Miller, R.D.; Xu, Y.; Liu, J.; Liu, Q.

2009-01-01

Multichannel analysis of surface waves (MASW) method is an effective tool for obtaining vertical shear wave profiles from a single non-invasive measurement. One key step of the MASW method is generation of a dispersion image and extraction of a reliable dispersion curve from raw multichannel shot records. Because different Rayleigh-wave modes normally interfere with each other in the time and space domain, it is necessary to perform mode separation and reconstruction to increase the accuracy of phase velocities determined from a dispersion image. In this paper, we demonstrate the effectiveness of high-resolution linear Radon transform (LRT) as a means of separating and reconstructing multimode, dispersive Rayleigh-wave energy. We first introduce high-resolution LRT methods and Rayleigh-wave mode separation using high-resolution LRT. Next, we use synthetic data and a real-world example to demonstrate the effectiveness of Rayleigh-wave mode separation using high-resolution LRT. Our synthetic and real-world results demonstrate that (1) high-resolution LRT successfully separates and reconstructs multimode dispersive Rayleigh-wave energy with high resolution allowing the multimode energy to be more accurately determined. The horizontal resolution of the Rayleigh-wave method can be increased by extraction of dispersion curves from a pair of traces in the mode-separated shot gather and (2) multimode separation and reconstruction expand the usable frequency range of higher mode dispersive energy, which increases the depth of investigation and provides a means for accurately determining cut-off frequencies. ?? 2009 The Authors Journal compilation ?? 2009 RAS.

Radon as a natural tracer for underwater cave exploration.

PubMed

Csondor, Katalin; Erőss, Anita; Horváth, Ákos; Szieberth, Dénes

2017-07-01

The Molnár János cave is one of the largest hypogenic caves of the Buda Thermal Karst (Budapest, Hungary) and mainly characterized by water-filled passages. The major outflow point of the waters of the cave system is the Boltív spring, which feeds the artificial Malom Lake. Previous radon measurements in the cave system and in the spring established the highest radon concentration (71 BqL -1 ) in the springwater. According to previous studies, the origin of radon was identified as iron-hydroxide containing biofilms, which form where there is mixing of cold and thermal waters, and these biofilms efficiently adsorb radium from the thermal water component. Since mixing of waters is responsible for the formation of the cave as well, these iron-hydroxide containing biofilms and the consequent high radon concentrations mark the active cave forming zones. Based on previous radon measurements, it is supposed that the active mixing and cave forming zone has to be close to the spring, since the highest radon concentration was measured there. Therefore radon mapping was carried out with the help of divers in order to get a spatial distribution of radon in the cave passages closest to the spring. Based on our measurements, the highest radon activity concentration (84 BqL -1 ) was found in the springwater. Based on the distribution of radon activity concentrations, direct connection was established between the spring and the István-room of the cave, which was verified by an artificial tracer. However, the distribution of radon in the cave passages shows lower concentrations (18-46 BqL -1 ) compared to the spring, therefore an additional deep inflow from hitherto unknown cave passages is assumed, from which waters with high radon content arrive to the spring. These passages are assumed to be in the active cave formation zone. This study proved that radon activity concentration distribution is a useful tool in underwater cave exploration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comprehensive survey of household radon gas levels and risk factors in southern Alberta

PubMed Central

Stanley, Fintan K.T.; Zarezadeh, Siavash; Dumais, Colin D.; Dumais, Karin; MacQueen, Renata; Clement, Fiona; Goodarzi, Aaron A.

2017-01-01

Background: The inhalation of naturally occurring radon (222Rn) gas from indoor air exposes lung tissue to α-particle bombardment, a highly mutagenic form of ionizing radiation that damages DNA and increases the lifetime risk of lung cancer. We analyzed household radon concentrations and risk factors in southern Alberta, including Calgary, the third-largest Canadian metropolis. Methods: A total of 2382 residential homes (2018 in Calgary and 364 in surrounding townships) from an area encompassing 82% of the southern Alberta population were tested for radon, per Health Canada guidelines, for at least 90 days (median 103 d) between 2013 and 2016. Participants also provided home metrics (construction year, build type, foundation type, and floor and room of deployment of the radon detector) via an online survey. Homes that were subsequently remediated were retested to determine the efficacy of radon reduction techniques in the region. Results: The average indoor air radon level was 126 Bq/m3, which equates to an effective absorbed radiation dose of 3.2 mSv/yr. A total of 1135 homes (47.6%) had levels of 100 Bq/m3 or higher, and 295 homes (12.4%) had levels of 200 Bq/m3 or higher; the range was less than 15 Bq/m3 to 3441 Bq/m3. Homes built in 1992 or later had radon levels 31.5% higher, on average, than older homes (mean 142 Bq/m3 v. 108 Bq/m3). For 90 homes with an average radon level of 575 Bq/m3 before mitigation, radon suppression successfully reduced levels to an average of 32.5 Bq/m3. Interpretation: Our findings show that radon exposure is a genuine public health concern in southern Alberta, suggest that modern building practices are associated with increased indoor air radon accumulation, legitimatize efforts to understand the consequences of radon exposure to the public, and suggest that radon testing and mitigation are likely to be impactful cancer prevention strategies. PMID:28401142

Iowa radon leukaemia study: a hierarchical population risk model for spatially correlated exposure measured with error.

PubMed

Smith, Brian J; Zhang, Lixun; Field, R William

2007-11-10

This paper presents a Bayesian model that allows for the joint prediction of county-average radon levels and estimation of the associated leukaemia risk. The methods are motivated by radon data from an epidemiologic study of residential radon in Iowa that include 2726 outdoor and indoor measurements. Prediction of county-average radon is based on a geostatistical model for the radon data which assumes an underlying continuous spatial process. In the radon model, we account for uncertainties due to incomplete spatial coverage, spatial variability, characteristic differences between homes, and detector measurement error. The predicted radon averages are, in turn, included as a covariate in Poisson models for incident cases of acute lymphocytic (ALL), acute myelogenous (AML), chronic lymphocytic (CLL), and chronic myelogenous (CML) leukaemias reported to the Iowa cancer registry from 1973 to 2002. Since radon and leukaemia risk are modelled simultaneously in our approach, the resulting risk estimates accurately reflect uncertainties in the predicted radon exposure covariate. Posterior mean (95 per cent Bayesian credible interval) estimates of the relative risk associated with a 1 pCi/L increase in radon for ALL, AML, CLL, and CML are 0.91 (0.78-1.03), 1.01 (0.92-1.12), 1.06 (0.96-1.16), and 1.12 (0.98-1.27), respectively. Copyright 2007 John Wiley & Sons, Ltd.

Canadian individual risks of radon-induced lung cancer for different exposure profiles.

PubMed

Chen, Jing

2005-01-01

Indoor radon has been determined to be the second leading cause of lung cancer after tobacco smoking. There is an increasing need among radiation practitioners to have numerical values of lung cancer risks for men and women, ever-smokers and never-smokers exposed to radon in homes. This study evaluates individual risks for the Canadian population exposed to radon in homes at different radon concentrations and for different periods of their lives. Based on the risk model developed recently by U.S. Environmental Protection Agency (EPA), individual risks of radon-induced lung cancers are calculated with Canadian age-specific rates for overall and lung cancer mortalities (1996-2000) as well as the Canadian smoking prevalence data in 2002. Convenient tables of lifetime relative risks are constructed for lifetime exposures and short exposures between any two age intervals from 0 to 110, and for various radon concentrations found in homes from 50 to 1000 Bq/m3. The risk of developing lung cancer from residential radon exposure increases with radon concentration and exposure duration. For short exposure periods, such as 10 or 20 years, risks are higher in middle age groups (30-50) compared especially to the later years. Individuals could lower their risks significantly by reducing radon levels earlier in life. The tables could help radiation protection practitioners to better communicate indoor radon risk to members of the public.

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

PubMed

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

2010-05-01

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

Optimizing laboratory-based radon flux measurements for sediments.

PubMed

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

2016-07-01

Radon flux via diffusion from sediments and other materials may be determined in the laboratory by circulating air through the sample and a radon detector in a closed loop. However, this approach is complicated by the necessity of having to determine the total air volume in the system and accounting for any small air leaks that can arise if using extended measurement periods. We designed a simple open-loop configuration that includes a measured mass of wet sediment and water inside a gas-tight reaction flask connected to a drying system and a radon-in-air analyzer. Ambient air flows through two charcoal columns before entering the reaction vessel to eliminate incoming radon. After traveling through the reaction flask, the air passes the drier and the radon analyzer and is then vented. After some time, the radon activity will reach a steady state depending upon the airflow rate. With this approach, the radon flux via diffusion is simply the product of the steady-state radon activity (Bq/m(3)) multiplied by the airflow rate (mL/min). We demonstrated that this setup could produce good results for materials that produce relatively high radon fluxes. We also show that a modified closed system approach, including radon removal of the incoming air by charcoal filtration in a bypass, can produce very good results including samples with very low emission rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

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

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

RESIDENTIAL RADON RESISTANT CONSTRUCTION FEATURE SELECTION SYSTEM

EPA Science Inventory

The report describes a proposed residential radon resistant construction feature selection system. The features consist of engineered barriers to reduce radon entry and accumulation indoors. The proposed Florida standards require radon resistant features in proportion to regional...

Impact of radon gas concentration in the aerosoles profile

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lukaj, Edmond, E-mail: mondilukaj@yahoo.com; Vila, Floran, E-mail: floranvila@yahoo.com; Mandija, Florian, E-mail: fmandija@yahoo.com

Radon gases relased from building materials and from earth surface are the major responsibility of air ionization. Radon nuclear decay can produce an alpha particle with high energy and Radon progeny. This particle and gamma rays can deliver particles in the air and produce ions with different polarities. This ions, because of induced electric charge, can attach with air aerosols and charge them with their electric charge. The charged aerosols can interact with the other aerosols and ions. Because of this exchange, the air conductivity and the aerosol profiles will change dependently by Radon gas concentration and gamma radiation. Observationsmore » show an increase in concentration of Radon during the night, and a decrease during the daylight time. The Radon gas concentration changed hour by hour can induce aerosol profile to change. This dependency between the aerosol profiles and the Radon gas concentrations is discussed.« less

Factors Affecting Radon Concentration in Houses

NASA Astrophysics Data System (ADS)

Al-Sharif, Abdel-Latif; Abdelrahman, Y. S.

2001-03-01

The dangers to the human health upon exposure to radon and its daughter products is the main motivation behind the vast number of studies performed to find the concentration of radon in our living environment, including our houses. The presence of radon and its daughter products in houses are due to various sources including building materials and the soil under the houses. Many factors affect radon concentration in our houses, the elevation above ground level,ventilation, building materials and room usage being among these factors. In our paper, we discuss the effect of elevation above ground level, room usage and ventilation on the Radon concentration in houses. The faculty residences of the Mu'tah University (Jordan) were chosen in our study. Our results showed that the concentration of radon decreases with elevation. Ventilation rate was also found to affect radon concentration, where low concentrations observed for areas with good ventilation.

Creating Geologically Based Radon Potential Maps for Kentucky

NASA Astrophysics Data System (ADS)

Overfield, B.; Hahn, E.; Wiggins, A.; Andrews, W. M., Jr.

2017-12-01

Radon potential in the United States, Kentucky in particular, has historically been communicated using a single hazard level for each county; however, physical phenomena are not controlled by administrative boundaries, so single-value county maps do not reflect the significant variations in radon potential in each county. A more accurate approach uses bedrock geology as a predictive tool. A team of nurses, health educators, statisticians, and geologists partnered to create 120 county maps showing spatial variations in radon potential by intersecting residential radon test kit results (N = 60,000) with a statewide 1:24,000-scale bedrock geology coverage to determine statistically valid radon-potential estimates for each geologic unit. Maps using geology as a predictive tool for radon potential are inherently more detailed than single-value county maps. This mapping project revealed that areas in central and south-central Kentucky with the highest radon potential are underlain by shales and karstic limestones.

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

PubMed

Ishimori, Yuu; Mitsunobu, Fumihiro; Yamaoka, Kiyonori; Tanaka, Hiroshi; Kataoka, Takahiro; Sakoda, Akihiro

2011-07-01

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

Radon Levels in Nurseries and Primary Schools in Bragança District-Preliminary Assessment.

PubMed

Sousa, S I V; Branco, P T B S; Nunes, R A O; Alvim-Ferraz, M C M; Martins, F G

2015-01-01

Lung cancer has been associated with radon concentration even at low levels such as those found in dwellings. This study aimed to (i) determine radon diurnal variations in three nurseries and one primary school in the Bragança district (north of Portugal) and (ii) compare radon concentrations with legislated standards and assess the legislated procedures. Radon was measured in three nurseries and a primary school in a rural area with nongranite soil. Measurements were performed continuously to examine differences between occupation and nonoccupation periods. Indoor temperature and relative humidity were also measured continuously. A great variability was found in radon concentrations between the microenvironments examined. Radon concentrations surpassed by severalfold the recommended guidelines and thresholds, and excessive levels of health concern were sporadically found (361.5-753.5 Bq m(-3)). Thus, it is of importance to perform a national campaign on radon measurements and to reduce exposure.

