The Riesz-Radon-Frechet problem of characterization of integrals

Energy Technology Data Exchange (ETDEWEB)

Zakharov, Valerii K; Rodionov, Timofey V [M. V. Lomonosov Moscow State University, Moscow (Russian Federation); Mikhalev, Aleksandr V [Centre for New Information Technologies, Moscow State University (Russian Federation)

2010-11-16

This paper is a survey of results on characterizing integrals as linear functionals. It starts from the familiar result of F. Riesz (1909) on integral representation of bounded linear functionals by Riemann-Stieltjes integrals on a closed interval, and is directly connected with Radon's famous theorem (1913) on integral representation of bounded linear functionals by Lebesgue integrals on a compact subset of R{sup n}. After the works of Radon, Frechet, and Hausdorff, the problem of characterizing integrals as linear functionals took the particular form of the problem of extending Radon's theorem from R{sup n} to more general topological spaces with Radon measures. This problem turned out to be difficult, and its solution has a long and rich history. Therefore, it is natural to call it the Riesz-Radon-Frechet problem of characterization of integrals. Important stages of its solution are associated with such eminent mathematicians as Banach (1937-1938), Saks (1937-1938), Kakutani (1941), Halmos (1950), Hewitt (1952), Edwards (1953), Prokhorov (1956), Bourbaki (1969), and others. Essential ideas and technical tools were developed by A.D. Alexandrov (1940-1943), Stone (1948-1949), Fremlin (1974), and others. Most of this paper is devoted to the contemporary stage of the solution of the problem, connected with papers of Koenig (1995-2008), Zakharov and Mikhalev (1997-2009), and others. The general solution of the problem is presented in the form of a parametric theorem on characterization of integrals which directly implies the characterization theorems of the indicated authors. Bibliography: 60 titles.

The Riesz-Radon-Frechet problem of characterization of integrals

International Nuclear Information System (INIS)

Zakharov, Valerii K; Rodionov, Timofey V; Mikhalev, Aleksandr V

2010-01-01

This paper is a survey of results on characterizing integrals as linear functionals. It starts from the familiar result of F. Riesz (1909) on integral representation of bounded linear functionals by Riemann-Stieltjes integrals on a closed interval, and is directly connected with Radon's famous theorem (1913) on integral representation of bounded linear functionals by Lebesgue integrals on a compact subset of R n . After the works of Radon, Frechet, and Hausdorff, the problem of characterizing integrals as linear functionals took the particular form of the problem of extending Radon's theorem from R n to more general topological spaces with Radon measures. This problem turned out to be difficult, and its solution has a long and rich history. Therefore, it is natural to call it the Riesz-Radon-Frechet problem of characterization of integrals. Important stages of its solution are associated with such eminent mathematicians as Banach (1937-1938), Saks (1937-1938), Kakutani (1941), Halmos (1950), Hewitt (1952), Edwards (1953), Prokhorov (1956), Bourbaki (1969), and others. Essential ideas and technical tools were developed by A.D. Alexandrov (1940-1943), Stone (1948-1949), Fremlin (1974), and others. Most of this paper is devoted to the contemporary stage of the solution of the problem, connected with papers of Koenig (1995-2008), Zakharov and Mikhalev (1997-2009), and others. The general solution of the problem is presented in the form of a parametric theorem on characterization of integrals which directly implies the characterization theorems of the indicated authors. Bibliography: 60 titles.

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

International Nuclear Information System (INIS)

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

1995-12-01

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

Long-term measurement of radon concentration in the family house

International Nuclear Information System (INIS)

Muellerova, M.; Holy, K.

2009-01-01

The aim of this report was monitored the family house with radon concentration above radon limit for inhabited areas during one year. We were studied radon concentration changes in different rooms this house. Knowledge concerning of variations of radon activity concentration in family house were obtained. Daily variations show a maximum in the morning and a minimum in the afternoon. The seasonal variations show a minimum in spring months (March -April) and a maximum in early autumn (September). The radon concentration in the upstairs room was similar but ten-times lower than radon concentration in the downstairs room. In next period, the obtained results will be analysed in detail and different model describing the behaviour of radon in indoor air will be tested too. (authors)

Measurements of radon concentrations in dwelling houses

International Nuclear Information System (INIS)

Birkholz, W.; Klink, T.

1993-01-01

Radon and its daughter products gain in importance in health protection and radiation safety. Especially in the southern region of Saxony radon concentrations in dwellings may be high by former silver and uranium mines. We found radon contents of about 20.000 Bq/m 3 in dwellings. To redevelop such houses it is necessary to know intrude path of radon. In present work we studied different measuring systems, active and passive detectors, short and long term integrating devices. By means of investigation of radon sources several redeveloping methods are rates as well from radiological as from civil engineering point of view. (author)

The Riesz-Radon-Fréchet problem of characterization of integrals

Science.gov (United States)

Zakharov, Valerii K.; Mikhalev, Aleksandr V.; Rodionov, Timofey V.

2010-11-01

This paper is a survey of results on characterizing integrals as linear functionals. It starts from the familiar result of F. Riesz (1909) on integral representation of bounded linear functionals by Riemann-Stieltjes integrals on a closed interval, and is directly connected with Radon's famous theorem (1913) on integral representation of bounded linear functionals by Lebesgue integrals on a compact subset of {R}^n. After the works of Radon, Fréchet, and Hausdorff, the problem of characterizing integrals as linear functionals took the particular form of the problem of extending Radon's theorem from {R}^n to more general topological spaces with Radon measures. This problem turned out to be difficult, and its solution has a long and rich history. Therefore, it is natural to call it the Riesz-Radon-Fréchet problem of characterization of integrals. Important stages of its solution are associated with such eminent mathematicians as Banach (1937-1938), Saks (1937-1938), Kakutani (1941), Halmos (1950), Hewitt (1952), Edwards (1953), Prokhorov (1956), Bourbaki (1969), and others. Essential ideas and technical tools were developed by A.D. Alexandrov (1940-1943), Stone (1948-1949), Fremlin (1974), and others. Most of this paper is devoted to the contemporary stage of the solution of the problem, connected with papers of König (1995-2008), Zakharov and Mikhalev (1997-2009), and others. The general solution of the problem is presented in the form of a parametric theorem on characterization of integrals which directly implies the characterization theorems of the indicated authors. Bibliography: 60 titles.

Integral measurement system for radon

International Nuclear Information System (INIS)

Garcia H, J.M.; Pena E, R.

1996-01-01

The Integral measurement system for Radon is an equipment to detect, counting and storage data of alpha particles produced by Radon 222 which is emanated through the terrestrial peel surface. This equipment was designed in the Special Designs Department of the National Institute of Nuclear Research. It supplies information about the behavior at long time (41 days) on each type of alpha radiation that is present into the environment as well as into the terrestrial peel. The program is formed by an User program, where it is possible to determine the operation parameters of a portable probe that contains, a semiconductor detector, a microprocessor as a control central unit, a real time clock and calendar to determine the occurred events chronology, a non-volatile memory device for storage the acquired data and an interface to establish the serial communications with other personal computers. (Author)

Glass implanted 210Po as a method of determination of long term exposure to radon: First experiments in Israel

International Nuclear Information System (INIS)

Haquin, G.; Lang, B.; Even, O.; Asael, Y.; Shamai, Y.; Margaliot, M.; Shirav, M.

2002-01-01

Radon gas ( 222 Rn) is known to be the major contributor of the total exposure of the population to ionizing radiation. Retrospective assessment techniques have been developed to estimate long term exposures to ( 222 Rn and its progeny in epidemiological studies. Measurements of implanted 210 Po on glass panes surfaces characterize room radon concentration or habitant characterization.Various methods for retrospective radon measurement are described in the literature. The surface trap method is based on the 210 Po implanted on glass or other vitreous objects, measured using solid-state nuclear track detectors (SSNTD). The volume trap method is based on measurements of 210 Po in spongy, porous materials ( 210 Po volume traps). Other approach is in-vivo measurements of 210 Pb in the human skeleton. The present study uses the surface trap retrospective technique for the first time in Israel, coupled with an approach to estimate the 210 Po concentration in glasses exposed to 222 Rn using alpha spectrometry

A detailed study of inexpensive radon control techniques in New York state houses

International Nuclear Information System (INIS)

Nitschke, I.A.; Wadach, J.B.; Clarke, W.A.; Traynor, G.W.; Adams, G.P.; Rizzuto, J.E.

1984-01-01

As part of a comprehensive indoor air quality and infiltration field study, radon concentrations were measured in 60 houses in upstate New York using passive integrating monitors. Indoor air radon concentrations ranged from 0.2 pCi/l to 50 pCi/l. Four houses with the highest radon levels were then extensively monitored using real-time continuous instruments for the measurement of radon, radon daughters, respirable particles, infiltration, inside-outside pressure difference, and weather parameters. Several inexpensive radon mitigation techniques were tested in these four houses. Their effectiveness ranged widely. Techniques identified as effective were permanently installed in 14 houses having indoor air radon concentration above 2 pCi/l. Finally, the long-term effectiveness of the installed control techniques is being tested using passive integrating radon monitors. (Author)

Some investigations and use of LR-115 track detectors for radon measurements

CERN Document Server

Amrani, D

2001-01-01

Closed passive integrating radon dosimeters based on the use of cellulose nitrate (LR-115 type II) have been developed for assessment of long term radon exposure. This paper presents and comments the results of investigations, of registration efficiency, calibration factors, linearity tests and lower limit of detection for LR-115 detectors from different batches.

Monitoring of radon concentration in dwellings

International Nuclear Information System (INIS)

Kurosawa, Ryuhei

1991-01-01

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

Sampling strategies for indoor radon investigations

International Nuclear Information System (INIS)

Prichard, H.M.

1983-01-01

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

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

Directory of Open Access Journals (Sweden)

R. G. M. Crockett

2011-07-01

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

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

CERN Document Server

Steck, D J

1999-01-01

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

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

International Nuclear Information System (INIS)

Nikezic, D.; Yu, K.N.

2010-01-01

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

Secular variations of radon in metropolitan Vancouver, British Columbia, Canada

International Nuclear Information System (INIS)

Ghomshei, M.M.; Slawson, W.F.

1990-01-01

In this paper sampling of radon within the soil from three sites in metropolitan Vancouver is reported. Alpha trace bi-weekly measurements during a period of 4 years show secular variations with a period of 8-15 months. There are low-radon and high-radon episodes enduring several months to a year. Average radon level during the high-radon episodes reaches 5-10 times that of the low-radon periods. During high-radon episodes the high-frequency variations show very high amplitudes. After filtering of the high-frequency fluctuations, the data from different sites demonstrate remarkably similar trends. It is suggested that along with hydrogeological events, stress relaxation in rocks, earthquake, and magma emplacement may contribute to the sources of secular variations of radon. Because of long-term variations, radon level in urban areas should be monitored on a continuous basis. Single measurements, even those integrating radiation over a period of few months, may sample a low-radon episode, and provide a false assurance, or occur during a high-radon episode and give a false alarm

Radon emanation over an orebody: search for long-distance transport of radon

International Nuclear Information System (INIS)

Fleischer, R.L.; Hart, H.R. Jr.; Mogro-Campero, A.

1980-01-01

Discovery of subsurface uranium ore could be facilitated by recognition of measurable concentrations of the radioactive gas 222 Rn near the surface of the earth. Integrated measurements made over several weeks' time show promise of giving greater reproducibility than short-term measurements, which are more subject to meteorological variability. Improved methods of integrated randon measurements-free of 220 Rn, thermal-track fading, and mositure-condensation effects-allow readings that generally are highly stable over time. Sixteen kilometers north of Thoreau, New Mexico, reading taken at 60-cm depth over a 13-month interval for 55 positions give different-but nearly constant-monthly readings at each position; the typical standard deviation was 22 percent. Superimposed on that stable pattern have been three periods during which spatially grouped radon readings increased by a factor of two or more over their normal values. The simplest tenable description of the increases is sporadic puffs of upflowing gas, originating from unknown depths. The measurements are consistent with an upward velocity of flow of about 10 -3 cm/s (centimeters per second). If this velocity is maintained to depth, it is still insufficient to transport detectable amounts of radon from the orebody at 90-m depth, but it would be sufficient to reveal ore at 50 m or less. Downhole measurements of permeability yield values generally too low for signals to be delivered from the orebody by any of the mechanisms already modeled

Daily and seasonal variation of short-lived radon decay product concentrations in ground-level air at Munich-Neuherberg - a long-term study

International Nuclear Information System (INIS)

Winkler, R.

2001-09-01

Daily and seasonal variation of the equilibrium equivalent radon concentration (EEC Rn-222 ) and of the concentration of the short-lived radon decay product 214 Pb in ground-level air was investigated at Munich-Neuherberg from 1982 to 2000, and from 1989 to 2000, respectively. For this, the EEC was measured continuously with an alpha/beta aerosol monitor at 2.5 m above ground, and 214 Pb was determined by online gamma spectrometry at about 12 m above ground. The resulting time series were analysed statistically. For the respective periods, the measurements yielded a long-term average concentration of 7.8 Bq m -3 (geometric mean: 6.1 Bq m -3 ) for the EEC, and 6.0 Bq m -3 (geom. mean: 5.0 Bq m -3 ) for 214 Pb. In these periods, daily averages ranged from 0.6 to 49 Bq m -3 (EEC), and from 0.6 to 43 Bq m -3 ( 214 Pb). Monthly mean concentrations varied between 3.0 Bq m -3 in March 1988 and 20 Bq m -3 in October 1985 (EEC), and from 3.4 Bq m -3 in April 1992 to 11 Bq m -3 in October 1995 ( 214 Pb), respectively. The annual average concentrations were from 5.9 Bq m -3 in 1999 to 10.6 Bq m -3 in 1985 (EEC), and from 5.3 Bq m -3 in 1999 to 6.8 Bq m -3 in 1991 ( 214 Pb). From the long-term average equilibrium equivalent radon concentration (EEC), an average annual effective dose of 0.13 mSv due to the short-lived radon progeny outdoors was estimated. The time series showed distinct daily and seasonal variations. The variations from day to day are mainly caused by the actual weather conditions (wind, rain, etc.), i.e. the short-term turbulent conditions. The seasonal pattern is characterised by an autumn to winter maximum and an early summer minimum, and reflects the prevailing turbulent conditions at the respective seasons. As known, at Munich-Neuherberg during autumn and winter months (October/November to February) inversion weather conditions frequently occur, while the other months are characterised by more turbulent conditions. (orig.)

Impact of environmental factors on PADC radon detector sensitivity during long term storage

Science.gov (United States)

Wasikiewicz, J. M.

2018-01-01

A broad set of data on poly-allyl diglycol carbonate (PADC) exposure to various environmental conditions has been collected for a period of 1 year in order to study the aging effect on the sensitivity to radon detection. Aging is a phenomenon that occurs during long PADC storage resulting in a loss of sensitivity and/or creation of false tracks. Conditions under investigation were storages under pure nitrogen or air atmospheres, in water solutions of different pHs, in a range of temperatures, humidity and exposure to UV, gamma and neutron radiations. It was found that PADC strongly responds to some external conditions through physical changes in the polymer material; for example, etching of UV exposed detectors led to 10% loss of their thickness and the removal of the tracks layer. Performance of detectors was compared with a control that was the sensitivity of detectors from the same sheet at the time of primary calibration - within 1 month of each sheet being manufactured. Substantial difference in performance was found between storage under pure, dry nitrogen and in the presence of water. The former preserves PADC radon detection properties for the period of one year without noticeable change. The latter, on the other hand significantly reduces its performance even after 3 months' storage. It was also established that storage under low temperature is not a suitable means to preserve PADC sensitivity to radon detection due to significant loss in the detector sensitivity.

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

Science.gov (United States)

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

2013-12-01

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

Radon in the indoor environment

International Nuclear Information System (INIS)

Vanmarcke, H.

1998-01-01

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

Study of the calibration of the medical physics department - radon dosimeter in a radon facility

International Nuclear Information System (INIS)

Nikololpoulos, D.; Louizi, A.; Papadimitriou, D.; Proukakis, C.

1997-01-01

Several techniques have been developed to measure radon indoors.The use of a Solid State Nuclear Track Detector closed in a cup, has turned out to be the most appropriate for long term measurements. The Medical Physics Department of the Athens University is carrying out radon measurements in dwellings, apartments, outdoor air and mines since 1996. For this purpose a simple device, the so called Medical Physics Department radon dosimeter, has been constructed, which measures the radon concentration averaged over a long period of time. In the present paper the calibration technique introduced and the results of the calibration of the Medical Physics Department. (authors)

Long-term stabilization of uranium mill tailings

International Nuclear Information System (INIS)

Voorhees, L.D.; Sale, M.J.; Webb, J.W.; Mulholland, P.J.

1984-01-01

The primary hazard associated with uranium mill tailings is exposure to a radioactive gas, radon-222, the concentration of which has been correlated with the occurrence of lung cancer. Previous studies on radon attenuation conclude that the placement of earthen cover materials over the tailings is the most effective technique for reducing radioactive emissions and dispersal of tailings. The success of such a plan, however, is dependent on ensuring the long-term integrity of these cover materials. Soil erosion from water and wind is the major natural cause of destabilizing earthen cover materials. Field data related to the control of soil loss are limited and only indirectly apply to the problem of isolation of uranium mill tailings over very long time periods (up to 80,000 a). However, sufficient information is available to determine benefits that will result from changes in specific design variables and to evaluate the need for different design strategies among potential disposal sites. The three major options available for stabilization of uranium mill tailings are (1) rock cover, (2) soil and revegetation, or (3) a combination of both on different portions of the tailings cover. The optimal choice among these alternatives depends on site-specific characteristics such as climate and local geomorphology and soils, and on design variables such as embankment heights and slopes, modification of upstream drainage, and revegetation practices. Generally, geomorphic evidence suggests that use of soil and vegetation alone will not be adequate to reduce erosion on slopes greater than about 5 to 9%. For these steeper slopes, the use of rock talus or riprap will be necessary to maximize the probability of long-term stability. The use of vegetation to control erosion on the flatter portions of the site may be practicable in regions of the USA with sufficient rainfall and suitable soil types, but revegetation practices must be carefully evaluated to ensure that long-term

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

International Nuclear Information System (INIS)

1991-02-01

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

Long term indoor radon measurements in the pelletron laboratory at the UNAM physics institute

International Nuclear Information System (INIS)

Espinosa, G.; Golzarri, J. I.; Lopez, K.; Rickards, J.

2011-01-01

The results of six months of continuous measurement of the indoor radon concentration levels in the building where the Physics Institute 3 MV Pelletron particle accelerator is located are presented. This study has three major objectives: a) to know the actual values of the levels of indoor radon in this installation, where personnel spend many hours and sometimes days; b) assess the radiological risk from radon inhalation for personnel working permanently in the laboratory, as well as incidental users; and c) establish, if necessary, time limits for continuous permanence on the location for indoor radon exposure. Passive nuclear track detectors and dynamic systems were employed, covering six months (August, 2009 to January, 2010). For the calculation of internal dose the Radon Individual Dose Calculator was used. The results indicate that the indoor radon levels are below the US EPA recommended levels (400 Bq/m 3 ) in workplaces. The measurements help to establish levels for workplaces in Mexico. (Author)

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

International Nuclear Information System (INIS)

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

1986-01-01

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

Procedure manual for the estimation of average indoor radon-daughter concentrations using the radon grab-sampling method

International Nuclear Information System (INIS)

George, J.L.

1986-04-01

The US Department of Energy (DOE) Office of Remedial Action and Waste Technology established the Technical Measurements Center to provide standardization, calibration, comparability, verification of data, quality assurance, and cost-effectiveness for the measurement requirements of DOE remedial action programs. One of the remedial-action measurement needs is the estimation of average indoor radon-daughter concentration. One method for accomplishing such estimations in support of DOE remedial action programs is the radon grab-sampling method. This manual describes procedures for radon grab sampling, with the application specifically directed to the estimation of average indoor radon-daughter concentration (RDC) in highly ventilated structures. This particular application of the measurement method is for cases where RDC estimates derived from long-term integrated measurements under occupied conditions are below the standard and where the structure being evaluated is considered to be highly ventilated. The radon grab-sampling method requires that sampling be conducted under standard maximized conditions. Briefly, the procedure for radon grab sampling involves the following steps: selection of sampling and counting equipment; sample acquisition and processing, including data reduction; calibration of equipment, including provisions to correct for pressure effects when sampling at various elevations; and incorporation of quality-control and assurance measures. This manual describes each of the above steps in detail and presents an example of a step-by-step radon grab-sampling procedure using a scintillation cell

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

International Nuclear Information System (INIS)

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

1989-01-01

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

What did we learn from the Austrian radon project?

International Nuclear Information System (INIS)

Friedmann, H.

2004-01-01

Approximately 40000 measurements of indoor radon concentrations were performed in randomly selected homes during the Austrian Radon Project. These measurements were carried out by using long-term measuring devices (SSNTD and Electret detectors) and short-term charcoal detectors with liquid scintillation counting as the method of analysis. In addition to the equilibrium factor, soil gas measurements and quasi-continuous indoor measurements, parallel-measurements with different detector systems in randomly selected homes were also performed. Very different results were occasionally obtained for one and the same room at the same time. This was so not only when comparing the long-term and short-term measuring devices; actually, different long-term detector systems also often showed significant discrepancies in results, although all detector systems had been carefully calibrated and tested in laboratories. The essential conclusion was that during a longer exposure in randomly selected homes, the detectors may be moved, opened, or handled in other unfavourable ways which introduce additional uncertainties in the measuring results. The aim of the Austrian Radon Project was to estimate the radon risk for geographic areas (municipalities). This task is different from the evaluation of the mean radon concentration in a single home. Generally, while long-term measurements (a year or even longer) are necessary to get reliable results for a particular house, this is not so where only the mean indoor radon concentrations for an area are of interest. Observed indoor radon concentrations give information about the actual radon exposures of the inhabitants but not about the radon risk from the ground. The house type, the way the house is constructed, the storey where people live, and some living patterns (ventilation rate etc.) modify the geological risk significantly, although it is the geological situation that has to be primarily taken into account when planning and constructing

A complete low cost radon detection system

International Nuclear Information System (INIS)

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

2013-01-01

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

Radon in public buildings; Radon in oeffentlichen Gebaeuden

Energy Technology Data Exchange (ETDEWEB)

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

2009-07-01

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

Effect of ventilation type on radon concentration at places of work

International Nuclear Information System (INIS)

Oksanen, E.

1994-01-01

Indoor radon ( 222 Rn) concentrations were measured at 76 child care facilities and 36 schools in southern Finland. The buildings had three different types of ventilation systems: mechanical air supply and exhaust, mechanical exhaust, and natural ventilation, the first being most common. The effect of the ventilation type on the long-term radon concentration was studied in child care facilities. The radon concentrations were highest in the naturally ventilated buildings. The mechanical air supply and exhaust system maintained the lowest values in cold wintertime. In school buildings both the long-term radon concentration and short-term radon and daughter concentrations were measured. The correlation of the ventilation type and the radon concentration was not obvious in this group of measurements, but the radon concentrations and the equilibrium factors were highest in buildings with natural ventilation. Radon concentrations were generally lower during the working hours than during the one-month period, as expected. (author)

Radon

Energy Technology Data Exchange (ETDEWEB)

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

1978-09-01

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

Containment long-term operational integrity

International Nuclear Information System (INIS)

Sammataro, R.F.

1990-01-01

Periodic integrated leak rate tests are required to assure that containments continue to meet allowable leakage limits. Although overall performance has been quite good to date, several major containment aging and degradation mechanisms have been identified. Two pilot plant life extension (PLEX) studies serve as models for extending the operational integrity of present containments for light-water cooled nuclear power plants in the United States. One study is for a Boiling-Water Reactor (BWR) and the second is for a Pressurized-Water Reactor (PWR). Research and testing programs for determining the ultimate pressure capacity and failure mechanisms for containments under severe loading conditions and studies for extending the life of current plants beyond the present 40-year licensed lifetime are under way. This paper presents an overview of containment designs in the United States. Also presented are a discussion of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) and regulatory authority requirements for the design, construction, inservice inspection, leakage testing and repair of steel and concrete containments. Findings for containments from the pilot PLEX studies and continuing containment integrity research and testing programs are discussed. The ASME Code and regulatory requirements together with recommendations from the PLEX studies and containment integrity research and testing provide a basis for continued containment long-term operational integrity. (orig./GL)

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

International Nuclear Information System (INIS)

Marley, F.

2000-01-01

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

Indoor radon epidemiological study

Energy Technology Data Exchange (ETDEWEB)

Kunz, E; Tomasek, L; Mueller, T [National Radiation Protection Institute, Prague (Czech Republic); Placek, V [Inst. for Expertises and Emergencies, Pribram-Kamenna (Czech Republic); Matzner, J; Heribanova, A [State Office for Nuclear Safety, Prague (Czech Republic)

1996-12-31

The study is a long-term prospective cohort study of lung cancer and possibility other causes of death. The study population includes inhabitants of the area, who had resided there for at three years and at least one of these between 1.1.1960 and 21.12.1989. A total of 11865 inhabitants satisfied these criteria. The cumulative exposure of each respondent is being assessed on the basis of measurements in dwellings, time spent there and estimation of previous exposure levels by a model accounting for constructional changes in buildings. One year lasting measurements of radon daughter products by integral dosimeters (Kodak film LR 115) were performed in practically all dwellings of the specified area. Radon measurements in houses in term of equilibrium concentration are compared with the results of a pilot study in Petrovice in 1990-91 which gave the stimulus for the epidemiological study. The distribution of death causes and ratio of observed (O) to expected (E) cases among collected death cases in the cohort, generally, somewhat lower ratios than one reflect the non-industrial character of the region, with the exception of lung cancer in man. The differences in the O/E ratios for lung cancer among the separate communities indicate that even in the situation of generally lower mortality, the dependence of lung cancer mortality on radon.

Long term indoor radon measurements in the pelletron laboratory at the UNAM physics institute

OpenAIRE

Espinosa, G.; Golzarri, J.I.; Lopez, K.; Rickards, J.

2011-01-01

The results of six months of continuous measurement of the indoor radon concentration levels in the building where the Instituto de Física 3 MV Pelletron particle accelerator is located are presented. This study has three major objectives: (a) to know the actual values of the levels of indoor radon in this installation, where personnel spend many hours and sometimes days; (b) assess the radiological risk from radon inhalation for personnel working permanently in the laboratory, as well as inc...

Radon monitoring using long-range alpha detector-based technology

International Nuclear Information System (INIS)

Bolton, R.D.

1994-01-01

Long-Range Alpha Detector (LRAD) technology is being studied for monitoring radon gas concentrations. LRAD-based instruments collect and measure the ionization produced in air by alpha decays. These ions can be moved to a collection grid via electrostatic ion-transport design collected approximately 95% of the radon produced ions, while instruments using an airflow transport design collected from 44% to 77% of these ions, depending on detector geometry. The current produced by collecting this ionization is linear with respect to 222 Rn concentration over the available test range of 0.07 to 820 pCi/L. In the absence of statistical limitations due to low radon concentrations, the speed of response of LRAD-based instruments is determined by the air exchange rate, and therefore changes in radon concentration can be detected in just a few seconds. Recent tests show that at radon concentrations below 20 pCi/L current pulses produced by individual alpha decays can be counted, thus improving detector sensitivity and stability even further. Because these detectors are simple, rugged, and do not consume much power, they are natural candidates for portable, battery operation

Residential Radon and Brain Tumour Incidence in a Danish Cohort

DEFF Research Database (Denmark)

Bräuner, Elvira V.; Andersen, Zorana J.; Andersen, Claus Erik

2013-01-01

Background: Increased brain tumour incidence over recent decades may reflect improved diagnostic methods and clinical practice, but remain unexplained. Although estimated doses are low a relationship between radon and brain tumours may exist. Objective: To investigate the long-term effect of expo...... significant associations and exposure-response patterns between long-term residential radon exposure radon in a general population and risk of primary brain tumours, adding new knowledge to this field. This finding could be chance and needs to be challenged in future studies.......Background: Increased brain tumour incidence over recent decades may reflect improved diagnostic methods and clinical practice, but remain unexplained. Although estimated doses are low a relationship between radon and brain tumours may exist. Objective: To investigate the long-term effect...... of exposure to residential radon on the risk of primary brain tumour in a prospective Danish cohort. Methods: During 1993–1997 we recruited 57,053 persons. We followed each cohort member for cancer occurrence from enrolment until 31 December 2009, identifying 121 primary brain tumour cases. We traced...

Outdoor radon variation in Romania

International Nuclear Information System (INIS)

Simion, Elena; Simion, Florin

2008-01-01

Full text: The results of a long-term survey (1992 - 2006) of the variations of outdoor radon concentrations in semi-natural location from Romania are reported in the present paper. Measurements, covering between two and four sessions of the day (morning, afternoon, evening and night), were performed on a daily bases by 37 Environmental Radioactivity Monitoring Stations from National Environmental Radioactivity Survey Network. The method used was based on indirect determination of outdoor radon from aerosol samples collected on glass micro-fibre filters by drawing the air through the filters. The sampling was performed in a fixed place at a height of 2 m above the ground surface. Total beta counting of aerosol samples collected was performed immediately and after 20 hours. Values recorded during the years of continuous measurement indicated the presence of several patterns in the long-term variation of outdoor radon concentration: diurnal, seasonal and annual variation. For diurnal variation, outdoor radon concentration shows a maximum values in the night (early hours) and minimum values by day (in the afternoon). On average, this maximum is a factor of 2 higher than the minimum. Late autumn - beginning of winter maximum and an early spring minimum are characteristic for seasonal patterns. In the long term a seasonal pattern was observed for diurnal variation, with an average diurnal maximum to minimum ratio of 1.33 in winter compared with 3.0 in the summer months. The variations of outdoor radon levels showed little correlation with the uranium concentration of the ground and were attributed to changes in soil moisture content. In dry seasons, because of the low precipitation, the soil was drying out in the summer allowing fractures to develop and radon to migrate easily through the ground. Depending on micro-climatic and geological conditions, outdoor radon average concentrations in different regions of Romania are from 1200 mBq/mc to 13065 mBq/mc. The smallest

Radon measurements: the sources of uncertainties

International Nuclear Information System (INIS)

Zhukovsky, Michael; Onischenko, Alexandra; Bastrikov, Vladislav

2008-01-01

Full text: Radon measurements are quite complicated process and the correct estimation of uncertainties is very important. The sources of uncertainties for grab sampling, short term measurements (charcoal canisters), long term measurements (track detectors) and retrospective measurements (surface traps) are analyzed. The main sources of uncertainties for grab sampling measurements are: systematic bias of reference equipment; random Poisson and non-Poisson errors during calibration; random Poisson and non-Poisson errors during measurements. These sources are also common both for short term measurements (charcoal canisters) and long term measurements (track detectors). Usually during the calibration the high radon concentrations are used (1-5 kBq/m 3 ) and the Poisson random error rarely exceed some percents. Nevertheless the dispersion of measured values even during the calibration usually exceeds the Poisson dispersion expected on the basis of counting statistic. The origins of such non-Poisson random errors during calibration are different for different kinds of instrumental measurements. At present not all sources of non-Poisson random errors are trustworthy identified. The initial calibration accuracy of working devices rarely exceeds the value 20%. The real radon concentrations usually are in the range from some tens to some hundreds Becquerel per cubic meter and for low radon levels Poisson random error can reach up to 20%. The random non-Poisson errors and residual systematic biases are depends on the kind of measurement technique and the environmental conditions during radon measurements. For charcoal canisters there are additional sources of the measurement errors due to influence of air humidity and the variations of radon concentration during the canister exposure. The accuracy of long term measurements by track detectors will depend on the quality of chemical etching after exposure and the influence of season radon variations. The main sources of

Fractal characters and hurst exponent of radon exhalation rate from uranium Tailings

International Nuclear Information System (INIS)

Hu Hanqiao; Tan Kaixuan; Li Chunguang; Lv Junwen; Liu Dong

2010-01-01

The uranium tailings radon exhalation is an important environmental problem. The change of the radon exhalation rate of uranium tailings with the time through laboratory experiments is measured, and the results show that the radon exhalation rate of the tailings change obviously with time in non-periodic oscillations. Applying fractal analysis to the radon exhalation rate time-series data by R/S method, the Hurst exponent of the entire time series data is 0.83, the fractal dimension is 1.17. Mobile Hurst exponent is between 0.5 and 0.8 in most cases. The Hurst exponent of the experiments in the later part are below 0.5. The exhalation rate of uranium tailings radon does not meet the long-term trend of random walk theory, the radon exhalation rate has long-term memory, but the short-term memory is not distinct. The radon exhalation from uranium tailings is a deterministic chaotic dynamics. (authors)

Workshop on dosimetry for radon and radon daughters

International Nuclear Information System (INIS)

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

1978-05-01

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

Time-integrated radon measurements in spring and well waters by track technique

International Nuclear Information System (INIS)

Somogyi, G.

1986-01-01

The radon content dissolved in natural waters seems to be a very sensitive indicator of potential uranium deposits. We have developed different track methods to perform time-integrated, ''in-situ'' measurements of radon in different natural waters (spring, lake, well) and their neighbouring soil gas. One of our main purposes was to study the seasonal variation of radon content and its possible correlation with certain water (yield, flow rate) and environmental (depth, temperature) parameters. Simultaneous radon measurements have been carried out in lake and spring waters in a cave, in thermal and cold water springs of a public bath and in a deep drilled well. The radon profiles obtained in the deep well lend support to the idea that the environmental radon can travel large distances in microbubbles of a ''carrier geogas''. (author)

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

International Nuclear Information System (INIS)

Streil, T.; Oeser, V.

2002-01-01

calculated and displayed online during the exposure time, given dose limits can be watched by an alert function. Rapid changes of the concentration can be detected and the dose gets available in its time distribution as well. The PC-based dose management provides an administrator desk for stuff planning and enables the channel of measurement pre-set. The standard infrared interface handles the data communication with a PC. As required, the electronic dosimeter is easy to handle and rugged enough to withstand the rough working conditions. The device is water protected and can work up to 98 % relative humidity. The smallest adjustable integration time is 1 min (correspond to a radon progeny detection limit of nearly 6 Bq/m 3 ). The following acquired measurement data will be stored to the internal memory (capacity 300 cycles): 60 channel sum spectra, time distribution of 5 region of interest (ROI), PAEC, PAEE, ERC and dose, average values. Free ROI set up enables for instance to focus on Po218, adjust the next ROI on Po214, one on Po212, the next on U238/Ra226 3,5 ... 4.9 MeV and the last on Pu239/ Po210 / Am241 4.9 ... 5.6 MeV. DOSEman Pro is a unique continuous WL monitor with a efficiency in the order of the state-of-the-art devices but cost-effective with a price that is a tenth of a progeny monitor. DOSEman Pro will fit the requirements for personal dosimetry as well as local dosimetry or long term monitoring. The system can be used for the online detection with alert function of 'dirty bombs'. First results from plutonium, polonium and radium in air will be presented. (author)

Long term integrity of spent fuel and construction materials for dry storage facilities

Energy Technology Data Exchange (ETDEWEB)

Saegusa, T [CRIEPI (Japan)

2012-07-01

In Japan, two dry storage facilities at reactor sites have already been operating since 1995 and 2002, respectively. Additionally, a large scale dry storage facility away from reactor sites is under safety examination for license near the coast and desired to start its operation in 2010. Its final storage capacity is 5,000tU. It is therefore necessary to obtain and evaluate the related data on integrity of spent fuels loaded into and construction materials of casks during long term dry storage. The objectives are: - Spent fuel rod: To evaluate hydrogen migration along axial fuel direction on irradiated claddings stored for twenty years in air; To evaluate pellet oxidation behaviour for high burn-up UO{sub 2} fuels; - Construction materials for dry storage facilities: To evaluate long term reliability of welded stainless steel canister under stress corrosion cracking (SCC) environment; To evaluate long term integrity of concrete cask under carbonation and salt attack environment; To evaluate integrity of sealability of metal gasket under long term storage and short term accidental impact force.

Long-term stabilization of uranium mill tailings

International Nuclear Information System (INIS)

Voorhees, L.D.; Sale, M.J.; Webb, J.W.; Mulholland, P.J.

1983-01-01

The primary hazard associated with uranium mill tailings is exposure to a radioactive gas, radon-222, the concentration of which has been correlated with the occurrence of lung cancer. Previous studies on radon attenuation conclude that the placement of earthen cover materials over the tailings is the most effective technique for reducing radioactive emissions and dispersal of tailings. The success of such a plan, however, is dependent on ensuring the long-term integrity of these cover materials. Soil erosion from water and wind is the major natural cause of destabilizing earthen cover materials. Field data related to the control of soil loss are limited and only indirectly apply to the problem of isolation of uranium mill tailings over very long time periods (up to 80,000 a). However, sufficient information is available to determine benefits that will result from the changes in specific design variables and to evaluate the need for different design strategies among potential disposal sites. The three major options available for stabilization of uranium mill tailings are: rock cover, soil and revegetation, or a combination of both on different portions of the tailings cover. The optimal choice among these alternatives depends on site-specific characteristics such as climate and local geomorphology and soils, and on design variables such as embankment, heights and slopes, modification of upstream drainage, and revegetation practices. Generally, geomorphic evidence suggests that use of soil and vegetation alone will not be adequate to reduce erosion on slopes greater than about 5 to 9%

Time-integrated radon measurements in spring and well waters by track technique

Energy Technology Data Exchange (ETDEWEB)

Somogyi, G.; Lenart, L.

1986-01-01

The radon content dissolved in natural waters seems to be a very sensitive indicator of potential uranium deposits. We have developed different track methods to perform time-integrated, ''in-situ'' measurements of radon in different natural waters (spring, lake, well) and their neighbouring soil gas. One of our main purposes was to study the seasonal variation of radon content and its possible correlation with certain water (yield, flow rate) and environmental (depth, temperature) parameters. Simultaneous radon measurements have been carried out in lake and spring waters in a cave, in thermal and cold water springs of a public bath and in a deep drilled well. The radon profiles obtained in the deep well lend support to the idea that the environmental radon can travel large distances in microbubbles of a ''carrier geogas''.

