Suggestions for inclulsion of radon exhalation control target in building materials radioactivity standards

International Nuclear Information System (INIS)

Liu Fudong; Liu Senlin; Pan Ziqiang; Zhang Yonggui

2010-01-01

The specific-activity and radon exhalation rate from 26 building material samples from different areas were measured with high pure germanium (HPGe) gamma spectrometer and activated carbon cartridge. It is shown that the radium content is not completely relevant to radon exhalation rate from some building material. The existing national standards on 'The Limit of Radionuclides in Building Materials' (GB 6566-2001) only present internal exposure index as control target but not for radon exhalation rate; in fact, the radon exhalation rate from building materials is closely nearly related to indoor radon concentration. So we suggest that the radon exhalation control target should be included in the national standards on 'The Limit of Radionuclides in Building Materials'. (authors)

Postprandial changes in the exhalation of radon from the environment

International Nuclear Information System (INIS)

Rundo, J.; Markun, F.; Plondke, N.J.

1978-01-01

The exhalation of radon originally inhaled from the home environment and dissolved in body fluids and tissues has been studied serially for periods of several hours in six persons. The observation of a pronounced postprandial peak in the rate of exhalation of radon shows that the similar peak observed in the exhalation of radon produced from radium in vivo results from the flushing of a reservoir in soft tissue and not from a change in the fraction lost from bone

Influence of building materials process technology on radon exhalation

International Nuclear Information System (INIS)

Liu Fudong; Wang Chunhong; Liu Senlin; Ji Dong; Zhang Yonggui; Pan Ziqiang

2009-01-01

The building materials were produced through changing raw material ingredient, baking temperature, pressure difference between surface and interior of building material, grain diameter etc. Experiment indicates that change of raw material ingredient ratio can obviously influence the radon exhalation from building material, followed by baking temperature; and pressure difference does not have significant influence on radon exhalation. For the factory to produce shale-brick, the radon exhalation is relatively low under the condition that coal gangue accounts for 40%-50%, the grain diameter is less than 2 mm, the baking temperature is about 960 degree C or 1 020 degree C and the pressure difference is 85 kPa. (authors)

Radon exhalation rate on the Sivrice (Elazig ) fault zone

International Nuclear Information System (INIS)

Sahin, S.; Kuluoeztuerk, M. F.; Dogru, M.

2009-01-01

Four radon monitoring stations were built on the Sivrice Fault Zone which is a part of the East Anatolian Fault System that one of the very important two fault systems which tends to produce earthquake in Turkey. Radon exhalation rate were analyzed in the soil and water samples which collected around the stations. Radon exhalation rate in the soil and water samples were determined by using CR-39 that it is plastic detector.

Determination of radon exhalation rates from tiles using active and passive techniques

International Nuclear Information System (INIS)

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

2001-01-01

Measurements of radon exhalation rates for selected samples of tiles used in Saudi Arabia were carried out using active and passive measuring techniques. These samples were granite, marble and ceramic. In the active method, a PC-based radon gas analyzer with emanation container was used, while, in the passive method, PM-355 nuclear track detectors with the 'can technique' were applied for 180 days. A comparison of the exhalation rates measured by the two techniques showed a good linear correlation coefficient of 0.7. The granite samples showed an average radon exhalation rate of 0.7 Bq m -2 h -1 , which was higher than that of marble and ceramic by more than twofold. The radon exhalation rates measured by the 'can technique' showed a non-uniform exhalation from the surface of the same tile

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.

Determination of radon exhalation rates from tiles using active and passive techniques

Energy Technology Data Exchange (ETDEWEB)

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

2001-06-01

Measurements of radon exhalation rates for selected samples of tiles used in Saudi Arabia were carried out using active and passive measuring techniques. These samples were granite, marble and ceramic. In the active method, a PC-based radon gas analyzer with emanation container was used, while, in the passive method, PM-355 nuclear track detectors with the 'can technique' were applied for 180 days. A comparison of the exhalation rates measured by the two techniques showed a good linear correlation coefficient of 0.7. The granite samples showed an average radon exhalation rate of 0.7 Bq m{sup -2} h{sup -1}, which was higher than that of marble and ceramic by more than twofold. The radon exhalation rates measured by the 'can technique' showed a non-uniform exhalation from the surface of the same tile.

Radium and radon exhalation rate in soil samples of Hassan district of South Karnataka, India

International Nuclear Information System (INIS)

Jagadeesha, B.G.; Narayana, Y.

2016-01-01

The radon exhalation rate was measured in 32 soil samples collected from Hassan district of South Karnataka. Radon exhalation rate of soil samples was measured using can technique. The results show variation of radon exhalation rate with radium content of the soil samples. A strong correlation was observed between effective radium content and radon exhalation rate. In the present work, an attempt was made to assess the levels of radon in the environment of Hassan. Radon activities were found to vary from 2.25±0.55 to 270.85±19.16 Bq m"-"3 and effective radium contents vary from 12.06±2.98 to 1449.56±102.58 mBq kg"-"1. Surface exhalation rates of radon vary from 1.55±0.47 to 186.43±18.57 mBq m"-"2 h"-"1, and mass exhalation rates of radon vary from 0.312±0.07 to 37.46±2.65 mBq kg"-"1 h"-"1. (authors)

Radon exhalation rates of concrete modified with fly ash and silica fumes

International Nuclear Information System (INIS)

Amit Kumar; Chauhan, R.P.; Mehta, Vimal; Kant, K.

2013-01-01

The radiological impact of the environmental gas radon to the health of general public is of concern since many decades. Cement used for the construction blended with fly ash and silica fumes is recommended by Government in order to avoid the soil and environmental pollution. But these addition step-up the Indoor radon level in the dwelling due to radioactivity contents. The exhalation of radon from concrete blended with silica fumes and fly ash depends upon addition level, porosity, moisture and radioactivity content. In order to optimize the level of substitution of silica fumes and fly ash, measurements of radon exhalation rates from the concrete blended with different proportions of fly ash and silica fumes was carried out using active scintillation radon monitor. The effect of porosity, moisture, back diffusion and radioactivity content of the concrete on exhalation rates is studied. The measured exhalation rates were extrapolated for indoor radon concentration and effective dose equivalent using ICRP, 1987 recommendations. (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 exhalation and its dependence on moisture content from samples of soil and building materials

International Nuclear Information System (INIS)

Faheem, Munazza; Matiullah

2008-01-01

Indoor radon has long been recognized as a potential health hazard for mankind. Building materials are considered as one of the major sources of radon in the indoor environment. To study radon exhalation rate and its dependence on moisture content, samples of soil and some common types of building materials (sand, cement, bricks and marble) were collected from Gujranwala, Gujrat, Hafizabad, Sialkot, Mandibahauddin and Narowal districts of the Punjab province (Pakistan). After processing, samples of 200 g each were placed in plastic vessels. CR-39 based NRPB detector were placed at the top of these vessels and were then hermetically sealed. After exposing to radon for 30 days within the closed vessels, the CR-39 detectors were processed. Radon exhalation rate was found to vary from 122±19 to 681±10mBqm -2 h -1 with an average of 376±147mBqm -2 h -1 in the soil samples whereas an average of 212±34, 195±25, 231±30 and 292±35mBqm -2 h -1 was observed in bricks, sand, cement and marble samples, respectively. Dependence of exhalation on moisture content has also been studied. Radon exhalation rate was found to increase with an increase in moisture, reached its maximum value and then decreased with further increase in the water content

Variability in the exhalation rate of radon

International Nuclear Information System (INIS)

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

1976-01-01

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

Investigation of the Radon exhalation potential in the PACA region. Phase II: case of high potential exhalation areas in Medium Champsaur (05) and South Esterel (83). Final report

International Nuclear Information System (INIS)

2009-01-01

After having recalled the results of the first phase of the study and the objectives of the second phase, the authors present the methodology: uranium and thorium analysis on rock, radon-222 activity measurement in soil gases, and gamma radiation measurement. They discuss the influence of rock uranium content on radon exhalation (natural contextual and physical phenomena governing radon transport, radon properties, uranium geochemistry). They report the results obtained in the two considered areas (meteorological conditions, radon 222 content in soils, uranium and thorium contents in geological formations, influence of geological formation type and distribution on radon activity)

Variation in radon exhalation from the ground on the active fault in Kobe

Energy Technology Data Exchange (ETDEWEB)

Yasuoka, Y.; Shinogi, M. [Kobe Pharmaceutical Univ., Kobe, Hyogo (Japan)

1998-12-31

Since 27 January 1997, the measurements of radon (Rn-222) exhaled from the ground have been made continuously by the use of PICO-RAD detector (Packard instrument Co.) at monitoring stations on Ashiya active fault. The fault may have been slipped by the Kobe earthquake (magnitude 7.2, 17 January 1995). The variation of relative radon exhalation on the fault was large. We guessed the large variation of relative radon exhalation on the fault was caused by not only the influence of meteorology but also the influence of other factors. (author)

Discussion on the formula of electrostatic collection radon exhalation rate monitor

International Nuclear Information System (INIS)

Gou Quanlu; Zhang Zhihui

1998-01-01

The formula for calculating radon exhalation rate from the surface of materials are deduced based the theory of radioactivity decay by considering factors which effect the change of radon and its decay products. The selection of value of Z in the formula are also discussed and some problems that exist in the available formula used to calculate the radon exhalation rate are explicated. The practical formula are deduced by adopting the effective decay constant λ e of radon in the collector. The fraction of α particles emitted by radon which effects the measurement results and the contribution of radon decay products left in the former measurement to the next measurement are also considered, and the correction factors are given respectively. The method is more complete and more practical

Measurement of radon exhalation rate and soil gas radon concentration in areas of southern Punjab (Pakistan)

International Nuclear Information System (INIS)

Mujahid, S. A.; Hussain, S.; Ramzan, M.

2010-01-01

Plastic track detectors were used to measure the radon concentration and exhalation rate from the soil samples. The samples were collected from areas of southern Punjab (Pakistan). In a laboratory experiment, passive alpha dosemeters were installed inside cylindrical bottles containing the soil samples. The radon concentrations and the radon exhalation rate were found in the ranges of 34±7 to 260±42 Bq m -3 and 38±8 to 288±46 mBq m -2 h -1 , respectively. The on-site measurements of radon in the soil gas were also carried out in these areas using a scintillation alpha counter. The concentration of radon in the soil gas was found in the range of 423±82-3565±438 Bq m -3 . (authors)

Natural radioactivity content and radon exhalation from materials used for construction and decoration

International Nuclear Information System (INIS)

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

2007-02-01

The present work deals with the measurement of radioactivity and radon exhalation rate from geological samples manufactured in Douala city and used as building materials. Nine types of building materials were surveyed for their natural radioactivity content using a hyper purity germanium (HPGe) detector. The absorbed dose rate in the samples investigated ranged from 28.5 to 66.6 nGy h -1 for brick samples, from 32.4 to 63.1 nGy h -1 for roofing tiles and was 30.3 nGy h -1 for concrete. External and internal hazard indexes were also estimated as defined by the European Commission. The study of radon exhalation rate from building materials is important for well understanding the individual contribution of each material to the total indoor radon exposure. Solid state nuclear track detectors, CR-39 were used for measuring the radon concentration from different materials. Samples were hermetically closed in glass vessels and the radon growth was followed as a function of time. Exploring the one-dimension radon transport equation, we derived the radon exhalation rate from the experimental measurement of α-track densities. The radon exhalation varied from (5.77±0.06) x 10 -5 to (7.61±0.07) x 10 -5 Bq cm -2 h -1 in bricks, from (5.79±0.05) x 10 -5 to (11.6±0.12) x 10 -5 in tiles and was (6.95±0.03) x 10 -5 Bq cm -2 h -1 in concrete. A positive correlation was found between uranium concentration measured with HPGe detector radon exhalation rate and radium content obtained using nuclear track detectors. (author)

Comparison of active and passive methods for radon exhalation from a high-exposure building material

International Nuclear Information System (INIS)

Abbasi, A.; Mirekhtiary, F.

2013-01-01

The radon exhalation rates and radon concentrations in granite stones used in Iran were measured by means of a high-resolution high purity Germanium gamma-spectroscopy system (passive method) and an AlphaGUARD model PQ 2000 (active method). For standard rooms (4.0 x 35.0 m area x 32.8 height) where ground and walls have been covered by granite stones, the radon concentration and the radon exhalation rate by two methods were calculated. The activity concentrations of 226 Ra in the selected granite samples ranged from 3.8 to 94.2 Bq kg -1 . The radon exhalation rate from the calculation of the 226 Ra activity concentration was obtained. The radon exhalation rates were 1.31-7.86 Bq m -2 h -1 . The direction measurements using an AlphaGUARD were from 218 to 1306 Bq m -3 with a mean of 625 Bq m -3 . Also, the exhalation rates measured by the passive and active methods were compared and the results of this study were the same, with the active method being 22% higher than the passive method. (authors)

Exhalation of radon and thoron from phosphogypsum uses as building material

International Nuclear Information System (INIS)

Vanmarcke, H.

1996-01-01

The radioactive properties of two types of phosphogypsum, were determined. Gypsum plates with different thickness were produced. The 226 Ra and 232 Th concentrations were measured by means of high resolution gamma spectrometry. The results are for type 1 226 Ra: 75 Bq/kg and 232 Th 230 Bq/kg and for type 2 226 Ra: 155 Bq/kg and 232 Th: 160 Bq/kg. The radon ( 222 Rn) exhalation rate was evaluated by closing the plates in airtight barrels and measuring the radon concentration. The exhalation rate of type 1 is 1.2 10-5 Bq/(kg s) and type 2 4.7 10-5 Bq/(kg s). In combination with the 226 Ra concentration an emanating fraction of respectively 7.6% and 14% is obtained. The 222 Rn (thoron) exhalation of the plates was determined by measuring the concentration of the decay products in a chamber of 1 m 3 with normal aerosol concentrations. The exhalation rate was found to be independent of the thickness of the plates, as expected from the short half-life of 220 Rn. Covering the entire surface of the plates with two layers of a common Latex paint decreased the thoron exhalation by a factor of 10 to 20. The laboratory results for the radon and thoron exhalation were converted using realistic assumptions for a room. The contribution of phosphogypsum to the average radon concentration in a room is found to be about 1 Bq/m 3 for type 1 and 4 Bq/m 3 for type 2 resulting in an annual effective dose of the order of 0.1 mSv/year. The contribution to the effective dose from the thoron exhalation is much greater, namely, 1.8 mSv/year for type I and 0.9 mSv/year for type 2. Painting the gypsum lowers the thoron dose by a factor of 10 to 20 making the thoron dose comparable to that of radon. (author)

Uranium distribution and radon exhalation from Brazilian dimension stones

International Nuclear Information System (INIS)

Amaral, P.G.Q.; Galembeck, T.M.B.; Bonotto, D.M.; Artur, A.C.

2012-01-01

This paper provides evaluations of the radiometric behavior and exhalation patterns of radon gas in decorative and dimension stones explored in the Brazilian states of Minas Gerais and Espírito Santo, given the importance of determining radon gas concentrations in human-inhabited environments. A total of 10 silicate rock types were studied, featuring different petrographic/petrophysical characteristics given by seven magmatic rocks (three of which are granitic pegmatites) and three metamorphic rocks. The study, comprising radiometric data of U and monitoring of 222 Rn gas exhalation, shows a strong correlation between petrographic parameters and the physical properties of rocks. U levels ranged between 2.9 and 37 ppm, revealing a good coherence between the presence and the absence of radioactive element-bearing accessory minerals for each rock type. The rate of radon exhalation from the stones is related to the petrographic/petrophysical features of each material. By comparing the 222 Rn level generated by a rock to the amount effectively emanated by it, the rate of emanated gas proves to be insignificant; also, a rock that produces more Rn will not always emanate more. Simulations performed to estimate the radon levels inside residences or any given indoor environment showed that nine samples attained values below the 4 pCi/L EPA limit, whereas one was above that limit. - Highlights: ► Integration of distinct radiometric data acquired in dimension stones. ► Dimension stones are extensively commercialized abroad. ► Rn exhalation above the EPA threshold limit of 4 pCi/L.

Uranium distribution and radon exhalation from Brazilian dimension stones

Energy Technology Data Exchange (ETDEWEB)

Amaral, P.G.Q.; Galembeck, T.M.B. [Departamento de Petrologia e Metalogenia, Instituto de Geociencias e Ciencias Exatas, Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil); Bonotto, D.M., E-mail: danielbonotto@yahoo.com.br [Departamento de Petrologia e Metalogenia, Instituto de Geociencias e Ciencias Exatas, Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil); Artur, A.C. [Departamento de Petrologia e Metalogenia, Instituto de Geociencias e Ciencias Exatas, Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil)

2012-04-15

This paper provides evaluations of the radiometric behavior and exhalation patterns of radon gas in decorative and dimension stones explored in the Brazilian states of Minas Gerais and Espirito Santo, given the importance of determining radon gas concentrations in human-inhabited environments. A total of 10 silicate rock types were studied, featuring different petrographic/petrophysical characteristics given by seven magmatic rocks (three of which are granitic pegmatites) and three metamorphic rocks. The study, comprising radiometric data of U and monitoring of {sup 222}Rn gas exhalation, shows a strong correlation between petrographic parameters and the physical properties of rocks. U levels ranged between 2.9 and 37 ppm, revealing a good coherence between the presence and the absence of radioactive element-bearing accessory minerals for each rock type. The rate of radon exhalation from the stones is related to the petrographic/petrophysical features of each material. By comparing the {sup 222}Rn level generated by a rock to the amount effectively emanated by it, the rate of emanated gas proves to be insignificant; also, a rock that produces more Rn will not always emanate more. Simulations performed to estimate the radon levels inside residences or any given indoor environment showed that nine samples attained values below the 4 pCi/L EPA limit, whereas one was above that limit. - Highlights: Black-Right-Pointing-Pointer Integration of distinct radiometric data acquired in dimension stones. Black-Right-Pointing-Pointer Dimension stones are extensively commercialized abroad. Black-Right-Pointing-Pointer Rn exhalation above the EPA threshold limit of 4 pCi/L.

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)

Radon exhalation from samples of Danish soils, subsoils and sedimentary rocks

International Nuclear Information System (INIS)

Korsbech, U.

1985-01-01

For some years it has been known that the ground below a house could be the major source of radon and radon daughters in the indoor air. Th amount of radon penetrating into buildings from the ground depends on several factors e.g. the amount of radon produced in the ground, the amount of cracks and holes in the foundation of buildings, and the pressure difference between the air in the ground (sol air) and the indoor air. As a first step in determining the influence of the ground below Danish buildings 60 samples of soils, subsoils, and sedimentary rocks have been measured for their exhalation rates of radon i.e. the amount of radon escaping the sample per mass unit and per second (Bq.kg -1 .s -1 or radon atoms per kg and per sec.). The results of the measurements of the radon exhalation are presented and commented, and a conclusion concerning the methods for finding geological deposits with a high radon halation rate is presented. (author)

White sand potentially suppresses radon emission from uranium tailings

Science.gov (United States)

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

2018-03-01

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

Impact of structural parameters on the radon exhalation of building materials: Preliminary study

International Nuclear Information System (INIS)

Roelofs, L.M.M.

1993-01-01

Samples of mortar and sand-lime pieces with different percentages of fly ash are hardened at different relative humidities. The porosity distribution, the moisture and the radon exhalation of these samples are determined. Based on the data of the above-mentioned analyses, the thickness of the adsorbed water layer in the water-filled pores is estimated. The correlation between the structural parameters and the radon exhalation is investigated. If the radon exhalation process can be modelled, the radiation risk of applying fly ash in building materials can be controlled or reduced. The results do not yet show a clear indication. The applied methods have to be considered in more detail

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

Comparison of calculated and measured soil-gas radon concentration and radon exhalation rate

International Nuclear Information System (INIS)

Neznal, Martin; Neznal, Matej; Jiranek, Martin

2000-01-01

The computer model RADON2D for WINDOWS, which makes it possible to estimate the radon exhalation rate from the ground surface and the distribution of soil-gas radon concentration, was tested using a large set of experimental data coming from four reference areas located in regions with different geological structure. A good agreement between calculated and experimental data was observed. In the majority of cases, a correct description of the real situation was obtained using non-modified experimental input data. (author)

Phosphogypsum recycling in the building materials industry: assessment of the radon exhalation rate.

Science.gov (United States)

Campos, M P; Costa, L J P; Nisti, M B; Mazzilli, B P

2017-06-01

Phosphogypsum can be classified as a Naturally Occurring Radioactive Material (NORM) residue of the phosphate fertilizer industry. One of the main environmental concerns of its use as building material is the radon exhalation. The aim of this study is to measure the radon exhalation rate from plates and bricks manufactured with phosphogypsum from three installations of the main Brazilian producer, Vale Fertilizantes, in order to evaluate the additional health risk to dwellers. A simple and reliable accumulator method involving a PVC pipe sealed with a PVC pipe cover commercially available with CR-39 radon detector into a diffusion chamber was used for measuring radon exhalation rate from phosphogypsum made plates and bricks. The radon exhalation rate from plates varied from 0.19 ± 0.06 Bq m -2 h -1 , for phosphogypsum from Bunge Fertilizers, from 1.3 ± 0.3 Bq m -2 h -1 , for phosphogypsum from Ultrafertil. As for the bricks, the results ranged from 0.11 ± 0.01 Bq m -2 h -1 , for phosphogypsum from Bunge Fertilizers, to 1.2 ± 0.3 Bq m -2 h -1 , for phosphogypsum from Ultrafertil. The results obtained in this study for the radon exhalation rate from phosphogypsum plates and bricks are of the same order of magnitude than those from ordinary building materials. So, it can be concluded that the recycling of phosphogypsum as building material is a safe practice, since no additional health risk is expected from the radiological point of view. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of sand/cement ratio on radon exhalation from cement specimens containing 226Ra

International Nuclear Information System (INIS)

Takriti, S.; Shweikani, R.; Ali, A. F.; Rajaa, G.

2002-09-01

Portland cement was mixed with different kind of sand (calcite and silica) in different ratio to produce radioactive specimens with radium chloride. The release of radon from these samples was studied. The results showed that radon release from the calcite-cement samples increased with the increases of the sand mixed ratio until fixed value (about 20%) then decreased to less than its release from the beginning, and the release changed with the sand size also. Radon release from silica-cement samples had the same observations of calcite-cement samples. It was found that calcite-cement reduced the radon exhalation quantity rather than the silica-cement samples. The decreases of the radon exhalation from the cement-sand may be due to the creation of free spaces in the samples, which gave the possibility to radon to decay into these free spaces rather than radon exhalation. The daughters of the radon decay 214 Bi and 214 Pb reported by gamma measurements of the cement-sand samples. (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 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)

Radon exhalation in some building construction materials and effect of plastering and paints on the radon exhalation rate using fired bricks

International Nuclear Information System (INIS)

Sharma, Anil; Mahur, A.K.; Rajendra Prasad; Sonkawade, R.G.; Sharma, A.C.

2013-01-01

The technological endeavors of human beings have modified the levels of radiation exposure slightly. The emanation of radon is primarily associated with radium and its ultimate precursor uranium. The radiation dose received by human beings from indoor radon and its progeny is the largest of all doses received either by natural or man-made sources. In order to investigate the effect of paints available in the market on the radon exhalation rate from building materials, several bricks were collected. These bricks were plastered with a mixture of cement and sand. Before measurements bricks were dried for 24 hours. These plastered bricks were then coated with white wash and again dried for 1- 2 hours. After drying the bricks were coated with different brands and colors of paints. Radon exhalation rates measurements were carried out for these painted bricks using 'Sealed can Technique' cylindrical plastic 'Can' of 7.5 cm height and 7.0 cm diameter was sealed to the individual samples by plastic can. In each 'Can' a LR-115 type II plastic detector (2 cm 2cm) was fixed at the top inside of the 'Can', such that the sensitive surface of the detector faces the material and is freely exposed to the emergent radon. Radon decays in the volume of the can record the alpha particles resulting from the 218 Po and 214 Po deposited on the inner wall of the 'Can'. Radon and its daughters will reach an equilibrium in concentration after one week or more. Hence the equilibrium activity of the emergent radon can be obtained from the geometry of the can and the time of exposure. The results will be discussed. (author)

Radon exhalation of hardening concrete: monitoring cement hydration and prediction of radon concentration in construction site.

Science.gov (United States)

Kovler, Konstantin

2006-01-01

The unique properties of radon as a noble gas are used for monitoring cement hydration and microstructural transformations in cementitious system. It is found that the radon concentration curve for hydrating cement paste enclosed in the chamber increases from zero (more accurately - background) concentrations, similar to unhydrated cement. However, radon concentrations developed within 3 days in the test chamber containing cement paste were approximately 20 times higher than those of unhydrated cement. This fact proves the importance of microstructural transformations taking place in the process of cement hydration, in comparison with cement grain, which is a time-stable material. It is concluded that monitoring cement hydration by means of radon exhalation method makes it possible to distinguish between three main stages, which are readily seen in the time dependence of radon concentration: stage I (dormant period), stage II (setting and intensive microstructural transformations) and stage III (densification of the structure and drying). The information presented improves our understanding of the main physical mechanisms resulting in the characteristic behavior of radon exhalation in the course of cement hydration. The maximum value of radon exhalation rate observed, when cement sets, can reach 0.6 mBq kg(-1) s(-1) and sometimes exceeds 1.0 mBq kg(-1) s(-1). These values exceed significantly to those known before for cementitious materials. At the same time, the minimum ventilation rate accepted in the design practice (0.5 h(-1)), guarantees that the concentrations in most of the cases will not exceed the action level and that they are not of any radiological concern for construction workers employed in concreting in closed spaces.

Assessment of radon and thoron exhalation from Indian cement samples using smart radon and thoron monitors

International Nuclear Information System (INIS)

Sahoo, B.K.; Sapra, B.K; Agarwal, T.K.; Babu, D.A.R.

2015-01-01

It has been established that primarily, there exist two important sources that contribute to indoor radon/thoron namely, the exhalation from ground and building materials. The contribution from ground, although significant, is treated as a case of existing exposure. Then, the only source that can be controlled during the construction is the choice of building materials. Cement is an important building material used in the construction of houses and buildings in India. The housing sector is the largest cement consumer with 53% of the total Indian cement demand followed by the infrastructure sector. India with a production capacity of 165 million tones (MT) (in 2007), was the second largest cement producer in the world after China. The industry produces various types of cement like ordinary portland cement (OPC), Portland pozzolana cement (PPC), portland slag cement (PSC), rapid hardening portland cement (RHPC), sulphate resistant cement (SRC) and white cement (WC). Several studies have been undertaken on cement in various countries because it is commonly used in bulk quantities in the construction of houses and other civil structures. However, detailed information regarding the radon and thoron exhalation into indoor air from various types of cements produced in India is scarce. In the present work, an attempt has been made to systematically determine the radon and thoron exhalation from 50 cement samples (17 OPC, 15 PPC, 04 PSC, 06 RHPC, 04 WC and 04 SRC). The data thus obtained is used to calculate the indoor radon and thoron source term and the contributed inhalation dose based on a model room structure. The measured values of radon and thoron exhalation from cement samples were comparable with the reported values in other countries. This study showed that the cement samples used in civil constructions do not pose any radiological hazard to the Indian population. (author)

Calibration of track detectors and measurement of radon exhalation rate from solid samples

International Nuclear Information System (INIS)

Singh, Ajay Kumar; Jojo, P.J.; Prasad, Rajendra; Khan, A.J.; Ramachandran, T.V.

1997-01-01

CR-39 and LR-115 type II track detectors to be used for radon exhalation measurements have been calibrated. The configurations fitted with detectors in Can technique in the open cup mode are cylindrical plastic cup (PC) and conical plastic cup (CPC). The experiment was performed in radon exposure chamber having monodisperse aerosols of 0.2 μm size, to find the relationship between track density and the radon concentration. The calibration factors for PC and CPC type dosimeters with LR-115 type II detector were found to be 0.056 and 0.083 tracks cm -2 d -1 (Bqm -3 ) -1 respectively, while with CR-39 detector the values were 0.149 and 0.150 tracks cm -2 d -1 (Bq m -3 ) -1 . Employing the Can technique, measurements of exhalation rates from solid samples used as construction materials, are undertaken. Radon exhalation rate is found to be minimum in cement samples while in fly ash it is not enhanced as compared to coal samples. (author)

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)

Characteristics of radon and thoron exhalation rates in Okinawa, subtropical region of Japan

International Nuclear Information System (INIS)

Shiroma, Y.; Kina, S.; Fujitani, T.; Hosoda, M.; Sorimachi, A.; Ishikawa, T.; Sahoo, S. K.; Tokonami, S.; Furukawa, M.

2012-01-01

Radon and thoron exhalation rates from the ground surface were estimated in three islands of Okinawa Prefecture, a subtropical region of Japan. In situ measurements of the exhalation rates were conducted at a total of 88 points using an accumulation technique with a ZnS(Ag) scintillation detector. The radon and thoron exhalation rates were calculated to be 1-137(arithmetic mean: 21) mBq m -2 s -1 and 32-6244 (1801) mBq m -2 s -1 , respectively. In the surface soil samples collected at 53 measurement points, 238 U and 232 Th series concentrations were estimated to be 17.9-254.0 (64.0) Bq kg -1 dry and 17.8-136.1 (58.8) Bq kg -1 dry, respectively. The maximum rates and concentrations were observed in the dark red soil area. Recent studies strongly suggest that the base material of the soils may be the eolian dust derived from the southeastern part of China, a high background radiation area. The eolian dust is, therefore, considered to be an enhancer for the radon and thoron exhalations in Okinawa. (authors)

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

Science.gov (United States)

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

2013-03-01

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

Correlation between radon exhalation and radium content in granite samples used as construction material in Saudi Arabia

Energy Technology Data Exchange (ETDEWEB)

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); Musazay, M.S. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Aksoy, A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

2005-11-15

Measurements of radon exhalation for a total of 205 selected samples of construction materials used in Saudi Arabia were carried out using an active radon gas analyzer with an emanation container. It was found that granite samples were the main source of radon exhalation. The radon exhalation rates per unit area from these granite samples varied from below the minimum detection limit up to 13.1Bqm{sup -2}h{sup -1} with an average of 1.5 +/-1.9(1{sigma})Bqm{sup -2}h{sup -1}. The radium contents of 27 granite samples were measured using an HPGe-based {gamma} spectroscopy setup. The {sup 226}Ra content of the granites varied from below the minimum detection limit up to 297Bqkg{sup -1}, with an average of 83+/-73(1{sigma})Bqkg{sup -1}. The linear correlation coefficient between exhaled radon and radium content was found to be 0.90.

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

Science.gov (United States)

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

2016-10-01

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

Natural radioactivity and radon specific exhalation rate of zircon sands

International Nuclear Information System (INIS)

Righi, S.; Verita, S.; Bruzzi, L.; Albertazzi, A.

2006-01-01

The study focuses on the radon emanation from zircon sands and their derivatives, which are widely used in many sectors of industry. In particular, the results obtained by experimental measurements on samples of zircon sands and zircon flours commonly used in Italian ceramic industries are reported. Zircon sands contain a significant concentration of natural radioactivity because Th and U may substitute zirconium in the zircon crystal lattice. The relevant routes of exposure of workers to T.E.N.O.R.M. from zircon materials are external radiation and internal exposure, either by inhalation of aerosols in dusty working conditions or by inhalation of radon in workplaces. The main objective of this investigation is to provide experimental data able to better calculate the internal exposure of workers due to radon inhalation. Zircon samples were surveyed for natural radioactivity, radon specific exhalation rate and emanation fraction. Measurements of radioactivity concentration were carried out using γ-spectrometry. Methods used for determining radon consisted in determining the 222 Rn activity accumulated in a vessel after a given accumulation build-up time. The average activity concentrations of 238 U and 232 Th in samples result about 2600 and 550 Bq kg-1, respectively; these concentrations are significantly higher than the world average noticed in soils, rocks and Earth crust. The 222 Rn specific exhalation rates result very low probably due to the low porosity of the material and the consequent difficulty for radon to be released from the zircon crystal lattice. (author)

Measurement of exhalation and diffusion parameters of radon in solids by plastic track detectors

Energy Technology Data Exchange (ETDEWEB)

Somogyi, G.; Haffez, A.-F.; Hunyadi, I.; Toth-Szilagyi, M.

1986-01-01

There are large discrepancies in data available in the literature for the exhalation and diffusion behaviour of radon in various materials. Therefore there is a need for more studies in this field. For this purpose we have developed and used track methods to measure mass and areal exhalation rates of radon from different fly ashes and sand. In addition, methods were also developed to determine the diffusion length of radon and the porosity of materials. For getting the radon emanation coefficient we have applied the autoradiographic method and the ''can-technique'' for determining the real and effective radium contents. The disturbing effect expected from the geometry of measuring cans and samples is discussed. Relations are derived for the correction of such effect.

Radon exhalations of rock samples from the Muellenbach uranium test mine

International Nuclear Information System (INIS)

Keller, G.; Dudler, R.

1985-01-01

Radiation exposure of workers in underground mines with high U/Ra concentration is mostly due to inhalation of the short-lived radioactive decay products of the noble gas radon. Knowledge of the Rn-222 exhalation rates of walls and rocks as well as the contributing influencing parameters is therefore of interest for radiation protection purposes. Measurements showed that in the hours following shortfiring operations, the fresh dirt and the new walls had several times the exhalation rates of older dirt and walls. Measurements of exhalation rates on drill cores can help to assess exhalation for an adequate layout of the mine ventilation system. (orig./PW) [de

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

Directory of Open Access Journals (Sweden)

M. Abo-Elmagd

2014-10-01

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

Radon-222 exhalation from Danish building materials: H + H Industri A/S results

International Nuclear Information System (INIS)

Andersen, C.E.