Radon in Wisconsin.

PubMed

Weiffenbach, C; Anderson, H A

2000-11-01

Owners of about 15% to 20% of the homes in Wisconsin have tested their indoor air for the carcinogenic gas radon. Five percent to 10% of homes have year-average main-floor radon levels that exceed the US Environmental Protection Agency (EPA) exposure guideline, and they are found in most regions of the state. Attempting to retroactively seal foundations to keep radon from the ground out of a home is largely ineffective. However, a soil-depressurization radon mitigation system is highly effective for existing houses, and new homes can easily be built radon-resistant. As the number of homeowners obtaining needed repairs increases, significant lung cancer risk reduction is being achieved in a voluntary, non-regulatory setting. In coming years, as radon in community drinking water supplies becomes regulated under the federal 1996 Safe Drinking Water Act, the "multimedia" option of the act may result in additional attention to mitigation of radon in indoor air.

Results of a Test and Win Contest to Raise Radon Awareness in Urban and Rural Settings

ERIC Educational Resources Information Center

Hahn, Ellen J.; Rayens, Mary Kay; Kercsmar, Sarah E.; Robertson, Heather; Adkins, Sarah M.

2014-01-01

Background: Radon is a leading cause of lung cancer, but few test their homes to determine radon levels. Purpose: The study assessed feasibility and success of a Test and Win Contest to promote radon testing in rural and urban communities. Methods: The prospective, quasi-experimental study tested a novel contest to raise radon awareness. Paid and…

The mathematical model of radon-222 accumulation in underground mines

NASA Astrophysics Data System (ADS)

Klimshin, A.

2012-04-01

Necessity to control underground mine air radon level arises during building and operating mines as well as auto and railway tunnels including those for metros. Calculation of underground mine air radon level can be fulfilled for estimation of potential radon danger of area for underground structure building. In this work the new mathematical model of radon accumulation in underground mines has been suggested. It takes into consideration underground mine dimensions, air exchange factor and soils ability to emanate radon. The following assumptions have been taken for model development. It is assumed that underground mine is a cylinder of length L and of base area S. Due to ventilation atmosphere air of volume activity Catm, is coming in through one cylinder base and is going out of volume activity Cind from underground mine. Diffusion radon flux is coming in through side surfaces of underground mine. The sources of this flux are radium-226 atoms distributed evenly in rock. For simplification of the task it considered possible to disregard radon emanation by loosened rock and underground waters. As a result of solution of the radon diffusion equation the following expression for calculation of radon volume activity in underground space air has been got: 2·r0 ·λv ·Catm-·l·K0(r0/l)-+D-·K1(r0/l)·C0- Cind = 2·(λ+ λv)·r0 ·l·K0 (r0/l)+ D ·K1(r0/l) . The following designations are used in this expression: Kν(r) - the second genus modified Bessel's function, C0 - equilibrium radon volume activity in soil air, l - diffusion radon length in soil, D - radon diffusion factor, r0 - radius of underground tunnel, λv - factor of air exchange. Expression found may be used for calculation of the minimum factor of necessary air exchange for ensuring safe radon levels in underground spaces. With this worked out model expected levels of radon volume activity were calculated for air in the second metro line underground spaces in the city of Yekaterinburg, Russia.

Kinetics of the water/air phase transition of radon and its implication on detection of radon-in-water concentrations: practical assessment of different on-site radon extraction methods.

PubMed

Schubert, Michael; Paschke, Albrecht; Bednorz, Denise; Bürkin, Walter; Stieglitz, Thomas

2012-08-21

The on-site measurement of radon-in-water concentrations relies on extraction of radon from the water followed by its detection by means of a mobile radon-in-air monitor. Many applications of radon as a naturally occurring aquatic tracer require the collection of continuous radon concentration time series, thus necessitating the continuous extraction of radon either from a permanent water stream supplied by a water pump or directly from a water body or a groundwater monitoring well. Essentially, three different types of extraction units are available for this purpose: (i) a flow-through spray chamber, (ii) a flow-through membrane extraction module, and (iii) a submersible (usually coiled) membrane tube. In this paper we discuss the advantages and disadvantages of these three methodical approaches with particular focus on their individual response to instantaneously changing radon-in-water concentrations. After a concise introduction into theoretical aspects of water/air phase transition kinetics of radon, experimental results for the three types of extraction units are presented. Quantitative suggestions for optimizing the detection setup by increasing the water/air interface and by reducing the air volume circulating through the degassing unit and radon detector are made. It was shown that the flow-through spray chamber and flow-through membrane perform nearly similarly, whereas the submersible membrane tubing has a significantly larger delay in response to concentration changes. The flow-through spray chamber is most suitable in turbid waters and to applications where high flow rates of the water pump stream can be achieved (e.g., where the power supply is not constrained by field conditions). The flow-through membrane is most suited to radon extraction from clear water and in field conditions where the power supply to a water pump is limited, e.g., from batteries. Finally, the submersible membrane tube is most suitable if radon is to be extracted in situ without any water pumping, e.g., in groundwater wells with a low yield, or in long-term time series, in which short-term variations in the radon concentration are of no relevance.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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- andmore » beta-liquid scintillation counting. 23 private firms, government laboratories and universities participated with a 165 passive integrating devices consisting of: Activated carbon collectors, nuclear alpha track detectors and electret ionization chambers, and 11 active and passive continuous radon monitors. Five portable integrating and continuous instruments were intercompared for radon progeny. Forty grab samples for radon progeny were taken by five groups that participated in person to test and evaluate their primary instruments and methods that measure individual radon progeny and the potential alpha energy concentration (PAEC) in indoor air. Results indicate that more than 80% of the measurements for radon performed with a variety of instruments, are within {plus_minus}10% of actual value. The majority of the instruments that measure individual radon progeny and the PAEC gave results that are in good agreement with the EML reference value. Radon progeny measurements made with continuous and integrating instruments are satisfactory with room for improvement.« less

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

NASA Astrophysics Data System (ADS)

Tadolini, T.; Spizzico, M.

The radon-222 (222Rn) activity in groundwater of the Apulian karstic aquifer in southern Italy is as great as 500 Becquerel per liter (Bq/L) locally. Normal radium-226 (226Ra) activity in the limestone and calcareous dolomites of the aquifer is not enough to explain such a high level. Laboratory investigations identified high 226Ra activity in the "terra rossa," the residuum occupying fissures and cavities in the bedrock, and also the relation between (1) 226Ra-bearing bedrock and "terra rossa" and (2) 222Rn in water. The "terra rossa" is the primary source of the radon in the groundwater. The experimental results show the need to characterize the "terra rossa" of Apulia on the basis of 226Ra activity and also to study the distribution and variations in 222Rn activity over time in the aquifer. Résumé L'activité du radon-222 (222Rn) dans les eaux souterraines de l'aquifère karstique des Pouilles, dans le sud de l'Italie, atteint localement 500 Becquerel par litre (Bq/L). L'activité normale du radium-226 (226Ra) dans les calcaires et dans les calcaires dolomitiques de l'aquifère n'est pas assez élevée pour expliquer des valeurs aussi élevées. Des analyses de laboratoire ont mis en évidence une forte activité en 226Ra dans la terra rossa, remplissage de fissures et de cavités de la roche, ainsi qu'une relation entre (1) la roche et la terra rossa contenant du 226Ra et (2) le 222Rn dans l'eau. La terra rossa est la source primaire de radon dans l'eau souterraine. Les résultats expérimentaux montrent qu'il est nécessaire de caractériser la terra rossa des Pouilles par son activité en 226Ra et d'étudier la distribution et les variations de l'activité en 222Rn au cours du temps dans l'aquifère. Resumen La actividad del radon-222 (222Rn) en el agua subterránea del acuífero cárstico de Apulia, al sur de Italia, alcanza localmente los 500Bq/L. La actividad normal del radio-226 (226Ra) en las calcitas y dolomitas del acuífero no es suficiente para explicar estos niveles tan altos. Las investigaciones de laboratorio han identificado alta actividad de 226Ra en la "terra rossa", el material que rellena las fisuras y cavidades de la matriz rocosa, y han identificado también la relación entre (1) el 226Ra presente en la roca portante y la "terra rossa" y (2) el contenido de 222Rn en el agua. La "terra rossa" es, pues, la fuente principal de radón en las aguas subterráneas. Los resultados experimentales muestran la necesidad de caracterizar la "terra rossa" de Apulia sobre la base de la actividad de 226Ra, así como de estudiar la distribución y las variaciones en la actividad del 222Rn en el acuífero a lo largo del tiempo.

Thoron in the environment and its related issues

NASA Astrophysics Data System (ADS)

Tokonami, Shinji

2009-06-01

Since radon is internationally noted as the second cause of lung cancer, many countries are trying about to solve the problem worldwide. In addition, a new evidence of lung cancer risk has been recently found out with a low level below 200 Bq m-3. Thus the action level will have to be set lower than before. Importance of radon exposure has been further recognized and accurate radon concentrations will be required. Recently thoron has also been recognized from the viewpoint of accurate radon measurements. The present paper describes specification of the NIRS radon and thoron chambers, passive measurement technique of radon and thoron and thoron interference on radon measurements from both experimental studies and field experiences on epidemiological study area.

Field comparison of several commercially available radon detectors.

PubMed Central

Field, R W; Kross, B C

1990-01-01

To determine the accuracy and precision of commercially available radon detectors in a field setting, 15 detectors from six companies were exposed to radon and compared to a reference radon level. The detectors from companies that had already passed National Radon Measurement Proficiency Program testing had better precision and accuracy than those detectors awaiting proficiency testing. Charcoal adsorption detectors and diffusion barrier charcoal adsorption detectors performed very well, and the latter detectors displayed excellent time averaging ability. Alternatively, charcoal liquid scintillation detectors exhibited acceptable accuracy but poor precision, and bare alpha registration detectors showed both poor accuracy and precision. The mean radon level reported by the bare alpha registration detectors was 68 percent lower than the radon reference level. PMID:2368851

Radon

MedlinePlus

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

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

PubMed Central

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

2013-01-01

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

Radon Risk Communication Strategies: A Regional Story.

PubMed

Cheng, Winnie

2016-01-01

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

Measurement of radon/thoron exhalation rates and gamma-ray dose rate in granite areas in Japan.

PubMed

Prasad, G; Ishikawa, T; Hosoda, M; Sahoo, S K; Kavasi, N; Sorimachi, A; Tokonami, S; Uchida, S

2012-11-01

Radon and thoron exhalation rates and gamma-ray dose rate in different places in Hiroshima Prefecture were measured. Exhalation rates were measured using an accumulation chamber method. The radon exhalation rate was found to vary from 3 to 37 mBq m(-2) s(-1), while the thoron exhalation rate ranged from 40 to 3330 mBq m(-2) s(-1). The highest radon exhalation rate (37 mBq m(-2) s(-1)) and gamma-ray dose rate (92 nGy h(-1)) were found in the same city (Kure City). In Kure City, indoor radon and thoron concentrations were previously measured at nine selected houses using a radon-thoron discriminative detector (Raduet). The indoor radon concentrations varied from 16 to 78 Bq m(-3), which was higher than the average value in Japan (15.5 Bq m(-3)). The indoor thoron concentration ranged from ND (not detected: below a detection limit of approximately 10 Bq m(-3)) to 314 Bq m(-3). The results suggest that radon exhalation rate from the ground is an influential factor for indoor radon concentration.

Study of radon dispersion in typical dwelling using CFD modeling combined with passive-active measurements

NASA Astrophysics Data System (ADS)

Rabi, R.; Oufni, L.

2017-10-01

Inhalation of radon (222Rn) and its decay products are a major source of natural radiation exposure. It is known from recent surveys in many countries that radon and its progeny contribute significantly to total inhalation dose and it is fairly established that radon when inhaled in large quantity causes lung disorder. Indoor air conditions and ventilation systems strongly influence the indoor radon concentration. This study focuses on investigating both numerically and experimentally the influence of environmental conditions on the indoor radon concentration and spatial distribution. The numerical results showed that ventilation rate, temperature and humidity have significant impacts on both radon content and distribution. The variations of radon concentration with the ventilation, temperature and relative humidity are discussed. The measurement results show the diurnal variations of the indoor radon concentration are found to exhibit a positive correlation with relative humidity and negatively correlate with the air temperature. The analytic solution is used to validate the numeric results. The comparison amongst analytical, numerical and measurement results shows close agreement.

