Reasons for increasing radon concentrations in radon remediated houses

International Nuclear Information System (INIS)

Clavensjoe, B.

1997-01-01

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

Radon levels and transport parameters in Atlantic Forest soils

International Nuclear Information System (INIS)

Farias, E.E.G. de; Silva Neto, P.C. da; Souza, E.M. de; De Franca, E.J.; Hazin, C.A.

2016-01-01

In natural forest soils, the radon transport processes can be significantly intensified due to the contribution of living organism activities to soil porosity. In this paper, the first results of the radon concentrations were obtained for soil gas from the Atlantic Forest, particularly in the Refugio Ecologico Charles Darwin, Brazil. The estimation of permeability and radon exhalation rate were carried out in this conservation unit. For forested soils, radon concentrations as high as 40 kBq m -3 were found. Based on the radon concentrations and on the permeability parameter, the results indicated considerable radon hazard for human occupation in the neighborhood. (author)

Study of a Greek area with enhanced indoor radon concentrations

International Nuclear Information System (INIS)

Louizi, A.; Nikolopoulos, D.; Koukouliou, V.; Kehagia, K.

2003-01-01

In this paper the focus is on Arnea Chalkidikis, an area in Greece with granitic geological background and indications of possible elevated radon concentration indoors. Data are reported of indoor radon measurements with etched track detectors and those used for dosimetric estimations. Moreover, data are reported on soil gas and soil radon concentrations in Arnea, as well as radon and uranium concentrations in water samples. From the measured radon concentrations in water samples the contribution to the overall dose has been calculated. For a period of 1 month, indoor radon and progeny activity has also been monitored in the dwelling that has the maximum indoor radon concentration in Greece. This dwelling is in Arnea and the dose delivered to the inhabitants has been calculated. Mean annual effective dose due to indoor radon was 4.5 mSv and about 11% of this was due to the use of water. Mean soil gas concentration and soil radon concentration were (90 ± 30) kBq m -3 (P -3 (P -1 (P<0.05). (author)

Radon-222 exhalation and its variation in soil air

International Nuclear Information System (INIS)

Mochizuki, S.; Sekikawa, T.

1980-01-01

A new method has been designed and developed for measuring the concentration of radon in soil air without disturbing the natural condition of the soil. By this method, radon concentrations in the soil air at various points down to a depth of 1 m below the ground are obtained from the concentrations of radium A ( 218 Po) measured in the same air. The radium A concentration is measured by spectrometry of alpha particles from radioactive ions in the soil air. The basic experiments and preliminary observations made in the soil air below the ground confirmed the usefulness of the newly constructed apparatus for measuring the radon concentration in the soil air. Our preliminary observations showed that the radon concentration in the soil air near the surface of the earth varied remarkably before heavy thunderstorms

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.)

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)

Ground-truthing predicted indoor radon concentrations by using soil-gas radon measurements

International Nuclear Information System (INIS)

Reimer, G.M.

2001-01-01

Predicting indoor radon potential has gained in importance even as the national radon programs began to wane. A cooperative study to produce radon potential maps was conducted by the Environmental Protection Agency (EPA), U.S. Geological Survey (USGS), Department of Energy (DOE), and Lawrence Berkeley Laboratory (LBL) with the latter taking the lead role. A county-wide predictive model based dominantly on the National Uranium Resource Evaluation (NURE) aerorad data and secondly on geology, both small-scale data bases was developed. However, that model breaks down in counties of complex geology and does not provide a means to evaluate the potential of an individual home or building site. Soil-gas radon measurements on a large scale are currently shown to provide information for estimating radon potential at individual sites sort out the complex geology so that the small-scale prediction index can be validated. An example from Frederick County, Maryland indicates a positive correlation between indoor measurements and soil-gas data. The method does not rely on a single measurement, but a series that incorporate seasonal and meteorological considerations. (author)

Estimation of Soil Radon Concentration in Al-Qateef's Date Palm Farms, Saudi Arabia

International Nuclear Information System (INIS)

Al-Ghamdi, S. S.; Al-Garawi, M. S.; Baig, M. R.; Al-Sameen, M.

2011-01-01

This study involves the measurement of radon concentrations in agricultural soil from two date Palm farms in Al-Qateef province using CR-39 detector. In each farm the palm trees are arranged in rows separated by the irrigation reservoirs. The first farm is about 10000 m 2 and has 350 palm trees and the second farm is about 7000 m 2 and has 320 palm trees. The average distance between trees is about 5.5 m. The rows are separated by an irrigation reservoir where fertilizers are added. Sixty soil samples were collected from each farm and classified in paperboard boxes. These samples were taken from different depths and positions between the trees and from the irrigation reservoir.A newly designed tag type dosimeter is used in which the alpha tracks are registered on both sides of the CR-39 detector. The tag dosimeter was calibrated against a cup type dosimeter which was calibrated at the National Radiological Protection Board (NRPB) at the U.K.The detectors were left to count for five months and then chemically treated in the standard way. Finally an optical microscope is used to count alpha tracks and the data are treated statistically.The study is set to test for significant differences in radon concentrations at different positions and depths in the barren and fertilized soils in the two farms. Measured radon concentrations ranged between 42 and 344Bq/m 3 . No significant difference between the mean concentration values in soil samples taken between the trees and that taken at the depth of 50 cm from the irrigation reservoir. Significant difference was however found between radon concentrations in samples collected directly from the surface of the irrigation reservoir where fertilizers are introduced and those taken from the other two positions. The used fertilizers are found to have higher contents of uranium which is limited to the surface soil of the irrigation reservoir.

Radon concentration, absorbed dose rate in air and concentration of natural radionuclides in soil in the Osaka district of Japan

International Nuclear Information System (INIS)

Megumi, K.; Matsunami, T.; Ishiyama, T.; Abe, M.; Kimura, S.; Yamazaki, K.; Tsujimoto, T.

1992-01-01

Radon concentrations in outdoor air at 18 sites in the Osaka district, in the central part of Japan's main island, were measured with electrostatic integrating radon monitors which were developed by Y Ikebe et al of the Osaka survey centre as part of a nationwide survey of radon indoors and outdoors in Japan conducted by the National Institute of Radiological Science. The mean radon concentration in outdoor air during 2-month periods was measured over a period of a year and a half. In addition, the absorbed dose rate in air and the concentration of natural radionuclides in soil were measured at 40 sites in Osaka Prefecture which is located in the central part of the Osaka district using thermoluminescence dosemeters and with gamma ray spectrometry, respectively. Radon concentration in outdoor air showed a seasonal pattern, reaching its maximum during the winter and its minimum during the summer, but this variation was not significant at the coastal sites. It was concluded that this variation is correlated with a seasonal wind which blows from the continental interior to the ocean in winter and in the opposite direction in summer, as well as with geographical factors. Radon concentration in outdoor air in the Osaka district ranged from 0.6 to 17.9 Bq.m -3 and mean annual radon concentration in outdoor air at the 18 sites ranged from 2.7 to 6.9 Bq.m -3 . It was discovered that radon concentration in outdoor air decreased with wind speed in both winter and summer. The absorbed dose rate in air ranged from 66 to 114 nGy.h -1 , and the concentration of 226 Ra in soil ranged from 20 to 60 Bq.kg -1 respectively. (author)

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.

High annual radon concentration in dwellings and natural radioactivity content in nearby soil in some rural areas of Kosovo and Metohija

Directory of Open Access Journals (Sweden)

Gulan Ljiljana R.

2013-01-01

Full Text Available Some previous studies on radon concentration in dwellings of some areas of Kosovo and Metohija have revealed a high average radon concentration, even though the detectors were exposed for three months only. In order to better design a larger study in this region, the annual measurements in 25 houses were carried out as a pilot study. For each house, CR-39-based passive devices were exposed in two rooms for the two consecutive six-month periods to account for seasonal variations of radon concentration. Furthermore, in order to correlate the indoor radon with radium in nearby soil and to improve the knowledge of the natural radioactivity in the region, soil samples near each house were collected and 226Ra, 232Th, 40K activity concentration were measured. The indoor radon concentration resulted quite high from the average (163 Bq/m3 and generally it did not differ considerably between the two rooms and the two six-month periods. The natural radionuclides in soil resulted to be distributed quite uniformly. Moreover, the correlation between the226Ra content in soil and radon concentration in dwellings resulted to be low (R2=0.26. The annual effective dose from radon and its short-lived progeny (5.5 mSv, in average was calculated by using the last ICRP dose conversion factors. In comparison, the contribution to the annual effective dose of outdoor gamma exposure from natural radionuclides in soil is nearly negligible (66 mSv. In conclusion, the observed high radon levels are only partially correlated with radium in soil; moreover, a good estimate of the annual average of radon concentration can be obtained from a six-month measurement with a proper choice of exposure period, which could be useful when designing large surveys.

An investigation of factors influencing indoor radon concentrations

International Nuclear Information System (INIS)

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

1988-05-01

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

PO.RA project. An analysis on gas radon concentrations in soil versus fluctuations in the groundwater table

International Nuclear Information System (INIS)

Serentha', C.; Torretta, M.

2001-01-01

Man is daily exposed to natural radiation, mainly due to cosmic rays and natural radioactive elements, whose most important radioactive daughters are 222 Rn (radon) and 220 Rn (thoron). Being these ones gaseous, they can spread through the ground, reaching the atmosphere and accumulating in rooms, where their concentrations may be very high. As radon exhalation is strongly connected with the hydrogeological features of the environment, this study tried to find a relationship between fluctuations in the groundwater table and gas radon concentrations in soil, in order to try estimates of indoor radon concentrations [it

Radon chamber for soil gas detectors

International Nuclear Information System (INIS)

Andersson, P.

1987-01-01

Swedish Geological Co (SGAB) has designed and constructed a chamber for the calibration of detectors and instruments intended for the measurement of radon-222 in soil gas. In the chamber radon detectors may be exposed in a model environment which simulates ground conditions with respect to radon concentration, temperature and humidity. Also included in the research project is the development of methods for calibration procedures, together with test measurements. In general, these measurements indicate that the radon detectors tested are sufficiently accurate and reliable for radon measurements in Swedish soils if they are calibrated in an environment which simulates ground conditions. (orig./HP)

Indoor and soil radon measurements in the Hyblean Foreland (South-East Sicily

Directory of Open Access Journals (Sweden)

G. Alessandro

2007-06-01

Full Text Available Indoor radon behavior in two sites of SE Sicily was studied as a function of the soil radon concentration. The chosen locations were Ragusa and Modica towns, placed in the Hyblean Plateau (northern margin of the African Plate. Soil samples were analysed by gamma spectrometry to determine the amount of radionuclides. Indoor air and soil gas radon measurements were simultaneously performed in both sites using active detectors. Radon in soil was measured one meter deep. A positive correlation was obtained between indoor radon concentration and the soil gas concentration.

Comparative measurements of soil gas radon concentration using thermoluminescent and track detectors

Czech Academy of Sciences Publication Activity Database

Turek, Karel; Gelev, M.; Dimov, I.

2004-01-01

Roč. 38, spec. iss. (2004), s. 843-846 ISSN 1350-4487 Institutional research plan: CEZ:AV0Z1048901 Keywords : soil gas * radon concentration * thermoluminescent detectors Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.664, year: 2004

Variations of soil radon and thoron concentrations in a fault zone and prospective earthquakes in SW Taiwan

International Nuclear Information System (INIS)

Yang, T.F.; Walia, V.; Chyi, L.L.; Fu, C.C.; Chen, C.-H.; Liu, T.K.; Song, S.R.; Lee, C.Y.; Lee, M.

2005-01-01

An automatic station for soil gas monitoring was set up on an active fault zone of SW Taiwan. After more than one year of continuous measurements, some spike-like anomalous high radon and thoron concentrations could be observed. A similar soil radon spectrum was also obtained from an independent monitoring station, which was only 100m away. These anomalous peaks usually occurred a few days or weeks before the earthquakes (M L >=4.5). This indicates that variations of both soil radon and thoron can serve as useful tools for earthquake surveillance, esp. at fault zones

Soil radon monitoring in the NE flank of Mt. Etna (Sicily)

International Nuclear Information System (INIS)

Imme, G.; La Delfa, S.; Lo Nigro, S.; Morelli, D.; Patane, G.

2006-01-01

Soil radon has been monitored at a fixed location on the northeastern flank of Mt. Etna, a high-risk volcano in Sicily. The aim of this study was to evaluate the effects of the recent volcanic activity on soil radon concentration. Continuous radon measurements have been performed since July 2001. While comparison between the trend in in-soil radon concentration and the acquired meteorological series (temperature, humidity and pressure) appear to confirm a general seasonal correlation, nevertheless particular anomalies suggest a possible dependence of the radon concentration on volcanic dynamics

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

International Nuclear Information System (INIS)

Tanner, A.B.

1991-01-01

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

Influence of moisture content on radon diffusion in soil

International Nuclear Information System (INIS)

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

1990-01-01

Radon diffusion from soil has been studied as a function of the moisture content of the soil. A few simple experiments showed that up to a certain moisture content the radon diffusion increased with increasing moisture. A sharp rise in radon concentration occurred as the moisture was increased from the completely dry state to 13% water by weight. The radon flux was measured for columns of dry, moist and water saturated soil. The highest flux came from the column filled with moist soil. Water saturated soil gave the lowest flux because of the much lower diffusion coefficient of radon through water. (author)

Uranium-238 and thorium-232 series concentrations in soil, radon-222 indoor and drinking water concentrations and dose assessment in the city of Alameda, Chihuahua, Mexico

Energy Technology Data Exchange (ETDEWEB)

Colmenero Sujo, L.; Montero Cabrera, M.E. E-mail: elena.montero@cimav.edu.mx; Villalba, L.; Renteria Villalobos, M.; Torres Moye, E.; Garcia Leon, M.; Garcia-Tenorio, R.; Mireles Garcia, F.; Herrera Peraza, E.F.; Sanchez Aroche, D

2004-07-01

High-resolution gamma spectrometry was used to determine the concentration of {sup 40}K, {sup 238}U and {sup 232}Th series in soil samples taken from areas surrounding the city of Aldama, in Chihuahua. Results of indoor air short-time sampling, with diffusion barrier charcoal detectors, revealed relatively high indoor radon levels, ranging from 29 to 422 Bq/m{sup 3}; the radon concentrations detected exceeded 148 Bq/m{sup 3} in 76% of the homes tested. Additionally, liquid scintillation counting showed concentrations of radon in drinking water ranging from 4.3 to 42 kBq/m{sup 3}. The high activity of {sup 238}U in soil found in some places may be a result of the uranium milling process performed 20 years ago in the area. High radon concentrations indoor and in water may be explained by assuming the presence of uranium-bearing rocks underneath of the city, similar to a felsic dike located near Aldama. The estimated annual effective dose of gamma radiation from the soil and radon inhalation was 3.83 mSv.

Uranium-238 and thorium-232 series concentrations in soil, radon-222 indoor and drinking water concentrations and dose assessment in the city of Aldama, Chihuahua, Mexico.

Science.gov (United States)

Colmenero Sujo, L; Montero Cabrera, M E; Villalba, L; Rentería Villalobos, M; Torres Moye, E; García León, M; García-Tenorio, R; Mireles García, F; Herrera Peraza, E F; Sánchez Aroche, D

2004-01-01

High-resolution gamma spectrometry was used to determine the concentration of 40K, 238U and 232Th series in soil samples taken from areas surrounding the city of Aldama, in Chihuahua. Results of indoor air short-time sampling, with diffusion barrier charcoal detectors, revealed relatively high indoor radon levels, ranging from 29 to 422 Bq/m3; the radon concentrations detected exceeded 148 Bq/m3 in 76% of the homes tested. Additionally, liquid scintillation counting showed concentrations of radon in drinking water ranging from 4.3 to 42 kBq/m3. The high activity of 238U in soil found in some places may be a result of the uranium milling process performed 20 years ago in the area. High radon concentrations indoor and in water may be explained by assuming the presence of uranium-bearing rocks underneath of the city, similar to a felsic dike located near Aldama. The estimated annual effective dose of gamma radiation from the soil and radon inhalation was 3.83 mSv.

Estimation of radon emanation coefficient for soil and flyash

International Nuclear Information System (INIS)

Sahu, S.K.; Swarnkar, M.; Ajmal, P.Y.; Pandit, G.G.; Puranik, V.D.

2012-01-01

Since terrestrial materials include radium ( 226 Ra) originating from the decay of uranium ( 238 U), all such materials release radon ( 222 Rn) to varying degrees. When a radium atom decays to radon, the energy generated is strong enough to send the radon atom a distance of about 40 nanometers-this is known as alpha recoil. For a radon atom to escape the radium atom must be within the recoil distance from the grain surface of flyash or soil and the direction of recoil must send the radon atom toward the outside of the grain. Therefore, all of the radon atoms generated by the radium contained in flyash or soil grain are actually not released into pore spaces and mobilized. The fraction of radon atoms generated from radium decay that are released from into flyash or soil pore space is defined as the radon emanation coefficient or emanating power, of the material. Grain size and shape are two of the important factors that control the radon emanation coefficient because they determine in part how much uranium and radium is near enough to the surface of the grain to allow the newly-formed radon to escape into a pore space. In a porous medium, where the radon is in radioactive equilibrium with its parent radium, the emanation coefficient is given by the expression: where C 0 is the undiluted radon activity concentration in the pores of the medium, and C Ra is the radium activity concentration of the sample. The 226 Ra activity concentration of the flyash and soil sample were determined by using the g-spectrometry. C 0 was determined by the can experiment using LR-115 for flyash and soil samples. The C 0 values for flyash and soil samples were found to be 245.7 Bq/m 3 and 714.3 Bq/m 3 respectively. The radon emanation coefficient for flyash was found to be 0.0024 while that for soil was 0.0092. Therefore the soil sample was found to be four times higher radon emanation coefficient than flyash which is in line with the results reported in the literatures. This may suggest

Study on the influence factors about the soil radon measurement

International Nuclear Information System (INIS)

Wu Zixiang; Liu Yanbin; Jia Yuxin; Mai Weiji; Liu Xiaolian; Yang Yuhua

2006-01-01

Objective: To explore relevant factors about the soil radon measurement and provide gist of formulating correct measure method by studying the way of the soil radon measurement. Methods: Deflation-ionization room standard is adopted. Results: The concentration of soil radon becomes higher with the sample's volume added, it also augmented with the measure depth increased in certain degree; The concentration of soil radon changes little when sample's depth is above 60 cm; The time of deflation has no obvious influence on the concentration of soil radon, but microwave show serious effect on it; The results will be lowered when the desiccant is humidified, raining has the same affection on it; Plant has some impact on it. Conclusion: The measured results will be affected by microwave, oscillate and plant. Sample's volume and depth, soil's humidity can influence it too. The result's veracity can be guaranteed by choosing appropriate sample and measure condition. (authors)

Characterization of radon entry rates and indoor concentrations in underground structures

International Nuclear Information System (INIS)

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

1992-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-01-15

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

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Radon in Soil and Tap Water in Lika-Senj County

International Nuclear Information System (INIS)

Krpan, I.; Miklavcic, I.; Muzevic, I.; Poje, M.; Radolic, V.; Stanic, D.; Vukovic, B.; Petrinec, B.

2013-01-01

Radon concentration in soil and water in settlements of Lika-Senj County was measured in September 2012 with the Alpha GUARD measuring system. The measured values of radon concentrations in soil at 19 locations were in range from 12.6 (Novalja) to 258.7 kBq/m 3 (Plitvièka Jezera) with the mean of 83.5 kBq/m 3 and standard deviation of 69.3 kBq/m 3 . The obtained average value puts the soil of Lika-Senj County, and according to the used soil classification, into soil of medium geogenic radon potential. It is important to emphasize that radon concentration exceeds the value of 100 kBq m -3 in one third of the measured locations which classifies those areas into areas with high geogenic radon potential. Other radionuclides in soil (40K, 137Cs, 226Ra, 238U, 232Th) were also measured and their values were commented and correlated with the values of radon and thoron. Radon concentrations in the municipal water supply systems of Lika-Senj County were in range from 0.2 Bq/l (Otocac) to 11.2 Bq/l (Gospiæ). The highest value was ten times lower than the usual reference level of 100 Bq/l. The estimated maximum annual radon dose, for children, received by drinking water (75 liters per year) from the municipal water supply Gospiæ is 2.9 μSv.(author)

The correlations between Radon in soil gas and its exhalation and concentration in air in the southern part of Syria

International Nuclear Information System (INIS)

Shweikani, R.; Hushari, M.

2005-01-01

The aim of this work is to measure the concentration of the radon ( 222 Rn) in soil air, 222 Rn exhalation from soil and 222 Rn in outdoor air which may have great influence on 222 Rn levels in houses. 222 Ra activity concentrations were also determined in soil samples. The studied areas are located in southern part of Syria. The common bed rock of this area is black and massive granite which are poor in uranium content [Jubeli Y.M., 1990. Uranium exploration in Syria. Internal Technical Report, vol. 1 (in English), vol. 2 (in Arabic), SAEC, Damascus; Technoexport (USSR), 1966. In: Ponikarov (Ed.), The Geological Map of Syria Scale: 1:200.000, Ministry of Industry, Damascus, Syria]. Results showed that the maximum measurement in all areas was 32500Bqm -3 in soil air with an exhalation rate of 9Bqm -2 s -1 in Darra region and 66.43Bqm -3 of radon in open air, with 77Bqkg -1 of radium content in soil (Damascus suburb). In addition, correlations between Rn in soil and exhalation of Radon from soil and radon in houses were found in some areas (Sweda and Darra), while, no correlations were found in other studied areas. Moreover, no correlation between radon in houses and radon measurements in soil and in outdoors were found. This was attributed to the methodology used and the influence of building design and inhabitants behavior

Comparative Measurements of Radon Concentration in Soil Using Passive and Active Methods in High Level Natural Radiation Area (HLNRA of Ramsar

Directory of Open Access Journals (Sweden)

Amanat B

2013-12-01

Full Text Available Background: Radon and its daughters are amongst the most important sources of natural exposure in the world. Soil is one of the signifcant sources of radon/thoron due to both radium and thorium so that the emanated thoron from it may cause in creased uncertainties in radon measurements. Recently, a diffusion chamber has been designed and optimized for passive discriminative measurements of radon/thoron concentrations in soil. Objective: In order to evaluate the capability of the passive method, some com parative measurements (with active methods have been performed. Method: The method is based upon measurements by a diffusion chamber, includ ing two Lexan polycarbonate SSNTDs, which can discriminate the emanated radon/ thorn from the soil by delay method. The comparative measurements have been done in ten selected points of HLNRA of Ramsar in Iran. The linear regression and cor relation between the results of two methods have been studied. Results: The results show that the radon concentrations are within the range of 12.1 to 165 kBq/m3 values. The correlation between the results of active and passive methods was measured by 0.99 value. As well, the thoron concentrations have been measured between 1.9 to 29.5 kBq/m3 values at the points. Conclusion: The sensitivity as well as the strong correlation with active mea surements shows that the new low-cost passive method is appropriate for accurate seasonal measurements of radon and thoron concentration in soil.

Radon in soil gas survey in Curitiba (Brazil)

International Nuclear Information System (INIS)

Paschuk, Sergei A.; Correa, Janine Nicolosi; Schelin, Hugo R.; Barbosa, Laercio; Sadula, Tatyana; Matsuzaki, Cristiana A.

2009-01-01

This work describes the radon in soil gas measurements performed during the last two years in cooperation between the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR), the Nuclear Technology Development Center (CDTN) and the Institute of Radiation Protection and Dosimetry (IRD) from the Brazilian Nuclear Energy Commission (CNEN). Following previously concluded measurements of radon concentration in dwellings and the measurements of 222 Rn activity in drinking water collected at artesian bores of Curitiba urban area, present step of activities has been dedicated to measurements of radon concentration in soil gas. Experimental setup was based on the Professional Radon Monitor (ALPHA GUARD) connected to specially developed for such measurements Soil Gas Probe through the air pump and filter system. After the Probe was inserted, the ground has been tamped down around the probe, to prevent air from moving vertically along the outside of the shaft. The equipment was adjusted with air flow of 0.03 L/min and the measurements were performed during 90 min approximately. The 222 Rn concentration levels were detected and analyzed by the computer every 5 minutes using the software DataEXPERT by GENITRON Instruments. Collected average levels of 222 Rn concentration were processed taking into account the internal volume of Soil Probe and connection vessels. Radon sampling was performed at a depth of 50 - 70 cm. Obtained experimental data of radon concentration present rather big variation but correlates perfectly with previously obtained results for 222 Rn activity in drinking water. Further measurements are planned to be performed at other regions of Parana State and will involve the mineral analysis of soil samples. (author)''

Emission of soil gas radon concentration around main central thrust in Ukhimath (Rudraprayag) region of Garhwal Himalaya

International Nuclear Information System (INIS)

Aswal, Sunita; Kandari, Tushar; Bourai, A.A.; Ramola, R.C.; Sahoo, B.K.

2016-01-01

In this paper, the result of systematic measurement of the soil gas radon concentrations is discussed and the background values are defined along and around the Main Central Thrust (MCT) in Ukhimath region of Garhwal Himalaya, India. The Ukhimath region is being subjected to intense neotectonic activities like earthquake and landslide. For the systematic study, the measurement has been done in grid pattern form along and across the MCT. The soil gas radon concentrations were measured using RAD7 with appropriate accessories and followed proper protocol proposed by the manufacturer. The soil gas concentration was measured at different depths 10, 30 and 50 cm with a wide range of different points from the MCT. At 10 cm depth, the soil gas radon concentration was found to vary from 125 to 800 Bq m -3 with an average of 433 Bq m -3 ; at 30 cm, it was found to vary from 203 to 32 500 Bq m -3 with an average of 2387 Bq m -3 ; and at 50 cm, it was found to vary from 1330 to 46 000 Bq m -3 with an average of 15 357 Bq m -3 . The data analysis clearly reveals anomalous values along the fault. (authors)

The use of soil gas as radon source in radon chambers

International Nuclear Information System (INIS)

Al-Azmi, Darwish

2009-01-01

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

Radon-in-soil concentration levels in Mexico

International Nuclear Information System (INIS)

Segovia, N.; Tamez, E.; Mena, M.

1992-01-01

Radon-in-soil surveys in Mexico have been carried out since 1974 both for uranium prospecting and to correlate mean values of the gas emanation with local telluric behaviour. The mapping covers the northern uranium mining region, the Mexican Neovolcanic Belt, the coastal areas adjacent to the zone of subduction of the Cocos Plate under the North American Plate, some of the active volcanoes of Southern Mexico and several sedimentary valleys in Central Mexico. Recording of 222 Rn alpha decay is systematically performed with LR115 track detectors. Using mean values averaged over different observation periods at fixed monitoring stations, a radon-in-soil map covering one third of the territory of Mexico is presented. The lowest mean values occur in areas associated with active volcanoes. The highest levels are found in uranium ore zones. Intermediate values are obtained in regions with enhanced hydrothermal activity and stations associated with intrusive rocks. (author)

Radon in soil concentration levels in Mexico

International Nuclear Information System (INIS)

Segovia, N.; Tamez, E.; Mena, M.