1999-08-01

This report describes a closed-chamber method for laboratory measurements of the rate at which radon-222 degasses (exhales) from small building material samples. The chamber is 55 L in volume and the main sample geometry is a slab of dimensions 5x30x30 cm 3 . Numerical modelling is used to assess (and partly remove) the bias of the method relative to an ideal measurement of the free exhalation rate. Experimental results obtained with the method are found to be in agreement with the results of an open-chamber method (which is subject to different sources of error). Results of radon-222 exhalation rate measurements for 10 samples of Danish building materials are reported. Samples include ordinary concrete, lightweight aggregate concrete, autoclaved aerated concrete, bricks, and gypsum board. The maximum mass-specific exhalation rate is about 20 mBq h -1 kg -1 . Under consideration of the specific applications of the investigated building materials, the contribution to the indoor radon-222 concentration in a single-family reference house is calculated. Numerical modelling is used to help extrapolate the laboratory measurements on small samples to full scale walls. Application of typical materials will increase the indoor concentration by less than 10 Bq m -3 . (au)

Radon exhalation study from cement, cement slabs and concrete slabs with variation in fly ash

International Nuclear Information System (INIS)

Sharma, Nisha; Singh, Jaspal

2012-01-01

Fly ash is a waste product from coal-fired power plants. Fly ash has become a subject of world-wide interest in recent years because of its diverse uses, e.g. in the manufacture of concrete for building purposes, for the filling of underground cavities, or as a component of building material. The fly ash may contain enhanced levels of the natural radionuclides in the uranium and thorium series and by using the fly ash in building materials, the radiation levels in houses may thus be technologically enhanced. Because of its relatively high radionuclide contents (including 226 Ra), fly ash may, however, present a potential hazard to the population through its radon emanation, which would be highly undesirable. Since fly ash is frequently used as a building material, the idea of the experiment was to mix fly ash in different proportions in the cement in the powder form, cemented slabs and concrete slabs to study the combined behaviors. Alpha sensitive LR-115 type II plastic track detector, commonly known as Solid State Nuclear Track Detectors (SSNTDs), were used to measure the radon concentration. The alpha particles emitted from the radon causes the radiation damaged tracks. The chemical etching in NaOH at 60°C for about 90 minutes was done to reveal these latent tracks, which were then scanned and counted by an optical microscope of suitable magnification. By calculating the track density of registered tracks, the radon concentrations were determined. In case of cement in the powder form and in cemented slab, starting from the pure cement, fly ash was added up to 70% by weight. In this case the radon exhalation rate has increased by addition of fly ash in the cement and in case of concrete slabs by the addition of fly ash in the cement the radon exhalation increases up to 60% and then decreases. Therefore, on the basis of our investigations we concluded that in general radon exhalation rate increases with the addition of fly ash. (author)

Radiometric surveying for the assessment of radiation dose and radon specific exhalation in underground environment

Science.gov (United States)

Bochiolo, M.; Verdoya, M.; Chiozzi, P.; Pasquale, V.

2012-08-01

We performed a radiometric survey for evaluating the natural radioactivity and the related potential hazard level both outdoor and indoor a mine tunnel. The mine is located in a zone of uranium enrichment in the Western Alps (Italy). At first, a γ-ray spectrometry survey of the area surrounding the mine was carried out to define the extent of the ore deposit. Then, spectrometric measurements were performed in the tunnel and rock samples were collected for laboratory analyses. The results point to significant heterogeneity in uranium concentration and consequently in the absorbed dose rate spatial distribution. Spectrometric results in situ and in the laboratory, together with radon air concentration measurements, were used to infer the radon specific exhalation and flow from the mine rocks. The specific exhalation is positively related to the activity concentration of uranium.

A study of indoor radon, thoron and their exhalation rates in the environment of Fazilka district, Punjab, India

Science.gov (United States)

Narang, Saurabh; Kumar, Deepak; Sharma, Dinesh Kumar; Kumar, Ajay

2018-02-01

Over the last few decades, the study of radioactive radon gas has gained huge momentum due to its possible role in health related hazards. In the present work, pin-hole twin chamber single entrance dosimeters have been used for track measurements of radon and thoron. The annual average radon concentration varies from 50.3 to 204 Bq/m3 at all locations. Almost all the values are below the safe range provided by ICRP. Radon concentration is found to be higher in winter as compared to other seasons. Variation of radon with quality of dwellings is also discussed. The values of annual effective dose due to radon and thoron are also well within the range provided by ICRP and WHO. Radon and thoron exhalation rates are measured using SMART RnDuo monitor. The radon mass exhalation rates ranged from 11 to 71 mBq/kg/h while the thoron surface values ranged from 36 to 2048 Bq/m2/h. All the values are on the lower side. A weak correlation is found between radon and thoron concentrations and their exhalation rates. When compared with the values of other parts of northern India, the values of present investigation are on higher side.

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

International Nuclear Information System (INIS)

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

2013-01-01

Radon exhalation rates from building materials used in high background radiation areas (HBRA) of Ramsar were measured using an active radon gas analyzer with an emanation container. Radon exhalation rates from these samples varied from below the lower detection limit up to 384 Bq.m −2 h −1 . The 226 Ra, 232 Th and 40 K contents were also measured using a high resolution HPGe gamma- ray spectrometer system. The activity concentration of 226 Ra, 232 Th and 40 K content varied from below the minimum detection limit up to 86,400 Bq kg −1 , 187 Bq kg −1 and 1350 Bq kg −1 , respectively. The linear correlation coefficient between radon exhalation rate and radium concentration was 0.90. The result of this survey shows that radon exhalation rate and radium content in some local stones used as basements are extremely high and these samples are main sources of indoor radon emanation as well as external gamma radiation from uranium series. -- Highlights: ► In the selection process of local samples, portable scintillometer (NaI) was used. ► The activity concentration of 226 Ra varied from below the MDL up to 86400 Bq kg −1 . ► The activity concentration of 232 Th varied from below the MDL up to 187 Bq kg −1 . ► The activity concentration of 40 K varied from below the MDL up to 1350 Bq kg −1

Radon soil-gas concentration and exhalation from mine tailings dams in South Africa

Energy Technology Data Exchange (ETDEWEB)

Ongori, J.; Lindsay, R. [University of the Western Cape, Department of Physics, Private Bag X17, Bellville 7535 (South Africa); Newman, R. [Stellenbosch University, Department of Physics, Private Bag X1 Matieland 7602 (South Africa); Maleka, P. [iThemba LABS, Department of Nuclear Physics, P. O. Box 722, Somerset West 7129 (South Africa)

2014-07-01

In Africa as well as in the world, South Africa plays an important role in the mining industry which dates back almost 120 years. Mining activities in South Africa mainly take place in Gauteng Province. Every year million of tons of rocks are taken from underground, milled and processed to extract gold. The uranium bearing tailings are disposed in dumpsites. These tailings dumps contain considerable amounts of radium ({sup 226}Ra) and have therefore been identified as large sources of radon ({sup 222}Rn). Radon is a noble gas formed by the decay of radium which in turn is derived from the radioactive decay of uranium ({sup 238}U). Radon release from these tailings dumps pose health concerns for the surrounding communities. Radon soil gas concentrations and exhalations from a non-operational mine dump (Kloof) which belongs to Carletonville Gold Field, Witwatersrand, South Africa have been investigated. The continuous radon monitor, the Durridge RAD7 was used to measure {sup 222}Rn soil gas concentration in the tailings dump at five different spots. The radon soil gas concentration levels were measured at depths starting from 30 cm below ground/air interface up to 110 cm at intervals of 20 cm. The concentrations recorded ranged from 26±1 to 472±23 kBq.m{sup -3}. Furthermore, thirty four soil samples were taken from the spots where radon soil gas measurements were measured for laboratory-based measurement using the low background Hyper Pure Germanium (HPGe) gamma-ray detector available at the Environmental Radioactivity Laboratory (ERL), iThemba LABS, Western Cape Province. The soil samples were collected in the depth range 0-30 cm. After analysis the weighted average activity concentrations in the soils samples were 308±7 Bq.kg{sup -1}, 255±5 Bq.kg{sup -1} and 18±1 Bq.kg{sup -1} for {sup 238}U, {sup 40}K and {sup 232}Th, respectively. A number of factors such as the radium activity concentration and its distribution in soil grains, soil grain size, soil porosity

Measurement of radon activity, exhalation rate and radiation dose in fly ash and coal samples from NTPC, Badarpur, Delhi, India

International Nuclear Information System (INIS)

Gupta, Mamta; Verma, K.D.; Mahur, A.K.; Prasad, R.; Sonkawade, R.G.

2013-01-01

In the present study radon activities and exhalation rates from fly ash and coal samples from NTPC (National Thermal Power Corporation) situated at Badarpur, Delhi, India, have been measured. 'Sealed Can Technique' using LR-115 type II track detectors was employed. In fly ash samples, radon activity has been found to vary from 400.0 ± 34.7 to 483.9 ± 38.1Bqm -3 with an average value of 447.1 ± 36.6 Bqm -3 and in coal samples, radon activity has been found to vary from 504.0 ± 39.0 to 932.1 ± 52.9 Bqm -3 with an average value of 687.2 ± 45.2 Bqm -3 . Radon exhalation rate from coal is found to be higher than radon exhalation rate from its ash products, whereas the opposite is expected. Indoor inhalation exposure (radon) effective dose has also been estimated. (author)

Measurement of Radon Exhalation Rate in Sand Samples from Gopalpur and Rushikulya Beach Orissa, Eastern India

Science.gov (United States)

Mahur, Ajay Kumar; Sharma, Anil; Sonkawade, R. G.; Sengupta, D.; Sharma, A. C.; Prasad, Rajendra

Natural radioactivity is wide spread in the earth's environment and exists in various geological formations like soils, rocks, water and sand etc. The measurement of activities of naturally occurring radionuclides 226Ra, 232Th and 40K is important for the estimation of radiation risk and has been the subject of interest of research scientists all over the world. Building construction materials and soil beneath the house are the main sources of radon inside the dwellings. Radon exhalation rate from building materials like, cement, sand and concrete etc. is a major source of radiation to the habitants. In the present studies radon exhalation rates in sand samples collected from Gopalpur and Rushikulya beach placer deposit in Orissa are measured by using "Sealed Can technique" with LR-115 type II nuclear track detectors. In Samples from Rushikulya beach show radon activities varying from 389 ± 24 to 997 ± 38 Bq m-3 with an average value of 549 ±28 Bq m-3. Surface exhalation rates in these samples are found to vary from 140 ± 9 to 359 ± 14 mBq m-2 h-1with an average value of 197 ±10 mBq m-2 h-1, whereas, mass exhalation rates vary from 5 ± 0.3 to 14 ± 0.5 mBq kg-1 h-1 with an average value of 8 ± 0.4 mBq kg-1 h-1. Samples from Gopalpur radon activities are found to vary from 371 ± 23 to 800 ± 34 Bq m-3 with an average value of 549 ± 28 Bq m-3. Surface exhalation rates in these samples are found to vary from 133 ± 8 to 288 ± 12 mBq m-2h-1 with an average value of 197 ± 10 mBq m-2 h-1, whereas, mass exhalation rates vary from 5 ± 0.3 to 11 ± 1 mBq kg-1 h-1 with an average value of 8 ± 0.4 mBq kg-1 h-1.

Survey of Gamma Dose and Radon Exhalation Rate from Soil Surface of High Background Natural Radiation Areas in Ramsar, Iran

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Rouhollah Dehghani

2013-09-01

Full Text Available Background: Radon is a radioactive gas and the second leading cause of death due to lung cancer after smoking. Ramsar is known for having the highest levels of natural background radiation on earth. Materials and Methods: In this research study, 50 stations of high radioactivity areas of Ramsar were selected in warm season of the year. Then gamma dose and radon exhalation rate were measured.Results: Results showed that gamma dose and radon exhalation rate were in the range of 51-7100 nSv/hr and 9-15370 mBq/m2s, respectively.Conclusion: Compare to the worldwide average 16 mBq/m2s, estimated average annual effective of Radon exhalation rate in the study area is too high.

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)

Exhalation velocity of radon-222 of Dutch building materials and the influence of paint systems

International Nuclear Information System (INIS)

Dijk, W. van; Jong, P. de

1989-02-01

In order to achieve a better insight concerning the source terms of radon in the Dutch dwelling in the framework of the RENA-programme an investigation has been performed into the exhalation velocity of radon-222 from building materials. From this investigation it turned out that the ventilation factor does not have any influence upon the exhalation velocity, neither an influence of alteration of air pressure could be demonstrated. The influence of air humidity upon the exhalation velocity showed a twofold picture; for gypsum a linear increase of the exhalation velocity with vapour pressure was found, while for concrete a linear decrease with vapour pressure was observed. Further it has been investigated in how far paint systems diminish the exhalation velocity of the Rn-222 from gypsum and concrete. Acryl paints, mostly used in the Dutch dwelling, did not show a decrease of the exhalation velocity and structure paints did even cause an increase of the exhalation velocity. Other types of paint based on chlorous rubber, epoxy resins and poly-urethane, in contrast, showed a clear reduction. From these those based on poly-urethane showed the largest reduction (60-75%) at a double sided treatment of the wall. With the help of a mathematical modelling of the exhalation estimations have been made of the exhalation velocity of Rn-222 at single sided treatment of a wall and for the exhalation velocity of Rn-220. For the fore mentioned poly-urethane-paints this yelds, at an estimate, a reduction of respectively 90-95% and 100%. (author). 40 refs.; 15 figs.; 8 tabs

Modelling radiation exposure in homes from siporex blocks by using exhalation rates of radon

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Nikolić Mladen D.

2015-01-01

Full Text Available Building materials are the second major source of indoor radon, after soil. The contribution of building materials to indoor radon amount depends upon the radium content and exhalation rates, which can be used as a primary index for radon levels in the dwellings. This paper presents the results of using the experimentally determined exhalation rates of siporex blocks and concrete plates, to assess the radiation exposure in dwellings built of siporex blocks. The annual doses in rooms have been estimated depending on the established modes of ventilation. Realistic scenario was created to predict an annual effective dose for an old person, a housewife, a student, and an employed tenant, who live in the same apartment, spending different periods of time in it. The results indicate the crucial importance of good ventilation of the living space.

Radon exhalation from granitic rocks

International Nuclear Information System (INIS)

Del Claro, Flávia; Paschuk, Sergei A.; Corrêa, Janine N.; Mazer, Wellington; Narloch, Danielle Cristine; Martin, Aline Cristina; Denyak, Valeriy

2017-01-01

Naturally occurring radionuclides such as radon ( 222 Rn), its decay products and other elements from the radioactive series of uranium ( 238 U and 235 U) and thorium ( 232 Th) are an important source of human exposure to natural radioactivity. The worldwide evaluation of health radiobiological effects and risks from population exposure to natural radionuclides is a growing concern. About 50% of personal radiation annual dose is related to radionuclides such as radon ( 222 Rn), thoron ( 220 Rn), radium ( 226 Ra), thorium ( 232 Th) and potassium ( 40 K), which are present in modern materials commonly used in construction of dwellings and buildings. The radioactivity of marbles and granites is of big concern since under certain conditions the radioactivity levels of these materials can be hazardous to the population and require the implementation of mitigation procedures. Present survey of the 222 Rn and 220 Rn activity concentration liberated in the air was performed using commercialized Brazilian granite rocks at national market as well as exported to other countries. The 222 Rn and 220 Rn measurements were performed using the AlphaGUARD instant monitor and RAD7 detector, respectively. This study was performed at the Applied Nuclear Physics Laboratory of the Federal University of Technology – Paraná (UTFPR). Obtained results of radon concentration activity in air exhaled studied samples of granites varied from 3±1 Bq/m 3 to 2087±19 Bq/m 3 , which shows that some samples of granitic rocks represent rather elevated health risk the population. (author)

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Radon exhalation from granitic rocks

Energy Technology Data Exchange (ETDEWEB)

Del Claro, Flávia; Paschuk, Sergei A.; Corrêa, Janine N.; Mazer, Wellington; Narloch, Danielle Cristine; Martin, Aline Cristina [Universidade Tecnológica Federal do Paraná (UTFPR), Curitiba, PR (Brazil); Denyak, Valeriy, E-mail: flaviadelclaro@gmail.com, E-mail: spaschuk@gmail.com, E-mail: janine_nicolosi@hotmail.com, E-mail: denyak@gmail.com [Instituto de Pesquisa Pelé Pequeno Príncipe (IPPP), Curitiba, PR (Brazil)

2017-07-01

Naturally occurring radionuclides such as radon ({sup 222}Rn), its decay products and other elements from the radioactive series of uranium ({sup 238}U and {sup 235}U) and thorium ({sup 232}Th) are an important source of human exposure to natural radioactivity. The worldwide evaluation of health radiobiological effects and risks from population exposure to natural radionuclides is a growing concern. About 50% of personal radiation annual dose is related to radionuclides such as radon ({sup 222}Rn), thoron ({sup 220}Rn), radium ({sup 226}Ra), thorium ({sup 232}Th) and potassium ({sup 40}K), which are present in modern materials commonly used in construction of dwellings and buildings. The radioactivity of marbles and granites is of big concern since under certain conditions the radioactivity levels of these materials can be hazardous to the population and require the implementation of mitigation procedures. Present survey of the {sup 222}Rn and {sup 220}Rn activity concentration liberated in the air was performed using commercialized Brazilian granite rocks at national market as well as exported to other countries. The {sup 222}Rn and {sup 220}Rn measurements were performed using the AlphaGUARD instant monitor and RAD7 detector, respectively. This study was performed at the Applied Nuclear Physics Laboratory of the Federal University of Technology – Paraná (UTFPR). Obtained results of radon concentration activity in air exhaled studied samples of granites varied from 3±1 Bq/m{sup 3} to 2087±19 Bq/m{sup 3}, which shows that some samples of granitic rocks represent rather elevated health risk the population. (author)

The natural radionuclide concentration and radon exhalation rate of Turkish natural stones

International Nuclear Information System (INIS)

Yasar, O.; Yaprak, G.; Guer, F.

2006-01-01

Geological materials usually contaminated with naturally occurring radioactive materials (NORM) have become a focus great attention. These NORM under certain conditions can reach hazardous contamination levels. Some contamination levels may be sufficiently severe that precautions must be taken. The Turkey has very important natural stones potential with over 5 billion m 3 marble reserves. According to 2002 giving data the number of Turkish stones export is 303 million US Dollars. In this regards, the present study deals with 120 Turkish natural stones. The studied samples were analyzed and the concentrations in Bq/kg dry weight of radioisotopes were determined by gamma-ray spectrometry using HPGe defector in Bq/kg dry weight. For the measurement of the radon exhalation rate, the 'can technique' using sensitive alpha sensitive LR-115 type II plastic defectors were used. The radium equivalent activity varied from 285 Bq/kg to 325 Bq/kg for granite samples and from 2 Bq/kg to 32 Bq/kg for marble samples. The value of radon exhalation rate ranged from 0.06 Bq/m 2 h - 1 to 0.46 Bq/m 2 h - 1 for garnite samples and from 0.006 Bq/m 2 h - 1 to 0.011 Bq/m 2 h - 1 for marble samples. According to the recommended values and the calculated external hazard index values the samples are acceptable for use as building materials and decoration

Measurement of radon exhalation rates in some soil samples collected near the international monument Taj Mahal, Agra

International Nuclear Information System (INIS)

Sharma, Jyoti; Kumar, Rupesh; Indolia, R.S.; Swarup, R.; Mahur, A.K.; Singh, Hargyan; Sonkawade, R.G.

2011-01-01

Human beings are exposed to ionizing radiation from natural sources due to the occurrence of natural radioactive elements in solids, rocks, sand, soil etc. used as building construction materials and to the internal exposure from radioactive elements through good, water and air. Radon exhalation rate is of prime importance for the estimation of radiation risk from various materials. In the present study soil samples collected near the Tajmahal Agra. Sealed Can Technique was adopted for radon exhalation measurements. All the soil samples collected were grinded, dried and sieved through a 100 mesh sieve. Equal amount of each sieved (100μm grain size) sample (100 gm) was placed at the base of the Cans of 7.5 cm height and 7.0 cm diameter similar to those used in the calibration experiment (Singh et al., 1997). LR-115 type II plastic track detector (2 cm x 2 cm) was fixed on the top inside of the cylindrical Can. Radon exhalation rate varies from 529 mBqm -2 h -1 to 1254 mBqm -2 h -1 . The results will be presented. (author)

226Ra, 232Th and 40K contents and radon exhalation rate from materials used for construction and decoration in Cameroon

International Nuclear Information System (INIS)

Ngachin, M; Njock, M G Kwato; Garavaglia, M; Giovani, C; Scruzzi, E; Nourreddine, A; Lagos, L

2008-01-01

This work deals with the measurement of radioactivity and radon exhalation rate from building materials manufactured in Douala city from geological materials. Nine types of building material were surveyed for their natural radioactivity contents using high-resolution gamma-ray spectrometry. The activity concentrations for 226 Ra, 232 Th and 40 K varied from 11.5 to 49 Bq kg -1 , 16 to 37 Bq kg -1 and 306 to 774 Bq kg -1 , respectively. The absorbed dose rate in the samples investigated at 1 m above ground level ranged from 28.5 to 66.6 nGy h -1 . External and internal hazard indices were also estimated as defined by the European Commission. The Ra equivalents of the materials studied ranged from 57.5 to 133 Bq kg -1 and are much smaller than the recommended limit of 370 Bq kg -1 for construction materials for dwellings. Polycarbonate nuclear track detectors (NTDs), type CR-39, were used for measuring the radon concentration from different materials. In fact, knowledge of the radon exhalation rate from building materials is important for understanding the individual contribution of each material to the total indoor radon exposure. Samples were hermetically closed in glass vessels and the radon growth was followed as a function of time. The radon exhalation rate was therefore derived from the experimental measurement of α-track densities. The radon exhalation varied from (5.77 ± 0.06) x 10 -5 to (7.61 ± 0.07) x 10 -5 Bq cm -2 h -1 in bricks, from (5.79 ± 0.05) x 10 -5 to (11.6 ± 0.12) x 10 -5 in tiles, and was (6.95 ± 0.03) x 10 -5 Bq cm -2 h -1 in concrete. A correlation (correlation coefficient approx. = 0.8) was found between radium concentration measured with a HPGe detector and the radon exhalation rate obtained using nuclear track detectors

Study of radon exhalation and emanation rates from fly ash samples

International Nuclear Information System (INIS)

Raj Kumari; Jain, Ravinder; Kant, Krishan; Gupta, Nitin; Garg, Maneesha; Yadav, Mani Kant

2013-01-01

Fly ash, a by-product of burnt coal is technologically important material being used for manufacturing of bricks, sheets, cement, land filling etc. The increased interest in measuring radon exhalation and emanation rates in fly ash samples is due to its health hazards and environmental pollution and the same have been measured to assess the radiological impact of radon emanated from fly ash disposal sites. Samples of fly ash from different thermal power stations in northern India and National Council for Cement and Building Materials (NCB) were collected and analysed for the measurements. For the measurement, alpha sensitive LR-115 type II plastic track detectors were used. Gamma spectrometry and can technique was used for the measurements. The experimental data show that fly ash samples emanate radon in significant amount and this consequently, may result in increased radon levels in dwellings built by using fly ash bricks and excessive radiation exposure to workers residing in the surroundings of fly ash dumping sites. (author)

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

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Akbar Abbasi

2017-01-01

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

Estimation of the radon dose in buildings by measuring the exhalation rate from building materials

International Nuclear Information System (INIS)

Steiner, V.; Kovler, K.; Perevalov, A.; Kelm, H.

2004-01-01

We review the accumulator technique using active (CRM) and passive detectors (activated charcoal and electret). We describe the ERS2 detector, an electrostatic radon sampler followed by alpha spectrometry, with improved algorithm and adapted to measure the exhalation rate from walls. The technique produces accurate results over a broad range of materials: concrete, Pumice, ceramics, tiles, granite, etc. The measured exhalation rate is the same, within errors, as measured by the standard detectors

Cost-benefit analysis of decreased ventilation rates and radon exhalation from building materials

International Nuclear Information System (INIS)

Ericson, S.O.

1984-01-01

Decreased ventilation, achieved by weather stripping and other tightening measures, is the most cost effective way to energy conservation. A very low investment can result in a considerable decrease in ventilation rate. For a typical detached house in Sweden this can be equivalent to a decrease in oil consumption of 0.5 m 3 . At present price this corresponds to a saving of SEK 1200, 150 US dollars per annum. The contribution of the building materials to the concentration of radon in indoor air is approximately the inverse to air exchange rate. For a small change in ventilation rate and cost, in SEK/man Sv or US dollar/man Sv, is a function of ventilation rate, exhalation from building materials, the ratio between surface of walls, floor and ceiling to the volume of air. Thus, it is possible to find the specific ventilation rate where the marginal cost for a small increase in ventilation rate and the marginal reduction in radon concentration will give a specific amount of money for each man Sv. Examples are given. Conclusions are that for most building materials in a climate like the Swedish, there are other factors than exhalation of radon from building materials that sets the lower limit of recommendable ventilation rate. (Author)

Radon and its daughters in vivo

Energy Technology Data Exchange (ETDEWEB)

Rundo, J

1984-05-01

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

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

Field measurements of radon exhalation and Ra-226 content in soil using the can-technique

International Nuclear Information System (INIS)

Hafez, A.F.; El-Khatib, A.M.; Moharram, B.M.; Kotb, M.A.; Abdel-Naby, A.

1991-01-01

CR-39 and LR-115 plastic nuclear track detectors in the can-technique have been employed in the field measurements of radon exhalation, Ra-226 and U-238 content in dry-soil air at numerous regions in Sudan (the Blue and White Nile and Mogran regions). Measurements gave an average radon exhalation from the soil to the atmosphere and Ra-226 content of (23.4±2.60) kBq.m -2 and (123±13.65) Bq.kg -1 respectively. A polyethylene permeable memebrane cover was used to eliminate the contribution of thoron activity inside the can. Assuming a radioactive equilibrium between the U-series, the average U-238 content in the soil was found to be (9.92±1.01) ppm. This survey may be used for uranium prospection in soil. (orig.) [de

Radon and its daughters in vivo

Energy Technology Data Exchange (ETDEWEB)

Rundo, J

1984-05-01

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

Evaluation of color and radon exhalation rate in granite rocks between accelerated aging cycles

International Nuclear Information System (INIS)

Silva, Francisco Diones Oliveira

2016-01-01

Data used for the assessment of the analyzes performed on three types of dimension stone (Juparana Bordeaux, Branco Nevasca and Golden Artico), in natural state and after several cycles of accelerated aging are presented, correlating them with the gas exhalation rate radon issued by the analyzed lithologies. In the samples were conducted permeability, porosity, colorimetry, image analysis, petrographic and exhalation rate of radon, accompanied by aging tests on climate simulation chamber which simulates change situations of materials by weathering agents, accelerating wear and tear samples. The measurements were performed on samples in natural state, with 50 and 100 cycles of aging acceleration, where each cycle corresponds to variations in temperature and humidity in climatic simulation chamber, with the addition of an internal atmosphere of SO_2 with 25 concentration ppm. The results obtained during the tests were related to better analysis of the changes observed on the samples and the variation rate of exhalation radon emitted. The rocks have radon concentration values above the limits suggested by relevant international agencies (200-400 Bq/m³), with average values in the natural state, in 6149, 1619 and 866 Bq/m³ for Juparana Bordeaux, Branco Nevasca and Golden Arctic, respectively. The other aging cycles (50 and 100 cycles) showed an average increase of 0.8% for Juparana Bordeaux, 6.9% for White Blizzard and -23.87% for the Golden Arctic, with 50 cycles. From 50 to 100 cycles, there was reduction of 3.43% for Juparana Bordeaux and 22.15% for Branco Nevasca and an increase of 13.82% in the Golden Artico. The porosity results in the natural state obtained values an average of 0.696% for Juparana Bordeaux, 0.919% for Branco Nevasca and 0.830% for Golden Artico, and after 50 cycles of accelerated aging, obtained 0.621% to Juparana Bordeaux, 0.910% for Branco Nevasca and 0.840% for Golden Artico. The permeability of the samples showed values in the natural

Radon exhalation of cementitious materials made with coal fly ash: Part 2 - testing hardened cement-fly ash pastes

International Nuclear Information System (INIS)

Kovler, K.; Perevalov, A.; Levit, A.; Steiner, V.; Metzger, L.A.

2005-01-01

Increased interest in measuring radionuclides and radon concentrations in fly ash (FA), cement and other components of building products is due to the concern about health hazards of naturally occurring radioactive materials (NORM). The paper focuses on studying the influence of FA on radon exhalation rate (radon flux) from cementitious materials. In the previous part of the paper the state of the art was presented, and the experiments for testing raw materials, Portland cement and coal fly ash, were described. Since the cement and FA have the most critical role in the radon release process relative to other concrete constituents (sand and gravel), and their contribution is dominant in the overall radium content of concrete, tests were carried out on cement paste specimens with different FA contents, 0-60% by weight of the binder (cement+FA). It is found that the dosage of FA in cement paste has a limited influence on radon exhalation rate, if the hardened material is relatively dense. The radon flux of cement-FA pastes is lower than that of pure cement paste: it is about ∼3 mBq m -2 s -1 for cement-FA pastes with FA content as high as 960 kg m -3

{sup 226}Ra, {sup 232}Th and {sup 40}K contents and radon exhalation rate from materials used for construction and decoration in Cameroon

Energy Technology Data Exchange (ETDEWEB)

Ngachin, M; Njock, M G Kwato [Center for Atomic, Molecular Physics and Quantum Optics, University of Douala, PO Box 8580, Douala (Cameroon); Garavaglia, M; Giovani, C; Scruzzi, E [Regional Agency for Environmental Protection (ARPA), 91 via Tavagnacco, 33100 Udine (Italy); 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); Lagos, L [Applied Research Center, Florida International University, 10555 W Flagler Street, EC 2100, Miami, FL 33174 (United States)], E-mail: mngachin@yahoo.com

2008-09-01

This work deals with the measurement of radioactivity and radon exhalation rate from building materials manufactured in Douala city from geological materials. Nine types of building material were surveyed for their natural radioactivity contents using high-resolution gamma-ray spectrometry. The activity concentrations for {sup 226}Ra, {sup 232}Th and {sup 40}K varied from 11.5 to 49 Bq kg{sup -1}, 16 to 37 Bq kg{sup -1} and 306 to 774 Bq kg{sup -1}, respectively. The absorbed dose rate in the samples investigated at 1 m above ground level ranged from 28.5 to 66.6 nGy h{sup -1}. External and internal hazard indices were also estimated as defined by the European Commission. The Ra equivalents of the materials studied ranged from 57.5 to 133 Bq kg{sup -1} and are much smaller than the recommended limit of 370 Bq kg{sup -1} for construction materials for dwellings. Polycarbonate nuclear track detectors (NTDs), type CR-39, were used for measuring the radon concentration from different materials. In fact, knowledge of the radon exhalation rate from building materials is important for understanding the individual contribution of each material to the total indoor radon exposure. Samples were hermetically closed in glass vessels and the radon growth was followed as a function of time. The radon exhalation rate was therefore derived from the experimental measurement of {alpha}-track densities. The radon exhalation varied from (5.77 {+-} 0.06) x 10{sup -5} to (7.61 {+-} 0.07) x 10{sup -5} Bq cm{sup -2} h{sup -1} in bricks, from (5.79 {+-} 0.05) x 10{sup -5} to (11.6 {+-} 0.12) x 10{sup -5} in tiles, and was (6.95 {+-} 0.03) x 10{sup -5} Bq cm{sup -2} h{sup -1} in concrete. A correlation (correlation coefficient approx. = 0.8) was found between radium concentration measured with a HPGe detector and the radon exhalation rate obtained using nuclear track detectors.

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

Radon dynamics in underwater thermal radon therapy

International Nuclear Information System (INIS)

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

1998-01-01

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

A model to predict radon exhalation from walls to indoor air based on the exhalation from building material samples

International Nuclear Information System (INIS)

Sahoo, B.K.; Sapra, B.K.; Gaware, J.J.; Kanse, S.D.; Mayya, Y.S.

2011-01-01

In recognition of the fact that building materials are an important source of indoor radon, second only to soil, surface radon exhalation fluxes have been extensively measured from the samples of these materials. Based on this flux data, several researchers have attempted to predict the inhalation dose attributable to radon emitted from walls and ceilings made up of these materials. However, an important aspect not considered in this methodology is the enhancement of the radon flux from the wall or the ceiling constructed using the same building material. This enhancement occurs mainly because of the change in the radon diffusion process from the former to the latter configuration. To predict the true radon flux from the wall based on the flux data of building material samples, we now propose a semi-empirical model involving radon diffusion length and the physical dimensions of the samples as well as wall thickness as other input parameters. This model has been established by statistically fitting the ratio of the solution to radon diffusion equations for the cases of three-dimensional cuboidal shaped building materials (such as brick, concrete block) and one dimensional wall system to a simple mathematical function. The model predictions have been validated against the measurements made at a new construction site. This model provides an alternative tool (substitute to conventional 1-D model) to estimate radon flux from a wall without relying on 226 Ra content, radon emanation factor and bulk density of the samples. Moreover, it may be very useful in the context of developing building codes for radon regulation in new buildings. - Research highlights: → A model is proposed to predict radon flux from wall using flux of building material. → It is established based on the diffusion mechanism in building material and wall. → Study showed a large difference in radon flux from building material and wall. → Model has been validated against the measurements made at

Thoron exhalation rate monitor with absorber

International Nuclear Information System (INIS)

Xiao Detao; Zhao Guizhi

2003-01-01

A measurement method of thoron exhalation rate is developed based on the characteristic of thorium C' which emits a α particle with higher energy than those of α particles released from radon and radon progenies. The principles of discriminating radon and realizing thoron exhalation rate measurement on the material surface with absorber, the passive and integrated thoron exhalation rate monitor studied, and its calibration coefficient determination method are introduced. The effectiveness of mitigating thoron exhalation rate of wall surface by depressurization inside wall and thoron exhalation rates on some materials surfaces were measured by using the studied monitors. The calibration coefficient of the studied monitor is R=0.246 cm -2 ·(kBq·m -3 ·h) -1 . The lower limit of detection is LLD=18.4 mBq·m -2 ·s -1 when the sampling period is 7 days and the standard deviation of background track densities of the adopted CR-39 SSNTD is s T =1.6 cm -2

Determination of radon exhalation from construction materials using VOC emission test chambers.

Science.gov (United States)

Richter, M; Jann, O; Kemski, J; Schneider, U; Krocker, C; Hoffmann, B

2013-10-01

The inhalation of (222) Rn (radon) decay products is one of the most important reasons for lung cancer after smoking. Stony building materials are an important source of indoor radon. This article describes the determination of the exhalation rate of stony construction materials by the use of commercially available measuring devices in combination with VOC emission test chambers. Five materials - two types of clay brick, clinker brick, light-weight concrete brick, and honeycomb brick - generally used for wall constructions were used for the experiments. Their contribution to real room concentrations was estimated by applying room model parameters given in ISO 16000-9, RP 112, and AgBB. This knowledge can be relevant, if for instance indoor radon concentration is limited by law. The test set-up used here is well suited for application in test laboratories dealing with VOC emission testing. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Studies on radon exhalation rate from building materials of Mysuru district, Karnataka

International Nuclear Information System (INIS)

Chandini, M.; Lavanya, B.S.K.; Chandrashekara, M.S.; Pruthvi Rani, K.S.