Preliminary Monitoring of Soil gas Radon in Potentially Active Faults, San Sai District, Chiang Mai Province, Thailand

NASA Astrophysics Data System (ADS)

Pondthai, P.; Udphuay, S.

2013-05-01

The magnitude of 5.1 Mw earthquake occurred in San Sai District, Chiang Mai Province, Thailand in December 2006 was considered an uncommon event due to the fact that there was no statistical record of such significant earthquake in the area. Therefore the earthquake might have been associated with a potentially active fault zone within the area. The objective of this study is to measure soil gas radon across this unknown fault zone within the Chiang Mai Basin, northern Thailand. Two profiles traversing the expected fault zone of soil gas radon measurements have been monitored, using TASTRAK solid state track nuclear detectors (SSNTDs). Radon signals from three periods of measurement show a distinctive consistent spatial distribution pattern. Anomalous radon areas along the profiles are connected to fault locations previously interpreted from other geophysical survey results. The increased radon signal changes from the radon background level with the signal-to-background ratio above 3 are considered anomalous. Such pattern of radon anomaly supports the existence of the faults. The radon measurement, therefore is a powerful technique in mapping active fault zone.

Study of indoor radon distribution using measurements and CFD modeling.

PubMed

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

2014-10-01

Measurement and/or prediction of indoor radon ((222)Rn) concentration are important due to the impact of radon on indoor air quality and consequent inhalation hazard. In recent times, computational fluid dynamics (CFD) based modeling has become the cost effective replacement of experimental methods for the prediction and visualization of indoor pollutant distribution. The aim of this study is to implement CFD based modeling for studying indoor radon gas distribution. This study focuses on comparison of experimentally measured and CFD modeling predicted spatial distribution of radon concentration for a model test room. The key inputs for simulation viz. radon exhalation rate and ventilation rate were measured as a part of this study. Validation experiments were performed by measuring radon concentration at different locations of test room using active (continuous radon monitor) and passive (pin-hole dosimeters) techniques. Modeling predictions have been found to be reasonably matching with the measurement results. The validated model can be used to understand and study factors affecting indoor radon distribution for more realistic indoor environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Radon emissions from natural gas power plants at The Pennsylvania State University.

PubMed

Stidworthy, Alison G; Davis, Kenneth J; Leavey, Jeff

2016-11-01

Burning natural gas in power plants may emit radon ( 222 Rn) into the atmosphere. On the University Park campus of The Pennsylvania State University, atmospheric radon enhancements were measured and modeled in the vicinity of their two power plants. The three-part study first involved measuring ambient outdoor radon concentrations from August 2014 through January 2015 at four sites upwind and downwind of the power plants at distances ranging from 80 m to 310 m. For each plant, one site served as a background site, while three other sites measured radon concentration enhancements downwind. Second, the radon content of natural gas flowing into the power plant was measured, and third, a plume dispersion model was used to predict the radon concentrations downwind of the power plants. These predictions are compared to the measured downwind enhancements in radon to determine whether the observed radon concentration enhancements could be attributed to the power plants' emissions. Atmospheric radon concentrations were consistently low as compared to the EPA action level of 148 Bq m -3 , averaging 34.5 ± 2.7 Bq m -3 around the East Campus Steam Plant (ECSP) and 31.6 ± 2.7 Bq m -3 around the West Campus Steam Plant (WCSP). Significant concentrations of radon, ranging from 516 to 1,240 Bq m -3 , were detected in the natural gas. The measured enhancements downwind of the ECSP averaged 6.2 Bq m -3 compared to modeled enhancements of 0.08 Bq m -3 . Measured enhancements around the WCSP averaged -0.2 Bq m -3 compared to the modeled enhancements of 0.05 Bq m -3 , which were not significant compared to observational error. The comparison of the measured to modeled downwind radon enhancements shows no correlation over time. The measurements of radon levels in the vicinity of the power plants appear to be unaffected by the emissions from the power plants. Radon measurements at sites surrounding power plants that utilize natural gas did not indicate that the radon concentrations originated from the plants' emissions. There were elevated radon concentrations in the natural gas supply flowing into the power plants, but combustion dilution puts the concentration below EPA action levels coming out of the stack, so no hazardous levels were expected downwind. Power plant combustion of natural gas is not likely to pose a radiation health hazard unless very different gas radon concentrations or combustion dilution ratios are encountered.

The relation of seismic activity and radon concentration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulali, Feride, E-mail: feridekulali@gmail.com, E-mail: iskender@fef.sdu.edu.tr; Akkurt, İskender, E-mail: feridekulali@gmail.com, E-mail: iskender@fef.sdu.edu.tr; Vogiannis, Efstratios, E-mail: svog@env.aegean.gr

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

Measurements of radon concentrations in Spa waters in Amasya, Turkey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yigitoglu, I., E-mail: ibrahim.yigitoglu@gop.edu.tr; Ucar, B.; Oner, F.

The aim of this study is to determine the radon concentrations in thermal waters in the Amasya basin in Turkey and to explore the relationship between radon anomalies and active geological faults. The radon concentration measurements were performed in four thermal Spas around Amasya basin. The water samples were collected from tap waters in thermal water sources. The obtained radon concentrations ranged from 0.15 ± 0.12 to 0.71 ± 0.32 BqL{sup −1} for Spa waters. The relationship between the radon concentration anomalies and earthquakes that occurred in the sampling period are discussed.

Radon: Counseling patients about risk

DOE Office of Scientific and Technical Information (OSTI.GOV)

Birrer, R.B.

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

Indoor residential radon exposure and risk of childhood acute myeloid leukaemia.

PubMed

Steinbuch, M; Weinberg, C R; Buckley, J D; Robison, L L; Sandler, D P

1999-11-01

Exposure to radon has been identified as a risk factor for lung cancer in uranium miners, but evidence of adverse health effects due to indoor radon exposure is inconsistent. Ecological studies have suggested a correlation between indoor radon levels and leukaemia incidence. We evaluated the risk associated with indoor residential radon exposure within a larger interview-based case-control study of risk factors for childhood acute myeloid leukaemia (AML). A total of 173 cases and 254 controls met the eligibility criteria, and information was collected through telephone interviews with parents and analysis of alpha-track radon detectors placed in the home for a period of 1 year. No association was observed between radon exposure and risk of AML, with adjusted odds ratios of 1.2 (95% confidence interval (CI) 0.7-1.8) for 37-100 Bq m(-3) and 1.1 (95% CI 0.6-2.0) for > 100 Bq m(-3) compared with < 37 Bq m(-3). Although there was an inverse association between radon level and AML risk among children < 2 years at diagnosis, among children > or = 2 years, AML risk was increased among those with higher radon exposure. The observed association after age 2 is most likely due to chance. Overall, there was no association between residential radon and risk of childhood AML.

A study of indoor radon, thoron and their exhalation rates in the environment of Fazilka district, Punjab, India

NASA Astrophysics Data System (ADS)

Narang, Saurabh; Kumar, Deepak; Sharma, Dinesh Kumar; Kumar, Ajay

2018-02-01

Over the last few decades, the study of radioactive radon gas has gained huge momentum due to its possible role in health related hazards. In the present work, pin-hole twin chamber single entrance dosimeters have been used for track measurements of radon and thoron. The annual average radon concentration varies from 50.3 to 204 Bq/m3 at all locations. Almost all the values are below the safe range provided by ICRP. Radon concentration is found to be higher in winter as compared to other seasons. Variation of radon with quality of dwellings is also discussed. The values of annual effective dose due to radon and thoron are also well within the range provided by ICRP and WHO. Radon and thoron exhalation rates are measured using SMART RnDuo monitor. The radon mass exhalation rates ranged from 11 to 71 mBq/kg/h while the thoron surface values ranged from 36 to 2048 Bq/m2/h. All the values are on the lower side. A weak correlation is found between radon and thoron concentrations and their exhalation rates. When compared with the values of other parts of northern India, the values of present investigation are on higher side.

Incidence of leukemia, lymphoma, and multiple myeloma in Czech uranium miners: a case-cohort study.

PubMed

Rericha, Vladimír; Kulich, Michal; Rericha, Robert; Shore, David L; Sandler, Dale P

2006-06-01

Uranium miners are chronically exposed to low levels of radon and its progeny. We investigated whether radon exposure is associated with increased incidence of leukemia, lymphoma, or multiple myeloma in this population. We conducted a retrospective case-cohort study in 23,043 uranium miners and identified a total of 177 incident cases of leukemia, lymphoma, and myeloma. Detailed information on occupational radon exposure was obtained for the cases and a randomly selected subcohort of 2,393 subjects. We used the proportional hazards model with power relative risk (RR) function to estimate and test the effects of cumulative radon exposures on incidence rates. Incidence of all leukemia combined and chronic lymphocytic leukemia (CLL) alone was positively associated with cumulative radon exposure. The RR comparing high radon exposure [110 working level months (WLM) ; 80th percentile] to low radon exposure (3 WLM ; 20th percentile) was 1.75 [95% confidence interval (CI) , 1.10-2.78 ; p = 0.014] for all leukemia combined and 1.98 (95% CI, 1.10-3.59 ; p = 0.016) for CLL. Myeloid leukemia and Hodgkin lymphoma were also associated with radon, but RRs were not statistically significant. There was no apparent association of radon with either non-Hodgkin lymphoma or multiple myeloma. Exposure to radon and its progeny was associated with an increased risk of developing leukemia in underground uranium miners. CLL, not previously believed to be radiogenic, was linked to radon exposure.

Incidence of Leukemia, Lymphoma, and Multiple Myeloma in Czech Uranium Miners: A Case–Cohort Study

PubMed Central

Řeřicha, Vladimír; Kulich, Michal; Řeřicha, Robert; Shore, David L.; Sandler, Dale P.

2006-01-01

Objective Uranium miners are chronically exposed to low levels of radon and its progeny. We investigated whether radon exposure is associated with increased incidence of leukemia, lymphoma, or multiple myeloma in this population. Design We conducted a retrospective case–cohort study in 23,043 uranium miners and identified a total of 177 incident cases of leukemia, lymphoma, and myeloma. Detailed information on occupational radon exposure was obtained for the cases and a randomly selected subcohort of 2,393 subjects. We used the proportional hazards model with power relative risk (RR) function to estimate and test the effects of cumulative radon exposures on incidence rates. Results Incidence of all leukemia combined and chronic lymphocytic leukemia (CLL) alone was positively associated with cumulative radon exposure. The RR comparing high radon exposure [110 working level months (WLM); 80th percentile] to low radon exposure (3 WLM; 20th percentile) was 1.75 [95% confidence interval (CI), 1.10–2.78; p = 0.014] for all leukemia combined and 1.98 (95% CI, 1.10–3.59; p = 0.016) for CLL. Myeloid leukemia and Hodgkin lymphoma were also associated with radon, but RRs were not statistically significant. There was no apparent association of radon with either non-Hodgkin lymphoma or multiple myeloma. Exposure to radon and its progeny was associated with an increased risk of developing leukemia in underground uranium miners. CLL, not previously believed to be radiogenic, was linked to radon exposure. PMID:16759978

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

PubMed Central

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

2014-01-01

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

Determination of recharge fraction of injection water in combined abstraction-injection wells using continuous radon monitoring.

PubMed

Lee, Kil Yong; Kim, Yong-Chul; Cho, Soo Young; Kim, Seong Yun; Yoon, Yoon Yeol; Koh, Dong Chan; Ha, Kyucheol; Ko, Kyung-Seok

2016-12-01

The recharge fractions of injection water in combined abstraction-injection wells (AIW) were determined using continuous radon monitoring and radon mass balance model. The recharge system consists of three combined abstraction-injection wells, an observation well, a collection tank, an injection tank, and tubing for heating and transferring used groundwater. Groundwater was abstracted from an AIW and sprayed on the water-curtain heating facility and then the used groundwater was injected into the same AIW well by the recharge system. Radon concentrations of fresh groundwater in the AIWs and of used groundwater in the injection tank were measured continuously using a continuous radon monitoring system. Radon concentrations of fresh groundwater in the AIWs and used groundwater in the injection tank were in the ranges of 10,830-13,530 Bq/m 3 and 1500-5600 Bq/m 3 , respectively. A simple radon mass balance model was developed to estimate the recharge fraction of used groundwater in the AIWs. The recharge fraction in the 3 AIWs was in the range of 0.595-0.798. The time series recharge fraction could be obtained using the continuous radon monitoring system with a simple radon mass balance model. The results revealed that the radon mass balance model using continuous radon monitoring was effective for determining the time series recharge fractions in AIWs as well as for characterizing the recharge system. Copyright © 2016 Elsevier Ltd. All rights reserved.

Radon Risk Perception and Testing: Sociodemographic Correlates.

ERIC Educational Resources Information Center

Halpern, Michael T.; Warner, Kenneth E.