Persistence of radon-222 flux during monsoon at a geothermal zone in Nepal

International Nuclear Information System (INIS)

Girault, Frederic; Koirala, Bharat Prasad; Perrier, Frederic; Richon, Patrick; Rajaure, Sudhir

2009-01-01

The Syabru-Bensi hydrothermal zone, Langtang region (Nepal), is characterized by high radon-222 and CO 2 discharge. Seasonal variations of gas fluxes were studied on a reference transect in a newly discovered gas discharge zone. Radon-222 and CO 2 fluxes were measured with the accumulation chamber technique, coupled with the scintillation flask method for radon. In the reference transect, fluxes reach exceptional mean values, as high as 8700 ± 1500 g m -2 d -1 for CO 2 and 3400 ± 100 x 10 -3 Bq m -2 s -1 for radon. Gases fluxes were measured in September 2007 during the monsoon and during the dry winter season, in December 2007 to January 2008 and in December 2008 to January 2009. Contrary to expectations, radon and its carrier gas fluxes were similar during both seasons. The integrated flux along this transect was approximately the same for radon, with a small increase of 11 ± 4% during the wet season, whereas it was reduced by 38 ± 5% during the monsoon for CO 2 . In order to account for the persistence of the high gas emissions during monsoon, watering experiments have been performed at selected radon measurement points. After watering, radon flux decreased within 5 min by a factor of 2-7 depending on the point. Subsequently, it returned to its original value, firstly, by an initial partial recovery within 3-4 h, followed by a slow relaxation, lasting around 10 h and possibly superimposed by diurnal variations. Monsoon, in this part of the Himalayas, proceeds generally by brutal rainfall events separated by two- or three-day lapses. Thus, the recovery ability shown in the watering experiments accounts for the observed long-term persistence of gas discharge. This persistence is an important asset for long-term monitoring, for example to study possible temporal variations associated with stress accumulation and release.

FOLLOW-UP RADON MEASUREMENTS IN 14 MITIGATED SCHOOLS

Science.gov (United States)

The report gives results of a determination of the long-term performance of radon mitigation systems installed in U. S. EPA research schools: radon measurements were conducted in 14 schools that had been mitigated between 1988 and 1991. The measurements were made between Februar...

Radon in Irish schools: the results of a national survey

International Nuclear Information System (INIS)

Synnott, H; Hanley, O; Fenton, D; Colgan, P A

2006-01-01

This paper presents the results of a survey of radon concentrations in Irish primary and post-primary schools. The objective of this survey was to assess the distribution of radon in Irish schools and to identify those requiring remedial work to reduce radon exposure to children and staff. All primary and post-primary schools were invited to participate in the survey. Indoor radon concentrations were measured during the academic year using integrating passive alpha track-etch detectors with a measurement period from three to nine months. The survey was carried out on a phased basis from 1998 to 2004 and is one of the most comprehensive of its kind undertaken in Europe. Measurements were completed in 38 531 ground floor classrooms and offices in 3826 schools, representing over 95% of the approximate 4000 primary and post-primary schools in Ireland. Of these, 984 schools had radon concentrations greater than 200 Bq m -3 in 3028 rooms and 329 schools had radon concentrations in excess of 400 Bq m -3 in 800 rooms. The average radon concentration in schools was 93 Bq m -3 . This results in an annual average effective dose to an Irish child from exposure to radon of 0.3 mSv per year, assuming that the long-term radon concentration is equal to the radon concentration present during the working hours and that the annual average occupancy is 1000 h per year. A programme of remediation of schools with radon concentrations above 200 Bq m -3 has been put in place

The use of an empirical correlation between surface activity and integrated radon exposure in a retrospective radon measurement

International Nuclear Information System (INIS)

Cauwels, P.; Poffijn, A.

1998-01-01

Retrospective measurements of integrated radon concentration in dwellings over the past decades are dealt with, based on the fact that glass sheets act as a memory for the airborne radon activity due to the implanted 210 Po and 210 Bi activity. The room model established to this purpose by Jacobi in 1972 seems to need some modifications; calculated and measured data suggest the existence of a possible loss of implanted daughter products. (A.K.)

Study of the behavior of automatic track detectors for radon determination

International Nuclear Information System (INIS)

Moreno C, A.

1997-01-01

Both the alpha decay and the alpha and beta emitting radon daughters, may affect the living cells. In this thesis, experiments have been performed to study the response of environmental radon using different alpha particle detectors. A study was performed both in the laboratory and in the field of two kinds of detectors: a) Passive solid state nuclear track detectors, LR 115 type II, capable to integrate the alpha particles in a given period of time and, b) an automatic active detector, Clipperton, that continuously accumulate the alpha counting from radon decay. LR-115 track detectors were exposed in the laboratory to alpha particles from a radioactive source and a controlled radon atmosphere. The detectors were also exposed to electrons from an electron accelerator. The number of alpha tracks in the detectors were evaluated with two kinds of spark counters. The response of the track detectors as a function of the number of alpha tracks showed a reproducibility of 92%, and the effect of electron doses showed that the bulk etching velocity varied as a function of the electron dose. Additionally some changes were introduced in an SSNTD exchanger, exposed to the radon chamber in order to reduce the background in the non exposed positions. A conversion factor of 0.016 tracks/cm 2 . 10h per Bq/m 3 was obtained. The response of the two spark counters was similar. Field soil radon determinations were performed with track detectors during 11 months and with the active detector during 5 months with exposures each month and each hour respectively. When calculated for the same time periods exposure the response of both systems was similar. However differences were quite striking in the patterns of short and long term exposure periods since short term fluctuations are explicitly shown with the active detector while integrated within the passive one. (Author)

Property transfer assessments should include radon gas testing

International Nuclear Information System (INIS)

Nardi, M.A.

1992-01-01

There are two emerging influences that will require radon gas testing as part of many property transfers and most environmental assessments. These requirements come from lending regulators and state legislatures and affect single family, multifamily, and commercial properties. Fannie Mae and others have developed environmental investigation guidelines for protection from long term legal liabilities in the purchase of environmentally contaminated real estate. These guidelines include radon gas testing for many properties. Several states have enacted laws that require environmental disclosure forms be prepared to ensure that the parties involved in certain real estate transactions are aware of the environmental liabilities that may come with the transfer of property. Indiana has recently enacted legislation that would require the disclosure of the presence of radon gas on many commercial real estate transactions. With more banks and state governments following this trend, radon gas testing should be performed during all property transfers and environmental assessments to protect the parties involved from any long term legal liabilities

Radon in public buildings

International Nuclear Information System (INIS)

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

2009-01-01

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

Radon remediation in irish schools

International Nuclear Information System (INIS)

Synnott, H.

2006-01-01

average an approximate 50% reduction in radon concentrations. Active systems require the use of electric fans for their continued successful long-term operation. The performance of a number of fan assisted sub-slab de pressurization systems and fan assisted under floor ventilation systems were evaluated after a minimum of three years operation. It was found that all systems were still operating satisfactorily. It is recommended however that periodic retesting of rooms where active systems are installed should be carried out to ensure the continued successful long-term operation of these systems. (author)

How well do radon mitigation strategies work?

International Nuclear Information System (INIS)

Matson, N.

1992-01-01

Naturally occurring radon in homes can't be completely avoided, but it can be minimized. Indoor air quality researchers compared results of six popular ways to mitigate radon in houses in the Spokane River Valley and New Jersey. Over the course of the past decade, Americans have become aware of the health hazards from radon, a naturally occurring gas that can enter a home through a variety of pathways from the surrounding terrain. Recent research carried out at Lawrence Berkeley Laboratory (LBL) and elsewhere suggests that radon mitigation is feasible but requires long-term monitoring to ensure lasting effectiveness. These studies compare the selection, installation, and performance evaluations of several common radon mitigation strategies

Radon in houses and soil of Croatia

Energy Technology Data Exchange (ETDEWEB)

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

2006-07-01

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

Radon and radon daughters indoors, problems in the determination of the annual average

International Nuclear Information System (INIS)

Swedjemark, G.A.

1984-01-01

The annual average of the concentration of radon and radon daughters in indoor air is required both in studies such as determining the collective dose to a population and at comparing with limits. Measurements are often carried out during a time period shorter than a year for practical reasons. Methods for estimating the uncertainties due to temporal variations in an annual average calculated from measurements carried out during various lengths of the sampling periods. These methods have been applied to the results from long-term measurements of radon-222 in a few houses. The possibilities to use correction factors in order to get a more adequate annual average have also been studied and some examples have been given. (orig.)

Integrated modeling of long-term vegetation and hydrologic dynamics in Rocky Mountain watersheds

Science.gov (United States)

Robert Steven Ahl

2007-01-01

Changes in forest structure resulting from natural disturbances, or managed treatments, can have negative and long lasting impacts on water resources. To facilitate integrated management of forest and water resources, a System for Long-Term Integrated Management Modeling (SLIMM) was developed. By combining two spatially explicit, continuous time models, vegetation...

Earthquake forecasting studies using radon time series data in Taiwan

Science.gov (United States)

Walia, Vivek; Kumar, Arvind; Fu, Ching-Chou; Lin, Shih-Jung; Chou, Kuang-Wu; Wen, Kuo-Liang; Chen, Cheng-Hong

2017-04-01

For few decades, growing number of studies have shown usefulness of data in the field of seismogeochemistry interpreted as geochemical precursory signals for impending earthquakes and radon is idendified to be as one of the most reliable geochemical precursor. Radon is recognized as short-term precursor and is being monitored in many countries. This study is aimed at developing an effective earthquake forecasting system by inspecting long term radon time series data. The data is obtained from a network of radon monitoring stations eastblished along different faults of Taiwan. The continuous time series radon data for earthquake studies have been recorded and some significant variations associated with strong earthquakes have been observed. The data is also examined to evaluate earthquake precursory signals against environmental factors. An automated real-time database operating system has been developed recently to improve the data processing for earthquake precursory studies. In addition, the study is aimed at the appraisal and filtrations of these environmental parameters, in order to create a real-time database that helps our earthquake precursory study. In recent years, automatic operating real-time database has been developed using R, an open source programming language, to carry out statistical computation on the data. To integrate our data with our working procedure, we use the popular and famous open source web application solution, AMP (Apache, MySQL, and PHP), creating a website that could effectively show and help us manage the real-time database.

Why measure radon decay products?

International Nuclear Information System (INIS)

Rolle, R.; Lettner, H.

1997-01-01

Combined development in spectrometry, instrumentation and ventilation modelling with its dependence on short- and long-term weather fluctuations renders possible a new, economical metrology for radon decay products. Short-term measurements can, with few restrictions, be converted to annual exposures of an accuracy superior to that from conventional medium-term Rn gas measurements. (orig.) [de

Canadian population risk of radon induced lung cancer variation range assessment based on various radon risk models

International Nuclear Information System (INIS)

Chen, Jing

2017-01-01

To address public concerns regarding radon risk and variations in risk estimates based on various risk models available in the literature, lifetime lung cancer risks were calculated with five well-known risk models using more recent Canadian vital statistics (5-year averages from 2008 to 2012). Variations in population risk estimation among various models were assessed. The results showed that the Canadian population risk of radon induced lung cancer can vary from 5.0 to 17% for men and 5.1 to 18% for women based on different radon risk models. Averaged over the estimates from various risk models with better radon dosimetry, 13% of lung cancer deaths among Canadian males and 14% of lung cancer deaths among Canadian females were attributable to long-term indoor radon exposure. (authors)

Variability in the exhalation rate of radon

International Nuclear Information System (INIS)

Rundo, J.; Markun, F.; Sha, J.Y.; Cameron, P.

1976-01-01

In a day-long study, twenty-eight 10-min samples of breath were collected from a former radium dial painter and were analyzed for radon. The radon exhalation rate showed good short-term reproducibility, but there was a dramatic short-lived increase in the first samples collected after lunch and a slow but steady increase during the course of the day

Radon testing in schools in New York State: a 20-year summary

International Nuclear Information System (INIS)

Kitto, Michael

2014-01-01

For nearly 20 years the Department of Health has conducted programs to assist in the measurement and reduction of indoor radon concentrations in 186 schools located primarily in Zone 1 areas of New York State. Although many schools had few or no rooms containing radon above 148 Bq/m 3 , some rooms had >740 Bq/m 3 and remediation techniques were utilized to reduce exposure. Short-term radon measurements in the schools showed little correlation to basement and first-floor radon results from single-family homes in the towns. - Highlights: • Relatively few schools in New York State have been tested for indoor radon. • We provide a summary of radon-testing results for measured schools. • The radon potential in schools is often less than in local houses. • Short-term measurement results exceeded their long-term counterparts in nearly every case

Survey of radon in dwellings in area strongly affected by mining

International Nuclear Information System (INIS)

Wysocka, M.; Chalupnik, S.; Mielnikow, A.; Skowronek, J.

2002-01-01

Due to the Decree of the President of Polish Atomic Energy Agency [21], the permissible level of radon concentration in new houses is 200 Bq/m 3 , while in existing houses -400 Bq/m 3 . This Decree is valid since January 1, 1998. Till now, radon investigations in Poland were done on a small scale. Therefore Central Mining Institute started at first screening campaign and later long term measurements of radon concentrations were done in area of Upper Silesia. Usually measurements of radon concentration in dwellings are performed at two stages. On the first stage, a screening is made by means of short term methods of radon measurement, like activated charcoal canisters or grab sampling to find places with elevated radon risk. On the second stage a long term measurements have been done in dwellings chosen during screening campaign.The method of the radon measurement by means of charcoal canisters was developed in our Laboratory in early 90's. We designed our own detectors with the activated charcoal, after the exposure radon from the charcoal is washed out with toluene-based liquid scintillator and measured in the liquid scintillation counter. The reliability of the results was proved in many intercomparison runs. For long term radon measurements the method of track etched detectors was applied. As a detector the LR-115 strippable foil was chosen and as a reader the spark counter was applied. As predicted, the highest values in dwellings were found at the ground floor level in several towns in northern part of Upper Silesia. All these sites are situated in area without an overburden of impermeable Miocene clays. Moreover, these towns are located within a specific geological structure, known as Bytom Syncline. In the underlying strata, the dominant rocks are Triassic, strongly weathered formations, in form of carbonates. We supposed, that the influence of geology would be intensified by coal mining. The presence of abandoned workings, excavations and cavities on

Coordinated indoor radon surveys in some Arab countries

International Nuclear Information System (INIS)

Al-Azmi, D.; Al-Abed, T.; Alnasari, M.S.; Borham, E.E.; Chekir, Z.; Khalifa, M.S.; Shweikani, R.

2012-01-01

Indoor radon surveys were carried out in some of the Arab countries through a Coordination Research Program (CRP) organized by the Arab Atomic Energy Agency (AAEA). The objectives of the program aim at establishing a database on indoor radon concentration levels in the region and investigating any anomalies, where they exist. The approach adopted by the survey teams to achieve public participation in accepting the radon detectors in dwellings is presented and discussed. Most of the participants in the CRP used the passive method (CR-39 plastic detectors) for long-term radon measurements, while others used charcoal detectors and E-Perm systems for short-term measurements. The results of the surveys showed that radon concentration levels in most of the dwellings were low, whilst in some old cities and in an area close to a phosphate mine the levels were found to be relatively high. (authors)

Measurement of radon flux and tailings parameters for quantifying the source term due to radon exhalation from U tailings pile at Jaduguda

International Nuclear Information System (INIS)

Sahoo, B.K.; Mayya, Y.S.; Sapra, B.K.; Gaware, J.J.; Khuswaha, H.S.

2010-01-01

Full text: The exposures from radon ( 222 Rn) and its decay products have been received considerable attention in the world community because of their adverse health effect. There are various natural and man-made sources of radon present in our environment. Among the man-made sources, the U tailings (waste product from U mining and milling facility) may be considered an important one because it contains significant amount of 226 Ra activity after the U extraction from the ore bodies. These tailings (slurry form) are being impounded into a repository site nearby the facility called 'Tailings Pile' (TP). Significant amount of radon emission takes place from this area by the process of emanation and exhalation. Hence, a study was taken up to quantify the source term arising due to radon emission from uranium tailings pile at Jaduguda in Jharkhand state. In-situ experiments were conducted at 40 locations of the uranium tailings pile in three seasons namely summer, rainy and winter to measure the radon fluxes. The measurements were carried out by deploying a cylindrical chamber, attached to a continuous radon monitor, on the surface of the tailings pile. The dimension of the chamber was selected by using a recently developed two dimensional theory of soil chamber, so that radon concentration growth will be in exponential fashion and the data generated within 2-3 hours of deployment period will be sufficient for accurately deriving the actual radon flux. After the data collection, the fluxes were derived by fitting an exponential growth function to the plot of radon concentration with time. The fluxes were also predicted by diffusion theory using the measured tailings parameters such as 226 Ra content, radon emanation factor, porosity, temperature and moisture. An excellent matching between the predicted and measured fluxes was observed. The validity of diffusion theory in the matrix of U tailings pile provides an alternate method for back-calculating the tailings

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

International Nuclear Information System (INIS)

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

2003-01-01

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

Occupational exposure to radon in Australian Tourist Caves an Australian-wide study of radon levels

International Nuclear Information System (INIS)

Solomon, S.B.; Langroo, R.; Peggie, J.R.; Lyons, R.G.; James, J.M.

1996-02-01

The study described in this report sets out to determine which Australian show caves have long- term radon levels in excess of the proposed action level of 1000 Bq m -3 . The collaborative study between the Australian Radiation Laboratory (ARL), the University of Sydney and the University of Auckland, was carried out with the support of a Research Grant from Worksafe Australia. The aims of this study were to measure radon levels for each season over a period of one year, at representative sites in all developed show caves around Australia, to determine yearly average radon levels for each cave tour, based on these site measurements, to estimate the radiation doses to the tour guides employed in these caves, and to identify caves with radon concentrations in excess of the action level. (authors)

Radon in soil variations for Vrancea seismic area

International Nuclear Information System (INIS)

Zoran, M.

2002-01-01

Earthquakes occur as a result of a build up of pressure between colliding sections of the Earth's crust. These sections, known as continental plates, meet at 'fault lines'. According to classical earthquake theory, small earthquakes should continue to grow into large earthquakes until they spread all along the fault line. Vrancea region is fitted to such a model. The mechanical processes of earthquake preparation are always accompanied by deformations, afterwards complex short- or long term precursory phenomena can appear. Macro-fracturing processes are preceded by micro-fracturing phenomena with a resulting radon and other gas precursors (He, CH 4 , NO) anomalies in soil-gas and groundwater. Studies of geochemical and hydrological anomalies preceding significant earthquakes have been reported from China, Japan, Uzbekistan, Mexico, Italy, India and Germany. However, studies of these pre-seismic phenomena have been controversial for several reasons. Temporal variations of radon in soil or water, can give evidence that the emanation of this gas can be correlated with tectonic disturbances. I used nuclear track detectors LR-115 and CN-85 for radon concentration monitoring in soil at 50 cm depth exposed for a period of 30 days in Vrancioaia test area. Time series radon data in soil-gas during of two years long observation period have established that more than 50% of radon concentration increases were correlated with microseismic events of 2-4 magnitude on Richter scale. A clear positive correlation for radon concentration prior one month of seismic event was associated with a registered event of magnitude 5. In order to differentiate the changes due to tectonic disturbances and that of meteorological parameters, were measured barometric pressure, precipitation and temperature. Negative correlation between radon concentration in soil and meteorological parameters was found. To predict a future earthquake, all precursory phenomena must be investigated. The

Changes in environmental radon related with the day eclipse

International Nuclear Information System (INIS)

Gaso P, M.I.; Cervantes, M.L.; Segovia A, N.; Espindola, V.H.

1992-05-01

Systematic studies of radon and of gamma dose in air in the Nuclear Center of Mexico during a period of nine months that include the total Sun eclipse happened at July 11, 1991 were carried out. The radon concentrations were measured with an electronic equipment that measures in continuous form and the rate of gamma dose in air was obtained with a ionization chamber. The results show that the radon fluctuations in air are influenced by the meteorological changes showing behaviors different to long and short term. The variations of long term are correlated directly with the external temperature while those of short term have an inverse relationship with the temperature. These last results are discussed regarding drastic atmospheric changes happened in the period and those light changes result of the total Sun eclipse. The rate of gamma dose in air showed stability during the study. (Author)

Changes in environmental radon related with the day eclipse; Cambios de radon ambiental relacionados con el eclipse del dia 11 de julio 1991

Energy Technology Data Exchange (ETDEWEB)

Gaso P, M I; Cervantes, M L; Segovia A, N; Espindola, V H

1992-05-15

Systematic studies of radon and of gamma dose in air in the Nuclear Center of Mexico during a period of nine months that include the total Sun eclipse happened at July 11, 1991 were carried out. The radon concentrations were measured with an electronic equipment that measures in continuous form and the rate of gamma dose in air was obtained with a ionization chamber. The results show that the radon fluctuations in air are influenced by the meteorological changes showing behaviors different to long and short term. The variations of long term are correlated directly with the external temperature while those of short term have an inverse relationship with the temperature. These last results are discussed regarding drastic atmospheric changes happened in the period and those light changes result of the total Sun eclipse. The rate of gamma dose in air showed stability during the study. (Author)

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

Science.gov (United States)

Mudd, Gavin M

2008-02-01

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

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

International Nuclear Information System (INIS)

Mudd, Gavin M.

2008-01-01

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

Radiometers for radon concentration in air

International Nuclear Information System (INIS)

Bartak, J.; Machaj, B.; Pienkos, J.P.

2002-01-01

Constant grow of science and technology stimulates development of new improved measuring tools. New measuring demand arise also in radon concentration measurements. Varying rock stress and rock cracks influencing radon emanation encouraged research aimed at use of this phenomenon to predict crumps of mine formation among others based on variation of radon emanation. A measuring set was developed in the Institute of Nuclear Chemistry and Technology enabling long term monitoring of radon concentration in mine bore-hole. The set consists probe and probe controller. Detection threshold of the probe is 230 Bq/m 3 . The set can operate in the environment with methane explosion hazard. A radiometer employing Lucas cell as radiation detector for radon concentration in air was also developed its detection threshold is approx. 10 Bq/m 3 . Replaceable Lucas cell of the radiometer allows for measurement of high as well as low radon concentration in short time interval. (author)

Intercomparisons for integrating the radon-thoron detector of NIRP, China with NIRS, Japan

International Nuclear Information System (INIS)

Wu, Yunyun; Cui, Hongxing; Zhang, Qingzhao; Shang, Bing

2015-01-01

Intercomparisons play an important role in maintaining a reasonable and accurate standard of measurement and quality. Integrating the radon-thoron detector of the National Institute for Radiological Protection (NIRP), China has continuously been a subject of four rounds of international intercomparisons organised by the National Institute of Radiological Sciences (NIRS), Japan during 2007-12. The intercomparisons were held at NIRS. The exercises included different exposures for both radon and thoron. The results of the intercomparison for the detectors of NIRP for both radon and thoron exposures were in the range of ±20 % from the reference value and were categorised as 'Category I' in the intercomparison carried out in 2011. The radon and thoron results of the LD-P detector in four rounds of intercomparison exercises were summarised, and uncertainties of all the radon and thoron results of NIRP were within the acceptable range of 30 % in environment. Radon and thoron measurement results between NIRP and NIRS were basically in agreement. (authors)

Radon: a case for public persuasion

International Nuclear Information System (INIS)

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

1996-01-01

The importance of reducing individual to elevated levels of radon is well understood by radiation protection specialists, and successful methods of locating the areas most at risk have been developed. However, less attention has been paid to informing the general public about the health rifles and encouraging those in radon-prone areas to take action. In the United Kingdom, techniques have been developed to persuade householders in high radon areas to take advantage of a government scheme that provides free long-term measurements of radon in the home. Improvements in the methods of contacting householders in the target areas and in the presentation of the facts has resulted in a twofold increase in the rate of take-up of measurements since the first large-scale surveys. (author)

Factors affecting passive monitoring of radon

International Nuclear Information System (INIS)

Asano, Tomohiro; Kahn, B.

1989-09-01

In recent years, increasing cancer has been expressed as a possible health hazards associated with long-term exposures to a large population at a low level of radon in the environment. Because radon is ubiquitous nuclide, nation-wide monitoring is necessary to determine lung cancer risk. For such purpose, passive sampling methods with track etch detector or charcoal adsorption collector may have the advantage in lower cost and convenience. The charcoal adsorption collector is considered in this study. Various factors may significantly affect the charcoal adsorption mechanism on its practical application. Moisture effects are discussed here as having major impact on radon collection by charcoal. Set of equations are presented in this report to describe adsorption of radon including moisture effects. (author) 61 refs

A passive integrating charcoal detector for indoor radon survey

International Nuclear Information System (INIS)

Lin Lianqing; Ren Tianshan; Li Guiyun

1986-01-01

This paper describes the principle, design, calibration and characteristics of a passive integrating charcoal detector for measuring average radon concentration indoors. The uncertainties of the detector are also evaluated. Under conditions of room temperature at 17 deg C and relative humidity at 30%, the minimum limit of detection is 0.16 pCi/1 for 72 hours exposure. Besides higher sensitivity, the other advantages of this detector are passive, simple and less expensive. It requires no power and makes no noise and gives no interference to daily activities of the residents of dwellings being surveyed. Therefore the detector is suitable for a large-scale survey of radon levels indoors

A process-based 222radon flux map for Europe and its comparison to long-term observations

Science.gov (United States)

Karstens, U.; Schwingshackl, C.; Schmithüsen, D.; Levin, I.

2015-11-01

Detailed 222radon (222Rn) flux maps are an essential pre-requisite for the use of radon in atmospheric transport studies. Here we present a high-resolution 222Rn flux map for Europe, based on a parameterization of 222Rn production and transport in the soil. The 222Rn exhalation rate is parameterized based on soil properties, uranium content, and modelled soil moisture from two different land-surface reanalysis data sets. Spatial variations in exhalation rates are primarily determined by the uranium content of the soil, but also influenced by soil texture and local water-table depth. Temporal variations are related to soil moisture variations as the molecular diffusion in the unsaturated soil zone depends on available air-filled pore space. The implemented diffusion parameterization was tested against campaign-based 222Rn soil profile measurements. Monthly 222Rn exhalation rates from European soils were calculated with a nominal spatial resolution of 0.083° × 0.083° and compared to long-term direct measurements of 222Rn exhalation rates in different areas of Europe. The two realizations of the 222Rn flux map, based on the different soil moisture data sets, both realistically reproduce the observed seasonality in the fluxes but yield considerable differences for absolute flux values. The mean 222Rn flux from soils in Europe is estimated to be 10 mBq m-2 s-1 (ERA-Interim/Land soil moisture) or 15 mBq m-2 s-1 (GLDAS (Global Land Data Assimilation System) Noah soil moisture) for the period 2006-2010. The corresponding seasonal variations with low fluxes in winter and high fluxes in summer range in the two realizations from ca. 7 to ca. 14 mBq m-2 s-1 and from ca. 11 to ca. 20 mBq m-2 s-1, respectively. These systematic differences highlight the importance of realistic soil moisture data for a reliable estimation of 222Rn exhalation rates. Comparison with observations suggests that the flux estimates based on the GLDAS Noah soil moisture model on average better

A process-based 222radon flux map for Europe and its comparison to long-term observations

International Nuclear Information System (INIS)

Karstens, U.; Schwingshackl, C.; Schmithuesen, D.; Levin, I.

2015-01-01

Detailed 222 radon ( 222 Rn) flux maps are an essential pre-requisite for the use of radon in atmospheric transport studies. Here we present a high-resolution 222 Rn flux map for Europe, based on a parameterization of 222 Rn production and transport in the soil. The 222 Rn exhalation rate is parameterized based on soil properties, uranium content, and modelled soil moisture from two different land-surface reanalysis data sets. Spatial variations in exhalation rates are primarily determined by the uranium content of the soil, but also influenced by soil texture and local water-table depth. Temporal variations are related to soil moisture variations as the molecular diffusion in the unsaturated soil zone depends on available air-filled pore space. The implemented diffusion parameterization was tested against campaign-based 222 Rn soil profile measurements. Monthly 222 Rn exhalation rates from European soils were calculated with a nominal spatial resolution of 0.083 x 0.083 and compared to long-term direct measurements of 222 Rn exhalation rates in different areas of Europe. The two realizations of the 222 Rn flux map, based on the different soil moisture data sets, both realistically reproduce the observed seasonality in the fluxes but yield considerable differences for absolute flux values. The mean 222 Rn flux from soils in Europe is estimated to be 10 mBq m -2 s -1 (ERA-Interim/Land soil moisture) or 15 mBq m -2 s -1 (GLDAS (Global Land Data Assimilation System) Noah soil moisture) for the period 2006-2010. The corresponding seasonal variations with low fluxes in winter and high fluxes in summer range in the two realizations from ca. 7 to ca. 14 mBq m -2 s -1 and from ca. 11 to ca. 20 mBq m -2 s -1 , respectively. These systematic differences highlight the importance of realistic soil moisture data for a reliable estimation of 222 Rn exhalation rates. Comparison with observations suggests that the flux estimates based on the GLDAS Noah soil moisture model on

Results of long-term measurement of 222Rn concentrations in outdoor atmosphere

International Nuclear Information System (INIS)

Holy, K.; Boehm, R.; Polaskova, A.; Hola, O.

1998-01-01

Results are reported of the authors' long-term measurement of 222 Rn concentrations in the outdoor atmosphere. The measurements started in 1987 and were performed at a height of 1.5 m over a grass-covered ground surface, using till 1991 a Lucas type scintillation chamber and later a large volume scintillation chamber. Graphs are presented and discussed of the course of average monthly radon concentration in 1987-1996 and of annual courses of radon concentration for different time intervals of the day over 1991 to 1995. (A.K.)

A Radon Micro Study of Salthill, Galway

International Nuclear Information System (INIS)

Boyle-Tobin Ann

2006-01-01

This project presents a study of radon gas, when it enters from the ground into the built environment. In order to further inform the present body of knowledge on this potentially dangerous gas, a radon micro study is carried out in the area of Salthill, Galway. A total of 51 households are measured for radon. The results indicate a high variation in the levels recorded, with over a third of the houses measuring above the national safe standard of 200 becquerels per cubic meter, with a small percentage of houses exhibiting very high levels. The results are spatially analysed against the local geology, as radon is a by-product of the breakdown of uranium in rocks. Householders' knowledge and awareness of radon is explored to inform the reasons why more people are not testing their homes for radon, and not installing remedial measures when high levels are detected. The findings indicate significant gaps in householders' knowledge of radon. A certain complacency is noted, which may indicate that people still do not recognise a need to know about this invisible threat. As ways to encourage further testing and remediation levels are equally explored, the government is viewed to play a central role in these processes through partial state funding. Further evidence supports continued and more effective and widespread advertising of radon issues, through all types of media, with emphasis at local level. Incidents of lung cancer and lung disease of long term residents are recorded in an attempt to find out if there is a correlation between them. The results indicate no correlation; however, not all households could participate in this part of the survey as it was limited to long-term residents only

Difficulties in radon measurements at workplaces

International Nuclear Information System (INIS)

Kavasi, Norbert; Kovacs, Tibor; Nemeth, Csaba; Szabo, Tibor; Gorjanacz, Zoran; Varhegyi, Andras; Hakl, Jozsef; Somlai, Janos

2006-01-01

Different legislation systems can be found in the world concerning radon levels at workplaces. Following the European Union suggestion, a reference level for radon concentration in the air at workplaces was established in several European countries. In Hungary, the relevant legislation has come into effect on 1 January 2003. The determination of average radon concentration might present a problem, especially in places where the monthly average concentrations vary to a great extent. For example, the monthly averages measured in a hospital cave used for treating respiratory diseases showed a 24-fold difference depending on the chosen month. In such cases, attention should be paid when choosing the months and using the results of measurements for dose assessment. Another uncertainty emerges when estimating the annual dose, based on the data coming from long-term measurements, usually using integrated methods such as track detectors. There is a considerable difference between the averages measured during the working hours and over the total time (including nights and weekends), mostly in the cases of rooms with frequent air change like schools, kindergartens and ventilated workplaces. This can lead to a significant overestimation in dose calculation. Special attention needs to be paid to workplaces such as mines, tunnels and open air uranium tailings sites. This paper discusses the possible inaccuracies caused by the improper selection of time periods and methods in the measurements of the average radon concentration at workplaces

Uranium and radon surveys in western Himalaya

International Nuclear Information System (INIS)

Virk, H.S.

1997-01-01

The water samples from mountain springs, streams and river systems in the western Himalaya were collected and analysed in the laboratory for uranium and radon contents. It is observed that the Himalayan river system is conspicuous by its high dissolved uranium and radium concentration. The water samples contain from 0.89 ppb to 63.4 ppb of uranium and from 34 Bq/I to 364 Bq/I of radon. The radon emanation in soil is measured by the track-etch method, emanometry and alpha-logger technique. The daily and long-term variation of radon was monitored in some mineralized zones of Himachal Pradesh (HP) state with high uranium content in the soil. The maximum values of radon are recorded in Chhinjra, Rameda, Samurkala and Kasol areas of HP. (author)

Occupational exposure to radon in Australian Tourist Caves an Australian-wide study of radon levels

Energy Technology Data Exchange (ETDEWEB)

Solomon, S B; Langroo, R; Peggie, J R [Australian Radiation Laboratory. Yallambie, VIC (Australia); Lyons, R G [University of Auckland, Auckland, (New Zealand). Department of Physics; James, J M [University of Sydney, Sydney, NSW (Australia). Department of Chemisty

1996-02-01

The study described in this report sets out to determine which Australian show caves have long- term radon levels in excess of the proposed action level of 1000 Bq m{sup -3}. The collaborative study between the Australian Radiation Laboratory (ARL), the University of Sydney and the University of Auckland, was carried out with the support of a Research Grant from Worksafe Australia. The aims of this study were to measure radon levels for each season over a period of one year, at representative sites in all developed show caves around Australia, to determine yearly average radon levels for each cave tour, based on these site measurements, to estimate the radiation doses to the tour guides employed in these caves, and to identify caves with radon concentrations in excess of the action level. (authors) 7 refs., 10 tabs., 2 figs.

Application of nuclear track detectors for radon related measurments

International Nuclear Information System (INIS)

Abu-Jarad, F.A.

1988-01-01

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

The use of long-lived 222Rn decay products (LRnD) as natural tracers in the indoor environment

International Nuclear Information System (INIS)

Samuelsson, C.

1998-01-01

In the radioactive decay chain following 222 Rn (radon) the first long-lived product 210 Pb (t 1/2 = 22.3 y) acts like a stopper and its decay products can be utilized as integrators of passed radon gas levels and a tracer reflecting long-term aerosol particle deposition processes. Long-term integration is feasible only if the LRnD activity is hidden away from the destructive practices of everyday life, such as cleaning and refurbishing. Three type of LRnD hide away places (traps) can be identified: i) Inside the human body, ii) Inside porous volumes, and iii) In surface implants. The volume trap (ii) is advantageous as it is a pure radon gas detector and as such not influenced by the indoor aerosol conditions. The drawbacks are that suitable samples is difficult to find and that tedious radio chemistry is mandatory. Alpha-recoil implanted LRnD activity (iii) into hard surfaces is the only type of trap that is suitable for large-scale retrospective measurements and the main emphasis of this contribution will be on implanted activity. Fortunately, cheap in-situ track-etch methods are now available for specific detection of implanted 210 Po into flat glass surfaces. In the ongoing Swedish non-smoker radon study only samples older than 20 years are accepted and a tentative calibration factor of 0.84 Bq.m -2 of implanted 210 Po per kBq.y.m -3 radon gas exposure is used. The aim of this contribution is to draw attention to a fairly recent field of application in the radon indoor environment, where long-lived radon daughter are used to indicate past radon concentration levels

Radon measurements in Rio de Janeiro

International Nuclear Information System (INIS)

Magalhaes, M.H.; Amaral, E.C.S.; Sachett, I.

2002-01-01

Few data are available on the dynamic of radon in the air for tropical climate conditions. The strong influence of the climatological characteristics on the transport of gases and particulates in air makes not adequate the use of data obtained at regions with different climate. Outdoor and indoor measurements of radon equilibrium equivalent concentrations (EEC) have been done for one-year period in Rio de Janeiro. Continuous measurements were performed using a radon monitor with an alpha spectrometry detector. Pluviometric index, temperature and humidity were registered. The paper presents the long term behaviour of outdoor radon equilibrium equivalent concentration results, their correlation with temperature and the influence of the pluviometric index. Maximum values were obtained during winter and minimum in summer, strongly influenced by the rain. A strong inverse correlation with temperature was found. (author)

On the behaviour of radon in indoor air

International Nuclear Information System (INIS)

Lehtimaeki, M.; Kivistoe, T.

1983-01-01

In this work the behaviour of radon in indoor air has been studied. A simple mathematical model is presented to describe the variations in radon concentration in case of a periodic ventilation. This model has been tested with the aid of long-term measurements in two office buildings, in a large shipyard hall, and in a dwelling. The variations predicted by the simple model were observed in all buildings studied. It seems even possible that if the mixing of radon in the building is effective, the radon measurements can be used in estimating the infiltration rates. The measurement in one of the office buildings, however, indicated that the mixing of radon in a many-storied building can be extremely incomplete. The measurements also indicate that the soil can be a very important source of radon. (orig.) [de

Monitoring of the Syrian rift valley using radon technique

International Nuclear Information System (INIS)

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

1997-02-01

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

Benefit-cost aspects of long-term isolation of uranium mill tailings

International Nuclear Information System (INIS)

Van Dyke, J.

1983-11-01

The Uranium Mill Tailings Radiation Control Act of 1978 provides for regulations for control of radon diffusion from uranium mill tailings to protect the public welfare. In developing these regulations, the Office of Nuclear Material Safety and Safeguards of the Nuclear Regulatory Commission has sought to establish the benefits and costs for alternative regulatory criteria. This report provides a perspective on some economic issues associated with long-term radiation effects from disposal of uranium mill tailings. The general problem of developing an economic rationale for regulating this activity is complicated by the very long-term and widespread effects which could result from radon gas diffusion associated with tailings piles. The economic issues are also complex because of the trade-offs between costs of disposal and intangible social values. When intergenerational implications were considered the traditional basis for discounting in a benefit-cost framework was found to shift. The appropriate rate of discount was found to depend on ethical assumptions and expectations about the relative welfare of future generations. 30 references, 1 figure, 2 tables

Benefit-cost aspects of long-term isolation of uranium mill tailings

Energy Technology Data Exchange (ETDEWEB)

Van Dyke, J.

1983-11-01

The Uranium Mill Tailings Radiation Control Act of 1978 provides for regulations for control of radon diffusion from uranium mill tailings to protect the public welfare. In developing these regulations, the Office of Nuclear Material Safety and Safeguards of the Nuclear Regulatory Commission has sought to establish the benefits and costs for alternative regulatory criteria. This report provides a perspective on some economic issues associated with long-term radiation effects from disposal of uranium mill tailings. The general problem of developing an economic rationale for regulating this activity is complicated by the very long-term and widespread effects which could result from radon gas diffusion associated with tailings piles. The economic issues are also complex because of the trade-offs between costs of disposal and intangible social values. When intergenerational implications were considered the traditional basis for discounting in a benefit-cost framework was found to shift. The appropriate rate of discount was found to depend on ethical assumptions and expectations about the relative welfare of future generations. 30 references, 1 figure, 2 tables.