1991-09-01

Radon in soil surveys in Mexico have been carried out since 1974 both for uranium prospectus and to correlate mean values of the gas emanation with local telluric behaviour. The mapping includes the northern uranium mining region, the Mexican Neo volcanic Belt, the coastal areas adjacent to the zone of subduction of the Cocos Plate under the North American Plate, some of the active volcanoes of Southern Mexico and several sedimentary valleys in Central Mexico. Recording of 222 Rn alpha decay is systematically performed with LR115 track detectors. Using mean values averaged over different observation periods at fixed monitoring stations, a radon in soil map covering one third of the Mexican territory is presented. The lowest mean values have been found in areas associated with active volcanoes. The highest levels are found in uranium ore zones. Intermediate values are obtained in regions with enhanced hydrothermal activity and stations associated with intrusive rocks. (Author)

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

International Nuclear Information System (INIS)

Iida, Takao

2000-03-01

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

Mitigation of houses with extremely high indoor radon concentrations

International Nuclear Information System (INIS)

Jiranek, M.; Neznal, M.

2006-01-01

Full text of publication follows: The paper reports on the experience of the Czech Technical University in dealing with mitigation of houses in which unusually high indoor radon concentrations were found. The whole process of remediation is illustrated by example of an old single-family house that was built in the area formed by highly permeable soils with high radon content in the soil air. T he house has a small cellar located under 1/5 of the ground floor area. Two types of floors, i.e. timber floors and cracked concrete slabs were found in the house. As a result of extremely high radon concentration in the sub-floor region (up to 600 kBq/m 3 ) and leaky structures in contact with soil, radon concentrations around 100 kBq/m 3 in the cellar and up to 60 kBq/m 3 in the living rooms on the ground floor were measured prior to mitigation. Mitigation measures that were carried out in the house consist of reconstruction of timber floors and installation of active soil depressurization. Timber floors were replaced with concrete slab fitted with damp proof membrane, thermal insulation and floor covering. The soil depressurization system was made up of two sections. The first section is composed of the network of perforated pipes inserted in the drainage layer placed under the new floors and four perforated tubes drilled under the existing floors. The soil air from this section is extracted by means of a roof fan installed at the top of the vertical exhaust pipe running inside the living space and terminating above the roof. The second section was designed to withdraw by means of a small fan radon-laden air from the filling in the floor above the cellar and from perforated tubes drilled into the sub-floor region under the rooms adjacent to the cellar. It serves also for the active ventilation of the cellar. Pressure, temperature and radon concentration sensors were installed into the drainage layer during the reconstruction of floors to record variations in these

EMISSION OF SOIL GAS RADON CONCENTRATION AROUND MAIN CENTRAL THRUST IN UKHIMATH (RUDRAPRAYAG) REGION OF GARHWAL HIMALAYA.

Science.gov (United States)

Aswal, Sunita; Kandari, Tushar; Sahoo, B K; Bourai, A A; Ramola, R C

2016-10-01

In this paper, the result of systematic measurement of the soil gas radon concentrations is discussed and the background values are defined along and around the Main Central Thrust (MCT) in Ukhimath region of Garhwal Himalaya, India. The Ukhimath region is being subjected to intense neotectonic activities like earthquake and landslide. For the systematic study, the measurement has been done in grid pattern form along and across the MCT. The soil gas radon concentrations were measured using RAD7 with appropriate accessories and followed proper protocol proposed by the manufacturer. The soil gas concentration was measured at different depths 10, 30 and 50 cm with a wide range of different points from the MCT. At 10 cm depth, the soil gas radon concentration was found to vary from 125 to 800 Bq m -3 with an average of 433 Bq m -3 ; at 30 cm, it was found to vary from 203 to 32 500 Bq m -3 with an average of 2387 Bq m -3 ; and at 50 cm, it was found to vary from 1330 to 46 000 Bq m -3 with an average of 15 357 Bq m -3 The data analysis clearly reveals anomalous values along the fault. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Continuous measurements of soil radon under regular field conditions

International Nuclear Information System (INIS)

Font, LL

1999-01-01

Continuous soil radon measurements were performed in the frame of an European Community-radon network using the Clipperton II detector. It has been found that in some periods, soil radon levels obtained with one Clipperton II probe are very different from those obtained with another probe placed at the same depth but a short distance apart. It has been also found that the response of the probes to a sudden change of radon concentration is controlled by the diffusion process along the bottom tube of the probe. Therefore, this study shows that the experimental data can be attributed to the natural behaviour of soil radon

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

Science.gov (United States)

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

2011-03-01

Least squares (LS), Theil's (TS) and weighted total least squares (WTLS) regression analysis methods are used to develop empirical relationships between radium in the ground, radon in soil and radon in dwellings to assist in the post-closure assessment of indoor radon related to near-surface radioactive waste disposal at the Low Level Waste Repository in England. The data sets used are (i) estimated ²²⁶Ra in the < 2 mm fraction of topsoils (eRa226) derived from equivalent uranium (eU) from airborne gamma spectrometry data, (ii) eRa226 derived from measurements of uranium in soil geochemical samples, (iii) soil gas radon and (iv) indoor radon data. For models comparing indoor radon and (i) eRa226 derived from airborne eU data and (ii) soil gas radon data, some of the geological groupings have significant slopes. For these groupings there is reasonable agreement in slope and intercept between the three regression analysis methods (LS, TS and WTLS). Relationships between radon in dwellings and radium in the ground or radon in soil differ depending on the characteristics of the underlying geological units, with more permeable units having steeper slopes and higher indoor radon concentrations for a given radium or soil gas radon concentration in the ground. The regression models comparing indoor radon with soil gas radon have intercepts close to 5 Bq m⁻³ whilst the intercepts for those comparing indoor radon with eRa226 from airborne eU vary from about 20 Bq m⁻³ for a moderately permeable geological unit to about 40 Bq m⁻³ for highly permeable limestone, implying unrealistically high contributions to indoor radon from sources other than the ground. An intercept value of 5 Bq m⁻³ is assumed as an appropriate mean value for the UK for sources of indoor radon other than radon from the ground, based on examination of UK data. Comparison with published data used to derive an average indoor radon: soil ²²⁶Ra ratio shows that whereas the published data are

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)

Correlations of soil-gas and indoor radon with geology in glacially derived soils of the northern Great Plains

International Nuclear Information System (INIS)

Schumann, R.R.; Owen, D.E.; Peake, R.T.; Schmidt, K.M.

1990-01-01

This paper reports that a higher percentage of homes in parts of the northern Great Plains underlain by soils derived from continental glacial deposits have elevated indoor radon levels (greater than 4 pCi/L) than any other area in the country. Soil-gas radon concentrations, surface radioactivity, indoor radon levels, and soil characteristics were studied in areas underlain by glacially-derived soils in North Dakota and Minnesota to examine the factors responsible for these elevated levels. Clay-rich till soils in North Dakota have generally higher soil-gas radon levels, and correspondingly higher indoor radon levels, than the sandy till soils common to west-central Minnesota. Although the proportions of homes with indoor radon levels greater than 4 pCi/L are similar in both areas, relatively few homes underlain by sandy tills have screening indoor radon levels greater than 20 pCi/L, whereas a relatively large proportion of homes underlain by clayey tills have screening indoor radon levels exceeding 20 pCi/L. The higher radon levels in North Dakota are likely due to enhanced emanation from the smaller grains and to relatively higher soil radium concentrations in the clay-rich soils, whereas the generally higher permeability of the sandy till soils in Minnesota allows soil gas to be drawn into structures from a larger source volume, increasing indoor radon levels in these areas

Statistical uncertainty analysis of radon transport in nonisothermal, unsaturated soils

International Nuclear Information System (INIS)

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

1990-10-01

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

Evidence of soil radon as tracer of magma uprising in Mt. Etna

International Nuclear Information System (INIS)

Morelli, D.; Martino, S. Di; Imme, G.; La Delfa, S.; Lo Nigro, S.; Patane, G.

2006-01-01

Soil radon has been monitored at one fixed site located in the northeastern flank of Mt. Etna, high-risk volcano in Sicily. The aim of this study was the evaluation of a possible link between magma uprising and soil radon concentration. Continuous radon measurements were performed since July 2001. Comparison between the in-soil radon trend and the acquired meteorological series (Temperature, Humidity and Pressure) seems to confirm a general seasonal correlation; nevertheless some anomalies suggest a possible dependence of the radon concentration on volcanic dynamics, as confirmed by the volcanic tremor and strain-release analysis

Entry of soil gas and radon into houses

International Nuclear Information System (INIS)

Andersen, C.E.

1992-04-01

Entry of soil gas and radon into houses has been investigated by experiments conducted at radon test structures and numerical or analytical modelling. The numerical model solves the steady-state equations for Darcy flow of soil-gas and combined diffusive and advective transport of radon. Model calculations were compared with results from field experiments conducted at Risoe National Laboratory, and it was found that there was good agreement between measured and modelled pressure coupling and radon concentration profiles. Discrepancies regarding absolute values of soil-gas entry rates and radon concentrations were observed. The numerical model has been used to study the importance of soil and building related factors on radon entry rates into slab-on-grade houses. It was found that, for a house with a 3 mm perimeter crack along the floor-wall joint, the entry was mainly determined by the soil permeability and building related factors such as house depressurization and presence of a capillary breaking layer of gravel below the slab. In a house with a bare soil floor, the diffusivity of the soil was found to be of principal importance for the entry rate even for moderate permeabilities. An analytical model was developed for the purpose of studying soil-gas entry rates into houses in response to non-static driving forces. It is based on the analogy between a 'buried drain' and a basement house with a perimeter crack. The structure was depressurized sinusoidally in time and the frequency dependent pressure couplings were measured. There was fairly good agreement between theoretical and experimental results. (LN) (26 tabs., 30 ills., 66 refs.)

Temporal variations of radon concentration in the saturated soil of Alpine grassland: The role of groundwater flow

International Nuclear Information System (INIS)

Perrier, Frederic; Richon, Patrick; Sabroux, Jean-Christophe

2009-01-01

Radon concentration has been monitored from 1995 to 1999 in the soil of the Sur-Fretes ridge (French Alps), covered with snow from November to April. Measurements were performed at 70 cm depth, with a sampling time of 1 h, at two points: the summit of the ridge, at an altitude of 1792 m, and the bottom of the ridge, at an altitude of 1590 m. On the summit, radon concentration shows a moderate seasonal variation, with a high value from October to April (winter), and a low value from May to September (summer). At the bottom of the ridge, a large and opposite seasonal variation is observed, with a low value in winter and a high value in summer. Fluctuations of the radon concentration seem to be associated with temperature variations, an effect which is largely delusory. Indeed, these variations are actually due to water infiltration. A simplified mixing model is used to show that, at the summit of the ridge, two effects compete in the radon response: a slow infiltration response, rich in radon, with a typical time scale of days, and a fast infiltration of radon-poor rainwater. At the bottom of the ridge, similarly, two groundwater contributions compete: one slow infiltration response, similar to the response seen at the summit, and an additional slower response, with a typical time scale of about a month. This second slower response can be interpreted as the aquifer discharge in response to snow melt. This study shows that, while caution is necessary to properly interpret the various effects, the temporal variations of the radon concentration in soil can be understood reasonably well, and appear to be a sensitive tool to study the subtle interplay of near surface transfer processes of groundwater with different transit times

Temporal variations of radon concentration in the saturated soil of Alpine grassland: the role of groundwater flow.

Science.gov (United States)

Perrier, Frédéric; Richon, Patrick; Sabroux, Jean-Christophe

2009-03-15

Radon concentration has been monitored from 1995 to 1999 in the soil of the Sur-Frêtes ridge (French Alps), covered with snow from November to April. Measurements were performed at 70 cm depth, with a sampling time of 1 h, at two points: the summit of the ridge, at an altitude of 1792 m, and the bottom of the ridge, at an altitude of 1590 m. On the summit, radon concentration shows a moderate seasonal variation, with a high value from October to April (winter), and a low value from May to September (summer). At the bottom of the ridge, a large and opposite seasonal variation is observed, with a low value in winter and a high value in summer. Fluctuations of the radon concentration seem to be associated with temperature variations, an effect which is largely delusory. Indeed, these variations are actually due to water infiltration. A simplified mixing model is used to show that, at the summit of the ridge, two effects compete in the radon response: a slow infiltration response, rich in radon, with a typical time scale of days, and a fast infiltration of radon-poor rainwater. At the bottom of the ridge, similarly, two groundwater contributions compete: one slow infiltration response, similar to the response seen at the summit, and an additional slower response, with a typical time scale of about a month. This second slower response can be interpreted as the aquifer discharge in response to snow melt. This study shows that, while caution is necessary to properly interpret the various effects, the temporal variations of the radon concentration in soil can be understood reasonably well, and appear to be a sensitive tool to study the subtle interplay of near surface transfer processes of groundwater with different transit times.

Determination of radon in soil and water in parts of Accra, and generation of preliminary radon map for Ghana

International Nuclear Information System (INIS)

Osei, Peter

2016-07-01

The research was focused on determining the radon levels in soil and water in parts of Accra, generate a preliminary radon map for Ghana and estimate a pilot reference level for the country, using the data obtained from this research and collated data from other researchers. The radon gas measurement was done with the passive method, using the SSNTDs which are sensitive to alpha particles emitted by radon. Cellulose nitrate LR – 115 type II alpha particle detectors were used. The detectors were chemically etched in a 2.5 M NaOH solution at a temperature of 60 °C for 90 minutes, after two weeks and two months of exposure to soil and water respectively. The images of the etched detectors were acquired by means of a scanner and then tracks counted with ImageJ software. Inverse Distance Weighing (IDW) method of ArcGIS 10.2 was used to spatially distribute the radon concentration on a map. The average soil radon concentration in the study area ranges from 0.191 kBqm"-"3 to 3.416 kBqm"-"3 with a mean of 1.193 kBqm"-"3. The radon concentration in water from the study area ranges from 0.00346 BqL"-"1 to 0.00538 BqL"-"1 with an average of 0.00456 BqL"-"1. A strong negative correlation has been established between radon in soil and water in the study area. The preliminary national average indoor, water and soil radon concentrations are 137 Bqm"-"3, 361.93 Bqm"-"3 and 3716.74 Bqm"-"3 respectively. The average levels of water and indoor radon exceeded WHO’s reference level of 100 Bqm"-"3. Accordingly, the pilot national indoor radon reference level for Ghana is set as 200 Bqm"-"3. (au)

Radon remediation of a two-storey UK dwelling by active sub-slab depressurization: observations on hourly Radon concentration variations

International Nuclear Information System (INIS)

Denman, A.R.

2008-01-01

Radon concentration levels in a two-storey detached single-family dwelling in Northamptonshire, UK, were monitored at hourly intervals throughout a 5-week period during which sub-slab depressurization remediation measures, including an active sump system, were installed. Remediation of the property was accomplished successfully, with the mean radon levels upstairs and downstairs greatly reduced and the prominent diurnal variability in radon levels present prior to remediation almost completely removed. Following remediation, upstairs and downstairs radon concentrations were 32% and 16% of their pre-remediation values respectively. The mean downstairs radon concentration was lower than that upstairs, with pre-and post-remediation values of the upstairs/downstairs concentration ratio, R U/D , of 0.93 and 1.76 respectively. Cross-correlation between upstairs and downstairs radon concentration time-series indicates a time-lag of the order of 1 hour or less, suggesting that diffusion of soil-derived radon from downstairs to upstairs either occurs within that time frame or forms a relatively insignificant contribution to the upstairs radon level. Cross-correlation between radon concentration time-series and the corresponding time-series for local atmospheric parameters demonstrated correlation between radon concentrations and internal/external pressure-difference prior to remediation. This correlation disappears following remediation, confirming the effectiveness of the remediation procedure in mitigating radon ingress from the ground via the stack-effect. Overall, these observations provide further evidence that radon emanation from building materials makes a not insignificant contribution to radon concentration levels within the building. Furthermore, since this component remains essentially unaffected by sub-slab depressurization, its proportional contribution to the total radon levels in the home increases following remediation, leading to the conclusion that where

High indoor radon concentrations in some Swedish waterworks

International Nuclear Information System (INIS)

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

2002-01-01

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

Radon concentration in dwellings of Lanzarote (Canary Islands)

Energy Technology Data Exchange (ETDEWEB)

Pinza, C.; Armas, J.H. [La Laguna Univ., Tenerife (Spain). Faculty of Medicine; Poffijn, A. [Ghent Rijksuniversiteit (Belgium). Lab. voor Kernfysica

1997-07-01

A total of 126 radon passive dosemeters were distributed in 63 dwellings on the island of Lanzarote (Canary Islands) to measure the indoor radon concentration in the period April-June 1994. The mean overall indoor concentration was 50 Bq.m{sup -3} with a standard deviation of 17 Bq.m{sup -3}. Applying the conversion factor for the effective dose, recommended by ICRP 65, this results in a mean effective dose of 0.75 mSv.y{sup -1}. The mean radon concentration in single-family houses proves to be higher at the ground floor than in upper levels. The mean radon concentration obtained in bedrooms is higher than in living-rooms, independently of the floor they are located at. Statistically significant differences in the mean radon concentration have been found depending on the soil permeability (P = 0.001) and building materials used (P 0.0006). (author).

Radon concentration in dwellings of Lanzarote (Canary Islands)

International Nuclear Information System (INIS)

Pinza, C.; Armas, J.H.; Poffijn, A.

1997-01-01

A total of 126 radon passive dosemeters were distributed in 63 dwellings on the island of Lanzarote (Canary Islands) to measure the indoor radon concentration in the period April-June 1994. The mean overall indoor concentration was 50 Bq.m -3 with a standard deviation of 17 Bq.m -3 . Applying the conversion factor for the effective dose, recommended by ICRP 65, this results in a mean effective dose of 0.75 mSv.y -1 . The mean radon concentration in single-family houses proves to be higher at the ground floor than in upper levels. The mean radon concentration obtained in bedrooms is higher than in living-rooms, independently of the floor they are located at. Statistically significant differences in the mean radon concentration have been found depending on the soil permeability (P = 0.001) and building materials used (P 0.0006). (author)

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

Analysis of the average daily radon variations in the soil air

International Nuclear Information System (INIS)

Holy, K.; Matos, M.; Boehm, R.; Stanys, T.; Polaskova, A.; Hola, O.

1998-01-01

In this contribution the search of the relation between the daily variations of the radon concentration and the regular daily oscillations of the atmospheric pressure are presented. The deviation of the radon activity concentration in the soil air from the average daily value reaches only a few percent. For the dry summer months the average daily course of the radon activity concentration can be described by the obtained equation. The analysis of the average daily courses could give the information concerning the depth of the gas permeable soil layer. The soil parameter is determined by others method with difficulty

Radon in soil gas

International Nuclear Information System (INIS)

Rector, H.E.

1990-01-01

This paper presents the results of a technology review conducted to identify and organize the range of options for measuring radon in soil gas as a means to evaluate radon exposure potential in buildings. The main focus of the review includes identifying the following: Measurement of objectives - the specific parameter(s) that each technology is designed to measure( e.g., soil gas concentration, flux density, etc.); Equipment needs -commercial availability of systems and/or components, specifications for fabricated components; Procedural information - documented elements of field and laboratory methodology and quality assurance; Underlying assumptions - conceptual and mathematical models utilized to convert analytical outcomes to estimators of radon. Basic technologies and field data were examined from a generic perspective (e.g., the common denominators of passive detectors, hollow sampling probes, flux monitors)( as well as specific configurations developed by individual investigators (e.g., sample volume, depth) to develop the basis for separating analytical uncertainties form sampling uncertainties

Prediction of indoor radon concentration based on residence location and construction

International Nuclear Information System (INIS)

Maekelaeinen, I.; Voutilainen, A.; Castren, O.

1992-01-01

We have constructed a model for assessing indoor radon concentrations in houses where measurements cannot be performed. It has been used in an epidemiological study and to determine the radon potential of new building sites. The model is based on data from about 10,000 buildings. Integrated radon measurements were made during the cold season in all the houses; their geographic coordinates were also known. The 2-mo measurement results were corrected to annual average concentrations. Construction data were collected from questionnaires completed by residents; geological data were determined from geological maps. Data were classified according to geographical, geological, and construction factors. In order to describe different radon production levels, the country was divided into four zones. We assumed that the factors were multiplicative, and a linear concentration-prediction model was used. The most significant factor in determining radon concentration was the geographical region, followed by soil type, year of construction, and type of foundation. The predicted indoor radon concentrations given by the model varied from 50 to 440 Bq m -3 . The lower figure represents a house with a basement, built in the 1950s on clay soil, in the region with the lowest radon concentration levels. The higher value represents a house with a concrete slab in contact with the ground, built in the 1980s, on gravel, in the region with the highest average radon concentration

Survey of radon concentrations in three Italian towns

International Nuclear Information System (INIS)

Malanca, A.; Pessina, V.; Dallara, G.

1992-01-01

Radon-222 was measured in 187 dwellings in Parma, Reggio Emilia, and Orvieto. Samples were collected using activated carbon canisters, placed in basements and on the upper floors for at least 48 h in the period starting from January 1989 to July 1990. Gamma spectroscopy was used for the measurement of 222 Rn and its progeny. The data for the three towns show a lognormal distribution. Owing to the high radium concentration in building materials and underlying soil, high radon concentrations were observed in Orvieto's dwellings. Additional measurements carried out in 22 public schools of Parma and Reggio Emilia showed moderate radon concentrations, while significant radon levels were recorded in 37 castles and ancient buildings in Parma and Reggio Emilia provinces

Radon concentration of waters in Greece and Cyprus

Science.gov (United States)

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

2009-04-01

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

Origin of radon concentration of Csalóka Spring in the Sopron Mountains (West Hungary)

International Nuclear Information System (INIS)

Freiler, Ágnes; Horváth, Ákos; Török, Kálmán; Földes, Tamás

2016-01-01

We examined the Csalóka Spring, which has the highest radon concentration in the Sopron Mountains (West Hungary) (, yearly average of 227 ± 10 Bq L"−"1). The main rock types here are gneiss and micaschist, formed from metamorphism of former granitic and clastic sedimentary rocks respectively. The aim of the study was to find a likely source of the high radon concentration in water. During two periods (2007–2008 and 2012–2013) water samples were taken from the Csalóka Spring to measure its radon concentration (from 153 ± 9 Bq L"−"1 to 291 ± 15 Bq L"−"1). Soil and rock samples were taken within a 10-m radius of the spring from debrish and from a deformed gneiss outcrop 500 m away from the spring. The radium activity concentration of the samples (between 24.3 ± 2.9 Bq kg"−"1 and 145 ± 6.0 Bq kg"−"1) was measured by gamma-spectroscopy, and the specific radon exhalation was determined using radon-chamber measurements (between 1.32 ± 0.5 Bq kg"−"1 and 37.1 ± 2.2 Bq kg"−"1). Based on these results a model calculation was used to determine the maximum potential radon concentration, which the soil or the rock may provide into the water. We showed that the maximum potential radon concentration of these mylonitic gneissic rocks (c_p_o_t = 2020 Bq L"−"1) is about eight times higher than the measured radon concentration in the water. However the maximum potential radon concentration for soils are significantly lower (41.3 Bq L"−"1) Based on measurements of radon exhalation and porosity of rock and soil samples we concluded that the source material can be the gneiss rock around the spring rather than the soil there. We determined the average radon concentration and the time dependence of the radon concentration over these years in the spring water. We obtained a strong negative correlation (−0.94 in period of 2007–2008 and −0.91 in 2012–2013) between precipitation and radon concentration. - Highlights: • A yearly dataset

Control of radon and its progeny concentration in indoor atmosphere

International Nuclear Information System (INIS)

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

1986-01-01

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

A study of radon levels in the soil of Nasir's College of Agriculture - Yemen

International Nuclear Information System (INIS)

Ali, Taher M.; Ahmed, Hayel A.; Zumalian, Abubaker A.

2000-01-01

The radon diffusion in the atmosphere and dwelling interior comes from one source, it is the soil. Emitting alpha particles, radon daughters may be deposited in to the lungs and cause health hazards, so for this reason, estimation of radon levels in soil and dwelling were done in may countries. in the present work, we have used the passive dosimeters (SSNTD s ) containing (Cr-39) detectors. The dosimeters were distributed at the surface of the ground, in the soil horizontally (at depth 50 cm) and in soil with depth. The overall mean for radon levels in soil horizontally was (1.28 ± 0.05) KBq/m 3 and the mean radon concentration at the surface of the ground was (0.42 ± 0.03) KBq/m 3 . It is found that radon concentration increases as the depth increases up to (90 cm) depth after that radon levels decrease as the depth increases. (author)

Measurements on, and modelling of diffusive and advective radon transport in soil

DEFF Research Database (Denmark)

Graff, E.R. van der; Witteman, G.A.A.; Spoel, W.H. van der

1994-01-01

Results are presented of measurements on radon transport in soil under controlled conditions with a laboratory facility consisting of a stainless steel vessel (height and diameter 2 m) filled with a uniform column of sand. At several depths under the sand surface, probes are radially inserted...... into the vessel to measure the radon concentration in the soil gas. To study advective radon transport a perforated circular box is placed in the sand close to the bottom of the vessel. By pressurising this box, an air flow through the sand column is induced. Radon concentration profiles were measured without...... an air flow as a function of time, and for several values of the air flow, equilibrium radon concentration profiles were measured....

Radon in soils: intercomparative studies

International Nuclear Information System (INIS)

Segovia, N.; Galle, C.; Seidel, J.-L.; Monnin, M.