2017-01-01

In the present study, mass exhalation rate of 222 Rn from soil and building materials was studied using scintillation based Smart Radon Monitor (SRM) and also using Solid State Nuclear Track Detectors (SSNTD) employing Can Technique, following standard procedure. Mass exhalation rate of 222 Rn from various building material samples such as brick, sand, cement, concrete and from different types of flooring materials was determined. The results obtained from these methods were compared and analysed. The samples of construction materials were collected from various locations of Mysuru city. The city has an area of about 128 sq km with population of about 1 million. Mining industries of magnetite, dunite and lime stone are located around Mysuru city. In addition to this, quarrying and crushing of granite stones for building activities also exist nearby

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)

Determination of the exhalation rate of radon and thoron from building materials by detectors Cr-39

International Nuclear Information System (INIS)

Vasidov, A.

2005-01-01

Full text: The building materials (BM) such as granite, bricks, sand, cement etc., contain uranium and thorium in various amounts. Therefore the knowledge of true value exhalation rate of Rn and Tn from BM represents scientific and practical interest in environmental radiation protection. In present work, we have used calibrated plastic cups with two detectors Cr-39. The detected surface of the cup is situated in perpendicular position surface BM and were exposed for 20-30 days. The first detector fixed the bottom on distance from surface of BM and records alpha particles from Rn-222 only. The second detector records alpha particles of the thoron and radon. After exposition, the detectors chemically etched and analyzed. The values of the exhalation rate per unit area of the granite, concrete, fired and unfired bricks, sand, cement, alabaster varied 0.091 - 0.1 Bq m -2 h -1 for the radon, 200 - 5800 Bq m -2 h - 1 for the thoron, accordingly

Utilization of rice husk ash to enhance radon resistant potential of concrete

International Nuclear Information System (INIS)

Jain, Ravinder; Kant, Krishan; Yadav, Mani Kant; Chauhan, R.P.

2013-01-01

The radiological and health implication posed by radon and their decay products are well known. The soil containing varying amount of radionuclides is the primary source of indoor radon. The indoor radon level depends upon its entrance through the pores of the ground and floor. Thus it is necessary to restrict the radon from soil to enter indoors by application of materials with low radon diffusion coefficient. The method used for radon shielding purpose in present study utilizes the rice husk ash for substitution with cement to achieve low diffusion coefficient. The study describes the method to optimize the condition of preparation of rice husk ash using X-ray diffraction and fluorescence spectroscopy techniques. The rice husk substitution with cement was optimized by compressive and porosity test of concrete cubes. The diffusion coefficient through concrete modified by rice husk ash was carried out by scintillation radon monitor and specially design radon diffusion chamber. The radon exhalation rates from concrete carried out using active technique decreasing radon emanation from concrete with increase of rice husk ash. The result of present study suggest substitution of 20-30% rice husk ash with cement to achieve lower radon diffusion and exhalation rates with higher compressive strength as compared to control concrete. (author)

Field GE gamma spectrometry for on site measurements of some parameters characterizing radon-222 exhalation rates from soils and covers

International Nuclear Information System (INIS)

Zettwoog, P.; Kobal, I.; Pineau, J.F.

1997-01-01

We describe a new method based on differential gamma spectrometry for on site determination of some of the parameters which are relevant for the production of radon 222 in soil gas and its transfer from soil to indoor and outdoor atmospheres. This method is investigated in the context of a 3-year Slovenian-French cooperation programme, the PROTEUS project. We are currently using a germanium detector of 100 cm 3 . The height of the 20 deg. C collimated detector above the soil surface is from 1.5 to 3 m when using a tripod. This arrangement provides results which are representative of soil areas ranging from 1 to 4 square metres. Routine measurements would require larger detector volumes. The main objective is to provide technology and methodology for an efficient mapping of zones with potential for being the source of a high level of indoor radon, eliminating the need for soil sampling followed by laboratory analysis. The feasibility of an airborne mapping laboratory flying at low altitude will be investigated. Another objective is the rapid measurement of radon profiles across covers used to reduce exhalation rates from the surface of a pile of tailings, with characterisation of the influence of humidity content of the top layer. Airborne survey would allow for measuring exhalations from surfaces of slurries not otherwise accessible. (author)

Study of radon exhalation rates using solid state nuclear track detectors in stone mining area of Aravali range in Pali region, district Faridabad

International Nuclear Information System (INIS)

Raj Kumari; Yadav, A.S.; Kant, Krishan; Garg, Maneesha

2013-01-01

It is well established that indoor radon-thoron and daughters are the largest contributor to total radiation dose received by populations. They account for more than 50% of the total dose and the radiation exposure beyond permissible levels can lead to deleterious effects on health. This fact necessitates extensive studies of natural radioactivity levels in the stone mining area of Aravali range in Faridabad. The stone mining area of Aravali Range in Pali, District Faridabad bears significant geological features. Radon exhalation from ground plays an important role in enhanced indoor radon levels and can pose grave health hazards to the workers and the residents. Exhalation rates (mass and surface) from stone samples of the area have been studied using LR-115, Type II nuclear track detectors. The mass and surface exhalation rates from crushed stone samples, also called stone dust varied in the range 3.41-9.11 mBq kg -1 h - 1 and 75.9-202.7 mBq m -2 h -1 , respectively. The study has revealed substantial presence of radionuclides in the samples collected from the mining area. (author)

Preliminary assessment, by means of Radon exhalation rate measurements, of the bio-sustainability of microwave treatment to eliminate biodeteriogens infesting stone walls of monumental historical buildings.

Science.gov (United States)

Mancini, S.; Caliendo, E.; Guida, M.; Bisceglia, B.

2017-10-01

The main purpose of the work described in this paper has been to establish the protocol for a new non-disruptive technique of intervention, based on microwave treatment, for cleaning operations on monumental historical buildings, to eliminate biodeteriogens infesting stones. Non-destructive methods in the cleaning operations, should not only preserve the physical integrity, the chemical-mineralogical and structural identity of materials, but, when the exhalation of pollutant agents (like for example Radon gas) from building materials is considered, also, make the indoor air quality (IAQ) levels healthy. Therefore, one of the main steps of the protocol proposed in this paper is concerned with the assessment of the Radon exhalation rate in order to verify that microwave treatments do not increase the Radon naturally exhalated by building materials. In this paper, the preliminary results of the Radon measurements performed on two different type of tuff samples (grey tuff and yellow tuff), typical of the Italian traditional construction heritage, with the E-PERM passive technique at the Environmental Radioactivity Laboratory (Amb.Ra.), University of Salerno, Italy, ISO 9001:2008 certified, are summarized.

MEASUREMENT OF RADON EXHALATION RATE, RADIUM ACTIVITY AND ANNUAL EFFECTIVE DOSE FROM BRICKS AND CEMENT SAMPLES COLLECTED FROM DERA ISMAIL KHAN

OpenAIRE

Nisar Ahmad; Mohamad Suhaimi Jaafar; Sohail Aziz Khan; Tabassum Nasir; Sajjad Ahmad; Muhammad Rahim

2014-01-01

Radon concentration, exhalation rate, radium activity and annual effective dose have been measured from baked and unbaked bricks and cement samples commonly used as construction material in the dwellings of Dera Ismail Khan City, Pakistan. CR-39 based NRPB radon dosimeters and RAD7 have been used as passive and active devises. The values of radon concentration for baked, unbaked bricks and cements obtained from passive and active techniques were found in good agreement. Average values of rado...

Measurement of thoron exhalation rates from building materials.

Science.gov (United States)

de With, G; de Jong, P; Röttger, A

2014-09-01

Thoron (220Rn) exhalation from building materials has become increasingly recognized as a potential source for radiation exposure in dwellings. However, contrary to radon (220Rn), limited information on thoron exposure is available. The purpose of this study is to develop a test method for the determination of the thoron exhalation rate from building materials. The method is validated, and subsequently the thoron exhalation rates from 10 widely-applied concretes, gypsums, brick, limestone, and mortar are determined. The measured thoron exhalation rates of these materials range from 0.01 Bq m-2 s-1 to 0.43 Bq m-2 s-1, with relative standard uncertainties between 6% to 14%.

Assessment of natural radiation exposure and radon exhalation rates from the soil of Islamabad District of Pakistan

International Nuclear Information System (INIS)

Mujahid, S.A.

2007-01-01

Complete text of publication follows. The earth's crust is a main source of natural radionuclides in soils and rocks. The specific levels of background gamma radiation depend upon the geological composition of each lithologically separated area, and the content of the rock from which the soils originate the radioactive elements of 226Rn, 232Th and 40K. These naturally occurring radionuclides of terrestrial origin in soil can be a source of external radiation exposure through the gamma ray emission whereas internal exposure occurs through the inhalation of radon gas. The measurements of natural radioactivity and the assessment of radiological hazards in the soil samples of Islamabad district of Pakistan have been carried out using High Purity Germanium (HPGe) detector. The radon exhalation rates from these samples have also been estimated employing the 'closed-can' technique of passive dosimeters. The measured activities of 226Ra, 232Th and 40K were found in the range 14 - 30, 18 - 40 and 301 - 655 Bq.kg-1. The annual effective dose was calculated in the range 0.15 - 0.31 mSv. The values of external and internal hazard indices were less than 1. The radon exhalation rates these areas were found in the range 200 - 345 mBq.m-2h-1.

Radon and its daughters in vivo

International Nuclear Information System (INIS)

Rundo, J.

1983-01-01

Some aspects of the behavior of radon and its short-lived daughters in vivo are described and a relationship between the radon exhalation rate and time after a meal is demonstrated. A major but short-lived postprandial increase in the exhalation rate of radon produced from skeletally-deposited radium was observed and a similar effect in exhalation rate of environmental radon by persons containing no radium was noted. Persons living in houses with elevated concentrations of radon may contain sufficient activity for its detection by external gamma-ray counting. Some of the activity observed is due to inhaled daughter-products in the chest, and some to daughter-products associated with and produced by the decay of radon throughout the body. 3 references, 8 figures. (MF)

Active and passive measurements of radon/thoron exhalation from coal and flyash samples collected from various thermal power plants of Delhi, India

International Nuclear Information System (INIS)

Singh, Lalit Mohan; Kumar, Rajesh; Sahoo, B.K.; Sapra, B.K.; Rajendra Prasad

2013-01-01

Measurement of radon ( 222 Rn) exhalation from coal, flyash and soil samples was carried out using active (Scintillation based Smart Radon Monitor) as well as passive technique (SSNTD based Can technique). In addition, thoron ( 220 Rn) exhalation measurements were also made for the above samples using Scintillation based Smart Thoron Monitor. To the best of our knowledge, thoron exhalation measurement is first of its kind in India. In this study, a total of 26 samples collected from Badarpur Thermal Power Station, Badarpur and Rajghat Power Station, Rajghat, Delhi were analysed. Thoron surface exhalation rate measured by Scintillation based Thoron Monitor for Badarpur Thermal Power Station varied from 327.8 Bq/m 2 /h to 874.2 Bq/m 2 /h and for Rajghat Thermal Power Station it varied from 176.0 Bq/m 2 /h to 781.1 Bq/m 2 /h. Similarly, the radon mass exhalation rate measured by active technique varied from 12.13 mBq/Kg/h to 118.08 mBq/Kg/h for the samples collected from Badarpur Thermal Power Station; while it varied from 15.00 Bq/Kg/h to 168.07 mBq/Kg/h for the samples collected from Rajghat Thermal Power station. On the other hand, result of measurements made by the conventional Can technique were significantly lower varying from 0.44 mBq/Kg/h to 2.34 mBq/Kg/h for Rajghat Thermal Power Station and from 0.78 mBq/Kg/h to 2.88 mBq/Kg/h for Badarpur Thermal Power Station. This vast variation in the results obtained by active and passive techniques is due to the fact that the active technique accounts for the effect of back-diffusion and possible leakage from the chamber in the process of least square fitting of exponential model while it is not so in the case of SSNTD based Can technique. In view of this, results of active technique are more reliable as compared to the passive technique. More importantly, there was no thoron interference in the radon measurement by the active technique. Further experiments are being carried out using controlled radon and thoron

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

Science.gov (United States)

Juhásová Šenitková, Ingrid; Šál, Jiří

2017-12-01

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

Airborne geophysical radon hazard mapping

International Nuclear Information System (INIS)

Walker, P.

1993-01-01

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

Remedial measures in Swedish and Norwegian houses - application of radon and radon decay product measurements

International Nuclear Information System (INIS)

Just, G.; Philipsborn, H. von; Matolin, M.; Molzahn, D.

1998-01-01

Houses and apartments in Sweden and Norway with excessive indoor radon concentrations were studied in detail with a variety of methods, standard and novel ones recently developed. For suitable remediation it is necessary to distinguish soil radon and exhalation from blue (porous) concrete. Our CARBOTEST-S is a simple, sensitive, in-situ method to quantify radon exhalation from existing walls, as well as radon permeability of different protective foils and final quality control of foils applied to existing walls. (orig.) [de

Study of radon exhalation from phosphogypsum plates and blocks from different origins

International Nuclear Information System (INIS)

Costa, Lucas Jose Pereira da

2011-01-01

Phosphogypsum is a waste of the fertilizer industry that concentrates radionuclides. In this work, the 222 Rn exhalation rate from phosphogypsum plates and blocks from different origins used at dwellings construction was studied. The 222 Rn exhalation rate was determined through the accumulation chamber technique with solid state nuclear track detectors (SSNTD). The effective dose for an individual living in a residence built with phosphogypsum based materials was evaluated. It also was calculated the 222 Rn exhalation rate through the UNSCEAR model, from the 226 Ra concentration in the materials, in order to compare the experimental results. It was evaluated the contribution of building component (paint) to the reduction of 222 Rn exhalation rate. The plates and blocks were manufactured with phosphogypsum from Bunge Fertilizantes, Ultrafertil and Fosfertil. Blocks manufactured with ordinary gypsum was also evaluated. The average results obtained were 0.19 ± 0.06 Bq m-2 h-1, 1.3 ± 0.3 Bq m -2 h -1 and 0.41 ± 0.07 Bq m -2 h -1 for plates manufactured with phosphogypsum from Bunge Fertilizer, Ultrafertil and Fosfertil, respectively. For the phosphogypsum blocks the values were 0.11 ± 0.01 Bq m -2 h-1, 1.2 ± 0.6 Bq m -2 h -1 , 0.47 ± 0.15 Bq m -2 h -1 , for Bunge, Ultrafertil and Fosfertil. The blocks manufactured with ordinary gypsum presented average value of 0.18 ± 0.08 Bq m -2 h'- 1 . All phosphogypsum plates and blocks evaluated in this study presented effective dose for radon inhalation lower than the recommended value of 1mSv y -1 , the annual effective dose limit for public exposure by International Commission on Radiological Protection. (author)

The influence of mechanical vibrations of railway and car traffics on the radon exhalation using track detector technique

International Nuclear Information System (INIS)

Moharram, B.M.

2000-01-01

The influence of train and car traffic vibrations on the radon concentration (CRn) increase near the railway tracks and the heavy traffic roads. It was estimated along the railway road, and perpendicular directions using CR-39 detectors. The special radius of the influence is about 32 m, while the related value for car traffics is found to be about 25 m. The base line of radon concentration in soil gas and radon exhalation are estimated in the whole area, far from the center of traffic roads by a distance (> 100 m) in different different directions and found to be 0.6 Bq/L and 1.25 x 10 4 Bq m -2 respectively.It is easy to detect that the average ratio between the radon concentration at its higher level and its base line, which is regular concentration of radon in the ordinary positions far from the effect of traffics, is about 1.18 for railway traffics. While the related value to vehicle traffic is about 1.23, which is higher than that of railway traffic because the ground is stimulated per minutely

Natural radioactivity and radon exhalation rates in man-made tiles used as building materials in Japan.

Science.gov (United States)

Iwaoka, K; Hosoda, M; Suwankot, N; Omori, Y; Ishikawa, T; Yonehara, H; Tokonami, S

2015-11-01

Man-made tiles frequently used in Japan were collected, and activity concentrations and radon ((222)Rn) exhalation rates in these tiles were measured. Dose estimations for inhabitants living in houses built using these tiles were also carried out. The activity concentrations of (226)Ra, (228)Ra and (40)K in the man-made tiles were 31-170, 35-110 and 260-980 Bq kg(-1), respectively. The (222)Rn exhalation rates in the tiles were 8.8-21 μBq m(-2) s(-1). The ranges of experimental activity concentrations and (222)Rn exhalation rates were almost identical to those of natural rocks used as typical building materials in Japan. The maximum value of effective dose to inhabitants living in houses built with the man-made tiles was 0.14 mSv y(-1), which is lower than the reference level range (1-20 mSv y(-1)) for abnormally high levels of natural background radiation published in the ICRP Publication 103. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-10-15

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

Sources and protective measures of indoor radon

International Nuclear Information System (INIS)

Gou Quanlu; Wang Hengde

1993-01-01

This paper presents the relative contribution to indoor radon 222 Rn of various sources in twenty three rooms of three kinds in Taiyuan area. The results show that the major sources in this area are radon emanation from surfaces of soil and building materials and that from outdoor air, while the contribution of water and gas consumed in the rooms is less important. These results suggest a basis for taking suitable protective measures against indoor radon. Some materials are also recommended which are effective in restraining radon exhalation and low in price, by testing more than ten kinds of materials and comparing them using cost-effectiveness analysis technique, such as painting materials, polyvinyl alcohol (CH 2 :CHOH)n, etc. Their sealing effects on radon exhalation were examined with home-made REM-89 Radon Exhalation Monitor. The deposition effects of negative ion generator and humidifier on radon progeny were also tested. The maximum deposition may reach 70-90%, which proves they are also effective and economical in radon protection. (2 tabs., 3 figs.)

Exhalation of Rn-222 from soil: some aspects of variations

International Nuclear Information System (INIS)

Raghavayya, M.; Khan, A.H.; Padmanabhan, N.; Srivastava, G.K.

1982-01-01

The exhalation of radon from soil and uranium mill tailings piles is discussed. This process is a complex phenomenon. The exhalation rate depends on such variables as radium content, moisture content and porosity of soil, variation of atmospheric pressure, humidity, temperature, wind speed, etc. In an attempt to eliminate variations introduced by geographical location the exhalation rate is estimated at a fixed location. Measurements were carried out almost daily over a one year period. Exhalation rate has shown a wide variation, from almost zero to plus 900 pCi/m 2 .min. Measurements are still being continued. It was seen that exhalation rate fell drastically soon after a heavy shower when the ground was soaking wet. Emanation was found to increase as the ground began to dry and fall again when the ground was bone dry. Radon exhalation rates were also measured at different locations on a uranium tailings pile. Here also wide variation was observed

Thoron (RN-220) interference in the determination of RN-222 exhalation rate of soils

Energy Technology Data Exchange (ETDEWEB)

Amaral, Déric S.; Farias, Emerson E.G.; Santos, Mariana L.O.; Silva, Karolayne E.M.; Hazin, Clovis A.; França, Elvis J., E-mail: emersonemiliano@yahoo.com [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Souza Neto, João A., E-mail: adauto@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Geologia

2017-07-01

The transport of Rn-222 from the soil to the atmosphere known as exhalation is influenced by meteorological conditions and soil geophysical parameters. In closed and poorly ventilated rooms, this radioactive gas can reach high activity concentrations, in which the energy of alpha particles released by this radionuclide and its progeny is the second leading cause of lung cancer. Soil exhalation rate is an important parameter for assessing human health risks associated with radon. For radon determination using an exhalation chamber, an ionization chamber detector is used to count the electrical pulses generated by the interaction between the alpha particles produced by Rn-222 and its progeny and the air inside the chamber. In this work, the interference of thoron (Rn-220) in the determination of soil exhalation rate of Rn-222 was studied. For this, the RadonBOX exhalation chamber and the AlphaGuard ionization chamber detector were utilized for analyzing the same soil during two hours on different days under similar meteorological conditions. From zero up to approximately 2,400 s, the radon activity concentrations decreased. After 40 minutes, the radon concentrations started to increase, thereby allowing the calculation of soil exhalation rate. This initial decreasing could be explained by a high Rn-220 than Rn-222 presence in the soil, in which, because of its short half-life, after 40 minutes, most thoron present in the chamber has undergone so that the main alpha emitter become Rn-222. In order to confirm this, Rn-220 activity was estimated by the Ra-228 concentration in the soil determined after 30 days using High Resolution Gamma-Ray Spectrometry with HPGe detectors. Therefore, the thoron interference in the determination of soil radon exhalation rate was considered negligible after 40 minutes of measurement time for the analyzed soil. (author)

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

International Nuclear Information System (INIS)

Kojima, Hiroshi

1989-01-01

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

Evaluation of the open vial method in the radon measurement

International Nuclear Information System (INIS)

Lopez del Rio, H.; Davila R, J. I.; Mireles G, F.

2014-10-01

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

Seasonal variations of natural ventilation and radon-222 exhalation in a slightly rising dead-end tunnel.

Science.gov (United States)

Perrier, Frédéric; Richon, Patrick; Gautam, Umesh; Tiwari, Dilli Ram; Shrestha, Prithvi; Sapkota, Soma Nath

2007-01-01

The concentration activity of radon-222 has been monitored, with some interruptions, from 1997 to 2005 in the end section of a slightly rising, dead-end, 38-m long tunnel located in the Phulchoki hill, near Kathmandu, Nepal. While a high concentration varying from 6 x 10(3) Bq m(-3) to 10 x 10(3) Bq m(-3) is observed from May to September (rainy summer season), the concentration remains at a low level of about 200 Bq m(-3) from October to March (dry winter season). This reduction of radon concentration is associated with natural ventilation of the tunnel, which, contrary to expectations for a rising tunnel, takes place mainly from October to March when the outside air temperature drops below the average tunnel temperature. This interpretation is supported by temperature measurements in the atmosphere of the tunnel, a few meters away from the entrance. The temporal variations of the diurnal amplitude of this temperature indeed follow the ventilation rate deduced from the radon measurements. In the absence of significant ventilation (summer season), the radon exhalation flux at the rock surface into the tunnel atmosphere can be inferred; it exhibits a yearly variation with additional transient reductions associated with heavy rainfall, likely to be due to water infiltration. No effect of atmospheric pressure variations on the radon concentration is observed in this tunnel. This experiment illustrates how small differences in the location and geometry of a tunnel can lead to vastly different behaviours of the radon concentration versus time. This observation has consequences for the estimation of the dose rate and the practicability of radon monitoring for tectonic purposes in underground environments.

Radon exhalation of cementitious materials made with coal fly ash: Part 1 - scientific background and testing of the cement and fly ash emanation

International Nuclear Information System (INIS)

Kovler, K.; Perevalov, A.; Steiner, V.; Metzger, L.A.

2005-01-01

Increased interest in measuring radionuclides and radon concentrations in fly ash, cement and other components of building products is due to the concern of health hazards of naturally occurring radioactive materials (NORM). The current work focuses on studying the influence of fly ash (FA) on radon-exhalation rate (radon flux) from cementitious materials. The tests were carried out on cement paste specimens with different FA contents. The first part of the paper presents the scientific background and describes the experiments, which we designed for testing the radon emanation of the raw materials used in the preparation of the cement-FA pastes. It is found that despite the higher 226 Ra content in FA (more than 3 times, compared with Portland cement) the radon emanation is significantly lower in FA (7.65% for cement vs. 0.52% only for FA)

Radon transport from uranium mill tailings via plant transpiration. Final report

International Nuclear Information System (INIS)

Lewis, B.A.G.

1985-01-01

Radon exhalation by vegetation planted on bare or soil-covered uranium mill wastes was studied based on an assumption that radon transport from soil to atmosphere via plants takes place in the transpiration stream. Results show that radon exhalation by plants is inversely related to water transpired, primarily a dilution effect. Radon released appeared directly related to leaf area, suggesting that radon is carried into the plant by mass flow in water; however, once within the plant, radon very likely diffuses through the entire leaf cuticle, while water vapor diffuses primarily through open stomates. Application of a computerized model for water transpiration to radon exhalation is not immediately useful until the role of water in radon transport is defined throughout the continuum from rooting medium to the atmosphere. Until then, a simple calculation based on leaf area index and Ra-226 concentration in the rooting medium can provide an estimate of radon release from revegetated wastes containing radium

Modeling dynamic behavior of Radon-222 in the planetary boundary layer

International Nuclear Information System (INIS)

Yuan, Y.C.; Stunder, M.J.

1983-01-01

A model has been used to simulate the dynamic behavior of radon concentration in the lower atmosphere from naturally occurring sources. The model includes prediction of radon exhalation rate from the surface of the ground due to convection and diffusion processes and the radon concentration profile in the planetary boundary layer. A time-dependent radon exhalation rate, variable mixing height, and altitude-dependent diffusivity are incorporated into the diffusion model by transforming the governing equation. The Galerkin finite-element technique and Crank-Nicholson finite different time marching are used in solving the discretized differential equations. The model-simulated time-varying radon concentrations near the ground agree well with measurements made over a period of seven days. It has been demonstrated that the model provides a reasonably good prediction of ambient radon concentration. As a general tool, with the input of actual radon concentration measurements, the model is also capable of estimating average radon exhalation rate from the ground surface. With current techniques, radon flux measurement is still a time-consuming and difficult task

Estimation of radon exhalation rate, natural radioactivity and radiation doses in fly ash samples from NTPC Dadri, (UP) India

International Nuclear Information System (INIS)

Gupta, Mamta; Verma, K.D.; Mahur, A.K.; Rajendra Prasad; Sonkawade, R.G.

2010-01-01

Fly ash produced by coal-burning in thermal power station has become a subject of world wide interest in recent years, because of its diverse uses in building materials such as bricks, sheets, cement and land filling etc. The knowledge of radio nuclides in fly ash plays an important role in health physics. Natural radioactivity and radon exhalation rate in fly ash samples collected from NTPC (National Thermal Power Corporation) Dadri, (UP.) India, have been studied. A high resolution gamma ray spectroscopic system has been used for the measurement of natural radioactivity. The activity concentration of natural radionuclides radium ( 226 Ra), thorium ( 232 Th) and potassium ( 40 K) were measured and radiological parameters were calculated. Radium concentration was found to vary from (81.01 ± 3.25) to (177.33 ±10.00) Bq kg -1 . Activity concentration of thorium was found to vary from (111.57 ± 3.21) to (178.50 ± 3.96) Bq kg -1 . Potassium activity was not significant in some samples, whereas, some other samples have shown potassium activity vary from (365.98 ± 4.85) to (495.95 ± 6.23) Bq kg -1 . Radon exhalation rates in these samples were also calculated by 'Sealed Can technique' using LR-115 type II detectors and found to vary from (80 ± 9) to (243 ± 16) mBqm -2 h -1 with an average value (155 ± 13) mBqm -2 h -1 . This study also presents the results of estimation of effective dose equivalent from exhalation rate, radium equivalent, absorbed gamma dose rates, external annual effective dose rate and values of external hazard index for the fly ash samples. (author)

Monitoring the radon flux from gold-mine dumps by gamma-ray mapping

NARCIS (Netherlands)

Lindsay, R; de Meijer, RJ; Maleka, PP; Newman, RT; Motlhabane, TGK; de Villiers, D

The exhalation of radon from the large mine dumps at the gold mines in South Africa is a potential health hazard. Determination of radon fluxes from these dumpsites is problematic due to the scatter in the data in time and place and the cost involved in getting a representative sample. gamma-ray

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

Locating and limiting radon in dwellings

International Nuclear Information System (INIS)

Hildingson, O.; Gustafsson, J.; Nilsson, I.

1984-01-01

More than 3,300 Swedish dwellings have an indoor radon daughter concentration above 400 Bq.m -3 (or 0.108 WL). It is considered to be unsafe to live in any of these dwellings and the radon daughter concentration has to be reduced. Before deciding what measures to take, it is important to determine the radon sources. Possible sources are exhalation from building materials and/or radon transport from the ground into the building through cracks and joints in the slab. Different methods of locating the sources have been developed. To locate cracks and joints in slabs the ventilation rate and the air pressure difference relative to the ground are changed while monitoring radon/radon daughter concentration. The effect of five different measures to reduce the indoor radon daughter concentration have also been evaluated: increased ventilation rate by mechanical ventilation, ventilation of the small spaces between the floor and the slab, sealing the surface of radon exhaling walls, sealing joints and cracks in the slab, and ventilation of the drainage under the slab. (author)

Factors influencing indoor concentrations of radon and daughter products

International Nuclear Information System (INIS)

Wang Hengde

1985-01-01

The correlation between indoor concentrations of 222 Rn and its daughters and some influencing factors is discussed and expressions of concentrations are derived with relation to radon exhalation rate from indoor surfaces, air exchange rate and daughter deposition velocities on indoor surfaces. Experimental methods for determining radon exhalation rate, air exchange rate and daughter deposition velocities are also mentioned

Mapping of gas radon in soil of the Fresnillo City, Zacatecas; Mapeo de gas radon en suelo de la Ciudad de Fresnillo, Zacatecas

Energy Technology Data Exchange (ETDEWEB)

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

2012-10-15

With the purpose of locating areas with high rates of gas radon exhalation, it has begun to measure the radon flow in soil for residence use in the Fresnillo City, Zacatecas State, Mexico, applying the method of the open vial and liquid scintillation. The gas radon accumulation is made in a camera situated to a depth between 25 and 35 cm. In this work the partial results of the research in course are presented. The values obtained for the radon exhalation have varied of <2.25 up to 14.42 Bq/m{sup 2}{center_dot}h. (Author)

Development of model DTY-104 radon measuring meter

International Nuclear Information System (INIS)

Shi Zhixia; Zhang Aiming; Li Yachun; Wang Qingheng

2000-01-01

Model DTY-104 radon measuring meter is an improvement on Model DTY-103. 'Difference value method' is used, which has been strictly developed and makes the radon exhalation rate more accurate, instead of using 'simplified difference value method'. The electronic circuit is redesigned and 80C31 single chip processor is used, which makes the operation more convenient and the function strengthened. In a more reasonable manner, the humidity sensor is mounted in the collection chamber. The collection efficiency can be automatically corrected. The technique of exchanging the collection mylar reduces the waiting time and improves work efficiency. The apparatus is applied to the measurement of the radon concentration in the environment and the radon exhalation from the surface of the building materials, walls and ground. The lower detection limit is about 4Bq/m 3 for 222 Rn concentration and 5 x 10 -5 Bq/s/m 2 for 222 Rn exhalation rate

Radon-222 Study in Ceramics and Indoor Air

International Nuclear Information System (INIS)

Moussa, N.L.A.A.

2011-01-01

A total 50 samples of 13 different ceramic tiles companies collected from the Egyptian market for the measurements of radon exhalation rate. Three homes include twenty rooms were selected. The period of the survey was in range 2-3 months for homes for each season while it was about 15 days for ceramic tiles. The radon exhalation rate of ceramic tiles (clay and glaze) and indoor radon activity concentration were measured by alpha tracks technique. The average radon exhalation rate in three homes was observed to be in the range 2.2-5.2 mBq.m -2 .h -1 . The average of Ra-226 activity for all ceramic tiles either the floor or wall tile is in the range 16-64 Bq.kg -1 . The porosity of ceramic tiles is found in the range 0.19-0.29. The effective dose in all rooms is found in the range 0.9- 1.3 mSv.y -1 .

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Radon progeny monitoring at the Eastern North Atlantic (ENA), Graciosa Island ARM facility and a potential earthquake precursory signal

Science.gov (United States)

Barbosa, Susana; Mendes, Virgilio B.; Azevedo, Eduardo B.

2016-04-01

Radon has been considered a promising earthquake precursor, the main rationale being an expected increase in radon exhalation in soil and rocks due to stress associated with the preparatory stages of an earthquake. However, the precursory nature of radon is far from being convincingly demonstrated so far. A major hindrance is the many meteorological and geophysical factors diving radon temporal variability, including the geophysical parameters influencing its emanation (grain size, moisture content, temperature), as well as the meteorological factors (atmospheric pressure, moisture, temperature, winds) influencing its mobility. Despite the challenges, radon remains one of the strongest candidates as a potential earthquake precursor, and it is of crucial importance to investigate the many factors driving its variability and its potential association with seismic events. Continuous monitoring of radon progeny is performed at the Eastern North Atlantic (ENA) facility located in the Graciosa island (Azores, 39N; 28W), a fixed site of the Atmospheric Radiation Measurement programme (ARM), established and supported by the Department of Energy (DOE) of the United States of America with the collaboration of the local government and University of the Azores. The Azores archipelago is associated with a complex geodynamic setting on the Azores triple junction where the American, Eurasian and African litospheric plates meet, resulting in significant seismic and volcanic activity. A considerable advantage of the monitoring site is the availability of a comprehensive dataset of concurrent meteorological observations performed at the ENA facility and freely available from the ARM data archive, enabling a detailed analysis of the environmental factors influencing the temporal variability of radon's progeny. Gamma radiation is being measured continuously every 15 minutes since May 2015. The time series of gamma radiation counts is dominated by sharp peaks lasting a few hours and

The application of air pressure difference in reducing indoor radon concentration

International Nuclear Information System (INIS)

Leung, J.K.C.; Tso, M.Y.W.

2000-01-01

In densely populated tropical cities like Hong Kong, people usually live and work inside high-rise buildings. And because of the hot and humid climate, air conditioning systems are used throughout the year, particularly in commercial buildings. Previous territory-wide surveys have shown that over 10% of commercial buildings in Hong Kong have indoor radon concentrations above 200 Bq m -3 . Since the major source of indoor radon in high-rise buildings is the building materials, increasing ventilation and applying radon barriers on wall surfaces seem to be the only ways to reduce the indoor radon concentration. But it was noted that the ventilation rate the many commercial buildings are not efficient enough to remove the radon because of various reasons such as energy saving, lack of maintenance, etc. In this study, radon mitigation was achieved by reducing the rate of radon exhaled from the building materials. A special laboratory, which has the capability of simulating any meteorological conditions that could be faced by high-rise buildings in Hong Kong, was built. The reduction of radon exhalation rate by applying pressure difference and temperature difference across walls was studied in the laboratory. This paper summarizes the results and tactics for applying pressure difference in existing commercial buildings. A new technique of reducing radon exhalation rate in new buildings by depressurizing the interior of walls was also developed. Tunnels can be embedded in the concrete walls of new buildings during construction. By using simple vacuum pumps, radon exhalation rate from the walls can be reduced significantly by depressurizing the tunnels. The feasibility and applicability of the technique is presented in this paper. (author)

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

Radon variations in a Hungarian village

International Nuclear Information System (INIS)

Toth, E.; Deak, F.; Marx, G.; Sajo-Bohus, L.; Vajda, N.

1997-01-01

A steady radon exhalation is assumed in most publications. In a village of North-East Hungary, however, high radon concentrations have been measured, differing strongly in neighbouring houses and varying in time, due to the interplay of geochemical phenomena. (orig.)