1994-01-01

Using information from the 1990 National Health Interview Survey, examined beliefs regarding radon and radon-testing activities among different sociodemographic groups. Results suggest relatively superficial knowledge regarding radon, and little testing, within the survey population. Significantly less knowledge was observed among female and…

RADON GENERATION AND TRANSPORT THROUGH CONCRETE FOUNDATIONS

EPA Science Inventory

The report gives results of an examination of radon generation and transport through Florida residential concretes for their contribution to indoor radon concentrations. Radium concentrations in the 11 concretes tested were all <2.5 pCi/g and radon emanation coefficients were all...

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

NASA Astrophysics Data System (ADS)

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

2017-11-01

We analyze in this paper a Waste Water Pre-Treatment Plant (WWTP) located at the Mediterranean coast with air radon concentration above Spanish action level (600 Bq per cubic meter). This paper presents a method for radon equilibrium determination by gamma spectrometry measuring of the radon progeny concentrations in the air, in order to estimate WWTP workers effective dose more exactly. The method is based on simultaneous sampling of air through a filter paper and alpha spectrometry measurement of radon activity concentration in the air. According to the measured radon activity concentration in the air of 368±45 Bq/m3 the equilibrium factor between radon and progenies is estimated to be F=0.27, which is in good agreement with expected values.

Construction and measurements of an improved vacuum-swing-adsorption radon-mitigation system

NASA Astrophysics Data System (ADS)

Street, J.; Bunker, R.; Dunagan, C.; Loose, X.; Schnee, R. W.; Stark, M.; Sundarnath, K.; Tronstad, D.

2015-08-01

In order to reduce backgrounds from radon-daughter plate-out onto detector surfaces, an ultra-low-radon cleanroom is being commissioned at the South Dakota School of Mines and Technology. An improved vacuum-swing-adsorption radon mitigation system and cleanroom build upon a previous design implemented at Syracuse University that achieved radon levels of ˜0.2 Bq m-3. This improved system will employ a better pump and larger carbon beds feeding a redesigned cleanroom with an internal HVAC unit and aged water for humidification. With the rebuilt (original) radon mitigation system, the new low-radon cleanroom has already achieved a > 300× reduction from an input activity of 58.6 ± 0.7 Bq m-3 to a cleanroom activity of 0.13 ± 0.06 Bq m-3.

Incidence rates of chronic lymphocytic leukemia in US states are associated with residential radon levels.

PubMed

Schwartz, Gary G; Klug, Marilyn G

2016-01-01

Environmental risk factors for chronic lymphocytic leukemia (CLL) have not been consistently identified. An etiologic role for ionizing radiation in CLL is controversial. Because most of the ionizing radiation to which individuals are exposed comes from radon at home, we examined CLL incidence rates in relation to residential radon levels. We used population-based rates for CLL for US states from 2007 to 2011 and measurements of residential radon made by the US Environmental Protection Agency. Incidence rates for CLL were significantly correlated with residential radon levels among whites (both genders together and each gender separately; p < 0.005) and among blacks (p < 0.05). We speculate that radon increases CLL risk and that the mechanisms may be similar to those by which radon causes lung cancer.

A tentative protocol for measurement of radon availability from the ground

USGS Publications Warehouse

Tanner, A.B.

1988-01-01

A procedure is being tested in order to determine its suitability for assessing the intrinsic ability of the ground at a particular site to supply radon (222Rn) to a basement structure to be built on the site. The mean migration distance, multiplied by the measured radon concentration gives the "Radon Availability Number' (RAN). Measurements at sites of known indoor radon concentration suggest that RANs below 2 kBq/m2 (5x104 pCi/m2) indicate little chance of elevated indoor radon and RANs above 20 kBq/m2 (5x105 pCi/m2) indicate that elevated indoor radon is likely. The range of uncertainty and the point-to-point and seasonal variations to be expected are under investigation. -from Author

Four passive sampling elements (quatrefoil)--II. Film badges for monitoring radon and its progeny.

PubMed

Tommasino, L; Tokonami, S

2011-05-01

The four passive samplers (quatrefoil) already described in a parallel paper, make it possible to obtain thin radiation sources, useful for alpha and beta counting by any passive and real-time detector. In the present paper, the applications of this quatrefoil for measuring radon gas by etch-track detectors will be described. In the case of radon measurements, different solids have been identified, with radon-sorption partition coefficients related to air from 1 to 2000. Uniquely compact radon badges can be obtained by using a layer of these solids facing an alpha track-etch detector. These radon badges make it possible to overcome most of the shortcomings of existing passive monitors. Moreover, these badges show promise for studying the radon solubility of polymer films.

Indoor radon regulation using tabulated values of temporal radon variation.

PubMed

Tsapalov, Andrey; Kovler, Konstantin

2018-03-01

Mass measurements of indoor radon concentrations have been conducted for about 30 years. In most of the countries, a national reference/action/limit level is adopted, limiting the annual average indoor radon (AAIR) concentration. However, until now, there is no single and generally accepted international protocol for determining the AAIR with a known confidence interval, based on measurements of different durations. Obviously, as the duration of measurements increases, the uncertainty of the AAIR estimation decreases. The lack of the information about the confidence interval of the determined AAIR level does not allow correct comparison with the radon reference level. This greatly complicates development of an effective indoor radon measurement protocol and strategy. The paper proposes a general principle of indoor radon regulation, based on the simple criteria widely used in metrology, and introduces a new parameter - coefficient of temporal radon variation K V (t) that depends on the measurement duration and determines the uncertainty of the AAIR. An algorithm for determining K V (t) based on the results of annual continuous radon monitoring in experimental rooms is proposed. Included are indoor radon activity concentrations and equilibrium equivalent concentration (EEC) of radon progeny. The monitoring was conducted in 10 selected experimental rooms located in 7 buildings, mainly in the Moscow region (Russia), from 2006 to 2013. The experimental and tabulated values of K V (t) and also the values of the coefficient of temporal EEC variation depending on the mode and duration of the measurements were obtained. The recommendations to improve the efficiency and reliability of indoor radon regulation are given. The importance of taking into account the geological factors is discussed. The representativity of the results of the study is estimated and the approach for their verification is proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intercomparison of active, passive and continuous instruments for radon and radon progeny measurements in the EML chamber and test facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scarpitta, S.C.; Tu, K.W.; Fisenne, I.M.

1996-10-01

Results are presented from the Fifth Intercomparison of Active, Passive and Continuous Instruments for Radon and Radon Progeny Measurements conducted in the EML radon exposure and test facility in May 1996. In total, thirty-four government, private and academic facilities participated in the exercise with over 170 passive and electronic devices exposed in the EML test chamber. During the first week of the exercise, passive and continuous measuring devices were exposed (usually in quadruplicate) to about 1,280 Bq m{sup {minus}3} {sup 222}Rn for 1--7 days. Radon progeny measurements were made during the second week of the exercise. The results indicate thatmore » all of the tested devices that measure radon gas performed well and fulfill their intended purpose. The grand mean (GM) ratio of the participants` reported values to the EML values, for all four radon device categories, was 0.99 {plus_minus} 0.08. Eighty-five percent of all the radon measuring devices that were exposed in the EML radon test chamber were within {plus_minus}1 standard deviation (SD) of the EML reference values. For the most part, radon progeny measurements were also quite good as compared to the EML values. The GM ratio for the 10 continuous PAEC instruments was 0.90 {plus_minus} 0.12 with 75% of the devices within 1 SD of the EML reference values. Most of the continuous and integrating electronic instruments used for measuring the PAEC underestimated the EML values by about 10--15% probably because the concentration of particles onto which the radon progeny were attached was low (1,200--3,800 particles cm{sup {minus}3}). The equilibrium factor at that particle concentration level was 0.10--0.22.« less

Protective effects of hot spring water drinking and radon inhalation on ethanol-induced gastric mucosal injury in mice.

PubMed

Etani, Reo; Kataoka, Takahiro; Kanzaki, Norie; Sakoda, Akihiro; Tanaka, Hiroshi; Ishimori, Yuu; Mitsunobu, Fumihiro; Taguchi, Takehito; Yamaoka, Kiyonori

2017-09-01

Radon therapy using radon (222Rn) gas is classified into two types of treatment: inhalation of radon gas and drinking water containing radon. Although short- or long-term intake of spa water is effective in increasing gastric mucosal blood flow, and spa water therapy is useful for treating chronic gastritis and gastric ulcer, the underlying mechanisms for and precise effects of radon protection against mucosal injury are unclear. In the present study, we examined the protective effects of hot spring water drinking and radon inhalation on ethanol-induced gastric mucosal injury in mice. Mice inhaled radon at a concentration of 2000 Bq/m3 for 24 h or were provided with hot spring water for 2 weeks. The activity density of 222Rn ranged from 663 Bq/l (start point of supplying) to 100 Bq/l (end point of supplying). Mice were then orally administered ethanol at three concentrations. The ulcer index (UI), an indicator of mucosal injury, increased in response to the administration of ethanol; however, treatment with either radon inhalation or hot spring water inhibited the elevation in the UI due to ethanol. Although no significant differences in antioxidative enzymes were observed between the radon-treated groups and the non-treated control groups, lipid peroxide levels were significantly lower in the stomachs of mice pre-treated with radon or hot spring water. These results suggest that hot spring water drinking and radon inhalation inhibit ethanol-induced gastric mucosal injury. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

A model to predict radon exhalation from walls to indoor air based on the exhalation from building material samples.

PubMed

Sahoo, B K; Sapra, B K; Gaware, J J; Kanse, S D; Mayya, Y S

2011-06-01

In recognition of the fact that building materials are an important source of indoor radon, second only to soil, surface radon exhalation fluxes have been extensively measured from the samples of these materials. Based on this flux data, several researchers have attempted to predict the inhalation dose attributable to radon emitted from walls and ceilings made up of these materials. However, an important aspect not considered in this methodology is the enhancement of the radon flux from the wall or the ceiling constructed using the same building material. This enhancement occurs mainly because of the change in the radon diffusion process from the former to the latter configuration. To predict the true radon flux from the wall based on the flux data of building material samples, we now propose a semi-empirical model involving radon diffusion length and the physical dimensions of the samples as well as wall thickness as other input parameters. This model has been established by statistically fitting the ratio of the solution to radon diffusion equations for the cases of three-dimensional cuboidal shaped building materials (such as brick, concrete block) and one dimensional wall system to a simple mathematical function. The model predictions have been validated against the measurements made at a new construction site. This model provides an alternative tool (substitute to conventional 1-D model) to estimate radon flux from a wall without relying on ²²⁶Ra content, radon emanation factor and bulk density of the samples. Moreover, it may be very useful in the context of developing building codes for radon regulation in new buildings. Copyright © 2011 Elsevier B.V. All rights reserved.

Concentration en radon dans une maison du Calvados

NASA Astrophysics Data System (ADS)

Leleyter, Lydia; Riffault, Benoit; Mazenc, Bernard

2010-03-01

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

Radon in ground water of the Lower Susqehanna and Potomac River basins

USGS Publications Warehouse

Lindsey, Bruce D.; Ator, Scott W.

1996-01-01

Ground-water samples collected from 267 wells were analyzed for radon as part of a water-quality reconnaissance of subunits of the Lower Susquehanna and Potomac River Basins conducted by the United States Geological Survey (USGS) as part of the National Water-Quality Assessment (NAWQA) program. Radon is a product of the radioactive decay of uranium. Airborne radon has been cited by the Surgeon General of the United States as the second-leading cause of lung cancer and the United States Environmental Protection Agency (USEPA) has identified ground-water supplies as possible contributing sources of indoor radon. Eighty percent of ground-water samples collected for this study were found to contain radon at activities greater than 300 pCi/L (picocuries per liter), the USEPA's proposed Maximum Contaminant Level for radon in drinking water, and 31 percent of samples contained radon at activities greater than 1,000 pCi/L. The 10 subunits where samples were collected were grouped into three classes - median ground-water radon activity less than 300 pCi/L, between 300 pCi/L and 1,000 pCi/L, and greater than 1,000 pCi/L. Subunits underlain by igneous and metamorphic rocks of the Piedmont Physiographic Province typically have the highest median ground-water radon activities (greater than 1,000 pCi/L); although there is a large variation in radon activities within most of the subunits. Lower median radon activities (between 300 pCi/L and 1,000 pCi/L) were found in ground water in subunits underlain by limestone and dolomite. Of three subunits underlain by sandstone and shale, one fell into each of the three radon-activity classes. The large variability within these subunits may be attributed to the fact that the uranium content of sandstone and shale is related to the uranium content of the sediments from which they formed.

Implications of alteration processes on radon emanation, radon production rate and W-Sn exploration in the Panasqueira ore district.