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

International Nuclear Information System (INIS)

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

2018-01-01

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

Response of Radon in a seismic calibration explosion, Israel

International Nuclear Information System (INIS)

Zafrir, H.; Steinitz, G.; Malik, U.; Haquin, G.; Gazit-Yaari, N.

2009-01-01

Radon measurements were performed at shallow levels during an in-land 20-ton seismic calibration explosion experiment, simulating a 2.6-M L earthquake, to investigate the influence of the explosive blast and the transitory seismic wave fields on the Radon transport in the country rock, adjacent to the focus of the explosion. The experiment was conducted in a basalt quarry in the northern margin of the Beit Shean valley (Israel). Five gamma-ray sensors were placed, at a depth of about 2 m, along a line located 17-150 m from the edge of the explosion zone. Measurements commenced 4 days before and continued for 9 days after the explosion with 15 min integrations. A 10-s sampling was used in the interval of several hours before and after the explosion itself. Diurnal variations of Radon, reflecting the typical variation pattern of Radon in the shallow environment, were registered before and after the explosion. No significant change in the overall Radon concentration was observed as a consequence of the main explosion as well as three smaller experimental shots (0.5-2 tons) in the 2 h prior to the calibration blast. The seismological data indicate that the transient excess pressure at the farthest Radon sensor was above 5 bar m -1 during 0.2-0.4 s, and evidently much higher at the nearest sensors, but none of the sensors responded by recording any exceptional change in the Radon concentration. Moreover the hypothesis that additional Radon may emanate from solid grains as a result of the excess local pressure exerted by the blast is also not observed. In contrast to a real earthquake event an explosion experiment has neither eventual preceding nor following geodynamic activity. Therefore the absence of significant Radon anomalies during or after the blast does not contradict assumptions, observations or conclusions as the occurrence of Radon anomalies prior or after an earthquake event due to associated long-term geodynamic processes.

A passive monitor for radon using electrochemical track etch detector

International Nuclear Information System (INIS)

Massera, G.E.; Hassib, G.M.; Piesch, E.

1980-01-01

A passive, inexpensive monitor for radon detection and dosimetry is described in detail. It consists of a Makrofoil track etch detector inside a diffusion chamber which is sealed by a fibreglass filter through which radon may diffuse while radon daughters and aerosols are retained on the surface of the filter. The α-particle tracks are revealed by etching the Makrofoil in KOH. The lower detection limit of the radon dosimeter is equivalent to a mean dose in the lung of 130 mrem. After an exposure period of 3 months, a mean radon concentration of 0.3 pCi/l can be detected. The instrument is intended for use in a study to measure the long-term radon exposure in buildings in West Germany. (UK)

Short- and long-term monitoring of radon, thoron and carbon dioxide in soil-gas at Altos de pipe, Venezuela

International Nuclear Information System (INIS)

LaBrecque, J.J.; Cordoves, P.R.

2004-01-01

Radon and thoron activities in soil-gases have been measured since July 9, 1997 Cariaco earthquake (Mw=6.9) until the end of 2000. Carbon dioxide concentrations were also monitored between 1998-2000. The soil-gas was collected between 50-55 cm depths at two sampling points at Altos de pipe (Instituto Venezolano de Investigaciones Cientificas-IVIC) near Caracas, Venezuela. The radon and thoron measurements were performed daily employing radiation monitors with scintillation cells and the carbon dioxide was monitored with portable gas analyzers. Average weekly and monthly values were calculated and plotted for this three-four year period. In general, both the radon and carbon dioxide values showed sinusoidal trends due to seasonal changes. During the dry season the radon and carbon dioxide values decreased, while the radon activity was relative constant (flat) during the rainy season at one of the sampling points. Only two monthly radon values were seen to be anomalous in the graphs in respect to seven anomalous periods for the average weekly values. No anomalous periods were clearly seen for carbon dioxide. Finally, it was difficult to try to relate these radon anomalous periods with specific earthquakes due to the large number of minor earthquakes during these years, but it seem that the minor earthquake (Mb=5.9) of October 4, 2000 could be associated with the radon anomalous period in September, when there were no other minor earthquakes (Mb≥4.0). (author)

Health effects of radon

International Nuclear Information System (INIS)

Easterly, C.

1994-01-01

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

THE REPUBLIC OF BELARUS RADON DANGER MAP

Directory of Open Access Journals (Sweden)

L. A. Chunikhin

2016-01-01

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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. (authors)

Construction materials and Radon

International Nuclear Information System (INIS)

Paschuk, Sergei A.; Correa, Janine Nicolosi; Loriane, Fior; Schelin, Hugo R.; Pottker, Fabiana; Paula Melo, Vicente de

2008-01-01

Full text: Current studies have been performed with the aim to find the correlation of radon concentration in the air and used construction materials. At the first stage of the measurements different samples of materials used in civil construction were studied as a source of radon in the air and at the second step it was studied the radon infiltration insulation using different samples of finishing materials. For 222 Rn concentration measurements related to different construction materials as well as for the studies of radon emanation and its reduction, the sealed cell chambers, of approximately 60 x 60cm 2 , have been built using the ceramic and concrete blocks. This construction has been performed within protected and isolated laboratory environment to maintain the air humidity and temperature stable. These long term measurements have been performed using polycarbonate alpha track passive detectors. The exposure time was set about 15 days considering previous calibration performed at the Institute of Radiation Protection and Dosimetry (IRD/CNEN), where the efficiency of 70% was obtained for the density of alpha particle tracks about 13.8 cm -2 per exposure day and per kBq/m 3 of radon activity concentration. The chemical development of alpha tracks has been achieved by electrochemical etching. The track identification and counting have been done using a code based on the MATLAB Image Processing Toolbox. The cell chambers have been built following four principle steps: 1) Assembling the walls using the blocks and mortar; 2) Plaster installation; 3) Wall surface finishing using the lime; 4) Wall surface insulation by paint. Making the comparison between three layers installed at the masonry walls from concrete and ceramic blocks, it could be concluded that only wall painting with acrylic varnish attended the expectation and reduced the radon emanation flow by the factor of 2.5 approximately. Studied construction materials have been submitted the instant

A continuous monitor for the measurement of environmental radon

International Nuclear Information System (INIS)

Chittaporn, P.; Eisenbud, M.; Harley, N.H.

1981-01-01

Although inhaled short-lived 222 Rn daughters deliver the pertinent α dose for assessing human health effects, radon daughters do not of themselves exist in any atmosphere for more than 2-3 hr. Their long-lived parent (3.82 day) 222 Rn supports the daughter activity and it is the transport of 222 Rn which ultimately determines dose. Without an understanding of the long and short-term temporal patterns of indoor and outdoor 222 Rn it is impossible to understand the factors which are important in establishing any human health hazard from the daughters. This work describes a new continuous environmental radon monitor which measures radon alone without interference from radon daughters. The detector is a cylinder (13 cm diameter x 14 cm high), is lined with alpha scintillation phospor on a Mylar substrate and is portable and easily constructed from inexpensive and commercially available materials. (author)

Draft of „National Radon Programme” 2013-2017

International Nuclear Information System (INIS)

Ivanova, K.; Badulin, V.; Georgieva, R.

2013-01-01

The World Health Organization defines radon as the second most important causal factor for lung cancer after smoking and the number one factor for people who have never smoked. The draft of the new European Directive takes accounts the latest ICRP Recommendations for reducing radon exposure in buildings. The Directive requires Member States to bring into force the laws, regulations and administrative provisions. The main goal of „National Radon Programme” is establishment and implementation of long-term policy to reduce and prevent risks of public health resulting from exposure to high concentrations of indoor radon in buildings. To achieve this are required: – to establish an appropriate system; – to carry out national survey and mapping of areas with radon background; – to establish radon prevention strategies in newly constructed buildings and radon mitigation strategies in existing buildings; – to improve public awareness; – to lay down a system for protection against radon in workplaces. The implementation of the program will contribute to reducing the public exposure due to indoors due to radon. Along with the reduction of smoking, it will directly and indirectly improve the prevention of lung cancer risks. (author)

Measurement of Radon concentration in groundwater by technique of nuclear track detector

International Nuclear Information System (INIS)

Trinh Van Giap; Nguyen Manh Hung; Dang Duc Nhan

2000-01-01

A method for measuring radon concentration in groundwater using nuclear track detector LR-115 stripping is reported. The radon-monitoring device in groundwater is a small box with two pieces of nuclear track detector and all these materials is placed in a plastic bag made by polyethylene. It is very suitable to measure radon concentration in groundwater well in long term. Alpha tracks produced by radon and it daughter on nuclear track detector is counted automatically by spark counting method. The paper also presents some results of radon concentration in some groundwater well and mineral water sources. (author)

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

International Nuclear Information System (INIS)

Mayya, Y.S.

2008-01-01

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

Radon variations in the Wellington region, New Zealand, and their relation to earthquakes

International Nuclear Information System (INIS)

Robinson, R.; Whitehead, N.E.

1992-01-01

Temporal changes in the radon content of ground water and soil gas have been monitored in the Wellington region since early 1978 in order to examine their relation to earthquakes. New Zealand is a region of plate convergence and subduction with a moderate level of seismicity, both crustal and deep. The measurement technique is of the 'Track Edge' type and is simple and inexpensive to implement but is subject to several sources of error. The major feature of the data, in the form of monthly mean radon levels, is a large long term rise and fall in level lasting 2 1/2 to 3 years. Data from five sites are well correlated due to this feature but shorter term fluctuations are less well correlated. Effects of changes in the weather are small. The long term radon 'anomaly' cannot be convincingly related to any particular earthquake. Nor do earthquakes up to magnitude 5.2 within 100km show any clear effect on the radon level. Despite the lack of clear precursory effects due to specific earthquakes, there are some weak correlations between the radon level and the seismicity as a whole. These correlations, if physically real imply that post-event effects on radon are at least as important as precursory effects. However, it is not certain that the radon level is directly affected by earthquakes at all. It seems likely that the radon level reflects changes in regional strain rate that also monitor the seismicity. (auth). 14 refs., 6 figs., 4 tabs

Radon programme in Czech Republic. Results, experience and future

International Nuclear Information System (INIS)

Hulka, J.; Thomas, J.; Fojtikova, I.; Vlcek, J.; Moucka, L.; Fronka, A.; Jilek, K.; Heribanova, A.; Slovak, J.; Barnet, I.; Burian, I.; Jiranek, M.; Cechak, T.

2004-01-01

, identified with the help of geological radon prediction maps and results of representative indoor radon surveys. It is expected that some 60000-70000 family houses will be above the intervention level of 400 Bq/m 3 . A total of 130000 such houses have been examined so far, and 20000 of them were above the intervention level. Building owners can apply for governmental radon mitigation subsidy. Prior to remedial measures, radon diagnosis is carried out to objectify the radon concentrations, identify radon sources and prepare the radon mitigation design. Since a survey of the long-term effectiveness of remedial measures has shown that 25 % of them failed in some years, long-term after-mitigation test measurements are of importance. A Radon Bulletin and special leaflets are published periodically to improve public awareness of the radon issue. A quantitative survey gave evidence that the level of awareness among the Czech population is 75 %

Measurement Techniques for Radon in Mines, Dwellings and the Environment

International Nuclear Information System (INIS)

Snihs, J.O.

1983-06-01

Definitions and units appropriate for radon and radon daughters are given. The principle methods of detection are ionization chamber, scintillation technique, nuclear track detector, thermoluminescent discs and alpha spectrometry. The activity concentration is determined by grab sampling and subsequent measurement, frequent or continuous grab sampling and measurement and continuous sampling and long time integrated measurement. Sampling and measurement strategies for mines, dwellings and the environment are discussed. (author)

Indoor radon measurements and methodologies in Latin American countries

International Nuclear Information System (INIS)

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

2001-01-01

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

Indoor radon survey in Eastern Sicily

International Nuclear Information System (INIS)

Catalano, R.; Immè, G.; Mangano, G.; Morelli, D.; Tazzer, A. Rosselli

2012-01-01

Inhalation of radon (Rn-222) and its progeny is one of the most significant sources of natural radiation exposure of the population. Nowadays, high radon exposures have been shown to cause lung cancer and many governments all over the world have therefore recommended that radon exposures in dwellings and indoor workplaces should be limited. Radon levels in buildings vary widely from area to area depending on local geology. This paper presents the results of a long-term survey of radon concentrations carried out from 2005 till 2010 in schools and dwellings of Eastern Sicily, using the solid-state nuclear track detector (SSNTD) technique. The investigated area shows medium-high indoor radon concentrations, higher than the Italian average of about 70 Bq/m 3 , with peaks of 500 Bq/m 3 or more in buildings near active faults. Fortunately, only a small fraction of the measurements, about 1.5% of total, was found greater than EU and Italian action limits for indoor and workplaces. - Highlights: ► In this paper we report radon monitoring survey carried out in the east Sicily in schools and dwellings. ► The detection methodology was the solid-state nuclear track detector one. ► The work was supported by a national projects financed by the National Institute of Nuclear Physics.

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

International Nuclear Information System (INIS)

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

1995-02-01

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

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

DEFF Research Database (Denmark)

Brauner, Elvira Vaclavik; Loft, Steffen; Sørensen, Mette

2015-01-01

Background Although exposure to UV radiation is the major risk factor for skin cancer, theoretical models suggest that radon exposure can contribute to risk, and this is supported by ecological studies. We sought to confirm or refute an association between long-term exposure to residential radon...... and the risk for malignant melanoma (MM) and non-melanoma skin cancer (NMSC) using a prospective cohort design and long-term residential radon exposure. Methods During 1993-1997, we recruited 57,053 Danish persons and collected baseline information. We traced and geocoded all residential addresses...... exposure may contribute to development of basal cell carcinoma of the skin. We cannot exclude confounding from sunlight and cannot conclude on causality, as the relationship was stronger amongst persons living in apartments and nonexistent amongst those living in single detached homes....

The use of track-etch detectors for assessing radon concentrations

International Nuclear Information System (INIS)

Kendall, G.M.

2002-01-01

The author describes the track-etch dosimetry system used by the National Radiological Protection Board for measuring radon concentrations in dwellings and in workplaces. It also considers the criteria which should be satisfied by an ideal radon dosimetry system aimed at large-scale assessments of the risk from inhalation of radon decay products in room air. The present NRPB track-etch dosimetry system is matched against the requirements of such and ideal system. There is a brief description of the role of screening measurements designed to show whether there are dangerous levels of radon decay products in a house without giving an accurate assessment of their true long-term average concentration

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

International Nuclear Information System (INIS)

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

2007-01-01

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

Development of a Risk-Based Performance Assessment Method for Long-Term Cover Systems--Application to the Monticello Mill Tailings Repository

International Nuclear Information System (INIS)

HO, CLIFFORD K.; ARNOLD, BILL W.; COCHRAN, JOHN R.; WEBB, STEPHEN W.; TAIRA, RANDAL Y.

2001-01-01

A probabilistic, risk-based performance-assessment methodology is being developed to assist designers, regulators, and involved stakeholders in the selection, design, and monitoring of long-term covers for contaminated subsurface sites. This report presents an example of the risk-based performance-assessment method using a repository site in Monticello, Utah. At the Monticello site, a long-term cover system is being used to isolate long-lived uranium mill tailings from the biosphere. Computer models were developed to simulate relevant features, events, and processes that include water flux through the cover, source-term release, vadose-zone transport, saturated-zone transport, gas transport, and exposure pathways. The component models were then integrated into a total-system performance-assessment model, and uncertainty distributions of important input parameters were constructed and sampled in a stochastic Monte Carlo analysis. Multiple realizations were simulated using the integrated model to produce cumulative distribution functions of the performance metrics, which were used to assess cover performance for both present- and long-term future conditions. Performance metrics for this study included the water percolation reaching the uranium mill tailings, radon flux at the surface, groundwater concentrations, and dose. Results of this study can be used to identify engineering and environmental parameters (e.g., liner properties, long-term precipitation, distribution coefficients) that require additional data to reduce uncertainty in the calculations and improve confidence in the model predictions. These results can also be used to evaluate alternative engineering designs and to identify parameters most important to long-term performance

Nucleolar integrity is required for the maintenance of long-term synaptic plasticity.

Directory of Open Access Journals (Sweden)

Kim D Allen

Full Text Available Long-term memory (LTM formation requires new protein synthesis and new gene expression. Based on our work in Aplysia, we hypothesized that the rRNA genes, stimulation-dependent targets of the enzyme Poly(ADP-ribose polymerase-1 (PARP-1, are primary effectors of the activity-dependent changes in synaptic function that maintain synaptic plasticity and memory. Using electrophysiology, immunohistochemistry, pharmacology and molecular biology techniques, we show here, for the first time, that the maintenance of forskolin-induced late-phase long-term potentiation (L-LTP in mouse hippocampal slices requires nucleolar integrity and the expression of new rRNAs. The activity-dependent upregulation of rRNA, as well as L-LTP expression, are poly(ADP-ribosylation (PAR dependent and accompanied by an increase in nuclear PARP-1 and Poly(ADP ribose molecules (pADPr after forskolin stimulation. The upregulation of PARP-1 and pADPr is regulated by Protein kinase A (PKA and extracellular signal-regulated kinase (ERK--two kinases strongly associated with long-term plasticity and learning and memory. Selective inhibition of RNA Polymerase I (Pol I, responsible for the synthesis of precursor rRNA, results in the segmentation of nucleoli, the exclusion of PARP-1 from functional nucleolar compartments and disrupted L-LTP maintenance. Taken as a whole, these results suggest that new rRNAs (28S, 18S, and 5.8S ribosomal components--hence, new ribosomes and nucleoli integrity--are required for the maintenance of long-term synaptic plasticity. This provides a mechanistic link between stimulation-dependent gene expression and the new protein synthesis known to be required for memory consolidation.

Radiation exposure due to radon and radon daughters

International Nuclear Information System (INIS)

Ullmann, W.

1976-01-01

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

Radon exhalation from building materials for decorative use

Energy Technology Data Exchange (ETDEWEB)

Chen Jing, E-mail: jing.chen@hc-sc.gc.c [Radiation Protection Bureau, Health Canada, 775 Brookfield Road, Ottawa K1A 1C1 (Canada); Rahman, Naureen M.; Atiya, Ibrahim Abu [Radiation Protection Bureau, Health Canada, 775 Brookfield Road, Ottawa K1A 1C1 (Canada)

2010-04-15

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{sup -2} d{sup -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{sup -2} d{sup -1} for slate tiles and 42 Bq m{sup -2} d{sup -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{sup -2} d{sup -1}, it would contribute only 18 Bq m{sup -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.

Seasonal Variability in European Radon Measurements

Science.gov (United States)

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

2009-04-01

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

A process-based {sup 222}radon flux map for Europe and its comparison to long-term observations

Energy Technology Data Exchange (ETDEWEB)

Karstens, U. [Max-Planck-Instistut fuer Biogeochemie, Jena (Germany); Schwingshackl, C.; Schmithuesen, D.; Levin, I. [Heidelberg Univ. (Germany). Inst. fuer Umweltphysik

2015-07-01

Detailed {sup 222}radon ({sup 222}Rn) flux maps are an essential pre-requisite for the use of radon in atmospheric transport studies. Here we present a high-resolution {sup 222}Rn flux map for Europe, based on a parameterization of {sup 222}Rn production and transport in the soil. The {sup 222}Rn exhalation rate is parameterized based on soil properties, uranium content, and modelled soil moisture from two different land-surface reanalysis data sets. Spatial variations in exhalation rates are primarily determined by the uranium content of the soil, but also influenced by soil texture and local water-table depth. Temporal variations are related to soil moisture variations as the molecular diffusion in the unsaturated soil zone depends on available air-filled pore space. The implemented diffusion parameterization was tested against campaign-based {sup 222}Rn soil profile measurements. Monthly {sup 222}Rn exhalation rates from European soils were calculated with a nominal spatial resolution of 0.083 x 0.083 and compared to long-term direct measurements of {sup 222}Rn exhalation rates in different areas of Europe. The two realizations of the {sup 222}Rn flux map, based on the different soil moisture data sets, both realistically reproduce the observed seasonality in the fluxes but yield considerable differences for absolute flux values. The mean {sup 222}Rn flux from soils in Europe is estimated to be 10 mBq m{sup -2} s{sup -1} (ERA-Interim/Land soil moisture) or 15 mBq m{sup -2} s{sup -1} (GLDAS (Global Land Data Assimilation System) Noah soil moisture) for the period 2006-2010. The corresponding seasonal variations with low fluxes in winter and high fluxes in summer range in the two realizations from ca. 7 to ca. 14 mBq m{sup -2} s{sup -1} and from ca. 11 to ca. 20 mBq m{sup -2} s{sup -1}, respectively. These systematic differences highlight the importance of realistic soil moisture data for a reliable estimation of {sup 222}Rn exhalation rates. Comparison with

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

NARCIS (Netherlands)

DEMEIJER, RJ; STOOP, P; PUT, LW

1992-01-01

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

Radon/radon-daughter measurement methods and instrumentation

International Nuclear Information System (INIS)

Rock, R.L.

1977-01-01

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

Environmental implications of electricity generation in an integrated long-term planning framework

International Nuclear Information System (INIS)

Turner, Graham M.; West, James

2012-01-01

Long-term, integrated modelling of electricity generation capacity and its operational requirements is important for coherent energy policy because of the multi-decadal lifespan of such plant, and because related fuel requirements, water consumption, and greenhouse gas emissions impact other sectors. This paper describes a physical model of electricity generation designed for long-term simulations, including the reproduction of decades of historical data, and its application to key policy questions. The simulation uses a dynamic, physical input–output model for the basic material and energy industries, embedded in an economy-wide stocks and flows framework (SFF). The historical reproduction, illustrated for the state of Victoria, is based on integrating bottom-up technical data on physical processes as inputs, and validating output against top-down aggregate data. We show that while greenhouse gas emissions would decrease significantly with the aggressive introduction of cleaner generation technology, long-term reductions are difficult to maintain against ongoing growth in consumption. Additionally, our sensitivity analysis identifies the importance of rapid action due to the age structure of operating power stations. We also identify significant imposts of alternative power generation on land and water resources, though a business-as-usual scenario would impose greater losses of water resources. - Highlights: ► System-wide dynamic analysis is needed to avoid unintended adverse environmental outcomes. ► Dynamics of long-lived plant is important in transitions for reducing greenhouse gas emissions. ► Large gains in GHG emissions efficiency of generation portfolios fail to maintain low emissions.

Do the earth tides have an influence on short-term variations in radon concentration?

International Nuclear Information System (INIS)

Barnet, I.; Prochazka, J.; Skalsky, L.

1997-01-01

The short term (diurnal) indoor radon variations are often explained as a result of temperature and air pressure changes inside a dwelling (the so-called stack effect). The observations of indoor and soil gas radon variations related to the temperature and pressure variations in a test dwelling at Lipova, Northern Bohemia, have not proved the expected correlation between the radon and climatic parameters. The stack effect was clearly observed at the beginning of the four week cycles, when the indoor temperature growth was obvious. However, the indoor radon variations were of the same range or higher than at the beginning of the cycles during the whole week cycles, even when the temperature changes were of the 1-3 o C range. A theory is therefore presented, supported by the known fluctuations of the groundwater level caused by the Earth tides, and the widely observed free air radon variations. According to this theory, the Earth tides lead to the compression of the aquifers and synchronous rise of the groundwater level, which displaces the soil gas with radon into the atmosphere or dwellings. The Earth tide components were calculated for the studied locality and time intervals. The very good phase fit of the amplitudes of gravity variations, vertical and volume strain and vertical displacement with the indoor radon variations was found. This agreement leads to the conclusion that the Earth tides can be considered as one of the causes of the indoor radon variations. This conclusion is also supported by the observations of the radon variations in the underground unventilated spaces under constant temperature and air pressure conditions. (Author)

Human perception of radon risk and radon mitigation: Some remarks

International Nuclear Information System (INIS)

Neznal, M.; Neznal, M.

2008-01-01

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

Development of a Risk-Based Probabilistic Performance-Assessment Method for Long-Term Cover Systems - 2nd Edition

International Nuclear Information System (INIS)

HO, CLIFFORD K.; ARNOLD, BILL W.; COCHRAN, JOHN R.; TAIRA, RANDAL Y.

2002-01-01

A probabilistic, risk-based performance-assessment methodology has been developed to assist designers, regulators, and stakeholders in the selection, design, and monitoring of long-term covers for contaminated subsurface sites. This report describes the method, the software tools that were developed, and an example that illustrates the probabilistic performance-assessment method using a repository site in Monticello, Utah. At the Monticello site, a long-term cover system is being used to isolate long-lived uranium mill tailings from the biosphere. Computer models were developed to simulate relevant features, events, and processes that include water flux through the cover, source-term release, vadose-zone transport, saturated-zone transport, gas transport, and exposure pathways. The component models were then integrated into a total-system performance-assessment model, and uncertainty distributions of important input parameters were constructed and sampled in a stochastic Monte Carlo analysis. Multiple realizations were simulated using the integrated model to produce cumulative distribution functions of the performance metrics, which were used to assess cover performance for both present- and long-term future conditions. Performance metrics for this study included the water percolation reaching the uranium mill tailings, radon gas flux at the surface, groundwater concentrations, and dose. Results from uncertainty analyses, sensitivity analyses, and alternative design comparisons are presented for each of the performance metrics. The benefits from this methodology include a quantification of uncertainty, the identification of parameters most important to performance (to prioritize site characterization and monitoring activities), and the ability to compare alternative designs using probabilistic evaluations of performance (for cost savings)

Psychosocial aspects of Czech Radon Programme

International Nuclear Information System (INIS)

Fojtikova, I.; Neznal, M.; Hrdy, L.

2004-01-01

In November 1999 a radon awareness survey was conducted among Czech republic residents to evaluate their general awareness and the factual knowledge about radon, radon measurements and radon mitigation. This survey, however, did not provide any detailed information on whether the respondents' knowledge is deep and structured or it is just a chaotic mixture of impressions. Therefore, a new survey was conducted from May to November 2001. About 20 respondents, in whose houses the long term testing for radon levels had just been finished, were interviewed. The in-depth interviews had several main aims: a) to obtain a more detailed understanding of their general awareness and factual knowledge about radon; b) to learn more about the sources of their knowledge and of their perception of the radon risk; c) to get information as to whether householders accept radon remediation, and to identify any personal, attitudinal or other variables that can influence the householder's decision; and d) to experience the direct risk communication and conceive its effectiveness. The interviews confirmed some results of the former quantitative study, e.g. increasing knowledge correlating with increasing education level. They showed that the public, overloaded with information, is not disposed to search actively for other information sources (e.g. on the Internet). People perceive their knowledge as adequate and sufficient. Their approach to gathering information is very passive. Therefore, to enhance public understanding of radiation phenomena it is necessary to make efforts, including the use of public media, otherwise radioactivity will remain shrouded in myths. These myths often lead to underestimation of the radon risk. A typical example of such underestimation is a contention that there exist long-aged healthy people who live in extreme radon concentrations. Together with the interviews, a questionnaire describing 11 presumably risky situations or practices was used. Among other

Factors affecting long-term integrity of transmission pipelines; Facteurs affectant l'integrite a long terme des gazoducs

Energy Technology Data Exchange (ETDEWEB)

Hagiwara, N.; Masuda, T.; Oguchi, N. [Tokyo Gas Co., Ltd. (Japan)

2000-07-01

For upgrading long-term integrity of transmission pipelines, two types of delayed fracture in regions of mechanical damage in pipelines were investigated. Experimental and numerical studies clarified factors affecting the fatigue behavior of line pipes containing an idealized flaw under fluctuating internal pressure. To investigate fatigue cracking at mechanical damage in pipelines, degradation of fracture toughness and fatigue properties due to plastic pre-strain was also evaluated. A fracture mechanics-based study revealed conditions necessarily for initiation of hydrogen stress cracking (HSC) at a surface defect in line pipes under cathodic protection. (authors)

Radon and the seal offered by the building shell

International Nuclear Information System (INIS)

Crameri, R.; Furrer, D.; Burkart, W.

1992-01-01

Long term measurements of the radon level before and after the building shell is sealed were carried out in 25 apartment buildings and 7 houses. The average values of the most important meteorological parameters of wind speed, external temperature and barometric pressure which may influence the radon level, were absolutely comparable during the measurement periods before and after the energy renovation of the buildings. Both in houses and in apartment buildings the radon level remained practically unchanged after the building shell was sealed. The lack of any increase in the radon level after reducing the air exchange rate can be explained by virtue of the fact that the balance between the infiltration and elimination of the radon before and after the energy renovation of the buildings remained unchanged. In addition to reducing the air exchange rate, sealing the building shell therefore also results in a reduction in radon infiltration from the soil. Although it is possible in certain cases for the radon level to increase after the building shell has been sealed, a general increase in radon levels inside living areas as a result of energy renovation work can be dismissed. 2 figs., 3 tabs., 30 refs

Perspectives of survivors of traumatic brain injury and their caregivers on long-term social integration.

Science.gov (United States)

Lefebvre, Hélène; Cloutier, Geneviève; Josée Levert, Marie

2008-07-01

Traumatic brain injury (TBI) has damaging impacts on victims and family members' lives and their long-term social integration constitutes a major challenge. The objective of the study was to document the repercussions of TBI on victims' long-term social integration (10 years post-trauma) and the contribution made by the services received from the point of view of TBI victims and family caregivers. This article examines the determinants of long-term social integration as well as the impact of TBI on family caregivers. A qualitative design was used (semi-directed interviews). The sample consisted of 22 individuals who had sustained a moderate or severe TBI and 21 family caregivers. The results show that TBI is an experience that continues to present difficulties, even 10 years after the accident, and that different barriers contribute to this difficulty: not going back to work, depressive episodes, problems in relationships and sequellae. Family caregivers must help TBI victims confront the barriers in their path. This study adopts a longitudinal perspective to help professionals determine how to intervene with TBI victims and their families. It validates the importance of having clients and family caregivers describe their reality.

Naturalization fosters the long-term political integration of immigrants

Science.gov (United States)

Hainmueller, Jens; Hangartner, Dominik; Pietrantuono, Giuseppe

2015-01-01

Does naturalization cause better political integration of immigrants into the host society? Despite heated debates about citizenship policy, there exists almost no evidence that isolates the independent effect of naturalization from the nonrandom selection into naturalization. We provide new evidence from a natural experiment in Switzerland, where some municipalities used referendums as the mechanism to decide naturalization requests. Balance checks suggest that for close naturalization referendums, which are decided by just a few votes, the naturalization decision is as good as random, so that narrowly rejected and narrowly approved immigrant applicants are similar on all confounding characteristics. This allows us to remove selection effects and obtain unbiased estimates of the long-term impacts of citizenship. Our study shows that for the immigrants who faced close referendums, naturalization considerably improved their political integration, including increases in formal political participation, political knowledge, and political efficacy. PMID:26417099

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-07-01

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

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

International Nuclear Information System (INIS)

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

2006-01-01

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

Radon in workplaces

International Nuclear Information System (INIS)

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

2000-01-01

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

Radon integral measurement system

International Nuclear Information System (INIS)

Garcia H, J.M.

1994-01-01

The Radon Integral Measurement System (SMIR) is a device designed specially to detect, to count and to store the data of the acquisition of alpha particles emitted by Radon-222 coming from the underground. The system includes a detection chamber, a radiation detector, a digital system with bateries backup and an auxiliary photovoltaic cell. A personal computer fixes the mode in which the system works, transmitting the commands to the system by the serial port. The heart of the system is a microprocesor working with interrupts by hardware. Every external device to the microprocessor sends his own interrupt request and the microprocessor handles the interrupts with a defined priority. The system uses a real time clock, compatible with the microprocessor, to take care of the real timing and date of the acquisition. A non volatile RAM is used to store data of two bytes every 15 minutes along 41 days as a maximum. After the setting up to the system by the computer, it can operate in stand alone way for up 41 days in the working place without the lose of any data. If the memory is full the next data will be written in the first locations of the memory. The memory is divided in pages corresponding every one of this to a different day of the acquisition. The counting time for every acquisition can be programmed by the user from 15 minutes to 65535 minutes but it is recommended to use a small time not to reach the limit of 65535 counts in every acquisition period. We can take information of the system without affecting the acquisition process in the field by using a lap top computer, then the information can be stored in a file. There is a program in the computer that can show the information in a table of values or in a bar graph. (Author)

Exposures to radon in homes in Adana

International Nuclear Information System (INIS)

Yegingil, Z.

1990-01-01

Radon escaping from soil into homes appears to present the single greatest source of radiation exposure that most people will ever face. The use of solid state nuclear tracks detectors (SSNTD) is one of the most convenient techniques to assess the average radiation levels of alpha activities in the environment. By using CR-39 and LR-115 detectors long term alpha activities have been investigated to be noticeable the concentrations of natural radionuclides and Rn-222 exhalation rate under different environmental conditions in Adana. The radon distributions have been measured in soils an in single houses and apartment buildings in various floors in the summer and winter time. The seasonal variation of the radon concentration measured by CR-39 and LR-115 displayed a correlation. (author). 25 refs, 2 tabs

A study of radon activity inside some houses in Bangladesh

International Nuclear Information System (INIS)

Islam, G.S.; Islam, M.A.; Farid, S.M.; Rahman, A.

1988-01-01

The solid state nuclear track detector CR-39 has been used for long term measurements of the radon-222 emanation from building materials and the resultant activity inside houses in Bangladesh. Particular attention is paid to a special type of house with thick walls made entirely of mud. The radon-exhalation rate of the walls of these mud-built houses is found to be consistently higher than that of brick-built houses. (author)

Measurement of radon, radon daughters and thoron concentrations by multi-detector devices. No. E/12

International Nuclear Information System (INIS)

Somogyi, G.; Varga, Zs.

1983-01-01

There is a growing interest in collection of data concerning human exposures to naturally occurring alpha-emitting radionuclides (e.g. in mines, dwellings, building materials, industrial wastes, coal fuel cycle, water supply, soil, plants, etc.). Most of such studies are incomplete for the following reasons: in radon measurements the contribution of thoron is generally neglected, the determination of equilibrium factor is complicated or not possible at all, short- and long-term concentration fluctuations cause difficulties in obtaining representative mean values, the plate-out effect is generally not taken into account. A variety of simple methods were studied that could be used to overcome some of these difficulties by using cups equipped with two or more alpha-sensitive nuclear track detectors. A theoretical foundation of the quantitative measurements with such devices is presented. Experimental data are reported on radon, radon daughters and thoron concentrations measured by multi-detector devices in cave soil gas and in air of Hungarian dwellings. (author)

Radon-hazard potential the Beaver basin, Utah

International Nuclear Information System (INIS)

Bishop, C.E.

1995-01-01

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

Working level measurement of radon daughters and thoron daughters by personal dosimetry and continuous monitoring

International Nuclear Information System (INIS)

Phillips, C.R.; Leung, H.

1981-01-01

The performance of personal alpha dosimeters in mixed radon daughter and thoron daughter atmospheres in Ontario uranium mines is described together with monitoring developments which enable the radon daughter working level to be determined separately. The theoretical bases for continuous and integrated working level measurements based on individual and gross counts are presented in terms of the weighting factor for combining the thoron daughter working level with the radon daughter working level, and in terms of the in-growth time of the air. Implications for the determination of working level in the presence of thoron daughters are discussed

Low-level radon measurements by nuclear track detectors

International Nuclear Information System (INIS)

Koksal, E. M.; Goksel, S. A.; Alkan, H.

1985-01-01

In the work to be described here we have developed a passive nuclear track dosimeter to measure the integrated value of indoor radon (Rn-222) over a long period of time. Passive radon dosimeter which we have developed in our laboratories makes use of two small pieces of CR-39 plastic (Allyl diglycol carbonate) as detectors for registering tracks of alpha particles emitted by radon. These CR-39 plastic detectors are fixed on the inside bottom of a cup-shaped polystrene enclosure which is closed at the top by a tissue permeable for gases only. CR-39 detectors exposed to radon gas in the indoor air for a period of six months then are removed and chemically etched to make the alpha particle tracks visible under the microscope. The counts of tracks are evaluated to determine the radon concentration in the air in comparison with the number of tracks produced by a known concentration of radon gas. By using the passive dosimeters developed and the chemical etching procedure descriped here, measurements of indoor radon concentrations were carried out in 45 houses in different districts of the city of Istanbul. In this pilot experiment mean radon concentrations between 0.7 and 3.5 pCi/l have been found in these houses. In order to improve the counting of alpha tracks produced on the detectors a prototype electrochemical etching system in addition to chemical etching, is being developed. (author)

Modeled atmospheric radon concentrations from uranium mines

Energy Technology Data Exchange (ETDEWEB)

Droppo, J.G.

1985-04-01

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

Modeled atmospheric radon concentrations from uranium mines

International Nuclear Information System (INIS)

Droppo, J.G.

1985-04-01

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

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

International Nuclear Information System (INIS)

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

1990-01-01

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

Research priorities for grassland science: the need of long term integrated experiments networks

Directory of Open Access Journals (Sweden)

G. Lemaire

2007-07-01

Full Text Available Grasslands have to be considered not only as a mean for providing foods for domestic herbivore but also as an important biome of terrestrial biosphere. This function of grasslands as an active component of our environment requires specific studies on the role and impact of this ecosystem on soil erosion and soil quality, quality and quantity of water resources, atmosphere composition and greenhouse gas emission or sequestration, biodiversity dynamics at different scales from field plot to landscape. All these functions have to be evaluated in conjunction with the function of providing animal products for increasing human population. So multifunctionality of grasslands become a new paradigm for grassland science. Environmental and biodiversity outputs require long term studies, being the long term retro-active processes within soil, vegetation and micro-organism communities in relation to changes in management programme. So grassland science needs to carry on long term integrated experimentation for studying all the environmental outputs and ecological services associated to grassland management systems.

Radon emanation coefficients in sandy soils

International Nuclear Information System (INIS)

Holy, K.; Polaskova, A.; Baranova, A.; Sykora, I.; Hola, O.

1998-01-01

In this contribution the results of the study of an influence of the water content on the emanation coefficient for two sandy soil samples are reported. These samples were chosen on the because of the long-term continual monitoring of the 222 Rn concentration just in such types of soils and this radon concentration showed the significant variations during a year. These variations are chiefly given in connection with the soil moisture. Therefore, the determination of the dependence of the emanation coefficient of radon on the water content can help to evaluate the influence of the soil moisture variations of radon concentrations in the soil air. The presented results show that the emanation coefficient reaches the constant value in the wide interval of the water content for both sandy soil samples. Therefore, in the common range of the soil moisture (5 - 20 %) it is impossible to expect the variations of the radon concentration in the soil air due to the change of the emanation coefficient. The expressive changes of the radon concentration in the soil air can be observed in case of the significant decrease of the emanation coefficient during the soil drying when the water content decreases under 5 % or during the complete filling of the soil pores by the water. (authors)

Radon and its decay products in housing

International Nuclear Information System (INIS)

Swedjemark, G.A.