1988-01-01

Two kinds of experiments were designed to evaluate some of the variations that can be expected from radon in soil concentrations as monitored by closely spaced solid state nuclear track detectors (SSNTDs). Measurements were performed by the Insituto Nacional de Investigations Nucleares in Mexico and the Laboratoire de Physique Corpusculaire in France. The first experimental design consisted of a series of 15 day exposures of twenty monitoring devices placed inside a single bore hole. Fluctuations obtained in the radon levels at the twenty closely spaced monitoring sites ranged from 9% to 33%. The second experiment was performed with 4 pairs of radon monitoring devices located at 4 different sites at the summit of the Nevado de Toluca volcano. Results show that the SSNTD technique is well suited for radon measurements intended for geophysical studies. (author)

Radon in soils: intercomparative studies

Energy Technology Data Exchange (ETDEWEB)

Segovia, N.; Galle, C. (Instituto Nacional de Investigaciones Nucleares, Mexico City (Mexico)); Seidel, J.-L.; Monnin, M. (Clermont-Ferrand-2 Univ., 63 - Aubiere (France). Lab. de Physique Corpusculaire)

1988-01-01

Two kinds of experiments were designed to evaluate some of the variations that can be expected from radon in soil concentrations as monitored by closely spaced solid state nuclear track detectors (SSNTDs). Measurements were performed by the Insituto Nacional de Investigations Nucleares in Mexico and the Laboratoire de Physique Corpusculaire in France. The first experimental design consisted of a series of 15 day exposures of twenty monitoring devices placed inside a single bore hole. Fluctuations obtained in the radon levels at the twenty closely spaced monitoring sites ranged from 9% to 33%. The second experiment was performed with 4 pairs of radon monitoring devices located at 4 different sites at the summit of the Nevado de Toluca volcano. Results show that the SSNTD technique is well suited for radon measurements intended for geophysical studies. (author).

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

Directory of Open Access Journals (Sweden)

Syarbaini Syarbaini

2015-03-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Andersen, C.E

2001-07-01

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

Analysis of problems and failures in the measurement of soil-gas radon concentration.

Science.gov (United States)

Neznal, Martin; Neznal, Matěj

2014-07-01

Long-term experience in the field of soil-gas radon concentration measurements allows to describe and explain the most frequent causes of failures, which can appear in practice when various types of measurement methods and soil-gas sampling techniques are used. The concept of minimal sampling depth, which depends on the volume of the soil-gas sample and on the soil properties, is shown in detail. Consideration of minimal sampling depth at the time of measurement planning allows to avoid the most common mistakes. The ways how to identify influencing parameters, how to avoid a dilution of soil-gas samples by the atmospheric air, as well as how to recognise inappropriate sampling methods are discussed. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Soil gas radon response to environmental and soil physics variables

International Nuclear Information System (INIS)

Thomas, D.M.; Chen, C.; Holford, D.

1991-01-01

During the last three years a field study of soil gas radon activities conducted at Poamoho, Oahu, has shown that the primary environmental variables that control radon transport in shallow tropical soils are synoptic and diurnal barometric pressure changes and soil moisture levels. Barometric pressure changes drive advective transport and mixing of soil gas with atmospheric air; soil moisture appears to control soil porosity and permeability to enhance or inhibit advective and diffusive radon transport. An advective barrier test/control experiment has shown that advective exchange of soil gas and air may account for a substantial proportion of the radon loss from shallow soils but does not significantly affect radon activities at depths greater than 2.3 m. An irrigation test/control experiment also suggests that, at soil moisture levels approaching field capacity, saturation of soil macroporosity can halt all advective transport of radon and limit diffusive mobility to that occurring in the liquid phase. The results of the authors field study have been used to further refine and extend a numerical model, RN3D, that has been developed by Pacific Northwest Laboratories to simulate subsurface transport of radon. The field data have allowed them to accurately simulate the steady state soil gas radon profile at their field site and to track transient radon activities under the influence of barometric pressure changes and in response to changes in soil permeability that result from variations in soil moisture levels. Further work is continuing on the model to enable it to properly account for the relative effects of advective transport of soil gas through cracks and diffusive mobility in the bulk soils

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.)

Soil gas radon concentration across faults near Caracas, Venezuela

International Nuclear Information System (INIS)

Sajo-Bohus, L.; Flores, N.; Urbani, F.; Carreno, R.

2001-01-01

SSNTD were used across tectonic features of different degree of activity and lithology in four localities north of Caracas, Venezuela. The homemade dosimeters with LR115 film were buried 20-30 cm in the ground. This cheap and low- tech method proved very useful to understand the tectonic features involved, measuring higher Radon concentration above traces of active faults while in old and sealed faults the results only show the effect of the surrounding lithology. Radon concentration range is 4.3 - 27.2 kB/m 3 . (Author)

Pumping time required to obtain tube well water samples with aquifer characteristic radon concentrations

International Nuclear Information System (INIS)

Ricardo, Carla Pereira; Oliveira, Arno Heeren de

2011-01-01

Radon is an inert noble gas, which comes from the natural radioactive decay of uranium and thorium in soil, rock and water. Radon isotopes emanated from radium-bearing grains of a rock or soil are released into the pore space. Radon that reaches the pore space is partitioned between the gaseous and aqueous phases. Thus, the groundwater presents a radon signature from the rock that is characteristic of the aquifer. The characteristic radon concentration of an aquifer, which is mainly related to the emanation, is also influenced by the degree of subsurface degassing, especially in the vicinity of a tube well, where the radon concentration is strongly reduced. Looking for the required pumping time to take a tube well water sample that presents the characteristic radon concentration of the aquifer, an experiment was conducted in an 80 m deep tube well. In this experiment, after twenty-four hours without extraction, water samples were collected periodically, about ten minutes intervals, during two hours of pumping time. The radon concentrations of the samples were determined by using the RAD7 Electronic Radon Detector from Durridge Company, a solid state alpha spectrometric detector. It was realized that the necessary time to reach the maximum radon concentration, that means the characteristic radon concentration of the aquifer, is about sixty minutes. (author)

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.

Determination of the Radon Concentration and Radioactivity Level in Karaca Cave

International Nuclear Information System (INIS)

Kara, A.

2008-01-01

In this study, the radon gas concentration in the Karaca cave which is open to tourism has been determined and the negative effects of radon gas on people were discussed. Karaca cave (Gumushane) is visited by many tourists every year. The measurements of radon gas concentration which affects the health of human beings negatively and even causes the lung cancer when it reaches high points have been done for the summer and winter season. LR-115 passive radon detector was used to determine radon concentrations in the cave both winter and summer season. The average radon concentration in the Karaca cave were determined as 823 Bq/m 3 and 1023 Bq/m 3 for the summer and winter season, respectively. Moreover, to find out the natural radioactivity in the cave, the gamma spectroscopic analysis of soil, stone and stalagmite samples were carried out and their relations with the radon gas in the cave atmosphere was analyzed

Radon survey related to construction materials and soils in Zacatecas, Mexico using LR-115

International Nuclear Information System (INIS)

Mireles, F.; Garcia, M.L.; Quirino, L.L.; Davila, J.I.; Pinedo, J.L.; Rios, C.; Montero, M.E.; Colmenero, L.; Villalba, L.

2007-01-01

Indoor radon gas ( 222 Rn), present in the air inside buildings, is one of the most important sources of radiation exposure to the population. This gas originates in the 238 U radioactive decay chain, which is contained in rock and solid soil particles. Radon accumulation in confined spaces, inside buildings, depends on several factors such as the type of soils, type of constructions, building materials, and ventilation. The aim of this work is to present indoor and outdoor radon concentrations for 202 dwellings and indoor concentrations for 148 public clinics; and the radon concentrations relate to the type of predominant soils, the construction years; and building materials used in the ceilings, walls and floors, for cities and towns of the 57 municipalities in the State of Zacatecas, Mexico. The 222 Rn concentrations were measured with a passive-type radon monitor, with LR-115 as detector material; and the radon survey was made during four stages of three months each throughout Zacatecas from 2001 to 2002. The indoor and outdoor radon concentration averages in dwellings were 55.6±4.9Bqm -3 and 46.5±5.3Bqm -3 , respectively. The indoor radon concentration average in public clinics was 57.8±5.4Bqm -3 . These values were lower than the US EPA action limit of 148Bqm -3

Soil-gas radon as seismotectonic indicator in Garhwal Himalaya

International Nuclear Information System (INIS)

Ramola, R.C.; Prasad, Yogesh; Prasad, Ganesh; Kumar, Sushil; Choubey, V.M.

2008-01-01

Research on earthquake-related radon monitoring has received enormous attention recently. Anomalous behaviour of radon in soil and groundwater can be used as a reliable precursor for an impending earthquake. While earthquake prediction may not yet be possible, earthquake prediction research has greatly increased our understanding of earthquake source mechanisms, the structural complexities of fault zones, and the earthquake recurrence interval, expected at a given location. This paper presents some results of continuous monitoring of radon in soil-gas in Garhwal Himalaya, India. Daily soil-gas radon monitoring with seismic activity and meteorological parameters were performed in the same laboratory system, located at H.N.B. Garhwal University Campus, Tehri Garhwal, India. Radon anomalies along with meteorological parameters were found to be statistically significant for the seismic events within the magnitudes M2.0-M6.0 and epicentral distances of 16-250 km from the monitoring station. The frequent positive and negative anomalies with constant environmental perturbation indicate the opening and closing of micro cracks within the volume of dilatancy by strain energy. The spike-like and sharp peak anomalies were recorded before, during and after earthquakes occurred in the area. The variations in radon concentrations in soil-gas are found to be correlated with seismic activities in the Garhwal Himalaya. The correlation between radon level and meteorological parameters is also discussed

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

International Nuclear Information System (INIS)

Andersen, C.E.

2001-07-01

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

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

International Nuclear Information System (INIS)

Teixeira, Giane Gariglio; Rocha, Zildete

2007-01-01

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

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)

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

Soil gas radon and thoron measurements in some Venezuelan oilfields

International Nuclear Information System (INIS)

Fernandez, Daniel Palacios; Yininber Avila; Teixeira, Diana; Sajo-Bohus, Laszlo; Greaves, Eduardo; Barros, Haydn; Fusella, Emidio; Salas, Johnny; Fernandez, Guillermo; Bolivar, Manuel; Regalado, Jimmy

2016-01-01

Radon and thoron concentrations in soil gas were studied in some Venezuelan oilfields using passive and active methods. In some cases, investigations indicated a strong correlation between oil production areas and the intensity of radon signals, while in others a decrease in radon concentration was observed. This behavior was explained on the basis of different geological structures of the associated reservoir traps. Geological faults associated with petroleum systems were well recognized by the radon and thoron anomalies. Possible conduits and sources responsible for the occurrence of natural gas in a river and in an aquifer were identified and localized. (author)

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

Science.gov (United States)

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

2015-11-01

Radon is the second-leading cause of lung cancer worldwide. Most indoor exposure occurs by diffusion of soil gas. Radon is also found in well water, natural gas, and ambient air. Pennsylvania has high indoor radon concentrations; buildings are often tested during real estate transactions, with results reported to the Department of Environmental Protection (PADEP). We evaluated predictors of indoor radon concentrations. Using first-floor and basement indoor radon results reported to the PADEP between 1987 and 2013, we evaluated associations of radon concentrations (natural log transformed) with geology, water source, building characteristics, season, weather, community socioeconomic status, community type, and unconventional natural gas development measures based on drilled and producing wells. Primary analysis included 866,735 first measurements by building, with the large majority from homes. The geologic rock layer on which the building sat was strongly associated with radon concentration (e.g., Axemann Formation, median = 365 Bq/m3, IQR = 167-679 vs. Stockton Formation, median = 93 Bq/m3, IQR = 52-178). In adjusted analysis, buildings using well water had 21% higher concentrations (β = 0.191, 95% CI: 0.184, 0.198). Buildings in cities (vs. townships) had lower concentrations (β = -0.323, 95% CI: -0.333, -0.314). When we included multiple tests per building, concentrations declined with repeated measurements over time. Between 2005 and 2013, 7,469 unconventional wells were drilled in Pennsylvania. Basement radon concentrations fluctuated between 1987 and 2003, but began an upward trend from 2004 to 2012 in all county categories (p Pennsylvania, 1989-2013. Environ Health Perspect 123:1130-1137; http://dx.doi.org/10.1289/ehp.1409014.

Background concentrations of radon and radon daughters in Canadian homes

International Nuclear Information System (INIS)

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

1980-01-01

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

Investigations on indoor radon in Austria, Part 1: Seasonality of indoor radon concentration

International Nuclear Information System (INIS)

Bossew, Peter; Lettner, Herbert

2007-01-01

In general, indoor radon concentration is subject to seasonal variability. The reasons are to be found (1) in meteorological influence on the transport properties of soil, e.g. through temperature, frozen soil layers and soil water saturation; and (2) in living habits, e.g. the tendency to open windows in summer and keep them closed in winter, which in general leads to higher accumulation of geogenic Rn in closed rooms in winter. If one wants to standardize indoor Rn measurements originally performed at different times of the year, e.g. in order to make them comparable, some correction transform as a function of measurement time which accounts for these effects must be estimated. In this paper, the seasonality of indoor Rn concentration measured in Austria is investigated as a function of other factors that influence indoor Rn. Indoor radon concentration is clearly shown to have seasonal variability, with higher Rn levels in winter. However, it is complicated to quantify the effect because, as a consequence of the history of an Rn survey, the measurement season maybe correlated to geological regions, which may introduce a bias in the estimate of the seasonality amplitude

Radon in soil gas: distributions and correlations with the lithologies and pedologies of RMBH - Metropolitan region of Belo Horizonte - Minas Gerais - Brazil

International Nuclear Information System (INIS)

Lara, Evelise G.; Santos, Talita de O.; Oliveira, Arno Heeren de

2013-01-01

The concentration of radon in the soil gas is an important indicator to predict the radon geologic potential, usually indicated by Geological Radon Potential - GEORP, which is defined as the percent number of dwellings with indoor air radon concentration above the U.S.EPA action limit. The objective of this work was to investigate the distribution of radon concentration in soil gas and its relation with the pedologies and lithologies in the RMBH. The radon concentrations in soil gas were determined by using an AlphaGUARD monitor at 150 measurement points over the lithologies and pedologies of the area. The concentrations 226 Ra were determined by gamma spectrometry (HPGe) and U and Th by ICP-MS. The permeabilities of the soil were determined by using the RADON-JOK permeameter. Regarding pedologies, the perferric Red Latosols had the highest concentrations, with arithmetic mean to 60.6 ± 8.7 kBq.m -3 . Regarding lithologies, areas where the bedrocks are predominantly schists and metagraywackes showed the highest radon concentrations, with arithmetic mean to 46.5 ± 9.9 kBq.m -3 . The areas of lithology or pedology, in which the average radon concentrations are the highest also exhibit higher GEORP, e.g. for the perferric Red Latosol pedology shows GEORP of 26,5%. In this pedology, over 50% of the measurement points shows radon concentrations above of 50.0 kBq.m -3 , that, by the 'Swedish Criteria' classifies the area as high radon risk. The correlation with GEORP is even more significant when the radon concentration in soil gas is combined with soil permeability, through the Soil Radon Index indicator. (author)

Radon in soil gas: distributions and correlations with the lithologies and pedologies of RMBH - Metropolitan region of Belo Horizonte - Minas Gerais - Brazil

Energy Technology Data Exchange (ETDEWEB)

Lara, Evelise G.; Santos, Talita de O.; Oliveira, Arno Heeren de, E-mail: evelise.lara@gmail.com, E-mail: talitaolsantos@yahoo.com.br, E-mail: heeren@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, M.G (Brazil). Dept. de Engenharia Nuclear; Rocha, Zildete; Palmieri, Helena E. Leonhardt; Brito, Walter de; Araujo, Gabriela Bastos D. de, E-mail: rochaz@cdtn.br, E-mail: help@cdtn.br, E-mail: britow@cdtn.br, E-mail: gabibastosdias@hotmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2013-07-01

The concentration of radon in the soil gas is an important indicator to predict the radon geologic potential, usually indicated by Geological Radon Potential - GEORP, which is defined as the percent number of dwellings with indoor air radon concentration above the U.S.EPA action limit. The objective of this work was to investigate the distribution of radon concentration in soil gas and its relation with the pedologies and lithologies in the RMBH. The radon concentrations in soil gas were determined by using an AlphaGUARD monitor at 150 measurement points over the lithologies and pedologies of the area. The concentrations {sup 226}Ra were determined by gamma spectrometry (HPGe) and U and Th by ICP-MS. The permeabilities of the soil were determined by using the RADON-JOK permeameter. Regarding pedologies, the perferric Red Latosols had the highest concentrations, with arithmetic mean to 60.6 ± 8.7 kBq.m{sup -3}. Regarding lithologies, areas where the bedrocks are predominantly schists and metagraywackes showed the highest radon concentrations, with arithmetic mean to 46.5 ± 9.9 kBq.m{sup -3}. The areas of lithology or pedology, in which the average radon concentrations are the highest also exhibit higher GEORP, e.g. for the perferric Red Latosol pedology shows GEORP of 26,5%. In this pedology, over 50% of the measurement points shows radon concentrations above of 50.0 kBq.m{sup -3}, that, by the 'Swedish Criteria' classifies the area as high radon risk. The correlation with GEORP is even more significant when the radon concentration in soil gas is combined with soil permeability, through the Soil Radon Index indicator. (author)

ASSESSMENT OF RADON IN SOIL AND WATER IN DIFFERENT REGIONS OF KOLHAPUR DISTRICT, MAHARASHTRA, INDIA.

Science.gov (United States)

Raste, P M; Sahoo, B K; Gaware, J J; Sharma, Anil; Waikar, M R; Shaikh, A A; Sonkawade, R G

2018-03-19

Researchers have already established that inhalation of high radon concentration is hazardous to human health. Radon concentration has been measured in water and soil, in various part of Kolhapur district has been carried out by the AQTEK Smart RnDuo which is an active device technique. The observed minimum value of the radon mass exhalation rate of the soil is 13.16 ± 0.83 mBq/kg/h and maximum is 35.11 ± 1.84 mBq/kg/h. The minimum value of the Radon concentration in water is 0.33 ± 0.052 Bq/L and maximum is 7.32 ± 0.078 Bq/L. These values of radon concentration are below the action of recommended level by the USEPA, which is set as the maximum contaminant level of 11.1-148 Bq/L of radon in drinking water. Total annual effective dose rate of water is 11 μSv/y. The purpose of present study is to assess radiological risk from consumption of water that provide in Kolhapur district and to evaluate the radon mass exhalation rate of soil in few places of Kolhapur district.

Control methods of radon and its progeny concentration in indoor atmosphere

International Nuclear Information System (INIS)

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

1990-01-01

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

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

International Nuclear Information System (INIS)

Al-Azmi, D.; Karunakara, N.

2008-01-01

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

In-situ potential risk dependence of environmental radon concentration mapping

International Nuclear Information System (INIS)

Sajo B, L.; Horvath, A.; Mark, G.; Kasztovszky, Z.; Toth, E.

1996-01-01

In this study we present the importance of a close mesh measurements for radon concentration mapping and we demonstrate its necessity when dose calculations are involved. Our results indicate that large errors may be derived from data related to large area mapped with measurements considered characteristic; mean value of a selected region. We point out also that from place to place distant 30 cm radon concentration in the soil at the relaxation depth of 70 cm may differ by a factor of 2 or more. Waters of household wells were monitored also for information on the radon dynamic behaviour. We conclude that for effective dose calculations, particularly in areas with high radon concentration gradient and relatively high population density, the approximate spatial scale variation should be replaced by a systematic dose mesh sampling approach. (authors). 13 refs., 3 figs

Correlation between indoor radon and soil gas availability: Results of field studies

International Nuclear Information System (INIS)

Kothari, B.K.; Kunz, C.; Lilley, W.

1990-01-01

To correlate indoor radon concentrations with soil gas, the authors have carried out a field survey of surficial material in selected regions of New York State. The survey consisted of measurements of gamma radiation, Ra-226, Rn-222 and the permeability for gas flow in surficial material. Based on the data, three areas with a potential for above average indoor radon concentrations have been identified: (1) a black shale region in Onondaga County; (2) a granitic region in Orange County; and (3) a black shale region in Erie County. For an area with potential for below-average indoor radon concentrations, sandy deposits on Long Island with an average concentration of 0.7 pCi Ra-226/g and 160 pCi Rn-222/L at 2-feet depth, have been selected. Fifteen homes from each of these four areas are under test for indoor radon. Measurements of air infiltration rates and soil gas availability parameters are planned for all 60 homes

Radon Gas Concentration Measurement In Soil For Some Holy Positions In Al-Najaf Al-Ashraf Governorate

International Nuclear Information System (INIS)

Hasan, K.H.; Hussain, H.H.

2014-01-01

In this search we measurement Radon gas concentration in the soil of holy positions in Al-Najaf Al-Ashraf city.We choice it for honorable position in all the world and, because millions of peoples and religious sciences students visit it.we selected 23 positions .By using a short-term way in modern technology its (RAD7) to measured concentration for depths (10,30,50,70)cm in all the holy positions.All the concentration in position studies within the range allowed of the global

Determination of the radon concentration in soil and ground water and its association with the seismicity

International Nuclear Information System (INIS)

Pena, P.; Segovia, N.; Azorin, J.

2003-01-01

The coast of the Mexican Pacific is one of the seismic areas more active of the world due to the subduction of the badges of Coconuts and Rivera under the badge of North America. The earthquakes that happen in this part of Mexico they are of great magnitude and they affect to the central plateau of the country where finds the biggest population density. On the other hand the coast of the Gulf of Mexico presents one relatively low seismic activity. It is in this region where it is the nuclear plant of Laguna Verde (PNLV) and the studies of seismicity of the area should be carried out for questions of nuclear security. One carries out a study of fluctuations of the concentration of the radon in floor and it dilutes underground in the mentioned areas using accustomed to detectors of nuclear appearances (LR-115). Possibly they were also used detecting automatic (Clipperton sounds out). In some cases it was analysed the gamma radiation in soil using thermoluminescent dosemeters (CaSO 4 : Dy + Ptfe). The mineralogical composition of rock samples was obtained, by means of technical conventional and Electron scanning microscopy and an X-ray diffractometer. The study one carries out along the coast of Guerrero, from Guacamayas, Mich. until Marquelia, Gro., of 1993 at 1998 and in the coast of the Gulf of Mexico, in the PNLV and their surroundings, of 1994 at 1996. The fluctuations of the radon concentration and of the gamma radiation, were analysed in function of the local seismic activity, the meteorological parameters and those characteristic geologic. In the area of the PNLV, the results showed that in general the averages of those value of the radon concentration, as much in floor as in water, they were low. A station located in a flaw area (New Ranch) the one that I present the values was but high of radon concentration, corresponding those but first floor to the PNLV. The seismic activity during the one period of sampling was sporadic and of low intensity and alone one

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

International Nuclear Information System (INIS)

Riley, W.J.

1996-05-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-05-01

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

Radon soil increases before volcano-tectonic earthquakes in Colombia

International Nuclear Information System (INIS)

Garzon, G.; Serna, D.; Diago, J.; Moran, C.

2003-01-01

Continuous studies of radon concentration changes in soils for the purpose of earthquake monitoring have been carried out in three colombian districts and in the edifices of Galeras and nevado del Ruiz volcanoes since 1995. In zones of active faulting have been measured radon soil emissions between 1000 and 2500 pCi/L. In an intersection of two active geological faults have been measured levels of 25 000 pCi/L. In the present work appears a compilation of examples of the registered anomalous radon emissions in several stations before earthquakes of tectonic character. Examples of registered radon increases before: (1) events of magnitudes between 2 and 4; (2) the occurrence of seismic swarms; and (3) the Quindio (Colombia) earthquake (M w = 6, 2) of January 1999, are described. A model of transport mechanism for the studied isotopes is presented. (orig.)

Radon gas sampler for indoor and soil measurements and its applications

International Nuclear Information System (INIS)

Azimi-Garakani, D.; Flores, B.; Piermattei, S.; Susanna, A.F.; Seidel, J.L.; Tommasino, L.; Torri, G.

1988-01-01

A national large scale survey of indoor radon (based on an optimised sampling strategy) is needed in Italy to obtain average population dose for use in epidemiological studies. Since in the great majority of cases, one of the most important radon sources is the soil and rock beneath the houses, it would be interesting to combine this survey with measurements of bed-soil radon. With these objectives in mind, a new radon monitor device has been developed consisting of two etched track detectors enclosed in a heat-sealed polyethylene bag. When compared with existing techniques, this radon gas sampler presents several advantages for both indoor and outdoor measurements. As a pilot project, radon gas measurements have been carried out in hundreds of different sites and for several locations; measurements have been made for different years. Typical houses with relatively high radon concentrations have also been thoroughly investigated. (author)

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

Natural radioactivity and radon exhalation rate of soil in southern Egypt

International Nuclear Information System (INIS)

Sroor, A.; El-Bahi, S.M.; Ahmed, F.; Abdel-Haleem, A.S.

2001-01-01

The level of natural radioactivity in soil of 30 mining samples collected from six locations in southern Egypt was measured. Concentrations of radionuclides in samples were determined by γ-ray spectrometer using HPGe detector with a specially designed shield. The obtained results of uranium and thorium series as well as potassium (K-40) are discussed. The present data were compared with data obtained from different areas in Egypt. Also, a solid state nuclear track detector SSNTD (Cr-39) was used to measure the radon concentration as well as exhalation rate for these samples. The radon concentrations were found to vary from 1.54 to 5.37 Bq/kg. The exhalation rates were found to vary from 338.81 to 1426.47 Bq/m 2 d. The values of the radon exhalation rate are found to correspond with the uranium concentration values measured by the germanium detector in the corresponding soil samples

Modeling of indoor radon

International Nuclear Information System (INIS)

Paschoa, A.S.

1990-01-01

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

Ion climate and radon concentration

International Nuclear Information System (INIS)

Busbarna, L.

1981-01-01

Characteristic values of radon concentration in natural ion climate and in open air were compared and the effect of artificially produced negative ion excess on the radon concentration of air was studied. The results show that the radon concentration measurable at the rise of negative ion excess is smaller than that in the case of natural equilibrium. This effect can be utilized lowering the background of the scintillation chambers, thus increasing their sensitivity. The negative ions of the artificial ion climate lower radon concentration in closed space. The question arises whether only the ion climate is responsible for the effects on the organism and on the nervous system or the radon concentration of the air also contributes to them. (author)

Modified design in new construction prevents infiltration of soil gas that carries radon

International Nuclear Information System (INIS)

Ericson, S.O.; Schmied, H.

1987-01-01

Dwellings located on permeable soil with strong exhalation of radon often get a contribution to indoor radon from infiltrating soil gas carrying radon from the ground into the building. 100 dwellings have been built on radon dangerous land with different modifications in design and construction in order to prevent infiltration of radon. Tight construction, ventilated crawl space, ventilation/depressurization of the capillary breaking layer (crushed stone), and mechanical ventilation with heat recovery by air to air heat exchangers or heat pumps have been tested. Added building costs and measured concentration of radon after construction and 3-5 years later are reported. It is concluded that it is possible to build radon protective and radon safe dwellings on any land. The added costs have ranged from zero to 4% of total building costs

Radon as an environmental risk: concentration measurements in family buildings at Cordoba city

International Nuclear Information System (INIS)

Bonzi, A.; Murua, C.; Martin, H.R.