PubMed

Domingos, Filipa; Pereira, Alcides

2018-05-01

Alteration processes have strong impacts on the chemical and physical properties of rock masses. Because they can affect the contents and the distribution of U as well as enhance the permeability of the bedrock, they may lead to a significant increase of radon release to the environment. However, their influence on radon emanation and radon production rate has yet to be properly assessed. To investigate the impact of alteration processes on the radiological properties, samples were collected in the Panasqueira region under the influence of surface weathering, deuteric, hydrothermal and fault related alteration. Major and trace elements (U, Th), physical, and radiological properties were measured in metasedimentary and fault rocks. The degree of alteration and weathering progress were assessed through indices of alteration, porosity and bulk density. Overall, an increase of the radon emanation coefficient from (approximately) 0.1 to 0.4 and radon production rate (from 40 to over 160Bq·m -3 ·h -1 ) is observed with the progress of physicochemical alteration. Decoupling of physical and chemical alteration however implies both must be quantified towards a proper assessment of the degree of alteration. The behavior of radiogenic elements upon alteration is shown to be complex and contingent upon the alteration process. An atypical increase of radon emanation in the ore district due to U mobilization was caused by hydrothermal alteration. Because radon emanation is not dependent upon the pelitic nature of the metasedimentary rocks, it may thus become a proxy for W-Sn exploration. The dependency of radon production rate from the latter constrains its use for exploration. Nevertheless, it may provide a reliable estimation of the bedrock contribution to indoor radon concentrations. Higher indoor radon concentrations, hence, a higher risk of exposure to radon are expected in the ore district as well as within fault zones. Copyright © 2017 Elsevier B.V. All rights reserved.

Radon Guide for Tenants

EPA Pesticide Factsheets

This guide is for people who rent their apartments or houses. The guide explains what radon is, and how to find out if there is a radon problem in your home. The guide also talks about what you can do if there are high radon levels in your home.

Protecting People and Families from Radon: A Federal Action Plan for Saving Lives

EPA Pesticide Factsheets

This strategy for radon action outlines actions federal agencies can take within existing resources and program capacities to advance the Healthy People 2020 radon objectives and launch a national effort to end all avoidable radon-induced lung cancer death

SITE-SPECIFIC PROTOCOL FOR MEASURING SOIL RADON POTENTIALS FOR FLORIDA HOUSES

EPA Science Inventory

The report describes a protocol for site-specific measurement of radon potentials for Florida houses that is consistent with existing residential radon protection maps. The protocol gives further guidance on the possible need for radon-protective house construction features. In a...

Diurnal variations of radon and thoron activity concentrations and effective doses in dwellings in Niška Banja, Serbia.

PubMed

Vaupotič, J; Streil, T; Tokonami, S; Žunic, Z S

2013-12-01

In Niška Banja, a spa town in a radon-prone area in southern Serbia, radon ((222)Rn) and thoron ((220)Rn) activity concentrations were measured continuously for one day in indoor air of 10 dwellings with a SARAD RTM 2010-2 Radon/Thoron Monitor, and equilibrium factor between radon and its decay products and the fraction of unattached radon decay products with a SARAD EQF 3020-2 Equilibrium Factor Monitor. Radon concentration in winter time ranged from 26 to 73 100 Bq m(-3) and that of thoron, from 10 to 8650 Bq m(-3). In the same period, equilibrium factor and the unattached fraction varied in the range of 0.08 to 0.90 and 0.01 to 0.27, respectively. One-day effective doses were calculated and were in winter conditions from 4 to 2599 μSv d(-1) for radon and from 0.2 to 73 μSv d(-1) for thoron.

An assessment of radon in groundwater in New York State

USGS Publications Warehouse

Shaw, Stephen B.; Eckhardt, David A.V.

2012-01-01

Abstract: A set of 317 samples collected from wells throughout New York State (excluding Long Island) from 2003 through 2008 was used to assess the distribution of radon gas in drinking water. Previous studies have documented high concentrations of radon in groundwater from granitic and metamorphic bedrock, but there have been only limited characterizations of radon in water from sedimentary rock and unconsolidated sand-and-gravel deposits in New York. Approximately 8% of the samples from bedrock wells exceed 89 Bq L-1 (eight times the proposed regulatory limit), but only 2% of samples from sand-and-gravel wells exceed 44 Bq L-1. Specific metamorphic and sedimentary rock formations in New York are associated with the high radon concentrations, indicating that specific areas of New York could be targeted with efforts to reduce the risk of exposure to radon in groundwater. Additionally, radon in groundwater from the sand-and-gravel aquifers was found to be directly correlated to radon in indoor air when assessed by county.

Radon inhalation protects mice from carbon-tetrachloride-induced hepatic and renal damage.

PubMed

Kataoka, Takahiro; Nishiyama, Yuichi; Toyota, Teruaki; Yoshimoto, Masaaki; Sakoda, Akihiro; Ishimori, Yuu; Aoyama, Yutaka; Taguchi, Takehito; Yamaoka, Kiyonori

2011-12-01

We assessed whether radon inhalation provided protection from carbon tetrachloride (CCl4)-induced hepatic and renal damage in mice. Mice were subjected to intraperitoneal injection of CCl4 after inhaling approximately 18 kBq/m3 radon for 6 h. Radon inhalation significantly increased total glutathione (t-GSH) content and glutathione peroxidase (GPx) activity in the liver and kidney. Injection of CCl4 was associated with significantly higher levels of glutamic oxaloacetic transaminase (GOT) and alkaline phosphatase (ALP) activity and creatinine level in serum, and pretreatment with radon significantly decreased the GOT and ALP activity and creatinine level associated with CCl4 injection, suggesting that radon inhalation alleviates CCl4-induced hepatic and renal damage. The t-GSH contents and GPx activity in the liver and kidney of animals pretreated with radon were significantly higher than those of the CCl(4)-only group. These findings suggested that radon inhalation activated antioxidative functions and inhibited CCl4-induced hepatic and renal damage in mice.

The Therapeutic use of Radon: A Biomedical Treatment in Europe; An “Alternative” Remedy in the United States

PubMed Central

Erickson, Barbra E.

2007-01-01

There is a growing recognition in the United States and Europe that health care is driven to a significant extent by an emphasis on consumer choice and demand. As consumers, people regularly choose their own solutions for health promotion and maintenance, solutions which may or may not be sanctioned by mainstream medicine. Radioactive radon therapy exemplifies a non-sanctioned treatment eagerly sought by certain patients, but scorned or dismissed by many physicians. This is certainly the case in the United States, where well-publicized Environmental Protection Agency (EPA) warnings portray radon as a potential carcinogen. Between 1997 and 2001, I worked with a population of arthritis sufferers who expose themselves to radon gas in Montana radon health mines in order to alleviate their symptoms. In this paper I discuss the decision-making process involved in using radon, and compare the Montana radon health mine facilities with selected radon mines and spas in Europe. PMID:18648554

A Critical Analysis of Changing Radon Concentration Patterns on Gyokusen-dou Cave in Okinawa Island

NASA Astrophysics Data System (ADS)

Tanahara, A.; Iha, H.

2009-04-01

Radon concentrations were measured at 1 hour intervals for a year in Gyokuse-dou Cave, Okinawa Island. An apparatus for continuous radon monitoring connected to a data logger was installed in a large chamber of the cave along the tour route for visitors. Radon concentration ranged from 8000 Bq/m3 in the summer to 100 Bq/m3 in the winter. Seasonal changes in radon concentration correlate with difference between outside and inside air densities. The same effect seems to occur in a short time period. However, changing radon concentration pattern does not synchronize with air density difference pattern in the sites. The results of statistical treatment show that the outside air takes about 8-18 hours to reach the measuring point of radon in the Cave. The average airflow velocity from the site to the exit was estimated to be about 0.52-0.23 m/min. During the summer, the south wind blowing into the cave also affects the radon concentration.

Geochemical Characteristics of Aquifer system in Taichung Area, Central Taiwan

NASA Astrophysics Data System (ADS)

Tsai, Jui-Fen; Chen, Cheng-Hong; Liu, Tsung-Kwei

2016-04-01

For understanding the relationship between water bodies and host rocks and getting more information for groundwater in Taichung area, Central Taiwan, we systematically analyzed the stable isotopes (hydrogen and oxygen), helium isotopes and radon concentrations of dissolved gases from 54 groundwater, 39 river and 4 rain samples collected from Taichung Basin in wet and dry seasons of the year 2015. In the δ18O vs. δD plot, all samples present a linear trend similar to local meteoric water, indicating a meteoric origin. However, river samples are relative lighter than rain samples, it appears that the rivers are mainly recharged from precipitation of high-elevation areas with a lighter isotopic composition. Because the seasonal isotopic variation of river samples is significant, we calculated relative contribution of precipitation by seasons using the mass balance equation. Results show that the precipitation in the rainy season is the major source of groundwater. The helium isotopic ratio in dissolved gases of most groundwater samples are close to 1 RA (RA = 3He/4He ratio of air), except the sample from Wu-Feng well that exhibits 0.3 RA. This sample also has an older C-14 age (˜27000 yrs.) than others (<200 yrs.), implying that the dissolved helium is likely affected by radiogenic 4He of surrounding rocks. The average concentration of radon for groundwater in the northern section of Taichung Basin is 20.3 Bq/L, which is higher than that of the southern section (14.5 Bq/L). Variations of radon concentrations in the two sections may be related to the different drainage systems (Paleo-Dajia River vs. Wu River), in which sediments from Paleo-Dajia River may contain higher uranium concentrations. On the other hand, water in rivers usually contains undetectable radon (<0.37 Bq/L) because it rapidly escapes to the atmosphere. However, river samples from the central part of basin have radon concentrations ranging between 1 and 3 Bq/L, reflecting that the sampling sites are in the vicinity of points of groundwater inflow. This study illustrates the utility of hydrogen and oxygen isotopes to trace the groundwater source and determine the seasonal contribution ratios of precipitation to groundwater recharge, and demonstrates the advantage of using dissolved gas to investigate the groundwater-host rocks interaction. Key words: Central Taiwan, groundwater, dissolved gas, helium isotope, hydrogen and oxygen isotopes, water radon

Radon in the soil air of Estonia.

PubMed

Petersell, Valter; Täht-Kok, Krista; Karimov, Mark; Milvek, Heli; Nirgi, Siim; Raha, Margus; Saarik, Krista

2017-01-01

Several investigations in Estonia during 1996¬-1999 have shown that permissible level (200 Bq/m 3 ) of radon (222Rn) in indoor air is exceeded in 33% of the inspected dwellings. This makes Estonia one of the five countries with highest radon risk in Europe (Fig 1). Due to correlation between the soil radon risk level and radon concentration in houses, small scale radon risk mapping of soil air was carried out (one study point per 70-100 km 2 ). It turned out that one-third of Estonian mainland has high radon risk potential, where radon concentration in soil air exceeds safe limit of 50 kBq/m 3 . In order to estimate radon content in soil air, two different methods developed in Sweden were used simultaneously. Besides measuring radon content from soil air at the depth of 80 cm with an emanometer (RnM), maximum potential content of radon in soil (RnG) was estimated based on the rate of eU (226Ra) concentration in soil, which was acquired by using gamma-ray spectrometer. Mapping and following studies revealed that simultaneously measured RnG and RnM in study points may often differ. To inspect the cause, several monitoring points were set up in places with different geological conditions. It appeared that unlike the RnG content, which remains close to average level in repeated measurements, the RnM content may differ more than three times periodically. After continuous observations it turned out that concentration of directly measured radon depended on various factors being mostly controlled by mineral composition of soil, properties of topsoil as well as different factors influencing aeration of soil. The results of Rn monitoring show that reliable level of radon risk in Estonian soils can only be acquired by using calculated Rn-concentration in soil air based on eU content and directly measured radon content of soil air in combination with interpreting specific geological and geochemical situations in the study points. Copyright © 2016 Elsevier Ltd. All rights reserved.

Estimating the burden of lung cancer and the efficiency of home radon mitigation systems in some Canadian provinces.

PubMed

Al-Arydah, Mo'tassem

2018-06-01

Lung cancer (LC) is the leading cause of death of cancer in Canada in both men and women, and indoor radon is the second leading cause of LC after tobacco smoking. The Population Attributable Risk (PAR) is used to assess radon exposure risk. In this work we estimate the burden of LC in some Canadian provinces. We use the PAR to identify the radon levels responsible for most LC cases. Finally, we use the PAR function of the two variables, radon action and target levels, to search for a possible optimal mitigation program. The LC burden for Ontario, Alberta, Manitoba, Quebec and British Columbia was estimated using provincial radon and mortality data. Then the PAR and LC cases for these provinces were estimated over the period 2006-2009 at different given indoor radon exposure levels. Finally, the PAR function when radon action levels and radon target levels are variables was analyzed. The highest burden of LC in 2006-2009 was in Ontario and Quebec. During the period 2006-2009, 6% of houses in Ontario, 9% of houses in Alberta, 19% of houses in Manitoba, 7% of houses in Quebec, and 5% of houses in British Columbia had radon levels higher than 200 Bq/m 3 and were responsible about 913, 211, 260, 972, and 258 lives, respectively. Radon mitigation programs could have prevented these LC cases. The BEIR VI assumption for the United States (US) population, 95% of LC deaths in men and 90% of LC deaths in women are Ever-Smokers (ES), can be applied to the Canadian population. The PAR is a linear function in the target radon value with an estimated slope of 0.0001 for Ontario, Alberta, Quebec and British Columbia, and 0.0004 for Manitoba. The PAR is almost a square root function in the radon action level. The PAR is sensitive to changes in the radon mitigation program and as such, any improvement is a worthwhile investment. Copyright © 2018 Elsevier B.V. All rights reserved.