1985-01-01

Methods have been worked out for evaluation of the uncertainties due to temporal variations in the annual averages for the concentrations of radon-222 (radon) and radon daughters (RnD) indoors. These methods have been applied to the results from long-term measurements of radon in a few houses. The possible use of correction factors in order to get a more adequate annual average have also been studied and some examples have been given. On the basis of country-wide investigations carried out during 1955-56 and during 1972-75 averages of the radon concentrations in housing existing in 1950 and 1975 were calculated six years ago to be 29 and 71 Bq m -3 respectively. A new country-wide investigation with the aim of obtaining values representative for the country was carried out during 1980-82. On the basis of these results a new calculation was made of the concentrations in dwelllings existing in 1975 to 101 Bq m -3 and also for the 1980 housing stock to 98 Bq m -3 . These results are discussed and the collective dose equivalents in the Swedish population have been calculated. (author)

Integrating Modeling and Monitoring to Provide Long-Term Control of Contaminants

International Nuclear Information System (INIS)

Fogwell, Th.

2009-01-01

An introduction is presented of the types of problems that exist for long-term control of radionuclides at DOE sites. A breakdown of the distributions at specific sites is given, together with the associated difficulties. A paradigm for remediation showing the integration of monitoring with modeling is presented. It is based on a feedback system that allows for the monitoring to act as principal sensors in a control system. Currently the establishment of a very prescriptive monitoring program fails to have a mechanism for improving models and improving control of the contaminants. The resulting system can be optimized to improve performance. Optimizing monitoring automatically entails linking the monitoring with modeling. If monitoring designs were required to be more efficient, thus requiring optimization, then the monitoring automatically becomes linked to modeling. Records of decision could be written to accommodate revisions in monitoring as better modeling evolves. The technical pieces of the required paradigm are already available; they just need to be implemented and applied to solve the long-term control of the contaminants. An integration of the various parts of the system is presented. Each part is described, and examples are given. References are given to other projects which bring together similar elements in systems for the control of contaminants. Trends are given for the development of the technical features of a robust system. Examples of monitoring methods for specific sites are given. The examples are used to illustrate how such a system would work. Examples of technology needs are presented. Finally, other examples of integrated modeling-monitoring approaches are presented. (authors)

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

International Nuclear Information System (INIS)

Collignan, Bernard; Powaga, Emilie

2014-01-01

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

Radon: Not so Noble

Indian Academy of Sciences (India)

Radon in the Environment and Associated Health Problems ... is presently working on emission of ... Radon isotope 222 has a half-life of 3.8 days, long enough to ..... 222Rn concentration of one WL for 170 working hours in one month.

Radon in Estonian buildings. Establishment of a measurement system and obtained results

International Nuclear Information System (INIS)

Pahapill, L.; Rulkov, A.; Swedjemark, G.A.

1996-12-01

One purpose of this project was the establishment of a radon monitoring programme inside the state environmental monitoring programme. Another purpose was to investigate regions, expected to have high radon levels indoors. A new method for the long-term measurement of indoor radon was established and the staff for these measurements was trained. The results of the measurement can be used by Estonian decision-makers to work out rules and standards. There is no legislative act in the field of radiation in Estonian at this time. To summarize the results of the measurements we can say that indoor radon concentrations vary by region. The radon investigations must be continued to identify the risk areas and types of housing construction. The results of the state radon monitoring are provided to the municipalities, who advice the owners of planned new houses to select the right construction for the house. A new project will follow with an investigation of radon in randomly selected dwellings, training and equipment for radon measurement in soil, and general advice with regard to radon, as well as assistance in preparing information about radon. 7 refs, 5 figs

Radon problems

International Nuclear Information System (INIS)

Cohen, B.L.

1985-01-01

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

Lung dosimetry for inhaled radon progeny in smokers

International Nuclear Information System (INIS)

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

2010-01-01

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

Environmental effects of the long term management of wastes

International Nuclear Information System (INIS)

Henry, L.C.

1980-08-01

Criteria for interim application in uranium mill tailings management, pending the outcome of a thorough investigation of the tailings problem, are outlined. For a closed-out tailings site only passive or natural barriers are to be used to control releases; surface water recharge is to be limited to that from direct natural precipitation, and no permanent water pool will be allowed; all designed systems must be evaluated in terms of their long-term durability; long-term performance and economic guarantees will be required; access must be limited to the maximum extent practical; and pathway analyses should be performed to determine the health, safety and environmental impacts of the expected level of releases. Releases to water should be no greater than those experienced during the operating phase of the facility. Radon emanation should not exceed 2-10 pCi/m 2 .s, and gamma radiation should be reduced to 10-50 μR/hr at 1 metre above the surface. Particulate emissions originating from the tailings material should be virtually non-existent

Radon in Austrian tourist mines and show caves

International Nuclear Information System (INIS)

Ringer, W.; Graeser, J.

2009-01-01

The radon situation in tourist mines and show caves is barely investigated in Austria. This paper investigates the influence of its determining factors, such as climate, structure and geology. For this purpose, long-term time-resolved measurements over 6 to 12 months in 4 tourist mines and 2 show caves - with 5 to 9 measuring points each - have been carried out to obtain the course of radon concentration throughout the year. In addition, temperature and air-pressure were measured and compared to the data outside where available. Results suggest that the dominating factors of the average radon concentration are structure and location (geology) of the tunnel-system, whereas the diurnal and annual variation is mainly caused by the changing airflow, which is driven by the difference in temperature inside and outside. Downcast air is connected with very low radon concentrations, upcast air with high concentrations. In some locations the maximum values appear when the airflow ceases. But airflow can be different in different parts of mines and caves. Systems close to the surface show generally lower radon levels than the ones located deeper underground. Due to variation of structure, geology and local climate, the radon situation in mines and caves can only be described by simultaneous measurements at several measuring points. (orig.)

Residential radon and lung cancer incidence in a Danish cohort

DEFF Research Database (Denmark)

Bräuner, Elvira Vaclavik; Andersen, Claus Erik; Sørensen, Mette

2012-01-01

High-level occupational radon exposure is an established risk factor for lung cancer. We assessed the long-term association between residential radon and lung cancer risk using a prospective Danish cohort using 57,053 persons recruited during 1993–1997. We followed each cohort member for cancer...... occurrence until 27 June 2006, identifying 589 lung cancer cases. We traced residential addresses from 1 January 1971 until 27 June 2006 and calculated radon at each of these addresses using information from central databases regarding geology and house construction. Cox proportional hazards models were used...... to estimate incidence rate ratios (IRR) and 95% confidence intervals (CI) for lung cancer risk associated with residential radon exposure with and without adjustment for sex, smoking variables, education, socio-economic status, occupation, body mass index, air pollution and consumption of fruit and alcohol...

Radon anomaly in soil gas as an earthquake precursor

International Nuclear Information System (INIS)

Miklavcic, I.; Radolic, V.; Vukovic, B.; Poje, M.; Varga, M.; Stanic, D.; Planinic, J.

2008-01-01

The mechanical processes of earthquake preparation are always accompanied by deformations; afterwards, the complex short- or long-term precursory phenomena can appear. Anomalies of radon concentrations in soil gas are registered a few weeks or months before many earthquakes. Radon concentrations in soil gas were continuously measured by the LR-115 nuclear track detectors at site A (Osijek) during a 4-year period, as well as by the Barasol semiconductor detector at site B (Kasina) during 2 years. We investigated the influence of the meteorological parameters on the temporal radon variations, and we determined the equation of the multiple regression that enabled the reduction (deconvolution) of the radon variation caused by the barometric pressure, rainfall and temperature. The pre-earthquake radon anomalies at site A indicated 46% of the seismic events, on criterion M≥3, R<200 km, and 21% at site B. Empirical equations between earthquake magnitude, epicenter distance and precursor time enabled estimation or prediction of an earthquake that will rise at the epicenter distance R from the monitoring site in expecting precursor time T

Radon anomaly in soil gas as an earthquake precursor

Energy Technology Data Exchange (ETDEWEB)

Miklavcic, I.; Radolic, V.; Vukovic, B.; Poje, M.; Varga, M.; Stanic, D. [Department of Physics, University of Osijek, Trg Ljudevita Gaja 6, POB 125, 31000 Osijek (Croatia); Planinic, J. [Department of Physics, University of Osijek, Trg Ljudevita Gaja 6, POB 125, 31000 Osijek (Croatia)], E-mail: planinic@ffos.hr

2008-10-15

The mechanical processes of earthquake preparation are always accompanied by deformations; afterwards, the complex short- or long-term precursory phenomena can appear. Anomalies of radon concentrations in soil gas are registered a few weeks or months before many earthquakes. Radon concentrations in soil gas were continuously measured by the LR-115 nuclear track detectors at site A (Osijek) during a 4-year period, as well as by the Barasol semiconductor detector at site B (Kasina) during 2 years. We investigated the influence of the meteorological parameters on the temporal radon variations, and we determined the equation of the multiple regression that enabled the reduction (deconvolution) of the radon variation caused by the barometric pressure, rainfall and temperature. The pre-earthquake radon anomalies at site A indicated 46% of the seismic events, on criterion M{>=}3, R<200 km, and 21% at site B. Empirical equations between earthquake magnitude, epicenter distance and precursor time enabled estimation or prediction of an earthquake that will rise at the epicenter distance R from the monitoring site in expecting precursor time T.

Radon house doctor

International Nuclear Information System (INIS)

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

1986-01-01

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

Study of indoor radon levels in some radioactive areas of Himachal Pradesh: an inter-comparison of active and passive techniques

International Nuclear Information System (INIS)

Bajwa, B.S.; Singh, S.; Sharma, N.; Virk, H.S.

2006-01-01

Full text of publication follows: Indoor radon levels measurements were carried using both the active and passive techniques in the dwellings of some villages, known to be located in the vicinity of uranium mineralized zones of Hamirpur district, Himachal Pradesh. Even in the passive technique using Solid State Nuclear Track Detectors (S.S.N.T.D.), both the bare-slide and twin chamber dosemeter cup modes were utilized. An attempt has also been made to assess the levels of the indoor radon in these dwellings and inhalation dose rates of the population living in these villages. The average value of radon concentration levels using the bare-slide mode varies from 109.0 to 741.5 Bq/m3 in these dwellings, where as the maximum radon level using the twin cup dosemeter technique was found to be 140.3 Bq/m3. As usual the radon concentrations were found to be varying with seasonal changes, building materials etc. The radon survey in the dwellings of these villages has also been carried out using the Alpha- Guard technique, which is based on the pulse ionization chamber. The indoor radon concentration levels measured using the active technique of Alpha Guard have been found to be quite different from those measured in these dwellings by the passive technique of S.S.N.T.D.; indicating the importance of the S.S.N.T.D. in the long-term integrated measurement of the indoor radon levels in the dwellings. (authors)

Study of indoor radon levels in some radioactive areas of Himachal Pradesh: an inter-comparison of active and passive techniques

International Nuclear Information System (INIS)

Bajwa, B.S.; Singh, S.; Sharma, N.; Virk, H.S.

2006-01-01

Full text of publication follows: Indoor radon levels measurements were carried using both the active and passive techniques in the dwellings of some villages, known to be located in the vicinity of uranium mineralized zones of Hamirpur district, Himachal Pradesh. Even in the passive technique using S.S.N.T.D., both the bare -slide and twin chamber dosemeter cup modes were utilized. An attempt has also been made to assess the levels of the indoor radon in these dwellings and inhalation dose rates of the population living in these villages. The average value of radon concentration levels using the bare-slide mode varies from 109.0 to 741.5 Bq/m3 in these dwellings, where as the maximum radon level using the twin cup dosemeter technique was found to be 140.3 Bq/m3. As usual the radon concentrations were found to be varying with seasonal changes, building materials etc. The radon survey in the dwellings of these villages has also been carried out using the Alpha-Guard technique, which is based on the pulse ionization chamber. The indoor radon concentration levels measured using the active technique of Alpha Guard have been found to be quite different from those measured in these dwellings by the passive technique of S.S.N.T.D.; indicating the importance of the S.S.N.T.D. in the long -term integrated measurement of the indoor radon levels in the dwellings. (authors)

Seasonal correction factors in radon exposure assessment: are they help or hindrance?

International Nuclear Information System (INIS)

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

2008-01-01

Northern Hemisphere radon levels are generally higher in Winter than in Summer, primarily due to the increased interior/exterior temperature difference during the heating season, which results in greater atmospheric pressure differential and enhanced radon ingress. Following a survey of domestic radon levels in the United Kingdom (UK), the former National Radiological Protection Board (NRPB) established measurement protocols and promulgated nationally-applicable Seasonal Correction Factors (SCF). These factors convert a one-month or three-month radon concentration measurement, commencing in any month of the year, to an annual mean radon concentration. Subsequent study suggests that this approach may not be sufficiently sensitive to local conditions, and a major independent investigation reported seasonal correction factors specific to nine geographic regions, together with a composite set applicable to all regions. Similar geographical variability has been observed in other countries. In a recent evaluation of the applicability of short-term exposures in quantifying long-term domestic radon levels, radon levels in 34 houses were monitored over a 12-month period with 1-week, 1-month and 3-month exposures. Radon concentration variation departed significantly from that expected on the basis of the recommended SCFs, with year-end discontinuities at all exposure durations. Weekly monitoring with electrets was continued in three of these locations for four years. Short-term variations in radon levels were observed, particularly during the shorter exposures, and this dataset has also shown year-on-year variations. Overall, SCFs derived from this dataset are significantly lower than those recommended, but are comparable with other results from the UK and elsewhere, particularly those that recognise geological diversity and are consequently prepared on a regional rather than a national basis. These findings call into question the validity of using nationally

Containment long-term operational integrity--a 1988 status report

International Nuclear Information System (INIS)

Sammataro, R.F.

1988-01-01

Design and in-service codes and standards provide a comprehensive set of requirements for containment design, construction, inspection, testing and repair. Metal and concrete containments must be designed, fabricated, constructed, inspected, tested and maintained to quality standards commensurate with the importance of the safety function to be performed. Periodic integrated leak rate tests are required to assure that containments continue to meet allowable leakage limits. Although overall performance has been quite good to date, several major containment aging and degradation mechanisms have been identified. Two pilot plant life extension studies, one for a boiling water reactor and one for a pressurized water reactor, serve as models for extending the operational integrity of present containments in the United States. Research and testing programs for determining the ultimate pressure capacity and failure mechanisms for containments under severe loading conditions and studied for extending the life of current plants beyond the present 40 year licensed lifetime are underway. This paper presents an overview of containment designs in the USA and a discussion of the regulatory and ASME Code requirements for the design, construction, in-service inspection, testing and repair for containments. Findings for containments from the pilot plant life extension studies and the ongoing containment research and testing programs are also discussed. The regulatory and ASME Code requirements for design, construction, in-service inspection and periodic integrated leakage testing together with recommendations from the plant life extension studies and containment integrity research and testing provide a basis for continued containment long-term operational integrity

Comparison of passive and active radon measurement methods for personal occupational dose assessment

Directory of Open Access Journals (Sweden)

Hasanzadeh Elham

2016-01-01

Full Text Available To compare the performance of the active short-term and passive long-term radon measurement methods, a study was carried out in several closed spaces, including a uranium mine in Iran. For the passive method, solid-state nuclear track detectors based on Lexan polycarbonate were utilized, for the active method, AlphaGUARD. The study focused on the correlation between the results obtained for estimating the average indoor radon concentrations and consequent personal occupational doses in various working places. The repeatability of each method was investigated, too. In addition, it was shown that the radon concentrations in different stations of the continually ventilated uranium mine were comparable to the ground floor laboratories or storage rooms (without continual ventilation and lower than underground laboratories.

Higher integrity of the motor and visual pathways in long-term video game players.

Science.gov (United States)

Zhang, Yang; Du, Guijin; Yang, Yongxin; Qin, Wen; Li, Xiaodong; Zhang, Quan

2015-01-01

Long term video game players (VGPs) exhibit superior visual and motor skills compared with non-video game control subjects (NVGCs). However, the neural basis underlying the enhanced behavioral performance remains largely unknown. To clarify this issue, the present study compared the whiter matter integrity within the corticospinal tracts (CST), the superior longitudinal fasciculus (SLF), the inferior longitudinal fasciculus (ILF), and the inferior fronto-occipital fasciculus (IFOF) between the VGPs and the NVGCs using diffusion tensor imaging. Compared with the NVGCs, voxel-wise comparisons revealed significantly higher fractional anisotropy (FA) values in some regions within the left CST, left SLF, bilateral ILF, and IFOF in VGPs. Furthermore, higher FA values in the left CST at the level of cerebral peduncle predicted a faster response in visual attention tasks. These results suggest that higher white matter integrity in the motor and higher-tier visual pathways is associated with long-term video game playing, which may contribute to the understanding on how video game play influences motor and visual performance.

Calibration of environmental monitors operating on time integrating principles for radon/thoron decay products

International Nuclear Information System (INIS)

Bigu, J.; Grenier, M.

1982-03-01

An environmental radiation monitor for radon decay products has been tested under laboratory controlled conditions. The instrument is of a quasi-time-integrating type and was tested in conjunction with a radon 'box' calibration facility. It has been found that the instrument appreciably underestimates the radon daughter Working Level (WL). This is attributed to plate-out of decay products in the monitor sampling head. The difference between monitor reading and the WL by grab-sampling was higher for low aerosol concentrations. Plate-out on the instrument detector and sampling head, and contamination effects have been observed for the thoron case. There is partial agreement between experimental results and theoretical expectation. The monitor is slow to react to sudden changes in radiation level. The instrument should prove quite useful in the routine monitoring of surface and underground environments provided some suggested changes in the instrument are introduced

Integrated system for long-term radioactive waste management in the UK

International Nuclear Information System (INIS)

Dalton, J.; Wisbey, S.

2003-01-01

Since the failure of Nirex application to build a Rock Characterisation Facility near Sellafield in 1997, Nirex has been applying lessons learnt from that failure. Some of the issues involved are generic and relate to the process by which legitimate authority can be gained for government policy development, the structure of the nuclear industry and the behaviour of institutions. Transparency must be central to the culture of organisations attempting to win public acceptance. In the UK, the Department for Environment, Food and Rural Affairs (DEFRA) have started a consultation process - stage one completed in March 2002 - to consult about the safe management of radioactive waste. Nirex has modified its approach to long-term waste management, using a concept of phased (stepwise and reversible) geological disposal. Nirex also provides waste producers with advice on, and endorsement of, the packaging and transport of wastes. Through these examples, this paper will demonstrate how Nirex is providing an integrated approach to the long-term management of radioactive wastes in the UK. (orig.)

The seasonal variation of radon concentration in the atmosphere of Chichi-jima island in the pacific ocean

International Nuclear Information System (INIS)

Yoshioka, Katsuhiro

2008-01-01

We continuously measured the radon concentration from April 2001 to December 2004 in Chichi-jima Is. We expect that the radon concentration at Chichi-jima Is. would be influenced only by the air mass transported through the long distance. The hourly values had very large variations, ranging from 0.2 to 6.0 Bqm -3 . No diurnal periodicity was found in the variation of the radon concentration. We found that the monthly averages of the radon concentration had a clear long term pattern, showing the highest in the winter and the lowest in the summer. To analyze the radon long time variation, an arriving air mass is grouped into five sectors according to the backward trajectory. Sector I is the sea areas surrounding Chichi-jima Is. Sector II including Philippines, Indonesia and the southeast Asia is spread the southwestern Pacific Ocean from Chichi-jima Is. and sector V is spread the northeastern way to the southeast. Sector III includes China, Mongolia, Korea and the western Japan region and sector IV two regions of the eastern Siberia and the eastern Japan. The radon long time variation showed a high positive correlation between the number of arrivals of the continental air mass, while strong negative correlation between the maritime air mass. (author)

Year-long comparison of two techniques to monitor outdoor radon concentrations at Shiprock, New Mexico

International Nuclear Information System (INIS)

Novak, E.F.

1988-08-01

The US Department of Energy (DOE) Office of Remedial Action and Waste Technology established the Technical Measurements Center (TMC) at the DOE Grand Junction Projects Office (GJPO) in Grand Junction, Colorado, to standardize, calibrate, and compare measurements made in support of DOE remedial action programs. Outdoor radon concentration measurements were made by the TMC in Shiprock, New Mexico, to compare two different methods of measuring radon in an attempt to determine the feasibility of using passive alpha-track detectors to assess the adequacy of remedial action undertaken at the Shiprock uranium mill tailings pile. The results of the first three quarters of monitoring have been detailed in previous reports. An analysis of the data from the fourth quarter of monitoring at Shiprock reveals a somewhat poorer correlation between the two sets of measurements than was seen in the third quarter of this study, but a better correlation than was found for the first and second quarters. The results of a nearly year-long exposure of alpha-track detectors were in much better agreement with the annual-average results of the second measurement method than were any of the quarterly results. The results of a calibration exposure of several alpha-track detectors in an environmentally controlled radon chamber differed significantly from the detector manufacturer's calibrations. The most significant conclusion is that alpha-track detectors require a year-long exposure to provide a reliable estimate of the annual-average outdoor radon concentration. Annual averages calculated from quarterly exposures are more prone to errors occurring during the track-counting process. 7 refs., 5 figs., 5 tabs

Radon emanation in tectonically active areas

International Nuclear Information System (INIS)

King, C.Y.

1980-01-01

Subsurface radon emanation has been continuously monitored for up to three years by the Track Etch method in shallow dry holes at more than 60 sites along several tectonic faults in central California and at 9 sites near the Kilauea volcano in Hawaii. The measured emanation in these tectonically active areas shows large long-term variations that may be related mainly to crustal strain changes

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

International Nuclear Information System (INIS)

Pearson, M.D.

1989-04-01

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

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

Science.gov (United States)

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

Characteristic behavior of water radon associated with Wenchuan and Lushan earthquakes along Longmenshan fault

International Nuclear Information System (INIS)

Ye, Qing; Singh, Ramesh P.; He, Anhua; Ji, Shouwen; Liu, Chunguo

2015-01-01

In China, numerous subsurface, surface water well and spring parameters are being monitored through a large network of stations distributed in China sponsored by China Earthquake Administration (CEA). All the data from these network is managed by China Earthquake Network Center (CENC). In this paper, we have used numerous data (water radon, gas radon, water level, water temperature) available through CENC for the period 2002–2014 and studied the behavior and characteristics of water 222 radon [Rn(w)]. The observed parameters were also complemented by rainfall data retrieved from Tropical Rainfall Measuring Mission (TRMM) satellite. Our detailed analysis shows pronounced changes in the observed parameters (especially water and gas radon) prior to the earthquake. The changes in water radon, ground water level and rainfall showing characteristics behavior for Wenchuan and Lushan earthquakes. The long term data analysis of water radon and water level at various locations around epicenters of two major earthquakes along Longmenshan fault show a positive and negative relation of water radon and water level prior to these earthquakes. It is difficult to find any trend of water radon and changes in water radon pattern with these two earthquakes that could prove as a reliable precursor of earthquakes. Changes in the water radon concentrations from one location to other may be associated with the changes in ground water regime and geological settings in the epicentral and surrounding regions. - Highlights: • Long trend of water radon measured in China during 2003–2014 at six stations round Longmenshan fault. • Water radon shows characteristics behavior associated with Wenchuan and Lushan earthquakes. • Water radon shows one to one relation with rainfall and ground water level variations. • Sharp increase or decrease in water radon concentrations are found few days prior to the earthquake

Radon and radon-daughter exposure measurements by through-etched track registration in cellulose nitrate

International Nuclear Information System (INIS)

Knoefell, T.M.J.; Silva Estrada, J.J. da; Tavares, O.A.P.; Martins, J.B.

1981-01-01

The use of cellulose nitrate films LR-115 type II (Kodak-Pathe) as a practical, exposure integrating device to measure the level of exposure to alpha particles in atmospheres which contain radon and radon-daughter products is investigated. The analysis of a number of cellulose nitrate films that have been exposed to calibrated radon test-chamber atmospheres has indicated good correlations between through-etched track density p and integrated alpha-particle exposure Σa (Working-Level-Hour). It is shown that the response of the cellulose nitrate detector to radon-daughter alpha-particle exposures is linear, and that reliable conservative estimations of the Working-Level-Hour can be obtained from Σa = 3.0(p-b), where p is expressed in tracks/mm 2 (b is the background level). These results recommend the use of the special red cellulose nitrate films as a convenient dosimeter for monitoring radioactive contaminants in mine atmospheres. (Author) [pt

Improving long term resistance of uranium mill tailings covers to hydrologic stress using RIPRAP: a preliminary assessment

International Nuclear Information System (INIS)

Walters, W.H.; Skaggs, R.L.

1980-01-01

The long term effectiveness of riprap to protect uranium mill tailings repositories against erosion by flowing water is currently being evaluated by Pacific Northwest Laboratory for the US Nuclear Regulatory Commission. The investigation is part of a comprehensive study to determine technically justified and cost effective alternatives for armoring of radon suppression covers. As a protective cover, riprap appears to be one of the most reliable methods because of its proven durability to resist channel bed scour around bridge piers and erosion of river banks. Damage to radon suppression covers by water could occur under similar circumstances where the erosion would be due to overland flow or a large flood event. The principal mechanisms of soil erosion by water are discussed with respect to earth surfaces of mounted or flat geometries. Since long time periods on the order of one thousand years may be involved, any riprap design procedure should consider allowances for partial failures of the cover. Design procedures are summarized and both advantages and disadvantages are discussed. Problems that may occur over long term storage of mill tailings are evaluated in order to put the use of riprap in proper perspective

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

Science.gov (United States)

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

2009-08-01

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

Remote Lower White Matter Integrity Increases the Risk of Long-Term Cognitive Impairment After Ischemic Stroke in Young Adults.

Science.gov (United States)

Schaapsmeerders, Pauline; Tuladhar, Anil M; Arntz, Renate M; Franssen, Sieske; Maaijwee, Noortje A M; Rutten-Jacobs, Loes C A; Schoonderwaldt, Hennie C; Dorresteijn, Lucille D A; van Dijk, Ewoud J; Kessels, Roy P C; de Leeuw, Frank-Erik

2016-10-01

Poststroke cognitive impairment occurs frequently in young patients with ischemic stroke (18 through 50 years of age). Accumulating data suggest that stroke is associated with lower white matter integrity remote from the stroke impact area, which might explain why some patients have good long-term cognitive outcome and others do not. Given the life expectancy of decades in young patients, we therefore investigated remote white matter in relation to long-term cognitive function. We included all consecutive first-ever ischemic stroke patients, left/right hemisphere, without recurrent stroke or transient ischemic attack during follow-up, aged 18 through 50 years, admitted to our university medical center between 1980 and 2010. One hundred seventeen patients underwent magnetic resonance imaging scanning including a T1-weighted scan, a diffusion tensor imaging scan, and completed a neuropsychological assessment. Patients were compared with a matched stroke-free control group (age, sex, and education matched). Cognitive impairment was defined as >1.5 SD below the mean cognitive index score of controls and no cognitive impairment as ≤1 SD. Tract-Based Spatial Statistics was used to assess the white matter integrity (fractional anisotropy and mean diffusivity). About 11 years after ischemic stroke, lower remote white matter integrity was associated with a worse long-term cognitive performance. A lower remote white matter integrity, even in the contralesional hemisphere, was observed in cognitively impaired patients (n=25) compared with cognitively unimpaired patients (n=71). These findings indicate that although stroke has an acute onset, it might have long lasting effects on remote white matter integrity and thereby increases the risk of long-term cognitive impairment. © 2016 American Heart Association, Inc.

Ambient Radon-222 Monitoring in Amargosa Valley, Nevada

International Nuclear Information System (INIS)

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

2008-01-01

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

Radon Sources and Associated Risk in terms of Exposure and Dose

Directory of Open Access Journals (Sweden)

Efstratios Gregory Vogiannis

2015-01-01

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

Accurate measurement of indoor radon concentration using a low-effective volume radon monitor

International Nuclear Information System (INIS)

Tanaka, Aya; Minami, Nodoka; Mukai, Takahiro; Yasuoka, Yumi; Iimoto, Takeshi; Omori, Yasutaka; Nagahama, Hiroyuki; Muto, Jun

2017-01-01

AlphaGUARD is a low-effective volume detector and one of the most popular portable radon monitors which is currently available. This study investigated whether AlphaGUARD can accurately measure the variable indoor radon levels. The consistency of the radon-concentration data obtained by AlphaGUARD is evaluated against simultaneous measurements by two other monitors (each ∼10 times more sensitive than AlphaGUARD). When accurately measuring radon concentration with AlphaGUARD, we found that the net counts of the AlphaGUARD were required of at least 500 counts, <25% of the relative percent difference. AlphaGUARD can provide accurate measurements of radon concentration for the world average level (∼50 Bq m -3 ) and the reference level of workplace (1000 Bq m -3 ), using integrated data over at least 3 h and 10 min, respectively. (authors)

Measuring your radon risk

International Nuclear Information System (INIS)

Mackmurdo, R.

1994-01-01

In its annual report for 1992/93, the NRPB has warned that tens of thousands of UK employees may be exposed to high levels of radon at work. In addition to those who work underground, employees at risk of radon-induced lung cancer are typically those who spend long periods indoors. This article reviews the implications for all employers especially those in low or unknown levels of radon who resist taking measurements in the belief that by not measuring, they are not liable. (UK)

Surface-deposition and distribution of the radon-decay products indoors

International Nuclear Information System (INIS)

Espinosa, G.; Tommasino, L.

2015-01-01

The exposure to radon-decay products is of great concern both in dwellings and workplaces. The model to estimate the lung dose refers to the deposition mechanisms and particle sizes. Unfortunately, most of the dose data available are based on the measurement of radon concentration and the concentration of radon decay products. These combined measurements are widely used in spite of the fact that accurate dose assessments require information on the particle deposition mechanisms and the spatial distribution of radon decay products indoors. Most of the airborne particles and/or radon decay products are deposited onto indoor surfaces, which deposition makes the radon decay products unavailable for inhalation. These deposition processes, if properly known, could be successfully exploited to reduce the exposure to radon decay products. In spite of the importance of the surface deposition of the radon decay products, both for the correct evaluation of the dose and for reducing the exposure; little or no efforts have been made to investigate these deposition processes. Recently, two parallel investigations have been carried out in Rome and at Universidad Nacional Autónoma de México (UNAM) in Mexico City respectively, which address the issue of the surface-deposited radon decay products. Even though these investigations have been carried independently, they complement one another. It is with these considerations in mind that it was decided to report both investigations in the same paper. - Highlights: • Distribution of Radon and Thoron decay indoor products. • Indoor radon measurements complexity. • Short and long term measurements of surface deposit of Radon and Thoron decay products. • Microclimate controlled conditions room. • Nuclear Tracks Detectors

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

International Nuclear Information System (INIS)

Horiuchi, Kimiko; Ishii, Tadashi.

1991-01-01

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

Influence of energy-saving measures on the radon concentration in some kindergartens in the Czech Republic

International Nuclear Information System (INIS)

Fojtikova, I.; Navratilova Rovenska, K.

2014-01-01

Due to the large number of subsidies for energy-saving reconstructions granted, and expecting a strong influence of reconstruction on the radon level in building, the long-term measurements of radon concentration are offered free of charge to kindergartens in the Czech Republic. Classrooms and playrooms where the radon levels exceeded the reference value for kindergartens, which is 400 Bq m -3 , are monitored continuously for at least a week to obtain the average activity concentration of radon when children are present. Some of the kindergartens were previously measured in the 1990's. These earlier measurements have provided an opportunity to compare the results. This paper presents some lessons learned from radon diagnosis carried out in particular cases and an analysis of the influence of reconstruction work on the radon level in the buildings. (authors)

Radon in soil gas in Kosovo.

Science.gov (United States)

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

2016-11-01

An assessment of the radiological situation due to exposure to radon and gamma emitting radionuclides was conducted in southern Kosovo. This study deals with sources of radon in soil gas. A long-term study of radon concentrations in the soil gas was carried out using the SSNTDs (CR-39) at 21 different locations in the Sharr-Korabi zone. The detectors were exposed for an extended period of time, including at least three seasonal periods in a year and the sampling locations were chosen with respect to lithology. In order to determine the concentration of the natural radioactive elements 238 U and 226 Ra, as a precursor of 222 Rn, soil samples were collected from each measuring point from a depth of 0.8 m, and measured by gamma spectrometry. The levels (Bq kg -1 ) of naturally occurring radionuclides and levels (kBq m -3 ) of radon in soil gas obtained at a depth 0.8 m of soil were: 21-53 for 226 Ra, 22-160 for 238 U and 0.295-32 for 222 Rn. With respect to lithology, the highest value for 238 U and 226 Ra were found in limestone and the highest value for 222 Rn was found in metamorphic rocks. In addition, the results showed seasonal variations of the measured soil gas radon concentrations with maximum concentration in the spring months. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of radon and radon-daughter grab samples obtained during the winter and summer

International Nuclear Information System (INIS)

Karp, K.E.

1987-08-01

The Technical Measurements Center (TMC), under the auspices of the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) program, is investigating short-term methods for estimating annual average indoor radon-daughter concentrations (RDC). A field study at 40 sample locations in 26 residential structures in Grand Junction, Colorado, was conducted once in the winter and once in the summer. The short-term methods investigated as part of this study include ten-minute radon and radon-daughter grab sampling and hourly RDC measurements. The results of the field study indicate that ten-minute radon grab samples from basement locations are reproducible over different seasons during controlled sampling conditions. Nonbasement radon and RDC grab samples are highly variable even when the use of the location by the occupant is controlled and the ventilation rate is restricted. The grab sampling was performed under controlled occupied conditions. These results confirm that a short-term radon or RDC measurement in a nonbasement location in a house is not a standardized measurement that can be used to infer an annual average concentration. The hourly RDC measurements were performed under three sets of conditions over a 72-hour period. The three sets of conditions were uncontrolled occupied, controlled occupied, and controlled unoccupied. These results indicate that it is not necessary to relocate the occupants during the time of grab sampling. 8 refs., 8 figs., 10 tabs

AlphaGUARD, the new reference for continuous radon monitoring in air, soil, gas, water and material

International Nuclear Information System (INIS)

Roessler, F.; Buerkin, W.; Villert, J.

2016-01-01

The company Saphymo GmbH has more than 25 years of experience in the field of radon measurement. More than 20 years ago Saphymo developed the professional and robust radon monitor AlphaGUARD, quickly recognized as a standard for reliable and continuous measurements of the radon concentration. Today AlphaGUARD is internationally established as the reference in radon measurement. Following up on this success story the new generation of AlphaGUARD can now be presented. Based on the excellent measurement characteristics of its predecessor the new AlphaGUARD combines the well-proven principle of the pulse ionisation chamber with new and additional features. The robust housing is oriented on the well-proven design of the predecessor and includes now an integrated flow controlled and powerful pump. The instrument can be operated in flow as well as in diffusion mode (without pump). Via the new large display and the intuitive menu navigation all measurement data can be retrieved. The presentation of time series in charts is possible as well as the parametrisation of the instrument. A wide range of accessories, developed in cooperation with various radon experts of universities and laboratories, enables the user a varied and flexible application of the AlphaGUARD: Measurement of the radon concentration in air (radon, thoron, radon progenies), in water (sampling and time resolved measurements) and in soil (soil gas measurements, exhalation measurements), emanation measurements from material, multi spot measurement, online measurement with remote data transmission via Ethernet/DSL, Bluetooth, Wi-Fi, GPRS/3G or satellite. Due to its high sensitivity and its fast and linear response over a large measuring range the AlphaGUARD is excellently suited for calibration laboratories. Furthermore the AlphaGUARD enables ideal prerequisites for field applications: robust housing for operations under harsh conditions, long battery life for the measurement at any location, low

Radon exposure at a radioactive waste storage facility.

Science.gov (United States)

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

2014-06-01

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

A study of long-term static load on degradation and mechanical integrity of Mg alloys-based biodegradable metals

International Nuclear Information System (INIS)

Koo, Youngmi; Jang, Yongseok; Yun, Yeoheung

2017-01-01

Highlights: • Long-term stress corrosion cracking (SCC) test of Mg alloys was performed. • AZ31B-H24 shows transgranular stress corrosion cracking (TGSCC) and ZE41A-T5 intergranular stress corrosion cracking (IGSCC). • Long-term static loading accelerated crack propagation, leading to the loss of mechanical strength. - Abstract: Predicting degradation behavior of biodegradable metals in vivo is crucial for the clinical success of medical devices. This paper reports on the effect of long-term static stress on degradation of magnesium alloys and further changes in mechanical integrity. AZ31B (H24) and ZE41A (T5) alloys were tested to evaluate stress corrosion cracking (SCC) in a physiological solution for 30 days and 90 days (ASTM G39 testing standard). Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) and micro-computed tomography (micro-CT) were used to characterize surface morphology and micro-structure of degraded alloys. The results show the different mechanisms of stress corrosion cracking for AZ31B (transgranular stress corrosion cracking, TGSCC) and ZE41A (intergranular stress corrosion cracking, IGSCC). AZ31B was more susceptible to stress corrosion cracking under a long term static load than ZE41A. In conclusion, we observed that long-term static loading accelerated crack propagation, leading to the loss of mechanical integrity.

A study of long-term static load on degradation and mechanical integrity of Mg alloys-based biodegradable metals

Energy Technology Data Exchange (ETDEWEB)

Koo, Youngmi; Jang, Yongseok; Yun, Yeoheung, E-mail: yyun@ncat.edu

2017-05-15

Highlights: • Long-term stress corrosion cracking (SCC) test of Mg alloys was performed. • AZ31B-H24 shows transgranular stress corrosion cracking (TGSCC) and ZE41A-T5 intergranular stress corrosion cracking (IGSCC). • Long-term static loading accelerated crack propagation, leading to the loss of mechanical strength. - Abstract: Predicting degradation behavior of biodegradable metals in vivo is crucial for the clinical success of medical devices. This paper reports on the effect of long-term static stress on degradation of magnesium alloys and further changes in mechanical integrity. AZ31B (H24) and ZE41A (T5) alloys were tested to evaluate stress corrosion cracking (SCC) in a physiological solution for 30 days and 90 days (ASTM G39 testing standard). Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) and micro-computed tomography (micro-CT) were used to characterize surface morphology and micro-structure of degraded alloys. The results show the different mechanisms of stress corrosion cracking for AZ31B (transgranular stress corrosion cracking, TGSCC) and ZE41A (intergranular stress corrosion cracking, IGSCC). AZ31B was more susceptible to stress corrosion cracking under a long term static load than ZE41A. In conclusion, we observed that long-term static loading accelerated crack propagation, leading to the loss of mechanical integrity.