1992-01-01

Measurements of radon concentration at homes are usual activities in the last years at the countries with uranium in their soils. On the other hand, the man's radiological protection about radiation is related to the environmental actions for a healthy life, but not much known for a public. The great quantities of ore with uranium can be an important source of irradiation when they are used as building materials. The soils are important too for the emanations of radon in the interior of buildings and for these reasons, the radon concentration measurements in Cordoba familiar houses were implemented in the summer of 1991. The Alpha Track Technique and the results obtained indicate the need of other measurements and a winter measurement for investigation variations of radon concentration. The typical values measured were low, about 4.13 Bq/m 3 if they are compared with other Argentine values measured. This paper discusses the procedure, techniques and criteria used in the work held in Cordoba city, Argentina. (Author)

Radon exhalation rates from soil and sand samples collected from the vicinity of Yamuna river

International Nuclear Information System (INIS)

Garg, A.K.; Sushil Kumar; Chauhan, Pooja; Chauhan, R.P.

2011-01-01

Soil, sand and stones are the most popular building materials for Indian dwellings. Radon is released into ambient air from these materials due to ubiquitous uranium and radium in them, thus increasing the airborne radon concentration. The radioactivity in sand and soils is related to radioactivity in the rocks from which they are formed. These materials contain varying amount of uranium. In the present investigation, the radon emanated from soil and sand samples from different locations in the vicinity of Yamuna river has been estimated. The samples have been collected from different locations near the Yamuna river. The samples collecting sites are from Yamunanagar in Haryana to Delhi. The radon concentration in different samples has been calculated, based upon the data, the mass and the surface exhalation rates of radon emanated from them have also been calculated

Predictors of Indoor Radon Concentrations in Pennsylvania, 1989–2013

Science.gov (United States)

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

2015-01-01

Background Radon is the second-leading cause of lung cancer worldwide. Most indoor exposure occurs by diffusion of soil gas. Radon is also found in well water, natural gas, and ambient air. Pennsylvania has high indoor radon concentrations; buildings are often tested during real estate transactions, with results reported to the Department of Environmental Protection (PADEP). Objectives We evaluated predictors of indoor radon concentrations. Methods Using first-floor and basement indoor radon results reported to the PADEP between 1987 and 2013, we evaluated associations of radon concentrations (natural log transformed) with geology, water source, building characteristics, season, weather, community socioeconomic status, community type, and unconventional natural gas development measures based on drilled and producing wells. Results Primary analysis included 866,735 first measurements by building, with the large majority from homes. The geologic rock layer on which the building sat was strongly associated with radon concentration (e.g., Axemann Formation, median = 365 Bq/m3, IQR = 167–679 vs. Stockton Formation, median = 93 Bq/m3, IQR = 52–178). In adjusted analysis, buildings using well water had 21% higher concentrations (β = 0.191, 95% CI: 0.184, 0.198). Buildings in cities (vs. townships) had lower concentrations (β = –0.323, 95% CI: –0.333, –0.314). When we included multiple tests per building, concentrations declined with repeated measurements over time. Between 2005 and 2013, 7,469 unconventional wells were drilled in Pennsylvania. Basement radon concentrations fluctuated between 1987 and 2003, but began an upward trend from 2004 to 2012 in all county categories (p Pennsylvania, 1989–2013. Environ Health Perspect 123:1130–1137; http://dx.doi.org/10.1289/ehp.1409014 PMID:25856050

Indoor radon concentration and outdoor/indoor pressure difference correlation

International Nuclear Information System (INIS)

Cechak, T.; Fronka, A.; Moucka, L.

2004-01-01

In the current approach to the radon issue, the radon risk for people living in a building is estimated based on the average indoor radon concentration. Short-term measurements as usually applied fail to reflect the wide range of radon variations arising from ventilation, radon supply and, in particular, human activities in the building. For this reason, efforts are made to find a new approach to the assessment of the quality of a building as a radon barrier, independent of the weather conditions and residential habits. A simple model of radon volume activity entering the building at a constant rate and simultaneously ventilated at a constant rate is applicable to this task. The rate of radon ingress can be regarded as a parameter making it possible to quantify the leakage of structures provided the barrier against the radon in a soil gas. The ventilation rate, on the other hand, characterizes the leakage of the whole building envelope at a given outdoor/indoor pressure difference. A unique measuring technique called the blower door exists whereby a defined pressure difference between the indoor and outdoor atmosphere can be established. Under such conditions both the ventilation rate and the rate of radon ingress can be measured and expressed as a function of the pressure difference. An analysis of the model of a room with a constant ventilation and constant radon supply is presented and the relationship between radon supply and ventilation rate can be assumed. Some experimental results show how the model can be utilized. The real indoor-outdoor air pressure differences, the indoor-soil air pressure differences, and some effects of different ventilation regimes are given. Other experiments, which have been done by using the blower door method, illustrate the possible effects and some restrictions for a routine application are discussed

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

International Nuclear Information System (INIS)

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

2014-01-01

Radon is a natural gas known to be the main contributor to natural background radiation exposure and only second to smoking as major leading cause of lung cancer. The main concern is in indoor environments where the gas tends to accumulate and can reach high concentrations. The primary contributor of this gas into the building is from the soil although architectonic characteristics, such as building materials, can largely affect concentration values. Understanding the factors affecting the concentration in dwellings and workplaces is important both in prevention, when the construction of a new building is being planned, and in mitigation when the amount of Radon detected inside a building is too high. In this paper we investigate how several factors, such as geologic typologies of the soil and a range of building characteristics, impact on indoor concentration focusing, in particular, on how concentration changes as a function of the floor level. Adopting a mixed effects model to account for the hierarchical nature of the data, we also quantify the extent to which such measurable factors manage to explain the variability of indoor radon concentration. - Highlights: • It is assessed how the variability of indoor radon concentration depends on buildings and lithologies. • The lithological component has been found less relevant than the building one. • Radon-prone lithologies have been identified. • The effect of the floor where the room is located has been estimated. • Indoor radon concentration have been predicted for different dwelling typologies

Analysis of soil radon data in earthquake precursory studies

Directory of Open Access Journals (Sweden)

Hari Prasad Jaishi

2014-10-01

Full Text Available Soil radon data were recorded at two selected sites along Mat fault in Mizoram (India, which lies in the highest seismic zone in India. The study was carried out during July 2011 to May 2013 using LR-115 Type II films. Precursory changes in radon concentration were observed prior to some earthquakes that occurred around the measuring sites. Positive correlation was found between the measured radon data and the seismic activity in the region. Statistical analysis of the radon data together with the meteorological parameters was done using Multiple Regression Method. Results obtained show that the method employed was useful for removing the effect of meteorological parameters and to identify radon maxima possibly caused by seismic activity.

Radon mass exhalation rate in soil samples at South Bengaluru city, Karnataka, India

International Nuclear Information System (INIS)

Poojitha, C.G.; Pranesha, T.S.; Ganesh, K.E.; Sahoo, B.K.; Sapra, B.K.

2017-01-01

Radon mass exhalation rate in soil samples collected from different locations of South Bengaluru city were measured using scintillation based Smart radon thoron monitor (RnDuo). It has been observed that the mass exhalation rate estimated due to presence of radon concentration in soil samples ranges from 39.18 - 265.58 mBq/kg/h with an average value of 115.64 mBq/kg/h. Finally we compare our results with similar investigation from different parts of India. (author)

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

International Nuclear Information System (INIS)

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

1995-01-01

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

Soil radon response around an active volcano

International Nuclear Information System (INIS)

Segovia, N.; Valdes, C.; Pena, P.; Mena, M.; Tamez, E.

2001-01-01

Soil radon behavior related to the volcanic eruptive period 1997-1999 of Popocatepetl volcano has been studied as a function of the volcanic activity. Since the volcano is located 60 km from Mexico City, the risk associated with an explosive eruptive phase is high and an intense surveillance program has been implemented. Previous studies in this particular volcano showed soil radon pulses preceding the initial phase of the eruption. The radon survey was performed with LR-115 track detectors at a shallow depth and the effect of the soil moisture during the rainy season has been observed on the detectors response. In the present state of the volcanic activity the soil radon behavior has shown more stability than in previous eruptive stages

Indoor radon concentration in Poland

International Nuclear Information System (INIS)

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

1996-01-01

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

Uranium, radium and radon exhalation study in some soil samples using track etch technique

International Nuclear Information System (INIS)

Harmanjit, Singh; Joga, Singh; Surinder, Singh; Bajwa, B.S.

2006-01-01

Full text of publication follows: Uranium, radium concentration and radon exhalation rates have been determined in the soil samples collected from some areas of Punjab using the L.R.-115 nuclear track detectors. Radium concentration in these samples has been found to be varying from 0.80 to 5.34 Bq Kg-1. The radon exhalation rate in these samples has been found to be varying from 0.99 to 6.60 mBq Kg -1 h -1 (32.82 to 218.49 mBqm -2 h -1 ). A good correlation has been observed between radon exhalation rate and radium concentration observed in the soil samples. The uranium concentration in all these samples is being carried out and the other correlations will also be established. (authors)

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

International Nuclear Information System (INIS)

Akbari, Keramatollah; Mahmoudi, Jafar; Ghanbari, Mahdi

2013-01-01

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

Correlation between geology and radon levels in groundwater, soil and indoor air in Bhilangana Valley, Garhwal Himalaya, India

International Nuclear Information System (INIS)

Choubey, V.M.; Ramola, R.C.

1997-01-01

Radon concentrations were measured in soil, air and groundwater in Bhilangana Valley, Garhwal Himalaya, India by using an LR-115 plastic track detector and radon emanometer. Radon concentrations were found to vary from 1 KBq/m 3 to 57 KBq/m 3 in soil, 5 Bq/l to 887 Bq/l in water and 95 Bq/m 3 to 208 Bq/m 3 in air. The recorded values are quite high due to associated uranium mineralization in the area. Radon concentration was also found to depend on the tectonic structure and geology of the area. (orig.)

Soil-Gas Radon Anomaly Map of an Unknown Fault Zone Area, Chiang Mai, Northern Thailand

Science.gov (United States)

Udphuay, S.; Kaweewong, C.; Imurai, W.; Pondthai, P.

2015-12-01

Soil-gas radon concentration anomaly map was constructed to help detect an unknown subsurface fault location in San Sai District, Chiang Mai Province, Northern Thailand where a 5.1-magnitude earthquake took place in December 2006. It was suspected that this earthquake may have been associated with an unrecognized active fault in the area. In this study, soil-gas samples were collected from eighty-four measuring stations covering an area of approximately 50 km2. Radon in soil-gas samples was quantified using Scintrex Radon Detector, RDA-200. The samplings were conducted twice: during December 2014-January 2015 and March 2015-April 2015. The soil-gas radon map obtained from this study reveals linear NNW-SSE trend of high concentration. This anomaly corresponds to the direction of the prospective fault system interpreted from satellite images. The findings from this study support the existence of this unknown fault system. However a more detailed investigation should be conducted in order to confirm its geometry, orientation and lateral extent.

Emission of radon from soil

International Nuclear Information System (INIS)

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

1980-03-01

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

Spatial distribution of the radon concentration in soil and subterranean water in the Nuclear Center of Mexico and its surrounding using a geographical information system

International Nuclear Information System (INIS)

Cardenas, S.; Pena, P.; Lopez, M.B.E.; Balcazar, M.; Madrigal, D.

2003-01-01

The radon concentration in soil of the Nuclear Center of Mexico using solid detectors of nuclear traces (LR 115, type ll) and in water of two aquifers of the Asuncion Tepexoyuca, by means of the liquid scintillation technique it was determined; both places located in the Ocoyoacac municipality, Estado de Mexico. The analysis of spatial distribution it was supported by means of a Geographic Information System. The results of the radon concentration in soil, they registered an average of 2. 64 kBq m -3 in the study area, the more high average value it was of 5. 25 kBq m -3 in the station 12-ZM (Military Area) and the minimum value was of 0. 54 kBq m -3 in the point 7-CO (Dining room). In the radon concentration in water of La Perita it was observed an average value 0.52 Bq L -1 and in El Tunel it was of 0.7 Bq L -1 . (Author)

Contribution to the relation between volume activity of soil and indoor radon

International Nuclear Information System (INIS)

Mojzes, A.

1999-01-01

There were carried out some repeated manual measurements of volume activity of radon-222 (VAR) in both soil air of subsoil and also indoor air of buildings in two different areas in Bratislava. All measurements were done with a portable scintillation detector based on exchangeable Lucas cells. The measurements were repeated in different day and year intervals. There were repeated 259 measurements of volume activity of radon-222 in soil air with the average valuer 11.95 kBq/m 3 and the standard deviation 1.53 kBq/m 3 in the subsoil of the one-story house and 597 measurements of VAR in soil air of the subsoil of the second study building with the average 9.44 kBq/m 3 and the standard deviation 3.08 kBq/m 3 . Presented results of measurement of radon-222 volume activity in both soil and indoor air demonstrate that also in case of low radon concentrations in soil air of geological basement the level of radon in indoor air could be considerably high. It depends mainly on used technology of laying building foundations, on the distance from subsoil and on regime of ventilation. In case of older buildings the ventilation is very effective way to reduce the presence of radon in indoor air. (author)

Radon transport in fractured soil. Laboratory experiments and modelling

International Nuclear Information System (INIS)

Hoff, A.

1997-10-01

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

Radon transport in fractured soil. Laboratory experiments and modelling

Energy Technology Data Exchange (ETDEWEB)

Hoff, A

1997-10-01

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

Studies on spatial distribution of indoor radon concentration at Mysore city, India

International Nuclear Information System (INIS)

Pruthvi Rani, K.S.; Chandrashekara, M.S.; Paramesh, L.

2016-01-01

Radon is a radioactive inert gas, with a half life of 3.82 days. Radium present in soil rocks and building material are the sources of atmospheric radon. Radon and its short-lived decay products ( 218 Po, 214 Pb, 214 Bi, and 214 Po) can be deposited in the lung tissues and give rise to higher radiation doses. Radon is now recognized as the second most important cause of lung cancer after smoking in the general population. In the present investigation a systematic study of the distribution of radon concentration has been carried out in a small room at different co-ordinates and time scales

Determination of the radon Concentration in underground water in selected areas in and around Kumasi

International Nuclear Information System (INIS)

Owusu, Seth Adjei

2012-06-01

Radon (Rn-222) is a radioactive noble gas of natural origin that may be found anywhere in soil, air and different types of water: surface, borehole, well and spring. It is worth to carry out surveys for the radon in water for radiation protection as well as for geological considerations. The research presenters here was carried out in selected towns in and around Kumasi for the determination of radon concentration in groundwater. The major towns from which samples were taken are , Mowire, Kronum, Aburaso, Medoma, Kenyase, Buokrom, Bomfa, Ayeduase, Kotei, Tikrom. All the samples are used for domestic purposes such as cooking, drinking, bathing and washing. Waters from boreholes and wells in the selected towns were sampled and the radon concentration level measured. The Roll’s method was used for the radon concentration analysis on all the 100 samples. The results shows that, the minimum radon concentration in groundwater was 13015.934 Bq/m3 and it was found at Bomfa, and the highest was found to be 964628.480 Bq/m3, recorded at Mowire. It is believed that this variation of levels is mainly due to the difference in rock type, soil type and geology of the area as well as the depth of the water samples. This information can be used to estimate the possible health hazards from radon in the selected towns in the future from environmental point of view. The data would promote public awareness related to risk of radon exposure. (au)

Measurement of concentrations of radon and its daughters in indoor atmosphere using CR-39 nuclear track detector

International Nuclear Information System (INIS)

Khan, A.J.; Sharma, K.C.; Varshney, A.K.; Prasad, Rajendra; Tyagi, R.K.

1988-01-01

The concentrations of radon and its daughters in rooms having different environmental conditions are measured using CR-39 nuclear track detector. It has been found that the radon concentration inside the rooms depends on ventilation, sub-soil emanation and the housed materials. The use of internal wall coverings such as plaster, distemper and white washing may reduce the radon emanation inside the rooms. The use of paints on walls is the best for reducing the radon concentration inside the rooms. (author). 11 refs

Radon survey and soil gamma doses in primary schools of Batman, Turkey.

Science.gov (United States)

Damla, Nevzat; Aldemir, Kamuran

2014-06-01

A survey was conducted to evaluate levels of indoor radon and gamma doses in 42 primary schools located in Batman, southeastern Anatolia, Turkey. Indoor radon measurements were carried out using CR-39 solid-state nuclear track detector-based radon dosimeters. The overall mean annual (222)Rn activity in the surveyed area was found to be 49 Bq m(-3) (equivalent to an annual effective dose of 0.25 mSv). However, in one of the districts (Besiri) the maximum radon value turned out to be 307 Bq m(-3). The estimated annual effective doses are less than the recommended action level (3-10 mSv). It is found that the radon concentration decreases with increasing floor number. The concentrations of natural and artificial radioisotopes were determined using gamma-ray spectroscopy for soil samples collected in close vicinity of the studied schools. The mean gamma activity concentrations in the soil samples were 31, 25, 329 and 12 Bq kg(-1) for (226)Ra, (232)Th, (40)K and (137)Cs, respectively. The radiological parameters such as the absorbed dose rate in air and the annual effective dose equivalent were calculated. These radiological parameters were evaluated and compared with the internationally recommended values.

Comparative survey of outdoor, residential and workplace radon concentrations

International Nuclear Information System (INIS)

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

2015-01-01

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

Parametric modelling of temporal variations in radon concentrations in homes

International Nuclear Information System (INIS)

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

1988-01-01

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

Indoor radon concentrations in Vushtrri, Kosovo

International Nuclear Information System (INIS)

Xhafa, B.; Jonuzaj, A.; ); Bekteshi, S.; Ahmetaj, S.; Kabashi, S.; )

2009-01-01

Indoor air radon concentration was measured by exposing trac ketch detectors in the two elementary schools, one high school, a kindergarten and the hospital in the city of Vushtrri. Measurements were performed with the radon monitor PRM-145, which uses alpha scintillation cells and serves to determine the current concentration of radon. The results we obtained are in the range between the average values of radon for the interior spaces, and values that pose a potential risk for lung cancer. Measuring the concentration of radon was done in total of 34 rooms and came up with values which are between 28Bqm -3 and 398Bqm -3 . In order to reduce the concentration of radon, we have built a ventilation pump, then we performed repeated measurements and finally came with results between 130-145Bqm -3 .

Swiss radon programme 'RAPROS'

International Nuclear Information System (INIS)

Zeller, W.

1992-03-01

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

Risk assessment of radon gas concentration for some selected offices of KNUST campus, Kumasi

International Nuclear Information System (INIS)

Bediako, Yaw Addo

2013-11-01

Radon (Rn-222) has been identified as an factor that could result in a health hazard by studies all around the world. The health risks can be minimised by preventing measures where radon is highly concentrated as in some mines or homes or offices. A study in the buildup concentration of the inert gas, will give us a better understanding of its possible pathways through soil into the air surrounding and offices where radon releases can become hazardous. Measuring the radon concentrations on campus, can help to deduce the radon flux to identify the problem areas for rehabilitation. An active method incorporating Trace level radon gas detection and continious monitoring method was used in this study to determine the radon concentration of the selected offices. Concentrations ranging from 0.010 to 0.498 pCi/I were detected, with the head of optometry and Visual Science recording the highest concentration of 0.498 pCi/I, while the head of Agricultural Engineering Department office with the least concentration of 0.010 pCi/I. Although these concentrations are generally low as compared with the EPA guidelines of an action level of 4 pCi/I, but no amount of radiation is said to be safe. (au)

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Radon gas. A review with emphasis on site investigations and measurements of soil gas and indoor house levels

International Nuclear Information System (INIS)

Mitchell, Seamus.

1992-09-01

A review of radon gas, with particular reference to its source and transport through soils and into buildings is examined. The principal parameters affecting the movement of radon has been discussed. The levels of radon gas in soils and in dwelling houses has been examined. Radon levels in the soil gas were highest in mineral soils with pear soils giving low readings but there was no significant differences between the results. Houses situated over granite and limestone bedrock gave similar results for indoor radon concentrations, with no significant differences being recorded. Results were expected to be much higher in houses over granite areas, in view of the higher uranium series activity in granites. It is concluded that high radon gas levels in soils under and in he vicinity of houses is the probable explanation for the indoor radon levels found. The influence of the underlying bedrock is not the most important parameter as was surmised before the study. (author)

Determination of indoor radon concentrations at the elementary schools of Fatih district in Istanbul

Energy Technology Data Exchange (ETDEWEB)

Kurt, A., E-mail: aziz.kurt@istanbul.edu.tr; Yalcin, L. Sahin, E-mail: latife.sahin@gmail.com; Oktem, Y., E-mail: sgyks@istanbul.edu.tr; Akkus, B., E-mail: akkus@istanbul.edu.tr; Bozkurt, E., E-mail: enginbozkurt88@gmail.com; Hafizoglu, N., E-mail: nurgulhfz87@gmail.com; Ozturk, F. C., E-mail: fcaglaozturk@gmail.com; Aytan, O., E-mail: ozgur@aytan.net; Ertoprak, A., E-mail: aysegulertoprak@gmail.com [Istanbul University, Science Faculty, Physics Department, 34134, Istanbul (Turkey)

2016-03-25

Radon is an odorless, tasteless, colorless noble radioactive gas which is produced within the radioactive decay chain of Uranium. The Radon forms in rocks, diffuses into soil and then escapes into atmosphere. When human exposure to high concentration of radon gas from inside, risk of developing lung cancer is increased. There are many methods to determine {sup 222}Rn concentration in the air. In this study, radon concentration of confined air spaces were measured by using LR-115 solid state nuclear track detectors. 509 LR-115 nuclear trace detectors were placed to 25 schools in Fatih District and they effective dose values were calculated. The results of measurements showed that the radon concentration varies between 40-395 Bq/m{sup 3}. This results compared with Turkey’s limits (400 Bq/m{sup 3}) are low, conversely higher compared with WHO’s limits (100 Bq/m{sup 3}).

Development of a portable instantaneous soil radon measurement instrument

International Nuclear Information System (INIS)

Wang Yushuang; Ge Liangquan; Jiang Haijing; Lin Yanchang

2007-01-01

A dual-channel instantaneous soil radon measurement instrument based on the method of electrostatic collection is designed. It has the features of small size, low cost, and high sensitivity, etc. A single chip microcomputer is adopted as the data processing and control unit. The concentration of radon can be reported in field. The result is also corrected by the pressure sensing system. A double channel discriminator is used so that the detector can eliminate the interference from the progenies of radon except RaA. LCD and MCU based encoding keyboard are used to give users a friendly interface. Operating and function setting is easy. (authors)

Radon Mapping of the Osijek Town

International Nuclear Information System (INIS)

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

1998-01-01

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

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)

Soil-gas radon/helium surveys in some neotectonic areas of NW Himalayan foothills, India

Directory of Open Access Journals (Sweden)

S. Mahajan

2010-06-01

Full Text Available The present research is aimed at accessing the relationship between variation in the soil gases radon (²²²Rn and helium (⁴He and recently developed fissures and other neotectonic features in Nurpur and Nadha areas of the NW Himalayas, India. Two soil-gas surveys were conducted on/near known faults to reconfirm their position using soil gas technique and to check their present activity. During these surveys, soil-gas samples were collected along traverses crossing the observed structures. The data analysis reveals that the concentrations of radon and helium along the Dehar lineament and the longitudinal profile (Profile D are very high compared to any other thrust/lineament of the Nurpur area. The Nadha area shows high values of radon and helium concentrations along/near the Himalayan Frontal Fault (HFF as compared to the adjoining areas. This indicates the presence of some buried fault/fault zone running parallel to the HFF, not exposed to the surface and not delineated by satellite data but is geochemically active and might be tectonically active too. Hence, soil helium and radon gas patterns have been combined with morphological and geological observations to supply useful constraints for deformation of tectonic environments.

Final survey reports on radon concentration in Japan

International Nuclear Information System (INIS)

1997-03-01

In order to grasp the present state of indoor radon concentration all over Japan, this survey was conducted in five years from Heisei 4 FY to 8 FY. Measurements were conducted using a radon and thoron separation apparatus so as to enable to develop radon and thoron separately. This was only one survey all over Japan obtained the only radon concentration by removing thoron perfectly. However, it was planned to obtain the mean indoor radon concentration all over Japan by limiting 20 houses for measurement aim because of limitation on numbers of the apparatus. In this survey, no extremely high region of the radon concentration was found. However, it was comparatively higher in Chugoku, Kinki and Kyushu-Okinawa areas, but was comparatively low in Kanto area. These results showed the same tendency as those of γ-ray level from the ground, and the radon concentration also showed temperature difference of a tendency of higher west and lower east. In this survey, seasonal variation of the radon concentration was found. In the third quarter (from October to December) maximum radon concentration (mean value: 15 Bq/cu m) and in the second quarter, the minimum concentration (mean value: 9 Bq/cu m) were observed, respectively. On comparing the indoor radon concentration of each housing structure used in enquete survey, concrete block house showed higher radon concentration. On its arithmetic mean, the radon concentration was high in order of concrete, steel frame, and wood constructions, and lowest in prefabricated house. The radon concentration of the concrete construction showed about 1.8 times higher than that of the wood construction. (G.K.)

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

International Nuclear Information System (INIS)

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

1989-01-01

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

Reducing indoor radon concentrations by passive subslab ventilation

International Nuclear Information System (INIS)

Jiranek, M.