Long-term temporal variability of the radon-222 exhalation flux from a landform covered by low uranium grade waste rock

International Nuclear Information System (INIS)

Bollhöfer, Andreas; Doering, Che

2016-01-01

Radon-222 exhalation flux densities from two different substrates of several metres thickness, waste rock and waste rock mixed with approximately 30% lateritic material, were measured over a period of five years in the wet-dry tropics of Northern Australia. Fourteen measurement campaigns using activated charcoal canisters (n > 1000) covered both dry and wet seasons and showed differences in seasonal and long term trends of the "2"2"2Rn exhalation flux densities normalised to the "2"2"6Ra activity concentrations of the substrate. Dry season "2"2"2Rn exhalation was generally higher for the mixed substrate, due to the larger fraction of fines. Seasonality established within the first year of landform construction on the mixed substrate, due to the higher water holding capacity of the lateritic material. In contrast, waste rock only shows no seasonality until years four and five after construction, when average normalised dry season "2"2"2Rn exhalation flux densities from waste rock increase to values (0.47 ± 0.06 mBq m"−"2 s"−"1 per Bq kg"−"1) similar to the mixed substrate (0.64 ± 0.08 mBq m"−"2 s"−"1 per Bq kg"−"1), likely due to an increase in fines from rapid weathering of the schistose waste rock. Volumetric water content has been used to parametrize relative "2"2"2Rn exhalation and we determined that wet season "2"2"2Rn exhalation is about 40% of the dry season exhalation. - Highlights: • We determined "2"2"2Rn exhalation flux densities normalised to "2"2"6Ra activity concentrations (R_E_-_R) for two substrates. • R_E_-_R was lower for waste rock only compared to waste rock blended with 30% fine grained lateritic material. • Seasonality in waste rock "2"2"2Rn exhalation flux densities established 4 years after construction. • Wet season R_E_-_R was about 40% of the dry season R_E_-_R.

Radon levels in dwelling shielded spaces (DSS) in Israel

International Nuclear Information System (INIS)

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

2002-01-01

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

Radon in outdoor air at various sites in Slovakia

International Nuclear Information System (INIS)

Bulko, Martin; Holy, Karol; Muellerova, Monika; Polaskova, Anna; Hola, Olga

2010-01-01

Radon 222 was continuously monitored at four sites of Slovakia, viz. at the campus of the Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava (FMPI CU), at the Slovak Metrological Institute in Bratislava (SMI), at Jaslovske Bohunice (with its nuclear power plant), and at Novaky (coal mining area). The minima and maxima of the daily radon waves occurred at different periods of the day. The average radon activity concentration (RAC) in Novaky was more than twice as high as at the remaining sites, presumably due to a higher rate of radon exhalation from soil. By using the 'box' model, the exhalation rate at Novaky was estimated to be 40 mBq.m -2 .s -1 , which is about 2.5 times that at the FMPI CU in Bratislava. This higher exhalation rate in Novaky is probably caused by a different bedrock in this area. The average annual effective dose from radon and its daughters estimated by the UNSCEAR methodology is 0.06 mSv in the atmosphere of Bratislava and Jaslovske Bohunice and 0.13 mSv in the atmosphere of Novaky

Internal exposure from building materials exhaling (222)Rn and (220)Rn as compared to external exposure due to their natural radioactivity content.

Science.gov (United States)

Ujić, Predrag; Celiković, Igor; Kandić, Aleksandar; Vukanac, Ivana; Durasević, Mirjana; Dragosavac, Dusan; Zunić, Zora S

2010-01-01

The main scope of this paper is to point out the importance of introducing radon and thoron exhalation measurements from building materials in the regulating frame. Currently (2009), such a regulation of this kind of exposure is not explicitly included in the Serbian regulating network. To this end, this work reports concentration measurements of (226)Ra, (232)Th and (40)K and radon and thoron exhalation rates from building materials used in Serbia. Following detailed analysis, it was noticed that both internal exposures to radon and/or thoron exhaling from building materials may exceed external exposures to their precursors contained therein.

ERRICCA radon model intercomparison exercise

DEFF Research Database (Denmark)

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

1999-01-01

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

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)

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

International Nuclear Information System (INIS)

Soroka, Y.; Molchanov, A.

1998-01-01

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

Scopingreport radon

International Nuclear Information System (INIS)

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

1989-09-01

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

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)

Diffusion of radon through varying depths of cement

International Nuclear Information System (INIS)

Takriti, S.; Shweikani, R.; Ali, A.F.; Hushari, M.; Kheitou, M.

2001-01-01

Portland cement was mixed with different concentrations of radium chloride (1200, 2400 and 3600 Bq) to produce radioactive sources. These sources were surrounded with cement of different thickness (1, 2 and 4 cm). The release of radon from these sources (before and after being surrounded) was studied. The results showed that radon release from the sources itself was less then its release from the same source after being surrounded by cement, and the release did not change with the thickness of cement. Samples were covered with a thin layer of polyethylene before being surrounded with cement. It was found that this additional layer reduced the radon exhalation. This thin layer stopped any reaction between the source and the surrounding cement during solidification of the cement layers. These reactions are thought to be the reason for the increase of radon exhalation from the sources surrounded by cement

Radiological risk assessment of environmental radon

Energy Technology Data Exchange (ETDEWEB)

Khalid, Norafatin; Majid, Amran Ab; Yahaya, Redzuwan; Yasir, Muhammad Samudi [Nuclear Science Programme, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan (Malaysia)

2013-11-27

Measurements of radon gas ({sup 222}Rn) in the environmental are important to assess indoor air quality and to study the potential risk to human health. Generally known that exposure to radon is considered the second leading cause of lung cancer after smoking. The environmental radon concentration depends on the {sup 226}Ra concentration, indoor atmosphere, cracking on rocks and building materials. This study was carried out to determine the indoor radon concentration from selected samples of tin tailings (amang) and building materials in an airtight sealed homemade radon chamber. The radiological risk assessment for radon gas was also calculated based on the annual exposure dose, effective dose equivalent, radon exhalation rates and fatal cancer risk. The continuous radon monitor Sun Nuclear model 1029 was used to measure the radon concentration emanates from selected samples for 96 hours. Five types of tin tailings collected from Kampar, Perak and four samples of building materials commonly used in Malaysia dwellings or building constructions were analysed for radon concentration. The indoor radon concentration determined in ilmenite, monazite, struverite, xenotime and zircon samples varies from 219.6 ± 76.8 Bq m{sup −3} to 571.1 ± 251.4 Bq m{sup −3}, 101.0 ± 41.0 Bq m{sup −3} to 245.3 ± 100.2 Bq m{sup −3}, 53.1 ± 7.5 Bq m{sup −3} to 181.8 ± 9.7 Bq m{sup −3}, 256.1 ± 59.3 Bq m{sup −3} to 652.2 ± 222.2 Bq m{sup −3} and 164.5 ± 75.9 Bq m{sup −3} to 653.3 ± 240.0 Bq m{sup −3}, respectively. Whereas, in the building materials, the radon concentration from cement brick, red-clay brick, gravel aggregate and cement showed 396.3 ± 194.3 Bq m{sup −3}, 192.1 ± 75.4 Bq m{sup −3}, 176.1 ± 85.9 Bq m{sup −3} and 28.4 ± 5.7 Bq m{sup −3}, respectively. The radon concentration in tin tailings and building materials were found to be much higher in xenotime and cement brick samples than others. All samples in tin tailings were exceeded the

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

International Nuclear Information System (INIS)

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

2018-01-01

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

Potential of Mass Spectrometry in Developing Clinical Laboratory Biomarkers of Nonvolatiles in Exhaled Breath.

Science.gov (United States)

Beck, Olof; Olin, Anna-Carin; Mirgorodskaya, Ekaterina

2016-01-01

Exhaled breath contains nonvolatile substances that are part of aerosol particles of submicrometer size. These particles are formed and exhaled as a result of normal breathing and contain material from distal airways of the respiratory system. Exhaled breath can be used to monitor biomarkers of both endogenous and exogenous origin and constitutes an attractive specimen for medical investigations. This review summarizes the present status regarding potential biomarkers of nonvolatile compounds in exhaled breath. The field of exhaled breath condensate is briefly reviewed, together with more recent work on more selective collection procedures for exhaled particles. The relation of these particles to the surfactant in the terminal parts of the respiratory system is described. The literature on potential endogenous low molecular weight compounds as well as protein biomarkers is reviewed. The possibility to measure exposure to therapeutic and abused drugs is demonstrated. Finally, the potential future role and importance of mass spectrometry is discussed. Nonvolatile compounds exit the lung as aerosol particles that can be sampled easily and selectively. The clinical applications of potential biomarkers in exhaled breath comprise diagnosis of disease, monitoring of disease progress, monitoring of drug therapy, and toxicological investigations. © 2015 American Association for Clinical Chemistry.

Methodology developed to make the Quebec indoor radon potential map

International Nuclear Information System (INIS)

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

2014-01-01

This paper presents a relevant approach to predict the indoor radon potential based on the combination of the radiogeochemical data and the indoor radon measurements in the Quebec province territory (Canada). The Quebec ministry of health asked for such a map to identify the radon-prone areas to manage the risk for the population related to indoor radon exposure. Three radiogeochemical criteria including (1) equivalent uranium (eU) concentration from airborne surface gamma-ray surveys, (2) uranium concentration measurements in sediments, (3) bedrock and surficial geology were combined with 3082 basement radon concentration measurements to identify the radon-prone areas. It was shown that it is possible to determine thresholds for the three criteria that implied statistically significant different levels of radon potential using Kruskal–Wallis one way analyses of variance by ranks. The three discretized radiogeochemical datasets were combined into a total predicted radon potential that sampled 98% of the studied area. The combination process was also based on Kruskal–Wallis one way ANOVA. Four statistically significant different predicted radon potential levels were created: low, medium, high and very high. Respectively 10 and 13% of the dwellings exceed the Canadian radon guideline of 200 Bq/m 3 in low and medium predicted radon potentials. These proportions rise up to 22 and 45% respectively for high and very high predicted radon potentials. This predictive map of indoor radon potential based on the radiogeochemical data was validated using a map of confirmed radon exposure in homes based on the basement radon measurements. It was shown that the map of predicted radon potential based on the radiogeochemical data was reliable to identify radon-prone areas even in zones where no indoor radon measurement exists. - Highlights: • 5 radiogeochemical datasets were used to map the geogenic indoor radon potential. • An indoor radon potential was determined for each

Creating Geologically Based Radon Potential Maps for Kentucky

Science.gov (United States)

Overfield, B.; Hahn, E.; Wiggins, A.; Andrews, W. M., Jr.

2017-12-01

Radon potential in the United States, Kentucky in particular, has historically been communicated using a single hazard level for each county; however, physical phenomena are not controlled by administrative boundaries, so single-value county maps do not reflect the significant variations in radon potential in each county. A more accurate approach uses bedrock geology as a predictive tool. A team of nurses, health educators, statisticians, and geologists partnered to create 120 county maps showing spatial variations in radon potential by intersecting residential radon test kit results (N = 60,000) with a statewide 1:24,000-scale bedrock geology coverage to determine statistically valid radon-potential estimates for each geologic unit. Maps using geology as a predictive tool for radon potential are inherently more detailed than single-value county maps. This mapping project revealed that areas in central and south-central Kentucky with the highest radon potential are underlain by shales and karstic limestones.

EML indoor radon workshop, 1982

International Nuclear Information System (INIS)

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

1983-07-01

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

Radon measurements along active faults in the Langadas Basin, northern Greece

Directory of Open Access Journals (Sweden)

C. Papastefanou

2001-01-01

Full Text Available A network of three radon stations has been established in the Langadas Basin, northern Greece for radon monitoring by various techniques in earthquake prediction studies. Specially made devices with plastic tubes including Alpha Tracketch Detectors (ATD were installed for registering alpha particles from radon and radon decay products exhaled from the ground, every 2 weeks, by using LR-115, type II, non-strippable Kodak films, starting from December 1996. Simultaneous measurements started using Lucas cells alpha spectrometer for instantaneous radon measurements in soil gas, before and after setting ATDs at the radon stations. Continuous monitoring of radon gas exhaling from the ground started from the middle of August 1999 by using silicon diode detectors, which simultaneously register meteorological parameters, such as rainfall, temperature and barometric pressure. The obtained data were studied together with the data of seismic events, such as the magnitude, ML, of earthquakes that occurred at the Langadas Basin during the period of measurements, as registered by the Laboratory of Geophysics, Aristotle University of Thessaloniki, in order to find out any association between them.

Methodology developed to make the Quebec indoor radon potential map

Energy Technology Data Exchange (ETDEWEB)

Drolet, Jean-Philippe, E-mail: jean-philippe.drolet@ete.inrs.ca [Institut national de la recherche scientifique, Eau Terre Environnement Research Centre (ETE-INRS), 490 de la Couronne, G1K 9A9 Quebec (Canada); Martel, Richard [Institut national de la recherche scientifique, Eau Terre Environnement Research Centre (ETE-INRS), 490 de la Couronne, G1K 9A9 Quebec (Canada); Poulin, Patrick [Institut national de santé publique du Québec (INSPQ), 945 avenue Wolfe, G1V 5B3 Quebec (Canada); Dessau, Jean-Claude [Agence de la santé et des services sociaux des Laurentides, 1000 rue Labelle, J7Z 5 N6 Saint-Jérome (Canada)

2014-03-01

This paper presents a relevant approach to predict the indoor radon potential based on the combination of the radiogeochemical data and the indoor radon measurements in the Quebec province territory (Canada). The Quebec ministry of health asked for such a map to identify the radon-prone areas to manage the risk for the population related to indoor radon exposure. Three radiogeochemical criteria including (1) equivalent uranium (eU) concentration from airborne surface gamma-ray surveys, (2) uranium concentration measurements in sediments, (3) bedrock and surficial geology were combined with 3082 basement radon concentration measurements to identify the radon-prone areas. It was shown that it is possible to determine thresholds for the three criteria that implied statistically significant different levels of radon potential using Kruskal–Wallis one way analyses of variance by ranks. The three discretized radiogeochemical datasets were combined into a total predicted radon potential that sampled 98% of the studied area. The combination process was also based on Kruskal–Wallis one way ANOVA. Four statistically significant different predicted radon potential levels were created: low, medium, high and very high. Respectively 10 and 13% of the dwellings exceed the Canadian radon guideline of 200 Bq/m{sup 3} in low and medium predicted radon potentials. These proportions rise up to 22 and 45% respectively for high and very high predicted radon potentials. This predictive map of indoor radon potential based on the radiogeochemical data was validated using a map of confirmed radon exposure in homes based on the basement radon measurements. It was shown that the map of predicted radon potential based on the radiogeochemical data was reliable to identify radon-prone areas even in zones where no indoor radon measurement exists. - Highlights: • 5 radiogeochemical datasets were used to map the geogenic indoor radon potential. • An indoor radon potential was determined for

Passive and Active Measurements of Radon related parameters inside ancient Egyptian Tombs in Luxor

International Nuclear Information System (INIS)

Abo-Elmagd, M.; Eissa, H.M.; Metwally, S.M.; Fiki, S.A.; Salama, E.

2005-01-01

Radon concentration and its exhalation rate were measured using active (Alpha-Guard analyzer) and passive (CR-39) techniques inside seven ancient Egyptian tombs of the Kings valley in Luxor. The measurements were performed during the winter season of tourism (15/10/2003 up to 09/02/2004). The real radium content was determine for all examined tombs by HPGe detector, while the effective radium content was obtained by Alpha-Guard and sealed cup techniques. The average radon concentration inside the tombs based on the active technique ranges from 116 42 to 362 115 Bq m-3 and the exhalation rate ranges from 0.68 to 1.47 Bq m-2 h-1. For passive measurements, the average radon concentrations inside the tombs vary from 88 5 to 517 8 Bq m-3 while the exhalation rate ranges from 0.60 to 1.42 0.05 Bq m-2 h-1. Because of the variations of tombs dimensions and their ventilation systems, the equilibrium factor between radon and its progeny ranges from 0.10 0.04 to 0.99 0.14 based on Can and Bare measurement method. The effective dose rate inside the tombs varies from 0.11 0.04 to 4.28 0.68 Sv/h, based on UNSCEAR 2000 dose conversion factors for radon and its progeny. Radon exhalation rate was correlated with the real radium content. Moreover, a good correlation was found between active and passive measurements. So it may be useful to use passive technique in large scale instead of the active one

Passive and Active Measurements of Radon related parameters inside ancient Egyptian Tombs in Luxor

Energy Technology Data Exchange (ETDEWEB)

Abo-Elmagd, M; Eissa, H M [National institute for standerd, radiation Measurements department, Giza (Egypt); Metwally, S M; Fiki, S A; Salama, E [Faculty of Science Department of physics, Ain Shams University, Cairo (Egypt)

2005-04-01

Radon concentration and its exhalation rate were measured using active (Alpha-Guard analyzer) and passive (CR-39) techniques inside seven ancient Egyptian tombs of the Kings valley in Luxor. The measurements were performed during the winter season of tourism (15/10/2003 up to 09/02/2004). The real radium content was determine for all examined tombs by HPGe detector, while the effective radium content was obtained by Alpha-Guard and sealed cup techniques. The average radon concentration inside the tombs based on the active technique ranges from 116 42 to 362 115 Bq m-3 and the exhalation rate ranges from 0.68 to 1.47 Bq m-2 h-1. For passive measurements, the average radon concentrations inside the tombs vary from 88 5 to 517 8 Bq m-3 while the exhalation rate ranges from 0.60 to 1.42 0.05 Bq m-2 h-1. Because of the variations of tombs dimensions and their ventilation systems, the equilibrium factor between radon and its progeny ranges from 0.10 0.04 to 0.99 0.14 based on Can and Bare measurement method. The effective dose rate inside the tombs varies from 0.11 0.04 to 4.28 0.68 Sv/h, based on UNSCEAR 2000 dose conversion factors for radon and its progeny. Radon exhalation rate was correlated with the real radium content. Moreover, a good correlation was found between active and passive measurements. So it may be useful to use passive technique in large scale instead of the active one.

Passive and active measurements of radon-related parameters inside ancient Egyptian tombs in Luxor

Energy Technology Data Exchange (ETDEWEB)

Abo-Elmagd, M [Radiation Measurements Department, National Institute for Standard, Giza (Egypt); Metwally, S M [Faculty of Science, Department of Physics, Ain Shams University, Cairo (Egypt); El-Fiki, S A [Faculty of Science, Department of Physics, Ain Shams University, Cairo (Egypt); Eissa, H M [Radiation Measurements Department, National Institute for Standard, Giza (Egypt); Salama, E [Faculty of Science, Department of Physics, Ain Shams University, Cairo (Egypt)

2007-01-15

Radon and its related parameters were measured using passive (CR-39) and active (Alpha-Guard analyzer) techniques inside seven ancient Egyptian tombs of the Valley of the Kings in Luxor. The measurements were performed throughout the winter and summer seasons. The average radon concentration inside the tombs ranges from 96.9+/-10.8 to 415+/-43Bqm{sup -3} in winter and from 86.4+/-13.8 to 6102.8+/-573.6 in summer. Because of the variations of tombs dimensions and their ventilation systems, the equilibrium factor between radon and its progeny ranges from 0.228+/-0.02 to 0.95+/-0.05. The effective doses for the tomb workers, the tour guide and visitors were calculated. Active measurements show that radon exhalation rates range from 0.68+/-0.30 to 1.47+/-0.27Bqm{sup -2}h{sup -1} and from 0.60+/-0.03 to 1.42+/-0.05Bqm{sup -2}h{sup -1} for passive measurements. The real radium content was determined for all examined tombs by HPGe detector, while the effective radium content was obtained by Alpha-Guard and sealed cup techniques. Radon exhalation rates were correlated with the real radium content. A good correlation was found between active and passive measurements of radon exhalation rate.

Passive and active measurements of radon-related parameters inside ancient Egyptian tombs in Luxor

International Nuclear Information System (INIS)

Abo-Elmagd, M.; Metwally, S.M.; El-Fiki, S.A.; Eissa, H.M.; Salama, E.

2007-01-01

Radon and its related parameters were measured using passive (CR-39) and active (Alpha-Guard analyzer) techniques inside seven ancient Egyptian tombs of the Valley of the Kings in Luxor. The measurements were performed throughout the winter and summer seasons. The average radon concentration inside the tombs ranges from 96.9+/-10.8 to 415+/-43Bqm -3 in winter and from 86.4+/-13.8 to 6102.8+/-573.6 in summer. Because of the variations of tombs dimensions and their ventilation systems, the equilibrium factor between radon and its progeny ranges from 0.228+/-0.02 to 0.95+/-0.05. The effective doses for the tomb workers, the tour guide and visitors were calculated. Active measurements show that radon exhalation rates range from 0.68+/-0.30 to 1.47+/-0.27Bqm -2 h -1 and from 0.60+/-0.03 to 1.42+/-0.05Bqm -2 h -1 for passive measurements. The real radium content was determined for all examined tombs by HPGe detector, while the effective radium content was obtained by Alpha-Guard and sealed cup techniques. Radon exhalation rates were correlated with the real radium content. A good correlation was found between active and passive measurements of radon exhalation rate

Study of radon transport through concrete modified with silica fume

International Nuclear Information System (INIS)

Chauhan, R.P.; Kumar, Amit

2013-01-01

The concentration of radon in soil usually varies between a few kBq/m 3 and tens or hundreds of kBq/m 3 depending upon the geographical region. This causes the transport of radon from the soil to indoor environments by diffusion and advection through the pore space of concrete. To reduce indoor radon levels, the use of concrete with low porosity and a low radon diffusion coefficient is recommended. A method of reducing the radon diffusion coefficient through concrete and hence the indoor radon concentration by using silica fume to replace an optimum level of cement was studied. The diffusion coefficient of the concrete was reduced from (1.63 ± 0.3) × 10 −7 to (0.65 ± 0.01) × 10 −8 m 2 /s using 30% substitution of cement with silica fume. The compressive strength of the concrete increased as the silica-fume content increased, while radon exhalation rate and porosity of the concrete decreased. This study suggests a cost-effective method of reducing indoor radon levels. -- Highlights: • Radon diffusion study through silica fume modified concrete was carried out. • Radon diffusion coefficient of concrete decreased with increase of silica fume contents. • Compressive strength increased with increase of silica fume. • Radon exhalation rates and porosity of samples decreased with addition of silica fume. • Radon diffusion coefficient decreased to 2.6% by 30% silica fume substitution

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

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)

Uranium mill tailings and radon

International Nuclear Information System (INIS)

Hanchey, L.A.

1981-01-01

The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the US may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action Program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100

Uranium mill tailings and radon

Energy Technology Data Exchange (ETDEWEB)

Hanchey, L A

1981-04-01

The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the United States may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100.

Uranium mill tailings and radon

Energy Technology Data Exchange (ETDEWEB)

Hanchey, L A

1981-01-01

The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the US may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action Program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100.

Evaluation of color and radon exhalation rate in granite rocks between accelerated aging cycles; Avaliacao da cor e taxa de exalacao de radonio em rochas graniticas entre ciclos de envelhecimento acelerado

Energy Technology Data Exchange (ETDEWEB)

Silva, Francisco Diones Oliveira

2016-07-01

Data used for the assessment of the analyzes performed on three types of dimension stone (Juparana Bordeaux, Branco Nevasca and Golden Artico), in natural state and after several cycles of accelerated aging are presented, correlating them with the gas exhalation rate radon issued by the analyzed lithologies. In the samples were conducted permeability, porosity, colorimetry, image analysis, petrographic and exhalation rate of radon, accompanied by aging tests on climate simulation chamber which simulates change situations of materials by weathering agents, accelerating wear and tear samples. The measurements were performed on samples in natural state, with 50 and 100 cycles of aging acceleration, where each cycle corresponds to variations in temperature and humidity in climatic simulation chamber, with the addition of an internal atmosphere of SO{sub 2} with 25 concentration ppm. The results obtained during the tests were related to better analysis of the changes observed on the samples and the variation rate of exhalation radon emitted. The rocks have radon concentration values above the limits suggested by relevant international agencies (200-400 Bq/m³), with average values in the natural state, in 6149, 1619 and 866 Bq/m³ for Juparana Bordeaux, Branco Nevasca and Golden Arctic, respectively. The other aging cycles (50 and 100 cycles) showed an average increase of 0.8% for Juparana Bordeaux, 6.9% for White Blizzard and -23.87% for the Golden Arctic, with 50 cycles. From 50 to 100 cycles, there was reduction of 3.43% for Juparana Bordeaux and 22.15% for Branco Nevasca and an increase of 13.82% in the Golden Artico. The porosity results in the natural state obtained values an average of 0.696% for Juparana Bordeaux, 0.919% for Branco Nevasca and 0.830% for Golden Artico, and after 50 cycles of accelerated aging, obtained 0.621% to Juparana Bordeaux, 0.910% for Branco Nevasca and 0.840% for Golden Artico. The permeability of the samples showed values in the natural

Radon health hazards of some rocks of Iranian origin, frequently used as building stones

International Nuclear Information System (INIS)

Noori, H.; Ranjbar, A.H.

2011-01-01

Radon exhalation rate from various types of stones, used inside the living buildings, is a major factor for evaluation of the environmental radon level. To verify the significance and lethal impacts of this unknown and obscure source of radiation upon the people around the world, the exhaled radon gas concentrations from the rocks, granodiorite, granite, limestone and aragonite, and the effect of their block sizes on the exhalation rate, have been studied. The block samples, collected from their ores, were transferred to plastic containers in which the CR-39 detectors could properly be placed and air tightened, for concentration measurements. The results show the radon concentration of 7.4 ± 0.8, 6.6 ± 0.6, 0.08 ± 0.02 and 0.09 ± 0.02 kBq m -3 for granodiorite, granite, limestone and aragonite, respectively. The corresponding annual dose values in a closed environment are: 186 ± 20, 166 ± 15, 2.5 ± 1 and 2 ± 1 mSv y -1 . These absorbed dose values indicate that granodiorite and granite when used inside the buildings could increase the risk of various cancers while aragonite and limestone have much lower risks and are recommended for use inside the buildings. The former ones when used in the closure areas remedial action should be implemented. The results do not show obvious dependence between the rock size of the samples and their radon exhalation rate. (author)

Study of Rn-222 exhalation in phosphogypsum through the adsorption technique in activated coal; Estudo da exalacao de Rn-222 em fosfogesso por meio da tecnica de adsorcao em carvao ativado

Energy Technology Data Exchange (ETDEWEB)

Nisti, Marcelo Bessa; Campos, Marcia Pires de, E-mail: mbnisti@ipen.b, E-mail: mpcampos@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2011-10-26

The radon exhalation was estimated through the adsorption in activated carbon technique. Classified as TENORM, the radon exhalation determination on the phosphogypsum piles was performed through the adsorption ratio of radon in activated carbon, from the concentration of descendants of {sup 222}Rn, {sup 214}Pb and {sup 214}Bi obtained by gamma spectrometry. The results obtained in this work were compatibles with the values found in the literature

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

International Nuclear Information System (INIS)

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

2001-01-01

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

Does natural gas increase the indoor radon levels?

International Nuclear Information System (INIS)

Abdel-Ghany, H.A.; Shabaan, D.H.

2015-01-01

The natural gas is naturally occurring hydrocarbon consists mainly of methane and includes varying amounts of other hydrocarbons, carbon dioxide and other impurities such as: nitrogen, and hydrogen sulfide. It is used domestically and industrially as a preferable energy source compared to coal and oil. Because natural gas is found in deep underground natural formations or associated with other underground hydrocarbon reservoirs, there is a potential to contain radon as a contaminant. This work was designated to measure indoor radon concentrations in dwellings supplied with natural gas compared with those not supplied with it, where radon level was estimated using solid state nuclear track detectors (CR-39). The results showed that radon concentration was significantly higher in dwellings supplied with natural gas, where it was 252.30 versus 136.19 Bqm -3 in dwelling not supplied with natural gas (P < 0.001). The mean values of radon exhalation rate was 0.02 ± 6.34 · 10 -4 Bq · m -2 · h -1 in dwellings supplied with natural gas and 0.01 +- 0.008 Bq · m -2 · h -1 in dwellings lacking it. In addition, a significant difference was observed in the mean annual effective doses (4.33 and 2.34 mSv · y -1 , respectively) between both groups. Conclusively, the data indicate that natural gas may represent a potential source of indoor radon

Study on radon geological potential of Beijing city

International Nuclear Information System (INIS)

Liu Qingcheng; Wu Xinmin; Liu Yujuan; Yang Yaxin; Zhang Ye

2009-01-01

According to elemental geochemistry in Beijing, the uranium content in the area was measured, and distribution of radon concentration was predicted. Based on the uranium-radium equilibrium coefficient, porosity and diffusion coefficient, which were either measured or calculated, the radon geological potential of Beijing city was studied using γ-ray spectroscopy or mass spectroscopy and certain models were used to calculate the relation between radon geological potential and lithology and geological structure. The results showed that radon geological potential of Beijing city could be divided into four zones, tend of every zone coincides with the main structure, and the potential values nearly relate with geological factors. (authors)

Measurements of radon exhalation from building materials under model climate conditions

International Nuclear Information System (INIS)

Jann, O.; Schneider, U.; Koeppke, J.; Lehmann, R.

2003-01-01

The inhalation of 222 Rn (radon) is the most important reason for lung cancer as a result of smoking. The cause for enhanced radon concentration in the air of buildings is mostly the building ground. But also building products can lead to increased radon concentrations in indoor air when the products contain raw materials or residues with higher contents of 226 Ra (radium), especially in combination with low air exchange rates. For a realistic estimation of radon concentrations it is helpful to perform emission tests on the basis of emission test chambers. Emissions test chambers are already used successfully for the measurement of volatile organic compounds (VOC) emitted from different materials and products. The analysis of radon in air was performed with a test device based on the principle of ionisation chamber (ATMOS 12 D). It could be show that radon concentrations emitted from building materials can be determined reliably if certain boundary conditions such as temperature, relative humidity and especially area specific air flow rate are met. It was also shown that reduced area specific air flow rates or reduced air exchange rates lead to higher radon concentrations. It is remarkable that no conclusion can be drawn from the activity concentration of radium to the radon concentration in the air. Therefore in some cases much higher radon concentrations in air were determined that had been expected. Obviously diffusion within the material plays an important role. (orig.)

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-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

A universal laboratory method for determining physical parameters of radon migration in dry granulated porous media.

Science.gov (United States)

Ye, Yong-Jun; Zhang, Yun-Feng; Dai, Xin-Tao; Ding, De-Xin

2017-10-01

The particle size and heaped methods of exhalation media have important effects on physical parameters, such as the free radon production rate, porosity, permeability, and radon diffusion coefficient. However, existing methods for determining those parameters are too complex, and time-consuming. In this study, a novel, systematic determining method was proposed based on nuclide decay, radon diffusion migration theory, and the mass conservation law, and an associated experimental device was designed and manufactured. The parameters of uranium ore heap and sandy soil of radon diffusion coefficient (D), free radon production rate (α), media permeability (k), and porosity (ε) were obtained. At the same time, the practicality of the novel determining method was improved over other methods, with the results showing that accuracy was within the acceptable range of experimental error. This novel method will be of significance for the study of radon migration and exhalation in granulated porous media. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of radon levels in indoor air

International Nuclear Information System (INIS)

George, A.C.

1982-01-01

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

Radon in houses - identification of sources and pathways of transfer

International Nuclear Information System (INIS)

Robe, M.C.; Rannou, A.; Le Bronec, J.

1992-01-01

The Institut de Protection et de Surete Nucleaire (IPSN) is studying the remedial actions to reduce high concentration of radon in houses. The first step to know how to modify houses is to identify radon sources and pathways of transfer to upper floors. A pilot study in Brittany was designed to develop a simple method of diagnosis. This investigation was based on indoor and outdoor measurements of 222 Rn activity concentration in the air and 222 Rn area exhalation rate from the soils and walls, measurements of the potential alpha energy concentration of 222 Rn daughters and the ventilation rate. The structural characteristics of houses and the influence of the life style of the inhabitants were examined. Analysis of the results showed that a limited number of parameters can be selected for use in a rapid radon diagnosis. (author)

Radon levels after restoration of the U-mine disposal site

International Nuclear Information System (INIS)

Krizman, M.J.; Rojc, J.; Jovanovic, P.

2010-01-01

After cessation of the underground mining of uranium ore and production of uranium concentrate at Zirovski Vrh (Slovenia) in the period 1985-1990, two permanent surface disposal sites remained, namely, tailings pile and mine waste rock pile. Both disposal sites were of equal size of 4 hectares and were significant sources of radon. Their final restoration was designed in compliance with the condition of dose constraint for the public and authorized limits for radon exhalation from the remediated piles. In the late summer of 2008, a restoration of the mine waste pile was finished. Radon releases were reduced significantly by constructing an effective radon barrier of well compacted clay material and a thick complex protective cover layer constructed over it. Radon exhalation rate from the mine waste area was lowered from primary level of 0.7 Bq/m 2 ·s to natural levels (0.01 Bq/m 2 ·s), and consequently, ambient radon levels also decreased on the site and nearby environment. The average radon contribution from the remaining U-mine sources was estimated on the basis of the environmental measurements of radon concentrations; they dropped from initial 7-9 Bq/m 3 to approximately 3 Bq/m 3 . Further reduction of outdoor radon concentrations is expected after 2010, since the restoration of another disposal site will have been completed by the end of this year. Public exposure due to industrial radon after the first phase of restoration satisfactorily meets the dose constraint level of 0.3 mSv/y, since it decreased to less than 0.1 mSv/y. (authors)

Measurements of radon in soil gas

International Nuclear Information System (INIS)

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

2009-01-01

Full text: After the decades of systematic and numerous studies performed at different countries of the World, it has been concluded that radon as well as its progeny is the main cause of lung cancer. It is well known that more than 50% of the effective annual radiation dose received by a human being is related to the radon and its progenies. Among the principle mechanisms that bring the radon inside the dwelling is the soil exhalation as well as exhalation and release from the water. Radon concentration in the soil and its transport (emanation, diffusion, advection and adsorption) to the surface depends on different physical, geological and ambient parameters such as the geology of the area, geochemical composition of the soil, its porosity and permeability, grain size, soil humidity, bottom sediments and inputs from streams, temperature, atmospheric pressure, etc. Since the main part of indoor radon originates in the soil, the measurements of radon concentration in soil gas have to be considered as an important tool and indicator of probable high levels of radon inside the dwellings. Present 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. The equipment was adjusted with air flow of 0

Spatial and time variations of radon-222 concentration in the atmosphere of a dead-end horizontal tunnel

International Nuclear Information System (INIS)

Richon, Patrick; Perrier, Frederic; Sabroux, Jean-Christophe; Trique, Michaeel; Ferry, Cecile; Voisin, Vincent; Pili, Eric

2004-01-01

The concentration of radon-222 has been monitored since 1995 in the atmosphere of a 2 m transverse dimension, 128 m long, dead-end horizontal tunnel located in the French Alps, at an altitude of 1600 m. Most of the time, the radon concentration is stable, with an average value ranging from 200 Bq m -3 near the entrance to about 1000 Bq m -3 in the most confined section, with an equilibrium factor between radon and its short-lived decay products varying from 0.61 to 0.78. However, radon bursts are repeatedly observed, with amplitudes reaching up to 36 x 10 3 Bq m -3 and durations varying from one to several weeks, with similar spatial variations along the tunnel as the background concentration. These spatial variations are qualitatively interpreted in terms of natural ventilation. Comparing the radon background concentration with the measured radon exhalation flux at the wall yields an estimate of 8 ± 2 x 10 -6 s -1 (0.03 ± 0.007 h -1 ) for the ventilation rate. The hypothesis that the bursts could be due to transient changes in ventilation can be ruled out. Thus, the bursts are the results of transient increased radon exhalation at the walls, that could be due to meteorological effects or possibly combined hydrological and mechanical forcing associated with the water level variations of the nearby Roselend reservoir lake. Such studies are of interest for radiation protection in poorly ventilated underground settings, and, ultimately, for a better understanding of radon exhalation associated with tectonic or volcanic processes

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.