Indoor radon levels and inhalation doses in dwellings near the some sites of Himachal Pradesh, India

International Nuclear Information System (INIS)

Bajwa, B.S.; Singh, S.; Virk, H.S.

2005-01-01

In view of the fact that radon and its daughters are a major source of natural radiation exposure, the measurement of radon concentration levels in dwellings has assumed ever-increasing importance. Keeping this in view, the indoor radon level measurements were carried out in the dwellings of different villages known to be located in the vicinity of uranium-mineralized pockets of Hamirpur district, Himachal Pradesh. Track-etch technique, a passive method using the Solid State Nuclear Track Detectors (SSNTDs), LR-115 type II, was utilized for these measurements. An attempt has been made to assess the levels of the indoor radon in the dwellings and inhalation dose rates of the population living in these villages. The radon concentrations were found to be varying with seasonal changes, building materials and mode of construction of houses. The radon concentrations were found to be higher in houses made from local sandstone and with mud floor in comparison to the houses having cemented brick floors. The annual indoor radon concentration and thus annual effective dose in most of the dwellings of these villages is certainly quite higher and even in some of the dwellings it even exceeds the upper limit of the proposed action level of ICRP, 1993. The inhalation dose rates in dwellings of these villages located in the vicinity of uranium mineralized pockets of Hamirpur district, Himachal Pradesh have been found to be quite higher than dose rate in the dwellings in the Amritsar city, Punjab, which is located in a completely uranium free zone. The radon survey in the dwellings of these villages has also been carried out using the Alpha-Guard technique, which is based on the pulse ionization chamber. The indoor radon concentration levels measured using the active technique of Alpha Guard have been found to be quite different from those measured in these dwellings by the passive technique of SSNTDs; indicating the importance of the SSNTDs in the long-term integrated measurement

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

Science.gov (United States)

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

2009-01-01

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

Diurnal radon-222 concentrations in the outflow of a complex basin

International Nuclear Information System (INIS)

Clements, W.E.; Wilkening, M.

1981-01-01

Radon 222 concentrations were monitored continuously in the outflow from the Anderson and Putah Creek air drainage basin as part of the Department of Energy's Atmospheric Studies in Complex Terrain September 1980 field studies. Radon 222, an inert gas having a half-life of 3.8 days, can be considered to be exhaled uniformly at a constant rate from the earth's surface throughout the basin. The contribution to the total radon budget from vented steam from geothermal wells in the Geysers area is neglected. Hence, radon in this application is used as an extended-source atmospheric tracer in contrast with point-source release of tracer materials. One of the purposes of this study is to help classify drainage flow nights in terms of the diurnal patterns of radon concentration. As cool slope winds move along the terrain and into the valley, the air masses involved accumulate radon through the night until morning instabilities mix it to greater depths. Hence, the measured diurnal trend of radon in the outflow of the basin reflects the integrated behavior of nocturnal flows in the basin and subsequent breakup in the morning. The use of this technique to classify drainage flows has been used by Wilkening and Rust

Fluorescent multiple staining and CASA system to assess boar sperm viability and membranes integrity in short and long-term extenders

OpenAIRE

F. Cremonesi; A. Meucci; A. Lange-Consiglio

2013-01-01

The aim of this study was to assess the effect on boar spermatozoa quality of in vitro storage in short and long-term extenders by fluorescent multiple staining (FMS) and computer assisted semen analyzer (CASA). Fresh ejaculates from three healthy, sexually mature boars were diluted with equal volumes of six short-term or three long-term commercial extenders and stored at 19?C for 6 days (short-term) or 12 days (long-term). The integrity of spermatozoa membranes was analyzed by FMS using prop...

Sleep facilitates long-term face adaptation

OpenAIRE

Ditye, Thomas; Javadi, Amir Homayoun; Carbon, Claus-Christian; Walsh, Vincent

2013-01-01

Adaptation is an automatic neural mechanism supporting the optimization of visual processing on the basis of previous experiences. While the short-term effects of adaptation on behaviour and physiology have been studied extensively, perceptual long-term changes associated with adaptation are still poorly understood. Here, we show that the integration of adaptation-dependent long-term shifts in neural function is facilitated by sleep. Perceptual shifts induced by adaptation to a distorted imag...

Development of a low-level radon reference chamber; Entwicklung einer Low-Level-Radon-Referenzkammer

Energy Technology Data Exchange (ETDEWEB)

Linzmaier, Diana

2013-01-04

The naturally occurring, radioactive noble gas radon-222 exists worldwide in different activity concentrations in the air. During the decay of radon-222, decay products are generated which are electrically charged and attach to aerosols in the air. Together with the aerosols, the radon is inhaled and exhaled by humans. While the radon is nearly completely exhaled, ca. 20 % of the inhaled aerosols remain in the lungs in one breath cycle. Due to ionizing radiation, in a chain of events, lung cancer might occur. Consequently, radon and its decay products are according to the current findings the second leading cause of lung cancer. At the workplace and in the home measurements of radon activity concentration are performed to determine the radiation exposition of humans. All measurement devices for the determination of radon activity concentration are calibrated above 1000 Bq/m{sup 3}, even though the mean value of the present investigation in Germany shows only 50 Bq/m{sup 3}. For the calibration of measurement devices in the range below 1000 Bq/m{sup 3} over a long time period, the generation of a stable reference atmosphere is presented in this work. Due to a long term calibration (t>5 days) of the measurement devices, smaller uncertainties result for the calibration factor. For the calibration procedure, a so-called low-level radon reference chamber was set up and started operation. The generation of a stable reference atmosphere is effected by means of emanation sources which consist of a radium-226 activity standard. On the basis of {gamma}-spectrometry, the effective emanation coefficient ofthe emanation sources is determined. The traceability of the activity concentration in the reference volume is realized via the activity ofthe radium-226, the emanation coefficient and the volume. With the emanation sources produced, stable reference atmospheres within the range of 150 Bq/m{sup 3} to 1900 Bq/m{sup 3} are achieved. For the realization, maintenance and

Radon availability in New Mexico

International Nuclear Information System (INIS)

McLemore, V.T.

1995-01-01

The New Mexico Bureau of Mines and Mineral Resources (NMBMMR) in cooperation with the Radiation Licensing and Registration Section of the New Mexico Environment Department (NMED) and the US Environmental Protection Agency (EPA) have been evaluating geologic and soil conditions that may contribute to elevated levels of indoor radon throughout New Mexico. Various data have been integrated and interpreted in order to determine areas of high radon availability. The purpose of this paper is to summarize some of these data for New Mexico and to discuss geologic controls on the distribution of radon. Areas in New Mexico have been identified from these data as having a high radon availability. It is not the intent of this report to alarm the public, but to provide data on the distribution of radon throughout New Mexico

The determination of a continuous radon daughter equilibrium factor in an operating uranium mine

International Nuclear Information System (INIS)

Billingsley, D.

1992-01-01

Radon daughter exposures to workers at the Olympic Dam Operations copper and uranium mine are calculated from a series of grab samples obtained from various work locations around the mine. Currently under consideration is the introduction of personal passive radon dosimeters to determine the workers' radon daughter exposures. The study reported in this paper involved the determination of long-term equilibrium factors using real-time monitoring of radon and radon daughters. Consequently, variation in equilibrium factor for different tasks can be identified. In practice, the equilibrium factor varies with location and task; however, a conservative over-estimate of 0.28 can be confidently applied to all tasks. The error due to over-estimation remains minimal for all workers. This real-time monitoring method will reduce potential errors in dose assessment compared with the grab sampling technique. 5 refs., 1 tab., 4 figs

Appraisal of Environmental Influence on Radon Variability in 10 m deep Borehole at Ghuttu, Northwest Himalaya, India

Science.gov (United States)

Arora, B.. R.; Choubey, V. M.; Barbosa, S. M.

2009-04-01

Wadia Institute of Himalayan Geology (WIHG) has recently established the first Indian Multi-Parametric Geophysical Observatory (MPGO) at Ghuttu (30.53 N, 78.74 E) in Garhwal Himalayas (Uttarakhand), India to study the earthquake precursors in integrated manner. Given the rationale and significance of this inter-disciplinary approach, the paper with the help of recorded radon time series shall illustrate the complex time variability that needs to be quantified in terms of influencing environmental factors before residual field can be used to search anticipated earthquake precursory signals. Monitoring of 222radon (Rn) is carried out using a gamma ray radon monitoring probe based on 1.5" x 1.5" NaI scintillation. Measurement of radon concentration at 15 min interval has been done at 10m depth in air column above the variable water level in a 68m deep borehole together with simultaneous recordings of ground water level and environmental variables such as atmospheric pressure, temperature, rain fall etc. Apart from strong seasonal cycle in Rn concentration, with high values in summer (July to September) and low values in the winter months (January to March), the most obvious feature in the time series is the distinct nature of daily variation pattern. Four types of daily variations observed are a) positive peaks, b) negative peaks and c) sinusoidal peaks and d) long intervals when daily variations are conspicuously absent, particularly in winter and rainy season. Examination and correlation with environmental factors has revealed that when surface atmospheric temperature is well below the water temperature in borehole (later is constant around 19oC in all seasons) temperature gradients are not conducive to set up the convection currents for the emanation of radon to surface, thus explaining the absence of daily variation in radon concentration in winter. During the rainy season, following continuous rainfalls, once the soil/rocks are saturated with water radon

Investigation of radon and thoron concentrations in a landmark skyscraper in Tokyo

International Nuclear Information System (INIS)

Kazumasa Inoue; Masahiro Fukushi

2013-01-01

The temporal variation of the radon concentration, and the radon and thoron concentrations every 3 months for a year were measured using two types of devices in a landmark skyscraper, the Tokyo Metropolitan Government Daiichi Building. In the measurement of temporal variation of the radon concentration using a pulse type ionization chamber, the average radon concentration was 21 ± 13 Bq m -3 (2-68 Bq m -3 ). The measured indoor radon concentration had a strong relationship with the operation of the mechanical ventilation system and the activities of the office workers. The radon concentration also increased together with temperature. Other environmental parameters, such as air pressure and relative humidity, were not related to the radon concentration. In the long-term measurements using a passive radon and thoron discriminative monitor, no seasonal variation was observed. The annual average concentrations of radon and thoron were 16 ± 8 and 16 ± 7 Bq m -3 , respectively. There was also no relationship between the two concentrations. The annual average effective dose for office workers in this skyscraper was estimated to be 0.08 mSv y -1 for 2000 working hours per year. When considering the indoor radon exposure received from their residential dwellings using the annual mean radon concentration indoors in Japan (15.5 Bq m -3 ), the annual average effective dose was estimated to be 0.37 mSv y -1 . This value was 31 % of the worldwide average annual effective dose. (author)

Dependence of radon level on ventilation systems in residences

International Nuclear Information System (INIS)

Kokotti, H.

1995-01-01

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

Mapping variation in radon potential both between and within geological units

International Nuclear Information System (INIS)

Miles, J C H; Appleton, J D

2005-01-01

Previously, the potential for high radon levels in UK houses has been mapped either on the basis of grouping the results of radon measurements in houses by grid squares or by geological units. In both cases, lognormal modelling of the distribution of radon concentrations was applied to allow the estimated proportion of houses above the UK radon Action Level (AL, 200 Bq m -3 ) to be mapped. This paper describes a method of combining the grid square and geological mapping methods to give more accurate maps than either method can provide separately. The land area is first divided up using a combination of bedrock and superficial geological characteristics derived from digital geological map data. Each different combination of geological characteristics may appear at the land surface in many discontinuous locations across the country. HPA has a database of over 430 000 houses in which long-term measurements of radon concentration have been made, and whose locations are accurately known. Each of these measurements is allocated to the appropriate bedrock-superficial geological combination underlying it. Taking each geological combination in turn, the spatial variation of radon potential is mapped, treating the combination as if it were continuous over the land area. All of the maps of radon potential within different geological combinations are then combined to produce a map of variation in radon potential over the whole land surface

Radon classification of building ground

International Nuclear Information System (INIS)

Slunga, E.

1988-01-01

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

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

International Nuclear Information System (INIS)

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

1979-11-01

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

Indoor radon concentrations in kindergartens from different regions of Yugoslavia

International Nuclear Information System (INIS)

Vaupotic, J.; Krizman, M.; Sutej, T.

1992-01-01

In the winter period of 1990-1991 instantaneous radon concentrations in air were measured in around 450 kindergartens from different regions from Yugoslavia. Alpha scintillation counting was used as a screening method, and the measurements were carried out in rooms where the children spent the majority of their time. All of the air grab samples were taken under the same conditions which excluded ventilation of the interior 12 h prior to sampling. In addition to indoor radon concentrations, gamma dose rate was measured using portable equipment. The indoor radon concentrations were generally low, in the range from 10 to 180 Bq.m -3 of air, with an overall average of about 100 Bq.m -3 . There were a few exceptions where indoor radon levels exceeded 150 Bq.m -3 ; mainly in old buildings containing higher contents of natural radionuclides in the building materials, and in the cellars or basements of the buildings. In all rooms with a level exceeding 150 Bq of 222 Rn per m 3 , solid-state nuclear track detectors were applied for long-term measurements. In order to investigate the equilibrium between radon and its short-lived daughters, mainly with respect to their contribution to the effective dose, alpha spectrometry is also being introduced in selected kindergartens with elevated radon concentrations. (author)

Measurement and apportionment of radon source terms for modeling indoor environments

International Nuclear Information System (INIS)

Harley, N.H.

1990-01-01

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

Radon risk in the house; Il rischio radon nelle abitazioni

Energy Technology Data Exchange (ETDEWEB)

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

2001-04-01

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

Comparison of the large-scale radon risk map for southern Belgium with results of high resolution surveys

International Nuclear Information System (INIS)

Zhu, H.-C.; Charlet, J.M.; Poffijn, A.

2000-01-01

A large-scale radon survey consisting of long-term measurements in about 5200 singe-family houses in the southern part of Belgium was carried from 1995 to 1999. A radon risk map for the region was produced using geostatistical and GIS approaches. Some communes or villages situated within high risk areas were chosen for detailed surveys. A high resolution radon survey with about 330 measurements was performed in half part of the commune of Burg-Reuland. Comparison of radon maps on quite different scales shows that the general Rn risk map has similar pattern as the radon map for the detailed study area. Another detailed radon survey in the village of Hatrival, situated in a high radon area, found very high proportion of houses with elevated radon concentrations. The results of this detailed survey are comparable to the expectation for high risk areas on the large-scale radon risk map. The good correspondence between the findings of the general risk map and the analysis of the limited detailed surveys, suggests that the large-scale radon risk map is likely reliable. (author)

Radon in Croatian spas

International Nuclear Information System (INIS)

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

2004-01-01

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

Radon monitoring technique with electret collecting

International Nuclear Information System (INIS)

Tian Zhiheng; Zuo Fuqi; Xiao Detao; Zhao Xkiuliang

1991-12-01

The integrating radon monitoring technique with electret collecting is a method which collects the 218 Po + positive ions by electrostatic field produced by electret. It has greatly improved the sensitivity of radon measurement. The response factor of this method reaches to 4.7 cm -2 Bq -1 m 3 h -1 , 1000 times larger than that of common passive sampling method. The monitoring device and its principle are introduced. The measuring results of radon concentration and radon flux rate and quality assurance system by using this method in the Qinshan Nuclear Power Plant, Human Environmental Monitoring Central Station and some uranium mines are also presented. The analytical results show that the radon concentration in the Qinshan Nuclear Power Plant is affected by wind direction. When wind directs toward sea, the radon concentration is high. If the wind is to the contrary, it is low. The radon concentration ratio of both is about 2

Scopingreport radon

International Nuclear Information System (INIS)

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

1989-09-01

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

Radon and lung cancer in Bangalore Metropolitan, India

International Nuclear Information System (INIS)

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

2012-01-01

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

Suppression of the radon background by a prototype PICASSO emulsion container

International Nuclear Information System (INIS)

Bocan, J.; Bocarov, V.; Cermak, P.; Konicek, J.; Pospisil, S.; Stekl, I.; Leroy, C.; Jilek, K.

2004-01-01

A new PICASSO droplet detector is under development for its installation at the Sudbury Neutrino Observatory (SNO). The concept of the PICASSO experiment rests on an approach consisting of the detection of Cold Dark Matter (CDM) candidate particles, the neutralino in particular, through the use of large mass superheated droplet modular detectors. The sources of background signal for PICASSO detector are gamma rays, mips's, neutrons, radon and alpha particles due to U/Th contamination of the detector and its environment. Droplet detectors have high efficiency for detecting neutrons while being insensitive to mip's, gamma rays when operated at proper temperature and pressure. As in the case of other low background experiments radon is a very important source of background. Radon can diffuse into the detector during fabrication, storage, operation and induce an alpha background by its disintegration. The purpose of our long-term measurement was to define the tightness and penetrability of the PICASSO emulsion container against radon. The PICASSO box has been placed into a bigger plastic box and a Si detector has been installed in both boxes. The source of radon (pitchblende) has been inserted into an outer plastic box to obtain a high level radon environment. Radon monitoring was based on an electrostatic collection of its progeny 218 Po and 214 Po on the Si detector entrance window with spectroscopic counting of alpha particles (e.g. [2]). The spectrometer TAIP was used for a particle energy measurement. The spectrometer was developed at the Czech Technical University in Prague. The spectrometer contains all the spectrometric modules needed for energy measurement as well as the source of voltage for Si detector. It also includes digital memory to save spectra during measurement (up to 1792 spectra). Two long-time tests (2 months and 2.5 months) were performed. Radon concentrations in both containers (the outer plastic box, the PICASSO container) have been measured

Radon in Dwellings in the Republic of Kalmykia. Results from the National Radon Survey 2006-2007

International Nuclear Information System (INIS)

Aakerblom, Gustav; German, Olga; Soederman, Ann-Louise; Stamat, Ivan; Venkov, Vladimir

2009-02-01

The National Radon Survey in the Republic of Kalmykia, Russian Federation during 2006-2007 was carried out in a cooperation project between the Swedish Radiation Protection Authority (SSI) and the Russian Institute of Radiation Hygiene (RIRH). In August 2006 SSI, RIRH, federal and local authorities carried out a field study in Kalmykia when radon daughter measurements (equilibrium equivalent radon concentrations in the air) and gamma radiation measurements were made in 103 buildings. Gamma spectrometry measurements were made at several sites. During the visit the cooperating parties devoted some time to the education of local authorities on radon related issues. During three months in the winter season 2006-2007, long term radon trace measurements were made in 525 randomly chosen dwellings in the Republic of Kalmykia. The radon gas activity varied between 3 and 973 Bq/m 3 , with a mean value of 122 Bq/m 3 . In 19 of a total of 835 measurement points, the radon activity exceeded the maximum permitted value in Russia of 200 Bq/m 3 of EERC. The year-round radon trace measurement were made in 20 houses in Elista, the capital of the Republic of Kalmykia, for comparison with the three-month measurements. The year-round measurements showed some higher values for the radon activity, and a correction factor of 0.85 was applied. Using data on the number of people living in detached houses and apartments, and applying the radon activities measured, the number of new lung cancer cases caused by radon was calculated to be 20 to 40 of the 100 new cases reported annually. The methods of construction of the dwellings in Kalmykia is greatly influenced by the history and culture. Most of them were built after World War II and there are only a few that are newly built because of the poor economic situation and the low population growth rate in the Republic. Most people live in detached houses, one-storied with 3-5 rooms, built directly on the ground or on coquina blocks or on a cast

Radon safety in terms of energy efficiency classification of buildings

Science.gov (United States)

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

2017-06-01

According to the results of survey in Ekaterinburg, Russia, indoor radon concentrations above city average level have been found in each of the studied buildings with high energy efficiency class. Measures to increase energy efficiency were confirmed to decrease the air exchange rate and accumulation of high radon concentrations indoors. Despite of recommendations to use mechanical ventilation with heat recovery as the main scenario for reducing elevated radon concentrations in energy-efficient buildings, the use of such systems did not show an obvious advantage. In real situation, mechanical ventilation system is not used properly both in the automatic and manual mode, which does not give an obvious advantage over natural ventilation in the climate of the Middle Urals in Ekaterinburg. Significant number of buildings with a high class of energy efficiency and built using modern space-planning decisions contributes to an increase in the average radon concentration. Such situation contradicts to “as low as reasonable achievable” principle of the radiation protection.

Predicting long-term moisture contents of earthen covers at uranium mill tailings sites

International Nuclear Information System (INIS)

Gee, G.W.; Nielson, K.K.; Rogers, V.C.

1984-09-01

The three methods for long-term moisture prediction covered in this report are: estimates from water retention (permanent wilting point) data, correlation with climate and soil type, and detailed model simulation. The test results have shown: soils vary greatly in residual moisture. Expected long-term moisture saturation ratios (based on generalized soil characteristics) range from 0.2 to 0.8 for soils ranging in texture from sand to clay, respectively. These values hold for noncompacted field soils. Measured radon diffusion coefficients for soils at 15-bar water contents ranged from 5.0E-2 cm 2 /s to 5.0E-3 cm 2 /s for sands and clays, respectively, at typical field densities. In contrast, fine-textured pit-run earthen materials, subjected to optimum compaction (>85% Proctor density) and dried to the 15-bar water content, ranged from 0.7 to 0.9 moisture saturation. Compacted pit-run soils at these moisture contents exhibited radon diffusion coefficients as low as 3.0E-4 cm 2 /s. The residual moisture saturation for cover soils is not known since no engineered barrier has been in place for more than a few years. A comparison of methods for predicting moisture saturation indicates that model simulations are useful for predicting effects of climatic changes on residual soil moisture, but that long-term moisture also can be predicted with some degree of confidence using generalized soil properties or empirical correlations based both on soils and climatic information. The optimal soil cover design will likely include more than one layer of soil. A two-layer system using a thick (1-m minimum) plant root zone of uncompacted soil placed over a moistened, tightly compacted fine-textured soil is recommended. This design concept has been tested successfully at the Grand Junction, Colorado, tailings piles

Radon in the Hotels in Montenegro

International Nuclear Information System (INIS)

Vukotic, P.; Antovic, N.; Dapcevic, S.; Uvarov, V.V.; Mrdak, R.

1997-01-01

Indoor radon concentrations in the 16 hotels in Montenegro, well known by tourists, were measured in winter period by an integral method, with etch-track detectors. Radon concentrations obtained at the 30 measuring sites are in a range (22 - 90) Bq/m 3 , with an arithmetic mean of 43 Bq/m 3 . This means that the radon levels in the all surveyed hotels in Montenegro are much bellow the most stringent reference level internationally recommended. (author)

One cubic metre NIST traceable radon test chamber

International Nuclear Information System (INIS)

Kotrappa, P.; Stieff, F.

2008-01-01

With the availability of the National Inst. of Standards and Technology (NIST) Radon Emanation Standard with a content of ∼5000 Bq of 226 Ra, it is possible to build a flow through a practical radon test chamber. A standard glove box with four gloves and a transfer port is used. Air is pumped through a flow integrator, water jar for humidification and NIST source holder, and into the glove box through a manifold. A derived theoretical expression provides the calculated radon concentration inside the chamber. The calculation includes a derived decay correction due to the large volume and low flow rate of the system. Several calibrated continuous radon monitors and passive integrating electret ion chambers tested in the chamber agreed fairly well with the calculated radon concentrations. The chamber is suitable for handling the calibration of several detectors at the same time. (authors)

Radon concentrations in different types of dwellings in Israel

International Nuclear Information System (INIS)

Epstein, L.; Koch, J.; Riemer, T.; Haquin, G.; Orion, I.

2014-01-01

The average radon concentration in Israeli dwellings was assessed by combining the results of a 2006 radon survey in single family houses with the results of a 2011 radon survey in apartments of multi-storey buildings. Both surveys were based on long-term measurements using CR-39 detectors. The survey in multi-storey buildings was intended to assess the influence of recent practices in the local building industry on the radon concentrations. These practices include the use of building materials with higher concentrations of the natural radionuclides in the last 20 y than before, as well as the improvement in sealing techniques over that period. Another practice in place since the early 1990's is the building of a shielded area in every apartment that is known as an RSS (residential secure space). The RSS is a room built from massive concrete walls, floor and ceiling that can be hermetically sealed and is intended to protect its residents from a missile attack. The influence of the above-mentioned features on radon concentrations was estimated by dividing the participating apartments into two groups: apartments in buildings >20 y, built using building materials with low concentrations of the natural radionuclides, regular sealing and without an RSS and apartments in buildings newer than 10 y, built using building materials with higher concentrations of the natural radionuclides, improved sealing and including an RSS. It was found that the average radon concentration in apartments in new buildings was significantly higher than in old buildings and the average radon concentration in single-family houses was significantly higher than in apartments in multi-storey buildings. Doses due to indoor radon were estimated on the basis of the updated information included in the 2009 International Commission on Radiological Protection statement on radon. (authors)

Solar eruptions - soil radon - earthquakes

International Nuclear Information System (INIS)

Saghatelyan, E.; Petrosyan, L.; Aghbalyan, Yu.; Baburyan, M.; Araratyan, L.

2004-01-01

For the first time a new natural phenomenon was established: a contrasting increase in the soil radon level under the influence of solar flares. Such an increase is one of geochemical indicators of earthquakes. Most researchers consider this a phenomenon of exclusively terrestrial processes. Investigations regarding the link of earthquakes to solar activity carried out during the last decade in different countries are based on the analysis of statistical data ΣΕ (t) and W (t). As established, the overall seismicity of the Earth and its separate regions depends of an 11-year long cycle of solar activity. Data provided in the paper based on experimental studies serve the first step on the way of experimental data on revealing cause-and-reason solar-terrestrials bonds in a series s olar eruption-lithosphere radon-earthquakes . They need further collection of experimental data. For the first time, through radon constituent of terrestrial radiation objectification has been made of elementary lattice of the Hartmann's network contoured out by bio location method. As found out, radon concentration variations in Hartmann's network nodes determine the dynamics of solar-terrestrial relationships. Of the three types of rapidly running processes conditioned by solar-terrestrial bonds earthquakes are attributed to rapidly running destructive processes that occur in the most intense way at the juncture of tectonic massifs, along transformed and deep failures. The basic factors provoking the earthquakes are both magnetic-structural effects and a long-term (over 5 months) bombing of the surface of lithosphere by highly energetic particles of corpuscular solar flows, this being approved by photometry. As a result of solar flares that occurred from 29 October to 4 November 2003, a sharply contrasting increase in soil radon was established which is an earthquake indicator on the territory of Yerevan City. A month and a half later, earthquakes occurred in San-Francisco, Iran, Turkey

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

Energy Technology Data Exchange (ETDEWEB)

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

1979-11-01

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

Fluorescent multiple staining and CASA system to assess boar sperm viability and membranes integrity in short and long-term extenders.

Science.gov (United States)

Lange-Consiglio, A; Meucci, A; Cremonesi, F

2013-01-01

The aim of this study was to assess the effect on boar spermatozoa quality of in vitro storage in short and long-term extenders by fluorescent multiple staining (FMS) and computer assisted semen analyzer (CASA). Fresh ejaculates from three healthy, sexually mature boars were diluted with equal volumes of six short-term or three long-term commercial extenders and stored at 19°C for 6 days (short-term) or 12 days (long-term). The integrity of spermatozoa membranes was analyzed by FMS using propidium iodide, 5,5',6,6'-tetrachloro-1,1',3,3' tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) and fluorescein isothiocyanate-conjugated peanut agglutinin (PNA). The results obtained from this staining were compared with spermatozoa motility assessed by CASA. Our study showed that the number of viable spermatozoa with non-reacted acrosomes and intact mitochondria was positively correlated with the rate of motile spermatozoa (r(2)>0.9) irrespective of the extender used. In all extenders the number of motile spermatozoa significantly decreased as preservation period increased (P<0.05). FMS test is a potent indicator of sperm motility because it analyses mitochondrial integrity independently from observable alterations in motility. The best performing extenders were BTS for short-term storage and TRI-x-Cell for long-term storage.

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

International Nuclear Information System (INIS)

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

1993-06-01

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

Measurement and apportionment of radon source terms for modeling indoor environments

International Nuclear Information System (INIS)

Harley, N.H.

1992-01-01

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

Characterization of radon levels in indoor air

International Nuclear Information System (INIS)

George, A.C.

1982-01-01

The purpose is to describe the different types of monitoring and sampling techniques that can determine the radiation burden of the general public from radon and its decay products. This is accomplished by measuring the range and distribution of radon and radon decay products through broad surveys using simple and convenient integrating monitoring instruments. For in-depth studies of the behavior of radon decay products and calculation of the radiation dose to the lung, fewer and more intensive and complex measurements of the particle size distribution and respiratory deposition of the radon decay products are required. For diagnostic purposes, the paper describes measurement techniques of the sources and exhalation rate of radon and the air exchange inside buildings. Measurement results form several studies conducted in ordinary buildings in different geographical areas of the United States, using the described monitoring techniques, indicate that the occupants of these buildings are exposed to radon and radon decay product concentrations, varying by as much as a factor of 20

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

Science.gov (United States)

Juhásová Šenitková, Ingrid; Šál, Jiří

2017-12-01

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

Residential radon and lung cancer incidence in a Danish cohort

Energy Technology Data Exchange (ETDEWEB)

Braeuner, Elvira V., E-mail: ole@cancer.dk [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Danish Building Research Institute, Aalborg University (Denmark); Andersen, Claus E. [Center for Nuclear Technologies, Radiation Research Division, Riso National Laboratory for Sustainable Energy, Technical University of Denmark, Roskilde (Denmark); Sorensen, Mette [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Jovanovic Andersen, Zorana [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Center for Epidemiology Screening, Department of Public Health, University of Copenhagen (Denmark); Gravesen, Peter [Geological Survey of Denmark and Greenland, Copenhagen (Denmark); Ulbak, Kaare [National Institute of Radiation Protection, Herlev (Denmark); Hertel, Ole [Department of Environmental Science, Aarhus University, Aarhus (Denmark); Pedersen, Camilla [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Overvad, Kim [Department of Epidemiology, School of Public Health, Aarhus University, Aarhus (Denmark); Tjonneland, Anne; Raaschou-Nielsen, Ole [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark)

2012-10-15

High-level occupational radon exposure is an established risk factor for lung cancer. We assessed the long-term association between residential radon and lung cancer risk using a prospective Danish cohort using 57,053 persons recruited during 1993-1997. We followed each cohort member for cancer occurrence until 27 June 2006, identifying 589 lung cancer cases. We traced residential addresses from 1 January 1971 until 27 June 2006 and calculated radon at each of these addresses using information from central databases regarding geology and house construction. Cox proportional hazards models were used to estimate incidence rate ratios (IRR) and 95% confidence intervals (CI) for lung cancer risk associated with residential radon exposure with and without adjustment for sex, smoking variables, education, socio-economic status, occupation, body mass index, air pollution and consumption of fruit and alcohol. Potential effect modification by sex, traffic-related air pollution and environmental tobacco smoke was assessed. Median estimated radon was 35.8 Bq/m{sup 3}. The adjusted IRR for lung cancer was 1.04 (95% CI: 0.69-1.56) in association with a 100 Bq/m{sup 3} higher radon concentration and 1.67 (95% CI: 0.69-4.04) among non-smokers. We found no evidence of effect modification. We find a positive association between radon and lung cancer risk consistent with previous studies but the role of chance cannot be excluded as these associations were not statistically significant. Our results provide valuable information at the low-level radon dose range.

Residential radon and lung cancer incidence in a Danish cohort

International Nuclear Information System (INIS)

Bräuner, Elvira V.; Andersen, Claus E.; Sørensen, Mette; Jovanovic Andersen, Zorana; Gravesen, Peter; Ulbak, Kaare; Hertel, Ole; Pedersen, Camilla; Overvad, Kim; Tjønneland, Anne; Raaschou-Nielsen, Ole

2012-01-01

High-level occupational radon exposure is an established risk factor for lung cancer. We assessed the long-term association between residential radon and lung cancer risk using a prospective Danish cohort using 57,053 persons recruited during 1993–1997. We followed each cohort member for cancer occurrence until 27 June 2006, identifying 589 lung cancer cases. We traced residential addresses from 1 January 1971 until 27 June 2006 and calculated radon at each of these addresses using information from central databases regarding geology and house construction. Cox proportional hazards models were used to estimate incidence rate ratios (IRR) and 95% confidence intervals (CI) for lung cancer risk associated with residential radon exposure with and without adjustment for sex, smoking variables, education, socio-economic status, occupation, body mass index, air pollution and consumption of fruit and alcohol. Potential effect modification by sex, traffic-related air pollution and environmental tobacco smoke was assessed. Median estimated radon was 35.8 Bq/m 3 . The adjusted IRR for lung cancer was 1.04 (95% CI: 0.69–1.56) in association with a 100 Bq/m 3 higher radon concentration and 1.67 (95% CI: 0.69–4.04) among non-smokers. We found no evidence of effect modification. We find a positive association between radon and lung cancer risk consistent with previous studies but the role of chance cannot be excluded as these associations were not statistically significant. Our results provide valuable information at the low-level radon dose range.

Multi-year monitoring of radon in boreholes at the Modra geophysical observatory, Slovakia

International Nuclear Information System (INIS)

Smetanova, I.; Steinitz, G.; Holy, K.

2017-01-01

Long-term radon monitoring was performed in two boreholes, at a depth of 13 m in the 40 m deep V-2 borehole (August 2003 September 2005), and at 3 m depth in the 10 m deep V-3 borehole (August 2003 April 2008). Diurnal, multi-day and annual variations in radon time-series were observed. Daily average of radon activity in V-2 borehole was significantly higher and ranged from 6.5 to 383.7 kBq/m 3 , while in V-3 borehole only between 1.2 and 139.4 kBq/m 3 . The seasonal pattern was more pronounced in V-3 time series, with the maximum occurring from October to March. Multi-day variations (2-10 days) were registered in V-2 and V-3 mostly simultaneously, with higher discrepancy in spring and summer periods, when radon activity in V-3 borehole was low. Diurnal radon variations with two maxima and two minima per day were registered in both boreholes. The influence of meteorological parameters on radon concentrations was investigated. The overall impression is that seasonal variation in radon in V-3 borehole seems to be connected with the temperature variation. Multi-day variations of radon in both boreholes coincided with the atmospheric pressure changes. An increase in radon activity was observed in V-3 borehole after the rainfall in spring and summer seasons. (authors)

The use of radon as an earthquake precursor

International Nuclear Information System (INIS)

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

1990-01-01

Radon monitoring for earthquake prediction is part of an integral approach since the discovery of coherent and time anomalous radon concentrations prior to, during and after the 1966 Tashkent earthquake. In this paper some studies of groundwater and soil gas radon content in relation to earthquake activities are reviewed. Laboratory experiments and the development of groundwater and soil gas radon monitoring systems are described. In addition, radon monitoring studies conducted at the Guru Nanak Dev University Campus since 1986 are presented in detail. During these studies some anomalous changes in radon concentration were recorded before earthquakes occurred in the region. The anomalous radon increases are independent of meteorological conditions and appear to be caused by strain changes, which precede the earthquake. Anomalous changes in radon concentration before an earthquake suggest that radon monitoring can serve as an additional technique in the earthquake prediction programme in India. (author)

Radon in Houses of Vukovar-Srijem County

International Nuclear Information System (INIS)

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

2008-01-01

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

Ceramic BeO exoelectron dosimeters for tritium and radon monitoring

International Nuclear Information System (INIS)

Gammage, R.B.

1979-01-01

An environmental monitoring device with BeO ceramic dosimeters can be used to measure 222 Rn in dwellings. Radon diffuses into a porous hemispheric chamber and the radon daughters are electrostatically collected on aluminized Mylar foil covering the BeO dosimeter that records the alpha activity. A 10:1 signal-to-background ratio results from a radon exposure of only pCi-h/l. This high sensitivity makes accurate radon measurement possible within one day, even at near background levels of a few tenths pCi/l. The BeO exoelectron dosimeter is also uniquely suited for monitoring occupational exposure to insoluble tritium gas. At one-fifth the maximum permissible concentration, exposure for 8 hours gives a 10:1 signal-to-background exoelectron response to the low energy beta rays. Compensation for any exoelectron response caused by photon radiation can be made by reading the thermoluminescence. The tritium exposure produces negligible thermoluminescence. Progress in these and other applications is now totally dependent on achieving reliability and long-term stability of the exoelectron dosimeter

Radon in the human life

International Nuclear Information System (INIS)

Thomas, J.

1995-01-01

Radon causes the utmost but controllable radiation exposure of the population. This is now clear, nearly hundred years after the discovery of radioactivity. Remediate and preventive activities have been stated with a complex approach using building engineering, geological sciences, physics and medicine. Despite of long experience in radon problems all these approaches need further development. (J.K.)

Radon in the human life

Energy Technology Data Exchange (ETDEWEB)

Thomas, J [State Office for Nuclear Safety, Prague (Czech Republic)

1996-12-31

Radon causes the utmost but controllable radiation exposure of the population. This is now clear, nearly hundred years after the discovery of radioactivity. Remediate and preventive activities have been stated with a complex approach using building engineering, geological sciences, physics and medicine. Despite of long experience in radon problems all these approaches need further development. (J.K.).

The radon 222 transport in soils. The case of the storage of residues coming from uranium ores processing; La migration du radon 222 dans un sol. Application aux stockages de residus issus du traitement des minerais d'uranium

Energy Technology Data Exchange (ETDEWEB)

Ferry, C

2000-07-01

Uranium Mill Tailings (UMT) contain comparatively large quantities of radium-226. This radionuclide yields, by radioactive decay, the radioactive gas radon-222. Tailing piles are routinely covered to reduce the radon release-rate into the atmosphere. In order to assess the long term environmental impact of a UMT repository, mechanisms governing radon exhalation at the soil surface must be deciphered and understood. A model of radon transport in the unsaturated zone is developed for this purpose: water- and air-flow in the porous material are determined, as well as radon transport by diffusion in the pore space and advection by the gas phase. The radon transport model in the unsaturated zone - TRACI (which stands, in French, for Radon Transport within the Unsaturated Layer) - calculates moisture contents in the soil, Darcy's velocities of the liquid and gas phases, radon concentrations in the gas phase and radon flux at the soil surface. TRACI's results are compared with observations carried out on a UMT and a cover layer. Input parameters are derived from the textural analysis of the material under study, whereas upper boundary conditions are given by meteorological data. If we consider measurement errors and uncertainties on the porous medium characterisation, model's results are generally in good agreement with observations, at least on the long run. Moreover, data analysis shows hat transient phenomena are understood as well, in most situations. (author)

In Vivo Transplantation of Enteric Neural Crest Cells into Mouse Gut; Engraftment, Functional Integration and Long-Term Safety.