Real-time measurements of radon activity with the Timepix-based RADONLITE and RADONPIX detectors

NASA Astrophysics Data System (ADS)

Caresana, M.; Garlati, L.; Murtas, F.; Romano, S.; Severino, C. T.; Silari, M.

2014-11-01

Radon gas is the most important source of ionizing radiation among those of natural origin. Two new systems for radon measurement based on the Timepix silicon detector were developed. The positively charged radon daughters are electrostatically collected on the surface of the Si detector and their energy spectrum measured. Pattern recognition of the tracks on the sensor and particle identification are used to determine number and energy of the alpha particles and to subtract the background, allowing for efficient radon detection. The systems include an algorithm for real-time measurement of the radon concentration and the calculation of the effective dose to the lungs.

Radon Diffusion Measurement in Polyethylene based on Alpha Detection

NASA Astrophysics Data System (ADS)

Rau, Wolfgang

2011-04-01

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

Soil features and indoor radon concentration prediction: radon in soil gas, pedology, permeability and 226Ra content.

PubMed

Lara, E; Rocha, Z; Santos, T O; Rios, F J; Oliveira, A H

2015-11-01

This work aims at relating some physicochemical features of soils and their use as a tool for prediction of indoor radon concentrations of the Metropolitan Region of Belo Horizonte (RMBH), Minas Gerais, Brazil. The measurements of soil gas radon concentrations were performed by using an AlphaGUARD monitor. The (226)Ra content analysis was performed by gamma spectrometry (high pure germanium) and permeabilities were performed by using the RADON-JOK permeameter. The GEORP indicator and soil radon index (RI) were also calculated. Approximately 53 % of the Perferric Red Latosols measurement site could be classified as 'high risk' (Swedish criteria). The Litholic Neosols presented the lowest radon concentration mean in soil gas. The Perferric Red Latosols presented significantly high radon concentration mean in soil gas (60.6 ± 8.7 kBq m(-3)), high indoor radon concentration, high RI, (226)Ra content and GEORP. The preliminary results may indicate an influence of iron formations present very close to the Perferric Red Latosols in the retention of uranium minerals. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Measurements of radon activity concentration in mouse tissues and organs.

PubMed

Ishimori, Yuu; Tanaka, Hiroshi; Sakoda, Akihiro; Kataoka, Takahiro; Yamaoka, Kiyonori; Mitsunobu, Fumihiro

2017-05-01

The purpose of this study is to investigate the biokinetics of inhaled radon, radon activity concentrations in mouse tissues and organs were determined after mice had been exposed to about 1 MBq/m 3 of radon in air. Radon activity concentrations in mouse blood and in other tissues and organs were measured with a liquid scintillation counter and with a well-type HP Ge detector, respectively. Radon activity concentration in mouse blood was 0.410 ± 0.016 Bq/g when saturated with 1 MBq/m 3 of radon activity concentration in air. In addition, average partition coefficients obtained were 0.74 ± 0.19 for liver, 0.46 ± 0.13 for muscle, 9.09 ± 0.49 for adipose tissue, and 0.22 ± 0.04 for other organs. With these results, a value of 0.414 for the blood-to-air partition coefficient was calculated by means of our physiologically based pharmacokinetic model. The time variation of radon activity concentration in mouse blood during exposure to radon was also calculated. All results are compared in detail with those found in the literature.

Annual variation in the atmospheric radon concentration in Japan.

PubMed

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

2015-08-01

Anomalous atmospheric variations in radon related to earthquakes have been observed in hourly exhaust-monitoring data from radioisotope institutes in Japan. The extraction of seismic anomalous radon variations would be greatly aided by understanding the normal pattern of variation in radon concentrations. Using atmospheric daily minimum radon concentration data from five sampling sites, we show that a sinusoidal regression curve can be fitted to the data. In addition, we identify areas where the atmospheric radon variation is significantly affected by the variation in atmospheric turbulence and the onshore-offshore pattern of Asian monsoons. Furthermore, by comparing the sinusoidal regression curve for the normal annual (seasonal) variations at the five sites to the sinusoidal regression curve for a previously published dataset of radon values at the five Japanese prefectures, we can estimate the normal annual variation pattern. By fitting sinusoidal regression curves to the previously published dataset containing sites in all Japanese prefectures, we find that 72% of the Japanese prefectures satisfy the requirements of the sinusoidal regression curve pattern. Using the normal annual variation pattern of atmospheric daily minimum radon concentration data, these prefectures are suitable areas for obtaining anomalous radon variations related to earthquakes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Suppression of dextran sulfate sodium-induced colitis in mice by radon inhalation.

PubMed

Nishiyama, Yuichi; Kataoka, Takahiro; Yamato, Keiko; Taguchi, Takehito; Yamaoka, Kiyonori

2012-01-01

The enhanced release of reactive oxygen species from activated neutrophils plays important role in the pathogenesis of inflammatory bowel disease. We previously reported that radon inhalation activates antioxidative functions in various organs of mice. In this study, we examined the protective effects of radon inhalation on dextran sulfate sodium- (DSS) induced colitis in mice which were subjected to DSS for 7 days. Mice were continuously treated with air only (sham) or radon at a concentration of 2000 Bq/m³ from a day before DSS administration to the end of colitis induction. In the results, radon inhalation suppressed the elevation of the disease activity index score and histological damage score induced by DSS. Based on the changes in tumor necrosis factor-alpha in plasma and myeloperoxidase activity in the colon, it was shown that radon inhalation suppressed DSS-induced colonic inflammation. Moreover, radon inhalation suppressed lipid peroxidation of the colon induced by DSS. The antioxidant level (superoxide dismutase and total glutathione) in the colon after DSS administration was significantly higher in mice treated with radon than with the sham. These results suggested that radon inhalation suppressed DSS-induced colitis through the enhancement of antioxidative functions in the colon.

Suppression of Dextran Sulfate Sodium-Induced Colitis in Mice by Radon Inhalation

PubMed Central

Nishiyama, Yuichi; Kataoka, Takahiro; Yamato, Keiko; Taguchi, Takehito; Yamaoka, Kiyonori

2012-01-01

The enhanced release of reactive oxygen species from activated neutrophils plays important role in the pathogenesis of inflammatory bowel disease. We previously reported that radon inhalation activates antioxidative functions in various organs of mice. In this study, we examined the protective effects of radon inhalation on dextran sulfate sodium- (DSS) induced colitis in mice which were subjected to DSS for 7 days. Mice were continuously treated with air only (sham) or radon at a concentration of 2000 Bq/m3 from a day before DSS administration to the end of colitis induction. In the results, radon inhalation suppressed the elevation of the disease activity index score and histological damage score induced by DSS. Based on the changes in tumor necrosis factor-alpha in plasma and myeloperoxidase activity in the colon, it was shown that radon inhalation suppressed DSS-induced colonic inflammation. Moreover, radon inhalation suppressed lipid peroxidation of the colon induced by DSS. The antioxidant level (superoxide dismutase and total glutathione) in the colon after DSS administration was significantly higher in mice treated with radon than with the sham. These results suggested that radon inhalation suppressed DSS-induced colitis through the enhancement of antioxidative functions in the colon. PMID:23365486

Evaluation and equity audit of the domestic radon programme in England.

PubMed

Zhang, Wei; Chow, Yimmy; Meara, Jill; Green, Martyn

2011-09-01

The U.K. has a radon programme to limit the radon risk to health. This involves advice on protective measures in new buildings, technical guidance on their installation, encouragement of radon measurements and remediation in existing dwellings in high radon areas. We have audited the radon programme at the level of individual homes to identify factors that influence the likelihood of remediation. 49% of the householders responded to our survey and 30% of the respondents stated that they had done some remediation to reduce the indoor radon levels. We found that householders with higher incomes and higher socio-economic status are more likely than others to remediate. Householders are less likely to remediate if they have one of the following: living in a property with a high radon concentration, current smokers in the dwelling, being unemployed or an unskilled worker, long length of time living in that property or elderly (65+ years) living by themselves. Householders appeared to be more likely to remediate if they considered the information on radon and its risk to be very clear and useful. This emphasises the importance of communication with householders. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Estimation of the indoor radon and the annual effective dose from granite samples

NASA Astrophysics Data System (ADS)

Sola, P.; Srinuttrakul, W.; Kewsuwan, P.

2015-05-01

Inhalation of radon and thoron daughters increases the risk of lung cancer. The main sources of indoor radon are building materials. The aim of this research is to estimate the indoor radon and the annual effective dose from the building materials. Eighteen granite samples bought from the markets in Thailand were measured using an ionization chamber (ATMOS 12 DPX) for the radon concentration in air. Radon exhalation rates were calculated from the radon concentration in chamber. The indoor radon from the granite samples ranged from 10.04 to 55.32 Bq·m-2·h-1 with an average value of 20.30 Bq·m-2·h-1 and the annual effective dose ranged from 0.25 to 1.39 mSv·y-1 with an average value of 0.48 mSv·y-1. The results showed that the annual effective doses of three granite samples were higher than the annual exposure limit for the general public (1 mSv·y-1) recommended by the International Commission on Radiological Protection (ICRP). In addition, the relationship between the colours and radon exhalation rates of granite samples was also explained.

Pulsed excitation terahertz tomography - multiparametric approach

NASA Astrophysics Data System (ADS)

Lopato, Przemyslaw

2018-04-01

This article deals with pulsed excitation terahertz computed tomography (THz CT). Opposite to x-ray CT, where just a single value (pixel) is obtained, in case of pulsed THz CT the time signal is acquired for each position. Recorded waveform can be parametrized - many features carrying various information about examined structure can be calculated. Based on this, multiparametric reconstruction algorithm was proposed: inverse Radon transform based reconstruction is applied for each parameter and then fusion of results is utilized. Performance of the proposed imaging scheme was experimentally verified using dielectric phantoms.

RESOLVING THE RADON PROBLEM IN CLINTON, NEW JERSEY HOUSES

EPA Science Inventory

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

STATEWIDE MAPPING OF FLORIDA SOIL RADON POTENTIALS VOLUME 2. APPENDICES A-P

EPA Science Inventory

The report gives results of a statewide mapping of Florida soil radon potentials. Statewide maps identify Florida Regions with different levels of soil radon potential. The maps provide scientific estimates of regional radon potentials that can serve as a basis for implementing r...

DEVELOPMENT OF A RADON PROTECTION MAP FOR LARGE BUILDINGS IN FLORIDA

EPA Science Inventory

The report discusses the development of a radon protection map to show from soil and geological features the areas of Florida that require different levels of Radon protection for large building construction. The map was proposed as a basis for implementing radon-protective const...

STATEWIDE MAPPING OF FLORIDA SOIL RADON POTENTIALS VOLUME 1. TECHNICAL REPORT

EPA Science Inventory

The report gives results of a statewide mapping of Florida soil radon potentials. Statewide maps identify Florida Regions with different levels of soil radon potential. The maps provide scientific estimates of regional radon potentials that can serve as a basis for implementing r...

COST AND EFFECTIVENESS OF RADON RESISTANT FEATURES IN NEW SCHOOL BUILDINGS

EPA Science Inventory

The paper describes initial results of a study of several schools with radon resistant features that were recently constructed in the northeastern U. S. hese designs generally are based on experience with radon mitigation in existing houses and schools and radon- resistant new co...

Consumer's Guide to Radon Reduction: How to Fix Your Home

EPA Pesticide Factsheets

Radon is the leading cause of lung cancer for non-smokers and the second leading cause of lung cancer for the general population. Learn more about testing your home for radon, and how to select a contractor if you have high levels of radon present.

SOIL RADON POTENTIAL MAPPLING OF TWELVE COUNTIES IN NORTH-CENTRAL FLORIDA

EPA Science Inventory

The report describes the approach, methods, and detailed data used to prepare soil radon potential maps of 12 counties in North-Central Florida. he maps were developed under the Florida Radon Research Program to provide a scientific basis for implementing radon-protective buildin...