Spatial and vertical distribution of radon and thoron in a typical Indian dwelling

International Nuclear Information System (INIS)

Vinay Kumar Reddy, K.; Gopal Reddy, Ch.; Yadagiri Reddy, P.; Rama Reddy, K.

2012-01-01

Radon and thoron have been identified as potential radiological health hazard and the dose estimation due to their exposure is an important task. Understanding their behavior in indoor environment helps in calculating the inhalation doses due to them. Present study aims at the distribution of radon and thoron concentrations in a typical Indian dwelling. Solid state nuclear track detectors are employed in the study. The concentration of radon is found to be invariant in indoor environment. The thoron concentration is found to decrease exponentially as a function of distance from the source (wall/floor). Solution of one dimensional diffusion equation is used for regression fittings for thoron variation, from which the diffusion constants and the exhalation rates were calculated. The diffusion constants varied from 0.00195 to 0.00540 m 2 s -1 . (author)

Transport of radon through cracks in a concrete slab

Energy Technology Data Exchange (ETDEWEB)

Landman, K A; Cohen, D S

1983-03-01

A model involving the use of line sources is developed to describe the transport of radon through the cracks or gaps which appear in concrete slabs used in building foundations. The strength of these sources is determined from the results of the diffusion model proposed by Landman in a previous work. Once the strength of the source is known, additional transport mechanisms can be treated in a simple manner. Pressure differences across the slab and in the underlying soil are discussed. The rate of exhalation through a portion of the cracked slab is determined and compared to the rate of exhalation from the same surface area of bare soil. In typical cases, their ratios vary from 0.25 to 0.50. Therefore, these transport mechanisms account for a larger portion of the levels of radon found in many houses than do previous models.

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

Geological Structure and Radon Hazards in Lublin Region

Directory of Open Access Journals (Sweden)

Lucjan Gazda

2018-03-01

Full Text Available The purpose of the study was to show the relationship between the geological structure of the Lublin region (eastern Poland and radon concentrations in the ground air, and therefore, in the indoor environment of buildings located in that area. The study was based on the information pertaining to the geological structure of Lublin region available in the literature. The radon concentrations in buildings, caves, wells, as well as coal, phosphate and chalk mines were measured with both passive and active methods. Elemental analyses and uranium and lead isotope analyses of ground rocks were also performed. The conducted studies indicated that the sources of radon in Lublin region constitute Paleogene and Mesozoic sedimentary rocks rich in radionuclides. Application of radon remediation methods is recommended in the existing buildings located in the vicinity of these rocks, which are characterized by relatively high radon exhalations. On the other hand, the designed buildings should employ the measures protecting against harmful effects of radon presence.

Study on calculation models and distribution rules of the radon concentration and its progenies concentration in blind roadway with forced-exhaust ventilation

International Nuclear Information System (INIS)

Ye Yongjun; Wang Liheng; Zhou Xinghuo; Li Xiangyang; Zhong Yongming; Wang Shuyun; Ding Dexin

2014-01-01

The forced-exhaust ventilation is an important way to control the concentration of radon and its progenies in long-distance blind driving roadway. It is of great significance for guiding the design of ventilation and radiation protection to study distribution characteristics of the concentration of radon and its progenies in the wind of roadway adopting the forced-exhaust ventilation. Therefore, according to the decay relationship of radon and its progenies, a simplified mathematical calculation model was built, which relates to the radon activity concentration and the potential alpha concentration of radon progenies. The paper also analyzed the sources of radon and its progenies in the limited space of the blind roadway. Then, based on the turbulence mass transfer theory of ventilation air flow, the paper established mathematical calculation models of distribution characteristics of the radon activity concentration and the potential alpha concentration of radon progenies in blind roadway with forced-exhaust ventilation, respectively. Finally, the paper applied the calculation models to a special blind roadway, and discussed the influence of the ventilation air inflow and the radon exhalation rate of rock wall on the distribution of radon concentration and the potential alpha concentration of radon progenies in the roadway. Meanwhile, some protective measurements were put forward to reduce the radiation dose of worker caused by radon and its progenies in the blind roadway. (authors)

A study of radon activity inside some houses in Bangladesh

International Nuclear Information System (INIS)

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

1988-01-01

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

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

Study of properties of active charcoal used for measuring of low radon activities

International Nuclear Information System (INIS)

Muellerova, M.; Holy, K.

2011-01-01

We used the German charcoal Silicarbon for adsorption of radon from the air. From the column with activated carbon arranged in a row, we obtain cut-off dependence of radon on activated carbon at various temperatures, cooling and also at different speeds, drawing radon air through activated charcoal. From information we have chosen the most appropriate combination of temperature and cooling flow in order to maximize capture efficiency of radon in the first column of active charcoal. To change active carbon and optimization of operation allows us to measure the radon exhalation rate from various materials up to the level of 3·10 -9 Bq/s. (authors)

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

Measurement and Simulation of Radon Transport in East Asia and Their Implication on Source Distribution

International Nuclear Information System (INIS)

Hirao, S.; Yamazawa, H.; Moriizumi, J.; Iida, T.

2012-01-01

Outlines of the continuous monitoring of atmospheric radon concentration at several locations in East Asia, the development and validation of a long-range atmospheric transport model, and a trial of estimating and reducing uncertainty in radon exhalation flux density maps were presented. Atmospheric radon concentration data observed at a small solitary island in the Pacific Ocean were successfully used to improve the vertical diffusion scheme in the model although the uncertainty in the radon flux density data was the limitation. It was also pointed out that a kind of source-receptor analysis using the radon concentration observed at these islands would reduce uncertainty in the radon flux density maps. (author)

Some aspects of radon and its daughter-products in man and his environment

International Nuclear Information System (INIS)

Rundo, J.; Markun, F.; Plondke, N.J.; Sha, J.Y.

1981-01-01

A major but short-lived postprandial increase in the exhalation rate of radon by persons containing no radium was observed. The concentrations of radon and its short-lived daughter-products in houses was unusually high (> 5 to 10 pCi l - 1 , > 185 to 370 Bq m - 3 ) in some houses with unpaved crawl spaces, and with concrete basements. External counting of radon daughter-products in the residents of one of the radon-contaminated houses indicated that there may be interference with the assay of plutonium in the lungs of persons who live in those houses

Study of radon exhalation from phosphogypsum plates and blocks from different origins; Estudo da exalacao de radonio em placas e tijolos de fosfogesso de diferentes procedencias

Energy Technology Data Exchange (ETDEWEB)

Costa, Lucas Jose Pereira da

2011-07-01

Phosphogypsum is a waste of the fertilizer industry that concentrates radionuclides. In this work, the {sup 222}Rn exhalation rate from phosphogypsum plates and blocks from different origins used at dwellings construction was studied. The {sup 222}Rn exhalation rate was determined through the accumulation chamber technique with solid state nuclear track detectors (SSNTD). The effective dose for an individual living in a residence built with phosphogypsum based materials was evaluated. It also was calculated the {sup 222}Rn exhalation rate through the UNSCEAR model, from the {sup 226}Ra concentration in the materials, in order to compare the experimental results. It was evaluated the contribution of building component (paint) to the reduction of {sup 222}Rn exhalation rate. The plates and blocks were manufactured with phosphogypsum from Bunge Fertilizantes, Ultrafertil and Fosfertil. Blocks manufactured with ordinary gypsum was also evaluated. The average results obtained were 0.19 {+-} 0.06 Bq m-2 h-1, 1.3 {+-} 0.3 Bq m{sup -2} h{sup -1} and 0.41 {+-} 0.07 Bq m{sup -2} h{sup -1} for plates manufactured with phosphogypsum from Bunge Fertilizer, Ultrafertil and Fosfertil, respectively. For the phosphogypsum blocks the values were 0.11 {+-} 0.01 Bq m{sup -2} h-1, 1.2 {+-} 0.6 Bq m{sup -2} h{sup -1}, 0.47 {+-} 0.15 Bq m{sup -2} h{sup -1}, for Bunge, Ultrafertil and Fosfertil. The blocks manufactured with ordinary gypsum presented average value of 0.18 {+-} 0.08 Bq m{sup -2} h'-{sup 1}. All phosphogypsum plates and blocks evaluated in this study presented effective dose for radon inhalation lower than the recommended value of 1mSv y{sup -1}, the annual effective dose limit for public exposure by International Commission on Radiological Protection. (author)

Mapping variation in radon potential both between and within geological units

International Nuclear Information System (INIS)

Miles, J C H; Appleton, J D

2005-01-01

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

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 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

Radon emanation fractions from concretes containing fly ash and metakaolin

International Nuclear Information System (INIS)

Taylor-Lange, Sarah C.; Juenger, Maria C.G.; Siegel, Jeffrey A.

2014-01-01

Radon ( 222 Rn) and progenies emanate from soil and building components and can create an indoor air quality hazard. In this study, nine concrete constituents, including the supplementary cementitious materials (SCMs) fly ash and metakaolin, were used to create eleven different concrete mixtures. We investigated the effect of constituent radium specific activity, radon effective activity and emanation fraction on the concrete emanation fraction and the radon exhalation rate. Given the serious health effects associated with radionuclide exposure, experimental results were coupled with Monte Carlo simulations to demonstrate predictive differences in the indoor radon concentration due to concrete mixture design. The results from this study show that, on average, fly ash constituents possessed radium specific activities ranging from 100 Bq/kg to 200 Bq/kg and emanation fractions ranging from 1.1% to 2.5%. The lowest emitting concrete mixture containing fly ash resulted in a 3.4% reduction in the concrete emanation fraction, owing to the relatively low emanation that exists when fly ash is part of concrete. On average, the metakaolin constituents contained radium specific activities ranging from 67 Bq/kg to 600 Bq/kg and emanation fractions ranging from 8.4% to 15.5%, and changed the total concrete emanation fraction by roughly ± 5% relative to control samples. The results from this study suggest that SCMs can reduce indoor radon exposure from concrete, contingent upon SCM radionucleotide content and emanation fraction. Lastly, the experimental results provide SCM-specific concrete emanation fractions for indoor radon exposure modeling. - Highlights: • Fly ash or metakaolin SCMs can neutralize or reduce concrete emanation fractions. • The specific activity of constituents is a poor predictor of the concrete emanation fraction. • Exhalation from fly ash concretes represents a small fraction of the total indoor radon concentration

The effect of the composition and production process of concrete on the 222Rn exhalation rate

NARCIS (Netherlands)

Jong, P. de; Dijk, W. van; Hulst, J.G.A. van; Heijningen, R.J.J. van

1997-01-01

In a series of 18 concrete samples, the influence of several parameters related to composition and production processes on the radon exhalation rate was studied. The investigated parameters were: amount and type of cement, water-cement ratio, curing conditions and curing time, type of aggregates,

Development of apparatus and procedures for evaluating radon-resistant construction materials

International Nuclear Information System (INIS)

Pugh, T.D.; Greenfield, M.B.; MacKenzie, J.; Meijer, R.J. de

1992-01-01

Laboratory facilities and apparatus have been constructed to measure radon exhalation from, and radon permeability through, various construction materials. This phase of the project has focused on development of test apparatus and evaluation of instrumentation. Results indicate significant spatial variability in the radon permeability of polyethylene, even when all test samples were selected from the same roll of material, and when no visible differentiation could be made regarding sample quality. Implications for code enforcement are described, and recommendations are offered for refinement of equipment and the measurement process, prioritization of future materials testing, and specific building code provisions, based on our results

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)

Use of commercial radon monitors for low level radon measurements in dynamically operated VOC emission test chambers

International Nuclear Information System (INIS)

Hofmann, M.; Richter, M.; Jann, O.

2017-01-01

Compared to the intended EU reference level of 300 Bq m -3 for indoor radon concentrations, the contribution of building materials appears to be low. Considering the recommended limit of 100 Bq m -3 by WHO, their contribution is supposed to be relevant, especially at low air exchange rates. This study as part of a two-part research project investigated the suitability of direct low level 222 Rn measurement under simulated indoor conditions with commercial radon monitors and dynamically operated emission test chambers. Active measuring devices based on ionisation or scintillation chambers with 1-σ uncertainties below 8.6% at 20 Bq m -3 were found to be best suitable for a practical test procedure for the determination of radon exhalation rates of building materials. For the measurement of such low concentrations, the knowledge of the accurate device background level is essential. (authors)

Exposures to radon in homes in Adana

International Nuclear Information System (INIS)

Yegingil, Z.

1990-01-01

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

ERRICCA radon model intercomparison exercise

International Nuclear Information System (INIS)

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

1999-04-01

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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)

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

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 programme in Czech Republic. Results, experience and future

International Nuclear Information System (INIS)

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

2004-01-01

The beginning of the radon programme in the Czech republic dates back to the early 1980s. Incorporated in national legislation (Atomic Act, Radiation Protection Decree), the programme includes now both preventive measures and interventions. Preventive measures are based on the control of major potential radon sources (soil gas, building material and supplied water) to prevent construction of new houses where the recommended indoor radon level of 200 Bq/m 3 would be exceeded. Radon risk (index) assessment of the individual building site bedrock in the case of new house siting and building protection as stipulated by the technical building code are obligatory. The estimation of the radon-related index of building sites is based on a standard method involving a set of radon soil and soil permeability measurements. In addition, producers of building materials are obligated to monitor natural radioactivity in their products. The activity index (including 40 K, 226 Ra and 232 Th) is used as a screening level for regulation of the potential indoor gamma dose rate, and the 226R a mass activity is used as a limiting value for radon exhalation. A similar regulatory system is in place for public water supplies based on obligatory radon, total alpha and total beta measurements. A survey of effectiveness of the preventive measures was carried out during the past years. It appeared, however, that the indoor radon level of 200 Bq/m 3 is exceeded in some 20 % of new houses. An unexpectedly low air exchange rate in modern energy-saving houses seems to be among the reasons. Remedial actions are aimed at promoting targeted indoor radon survey in existing buildings and helping owners to put reasonable remedial measures into effect. Governmental activities include representative and targeted indoor radon survey, subsidies for remediation measures and test measurements, and improving the level of public awareness of the radon issue. Indoor radon survey is targeted on radon-prone areas

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

remediation by sub-slab depressurization has been effective, and also in areas of low soil-gas radon, upstairs radon levels may be dominated by radon exhalation from the walls of the dwelling. (author)

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

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)

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

Energy Technology Data Exchange (ETDEWEB)

Linzmaier, Diana

2013-01-04

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

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

International Nuclear Information System (INIS)

Collignan, Bernard; Powaga, Emilie

2014-01-01

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

Radionuclide content in some building materials and their radon exhalation

International Nuclear Information System (INIS)

Holy, K.; Sykora, I.; Chudy, M.; Polaskova, A.; Hola, O.

1995-01-01

The activity concentrations of natural radionuclides in sands, gravels, cements and in different kinds of concretes were measured by γ-spectrometric methods. The 222 Rn exhalation rate from concretes was measured by closed chamber method and the emanation coefficient was calculated. Both used methods are described in detail and obtained results are discussed from point of view of allowed hygienic limits. (author) 11 refs.; 2 figs.; 5 tabs

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

Science.gov (United States)

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

1988-01-01

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

Radon effective dose from TENORM waste associated with petroleum industries

International Nuclear Information System (INIS)

Abo-Elmagd, M.; Soliman, H. A.; Daif, M. M.

2009-01-01

Technically enhanced naturally occurring radioactive material (TENORM) associated with petroleum industries can be accumulated with elevated quantities and therefore can threat the workers through external and internal exposure. Measurements of radon-related parameters give information about the radioactivity levels in the TENORM waste using the well-established correlation. Also, it is useful to calculate the internal exposure due to radon inhalation in terms of effective radon dose. Among radon-related parameters, areal exhalation rate is the most suitable for characterising land and objects with only upper surface contamination in the case of petroleum waste. The TENORM in this study is collected from waste storage areas located near oil fields at south Sinai governorate (Egypt). The average values of exhalation rates as measured by Lucas cell based on delay count method are 273 ± 144 and 38 ± 8 Bq m -2 h -1 for scale and sludge, respectively. Whereas, two count method gives results with 18 and 20 % lower values for scale and sludge, respectively with good correlation coefficient of 0.999 and 0.852, respectively. Sealed cup fitted with CR-39 gives results compatible with Lucas cell with minor deviation in case of scale due to its thoron content. The results of CR-39 are qualified by taking into consideration the correction for back diffusion effect. The effective radon dose was calculated for different simulated radioactive waste storage areas with different contaminated areas and air ventilation rate. Minimising the contaminated areas and building up efficient ventilation systems can reduce the internal exposure even in the case of RWSA-containing TENORM with elevated radioactivity. (authors)

Geogenic factors of radiation exposure with special regard of the radon potential

International Nuclear Information System (INIS)

Kemski, J.; Siehl, A.; Stegemann, R.; Valdivia-Manchego, M.

1999-01-01

Classification and mapping of geogenic radon potential in Germany is based on detailed field studies of radon activity in soil gas and in situ gas permeability, using GIS techniques. The distribution of the two parameters is combined in a ranking procedure to asses the geogenic radon potential, with regionalization based on a distance-weighted interpolation of the measurements on a regular grid and information on the corresponding geological unit as an attribute to every raster field. Thereby, the boundaries of the geological units are defined implicitly. In areas with rather homogeneous geological conditions, where lower to intermediate radon potential is present, the measuring sites are widely spaced (i.e. Meso- and Cenozoic sedimentary rocks, covering 80 % of the area). Areas with more complicated hard rock geology and suspected high geogenic radon potential, like the outcrop areas of the Palaeozoic and Precambrian basement, were mapped in detail with a higher density of the measurement grid. The data material at hand make it possible to design maps of different types of parameter combinations and classifications, taking into account also administrative units. As a result, a set of detailed maps of geogenic radon potential for selected test areas as well as a general map for Germany (1:2 000 000) are presented. (orig./SR) [de

Measurement of dose-determining physical parameters (F-factor, fp factor,...) for comparative analysis of outdoor/indoor radon exposure

International Nuclear Information System (INIS)

Anon

1998-01-01

The purpose of the project was to measure the airborne natural radon activity concentrations outdoor and the dose-determining parameters [non-deposited fraction (f p ), radon daughter products (F, PAEC), as well as the radioactive aerosol size distribution]. The impacts of meteorological parameters (pressure, rainfalls, wind velocities and temperature) on the those parameters and the exhalation of radon from the soil were to be determined. The acquired information was to be applied for an evaluation of the radiological outdoor situation and subsequent comparative analysis with the indoor radon exposure. (orig./CB) [de

Measurement of 222Rn and 220Rn exhalation rate from soil samples of Kumaun Hills, India

Science.gov (United States)

Semwal, Poonam; Singh, Kuldeep; Agarwal, T. K.; Joshi, Manish; Pant, Preeti; Kandari, Tushar; Ramola, R. C.

2018-03-01

The source terms, i.e., exhalation and emanation from soil and building materials are the primary contributors to the radon (222Rn)/thoron (220Rn) concentration levels in the dwellings, while the ecological constraints like ventilation rate, temperature, pressure, humidity, etc., are the influencing factors. The present study is focused on Almora District of Kumaun, located in Himalayan belt of Uttarakhand, India. For the measurement of 222Rn and 220Rn exhalation rates, 24 soil samples were collected from different locations. Gamma radiation level was measured at each of these locations. Chamber technique associated with Smart Rn Duo portable monitor was employed for the estimation of 222Rn and 220Rn exhalation rates. Radionuclides (226Ra, 232Th and 40K) concentrations were also measured in soil samples using NaI(Tl) scintillation based gamma ray spectrometry. The mass exhalation rate for 222Rn was varying between 16 and 54 mBq/kg/h, while the 220Rn surface exhalation rate was in the range of 0.65-6.43 Bq/m2/s. Measured gamma dose rate for the same region varied from 0.10 to 0.31 µSv/h. Inter-correlation of exhalation rates and intra-correlation with background gamma levels were studied.

The role of house surveys in geological radon potential mapping

International Nuclear Information System (INIS)

Ball, K.

1997-01-01

Because radon levels vary widely between apparently identical buildings on the same geological unit, no map can predict the radon level in an individual building. Maps can, however, give the probability that a building in a particular locality is above a threshold of radon concentration such as a reference or action level. The probability may be calculated for a particular building type or for a mixture of building types. In the latter case the probability is in effect an estimate of the proportion of buildings above the threshold level. Alternatively maps can provide estimates of the mean radon levels in buildings by area. Maps showing the geographical variation in probability that new or existing building will exceed a radon reference level are used to prevent excessive exposures to radon. The information may be used in various ways, such as to target information campaigns encouraging measurement of radon levels in homes or to modify regulations for new buildings. The data which are used to provide the estimates of the proportion of buildings above a threshold may be radon measurements results from a sample of buildings, or may be indirect indicators such as ground radium concentrations, emanation coefficients and permeability measurements. Consistency in radon measurement protocols and detailed positional information are prerequisites for mapping radon prone areas based upon house data. Grouping building radon measurements by geological formation and superficial cover can produce radon potential maps which are more spatially accurate than grid square maps and more accurate in estimating numbers of homes affected than mapping based only on measuring geological and pedagogical properties

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

Science.gov (United States)

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

2017-01-01

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

Radon: a problem of terminology

International Nuclear Information System (INIS)

Pellegrini, D.; Demongeot, S.

1995-01-01

Here are detailed the difficulties to speak about the same thing if we don't use the same language. The example is the radon and what we want to tell about it; it is necessary to explain what words we are using and what mean we want to give them. Then, emanation and exhalation are given with their definitions. Also the terms as factor, flux and rate are redefined. It is a way to make scientific population sensitive to terminology

Mapping of groundwater radon potential

International Nuclear Information System (INIS)

Aekerblom, G.; Lindgren, J.

1997-01-01

The domestic use of water with elevated radon concentration may represent a public health hazard, partly due to the release of radon to the indoor air. While only a limited number of countries have implemented regulations with respect to radon in water, many more are considering doing so. The compulsory limits proposed by Swedish authorities are 100 Bq/1 for public water, while water from private wells is not to exceed 1000 Bq/1. Furthermore, it is recommended that water with a radon content above 500 Bq/1 should not be given to children under five years of age. In Sweden, the estimated number of wells with radon levels above 1000 Bq/1 exceeds 10,000, with a considerable amount in excess of 10,000 Bq/1. The highest radon concentration in a well supplying drinking water encountered so far is 57,000 Bq/1. Radon levels exceeding 500 Bq/1 are almost exclusively found in wells drilled into bedrock and in springs with intramontaneous water. Elevated ground water radon levels require that the water has passed through bedrock with elevated concentration of uranium, or through fractures with coatings of minerals containing enhanced concentrations of radium-226. Intramontaneous water from areas with uranium-bearing rock types (e.g. uranium-rich granites, pegmatites and vulcanites) often manifests elevated radon levels. Routines for the establishment of risk maps focusing on water are currently under development. The backbone of the process is the access to high spatial resolution radiometric information together with bedrock and soil information on a detailed scale (1:50,000). This information is available from the Geological Survey of Sweden, which is routinely carrying out airborne measurements at an altitude of 30 m and a line spacing of 200 m. While some 60% of Sweden is covered up to now, 75 % is expected to be covered within the next ten years. Other available databases utilized in the risk mapping process include radon measurements in wells, geochemical data from

Lung doses from radon in dwellings and influencing factors

International Nuclear Information System (INIS)

Stranden, E.

1980-01-01

The radon concentration in Norwegian dwellings and the lung doses received by the Norwegian population are reported. The biological effects of these doses are discussed. The mean value of radon-daughters in Norwegian dwellings was found to be about 7x10 -3 WL (working levels). This corresponds to an annual exposure of about 0.3 WLM (working level months). From studies of the lung cancer statistics of Norway, this exposure may account for about 10% of the annual lung cancer cases in Norway. The variations in the radon concentration inside dwellings are discussed, and the influence of exhalation, ventilation and meteorological parameters upon the respiratory dosage is studied. From the risk estimates performed, the consequences of an increased indoor radon concentration due to reduced ventilation or introduction of building materials with high radium concentrations are discussed. From comparison of the population doses from different sources of radiation, it is evident that a possible future increase in the radon concentration in dwellings is one of the most serious radiation protection problems of our time. (author)

Formulation of the fundamental basis for the evaluation of the comparability of different measuring method for the determination of ground air radon concentration. Vol. 2. Report on ground air radon measurements - influence factors, measuring methods, evaluation; Erarbeitung fachlicher Grundlagen zur Beurteilung der Vergleichbarkeit unterschiedlicher Messmethoden zur Bestimmung der Radonbodenluftkonzentration. Bd. 2. Sachstandsbericht ''Radonmessungen in der Bodenluft - Einflussfaktoren, Messverfahren, Bewertung''

Energy Technology Data Exchange (ETDEWEB)

Kemski, J.; Klingel, R.; Siehl, A.; Neznal, M.; Matolin, M.

2012-03-15

The report on ground air radon measurements covers the following issues: Introduction; Radon in the geogenic underground: emanation, migration, exhalation; Influencing factors: geochemical parameters, structural situation, geomorphology, exogenic effects; Ground air measurements: site exploration, tectonics, earth quake prognosis, radon in ground air and buildings; Radon measurement: sampling and measuring methods, error consideration, comparative measurements, practical examples; measuring regulations and recommendations; Variability of the radon concentration: temporal variation, sampling depth, spatial variations; Evaluation and conclusions.

Cost-benefit of ventilation and averted radon in dwellings

International Nuclear Information System (INIS)

Katona, T.; Kanyar, B.

2003-01-01

To assess an economically optimal ventilation rate we have introduced a cost-benefit analysis taking into account the cost of heating and benefit of averted dose due to ventilation. The cost of heating due to the elevated ventilation for mitigation of radon content in dwellings can be compensated by the monetary benefit of the averted dose, in case of higher (annually 3-10 mSv) exposure. During the heating season the economically optimal ventilation takes 0.1-0.5 h -1 , meanwhile the radon concentration in the indoor air decreases to 200-800 Bq/m 3 , depending on the exhalation of radon, number of persons living in the dwellings and other local parameters. Our results from the optimal planning correspond to the radon concentrations recommended by the international organizations as action levels. In general, the periodic ventilation in daytime provides a higher averted dose than the constant one in case of the same heating cost. (authors)

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

International Nuclear Information System (INIS)

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

2003-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2003-07-01

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

Comparison of Select Analytes in Exhaled Aerosol from E-Cigarettes with Exhaled Smoke from a Conventional Cigarette and Exhaled Breaths

Directory of Open Access Journals (Sweden)

Gerald A. Long

2014-10-01

Full Text Available Exhaled aerosols were collected following the use of two leading U.S. commercial electronic cigarettes (e-cigarettes and a conventional cigarette by human subjects and analyzed for phenolics, carbonyls, water, glycerin and nicotine using a vacuum-assisted filter pad capture system. Exhaled breath blanks were determined for each subject prior to each product use and aerosol collection session. Distribution and mass balance of exhaled e-cigarette aerosol composition was greater than 99.9% water and glycerin, and a small amount (<0.06% of nicotine. Total phenolic content in exhaled e-cigarette aerosol was not distinguishable from exhaled breath blanks, while total phenolics in exhaled cigarette smoke were significantly greater than in exhaled e-cigarette aerosol and exhaled breaths, averaging 66 µg/session (range 36 to 117 µg/session. The total carbonyls in exhaled e-cigarette aerosols were also not distinguishable from exhaled breaths or room air blanks. Total carbonyls in exhaled cigarette smoke was significantly greater than in exhaled e-cigarette aerosols, exhaled breath and room air blanks, averaging 242 µg/session (range 136 to 352 µg/session. These results indicate that exhaled e-cigarette aerosol does not increase bystander exposure for phenolics and carbonyls above the levels observed in exhaled breaths of air.

Prediction of the net radon emission from a model open pit uranium mine

International Nuclear Information System (INIS)

Nielson, K.K.; Perkins, R.W.; Schwendiman, L.C.; Enderlin, W.I.

1979-04-01

Radon emission from a model open pit uranium mining operation has been estimated by applying radon exhalation fluxes measured in an open pit uranium mine to the various areas of the model mine. The model mine was defined by averaging uranium concentrations and production and procedural statistics for eight major open pit uranium mines in the Casper, Wyoming area. The resulting emission rates were 740 Ci/AFR during mining operations and 33 Ci/AFR/yr after abandonment of the mine

Hourly indoor radon measurements in a research house.

Science.gov (United States)

Sesana, Lucia; Begnini, Stefania

2004-01-01

This paper reports and discusses the behaviour of radon concentration with time in an uninhabited dwelling. The relationship between variations in radon concentrations and indoor-outdoor temperatures and wind intensity has also been discussed. Radon concentration was measured hourly in a house located at a height of 800 m in the Lombard Prealps, at the top of the Valassina valley. The wind velocity and indoor-outdoor temperatures were measured by means of a meteorological station located on the terrace of the house. The data were analysed using the LBL model for indoor-outdoor air exchange and the models for the indoor accumulation of radon due to exhalation from building materials and pressure-driven infiltrations located underground. The role of wind and indoor-outdoor temperatures were analysed. The agreement of measurements with modelling clearly demonstrates the importance of the different sources of indoor radon. As the investigation was conducted in an uninhabited house, the measurements were not affected by the behaviour of people, e.g. opening and closing of windows. Measurements of the outdoor atmospheric concentrations of (222)Rn provide an index of the atmospheric stability, the formation of thermal inversions and convective turbulence.

Hourly indoor radon measurements in a research house

International Nuclear Information System (INIS)

Sesana, L.; Begnini, S.

2004-01-01

This paper reports and discusses the behaviour of radon concentration with time in an uninhabited dwelling. The relationship between variations in radon concentrations and indoor-outdoor temperatures and wind intensity has also been discussed. Radon concentration was measured hourly in a house located at a height of 800 m in the Lombard Pre-alps, at the top of the Valassina valley. The wind velocity and indoor-outdoor temperatures were measured by means of a meteorological station located on the terrace of the house. The data were analysed using the LBL model for indoor-outdoor air exchange and the models for the indoor accumulation of radon due to exhalation from building materials and pressure-driven infiltrations located underground. The role of wind and indoor-outdoor temperatures were analysed. The agreement of measurements with modelling clearly demonstrates the importance of the different sources of indoor radon. As the investigation was conducted in an uninhabited house, the measurements were not affected by the behaviour of people, e.g. opening and closing of windows. Measurements of the outdoor atmospheric concentrations of 222 Rn provide an index of the atmospheric stability, the formation of thermal inversions and convective turbulence. (authors)

Indoor randon concentration. Temperature and wind effects; Concentrazione di radon indoor. Effetto del vento e della temperatura

Energy Technology Data Exchange (ETDEWEB)

Sesana, L.; Benigni, S. [Milan Univ., Milan (Italy). Ist. di Fisica Generale Applicata

2000-12-01

The present study analyses and discusses the behaviour of the indoor radon concentration in a research house. Hourly measurements were carried out in the basement of the house from November 1998 up to June 1999. In many sequences of days radon concentration in the room under analysis shows strong variation all day long with accumulation in the evening and overnight and decrease in the morning and in the afternoon. Measurements of wind velocity, indoor and outdoor temperatures and outdoor-indoor pressure difference were performed and their trend is compared with the observed radon concentration. The exhalation of radon from walls, floor and ceiling and the pressure difference driven exhalation from the soil are discussed, particularly the relation with the temperature differences. The air exchange rates between the house and the outdoor air are studied. [Italian] Si analizza e si discute il comportamento della concentrazione di radon indoor nel seminterrato di una casa di ricerca. Misure orarie sono state effettuate da novembre 1998 a giugno 1999. In molte sequenze di giorni la concentrazione del radon nel locale in analisi presenta forti variazioni nel corso della giornata con un accumulo notturno e decrescita nelle ore diurne. Sono state eseguite misure della velocita' del vento, delle temperature outdoor e indoor e della differenza di pressione outdoor-indoor e il loro andamento e' stato confrontato con quello della concentrazione del radon. Vengono discusse l'esalazione del radon dalle pareti, dal pavimento e dal soffitto e l'esalazione pressure difference driven dal suolo. Il rateo dei ricambi d'aria tra il locale e l'aria outdoor e' studiato.

Modeling the dependency of radon concentration levels inside ancient Egyptian tombs on the ambient temperature variations

International Nuclear Information System (INIS)

Metwally, S.M.; Abo-Elmagdb, M.; Salamaa, E.