Directory of Open Access Journals (Sweden)

Julie E Cooper

Full Text Available Enteric neuropathies are severe gastrointestinal disorders with unsatisfactory outcomes. We aimed to investigate the potential of enteric neural stem cell therapy approaches for such disorders by transplanting mouse enteric neural crest cells (ENCCs into ganglionic and aganglionic mouse gut in vivo and analysing functional integration and long-term safety.Neurospheres generated from yellow fluorescent protein (YFP expressing ENCCs selected from postnatal Wnt1-cre;R26R-YFP/YFP murine gut were transplanted into ganglionic hindgut of wild-type littermates or aganglionic hindgut of Ednrbtm1Ywa mice (lacking functional endothelin receptor type-B. Intestines were then assessed for ENCC integration and differentiation using immunohistochemistry, cell function using calcium imaging, and long-term safety using PCR to detect off-target YFP expression.YFP+ ENCCs engrafted, proliferated and differentiated into enteric neurons and glia within recipient ganglionic gut. Transplanted cells and their projections spread along the endogenous myenteric plexus to form branching networks. Electrical point stimulation of endogenous nerve fibres resulted in calcium transients (F/F0 = 1.16 ± 0.01;43 cells, n = 6 in YFP+ transplanted ENCCs (abolished with TTX. Long-term follow-up (24 months showed transplanted ENCCs did not give rise to tumours or spread to other organs (PCR negative in extraintestinal sites. In aganglionic gut ENCCs similarly spread and differentiated to form neuronal and glial networks with projections closely associated with endogenous neural networks of the transition zone.Transplanted ENCCs successfully engrafted into recipient ganglionic and aganglionic gut showing appropriate spread, localisation and, importantly, functional integration without any long-term safety issues. This study provides key support for the development and use of enteric neural stem cell therapies.

Verification of geomechanical integrity and prediction of long-term mineral trapping for the Ketzin CO2 storage pilot site

Science.gov (United States)

Kempka, Thomas; De Lucia, Marco; Kühn, Michael

2014-05-01

Static and dynamic numerical modelling generally accompany the entire CO2 storage site life cycle. Thereto, it is required to match the employed models with field observations on a regular basis in order to predict future site behaviour. We investigated the coupled processes at the Ketzin CO2 storage pilot site [1] using a model coupling concept focusing on the temporal relevance of processes involved (hydraulic, chemical and mechanical) at given time-scales (site operation, abandonment and long-term stabilization). For that purpose, long-term dynamic multi-phase flow simulations [2], [3] established the basis for all simulations discussed in the following. Hereby, pressure changes resulting in geomechanical effects are largest during site operation, whereas geochemical reactions are governed by slow kinetics resulting in a long-term stabilization. To account for mechanical integrity, which may be mainly affected during site operation, we incorporated a regional-scale coupled hydro-mechanical model. Our simulation results show maximum ground surface displacements of about 4 mm, whereas shear and tensile failure are not observed. Consequently, the CO2 storage operation at the Ketzin pilot site does not compromise reservoir, caprock and fault integrity. Chemical processes responsible for mineral trapping are expected to mainly occur during long-term stabilization at the Ketzin pilot site [4]. Hence, our previous assessment [3] was extended by integrating two long-term mineral trapping scenarios. Thereby, mineral trapping contributes to the trapping mechanisms with 11.7 % after 16,000 years of simulation in our conservative and with 30.9 % in our maximum reactivity scenarios. Dynamic flow simulations indicate that only 0.2 % of the CO2 injected (about 67,270 t CO2 in total) is in gaseous state, but structurally trapped after 16,000 years. Depending on the studied long-term scenario, CO2 dissolution is the dominating trapping mechanism with 68.9 % and 88

Legal issues in radon affairs

International Nuclear Information System (INIS)

Massuelle, M.H.

1999-01-01

In France, it was only recently that cases related to high radon concentrations in dwellings received substantial publicity. This irruption of radon as a public health issue came with the general progress of scientific knowledge and the availability of a research capacity in France able to develop expertise. We are interested here in the legal implications of issues that arise from the lag between the activity of experts and the regulatory activity in the domain of radon. We use the term expertise very broadly, to cover the practical application of research findings, the relation of the researchers with the community, and finally the acts by which experts provide their knowledge to the community. We first examine the course by which science developed the radon issue and the way they organized to move from research to expertise; here we try to characterize the various needs for radon expertise. We then discuss the legal difficulties associated with radon expertise

Legal issues in radon affairs

Energy Technology Data Exchange (ETDEWEB)

Massuelle, M.H. [Inst. de Protection et de Surete Nucleaire, Fontenay aux Roses (France)

1999-12-01

In France, it was only recently that cases related to high radon concentrations in dwellings received substantial publicity. This irruption of radon as a public health issue came with the general progress of scientific knowledge and the availability of a research capacity in France able to develop expertise. We are interested here in the legal implications of issues that arise from the lag between the activity of expertsand the regulatory activity in the domain of radon. We use the term expertise very broadly, to cover the practical application of research findings, the relation of the researchers with the community, and finally the acts by which experts provide their knowledge to the community. We first examine the course by which science developed the radon issue and the way they organized to move from research to expertise; here we try to characterize the various needs for radon expertise. We then discuss the legal difficulties associated with radon expertise.

Induced Neural Stem Cells Achieve Long-Term Survival and Functional Integration in the Adult Mouse Brain

Directory of Open Access Journals (Sweden)

Kathrin Hemmer

2014-09-01

Full Text Available Differentiated cells can be converted directly into multipotent neural stem cells (i.e., induced neural stem cells [iNSCs]. iNSCs offer an attractive alternative to induced pluripotent stem cell (iPSC technology with regard to regenerative therapies. Here, we show an in vivo long-term analysis of transplanted iNSCs in the adult mouse brain. iNSCs showed sound in vivo long-term survival rates without graft overgrowths. The cells displayed a neural multilineage potential with a clear bias toward astrocytes and a permanent downregulation of progenitor and cell-cycle markers, indicating that iNSCs are not predisposed to tumor formation. Furthermore, the formation of synaptic connections as well as neuronal and glial electrophysiological properties demonstrated that differentiated iNSCs migrated, functionally integrated, and interacted with the existing neuronal circuitry. We conclude that iNSC long-term transplantation is a safe procedure; moreover, it might represent an interesting tool for future personalized regenerative applications.

Asphalt emulsion radon barrier systems for uranium mill tailings: an overview of the technology

International Nuclear Information System (INIS)

Baker, E.G.; Hartley, J.N.; Freeman, H.D.; Gates, T.E.; Nelson, D.A.; Dunning, R.L.

1984-03-01

Pacific Northwest Laboratory (PNL), under contract to the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action Project (UMTRAP) office, has developed an asphalt emulsion cover system to reduce the release of radon from uranium mill tailings. The system has been field tested at Grand Junction, Colorado. Results from laboratory and field tests indicate that this system is effective in reducing radon release to near-background levels ( -2 s -1 ) and has the properties required for long-term effectiveness and stability. Engineering specifications have been developed, and analysis indicates that asphalt emulsion covers are cost-competitive with other cover systems. This report summarizes the technology for asphalt emulsion radon barrier systems. 59 references, 45 figures, 36 tables

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

International Nuclear Information System (INIS)

Langner, G.H. Jr.

1987-06-01

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

Fluorescent multiple staining and CASA system to assess boar sperm viability and membranes integrity in short and long-term extenders

Directory of Open Access Journals (Sweden)

F. Cremonesi

2013-03-01

Full Text Available The aim of this study was to assess the effect on boar spermatozoa quality of in vitro storage in short and long-term extenders by fluorescent multiple staining (FMS and computer assisted semen analyzer (CASA. Fresh ejaculates from three healthy, sexually mature boars were diluted with equal volumes of six short-term or three long-term commercial extenders and stored at 19°C for 6 days (short-term or 12 days (long-term. The integrity of spermatozoa membranes was analyzed by FMS using propidium iodide, 5,5’,6,6’-tetrachloro-1,1’,3,3’ tetraethylbenzimidazolyl-carbocyanine iodide (JC-1 and fluorescein isothiocyanate-conjugated peanut agglutinin (PNA. The results obtained from this staining were compared with spermatozoa motility assessed by CASA. Our study showed that the number of viable spermatozoa with non-reacted acrosomes and intact mitochondria was positively correlated with the rate of motile spermatozoa (r2>0.9 irrespective of the extender used. In all extenders the number of motile spermatozoa significantly decreased as preservation period increased (P<0.05. FMS test is a potent indicator of sperm motility because it analyses mitochondrial integrity independently from observable alterations in motility. The best performing extenders were BTS for short-term storage and TRI-x-Cell for long-term storage.

Radon prevention in the design and construction of schools and other large buildings

International Nuclear Information System (INIS)

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

1991-01-01

The paper discusses radon prevention in the design and construction of schools and other large buildings. The U.S. EPA's Office of Research and Development (ORD) has started incorporating radon control measures into the design and construction of new schools and other large buildings. The goal of the new designs is twofold: (1) to prevent elevated radon levels in the completed building, and (2) to provide the protection at a fraction of the cost of retrofit systems. ORD's Air and Energy Engineering Research Laboratory (AEERL) has conducted the research necessary to develop viable designs. The Indoor Radon Abatement Act of 1988 set a national long-term goal for indoor radon of 0.5 picocurie per liter (pCi/L)--the same as that typically found in outdoor air. The EPA currently recommends that homeowners take action to reduce radon levels to below 4 pCi/L. To achieve the national goal set in the 1988 Act for new construction in radon-prone areas, AEERL research is using a combination of active subslab depressurization (ASD) and operation of the heating, ventilation, and air-conditioning (HVAC) system to pressurize buildings. These measures are described briefly, along with a case history of one building

Long-term integrity of buildings and systems

International Nuclear Information System (INIS)

Antoine, P.

1985-01-01

The present study relates to the conditions of holding nuclear power stations in a safe state after their final shutdown. To assess the reasonable duration of the waiting period before complete dismantling of the installations, it was deemed necessary: to investigate the causes and consequences of the ageing of a nuclear power station, with particular regard to the safety-relevant constituents such as the barriers against the dispersion of contamination, and to evaluate the possible problems of safety, maintenance and decommissioning cost. In the present document, the methodology is developed that is to apply in the particular case of a power station finally shut down which is to be decommissioned and dismantled later. For a detailed exercise of this methodology, the Framatome 900 MWe Pressurized Water Reactor station has been taken as a reference plant. The plan which has been elaborated for this study and for the examination of the technical problems has been conceived so as to suggest to the author of a similar study for a particular power station, all the points he has to consider. One chapter of this document has been devoted to showing the basic differences between the 900 MWe PWR reference plant and the other types of nuclear power station existing in the European Community (e.g., BWR, GCR, FBR) and to identify the consequences concerning the decommissioning and the long-term integrity of the installations. 84 refs [fr

Occupational and environmental exposures to radon: A perspective for mitigators

International Nuclear Information System (INIS)

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

1989-01-01

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

Physical stability of asphalt emulsion admix seal radon barrier for uranium mill tailings

International Nuclear Information System (INIS)

Gates, T.E.

1983-09-01

Pacific Northwest Laboratory, is investigating the use of an asphalt emulsion admix seal to reduce the release of radon from uranium mill tailings. A key requirement of any cover system is its long-term stability; the cover must withstand failure over very long periods of time. An important determinant of overall cover system stability is the integrity of the 6.35-cm (2.5-in.) thick asphalt admix seal. Therefore, the physical stability of this seal was examined. The investigation considered the mechanical interaction between the tailings pile and cover. The potential effect of differential settlement of the tailings pile on the integrity of the seal system was also examined. Results indicate that the minimum span length the seal could withstand without failing is 0.34 m (1.1 ft). This assumes a differential settlement of 4.92 cm (1.94 in.) at the center resulting from the application of a 0.76-m (2.5-ft) cover. At spans greater than 0.60 m (1.97 ft), no tensile strain would develop

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

Energy Technology Data Exchange (ETDEWEB)

Hopke, P.K.

1992-07-01

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

Short-term versus long-term market opportunities and financial constraints

International Nuclear Information System (INIS)

Ferrari, Angelo

1999-01-01

This presentation discusses gas developments in Europe, the European Gas Directive, short term vs. long term, and Snam's new challenges. The European gas market is characterized by (1) The role of gas in meeting the demand for energy, which varies greatly from one country to another, (2) A growing market, (3) Decreasing role of domestic production, and (4) Increasing imports. Within the European Union, the Gas Directive aims to transform single national markets into one integrated European market by introducing third party access to the network for eligible clients as a means of increasing the competition between operators. The Gas Directive would appear to modify the form of the market rather than its size, and in particular the sharing of responsibility and risk among operators. The market in the future will offer operators the possibility to exploit opportunities deriving mainly from demands for increased flexibility. Opportunities linked to entrepreneurial initiatives require long-term investments characteristic of the gas business. Risks and opportunities must be balanced evenly between different operators. If everyone takes on their own risks and responsibilities, this means a wider distribution of the risks of long-term vs. short-term, currently borne by the gas companies that are integrated, into a market that tends to favour the short-term. A gradual liberalization process should allow incumbent operators to gradually diversify their activities in new gas market areas or enter new business activities. They could move beyond their local and European boundaries in pursuit of an international dimension. The market will have to make the transition from the national to the European dimension: as an example, Snam covers 90% of the Italian market, but its share of an integrated European market will be about 15%

The 1996 Radon Intercomparison Exercise at PSI

International Nuclear Information System (INIS)

Schuler, C.; Butterweck-Dempewolf, G.

1997-05-01

The 1996 Radon Intercomparison Exercise at PSI was organized by the PSI Reference Laboratory for Radon Gas Activity Concentration Measurements. A total of 14 laboratories, companies and institutions participated with radon gas detectors and measuring instruments. The detectors and instruments were exposed in the PSI radon chamber during seven days in a reference atmosphere with an average radon gas concentration of about 6000 Bqm -3 . Comparison of the results of electret ionization chambers, track etch detectors and measuring instruments with the PSI target value showed the criteria for traceability and reproducibility demanded by the Federal Office for Health for the acknowledgement of Swiss Radon Gas Measurement Laboratories to be fulfilled for all participants. Exposure of track etch detectors stored for more than one year demonstrated that this detector type can suffer sensitivity loss by a too long storage period. (author) figs., tabs., refs

Radon concentrations inside public and commercial buildings in the Pittsburgh area

Energy Technology Data Exchange (ETDEWEB)

Cohen, B L; Kulwicki, D R; Warner, Jr, K R; Grassi, C L

1984-09-01

Radon concentrations in ambient air from numerous schools, stores and other public and commercial buildings in the Pittsburgh, PA, area were measured by grab sampling. This is more appropriate than using long-term integrating monitors because of the correlation between times of occupancy and Rn levels. Results indicate that Rn concentrations in these buildings are nearly an order of magnitude less than in homes, and not much higher than outdoors. Variations among sites is also much less than for homes, probably because there is less variability in ventilation and building maintenance practices. Colleges and universities have somewhat higher Rn levels and a larger degree of variability than commercial buildings or hospitals. There was no indication of higher Rn levels in cold weather than in warm weather, or of correlations with the age of the building.

Radon concentrations inside public and commercial buildings in the Pittsburgh area.

Science.gov (United States)

Cohen, B L; Kulwicki, D R; Warner, K R; Grassi, C L

1984-09-01

Radon concentrations in ambient air from numerous schools, stores and other public and commercial buildings in the Pittsburgh, PA, area were measured by grab sampling. This is more appropriate than using long-term integrating monitors because of the correlation between times of occupancy and Rn levels. Results indicate that Rn concentrations in these buildings are nearly an order of magnitude less than in homes, and not much higher than outdoors. Variations among sites is also much less than for homes, probably because there is less variability in ventilation and building maintenance practices. Colleges and universities have somewhat higher Rn levels and a larger degree of variability than commercial buildings or hospitals. There was no indication of higher Rn levels in cold weather than in warm weather, or of correlations with the age of the building.

Reconstruction of national distribution of indoor radon concentration in Russia using results of regional indoor radon measurement programs

International Nuclear Information System (INIS)

Yarmoshenko, I.; Malinovsky, G.; Vasilyev, A.; Zhukovsky, M.

2015-01-01

The aim of the paper is a reconstruction of the national distribution and estimation of the arithmetic average indoor radon concentration in Russia using the data of official annual 4-DOZ reports. Annual 4-DOZ reports summarize results of radiation measurements in 83 regions of Russian Federation. Information on more than 400 000 indoor radon measurements includes the average indoor radon isotopes equilibrium equivalent concentration (EEC) and number of measurements by regions and by three main types of houses: wooden, one-storey non-wooden, and multi-storey non-wooden houses. To reconstruct the national distribution, all-Russian model sample was generated by integration of sub-samples created using the results of each annual regional program of indoor radon measurements in each type of buildings. According to indoor radon concentration distribution reconstruction, all-Russian average indoor radon concentration is 48 Bq/m"3. Average indoor radon concentration by region ranges from 12 to 207 Bq/m"3. The 95-th percentile of the distribution is reached at indoor radon concentration 160 Bq/m"3. - Highlights: • Reconstruction of indoor radon concentration distribution in Russia was carried out. • Data of official annual 4-DOZ reports were used. • All-Russian average indoor radon concentration is 48 Bq/m"3. • The 95-th percentile is 160 Bq/m"3.

Development of a small-sized radon data logger

International Nuclear Information System (INIS)

Tasaka, Shigeki; Sasaki, Yoshimi

1996-01-01

A small-sized radon data logger and a electrostatic collecting radon monitor were developed for the continuous monitoring of environmental radon and radon daughters. A PIN photodiode (PD), an alpha particle defector, installed inside a container attracts radon daughters when charged electrostatically. Alpha particles are completely separated from each other according to the energy level. New logger has made it possible 10 analysts and save the radon data. Alpha particle count data from radon daughters are automatically integrated over preset time intervals and the energy regions. The desiccant P 2 O 5 was placed in the bottom of the monitor, since the collection efficiency of 218 Po atoms depends on the humidity of the air. We can get the 30 days continuous data logging at 30 min sampling frequency at any place with the car battery. We observed the radon concentration of the air inside the Super-Kamiokande dome from Jan-30 to Feb-8-1996. The average of radon concentration was found to be (46±13) Bq/m 3 . (author)

Techniques and principles for mapping of integrated radon emanation within the earth

International Nuclear Information System (INIS)

Fleischer, R.L; Mogro-Campero, A.

1980-01-01

Radon signals from within the ground are used in locating subsurface uranium deposits and are of potential use in sensing impending earthquakes. Several factors are documented that affect the reproducibility and reliability of radon measurements, and new methods are described that make current state-of-the-art radon measurements much improved over those obtainable in the past

Reinforced natural radioactivity: the case of radon measurement

International Nuclear Information System (INIS)

Bernhard, S.; Desray, M.

2009-01-01

Summarizing a presentation of radon measurement instruments, of their use and of the interpretation of their results, the authors briefly recall the origin of exposures to radon (geological or occupational), indicate the three types of control (detection of presence of radon, search for and characterization of sources and transfer ways, worker dosimetric follow-on) and the three types of measurement (selective, integrated or continuous), and evoke the range of measurement instruments

Control of indoor radon and radon progeny concentrations

International Nuclear Information System (INIS)

Sextro, R.G.

1985-05-01

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

Primary evaluation of the radon situation in dwellings in Saxony by long-time integrating measurements, comparison of the results with short-time measurements and determination of the radon activity concentration in the ground of the land; Erstbewertung zur Radonsituation von Haeusern im Freistaat Sachsen mittels langzeitintegrierenden Messungen, Vergleich der Ergebnisse mit Kurzzeitmessungen und Erfassung der Radon-Aktivitaetskonzentration in der Bodenluft der Grundstuecke

Energy Technology Data Exchange (ETDEWEB)

Alisch-Mark, M.; Keck, D.; Preusse, W.; Taube, A.; Busch, H.; Heinrich, T. [Staatliche Betriebsgesellschaft fuer Umwelt und Landwirtschaft, Sachsen (Germany)

2016-07-01

A measurement program was carried out for primary evaluation of dwellings in terms of radon situation. Short-time measurements were compared with annual averages and checked for their suitability for forecasting the annual averages. In 89% of the cases studied, the average annual values could be predicted by short-time measurements, differences were observed depending on the date of the short-time measure. In addition, radon activity concentrations were determined in the soil air in the ground and compared with the expected areas of forecasting map of Saxony. Discrepancies were found primarily in areas which are marked by a smallscale geology. The data obtained showed that the geogenic radon potential and the year of construction of the house represent factors influencing the probability of exceedance of the reference value of 300 Bq/m{sup 3}.

Environmental Radon Gas and Degenerative Conditions An Overview

International Nuclear Information System (INIS)

Groves-Kirkby, C.J.; Denman, A.R.; Woolridge, A.C.; Phillips, P.S.; Phillips, C.

2006-01-01

Radon, a naturally occurring radioactive gas, has variable distribution in the environment as a decay product of uranium occurring in a wide range of rocks, soils and building materials. Although radon dissipates rapidly in outdoor air, it concentrates in the built environment, and inhalation of 222 Rn and its progeny 218 Po and 214 Po is believed to provide the majority of the radioactive dose to the respiratory system. While the connection between radon and lung cancer has long been recognised and investigated, recent studies have highlighted potential links between radon and other conditions, among them Multiple Sclerosis, Alzheimer and Parkinson Diseases, and Paget Disease of Bone. A strong case exists for clarifying the relationship between radon and these other conditions, not least since radon remediation to reduce lung cancer may conceivably have additional benefits hitherto unrecognized. The present status of the postulated links between environmental radon gas and degenerative conditions is reviewed, and recommendations for further research into levering current anti-radon campaigns are made. (authors)

Radon risk in the house

International Nuclear Information System (INIS)

Bressa, G.

2001-01-01

Radon was discovered in 1900, but its potential dangerousness for man was fully understood only in 1950. Being a radioactive natural gas - and therefore particularly dangerous - radon results from the long decay chain of radionuclides, such as thorium and radium. Some igneous rocks (granite, tufa and lava) as well as coal are considered to be the main sources of this radionuclide. A number of epidemiologic studies have shown the carcinogenicity of this element, particularly among miners and workers subjected to high level exposure in confined spaces such as basements, garages, cellars, etc. There are, however, some techniques to remove radon in order to reduce exposure to minimum values [it

Induced neural stem cells achieve long-term survival and functional integration in the adult mouse brain.

Science.gov (United States)

Hemmer, Kathrin; Zhang, Mingyue; van Wüllen, Thea; Sakalem, Marna; Tapia, Natalia; Baumuratov, Aidos; Kaltschmidt, Christian; Kaltschmidt, Barbara; Schöler, Hans R; Zhang, Weiqi; Schwamborn, Jens C

2014-09-09

Differentiated cells can be converted directly into multipotent neural stem cells (i.e., induced neural stem cells [iNSCs]). iNSCs offer an attractive alternative to induced pluripotent stem cell (iPSC) technology with regard to regenerative therapies. Here, we show an in vivo long-term analysis of transplanted iNSCs in the adult mouse brain. iNSCs showed sound in vivo long-term survival rates without graft overgrowths. The cells displayed a neural multilineage potential with a clear bias toward astrocytes and a permanent downregulation of progenitor and cell-cycle markers, indicating that iNSCs are not predisposed to tumor formation. Furthermore, the formation of synaptic connections as well as neuronal and glial electrophysiological properties demonstrated that differentiated iNSCs migrated, functionally integrated, and interacted with the existing neuronal circuitry. We conclude that iNSC long-term transplantation is a safe procedure; moreover, it might represent an interesting tool for future personalized regenerative applications. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Real-time long term measurement using integrated framework for ubiquitous smart monitoring

Science.gov (United States)

Heo, Gwanghee; Lee, Giu; Lee, Woosang; Jeon, Joonryong; Kim, Pil-Joong

2007-04-01

Ubiquitous monitoring combining internet technologies and wireless communication is one of the most promising technologies of infrastructure health monitoring against the natural of man-made hazards. In this paper, an integrated framework of the ubiquitous monitoring is developed for real-time long term measurement in internet environment. This framework develops a wireless sensor system based on Bluetooth technology and sends measured acceleration data to the host computer through TCP/IP protocol. And it is also designed to respond to the request of web user on real time basis. In order to verify this system, real time monitoring tests are carried out on a prototype self-anchored suspension bridge. Also, wireless measurement system is analyzed to estimate its sensing capacity and evaluate its performance for monitoring purpose. Based on the evaluation, this paper proposes the effective strategies for integrated framework in order to detect structural deficiencies and to design an early warning system.

Indoor Radon Exposure in Italian Schools

Directory of Open Access Journals (Sweden)

Antonio Azara

2018-04-01

Full Text Available Background: The aim of the study was to assess radon concentration in schoolrooms in a city located in the midwest of Italy. Methods: A two-phase environmental study was carried out in 19 school buildings of 16 primary, secondary, and tertiary schools. Results: Median (interquartile range—IQR indoor radon concentration in schoolrooms was 91.6 (45.0–140.3 Bq/m3. The highest (median 952.8 Bq/m3 radon concentration was found in one (3.6% classroom, located in a building of a primary school whose median concentration was 185 Bq/m3. Radon concentration was significantly correlated with the number of students and teachers, foundation wall construction material, and with the absence of underground floors. A geopedological survey was performed close to the building with highest radon level, showing the presence of granite and tonalithic granodiorite in the soil. Conclusions: Radon levels should be routinely assessed where individuals live or work. Schools are susceptible targets, because of childhood stay and the long daily stay of occupants. Low-cost interventions, such as implementation of natural air ventilation and school maintenance, can reduce radon levels, limiting individual exposure.

Asphalt emulsion radon barrier systems for uranium mill tailings: an overview of the technology

Energy Technology Data Exchange (ETDEWEB)

Baker, E.G.; Hartley, J.N.; Freeman, H.D.; Gates, T.E.; Nelson, D.A.; Dunning, R.L.

1984-03-01

Pacific Northwest Laboratory (PNL), under contract to the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action Project (UMTRAP) office, has developed an asphalt emulsion cover system to reduce the release of radon from uranium mill tailings. The system has been field tested at Grand Junction, Colorado. Results from laboratory and field tests indicate that this system is effective in reducing radon release to near-background levels (<2.5 pCi m/sup -2/s/sup -1/) and has the properties required for long-term effectiveness and stability. Engineering specifications have been developed, and analysis indicates that asphalt emulsion covers are cost-competitive with other cover systems. This report summarizes the technology for asphalt emulsion radon barrier systems. 59 references, 45 figures, 36 tables.

Radon measurements in mines and dwellings

International Nuclear Information System (INIS)

Urban, M.

1985-01-01

Radon measurements using a time integrating passive radon dosemeter (MAKROFOL track etch detector) have been performed in Brazilian and German mines and dwellings. The present state of the measurement technique is summarized. The results are presented together with exposure calculations and dose estimations for occupational exposure in open pit and underground mines and for the general public in houses. (orig./HP) [de

Asphalt emulsion radon barrier systems for uranium mill tailings - a summary of the technology

International Nuclear Information System (INIS)

Baker, E.G.; Hartley, J.N.; Freeman, H.D.

1983-11-01

Pacific Northwest Laboratory (PNL), has developed an asphalt emulsion cover system to reduce the release of radon from uranium mill tailings. The system has been field-tested at the tailings site in Grand Junction, Colorado. Results from laboratory and field tests indicate that this system effectively reduces radon release to near-background levels ( -2 s -1 ) and has the properties required for long-term effectiveness and stability. Engineering specifications have been developed, and a cost analysis indicates that asphalt emulsion covers are competitive with other cover systems. 6 references, 2 figures, 4 tables

Long term radioactive waste management

International Nuclear Information System (INIS)

Lavie, J.M.

1984-01-01

In France, waste management, a sensitive issue in term of public opinion, is developing quickly, and due to twenty years of experience, is now reaching maturity. With the launching of the French nuclear programme, the use of radioactive sources in radiotherapy and industry, waste management has become an industrial activity. Waste management is an integrated system dealing with the wastes from their production to the long term disposal, including their identification, sortage, treatment, packaging, collection and transport. This system aims at guaranteing the protection of present and future populations with an available technology. In regard to their long term management, and the design of disposals, radioactive wastes are divided in three categories. This classification takes into account the different radioisotopes contained, their half life and their total activity. Presently short-lived wastes are stored in the shallowland disposal of the ''Centre de la Manche''. Set up within the French Atomic Energy Commission (CEA), the National Agency for waste management (ANDRA) is responsible within the framework of legislative and regulatory provisions for long term waste management in France [fr

Mapping of residential radon in the world

International Nuclear Information System (INIS)

Zielinskia, Jan M.; Chambers, Douglas B.

2008-01-01

We have created a database of national radon levels around the world building on initial information from the surveys conducted by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) from 2001 through 2007 for its 2006 Annex E on radon. We have conducted a systematic review of all original documents contributing information to the database, and of have collected all other relevant documents to enhance this database. Among the sources of data, in addition to the recent UNSCEAR surveys, the UNSCEAR 2000 Report, and 'An overview of radon surveys in Europe', the following sources were searched for keywords (indoor and radon): Medline, tables of content of Radiation Protection Dosimetry, tables of content of Radiation Measurements, and the Web. Initially for the purpose of data quality objectives (DQO) we used following valuation order to classify the reliability of the references: journal publication, conference proceedings, internal report, UNSCEAR Surveys, Who 2006 Survey, Personal communication. However, we realized that for the purpose of assessing the reliability of the national indoor radon levels the above classification did not work well given that most of the information had been published in 'gray literature' and that some of this literature was of very high quality. Therefore we treated journal publications, conference proceedings, and internal reports equally as long as they were publicly and relatively easily available (on the web for example). We evaluated each reference in terms of level of evidence for using national Average Radon Level reported in the reference (sufficient evidence, limited evidence, and inadequate evidence). Currently the database contains information on national indoor levels from 67 countries (out of 193 recognized by Who). These 67 countries represent 76% of the world's population and 71% of its land mass. Radon information varies by continent with only three African countries (out of 53) and 34

Determination of radon and uranium in the groundwater of Bangalore city

International Nuclear Information System (INIS)

Somashekar, R.K.; Davis, Deljo; Jeban Singh, M.; Prakash, K.L.; Shivanna, K.

2010-01-01

Groundwater is a precious source of drinking water. Radon and uranium are the naturally occurring radioactive elements in water. The present study attempts to identify the nature of groundwater with respect to the radon and uranium in and around Bangalore city. The radon in groundwater is measured by the integrated instrumental field screening techniques using a radon in air monitor (RAD-7) with attached bubbler. The water after the radon measurement, analysed for the total uranium using ICP- AES. The Radon in water represented in Bq/L and total uranium in μg/L

Radon levels in dwelling shielded spaces (DSS) in Israel

International Nuclear Information System (INIS)

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

2002-01-01

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

A radon progeny deposition model

International Nuclear Information System (INIS)

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

2010-01-01

The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly 222 Rn) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of 210 Pb on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to deposit radon progeny on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model are presented.

A Radon Progeny Deposition Model

International Nuclear Information System (INIS)

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

2011-01-01

The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly 222 Rn) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of 210 Pb on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to deposit radon progeny on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model are presented.

A self-calibrating radon monitor with statistical discrimination

International Nuclear Information System (INIS)

Valcov, N.; Purghel, L.

2002-01-01

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

Integrating Social Science into the Long-Term Ecological Research (LTER) Network: Social Dimensions of Ecological Change and Ecological Dimensions of Social Change

Science.gov (United States)

Charles L. Redman; J. Morgan Grove; Lauren H. Kuby; Lauren H. Kuby

2004-01-01

The integration of the social sciences into long-term ecological research is an urgent priority. To address this need, a group of social, earth, and life scientists associated with the National Science Foundation's (NSF) Long-Term Ecological Research (LTER) Network have articulated a conceptual framework for understanding the human dimensions of ecological change...

A fast butterfly algorithm for generalized Radon transforms

KAUST Repository

Hu, Jingwei

2013-06-21

Generalized Radon transforms, such as the hyperbolic Radon transform, cannot be implemented as efficiently in the frequency domain as convolutions, thus limiting their use in seismic data processing. We have devised a fast butterfly algorithm for the hyperbolic Radon transform. The basic idea is to reformulate the transform as an oscillatory integral operator and to construct a blockwise lowrank approximation of the kernel function. The overall structure follows the Fourier integral operator butterfly algorithm. For 2D data, the algorithm runs in complexity O(N2 log N), where N depends on the maximum frequency and offset in the data set and the range of parameters (intercept time and slowness) in the model space. From a series of studies, we found that this algorithm can be significantly more efficient than the conventional time-domain integration. © 2013 Society of Exploration Geophysicists.

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

Directory of Open Access Journals (Sweden)

S. M. Kiselev

2014-01-01

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

Environmental analysis of radiation exposure by radon in Saxon buildings and impact of the EnEV. An old problem in a new dimension; Umweltanalyse zur Strahlenbelastung durch Radon in saechsischen Gebaeuden und Auswirkungen der EnEV. Ein altes Problem mit neuen Dimensionen

Energy Technology Data Exchange (ETDEWEB)

Gottwald, Jan; Schneider, Lutz [Stoller Ingenieurtechnik GmbH, Dresden (Germany); Koeter, Nico [TU Bergakademie Freiberg (Germany)

2015-07-01

Radon in buildings is being widely studied since the 1990s. These studies have revealed some cases of very high radiation exposure for the inhabitants of residential buildings in Saxony in particular. Even a proposed raising of the radon reference values from 100 Bq/m{sup 3} to 300 Bq/m{sup 3} (in the case of an eventually 1:1 implementation of the EU recommendations into German law), would not even slightly aid the situation in the designated areas with high radon availability, as the standards of the Energieeinsparverordnung (Energy Saving Ordinance, EnEV) can result in significant radiation exposure, if no comprehensive radon protection is implemented. Based on long-term radon measurements in Saxony from the nineties, before the introduction of the EnEV, this report will show potential outcomes and estimate the extend of suitable remediation measures.

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

International Nuclear Information System (INIS)

Kojima, Hiroshi

1989-01-01

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

An Integrated Modeling Approach for Forecasting Long-Term Energy Demand in Pakistan

Directory of Open Access Journals (Sweden)

Syed Aziz Ur Rehman

2017-11-01

Full Text Available Energy planning and policy development require an in-depth assessment of energy resources and long-term demand forecast estimates. Pakistan, unfortunately, lacks reliable data on its energy resources as well do not have dependable long-term energy demand forecasts. As a result, the policy makers could not come up with an effective energy policy in the history of the country. Energy demand forecast has attained greatest ever attention in the perspective of growing population and diminishing fossil fuel resources. In this study, Pakistan’s energy demand forecast for electricity, natural gas, oil, coal and LPG across all the sectors of the economy have been undertaken. Three different energy demand forecasting methodologies, i.e., Autoregressive Integrated Moving Average (ARIMA, Holt-Winter and Long-range Energy Alternate Planning (LEAP model were used. The demand forecast estimates of each of these methods were compared using annual energy demand data. The results of this study suggest that ARIMA is more appropriate for energy demand forecasting for Pakistan compared to Holt-Winter model and LEAP model. It is estimated that industrial sector’s demand shall be highest in the year 2035 followed by transport and domestic sectors. The results further suggest that energy fuel mix will change considerably, such that oil will be the most highly consumed energy form (38.16% followed by natural gas (36.57%, electricity (16.22%, coal (7.52% and LPG (1.52% in 2035. In view of higher demand forecast of fossil fuels consumption, this study recommends that government should take the initiative for harnessing renewable energy resources for meeting future energy demand to not only avert huge import bill but also achieving energy security and sustainability in the long run.

How precise is the determination of the average radon concentration in buildings from measurements lasting only a few days

International Nuclear Information System (INIS)

Janik, M.; Loskiewicz, J.; Olko, P.; Swakon, J.

1998-01-01

Radon concentration in outdoor air and in buildings is very variable, showing diurnal and seasonal variations. Long term track etch detectors measurements lasting up to one year give the most precise one year averages. It arrives, however, that we are obliged to get results much sooner e.g. for screening measurements. How long should we measure to get proper results? We have studied the problem of selecting proper time interval on the basis of our five long term (ca. 30 days) measurements in Cracow using AlphaGUARD ionization chamber detector. The mean radon concentration ranged from 543 to 1107 Bq/m 3 . It was found that the relative error of k day average was decreasing exponentially with a time constant of 4 days. Therefore we recommended a minimal measuring time of four (k = 4) and better six days. (author)

Radon gas measurement in Corum

International Nuclear Information System (INIS)

Uzbey, S.; Celebi, N.

2009-01-01

The existence of the natural radioactive sources in earth's crust which has long half-life and the degradation products of these in the environmental medium such as earth, rocks, foods, water, air, forms the basis of radiation which people are exposed to. Radon is the unique radioactive gas in the nature and it is made up of radium which is the result of uranium degradation. It is necessary to determine the radon concentration because of the difference in the concentration of uranium existence in different places. TAEK (Turkish Atomic Energy Authority) allows 400 Bq/m 3 of radon concentration at houses, 1000 Bq/m 3 at offices per year. In this attempt, government buildings, houses and offices were determined as the sampling places in Corum city center and towns to represent Corum. While disposing the radon measuring detectors, places which are close to the ground level were preferred. 74 radon detectors were left in those places for 60 days and in the end the detectors were collected while discontinuing the connection of environment and they were assessed. According to the results, the average radon gas concentration in 14 government buildings is 71,71 Bq/m 3 , in 15 offices 32,26 Bq/m 3 and at houses 42,34 Bq/m 3 .

Monitoring the Long-Term Effectiveness of Integrated Safety Management System (ISMS) Implementation Through Use of a Performance Dashboard Process

International Nuclear Information System (INIS)

Kinney, Michael D.; Barrick, William D.