Radon exhalation rates from some soil samples of Kharar, Punjab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mehta, Vimal; Deptt of Physics, Punjabi University, Patiala- 147 001; Singh, Tejinder Pal, E-mail: tejinders03@gmail.com

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

Indoor residential radon exposure and risk of childhood acute myeloid leukaemia

PubMed Central

Steinbuch, M; Weinberg, C R; Buckley, J D; Robison, L L; Sandler, D P

1999-01-01

Exposure to radon has been identified as a risk factor for lung cancer in uranium miners, but evidence of adverse health effects due to indoor radon exposure is inconsistent. Ecological studies have suggested a correlation between indoor radon levels and leukaemia incidence. We evaluated the risk associated with indoor residential radon exposure within a larger interview-based case–control study of risk factors for childhood acute myeloid leukaemia (AML). A total of 173 cases and 254 controls met the eligibility criteria, and information was collected through telephone interviews with parents and analysis of alpha-track radon detectors placed in the home for a period of 1 year. No association was observed between radon exposure and risk of AML, with adjusted odds ratios of 1.2 (95% confidence interval (CI) 0.7–1.8) for 37–100 Bq m–3 and 1.1 (95% CI 0.6–2.0) for > 100 Bq m–3 compared with < 37 Bq m–3. Although there was an inverse association between radon level and AML risk among children < 2 years at diagnosis, among children ≥2 years, AML risk was increased among those with higher radon exposure. The observed association after age 2 is most likely due to chance. Overall, there was no association between residential radon and risk of childhood AML. © 1999 Cancer Research Campaign PMID:10555766

Radon testing in rapid access lung clinics: an opportunity for secondary prevention.

PubMed

Smyth, R; Long, S; Wiseman, E; Sharpe, D; Breen, D; O'Regan, A

2017-05-01

Radon is a naturally occurring radioactive gas and a level 1 carcinogen. It acts synergistically with cigarette smoke to cause lung cancer. In Ireland, radon is estimated to be associated with 13 % of all lung cancers. Rapid access lung cancer clinics (RALC's) were established in the UK and Ireland to improve lung cancer management outcomes. There has been no attempt to date to provide advice on household radon exposure assessments in this setting. We performed a prospective feasibility study of radon assessment in our RALC to test the hypothesis that patients would avail of this service and that it would provide an opportunity for secondary prevention in at risk persons. We investigated household radon levels in consecutive patients who were newly referred with symptoms of lung cancer to the RALC in Galway University Hospital, Ireland over a 6-month period. Of 50 patients enrolled, 42 returned valid results. Overall 21 % of patients had radon levels recorded above the national reference level. Only 5 % of patients were aware of the association between radon gas and lung cancer. Smokers were significantly less likely to engage fully in radon testing. The development of RALC's offers a novel opportunity to integrate the concepts of radon exposure, cigarette smoking and the development of lung cancer, and to reinforce this message in the minds of at risk patients.

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

PubMed

Lee, Kil Yong; Burnett, William C

A simple method for the direct determination of the air-loop volume in a RAD7 system as well as the radon partition coefficient was developed allowing for an accurate measurement of the radon activity in any type of water. The air-loop volume may be measured directly using an external radon source and an empty bottle with a precisely measured volume. The partition coefficient and activity of radon in the water sample may then be determined via the RAD7 using the determined air-loop volume. Activity ratios instead of absolute activities were used to measure the air-loop volume and the radon partition coefficient. In order to verify this approach, we measured the radon partition coefficient in deionized water in the temperature range of 10-30 °C and compared the values to those calculated from the well-known Weigel equation. The results were within 5 % variance throughout the temperature range. We also applied the approach for measurement of the radon partition coefficient in synthetic saline water (0-75 ppt salinity) as well as tap water. The radon activity of the tap water sample was determined by this method as well as the standard RAD-H 2 O and BigBottle RAD-H 2 O. The results have shown good agreement between this method and the standard methods.

Investigation of features in radon soil dynamics and search for influencing factors

NASA Astrophysics Data System (ADS)

Yakovlev, Grigorii; Cherepnev, Maxim; Nagorskiy, Petr; Yakovleva, Valentina

2018-03-01

The features in radon soil dynamics at two depths were investigated and the main influencing factors were revealed. The monitoring of radon volumetric activity in soil air was performed at experimental site of Tomsk Observatory of Radioactivity and Ionizing Radiation with using radon radiometers and scintillation detectors of alpha-radiation with 10 min sampling frequency. The detectors were installed into boreholes of 0.5 and 1 m depths. The analysis of the soil radon monitoring data has allowed revealing some dependencies at daily and annual scales and main influencing factors. In periods with clearly defined daily radon variations in the soil were revealed the next: 1) amplitude of the daily variations of the soil radon volumetric activity damps with the depth, that is related with the influence of convective fluxes in the soil; 2) temporal shift between times of occurrence of radon volumetric activity maximum (or minimum) values at 0.5 m and 1 m depths can reach 3 hours. In seasonal dynamics of the soil radon the following dependences were found: 1) maximal values are observed in winter, but minimal - in summer; 2) spring periods of snow melting are accompanied by anomaly increasing of radon volumetric activity in the soil up to about 3 times. The main influencing factors are atmospheric precipitations, temperature gradient in the soil and the state of upper soil layer.

Radon in the Workplace: the Occupational Safety and Health Administration (OSHA) Ionizing Radiation Standard.

PubMed

Lewis, Robert K

2016-10-01

On 29 December 1970, the Occupational Safety and Health Act of 1970 established the Occupational Safety and Health Administration (OSHA). This article on OSHA, Title 29, Part 1910.1096 Ionizing Radiation standard was written to increase awareness of the employer, the workforce, state and federal governments, and those in the radon industry who perform radon testing and radon mitigation of the existence of these regulations, particularly the radon relevant aspect of the regulations. This review paper was also written to try to explain what can sometimes be complicated regulations. As the author works within the Radon Division of the Pennsylvania Department of Environmental Protection, Bureau of Radiation Protection, the exclusive focus of the article is on radon. The 1910.1096 standard obviously covers many other aspects of radiation and radiation safety in the work place.

Modeling and experimental examination of water level effects on radon exhalation from fragmented uranium ore.

PubMed

Ye, Yong-Jun; Dai, Xin-Tao; Ding, De-Xin; Zhao, Ya-Li

2016-12-01

In this study, a one-dimensional steady-state mathematical model of radon transport in fragmented uranium ore was established according to Fick's law and radon transfer theory in an air-water interface. The model was utilized to obtain an analytical solution for radon concentration in the air-water, two-phase system under steady state conditions, as well as a corresponding radon exhalation rate calculation formula. We also designed a one-dimensional experimental apparatus for simulating radon diffusion migration in the uranium ore with various water levels to verify the mathematical model. The predicted results were in close agreement with the measured results, suggesting that the proposed model can be readily used to determine radon concentrations and exhalation rates in fragmented uranium ore with varying water levels. Copyright © 2016. Published by Elsevier Ltd.

Radon emanation during compression, fracturing and heating of granites

NASA Astrophysics Data System (ADS)

Pili, E.; Nicolas, A.; Girault, F.; Schubnel, A.; Fortin, J.; Passelègue, F. X.; Richon, P.

2013-12-01

Radon emanation during compression, fracturing and heating of granites É. Pili1,2, A. Nicolas3, F. Girault3, A. Schubnel3, J. Fortin3, F. Passelègue3, P. Richon1 1CEA, DAM, DIF, F-91297 Arpajon, France 2Institut de Physique du Globe, Sorbonne Paris Cité, 1 rue Jussieu, F-75005 Paris, France 3Ecole Normale Supérieure, 24 rue Lhomond, F-75005 Paris, France Precursory radon emissions have been reported previously in various seismically active areas. Nevertheless such observations, only partially understood, are the subject of much skepticism. Radon-222 is a radioactive gas, daughter of radium-226 from alpha-decay in the uranium-238 decay chain that is naturally present in rocks and soils. Its escape is facilitated by preferential pathways such as fractures. Its half-life is 3.8 days only. As a consequence, radon may accumulate during short period only, and is thought to be released prior, during and after earthquakes as stress is discharged and new fluid pathways are made available. However, the physical processes involved in radon emanation during stress variations remain mostly unknown in the field and poorly studied in the laboratory. Here, we investigate radon emanation from various granite samples: Isla Craig, Westerly, La Peyratte and various leucogranites. Radon emanation and diffusion length, measured first on intact samples, are compared with measurements performed after heating at 850°C. Despite extensive thermal fracturing, radon emanation decreases irreversibly after heating compared to intact sample, and the higher the heating temperature the smaller the radon emanation. This is explained by the disappearance of water-film at grain boundaries, which plays an important role in radon percolation through the porous space, and then, at higher temperatures, by dehydration and melting of biotites where radium is concentrated. The recoil range of radon is likely shorter in melted biotites than in intact ones. The effect of mechanical fracturing on radon emanation was also studied under confining pressure (20 MPa), using a conventional tri-axial cell apparatus. Cycles of increasing differential stress - from hydrostatic stress to a maximum differential stress, and then back to initial hydrostatic conditions - were performed until macroscopic failure. Radon emanation was measured after each cycle, using a system of pore fluid sampling coupled with the cell. Acoustic emissions and P-wave velocities were also recorded simultaneously to monitor crack damage. Repeated experiments confirmed that microcracking lead to a substantial increase (x2-4) of radon emanation. Our results demonstrate that thermal and mechanical cracks have very different effects on radon emanation, because of partial fluid saturation.. Our perspective is now to perform fatigue experiments, at constant differential stress, during which an automatic system will allow for continuous measurement of radon concentration. This, hopefully, will pave the way towards a better understanding of the physical processes involved in radon emanation under upper crustal stress conditions.

Modulating factors in the expression of radiation-induced oncogenic transformation.

PubMed Central

Hall, E J; Hei, T K

1990-01-01

Many assays for oncogenic transformation have been developed ranging from those in established rodent cell lines where morphological alteration is scored, to those in human cells growing in nude mice where tumor invasiveness is scored. In general, systems that are most quantitative are also the least relevant in terms of human carcinogenesis and human risk estimation. The development of cell culture systems has made it possible to assess at the cellular level the oncogenic potential of a variety of chemical, physical and viral agents. Cell culture systems afford the opportunity to identify factors and conditions that may prevent or enhance cellular transformation by radiation and chemicals. Permissive and protective factors in radiation-induced transformation include thyroid hormone and the tumor promoter TPA that increase the transformation incidence for a given dose of radiation, and retinoids, selenium, vitamin E, and 5-aminobenzamide that inhibit the expression of transformation. Densely ionizing alpha-particles, similar to those emitted by radon daughters, are highly effective in inducing transformations and appear to interact in a supra-additive fashion with asbestos fibers. The activation of a known dominant oncogene has not yet been demonstrated in radiation-induced oncogenic transformation. The most likely mechanism for radiation activation of an oncogene would be via the production of a chromosomal translocation. Radiation also efficiently induces deletions and may thus lead to the loss of a suppressor gene. Images FIGURE 4. PMID:2272310

Should radon be reduced in homes? A cost-effect analysis.

PubMed

Stigum, Hein; Strand, Terje; Magnus, Per

2003-02-01

Radon is a radioactive gas that may leak into buildings from the ground. Radon exposure is a risk factor for lung cancer. An intervention against radon exposure in homes may consist of locating homes with high radon exposure (above 200 Bq m(-3)) and improving these, and protecting future houses. The purpose of this paper is to calculate the costs and the effects of this intervention. We performed a cost-effect analysis from the perspective of the society, followed by an uncertainty and sensitivity analysis. The distribution of radon levels in Norwegian homes is lognormal with mean = 74.5 Bq m(-3), and 7.6% above 200 Bq m(-3). The preventable attributable fraction of radon on lung cancer was 3.8% (95% uncertainty interval: 0.6%, 8.3%). In cumulative present values the intervention would cost $238 (145, 310) million and save 892 (133, 1981) lives; each life saved costs $0.27 (0.09, 0.9) million. The cost-effect ratio was sensitive to the radon risk, the radon exposure distribution, and the latency period of lung cancer. Together these three parameters explained 90% of the variation in the cost-effect ratio. The uncertainty in the estimated cost per life is large, mainly due to uncertainty in the risk of lung cancer from radon. Based on estimates from road construction, the Norwegian society has been willing to pay $1 million to save a life. This is above the upper uncertainty limit of the cost per life. The intervention against radon in homes, therefore, seems justifiable.