2005-01-01

The primary objective of our study was to establish whether passive soil ventilation systems installed under existing houses have an effect on indoor radon concentrations. Experiments were conducted in two single-family houses. The soil ventilation under each house consists of the network of flexible perforated pipes laid into the layer of coarse gravel of the minimal thickness 150 mm. Soil air from the perforated pipes is ventilated by means of the vertical exhaust pipe that runs through the heated part of the house and ends above the roof of the house. At the top of the vertical exhaust a wind turbine is mounted in order to improve the stack effect during the windy weather .In addition to the soil ventilation both houses were provided with new floors composed of concrete slab and radon proof insulation made of LDPE membrane. The efficiency of passive soil ventilation systems varies within the year in dependence on the temperature gradient and wind speed. Preliminary results indicate that temperature gradient predominates. However the maximum under-pressure at the base of the vertical exhaust pipe caused by temperature differences is not so high. During one-year observation period the maximum temperature related under-pressure was only -8 Pa. The wind effect starts to be noticeable for speeds higher than 5 m/s and more apparent becomes for speeds above 10 m/s. The maximum values of under-pressure due to wind forces were measured within the range - 20 Pa and -30 Pa for wind speeds from 20 m/s to 25 m/s. Quite significant variations of the subslab under-pressure within one day were observed. The maximum under pressure was measured at late night or early morning when the outdoor temperature was the lowest. Annual variations were also confirmed. During the winter the temperature gradient is higher than in the summer time and thus the subslab under-pressure is consistently higher in the winter. Preliminary results indicate that passive soil ventilation systems with

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

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

Pilot study of the application of Tellus airborne radiometric and soil geochemical data for radon mapping

Energy Technology Data Exchange (ETDEWEB)

Appleton, J.D. [British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG (United Kingdom)], E-mail: jda@bgs.ac.uk; Miles, J.C.H.; Green, B.M.R. [Health Protection Agency (HPA) - Radiation Protection Division, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom); Larmour, R. [Environment and Heritage Service, Department of the Environment, Belfast BT7 2JA (United Kingdom)

2008-10-15

The scope for using Tellus Project airborne gamma-ray spectrometer and soil geochemical data to predict the probability of houses in Northern Ireland having high indoor radon concentrations is evaluated, in a pilot study in the southeast of the province, by comparing these data statistically with in-house radon measurements. There is generally good agreement between radon maps modelled from the airborne radiometric and soil geochemical data using multivariate linear regression analysis and conventional radon maps which depend solely on geological and indoor radon data. The radon maps based on the Tellus Project data identify some additional areas where the radon risk appears to be relatively high compared with the conventional radon maps. One of the ways of validating radon maps modelled on the Tellus Project data will be to carry out additional indoor measurements in these areas.

Metrology of radon and thoron concentrations

International Nuclear Information System (INIS)

Durcik, M; Vicanova, M.

1998-01-01

The alpha spectrometry measurements of radon (radon-222) and thoron (radon-220) concentrations by ionisation chamber, used only in laboratory conditions are described in this paper. For the measurements of radon and thoron in dwellings and work areas was proposed diffusion double chamber detector with track detector. The described dosimeter is very useful for routine measurement and would be applied in measuring of radon and thoron concentrations in caves and dwellings. Big disadvantage of the dosimeter is small holes in cover and it could not be used in dusty areas. From previous measurements of the equilibrium equivalent thoron concentrations by semiconductor detector the measured values ranged from 0.1 to 5.6 Bq m -3 in the Slovak kindergartens were obtained

Factors affecting yearly variations of indoor radon concentrations

International Nuclear Information System (INIS)

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

1996-01-01

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

Radon concentration in The Netherlands

International Nuclear Information System (INIS)

Meijer, R.J. de; Put, L.W.; Veldhuizen, A.

1986-02-01

In 1000 dwellings, which can be assumed to be an reasonable representation of the average Dutch dwellings, time averaged radon concentrations, radon daughter concentrations and gamma-exposure tempi are determined during a year with passive dosemeters. They are also determined outdoor at circa 200 measure points. (Auth.)

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

International Nuclear Information System (INIS)

Nero, A.V. Jr.

1985-04-01

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

Assessment of indoor radon gas concentration change of college

Energy Technology Data Exchange (ETDEWEB)

Park, Hoon Hee; Jeong, Eui Hwan; Kim, Hak Jae; Lyu, Kang Yeul [Dept. of of Radiological Technology, Shingu College, Seongnam (Korea, Republic of); Lee, Ju Young [Dept. of Radiological Technology, Songho College, Hoengseong (Korea, Republic of)

2017-03-15

The purpose of this study was to assess the impact by comparing the concentration of indoor radon and look for ways to lower the concentration of indoor radon gas measurements of three variables, the year of completion, volume of the building and ventilation. Measurement target is six classrooms on the sixth floor of building that was constructed in 1973 and was extended in 2011. Selected classroom's volume is different. Four classrooms were selected to compare the radon concentration in accordance with the year of completion, Classrooms that is same year of completion were selected to compare the radon concentration in accordance with the volume, six classroom was performed closure and ventilation to compare radon concentration according to ventilation. Radon concentrations in accordance with the year of building completion showed a high concentration of radon in a building recently built. Also, Radon concentration in volume is high the smaller the volume. Radon concentration change according to ventilation showed a reduction of about 80% when the ventilation than during closing. Especially, The radon concentrations were high detected while the recently year of building completion and the smaller volume. Ventilation of the three variables is considered that can be expected to exposure reduction effect by radon affecting the greatest radon concentration reduction.

Assessment of indoor radon gas concentration change of college

International Nuclear Information System (INIS)

Park, Hoon Hee; Jeong, Eui Hwan; Kim, Hak Jae; Lyu, Kang Yeul; Lee, Ju Young

2017-01-01

The purpose of this study was to assess the impact by comparing the concentration of indoor radon and look for ways to lower the concentration of indoor radon gas measurements of three variables, the year of completion, volume of the building and ventilation. Measurement target is six classrooms on the sixth floor of building that was constructed in 1973 and was extended in 2011. Selected classroom's volume is different. Four classrooms were selected to compare the radon concentration in accordance with the year of completion, Classrooms that is same year of completion were selected to compare the radon concentration in accordance with the volume, six classroom was performed closure and ventilation to compare radon concentration according to ventilation. Radon concentrations in accordance with the year of building completion showed a high concentration of radon in a building recently built. Also, Radon concentration in volume is high the smaller the volume. Radon concentration change according to ventilation showed a reduction of about 80% when the ventilation than during closing. Especially, The radon concentrations were high detected while the recently year of building completion and the smaller volume. Ventilation of the three variables is considered that can be expected to exposure reduction effect by radon affecting the greatest radon concentration reduction

Geographical information system for radon gas from soil measurement

International Nuclear Information System (INIS)

Orlando, P.; Amici, M.; Altieri, A.; Massari, P.; Miccadei, E.; Onofri, A.; Orlando, C.; Paolelli, C.; Paron, P.; Perticaroli, P.; Piacentini, T.; Silvestri, C.; Minach, L.; Verdi, L.; Bertolo, A.; Trotti, F.

2000-03-01

The working program foresees the realization of an geographical information system for the check in field of the geological parameters and determination of uranium and radium contents in various type of rocks. It is here also pointed out a measuring method for radon concentration in soil [it

Measurement of radon exhalation rate in various building materials and soil samples

Science.gov (United States)

Bala, Pankaj; Kumar, Vinod; Mehra, Rohit

2017-03-01

Indoor radon is considered as one of the potential dangerous radioactive elements. Common building materials and soil are the major source of this radon gas in the indoor environment. In the present study, the measurement of radon exhalation rate in the soil and building material samples of Una and Hamirpur districts of Himachal Pradesh has been done with solid state alpha track detectors, LR-115 type-II plastic track detectors. The radon exhalation rate for the soil samples varies from 39.1 to 91.2 mBq kg-1 h-1 with a mean value 59.7 mBq kg-1 h-1. Also the radium concentration of the studied area is found and it varies from 30.6 to 51.9 Bq kg-1 with a mean value 41.6 Bq kg-1. The exhalation rate for the building material samples varies from 40.72 (sandstone) to 81.40 mBq kg-1 h-1 (granite) with a mean value of 59.94 mBq kg-1 h-1.

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

Science.gov (United States)

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

2014-12-01

Radon is a natural gas known to be the main contributor to natural background radiation exposure and only second to smoking as major leading cause of lung cancer. The main concern is in indoor environments where the gas tends to accumulate and can reach high concentrations. The primary contributor of this gas into the building is from the soil although architectonic characteristics, such as building materials, can largely affect concentration values. Understanding the factors affecting the concentration in dwellings and workplaces is important both in prevention, when the construction of a new building is being planned, and in mitigation when the amount of Radon detected inside a building is too high. In this paper we investigate how several factors, such as geologic typologies of the soil and a range of building characteristics, impact on indoor concentration focusing, in particular, on how concentration changes as a function of the floor level. Adopting a mixed effects model to account for the hierarchical nature of the data, we also quantify the extent to which such measurable factors manage to explain the variability of indoor radon concentration. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of fresh air ventilation on indoor radon concentration

International Nuclear Information System (INIS)

Sun Hao; Wu Jianhua; Fu Shi

2012-01-01

The radon concentration of laboratory for radon simulation (LRS) was measured by the RAD7 radon monitor, and the effect of the different fresh air ventilations on indoor radon concentration was studied and analyzed. The indoor radon concentration of LRS can be accumulated up to 2000 Bq/m 3 and the average radon exhalation rate of the LRS is 14.5 Bq · m -2 . h -1 . Furthermore, when the fresh air enters into the LRS continuously, the indoor radon concentration decreases exponentially with the increase of time. The equilibrium radon concentration and equilibrium time of LRS decrease exponentially with the increase of the rate of fresh air ventilation. In addition, the indoor radon concentration increases by accumulation with the decrease of the rate of fresh air ventilation. (authors)

Radon atlas of Finland

International Nuclear Information System (INIS)

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

1997-11-01

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

Uranium in soil and gamma dose rate as proxies for the indoor radon risk: situation in Belgium

International Nuclear Information System (INIS)

Tondeur, F.; Cinelli, G.; Dehandschutter, B.

2017-01-01

Radon risk maps are usually based either on indoor radon data, or on measurements of soil gas radon and soil permeability. If these data are not available or not sufficient, it was suggested that other data could be used as an approximate substitute (a proxy) to the missing information, like the concentration of 238 U or 226 Ra in soils or the terrestrial gamma dose rate (TGDR). We examine here the correlation between airborne measurements of soil U and indoor radon, and between airborne U and TGDR, and their link with affected/unaffected areas. No clear correlation is found between airborne U and affected areas, as strongly affected areas are not characterised by a higher U level. Only the moderately affected area of Condroz can be connected to a higher U level, related to a few U anomalies. TGDR shows a rather good correlation with airborne U, but its relation with radon risk is less clear. Soil uranium and TGDR may help to screen out areas with very low U and very low TGDR, which have a low indoor radon risk, but they cannot be considered as good proxies for predicting radon-affected areas in Belgium. (authors)

Geologic influence on indoor radon concentrations and gamma radiation levels in Norwegian dwellings

Energy Technology Data Exchange (ETDEWEB)

Sundal, Aud Venche

2003-09-01

Indoor radon levels in 1618 Norwegian dwellings located in different geological settings were compared with geological information in order to determine potential correlations between geological factors and indoor radon concentrations in Norway and to establish whether geological information is useful in radon risk analysis. In two geographically limited areas, Kinsarvik and Fen, detailed geological and geochemical investigations were carried out in order to explain their elevated natural radiation environment. Significant correlations between geology and indoor radon concentrations in Norway are found when the properties of both the bedrock and the overburden are taken into account. Areas of high radon risk in Norway include 1) exposed bedrock with elevated levels of radium (mainly alum shale and granites) and b) highly permeable unconsolidated sediments derived from all rock types (mainly glaciofluvial and fluvial deposits) and moderately permeable sediments containing radium rich rock fragments (mainly basal till). More than 20 % of Norwegian dwellings located in the high-risk areas can be expected to contain radon levels exceeding 200 Bq/m3. The elevated radon risk related to penneable building grounds is illustrated in Kinsarvik where the highly permeable sediments and the large vadose zone underlying the Huse residential area enable the transport of radon from large volumes into the dwellings resulting in enhanced indoor radon concentrations. Subterranean air flows caused by temperature/pressure differences between soil air and atmospheric air and elevations differences within the Huse area are shown to strongly affect the annual variations in indoor radon concentrations. The marked contrasts in radon risk potential between different types of building grounds are clearly illustrated in the Fen area where outcrops of the radium rich Fen carbonatites represent areas of high radon risk while only low levels of both indoor radon concentrations and indoor gamma

Environmental radioactivity level and soil radon measurement of a volcanic region in Cameroon

International Nuclear Information System (INIS)

Ngachin, M.; Garavaglia, M.; Giovani, C.; Kwato Njock, M.G.

2007-02-01

A part of the survey programme on the evaluation of environmental radioactivity in Cameroon has just been initiated. The radioactivity level of soils in a volcanic area in Cameroon was determined and discussed. 30 soils samples were collected from Buea and Limbe cities located in the south-western Cameroon. These two regions are known for theirs volcanic grounds due to the presence of Mount Cameroon mountain. The activity concentrations of natural radionuclides as well as that of the fission product were evaluated by gamma-ray spectrometry using a hyper purity germanium detector (HPGe). The ranges of concentrations in the surveyed soils were 11 - 17 Bq kg -1 , 22 - 36 Bq kg -1 and 43 - 201 Bq kg -1 for 226 Ra, 232 Th and 40 K, respectively. The radioisotope 137 Cs was also found but in a very small amount. The outdoor absorbed dose rate 1 m above ground with the corresponding annual effective dose rate, assuming a 20% occupancy factor were estimated. The radium equivalent and the external hazard index were also evaluated and results are compared with available data from other studies and with the world average value (UNSCEAR, 1988, 2000). A solid state nuclear track detector (SSNTDs), LR-115 was used for soil radon measurements at a depth of 50 cm. The ranges of soil radon concentrations were 6.7 - 10.8 kBq m -3 and 5.5 - 8.7 kBq m -3 in Buea and Limbe, respectively. A positive correlation was found between concentrations of radium measured with γ-spectrometry and the soil radon concentrations measured with the nitrate cellulose detectors. The results of this study provide the radioactivity level in soil of a volcanic area, which has been found to be within the safety limits. The south-western Cameroon can be considered as having normal natural background radiation in normal living conditions. (author)

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/

Investigation of features in radon soil dynamics and search for influencing factors

Science.gov (United States)

Yakovlev, Grigorii; Cherepnev, Maxim; Nagorskiy, Petr; Yakovleva, Valentina

2018-03-01

The features in radon soil dynamics at two depths were investigated and the main influencing factors were revealed. The monitoring of radon volumetric activity in soil air was performed at experimental site of Tomsk Observatory of Radioactivity and Ionizing Radiation with using radon radiometers and scintillation detectors of alpha-radiation with 10 min sampling frequency. The detectors were installed into boreholes of 0.5 and 1 m depths. The analysis of the soil radon monitoring data has allowed revealing some dependencies at daily and annual scales and main influencing factors. In periods with clearly defined daily radon variations in the soil were revealed the next: 1) amplitude of the daily variations of the soil radon volumetric activity damps with the depth, that is related with the influence of convective fluxes in the soil; 2) temporal shift between times of occurrence of radon volumetric activity maximum (or minimum) values at 0.5 m and 1 m depths can reach 3 hours. In seasonal dynamics of the soil radon the following dependences were found: 1) maximal values are observed in winter, but minimal - in summer; 2) spring periods of snow melting are accompanied by anomaly increasing of radon volumetric activity in the soil up to about 3 times. The main influencing factors are atmospheric precipitations, temperature gradient in the soil and the state of upper soil layer.

Distribution of radon concentration in residences and others buildings of Belo Horizonte city, MG, Brazil

International Nuclear Information System (INIS)

Santos, Talita de Oliveira

2010-01-01

Human beings are exposed to ionizing radiation from many natural sources. Radon and its progeny have been recognized as the most important contributors to the natural radioactivity dose, accounting for about half of all human exposure to ionizing radiation. Radon is a α-radioactive noble gas derived from the natural series of uranium and thorium, which occurs in a wide concentration range in all geological materials, especially, in rocks, soils and waters. By diffusion and convection, radon migrates from the rocks and soils to atmosphere and through fissures, pipes and holes it may enter the dwellings and other buildings. Another important radon source in dwellings is its emanation from the construction material. The radon progeny concentration in dwellings has been receiving considerable global attention due to its potential effect in causing lung cancer if it deposited in upper respiratory tract when inhaled. This work presents radon concentration distribution in dwellings in Metropolitan Region of Belo Horizonte - RMBH. The geological settings of the area are Archean rocks of Granitic Gneissic Complex and of metasediments sequences of the great Precambrian unit of the Iron Quadrangle of Minas Gerais, Brazil. Radon concentration measurements were carried out with continuous detector AlphaGUARD PQ200PRO (Genitron), in passive mode and with passive detectors E-PERM Electrets Ion Chamber-EIC. The radon progeny concentration was carried out with a solid state alpha spectroscope, the DOSEman PRO (Sarad). It was found an indoor radon concentration varying in a large range from 4 to 2664,0 Bq.m"-"3, with an average value of 108.0 Bq.m"-"3, median of 70 Bq.m"-"3, geometric mean equal to 76 Bq.m"-"3 and standard deviation of 170 Bq.m"-"3. About 15% of the results are over the United States Environmental Protection Agency (U.S. EPA) actions level, which is 148 Bq.m"-"3.The equilibrium factor between radon and its progeny were determined in dwellings, as 0.3 in average

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

Monitoring of soil radon by SSNTD in Eastern India in search of possible earthquake precursor.

Science.gov (United States)

Deb, Argha; Gazi, Mahasin; Ghosh, Jayita; Chowdhury, Saheli; Barman, Chiranjib

2018-04-01

The present paper deals with monitoring soil radon-222 concentration at two different locations, designated Site A and Site B, 200 m apart at Jadavpur University campus, Kolkata, India, with a view to find possible precursors for the earthquakes that occurred within a few hundred kilometers from the monitoring site. The solid state nuclear track detector CR-39 has been used for detection of radon gas coming out from soil. Radon-222 time series at both locations during the period August 2012-December 2013 have been analysed. Distinct anomalies in the soil radon time series have been observed for seven earthquakes of magnitude greater than 4.0 M that occurred during this time. Of these, radon anomalies for two earthquakes have been observed at both locations A and B. Absence of anomalies for some other earthquakes has been discussed, and the observations have been compared with some earthquake precursor models. Copyright © 2018. Published by Elsevier Ltd.

Radioactivity level and soil radon measurement of a volcanic area in Cameroon

International Nuclear Information System (INIS)

Ngachin, M.; Garavaglia, M.; Giovani, C.; Kwato Njock, M.G.; Nourreddine, A.

2008-01-01

The radioactivity level of soils in a volcanic area in Cameroon was determined and discussed. Thirty soils samples were collected from Buea and Limbe cities located in the south-western Cameroon. These two regions are known for theirs volcanic grounds due to the presence of Mount Cameroon Mountain. The activity concentrations of natural radionuclides as well as that of the fission product were evaluated by gamma-ray spectrometry using a hyper-purity germanium detector (HPGe). The ranges of concentrations in the surveyed soils were 11-17 Bq kg -1 , 22-36 Bq kg -1 and 43-201 Bq kg -1 for 226 Ra, 232 Th and 40 K, respectively. The radioisotope 137 Cs was also found but in a very small amount. The outdoor absorbed dose rate 1 m above ground with the corresponding annual effective dose rate, assuming a 20% occupancy factor was estimated. The radium equivalent and the external hazard index were also evaluated and results are compared with available data from other studies and with the world average value [United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), 1988. Sources, Effects and Risks of Ionizing Radiation. Report to the General Assembly on the Effects of Atomic Radiation. United Nations, New York; UNSCEAR, 2000. Sources and Effects of Ionizing Radiations. Report to the General Assembly with Scientific Annexes. United Nations, New York]. A solid state nuclear track detector (SSNTD), LR-115 was used for soil radon measurements at a depth of 50 cm. The ranges of soil radon concentrations were 6.7-10.8 kBq m -3 and 5.5-8.7 kBq m -3 in Buea and Limbe, respectively. A positive correlation was found between concentrations of radium measured with γ-spectrometry and the soil radon concentrations measured with the nitrate cellulose detectors. The results of this study provide the radioactivity level in soil of a volcanic area, which has been found to be within the safety limits. The south-western Cameroon can be considered as having normal

Influence of source type and air exchange on variations of indoor radon concentration

International Nuclear Information System (INIS)

Arvela, H.; Winqvist, K.

1986-04-01

The model relates radon concentration to source strength and its variations, air exchange rate and meteorological factors. Two types of sources have been studied. The pressure difference dependent source is made up of radon transported with soil pore air and driven by pressure difference due to the stack effect. The constant source is made up of radon transported by diffusion from building materials or from soil. The air exchange rate depends exponentially on indoor-outdoor temperature difference and linearly on wind speed. These two inputs have been summed in quadrature. In a house with a constant source radon concentration decreases when the air exchange rate increases due to the increasing temperature difference, whereas the pressure difference dependent source causes an increasing concentration. This is due to the fact that the effect of the source strength increase is stronger than the decreasing effect of air exchange on concentration. The winter-summer concentration ratio depends on the combination of the two types of source. A pure pressure dependent source leads to the winter-summer ratio of 2-3.5 (winter -5 deg C, summer +15 deg C, wind speed 3 m/s). A strong contribution of a constant source is needed to cause a summer concentration higher than the winter concentration. The model is in agreement with the winter-summer concentration ratios measured. This ratio increases with the increasing winter concentration. The measured ratio was near 1.0 for houses with winter concentration of 200 Bq m''3 or less and near 2.0 with concentration of 1000 Bq m''3. In a house with a constant source, the diurnal maximum occurs in the afternoon, while in houses with a pressure difference dependent source the time of maximum is early in the morning

Radon concentrations in homes in an area of dolomite bedrock: Door County, Wisconsin

International Nuclear Information System (INIS)

Hawk, K.; Stieglitz, R.D.; Norman, J.C.

1993-01-01

A statewide survey by the Wisconsin Department of Health and Social Services with U.S.E.P.A. assistance reported an anomalously high percentage of homes in Door County with radon concentrations in excess of 20 pCi/L. The results were of interest because the county is underlain by marine sedimentary rocks rather than the igneous and metamorphic crystalline types usually associated with elevated radon concentrations. A voluntary population of 55 homes was tested for radon using activated charcoal canisters. This population was also asked to provide questionnaire response data on family, home, and socioeconomic aspects. The data were separated into socioeconomic, energy efficiency, radon access, and karst level categories and statistically analyzed. A subpopulation was selected from the larger population for detailed site investigation, which included additional in-home air testing and, at some sites, water supply analysis and in-ground testing for radon. The field investigations collected information on the geology, soil, topography, and home construction and use. The results of the investigation verified and characterized the radon occurrences in Door County. The presence or absence of karst features is shown to be statistically significant to radon levels. 23 refs., 5 figs., 3 tabs

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

Characterizing the source of radon indoors

International Nuclear Information System (INIS)

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

1983-09-01

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

Evaluation of radon concentration in dwellings and well water of Parana State-Brazil

International Nuclear Information System (INIS)

Correa, Janine Nicolosi

2011-01-01

Considering the growing interest of International Agencies and national Governmental organs in studies and measurements of radon activity in air, soil gas and ground water (mainly from artesian wells) as well as scarceness of such measurements at Brazilian territory, present studies were initiated by the Laboratory of Applied Nuclear Physics of Federal University of Technology - Parana (UTFPR) in collaboration with the Institute of Radiation Protection and Dosimetry (IRD) and the Center of Nuclear Technology Development (CDTN) of Brazilian Commission on Nuclear Energy (CNEN). This Collaboration started in 2003. Radon monitoring program is based mainly on use of Solid State Nuclear Track Detectors for radon activity measurements in air. Continuous electronic radon detectors are used for radon measurements in soil gas and water. Current work presents the results of indoor 222 Rn activity of dwellings and working places of Curitiba-PR and radon concentration in ground water samples from artesian wells from aquifers of the same area. The indoor measurements of radon activity were performed using Solid State Nuclear Track Detectors CR-39. After the exposition, CR-39 detectors were submitted to chemical development which permitted to make alpha particle tracks counting. The results of calibration of CR-39 together with efficiency of used exhalation chambers as well as alpha particle tracks chemical development procedure were performed in cooperation with CDTN and collaboration with the National Institute of Radiological Sciences (NIRS). The major part of indoor 222 Rn concentration in residences was found below 100 Bq/m3. In the case of working places, all measurements present 222 Rn concentration bellow 100 Bq/m3. The studies of radon activity in water were performed using the samples of water from artesian wells submitted to recursive measurements by instant radon detector AlphaGUARD PQ2000 PRO during few weeks with intervals of about 4 days between each measurement

A study of radon 222 permeation through plastic membranes. Application to a method of radon measurement in water and saturated soils

International Nuclear Information System (INIS)

Labed, V.

1991-04-01

In order to improve the BARASOL R device and to use it in water-saturated soils and in pressure constraint conditions, we have studied radon 222 permeation through plastic membranes. While the permeation process usually takes place between two media being in the same state, most often gaseous, the present study describes the transfer of radon 222 from the water to the air via a membrane. Polypropylene membranes have been tested with an experimental set-up by monitoring the evolution of radon concentrations in water and in air. The permeation coefficient and the activation energy were calculated in various conditions. With a second experimental set-up, we have tested the polyethylene membrane which has been adapted on the BARASOL. In these conditions, we have shown that it is possible to measure radon in water at concentrations around 10 3 Bq.m -3 [fr

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

NW Oregon radon potential based on soil radionuclides

International Nuclear Information System (INIS)

Ashbaugh, S.G.; Burns, S.F.

1993-01-01

Analysis of soil by gamma spectroscopy for Bi-214 (Ra-226) suggests low to moderate radon potentials for northwest Oregon in areas with low to moderate soil permeabilities. Very low radon potential zones (0.2 to 0.7 pCi/g) comprise 58% of the study area. These zones are frequently associated with soils developed from undifferentiated basalts and andesites of the Cascade Range, and basalts and undifferentiated mafic intrusives of the Coast Range. Low radon potential zones (0.7 to 1.2 pCi/g) comprise 28% of the study area. These zones are generally associated with Missoula Flood sediments, pre-Holocene loess in the Portland area, and Eocene/Oligocene marine sediments low in mica and/or tuff along the foothills of the Willamette Valley. Moderate radon potential zones (1.2 to 3.0 pCi/g) comprise 14% of the study area. These zones are often associated with the lateritic soils derived from Columbia River Basalts and Eocene/Oligocene marine sediments high in mica and/or tuff along the western edges of the Willamette Valley. A closer examination of soils in the Portland and Salem areas shows that: (1) Bi-214/K-40 ratios increase from 0.07 to 0.35 with respect to solid development, indicating K-40 to be preferentially leached over Ra-226; (2) clay development within B-horizons does not reflect a significant increase in Ra-226 mobility; and (3) elevated indoor radon within the Portland and Salem areas can be attributed to high soil permeabilities rather than soil chemistry

Radon concentration in a house of Calvados

International Nuclear Information System (INIS)

Leleyter, L.; Riffault, B.; Mazenc, B.

2010-01-01

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

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

Science.gov (United States)

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

1988-01-01

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

Theory of radon exhalation into accumulators placed at the soil-atmosphere interface

International Nuclear Information System (INIS)

Mayya, Y. S.