2007-01-01

Radon concentration inside partially closed places like dwellings, caves and tombs, depends on many parameters. Some parameters are known quantitatively as radon exhalation rate for walls, decay constant, surface to volume ratio and outdoor concentration while other parameters as ventilation rate is in common known qualitatively due to useless of traditional methods (tracer gases) in many places as ancient Egyptian tombs. This work introduces a derived mathematical model to evaluate the sensitivity of radon concentration levels inside single sided opening places as ancient Egyptian tombs on the ambient temperature differences. The obtained formula for the natural ventilation rate depends on the indoor and outdoor temperature difference and the geometrical dimensions of the doorway. The effects of in and out flow mixing, air viscosity, streamline contraction, swirling flow and turbulence, were taken into consideration in terms of an empirical correction factor. According UNSCEAR reports, the exhalation rate Φ=C ra λ rn fρ s (1-ε)L; C ra the effective radium content, λ rn decay constant, f emanation fraction, ρ s soil grain density, ε porosity and L diffusion length, these are approximately static parameters but the variability of ambient temperature introduces a source of energy of fluctuating strength to radon atoms in rocks which controls the flow rate and the ambient content of radon. Therefore, the change of outdoor and indoor temperature difference causes fluctuation of value and direction of volume flow rate in such places consequently causes the daily variation and on average the seasonal variation of radon concentration. Therefore according to the present model, the daily accurate expectation of radon concentrations inside ancient Egyptian tombs, require precise measurements of indoor and outdoor temperatures

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

Extensive radioactive characterization of a phosphogypsum stack in SW Spain: {sup 226}Ra, {sup 238}U, {sup 210}Po concentrations and {sup 222}Rn exhalation rate

Energy Technology Data Exchange (ETDEWEB)

Abril, Jose-Maria, E-mail: jmabril@us.es [Dpto. Fisica Aplicada I, Universidad de Sevilla, EUITA, Ctra Utrera Km 1, 41013 Seville (Spain); Garcia-Tenorio, Rafael, E-mail: gtenorio@us.es [Dpto. Fisica Aplicada II, Universidad de Sevilla, ETSA, Avda. Reina Mercedes s/n, 41012 Seville (Spain); Manjon, Guillermo, E-mail: manjon@us.es [Dpto. Fisica Aplicada II, Universidad de Sevilla, ETSA, Avda. Reina Mercedes s/n, 41012 Seville (Spain)

2009-05-30

Phosphogypsum (PG) is a by-product of the phosphate fertilizer industries that contains relatively high concentrations of uranium series radionuclides. The US-EPA regulates the agriculture use of PG, attending to its {sup 226}Ra content and to the {sup 222}Rn exhalation rate from inactive stacks. Measurements of {sup 222}Rn exhalation rates in PG stacks typically show a large and still poorly understood spatial and temporal variability, and the published data are scarce. This work studies an inactive PG stack in SW Spain of about 0.5 km{sup 2} from where PG can be extracted for agriculture uses, and an agriculture soil 75 km apart, being representative of the farms to be amended with PG. Activity concentrations of {sup 226}Ra, {sup 238}U and {sup 210}Po have been measured in 30 PG samples (0-90 cm horizon) allowing for the construction of maps with spatial distributions in the PG stack and for the characterization of the associated PG inputs to agriculture soils. Averaged {sup 226}Ra concentrations for the stack were 730 {+-} 60 Bq kg{sup -1} (d.w.), over the US-EPA limit of 370 Bq kg{sup -1}. {sup 222}Rn exhalation rate has been measured by the charcoal canister method in 49 sampling points with 3 canisters per sampling point. Values in PG stack were under the US-EPA limit of 2600 Bq m{sup -2} h{sup -1}, but they were one order of magnitude higher than those found in the agriculture soil. Variability in radon emissions has been studied at different spatial scales. Radon exhalation rates were correlated with {sup 226}Ra concentrations and daily potential evapotranspiration (ETo). They increased with ETo in agriculture soils, but showed an opposite behaviour in the PG stack.

The effect of laterite density on radon diffusion behavior.

Science.gov (United States)

Li, Yongmei; Tan, Wanyu; Tan, Kaixuan; Liu, Zehua; Fang, Qi; Lv, Junwen; Duan, Xianzhe; Liu, Zhenzhong; Guo, Yueyue

2018-02-01

Radon generated in porous media such as soils and rocks migrates into indoor and outdoor air mainly by diffusion, possessing significant hazards to human health. In order to reduce these hazards of radon, it is of great importance to study the diffusion behavior of radon. In this study, we systematically measured the radon diffusion coefficient of laterite with the density ranging from 0.917gcm -3 to 2.238gcm -3 , and studied the effect of laterite density on the radon diffusion. The results show that the radon diffusion coefficient of the laterite generally decreases with the increasing laterite density. In addition, three possible relationships between the radon diffusion coefficient and the laterite density are found out as follows: (1) the linear correlation with a slope of -4.48 × 10 -6 for laterite with density ranging from 0.917 to 1.095gcm -3 , (2) the exponential correlation for laterite with density from 1.095 to 1.63gcm -3 , (3) linear correlation with a slope of -3.1 × 10 -7 for laterite with density from 1.63 to 2.238gcm -3 . The complex relationship between the radon diffusion coefficient and density is caused by the change of porosity and tortuosity of the laterite. Therefore, we suggest that a suitable density should be adopted while using the laterite to effectively cover uranium tailings or economically produce building materials that can curb the radon exhalation. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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

2013-12-01

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

Radon-222 exhalation from Danish building materials: H + H Industri A/S results

DEFF Research Database (Denmark)

Andersen, Claus Erik

1999-01-01

rate measurements for 10 samples of Danish building materials are reported. Samples include ordinary concrete, lightweight aggregate concrete,autoclaved aerated concrete, bricks, and gypsum board. The maximum mass-specific exhalation rate is about 20 m Bq h"-"1 kg "-"1. Under consideration...

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.)

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

Science.gov (United States)

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

2003-04-01

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

Modeling the dependency of radon concentration levels inside ancient Egyptian tombs on the ambient temperature variations

Energy Technology Data Exchange (ETDEWEB)

Metwally, S M; Abo-Elmagdb, M [Faculty of Science, Department of Physics, Ain Shams University, P. O. Box 11566, Cairo (Egypt); Salamaa, E [National Institute for Standard, Radiation Measurements Department, Cairo (Egypt)

2007-06-15

Radon concentration inside partially closed places like dwellings, caves and tombs, depends on many parameters. Some parameters are known quantitatively as radon exhalation rate for walls, decay constant, surface to volume ratio and outdoor concentration while other parameters as ventilation rate is in common known qualitatively due to useless of traditional methods (tracer gases) in many places as ancient Egyptian tombs. This work introduces a derived mathematical model to evaluate the sensitivity of radon concentration levels inside single sided opening places as ancient Egyptian tombs on the ambient temperature differences. The obtained formula for the natural ventilation rate depends on the indoor and outdoor temperature difference and the geometrical dimensions of the doorway. The effects of in and out flow mixing, air viscosity, streamline contraction, swirling flow and turbulence, were taken into consideration in terms of an empirical correction factor. According UNSCEAR reports, the exhalation rate {phi}=C{sub ra}{lambda}{sub rn} f{rho}{sub s}(1-{epsilon})L; C{sub ra} the effective radium content, {lambda}{sub rn} decay constant, f emanation fraction, {rho}{sub s} soil grain density, {epsilon} porosity and L diffusion length, these are approximately static parameters but the variability of ambient temperature introduces a source of energy of fluctuating strength to radon atoms in rocks which controls the flow rate and the ambient content of radon. Therefore, the change of outdoor and indoor temperature difference causes fluctuation of value and direction of volume flow rate in such places consequently causes the daily variation and on average the seasonal variation of radon concentration. Therefore according to the present model, the daily accurate expectation of radon concentrations inside ancient Egyptian tombs, require precise measurements of indoor and outdoor temperatures.

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

International Nuclear Information System (INIS)

Clements, W.E.; Wilkening, M.

1981-01-01

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

Measurements of radon in drinking water (Curitiba, PR, Brazil)

International Nuclear Information System (INIS)

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

2009-01-01

Full text: Among the principle mechanisms that bring the radon inside the dwelling is the exhalation and release from the water. It was evaluated that considering the latest mechanism, the exhalation of radon from the water represents about 89% of the cancer risk and the consumption of water with high concentration of radon is related to about 11% of risk cancer. Radon concentration in water could be subject of different factors such as the geology of the area, bottom sediments and inputs from streams, temperature, atmospheric pressure, etc. It is well known that the solubility of radon in water is about 510 cm 3 kg -1 at 0 deg C and decreases at higher temperatures. The 222 Rn concentration in various types of natural water in different countries usually is about few Bq/L and is the subject of the National legislation as well as International norms and recommendations. For example, the United States Environmental Protection Agency (USEPA) established a limit of 11.1 Bq/L for the radon level in drinking water and this limit is considered as guideline in Canada and many countries of the European Union. Current work presents the results of more than 100 measurements of 222 Rn activity in drinking water collected at artesian bores at Curitiba region during the period of 2008 - 2009. The measurements were performed at the Laboratory of Applied Nuclear Physics of the Federal University of Technology in cooperation with the Nuclear Technology Development Center (CDTN) of Brazilian Nuclear Energy Committee (CNEN). Experimental setup was based on the Professional Radon Monitor (ALPHA GUARD) connected to specific kit of glass vessels Aqua KIT through the air pump. The equipment was adjusted with air flow of 0.5 L/min. The 222 Rn concentration levels were detected and analyzed by the computer using the software DataEXPERT by GENITRON Instruments. Collected average levels of 222 Rn concentration were processed taking into account the volume of water sample and its temperature

Soil radon profile of the Alhama de Murcia Fault: implications in tectonic segmentation

Science.gov (United States)

Bejar-Pizarro, M.; Perez Lopez, R.; Fernández Cortés, A.; Martínez-Díaz, J. J.; Staller, A.; Sánchez-Malo, A.; Sanz, E.; Cuezva, S.; Sánchez-Moral, S.

2017-12-01

Soil radon exhalation in active faults has been reported in several cases. Mobilization of radon gas in tectonic areas is related to CO2emission, acting as gas carrier from deeper fractured zones. Fluctuation of radon values can be correlated with earthquake occurrence. We have used the soil radon emission for characterizing different tectonic segment of the Alhama de Murcia Fault (FAM), one of the most active on-shore tectonic faults in Spain. The FAM is a NE-SW trending strike-slip fault with reverse component, 90 km long and it is capable to trigger M7 earthquakes, as far as several paleoseismic studies shown. The last destructive earthquake took place in 2011 and killed 9 people. Tectonic segmentation of this fault has been proposed, with a tectonic slip-rate close to 0.1 mm/yr from geomorphic evidence, whereas 0.5 mm/yr has been suggested from GPS geodetic measurements. We have developed a perpendicular profile for measuring the soil radon exhalation, in relationship with three principal segments of FAM from west to east: (1) Goñar-Lorca segment, (2) Lorca Totana segment and (3) Alhama segment. We have introduced radon passive detectors equipped with LR115 films in colluvium detritic deposits and at 0.8 m depth. Using detritic deposits affected by Quaternary fault movement we assure equal permeability conditions for radon transport. We used passive closed housings type DRF, with a filter that avoid thoron disturbance. Results show the largest values of radon emission close to the Quaternary surface ruptures (ca 3-5.5 kBq/m3). Furthermore, the Goñar segment exhibits the highest value (6 kBq/m3) although the Lorca segment shows an isotopic signal of 13dCO2 (-7.24‰) which indicates this is a mantle-rootled CO2, i.e. non-soil derived CO2 flux, likely related to CO2 produced by thermal decarbonation of underlying sedimentary rocks containing more marine carbonate minerals. These results are part of the combined Spanish projects GEIs-SUB (CGL2016- 78318-C2-1-R

Mapping geogenic radon potential by regression kriging

Energy Technology Data Exchange (ETDEWEB)

Pásztor, László [Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Department of Environmental Informatics, Herman Ottó út 15, 1022 Budapest (Hungary); Szabó, Katalin Zsuzsanna, E-mail: sz_k_zs@yahoo.de [Department of Chemistry, Institute of Environmental Science, Szent István University, Páter Károly u. 1, Gödöllő 2100 (Hungary); Szatmári, Gábor; Laborczi, Annamária [Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Department of Environmental Informatics, Herman Ottó út 15, 1022 Budapest (Hungary); Horváth, Ákos [Department of Atomic Physics, Eötvös University, Pázmány Péter sétány 1/A, 1117 Budapest (Hungary)

2016-02-15

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

Mapping geogenic radon potential by regression kriging

International Nuclear Information System (INIS)

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

2016-01-01

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

Implementation of radon measurements to evaluate the suitability of using cement containers for storing radioactive waste containing Ra-226

International Nuclear Information System (INIS)

Shweikani, R.; Kheituo, M.; Hushari, M.; Ali, A. F.

2003-12-01

This work aimed at studying radon diffusion through walls of cubic cement containers containing inside radioactive waste rich in Radium-226. In addition, the effect of the wall thickness on radon exhalation and external gamma exposure were also studded. Cubic cement molds were prepared with different dimensions ranged from 5 to 11 cm containing central cubic holes to contain the radioactive materials with dimensions ranged from 2 to 7 cm. The thicknesses of the walls were varied from 1 to 4 cm. Radon exhalation was studied by placing each pre-prepared cement specimen in a tightly closed glass container (desiccators, volume 7 liters) provided with input and output gas system circulation for one week. Active method (Lucas cell) was used to measure the concentration of radon in the container. It was noticed that radon concentration increased with the increase of the radioactive materials inside the specimens. This was simply explained as it is due to the increase of the amount of radium-226 in the specimen with will definitely lead to the increase of radon production. In addition, it was noticed that radon concentration were increased by increasing the thickness of the specimen wall for fixed amount of the radioactive materials inside. This result was unexpected. Therefore, many attempts were performed to explain it. For that, the mechanism of cement solidifications and structure of cement after solidification were studied. The conditions which affect the size and number of the formed pores in the specimens were also studied assuming that increasing the wall thickness will increase porosity and lead to the increase diffusion paths. It was concluded that it is possible to use the cubic cement containers to stop gamma radiation from the radioactive materials, but it is not possible to use them to stop radon unless special arrangements are performed. (author)

Time-scale invariant changes in atmospheric radon concentration and crustal strain prior to a large earthquake

Directory of Open Access Journals (Sweden)

Y. Kawada

2007-01-01

Full Text Available Prior to large earthquakes (e.g. 1995 Kobe earthquake, Japan, an increase in the atmospheric radon concentration is observed, and this increase in the rate follows a power-law of the time-to-earthquake (time-to-failure. This phenomenon corresponds to the increase in the radon migration in crust and the exhalation into atmosphere. An irreversible thermodynamic model including time-scale invariance clarifies that the increases in the pressure of the advecting radon and permeability (hydraulic conductivity in the crustal rocks are caused by the temporal changes in the power-law of the crustal strain (or cumulative Benioff strain, which is associated with damage evolution such as microcracking or changing porosity. As the result, the radon flux and the atmospheric radon concentration can show a temporal power-law increase. The concentration of atmospheric radon can be used as a proxy for the seismic precursory processes associated with crustal dynamics.

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

Science.gov (United States)

Gross, Eliza L.

2017-05-11

Results from 1,041 groundwater samples collected during 1986‒2015 from 16 geologic units in Pennsylvania, associated with 25 or more groundwater samples with concentrations of radon-222, were evaluated in an effort to identify variations in radon-222 activities or concentrations and to classify potential radon-222 exposure from groundwater and indoor air. Radon-222 is hereafter referred to as “radon.” Radon concentrations in groundwater greater than or equal to the proposed U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) for public-water supply systems of 300 picocuries per liter (pCi/L) were present in about 87 percent of the water samples, whereas concentrations greater than or equal to the proposed alternative MCL (AMCL) for public water-supply systems of 4,000 pCi/L were present in 14 percent. The highest radon concentrations were measured in groundwater from the schists, gneisses, and quartzites of the Piedmont Physiographic Province.In this study, conducted by the U.S. Geological Survey in cooperation with the Pennsylvania Department of Health and the Pennsylvania Department of Environmental Protection, groundwater samples were aggregated among 16 geologic units in Pennsylvania to identify units with high median radon concentrations in groundwater. Graphical plots and statistical tests were used to determine variations in radon concentrations in groundwater and indoor air. Median radon concentrations in groundwater samples and median radon concentrations in indoor air samples within the 16 geologic units were classified according to proposed and recommended regulatory limits to explore potential radon exposure from groundwater and indoor air. All of the geologic units, except for the Allegheny (Pa) and Glenshaw (Pcg) Formations in the Appalachian Plateaus Physiographic Province, had median radon concentrations greater than the proposed EPA MCL of 300 pCi/L, and the Peters Creek Schist (Xpc), which is in the Piedmont

Evaluation of exhaled nitric oxide in schoolchildren at different exhalation flow rates.

Science.gov (United States)

Pedroletti, Christophe; Zetterquist, Wilhelm; Nordvall, Lennart; Alving, Kjell

2002-09-01

Nitric oxide (NO) in exhaled air is believed to reflect allergic inflammation in the airways. Measured levels of exhaled NO vary with the exhaled flow rate, which therefore must be standardized. The aim of this study was to estimate the optimal exhalation flow rate when measuring NO in exhaled air. We studied 15 asthmatic children (8-18 y) with elevated NO levels and 15 age-matched controls and focused on how the quality of the NO curve profile, the discriminatory power, and the reproducibility were influenced by the exhalation flow rate. We used an on-line system for NO measurements at six different exhalation flow rates in the interval of 11-382 mL/s. The fraction of exhaled nitric oxide (FENO) was highly flow-dependent as was expected. Intermediate flow rates yielded a flat and stable NO plateau and were considerably easier to interpret than those obtained at the highest and lowest flow rates. The ratio of FENO between asthmatics and controls was lower at higher flow rates and a considerable overlap in NO values was demonstrated at all flow rates except 50 mL/s. The reproducibility was much lower at more extreme flow rates and was best at 50 mL/s. We conclude that a target exhalation flow rate of approximately 50 mL/s is to be preferred using the single-breath method for on-line NO measurements in schoolchildren.

Radiometric maps of Israel - Partial contribution to the understanding of potential radon emanations

International Nuclear Information System (INIS)

Vulkan, U.; Shirav, M.

1997-01-01

An airborne radiometric survey over parts of Israel was carried out in 1981. The system was comprised from 10 Nal 4 inch x 4 inch x 16 inch detectors, arranged in 4,4 and 2 sensors, with total volume of 1560 inch 3 , and one 4 inch x 4 inch x 16 inch uplooking Nal detector. Flight nominal height was 400 feet. It was found that the Mount Scopus Group (of Senonian origin) is the main source for high uranium - phosphorite rocks of this group contain up to 150 ppm U. Comparing the eU radiometric map with a map of potential radon emanation from rock units, reveals a fair correlation - high radon emanation usually follow the distribution of the Mount Scopus Group in Israel. The correlation between the two maps is excellent over arid terrain where soil cover is missing, whereas over semi-arid - humid areas (western and northern Israel), where soil and cultivation covers are developed, the eU levels over Mount Scopus Group's outcrops are much lower due to absorption of the radiation, and do not depict the full radon potential. Detailed mapping of radon hazards usually exhibit poor correlation between airborne eU data and direct pore radon measurements, even in arid terrain. This phenomenon is attributed to the fact that a radon ''source rock'' (e.g. phosphorite) could be covered with a few up to some tenths of meters of uranium-barren rock. About 0.5 meter cover is enough to absorb all radiation, causing very low airborne eU readings, while the radon free way in this rock is about 10 meters, yielding high pore radon levels when directly measured

Sources and transport of indoor radon

International Nuclear Information System (INIS)

Aldenkamp, F.J.; Stoop, P.

1994-01-01

An approach in the investigation was to use a multi-compartment model of a home describing the processes that determine how radon concentrations in dwellings are established. Because the model describes Rn-222 concentrations in terms of airflows and sources, the experimental research was focused on the measurement of these three quantities. Development, calibration and assessment of the instrumentation played a major role. The experiments involved measurements of Rn-222 exhalation of buildings materials and the soil underneath the house, Rn-222 concentrations in air and airflows between various parts of the house and between the inside and outside of the house. (DG)

Radon in the environment and the dwellings - a review of measurements carried out in France by IPSN

International Nuclear Information System (INIS)

Robe, M.C.; Rannou, A.; Le Bronec, J.

1992-01-01

Over the last decade, the monitoring of radon gas in various natural environments and regions of France has allowed the IPSN to construct a radon data base. In holes drilled in soils and in underground cavities, radon concentrations between a few hundred Bq.m -3 and many thousands Bq.m -3 were measured. Exhalation rates between 10 -3 and 50 mBq.m -2 .s -1 were measured in different regions and for different types of soil. In the open air, mean levels were observed in the range of a few Bq.m -3 to several hundred Bq.m -3 and concentrations as high as one thousand Bq.m -3 were measured over short periods. (author)

Contribution of radon and radon daughters to respiratory cancer

International Nuclear Information System (INIS)

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

1986-01-01

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

Potential study of bed filtration characteristics in impressed boreholes by radon tracer technique

International Nuclear Information System (INIS)

Litvinov, A.A.; Pinkenzon, D.B.; Makarov, M.S.; Vinarskij, M.S.

1977-01-01

Potential study of bed filtration characteristics in impressed boreholes by radon tracer method is shown. Effects recorded by radon tracer result from gamma radiation of short-living radon decay daughter products. During filtration of tracer through punched holes, cement stone, and rocks the products are deposited and cause a local effect for 2-3 hours. There is a shortage of short-living products in filtrated radon liquid and for some time (which is necessary for production of notable quantity of new decay products) it is practically not a gamma emitter. It is shown that the feature of effect formation governs the technique for well logging as well as interpretation of the results obtained

Radiation burden in dwelling-houses by Radon and its daughter elements

International Nuclear Information System (INIS)

Hofmann, W.

1982-01-01

The content of 222 Rn and its short-lived decay products in room air shows large local as well as temporal fluctuations. The local differences are caused mainly by the concentration of 226 Ra in building materials and the exhalation of radon from the walls. Temporal variations result from varying ventilation conditions and changing meteorological parameters. The influence of all these factors on the natural radiation burden of man is discussed. (Author) [de

Radon as a geophysical tracer on Mars: study of its transport, first evidence and development of an instrument for its measurement

International Nuclear Information System (INIS)

Meslin, Pierre-Yves

2008-01-01

Radon-222, an inert and radioactive gas stemming from the uranium decay series, and its progeny are often used as tracers to study transfers in soils and in the atmosphere. They have also been studied on the surface of the Moon in connection with lunar outgassing. On Mars, where radon has never been studied nor measured so far, we show that their measurement could provide new insight and constraints on the chemical nature of the hydrogen measured in the Martian soil, in surface-atmosphere exchange processes, in atmospheric transport and, finally, in the dust cycle. Our approach is based on a coupled soil-atmosphere transport model implemented into the Global Circulation Model LMDZ. It includes the source term, the diffusion and adsorption of radon within the soil, and its atmospheric transport. The model input parameters are derived either experimentally (emanation factor and adsorption coefficient extrapolated to low temperatures) or by realistic models of porous media (diffusion coefficient at low pressure and as a function of the water saturation level). The model yields predictive maps of the radon exhalation rate as well as 3D fields of concentration in the soil and atmosphere, which will allow direct comparison with bismuth-214 measurements made by the GRS onboard the Mars Odyssey orbiter. We present preliminary results on this subject. An analysis of alpha spectra acquired by the APXS of the rover Opportunity is also presented, which shows evidence of a polonium-210 deposit on atmospheric dust, providing the first indirect proof of the presence of radon in the Martian atmosphere. We propose a simplified dust cycle model that enables us to infer an estimate of the global average radon exhalation rate on Mars. Lastly, we simulate the performance of an alpha spectrometer aimed at measuring radon and its progeny on the surface of the planet. (author)

Radon transport modelling: User's guide to RnMod3d

International Nuclear Information System (INIS)

Andersen, C.E.

2000-08-01

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

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

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)

Prediction of the net radon emission from a model open pit uranium mine

International Nuclear Information System (INIS)

Nielson, K.K.; Perkins, R.W.; Schwendiman, L.C.; Enderlin, W.I.

1979-09-01

Radon emission from a model open pit uranium mining operation has been estimated by applying radon exhalation fluxes measured in an open pit uranium mine to the various areas of the model mine. The model mine was defined by averaging uranium concentrations, mine dimensions, production and procedural statistics for eight major open pit uranium mines in the Casper, Wyoming area. The resulting emission rates were 630 Ci/RRY (1 RRY one = 1000-MW(e) reactor operating for 1 year) during mining operations and 26 Ci/RRY/y after abandoment of the mine assuming 100% recovery of U 3 O 8 from the ore, or 700 Ci/RRY and 29 Ci/RRY/y assuming 90.5% recovery

Norm in coal, fly ash and cement

International Nuclear Information System (INIS)

Kant, K.; Upadhyay, S.B.; Sharma, G.S.

2006-01-01

Coal is technologically important materials being used for power generation and its cinder (fly ash) is used in manufacturing of bricks, sheets, cement, land filling etc. 222 Rn (radon) and its daughters are the most important radioactive and potentially hazardous elements, which are released in the environment from the naturally occurring radioactive material (NORM) present in coal, fly ash and cement. Thus it is very important to carry out radioactivity measurements in coal, fly ash and cement from the health and hygiene point of view. Samples of coal and fly ash from different thermal power stations in northern India and various fly ash using establishments and commercially available cement samples (O.P.C. and P.P.C.) were collected and analyzed for radon concentration and exhalation rates. For the measurements, alpha sensitive LR-115 type II plastic track detectors were used. The radon concentration varied from 147 Bq/m 3 to 443 Bq/m 3 , the radium concentration varied from 1.5 to 4.5 Bq/kg and radon exhalation rate varied from 11.8 mBq.kg -1 .h -1 to 35.7 mBq.kg -1 .h -1 for mass exhalation rate and from 104.5 mBq.m -2 .h -1 to 314.8 mBq.m -2 .h -1 for surface exhalation rate in coal samples. The radon concentration varied from 214 Bq/m 3 to 590 Bq/m 3 , the radium concentration varied from 1.0 to 2.7 Bq/kg and radon exhalation rate varied from 7.8 mBq.kg -1 .h -1 to 21.6 mBq.kg -1 .h -1 for mass exhalation rate and from 138 mBq m -2 h -1 to 380.6 mBq.m -2 .h -1 for surface exhalation rate in fly ash samples. The radon concentration varied from 157.62 Bq/m 3 to 1810.48 Bq/m 3 , the radium concentration varied from 0.76 Bq/kg to 8.73 Bq/kg and radon exhalation rate varied from 6.07 mBq.kg -1 .hr -1 to 69.81 mBq.kg -1 .hr -1 for mass exhalation rate and from 107.10 mBq.m -2 .hr -1 to 1230.21 mBq.m -2 .hr -1 for surface exhalation rate in different cement samples. The values were found higher in P.P.C. samples than in O.P.C. samples. (authors)

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

Science.gov (United States)

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

2015-11-01

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

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/

BGS Radon Protective Measures GIS

International Nuclear Information System (INIS)

Appleton, D.; Adlam, K.

2000-01-01

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

Measuring radon flux across active faults: Relevance of excavating and possibility of satellite discharges

Energy Technology Data Exchange (ETDEWEB)

Richon, Patrick, E-mail: patrick.richon@cea.f [CEA, DAM, DIF, F-91297 Arpajon (France); Institut de Physique du Globe de Paris, Equipe Geologie des Systemes Volcaniques, 4 place Jussieu, UMR-7154 CNRS, F-75005 Paris (France); Klinger, Yann; Tapponnier, Paul [Institut de Physique du Globe de Paris, Equipe de Seismotectonique, 4 place Jussieu, UMR-7154 CNRS, F-75005 Paris (France); Li Chenxia [Institute of Geology, Chinese Earthquake Administration, P.O. Box 9803, 100029 Beijing (China); Van Der Woerd, Jerome [Institut de Physique du Globe de Strasbourg, CNRS, UMR-7516, INSU, Universite Louis Pasteur, Strasbourg I, 5 Rue Rene Descartes, F-67084 Strasbourg Cedex (France); Perrier, Frederic [Institut de Physique du Globe de Paris, Equipe de Geomagnetisme, 4 place Jussieu, UMR-7154 CNRS et Universite Paris 7 Denis-Diderot, F-75005 Paris (France)

2010-02-15

Searching for gas exhalation around major tectonic contacts raises important methodological issues such as the role of the superficial soil and the possible long distance transport. These effects have been studied on the Xidatan segment of the Kunlun Fault, Qinghai Province, China, using measurement of the radon-222 and carbon dioxide exhalation flux. A significant radon flux, reaching up to 538 +- 33 mBq m{sup -2} s{sup -1} was observed in a 2-3 m deep trench excavated across the fault. On the soil surface, the radon flux varied from 7 to 38 mBq m{sup -2} s{sup -1}, including on the fault trace, with an average value of 14.1 +- 1.0 mBq m{sup -2} s{sup -1}, similar to the world average. The carbon dioxide flux on the soil surface, with an average value of 12.9 +- 3.3 g m{sup -2} day{sup -1}, also remained similar to regular background values. It showed no systematic spatial variation up to a distance of 1 km from the fault, and no clear enhancement in the trench. However, a high carbon dioxide flux of 421 +- 130 g m{sup -2} day{sup -1} was observed near subvertical fractured phyllite outcrops on a hill located about 3 km north of the fault, at the boundary of the large-scale pull-apart basin associated with the fault. This high carbon dioxide flux was associated with a high radon flux of 607 +- 35 mBq m{sup -2} s{sup -1}. These preliminary results indicate that, at the fault trace, it can be important to measure gas flux at the bottom of a trench to remove superficial soil layers. In addition, gas discharges need to be investigated also at some distance from the main fault, in zones where morphotectonics features support associated secondary fractures.

Feasibility and potential utility of multicomponent exhaled breath analysis for predicting development of radiation pneumonitis after stereotactic ablative radiotherapy.

Science.gov (United States)

Moré, Jayaji M; Eclov, Neville C W; Chung, Melody P; Wynne, Jacob F; Shorter, Joanne H; Nelson, David D; Hanlon, Alexandra L; Burmeister, Robert; Banos, Peter; Maxim, Peter G; Loo, Billy W; Diehn, Maximilian

2014-07-01

In this prospective pilot study, we evaluated the feasibility and potential utility of measuring multiple exhaled gases as biomarkers of radiation pneumonitis (RP) in patients receiving stereotactic ablative radiotherapy (SABR) for lung tumors. Breath analysis was performed for 26 patients receiving SABR for lung tumors. Concentrations of exhaled nitric oxide (eNO), carbon monoxide (eCO), nitrous oxide (eN2O), and carbon dioxide (eCO2) were measured before and immediately after each fraction using real-time, infrared laser spectroscopy. RP development (CTCAE grade ≥2) was correlated with baseline gas concentrations, acute changes in gas concentrations after each SABR fraction, and dosimetric parameters. Exhaled breath analysis was successfully completed in 77% of patients. Five of 20 evaluable patients developed RP at a mean of 5.4 months after SABR. Acute changes in eNO and eCO concentrations, defined as percent changes between each pre-fraction and post-fraction measurement, were significantly smaller in RP versus non-RP cases (p = 0.022 and 0.015, respectively). In an exploratory analysis, a combined predictor of baseline eNO greater than 24 parts per billion and acute decrease in eCO less than 5.5% strongly correlated with RP incidence (p =0.0099). Neither eN2O nor eCO2 concentrations were significantly associated with RP development. Although generally higher in patients destined to develop RP, dosimetric parameters were not significantly associated with RP development. The majority of SABR patients in this pilot study were able to complete exhaled breath analysis. Baseline concentrations and acute changes in concentrations of exhaled breath components were associated with RP development after SABR. If our findings are validated, exhaled breath analysis may become a useful approach for noninvasive identification of patients at highest risk for developing RP after SABR.

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

Science.gov (United States)

Rybalkin, Andrey

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

Variation of radon flux along active fault zones in association with earthquake occurrence

International Nuclear Information System (INIS)

Papastefanou, C.

2010-01-01

Radon flux measurements were carried out at three radon stations along an active fault zone in the Langadas basin, Northern Greece by various techniques for earthquake prediction studies. Specially made devices with alpha track-etch detectors (ATDs) were installed by using LR-115, type II, non-strippable cellulose nitrate films (integrating method of measurements). Continuous monitoring of radon gas exhaling from the ground was also performed by using silicon diode detectors, Barasol and Clipperton type, in association with various probes and sensors including simultaneously registration of the meteorological parameters, such as precipitation height (rainfall events), temperature and barometric pressure. The obtained radon data were studied in parallel with the data of seismic events, such as the magnitude, M L of earthquakes, the epicentral distance, the hypocentral distance and the energy released during the earthquake event occurred at the fault zone during the period of measurements to find out any association between the rad on flux and the meteorological and seismological parameters. Seismic events with magnitude M L ≥ 4.0 appeared to be preceded by large precursory signals produced a well-defined 'anomaly' (peak) of radon flux prior to the event. In the results, the radon peaks in the obtained spectra appeared to be sharp and narrow. The rise time of a radon peak, that is the time period from the onset of a radon peak until the time of radon flux maximum is about a week, while the after time, that is the time interval between the time of radon flux maximum and the time of a seismic event ranges from about 3 weeks or more.

Radon emanation fractions from concretes containing fly ash and metakaolin.

Science.gov (United States)

Taylor-Lange, Sarah C; Juenger, Maria C G; Siegel, Jeffrey A

2014-01-01

Radon ((222)Rn) and progenies emanate from soil and building components and can create an indoor air quality hazard. In this study, nine concrete constituents, including the supplementary cementitious materials (SCMs) fly ash and metakaolin, were used to create eleven different concrete mixtures. We investigated the effect of constituent radium specific activity, radon effective activity and emanation fraction on the concrete emanation fraction and the radon exhalation rate. Given the serious health effects associated with radionuclide exposure, experimental results were coupled with Monte Carlo simulations to demonstrate predictive differences in the indoor radon concentration due to concrete mixture design. The results from this study show that, on average, fly ash constituents possessed radium specific activities ranging from 100 Bq/kg to 200 Bq/kg and emanation fractions ranging from 1.1% to 2.5%. The lowest emitting concrete mixture containing fly ash resulted in a 3.4% reduction in the concrete emanation fraction, owing to the relatively low emanation that exists when fly ash is part of concrete. On average, the metakaolin constituents contained radium specific activities ranging from 67 Bq/kg to 600 Bq/kg and emanation fractions ranging from 8.4% to 15.5%, and changed the total concrete emanation fraction by roughly ±5% relative to control samples. The results from this study suggest that SCMs can reduce indoor radon exposure from concrete, contingent upon SCM radionucleotide content and emanation fraction. Lastly, the experimental results provide SCM-specific concrete emanation fractions for indoor radon exposure modeling. © 2013.

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)

Radon in the Gulf Coast area: Potential problem or exaggerated risk?

International Nuclear Information System (INIS)

Duex, T.W.