Radon surveys and monitoring at active volcanoes: an open window on deep hydrothermal systems and their dynamics

NASA Astrophysics Data System (ADS)

Cigolini, Corrado; Laiolo, Marco; Coppola, Diego

2017-04-01

The behavior of fluids in hydrothermal systems is critical in volcano monitoring and geothermal prospecting. Analyzing the time series of radon emissions on active volcanoes is strategic for detecting and interpreting precursory signals of changes in volcanic activity, eventually leading to eruptions. Radon is a radioactive gas generated from the decay of U bearing rocks, soils and magmas. Although radon has been regarded as a potential precursor of earthquakes, radon anomalies appear to be better suited to forecast volcanic eruptions since we know where paroxysms may occur and we can follow the evolution of volcanic activity. Radon mapping at active volcanoes is also a reliable tool to assess diffuse and concentrated degassing as well as efficiently detecting earthquake-volcano interactions. Systematic radon monitoring has been shown to be a key factor for evaluating the rise of volcanic and hydrothermal fluids. In fact, the decay properties of radon, the duration of radon anomalies together with sampling rates may be cross-checked with the chemistry of hydrothermal fluids (and their transport properties) to constrain fluids ascent rates and to infer the permeability and porosity of rocks in sectors surrounding the active conduits. We hereby further discuss the data of radon surveys and monitoring at Somma-Vesuvius, Stromboli and La Soufrière (Guadeloupe, Lesser Antilles). The integrated analysis of seismic and geochemical data, including radon emissions, may be successfully used in testing temperature distributions and variations of porosity and permeability in volcanic hydrothermal systems and can be used as a proxy to analyze geothermal reservoirs.

The physical behavior and geologic control of radon in mountain streams

USGS Publications Warehouse

Rogers, Allen S.

1956-01-01

Radon measurement were made in several small, turbulent mountain streams in the Wasatch Mountains near Salt Lake City and Ogden, Utah, to determine the relationship between the distribution of radon and its geologic environment. In this area, the distribution of radon in streams can be sued to locate points where relatively large amounts of radon-bearing ground water enter the stream, although other evidence of spring activity may be lacking. These points of influence ground water are marked by abrupt increases (as much as two orders of magnitude within a distance of 50 feet) in the radon content of the stream waters. The excess radon in the stream water is then rapidly lost to the atmosphere through stream turbulence. The rate of radon dissipation is an exponential function, of different slopes, with respect to distance of streamflow, and depend upon the rate and volume of streamflow, and the gradient and nature of the stream channel. The higher radon concentration can be generally related to specific stratigraphic horizons in several different drainage area. Thus, lithologic units which act as the primary aquifers can be identifies. In one area, thrust faults were found to control he influx of ground water into the stream. Estimates, based on radon concentration in stream and related spring waters, can also be made of the major increments of addition of ground water to streamflow where conventional methods such as stream gaging are not practical. The radon in the waters studied was found to be almost completely unsupported by radium in solution.

Indoor radon levels in selected hot spring hotels in Guangdong, China.

PubMed

Song, Gang; Zhang, Boyou; Wang, Xinming; Gong, Jingping; Chan, Daniel; Bernett, John; Lee, S C

2005-03-01

Guangdong is one of the provinces that have most hot springs in China, and many hotels have been set up near hot springs, with spring water introduced into the bath inside each hotel room for hot spring bathing to attract tourists. In the present study, we measured radon in indoor and outdoor air, as well as in hot spring waters, in four hot spring hotels in Guangdong by using NR-667A (III) continuous radon detector. Radon concentrations ranged 53.4-292.5 Bq L(-1) in the hot spring water and 17.2-190.9 Bq m(-3) in outdoor air. Soil gas intrusion, indoor hot spring water use and inefficient ventilation all contributed to the elevated indoor radon levels in the hotel rooms. From the variation of radon levels in closed unoccupied hotel rooms, soil gas intrusion was found to be a very important source of indoor radon in hotel rooms with floors in contact with soils. When there was spring water bathing in the bathes, average radon levels were 10.9-813% higher in the hotel rooms and 13.8-489% higher in bathes compared to their corresponding average levels when there was no spring water use. Spring water use in the hotel rooms had radon transfer coefficients from 1.6x10(-4) to 5.0x10(-3). Radon in some hotel rooms maintained in concentrations much higher than guideline levels might thus have potential health risks to the hotel workers, and technical and management measures should be taken to lower their exposure of radon through inhalation.

30 CFR 57.5037 - Radon daughter exposure monitoring.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Radon daughter exposure monitoring. 57.5037... Radon daughter exposure monitoring. (a) In all mines at least one sample shall be taken in exhaust mine...—radon daughter concentrations representative of worker's breathing zone shall be determined at least...

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

ERIC Educational Resources Information Center

Freije, Matthew R.

1989-01-01

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

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

EPA Science Inventory

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

41 CFR 102-80.20 - What are Federal agencies' responsibilities concerning the abatement of radon?

Code of Federal Regulations, 2010 CFR

2010-07-01

... agencies' responsibilities concerning the abatement of radon? 102-80.20 Section 102-80.20 Public Contracts... REGULATION REAL PROPERTY 80-SAFETY AND ENVIRONMENTAL MANAGEMENT Safety and Environmental Management Radon § 102-80.20 What are Federal agencies' responsibilities concerning the abatement of radon? Federal...

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

EPA Science Inventory

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

40 CFR 700.41 - Radon user fees.

Code of Federal Regulations, 2010 CFR

2010-07-01

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

Radon Q & A. What You Need to Know.

ERIC Educational Resources Information Center

Bayham, Chris

1994-01-01

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

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

EPA Science Inventory

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

41 CFR 102-80.20 - What are Federal agencies' responsibilities concerning the abatement of radon?

Code of Federal Regulations, 2011 CFR

2011-01-01

... agencies' responsibilities concerning the abatement of radon? 102-80.20 Section 102-80.20 Public Contracts... REGULATION REAL PROPERTY 80-SAFETY AND ENVIRONMENTAL MANAGEMENT Safety and Environmental Management Radon § 102-80.20 What are Federal agencies' responsibilities concerning the abatement of radon? Federal...

40 CFR 700.41 - Radon user fees.

Code of Federal Regulations, 2011 CFR

2011-07-01

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

Radon measurements in the Gran Sasso Underground Laboratory.

PubMed

Arpesella, C; Bam, B B; Bassignani, A; Cecchini, S; Colombo, G; Dekhissi, H; Fresca Fantoni, R; Giacomelli, G; Lembo, L; Maltoni, G; Mandrioli, G; Patrizii, L; Sartorio, C; Serra, P; Togo, V; Vilela, E

1997-04-01

Systematic radon monitoring in the Gran Sasso Underground Laboratory was performed in order to determine the background radon contribution to the sophisticated experimental apparatus and to check health physics standards for the personnel. As expected, the radon concentrations were found to depend strongly on the ventilation in the three experimental halls. Considerable reductions in the radon concentrations were obtained in 1993, when fresh air was drawn into the laboratory through a pipe and exhaust air was routed into the highway tunnel.

Radon depletion in xenon boil-off gas

NASA Astrophysics Data System (ADS)

Bruenner, S.; Cichon, D.; Lindemann, S.; Undagoitia, T. Marrodán; Simgen, H.

2017-03-01

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

Radon Mitigation Approach in a Laboratory Measurement Room

PubMed Central

Blanco-Rodríguez, Patricia; Fernández-Serantes, Luis Alfonso; Otero-Pazos, Alberto; Calvo-Rolle, José Luis; de Cos Juez, Francisco Javier

2017-01-01

Radon gas is the second leading cause of lung cancer, causing thousands of deaths annually. It can be a problem for people or animals in houses, workplaces, schools or any building. Therefore, its mitigation has become essential to avoid health problems and to prevent radon from interfering in radioactive measurements. This study describes the implementation of radon mitigation systems at a radioactivity laboratory in order to reduce interferences in the different works carried out. A large set of radon concentration samples is obtained from measurements at the laboratory. While several mitigation methods were taken into account, the final applied solution is explained in detail, obtaining thus very good results by reducing the radon concentration by 76%. PMID:28492468

Radon Mitigation Approach in a Laboratory Measurement Room.

PubMed

Blanco-Rodríguez, Patricia; Fernández-Serantes, Luis Alfonso; Otero-Pazos, Alberto; Calvo-Rolle, José Luis; de Cos Juez, Francisco Javier

2017-05-11

Radon gas is the second leading cause of lung cancer, causing thousands of deaths annually. It can be a problem for people or animals in houses, workplaces, schools or any building. Therefore, its mitigation has become essential to avoid health problems and to prevent radon from interfering in radioactive measurements. This study describes the implementation of radon mitigation systems at a radioactivity laboratory in order to reduce interferences in the different works carried out. A large set of radon concentration samples is obtained from measurements at the laboratory. While several mitigation methods were taken into account, the final applied solution is explained in detail, obtaining thus very good results by reducing the radon concentration by 76%.

Construction and measurements of an improved vacuum-swing-adsorption radon-mitigation system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Street, J., E-mail: joseph.street@mines.sdsmt.edu; Bunker, R.; Dunagan, C.

In order to reduce backgrounds from radon-daughter plate-out onto detector surfaces, an ultra-low-radon cleanroom is being commissioned at the South Dakota School of Mines and Technology. An improved vacuum-swing-adsorption radon mitigation system and cleanroom build upon a previous design implemented at Syracuse University that achieved radon levels of ∼0.2 Bq m{sup −3}. This improved system will employ a better pump and larger carbon beds feeding a redesigned cleanroom with an internal HVAC unit and aged water for humidification. With the rebuilt (original) radon mitigation system, the new low-radon cleanroom has already achieved a > 300× reduction from an input activitymore » of 58.6 ± 0.7 Bq m{sup −3} to a cleanroom activity of 0.13 ± 0.06 Bq m{sup −3}.« less

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

PubMed Central

Weinberg, C R

1995-01-01

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

Application of thoron interference as a tool for simultaneous measurement of radon and thoron with a pulse ionisation chamber.

PubMed

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

2013-07-01

Pulse ionisation chamber (PIC)-based monitors measuring radioactive gas radon ((222)Rn) without energy discrimination will have interference due to thoron ((220)Rn) present in the atmosphere. A technique has been developed to use this property of interference for simultaneous measurement of radon and thoron gas. These monitors work on the principle of counting of gross alphas emitted from radon and its progeny. A theoretical model has been developed for the variation of thoron sensitivity with respect to the flow rate of gas through the monitor. The thoron sensitivity of the monitor is found to vary with the flow rate of gas through the monitor. Using this sensitivity, the sampling procedure has been developed and verified for simultaneous measurement of radon and thoron. The PIC-measured radon and thoron concentration using this procedure agrees well with those measured by using standard radon and thoron discriminating monitor.

Radon in Devon and Cornwall and paediatric malignancies.

PubMed

Thorne, R; Foreman, N K; Mott, M G

1996-02-01

Exposure to radon in dwellings may cause cancer including paediatric malignancies. Devon and Cornwall have the highest exposure to radon of the counties of England. However, within these counties there is considerable variation in exposure. Exposure to radon in the 283 postcode sectors of the two counties has been published. The incidence of childhood malignancies between 1976 and 1985 was studied to compare postcode sectors of radon exposures > or = 100 Bq/m3 with sectors < 100 Bq/m3. No significant difference in the incidence rate of 106.7 per million child years in the high radon postcode sectors and 121.7 in the low (P = 0.29) was found. When the incidences of individual tumours were examined, a significantly increased rate of neuroblastoma (P = 0.02) and a non-significant increased rate of acute myeloid leukaemia were found in the high exposure postcode sectors. No association between radon exposure and overall rate of childhood malignancy was found.

Geologic and climatic controls on the radon emanation coefficient

USGS Publications Warehouse

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

1997-01-01

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

Indoor radon problem in energy efficient multi-storey buildings.

PubMed

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

2014-07-01

Modern energy-efficient architectural solutions and building construction technologies such as monolithic concrete structures in combination with effective insulation reduce air permeability of building envelope. As a result, air exchange rate is significantly reduced and conditions for increased radon accumulation in indoor air are created. Based on radon survey in Ekaterinburg, Russia, remarkable increase in indoor radon concentration level in energy-efficient multi-storey buildings was found in comparison with similar buildings constructed before the-energy-saving era. To investigate the problem of indoor radon in energy-efficient multi-storey buildings, the measurements of radon concentration have been performed in seven modern buildings using radon monitoring method. Values of air exchange rate and other parameters of indoor climate in energy-efficient buildings have been estimated. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riley, William Jowett

1996-05-01

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

Provision of Guidance, Information and Basic Criteria for Radiation Protection and Measurements.

DTIC Science & Technology

1984-02-27

Environmental Exposures to Radon and Radon Daughters in the. United States". The report is now in press and a copy of the proofs is enclosed. The report...treats sources of radon n the atmosphere, dosimetry of inhaled uranium mine aerosols, dosimetry of inhaled radon daughters n environmental atmosphere

Reducing Radon in Schools: A Team Approach.

ERIC Educational Resources Information Center

Ligman, Bryan K.; Fisher, Eugene J.

This document presents the process of radon diagnostics and mitigation in schools to help educators determine the best way to reduce elevated radon levels found in a school. The guidebook is designed to guide school leaders through the process of measuring radon levels, selecting the best mitigation strategy, and directing the efforts of a…