2004-01-01

A theoretical analysis is provided for the phenomenon of radon diffusion into cylindrical accumulators (inverted cups), which are commonly used for the measurement of radon exhalation rates from the earth's surface. Analytical solutions to the diffusion equations in the soil and the cup spaces are obtained by a two-dimensional (2-D) analysis that takes into account the perturbation in the horizontal and vertical radon concentration profiles brought about by the presence of the cup. The mixed nature of the boundary conditions at the soil surface and the cup-soil interface is handled by dual integral equation techniques. The treatment includes steady-state and time-dependent situations with and without ventilation. Formulae are derived for the effective time constant of radon build-up in the cup and for the back diffusion correction factors in different experimental situations. It is found that the effective time constant of radon build-up is much larger than the radon decay constant and it increases for smaller cups. The back diffusion correction factors to be employed in one-time measurement methods also increase as the cup dimensions decrease. The present work provides an analytical basis of an earlier numerical treatment for the growth curve analysis of the same problem. Although the results are based on the assumptions of somewhat ideal nature for mathematical tractability, they provide upper bound estimates of the phenomenon of back diffusion. Some practical applications of the results for extracting diffusion length of radon in materials are also suggested. (authors)

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.)

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)

Measurements of indoor radon concentration in Libyan cities

International Nuclear Information System (INIS)

Elarabiy, S. F.; Khalifa, M.; Misrati, N.; Chahboune, N.; Ahmed, M.

2012-12-01

Studies confirm that the risk of exposure to indor radon is attributable to lung cancer worldwide. The relationship between radon exposure and cancer is a linear one which necessitates for need for measurements of indoor radon concentration. This paper presents the results of measurements of indoor radon in several libya cities using CR-39 plastic. The results showed that the average radon concentration in the cities of Tripoli, Al-harcha and Alrajaban were 48.8 Bg/m 3 , 51.4 Bg/m 3 and 55.5 Bg/m 3 respectively. The average indoor radon concentration in Libya is low comparing with other studies. (Author)

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

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

International Nuclear Information System (INIS)

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

2010-01-01

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

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/.

PO.RA project. An analysis on gas radon concentrations in soil versus fluctuations in the groundwater table; Progetto PO.RA.. Analisi della concentrazione di gas radon nel non saturo in relazione alla soggiacenza della falda freatica

Energy Technology Data Exchange (ETDEWEB)

Serentha' , C.; Torretta, M. [Agenzia Regionale per la Protezione dell' Ambiente della Lombardia, Dipartimento di Monza, Monza (Italy)

2001-09-01

Man is daily exposed to natural radiation, mainly due to cosmic rays and natural radioactive elements, whose most important radioactive daughters are {sup 222}Rn (radon) and {sup 220}Rn (thoron). Being these ones gaseous, they can spread through the ground, reaching the atmosphere and accumulating in rooms, where their concentrations may be very high. As radon exhalation is strongly connected with the hydrogeological features of the environment, this study tried to find a relationship between fluctuations in the groundwater table and gas radon concentrations in soil, in order to try estimates of indoor radon concentrations. [Italian] L'uomo e' quotidianamente esposto ad una radioattivita' di origine naturale, dovuta principalmente ai raggi cosmici ed alla presenza di alcuni elementi radioattivi naturali, i cui discendenti radioattivi piu' importanti sono il {sup 222}Rn (radon) e il {sup 220}Rn (thoron). Tali elementi, a causa della loro natura gassosa, si possono diffondere attraverso il terreno e raggiungere l'atmosfera sovrastante; cio' puo' provocarne l'accumulo in ambienti chiusi, dando luogo a concentrazioni anche elevate con possibili conseguenze sulla salute. Poiche' l'esalazione del gas radon e' foremente legata alle caratteristiche idrogeologiche dell'ambiente, in questo lavoro si e' cercato di definire una relazione che legasse le variazioni della soggiacenza della falda freatica alle variazioni della concentrazione del gas radon nel non saturo, al fine di verificare se sia possibile effettuare un'attivita' previsionale applicabile ai rilievi di gas radon indoor.

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

International Nuclear Information System (INIS)

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

2015-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-07-01

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

Detecting buried radium contamination using soil-gas and surface-flux radon meaurements

International Nuclear Information System (INIS)

Karp, K.E.

1988-06-01

The Technical Measurements Center (TMC) has investigated the effectiveness of using radon soil-gas under surface-flux measurments to locate radium contamination that is buried sufficiently deep to be undetectable by surface gamma methods. At the first test site studied, an indication of a buried source was revealed by mapping anomalous surface-flux and soil-gas concentrations in the near surface overburden. The mapped radon anomalies were found to correspond in rough outline to the shape of the areal extent of the deposit as determined by borehole gamma-ray logs. The 5.9pCi/g radium deposit, buried 2 feet below the surface, went undetected by conventional surface gamma measurements. Similar results were obtained at the second test site where radon and conventional surface gamma measurements were taken in an area having radium concentrations ranging from 13.3 to 341.0 pCi/g at a depth of 4 feet below the surface. The radon methods were found to have a detection limit for buried radium lower than that of the surface gamma methods, as evidenced by the discovery of the 13.3 pCi/g deposit which went undetected by the surface gamma methods. 15 refs., 33 figs., 8 tabs

Generation and mobility of radon in soil

International Nuclear Information System (INIS)

1992-01-01

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

Measurement of radon concentration in water by means of {alpha}, {gamma} spectrometry. Radon concentration in ground and spring water in Hiroshima Prefecture

Energy Technology Data Exchange (ETDEWEB)

Shizuma, Kiyoshi [Hiroshima Univ. (Japan)

1997-02-01

Radon ({sup 222}Rn, T{sub 1/2}=3.8235{+-}0.0003d) is {alpha}-ray releasing nuclide, so that it can not be detected by {gamma}-ray measurement. But, the daughter nuclides {sup 214}Pb (T{sub 1/2}=26.8 min) and {sup 214}Bi (T{sub 1/2}=19.9 min) release {gamma}-ray, accordingly they are measured by Ge detector. Their radioactive equilibrium is kept in the closed vessel, because their half-lives are shorter than that of radon. We developed a measurement method of radon concentration by means of {gamma}-spectrometry. We applied this method to catch radon in the atmosphere by active carbon. The same principle can be applied to radon in water. Radon concentrations in the ground water were measured in 22 points in the Higashi-Hiroshima city and 82 points in the Hiroshima prefecture. The efficiencies of {gamma}-ray were determined. The radon concentration showed between 11 and 459 Bq/l and the average was 123 Bq/l. The high concentration of radon was distributed in the spring of granitic layer and higher concentration of radon were observed in the ground water of fault. (S.Y.)

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

Design Criteria for Achieving Low Radon Concentration Indoors

DEFF Research Database (Denmark)

Rasmussen, Torben Valdbjørn

2016-01-01

Design criteria for achieving low radon concentration indoors are presented in this paper. The paper suggests three design criteria. These criteria have to be considered at the early stage of the building design phase to meet the latest recommendations from the World Health Organization in most...... countries. The three design criteria are; first, establishing a radon barrier facing the ground; second, lowering the air pressure in the lower zone of the slab on ground facing downwards; third, diluting the indoor air with outdoor air. Three criteria when used can prevent radon infiltration and lower...... the radon concentration in the indoor air. In addition, a cheap and reliable method for measuring the radon concentration in the air indoors is described. The provision on radon in the Danish Building Regulations complies with the latest recommendations from the World Health Organization. Radon can cause...

Diagnostics of and measures against radon concentrations in a dwelling

International Nuclear Information System (INIS)

Berger, H.

1994-02-01

Results are presented of measurements in a test-dwelling in the period april 1993 - november 1993. The purpose of the measurements was to investigate the possibilities of using a blower door (a fan in a wall of the dwelling) for specifying sources of radon in the dwelling, employing the diagnostic method developed at the KVI (Nuclear Physics Accelerator Institute in Groningen, Netherlands). Special attention is paid to the measurement of two input variables for the diagnostic method: transparency of the walls of the dwelling and the strength of static sources. Also measures aimed at reducing radon concentrations in the dwelling are discussed. The main conclusions are that (a) the pressure-variation method is a valid procedure to measure the transparency of walls and floors; (b) the blower door is a suitable technique for arriving at a correct diagnosis; and (c) over-pressurizing the crawl-space is the most effective measure in reducing the radon concentration of the crawl-space. More research on air flows in the soil is recommended. 21 figs., 28 tabs., 7 refs

Identification of radon anomalies in soil gas using decision trees and neural networks

International Nuclear Information System (INIS)

Zmazek, B.; Dzeroski, S.; Torkar, D.; Vaupotic, J.; Kobal, I.

2010-01-01

The time series of radon ( 222 Rn) concentration in soil gas at a fault, together with the environmental parameters, have been analysed applying two machine learning techniques: (I) decision trees and (II) neural networks, with the aim at identifying radon anomalies caused by seismic events and not simply ascribed to the effect of the environmental parameters. By applying neural networks, 10 radon anomalies were observed for 12 earthquakes, while with decision trees, the anomaly was found for every earthquake, but, undesirably, some anomalies appeared also during periods without earthquakes. (authors)

Correlation of indoor radon levels with physical properties of local soil in Khammam district, Andhra Pradesh, India

International Nuclear Information System (INIS)

Sreenivasa Reddy, B.; Bhaskar Reddy, G.; Sreenath Reddy, M.; Gopal Reddy, Ch; Yadagiri Reddy, P.; Rama Reddy, K.

2006-01-01

Indoor radon contributes significantly to the total radiation exposure caused to human beings. As might be expected, the physical characteristics of soil play key roles in determining the radon concentration in nearby buildings. The physical characteristics of soil, such as density, specific gravity and porosity in the vicinity of the dwellings of Khammam district, Andhra Pradesh, India, have been determined using core cutter and specific gravity bottle. In the present paper, these parameters are correlated with the average indoor radon levels estimated for a year using solid state nuclear track detectors. (author)

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

International Nuclear Information System (INIS)

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

1999-01-01

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

Measurement of mean radon concentrations in the Tokai districts

International Nuclear Information System (INIS)

Iida, Takao; Ikebe, Yukimasa; Yamanishi, Hirokuni

1989-01-01

This paper describes an electrostatic integrating radon monitor designed for the environmental radon monitoring and longterm measurements of mean radon concentrations in outdoor and indoor air. The position of the collecting electrode within the monitor was determined based on the calculation of the internal electric field. The radon exchange rate between the monitor and the outside air through the filter was 0.75 h -1 . The exchange rate can make the radon concentration inside the monitor to follow thoroughly the outside concentration. Since the electrostatic collection of RaA + ( 218 Po + ) atoms depends on the humidity of the air, the inside of the monitor was dehumidified with a diphosphorus pentaoxide (P 2 O 5 ) drying agent which is powerful and dose not absorb radon gas. From the relationship between track density and radon exposure, the calibration factor was derived to be 0.52 ± 0.002 tracks cm -2 (Bq m -3 h) -1 . The detection limit of mean radon level is 1.2 Bq m -3 for an exposure time fo 2 months. The mean radon concentrations in various environments were measured through the year using the monitors this developed. The annual mean outdoor radon level in the Tokai districts was 7.0 Bq m -3 . The mean radon concentrations was found to vary from 3.5 to 11.7 Bq m -3 depending upon the geographical conditions even in this relatively small region. The annual indoor radon concentrations at Nagoya and Sapporo ranged from 6.4 to 11.9 Bq m -3 and from 15.5 to 121.1 Bq m -3 , respectively, with the type of building material and the ventilation rate. The mean radon concentrations in tightly built houses selected at Sapporo are about 10 times as high as those in drafty houses at Nagoya. (author)

Understanding the origin of radon indoors: Building a predictive capability

International Nuclear Information System (INIS)

Sextro, R.G.

1985-12-01

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

Soil Radon In The Nigerian Younger Granites | Dewu | Nigerian ...

African Journals Online (AJOL)

... not had enough time to attain equilibrium with its daughters. In general, the results suggest that with proper control, soil radon measurements over the Younger Granite can be used for uranium exploration in the region. Keywords: Radon, younger granite, soil uranium, half-lifeand thorium. Nigerian Journal of Physics Vol.

Radioactivity level and soil radon measurement of a volcanic area in Cameroon

Energy Technology Data Exchange (ETDEWEB)

Ngachin, M. [Center for Atomic, Molecular Physics and Quantum Optics, University of Douala, P.O. Box 8580, Douala (Cameroon); Abdus Salam International Center for Theoretical Physics, Strada Costiera 11, 34014 Trieste (Italy); Institut Pluridisciplinaire Hubert-Curien, UMR7178 CNRS-IN2P3 and Universite Louis Pasteur, 23 rue de Loess, BP 28, F-67037 Strasbourg cedex 02 (France)], E-mail: mngachin@yahoo.com; Garavaglia, M.; Giovani, C. [Regional Agency for Environmental Protection (ARPA), 91 via Tavagnacco, 33100 Udine (Italy); Kwato Njock, M.G. [Center for Atomic, Molecular Physics and Quantum Optics, University of Douala, P.O. Box 8580, Douala (Cameroon); Nourreddine, A. [Institut Pluridisciplinaire Hubert-Curien, UMR7178 CNRS-IN2P3 and Universite Louis Pasteur, 23 rue de Loess, BP 28, F-67037 Strasbourg cedex 02 (France)

2008-07-15

The radioactivity level of soils in a volcanic area in Cameroon was determined and discussed. Thirty soils samples were collected from Buea and Limbe cities located in the south-western Cameroon. These two regions are known for theirs volcanic grounds due to the presence of Mount Cameroon Mountain. The activity concentrations of natural radionuclides as well as that of the fission product were evaluated by gamma-ray spectrometry using a hyper-purity germanium detector (HPGe). The ranges of concentrations in the surveyed soils were 11-17 Bq kg{sup -1}, 22-36 Bq kg{sup -1} and 43-201 Bq kg{sup -1} for {sup 226}Ra, {sup 232}Th and {sup 40}K, respectively. The radioisotope {sup 137}Cs was also found but in a very small amount. The outdoor absorbed dose rate 1 m above ground with the corresponding annual effective dose rate, assuming a 20% occupancy factor was estimated. The radium equivalent and the external hazard index were also evaluated and results are compared with available data from other studies and with the world average value [United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), 1988. Sources, Effects and Risks of Ionizing Radiation. Report to the General Assembly on the Effects of Atomic Radiation. United Nations, New York; UNSCEAR, 2000. Sources and Effects of Ionizing Radiations. Report to the General Assembly with Scientific Annexes. United Nations, New York]. A solid state nuclear track detector (SSNTD), LR-115 was used for soil radon measurements at a depth of 50 cm. The ranges of soil radon concentrations were 6.7-10.8 kBq m{sup -3} and 5.5-8.7 kBq m{sup -3} in Buea and Limbe, respectively. A positive correlation was found between concentrations of radium measured with {gamma}-spectrometry and the soil radon concentrations measured with the nitrate cellulose detectors. The results of this study provide the radioactivity level in soil of a volcanic area, which has been found to be within the safety limits. The south

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

International Nuclear Information System (INIS)

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

1980-01-01

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

Building and environmental factors associated with elevated radon levels in rural Iowa homes

International Nuclear Information System (INIS)

Weih, L.M.B.

1993-01-01

This work examined the relationships between home construction, soil, and climatic factors with radon concentration in 585 rural Iowa homes, screened in winter of 1989. The specific goals of this work were to evaluate the utility of Soil Conservation data in describing radon occurrence in Iowa, and to assess the joint influence of construction and environmental characteristics on predicting radon concentration in homes. A follow-up study in a subset of homes evaluated the variability of radon screening measurements over time. The first part found that the relationship between radon concentration and home construction factors was dependent on location of the radon test in homes. In basements, wall construction and degree of energy efficiency predominated in predicting radon concentration. On upper floors, age of home predominated in predicting radon concentration, with a general decrease in radon concentration with age of home. The second part found that texture of the soil on which the home is located was the most important predictor of radon concentration for homes tested in basements, but the explanatory power was low. Precipitation in the year preceding screening was negatively correlated with radon concentration in homes, but the relationship was only apparent when basement wall type and soil texture were accounted for. Regional trends were not apparent except in describing the relative distribution of soil texture classes across the state. Radon concentration on upper floors of homes was not well described by either soil factors or precipitation. In 1992 a decrease of 36% and 51% from 1989 radon screening levels was found for homes tested in basements and upper floors, respectively. This data set included pair measurements of the same testing location in homes tested in winter 1989. Temperature differences were positively correlated with radon concentration and precipitation differences were not significantly associated with change in radon concentration

Concentration variation of radon in the room

International Nuclear Information System (INIS)

Komaruzaman Mohd Noor; Haziman Hassan; Rosli Mahat; Yusof Md Amin

1995-01-01

The study was carried out to determine the variation of radon concentration in the room. Radon detector used was solid nuclear tracks detector (SSNTD) LR-115. From this result, suitable points to make radon measurement was determined

Mapping the geogenic radon potential of the eastern Canary Islands.

Science.gov (United States)

Rubiano, Jesús G.; Alonso, Hector; Arnedo, Miguel. A.; Tejera, Alicia; Martel, Pablo; Gil, Juan M.; Rodriguez, Rafael; González, Jonay

2014-05-01

The main contribution of indoor radon comes from soils and thus, the knowledge of the concentration of this gas in soils is important for estimating the risk of finding high radon indoor concentrations. To characterize the behavior of radon in soils, it is common to use the a quantity named Radon Potential which results of a combination of properties of the soil itself and from the underlying rock, such as concentration and distribution of radium, porosity, permeability, the moisture content and meteorological parameters, among others. In this work, the results three year of campaigns of measurement radon gas as well as the permeability in soils of the Eastern Canary Islands (Gran Canaria, Fuerteventura and Lanzarote) are presented. By combining these two parameters and through the use of geostatistic interpolation techniques, the radon potential of soils is estimated and it is used to carry on a classification of the territory into hazard zones according to their potential for radon emanation. To measure the radon soil gas a probe equipped with a "lost" sharp tip is inserted to the desired sampling depth. One of the characteristics of the Canary Islands is the absence of developed soils and so the bedrock is found typically at very shallow depth. This fact has led us to adopt a sampling depth of 50 cm at most. The probe is connected to the continuous radon monitor Durridge RAD7 equipped with a solid-state alpha spectrometer to determine concentration radon using the activity its short-lived progeny. Dried soil air is delivered to the RAD7 radon monitor by pumping. A half hour counting time for all sampling points has been taken. In parallel to the radon measurement campaign, the permeability of soils has also been determined at each point using the permeameter RADON-JOK. The principle of operation of this equipment consists of air withdrawal by means of negative pressure. The gas permeability is then calculated using the known flow of air flowing through the probe

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)

Monitoring of radon isotopes and affiliated disintegration products (ADP) in soil air and water

International Nuclear Information System (INIS)

Anshakov, O. M.; Bogacheva, E. S.; Bouchawach, Fauzi Hadji; Chudakov, V. A.

2009-01-01

The subject of research is a physic and mathematical model of the process of radon determining in soil air and water by the way of its sampling for absorbent, preparation of a sample to measurement taking, ADP radiometry: Pb- 214, Bi-214 in a sample, calculation of radon activity concentration in an initial medium. The target of research is experimental determining of assignment parameters of devices, used for radon sampling and measurement of its ADP activity in relation to the methods being developed with estimation of their expected metrological performance, analysis of radon and ADP content for ecological research in relation to objectives of radon and ADP monitoring in environmental objects. (author)

Rapid determination of radon daughter concentrations

International Nuclear Information System (INIS)

Bigu, J.

1990-08-01

A technical evaluation of four radon 222 progeny measuring instruments has been conducted. The evaluation has been carried out under laboratory controlled conditions and at several locations in an underground uranium mine. The laboratory evaluation consisted of a thorough study of the behaviour and performance of the instruments under a wide variety of environmental conditions such as radon 222 gas concentration, radon 222 progeny concentration, temperature, relative humidity, aerosol concentration, and gamma-field exposure. The four instruments tested were: the Pylon WL-1000C, the MDA IWLM-811, the MIMIL IIM, and the EDA WLM-30. The readings of the instruments were compared with a widely accepted radon 222 progeny concentration measuring method, namely, the Thomas-Tsivoglou method. Two variables affected two instruments significantly, namely, under high aerosol concentration conditions, one of the instruments (EDA WLM-30) ceased to operate because of filter loading. The other variable was gamma-field exposure which affected another instrument (MDA-811) adversely. The instruments were rated according to several criteria. The overall best performer was the MIMIL IIM, although other instruments also fared quite well under a variety of experimental conditions

Influence of surficial soil and bedrock on indoor radon in New York State homes. Task 2, Subtask 2 of an investigation of infiltration and indoor air quality in New York State homes

International Nuclear Information System (INIS)

Kunz, C.

1989-10-01

Radon can enter a building from soil and bedrock through cracks or openings in the basement. Extrapolation from data obtained from studies of miners exposed to high concentrations of radon and other carcinogens over long periods indicates that radon gas in the home poses an increased risk of lung cancer. The project was initiated to determine the characteristics of soil and bedrock that contribute to the availability of radon for infiltration into the home, and the feasibility of using soil characteristics in mapping areas at higher risk for above-average indoor radon in New York State. After conducting soil surveys across the State, the researchers choose four areas for further study. Fifteen homes in each area were tested for indoor air concentrations of radon, air infiltration into the home, radon concentrations in the soil, and the permeability of the soil for gas flow. The researchers concluded that these parameters could be combined to obtain a Radon Index Number to predict mean indoor radon levels for a given area with similar soil geology. However, this measure has a limited ability to predict indoor radon levels for a particular home due to variations in construction as well as differences in soil and bedrock

Modelization of the radon emanation from natural sources in the soil

International Nuclear Information System (INIS)

Sabir, A.; Marah, H.; Hlou, L.; Klein, D.; Chambaudet, A.

1996-01-01

To evaluate the radon emanation and hence the risk to populations, we have adapted an original mathematical model based on the method of distribute parcels (L. Hlou, These d'etat, Faculte des Sciences, Kenitra, MAROC, 1994). This allows us to follow the migration, in time and space, of a quantity of radon produced in a unit volume as a function of the geological, morphological and structural characteristics of the site studied. Knowing the petrographic and pedologic parameters enables us to calculate the radon concentration in all points inside the soil of the site as well as the radon emanation in the atmosphere. It is therefore possible to calculate the radiological risk for populations brought to live on the site studied. Different applications of this model have been realised in Morocco and in France to demonstrate its efficiency. (author)

Indoor radon concentration forecasting in South Tyrol

International Nuclear Information System (INIS)

Verdi, L.; Weber, A.; Stoppa, G.

2004-01-01

In this paper a modern statistical technique of multivariate analysis is applied to an indoor radon concentration database. Several parameters are more or less significant in determining the radon concentration inside a building. The elaboration of the information available on South Tyrol makes it possible both to identify the statistically significant variables and to build up a statistical model that allows us to forecast the radon concentration in dwellings, when the values of the same variables involved are given. The results confirm the complexity of the phenomenon. (authors)

Determination of concentration of radon, volatile organic compounds (VOC) and water chemistry in springs near to Popocatepetl volcano

International Nuclear Information System (INIS)

Pena, P.; Segovia, N.; Lopez M, B.E.; Cisniega, G.; Valdes, C.; Armienta, M.A.; Mena, M.

2004-01-01

Popocatepetl volcano is a high-risk active volcano in Central Mexico where the highest population density in the country is settled. Radon in the soil and groundwater together with water chemistry from samples of nearby springs is analysed as a function of the 2002-2003 volcanic activity. Soil radon indicated fluctuations related both the meteorological parameters and sporadic explosive events. Groundwater radon showed essentially differences in concentration due to the specific characteristics of the studied springs. Water chemistry showed stability along the monitoring period indicating also differences between springs. No anthropogenic pollution from volatile organic compounds was observed. (Author)

Concentration en radon dans une maison du Calvados

Science.gov (United States)

Leleyter, Lydia; Riffault, Benoit; Mazenc, Bernard

2010-03-01

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

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)

Radon emanation and soil moisture effects on airborne gamma-ray measurements

International Nuclear Information System (INIS)

Grasty, R.L.

1997-01-01

A theoretical model is developed to explain variations in airborne gamma-ray measurements over a calibration range near Ottawa, Ontario. The gamma-ray flux from potassium and the thorium decay series showed an expected decrease with increasing soil moisture. However, the gamma-ray flux from the uranium decay series was highest in the spring when the ground was water-saturated and even covered with snow. These results are explained through the build-up of radon and its associated gamma-ray-emitting decay products in the clay soil of the calibration range with increasing soil moisture. Similar results were found from airborne measurements over other clay soils. However, measurements over sandy soils showed that the count rates from all three radio elements increased with decreasing soil moisture. This difference between soil types was attributed to the lower radon emanation of the more coarse-grained sandy soils compared to finer-grained clay soils. The theoretical and experimental results demonstrate that any estimate of the natural gamma-ray field caused by radium in the ground must take into consideration the radon emanation coefficient of the soil. The radon diffusion coefficient of the soil must also be considered since it depends strongly on soil moisture. This has significant implications for the assessment of outdoor radiation doses using laboratory analyses of soil samples and the use of ground and airborne gamma-ray measurements for radon potential mapping

Diurnal Variation of Radon Concentration in the Postojna Cave

International Nuclear Information System (INIS)

Gregoric, A.; Vaupotic, J.

2011-01-01

Postojna Cave, with 20 km of galleries, is the longest known cave system and also the largest of about 20 show caves in Slovenia and one of the most visited show caves in the world. It is well known that high concentrations of radon are common in karstic caves, although quantities of uranium (238U) in limestone are rather low. The reason for this is low natural ventilation of the underground cavities. Tectonic faults constitute an additional source of radon. Variations of radon concentration in cave air arise from a balance of the emission from cave surfaces and drip waters, decay in cave air, and exchange with the outside atmosphere. Because of its elevated radon concentrations, Postojna Cave has been under permanent radon survey since 1995. The influence of meteorological conditions on the radon levels and their temporal variations depends mostly on the shape of the cave, and the number and directions of cracks, corridors and fissures connecting the cave rooms with the outside atmosphere. The driving force for air movement in horizontal caves, and thus the inflow of fresh air and release of the cave air to the atmosphere, is the temperature difference between the cave air and outdoors, which causes seasonal pattern of radon concentration in the cave with high levels in summer and low in winter. However, on a daily scale different behaviour of radon can be observed at different locations in the cave. In this paper diurnal variation of radon concentration at two locations is presented and discussed. Postojna Cave is a horizontal cave with a stable yearly temperature around 10 degrees of @C. Continuous measurements of radon concentration were carried out from 2005 to 2010 at two locations along the guided tourist trail. Radon concentration was measured with Radim 5 WP monitors (SMM Company, Prague, Czech Republic) with sampling frequency once an hour. The evaluation of five-year radon monitoring at two sites in the Postojna Cave reveals significant diurnal and

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

International Nuclear Information System (INIS)

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

1992-01-01

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

Modified technology in new constructions, and cost effective remedial action in existing structures, to prevent infiltration of soil gas carrying radon

International Nuclear Information System (INIS)

Ericson, S.O.; Schmid, H.; Clavensjo, B.