2008-01-01

This session will examine a method developed by Federal and Contractor personnel at the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) to examine long-term maintenance of DOE Integrated Safety Management System (ISMS) criteria, including safety culture attributes, as well as identification of process improvement opportunities. This process was initially developed in the summer of 2000 and has since been expanded to recognize the importance of safety culture attributes, and associated safety culture elements, as defined in DOE M 450.4-1, 'Integrated Safety Management System Manual'. This process has proven to significantly enhance collective awareness of the importance of long-term ISMS implementation as well as support commitments by NNSA/NSO personnel to examine the continued effectiveness of ISMS processes

Determination of equilibrium factor between radon and its progeny using surface barrier detector for various shapes of passive radon dosimeters

Energy Technology Data Exchange (ETDEWEB)

Jamil, K. [PINSTECH, Islamabad (Pakistan). Environ. Radiat. Group; Fazal-ur-Rehman [PINSTECH, Islamabad (Pakistan). Environ. Radiat. Group; Ali, S. [PINSTECH, Islamabad (Pakistan). Environ. Radiat. Group; Khan, H.A. [PINSTECH, Islamabad (Pakistan). Environ. Radiat. Group

1997-03-21

In the field of radon dosimetry, it is customary to measure radon ({sup 222}Rn) concentration while potential health hazard is due to the radon short-lived progeny. When radon is in secular equilibrium, the measured activity of radon equals the activity of radon`s progeny. However, in practical cases an inequilibrium between radon and its progeny exists which is measured in terms of the equilibrium factor. To determine the equilibrium factor between radon and its progeny in a closed environment various shapes of passive dosimeters based upon solid state nuclear track detectors (SSNTDs) are employed. In order to observe the dependence of equilibrium factor upon shapes or effective volumes, experiments have been performed replacing the SSNTDs with a surface barrier detector in Karlsruhe diffusion chamber, pen-type and box-type dosimeters. Using the collected alpha spectra, the equilibrium factor has been determined for a radon-air mixture in a custom designed radon chamber simulating a closed environment of a room. The results show that the radon equilibrium factor is about 0.20 for different shapes of dosimeters studied in this research. It is concluded that the determination of equilibrium factor between radon and its progeny does not depend upon effective volume or shape of the passive dosimeters using alpha spectroscopic data acquired by surface barrier detector. (orig.).

Radon concentration distribution mapping in a small detached house

International Nuclear Information System (INIS)

Muellerova, Monika; Moravcsik, Attila; Holy, Karol; Hutka, Miroslav; Hola, Olga

2013-01-01

Radon activity concentration was investigated in an older, single storey detached house. The rooms of the house are in contact with the bedrock. The house is fitted with plastic windows and populated mostly during the summer. Integral (Raduet) and continuous (AlphaGUARD) methods were used to measure the radon activity concentration. Average radon and thoron activity concentrations in the house were 150 Bq/m 3 and 40 Bq/m 3 , respectively. The impact of the house occupancy on radon activity concentration was significant only during the summer months when a decrease of radon activity concentration was recorded due to an increased ventilation rate. In the autumn and winter months, the impact of the house occupancy on radon activity concentration was relatively small - up to 20 %. The increases in radon activity concentration after the room had been thoroughly ventilated were analysed in order to estimate the ventilation rate and the rate of radon supply into the house. (orig.)

Longitudinal Long-term Magnetic Resonance Imaging and Clinical Follow-up After Single-Row Arthroscopic Rotator Cuff Repair: Clinical Superiority of Structural Tendon Integrity.

Science.gov (United States)

Heuberer, Philipp R; Smolen, Daniel; Pauzenberger, Leo; Plachel, Fabian; Salem, Sylvia; Laky, Brenda; Kriegleder, Bernhard; Anderl, Werner

2017-05-01

The number of arthroscopic rotator cuff surgeries is consistently increasing. Although generally considered successful, the reported number of retears after rotator cuff repair is substantial. Short-term clinical outcomes are reported to be rarely impaired by tendon retears, whereas to our knowledge, there is no study documenting long-term clinical outcomes and tendon integrity after arthroscopic rotator cuff repair. To investigate longitudinal long-term repair integrity and clinical outcomes after arthroscopic rotator cuff reconstruction. Case series; Level of evidence, 4. Thirty patients who underwent arthroscopic rotator cuff repair with suture anchors for a full-tendon full-thickness tear of the supraspinatus or a partial-tendon full-thickness tear of the infraspinatus were included. Two and 10 years after initial arthroscopic surgery, tendon integrity was analyzed using magnetic resonance imaging (MRI). The University of California, Los Angeles (UCLA) score and Constant score as well as subjective questions regarding satisfaction with the procedure and return to normal activity were used to evaluate short- and long-term outcomes. At the early MRI follow-up, 42% of patients showed a full-thickness rerupture, while 25% had a partial rerupture, and 33% of tendons remained intact. The 10-year MRI follow-up (129 ± 11 months) showed 50% with a total rerupture, while the other half of the tendons were partially reruptured (25%) or intact (25%). The UCLA and Constant scores significantly improved from preoperatively (UCLA total: 50.6% ± 20.2%; Constant total: 44.7 ± 10.5 points) to 2 years (UCLA total: 91.4% ± 16.0% [ P rotator cuff repair showed good clinical long-term results despite a high rate of retears. Nonetheless, intact tendons provided significantly superior clinical long-term outcomes, making the improvement of tendon healing and repair integrity important goals of future research efforts.

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

International Nuclear Information System (INIS)

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

1994-01-01

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

Environmental Radon Gas and Degenerative Conditions An Overview

Energy Technology Data Exchange (ETDEWEB)

Groves-Kirkby, C.J. [Medical Physics Department, Northampton General Hospital, Northampton NN1 5BD (United Kingdom)]|[School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom); Denman, A.R. [Medical Physics Department, Northampton General Hospital, Northampton NN1 5BD (United Kingdom); Woolridge, A.C. [School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom)]|[School of Applied Sciences, University of Northampton, Northampton NN2 7AL (United Kingdom); Phillips, P.S. [School of Applied Sciences, University of Northampton, Northampton NN2 7AL (United Kingdom); Phillips, C. [School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom)

2006-07-01

Radon, a naturally occurring radioactive gas, has variable distribution in the environment as a decay product of uranium occurring in a wide range of rocks, soils and building materials. Although radon dissipates rapidly in outdoor air, it concentrates in the built environment, and inhalation of {sup 222}Rn and its progeny {sup 218}Po and {sup 214}Po is believed to provide the majority of the radioactive dose to the respiratory system. While the connection between radon and lung cancer has long been recognised and investigated, recent studies have highlighted potential links between radon and other conditions, among them Multiple Sclerosis, Alzheimer and Parkinson Diseases, and Paget Disease of Bone. A strong case exists for clarifying the relationship between radon and these other conditions, not least since radon remediation to reduce lung cancer may conceivably have additional benefits hitherto unrecognized. The present status of the postulated links between environmental radon gas and degenerative conditions is reviewed, and recommendations for further research into levering current anti-radon campaigns are made. (authors)

Long-term student outcomes of the Integrated Nutrition and Physical Activity Program.

Science.gov (United States)

Puma, Jini; Romaniello, Catherine; Crane, Lori; Scarbro, Sharon; Belansky, Elaine; Marshall, Julie A

2013-01-01

To examine the long-term effects of the Integrated Nutrition and Physical Activity Program (INPAP), a school-based nutrition education program. Quasi-experimental design comparing intervention and comparison cohorts at 3-6 years after delivery of the INPAP intervention on nutrition- and physical activity-related outcomes. This study was conducted in 1 school district in a low-income rural county of ∼15,000 residents in south-central Colorado. In second grade, intervention and comparison cohorts included 173 (fall 2000) and 190 (fall 1999) students, respectively. Approximately 60% of these students completed assessments in eighth grade. INPAP is an experiential school-based nutrition education program, grounded in social cognitive theory and Piaget's cognitive development theory and adapted for use in a rural setting. Nutrition and physical activity knowledge, self-efficacy, attitudes and behaviors, body mass index. Wilcoxon signed rank test, chi-square test for proportions, and t test for means. Long-term effects were observed in nutrition-related knowledge and attitudes but not self-efficacy or behavior change. The effects that did occur were attenuated over time. This study found that INPAP implemented in elementary school had limited lasting effects by the end of middle school, a time when students have increased autonomy to make food choices. Copyright © 2013 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Paloma-radon: atmospheric radon 222 as a geochemical probe for water in the martian subsoil

International Nuclear Information System (INIS)

Sabroux, J.Ch.; Michielsen, N.; Voisin, V.

2003-01-01

Radon exhalation from a porous soil is known to depend strongly on the soil moisture content: a minute amount of water, or water ice, in the pore space increases dramatically the possibility for radon to migrate far from its parent mineral. We propose to take advantage of this characteristic by using atmospheric radon 222 as a geochemical probe for water in the Martian soil, at least one order of magnitude deeper than the current Mars Odyssey neutron data. Strong thermal inversions during the Martian night will accumulate radon in the lowest atmospheric boundary layer, up to measurable levels despite the comparatively high environmental (cosmic and solar) background radiation and the assumed low uranium content of the upper crust of the planet. Preliminary studies and development of an instrument for the measurement of the Martian atmospheric alpha radioactivity is part of the CNES supported PALOMA experiment. Two test benches have been implemented, one of them allowing differential measurements of the diffusion of radon in the Martian soil simulant NASA JSC Mars-1, under relevant temperatures and pressures. The other, a 1 m3 radon-dedicated test bench, aims to characterize the instrument that will measure radon in the Mars environment (7 mb CO 2 ). Tests on several nuclear radiation detectors show that semiconductor alpha-particle detectors (PIPS) are the best option. In addition, the detection volume is left open in order to capitalize upon the long (ca. 4 m) alpha track at this low pressure. A stationary diffusion model was developed in order to assess the radon flux at the Mars soil surface. Diffusion of gas in Martian soil is governed by Knudsen diffusion. The radon Knudsen diffusion coefficient was estimated, depending on the soil moisture and relevant structural properties, leading to a radon diffusion length of the order of 20 m. The landed platform PALOMA-Radon instrument will consist of a set of alpha detectors connected to an electronic spectrometer, a

Paloma-radon: atmospheric radon 222 as a geochemical probe for water in the martian subsoil

Energy Technology Data Exchange (ETDEWEB)

Sabroux, J.Ch.; Michielsen, N.; Voisin, V

2003-07-01

Radon exhalation from a porous soil is known to depend strongly on the soil moisture content: a minute amount of water, or water ice, in the pore space increases dramatically the possibility for radon to migrate far from its parent mineral. We propose to take advantage of this characteristic by using atmospheric radon 222 as a geochemical probe for water in the Martian soil, at least one order of magnitude deeper than the current Mars Odyssey neutron data. Strong thermal inversions during the Martian night will accumulate radon in the lowest atmospheric boundary layer, up to measurable levels despite the comparatively high environmental (cosmic and solar) background radiation and the assumed low uranium content of the upper crust of the planet. Preliminary studies and development of an instrument for the measurement of the Martian atmospheric alpha radioactivity is part of the CNES supported PALOMA experiment. Two test benches have been implemented, one of them allowing differential measurements of the diffusion of radon in the Martian soil simulant NASA JSC Mars-1, under relevant temperatures and pressures. The other, a 1 m3 radon-dedicated test bench, aims to characterize the instrument that will measure radon in the Mars environment (7 mb CO{sub 2}). Tests on several nuclear radiation detectors show that semiconductor alpha-particle detectors (PIPS) are the best option. In addition, the detection volume is left open in order to capitalize upon the long (ca. 4 m) alpha track at this low pressure. A stationary diffusion model was developed in order to assess the radon flux at the Mars soil surface. Diffusion of gas in Martian soil is governed by Knudsen diffusion. The radon Knudsen diffusion coefficient was estimated, depending on the soil moisture and relevant structural properties, leading to a radon diffusion length of the order of 20 m. The landed platform PALOMA-Radon instrument will consist of a set of alpha detectors connected to an electronic spectrometer

Radon-222 signatures of natural ventilation regimes in an underground quarry.

Science.gov (United States)

Perrier, Frédéric; Richon, Patrick; Crouzeix, Catherine; Morat, Pierre; Le Mouël, Jean Louis

2004-01-01

Radon-222 activity concentration has been monitored since 1999 in an underground limestone quarry located in Vincennes, near Paris, France. It is homogeneous in summer, with an average value of 1700 Bq m(-3), and varies from 730 to 1450 Bq m(-3) in winter, indicating natural ventilation with a rate ranging from 0.5 to 2.4 x 10(-6) s(-1) (0.04-0.22 day(-1)). This hypothesis is supported by measurements in the vertical access pit where, in winter, a turbulent air current produces a stable radon profile, smoothly decreasing from 700 Bq m(-3) at 20 m depth to 300 Bq m(-3) at surface. In summer, a thermal stratification is maintained in the pit, but the radon-222 concentration jumps repeatedly between 100 and 2000 Bq m(-3). These jumps are due to atmospheric pressure pumping, which induces ventilation in the quarry at a rate of about 0.1 x 10(-6) s(-1) (0.009 day(-1)). Radon-222 monitoring thus provides a dynamical characterisation of ventilation regimes, which is important for the assessment of the long-term evolution of underground systems.

Review of high-sensitivity Radon studies

Science.gov (United States)

Wojcik, M.; Zuzel, G.; Simgen, H.

2017-10-01

A challenge in many present cutting-edge particle physics experiments is the stringent requirements in terms of radioactive background. In peculiar, the prevention of Radon, a radioactive noble gas, which occurs from ambient air and it is also released by emanation from the omnipresent progenitor Radium. In this paper we review various high-sensitivity Radon detection techniques and approaches, applied in the experiments looking for rare nuclear processes happening at low energies. They allow to identify, quantitatively measure and finally suppress the numerous sources of Radon in the detectors’ components and plants.

Temporal Patterns of Lung Cancer Risk from Radon, Smoking and their Interaction

International Nuclear Information System (INIS)

Tomasek, L.; Urban, S.; Kubik, A.; Zatloukal, P.

2004-01-01

Studies of uranium miners conducted since the late 1960s demonstrated that the risk depends on cumulated exposure in terms of working level months (WLM) integrating both duration of exposure and concentration of radon. It has been also demonstrated that the risk from radon decreases with time since exposure. The objective of the work is to study temporal patterns of lung cancer risk from occupational and residential radon and from smoking. The present analysis of temporal changes of relative risk is based on a model, where the total individual exposure is partitioned into components in dependence on time. Exposure to radon is studied in a cohort of 9411 Czech uranium miners with 766 cases of lung cancer and in a residential study of 1 803 inhabitants exposed to radon in houses with 218 cases. Temporal patterns of smoking are analyzed in a case-control study of patients from a major Prague hospital including 566 cases. for both carcinogens, the relative risk decreases with time since exposure. In comparison to period with exposure before 5-19 years, the risk from exposures before 20-34 years is 36% and 34% for smoking and randon, respectively. The effect of exposures from more distant periods 35-49 is only 5% for smoking and 14% for radon in comparison to 5-19 years. Combined effect of smoking and radon is studied by a nested case-control approach including 434 cases and 962 controls. Analyses of the joint effects of smoking and radon, conducted in the occupational and the residential studies, suggest a sub-multiplicative interaction. The relative risk from radon among non-smokers is higher by a factor of 2-3 in comparison to smokers, suggesting different patterns of lung deposition and clearance among smokers and non-smokers. (Author) 13 refs

Temporal Patterns of Lung Cancer Risk from Radon, Smoking and their Interaction

Energy Technology Data Exchange (ETDEWEB)

Tomasek, L.; Urban, S.; Kubik, A.; Zatloukal, P.

2004-07-01

Studies of uranium miners conducted since the late 1960s demonstrated that the risk depends on cumulated exposure in terms of working level months (WLM) integrating both duration of exposure and concentration of radon. It has been also demonstrated that the risk from radon decreases with time since exposure. The objective of the work is to study temporal patterns of lung cancer risk from occupational and residential radon and from smoking. The present analysis of temporal changes of relative risk is based on a model, where the total individual exposure is partitioned into components in dependence on time. Exposure to radon is studied in a cohort of 9411 Czech uranium miners with 766 cases of lung cancer and in a residential study of 1 803 inhabitants exposed to radon in houses with 218 cases. Temporal patterns of smoking are analyzed in a case-control study of patients from a major Prague hospital including 566 cases. for both carcinogens, the relative risk decreases with time since exposure. In comparison to period with exposure before 5-19 years, the risk from exposures before 20-34 years is 36% and 34% for smoking and randon, respectively. The effect of exposures from more distant periods 35-49 is only 5% for smoking and 14% for radon in comparison to 5-19 years. Combined effect of smoking and radon is studied by a nested case-control approach including 434 cases and 962 controls. Analyses of the joint effects of smoking and radon, conducted in the occupational and the residential studies, suggest a sub-multiplicative interaction. The relative risk from radon among non-smokers is higher by a factor of 2-3 in comparison to smokers, suggesting different patterns of lung deposition and clearance among smokers and non-smokers. (Author) 13 refs.

Extension of the service life and improvement of safety of near surface repositories of the type 'Radon'

International Nuclear Information System (INIS)

Rozdyalouvskaya, L.

2004-01-01

The paper discusses the application and implementation of the new international principles and approaches for the radioactive waste management in the existing 'Radon' type storage facilities. The characteristics of the 'Radon' facilities, their licensing, the inspection program as well as the technical assessment of the facility Puspokszilagy (Hungary) are presented. Other aspects of the safety of the facilities such as measures for modernisation implemented in some countries (Latvia, Belarus, Bulgaria and other), intervention criteria, and long term safety are also discussed

Cost effectiveness of radon mitigation in Canada

International Nuclear Information System (INIS)

Letourneau, E.G.; Krewski, D.; Zielinski, J.M.; McGregor, R.G.

1992-01-01

This paper examines the cost effectiveness of comprehensive strategies for reducing exposure to radon gas in indoor air in Canadian homes. The analysis is conducted within the context of a general framework for risk management programme evaluation which includes well-known evaluation techniques such as cost effectiveness and cost-benefit analyses as special cases. Based on this analysis, it is clear that any comprehensive programme to reduce exposure to environmental radon will be extremely expensive, and may not be justifiable in terms of health impact, particularly when considered in relation to other public health programmes. Testing of homes at the point of sale and installing sub-slab suction equipment to reduce exposure to indoor radon where necessary appears to be a relatively cost-effective radon mitigation strategy. In general, radon mitigation was found to be most cost effective in cities with relatively high levels of radon. (author)

A direct evidence for high carbon dioxide and radon-222 discharge in Central Nepal

International Nuclear Information System (INIS)

Perrier, F.; Byrdina, S.; Richon, P.; Bollinger, L.; Bureau, S.; Richon, P.; France-Lanord, Ch.; Rajaure, S.; Koirala, Bharat Prasad; Shrestha, Prithvi Lal; Gautam, Umesh Prasad; Tiwari, Dilli Ram; Sapkota, Soma Nath; Revil, A.; Revil, A.; Contraires, S.

2009-01-01

a function of time, especially in relation to the seismic activity. For this purpose, the observed high radon-222 flux is a particularly interesting asset. Indeed, while the relationship between radon and carbon dioxide needs to be better understood, radon measurements, using the available radon sensors, constitute a powerful tool for robust and cost effective long term monitoring. (authors)

Timber joints under long-term loading

DEFF Research Database (Denmark)

Feldborg, T.; Johansen, M.

This report describes tests and results from stiffness and strength testing of splice joints under long-term loading. During two years of loading the spicimens were exposed to cyclically changing relative humidity. After the loading period the specimens were short-term tested. The connectors were...... integral nail-plates and nailed steel and plywood gussets. The report is intended for designers and researchers in timber engineering....

Experiences of long-term tranquillizer use

DEFF Research Database (Denmark)

Skinhoj, K T; Larsson, S; Helweg-Joergensen, S

2001-01-01

, the psychodynamic perspective is integrated within a multi-dimensional model that considers biological, cognitive, identity, gender and social learning factors. The analysis reveals the possibility of achieving a detailed understanding of the dynamic processes involved in the development of long-term tranquillizer...

Determination of equilibrium factor between radon and its progeny using surface barrier detector for various shapes of passive radon dosimeters

International Nuclear Information System (INIS)

Jamil, K.; Fazal-ur-Rehman; Ali, S.; Khan, H.A.

1997-01-01

In the field of radon dosimetry, it is customary to measure radon ( 222 Rn) concentration while potential health hazard is due to the radon short-lived progeny. When radon is in secular equilibrium, the measured activity of radon equals the activity of radon's progeny. However, in practical cases an inequilibrium between radon and its progeny exists which is measured in terms of the equilibrium factor. To determine the equilibrium factor between radon and its progeny in a closed environment various shapes of passive dosimeters based upon solid state nuclear track detectors (SSNTDs) are employed. In order to observe the dependence of equilibrium factor upon shapes or effective volumes, experiments have been performed replacing the SSNTDs with a surface barrier detector in Karlsruhe diffusion chamber, pen-type and box-type dosimeters. Using the collected alpha spectra, the equilibrium factor has been determined for a radon-air mixture in a custom designed radon chamber simulating a closed environment of a room. The results show that the radon equilibrium factor is about 0.20 for different shapes of dosimeters studied in this research. It is concluded that the determination of equilibrium factor between radon and its progeny does not depend upon effective volume or shape of the passive dosimeters using alpha spectroscopic data acquired by surface barrier detector. (orig.)

Integrating housing and long-term care services for the elderly: a social marketing approach.

Science.gov (United States)

Moore, S T

1991-01-01

Subsidized senior high-rise apartments have tended to neglect the needs of an increasingly aged and frail resident population. Research demonstrates that this population has greater unmet needs than elderly who reside in traditional community housing. This paper makes the case for a vertically integrated marketing approach to serving the elderly. Such an approach would combine housing and community based long-term care services into a single system of care. Enriched senior high-rise apartments are a viable alternative for elders who need assistance in order to maintain an independent lifestyle.

Radon in Dwellings in the Republic of Kalmykia

Energy Technology Data Exchange (ETDEWEB)

Aakerblom, Gustav (Aakerblom och Aakerblom HP, Skaerholmen (Sweden)); German, Olga; Soederman, Ann-Louise (Swedish Radiation Safety Authority, Stockholm (Sweden)); Stamat, Ivan; Venkov, Vladimir (Research Inst. of Radiation Hygiene, St. Petersburg (Russian Federation))

2009-02-15

The National Radon Survey in the Republic of Kalmykia, Russian Federation during 2006-2007 was carried out in a cooperation project between the Swedish Radiation Protection Authority (SSI) and the Russian Institute of Radiation Hygiene (RIRH). In August 2006 SSI, RIRH, federal and local authorities carried out a field study in Kalmykia when radon daughter measurements (equilibrium equivalent radon concentrations in the air) and gamma radiation measurements were made in 103 buildings. Gamma spectrometry measurements were made at several sites. During the visit the cooperating parties devoted some time to the education of local authorities on radon related issues. During three months in the winter season 2006-2007, long term radon trace measurements were made in 525 randomly chosen dwellings in the Republic of Kalmykia. The radon gas activity varied between 3 and 973 Bq/m3, with a mean value of 122 Bq/m3. In 19 of a total of 835 measurement points, the radon activity exceeded the maximum permitted value in Russia of 200 Bq/m3 of EERC. The year-round radon trace measurement were made in 20 houses in Elista, the capital of the Republic of Kalmykia, for comparison with the three-month measurements. The year-round measurements showed some higher values for the radon activity, and a correction factor of 0.85 was applied. Using data on the number of people living in detached houses and apartments, and applying the radon activities measured, the number of new lung cancer cases caused by radon was calculated to be 20 to 40 of the 100 new cases reported annually. The methods of construction of the dwellings in Kalmykia is greatly influenced by the history and culture. Most of them were built after World War II and there are only a few that are newly built because of the poor economic situation and the low population growth rate in the Republic. Most people live in detached houses, one-storied with 3-5 rooms, built directly on the ground or on coquina blocks or on a cast

Natural radiation hazards. Radon in the home and in the workplace

Energy Technology Data Exchange (ETDEWEB)

McLaughlin, J P [University Coll., Dublin (Ireland). Dept. of Physics

1996-10-01

Natural radiation exposures account for more than 80% of the doses received by most people during their lifetime. Of these natural radiation doses the contribution arising from exposure to radon and its decay products is by far the greatest and the most variable. At present it is accepted that elevated radon concentrations increase the risk of lung cancer but a causal link with other cancers has been suggested. There is also a synergistic effect between smoking and radon exposure. For the Irish population it is estimated that radon exposure may be implicated in 10 to 15% of lung cancer deaths. On the basis of the data currently available from radon surveys it is estimated that the average indoor radon level in Ireland is in the region of 60 Bq/m{sup 3}. At this level the average effective dose from the inhalation of the associated radon decay products is estimated to be about 1500 microsievert per year. A small number of houses in Ireland with long term average radon levels in the 2000 to 4000 Bq/m{sup 3} have been identified. For these houses annual effective doses in the range 50,000 to 100,000 microsievert to the occupants may be applicable. In addition to dwellings a number of schools and other workplaces in Ireland have been surveyed and levels comparable to those in dwellings have been found. In Ireland the recommended reference or action level for dwellings is 200 Bq/{sup 3}. This is identical to the UK reference level and similar to those in operation in most EU countries. At present there is no recommended action level for radon in workplaces in Ireland. This is a matter presently under review. It is reasonable to expect that the chosen level for workplaces will be generally in keeping with the recommendation of the ICRP that it should be in the range 500 to 1500 Bq/m{sup 3}. The achievement of acceptable radon levels in existing and future buildings is technically possible in most cases. (Abstract Truncated)

Radon daughter dosimeter

International Nuclear Information System (INIS)

Durkin, J.

1977-01-01

This patent describes a portable radon daughter dosimeter unit used to measure radon gas alpha daughters in ambient air. These measurements can then be related to preselected preestablished standards contained in a remote central readout unit. The dosimeter unit is adapted to be worn by an operator in areas having alpha particle radiation such as in uranium mines. Within the dosimeter is a detector head housing having a filter head and a solid state surface barrier radiation detector; an air pump to get air to the detector head; a self contained portable power supply for the unit; and electronic circuitry to process detected charged electrons from the detector head to convert and count their pulses representatives of two alpha radon emitter daughters. These counted pulses are in binary form and are sent to a readout unit where a numerical readout displays the result in terms of working level-hours

Radon daughter dosimeter

International Nuclear Information System (INIS)

Durkin, J.

1977-01-01

A portable radon daughter dosimeter unit used to measure Radon gas alpha daughters in ambient air is described. These measurements can then be related to preselected preestablished standards contained in a remote central readout unit. The dosimeter unit is adapted to be worn by an operator in areas having alpha particle radiation such as uranium mines. Within the dosimeter is a detector head housing having a filter head and a solid state surface barrier radiation detector; an air pump to get air to the detector head; a self contained portable power supply for the unit; and electronic circuitry to process detected charged electrons from the detector head to convert and count their pulses representatives of two alpha radon emitter daughters. These counted pulses are in binary form and are sent to a readout unit where a numerical readout diplays the result in terms of working level-hours

SWOT analysis of the Czech Radon programme

International Nuclear Information System (INIS)

Fojtikova, I.

2014-01-01

Since the early 1990's, the Czech Republic has been one of the countries that carry out a radon programme on its territory, with the aim of protecting people from unnecessary long-term exposure in their homes. Since that time, many achievements have been registered, and many unexpected difficulties have cropped up. This may be the right moment to take some time out to analyse the state of the programme and to determine the direction for its future development. An extended SWOT analysis can serve as a useful tool for this purpose. Originally, SWOT analyses were used exclusively by for-profit organisations aiming to evaluate their perspectives, develop strategies and make plans in order to achieve their objectives. More recently, it has been used in a wide range of decision-making situations when a desired end-state is to be defined. Here, an extended SWOT analysis is used to formulate possible beneficial strategies for advancing anti-radon policy in the Czech Republic. (authors)

Risks from Radon: Reconciling Miner and Residential Epidemiology

International Nuclear Information System (INIS)

Chambers, Douglas B.; Harley, Naomi H.

2008-01-01

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

Investigation of Radon in drinking water from wells of the North-Eastern region of Bosnia and Herzegovina

International Nuclear Information System (INIS)

Adrovic, Feriz; Dedic, Amela

2008-01-01

Some areas of the Tuzla region (B and H) suffer heavily from the shortage of quality drinking water. The only real long-term water resource in this region is the Lake Modrac, the largest accumulation lake in Bosnia and Herzegovina. Due to the fact that radon is soluble in water it can be transported by water to long distances. In cases of intake of waters rich in radon the most affected are sensitive cells within the abdomen and other internal organs. In order to satisfy the needs for drinking water, people are forced to excavate and drill wells. In the area of Tuzla region and the entire B and H excavated wells are very frequent, and so are drilled wells lately, due to more developed and cheaper technology for soil drilling. Such activities in this area, and the whole of B and H, are carried out in an unorderly manner and without previously completed chemical and radiological analyses of soil and water samples. The University of Tuzla formed the Laboratory for detection of radon in all environments, and the survey displayed in this paper have been the first investigation of that kind in B and H. Here we presented the results of radon survey of drinking waters from excavated and drilled wells in the area of Tuzla region (North-Eastern region of B and H). The measurements were conducted over the period of one year (2006), so as to make possible monitoring of variations of radon concentrations in dependence of meteorological changes. These investigation works showed that radon concentration at most locations was significantly higher in drilled wells than in excavated wells. Mean values of radon concentration in the tested water samples ranged within the interval of 101-4200 Bq/m 3 . Radon activity concentration was measured with the Alpha GAURD radon system (Genitron instruments-Frankfurt). (author)

The Assessment of the Integrated Antioxidant System of the Body in the Course of Radon Therapy: A Pilot Study

Directory of Open Access Journals (Sweden)

Jadwiga Kuciel-Lewandowska

2018-01-01

Full Text Available Introduction. The sources of Reactive Oxidative Species (ROS in the organism are the respiratory processes occurring in cells catalyzed by different enzymes. Operation of ROS is balanced by antioxidants, the compounds; although present in low concentrations, they significantly inhibit the degree of oxidation of particular molecules. The Aim of the Study. The aim of this study was to assess the changes in the integrated antioxidant system under the influence of radon therapy in osteoarthritis patients. Material and Methods. Observation included 35 patients suffering from degenerative joints and disc disease (mean age 56.5 years undergoing radon water therapy and control group that consisted of 15 osteoarthritis patients (mean age 54.2 without contact with radon water. Before therapy and after 18 days of treatment, serum total antioxidant status (TAS was assessed with the use of standard colorimetric assay. Results. In the study group, we observed trends to increase TAS concentration, whereas, in the control group, TAS concentration was decreasing. Conclusions. (1 Radon waters treatment influenced the level of TAS of osteoarthritis patients treated with the radon water. (2 The change in TAS concentrations in the study group may be the result of low doses of ionizing radiation, but further studies on larger patient’s groups are demanded. This study is registered with number NCT03274128.

Comparison of long-term stability of containment systems for residues and wastes contaminated with naturally occurring radionuclides at an arid site and two humid sites

International Nuclear Information System (INIS)

Winters, M.; Merry-Libby, P.; Hinchman, R.

1985-01-01

The long-term stability of near-surface containment systems designed for the management of radioactive wastes and residues contaminated with naturally occurring radionuclides are compared at the three different sites. The containment designs are: (1) a diked 8.9-m high mound, including a 3.2-m layered cap at a site (humid) near Lewiston, New York, (2) a 6.8-m-high mound, including a similar 3.2-m cap at a site (humid) near Oak Ridge, Tennessee, and (3) 4.8-m deep trenches with 3.0-m backfilled caps at a site (arid) near Hanford, Washington. Geological, hydrological, and biological factors affecting the long-term (1000-year) integrity of the containment systems at each site are examined, including: erosion, flooding, drought, wildfire, slope and cover failure, plant root penetration, burrowing animals, other soil-forming processes, and land-use changes. For the containment designs evaluated, releases of radon-222 at the arid site are predicted to be several orders of magnitude higher than at the two humid sites - upon initial burial and at 1000 years (after severe erosion). Transfer of wastes containing naturally occurring radionuclides from a humid to an arid environment offers little or no advantage relative to long-term stability of the containment system and has a definite disadvantage in terms of gaseous radioactive releases. 26 references, 3 figures, 4 tables

Natural radiation hazards. Radon in the home and in the workplace

International Nuclear Information System (INIS)

McLaughlin, J.P.

1996-01-01

Natural radiation exposures account for more than 80% of the doses received by most people during their lifetime. Of these natural radiation doses the contribution arising from exposure to radon and its decay products is by far the greatest and the most variable. At present it is accepted that elevated radon concentrations increase the risk of lung cancer but a causal link with other cancers has been suggested. There is also a synergistic effect between smoking and radon exposure. For the Irish population it is estimated that radon exposure may be implicated in 10 to 15% of lung cancer deaths. On the basis of the data currently available from radon surveys carried out by both UCD and the RPII it is estimated that the average indoor radon level in Ireland is in the region of 60 Bq/m 3 . At this level the average effective dose from the inhalation of the associated radon decay products is estimated to be about 1500 microsievert per year. A small number of houses in Ireland with long term average radon levels in the 2000 to 4000 Bq/m 3 have been identified. For these houses annual effective doses in the range 50,000 to 100,000 microsievert to the occupants may be applicable. In addition to dwellings a number of schools and other workplaces in Ireland have been surveyed and levels comparable to those in dwellings have been found. In Ireland the recommended reference or action level for dwellings is 200 Bq/ 3 . This is identical to the UK reference level and similar to those in operation in most EU countries. At present there is no recommended action level for radon in workplaces in Ireland. This is a matter presently under review. It is reasonable to expect that the chosen level for workplaces will be generally in keeping with the recommendation of the ICRP that it should be in the range 500 to 1500 Bq/m 3 . The achievement of acceptable radon levels in existing and future buildings is technically possible in most cases. In areas already known to have high radon levels

Radon

Science.gov (United States)

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

Cornerstones of the Austrian radon risk communication strategy

International Nuclear Information System (INIS)

Kunte, A.; Ringer, W.

2015-01-01

On behalf of the Federal Ministry of Agriculture, Forestry, Environment and Water Management (BMLFUW), the National Radon Centre of Austria developed the National Radon Risk Communication Strategy. The superior goal is the reduction of the radon exposure of Austrian citizens as well as the reduction of radon-related lung cancer deaths. Austria, like many other countries, follows the approach to raise awareness and to inform the public to achieve this goal. The presented strategy deals with the question of how radon protection issues can be communicated to the public, existing fears can be reduced and affected people can be motivated to take action (perform a radon test, if necessary, mitigate or install preventive measures in new buildings). The cornerstones of the National Radon Risk Communication Strategy can be summarized as follows: - Definition of communication goals - Identification and categorization of target groups - Development of specific key messages for each of the target groups - Determination of communication channels and assessment of their efficiency - Integration of the radon issue in education and training - Cooperation with relevant organizations and platforms. The communication objectives, target groups and communication paths (and their evaluation) will be discussed during the presentation in detail.

Radon and hydrotherapy: application to French spas

International Nuclear Information System (INIS)

Ameon, R.

2004-01-01

Owing to the use of thermal water for treatments, the dissolved radon ends up, through degassing, in the atmosphere of the various spa premises. According to the type of treatments, the radon activity concentration in the air is very variable; it depends on two factors, the supply of thermal water, and therefore of radon, and the ventilation of the various premises. In unfavourable, even non-existent, ventilation conditions, it is not uncommon to measure radon concentration reaching several thousands of becquerels per air cubic meter. These high values of radon activity concentration, with or without its short-lived daughters, may lead to a staff exposure of approximately ten or several tens of mSv per year. A French spa was subject to a radon 'expertise' during which the radon source terms, 'ground in contact with the buildings' and 'thermal water' were characterized. The radon mapping in the internal atmosphere of the various spa premises and the workstations' analysis resulted in an assessment of the exposure due to radon inhalation. This study showed that on workstations, notably linked to hydrotherapy, the staff exposure to radon is in the same range as the dose assessments from foreign studies. The implementation of an appropriate ventilation of the treatment rooms and a better management of the thermal water in the spa resulted in a significant reduction of staff exposure

Long term radiological impact of thorium extraction

International Nuclear Information System (INIS)

Menard, S.; Schapira, J.P.

1995-01-01

Thorium extraction produces a certain amount of radioactive wastes. Potential long term radiological impact of these residues has been calculated using the recent ICRP-68 ingestion dose factors in connection with the computing code DECAY, developed at Orsay and described in this work. This code solves the well known Bateman's equations which govern the time dependence of a set of coupled radioactive nuclei. Monazites will be very likely the minerals to be exploited first, in case of an extensive use of thorium as nuclear fuel. Because monazites contain uranium as well, mining residues will contain not only the descendants of 232 Th and a certain proportion of non-extracted thorium (taken here to be 5%), but also this uranium, if left in the wastes for economical reasons. If no uranium would be present at all in the mineral, the potential radiotoxicity would strongly decrease in approximately 60 years, at the pace of the 5.8 years period of 228 Ra, which becomes the longest-lived radionuclide of the 4n radioactive family in the residues. Moreover, there is no risk due to radon exhalation, because of the very short period of 220 Rn. These significant differences between uranium and thorium mining have to be considered in view of some estimated long term real radiological impacts due to uranium residues, which could reach a value of the order of 1 mSv/year, the dose limit recommended for the public by the recent ICRP-60. (authors). 15 refs., 4 figs., 3 tabs., 43 appendices

A contemporary method for monitoring indoor radon and environmental conditions at a remote test site

International Nuclear Information System (INIS)

Renken, K.J.; Coursin, S.

1996-01-01

A state-of-the-art method for automatically monitoring indoor radon and environmental conditions at a remote test site is described. A Wisconsin home that exhibited elevated radon levels has been installed with automated PC-data acquisition system (PC-DAS) that includes: a laptop PC, a data acquisition cardcage, a commercial data acquisition software program plus sensors to measure radon gas concentrations, differential pressures, indoor air quality and meteorological conditions. The isolated PC-DAS is connected to a PC in a university laboratory via a modem and a communications software package. Experimental data is monitored and saved by the remote PC in real time and then automatically downloaded to the lab computer at selected intervals. An example of the formatted field results is presented and analysed. This documentation of the set-up, the off-the-shelf computer hardware and software, and the procedures should assist investigations requiring flexible remote long-term radon and environmental monitoring. (Author)

The radon

International Nuclear Information System (INIS)

1998-01-01

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

Evaluation of the open vial method in the radon measurement; Evaluacion del metodo del vial abierto en la medicion de radon

Energy Technology Data Exchange (ETDEWEB)

Lopez del Rio, H.; Davila R, J. I.; Mireles G, F., E-mail: hlopezdelrio@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

2014-10-15

The open vial method is a simple technique, under-utilized but that take advantage of the great radon solubility in organic solvents, therefore applies in the measurement of the radon concentration exhaled in soil. The method consists on the exposition to the gas radon of an open vial with scintillating solution. An integral mathematical model for indoors that describes the emanation processes and gas radon exhalation was developed, as well as the radon dissolution in the scintillation liquid, besides obtaining the characteristic parameters of the experimental system proposed for the radon concentration calculation exhaled by soils. Two experimental arrangements were designed with exposition cameras of 12 and 6 L and quantity of different soil. The open vial was prepared with a mixture of 8 ml of deionized water and 12 ml of scintillation liquid OptiPhase Hi Safe 3 in polyethylene vials; the measurements of the dissolved radon were carried out in scintillation liquid equipment. As a result, on average 2.0% of the exhaled radon is dissolved in the open vial and the dissolved fraction is independent of the experimental arrangement. Also was observed that the exposition time does not affect the radon dissolution significantly, in correspondence with the reported in the literature. (Author)

Global long-term cost dynamics of offshore wind electricity generation

NARCIS (Netherlands)

Gernaat, David E H J; Van Vuuren, Detlef P.; Van Vliet, Jasper; Sullivan, Patrick; Arent, Douglas J.