1994-01-01

Indoor air pollution from radon has been identified by the EPA as a serious health problem; estimates indicate that radon is the second leading cause of lung cancer (after smoking) and that high levels of radon may cause as many as 20,000 to 40,000 lung cancer deaths per year in the United States. Studies of the potential risk in the Gulf Coast have been sparse. This report summarizes over 7000 previously unreported radon analyses and relates them to geological information to identify possible problem areas for the Gulf Coast region of Louisiana, Texas, Mississippi, Alabama, and Florida. High levels of indoor radon are generally associated with older open-quotes crystallineclose quotes igneous and metamorphic bedrock; thus, most areas of the Gulf Coast are of relatively low risk because they are underlain by Cenozoic sedimentary rocks and unconsolidated deposits. However, some types of sedimentary deposits, such as open-quotes black shaleclose quotes and phosphate-rich rocks, can underlie areas of high risk. According to EPA indoor radon survey results the percentage of houses with screening levels greater than 4 pCi/1 (picocuries per liter) for given states is as follows: Alabama = 0.6%, Louisiana = 0.8%, Mississippi = 2.0%, and Texas = 4.0% (no data available for Florida). The data presented here for the percentage of houses with greater than 4 pCi/1 for given states is as follows: Alabama = 6.1 %, Louisiana = 0.6%, Mississippi = 2.0%, Texas = 1.6%, and Florida = 4.5%. The areas that appear to have the greatest risk are parts of northern Alabama and Mississippi, central Texas, and some areas in Florida

Radon exhalation and radiometric prospecting on rocks associated with Cu-U mineralizations in the Singhbhum shear zone, Bihar

Energy Technology Data Exchange (ETDEWEB)

Sengupta, D.; Kumar, Rajeev; Singh, A.K.; Prasad, Rajendra E-mail: aptolrp@amu.up.nic.in

2001-11-01

The Singhbhum thrust belt is a 200 km long arcuate orogenic belt in Bihar, eastern India. The huge mineral resources, viz. copper, uranium, magnetite, apatite and molybdenite, etc., make it significant from an economic as well as a geological point of view. The belt hosts three types of mineralization: sulphides of copper and other metals, uranium oxides and apatite-magnetite. Several distinct geological episodes are responsible for the evolution of mineralization and the thrust zone itself. Extensive and reliable radiometric prospecting and assaying have been carried out by us for the past 5 years from Dhobani in the east to Turamdih in the west of the Singhbhum shear zone. The present work indicates uranium mineralization in the Pathargora-Rakha area presently being mined for copper and also within areas in the vicinity of Bhatin. Studies on radon emanation have also been undertaken in some parts of the shear zone which indicate reasonably high radon emanation of the soils and rocks studied. This suggests the need for regular monitoring and suitable controls on the mine environment (air quality) and its vicinity. Radon emanation studies coupled with gamma-ray spectrometry and the subsequent modelling of the radiometric and radon measurements will help in the application of radon as a geophysical tracer in exploration of radioactive ore bodies and in radon risk assessment as well as in delineating active and passive faults and even in petroleum exploration.

Radon in Austria

International Nuclear Information System (INIS)

Friedmann, H.

2000-01-01

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

Radon potential mapping of the Tralee-Castleisland and Cavan areas (Ireland) based on airborne gamma-ray spectrometry and geology.

Science.gov (United States)

Appleton, J D; Doyle, E; Fenton, D; Organo, C

2011-06-01

The probability of homes in Ireland having high indoor radon concentrations is estimated on the basis of known in-house radon measurements averaged over 10 km × 10 km grid squares. The scope for using airborne gamma-ray spectrometer data for the Tralee-Castleisland area of county Kerry and county Cavan to predict the radon potential (RP) in two distinct areas of Ireland is evaluated in this study. Airborne data are compared statistically with in-house radon measurements in conjunction with geological and ground permeability data to establish linear regression models and produce radon potential maps. The best agreement between the percentage of dwellings exceeding the reference level (RL) for radon concentrations in Ireland (% > RL), estimated from indoor radon data, and modelled RP in the Tralee-Castleisland area is produced using models based on airborne gamma-ray spectrometry equivalent uranium (eU) and ground permeability data. Good agreement was obtained between the % > RL from indoor radon data and RP estimated from eU data in the Cavan area using terrain specific models. In both areas, RP maps derived from eU data are spatially more detailed than the published 10 km grid map. The results show the potential for using airborne radiometric data for producing RP maps.

Measurement of natural radioactivity contents in air and soil from Western, Haryana, India

International Nuclear Information System (INIS)

Mann, Nisha; Sushil Kumar; Amit Kumar; Garg, Ajay; Chauhan, R.P.

2015-01-01

Measurement of indoor radon and thoron is of importance because the radiation dose to human population due to inhalation of radon and its daughters contributes more than 50% of the total dose from natural sources. Thus it is important to study their levels in the dwellings and workplace. The gases are exhaled by soil and building materials due to presence of radium and thorium. One of the important index to find out the contribution of soil and building materials towards indoor radon is radon exhalation rates, which can be used for estimation of indoor radon levels. In present work the indoor radon and thoron levels from the air and radon exhalation rates from soil samples collected from the some districts (Sirsa, Hisar and Fatehabad) of North Haryana are reported. The indoor radon levels were measured by pin hole based radon thoron dosimeter and LR-115 solid state nuclear track detector while the radon exhalation rates from soil samples by well known canister techniques. The results show that indoor radon and thoron levels varied from 11 to 112 Bq/m 3 and 44 to 204 Bq/m 3 from the study area and within the ICRP safety limits. The radon mass exhalation rates from the soil sample varied from 12 to 37 mBq/kg/h. There exists a poor correlation between indoor radon and exhalation rates. An effort is made to explain the observed correlation. The results of the measurement are also compared with various National and International studies. (author)

Radon transport modelling: User's guide to RnMod3d

Energy Technology Data Exchange (ETDEWEB)

Andersen, C.E

2000-08-01

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

Investigations of radon and radon daughters in surficial aquifers of florida

International Nuclear Information System (INIS)

1991-05-01

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

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

International Nuclear Information System (INIS)

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

1983-07-01

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

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)

New devices for radon measurements

International Nuclear Information System (INIS)

Sevostyanov, V.N.

2004-01-01

This work includes the description of two new devices for radon surveys developed by the authors and produced in Kazakhstan. The first appliance is 'Ramon-Radon-01' used to measure 222 Rn radon in various mediums such as air, water, soil, and radon exhalation. The major advantage of the appliance lies in the absence of radioactive pollution in it after measurements. The appliances widely used in the CIS such as 'RAA-01', 'Alpharad' (produced by 'MTM Zaschita', Russia) and 'Alphaguard' (Germany) take samples directly to the measuring camera. For instance, the activity concentration of samples after they are taken by 'RAA-01' and 'Alpharad' is measured by means of electrostatic precipitation of RaA ( 218 Po) atoms to the square of semiconductor detector with subsequent registration of RaA alpha decay. The obvious disadvantage is that the subsequent measurement of relatively small 222 Rn activity concentration values after great values of 222 Rn activity concentration have been obtained requires a considerable exposure of the appliance sometimes exceeding 10 hours. Therefore, appliances register a relatively low value of the top measurement range of 20 KBq/m 3 . 'Alphaguard' has similar limitation resulting from precipitation of radon daughter decay products on the walls of ionizing chamber where radon activity concentration is measured. The radioactive lag of 'RAA-01', 'Alpharad' and 'Alphaguard' makes them of little use as well for automatic monitoring in the conditions of abruptly time negative derivatives on change of radon activity concentration. The second advantage is that 'Ramon-Radon-01', as opposed to above described appliances, registers almost zero radioactive lag, thanks to its constructive peculiarities which enable an abrupt increase of top range of measured value up to 5x10 5 Bq/m 3 , only limited by velocity of electron units of the appliance. The third advantage is that measurement discontinuity is determined only by time of full measurement cycle

Residents in a high radon potential geographic area: Their risk perception and attitude toward testing and mitigation

International Nuclear Information System (INIS)

Ferng, S.F.; Lawson, J.K.

1996-01-01

Boone County, Indiana was identified by the EPA as one of the high radon potential geographic areas. Health education campaigns are needed to prevent resident's unnecessary radon exposure. In order to design suitable programs, a questionnaire mail survey was conducted to measure socio-demographic characteristics of County resident's knowledge about radon, attitude toward radon testing and mitigation, support of education campaigns, and the best media to deliver radon education campaigns. A stratified random sampling method was applied for a total of 400 samples. The number of samples from each township/city was a proportion of their taxable parcels. The survey return rate was 39.8%. The data were analyzed by Epi Info and SPSS. The statistical significant level was set at α = 0.05. The results showed that resident's knowledge about radon was at a relatively superficial level. There was no association identified between the knowledge of radon and gender, age, family income, or education, except that females more frequently believed in false effects caused by radon. A significant correlation between radon knowledge and home radon tests was observed. Also found in this study was that respondents with better knowledge about diseases caused by radon had more confidence in radon mitigation actions. Newspaper was chosen by respondents as the most favorite media to deliver radon health education campaigns. Health education campaigns for the residents of Boone County might be conducted by local governments and/or other organizations

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

Energy Technology Data Exchange (ETDEWEB)

Ferry, C

2000-07-01

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

Experimental and theoretical study of radon levels in a house

Energy Technology Data Exchange (ETDEWEB)

Ameon, R.; Dupuis, M.; Marie, L.; Diez, O.; LionS, J. [Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-roses (France); Tymen, G. [LARAAH, Universite de Bretagne Occidentale, Brest (France)

2006-07-01

Full text of publication follows: Radon being a radioactive gas of natural origin is omnipresent everywhere at the surface of earth. It is created by the radium decay issued from the uranium contained in the earth crust and more specifically in granitic and volcanic subsoils. Because of the dilution due to air masses, its concentration in open air is low. On the other hand, radon may accumulate in the confined atmosphere of buildings and achieve high concentration levels. Across France, it has been estimated that 300 000 individual dwellings present concentration higher than the French reference level of 400 Bq.m{sup -3} and that 60 000 other ones would exhibit concentration above 1 000 Bq.m{sup -3}, the French warning threshold. Indoor radon concentration may vary significantly for various reasons, including design of buildings, radium content and texture of the soil in contact with the building's slab and walls, the under pressure value between the inside and outside and the fresh air supply rate. These considerations have led the I.R.S.N. to develop a code called R.A.D.O.N. 2 for conducting simple and methodical studies of indoor radon concentrations, to take into account the above-mentioned factors. But, the achievement of an effective diagnosis and risk management -aiding tool requires to first check its validity on the phenomenological model at the origin of the code. A 3-year experimental follow-up was, thus, conducted within an unoccupied house built on an uranium-bearing geological formation. After characterization of the subsoil, the instrumentation was implemented on site to continuously monitor the following parameters: - the radon source term in the building (exhalation rate of {sup 222}Rn at the ground/building interface and at soil surface, radon concentration at the soil and in outdoor air), - the radon penetration by advection (differential pressure in the house basement), - the driving mechanisms for natural ventilation in the house (weather

Experimental and theoretical study of radon levels in a house

International Nuclear Information System (INIS)

Ameon, R.; Dupuis, M.; Marie, L.; Diez, O.; LionS, J.; Tymen, G.

2006-01-01

Full text of publication follows: Radon being a radioactive gas of natural origin is omnipresent everywhere at the surface of earth. It is created by the radium decay issued from the uranium contained in the earth crust and more specifically in granitic and volcanic subsoils. Because of the dilution due to air masses, its concentration in open air is low. On the other hand, radon may accumulate in the confined atmosphere of buildings and achieve high concentration levels. Across France, it has been estimated that 300 000 individual dwellings present concentration higher than the French reference level of 400 Bq.m -3 and that 60 000 other ones would exhibit concentration above 1 000 Bq.m -3 , the French warning threshold. Indoor radon concentration may vary significantly for various reasons, including design of buildings, radium content and texture of the soil in contact with the building's slab and walls, the under pressure value between the inside and outside and the fresh air supply rate. These considerations have led the I.R.S.N. to develop a code called R.A.D.O.N. 2 for conducting simple and methodical studies of indoor radon concentrations, to take into account the above-mentioned factors. But, the achievement of an effective diagnosis and risk management -aiding tool requires to first check its validity on the phenomenological model at the origin of the code. A 3-year experimental follow-up was, thus, conducted within an unoccupied house built on an uranium-bearing geological formation. After characterization of the subsoil, the instrumentation was implemented on site to continuously monitor the following parameters: - the radon source term in the building (exhalation rate of 222 Rn at the ground/building interface and at soil surface, radon concentration at the soil and in outdoor air), - the radon penetration by advection (differential pressure in the house basement), - the driving mechanisms for natural ventilation in the house (weather conditions, indoor

Radon concentration and exhalation measurements with semiconductor detector and electrostatic precipitator working in a closed circulation system

International Nuclear Information System (INIS)

Wojcik, M.; Morawska, L.

1982-01-01

An apparatus is described and a method presented for the determination of concentration of radon emanated from solid and liquid samples. In this method an object or a sample of air is closed in an hermetically sealed chamber. The air contaminated by radon and its daughters is circulated in a closed system a few times through an electrostatic precipitator mounted in one housing with a semiconductor Si Li detector. The concentration of radon is determined by the alpha activity measurement of its daughters. The sensitivity of the apparatus is very high. While calculating a radon concentration from an activity measurement of RaA (fast method) the sensitivity is about 0.07 pCi/l and when measuring the activity of RaC' (slow method) it is 0.008 pCi/l. Due to the application of an electrostatic precipitator and a silicon detector it is possible to perform alpha spectrometric measurements and thus separate activities of RaA, RaC', and ThC and to calculate 222 Rn or 220 Rn concentrations. The efficiency of RaA, RaB, RaC, ThB and ThC collection is constant, due to the method involving the circulation of the air through the electrostatic precipitator several times. (author)

Hydrogeological controls of radon in a few hot springs in the Western Ghats at Ratnagiri district in Maharashtra, India

International Nuclear Information System (INIS)

Ansari, Md. Arzoo; Sharma, Suman; Saravana Kumar, U.; Chatterjee, Sitangshu; Diksha; Low, Upananda

2014-01-01

Geological structures (faults, fractures and weak zones) and high heat flow in geothermal areas allow easy passage for release of radon gas to the atmosphere. Radon is constantly transported from the Earth's interior and vented out through exhalation points at permeable fault zones. 222 Rn concentrations were measured in a few hot springs and nearby groundwater using RAD7 at Tural and Rajwadi, Ratnagiri district, Maharashtra. The 222 Rn concentrations in the hot springs vary from 1087 ± 132 to 1655 ± 177 Bq/m 3 at Tural and from 152 ± 67 to 350 ± 82 Bq/m 3 at Rajwadi. Groundwaters from wells within a radius of 200 m around the geothermal fields have radon concentration between 1087 ± 132 and 5445 ± 337 Bq/m 3 . We have assessed the radon activity in the vicinity of the hot springs to understand their hydrogeological control, origin of heat source and possible effect on the tourist and the human population residing nearby. (author)

Preliminary Monitoring of Soil gas Radon in Potentially Active Faults, San Sai District, Chiang Mai Province, Thailand

Science.gov (United States)

Pondthai, P.; Udphuay, S.

2013-05-01

The magnitude of 5.1 Mw earthquake occurred in San Sai District, Chiang Mai Province, Thailand in December 2006 was considered an uncommon event due to the fact that there was no statistical record of such significant earthquake in the area. Therefore the earthquake might have been associated with a potentially active fault zone within the area. The objective of this study is to measure soil gas radon across this unknown fault zone within the Chiang Mai Basin, northern Thailand. Two profiles traversing the expected fault zone of soil gas radon measurements have been monitored, using TASTRAK solid state track nuclear detectors (SSNTDs). Radon signals from three periods of measurement show a distinctive consistent spatial distribution pattern. Anomalous radon areas along the profiles are connected to fault locations previously interpreted from other geophysical survey results. The increased radon signal changes from the radon background level with the signal-to-background ratio above 3 are considered anomalous. Such pattern of radon anomaly supports the existence of the faults. The radon measurement, therefore is a powerful technique in mapping active fault zone.

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.; Schmied, H.; Clavensjoe, B.

1984-01-01

The general principles and mechanism of how soil gas infiltrates and carries radon from the foundation bed and subsoil into buildings are discussed. The Swedish Building Research Council has funded experiments and evaluation of cost effective remedial actions. The work has concerned existing dwellings with high concentration of radon, resulting from infiltrating soil gas and/or exhalation from building materials. A review and evaluation is given of experience and results acquired up to the summer of 1984. 100 dwellings have been constructed with consideration of possible infiltration of soil gas. In general minor modifications are sufficient to prevent infiltration. (Author)

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

International Nuclear Information System (INIS)

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

1999-01-01

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

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

CERN Document Server

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

1999-01-01

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

Laboratory research on tailings stabilization methods and their effectiveness in radiation containment

International Nuclear Information System (INIS)

Macbeth, P.J.; Jensen, C.M.; Rogers, V.C.; Overmyer, R.F.

1978-04-01

This report describes a study of various methods, techniques, and materials for stabilizing uranium mill tailings to reduce radon exhalation. Radon emanation from tailings particles, radon exhalation from tailings, and methods that could be used to reduce radon exhalation from tailings piles are discussed. Surface radon flux and soil gas concentrations were measured in experiment chambers or columns consisting of uranium tailings and various types and thicknesses of cover materials. The applicability of diffusion theory was examined and effective diffusion coefficients were determined for clay, soil, and sand. The variation of radon flux with atmospheric effects and moisture also was investigated. The effectiveness of several types of chemical stabilizers for both volumetric and surface application in reducing radon exhalation is reported. Some volumetric stabilizers reduced radon flux by 90 percent or more. Radon flux was determined through the use of charcoal gas mask canisters, and flux accumulation chambers sampled by Lucas cells. Both of these techniques are described. Soil gas concentration was sampled with Lucas cells and counted with a sodium iodide scintillation spectrometer system. Emanating power of uranium tailings was measured for several particle sizes and found to be relatively constant at about 20 percent. Two types of grasses were found that would grow in tailings if sufficient water and fertilizer were provided. The effect of vegetation on radon exhalation was not determined

Survey of radon in dwellings in area strongly affected by mining

International Nuclear Information System (INIS)

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

2002-01-01

shallow depths should enable easy migration of radon gas and its penetration into houses. Moreover numerous faults and other tectonic dislocations occur in this area. Also tremors, caused with underground excavation, might increase radon exhalation. (author)

Radon baseline monitoring around a potential shale gas development site in Yorkshire, England

International Nuclear Information System (INIS)

Daraktchieva, Z.; Wasikiewicz, J. M.; Howarth, C. B.; Bradley, E.J.

2017-01-01

The Vale of Pickering in Yorkshire, England has been identified as a potential area for shale gas extraction. Public Health England joined a collaboration led by the British Geological Survey for environmental baseline monitoring near the potential shale gas extraction site following a grant award from UK Government Department for Business, Energy and Industrial Strategy. The analysis of results for the first 6 months of indoor monitoring indicated that the results followed a log-normal distribution. The numbers of homes found to be at or above the Action Level followed the numbers predicted by the radon potential maps. The results from the measurements of outdoor air in this study indicated that the radon concentrations are slightly higher than previously measured but close to the detection limit of the technique. (authors)

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-07-01

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

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.

Factors influencing upstairs and downstairs radon levels in two-storey dwellings

International Nuclear Information System (INIS)

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

2006-01-01

Environmental radon exposure of residents of two-storey domestic premises is generally estimated on the basis of the measured radon concentrations in, and the relative occupancies of, the principal living-room and bed-room, assuming 45% and 55% occupancy of these two locations respectively. In practice, however, significant case-to-case variability exists, both in the relative periods that individuals spend in the upstairs and downstairs rooms of two-storey homes, and in the relative radon levels in these two areas. Moreover, while it is assumed that radon levels in upper storeys of multi-storey homes will be intrinsically lower than at ground level, this is not always the case, since radon exhalation from the materials from which the house is constructed may contribute significantly to indoor levels. While studies on radon level variability in the individual units in apartment blocks have been reported, the situation in two-storey low-rise dwellings appears not to have been considered. To investigate this, detailed extended measurements of radon concentrations were made in a set of thirty-four homes situated in areas of Northamptonshire known to exhibit high radon levels and declared a radon Affected Area by the United Kingdom (UK) National Radiological Protection Board (NRPB) in 1992. All homes were of typical UK construction of brick/block/stone walls under a pitched tile/slate roof. Approximately 50% of the sample were detached houses, the remainder being semidetached (duplex) or terraced (row-house). Around 25% of the sample possessed cellars, while 12% were single-storey dwellings. In two-storey homes, all monitored bedrooms were on the upper floor. Distribution of the ratios of bedroom/living-room radon levels in individual properties was left-skewed (mean 0.67, median 0.73, range 0.05 to 1.05). The mean is consistent with the outcome of early NRPB studies in England, while the variability depends principally on the characteristics of the property, and not

Factors influencing upstairs and downstairs radon levels in two-storey dwellings

Energy Technology Data Exchange (ETDEWEB)

Denman, A.R.; Groves-Kirkby, C.J.; Groves-Kirkby, N.P. [Northampton General Hospital, Medical Physics Dept. (United Kingdom); Crockett, R.G.M.; Phillips, P.S.; Woolridge, A.C. [Northampton Univ., School of Applied Sciences (United Kingdom); Woolridge, A.C. [Northampton Univ., School of Health (United Kingdom)

2006-07-01

Environmental radon exposure of residents of two-storey domestic premises is generally estimated on the basis of the measured radon concentrations in, and the relative occupancies of, the principal living-room and bed-room, assuming 45% and 55% occupancy of these two locations respectively. In practice, however, significant case-to-case variability exists, both in the relative periods that individuals spend in the upstairs and downstairs rooms of storey homes, and in the relative radon levels in these two areas. Moreover, while it is assumed that radon levels in upper storeys of multi-storey homes will be intrinsically lower than at ground level, this is not always the case, since radon exhalation from the materials from which the house is constructed may contribute significantly to indoor levels. While studies on radon level variability in the individual units in apartment blocks have been reported, the situation in two-storey low-rise dwellings appears not to have been considered. To investigate this, detailed extended measurements of radon concentrations were made in a set of thirty-four homes situated in areas of Northamptonshire known to exhibit high radon levels and declared a radon Affected Area by the United Kingdom (UK) National Radiological Protection Board (NRPB) in 1992. All homes were of typical UK construction of brick/block/stone walls under a pitched tile/slate roof. Approximately 50% of the sample were detached houses, the remainder being semidetached (duplex) or terraced (row-house). Around 25% of the sample possessed cellars, while 12% were single-storey dwellings. In two-storey homes, all monitored bedrooms were on the upper floor. Distribution of the ratios of bedroom/living-room radon levels in individual properties was left-skewed (mean 0.67, median 0.73, range 0.05 to 1.05). The mean is consistent with the outcome of early NRPB studies in England, while the variability depends principally on the characteristics of the property, and not on

Study of Behavior and detection of radon in environmental samples by scintillation method. Application for radium

International Nuclear Information System (INIS)

ZAFIMANJATO, J.L.R.

2007-01-01

Radon is considered as the major source of radiological exposure of natural radiations to the population. On an international scale, it represents about the half of exposures of natural radiation sources (UNSCEAR, 1993) Radon gets into human body with inhaled air and sometimes with drinking water. Then, the objective of this work is to know the radon concentrations in water and in indoor atmosphere, and the risk in order to set up a method of monitoring and to identify high radon level areas. A specific method of detection using liquid scintillation with special emphasis on α/β discrimination, the use of solvent extractive and enrichment of radionuclides have been developed for the determination of both 222 Rn and 226 Ra in water. The method is simple, rapid and sensitive. In a pilot project for a monitoring of drinking water in Madagascar, it was shown that the proposed method was suitable for a large scale monitoring and routine analysis. Considerable concentrations of radon were found in water and air samples from Vinaninkarena. Radon concentrations obtained by in situ and in laboratory measurements have been compared to the results of an international intercomparison campaigns organised by the German Society for Liquid Scintillation Spectrometry in 2011. A theoretical study of the behavior of radon is porous material containing radium is detailed in order to describe its exhalation phenomena. An assessment model of the dose due to ingestion and liberation of radon from water is presented and compared with other models especially to the Crawford Brown's model. [fr

Calibration of CR-39 for radon-related parameters using sealed cup technique

International Nuclear Information System (INIS)

Abo-Elmagd, M.; Daif, M. M.

2010-01-01

Effective radium content, mass and areal radon exhalation rates of soil and rock samples are important radon-related parameters and can be used as a better indicator of radon risk. A sealed cup fitted to a CR-39 detector and to the sample under measurement is an advantageous passive device for the measurement of these parameters. The main factors affecting the results are the detector calibration factor and the sample weight. The results of an active technique (Lucas cell) and the CR-39 detector have been found to be correlated resulting in a reliable detector calibration factor. The result illustrates the dependence of the CR-39 calibration factor with the sample weight which is difficult to use in practice, because each sample weight has its own calibration factor of CR-39. It is reported to demonstrate the advantage of a back diffusion correction. After correcting the results for back diffusion effects, one obtains an approximately constant calibration factor for the sample volumes up to one-third the total sealed cup volume. For this condition the calibration factor is equal to 0.237 track cm -2 per Bq m -3 d with about 1% uncertainty. (authors)

Radon and radon daughters in South African underground mines

International Nuclear Information System (INIS)

Rolle, R.

1980-01-01

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

Assessment of inhalation and ingestion doses from exposure to radon gas using passive and active detecting techniques

Energy Technology Data Exchange (ETDEWEB)

Ismail, A. H.; Jafaar, M. S. [Universiti Sains Malaysia, 11800 USM, Penang (Malaysia)

2011-07-01

The aim of this study was to assess an environmental hazard of radon exhalation rate from the samples of soil and drinking water in selected locations in Iraqi Kurdistan, passive (CR-39NTDs) and active (RAD7) detecting techniques has been employed. Long and short term measurements of emitted radon concentrations were estimated for 124 houses. High and lower radon concentration in soil samples was in the cities of Hajyawa and Er. Tyrawa, respectively. Moreover, for drinking water, high and low radon concentration was in the cities of Similan and Kelak, respectively. A comparison between our results with that mentioned in international reports had been done. Average annual dose equivalent to the bronchial epithelium, stomach and whole body in the cities of Kelak and Similan are estimated, and it was varied from 0.04{+-}0.01 mSv to 0.547{+-}0.018 mSv, (2.832{+-}0.22)x10{sup -5} to (11.972{+-}2.09)x10{sup -5} mSv, and (0.056 {+-}0.01) x10{sup -5} to (0.239{+-}0.01)x10{sup -5} mSv, respectively. This indicated that the effects of dissolved radon on the bronchial epithelium are much than on the stomach and whole body. (authors)

Ethane and n-pentane in exhaled breath are biomarkers of exposure not effect

DEFF Research Database (Denmark)

Gorham, Katrine A; Andersen, Mads Peter Sulbæk; Meinardi, Simone

2009-01-01

The relationship of exhaled ethane and n-pentane to exhaled NO, carbonylated proteins, and indoor/outdoor atmospheric pollutants were examined in order to evaluate ethane and n-pentane as potential markers of airway inflammation and/or oxidative stress. Exhaled NO and carbonylated proteins were...... found to have no significant associations with either ethane (p = 0.96 and p = 0.81, respectively) or n-pentane (p = 0.44 and 0.28, respectively) when outliers were included. In the case where outliers were removed n-pentane was found to be inversely associated with carbonylated proteins. Exhaled...... hydrocarbons adjusted for indoor hydrocarbon concentrations were instead found to be positively associated with air pollutants (NO, NO(2) and CO), suggesting pollutant exposure is driving exhaled hydrocarbon concentrations. Given these findings, ethane and n-pentane do not appear to be markers of airway...

Ethane and n-pentane in exhaled breath are biomarkers of exposure not effect.

Science.gov (United States)

Gorham, Katrine A; Sulbaek Andersen, Mads P; Meinardi, Simone; Delfino, Ralph J; Staimer, Norbert; Tjoa, Thomas; Rowland, F Sherwood; Blake, Donald R

2009-02-01

The relationship of exhaled ethane and n-pentane to exhaled NO, carbonylated proteins, and indoor/outdoor atmospheric pollutants were examined in order to evaluate ethane and n-pentane as potential markers of airway inflammation and/or oxidative stress. Exhaled NO and carbonylated proteins were found to have no significant associations with either ethane (p = 0.96 and p = 0.81, respectively) or n-pentane (p = 0.44 and 0.28, respectively) when outliers were included. In the case where outliers were removed n-pentane was found to be inversely associated with carbonylated proteins. Exhaled hydrocarbons adjusted for indoor hydrocarbon concentrations were instead found to be positively associated with air pollutants (NO, NO(2) and CO), suggesting pollutant exposure is driving exhaled hydrocarbon concentrations. Given these findings, ethane and n-pentane do not appear to be markers of airway inflammation or oxidative stress.

RADON BASELINE MONITORING AROUND A POTENTIAL SHALE GAS DEVELOPMENT SITE IN YORKSHIRE, ENGLAND.

Science.gov (United States)

Daraktchieva, Z; Wasikiewicz, J M; Howarth, C B; Bradley, E J

2017-11-01

The Vale of Pickering in Yorkshire, England has been identified as a potential area for shale gas extraction. Public Health England joined a collaboration led by the British Geological Survey for environmental baseline monitoring near the potential shale gas extraction site following a grant award from UK Government Department for Business, Energy and Industrial Strategy. The analysis of results for the first 6 months of indoor monitoring indicated that the results followed a log-normal distribution. The numbers of homes found to be at or above the Action Level followed the numbers predicted by the radon potential maps. The results from the measurements of outdoor air in this study indicated that the radon concentrations are slightly higher than previously measured but close to the detection limit of the technique. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radon: A health problem

International Nuclear Information System (INIS)

Pucci, J.; Gaston, S.

1990-01-01

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

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

International Nuclear Information System (INIS)

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

2006-01-01

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

Radon 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)

Measurement of radon concentration in dwellings in the region of highest lung cancer incidence in India

International Nuclear Information System (INIS)

Zoliana, B.; Rohmingliana, P.C.; Sahoo, B.K.; Mayya, Y.S.

2015-01-01

Monitoring of radon exhalation from soil and its concentration in indoor is found to be helpful in many investigations such as health risk assessment and others as radiation damage to bronchial cells which eventually can be the second leading cause of lung cancer next to smoking. The fact that Aizawl District, Mizoram, India has the highest lung cancer incidence rates among males and females in Age Adjusted Rate (AAR) in India as declared by Population Based Cancer Registry Report 2008 indicates the need for quantification of radon and its anomalies attached to it. Measurement of radon concentration had been carried out inside the dwellings in Aizawl district, Mizoram. A time integrated method of measurement was employed by using a solid state nuclear track detector (SSNTD) type (LR-115 films) kept in a twin cup dosimeter for measurement of concentration of radon and thoron. The dosimeters were suspended over bed rooms or living rooms in selected dwellings. They were deployed for a period of about 120 days at a time in 63 houses which were selected according to their place of location viz. fault region, places where fossil remains were found and geologically unidentified region. After the desired period of exposure, the detectors were retrieved and chemically etched which were then counted by using a spark counter. The recorded nuclear tract densities are then converted into air concentrations of Radon and Thoron

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)

Radon hazard map in Bas-Rhin, final report

International Nuclear Information System (INIS)

2010-01-01

After a presentation of radon (geochemical properties, origin, emanation and transfer to surface, related health hazard, exposure factor, modalities for the struggle against radon), of the study context, framework and objective, and of the Bas-Rhin geological context, this report presents the exploited data: definition of the geological uranium potential, direct measurements and geochemical analysis, indicators (lithologic characterization, surface radioactivity, drifting alluvial deposits), factors promoting inhalation, measurements in buildings. It presents and comments maps of the radon geological potential and of radon hazard. It proposes an assessment of radon potential hazard for different areas of the district, and reports measurements performed in Strasbourg, Eckbolsheim, Bischeim and Haguenau

The USGS/EPA ''radon potential of the U.S.'' project: A case study in the application of geoscience information to public policy

International Nuclear Information System (INIS)

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

1993-01-01

As part of an interagency agreement with the US Environmental Protection Agency (EPA), the US Geological Survey (USGS) has prepared a series of maps and reports, by state, describing and assessing the geologic radon potential of the United States. The documents were prepared with multiple uses in mind, including guidance for targeted radon sampling or information programs, to aid in the application of radon-resistant building codes, and as a starting point for more detailed investigations. The USGS and EPA were assisted in the planning and review stages by the Association of American State Geologists, and the draft reports were also reviewed by the state radon contact agencies (typically health departments or departments of environmental protection) and other state and federal agencies. A relative radon potential ranking scheme was developed by USGS to provide consistency and accountability. The scheme consists of a Radon Index, the sum of 5 individually-scored factors (geology, soil permeability, aerial radioactivity, architecture, and screening indoor radon data), and an associated Confidence Index, an expression of the quality and quantity of the data used to evaluate each factor. The assessments are presented on a scale that is useful for state- or regional-scale planning, but inapplicable to areas smaller than counties. The most common problems cited by the reviewers are: (1) the conflict of natural geologic boundaries and political boundaries; (2) the use of the NURE aerial radiometric data; (3) the use of short-term charcoal canister data as opposed to long-term annual average data; (4) the definition of ''high'' radon and the cost of dealing with the radon problem if ''high'' is 4 pCi/L; and (5) the potential misuse of geologic assessments by the public, the radon industry, and governments. The use of geological common sense in concert with policy decisions can alleviate many of the above problems

Rice Husk Ash (RHA): radon remediations and other applications

International Nuclear Information System (INIS)

Sethi, Beena; Sharma, Jyoti; Kant, Krishan

2013-01-01

Rice Husk Ash has been used to obstruct the diffusion of radon through building materials and it has been reported that the substitution of 20-30% rice husk ash with cement leads to lower radon diffusion and exhalation rates with higher compressive strength as compared to control concrete. It can also be used to treat dyes. The waste water containing dyes is very difficult to treat, since the dyes are recalcitrant organic molecules, resistant to aerobic digestion, and are stable to light, heat and oxidising agents. Light is one of the components which aquatic organisms require for their development and any deficit caused by coloured effluent leads to an imbalance of the ecosystem. Because of increasingly stringent restrictions on the organic content of industrial effluents, it is necessary and important to eliminate dyes from wastewater before it is discharged. In the present work, thermodynamic study of adsorption of Amaranth dye on to steam activated pigmented carbon prepared from rice husk (Oryza sativa) was investigated. The adsorbent was investigated under variable system parameters, such as initial concentration of dye, adsorbent dose and temperature. The adsorption equilibrium studied both by Langmuir and Freundlich isotherms. Linearity of the Langmuir isotherm plots indicate the chemical nature of the interactions while the linear Freundlich isotherms point to non specific and energetically non - uniform nature of the adsorption sites. The values of Langmuir monolayer capacity (q m ) are between 0.9 and 1.0 mg/g. The results obtained indicate a potential use of SAPRHC for removing dyes like Amaranth dye from water. (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

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

Radon programmes and health marketing.

Science.gov (United States)

Fojtikova, Ivana; Rovenska, Katerina

2011-05-01

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

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.)

The geo-genic radon potential map of the aspiring 'Buzau Land' Geo-park

International Nuclear Information System (INIS)

Moldovan, M. C.; Burghele, B. D.; Roba, C. A.; Sferle, T. L.; Buterez, C.; Mitrofan, H.