1984-01-01

The general principles and mechanisms of how soil gas carrying radon infiltrates from the foundation bed and subsoil into buildings are discussed. The Swedish Building Research Council has funded experiments and evaluations of cost effective remedial actions. The work has concerned existing dwellings with high concentration of radon where this is a result of infiltrating soil gas and/or exhalation from building materials. A review is given of experience and results acquired up to the summer of 1983. 100 dwellings have been erected with consideration of possible infiltration of soil gas. Modification of design, added costs (investment and operation) and resulting concentration of radon in indoor air is discussed. In general minor modifications are sufficient. (author)

Analysis of volatile phase transport in soils using natural radon gas as a tracer

International Nuclear Information System (INIS)

Chen, C.; Thomas, D.M.

1992-01-01

We have conducted a field study of soil gas transport processes using radon gas as a naturally occurring tracer. The experiment monitored soil gas radon activity, soil moisture, and soil temperature at three depths in the shallow soil column; barometric pressure, rainfall and wind speed were monitored at the soil surface. Linear and multiple regression analysis of the data sets has shown that the gas phase radon activities under natural environmental conditions are influenced by soil moisture content, barometric pressure variations, soil temperature and soil structure. The effect of wind speed on subsurface radon activities under our field conditions has not been demonstrated

Anomalous radon concentration in a nuclear research facility

International Nuclear Information System (INIS)

Balcazar, M.; Pena, P.

2014-08-01

Radon monitoring in more than 60 selected points were part of surveillance radiation activities in the nuclear center of Mexico; three major facilities were inspected, the TRIGA Mark III research reactor, the Tandem Van de Graaff Accelerator and the Pelletron electron Accelerator. During a major maintenance activities in the research reactor, the air extraction system was not functioning for more than a month causing of a radon build up exhaled from the massive concrete of the building, reaching concentrations in some places up to 2.1 kb m -3 . The irradiation room at the Tandem Accelerator presented high radon concentrations up to nearly 5 kb m -3 , manly in the trenches were pipes and electric wires are located, the radon source was identified as originated from small caves under the floor. Low radon concentrations were found inside a similar building where a Pelletron accelerator is located. The reasons for the abnormal radon concentrations and the mitigation actions to remove any risk for the worker are discussed in detail in this paper. (author)

Anomalous radon concentration in a nuclear research facility

Energy Technology Data Exchange (ETDEWEB)

Balcazar, M.; Pena, P., E-mail: miguel.balcazar@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2014-08-15

Radon monitoring in more than 60 selected points were part of surveillance radiation activities in the nuclear center of Mexico; three major facilities were inspected, the TRIGA Mark III research reactor, the Tandem Van de Graaff Accelerator and the Pelletron electron Accelerator. During a major maintenance activities in the research reactor, the air extraction system was not functioning for more than a month causing of a radon build up exhaled from the massive concrete of the building, reaching concentrations in some places up to 2.1 kb m{sup -3}. The irradiation room at the Tandem Accelerator presented high radon concentrations up to nearly 5 kb m{sup -3}, manly in the trenches were pipes and electric wires are located, the radon source was identified as originated from small caves under the floor. Low radon concentrations were found inside a similar building where a Pelletron accelerator is located. The reasons for the abnormal radon concentrations and the mitigation actions to remove any risk for the worker are discussed in detail in this paper. (author)

Radon risk in Alpine regions in Austria: Risk assessment as a settlement planning strategy

International Nuclear Information System (INIS)

Gruber, V.; Baumgartner, A.; Seidel, C.; Maringer, F. J.

2008-01-01

Soil gas radon measurements complement indispensable and well-established radon indoor measurements in Austria. Radon in soil gas is a result of geochemical conditions as well as of geology, mineralogy, geophysics and meteorology. Therefore, geological factors can help to predict potential indoor radon concentrations via soil gas. Soil gas radon measurements in well-defined geological units give an estimate of local and regional radon hazards and build the basis for radon risk maps, which could be used for land-use planning and urban development. The creation of maps makes an important contribution to health care. For this purpose, several research projects were carried out in Austria. On the one hand, a study was already conducted in Lower Austria to determine the influence of meteorological and soil physical parameters on radon concentrations in soil gas and to evaluate soil gas radon concentrations with a radon emanation and migration model. On the other hand, radon measurements on different geomorphologic formations in the Austrian Alps, which are potential settlement areas, are of special interest. (authors)

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)

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

Modelling uncertainties in the diffusion-advection equation for radon transport in soil using interval arithmetic.

Science.gov (United States)

Chakraverty, S; Sahoo, B K; Rao, T D; Karunakar, P; Sapra, B K

2018-02-01

Modelling radon transport in the earth crust is a useful tool to investigate the changes in the geo-physical processes prior to earthquake event. Radon transport is modeled generally through the deterministic advection-diffusion equation. However, in order to determine the magnitudes of parameters governing these processes from experimental measurements, it is necessary to investigate the role of uncertainties in these parameters. Present paper investigates this aspect by combining the concept of interval uncertainties in transport parameters such as soil diffusivity, advection velocity etc, occurring in the radon transport equation as applied to soil matrix. The predictions made with interval arithmetic have been compared and discussed with the results of classical deterministic model. The practical applicability of the model is demonstrated through a case study involving radon flux measurements at the soil surface with an accumulator deployed in steady-state mode. It is possible to detect the presence of very low levels of advection processes by applying uncertainty bounds on the variations in the observed concentration data in the accumulator. The results are further discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Radon concentration levels in Fatima Jinnah women university Pakistan

International Nuclear Information System (INIS)

Khan, S.A.; Ali, S.; Tufail, A.; Qureshi, A.A.

2005-01-01

Public exposure to radioactive gas radon and its progeny present in the air results in the largest contribution to total effective dose received by human beings. It is therefore of great concern to monitor radon concentration in energy conserved air tight buildings. Measurements of radon in the Fatima Jinnah Women University (FJWU) have been carried out for investigation and comparison of radon concentration in the new and old buildings of the campus at Rawalpindi, Pakistan. The study was done because according to the international guidelines concerning environmental problems, it is necessary to evaluate and know the radon levels, especially since most of the natural radiation dose to human beings comes from radon gas and its progeny. Solid State Nuclear Track Detectors (SSNTDs) being efficient, therefore, the measurements were carried out by passive, time integrated method, using CR-39 detector in polythene bags. The detectors were exposed for more than six month in various locations indoors and outdoors. The detectors were etched using NaOH, the tracks were counted manually, and the track density was converted to radon concentration. Radon concentration varied from 31 to 213 Bq.m -3 in old building and from 27 to 143 Bq.m -3 in new buildings, showing slight elevated values in the old buildings. Radon concentration values were found to be less than the values quoted by radiation protection agencies. Radiation dose due to radon varied in the university campus depending on occupancy factor. (author)

Turbidimetry for measurement of radon concentration

International Nuclear Information System (INIS)

Wang Huanqiang

1993-01-01

This paper describes a turbidimetric technique counting the tracks registered on CR-39 foils exposed to radon. Instead of eyeview through microscope, by using the differential spectrophotometer, strong correlation between the radon cumulative concentration and track turbidence was observed(r=0.999). Under the etching condition of 7.07 mol·L -1 KOH water solution at 80 o C for 16 hr, linear regression showed that the ratio of track turbidence and cumulative concentration of radon exposure was 1.99 x 10 -1 turbidence (KBq m -1 h) -1 and the determination limit was 36 KBq m -3 h. The details of the experiments are represented in this paper. (Author)

Survey of indoor radon concentrations in Fukuoka and Kagoshima prefectures

International Nuclear Information System (INIS)

Kunugita, Naoki; Norimura, Toshiyuki; Tsuchiya, Takehiko

1990-01-01

It is now well established that radon and its daughter products account for nearly half of the average population exposure to ionizing radiations and that radon is the greatest single source of natural radiation to the population. Radon and its daughters are alpha-emitters, which are more biologically damaging than beta- and gamma-radiations. A nationwide survey of radon concentration was conducted by the National Institute of Radiological Sciences in order to estimate the contribution of radon and its daughters to the population dose in Japan. Authors surveyed indoor radon concentrations in Fukuoka and Kagoshima prefectures as part of this project. A passive type radon dosimeter, in which a sheet of polycarbonate film as the alpha-ray detector was mounted, was used to measure indoor radon concentrations. The resulting distribution of the average annual indoor radon concentrations in both prefectures can be characterized by an arithmetic mean of 24.4 Bq/m 3 and a standard deviation of 13.1 Bq/m 3 , by a geometric mean of 22.2 Bq/m 3 , and by a median of 20.7 Bq/m 3 . The geometric means of the distributions for Fukuoka and Kagoshima were 25.4, and 18.4 Bq/m 3 , respectively. Radon concentrations were also generally high in winter and low in summer. Regarding the analysis of correlations between the concentrations and construction materials, radon concentrations were generally high in Japanese houses with earthen walls and in concrete structures. These results showed that seasons, the type of building materials, and regional differences were significant factors in the variation of indoor radon concentration. (author)

Soil gas and radon entry potential measurements in central Florida houses

International Nuclear Information System (INIS)

Turk, B.H.

1993-01-01

A technique to quantify the various parameters associated with the pressure-driven entry rate of soil gas and radon into buildings has been applied to five central Florida houses with slab-on-grade construction. Results indicate that the slabs of these Florida houses are more resistant to soil gas flow than slabs in previously studied New Jersey and New Mexico houses. The data for locations near the slab perimeter show that the resistance to soil gas flow is greater for the slab than for the underlying materials/soils, implying that the slab resistance is a slightly dominant factor controlling soil gas entry in these houses. As in the New Jersey and New Mexico houses, soil gas and radon entry potentials were highest near the slab perimeters. In contrast to the earlier studies, geometric mean radon entry potentials did not correlate well with measured indoor radon levels. (orig.). (4 refs., 1 fig., 2 tabs.)

Measurements of radon concentrations at caves in Jeju

Energy Technology Data Exchange (ETDEWEB)

Go, S. H.; Kang, D. H.; Jung, B. J. [Cheju National University, Cheju (Korea, Republic of)

2004-07-01

Radon is a radioactive gas emitting {alpha} particles. It is chemically stable due to its inert characteristic. While its daughter products, {sup 218}Po, {sup 214}Bi, {sup 214}Pb and {sup 214}Po, attached with aerosol particles, is known to cause lung cancer. As radon is produced from uranium and thorium, it accumulates in poorly ventilative underground voids such as caves and mine. Radon concentrations at caves in Jeju were measured in this study. The measurements were made by setting three CR-39 detectors for 70 days at 2 {approx} 4 positions in Manjang, Hyupjae and Ssangyong caves. The radon levels of the caves spread 403.1 . 606.7 Bq/m{sup 3}. With these results, it is concluded that the Jeju caves have 6 times higher radon concentrations than ordinary house of 65.3 Bq/m{sup 3} and that they are higher than Seoul subway stations due to poor ventilation. While, the caves in Jeju have lower radon concentrations than limestone caves of Robin Hood. The radon concentration in the middle of Manjang cave is slightly higher than the action level in the work place of 500 Bq/m{sup 3} suggested by the ICRP. The measurement errors are estimated to be less than 5 % from its calibration factor.

Measurements of radon concentrations at caves in Jeju

International Nuclear Information System (INIS)

Go, S. H.; Kang, D. H.; Jung, B. J.

2004-01-01

Radon is a radioactive gas emitting α particles. It is chemically stable due to its inert characteristic. While its daughter products, 218 Po, 214 Bi, 214 Pb and 214 Po, attached with aerosol particles, is known to cause lung cancer. As radon is produced from uranium and thorium, it accumulates in poorly ventilative underground voids such as caves and mine. Radon concentrations at caves in Jeju were measured in this study. The measurements were made by setting three CR-39 detectors for 70 days at 2 ∼ 4 positions in Manjang, Hyupjae and Ssangyong caves. The radon levels of the caves spread 403.1 . 606.7 Bq/m 3 . With these results, it is concluded that the Jeju caves have 6 times higher radon concentrations than ordinary house of 65.3 Bq/m 3 and that they are higher than Seoul subway stations due to poor ventilation. While, the caves in Jeju have lower radon concentrations than limestone caves of Robin Hood. The radon concentration in the middle of Manjang cave is slightly higher than the action level in the work place of 500 Bq/m 3 suggested by the ICRP. The measurement errors are estimated to be less than 5 % from its calibration factor

Comparative study of radon concentration in selected modern and traditional building at Kenyatta University

International Nuclear Information System (INIS)

Chege, W.M.; Rathore, I.V.S.; Chhabra, S.C.; Mustapha, A.O.

2010-01-01

in the huts (30.2 - 315.4 Bqm-3) than in the classrooms (115.76 - 257.2 Bqm-3). Possible cause: - Variation in huts due to prevailing meteorological conditions - Classrooms more isolated, little interaction with outside environment Overall mean radon concentration in the buildings was -188 Bqm-3. This was skewed towards higher values. About 20% of measured values reached the ICRP recommended reference levels (200–600 Bqm-3) -3) (ICRP 1993). Conclusion The concentration was significant especially in huts contrary to expectation. The ventilation and nature of the building materials are the principal factors affecting radon concentration Hence: - Both modern and traditional buildings should be well ventilated to prevent build-up of radon. - In areas where levels of 226Ra are high, alternative building materials other than soil should be used

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

International Nuclear Information System (INIS)

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

2002-01-01

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

Tracing and dealing with dwellings with high radon and radon daughter concentrations

International Nuclear Information System (INIS)

Ehdwall, Hans

1980-01-01

In the late 1970s it was found that a number of buildings in Sweden, primarily those made from alum shale-based concretes, had elevated radon and radon daughter levels. A special commission investigated the problem and established provisional limiting values for radon daughter exposures, gamma radiation from the ground, and the concentrations of radioactive materials in building materials. With regard to gamma radiation from the ground the commission proposed that no building be built in an area where outside gamma radiation exceeds 100 μR/h. For building materials a gamma index (mγ) and a radium index (mRa) are suggested: mγ = Csub(K)/10000 + Csub(Ra)/1000 + Csub(Th)/700; mRa = Csub(Ra)/200 (Csub(K), Csub(Ra) and Csub(Th) are the concentrations of potassium, radium and thorium respectively). The proposed limiting values are such that the gamma index and the radium index be less than 1. It is also suggested that action should be taken to reduce radon levels in buildings with radon daughter concentrations of 0.27 WL within two years and 0.10 WL within 5 years

Measurements of radon activity concentrations in air at Niska spa

International Nuclear Information System (INIS)

Adrovic, F.; Vuckovic, B.; Ninkovic, M.

2004-01-01

Radon activity concentrations in air were measured in the recreational-tourist center of Niska Banja. Alpha Guard PQ 2000/ MC50 instrumentation (Genitron instruments, Frankfurt) was used. The observed indoor radon concentrations in the air of the Radon Hotel pool lay within the range of 0.980-1.908 kBq/m 3 and were directly dependent on the exhalation of radon from thermomineral waters. Radon concentrations were also measured outdoors, at locations for capping thermomineral water, as well as at locations for draining used water from the Radon Hotel pool. Outdoor radon concentrations as high as over 500 Bq/m 3 were observed. Gamma dose rates were measured in parallel and found to lie within the range of 72-420 nSv/h. The gamma doses correlated well with the observed radon levels. The largest gamma dose rates in air were measured in the pool of Radon Hotel and at the site where this thermomineral water is being capped

Water chemistry and soil radon survey at the Poas volcano (Costa Rica

Directory of Open Access Journals (Sweden)

J. L. Seidel

2005-06-01

Full Text Available Radon-in-soil monitoring at the Poas volcano (Costa Rica has been performed together with water chemistry from the hot crater lake since 1981 and 1983 respectively. The results are discussed as a function of the eruptive evolution of the volcano over a 13 years period (1981-1994. It is shown that no definitely clear precursory radon signals have been recorded. On the contrary, ionic species concentrations are likely to be considered good precursors, together with the temperature variations of the crater lake water.

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 Concentration in Caves of Croatia - Assesing Effective Radon Doses for Occupational Workers and Visitors

International Nuclear Information System (INIS)

Radolic, V.; Miklavcic, I.; Poje, M.; Stanic, D.; Vukovic, B.; Paar, D.

2011-01-01

Radon monitoring at potentially highly radioactive location such as caves is important to assess the radiological hazards to occupational workers and occasional visitors. In its Publication 65 the ICRP has produced recommendations dealing with exposure to elevated background radiation, in particular, the risk associated with the inhalation of radon and radon progeny. Recommended annual effective dose from radon 222Rn and its short-lived progeny for workers should not exceed 20 mSv and for occasional users (visitors) the same recommendation is 1 mSv. Measurements were performed with series of track etched detectors (LR115 - type II) in several caves in Croatia. The obtained values for the radon concentration ranged from ambient values up to several thousand Bq m -3 . Radon concentration was measured in about 20 caves of Velebit and Zumberak mountains and the highest radon concentration was in Lubuska jama (3.8 kBq m -3 ) and cave Dolaca (21.8 kBq m -3 ), respectively. Djurovica cave is especially interesting because of its huge tourist potential due to its location bellow Dubrovnik airport. Its mean annual radon concentration of 17.6 kBq m -3 classifies Djurovica cave among caves with high radon concentration. A visitor during half an hour visit at summer time would receive an effective dose of 30.6 μSv. Calculated mean dose rate of 44 μSv/h means that workers (mainly tourist guides) should limit their time inside cave to 454 hours per year. Manita pec is the only cave open for tourists on the territory of Paklenica National Park. The preliminary radon measurements performed during summer 2010, gave an average radon concentration of 1.1 kBq m -3 . An exposure to average dose rate of 3.7 μSv/h means that the tourist guides would receive an effective dose of 0.42 mSv during summer period according to their working schedule. A visitor during half an hour visits would receive an effective dose of 1.86 μSv. (author)

Measurement of underground contamination of non-aqueous phase liquids (NAPLs) on the basis of the radon concentration in ground level air

International Nuclear Information System (INIS)

Schubert, M.

2001-01-01

It was investigated whether measurements of radon concentrations in ground level air are a suitable method of detecting sub-surface soil contamination with non-aqueous phase liquids (NAPLs). The working postulation was that, due to the very high solubility of radon in NAPLs, and the resulting accumulation of radon in NAPLs, radon exhalation to the ground level air in the proximity of such NAPL contamination should be locally reduced, thus indicating contamination of sub-surface soils with NAPLs. The research work reported was to verify the working theory by way of experiments, and to finally develop a reliable detection method for NAPL contaminations. The investigations comprised theoretical studies, laboratory experiments, experiments in defined soil columns, and extensive field studies [de

Determination of the radon concentration in soil and ground water and its association with the seismicity; Determinacion de la concentracion del radon en suelo y agua subterranea y su asociacion con la sismicidad

Energy Technology Data Exchange (ETDEWEB)

Pena, P.; Segovia, N. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)

2003-07-01

The coast of the Mexican Pacific is one of the seismic areas more active of the world due to the subduction of the badges of Coconuts and Rivera under the badge of North America. The earthquakes that happen in this part of Mexico they are of great magnitude and they affect to the central plateau of the country where finds the biggest population density. On the other hand the coast of the Gulf of Mexico presents one relatively low seismic activity. It is in this region where it is the nuclear plant of Laguna Verde (PNLV) and the studies of seismicity of the area should be carried out for questions of nuclear security. One carries out a study of fluctuations of the concentration of the radon in floor and it dilutes underground in the mentioned areas using accustomed to detectors of nuclear appearances (LR-115). Possibly they were also used detecting automatic (Clipperton sounds out). In some cases it was analysed the gamma radiation in soil using thermoluminescent dosemeters (CaSO{sub 4}: Dy + Ptfe). The mineralogical composition of rock samples was obtained, by means of technical conventional and Electron scanning microscopy and an X-ray diffractometer. The study one carries out along the coast of Guerrero, from Guacamayas, Mich. until Marquelia, Gro., of 1993 at 1998 and in the coast of the Gulf of Mexico, in the PNLV and their surroundings, of 1994 at 1996. The fluctuations of the radon concentration and of the gamma radiation, were analysed in function of the local seismic activity, the meteorological parameters and those characteristic geologic. In the area of the PNLV, the results showed that in general the averages of those value of the radon concentration, as much in floor as in water, they were low. A station located in a flaw area (New Ranch) the one that I present the values was but high of radon concentration, corresponding those but first floor to the PNLV. The seismic activity during the one period of sampling was sporadic and of low intensity and alone

Assessment of radon exposure in Austria based on geology and settlement

International Nuclear Information System (INIS)

Gruber, Valeria; Seidel, Claudia

2008-01-01

In Austria a fundamental radon indoor data net (about 40 000 measurements) exists. These radon indoor data are standardized and provide averaged political communities' values. This data net should be enhanced by soil gas measurements with regard to geological conditions, to avoid averaging and influences by political boundaries. Different geological units (characterized by geology, geochemical conditions, mineralogy, geophysics) will be surveyed regarding radon concentration by soil gas measurements and estimated to their potential radon hazard. To assess the radon exposure of the population geological units are selected which are either existing settlement areas or potential ones. So this survey can also provide a basis for land use planning. In this paper results of first studies for this purpose are shown. 160 soil gas measurements were carried out in different soil and sediment deposits originating from different ice age glacier movements in the Alps. These deposits are popular settlement areas, and indoor radon levels of some 1000 Bq/l were detected. 50 % of the results of soil gas radon measurements were above 60 kBq/m 3 , 18 % above 120 kBq/m 3 , which is likely to exceed the indoor radon standard of 400 Bq/l according to the Austrian standard ONORM S 5280-2. Higher radon activity concentrations were found in older ice ages, because of further progressed weathering. The radon soil gas measurements were carried out in different seasons to verify seasonal variations, and other parameters like Ra-226, Ra-228 activity concentration in soils, radon emanation factor, soil permeability and soil moisture were determined and related to the radon activity concentration. According to the example of this study, further soil gas measurements will be carried out in selected geological units. Additional research on the impact of actual dwelling and inhabitation situation on public exposure due to radon in Austria is being done currently. The soil gas radon measurement data

Track-etch detection of radon in soils

International Nuclear Information System (INIS)

Cervantes Gonzales, P.; Gonzalez, D.

1990-01-01

In this work it is described the methodology to apply the track-etch technique, using detectors of nitrocellulose LR-115, for the detection of radon in soil. It is supported the use of the new detector carries and determined the parameters for revealing and counting of tracks in our conditions. It is shown in a preliminary way that this method gives better possibilities for analysis than another traditional technique to radon detection. The existence of radon was determined in the test zone. 15 refs

Seasonal variations of radon concentrations in single-family houses with different sub-structures

DEFF Research Database (Denmark)

Majborn, B.

1992-01-01

Seasonal variations of indoor radon concentrations have been studied in 70 single-family houses selected according to the type of sub-structure and the type of soil underneath the house. Five categories of sub-structure were included - slab-on-grade, crawl space, basement, and combinations...... of basement with slab-on-grade or crawl space. Half of the houses are located on clayey till and the other half on glaciofluvial gravel. In each house radon was measured in a living room and a bedroom, in the basement if present, and in the crawl space if present and accessible. The measurements were made...... with track detectors on a quarterly basis throughout a year. For living rooms and bedrooms the seasonal variations range from being highly significant for the slab-on-grade houses to being insignificant for the crawl space houses. For basements and crawl spaces the geometric mean radon concentrations do...

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)

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.

A survey of indoor radon and particular concentration

International Nuclear Information System (INIS)

Ohta, Yukiko

1993-01-01

Lung disease risk from inhalation of radon can be enhanced by the presence of particular pollutants in indoor air. The indoor concentration of radon and particulates were measured in homes, a department store, and offices in a high building in Tokyo metropolis, as well as in homes in both northern and western Japan. Passive radon monitors were located in living rooms and offices for more than three months at 99 sites during the winter of 1988 and 1989. Indoor radon concentration ranged from 11.1 Bq/m 3 to 148 Bq/m 3 (n=99) and averaged value S.D. was 36.5±14.2 Bq/m 3 . However, the average concentration in air conditional buildings was 21.8±9.51 Bq/m 3 (n=17). Simultaneously at 65 of the radon sites, indoor particulates were collected using personal dust samplers by impaction methods. Deposited particulate concentrations on the sampler were measured and calculated in a unit of μm/m 3 . Concentrations were determined for particle sizes above and below 2.5 μm, for both smoking or non smoking sites. Consequently, concentration of particle size below 2.5 μm was high in smoking rooms. Finally, it was considered that smoking was a complex indoor pollutant as adherence of radon daughter to aerosols. (author)

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Design Criteria for Achieving Acceptable Indoor Radon Concentration

DEFF Research Database (Denmark)

Rasmussen, Torben Valdbjørn

2016-01-01

Design criteria for achieving an acceptable indoor radon concentration are presented in this paper. The paper suggests three design criteria. These criteria have to be considered at the early stage of the building design phase to meet the latest recommendations from the World Health Organization...... in most countries. The three design criteria are; first, establishing a radon barrier facing the ground; second, lowering the air pressure in the lower zone of the slab on ground facing downwards; third, diluting the indoor air with outdoor air. The first two criteria can prevent radon from infiltrating...... from the ground, and the third criteria can dilute the indoor air. By combining these three criteria, the indoor radon concentration can be lowered achieving an acceptable level. In addition, a cheap and reliable method for measuring the radon concentration in the indoor air is described. The provision...