2014-01-01

Using the IMAGE/TIMER (The Targets IMage Energy Regional) long-term integrated assessment model, this paper explores the regional and global potential of offshore wind to contribute to global electricity production. We develop long-term cost supply curve for offshore wind, a representation of the

Measurement of average radon gas concentration at workplaces

International Nuclear Information System (INIS)

Kavasi, N.; Somlai, J.; Kovacs, T.; Gorjanacz, Z.; Nemeth, Cs.; Szabo, T.; Varhegyi, A.; Hakl, J.

2003-01-01

In this paper results of measurement of average radon gas concentration at workplaces (the schools and kindergartens and the ventilated workplaces) are presented. t can be stated that the one month long measurements means very high variation (as it is obvious in the cases of the hospital cave and the uranium tailing pond). Consequently, in workplaces where the expectable changes of radon concentration considerable with the seasons should be measure for 12 months long. If it is not possible, the chosen six months period should contain summer and winter months as well. The average radon concentration during working hours can be differ considerable from the average of the whole time in the cases of frequent opening the doors and windows or using artificial ventilation. (authors)

Radon dynamics in underwater thermal radon therapy

International Nuclear Information System (INIS)

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

1998-01-01

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

Radon in Schools

Science.gov (United States)

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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

[The Development of Long-Term Care Policies and the Impact on Nursing].

Science.gov (United States)

Wu, Shiao-Chi; Tsai, Yin-Yin; Yeh, Shin-Ting

2015-10-01

The government must reform and enhance current medical and long-term care services in order to respond effectively to societal ageing and labor shortage trends and to ensure sustainable operations. The post-acute care system should be reoriented on the home and community instead of the hospital. The Long Term Care Service Act integrates long-term care services that were previously dispersed amongst different departments, sets up a long-term care development fund, and improves the quality and allocation of long-term care services. Moreover, the Long Term Care Insurance Act will implement a bundle payment system to assist disabled families. The integration of automation and information technology will make long-term care more efficient. Although nurses are more skilled at elderly care and counseling than other community care professionals, nurses generally lack training in business management. Home and community-based services thus require better-trained manpower, opportunities to set care agents, and opportunities to offer flexible caring jobs. Therefore, nurses should strengthen their capabilities in post-acute care, business management, cooperation, and coordination.

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

International Nuclear Information System (INIS)

Kettunen, A.V.

1993-01-01

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

Long term effects on potential repository sites: occurrence and diagenesis of anhydrite

International Nuclear Information System (INIS)

Bath, A.H.; George, I.A.; Milodowski, A.E.; Darling, W.G.

1985-10-01

The report deals with the long-term behaviour of anhydrite as a potential host rock for deep disposal of intermediate-level radioactive wastes. The principal long-term effect on the integrity of such a repository is the possibility of penetration of groundwater and consequent transformation to gypsum. Therefore, in order to assess the chydrological and geochemical processes of hydration in detail, mineralogical and geochemical analyses have been carried out on anhydrite samples in a drillcore taken near Darlington, United Kingdom. The results are discussed in terms of the long-term integrity of anhydrite as a repository site. (U.K.)

Radon in houses due to radon in potable water

International Nuclear Information System (INIS)

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

1987-01-01

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

Systematic radon survey over active volcanoes

Energy Technology Data Exchange (ETDEWEB)

Seidel, J.L.; Monnin, M.; Garcia Vindas, J.R. [Centre National de la Recherche Cientifique, Montpellier (France). Lab. GBE; Ricard, L.P.; Staudacher, T. [Observatoire Volcanologique Du Pitou de la Fournaise, La Plaine des Cafres (France)

1999-08-01

Data obtained since 1993 on Costa Rica volcanos are presented and radon anomalies recorded before the eruption of the Irazu volcano (December 8, 1994) are discussed. The Piton de la Fournaise volcano is inactive since mid 1992. The influence of the external parameters on the radon behaviour is studied and the type of perturbations induced on short-term measurements are individuate.

Surface-water radon-222 distribution along the west-central Florida shelf

Science.gov (United States)

Smith, C.G.; Robbins, L.L.

2012-01-01

In February 2009 and August 2009, the spatial distribution of radon-222 in surface water was mapped along the west-central Florida shelf as collaboration between the Response of Florida Shelf Ecosystems to Climate Change project and a U.S. Geological Survey Mendenhall Research Fellowship project. This report summarizes the surface distribution of radon-222 from two cruises and evaluates potential physical controls on radon-222 fluxes. Radon-222 is an inert gas produced overwhelmingly in sediment and has a short half-life of 3.8 days; activities in surface water ranged between 30 and 170 becquerels per cubic meter. Overall, radon-222 activities were enriched in nearshore surface waters relative to offshore waters. Dilution in offshore waters is expected to be the cause of the low offshore activities. While thermal stratification of the water column during the August survey may explain higher radon-222 activities relative to the February survey, radon-222 activity and integrated surface-water inventories decreased exponentially from the shoreline during both cruises. By estimating radon-222 evasion by wind from nearby buoy data and accounting for internal production from dissolved radium-226, its radiogenic long-lived parent, a simple one-dimensional model was implemented to determine the role that offshore mixing, benthic influx, and decay have on the distribution of excess radon-222 inventories along the west Florida shelf. For multiple statistically based boundary condition scenarios (first quartile, median, third quartile, and maximum radon-222 inshore of 5 kilometers), the cross-shelf mixing rates and average nearshore submarine groundwater discharge (SGD) rates varied from 100.38 to 10-3.4 square kilometers per day and 0.00 to 1.70 centimeters per day, respectively. This dataset and modeling provide the first attempt to assess cross-shelf mixing and SGD on such a large spatial scale. Such estimates help scale up SGD rates that are often made at 1- to 10-meter

Effect of indoor-generated airborne particles on radon progeny dynamics

Energy Technology Data Exchange (ETDEWEB)

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

2016-08-15

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

Radon diffusion coefficients for soils. Previous studies and their application to uranium-bearing wastes

International Nuclear Information System (INIS)

Sasaki, Tomozo; Gunji, Yasuyoshi; Iida, Takao

2008-01-01

Radon diffusion in soils has been studied over the years by many researchers. The application of such studies to the evaluation of radiation exposure caused by radon from uranium-bearing wastes disposed in a shallow land site is very important. The present paper surveyed closely relevant studies and elucidated the inherent nature of radon diffusion in terms of the definition of radon diffusion coefficients. Then, basic features of measurement methods for determining radon diffusion coefficients in soils were explained. Furthermore, theoretical aspects of radon diffusion in soils were discussed in terms of microscopic radon diffusion in soils and large-scale radon diffusion through cover soil defects for uranium mill tailings. Finally, in order to apply the radon diffusion studies to uranium-bearing waste disposal in shallow land sites, new challenges were presented: elucidation of radon diffusion in uranium-bearing wastes and cover-soil cracks, and demonstration of the validity of applying only radon diffusion in the evaluation of radiation exposure caused by radon, which would come through Japanese cover soils for uranium-bearing waste disposal. (author)

Radon in buildings: instrumentation of an experimental house

International Nuclear Information System (INIS)

Ameon, R.; Diez, O.; Dupuis, M.; Merle-Szeremeta, A.

2004-01-01

IRSN decided to develop a code called RADON 2 for conducting simple and methodical studies of indoor radon concentrations. Since a validity check must be performed of the phenomenological model on which the code is based, an experimental program was initiated in 2002, within which a house in Brittany, located on a well-characterized uranium-bearing geological formation, was fitted with special instruments. After characterizing the soil underlying the house, the instrumentation implemented on site continuously monitors a number of parameters to characterize: the radon source term in the building (exhalation rate of 222 Rn at the ground/building interface and at soil surface, radon concentration in the soil and in outdoor air); radon penetration by advection (differential pressure in the house basement); the driving mechanisms for natural ventilation in the house (weather conditions, indoor temperature and relative humidity); radon distribution throughout the house by air flow and radon diffusion (indoor radon concentration at each floor of the house). Using the experimental data acquired over the past two years, the phenomena governing radon penetration inside the house (wind and stack effect) and radon extraction (fresh air supply rate) have been characterized to lay down the bases for validating the newly developed code

Contribution of radon and radon daughters to respiratory cancer

International Nuclear Information System (INIS)

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

1986-01-01

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

Monitoring for radon in water

International Nuclear Information System (INIS)

Deininger, R.A.

1994-01-01

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

Assessment of indoor radon doses received by the students in the Azad Kashmir schools (Pakistan)

International Nuclear Information System (INIS)

Rafique, M.; Rahman, S. U.; Rahman, S.; Matiullah; Shahzad, M. I.; Ahmed, N.; Iqbal, J.; Ahmed, B.; Ahmed, T.; Akhtar, N.

2010-01-01

Several epidemiological studies conducted on thousands of underground miners suggest that long-term exposure to high radon concentration can increase the risk of lung cancer. Keeping in view the importance of the subject, numerous studies throughout the world have been carried out to measure indoor radon concentration and its resulting doses at occupational and non-occupational sites. The purpose of the current study was to measure indoor radon concentration and its resulting doses received by the students of Azad Kashmir government schools. For this purpose, CR-39 radon detectors were installed in 80 carefully selected schools. The detectors were placed at a height of 3-5 ft. (depending upon average height of students in particular class) from the ground. After exposure of 90 d detectors were etched for 9 h in 6 M NaOH at 70 deg. C and the observed track densities were related to radon concentrations. The measured indoor radon concentration ranged from 22 ± 9 to 228 ± 3 Bq m -3 with a mean value of 78 ± 5 Bq m -3 . Based on the measured indoor radon data, the annual effective doses were found to vary from 0.55 ± 0.04 to 0.71 ± 0.03 mSv y -1 . The overall mean effective dose for the studied area was found to be 0.63 ± 0.04 mSv y -1 . Reported values for radon concentrations and corresponding doses are lower than ICRP recommended limits for workplaces. (authors)

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Paloma-radon: Atmospheric radon-222 as a geochemical probe for water in the Martian subsoil.

Science.gov (United States)

Sabroux, J.-C.; Michielsen, N.; Voisin, V.; Ferry, C.; Richon, P.; Pineau, J.-F.; Le Roulley, J.-C.; Chassefière, E.

2003-04-01

Radon exhalation from a porous soil is known to depend strongly on the soil moisture content: a minute amount of water, or water ice, in the pore space increases dramatically the possibility for radon to migrate far from its parent mineral. We propose to take advantage of this characteristic by using atmospheric radon-222 as a geochemical probe for water in the Martian soil, at least one order of magnitude deeper than the current Mars Odyssey neutron data. Strong thermal inversions during the Martian night will accumulate radon in the lowest atmospheric boundary layer, up to measurable levels despite the comparatively high environmental (cosmic and solar) background radiation and the assumed low uranium content of the upper crust of the planet. Preliminary studies and development of an instrument for the measurement of the Martian atmospheric alpha radioactivity is part of the CNES-supported PALOMA experiment. Two test benches have been implemented, one of them allowing differential measurements of the diffusion of radon in the Martian soil simulant NASA JSC Mars-1, under relevant temperatures and pressures. The other, a 1 m^3 radon-dedicated test bench, aims to characterize the instrument that will measure radon in the Mars environment (7 mb CO_2). Tests on several nuclear radiation detectors show that semiconductor alpha-particle detectors (PIPS) are the best option (already on board the Mars Pathfinder Rover and other platforms). In addition, the detection volume is left open in order to capitalize upon the long (ca. 4 m) alpha track at this low pressure. A stationary diffusion model was developed in order to assess the radon flux at the Mars soil surface. Diffusion of gas in Martian soil is governed by Knudsen diffusion. The radon Knudsen diffusion coefficient was estimated, depending on the soil moisture and relevant structural properties, leading to a radon diffusion length of the order of 20 m. The landed platform PALOMA-Radon instrument will consist of a

Review of radon and lung cancer risk

International Nuclear Information System (INIS)

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

1990-01-01

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

An improved model for the reconstruction of past radon exposure.

Science.gov (United States)

Cauwels, P; Poffijn, A

2000-05-01

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

Radon in coal power plant areas

International Nuclear Information System (INIS)

Mauna, Traian; Mauna, Andriesica

2006-01-01

Radon, the radioactive colourless and inodorous noble gas, represents more than 55% of the natural average radioactivity. It is permanently released from the soil and majority of building materials, it builds up in the mine galleries, in dwelling houses and in other closed rooms. Radon gained increasingly in importance, particularly after 1990 when was doubtless identified as the second cause of lung cancer if a given concentration threshold is surpassed. This threshold is established differentially by each country as a function of the particular site and generally ranges between 150 Bq.m -3 and 600 Bq.m -3 . The telluric radon consists of two isotopes, 222 Rn, a daughter of radium descending from uranium, which induces 90% of the effects, and 220 Rn from thorium series which have too short a lifetime to count in the risk assessments of radon inhalation. The interest of the authorities and population for diminishing the radon effects was illustrated by specific studies which in USA were managed by the National Counsel of Research, the BEIR VI committee of which has issued a report concerning the lung cancer produced by radon and its descendants. Coal mining, the transport, processing, burning, slag and ash disposal are activities entailing radon release. The miners' dwellings are placed in areas with the high radon potential. The local building materials have a high content of radioactive elements from the uranium or thorium series so that radon can build up in the closed rooms of these buildings. Hence the social responsible authorities in the coal power industry zones should consider this aspect long time ignored in the Balkans macro zone so far. The radon issue must be differentially approached in different areas hence a zonal mapping of the radon emission should be first done. It is worth to underline that the gaseous radioactive emission from operational nuclear power plants amounts up to a few percents of the radon natural emissions what entails a

Radon and health

International Nuclear Information System (INIS)

Chobanova, Nina

2016-01-01

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

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

Science.gov (United States)

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

Intercomparison of different instruments for measuring radon concentration in air

International Nuclear Information System (INIS)

Shimo, Michikuni; Iida, Takao

1990-01-01

An intercomparison of different instruments for measurement of radon concentration was carried out. The instruments include an ionization chamber, the charcoal-trap method, a flow-type ionization chamber (pulse-counting method), a two-filter method, an electrostatic collection method and a passive integration radon monitor. All instruments except for the passive radon monitor have been calibrated independently. Measurements were performed over a concentration range from about 3.5 Bq·m -3 (in outdoor air) to 110 Bq·m -3 (in indoor air). The results obtained by these techniques, except the two-filter technique, are comparable. Radon daughter concentration measured using a filter-sampling method was about 52% of radon concentration. (author)

Intercomparison of different instruments that measure radon concentration in air

International Nuclear Information System (INIS)

Shimo, M.; Iida, T.; Ikebe, Y.

1987-01-01

An intercomparison of different instruments for measurement of radon concentration was carried out. The instruments include an ionization chamber, the charcoal-trap technique, a flow-type ionization chamber (pulse-counting technique), a two-filter method, an electrostatic collection method and a passive integrating radon monitor. All instruments except for the passive radon monitor have been calibrated independently. Measurements were performed over a concentration range from about 3.5 Bq/m/sup 3/ (in outdoor air) to 110 Bq/m/sup 3/ (in indoor air). The results obtained from these techniques, except the two-filter technique, are comparable. Radon daughter concentration measured using a filter-sampling technique was about 52% of radon concentrations

Soil radon levels across the Amer fault

International Nuclear Information System (INIS)

Font, Ll.; Baixeras, C.; Moreno, V.; Bach, J.

2008-01-01

Soil radon levels have been measured across the Amer fault, which is located near the volcanic region of La Garrotxa, Spain. Both passive (LR-115, time-integrating) and active (Clipperton II, time-resolved) detectors have been used in a survey in which 27 measurement points were selected in five lines perpendicular to the Amer fault in the village area of Amer. The averaged results show an influence of the distance to the fault on the mean soil radon values. The dynamic results show a very clear seasonal effect on the soil radon levels. The results obtained support the hypothesis that the fault is still active

Predicting radon/radon daughter concentrations in underground mines

International Nuclear Information System (INIS)

Leach, V.A.

1984-01-01

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

The history, development and the present status of the radon measurement programme in the United States of America

International Nuclear Information System (INIS)

George, A.C.

2015-01-01

The US radon measurement programme began in the late 1950's 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

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

Science.gov (United States)

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

2013-03-01

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

Integrating Long-Term Avian Studies with Planning and Adaptive Management: Department of Energy Lands as a Case Study.

Energy Technology Data Exchange (ETDEWEB)

Burger, J.

2000-10-01

Long-term bio-monitoring of avian communities have been initiated, but they often lack a management component. Integration of the managers needs at an early stage is suggested as a means to increase the use of the data. Variation in community structure is important in understanding impacts. In addition, reference site must be carefully selected.

What do near-term observations tell us about long-term developments in greenhouse gas emissions? A letter

NARCIS (Netherlands)

Vuuren, van D.P.; Edmonds, J.; Smith, S.J.; Calvin, K.V.; Karas, J.; Kainuma, M.; Nakicenovic, N.; Riahi, K.; Ruijven, B.J.; Swart, R.J.; Thomson, A.

2010-01-01

Long-term scenarios developed by integrated assessment models are used in climate research to provide an indication of plausible long-term emissions of greenhouse gases and other radiatively active substances based on developments in the global energy system, land-use and the emissions associated

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Detailed radon emanation mapping in Northern Latium

International Nuclear Information System (INIS)

Aumento, F.

1993-01-01

Detailed radon surveys over 5,000 km 2 of Northern Latium, covering the northern part of the volcanic province of Central Italy, commenced in the mid eighties as part of a geothermal exploration programme; the surveys have subsequently been continued and amplified with environmental protection in mind. The area is now covered by ground emission maps, radon levels in water supplies, emissions from the different lithologies and concentrations in houses. The high uraniferous content of the volcanics, the porous nature of the ubiquitous pyroclastics, and active geothermal systems in the area combine to convey to ground level high concentrations of radon. The emissions show strong lateral variations which are geologically and tectonically controlled, such that only detailed surveys reveal the extent and locations of anomalous radon emanations. Unfortunately, long ago towns often developed in strategic locations. For Northern Latium this means on volcanic highs formed by faulted tuff blocks, two geological features associated with particularly high radon emissions. As a result, in contrast to the low average indoor radon concentrations for the greater part of Italy, in some of these town the average values exceed 450 Bq/m 3 . (author). 1 fig

The radon monitoring system in Daya Bay Reactor Neutrino Experiment

International Nuclear Information System (INIS)

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

2016-01-01

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

Subsurface temporal variation of radon at the Conrad Geophysical Observatory, Austria

Science.gov (United States)

Leonhardt, Roman; Steinitz, Gideon; Piatibratova, Oksana

2015-04-01

The Conrad Observatory (COBS) housed the national geophysical observatory of Austria and is located 50 km south west of Vienna within the carbonate sequence of the "Wettersteinkalk". Parameters monitored at the facility comprise environmental data, seismic signals, gravity, geomagnetic components and also natural gamma rays. A subsurface tunnel, 150 meters long and oriented E-W is driven into the calcareous sequence at a depth of 50 meters. The tunnel is lined with a concrete carapace, ~20 cm thick. The tunnel observatory is separated from the external atmosphere by 3 tight doors, resulting in a stable temperature of 6.85±0.04°C. A gamma detector (3×3", NaI, SCA) is used measure the variation of the gamma radiation from radon in the air of the tunnel, at a resolution of 1 minute, which is accumulated to form a 15-minute count rate. The sensor is placed on a concrete block at 135 meters. Several SSNTD measurements in the tunnel indicated radon level in the level of 1.5 kBq/m^3. The background gamma radiation, due probably mainly to sources in the concrete is in the order to 2×105 counts (per 15-minutes). A long term variation of radon is reflected as an annual radon signal with large amplitude (2×105 counts) and a maximum in summer. Small to large (2×105 counts) non periodic multi-day signals lasting from two to several tens of days are superimposed. Daily periodic signals of much lower amplitude are observed, with amplitudes generally up to 4×104 counts. The amplitude of the non-periodic multi-day is coupled to amplitude of the annual signal, and the amplitude of the periodic daily signal is modulated by the multi-day variation. The source of the radon in the air of the tunnel is from the concrete lining the floor and walls of the tunnel. The variation patterns and their systematic characteristics cannot be ascribed to local variations of pressure and temperature (stable). These limitations indicate that other driver(s), external to the tunnel, are forcing

Overview of current radon and radon daughter research at LBL

International Nuclear Information System (INIS)

1983-01-01

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

Temporal patterns of lung cancer risk from radon and smoking - consequences to remediation measures

International Nuclear Information System (INIS)

Tomasek, L.

2004-01-01

Studies of uranium miners conducted since the late 1960s demonstrated that the risk depends on cumulated exposure in terms of working level months (WLM) integrating both duration of exposure and concentration of radon. It has been also demonstrated that the risk from radon decreases with time since exposure. The present analysis of temporal changes of relative risk is based on a model where the total individual exposure is partitioned into components in dependence on time. Exposure to radon is studied in a cohort of 9411 Czech uranium miners with 766 cases of lung cancer and in a residential study of 11 803 inhabitants exposed to radon in houses with 218 cases. In addition, temporal patterns of the risk from smoking are analyzed in a case-control study of patients from a major Prague hospital including 566 cases. For both carcinogens, the relative risk decreases with time since exposure. The risk from exposures before 20-34 years is 36% and 34% in comparison to period 5-19 for smoking and radon, respectively. The effect of exposures from more distant periods 35-49 is only 5% for smoking and 14% for radon in comparison to 5-19 years. This substantial decrease of relative risk with time may contribute to a better evaluation of remediation measures taken in houses and in the cost effectiveness of remediation. Combined effect of smoking and radon is studied by a nested case-control approach including 434 cases and 962 controls. Analyses of the joint effects of smoking and radon, conducted in the occupational and the residential studies, suggest a sub-multiplicative interaction. The relative risk from radon among non-smokers is higher by a factor of 2-3 in comparison to smokers, suggesting different patterns of lung deposition and clearance among smokers and non-smokers. (author)

Calibration of diffusion barrier charcoal detectors and application to radon sampling in dwellings

International Nuclear Information System (INIS)

Montero C, M.E.; Colmenero S, L.; Villalba, L.; Saenz P, J.; Cano J, A.; Moreno B, A.; Renteria V, M.; Herrera P, E.F.; Cruz G, S. De la; Lopez M, A.

2003-01-01

Some calibration conditions of diffusion barrier charcoal canister (DBCC) detectors for measuring radon concentration in air were studied. A series of functional expressions and graphs were developed to describe relationship between radon concentration in air and the activity adsorbed in DBCC, when placed in small chambers. A semi-empirical expression for the DBCC calibration was obtained, based on the detector integration time and the adsorption coefficient of radon on activated charcoal. Both, the integration time for 10 % of DBCC of the same batch, and the adsorption coefficient of radon for the activated charcoal used in these detectors, were experimentally determined. Using these values as the calibration parameters, a semi-empirical calibration function was used for the interpretation of the radon activities in the detectors used for sampling more than 200 dwellings in the major cities of the state of Chihuahua, Mexico. (Author)

Calibration of diffusion barrier charcoal detectors and application to radon sampling in dwellings

Energy Technology Data Exchange (ETDEWEB)

Montero C, M.E.; Colmenero S, L.; Villalba, L.; Saenz P, J.; Cano J, A.; Moreno B, A.; Renteria V, M.; Herrera P, E.F. [Cento de Investigacion en Materiales Avanzados, S. C. Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua, (Mexico); Cruz G, S. De la [Facultad de Enfermeria y Nutriologia, Universidad Autonoma de Chihuahua, Av. Politecnico Nacional 2714, Chihuahua, (Mexico); Lopez M, A. [Instituto Nacional de Investigaciones Nucleares, Apartado Postal 18-1027, 11801 Mexico D.F. (Mexico)

2003-07-01

Some calibration conditions of diffusion barrier charcoal canister (DBCC) detectors for measuring radon concentration in air were studied. A series of functional expressions and graphs were developed to describe relationship between radon concentration in air and the activity adsorbed in DBCC, when placed in small chambers. A semi-empirical expression for the DBCC calibration was obtained, based on the detector integration time and the adsorption coefficient of radon on activated charcoal. Both, the integration time for 10 % of DBCC of the same batch, and the adsorption coefficient of radon for the activated charcoal used in these detectors, were experimentally determined. Using these values as the calibration parameters, a semi-empirical calibration function was used for the interpretation of the radon activities in the detectors used for sampling more than 200 dwellings in the major cities of the state of Chihuahua, Mexico. (Author)

Radon analyser

International Nuclear Information System (INIS)

1981-01-01

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

Management of the radon-related risk. Guide for local authorities. Guide for employers

International Nuclear Information System (INIS)

Struillou, Yves; Gupta, Olivier

2017-01-01

A first guide aims at being an aid to decision by specifying obligations of local authorities as owners of buildings open to public or as employers, but also at being a support for their health and social actions in terms of information on radon risk in housing. After a presentation of the risk related to radon (health risks, radon propagation, regulatory areas concerned by radon risk management in France), the report indicates the various obligations and mandatory actions for local authorities as building owner and as employer, and actions to be undertaken for existing and new buildings. Technical sheets are provided regarding radon detection, certifications, simple actions, technical diagnosis, remediation works, efficiency control of technical solutions, expert in radiation protection. The second guide aims at being an aid to decision by specifying obligations for employers in terms of management of radon-related risk to which some workers might be exposed, and at providing some good practice recommendations. After a presentation of the risk related to radon (health risks, radon propagation, regulatory areas concerned by radon risk management in France), the report addresses how to organise the radon-related risk management, how to measure radon in work places, how to interpret results and which actions to undertake. Technical sheets are provided regarding radon detection, certifications, simple actions, technical diagnosis, remediation works, efficiency control of technical solutions, expert in radiation protection

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

International Nuclear Information System (INIS)

Scarpitta, S.C.; Tu, K.W.; Fisenne, I.M.; Cavallo, A.; Perry, P.

1996-10-01

Results are presented from the Fifth Intercomparison of Active, Passive and Continuous Instruments for Radon and Radon Progeny Measurements conducted in the EML radon exposure and test facility in May 1996. In total, thirty-four government, private and academic facilities participated in the exercise with over 170 passive and electronic devices exposed in the EML test chamber. During the first week of the exercise, passive and continuous measuring devices were exposed (usually in quadruplicate) to about 1,280 Bq m -3 222 Rn for 1--7 days. Radon progeny measurements were made during the second week of the exercise. The results indicate that all of the tested devices that measure radon gas performed well and fulfill their intended purpose. The grand mean (GM) ratio of the participants' reported values to the EML values, for all four radon device categories, was 0.99 ± 0.08. Eighty-five percent of all the radon measuring devices that were exposed in the EML radon test chamber were within ±1 standard deviation (SD) of the EML reference values. For the most part, radon progeny measurements were also quite good as compared to the EML values. The GM ratio for the 10 continuous PAEC instruments was 0.90 ± 0.12 with 75% of the devices within 1 SD of the EML reference values. Most of the continuous and integrating electronic instruments used for measuring the PAEC underestimated the EML values by about 10--15% probably because the concentration of particles onto which the radon progeny were attached was low (1,200--3,800 particles cm -3 ). The equilibrium factor at that particle concentration level was 0.10--0.22

Sensitive and long-term monitoring of intracellular microRNAs using a non-integrating cytoplasmic RNA vector.

Science.gov (United States)

Sano, Masayuki; Ohtaka, Manami; Iijima, Minoru; Nakasu, Asako; Kato, Yoshio; Nakanishi, Mahito

2017-10-04

MicroRNAs (miRNAs) are small noncoding RNAs that modulate gene expression at the post-transcriptional level. Different types of cells express unique sets of miRNAs that can be exploited as potential molecular markers to identify specific cell types. Among the variety of miRNA detection methods, a fluorescence-based imaging system that utilises a fluorescent-reporter gene regulated by a target miRNA offers a major advantage for long-term tracking of the miRNA in living cells. In this study, we developed a novel fluorescence-based miRNA-monitoring system using a non-integrating cytoplasmic RNA vector based on a replication-defective and persistent Sendai virus (SeVdp). Because SeVdp vectors robustly and stably express transgenes, this system enabled sensitive monitoring of miRNAs by fluorescence microscopy. By applying this system for cellular reprogramming, we found that miR-124, but not miR-9, was significantly upregulated during direct neuronal conversion. Additionally, we were able to isolate integration-free human induced pluripotent stem cells by long-term tracking of let-7 expression. Notably, this system was easily expandable to allow detection of multiple miRNAs separately and simultaneously. Our findings provide insight into a powerful tool for evaluating miRNA expression during the cellular reprogramming process and for isolating reprogrammed cells potentially useful for medical applications.

Orphan radon daughters at Denver Radium site

International Nuclear Information System (INIS)

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

1992-01-01

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

Experimental study of radon and thoron diffusion through barriers

Energy Technology Data Exchange (ETDEWEB)

Durcik, M; Havlik, F [Inst. of Preventive and Clinical Medicine, 83301 Bratislava (Slovakia)

1996-12-31

The measurement results of diffusion parameters for radon (radon-222) and thoron (radon-220) through barriers, experimental equipment and theoretical background of diffusion are presented in this paper. The diffusion barriers are used for measuring radon and thoron by passive detectors in order to test the reduction techniques in houses. Six samples (filter paper, rubber, polyethylene, glass laminate, polypropylene) were studied for radon diffusion. The thickness barriers were from 0.012 mm to 2 mm, the diffusion area was 16 cm{sup 2} and the volume V{sub 2} was 30 dm{sup 3}. The diffusion constants D were obtained using given expressions and the data from measurements. The procedures used in experiments are useful for study of diffusion ability of radon and thoron in barriers and determination diffusion parameters from short term measurements. (J.K.). 2 figs., 1 tab., 3 refs.

Experimental study of radon and thoron diffusion through barriers

International Nuclear Information System (INIS)

Durcik, M.; Havlik, F.

1995-01-01

The measurement results of diffusion parameters for radon (radon-222) and thoron (radon-220) through barriers, experimental equipment and theoretical background of diffusion are presented in this paper. The diffusion barriers are used for measuring radon and thoron by passive detectors in order to test the reduction techniques in houses. Six samples (filter paper, rubber, polyethylene, glass laminate, polypropylene) were studied for radon diffusion. The thickness barriers were from 0.012 mm to 2 mm, the diffusion area was 16 cm 2 and the volume V 2 was 30 dm 3 . The diffusion constants D were obtained using given expressions and the data from measurements. The procedures used in experiments are useful for study of diffusion ability of radon and thoron in barriers and determination diffusion parameters from short term measurements. (J.K.). 2 figs., 1 tab., 3 refs

Method for radon measurement in the subsoil in geothermal prospectus; Metodos de medicion de radon en el subsuelo en prospeccion geotermica

Energy Technology Data Exchange (ETDEWEB)

Balcazar G, M

1991-02-15

The present formless describe the technique for radon measurement in the underground, being able to be used as an additional study in the geothermal prospecting. This methodology has been developed in the National Institute of Nuclear Research of Mexico using a film of cellulose nitrate to detect those emanated alpha particles, by the Rn (222). By means of the trace account in this films its settle down the present radon levels in the underground. The present method thinks about as an alternating one to overcome in it leaves the limitations found in the development of the methodology using a radon emanometer ETR-1, of the trade mark SCINTREX. The radon detected by plastics is also an integral method of measuring in a geothermal field that avoids the problems of variations of radon to pluvial precipitations and barometric variations. These variations affect the results strongly when it is used the punctual sampler as it is the ETR-1. (Author)

SWOT analysis of the Czech Radon programme.

Science.gov (United States)

Fojtíková, I

2014-07-01

Since the early 1990s, the Czech Republic has been one of the countries that carry out a radon programme on its territory, with the aim of protecting people from unnecessary long-term exposure in their homes. Since that time, many achievements have been registered, and many unexpected difficulties have cropped up. This may be the right moment to take some time out to analyse the state of the programme and to determine the direction for its future development. An extended SWOT analysis can serve as a useful tool for this purpose. Originally, SWOT analyses were used exclusively by for-profit organisations aiming to evaluate their perspectives, develop strategies and make plans in order to achieve their objectives. More recently, it has been used in a wide range of decision-making situations when a desired end-state is to be defined. Here, an extended SWOT analysis is used to formulate possible beneficial strategies for advancing anti-radon policy in the Czech Republic. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Investigations of radon and radon daughters in surficial aquifers of florida

International Nuclear Information System (INIS)

1991-05-01

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

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

International Nuclear Information System (INIS)

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

1983-07-01

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

IMPACT OF EUROPEAN INTEGRATION PROCESSES ON THE NECESSITY OF LONG-TERM BUDGET PLANNING INTRODUCTION IN UKRAINE

Directory of Open Access Journals (Sweden)

Ganna Muzychenko

2017-12-01

Full Text Available The Association Agreement between Ukraine and the European Union was ratified in September 2014. Ukraine has undertaken to implement and enforce EU standards, including in the financial sphere, which are regulated by international law. The purpose of the study is to determine the impact of European integration processes on the necessity of the long-term budget forecasting process introduction into the budget process of Ukraine and the revelation of special budgetary rules regulated this process in the EU. The methodology. The list of requirements (budget procedures and rules for their introduction by law into the budget process of Ukraine was determined based on the generalization and systematization of normative legal acts that regulate the medium-term financial planning as the EU standard. The results showed that the long-term budget forecast developing procedure in the budget process will allow the government to timely identify the unfavourable trend in the state’s fiscal policy and introduce preventive measures, determine the full scale of economy’s and business’ reaction to the reforms’ introduction and new laws adoption, estimate fiscal space for fiscal policy implementation for coming years, take into consideration the budget forecast’s indicators during the annual adoption of budget decisions. The study defines the difference between the budget forecast and the planned budget: the forecast is for five years and more, the plan is for one year only; forecast indicators are not mandatory for implementation, they are only guidelines, and planned indicators are mandatory for implementation; the budget forecast is approved by the order of the Cabinet of Ministers of Ukraine and annually specified, the planned budget (for the current budget year is approved by the Verkhovna Rada of Ukraine by adopting the relevant law, amendments are an exception and also approved by law. The practical implementation. Governments of countries that

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

International Nuclear Information System (INIS)

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

1996-01-01

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

Short-term radon activity concentration changes along the Underground Educational Tourist Route in the Old Uranium Mine in Kletno (Sudety Mts., SW Poland)

International Nuclear Information System (INIS)

Fijałkowska-Lichwa, Lidia

2014-01-01

Short-term 222 Rn activity concentration changes along the Underground Educational Tourist Route in the Old Uranium Mine in Kletno were studied, based on continuous measurements conducted between 16 May 2008 and 15 May 2010. The results were analysed in the context of numbers of visitors arriving at the facility in particular seasons and the time per day spent inside by staff and visitors. This choice was based on partially published earlier findings (Fijałkowska-Lichwa and Przylibski, 2011). Results for the year 2009 were analysed in depth, because it is the only period of observation covering a full calendar year. The year 2009 was also chosen for detailed analysis of short-term radon concentration changes, because in each period of this year (hour, month, season) fluctuations of noted values were the most visible. Attention has been paid to three crucial issues linked to the occurrence and behaviour of radon and to the radiological protection of workers and visitors at the tourist route in Kletno. The object of study is a complex of workings in a former uranium mine situated within a metamorphic rock complex in the most radon-prone area in Poland. The facility has been equipped with a mechanical ventilation system, which is turned on after the closing time and at the end of the working day for the visitor service staff, i.e. after 6 p.m. Short-term radon activity concentration changes along the Underground Educational Tourist Route in the Old Uranium Mine in Kletno are related to the activity of the facility's mechanical ventilation. Its inactivity in the daytime results in the fact that the highest values of 222 Rn activity concentration are observed at the time when the facility is open to visitors, i.e. between 10 a.m. and 6 p.m. The improper usage of the mechanical ventilation system is responsible for the extremely unfavourable working conditions, which persist in the facility for practically all year. The absence of appropriate radiological

The problem of general Radon representation for an arbitrary Hausdorff space

Science.gov (United States)

Zakharov, V. K.; Mikhalev, A. V.

1999-10-01

After the fundamental work of Riesz, Radon and Hausdorff in the period 1909-1914, the following problem of general Radon representation emerged: for any Hausdorff space find the space of linear functionals that are integrally representable by Radon measures. In the early 1950s, a partial solution of this problem (the bijective version) for locally compact spaces was obtained by Halmos, Hewitt, Edwards, Bourbaki and others. For bounded Radon measures on a Tychonoff space, the problem of isomorphic Radon representation was solved in 1956 by Prokhorov. In this paper we give a possible solution of the problem of general Radon representation. To do this, we use the family of metasemicontinuous functions with compact support and the class of thin functionals. We present bijective and isomorphic versions of the solution (Theorems 1 and 2 of §2.5). To get the isomorphic version, we introduce the family of Radon bimeasures.

The problem of general Radon representation for an arbitrary Hausdorff space

Energy Technology Data Exchange (ETDEWEB)

Zakharov, V K [St Petersburg State University of Technology and Design (Russian Federation); Mikhalev, A V [M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

1999-10-31

After the fundamental work of Riesz, Radon and Hausdorff in the period 1909-1914, the following problem of general Radon representation emerged: for any Hausdorff space find the space of linear functionals that are integrally representable by Radon measures. In the early 1950s, a partial solution of this problem (the bijective version) for locally compact spaces was obtained by Halmos, Hewitt, Edwards, Bourbaki and others. For bounded Radon measures on a Tychonoff space, the problem of isomorphic Radon representation was solved in 1956 by Prokhorov. In this paper we give a possible solution of the problem of general Radon representation. To do this, we use the family of metasemicontinuous functions with compact support and the class of thin functionals. We present bijective and isomorphic versions of the solution (Theorems 1 and 2 of paragraph 2.5). To get the isomorphic version, we introduce the family of Radon bimeasures.

The problem of general Radon representation for an arbitrary Hausdorff space

International Nuclear Information System (INIS)

Zakharov, V K; Mikhalev, A V

1999-01-01

After the fundamental work of Riesz, Radon and Hausdorff in the period 1909-1914, the following problem of general Radon representation emerged: for any Hausdorff space find the space of linear functionals that are integrally representable by Radon measures. In the early 1950s, a partial solution of this problem (the bijective version) for locally compact spaces was obtained by Halmos, Hewitt, Edwards, Bourbaki and others. For bounded Radon measures on a Tychonoff space, the problem of isomorphic Radon representation was solved in 1956 by Prokhorov. In this paper we give a possible solution of the problem of general Radon representation. To do this, we use the family of metasemicontinuous functions with compact support and the class of thin functionals. We present bijective and isomorphic versions of the solution (Theorems 1 and 2 of paragraph 2.5). To get the isomorphic version, we introduce the family of Radon bimeasures