2017-01-01

Mapping the geo-genic radon potential in Buzau County is part of a research project aiming to apply research for sustainable development and economic growth following the principles of geo-conservation in order to support the 'Buzau Land' UNESCO Geo-park initiative. The mapping of geo-genic radon will be used as an overview for planning purposes. The main geological formations of the studied area were identified as Cretaceous and Paleogene flysch, included in a thin-skinned nappes pile and consisting of alternating sandstones, marls, clays and, subordinately, conglomerates, all tightly folded or faulted. Significant variations in the concentration of radon were therefore determined in the ground. However, no high values were determined, the maximum measured activity concentration being 101.6 kBq m -3 . (authors)

Radon mapping - Santa Barbara and Ventura counties

International Nuclear Information System (INIS)

Churchill, R.

1997-01-01

Since 1990, the Department of Conservation''s Division of Mines and Geology (DMG) has provided geologic information and conducted several research projects on geology and radon for the California Department of Health Services (DHS) Radon Program. This article provides a brief overview of radon''s occurrence and impact on human health, and summarizes a recent DMG project for DHS that used geologic, geochemical, and indoor radon measurement data to produce detailed radon potential zone maps for Santa Barbara and Ventura counties

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-07-01

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

Radon programmes and health marketing

International Nuclear Information System (INIS)

Fojtikova, I.; Rovenska, K.

2011-01-01

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

Prediction of 222 Rn exhalation rates from phosphogypsum based stacks. Part I: parametric mathematical modeling

International Nuclear Information System (INIS)

Rabi, Jose A.; Mohamad, Abdulmajeed A.

2004-01-01

Radon-222 is a radionuclide exhaled from phosphogypsum by-produced at phosphate fertilizer industries. Alternative large-scale application of this waste may indicate a material substitute for civil engineering provided that environmental issues concerning its disposal and management are overcome. The first part of this paper outlines a steady-state two-dimensional model for 222 Rn transport through porous media, inside which emanation (source term) and decay (sink term) exist. Boussinesq approach is evoked for the laminar buoyancy-driven interstitial air flow, which is also modeled according to Darcy-Brinkman formulation. In order to account for simultaneous effects of entailed physical parameters, governing equations are cast into dimensionless form. Apart from usual controlling parameters like Reynolds, Prandtl, Schmidt, Grashof and Darcy numbers, three unconventional dimensionless groups are put forward. Having in mind 222 Rn transport in phosphogypsum-bearing porous media, the physical meaning of those newly introduced parameters and representative values for the involved physical parameters are presented. A limiting diffusion-dominated scenario is addressed, for which an analytical solution is deduced for boundary conditions including an impermeable phosphogypsum stack base and a non-zero fixed concentration activity at the stack top. Accordingly, an expression for the average Sherwood number corresponding to the normalized 222 Rn exhalation rate is presented

Measurment of radon, thoron and their progeny in indoor environment of Mohali, Punjab, Northern India, using pinhole dosimeters

Directory of Open Access Journals (Sweden)

Mehta Vimal

2016-01-01

Full Text Available The health hazards of radon and its decay products above certain levels are well known. However, for any preventive measures to be taken, we have to be aware of radon levels of that particular area. Measurement of radon and its decay products in indoor environments is an important aspect of assessing indoor air quality and health conditions associated with it. Keeping this in mind, measurements of radon, thoron and their progeny concentrations were carried out in Mohali, Northern India, using pinhole-based twin cup dosimeters. Radon exhalation rates of soil samples in the dwellings/areas were measured via an active technique of a continuous radon monitor. The indoor radon concentration in Mohali varied from 15.03 ± 0.61 Bq/m3 to 39.21 ± 1.46 Bq/m3 with an average of 26.95 Bq/m3 ,while thoron concentration in the same dwellings varied from 9.62 ± 0.54 Bq/m3 to 52.84 ± 2.77 Bq/m3 with an average of 31.09 Bq/m3. Radon progeny levels in dwellings under study varied from 1.63 to 4.24 mWL, with an average of 2.94 mWL, while thoron progeny levels varied from 0.26 to 1.43 mWL , with an average of 0.84 mWL. The annual dose received by the inhabitants of dwellings under study varied from 0.78 to 2.36 mSv, with an average of 1.61 mSv. The in situ gamma dose rate varied from 0.12 to 0.32 mSv/h.

Radon in schools. An elevation measurement in schools in Baden-Wuerttemberg; Radon in Schulen. Eine Erhebungsmessung in Baden-Wuerttemberg

Energy Technology Data Exchange (ETDEWEB)

Fesenbeck, I.; Naber, C.; Frank, G.; Wilhelm, C.; Schaller, M. [Karlsruher Institut fuer Technologie (Germany). Sicherheit und Umwelt

2016-07-01

With an effective dose of about 1.1 mSv per year, radon and its secondary products have the biggest share in the population's natural radiation exposure. For implementation of the new EU directive 2013/59/EURATOM dated January 17, 2014, it is now planned to adapt the limit values of the Radiation Protection Ordinance and to extend the scope of validity in the EU member states. The ''Radon at Schools'' project is to cover an area-wide survey of radon concentrations in room air of schools in Baden-Wuerttemberg. Potential hazards caused by radon-222 and secondary products of radon are to be studied. For the project, 1600 schools were selected and requested to participate by an information letter. Half of the schools is distributed over the entire area of Baden-Wuerttemberg. The other half is located in areas of increased radon potential. Radon concentration in room air is determined passively by Karlsruhe radon exposimeters. Subsequently, active radon measurements will be made at conspicuous schools and information events will be offered for municipalities, teachers, interested parents, and pupils.

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

International Nuclear Information System (INIS)

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

1995-12-01

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

Modeling the potential impacts of different radon policies for the U.S. housing stock

International Nuclear Information System (INIS)

Peterson, M.D.; Ritchie, I.M.

1995-01-01

According to the Environmental Protection Agency (EPA) and other public health agencies in the United States, radon may be the leading cause (along with passive smoking) of lung cancer deaths among nonsmokers. Radon is estimated to be the second leading cause of lung cancer death in smokers behind smoking-related lung cancer. EPA estimates that 7,000 to 30,000 lung cancer deaths each year are due to radon exposure. (It is implied that radon-related lung cancer deaths can be prevented by reducing radon levels below EPA's guideline levels). Current EPA radon policy is based on a strategy of education, the transfer of testing and remediation technologies to the public and private sectors, and recently proposed radon-resistant construction standards for new homes. This paper models the effectiveness of current proposed, and alternative policies for reducing radon risks in U.S. residential construction. The results of our analysis suggest that EPS's projections of 2,200 'lives saved annually' as a result of its current action level of 4 pCi/l will not be achieved with its current policy in the near future. Overall, the response of radon-related mortality to most policy options is delayed and flat due in part to the large number of houses with low radon levels and the long latency period between radon exposure and the development of cancer. The modeling results suggest that more aggressive smoking reduction programs may yield greater benefits in overall lung cancer mortality (but not reduced radon exposure) than most radon-related policies. (au)

Radon and its decay product activities in the magmatic area and the adjacent volcano-sedimentary Intrasudetic Basin

Directory of Open Access Journals (Sweden)

D. Tchorz

2007-06-01

Full Text Available In the magmatic area of Sudetes covering the Karkonosze granite and adjacent volcano-sedimentary Intrasudetic Basin a study of atmospheric radon activity was performed by means of SSNTD Kodak LR-115. The study was completed by gamma spectrometric survey of eU and eTh determined by gamma activity of radon decay products 214Bi and 208Tl respectively. In the case of the western part of the Karkonosze granite area the radon decay products activity in the granitic basement was found to be as high as 343 Bq/kg for 214Bi and 496 Bq/kg for 208Tl respectively. Atmospheric radon content measured by means of Kodak LR115 track detector at the height of 1.5 m was found as high as 70 Bq/m3 in the regions, where no mining activities took place. However in the eastern part of the granitic massif in the proximity of abandoned uranium mine atmospheric radon content was found to be 6000 Bq/m3. In the case of sedimentary basin where sedimentary sequence of Carboniferous rocks has been penetrated by younger gases and fluids of volcanic origin uranium mineralization developed. The region known from its CO2 outburst during coal mining activity is characterized by good ventilation of the uranium enriched geological basement resulting in increased atmospheric radon activity being in average 72 Bq/m3. In the vicinity of coal mine tailing an increase up to 125 Bq/m3 can be observed. Seasonal variations of atmospheric radon content are influenced in agricultural areas by cyclic cultivation works (plough on soils of increased uranium content and in the case of post-industrial brownfields varying rates of radon exhalation from tailings due to different meteorological conditions.

Radon thematic days - Conference proceedings

International Nuclear Information System (INIS)

2011-03-01

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

What did we learn from the Austrian radon project?

International Nuclear Information System (INIS)

Friedmann, H.

2004-01-01

new houses. Therefore, we introduced the 'Radon Potential' as a measure of the radon risk from the ground. The Radon Potential is defined (in Austria) as the annual mean radon concentration that can be expected in a commonly used living room at the ground floor in a house without basement ... (several less important parameters are also defined). Observed data from each house can be extrapolated to this Radon Potential. The mean of such values within a municipality defines the Radon Potential of the municipality. Finally, the municipalities were categorized into three classes with respect to their Radon Potential. The uncertainty of the classification must be taken into account, though: underestimation of the radon risk is especially problematic. So it is fortunate that the government of Upper Austria launched projects to measure the radon concentrations (beside other indoor pollutants) in schools and kindergartens. Such independent projects provide ideal testing of the reliability of estimation of the Radon Potential and its limitations due to the different types of uncertainty

Epidemiological potentials of radon- and thoron-prone area in China

International Nuclear Information System (INIS)

Sun, Quanfu; Hou, Changsong; Tokonami, Shinji

2004-01-01

In order to explore the feasibility of an epidemiological study on lung cancer in areas with elevated indoor radon and thoron exposures, 202 residences including loess caves, brick caves, stone caves, and ordinary houses in twenty villages were selected from Yan'an and Luliang areas in the Chinese loess plateau, and indoor levels of thoron and its progeny as well as radon were determined with passive radon-thoron discriminative detectors and thoron progeny deposition rate devices. The indoor radon concentration in loess cave ranged from 17 to 179 Bq m -3 , with geometric means of 73 Bq m -3 and 71 Bq m -3 in Luliang and Yan'an, respectively. Geometric mean of EEC Tn was estimated to be 1.6 Bq m -3 in Luliang and 2.2 Bq m -3 in Yan'an. The study also revealed that the air pollution in Yan'an was small compared with that in Luliang. Residential migration was very low in Yan'an area: 86% of the subjects had no migration, mean number of houses for the family master was estimated to be 1, ranged from 1 to 3. It would be expected to have several hundreds of lung cancer cases diagnosed with pathological evidences in 3-5 years. Yan'an and surrounding area are suitable for conducting an epidemiological study on residential exposure to radon, thoron and lung cancer risk. (author)

Assessment of potential radiological population health effects from radon in liquefied petroleum gas

Energy Technology Data Exchange (ETDEWEB)

Gesell, Thomas F; Johnson, Jr, Raymond H; Bernhardt, David E

1977-02-01

Liquefied petroleum gas (LPG) contains varying amounts of radon-222 which becomes dispersed within homes when LPG is used in unvented appliances. Radon-222 decays to alpha-emitting daughter products which are associated with increased lung cancer when inhaled and deposited in the respiratory system. The average dose equivalents to the bronchial epithelium from the use of LPG in unvented kitchen ranges and space heaters are estimated to be about 0.9 and 4.0 mrem/year, respectively. When extrapolated to the United States population at risk, the estimated tracheobronchial dose equivalents are about 20,000 and 10,000 person-rems/year for these appliances, or a total of about 30,000 person-rems/year. These doses are very small compared to other natural and man-made sources of ionizing radiation. It is estimated that these low doses would result in less than one lung cancer a year for the total U.S. population. Consequently, the use of LPG containing radon-222 does not contribute significantly to the incidence of lung cancer in the United States. Furthermore, the cost for control of radon levels in LPG would be over $50 million for reduction of one health effect, therefore it is concluded that a requirement for such controls would not be cost effective on a national basis. This study did indicate that individual dose equivalents could possibly exceed 500 mrem/year. However, existing data are not sufficient to determine the significance of such potentially high individual doses. (author)

A radon progeny deposition model

International Nuclear Information System (INIS)

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

2010-01-01

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

A Radon Progeny Deposition Model

International Nuclear Information System (INIS)

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

2011-01-01

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

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)

Radon: Chemical and physical states of radon progeny. Final technical report

International Nuclear Information System (INIS)

Castleman, A.W. Jr.

1996-01-01

The evolving chemical and physical form of radon progeny influence their transport to the bioreceptor and the extent to which that receptor can take up these species into various tissues. When first born following radioactive decay processes, the potentially deleterious radon progeny undergo various physical and chemical transformations as they transcend from a highly charged to a neutral state, and interact with various constituents of the environment. These transformations impact on the extent to which the radon progeny become associated with aerosol particles on the one hand, and their ultimate chemical form that is available for uptake in the biosystem, on the other. The program, which originally commenced in 1987, dealt with the basic chemistry and physics of radon progeny and hence impacted on several themes of importance to the DOE/OHER radon program. One of these is dose response, which is governed by the physical forms of the radon progeny, their transport to the bioreceptor and the chemical forms that govern their uptake. The second theme had to do with cellular responses, one of the major issues motivating the work. It is well known that various sizes of ions and molecules are selectively transported across cell membrane to differing degrees. This ultimately has to do with their chemical and physical forms, charge and size. The overall objective of the work was threefold: (1) quantifying the mechanisms and rates of the chemical and physical transformation; (2) ascertaining the ultimate chemical forms, and (3) determining the potential interactions of these chemical species with biological functional groups to ascertain their ultimate transport and incorporation within cells

Radon risk in the house; Il rischio radon nelle abitazioni

Energy Technology Data Exchange (ETDEWEB)

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

2001-04-01

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

Influence of Meteorological Conditions in the Annual Variation of Environmental Radon Activity

International Nuclear Information System (INIS)

Márquez, J.L.; Sáez, J.C.; Álvarez, A.; Quiñones, J.

2015-01-01

The aim of this study is to determine the correlations that exist between Rn gas, the Rn progeny and the meteorological variables. Also it takes part from the study to observe which variables are responsible of ambient dose equivalent rate variations. The study of correlations between different variables was performed using two methodologies; the first of them is a graphical representation of all variables to observe the temporal evolution of each variable and the second is the application of a Principal Component Analysis. The study of variables behavior has been divided into three periods (day, month and year), considering the presence and absence of rainfall for daily and monthly period. Several correlations have been identified between the Rn gas, Rn progeny and meteorological variables. It has also identified the influence of rainfall on the ambient dose equivalent rate due to the radon progeny. To complete the study, a theoretical model based on an adjustment by the least-squares has been performed to estimate the levels of exhaled radon in atmosphere for any day of the year.

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

International Nuclear Information System (INIS)

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

2002-01-01

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

Control of indoor radon and radon progeny concentrations

International Nuclear Information System (INIS)

Sextro, R.G.

1985-05-01

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

The origin of mouth-exhaled ammonia.

Science.gov (United States)

Chen, W; Metsälä, M; Vaittinen, O; Halonen, L

2014-09-01

It is known that the oral cavity is a production site for mouth-exhaled NH3. However, the mechanism of NH3 production in the oral cavity has been unclear. Since bacterial urease in the oral cavity has been found to produce ammonia from oral fluid urea, we hypothesize that oral fluid urea is the origin of mouth-exhaled NH3. Our results show that under certain conditions a strong correlation exists between oral fluid urea and oral fluid ammonia (NH4(+)+NH3) (rs = 0.77, p oral fluid NH3 and mouth-exhaled NH3 (rs = 0.81, p oral fluid pH. Bacterial urease catalyses the hydrolysis of oral fluid urea to ammonia (NH4(+)+NH3). Oral fluid ammonia (NH4(+)+NH3) and pH determine the concentration of oral fluid NH3, which evaporates from oral fluid into gas phase and turns to mouth-exhaled NH3.

Van der Waals potential and vibrational energy levels of the ground state radon dimer

Science.gov (United States)

Sheng, Xiaowei; Qian, Shifeng; Hu, Fengfei

2017-08-01

In the present paper, the ground state van der Waals potential of the Radon dimer is described by the Tang-Toennies potential model, which requires five essential parameters. Among them, the two dispersion coefficients C6 and C8 are estimated from the well determined dispersion coefficients C6 and C8 of Xe2. C10 is estimated by using the approximation equation that C6C10/C82 has an average value of 1.221 for all the rare gas dimers. With these estimated dispersion coefficients and the well determined well depth De and Re the Born-Mayer parameters A and b are derived. Then the vibrational energy levels of the ground state radon dimer are calculated. 40 vibrational energy levels are observed in the ground state of Rn2 dimer. The last vibrational energy level is bound by only 0.0012 cm-1.

Radon investigations - Soil and commercial projects

International Nuclear Information System (INIS)

Goodwin, R.W.

1987-01-01

The liability issues of radon exposure have prompted potential purchasers of vacant land for commercial/industrial development, and commercial landlords, renting large commercial buildings, to determine the radon gas levels at such sites. This paper deals with both pre-construction sites subject to freezing conditions and to large commercial structures. A correlation of radon gas levels within a commercial building and a sister pre-construction site confirms the validity of using activated charcoal canisters as a cost effective means to combating radon in large structures

Some basic facts about radioactive radon

International Nuclear Information System (INIS)

Duval, J.S.; Tanner, A.B.

1990-01-01

This article presents some basic facts about 222 Rn. These facts include: half-life; diffusion patterns; how radon enters a house; health risks; and means of definition and estimation of radon hazard potential

Radon

Energy Technology Data Exchange (ETDEWEB)

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

1978-09-01

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

Sign of Radon for locate geothermic sources

International Nuclear Information System (INIS)

Gonzalez Teran, D.

1991-01-01

Evaluation of a geothermic field is based upon geological, geophysical and geochemical studies that enable the evaluation of the deposit potential, that is to say, the amount of energy per unit mass, the volume of the trapped fluid, vapor fraction and fluid chemistry. This thesis has as its objective the evaluation of radon gas emanation in high potential geothermic zones in order to utilize the results as a low cost and easy to manage complimentary tool in geothermic source prospection. In chapter I the importance and evaluation of a geothermic deposit is discussed. In chapter II the general characteristics of radon are discussed: its radioactivity and behavior upon diffusion over the earth's surface> Chapter III establishes the approach used in the geothermic field of Los Azufres, Michoacan, to carry out samplings of radon and the laboratory techniques that were used to evaluate the concentration of radon in the subsoil. Finally in chapter IV measurements of radon in the field are compared to geological faults in the area under study. The sampling zones were: low geothermic potential zone of the northern and the southern zone having a greater geothermic potential than that in the north. The study was carried out at different sampling times using plastics detectors of from 30 to 46 days from February to July. From the results obtained we concluded that the emission of radon was greater in the zones of greatest geothermic potential than in the low geothermic potential zones it was also affected by the fault structure and the time of year in which sampling was done. (Author)

Exhaled CO, a predictor of lung function?

DEFF Research Database (Denmark)

Fabricius, Peder; Scharling, Henrik; Løkke, Anders

2007-01-01

and whether CO could provide additional information to usual measures of smoking regarding prediction of present lung function and decline in lung function over an extended period of time. METHOD: Cigarette smokers from the Copenhagen City Heart Study with valid measures of lung function and exhaled CO......; in total 3738 subjects, 2096 women and 1642 men. RESULTS: Subjects not inhaling had slightly lower exhaled CO values than those inhaling, but substantially higher values than non-smokers (PSmokers of plain cigarettes had slightly lower CO values than smokers of filter cigarettes (P...BACKGROUND: Smoking is associated with an accelerated loss of lung function and inhalation accelerates the decline further. Exhaled CO reflects the exposure of smoke to the lungs. AIM: To investigate whether self-reported inhalation and type of cigarette influenced the level of exhaled CO...

Passive radon daughter dosimeters

International Nuclear Information System (INIS)

McElroy, R.G.C.; Johnson, J.R.

1986-03-01

On the basis of an extensive review of the recent literature concerning passive radon daughter dosimeters, we have reached the following conclusions: 1) Passive dosimeters for measuring radon are available and reliable. 2) There does not presently exist an acceptable passive dosimeter for radon daughters. There is little if any hope for the development of such a device in the foreseeable future. 3) We are pessimistic about the potential of 'semi-passive dosimeters' but are less firm about stating categorically that these devices cannot be developed into a useful radon daughter dosimeter. This report documents and justifies these conclusions. It does not address the question of the worker's acceptance of these devices because at the present time, no device is sufficiently advanced for this question to be meaningful. 118 refs

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

International Nuclear Information System (INIS)

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

1995-02-01

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

Development and evaluation of global radon transport model

International Nuclear Information System (INIS)

Kojima, H.; Nagano, K.

2003-01-01

The radioactive noble gas Radon-222 ( 222 Rn) is chemically inert and is removed only by radioactive decay (T1/2=3.8 d). Its primary source is uniformly distributed over the continents and the ocean represents a secondary source of atmospheric 222 Rn. The strong contrast in source strength between continents and the ocean makes 222 Rn an ideal marker of continental air masses. Because of its simple properties, the temporal and spatial distribution of 222 Rn in the troposphere is straightforward to simulate by means of atmospheric transport models. The simulation provides an intuitive visualization of the complex transport characteristics and more definite proof of phenomenon. In this paper, we present the results of an exploratory study, in which we investigated the performance of a three-dimensional transport model of the global troposphere in simulating the long range transport of 222 Rn. The transport equation has been solved by a numerical procedure based on some boundary conditions. The model structure which we have originally developed, has a horizontal resolution of 2.5deg in latitude and 2.5deg in longitude, and 10 layers in the vertical dimension. The basic computational time step used in the model runs was set to 5 min. The simulations described in this article were performed by means of a transport model driven by global objective analytical data of a time resolution of 6 h, supplied by the Japan Meteorological Agency. We focus on the west of North Pacific Ocean, were the influence of air pollution from an Asian Continent and the Japan Islands was received. For simulation experiments, radon data from some shipboard measurements on the North Pacific Ocean have been used in the present study. Figure shows time series of model prediction with different latitude distributions of radon exhalation rate and measured radon data. We find that our model consistently produce the observation. We will discuss the characteristics of the temporal and special

Health effects of radon

International Nuclear Information System (INIS)

Easterly, C.

1994-01-01

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

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 .

A law of removing radon by ventilation and air requirement calculation for eliminating radon daughters in uranium mines

International Nuclear Information System (INIS)

Wu Gang

1988-06-01

In accordance with testing data of removing radon and its daughters by ventilation from shrinkage and filling stopes of uranium mines, a law of removing radon by ventilation from the stopes is analyzed and summed. According to the decay law of radon and its daughters, an accumulation equation of potential alpha energy from radon daughters is presented with hyperbolic regression equation. the calculating formulae of ventilation flow are derived from the accumulation equation for eliminating radon daughters in inlet flow with or without contamination. It has been proved that the amount of ventilation air calcuated could meet the requirements of radiation safety rationally and economically

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

Science.gov (United States)

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

2016-04-01

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

Natural radioactivity and radon exhalation rate in Brazilian igneous rocks

Energy Technology Data Exchange (ETDEWEB)

Moura, C.L.; Artur, A.C. [Departamento de Petrologia e Metalogenia, Instituto de Geociencias e Ciencias Exatas, Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil); Bonotto, D.M., E-mail: danielbonotto@yahoo.com.b [Departamento de Petrologia e Metalogenia, Instituto de Geociencias e Ciencias Exatas, Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil); Guedes, S. [Departamento de Cronologia e Raios Cosmicos, Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas (UNICAMP), Rua Sergio Buarque de Holanda No. 777, CEP 13083-859, Campinas, Sao Paulo (Brazil); Martinelli, C.D. [Departamento de Petrologia e Metalogenia, Instituto de Geociencias e Ciencias Exatas, Universidade Estadual Paulista (UNESP), Av. 24-A No. 1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil)

2011-07-15

This paper reports the natural radioactivity of Brazilian igneous rocks that are used as dimension stones, following the trend of other studies on the evaluation of the risks to the human health caused by the rocks radioactivity as a consequence of their use as cover indoors. Gamma-ray spectrometry has been utilized to determine the {sup 40}K, {sup 226}Ra and {sup 232}Th activity concentrations in 14 rock types collected at different quarries. The following activity concentration range was found: 12.18-251.90 Bq/kg for {sup 226}Ra, 9.55-347.47 Bq/kg for {sup 232}Th and 407.5-1615.0 Bq/kg for {sup 40}K. Such data were used to estimate Ra{sub eq}, H{sub ex} and I{sub {gamma}}, which were compared with the threshold limit values recommended in literature. They have been exceeded for Ra{sub eq} and H{sub ex} in five samples, where the highest indices corresponded to a rock that suffered a process of ductile-brittle deformation that caused it a microbrecciated shape. The exhalation rate of Rn and daughters has also been determined in slabs consisting of rock pieces {approx}10 cm-long, 5 cm-wide and 3 cm-thick. It ranged from 0.24 to 3.93 Bq/m{sup 2}/h and exhibited significant correlation with eU (={sup 226}Ra), as expected. The results indicated that most of the studied rocks did not present risk to human health and may be used indoors, even with low ventilation. On the other hand, igneous rocks that yielded indices above the threshold limit values recommended in literature may be used outdoors without any restriction or indoors with ample ventilation.

Research on clay covering experiment in a abandoned uranium mining area

International Nuclear Information System (INIS)

Zhang Xueli; Xu Lechang; Zhang Wei

2014-01-01

The clay covering experiment was designed in a abandoned uranium mining area, including experiment principle, determining size of experimental site, experiment method, choosing cover materials and determining cover thickness. According to the experiment results, the relationship between the radon exhalation rate and cover thickness, the diffusion coefficient of radon in clay were fully discussed. Also, the corresponding function expressions were established. The linear correlation coefficient test results showed that the relationship between the radon exhalation rate and cover thickness was significantly correlated. According to the correlation function expression between the radon exhalation rate and the cover thickness, the cover thickness of the decommissioning sites can be determined, in order to provide a scientific basis for the design and environmental impact assessment on decommissioning disposal project of a uranium mine. (authors)

Radon: implications for the health professional

International Nuclear Information System (INIS)

Romano, C.A.

1990-01-01

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

A statistical evaluation of the geogenic controls on indoor radon concentrations and radon risk

Energy Technology Data Exchange (ETDEWEB)

Appleton, J.D., E-mail: jda@bgs.ac.u [British Geological Survey, Kingsley Dunham Centre, Nicker Hill, Keyworth, Nottingham, NG12 5GG (United Kingdom); Miles, J.C.H. [Health Protection Agency (HPA), Radiation Protection Division, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom)

2010-10-15

ANOVA is used to show that approximately 25% of the total variation of indoor radon concentrations in England and Wales can be explained by the mapped bedrock and superficial geology. The proportion of the total variation explained by geology is higher (up to 37%) in areas where there is strong contrast between the radon potential of sedimentary geological units and lower (14%) where the influence of confounding geological controls, such as uranium mineralisation, cut across mapped geological boundaries. When indoor radon measurements are grouped by geology and 1-km squares of the national grid, the cumulative percentage of the variation between and within mapped geological units is shown to be 34-40%. The proportion of the variation that can be attributed to mapped geological units increases with the level of detail of the digital geological data. This study confirms the importance of radon maps that show the variation of indoor radon concentrations both between and within mapped geological boundaries.

A complete low cost radon detection system

International Nuclear Information System (INIS)

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

2013-01-01

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

Radon emanation of heterogeneous basin deposits in Kathmandu Valley, Nepal

Science.gov (United States)

Girault, Frédéric; Gajurel, Ananta Prasad; Perrier, Frédéric; Upreti, Bishal Nath; Richon, Patrick

2011-01-01

Effective radium-226 concentration ( EC Ra) has been measured in soil samples from seven horizontal and vertical profiles of terrace scarps in the northern part of Kathmandu Valley, Nepal. The samples belong to the Thimi, Gokarna, and Tokha Formations, dated from 50 to 14 ky BP, and represent a diverse fluvio-deltaic sedimentary facies mainly consisting of gravelly to coarse sands, black, orange and brown clays. EC Ra was measured in the laboratory by radon-222 emanation. The samples ( n = 177) are placed in air-tight glass containers, from which, after an accumulation time varying from 3 to 18 days, the concentration of radon-222, radioactive decay product of radium-226 and radioactive gas with a half-life of 3.8 days, is measured using scintillation flasks. The EC Ra values from the seven different profiles of the terrace deposits vary from 0.4 to 43 Bq kg -1, with profile averages ranging from 12 ± 1 to 27 ± 2 Bq kg -1. The values have a remarkable consistency along a particular horizon of sediment layers, clearly demonstrating that these values can be used for long distance correlations of the sediment horizons. Widely separated sediment profiles, representing similar stratigraphic positions, exhibit consistent EC Ra values in corresponding stratigraphic sediment layers. EC Ra measurements therefore appear particularly useful for lithologic and stratigraphic discriminations. For comparison, EC Ra values of soils from different localities having various sources of origin were also obtained: 9.2 ± 0.4 Bq kg -1 in soils of Syabru-Bensi (Central Nepal), 23 ± 1 Bq kg -1 in red residual soils of the Bhattar-Trisuli Bazar terrace (North of Kathmandu), 17.1 ± 0.3 Bq kg -1 in red residual soils of terrace of Kalikasthan (North of Trisuli Bazar) and 10 ± 1 Bq kg -1 in red residual soils of a site near Nagarkot (East of Kathmandu). The knowledge of EC Ra values for these various soils is important for modelling radon exhalation at the ground surface, in particular

Radon emanation of heterogeneous basin deposits in Kathmandu Valley, Nepal

International Nuclear Information System (INIS)

Girault, F.; Perrier, F.; Ananta Prasad Gajurel; Bishal Nath Upreti; Richon, P.

2011-01-01

Effective radium-226 concentration (EC Ra ) has been measured in soil samples from seven horizontal and vertical profiles of terrace scarps in the northern part of Kathmandu Valley, Nepal. The samples belong to the Thimi, Gokarna, and Tokha Formations, dated from 50 to 14 ky BP, and represent a diverse fluvio-deltaic sedimentary facies mainly consisting of gravelly to coarse sands, black, orange and brown clays. EC Ra was measured in the laboratory by radon-222 emanation. The samples (n = 177) are placed in airtight glass containers, from which, after an accumulation time varying from 3 to 18 days, the concentration of radon-222, radioactive decay product of radium-226 and radioactive gas with a half-life of 3.8 days, is measured using scintillation flasks. The EC Ra values from the seven different profiles of the terrace deposits vary from 0.4 to 43 Bq kg -1 , with profile averages ranging from 12 ± 1 to 27 ± 2 Bq kg -1 . The values have a remarkable consistency along a particular horizon of sediment layers, clearly demonstrating that these values can be used for long distance correlations of the sediment horizons. Widely separated sediment profiles, representing similar stratigraphic positions, exhibit consistent EC Ra values in corresponding stratigraphic sediment layers. EC Ra measurements therefore appear particularly useful for lithologic and stratigraphic discriminations. For comparison, EC Ra values of soils from different localities having various sources of origin were also obtained: 9.2 ± 0.4 Bq kg -1 in soils of Syabru-Bensi (Central Nepal), 23 ± 1 Bq kg -1 in red residual soils of the Bhattar-Trisuli Bazar terrace (North of Kathmandu), 17.1 ± 0.3 Bq kg -1 in red residual soils of terrace of Kalikasthan (North of Trisuli Bazar) and 10 ± 1 Bq kg -1 in red residual soils of a site near Nagarkot (East of Kathmandu). The knowledge of EC Ra values for these various soils is important for modelling radon exhalation at the ground surface, in particular

Estimation of effective doses to cavers based on radon measurements carried out in seven caves of the Bakony Mountains in Hungary

International Nuclear Information System (INIS)

Kavasi, Norbert; Somlai, Janos; Szeiler, Gabor; Szabo, Balazs; Schafer, Istvan; Kovacs, Tibor

2010-01-01

Nowadays, as the practice of extreme sports is spreading, potholing is becoming more and more popular. As a result, both the number of cavers and the time spent in the caves have been on the rise. There are some cavers known to have spent some 5000 h in caves over a span of 10 years. In poorly ventilated caves, radon exhalated from cave rocks and deposits may accumulate and cause significant doses to cavers. In this study, the radon concentration in seven caves in the Bakony Mountains, Hungary, was measured by continuous and integrated measurement devices. Measured values for the different caves were rather different, and varied between 50 and 24,000 Bq m -3 . The average radon concentration over the measurement period was approximately 10,000 Bq m -3 in five of the seven caves inspected. By assuming an average of 470 h year -1 spent in caves, effective doses to cavers were estimated. The expected annual effective dose, in case of an equilibrium factor of 0.6, was 19.7 mSv.

Evaluation of tectonic impact on radon level of lithological units

International Nuclear Information System (INIS)

Wolkowicz, S.; Strzelecki, R.

2000-01-01

The radon potential maps of the Sudetes Mountains and Upper Silesian Coal Basin have been prepared on a base of arithmetic mean value of radon concentration in soil air in distinguished lithological/stratigraphic units. Both zones of shallow position of ground table and the fault zones influence value of this parameter: the first one affects in specific conditions lowering of background values, the second ones - origin of values several and teen times higher than rock background values. Estimation of power of tectonic influence on general radon potential of the lithological units has been made on a base of examination of histograms of distribution of radon concentration in soil air. In the Sudetes area, 0 % to about 30 % of the measurements is related to fault zones. Higher tectonic engagement (about 30 %) characterizes the Karkonosze Granites, Izera Gneisses and Strzegom Granites. In the cases of Karkonosze Granites and the Strzegom Granites, rock background values concentrations in soil air are a little than 50 kBq/m 3 , what is the value defined for lower threshold of high radon risk areas. In conclusion, presence of numerous fault zones and fissures increases radon risk category with one class. Background modal values of radon emanations, defined for the studied units, in the 5 cases fulfill criteria for medium radon risk areas, and in other cases do not exceed of the threshold 10 kBq/m 3 . It displays, that in the case of low radon potential rocks only a few-percent rich population of measurements related to tectonic zones, is sufficient to substantially deform of the image of the studied unit radon potential. For instance, medium radon potential characterizes the Klodzko - Zloty Stok Granites (the arithmetic mean value of this class is 36.15 kBq/m 3 , n=104) and small tectonic engagement (about 3.8 %). In the result the modal value belongs to the class 20-30 kBq/m 3 . The Poreba Beds in the Upper Silesian Coal Basin are characterised by almost the same radon

Radon

Science.gov (United States)

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

Radon Survey in Hospitals in Slovenia

International Nuclear Information System (INIS)

Vaupotic, J.

2003-01-01

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

Radon: Residential attitudes toward the risk

International Nuclear Information System (INIS)

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

1990-01-01

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