Radon concentration and exhalation rates in building material samples from crushing zone in Shivalik Foot Hills

International Nuclear Information System (INIS)

Pundir, Anil; Kamboj, Sunil; Bansal, Vakul; Chauhan, R.P.; Rana, Rajinder Singh

2012-01-01

Radon ( 222 Rn) is an inert radioactive gas in the decay chain of uranium ( 238 U). It continuously emanates from soil to the atmosphere. Radon and its progeny are the major natural radioactive sources for the ambient radioactivity on Earth. A number of studies on radon were performed in recent decades focusing on its transport and movement in the atmosphere under different meteorological conditions. Building materials are the main source of radon inside buildings. Some construction materials are naturally more radioactive and removal of such material from the earth's crust and their subsequent use in construction of buildings further enhances the radioactivity level. The knowledge of radioactivity level in the building materials makes us aware about the management, guidelines and standards in construction of buildings. The main objective of the present investigations is to measure radon Concentration and exhalation rates in the samples collected from the Crushing zone of Shivalik foot hills. Different types of materials are being used in Northern part of India for construction of dwellings. For the measurement of radon concentration and its exhalation rates in building materials, LR-115 detectors were exposed in closed plastic canisters for three months. At the end of the exposure time, the detectors were subjected to a chemical etching process in 2.5N NaOH solution. The tracks produced by the alpha particles were observed and counted under an optical Olympus microscope at 600X. The measured track density was converted into radon concentration using a calibration factor. The surface and mass exhalation rates of radon have also been calculated using present data. The results indicate that the radon concentration varies appreciably from sample to sample and they were found to satisfy the safety criteria. There are samples in which radon concentration is higher and may enhance the indoor radiation levels when used as building construction materials. (author)

Open charcoal chamber method for mass measurements of radon exhalation rate from soil surface

International Nuclear Information System (INIS)

Tsapalov, Andrey; Kovler, Konstantin; Miklyaev, Peter

2016-01-01

Radon exhalation rate from the soil surface can serve as an important criterion in the evaluation of radon hazard of the land. Recently published international standard ISO 11665-7 (2012) is based on the accumulation of radon gas in a closed container. At the same time since 1998 in Russia, as a part of engineering and environmental studies for the construction, radon flux measurements are made using an open charcoal chamber for a sampling duration of 3–5 h. This method has a well-defined metrological justification and was tested in both favorable and unfavorable conditions. The article describes the characteristics of the method, as well as the means of sampling and measurement of the activity of radon absorbed. The results of the metrological study suggest that regardless of the sampling conditions (weather, the mechanism and rate of radon transport in the soil, soil properties and conditions), uncertainty of method does not exceed 20%, while the combined standard uncertainty of radon exhalation rate measured from the soil surface does not exceed 30%. The results of the daily measurements of radon exhalation rate from the soil surface at the experimental site during one year are reported. - Highlights: • Radon exhalation rate from the soil surface area of 32 cm"2 can be measured at level of 10 mBq/(m"2s) at the uncertainty ≤30%. • The method has a metrological justification. • No need to consider climate conditions, soil properties and conditions, mechanism and rate of radon transport in the soil.

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)

IN-SITU MEASURING METHOD OF RADON AND THORON DIFFUSION COEFFICIENT IN SOIL

Directory of Open Access Journals (Sweden)

V.S. Yakovleva

2014-06-01

Full Text Available A simple and valid in-situ measurement method of effective diffusion coefficient of radon and thoron in soil and other porous materials was designed. The analysis of numerical investigation of radon and thoron transport in upper layers of soil revealed that thoron flux density from the earth surface does not depend on soil gas advective velocity and varies only with diffusion coefficient changes. This result showed the advantages of thoron using versus radon using in the suggested method. The comparison of the new method with existing ones previously developed. The method could be helpful for solving of problems of radon mass-transport in porous media and gaseous exchange between soil and atmosphere.

Radon concentrations in well water in Sichuan Province, China

International Nuclear Information System (INIS)

Chen Yibin; Wu Qun; Zhang Bo; Chen Daifu

1998-01-01

There are 110 million people in Sichuan Province, China. Although most of the people in cities of Sichuan use river water, which contains low levels of radon, as potable water, people in countryside and in some communities of big cities still use well water as domestic consumption. This paper reports the radon concentrations in well water investigated in four cities, i.e. Chengdu, Chongqing, Leshan and Leijiang in Sichuan Province. Of the 80 wells investigated, the radon concentrations range from 3.5 to 181.6 KBqm -3 . Of the four cities, Chongqing has the highest well water radon concentration with the average 49.6 ± 54.1 KBqm -3 and the greatest variation. The investigation in four cities showed that the radon concentrations in well water are much higher than that in tap-water. In Chongqing where there are complex geological structures, mainly granite stratum, for example, the average radon concentration in well water is 112 times higher than that in the tap-water, and even much higher than that in river water in Yangtse River, Jialing River, Jinsha River and Mingjiang River. The population in four cities is about one sixth of the total population in Sichuan Province. Because of the common use of well water and the high radon concentrations in well water in Sichuan Province, the health effect of radon in well water to the public should be stressed. (author)

The feasible research with measuring radon for taking the soils sample

International Nuclear Information System (INIS)

Zeng Bing, Ge Liangquan; Liu Hefan; Li Yeqiang; Zhang Jinzhao; Song Xiao'an

2010-01-01

It explains the mechanism of the separation of soil's radon. Through the designed experiment, it confirms the feasibility of measuring radon for taking the soil's sample. It determines the content of the radon and its sub field with indoor and outside through ways of the activated charcoal adsorption, the initiative suction and the diameter mark etching, also the 226 Ra. The paper indicates: it is feasible with measuring radon for taking the soil's sample, and the stability of data is that indoor data are better than outside's. The temperature, the humidity, the rainfall amount, the intensity and so on are the serious influence of the data. If you want to take a soil's sample, you must avoid the rain as far as possible, and avoid the fault zone, the belt of folded strata and complex geologic structure region, and so on. (authors)

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

Preliminary results regarding the first map of residential radon in some regions in Romania

International Nuclear Information System (INIS)

Cosma, C.; Cucos Dinu, A.; Dicu, T.

2013-01-01

Radon represents the most important contribution of population exposure to natural ionising radiation. This article presents the first indoor radon map in some regions of Romania based on 883 surveyed buildings in the Stei-Baita radon-prone region and 864 in other regions of Romania. Indoor radon measurements were performed in the last 10 y by using CR-39 nuclear track detectors exposed for 3-12 months on ground floor levels of dwellings. Excluding the Stei-Baita radon-prone region, an average indoor radon concentration of 126 Bq m -3 was calculated for Romanian houses. In the Stei-Baita radon-prone area, the average indoor concentration was 292 Bq m -3 . About 21 % of the investigated dwellings in the Stei-Baita radon-prone region exceed the threshold of 400 Bq m -3 , while 5 % of the dwellings in other areas of Romania exceed the same threshold. As expected, indoor radon concentration is not uniformly distributed throughout Romania. The map shows a high variability among surveyed regions, mainly due to the differences in geology. The radon emanation rate is substantially influenced by the soil characteristics, such as the soil permeability and soil gas radon concentration. Since higher permeability enables the increased migration of soil gas and radon from the soil into the building, elevated levels of indoor radon can be expected in more permeable soil environments. (authors)

Investigation on residential radon concentration in Jingchuan county

International Nuclear Information System (INIS)

Zhang Wei; Wan Yihong; Chen Hongxiao; Shang Bin

2009-01-01

This paper reports an investigated result of residential radon concentration in Jingchuan County, Gansu Province, during May 2004 to November 2006. Alpha track detectors were used to measure radon level. Construction types of house and percentages of residents living in the county were also investigated through questionnaires. The result showed that the mean radon concentration in 62 investigated houses was 96.2 Bq·m -3 . The radon concentration in cave dwelling was the highest among all type of dwellings. The average level in cave dwelling is 110.2 Bq·m -3 , which was significantly higher than the national mean value published in literatures, and exceed the WHO recommended value of 100 Bq·m -3 . A considerable number of rural residents are living in cave dwellings in Jingchuan County. Attention should be paid to the radon problem and some proper protection measures taken. (authors)

Studies on radon concentration at the work places of Mysuru, Bengaluru, Tumkuru and Kolar Districts of Karnataka State, South India

International Nuclear Information System (INIS)

Ningappa, C.; Reddy, K. Umesha; Rangaswamy, D.R.; Sannappa, J.

2015-01-01

Radon is a radioactive noble gas and is the decay product of naturally occurring uranium. It decays into radioactive metal ions polonium-218 and polonium-214 by alpha radiation, which are harmful to the human health. The concentrations of radon and its progeny inside a given working place depends on activity of radium both in the soil surrounding the workplace and in the building materials, atmospheric conditions, design of the workplace, porosity of the surrounding soil, building layout, and the ventilation habits of the inhabitants of the building. The estimation of dose due to radon and its progeny to the general public and workers at work places are very important. Thus, concentration of radon and its progeny and dose due to radon and its progeny to the public and workers were measured at sixty workplaces of Mysuru, Bengaluru, Tumkur and Kolar districts based on geology and willingness of the workplace owner using twin cup dosimeter based on Solid State Nuclear Track Detectors (SSNTDs) and results are discussed in the present study. The values measured indoor radon in the area of study ranged from a 11.6 to 284.8 Bq.m -3 . (author)

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)

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

International Nuclear Information System (INIS)

Vizzini, Fabio; Brai, Maria

2012-01-01

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

Comparison of two numerical modelling approaches to a field experiment of unsaturated radon transport in a covered uranium mill tailings soil (Lavaugrasse, France)

Energy Technology Data Exchange (ETDEWEB)

Saadi, Zakaria; Guillevic, Jerome [Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-DGE/SEDRAN/BRN, 31 avenue de la Division Leclerc, B.P. 17, 92262, Fontenay-aux-Roses, Cedex (France)

2014-07-01

Uncertainties on the mathematical modelling of radon transport in an unsaturated covered uranium mill tailings (UMT) soil at field scale can have a great impact on the estimation of the average measured radon flux to the atmosphere at the landfill cover, which must be less than the threshold value 0.74 Bq.m{sup -2}.s{sup -1}recommended by the federal standard (EPA 40 CFR 192). These uncertainties are usually attributed to the numerical errors from the numerical schemes dealing with soil layering and to inadequate representations of the modelling of physical processes at the soil/plant/atmosphere interface and of the soil hydraulic and transport properties, as well as their parameterization. In this work, we compare one-dimensional simulation results from two numerical models of two-phase (water-air) porous media flow and radon transport to the data of radon activity exhalation flux and depth-volumetric concentration measured during a field campaign from June to November of 1999 in a two-layered soil of 1.3 m thickness (i.e., cover material/UMT: 0.5/0.8 m) of an experimental pond located at the Lavaugrasse UMT-landfill site (France). The first numerical modelling approach is a coupled finite volume compositional (i.e., water, radon, air) transport model (TOUGH2/EOS7Rn code, Saadi et al., 2013), while the second one is a decoupled finite difference one-component (i.e., radon) transport model (TRACI code, Ferry et al., 2001). Transient simulations during six month of hourly rainfall and atmospheric pressure variations showed that calculations from the one-component transport model usually overestimate both measured radon exhalation flux and depth-concentration. However, considering the effective unsaturated pore air-component diffusivity to be different from that of the radon-component in the compositional transport model allowed to significantly enhancing the modelling of these radon experimental data. The time-averaged radon flux calculated by EOS7Rn (3.42 Bq

Radon as a groundwater tracer in Forsmark and Laxemar

Energy Technology Data Exchange (ETDEWEB)

Grolander, Sara

2009-10-15

caused by the homogenous radon concentrations measured in the Laxemar area. The radon concentrations in near surface water measured in Forsmark showed large variability with both low and high radon concentrations. This large variability in radon concentration could not be explained by the flow pattern of the groundwater since no clear correlation between radon concentration and recharge/discharge classification was found. The radon concentration was also measured at different depths in the soil profile at three locations in the Forsmark area. The results showed large differences with increasing radon concentration with increasing depth. This gradient of radon concentration can be explained largely by the radon emanation potential of the local soil type at different depths. High radon concentrations were found in wells with higher radon emanation potential like till and bedrock. These observations showed the importance of the radon emanation potential of the local soil for the radon concentration in groundwater. The main purpose of this study has been to evaluate the use of radon as a tracer for groundwater flow patterns. The method is based on the ingrowth of radon from its progenitor radium according to the law of radioactive decay. According to this law the radon concentration in groundwater will reach equilibrium conditions after approximately 30 days in contact with the surrounding soil. The equilibrium radon concentration of the near surface groundwater was measured at several location in the Forsmark area and a range of the steady state radon concentration was calculated. The measured steady state radon concentration was then used to evaluate the radon concentrations measured in near surface groundwater in the area. A recharge/discharge classification of the wells was done based on the range of steady state radon concentration and the measured radon concentrations in groundwater. All wells with radon concentration below the steady state radon concentration were

Relationship between indoor radon concentrations and air exchange rate

International Nuclear Information System (INIS)

Wang Jingshu; Liu Yuyu; Yao Xiaohua; Meng Jianfeng; Zhang Yongyi; Wang Xiaohe; Yu Xiufen.

1995-01-01

The indoor concentration of radon and the air exchange rate were simultaneously measured in four empty rooms, made of brick and cement, which were located in different floors of dwelling houses in Taiyuan, Shanxi, China. SF 6 tracer gas decay method was used to measure the air exchange rate. Indoor radon was collected with the dimembrane method. When the ventilation rate increased, the concentration of radon dropped rapidly. Regression analysis indicated that the indoor concentration of radon was equal to the outdoor level of radon when the air exchange rate was greater than 3-4. SF 6 decay method was an effective and convenient method for measuring the air exchange rate. There was no marked difference in measurements obtained in different locations of a room. (N.K.)

Soil and gas and radon entry potentials for substructure surfaces

International Nuclear Information System (INIS)

Harrison, J.; Sextro, R.G.

1990-01-01

This paper reports on measurement techniques and parameters that describe the potential for areas of a building substructure to have high soil gas and radon entry rates which have been developed. Flows and pressures measured at test holes in substructure surfaces while the substructure was intentionally depressurized were used in a highly simplified electrical circuit to model the substructure/soil network. Data from four New Jersey houses indicate that the soil was a factor of two to six times more resistant to soil gas flow than substructure surfaces, concrete slab floors, including perimeter gaps, cracks, and other penetrations, were approximately five times more resistant to soil gas movement than hollow block walls, and radon entry potentials were highest for slab floors. These indices of entry potential may be useful for characterizing the relative leakiness of below-grade substructure surfaces and for determining the selection and placement of radon control systems

High indoor radon variations and the thermal behavior of eskers

International Nuclear Information System (INIS)

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

1994-01-01

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

Short-term temporal variations of soil gas radon concentration and comparison of measurement techniques

Czech Academy of Sciences Publication Activity Database

Neznal, M.; Matolín, M.; Just, G.; Turek, Karel

2004-01-01

Roč. 108, č. 1 (2004), s. 55-63 ISSN 0144-8420 R&D Projects: GA AV ČR KSK2067107; GA AV ČR KSK4055109 Grant - others:Projekt SÚJB(CZ) R/2/2000 Institutional research plan: CEZ:AV0Z1048901 Keywords : radon * soil gas * temporal variations Subject RIV: DL - Nuclear Waste, Radioactive Pollution ; Quality Impact factor: 0.617, year: 2003

Radon concentration measurements in the desert caves of Saudi Arabia

Energy Technology Data Exchange (ETDEWEB)

Al-Mustafa, Hanan [Women College, P. O. Box 838, Dammam 31113 (Saudi Arabia); Al-Jarallah, M.I. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)]. E-mail: mibrahim@kfupm.edu.sa; Fazal-ur-Rehman [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Abu-Jarad, F. [Radiation Protection Unit, Environmental Protection Department, Saudi Aramco P.O. Box 13027, Dhahran 31311 (Saudi Arabia)

2005-11-15

Beneath the harsh deserts of Saudi Arabia lie dark chambers and complex mazes filled with strange shapes and wondrous beauty. Radon concentration measurements have been carried out in the desert caves of Al-Somman Plateau in the Eastern Province of Saudi Arabia. Passive radon dosimeters, based on alpha particle etch track detectors with an inlet filter, were used in this study. A total of 59 dosimeters were placed in five caves for a period of six months. Out of 59 dosimeters, 37 could be collected for analysis. Measurements showed significant variations in radon concentrations in caves depending upon their natural ventilation. The results of the study show that the average radon concentration in the different caves ranges from 74 up to 451Bqm{sup -3}. The average radon concentration in four of the caves was low in the range 74-114Bqm{sup -3}. However, one cave showed an average radon concentration of 451Bqm{sup -3}. Radon is not a problem for tourists in the majority of caves. However, sometimes it may imply some limitation to the working time of guides.

Radon concentration measurements in the desert caves of Saudi Arabia

International Nuclear Information System (INIS)

Al-Mustafa, Hanan; Al-Jarallah, M.I.; Fazal-ur-Rehman; Abu-Jarad, F.

2005-01-01

Beneath the harsh deserts of Saudi Arabia lie dark chambers and complex mazes filled with strange shapes and wondrous beauty. Radon concentration measurements have been carried out in the desert caves of Al-Somman Plateau in the Eastern Province of Saudi Arabia. Passive radon dosimeters, based on alpha particle etch track detectors with an inlet filter, were used in this study. A total of 59 dosimeters were placed in five caves for a period of six months. Out of 59 dosimeters, 37 could be collected for analysis. Measurements showed significant variations in radon concentrations in caves depending upon their natural ventilation. The results of the study show that the average radon concentration in the different caves ranges from 74 up to 451Bqm -3 . The average radon concentration in four of the caves was low in the range 74-114Bqm -3 . However, one cave showed an average radon concentration of 451Bqm -3 . Radon is not a problem for tourists in the majority of caves. However, sometimes it may imply some limitation to the working time of guides

Measurements of Radon Concentration in Yemen Using Spark Counter

International Nuclear Information System (INIS)

Arafa, W.; Abou-Leila, M.; Hafiz, M.E.; Al-Glal, N.

2011-01-01

Spark counter has been designed and realized and the optimum applied voltage was found to be 600 V. Excellent consistent agreements was observed between counted number of tracks by spark counter and reading by optical microscope. Radon concentration in some houses in Sana'a and Hodeidah cities in Yemen had been performed using LR-115 SSNTD and spark counter system. The average radon concentration in both cities was far lower the alert value. The results showed that radon concentration in the metropolitan area Sana'a was higher than that in Hodeidah city. Also, it was observed that old residential houses had higher levels of radon concentrations have compared to newly built houses in the metropolitan area Sana'a

Blower door method in radon diagnostics

International Nuclear Information System (INIS)

Fronka, A.; Moucka, L.

2004-01-01

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

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

Science.gov (United States)

Vizzini, Fabio; Brai, Maria

2012-11-01

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

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

International Nuclear Information System (INIS)

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

1986-01-01

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

Indoor radon risk potential of Hawaii

International Nuclear Information System (INIS)

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

2005-01-01

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

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

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)

Investigation of radon level in Chongqing

International Nuclear Information System (INIS)

Pan Chunzhen; Liu Jialie; Du Hengyan; Wang Ling; Li Yiwei

2009-01-01

Contents of radon in air in the urban district, building fields,diggings and hotel in Chongqing were investigated. Result shows that the mean concentration of radon is 10.8 Bq/m 3 in air in the urban district, and the mean concentration of radon is 1193 Bq/m 3 in soils on building fields. Radon level is obviously different in each of diggings, with the highest being in fluorite mine and the second in plumbum and zinc mine. The statistical mean value of radon concentration of 10 typles of diggings investigated is 65.2 Bq/m 3 , while the mean concentration of radon in fluorite mine is 369 Bq/m 3 , which is 35 times higher than in the urban area. The mean concentration of radon is 32.9 Bq/m 3 in eight hotels. (authors)

Radon concentration studies in houses on the territory of the former German Democratic Republic

International Nuclear Information System (INIS)

Lehmann, R.

1993-01-01

In cooperation with the Federal Institute of Water, Soil and Air Hygiene, studies have been made since March 1990 in mining centers in the South of the former GDR territory on radon concentration in as many differently used houses as possible, predominantly in dwelling houses, but also in plant buildings, schools, kindergartens, recreation homes, etc. Under this program, measurements were performed until October 1990 in the cities of Schneeberg, Johanngeorgenstadt and Ronneburg and in the municipality of Schlema. The results obtained from this radon screening covering almost the whole affected area, qualitatively correspond to those obtained from small random samples taken under a regional measuring program performed in the respective muncipalities. A summary presentation is given of the range of radon concentration in houses to be expected in East Germany, relating it to geologically different areas in accordance with the present state of knowledge. (orig./DG) [de

Indoor radon level in schools of Shillong, Meghalaya

International Nuclear Information System (INIS)

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

2010-01-01

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

Environmental Concentration of Radon and Radon Progeny in a Nuclear Facility in a Decommissioning Stage

International Nuclear Information System (INIS)

Ramirez, M. P.; Correa, E.; Sancho, C.

1999-01-01

According to the new European Directive 96/29/EURATOM the radiological risk due to natural radionuclides must be consider and the pertinent periodic control must be realized. During the works performed at CIEMAT an estimation of the effective average doses due to Radon inhalation in work places of the installation have been performed. Radon and Radon progeny concentration has been measured in continuous joint whit the meteorological conditions as temperature, pressure and relative humidity. Two different equipment has been used: Alpha-guard whit ionization chamber detector and Eda-wlm-300 whit a semiconductor detector. A passive Radon detector, E-perm has been simultaneously used in the monitoring system. The results obtained during the measuring of Radon and Radon progeny concentrations indoors and estimation of doses have been analyzed and are presented in the paper. (Author) 11 refs

Observation of radon content in soil gas

International Nuclear Information System (INIS)

Mino, Kazuo; Nishimura, Susumu

1979-01-01

For earthquake prediction, precursory phenomena before the large earthquakes have been investigated in many countries. In China and some other places, they made a success of predictions of the large earthquakes by catching precursory phenomena. Variation of Radon content of underground gas and water is also one of those phenomena. In our country, the decrease of Radon content was observed several days before the large earthquake which occured near Izu Peninsula on January, 14, 1978. We also begin to observe variation of Radon content of underground gas. The purpose of our observation is a study on the Radon gas content before and after earthquakes. According to the results of the test investigation, the change of atmospheric pressure is mutually related with variation of Radon content in soil gas. Effect of atmospheric pressure is about one Eman, which is significant value comparison with the change, before the large earthquake, a few or several Emans. But, when correction of atmospheric pressure's effect was done, the change of Radon content maybe decrease 5/100 Emans. Above result tells the possibility of detecting the precursor of large earthquake, if Radon content change was over a few Emans. (author)

How to Ensure Low Radon Concentrations in Indoor Environments

DEFF Research Database (Denmark)

Rasmussen, Torben Valdbjørn; Wraber, Ida Kristina

2011-01-01

This paper focuses on methods for measuring radon levels in the indoor air in buildings as well as on concrete solutions that can be carried out in the building to prevent radon leakage and to lower the radon concentration in the indoor air of new buildings. The radon provision in the new Danish...... Building Regulations from 2010 has been tightened as a result of new recommendations from the World Health Organization. Radon can cause lung cancer and it is not known whether there is a lower limit for its harmfulness. It is therefore important to reduce the radon concentration as much as possible in new...... buildings. The airtightness is a major factor when dealing with radon in buildings. Above the ground it is important to build airtight in compliance with energy requirements and against the ground it is important to prevent radon from seeping into the building. There is a direct connection between...

Radon in Estonian dwellings - Results from a National Radon Survey

Energy Technology Data Exchange (ETDEWEB)

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

2003-10-01

to be 60 Bq/m{sup 3}. Using the detriment factor given by ICRP, annually about 90 Estonians are expected to develop lung cancer due to exposure to radon in their homes. Most of them, about 75, are smokers, which are affected by the synergetic effect of the two carcinogens, smoking and radon. In Estonia the source of indoor radon is radon-containing soil air that is transported into the buildings from the ground. Building materials with enhanced radium concentrations are not known in Estonia. In this survey, the highest indoor radon concentrations have been found in the northern part of Estonia where uranium rich Dictyonema shale and uranium containing phosphorous Glauconite sandstone exist in the bedrock and as fragments in the soils. Radon concentrations higher than 400 Bq/m{sup 3} have also been measured in buildings situated in areas with karst formations. Areas with Dictyonema shale, Glauconite sandstone and karst are areas with a special risk for radon.

Radon in Estonian dwellings - Results from a National Radon Survey

International Nuclear Information System (INIS)

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

2003-10-01

the detriment factor given by ICRP, annually about 90 Estonians are expected to develop lung cancer due to exposure to radon in their homes. Most of them, about 75, are smokers, which are affected by the synergetic effect of the two carcinogens, smoking and radon. In Estonia the source of indoor radon is radon-containing soil air that is transported into the buildings from the ground. Building materials with enhanced radium concentrations are not known in Estonia. In this survey, the highest indoor radon concentrations have been found in the northern part of Estonia where uranium rich Dictyonema shale and uranium containing phosphorous Glauconite sandstone exist in the bedrock and as fragments in the soils. Radon concentrations higher than 400 Bq/m 3 have also been measured in buildings situated in areas with karst formations. Areas with Dictyonema shale, Glauconite sandstone and karst are areas with a special risk for radon

Relevance of air conditioning for 222Radon concentration in shops of the Savona Province, Italy

International Nuclear Information System (INIS)

Panatto, Donatella; Ferrari, Paola; Lai, Piero; Gallelli, Giovanni

2006-01-01

Radon ( 222 Rn) concentration was evaluated in shops of the Savona Province, Italy, between summer 2002 and winter 2002-2003. The main characteristics of each shops were recorded through a questionnaire investigating the ventilation rate and factors related to 222 Rn precursors in the soil and the construction materials. The main variables that were related to radon concentration were the following: age of the building, level of the shop above ground, season of the year, wind exposure, active windows, and type of heating system. Shops equipped with individual air heating/conditioning systems exhibited radon concentrations that were three times higher than those of shops heated by centralized furnaces. Our data indicate that the level of pollution in the shops was of medium level, with an expected low impact on the salespersons' health. Only in wintertime, the action level of 200 Bq m -3 for the confined environment was reached in 10 shops equipped with individual air heating/conditioning systems

Spatial radon anomalies on active faults in California

International Nuclear Information System (INIS)

King, C.-Y.; King, B.-S.; Evans, W.C.; Wei Zhang

1996-01-01

Radon emanation has been observed to be anomalously high along active faults in many parts of the world. We tested this relationship by conducting and repeating soil-air radon surveys with a portable radon meter across several faults in California. The results confirm the existence of fault-associated radon anomalies, which show characteristic features that may be related to fault structures but vary in time due to other environmental changes, such as rainfall. Across two creeping faults in San Juan Bautista and Hollister, the radon anomalies showed prominent double peaks straddling the fault-gouge zone during dry summers, but the peak-to-background ratios diminished after significant rain fall during winter. Across a locked segment of the San Andreas fault near Olema, the anomaly has a single peak located several meters southwest of the slip zone associated with the 1906 San Francisco earthquake. Across two fault segments that ruptured during the magnitude 7.5 Landers earthquake in 1992, anomalously high radon concentration was found in the fractures three weeks after the earthquake. We attribute the fault-related anomalies to a slow vertical gas flow in or near the fault zones. Radon generated locally in subsurface soil has a concentration profile that increases three orders of magnitude from the surface to a depth of several meters; thus an upward flow that brings up deeper and radon-richer soil air to the detection level can cause a significantly higher concentration reading. This explanation is consistent with concentrations of carbon dioxide and oxygen, measured in soil-air samples collected during one of the surveys. (Author)